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This study was initiated to determine the relative efficiency of systematic, stratified and simple random sampling for crown area and tree frequency estimation of five of the major forest types found in ...
Citation Citation
- Title:
- A computer simulation study of the relative efficiency of several forest sampling techniques as influenced by the spatial distribution of trees found in five major forest types of the Pacific Northwest
- Author:
- Payandeh, Bijan
This study was initiated to determine the relative efficiency of systematic, stratified and simple random sampling for crown area and tree frequency estimation of five of the major forest types found in the Pacific Northwest. Several of the more common methods of estimating spatial distribution coefficients were evaluated. Finally the effect of spatial distribution of trees in these forest types on the relative efficiency of two-dimensional systematic sampling was analyzed. Crown maps of five 48-acre tracts of the following types were made from large scale (1:2500) aerial photographs and photographically enlarged to the scale of 1:624: 1.Typical ponderosa-pine of Eastern Oregon 2.Mixed species of Oregon’s Coastal type 3.Mixed pine stands of Northeastern Oregon 4.Even aged Douglas-fir stands common to the Pacific Northwest 5.Typical old growth Douglas-fir of the Pacific Northwest. The basic data consisted of the location (by grid coordinates) and size of each tree crown as obtained from crown maps. These data were committed to the memory of the CDC 3300 computer and the entire analyses executed through computer simulation techniques as follows: Exhaustive two-dimensional systematic sampling was taken using one quarter acre sampling units, Sample mean variances were computed for the three sampling schemes using analysis of variance principles. Relative efficiency of systematic and stratified sampling was also computed. The same parameters were also estimated by variable plot sampling based on 24 points systematically located at the middle 24 acre of each type. The same principles were used to compute variances as close approximations. Eight of the more common non-randomness measures were compared. To evaluate these methods and obtain the required data for examining the effect of spatial variation on relative efficiency of systematic sampling, four new populations were generated from each forest type. These newly computer generated populations were sampled in the same way as for the original forest types. Spatial distribution coefficients of these populations were also computed. Multiple regression analysis was employed using stepwise computer program to establish relationships between the relative efficiency of systematic sampling and the coefficients of randomization. Logarithmic transformation was used to satisfy equality of variances in establishing regression equations. The results of this study indicated that the relative efficiency of two-dimensional systematic sampling may vary greatly depending on the parameter being estimated. For tree frequency estimation (a discrete variable) of the original forest types the gain in precision of systematic sampling varied from 20 to 167 percent. In estimating crown area (a continuous variable) systematic sampling was less precise than simple random sampling on one forest type, while yielding gains in precision ranging from 10 to 179 percent for the other original forest types. There were no significant differences in precision obtained by the three sampling schemes for estimating both parameters when applied to completely randomly dispersed populations. Systematic sampling was less precise than both stratified and random sampling when applied to uniformly spaced populations. The loss in precision in this case ranged from 15 to about 79 percent. Of the eight non-randomness measures (measures of spatial distribution) the point method proved to be best. Grosenbaugh' s Q-factor which is considered to be the most practical method was rejected as being invalid. All original forest types were found to be clustered. Regression equations of relative efficiency on the coefficient of randomization for crown area estimation of the five forest types were mostly non-linear. Since these predicting models produced low correlations and were obviously different from each other, no attempt was made to establish a generalized model. Relative efficiency of systematic sampling for tree frequency estimation was highly correlated with the coefficient of randomization. Of the five equations established, four were not significantly different from each other, thus they were pooled and a generalized model developed which turned out to be y = 1.402x with simple correlation coefficient of r=0.81 where: y = common log of relative efficiency of systematic sampling x = common log of spatial distribution coefficient measured by the point method. Therefore, when an estimate of spatial distribution of trees in a forest is known, the relative efficiency of systematic plot sampling can be predicted with a high degree of accuracy. Such relationships could also be applied as adjustment factors to systematic sampling variance when being treated as simple random samples.
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3122. [Article] Snag longevity, bird use of cavities, and conifer response across three silvicultural treatments in the Oregon Coast Range
In the interest of meeting multiple forest management goals that include maintenance of wildlife, particularly cavity-nesting birds, uneven-aged silvicultural treatments are used increasingly in the Pacific ...Citation Citation
- Title:
- Snag longevity, bird use of cavities, and conifer response across three silvicultural treatments in the Oregon Coast Range
- Author:
- Walter, Scott T.
