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• 12271. [Article] A comparison of braille and compressed speech as learning modes for legally blind adults

  The primary purpose of this research study was to determine whether significant differences occurred in the amount of knowledge achieved as a result of using Braille or compressed speech as learning modes. Biographic/demographic ...

  Citation × Citation Citation Abstract Copy Title: A comparison of braille and compressed speech as learning modes for legally blind adults Author: Hughes, Colleen Constance Carris The primary purpose of this research study was to determine whether significant differences occurred in the amount of knowledge achieved as a result of using Braille or compressed speech as learning modes. Biographic/demographic characteristics such as present age, highest educational level achieved, age at loss of vision, age at initial use of Braille and of talking books were analyzed to investigate which characteristics were able to predict success for Braille or compressed speech. Procedure Thirty legally blind adults residing in the Willamette Valley, Oregon, comprised the study population. All were Braille, grade two, readers. The adults in this group were randomly assigned either Brailled material or compressed speech material on diabetes as the experimental study treatment. Instruments chosen to assess knowledge achievement of the health education material on diabetes were developed and field tested, during the research pilot study. Both the group using Braille, grade two, and the group using compressed speech material were pre- and post-tested using the field tested multiple-choice instrument. A personal data questionnaire was given to collect biographic/demographic data, which were then statistically analyzed for a predictive model of successful correlates when using Braille or compressed speech. The one way analysis of covariance test was employed for the statistical inquiry of the data for hypothesis I, using the F statistic. A t-test was utilized to investigate the means of each group; pre-test scores were used as the covariate. Statistical inquiry into the second hypothesis used a multiple discriminant analysis procedure which determined whether the biographic/demographic characteristics could be distinguished from each other in their assessment of each variable category. Variables were analyzed and ranked according to mean scores to illustrate the degree of relative importance placed on each variable or biographic/demographic characteristic. This hypothesis was also resolved with the use of a stepwise multiple-regression analysis, which also yields a correlation coefficient. Scores for each variable were used to measure variable relationships. Findings The findings of this study indicated the following: 1. No significant differences were noted in achievement scores when using Braille or compressed speech as learning modes; and 2. Analysis of the biographic/demographic variables were not predictive of a success characteristic for using Braille or compressed speech. Based on these findings, it was concluded that legally blind adults who read Braille, grade two, may use either Braille or compressed speech with success. The use of either Braille or compressed speech becomes the choice of the user and depends upon the material studied. It is notable that the participants in this study were highly educated. Eighty percent had at least some college background; twentyseven percent hadamaster's or a doctoral degree. The study participants' level of income attainment and job securement did not match their respective educational levels achieved. The majority of the population were between the ages of 20 and 35 years; 40 percent were adventitiously blind and 60 percent were congenitally blind. One implication, based on this study's findings, suggests researching whether Braille should be considered a second written language structure. Braille is a learned tactual skill, but the imagery of Braille contractions and alphabet letter analogs make it suspect as does the fact that only five to ten percent of all visually impaired invididuals read Braille. Further, it should be researched why the other 90 to 95 percent do not read Braille in any form. Statistical significance is different from practical importance and the respondents' open -ended answers to questions asked on the personal data questionnaire revealed concern that: 1. Braille is being phased out of private and public school programs with "mainstreaming situations"; 2. Not all technology is suitable for all visually impaired persons; 3. An individual still needs to know and use Braille for such advanced technology as the "paperless Braille" machines; 4. The need remains for retaining Braille in self-communication; 5. Spelling, punctuation and composition are learned with Braille usage while syntax and grammar may be acquired through aural means (compressed speech, talking book cassettes, and discs); 6. Compressed speech becomes valuable in reducing time spent in listening to taped material, lectures, etc., and is especially helpful to speed up a slow speaker; 7. The speed of reading Braille needs further research; and 8. The use of either Braille or compressed speech is individualized; however, both could be used as complementary learning techniques. Recommendations for further study include using sensory-integration research to measure tactile and aural learning pathways as well as to predict success for the blind learner with either tactile or aural integration preference. This research should also include investigation into such questions as: 1. How does blindness effect motor outputs and perceptual skills, thus how does a visual impairment affect learning? 2. Of the primary sensory inputs, do the congenitally or adventitiously blind have a greater or lesser functional ability with one specific sensory modality? Studies considering personality characteristics of successful Braille or compressed speech users should be investigated. It is also recommended that this research include independence and dependence traits with respect to success with tactual or aural preference. It also appears appropriate to investigate the inconsistency of educational levels and paucity of job equivalency or opportunities. Research regarding the use of Braille and compressed speech in job related tasks might be informative data to gather. Title: A comparison of braille and compressed speech as learning modes for legally blind adults Author: Hughes, Colleen Constance Carris The primary purpose of this research study was to determine whether significant differences occurred in the amount of knowledge achieved as a result of using Braille or compressed speech as learning modes. Biographic/demographic characteristics such as present age, highest educational level achieved, age at loss of vision, age at initial use of Braille and of talking books were analyzed to investigate which characteristics were able to predict success for Braille or compressed speech. Procedure Thirty legally blind adults residing in the Willamette Valley, Oregon, comprised the study population. All were Braille, grade two, readers. The adults in this group were randomly assigned either Brailled material or compressed speech material on diabetes as the experimental study treatment. Instruments chosen to assess knowledge achievement of the health education material on diabetes were developed and field tested, during the research pilot study. Both the group using Braille, grade two, and the group using compressed speech material were pre- and post-tested using the field tested multiple-choice instrument. A personal data questionnaire was given to collect biographic/demographic data, which were then statistically analyzed for a predictive model of successful correlates when using Braille or compressed speech. The one way analysis of covariance test was employed for the statistical inquiry of the data for hypothesis I, using the F statistic. A t-test was utilized to investigate the means of each group; pre-test scores were used as the covariate. Statistical inquiry into the second hypothesis used a multiple discriminant analysis procedure which determined whether the biographic/demographic characteristics could be distinguished from each other in their assessment of each variable category. Variables were analyzed and ranked according to mean scores to illustrate the degree of relative importance placed on each variable or biographic/demographic characteristic. This hypothesis was also resolved with the use of a stepwise multiple-regression analysis, which also yields a correlation coefficient. Scores for each variable were used to measure variable relationships. Findings The findings of this study indicated the following: 1. No significant differences were noted in achievement scores when using Braille or compressed speech as learning modes; and 2. Analysis of the biographic/demographic variables were not predictive of a success characteristic for using Braille or compressed speech. Based on these findings, it was concluded that legally blind adults who read Braille, grade two, may use either Braille or compressed speech with success. The use of either Braille or compressed speech becomes the choice of the user and depends upon the material studied. It is notable that the participants in this study were highly educated. Eighty percent had at least some college background; twentyseven percent hadamaster's or a doctoral degree. The study participants' level of income attainment and job securement did not match their respective educational levels achieved. The majority of the population were between the ages of 20 and 35 years; 40 percent were adventitiously blind and 60 percent were congenitally blind. One implication, based on this study's findings, suggests researching whether Braille should be considered a second written language structure. Braille is a learned tactual skill, but the imagery of Braille contractions and alphabet letter analogs make it suspect as does the fact that only five to ten percent of all visually impaired invididuals read Braille. Further, it should be researched why the other 90 to 95 percent do not read Braille in any form. Statistical significance is different from practical importance and the respondents' open -ended answers to questions asked on the personal data questionnaire revealed concern that: 1. Braille is being phased out of private and public school programs with "mainstreaming situations"; 2. Not all technology is suitable for all visually impaired persons; 3. An individual still needs to know and use Braille for such advanced technology as the "paperless Braille" machines; 4. The need remains for retaining Braille in self-communication; 5. Spelling, punctuation and composition are learned with Braille usage while syntax and grammar may be acquired through aural means (compressed speech, talking book cassettes, and discs); 6. Compressed speech becomes valuable in reducing time spent in listening to taped material, lectures, etc., and is especially helpful to speed up a slow speaker; 7. The speed of reading Braille needs further research; and 8. The use of either Braille or compressed speech is individualized; however, both could be used as complementary learning techniques. Recommendations for further study include using sensory-integration research to measure tactile and aural learning pathways as well as to predict success for the blind learner with either tactile or aural integration preference. This research should also include investigation into such questions as: 1. How does blindness effect motor outputs and perceptual skills, thus how does a visual impairment affect learning? 2. Of the primary sensory inputs, do the congenitally or adventitiously blind have a greater or lesser functional ability with one specific sensory modality? Studies considering personality characteristics of successful Braille or compressed speech users should be investigated. It is also recommended that this research include independence and dependence traits with respect to success with tactual or aural preference. It also appears appropriate to investigate the inconsistency of educational levels and paucity of job equivalency or opportunities. Research regarding the use of Braille and compressed speech in job related tasks might be informative data to gather. Close

• 12272. [Article] Pesticides and produce : risk perceptions of extension clientele

  While there is growing public concern over the safety of the food supply, few studies have contrasted varying perceptions of pesticide risk. This study assessed and contrasted perceptions of three groups ...