In the interest of meeting multiple forest management goals that include maintenance of wildlife, particularly cavity-nesting birds, uneven-aged silvicultural treatments are used increasingly in the Pacific Northwest. However, questions remain regarding the responses of cavity-nesting birds and residual green trees to different harvest intensities and patterns. To study these issues, between 1989 and 1991 the Oregon State University College of Forestry Integrated Research Project (CFIRP) applied 3 silvicultural treatments to 30 mature (85-125 year old) Douglas-fir stands in the Oregon Coast Range. Silvicultural treatments consisted of group-selection cuts (18 stands with 33% of the timber volume extracted from 0.2-0.6 ha patches), two-story regeneration harvests (6 stands with 75% scattered removal of the timber volume resulting in 20-3 0 distributed residual trees/ha), and clearcuts (6 stands that retained 1.2 mature green trees/ha). In addition, 939 conifers 53 cm diameter at breast height [DBH]) were topped to create snags in clustered and scattered arrangements. In the current study, CFIRP stands were utilized to 1) test for differences in cavity-nesting bird use of snags across silvicultural treatments and snag arrangements 10 years after harvest, 2) compare 10 year with 5 year nesting levels, 3) evaluate associations between snag characteristics and cavity nest site location, 4) quantify snag fall, 5) assess silvicultural treatment effects on residual tree growth and condition, and 6) quantify tree mortality. Snags and topped conifers that remain alive were observed for nesting and foraging use during the 2001 breeding season. Eight species of birds nested in created snags and a mean of 5.1 total cavities/snag were found one decade after creation. However, no active nesting was observed in topped trees that remained alive. Higher cavity-nesting bird levels, species richness, and species diversity occurred in open-canopy stands (two-story and clearcut treatments) compared to closed-canopy stands (group-selection treatment). Bird species composition was most similar between two-story and clearcut stands, and least similar between clearcut and group-selections stands. No difference was found in nesting or foraging levels between clustered and scattered snags. Active nests in created snags were most commonly located in the top 25% of bole, cavities on average faced northeast, and created snags with and without dead branches received equal nesting use. Compared with 6 years prior, the mean number of cavities per created snag increased 3.3- to 6-fold, and 4 additional avian species were observed nesting. One topped conifer fell in the decade since creation. Residual green trees (n = 848) were measured for growth and condition from November, 2001 to February, 2002. Across silvicultural treatments, residual green tree basal area, DBH, and height growth, and crown width and crown fullness did not differ among silvicultural treatments 10-12 years following harvest. Overall, 45% of trees experienced greater basal area growth in the decade following harvest than in the decade prior to harvest. Among silvicultural treatments, mean live crown ratio (live crown length/total tree height) of residual trees was significantly greater (0.74) in clearcuts and the percentage of trees with epicormic branching (35%) was significantly higher in two-story stands. Over the last decade residual tree mortality resulted in 134 standing dead trees (snags) and 185 blowdowns. Two-story stands experienced the highest recruitment of snags (0.76 per ha) and blowdowns (1.12 per ha). Results from this study suggest that topped, large conifers provide snags that offer valuable nesting and foraging habitat for cavity-nesting birds during the first decade after treatment, if the tree dies. Snags in both clustered and scattered arrangements appear to receive equal use by cavity-nesting birds. Also, snags created by topping may have the potential to stand for several decades in the Oregon Coast Range. Furthermore, although silvicultural treatments in this study did not appear to affect residual tree basal area growth during the first 10 years after treatment, partial harvests can promote increased diversity in stand structural complexity, which includes longer tree crowns, epicormic branching, and new snag recruitment, that also can benefit cavity-nesting bird populations through increased nesting and foraging opportunities.