  Citation × Citation Citation Abstract Copy Title: Pesticides and produce : risk perceptions of extension clientele Author: Love, Margaret L. While there is growing public concern over the safety of the food supply, few studies have contrasted varying perceptions of pesticide risk. This study assessed and contrasted perceptions of three groups of Oregon State University Extension Service clientele (home food preservers, Master Gardener volunteers, commercial growers) and factors influencing these perceptions. The impact of the pesticide risk perceptions on purchasing decisions and pesticide application practices was assessed. Two questionnaires were developed: one for home food preservers/Master Gardener volunteers and one for commercial growers. One hundred twenty-seven questionnaires were completed by a convenience sample of home food preservers (85% adjusted return rate) and 155 questionnaires were completed by randomly selected Oregon State University Master Gardener volunteers (81% adjusted return rate). A shortened version of the questionnaire was completed by 124 participants at the annual meeting of Willamette Valley Processed Vegetable Growers. Home preservers were 84% female (mean age=49 ± 14 years), volunteers were 50% female/50% male (mean age=56 ±14 years), and commercial growers were 95% male (mean age=42 ± 11 years). Three different measures of pesticide risk perceptions were used to test six hypotheses: Respondents rated 1) "eating foods produced using pesticides" as high, low, or no risk, and agreed/disagreed (on Likert scales) whether 2) "chemical residues remaining on produce are a major health concern," and 3) "children are at a greater risk for illness from pesticides than adults." Produce selection decisions, pesticide application practices, life stages, gender, media awareness, and knowledge of agricultural production techniques and practices were also assessed to determine their relationship with risk perceptions. Perceptions of risk varied among the three groups. Fifty-five percent of preservers rated "eating foods produced using pesticides" as a "high" risk compared to 34% of volunteers and 2% of growers. Thirty-four percent of preservers strongly agreed that "chemical residues remaining on produce are a major health concern" compared to 25% of volunteers and 7% of growers. Forty-six percent of preservers strongly agreed that "children are at a greater risk of illness from pesticides than adults" compared to 42% of volunteers. Fifty-two percent of growers strongly/ somewhat agreed that children are at no greater risk. Gender was significantly associated with respondents' perceptions. Eighty-nine percent of preservers rating the risk of "eating food produced using pesticides" as "high" were female as were 65% of volunteers. Female volunteers moderately agreed that "chemical residues remaining on produce are a major health concern" compared to males who tended to neither agree nor disagree. The presence of children living in the home was significantly related to the volunteers' perceptions that chemicals are a major health concern and that children are at greater risk. Preservers and growers' results indicated there were no significant differences. Awareness of pesticide reports in the media was measured by recall of four media events. Media awareness was significantly associated with preservers' perceptions that eating foods produced with pesticides was "high" risk and that children are at a greater risk for illness because of pesticide residues. There was no media association for either volunteers or growers. Influence of risk perceptions on produce purchase decisions was measured with a series of questions about past, present, and future purchases. Results indicated that volunteers' pesticide risk perceptions were significantly related to more produce selection decisions than were home food preservers. The risk perception measure that "chemical residues remaining on produce are a major health concern" was most significantly associated with purchase decisions for both preservers and volunteers. For preservers and volunteers there were significant relationships between all three measures of pesticide risk perceptions and three of the twelve purchase decisions tested. Those who perceived a higher risk were 1) more willing to pay a higher price for certified residue free produce, 2) more concerned about pesticide residues when buying imported produce, and 3) intended to purchase produce grown without synthetic pesticides even if it costs more. Knowledge of agricultural practices was measured by a set of five questions. Mean scores ranged from 0.9 ± 0.9 for preservers to 1.6 ± 1.0 for volunteers out of a possible 5.0. Volunteers' with higher scores were significantly more likely to agree that chemicals are a major health concern and that children are at a greater risk of illness from pesticide residues. No significant associations were seen for preservers. Pesticide application practices were significantly related to pesticide risk perceptions. Preservers and volunteers who generally perceived the risks as "high" reported not using pesticides. Preservers reporting changes in application practices moderately agreed chemical residues are a major health concern while volunteers' reporting changes in application practices strongly agreed that children are at higher risk than adults. Growers tended to disagree that pesticides are a major health concern and they were less concerned that children are at a greater risk from pesticides. The study concluded that the home food preservers and Master Gardener volunteers perceived the risks associated with pesticides and produce as much higher than commercial vegetable growers. This difference in perceptions is reflected in some of their produce selection decisions and pesticide application practices. Children living at home, gender, media awareness, and knowledge of agricultural practices were associated with the pesticide risk perceptions of these Extension clientele. Results suggest that educational programming to increase knowledge about pesticide usage in agricultural production is warranted. There is also a need to foster better communications among groups with differing points of views about pesticide residue risks. Title: Pesticides and produce : risk perceptions of extension clientele Author: Love, Margaret L. While there is growing public concern over the safety of the food supply, few studies have contrasted varying perceptions of pesticide risk. This study assessed and contrasted perceptions of three groups of Oregon State University Extension Service clientele (home food preservers, Master Gardener volunteers, commercial growers) and factors influencing these perceptions. The impact of the pesticide risk perceptions on purchasing decisions and pesticide application practices was assessed. Two questionnaires were developed: one for home food preservers/Master Gardener volunteers and one for commercial growers. One hundred twenty-seven questionnaires were completed by a convenience sample of home food preservers (85% adjusted return rate) and 155 questionnaires were completed by randomly selected Oregon State University Master Gardener volunteers (81% adjusted return rate). A shortened version of the questionnaire was completed by 124 participants at the annual meeting of Willamette Valley Processed Vegetable Growers. Home preservers were 84% female (mean age=49 ± 14 years), volunteers were 50% female/50% male (mean age=56 ±14 years), and commercial growers were 95% male (mean age=42 ± 11 years). Three different measures of pesticide risk perceptions were used to test six hypotheses: Respondents rated 1) "eating foods produced using pesticides" as high, low, or no risk, and agreed/disagreed (on Likert scales) whether 2) "chemical residues remaining on produce are a major health concern," and 3) "children are at a greater risk for illness from pesticides than adults." Produce selection decisions, pesticide application practices, life stages, gender, media awareness, and knowledge of agricultural production techniques and practices were also assessed to determine their relationship with risk perceptions. Perceptions of risk varied among the three groups. Fifty-five percent of preservers rated "eating foods produced using pesticides" as a "high" risk compared to 34% of volunteers and 2% of growers. Thirty-four percent of preservers strongly agreed that "chemical residues remaining on produce are a major health concern" compared to 25% of volunteers and 7% of growers. Forty-six percent of preservers strongly agreed that "children are at a greater risk of illness from pesticides than adults" compared to 42% of volunteers. Fifty-two percent of growers strongly/ somewhat agreed that children are at no greater risk. Gender was significantly associated with respondents' perceptions. Eighty-nine percent of preservers rating the risk of "eating food produced using pesticides" as "high" were female as were 65% of volunteers. Female volunteers moderately agreed that "chemical residues remaining on produce are a major health concern" compared to males who tended to neither agree nor disagree. The presence of children living in the home was significantly related to the volunteers' perceptions that chemicals are a major health concern and that children are at greater risk. Preservers and growers' results indicated there were no significant differences. Awareness of pesticide reports in the media was measured by recall of four media events. Media awareness was significantly associated with preservers' perceptions that eating foods produced with pesticides was "high" risk and that children are at a greater risk for illness because of pesticide residues. There was no media association for either volunteers or growers. Influence of risk perceptions on produce purchase decisions was measured with a series of questions about past, present, and future purchases. Results indicated that volunteers' pesticide risk perceptions were significantly related to more produce selection decisions than were home food preservers. The risk perception measure that "chemical residues remaining on produce are a major health concern" was most significantly associated with purchase decisions for both preservers and volunteers. For preservers and volunteers there were significant relationships between all three measures of pesticide risk perceptions and three of the twelve purchase decisions tested. Those who perceived a higher risk were 1) more willing to pay a higher price for certified residue free produce, 2) more concerned about pesticide residues when buying imported produce, and 3) intended to purchase produce grown without synthetic pesticides even if it costs more. Knowledge of agricultural practices was measured by a set of five questions. Mean scores ranged from 0.9 ± 0.9 for preservers to 1.6 ± 1.0 for volunteers out of a possible 5.0. Volunteers' with higher scores were significantly more likely to agree that chemicals are a major health concern and that children are at a greater risk of illness from pesticide residues. No significant associations were seen for preservers. Pesticide application practices were significantly related to pesticide risk perceptions. Preservers and volunteers who generally perceived the risks as "high" reported not using pesticides. Preservers reporting changes in application practices moderately agreed chemical residues are a major health concern while volunteers' reporting changes in application practices strongly agreed that children are at higher risk than adults. Growers tended to disagree that pesticides are a major health concern and they were less concerned that children are at a greater risk from pesticides. The study concluded that the home food preservers and Master Gardener volunteers perceived the risks associated with pesticides and produce as much higher than commercial vegetable growers. This difference in perceptions is reflected in some of their produce selection decisions and pesticide application practices. Children living at home, gender, media awareness, and knowledge of agricultural practices were associated with the pesticide risk perceptions of these Extension clientele. Results suggest that educational programming to increase knowledge about pesticide usage in agricultural production is warranted. There is also a need to foster better communications among groups with differing points of views about pesticide residue risks. Close

• 12273. [Article] Characterizing perpendicular-to-grain compression in wood construction applications

  Current compression perpendicular-to-grain (c-perp) design values for wood members are based on mean stress using the ASTM D143 specimen. Base design value, as determined from 0.04-in deformation in the ...

  Citation × Citation Citation Abstract Copy Title: Characterizing perpendicular-to-grain compression in wood construction applications Author: Basta, Craig Thomas Current compression perpendicular-to-grain (c-perp) design values for wood members are based on mean stress using the ASTM D143 specimen. Base design value, as determined from 0.04-in deformation in the ASTM specimen, is applied to all c-perp applications. While the standard ASTM test was presumably believed to adequately reflect relevant c-perp applications at the time it was developed (likely railroad cross-ties, wall plates and similar cross-sections), the specimen has limited applicability to many of today's c-perp bearing applications. Previous work has shown that wood-on-wood c-perp bearing is a more severe case as opposed to metal-on-wood bearing. End bearing conditions have been shown to represent a more severe c-perp loading scenario as opposed to load applied over central area. Research has shown that c-perp behavior of wood members is dependant on angle of applied load to annual ring orientation and that the most severe loading case is usually at an angle between 30 and 60 degrees to direction of applied load. Past studies also suggest that depth of member affects c-perp MOE and that higher aspect ratio may lead to instability of the member. As the c-perp behavior observed in the ASTM testing procedure is that of continually increasing stress with increasing deflection and densification, c-perp is generally believed to be serviceability rather than a life safety issue. However, in engineered wood applications, c-perp bearing may occur at areas where structural cohesiveness of a member is necessary to transmit forces through fasteners, such as truss plates. In such scenarios, c-perp has the potential to be a life safety issue. A study was designed to evaluate c-perp behavior of typical as-constructed assemblies in which members experience c-perp stresses near their longitudinal end through wood-on-wood contact. The study included both finite element analysis and experimental testing. Two as-constructed assemblies were evaluated in the study. These included assembly of the bottom chord of a truss bearing on the top plate of a wall (BC assembly) and assembly of the compression chord of a shear wall bearing on the bottom plate (BP assembly) of a wall. Finite element analysis modeled wood material as a composite with alternating earlywood and latewood layers with infinite radius of curvature. BC, BP and ASTM configurations were modeled both with load applied perpendicular and parallel to annual rings. Three BC assemblies were tested. These included BC-2X4, BC-2X8, and BC- 2X12, which had nominal 2X4, 2X8, and 2X12 members as bottom chord members, respectively. Therefore, within BC test assemblies aspect ratio of the bottom chord members varied greatly. The three BC geometries were each tested with both Douglas-fir and Spruce-Pine-Fir top plate material. BP configuration was also tested with both Douglas-fir and Spruce-Pine-Fir bottom plate material. For each test assembly, paired ASTM tests of the main member (bottom chord member in BC tests, and bottom plate member in BP tests) were conducted. Results were analyzed utilizing a variety of statistical methods. Finite element analysis revealed that strain was more uniform throughout depth of the bottom chord member when loaded perpendicular to annual rings than when loaded parallel to annual rings. In BC tests majority of deflection was found to occur in the bottom chord member. In BP test, the majority of deflection was found to occur within the bottom plate with only minimal deflection occurring in the longitudinally loaded compression chord. Due to varying assembly depths, 0.04-in, deflection was found to be a poor criterion for determining c-perp stress values. In order to account for assembly depth, stress values were based on system strain. As 0.04-in, deflection corresponds to two percent strain in the 2-in, deep ASTM specimen, it was determined that stress determination be based on 2-percent system strain. Due to large settlement effects observed in the tested wood-onwood assemblies, an offset strain was adopted as the method for determining and comparing stress values across differing assemblies and configurations tested. Within BC tests, the species of top plate material was not found to significantly affect assembly performance. This was due to the overwhelming influence of bottom chord behavior on system behavior. Within BP tests there was suggestive but inconclusive evidence of a significant difference between Douglas-fir and Spruce-Pine-Fir tests. It was recommended that further BP tests be conducted with larger sample sizes in order to determine the influence of wood species on c-perp behavior of bottom plate members. Mean stress values of BC and BP assembly tests were found to be significantly lower than that of corresponding ASTM tests of the main member. This finding lends justification to the Canadian 2/3 reduction factor for these scenarios as well as to the design procedures suggested by German researchers. It was determined that the ASTM c-perp test does not adequately represent these bearing scenarios. Adjustment factors are recommended for wood-on-wood bearing and opposite side end bearing. Aspect ratio was found to affect c-perp failure mode and led to high potential for sudden and catastrophic failure of members. Fifteen percent of 2X12 members tested failed prior to NDS design stresses due to premature failure of the nominal 2X12 bottom chord member. It was estimated that the odds of a 2X1 2 failing catastrophically are at least 16 times that of a 2X8 failing catastrophically. It was determined that as aspect ratio increases c-perp becomes a life safety as well as a serviceability issue and an adjustment factor for aspect ratio is recommended. Title: Characterizing perpendicular-to-grain compression in wood construction applications Author: Basta, Craig Thomas Current compression perpendicular-to-grain (c-perp) design values for wood members are based on mean stress using the ASTM D143 specimen. Base design value, as determined from 0.04-in deformation in the ASTM specimen, is applied to all c-perp applications. While the standard ASTM test was presumably believed to adequately reflect relevant c-perp applications at the time it was developed (likely railroad cross-ties, wall plates and similar cross-sections), the specimen has limited applicability to many of today's c-perp bearing applications. Previous work has shown that wood-on-wood c-perp bearing is a more severe case as opposed to metal-on-wood bearing. End bearing conditions have been shown to represent a more severe c-perp loading scenario as opposed to load applied over central area. Research has shown that c-perp behavior of wood members is dependant on angle of applied load to annual ring orientation and that the most severe loading case is usually at an angle between 30 and 60 degrees to direction of applied load. Past studies also suggest that depth of member affects c-perp MOE and that higher aspect ratio may lead to instability of the member. As the c-perp behavior observed in the ASTM testing procedure is that of continually increasing stress with increasing deflection and densification, c-perp is generally believed to be serviceability rather than a life safety issue. However, in engineered wood applications, c-perp bearing may occur at areas where structural cohesiveness of a member is necessary to transmit forces through fasteners, such as truss plates. In such scenarios, c-perp has the potential to be a life safety issue. A study was designed to evaluate c-perp behavior of typical as-constructed assemblies in which members experience c-perp stresses near their longitudinal end through wood-on-wood contact. The study included both finite element analysis and experimental testing. Two as-constructed assemblies were evaluated in the study. These included assembly of the bottom chord of a truss bearing on the top plate of a wall (BC assembly) and assembly of the compression chord of a shear wall bearing on the bottom plate (BP assembly) of a wall. Finite element analysis modeled wood material as a composite with alternating earlywood and latewood layers with infinite radius of curvature. BC, BP and ASTM configurations were modeled both with load applied perpendicular and parallel to annual rings. Three BC assemblies were tested. These included BC-2X4, BC-2X8, and BC- 2X12, which had nominal 2X4, 2X8, and 2X12 members as bottom chord members, respectively. Therefore, within BC test assemblies aspect ratio of the bottom chord members varied greatly. The three BC geometries were each tested with both Douglas-fir and Spruce-Pine-Fir top plate material. BP configuration was also tested with both Douglas-fir and Spruce-Pine-Fir bottom plate material. For each test assembly, paired ASTM tests of the main member (bottom chord member in BC tests, and bottom plate member in BP tests) were conducted. Results were analyzed utilizing a variety of statistical methods. Finite element analysis revealed that strain was more uniform throughout depth of the bottom chord member when loaded perpendicular to annual rings than when loaded parallel to annual rings. In BC tests majority of deflection was found to occur in the bottom chord member. In BP test, the majority of deflection was found to occur within the bottom plate with only minimal deflection occurring in the longitudinally loaded compression chord. Due to varying assembly depths, 0.04-in, deflection was found to be a poor criterion for determining c-perp stress values. In order to account for assembly depth, stress values were based on system strain. As 0.04-in, deflection corresponds to two percent strain in the 2-in, deep ASTM specimen, it was determined that stress determination be based on 2-percent system strain. Due to large settlement effects observed in the tested wood-onwood assemblies, an offset strain was adopted as the method for determining and comparing stress values across differing assemblies and configurations tested. Within BC tests, the species of top plate material was not found to significantly affect assembly performance. This was due to the overwhelming influence of bottom chord behavior on system behavior. Within BP tests there was suggestive but inconclusive evidence of a significant difference between Douglas-fir and Spruce-Pine-Fir tests. It was recommended that further BP tests be conducted with larger sample sizes in order to determine the influence of wood species on c-perp behavior of bottom plate members. Mean stress values of BC and BP assembly tests were found to be significantly lower than that of corresponding ASTM tests of the main member. This finding lends justification to the Canadian 2/3 reduction factor for these scenarios as well as to the design procedures suggested by German researchers. It was determined that the ASTM c-perp test does not adequately represent these bearing scenarios. Adjustment factors are recommended for wood-on-wood bearing and opposite side end bearing. Aspect ratio was found to affect c-perp failure mode and led to high potential for sudden and catastrophic failure of members. Fifteen percent of 2X12 members tested failed prior to NDS design stresses due to premature failure of the nominal 2X12 bottom chord member. It was estimated that the odds of a 2X1 2 failing catastrophically are at least 16 times that of a 2X8 failing catastrophically. It was determined that as aspect ratio increases c-perp becomes a life safety as well as a serviceability issue and an adjustment factor for aspect ratio is recommended. Close

• 12274. [Article] Throughput optimization for single-hop wireless networks using network coding

  Recent advances in wireless technologies have helped the proliferation of wireless devices, ranging from hand-held devices such as cellular phones to more powerful mobile computing platforms as such laptops ...

  Citation × Citation Citation Abstract Copy Title: Throughput optimization for single-hop wireless networks using network coding Author: Tran, Tuan Tho Recent advances in wireless technologies have helped the proliferation of wireless devices, ranging from hand-held devices such as cellular phones to more powerful mobile computing platforms as such laptops [1]. Along with that, the end users’ applications running on these devices, ranging from text message to multimedia applications such as audio and video streamings, also have been growing explosively. Unfortunately, as compared to wired networks, wireless networks are even less reliable due to interference and fading. As a result, providing Quality of Service (QoS) such as a guarantee on minimum bandwidth and maximum delay for multimedia applications over wireless networks is a major challenge. Compounded to the problem, the current wireless networks such as Wi-Fi were not designed for efficient provisioning of network resources in order to guarantee some pre-specified QoS. That said, building new wireless infrastructures that provide abundant capacity will guarantee QoS for wireless multimedia applications without resolving to complex resource provisioning mechanisms. Such an approach, however, is costly and resource inefficient. A compromised approach is to find techniques for increasing the network capacity without substantially changing the wireless network infrastructure. One promising approach is the recent development of network coding (NC) paradigm which has been shown to improve performance and efficiency of wireless networks. Potential benefits of network coding range from bandwidth and power efficiency to robustness and network dynamics. However, our current understanding on the optimal integration of network coding in the existing network protocols is rather limited. Furthermore, many NC benefits are often theoretically derived or obtained via simulations in idealized settings. To that end, the main scope of this dissertation aims at an in-depth understanding of network coding, its potential benefits, and trade-offs in typical real-world scenarios. The dissertation contributions can be summarized into three thrusts. In the first thrust, we consider single-hop wireless networks such as Wi-Fi or WiMAX networks, where the access point (AP) or base station (BS) has the ability to intercept and mix packet belonging to different flows from the Internet to multiple wireless users. We investigate a hybrid network coding technique to be used at a BS or AP to increase the throughput efficiency of the networks. Traditionally, to provide reliability, lost packets from different flows (applications) are retransmitted separately, leading to inefficient use of wireless bandwidth. Using the proposed hybrid network coding approach, the BS encodes these lost packets, possibly from different flows together before broadcasting them to all wireless users. In this way, multiple wireless receivers can recover their lost packets simultaneously with a single transmission from the BS. Furthermore, simulations and theoretical analysis showed that when used in conjunction with an appropriate channel coding technique under typical channel conditions, this approach can increase the throughput efficiency up to 3.5 times over the Automatic Repeat reQuest (ARQ), and up to 1.5 times over the HARQ techniques. In the second thrust, we investigate the achievable throughput for scenarios involving prioritized transmissions. Prioritized transmissions are useful in many multimedia networking applications where the transmitted data have an inherent hierarchy such that a piece of data at one level is only useful if all the pieces of data at all the lower levels are present. We investigate the achievable throughput of prioritized transmissions from a source to multiple receivers via a shared and lossy channel. In particular, we assume that the source is an oracle such that it knows precisely whether a packet is lost or received at any receiver in any future time slot, thus it can schedule the packet transmissions in such a way to maximize the receiver throughputs. We show that using network coding technique, the achievable throughput region for the broadcast scenarios can be substantially enlarged. Furthermore, for some erasure patterns, the achievable throughput using network coding technique is optimal in the sense that no scheme can do better. In addition, a class of approximate algorithms based on the Markov Chain Mote Carlo (MCMC) method have been proposed for obtaining the maximum sum throughput. Theoretical analysis and simulation results have been provided to verify the correctness and convergence speed of the proposed algorithms. In the third thrust, we propose a framework for adaptively optimizing the quality of service of multiple data flows in wireless access networks via network coding. Specifically, we consider scenarios in which multiple flows originate from multiple sources in the Internet and terminate at multiple users in a wireless network. In the current infrastructure, the wireless base station is responsible for relaying the packets from the Internet to the wireless users without any modification to the packet content. On the other hand, in the proposed approach, the wireless base station is allowed to perform network coding by appropriate linear mixing and channel coding of packets from different incoming flows before broadcasting a single flow of mixed or coded packets to all wireless users. Each user then uses an appropriate decoding method to recover its own packets from the set of coded packets that it receives. Theoretically, we showed that for the given channel conditions and QoS requirements, appropriate mixing and channel coding of packets across different flows can lead to substantial quality improvement for both real-time and non-real time flows. On the other hand, blind mixing can be detrimental. We formulate the mixing problem as a combinatorial optimization problem, and propose a heuristic algorithm based on the simulated-annealing method to approximate the optimal solution. Simulation results verify the performance improvement resulting from the proposed approach over the non-network coding and the state-of-the-art network coding approaches. Title: Throughput optimization for single-hop wireless networks using network coding Author: Tran, Tuan Tho Recent advances in wireless technologies have helped the proliferation of wireless devices, ranging from hand-held devices such as cellular phones to more powerful mobile computing platforms as such laptops [1]. Along with that, the end users’ applications running on these devices, ranging from text message to multimedia applications such as audio and video streamings, also have been growing explosively. Unfortunately, as compared to wired networks, wireless networks are even less reliable due to interference and fading. As a result, providing Quality of Service (QoS) such as a guarantee on minimum bandwidth and maximum delay for multimedia applications over wireless networks is a major challenge. Compounded to the problem, the current wireless networks such as Wi-Fi were not designed for efficient provisioning of network resources in order to guarantee some pre-specified QoS. That said, building new wireless infrastructures that provide abundant capacity will guarantee QoS for wireless multimedia applications without resolving to complex resource provisioning mechanisms. Such an approach, however, is costly and resource inefficient. A compromised approach is to find techniques for increasing the network capacity without substantially changing the wireless network infrastructure. One promising approach is the recent development of network coding (NC) paradigm which has been shown to improve performance and efficiency of wireless networks. Potential benefits of network coding range from bandwidth and power efficiency to robustness and network dynamics. However, our current understanding on the optimal integration of network coding in the existing network protocols is rather limited. Furthermore, many NC benefits are often theoretically derived or obtained via simulations in idealized settings. To that end, the main scope of this dissertation aims at an in-depth understanding of network coding, its potential benefits, and trade-offs in typical real-world scenarios. The dissertation contributions can be summarized into three thrusts. In the first thrust, we consider single-hop wireless networks such as Wi-Fi or WiMAX networks, where the access point (AP) or base station (BS) has the ability to intercept and mix packet belonging to different flows from the Internet to multiple wireless users. We investigate a hybrid network coding technique to be used at a BS or AP to increase the throughput efficiency of the networks. Traditionally, to provide reliability, lost packets from different flows (applications) are retransmitted separately, leading to inefficient use of wireless bandwidth. Using the proposed hybrid network coding approach, the BS encodes these lost packets, possibly from different flows together before broadcasting them to all wireless users. In this way, multiple wireless receivers can recover their lost packets simultaneously with a single transmission from the BS. Furthermore, simulations and theoretical analysis showed that when used in conjunction with an appropriate channel coding technique under typical channel conditions, this approach can increase the throughput efficiency up to 3.5 times over the Automatic Repeat reQuest (ARQ), and up to 1.5 times over the HARQ techniques. In the second thrust, we investigate the achievable throughput for scenarios involving prioritized transmissions. Prioritized transmissions are useful in many multimedia networking applications where the transmitted data have an inherent hierarchy such that a piece of data at one level is only useful if all the pieces of data at all the lower levels are present. We investigate the achievable throughput of prioritized transmissions from a source to multiple receivers via a shared and lossy channel. In particular, we assume that the source is an oracle such that it knows precisely whether a packet is lost or received at any receiver in any future time slot, thus it can schedule the packet transmissions in such a way to maximize the receiver throughputs. We show that using network coding technique, the achievable throughput region for the broadcast scenarios can be substantially enlarged. Furthermore, for some erasure patterns, the achievable throughput using network coding technique is optimal in the sense that no scheme can do better. In addition, a class of approximate algorithms based on the Markov Chain Mote Carlo (MCMC) method have been proposed for obtaining the maximum sum throughput. Theoretical analysis and simulation results have been provided to verify the correctness and convergence speed of the proposed algorithms. In the third thrust, we propose a framework for adaptively optimizing the quality of service of multiple data flows in wireless access networks via network coding. Specifically, we consider scenarios in which multiple flows originate from multiple sources in the Internet and terminate at multiple users in a wireless network. In the current infrastructure, the wireless base station is responsible for relaying the packets from the Internet to the wireless users without any modification to the packet content. On the other hand, in the proposed approach, the wireless base station is allowed to perform network coding by appropriate linear mixing and channel coding of packets from different incoming flows before broadcasting a single flow of mixed or coded packets to all wireless users. Each user then uses an appropriate decoding method to recover its own packets from the set of coded packets that it receives. Theoretically, we showed that for the given channel conditions and QoS requirements, appropriate mixing and channel coding of packets across different flows can lead to substantial quality improvement for both real-time and non-real time flows. On the other hand, blind mixing can be detrimental. We formulate the mixing problem as a combinatorial optimization problem, and propose a heuristic algorithm based on the simulated-annealing method to approximate the optimal solution. Simulation results verify the performance improvement resulting from the proposed approach over the non-network coding and the state-of-the-art network coding approaches. Close

• 12275. [Article] The Roles of Dietary Nitrate in Bone and the Gut in an Ovarian Hormone-deficient Rodent Model

  Osteoporosis is a common metabolic bone disease, affecting a third of women and a fifth of men over age 65. In the US, annual health care costs associated with osteoporosis are estimated to be over $20 ...