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3123. [Article] Factors influencing growth of young Douglas-fir and red alder in the Oregon Coast Range : interference, nitrogen availability, and animal damage
Red alder (Alnus rubra Bong.) is a common associate and a potentially severe competitor of Douglas-fir (Pseudotsuga menziesii var. menziesii [Mirb.] Franco) in the Oregon Coast Range. However, because ...Citation Citation
- Title:
- Factors influencing growth of young Douglas-fir and red alder in the Oregon Coast Range : interference, nitrogen availability, and animal damage
- Author:
- Fuentes-Rodríquez, Laura Angélica
Red alder (Alnus rubra Bong.) is a common associate and a potentially severe competitor of Douglas-fir (Pseudotsuga menziesii var. menziesii [Mirb.] Franco) in the Oregon Coast Range. However, because it fixes nitrogen and increases rates of soil nutrient cycling, red alder has the potential to benefit Douglas-fir. The objective of this study was to quantify and attempt to explain differences in growth of young Douglas-fir and red alder, growing in mixed and pure stands, by analyzing six-year trends in survival, growth, animal damage of saplings, cover of understory vegetation, and foliar and soil nutrients. In March 1986, a replacement series study was established by planting Douglas-fir and red alder at 3-m spacing in 0.073-ha plots with the following species proportions (Douglas-fir/red alder): 1/0, 0.9/0.1, 0.7/0.3, 0.5/0.5, 0.25/0.75, 0/1. Each proportion was replicated three times in a randomized complete block design. Six annual measurements (fall 1986-1991) of survival, growth, and animal damage and one measurement of stand yield (1991 basal area, volume, and predicted biomass) were used in response surface analyses to test for significant polynomial relationships (a=0.05) between tree response and species proportion. Relationships of Douglas-fir height increment to red alder proportion varied from positive linear (year 2) to no relationship (years 3-4) to negative linear (years 5-6). Relationships of Douglas-fir diameter increment to red alder proportion varied from no relationship (years 2-3) to negative linear (year 4) to negative quadratic (years 5-6). In the sixth year, competition from red alder caused relative yield (relative to monoculture yield) of Douglasfir volume index and predicted biomass to be significantly less than the yield that would be expected in the absence of intraspecific competition (expected yield). Increasing proportion of Douglas-fir decreased intraspecific competition of red alder, and as a result, relative yield of basal area and predicted biomass for red alder was significantly greater than its expected yield. Two easurements (March 1986 and 1991) of mineralizable nitrogen (NH4 and NO3); total N, P, and C; and pH from 3 soil depths (0-15, 15-30, and 60-90 cm) were used in analysis of variance to test for significant differences (a=O.05) in sixth-year amount and five-year change in these variables among three species proportions (Douglas-fir/red alder): 1/0, 0.5/0.5, and 0/i. There was no net N accretion; however, there was higher mineralizable N as NH4 in pure Douglas-fir stands than in mixed stands. One explanation for these results is that possibly the more open conditions of Douglas-fir stands increased rates of N mineralization. Douglas-fir foliar N and P also were significantly higher in pure stands than in mixed stands, probably because of the increased ability of large, vigorous saplings growing in absence of red alder to absorb soil nutrients rather than because of greater supplies of soil nutrients. The effect of increased Douglas-fir vigor and size in enhancing nutrient uptake was more prominent for P than for N. These data indicate that the effects of red alder on Douglas-fir can range from positive to neutral to negative. In general, competition was the most important factor limiting survival and growth of Douglas-fir; animal damage and understory vegetation under red alder canopies caused further limitations in Douglas-fir response. In addition, results of this research suggest that red alder competition can be tolerated with little loss of Douglas-fir survival and growth through an age of 4 years.
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3124. [Article] Habitat associations of bird communities in shrub-steppe and western juniper woodlands
The encroachment of western juniper into mountain big sagebrush plant communities and the subsequent development of juniper stands results in significant changes in vegetation structure and complexity. ...Citation Citation
- Title:
- Habitat associations of bird communities in shrub-steppe and western juniper woodlands
- Author:
- Reinkensmeyer, Daniel P.
The encroachment of western juniper into mountain big sagebrush plant communities and the subsequent development of juniper stands results in significant changes in vegetation structure and complexity. This study described and compared vegetative structure and bird community measures among four cover types representing a broad range of structural stages among semi-arid, upland plant communities in central Oregon. Avian communities and vegetation were sampled in 4 vegetative structural stages (cover types), including: 1) post-burn grassland (<5years post-burn); 2) mountain big sagebrush-Idaho fescue shrub-steppe; 3) mid-successional western juniper; and 4) old-growth western juniper. The point count, or variable circular plot (VCP), method was used to survey birds in May and June of 1998 and 1999. Bird density estimates for each transect in each year, mean relative abundance, and species richness, evenness, and diversity were compared among cover types. Sixteen of 22 vegetation measurements were significantly different (P<_0.05) among the four cover types. Mean bird species richness was greatest in the old-growth and mid-successional juniper types, with means of 22.9 and 23.6 species transecf 1, respectively. Bird species diversity (H) was similar between the old-growth (H'=2.499) and mid-successional (H'=2.416) cover types. Mean species richness was lower in the grassland cover type (17.6 species transect ) and lowest in the shrub-steppe cover type (11.5 species transect 1). Bird species diversity was similar in grassland and shrubsteppe, H=1.820 and H=1.644. Habitat complexity was evaluated by comparing the diversity of coverage of plant structural types. Indices of habitat complexity were calculated for each transect by using physiognomic cover diversity (PCD). Bird species diversity was positively correlated with PCD (r2=0.535; P=0.0013). Total bird density was significantly greater in 1999 than in 1998 (P<_0.05). Total bird density was greatest in old-growth juniper (6.551 birds ha ) and lowest in post-burn grasslands (3.569 birds ha 1). Total bird density was similar in shrub-steppe and mid-successional juniper (5.968 and 5.542 birds ha-1, respectively). Old-growth juniper had the highest total densities of both tree and cavity nesters. Total density of ground nesting birds was greatest in the grassland type. Total density of shrub nesting species was highest in the shrub-steppe type. Species consistently detected within all four cover types were Empidonax spp. flycatchers, brown-headed cowbirds, and northern flickers. Species detected in juniper stands but not other types included chipping sparrows, mountain bluebirds, mountain chickadees, Cassin's finches, American robins, ash-throated flycatchers, and dark-eyed juncos. The most common species in the shrub-steppe were also present in mid-successional juniper, but at lower densities. Species composition in mid-successional juniper was a mixture of shrub-associated and tree-associated bird species. Many bird species that regularly occurred in old-growth juniper also occurred in mid-successional juniper, however, density and richness of shrub nesting species was lower in old-growth juniper. Mountain chickadees, Cassin's finches, chipping sparrows, brown-headed cowbirds, mountain bluebirds, and dark-eyed juncos, Empidonax spp. flycatchers, ashthroated flycatchers, and northern flickers were correlated with juniper canopy cover, canopy volume, total tree density, and average tree height. Vesper sparrows, western meadowlarks, green-tailed towhees, and horned larks were correlated with vertical density of herbaceous vegetation, total vertical density of all vegetative functional groups, and perennial grass cover. Brewer's sparrows, sage sparrows, sage thrashers, and horned larks were associated with total cover of all shrub species, cover of green rabbitbrush and sagebrush, vertical density of shrubs, and bare ground. In the absence of fire or direct management actions, the transition of mountain big sagebrush plant communities to juniper woodlands will likely result in decreased densities or loss of shrub nesting and sagebrush obligate birds. However, sites in the early stages of juniper transition, with an intact shrub component, may provide both shrub and tree-foliage nesting bird species with suitable breeding habitat. Old growth juniper stands provide both tree and cavity nesting species with breeding habitat, but shrub-nesting species will likely be absent or at very low densities because of low shrub cover. On a landscape level, a mixture of various ages of juniper stands, as well as juniper-free mountain big sagebrush and grassland will likely result in the greatest diversity of bird species.
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The purposes of this study were to (a) provide insight into the use of item response theory (IRT) with psychomotor skills, (b) assess the psychometric properties of the Test of Gross Motor Development ...