  Citation × Citation Citation Abstract Copy Title: The Roles of Dietary Nitrate in Bone and the Gut in an Ovarian Hormone-deficient Rodent Model Author: Conley, Melissa N. Osteoporosis is a common metabolic bone disease, affecting a third of women and a fifth of men over age 65. In the US, annual health care costs associated with osteoporosis are estimated to be over $20 billion. Osteoporosis is associated with increased fracture risk, which has been demonstrated to predict mortality rates and nursing home admittance. Altered bone remodeling, defined by excessive bone resorption and/or impaired bone formation, is a major risk factor for osteoporotic fracture. In menopause-induced ovarian hormone deficiency, bone resorption exceeds formation. Menopause-induced bone resorption is associated with a reduced bone mineral density (BMD), and there is a relationship between low BMD and increased fracture risk. Given the importance of bone remodeling and fracture risk, there have been significant efforts to understand the ability of dietary components to slow bone loss. Some observational studies report that fruit and vegetable consumption is associated with an increase in bone mineral content (BMC) and BMD. Dietary nitrates, present in high concentrations in leafy green vegetables, may serve as a dietary component that supports bone health. Vegetable intake accounts for ~80% of dietary nitrate consumption in the typical human diet. Dietary nitrates can be reduced to nitric oxide (NO) via non-enzymatic reduction by lingual bacteria and a variety of mammalian reductases through the nitrate-nitrite-NO pathway. There is evidence suggesting that strategies to increase NO bioavailability using organic nitrates (i.e., nitroglycerin) as an NO donor may decrease bone turnover and loss in ovariectomized (OVX) animals, which are animals that have had their ovaries surgically removed to induce a postmenopausal-like state, defined by diminished ovarian production of female hormones, particularly estrogen and progesterone. Some follow up trials in postmenopausal women have demonstrated similar results. Since non-enzymatic reduction of dietary nitrate can account for up to 50% of NO production, this provides a biologically plausible link between dietary nitrate and bone health and suggests that dietary nitrate, as an alternate NO donor, may offer efficacious means of decreasing bone loss in postmenopausal women. Here, using an in vivo approach, we examined the dose-response relationship between dietary nitrates and bone density, microarchitecture, and turnover in OVX rats. We show that dietary nitrates do not improve bone density, microarchitecture, or turnover. Further, dietary nitrate had no beneficial effect on mineral apposition rate, bone formation rate, or bone volume/tissue volume in OVX rats. Our novel findings demonstrate dietary nitrate does not slow ovx-induced bone loss. This knowledge clarified the relationship between a dietary compound found in large quantities in leafy greens and bone loss in an OVX model. As an exploratory component of this study, we used 16S rRNA gene sequencing to profile the composition of fecal microbiota associated with sham surgical controls, OVX, and nitrate-treated groups to evaluate the ability of OVX or dietary nitrate to modulate the gut microbiome in OVX mammals. While dietary nitrate did not alter the gut microbiome in the context of OVX, we did observe gut microbiome changes in structure and composition associated with OVX status and identified specific phylotypes whose abundance stratify sham and OVX rats, including Proteobacteria, Firmicutes, and Bacteroidetes. These results add to the growing body of evidence that there is an association between the gut microbiome and sex steroid deficiency. Our use of the OVX model also provided an important added opportunity to further our understanding of the tissue effects of sex steroid deficiency observed in menopause. While both progesterone and estrogen influence metabolism, most attention has been given to the effects of ovarian hormone deficiency. Complex interactions between estrogen and host metabolism suggest that tissues in addition to serum and urine must be examined to clarify the mechanistic underpinnings of ovarian hormone deficiency and associated disease risk. Insufficient data are available from tissue-based studies using NMR-based platforms in estrogen-deficient models. Metabolomic studies in OVX rats, a model for osteoporosis, and postmenopausal women have demonstrated major metabolic shifts in serum, plasma, and urine as a result of ovarian hormone deficiency. To our knowledge, metabolomics has not been used for investigating the metabolic phenotype observed in the postmenopausal colon. Metabolomic studies of ovarian hormone deficiency is limited to bone, adipose, skeletal muscle, serum, plasma, and urine. Further, while it is established that ovarian hormone deficiency causes metabolic dysregulation, and the gut is associated with metabolic diseases and bone metabolism, there is also limited information available on the effects of estrogen loss on both gut tissue and gut microbiota. In light of this and our observed gut microbiome differences in OVX rats, we evaluated the effects of OVX on the colon using a metabolomics approach. We found the OVX colon is characterized by elevated levels of antioxidants, such as taurine and hypotaurine, and osmolytes, such as glycerophospholine, glycine, and glutamate. These novel findings suggest alterations to the colonic transsulfuration and methylation pathways, and they are suggestive of hyperosmotic and oxidative stress in the OVX colon. Previous work has associated hyperosmotic and oxidative stress with inflammation and intestinal permeability. These processes may also be present in the OVX colon; however, we did not quantify either inflammation or intestinal permeability in the current body of work. This dissertation takes advantage of a postmenopausal osteoporosis animal model and integrative techniques, such as osteologic, immunological, metabonomic, microbiomic and bioinformatic methods, to evaluate different metrics of osteoporosis, including physiological determinants influencing the rate of bone loss and gut-associated changes in ovarian hormone deficiency. The central findings of this dissertation show that dietary nitrate does not slow bone loss in ovarian hormone deficiency-induced rat model of bone loss. Further, dietary nitrate does not appear to influence the gut microbiome in the context of OVX. This is important in furthering our understanding of the relationship between the consumption of this ubiquitous component of fruit and vegetables and bone health. We also demonstrate that OVX is associated with shifts in gut microbiome structure and composition. Finally, we show OVX influences the colon metabolic phenotype, inducing the upregulation of metabolites involved with hyperosmotic and oxidative stress. Since estrogen protects against oxidative stress in many other tissues, we hypothesize that ovarian hormone deficiency promotes oxidative and hyperosmotic stress in the colon, promoting intestinal permeability and elevating the inflammatory response. In response, the colonic transsulfuration and methylation pathways may adapt by upregulating osmolytes and antioxidants. However, the specific causative agents of oxidative stress cannot be derived from our current work. Further investigation of the role these metabolites and processes play in the development of inflammation and metabolic dysregulation will yield insights into the physiological effects of ovarian hormone deficiency in postmenopausal women, allowing for more informed diagnosis and treatment of susceptible individuals. Title: The Roles of Dietary Nitrate in Bone and the Gut in an Ovarian Hormone-deficient Rodent Model Author: Conley, Melissa N. Osteoporosis is a common metabolic bone disease, affecting a third of women and a fifth of men over age 65. In the US, annual health care costs associated with osteoporosis are estimated to be over $20 billion. Osteoporosis is associated with increased fracture risk, which has been demonstrated to predict mortality rates and nursing home admittance. Altered bone remodeling, defined by excessive bone resorption and/or impaired bone formation, is a major risk factor for osteoporotic fracture. In menopause-induced ovarian hormone deficiency, bone resorption exceeds formation. Menopause-induced bone resorption is associated with a reduced bone mineral density (BMD), and there is a relationship between low BMD and increased fracture risk. Given the importance of bone remodeling and fracture risk, there have been significant efforts to understand the ability of dietary components to slow bone loss. Some observational studies report that fruit and vegetable consumption is associated with an increase in bone mineral content (BMC) and BMD. Dietary nitrates, present in high concentrations in leafy green vegetables, may serve as a dietary component that supports bone health. Vegetable intake accounts for ~80% of dietary nitrate consumption in the typical human diet. Dietary nitrates can be reduced to nitric oxide (NO) via non-enzymatic reduction by lingual bacteria and a variety of mammalian reductases through the nitrate-nitrite-NO pathway. There is evidence suggesting that strategies to increase NO bioavailability using organic nitrates (i.e., nitroglycerin) as an NO donor may decrease bone turnover and loss in ovariectomized (OVX) animals, which are animals that have had their ovaries surgically removed to induce a postmenopausal-like state, defined by diminished ovarian production of female hormones, particularly estrogen and progesterone. Some follow up trials in postmenopausal women have demonstrated similar results. Since non-enzymatic reduction of dietary nitrate can account for up to 50% of NO production, this provides a biologically plausible link between dietary nitrate and bone health and suggests that dietary nitrate, as an alternate NO donor, may offer efficacious means of decreasing bone loss in postmenopausal women. Here, using an in vivo approach, we examined the dose-response relationship between dietary nitrates and bone density, microarchitecture, and turnover in OVX rats. We show that dietary nitrates do not improve bone density, microarchitecture, or turnover. Further, dietary nitrate had no beneficial effect on mineral apposition rate, bone formation rate, or bone volume/tissue volume in OVX rats. Our novel findings demonstrate dietary nitrate does not slow ovx-induced bone loss. This knowledge clarified the relationship between a dietary compound found in large quantities in leafy greens and bone loss in an OVX model. As an exploratory component of this study, we used 16S rRNA gene sequencing to profile the composition of fecal microbiota associated with sham surgical controls, OVX, and nitrate-treated groups to evaluate the ability of OVX or dietary nitrate to modulate the gut microbiome in OVX mammals. While dietary nitrate did not alter the gut microbiome in the context of OVX, we did observe gut microbiome changes in structure and composition associated with OVX status and identified specific phylotypes whose abundance stratify sham and OVX rats, including Proteobacteria, Firmicutes, and Bacteroidetes. These results add to the growing body of evidence that there is an association between the gut microbiome and sex steroid deficiency. Our use of the OVX model also provided an important added opportunity to further our understanding of the tissue effects of sex steroid deficiency observed in menopause. While both progesterone and estrogen influence metabolism, most attention has been given to the effects of ovarian hormone deficiency. Complex interactions between estrogen and host metabolism suggest that tissues in addition to serum and urine must be examined to clarify the mechanistic underpinnings of ovarian hormone deficiency and associated disease risk. Insufficient data are available from tissue-based studies using NMR-based platforms in estrogen-deficient models. Metabolomic studies in OVX rats, a model for osteoporosis, and postmenopausal women have demonstrated major metabolic shifts in serum, plasma, and urine as a result of ovarian hormone deficiency. To our knowledge, metabolomics has not been used for investigating the metabolic phenotype observed in the postmenopausal colon. Metabolomic studies of ovarian hormone deficiency is limited to bone, adipose, skeletal muscle, serum, plasma, and urine. Further, while it is established that ovarian hormone deficiency causes metabolic dysregulation, and the gut is associated with metabolic diseases and bone metabolism, there is also limited information available on the effects of estrogen loss on both gut tissue and gut microbiota. In light of this and our observed gut microbiome differences in OVX rats, we evaluated the effects of OVX on the colon using a metabolomics approach. We found the OVX colon is characterized by elevated levels of antioxidants, such as taurine and hypotaurine, and osmolytes, such as glycerophospholine, glycine, and glutamate. These novel findings suggest alterations to the colonic transsulfuration and methylation pathways, and they are suggestive of hyperosmotic and oxidative stress in the OVX colon. Previous work has associated hyperosmotic and oxidative stress with inflammation and intestinal permeability. These processes may also be present in the OVX colon; however, we did not quantify either inflammation or intestinal permeability in the current body of work. This dissertation takes advantage of a postmenopausal osteoporosis animal model and integrative techniques, such as osteologic, immunological, metabonomic, microbiomic and bioinformatic methods, to evaluate different metrics of osteoporosis, including physiological determinants influencing the rate of bone loss and gut-associated changes in ovarian hormone deficiency. The central findings of this dissertation show that dietary nitrate does not slow bone loss in ovarian hormone deficiency-induced rat model of bone loss. Further, dietary nitrate does not appear to influence the gut microbiome in the context of OVX. This is important in furthering our understanding of the relationship between the consumption of this ubiquitous component of fruit and vegetables and bone health. We also demonstrate that OVX is associated with shifts in gut microbiome structure and composition. Finally, we show OVX influences the colon metabolic phenotype, inducing the upregulation of metabolites involved with hyperosmotic and oxidative stress. Since estrogen protects against oxidative stress in many other tissues, we hypothesize that ovarian hormone deficiency promotes oxidative and hyperosmotic stress in the colon, promoting intestinal permeability and elevating the inflammatory response. In response, the colonic transsulfuration and methylation pathways may adapt by upregulating osmolytes and antioxidants. However, the specific causative agents of oxidative stress cannot be derived from our current work. Further investigation of the role these metabolites and processes play in the development of inflammation and metabolic dysregulation will yield insights into the physiological effects of ovarian hormone deficiency in postmenopausal women, allowing for more informed diagnosis and treatment of susceptible individuals. Close

• 12276. [Article] Dry weight and 15N-nitrogen and partitioning, growth, and development of young and mature blueberry plants

  The effect of planting density and nitrogen (N) fertilization on growth, yield, and N partitioning in young and mature 'Bluecrop' blueberry plants was studied over a two year period. Depleted 15N-ammonium ...

  Citation × Citation Citation Abstract Copy Title: Dry weight and 15N-nitrogen and partitioning, growth, and development of young and mature blueberry plants Author: Banados, Maria Pilar The effect of planting density and nitrogen (N) fertilization on growth, yield, and N partitioning in young and mature 'Bluecrop' blueberry plants was studied over a two year period. Depleted 15N-ammonium sulfate was applied at different rates and on different dates in a mature planting, and at different rates in a young, newly established planting during the first year of study (2002). Non-labeled fertilizer was applied the second year (2003). Three rates of N fertilizer (0, 100, and 200 kgha1 of N) in combination with two in-row spacing treatments (0.45 m and 1.2 m) were studied in the mature planting. In addition, three different dates of application of labeled fertilizer at the same rate was also tested. In a young planting, four N fertilizer rates (0, 50, 100 and 150 kgha^-1 of N) were applied in the establishment year. In all studies, the N fertilizer was divided into three equal portions and applied from April through June. Plants were destructively harvested from the field and divided into parts on 6 to 11 dates from Feb. 2002 to Jan. 2004, depending on experiment. Plant parts were analyzed for dry weight (DW), N, and '5N concentration (%) and nitrogen derived from the fertilizer (NDFF) calculated. Shoots on mature plants were divided into small (S), medium (M), large (L) and extra large (XL) categories, based on length, and the effect of N and plant spacing on the number, DW, and flushes of growth characterized. The number of shoots per plant ranged from 249 to 298 with plants spaced at 1.2 m having more shoots than those at 0.45 m. Fifty percent of the shoots in the plant were S, whereas only 8% were XL. Nitrogen rate did not affect shoot number, but higher rates of N did increase shoot biomass and the proportion of XL and S shoots. One to four flushes of growth per shoot were recorded, with the number of flushes dependent upon shoot size; 60 to 80% of S shoots had only one flush of growth compared to 8 to 12% of XL shoots. Eighty percent of total shoot biomass was in the first flush of growth and 20% in the second or later flushes with no effect of in-row spacing or N rate. Yield per plant was 30 to 80% greater at 1.2 m than at 0.45 m. However, yield per hectare was 30 to 140% higher in plants at 0.45 m than those at 1.2 m. The roots and crown were the heaviest organs, whereas roots and leaves contained the most nitrogen. Percent biomass partitioning was affected by sampling date for all plant parts, and by in-row spacing only for the crown and three-year-old wood. In the mature planting, total plant DW was affected by sampling date, in-row spacing, and N fertilization rate. Plants at the 1.2 m in-row spacing had 32% more DW over time than those at 0.45 m, but less DW per hectare. Nitrogen fertilization increased plant DW in the second year of study, affecting mainly the younger plant parts. Plants fertilized with 200 kgha^-1 of N had the greatest total N. Nitrogen concentration (%N) varied greatly with plant part and was affected by sampling date and N fertilization rate. Younger tissues had the highest %N in spring (3.5%) and flower buds in winter (2.4%). Total plant NDFF increased from Apr. 2002 to May 2003. The lowest NDFF per plant and per hectare was found in Apr. 2002, when almost 60% of the NDFF was in the new shoots. Nitrogen fertilization rate and in-row plant spacing had an impact on total NDFF accumulated per plant and per hectare. More total NDFF was found in plants fertilized with 200 kgha^-1 of N than with 100 kgha^-1 of N, independent of spacing. Fertilizer recovery was 17% for plants at 1.2 m and 23% for plants at 0.45 m, independent of N fertilization rate. Partitioning of 15N (mg per plant part) and percent of total 15N per part changed with sampling date. Nitrogen fertilization rate and spacing did affect the total amount of fertilizer-15N present in each part, but percent partitioning of 15N was only affected by plant part. Plants at 1.2 m had a higher percentage of 15N partitioned to the crown and three-year and older wood, but reduced partitioning to large roots than plants at 0.45 m. Application date had a large effect on the total amount of NIDFF recovered in the plant at the end of the first season. Application of N fertilizer in either April or May resulted in five times more NDFF in the plant than fertilizer application in July. Percent partitioning of NDFF was also affected by application date. Late fertilization resulted in labeled N allocated mainly to small roots, leaves and shoots, whereas spring-applied fertilizer was allocated mainly to leaves and fruits. In the new planting, established using two-year-old plants, N fertilization rate affected plant dry weight, total N content, percent NDFF, and fertilizer recovery. By October, plants fertilized with 50 kgha1 of N had the largest dry weight and N accumulation. Ammonium toxicity was observed in plants fertilized with 100 and 150 kgha1 of N. Percent NDFF was 60% and 67% for the 50 and 100 kgha^-1 of N, respectively. Fertilizer recovery reached a maximum of 10 to 17% in October, depending on N fertilization rate. Title: Dry weight and 15N-nitrogen and partitioning, growth, and development of young and mature blueberry plants Author: Banados, Maria Pilar The effect of planting density and nitrogen (N) fertilization on growth, yield, and N partitioning in young and mature 'Bluecrop' blueberry plants was studied over a two year period. Depleted 15N-ammonium sulfate was applied at different rates and on different dates in a mature planting, and at different rates in a young, newly established planting during the first year of study (2002). Non-labeled fertilizer was applied the second year (2003). Three rates of N fertilizer (0, 100, and 200 kgha1 of N) in combination with two in-row spacing treatments (0.45 m and 1.2 m) were studied in the mature planting. In addition, three different dates of application of labeled fertilizer at the same rate was also tested. In a young planting, four N fertilizer rates (0, 50, 100 and 150 kgha^-1 of N) were applied in the establishment year. In all studies, the N fertilizer was divided into three equal portions and applied from April through June. Plants were destructively harvested from the field and divided into parts on 6 to 11 dates from Feb. 2002 to Jan. 2004, depending on experiment. Plant parts were analyzed for dry weight (DW), N, and '5N concentration (%) and nitrogen derived from the fertilizer (NDFF) calculated. Shoots on mature plants were divided into small (S), medium (M), large (L) and extra large (XL) categories, based on length, and the effect of N and plant spacing on the number, DW, and flushes of growth characterized. The number of shoots per plant ranged from 249 to 298 with plants spaced at 1.2 m having more shoots than those at 0.45 m. Fifty percent of the shoots in the plant were S, whereas only 8% were XL. Nitrogen rate did not affect shoot number, but higher rates of N did increase shoot biomass and the proportion of XL and S shoots. One to four flushes of growth per shoot were recorded, with the number of flushes dependent upon shoot size; 60 to 80% of S shoots had only one flush of growth compared to 8 to 12% of XL shoots. Eighty percent of total shoot biomass was in the first flush of growth and 20% in the second or later flushes with no effect of in-row spacing or N rate. Yield per plant was 30 to 80% greater at 1.2 m than at 0.45 m. However, yield per hectare was 30 to 140% higher in plants at 0.45 m than those at 1.2 m. The roots and crown were the heaviest organs, whereas roots and leaves contained the most nitrogen. Percent biomass partitioning was affected by sampling date for all plant parts, and by in-row spacing only for the crown and three-year-old wood. In the mature planting, total plant DW was affected by sampling date, in-row spacing, and N fertilization rate. Plants at the 1.2 m in-row spacing had 32% more DW over time than those at 0.45 m, but less DW per hectare. Nitrogen fertilization increased plant DW in the second year of study, affecting mainly the younger plant parts. Plants fertilized with 200 kgha^-1 of N had the greatest total N. Nitrogen concentration (%N) varied greatly with plant part and was affected by sampling date and N fertilization rate. Younger tissues had the highest %N in spring (3.5%) and flower buds in winter (2.4%). Total plant NDFF increased from Apr. 2002 to May 2003. The lowest NDFF per plant and per hectare was found in Apr. 2002, when almost 60% of the NDFF was in the new shoots. Nitrogen fertilization rate and in-row plant spacing had an impact on total NDFF accumulated per plant and per hectare. More total NDFF was found in plants fertilized with 200 kgha^-1 of N than with 100 kgha^-1 of N, independent of spacing. Fertilizer recovery was 17% for plants at 1.2 m and 23% for plants at 0.45 m, independent of N fertilization rate. Partitioning of 15N (mg per plant part) and percent of total 15N per part changed with sampling date. Nitrogen fertilization rate and spacing did affect the total amount of fertilizer-15N present in each part, but percent partitioning of 15N was only affected by plant part. Plants at 1.2 m had a higher percentage of 15N partitioned to the crown and three-year and older wood, but reduced partitioning to large roots than plants at 0.45 m. Application date had a large effect on the total amount of NIDFF recovered in the plant at the end of the first season. Application of N fertilizer in either April or May resulted in five times more NDFF in the plant than fertilizer application in July. Percent partitioning of NDFF was also affected by application date. Late fertilization resulted in labeled N allocated mainly to small roots, leaves and shoots, whereas spring-applied fertilizer was allocated mainly to leaves and fruits. In the new planting, established using two-year-old plants, N fertilization rate affected plant dry weight, total N content, percent NDFF, and fertilizer recovery. By October, plants fertilized with 50 kgha1 of N had the largest dry weight and N accumulation. Ammonium toxicity was observed in plants fertilized with 100 and 150 kgha1 of N. Percent NDFF was 60% and 67% for the 50 and 100 kgha^-1 of N, respectively. Fertilizer recovery reached a maximum of 10 to 17% in October, depending on N fertilization rate. Close

• 12277. [Article] Physical activity in children attending family child care homes

  Family Child Care Homes (FCCHs) are the second largest provider of non-relative care in the U.S. However, despite providing care for nearly 1.9 million children under the age of 5, little is known about ...