Citation Citation
- Title:
- An application of item response theory to the test of gross motor development
- Author:
- Cole, Emily Lynne
The purposes of this study were to (a) provide insight into the use of item response theory (IRT) with psychomotor skills, (b) assess the psychometric properties of the Test of Gross Motor Development (TGMD) using IRT, and (c) provide a basis for future studies of the TGMD using IRT. The dichotomously scored TGMD is a test instrument which measures psychomotor skills in a framework similar to cognitive tests, thus providing a convenient "transitional" type test which can be used to examine the use of IRT with psychomotor skill tests. The present study employed data used by Ulrich (1985) in the original psychometric analysis of the TGMD. The data consisted of 913 subjects aged 3 to 10 years, nonhandicapped and 20 mildly mentally handicapped. Since IRT cannot provide accurate ability estimates at mastery levels of 0% and 100% mastery, 32 subjects were deleted from the record. Since the TGMD was found to be multidimensional, the test was analyzed by subtests so not to violate the unidimensionality assumption of IRT. Interpretation of traditional item statistics using classical test theory (CTT) and IRT item parameters revealed that item difficulty and item discrimination were closely related. The locomotor IRT difficulty parameters revealed a high negative correlation (r = -.87) with the CTT difficulty statistics, while the object control IRT difficulty parameters displayed a very high negative correlation (r = -.98) with their CTT counterparts. Item response theory discrimination parameters correlated highly with CTT discrimination statistics within the locomotor (r = .91) and the object control (r = .94) subtests. IRT analysis revealed that the locomotor subtest was less difficult (median difficulty = -.944) than the object control subtest (median difficulty = .053) and the object control subtest displayed a better discrimination index (median = 2.17) than the locomotor subtest (median = 1.54). In addition to difficulty and discrimination indices, IRT also provided the amount of information given by each item and subtest, which indicated the precision in measuring various ability levels. The locomotor subtest information was reported at I = 15.50, indicating adequate precision to measure low ability (Θ = -1.857). The object control information function showed that the subtest displayed more information (I = 18.24) at a slightly higher ability level (Θ = -1.643). The results of the item analysis revealed that all items (behavioral criteria) of the hop, leap, and the overhand throw displayed effective psychometric properties, while 9 out of 12 skills contained items that displayed poor psychometric characteristics and/or did not fit the two-parameter model. The run (items 1, 3, and 4), gallop (items 6 and 8), horizontal jump (item 18), skip (item 20), slide (items 23, 24, 25, 26), strike (items 27, 28, and 29), stationary bounce (item 32), catch (item 34 and 35), and the kick (item 38) should be revised. Since the TGMD is also used as a criterion-referenced test the decision validity of the mastery classification cut-off scores was analyzed. For the purposes of these analyses true mastery state was determined by IRT because it provides an estimation of underlying ability. It was found that IRT and CTT showed a high agreement of classifying masters and nonmasters at the 70% and 85% levels of mastery. The locomotor subtest revealed a decision validity coefficient of .93 and .99 for the 70% and 85% mastery levels, respectively. The object control subtest revealed higher decision validity coefficients of .99 and .997 for the 70% and 85% mastery levels, respectively. The TGMD subtests were found to best measure very low mastery levels, where the most precision for measuring ability represented 30% and 45% mastery for the locomotor and object control subtests, respectively. Item response theory has been successfully employed in the cognitive and affective domains and shows great promise for the psychomotor domain. The present study set forth evidence that the IRT two-parameter logistic model provides an effective psychometric analysis of dichotomously scored psychomotor skills. The theory addresses many of the shortcomings of CTT, such as the inability to generalize item statistics to various populations and determine the contribution of test items independently. The invariance property of IRT is very appealing to those who must assess atypical populations because a single test can accommodate various populations and wide ranges of ability. The results of this study provide evidence that the characteristics of IRT are well suited to improve measurement and evaluation in the psychomotor domain.
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3126. [Article] Satellite monitored dive characteristics of the northern right whale, Eubalaena glacialis
The western North Atlantic population of the northern right whale (Eubalaena glacialis) was severely depleted by whaling over the last century. Despite over fifty years of protection, fewer than four hundred ...Citation Citation
- Title:
- Satellite monitored dive characteristics of the northern right whale, Eubalaena glacialis
- Author:
- Nieukirk, Sharon L.