  Citation × Citation Citation Abstract Copy Title: Physical activity in children attending family child care homes Author: Rice, Kelly Rae, 1978- Family Child Care Homes (FCCHs) are the second largest provider of non-relative care in the U.S. However, despite providing care for nearly 1.9 million children under the age of 5, little is known about the physical activity levels of children attending FCCHs. This dissertation sought to provide new information with regards to physical activity in children attending FCCHs. The purpose of the first study was to objectively measure physical activity in children attending FCCHs. 114 children (60 boys and 54 girls) 3.7 ± 1.1 years of age from 47 FCCHs wore an ActiGraph GT1M accelerometer for the duration of child care attendance during a randomly selected week. Counts were classified as sedentary (SED), light (LPA), or moderate-to-vigorous (MVPA) using the cut-points developed by Pate et al. (2006). Total physical activity was calculated by summing time spent in LPA and MVPA. Non-wear time was estimated by summing the number of consecutive zero counts accumulated in strings of 10 minutes or longer. Children were included in the analyses if they had 2 or more monitoring days in which wear time was ≥75% of the attendance time. On average, children accumulated 25.9 ± 5.7 min of SED, 10.1 ± 4.2 min of MVPA, and 34.1 ± 5.7 min of total physical activity per hour of attendance. Further analysis revealed that among healthy weight children, 4 year-olds exhibited significantly lower levels of SED and significantly higher levels of MVPA and total physical activity than 2- and 3- year-olds. Among 4-year-olds, overweight and obese children exhibited significantly higher levels of SED and significantly lower levels of MVPA and total PHYSICAL ACTIVITY than healthy weight counterparts. The results from this study indicated that preschool-aged children attending FCCHs are mostly sedentary and accumulate low levels of MVPA during the child care day. The purpose of the second study was to assess the validity of two proxy report instruments designed to measure physical activity in children attending FCCHs. Valid self-report measures are needed for large scale intervention studies and/or population-based surveillance studies in which more burdensome objective measures are not feasible. In Year 1 of the study, FCCH Providers (N=37) completed the Burdette parent proxy report, modified for the family child care setting, for 107 children aged 3.4 ± 1.2 years. In Year 2, 42 Providers completed the Harro parent and teacher proxy report, modified for the family child care setting, for 131 children aged 3.8 ± 1.3 years. Both proxy-reports were assessed for validity using objectively measured physical activity as a criterion measure (accelerometry). Significant positive correlations were observed between scores from the modified Burdette proxy report and objectively measured total physical activity (r = 0.31, p < 0.01) and MVPA (r = 0.33, p < 0.01). Across levels of Provider-reported activity, both total physical activity and MVPA increased significantly in a linear dose-response fashion. Provider-reported MVPA scores from modified Harro proxy report were not associated with objectively measured physical activity. These findings suggested that the modified Burdette proxy report may be a useful measurement tool in larger-scale physical activity studies involving FCCHs in which objective measures, such as direct observation or accelerometry, are not practical. The purpose of the third study was to evaluate the effects of two strategies to increase the use of portable play equipment in FCCHs – a community-based train-the-trainer physical activity intervention (INT), and the same trainer-the-trainer intervention supplemented with monthly emails promoting the use of portable play equipment (INT+). We hypothesized that Providers completing the standard train-the-trainer intervention would report significantly greater portable play equipment use than Providers completing the food allergy control training (CON). We further hypothesized that Providers completing the supplementary email intervention would report significantly greater portable play equipment use than Providers completing standard train-the-trainer intervention or the food allergy control training. A total of 50 FCCH Providers from Marion, Linn, Benton, Washington, and Lane County, Oregon were randomized to the INT or CON conditions. Twelve Providers from Lincoln County were assigned to the (INT+). The type, variety, and frequency of portable play equipment use was measured by means of self-report via a checklist and two items from the previously validated NAP-SACC Self-Assessment instrument. FCCH Providers who completed the INT reported significantly greater use of portable play equipment than Providers completing the CON training. However, portable play equipment use among Providers completing the INT+ was not significantly different from that reported by Providers in the INT or CON. Notably, neither intervention had a significant impact on the amount or variety of portable play equipment. The results showed that a comprehensive trainer-the-trainer intervention to increase physical activity in FCCHs could successfully increase the use of portable play equipment in the home. However, supplementing the intervention with monthly emails encouraging the use of PPE was not effective. Title: Physical activity in children attending family child care homes Author: Rice, Kelly Rae, 1978- Family Child Care Homes (FCCHs) are the second largest provider of non-relative care in the U.S. However, despite providing care for nearly 1.9 million children under the age of 5, little is known about the physical activity levels of children attending FCCHs. This dissertation sought to provide new information with regards to physical activity in children attending FCCHs. The purpose of the first study was to objectively measure physical activity in children attending FCCHs. 114 children (60 boys and 54 girls) 3.7 ± 1.1 years of age from 47 FCCHs wore an ActiGraph GT1M accelerometer for the duration of child care attendance during a randomly selected week. Counts were classified as sedentary (SED), light (LPA), or moderate-to-vigorous (MVPA) using the cut-points developed by Pate et al. (2006). Total physical activity was calculated by summing time spent in LPA and MVPA. Non-wear time was estimated by summing the number of consecutive zero counts accumulated in strings of 10 minutes or longer. Children were included in the analyses if they had 2 or more monitoring days in which wear time was ≥75% of the attendance time. On average, children accumulated 25.9 ± 5.7 min of SED, 10.1 ± 4.2 min of MVPA, and 34.1 ± 5.7 min of total physical activity per hour of attendance. Further analysis revealed that among healthy weight children, 4 year-olds exhibited significantly lower levels of SED and significantly higher levels of MVPA and total physical activity than 2- and 3- year-olds. Among 4-year-olds, overweight and obese children exhibited significantly higher levels of SED and significantly lower levels of MVPA and total PHYSICAL ACTIVITY than healthy weight counterparts. The results from this study indicated that preschool-aged children attending FCCHs are mostly sedentary and accumulate low levels of MVPA during the child care day. The purpose of the second study was to assess the validity of two proxy report instruments designed to measure physical activity in children attending FCCHs. Valid self-report measures are needed for large scale intervention studies and/or population-based surveillance studies in which more burdensome objective measures are not feasible. In Year 1 of the study, FCCH Providers (N=37) completed the Burdette parent proxy report, modified for the family child care setting, for 107 children aged 3.4 ± 1.2 years. In Year 2, 42 Providers completed the Harro parent and teacher proxy report, modified for the family child care setting, for 131 children aged 3.8 ± 1.3 years. Both proxy-reports were assessed for validity using objectively measured physical activity as a criterion measure (accelerometry). Significant positive correlations were observed between scores from the modified Burdette proxy report and objectively measured total physical activity (r = 0.31, p < 0.01) and MVPA (r = 0.33, p < 0.01). Across levels of Provider-reported activity, both total physical activity and MVPA increased significantly in a linear dose-response fashion. Provider-reported MVPA scores from modified Harro proxy report were not associated with objectively measured physical activity. These findings suggested that the modified Burdette proxy report may be a useful measurement tool in larger-scale physical activity studies involving FCCHs in which objective measures, such as direct observation or accelerometry, are not practical. The purpose of the third study was to evaluate the effects of two strategies to increase the use of portable play equipment in FCCHs – a community-based train-the-trainer physical activity intervention (INT), and the same trainer-the-trainer intervention supplemented with monthly emails promoting the use of portable play equipment (INT+). We hypothesized that Providers completing the standard train-the-trainer intervention would report significantly greater portable play equipment use than Providers completing the food allergy control training (CON). We further hypothesized that Providers completing the supplementary email intervention would report significantly greater portable play equipment use than Providers completing standard train-the-trainer intervention or the food allergy control training. A total of 50 FCCH Providers from Marion, Linn, Benton, Washington, and Lane County, Oregon were randomized to the INT or CON conditions. Twelve Providers from Lincoln County were assigned to the (INT+). The type, variety, and frequency of portable play equipment use was measured by means of self-report via a checklist and two items from the previously validated NAP-SACC Self-Assessment instrument. FCCH Providers who completed the INT reported significantly greater use of portable play equipment than Providers completing the CON training. However, portable play equipment use among Providers completing the INT+ was not significantly different from that reported by Providers in the INT or CON. Notably, neither intervention had a significant impact on the amount or variety of portable play equipment. The results showed that a comprehensive trainer-the-trainer intervention to increase physical activity in FCCHs could successfully increase the use of portable play equipment in the home. However, supplementing the intervention with monthly emails encouraging the use of PPE was not effective. Close

• 12278. [Article] Effect of dietary fatty acids, time of feeding and immune response in poultry

  In the presence of internal or external stressors, the body requires sources of energy that aide cells to combat inflammation. Fatty acids are an important source of energy and are vital components of ...

  Citation × Citation Citation Abstract Copy Title: Effect of dietary fatty acids, time of feeding and immune response in poultry Author: Gonzalez, Dulmelis In the presence of internal or external stressors, the body requires sources of energy that aide cells to combat inflammation. Fatty acids are an important source of energy and are vital components of cell membranes. Dietary fatty acids (n-6 and n-3) are of importance in immune function because they are precursors to metabolites that are potent mediators of inflammation. Poultry diets are high in n-6 fatty acids, which exert pro-inflammatory effects, and low in n-3 fatty acids, which tend to be less inflammatory. Delayed access to feed after hatching has been reported to impact the development of organs associated with immunity. Based on this information, two experiments were conducted in broiler chickens to determine the effect of dietary polyunsaturated fatty acid (PUFA) and the influence of time of feeding on bird performance, tissue lipid status, immune responses and expression of cyclooxygenase 2 (COX-2) upon challenge. In experiment 1, birds were fed diets that contained 3.5% oxidized yellow grease (low n-3) or 3.5% canola oil (high n-3). Birds were fed early (<5 hrs post-hatch) or late (>24 hrs post-hatch). Intramuscular injection of lipopolysaccharide (LPS) or phosphate buffered saline (control) was used as the immune challenge. Feeding high n-3 diets resulted in an increase in n-3 fatty acids in the liver in all treatment groups upon LPS challenge (P<0.05). LPS injection led to a decrease in total n-6 fatty acids in the liver when compared with control birds (P<0.05) fed early high n-3 and late low n-3. However, in spleen tissue, upon LPS challenge, increase in total n-3 fatty acids was observed only in birds fed early high n-3 and birds fed late high n-3. Plasma non-esterified fatty acids were lowest in high n-3 birds fed early (P<0.05). The spleen tissue total fat content was lowest in early high and late high n-3 birds (P<0.05). Breast muscle thiobarbituric acid reactive substances (TBARS) were higher in birds fed high n-3 compared to birds fed diets low in n-3 (P< 0.05). The delayed type hypersensitivity response was higher in birds fed high n-3 diet when compared to all other treatments (P<0.05). Thigh muscle of LPS challenged birds from early low n-3 and late high n-3 was significantly higher in TBARS when compared to control birds (P<0.05). There was no difference in final body weight, cut-up yield and organ weight of birds (P>0.05) except liver and thigh muscle weight percents were lowest in birds fed low n-3 (P<0.05). In the second experiment, birds were fed diets containing 3.5% sunflower oil (low n-3) or 3.5% fish oil (high n-3). The birds were either fed early (<5 hrs post hatch) or late (>48 hrs post-hatch). No effect due to time of feeding was observed (P>0.05). Birds fed high n-3 diets had higher C20:5n-3, C22:5n-3, C22:6n-3 and total n-3 fatty acids and birds that were fed a low n-3 diet had higher levels of total n-6 PUFAs (P<0.05). LPS challenged led to a decrease in spleen C22:5n-3 of birds fed late high n-3 when compared to control birds within the same treatment group (P<0.05). LPS challenged birds showed an increase in C20:4n-6, total polyunsaturated fats and total n-6 fatty acids in birds that were late fed low n-3 compared to control birds within the same treatment group (P<0.05). LPS challenged birds from early and late high n-3 had higher liver total saturated fats when compared to control birds of the same diet (P<0.05). LPS challenge led to an increase in liver total n-6 fatty acids in birds fed late low n-3 when compared to control birds within the same treatment (P<0.05). LPS birds from early and late high n-3 diets were higher in total liver n-3 fatty acid content when compared to birds fed low n-3 diets (P<0.05). Plasma isoprostanes showed no difference among treatment groups (P>0.05). Liver vitamin E was higher in control birds from early high n-3 groups when compared to the other treatments (P<0.05). Plasma vitamin E was highest in early low n-3 upon challenge when compared to the other treatments (P<0.05). LPS challenge resulted in an increase in vitamin E in the lung, small intestine and plasma of low n-3 birds. COX-2 expression in the spleen tissue increased due to LPS challenge. Time of feeding and diet had a significant effect on COX-2 protein expression (P<0.05). These results indicate that type of dietary fat and time of feeding may alter the inflammatory response upon challenge in broiler birds. During inflammation, lipid substrates for the activated immune system are provided by fatty acids. Therefore, dietary management strategies directed at attenuating immune tissue lipid content may prove to be beneficial in enhancing bird health and in increasing production performance in broiler chickens. Title: Effect of dietary fatty acids, time of feeding and immune response in poultry Author: Gonzalez, Dulmelis In the presence of internal or external stressors, the body requires sources of energy that aide cells to combat inflammation. Fatty acids are an important source of energy and are vital components of cell membranes. Dietary fatty acids (n-6 and n-3) are of importance in immune function because they are precursors to metabolites that are potent mediators of inflammation. Poultry diets are high in n-6 fatty acids, which exert pro-inflammatory effects, and low in n-3 fatty acids, which tend to be less inflammatory. Delayed access to feed after hatching has been reported to impact the development of organs associated with immunity. Based on this information, two experiments were conducted in broiler chickens to determine the effect of dietary polyunsaturated fatty acid (PUFA) and the influence of time of feeding on bird performance, tissue lipid status, immune responses and expression of cyclooxygenase 2 (COX-2) upon challenge. In experiment 1, birds were fed diets that contained 3.5% oxidized yellow grease (low n-3) or 3.5% canola oil (high n-3). Birds were fed early (<5 hrs post-hatch) or late (>24 hrs post-hatch). Intramuscular injection of lipopolysaccharide (LPS) or phosphate buffered saline (control) was used as the immune challenge. Feeding high n-3 diets resulted in an increase in n-3 fatty acids in the liver in all treatment groups upon LPS challenge (P<0.05). LPS injection led to a decrease in total n-6 fatty acids in the liver when compared with control birds (P<0.05) fed early high n-3 and late low n-3. However, in spleen tissue, upon LPS challenge, increase in total n-3 fatty acids was observed only in birds fed early high n-3 and birds fed late high n-3. Plasma non-esterified fatty acids were lowest in high n-3 birds fed early (P<0.05). The spleen tissue total fat content was lowest in early high and late high n-3 birds (P<0.05). Breast muscle thiobarbituric acid reactive substances (TBARS) were higher in birds fed high n-3 compared to birds fed diets low in n-3 (P< 0.05). The delayed type hypersensitivity response was higher in birds fed high n-3 diet when compared to all other treatments (P<0.05). Thigh muscle of LPS challenged birds from early low n-3 and late high n-3 was significantly higher in TBARS when compared to control birds (P<0.05). There was no difference in final body weight, cut-up yield and organ weight of birds (P>0.05) except liver and thigh muscle weight percents were lowest in birds fed low n-3 (P<0.05). In the second experiment, birds were fed diets containing 3.5% sunflower oil (low n-3) or 3.5% fish oil (high n-3). The birds were either fed early (<5 hrs post hatch) or late (>48 hrs post-hatch). No effect due to time of feeding was observed (P>0.05). Birds fed high n-3 diets had higher C20:5n-3, C22:5n-3, C22:6n-3 and total n-3 fatty acids and birds that were fed a low n-3 diet had higher levels of total n-6 PUFAs (P<0.05). LPS challenged led to a decrease in spleen C22:5n-3 of birds fed late high n-3 when compared to control birds within the same treatment group (P<0.05). LPS challenged birds showed an increase in C20:4n-6, total polyunsaturated fats and total n-6 fatty acids in birds that were late fed low n-3 compared to control birds within the same treatment group (P<0.05). LPS challenged birds from early and late high n-3 had higher liver total saturated fats when compared to control birds of the same diet (P<0.05). LPS challenge led to an increase in liver total n-6 fatty acids in birds fed late low n-3 when compared to control birds within the same treatment (P<0.05). LPS birds from early and late high n-3 diets were higher in total liver n-3 fatty acid content when compared to birds fed low n-3 diets (P<0.05). Plasma isoprostanes showed no difference among treatment groups (P>0.05). Liver vitamin E was higher in control birds from early high n-3 groups when compared to the other treatments (P<0.05). Plasma vitamin E was highest in early low n-3 upon challenge when compared to the other treatments (P<0.05). LPS challenge resulted in an increase in vitamin E in the lung, small intestine and plasma of low n-3 birds. COX-2 expression in the spleen tissue increased due to LPS challenge. Time of feeding and diet had a significant effect on COX-2 protein expression (P<0.05). These results indicate that type of dietary fat and time of feeding may alter the inflammatory response upon challenge in broiler birds. During inflammation, lipid substrates for the activated immune system are provided by fatty acids. Therefore, dietary management strategies directed at attenuating immune tissue lipid content may prove to be beneficial in enhancing bird health and in increasing production performance in broiler chickens. Close

• 12279. [Article] Pseudoloma neurophilia in the Zebrafish (Danio rerio) : Consequences of Infection on Neurobehavioral and Biomedical Research using a Burgeoning Model Organism

  Since its inception as a laboratory animal in the early 1970s, the zebrafish has proven itself a rising star in the world of comparative biomedical sciences due to its short generation time, ease of care, ...

  Citation × Citation Citation Abstract Copy Title: Pseudoloma neurophilia in the Zebrafish (Danio rerio) : Consequences of Infection on Neurobehavioral and Biomedical Research using a Burgeoning Model Organism Author: Spagnoli, Sean Since its inception as a laboratory animal in the early 1970s, the zebrafish has proven itself a rising star in the world of comparative biomedical sciences due to its short generation time, ease of care, external fertilization, and transparent larvae. In a very few decades, the zebrafish has been utilized as a model organism for as many experimental topics and modalities as its rodent counterparts, which have been in use for centuries. Whereas the rodent world has had time to develop biosecurity protocols and specific pathogen free lines, the zebrafish community has had little time to cleanse the animals of contaminating infectious organisms from their tenure as ornamental fish in the pet trade. Initially, because they were used primarily for developmental genetics studies, the need for biosecurity and elimination of infectious disease was not viewed as particularly important. However, as zebrafish have been used as model organisms in sensitive studies of biomedical and neurobehavioral phenomena, the scientific community must evaluate the potential for subclinical infections to alter experimental data. Pseudoloma neurophilia, a microsporidian endoparasite, is currently one of the most commonly diagnosed infections in zebrafish facilities worldwide. Because of its tropism for the central nervous system, and because of the opportunistic nature of microsporidia, it is vital to understand the potential effects that infection can have on behavior and studies involving immunosuppression. Armed with this knowledge, researchers will be able to make informed decisions regarding biosecurity and husbandry protocols in order to mitigate the effects of infection-associated, non-protocol induced variation. The hypothesis of this dissertation is that infection of zebrafish by Pseudoloma neurophilia causes non-protocol induced variation in neurobehavioral and biomedical experiments. In order to explore experimental protocols most likely to be influenced by P. neurophilia, I first performed a retrospective study with the intention of identifying the most common features of neuronal and muscular infections. Five hundred fifty-nine zebrafish infected with P. neurophilia submitted to ZIRC (Zebrafish International Resource Center, Eugene, OR) from 86 laboratories between the years 2000 and 2013 were examined via histopathology. Parasite clusters (PCs) occurred in distinct axonal swellings, frequently with no associated inflammation. Inflammation was observed in viable cell bodies distant from PCs. Multiple PCs occasionally occurred within a single axon, suggesting axonal transport. PCs occurred most frequently in the spinal cord ventral white matter (40.3% of all PCs) and the spinal nerve roots (25.6%). Within the rhombencephalon, PCs were most common in the primary descending white matter tracts. Within the rhombencephalon gray matter, PCs occurred most frequently in the reticular formation and the griseum centrale (61% and 39%, respectively). High numbers of PCs within brain and spinal cord structures mediating startle responses and anxiety suggest that related behaviors could be altered by neural microsporidiosis. Infection could, therefore, introduce unacceptable variation in studies utilizing these behaviors. I chose a commonly utilized neurobehavioral testing protocol that involved motor activity and anxiety-associated responses since it appeared to be the most likely experimental protocol to be influenced by P. neurophilia infection: The progressive tap test for startle response habituation. Fish infected via cohabitation were tested for startle response habituation in parallel with controls in a device that administered ten taps over 10 min along with taps at 18 and 60 min to evaluate habituation extinction. After testing, fish were euthanized and evaluated for infection via histopathology. Infected fish had a significantly smaller reduction in startle velocity during habituation compared to uninfected tankmates and controls. Habituation was eliminated in infected and control fish at 18 min, whereas exposed negative fish retained partial habituation at 18 min. Infection was also associated with enhanced capture evasion: Despite the absence of external symptoms, infected fish tended to be caught later than uninfected fish netted from the same tank. The combination of decreased overall habituation, early extinction of habituation compared to uninfected cohorts, and enhanced netting evasion indicates that P. neurophilia infection is associated with a behavioral phenotype distinct from that of controls and uninfected cohorts. In order to demonstrate a causative link between infection and behavior change, and to evaluate another common neurobehavioral experimental protocol, we performed a shoaling test, which examines social behavior, before and after infection. Tanks containing 10 fish each were divided into 6 control and 6 experimental shoals and recorded prior to exposure. Over 123 days, control fish were exposed to water housing uninfected fish and experimental fish were exposed to water housing infected fish. Shoals were re-recorded following exposure and infection status was determined via histopathology. There were no significant differences in mean interfish distance and percent of top-dwelling fish between control and experimental shoals prior to exposure. Following the exposure period, shoals exposed to and infected by P. neurophilia showed a significantly reduced mean interfish distance compared to controls. The percentage of top-dwelling fish was also reduced in infected shoals, although this difference was not statistically significant. This study supports the fact that P. neurophilia infection causes altered behavior in zebrafish and it should act as a warning to neurobehavioral researchers to use parasite-free fish in their research. Because of the opportunistic nature of microsporidial infections as demonstrated by fatal Enterocytozoon bieneusii and Encephalitozoon intestinalis infections in human AIDS patients, we decided to evaluate the effects of immunosuppressive gamma irradiation protocols on zebrafish infected with P. neurophilia. In this study we exposed zebrafish to combinations of P. neurophilia infection and gamma irradiation in order to explore the interaction between this immunosuppressive experimental modality and a normally subclinical infection. Zebrafish infected with P. neurophilia and exposed to gamma irradiation exhibited higher mortality, increased parasite loads, and increased incidences of myositis and extraneural parasite infections than fish exposed either to P. neurophilia or gamma irradiation alone. Title: Pseudoloma neurophilia in the Zebrafish (Danio rerio) : Consequences of Infection on Neurobehavioral and Biomedical Research using a Burgeoning Model Organism Author: Spagnoli, Sean Since its inception as a laboratory animal in the early 1970s, the zebrafish has proven itself a rising star in the world of comparative biomedical sciences due to its short generation time, ease of care, external fertilization, and transparent larvae. In a very few decades, the zebrafish has been utilized as a model organism for as many experimental topics and modalities as its rodent counterparts, which have been in use for centuries. Whereas the rodent world has had time to develop biosecurity protocols and specific pathogen free lines, the zebrafish community has had little time to cleanse the animals of contaminating infectious organisms from their tenure as ornamental fish in the pet trade. Initially, because they were used primarily for developmental genetics studies, the need for biosecurity and elimination of infectious disease was not viewed as particularly important. However, as zebrafish have been used as model organisms in sensitive studies of biomedical and neurobehavioral phenomena, the scientific community must evaluate the potential for subclinical infections to alter experimental data. Pseudoloma neurophilia, a microsporidian endoparasite, is currently one of the most commonly diagnosed infections in zebrafish facilities worldwide. Because of its tropism for the central nervous system, and because of the opportunistic nature of microsporidia, it is vital to understand the potential effects that infection can have on behavior and studies involving immunosuppression. Armed with this knowledge, researchers will be able to make informed decisions regarding biosecurity and husbandry protocols in order to mitigate the effects of infection-associated, non-protocol induced variation. The hypothesis of this dissertation is that infection of zebrafish by Pseudoloma neurophilia causes non-protocol induced variation in neurobehavioral and biomedical experiments. In order to explore experimental protocols most likely to be influenced by P. neurophilia, I first performed a retrospective study with the intention of identifying the most common features of neuronal and muscular infections. Five hundred fifty-nine zebrafish infected with P. neurophilia submitted to ZIRC (Zebrafish International Resource Center, Eugene, OR) from 86 laboratories between the years 2000 and 2013 were examined via histopathology. Parasite clusters (PCs) occurred in distinct axonal swellings, frequently with no associated inflammation. Inflammation was observed in viable cell bodies distant from PCs. Multiple PCs occasionally occurred within a single axon, suggesting axonal transport. PCs occurred most frequently in the spinal cord ventral white matter (40.3% of all PCs) and the spinal nerve roots (25.6%). Within the rhombencephalon, PCs were most common in the primary descending white matter tracts. Within the rhombencephalon gray matter, PCs occurred most frequently in the reticular formation and the griseum centrale (61% and 39%, respectively). High numbers of PCs within brain and spinal cord structures mediating startle responses and anxiety suggest that related behaviors could be altered by neural microsporidiosis. Infection could, therefore, introduce unacceptable variation in studies utilizing these behaviors. I chose a commonly utilized neurobehavioral testing protocol that involved motor activity and anxiety-associated responses since it appeared to be the most likely experimental protocol to be influenced by P. neurophilia infection: The progressive tap test for startle response habituation. Fish infected via cohabitation were tested for startle response habituation in parallel with controls in a device that administered ten taps over 10 min along with taps at 18 and 60 min to evaluate habituation extinction. After testing, fish were euthanized and evaluated for infection via histopathology. Infected fish had a significantly smaller reduction in startle velocity during habituation compared to uninfected tankmates and controls. Habituation was eliminated in infected and control fish at 18 min, whereas exposed negative fish retained partial habituation at 18 min. Infection was also associated with enhanced capture evasion: Despite the absence of external symptoms, infected fish tended to be caught later than uninfected fish netted from the same tank. The combination of decreased overall habituation, early extinction of habituation compared to uninfected cohorts, and enhanced netting evasion indicates that P. neurophilia infection is associated with a behavioral phenotype distinct from that of controls and uninfected cohorts. In order to demonstrate a causative link between infection and behavior change, and to evaluate another common neurobehavioral experimental protocol, we performed a shoaling test, which examines social behavior, before and after infection. Tanks containing 10 fish each were divided into 6 control and 6 experimental shoals and recorded prior to exposure. Over 123 days, control fish were exposed to water housing uninfected fish and experimental fish were exposed to water housing infected fish. Shoals were re-recorded following exposure and infection status was determined via histopathology. There were no significant differences in mean interfish distance and percent of top-dwelling fish between control and experimental shoals prior to exposure. Following the exposure period, shoals exposed to and infected by P. neurophilia showed a significantly reduced mean interfish distance compared to controls. The percentage of top-dwelling fish was also reduced in infected shoals, although this difference was not statistically significant. This study supports the fact that P. neurophilia infection causes altered behavior in zebrafish and it should act as a warning to neurobehavioral researchers to use parasite-free fish in their research. Because of the opportunistic nature of microsporidial infections as demonstrated by fatal Enterocytozoon bieneusii and Encephalitozoon intestinalis infections in human AIDS patients, we decided to evaluate the effects of immunosuppressive gamma irradiation protocols on zebrafish infected with P. neurophilia. In this study we exposed zebrafish to combinations of P. neurophilia infection and gamma irradiation in order to explore the interaction between this immunosuppressive experimental modality and a normally subclinical infection. Zebrafish infected with P. neurophilia and exposed to gamma irradiation exhibited higher mortality, increased parasite loads, and increased incidences of myositis and extraneural parasite infections than fish exposed either to P. neurophilia or gamma irradiation alone. Close