The western North Atlantic population of the northern right whale (Eubalaena glacialis) was severely depleted by whaling over the last century. Despite over fifty years of protection, fewer than four hundred individuals are believed to exist in the North Atlantic. Relatively little is known about the diving behavior, respiratory physiology, or diel activity of these whales, although such information could be useful in predicting population abundance and distribution in relation to food or environmental variables. Dive behavior data can be collected visually, but collection is limited to daylight hours, calm weather, and fortuitous encounters with study animals. Satellite-monitored radio tags offer the opportunity to collect data on individual whales' diving behavior continuously, over long distances and periods of time, and at relatively low cost. Thirteen North Atlantic right whales were tagged and monitored in the Gulf of Maine between 1989 and 1991. One male was tagged in 1989; two adult males, six adult females (two with calves) and one juvenile were tagged in 1990; one adult female (with a calf) and two juveniles were tagged in 1991. The duration of monitoring for the whales varied from <1 day to 43 days. Characteristics of the radio tags were different over each year in order to evaluate different attachment mechanisms and methods of collecting and summarizing data for dive duration, dive frequency, and time submerged. These data were then used to describe the dive behavior and to predict aspects of the respiratory physiology for these whales. The number of dives, their duration, and the time submerged varied considerably among individual whales and between years. Over all, the whales spent 79% of their time underwater. However, most dives were short (i.e., 95% were <14 min; the mean dive duration was 92.3 sec), although dives of 30-40 min duration were observed for several individuals. In general, the number of dives a right whale made was inversely related to the average duration of its dives within a time interval. Furthermore, over a given time interval, the number of times a whale dove was a better predictor of the percent time it was submerged than was the average duration of its dives. There was no evidence of diel variation in dive behavior (i.e., number of dives, average dive duration, or percent time submerged) among these whales. Age, sex, and reproductive status may have affected dive behavior, although these trends were not statistically significant due to the small number of study animals and individual behavioral variability. Males tended to dive more often and averaged shorter dives than females. Females with calves dove more often and averaged shorter dives than females without calves. Juvenile females dove less often but averaged longer dives than adult males or females with calves. It was predicted that the aerobic dive limit of an "average" right whale was approximately 14 min. Ninety-five percent of the dives recorded for the 11 monitored right whales were < 14 min. Furthermore, there was no evidence of recuperative periods (i.e., prolonged periods at the surface) after long dives. These observations were consistent with the idea that the North Atlantic right whales dove within their aerobic scope. They further suggest that physiological parameters alone probably have little influence on dive characteristics, except to set an upper limit on the duration of a dive. Satellite telemetry provides an opportunity to monitor the movements and behavior of free-ranging animals, and overcome many of the short-comings associated with traditional, human-based visual techniques for tracking and studying such animals. Although the tags used in this study were prototypes and varied in their design from year to year, several right whales were monitored simultaneously and were tracked over thousands of kilometers. Advances in tag miniaturization, attachment, and software will likely extend the time tags stay attached and the detail of the behavioral and environmental variables that can be monitored. As testimony to the power of this technology, this application of satellite telemetry to monitor great whales yielded one of the most extensive, long-term, continuously-monitored data sets yet recorded on the diving behavior of a baleen whale.
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The objectives of the study were: to investigate career women's satisfaction with current career dress; to determine willingness of career women to trade styling options, time, and money for more sizing ...
Citation Citation
- Title:
- Effect of satisfaction and fit problems with career dress on career women's willingness to trade styling options, time, and money for more sizing options in career dress
- Author:
- Wright, Janith S.
The objectives of the study were: to investigate career women's satisfaction with current career dress; to determine willingness of career women to trade styling options, time, and money for more sizing choices in career dress; to determine the effect of satisfaction on willingness to trade styling options, time, and money; to investigate fit problems with career dress; to determine the relationship between satisfaction and experience with fit problems; to determine the relationship between fit problems and willingness to trade styling options, time, and money;and to investigate career women's actions to solve fit problems that they have experienced with career dress. A survey method was used to collect data. Questionnaires were completed by career women present at professional association meetings in western Oregon during the winter of 1986. The sample used in the study consisted of 218 women working in professional or managerial occupations. They tended to be middle-aged, college educated, of above average family income, married, and full-time workers. The data included general satisfaction