• 12280. [Article] Intelligence, creativity and sex-role preference among preschool-aged children

  This study explored the relationship between sex, age, intelligence, creativity and sex-role preference among preschool-aged children. Thirty-nine Caucasian children, 18 boys and 21 girls, ranging in ages ...

  Citation × Citation Citation Abstract Copy Title: Intelligence, creativity and sex-role preference among preschool-aged children Author: Frost, Nancy Sanger This study explored the relationship between sex, age, intelligence, creativity and sex-role preference among preschool-aged children. Thirty-nine Caucasian children, 18 boys and 21 girls, ranging in ages from three years-five months to five years-two months acted as subjects for this study, All subjects came from intact families, predominantly of the middle- and upper-socioeconomic classes as determined by Hollingshead's Two Factor Index of Social Position. The instruments used to collect the data for this study included: Brown's It Scale for Children to assess the subjects' sex-role preferences; Dunn's Peabody Picture Vocabulary Test to estimate the subjects' intelligence; and Ward's Alternative Uses and Pattern Meanings Tests to assess the subjects' creativity, Four null hypotheses were generated and the analysis of variance approach was used to test these hypotheses, F-values were generated for tests of the main effects of sex, age, intelligence and creativity and their interaction effects. The 01 level of significance was used as the criterion for statistical significance. Findings obtained are summarized below. There was a significant difference between the sex-role preference scores of boys and girls (F = 11. 7457, p < 0. 01) with boys having significantly higher own sex-role preference scores than girls. This finding was in support of theoretical positions that point to the cultural deterininants of sex-role learning. A study of the mean values associated with the sex interaction effect comparisons, while not statistically significant, revealed tendencies in the data which further substantiated the above finding. There was no significant difference between the sex-role preference scores of older and younger subjects. However, a study of the mean values associated with the main effect of age and its interactions, although not statistically significant, indicated a tendency for older subjects to have higher own sex-role preference scores than younger subjects. This finding is in support of the social learning theory of sex-role development. There was no significant difference between the sex-role preference scores of very-high and average-high intelligence subjects. A study of the mean values associated with the main effect of intelligence and its interaction effects, however, provided information which tended to support the cognitive- developmental theory of sex role learning that there will be a differential relationship between intelligence and sex-role learning among boys and girls. Boys of very-high intelligence tended to have higher own sex-role preference scores than boys of average-high intelligence at both the younger and older age groupings. Such a difference, however, tended to be greater among boys in the older age grouping thanin the younger age grouping. Among girls, findings indicated a tendency for girls of very-high intelligence to have slightly higher though minimally, own sex-role preference scores than girls of average-high intelligence at the younger age grouping while at the older age grouping girls of veryhigh intelligence had lower own sex-role preference scores than girls of average-high intelligence. Furthermore, while older girls of average-high intelligence tended to have much higher own sex-role preference scores than younger girls of average-high intelligence, the difference in sex-role preference scores of very-Thigh intelligence older and younger girls was. minimal. There was no significant difference between the sex-role preference scores of creative and less creative subjects. A study of the mean values associated with the main effect of creativity and its interaction effects tended to be inconsistent with or contradict findings that would be expected on the basis of previous theory and research, Previous theoretical positions have indicated that creativity would be positively related to opposite-sex role learning among individuals. In this study, creative and less creative subjects as determined by the Alt e r nate Uses Test showed no apparent differences in their own sex-role preferences. Furthermore, creative and less creative subjects, as determined by the Pattern Meanings Test, revealed creative subjects to have slightly higher own sex-role preference scores than less creative subjects. In addition, both creative boys and girls, as determined by the Alternate Uses Test, had slightly higher, own sex-role preference scores than less creative boys and girls. When the creativity of subjects was determined by the Pattern Meanings Test, however, creative boys tended to have higher own sex-role preference scores than less creative boys, while creative girls had slightly lower own sex-role preference scores than less creative girls. This difference among girls, however, was minimal. Finally, further analysis of the data regarding socioeconomic class differences among subjects in the present study indicated that subjects in the highest socioeconomic class (Class I) and lower socioeconomic classes (Classes III and IV) tended to have higher own sexrole preference scores than subjects between these classes (Class II). It should be emphasized that due to the statistical non-significance of many of these findings and the variety of limitations encountered in this study, extreme caution must be exercised in accepting these results. Title: Intelligence, creativity and sex-role preference among preschool-aged children Author: Frost, Nancy Sanger This study explored the relationship between sex, age, intelligence, creativity and sex-role preference among preschool-aged children. Thirty-nine Caucasian children, 18 boys and 21 girls, ranging in ages from three years-five months to five years-two months acted as subjects for this study, All subjects came from intact families, predominantly of the middle- and upper-socioeconomic classes as determined by Hollingshead's Two Factor Index of Social Position. The instruments used to collect the data for this study included: Brown's It Scale for Children to assess the subjects' sex-role preferences; Dunn's Peabody Picture Vocabulary Test to estimate the subjects' intelligence; and Ward's Alternative Uses and Pattern Meanings Tests to assess the subjects' creativity, Four null hypotheses were generated and the analysis of variance approach was used to test these hypotheses, F-values were generated for tests of the main effects of sex, age, intelligence and creativity and their interaction effects. The 01 level of significance was used as the criterion for statistical significance. Findings obtained are summarized below. There was a significant difference between the sex-role preference scores of boys and girls (F = 11. 7457, p < 0. 01) with boys having significantly higher own sex-role preference scores than girls. This finding was in support of theoretical positions that point to the cultural deterininants of sex-role learning. A study of the mean values associated with the sex interaction effect comparisons, while not statistically significant, revealed tendencies in the data which further substantiated the above finding. There was no significant difference between the sex-role preference scores of older and younger subjects. However, a study of the mean values associated with the main effect of age and its interactions, although not statistically significant, indicated a tendency for older subjects to have higher own sex-role preference scores than younger subjects. This finding is in support of the social learning theory of sex-role development. There was no significant difference between the sex-role preference scores of very-high and average-high intelligence subjects. A study of the mean values associated with the main effect of intelligence and its interaction effects, however, provided information which tended to support the cognitive- developmental theory of sex role learning that there will be a differential relationship between intelligence and sex-role learning among boys and girls. Boys of very-high intelligence tended to have higher own sex-role preference scores than boys of average-high intelligence at both the younger and older age groupings. Such a difference, however, tended to be greater among boys in the older age grouping thanin the younger age grouping. Among girls, findings indicated a tendency for girls of very-high intelligence to have slightly higher though minimally, own sex-role preference scores than girls of average-high intelligence at the younger age grouping while at the older age grouping girls of veryhigh intelligence had lower own sex-role preference scores than girls of average-high intelligence. Furthermore, while older girls of average-high intelligence tended to have much higher own sex-role preference scores than younger girls of average-high intelligence, the difference in sex-role preference scores of very-Thigh intelligence older and younger girls was. minimal. There was no significant difference between the sex-role preference scores of creative and less creative subjects. A study of the mean values associated with the main effect of creativity and its interaction effects tended to be inconsistent with or contradict findings that would be expected on the basis of previous theory and research, Previous theoretical positions have indicated that creativity would be positively related to opposite-sex role learning among individuals. In this study, creative and less creative subjects as determined by the Alt e r nate Uses Test showed no apparent differences in their own sex-role preferences. Furthermore, creative and less creative subjects, as determined by the Pattern Meanings Test, revealed creative subjects to have slightly higher own sex-role preference scores than less creative subjects. In addition, both creative boys and girls, as determined by the Alternate Uses Test, had slightly higher, own sex-role preference scores than less creative boys and girls. When the creativity of subjects was determined by the Pattern Meanings Test, however, creative boys tended to have higher own sex-role preference scores than less creative boys, while creative girls had slightly lower own sex-role preference scores than less creative girls. This difference among girls, however, was minimal. Finally, further analysis of the data regarding socioeconomic class differences among subjects in the present study indicated that subjects in the highest socioeconomic class (Class I) and lower socioeconomic classes (Classes III and IV) tended to have higher own sexrole preference scores than subjects between these classes (Class II). It should be emphasized that due to the statistical non-significance of many of these findings and the variety of limitations encountered in this study, extreme caution must be exercised in accepting these results. Close