with career clothing, satisfaction with a suit-type jacket worn to work, frequency of fit problems, actions taken to solve fit problems, willingness to trade styling options for more sizing choices, willingness to spend more time and money to get more sizing choices, and demographic characteristics. Descriptive statistics, chi square, correlation coefficients and analysis of variance were used to analyze the data. As hypothesized, respondents who were satisfied with career dress were also satisfied with a specific jacket (p <.001). The respondents were very satisfied with their career dress and with their own jacket. Over 90 percent of the respondents were willing to accept fewer styling options to get more sizing options. They were willing to spend "some" more time to get more sizing options, and they were willing to spend $20.99 or less to get more sizing options. The hypothesis that willingness to trade styling options, time, and money for more sizing options is a negative function of general satisfaction with career dress was partially accepted. Level of satisfaction with career dress had a significant effecton willingness to spend more time (p = .037) and money (p = .028) to get more sizing options. However, satisfaction with career dress had no significant effect on willingness to trade styling options for sizing options. The hypothesis that level of satisfaction is an inverse function of experience with fit problems was accepted (p = .001). The data revealed that every respondent had experienced fit problems when shopping for ready-to-wear career clothing. As the frequency of fit problems increased, the level of satisfaction decreased. Finally, the hypothesis that willingness to accept fewer styles, spend more shopping/travel time, and spend more money for more sizing options is a positive function of career women's experience with fit problems was accepted (p = .001). A surprising number of respondents altered their own garments, wore poorly fitting garments, sewed their own career clothing, and paid to have ready-to-wear altered. They also have shopped in alternative departments, hired garments custom made and have refused to purchase as responses to fit problems with ready-to-wear career clothing. The present findings suggested that perhaps measures of consumer problems would be a more useful indicator of how to satisfy the specific needs of clothing consumers than are satisfaction measures. Although widespread fit problems were reported, high career dress satisfaction was reported. Consumers' preconceived ideas about what to expect may have influenced the satisfaction process, leading to low expectations regarding fit, and therefore, a reported high level of satisfaction. While effect of satisfaction on willingness to make resource trade-offs was not as strong as expected, experience with fit problems was significantly correlated to willingness to make resource trade-offs. In this study, consumers with fit problems indicated that they wanted more sizing options in career dress and were willing to accept fewer styling options, spend more money, and spend additional time in order to get more sizing options.
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3128. [Article] Human exposure to polycyclic aromatic hydrocarbons : global cancer risk and metabolism
In recent decades, there has been increased attention on human exposure to, and subsequently toxicity of, Polycyclic Aromatic Hydrocarbons (PAHs). PAHs are widespread organic pollutants and some have been ...Citation Citation
- Title:
- Human exposure to polycyclic aromatic hydrocarbons : global cancer risk and metabolism
- Author:
- Motorykin, Oleksii
In recent decades, there has been increased attention on human exposure to, and subsequently toxicity of, Polycyclic Aromatic Hydrocarbons (PAHs). PAHs are widespread organic pollutants and some have been shown to be toxic, carcinogenic and mutagenic. This research was focused on understanding the link between global PAH emissions and lung cancer risk, as well as the metabolism of PAHs by humans. We investigated human exposure to PAHs via inhalation and ingestion, their metabolism to hydroxy-PAHs (OH-PAHs) and compared the results to the OH-PAH concentrations in the general US population. The objective of the first part of this research was to investigate the relationship between lung cancer mortality rates, carcinogenic PAH emissions, and smoking on a global scale. We also investigated this relationship in different socioeconomic country groups. The data from the World Health Organization provided two lung cancer mortality rates, including estimated lung cancer deaths per 100,000 people (ED100000) and age standardized lung cancer death rate per 100,000 people (ASDR100000) for 136 countries. Both mortality rates were regressed on PAH emissions in benzo[a]pyrene equivalence (BaPeq), smoking prevalence, cigarette price, gross domestic product per capita, percentage of people with diabetes, and average body mass index. Both simple linear regression and multiple linear regressions with stepwise procedure were used. The results showed a statistically significant positive linear relationship between log[subscript e](ED100000) and log[subscript e](BaPeq) emissions for high socioeconomic country group (p-value<0.01). Additionally, both log[subscript e](ED100000) and log[subscript e](ASDR100000) were significantly positively correlated with log[subscript e](BaPeq) emissions for the combination of upper middle and high (p-value<0.05) socioeconomic country groups. The objective of the second part of this research was to investigate human inhalation exposure to PAHs. We developed a method for the measurement of 19 parent PAHs and 34 hydroxylated PAHs (OH-PAHs) in urine and particulate matter less than 2.5 um in diameter (PM₂.₅) using GC-MS. We validated this method using NIST SRM 3672 (Organic Contaminants in Smoker's Urine) and SRM 3673 (Organic Contaminants in Nonsmoker’s Urine). The method was used to measure PAHs and OH-PAHs in urine and personal PM₂.₅ samples collected during fish smoking activities at the Confederated Tribes of Umatilla Indian Reservation (CTUIR). Two different fish smoking facilities (tipi and smoke shed) were used and two different wood types (alder and apple) were burned. Urine samples were hydrolyzed, concentrated using solid phase extraction, and fractionated using silica phase to separate PAHs and OH-PAHs. The 34 OH-PAHs were derivatized using N-(t-butyldimethylsilyl)-N-methyltrifluoroacetamide (MTBSTFA), and both OH-PAHs and PAHs were measured by GC-MS. The personal PM₂.₅ samples were extracted using pressurized liquid extraction, derivatized with MTBSTFA and analyzed by GC-MS for PAHs and OH-PAHs. Isotopically labeled surrogates of PAHs and OH-PAHs were added to accurately quantify analytes. The results showed an increase in OH-PAH concentrations in urine after 6 hours of fish smoking and an increase in PAH concentrations in air within each smoking facility. In general, the PAH exposure in the smoke shed was higher than in the tipi and the PAH exposure from burning apple wood was higher than burning alder. The objective of the third part of this research was to investigate human oral exposure to PAHs. We estimated excretion rates and half-lives of 4 PAHs and 10 OH-PAHs after the consumption of Native American traditionally smoked fish. Nine members of the CTUIR consumed smoked fish for breakfast and urine samples were collected during the following 24 hours. The results showed significant increase in OH-PAH concentrations 3 to 6 hr post-consumption. The lowest half-life was for retene (1.4 hr) and the highest was for 3-hydroxyfluorene (7.0 hr).
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This study focused on the relationship between energy related behaviors prior to and following structural modifications of the residence. If energy saving structural modifications are made, will there ...
Citation Citation
- Title:
- The effect of structural modifications on energy conservation behaviors
- Author:
- Beck, Becky Ohmer
This study focused on the relationship between energy related behaviors prior to and following structural modifications of the residence. If energy saving structural modifications are made, will there also be a concommitant change in energy conserving behavioral practices? The objectives of this study were: 1) to create a profile of the sample consisting of those who added one or more structural modifications between March, 1981 and March, 1983 and 2) to determine behavior changes for those respondents who added energy conserving structural features between March, 1981 and March, 1983. Two limitations of energy conservation research as identified by previous researchers in this field were addressed. The ability to address these limitations was accomplished through specific hypotheses testing and the use of data from the Western Regional Project W-159. Longitudinal data for Oregon were obtained by mail survey in March, 1981 and again in March, 1983 from a stratified (50% rural /50 % urban) random sample. With the exception of minor changes, the questionnaire sent in 1983 was identical to the questionnaire sent in 1981. The survey initiated in 1981 to 1,503 Oregon households yielded a 67.2 percent rate (834). In the 1983 survey, questionnaires were sent to the 1981 respondents and to 541 additional randomly selected individuals. Six hundred of the returned questionnaires from the original 834 respondents were usable, a return rate of 89.2 percent. Of the 600 respondents, 170 met two criteria for inclusion in the sample: 1) were homeowners and 2) had completed structural modifications after March, 1981 and prior to March, 1983. Of these 170 respondents, 93 were able to be identified longitudinally. For the present study, two detailed questions were selected from the questionnaire. These questions dealt with structural energy saving modifications which respondents had taken or planned to take in the future, whereas the second question asked what energy conserving behaviors respondents were taking. Six criteria were used to assess energy conserving behaviors, such as change the use of rooms to take advantage of sun-warmed or shaded areas and close off rooms. Nine housing structural modifications were used based on the number of energy conservation features the respondents had added to their homes, such as storm doors and floor insulation. Frequency distributions were used to develop descriptions of respondents and their homes. Males most often responded to the questionnaire. Respondents were characterized by an average age of 47.7 years, a median gross family income in the category of $25,000 through $29,000, some college education, and had an average of 4.4 investments. These respondents lived in homes characterized by an average value range and size range of $50,000 through $74,999 and 1001 square feet through 1500 square feet, respectively, and were most commonly constructed prior to 1945. The majority of homes were located in rural areas and utilized electricity for space heating. The fuel used for water heating was more equally distributed among electricity, oil, wood, and natural gas. Although the results of the t-test and analysis of variance were not statistically significant, possible behavior patterns which support and contradict previous studies related to structural modifications were found. First, the selection of structural modifications which were found to be related to an increase in conservation behaviors were also those which, comparatively, required a greater capital investment, an increased amount of physical labor, and had the greatest energy saving potential. Second, the behavior change scores for respondents who did not add the specific feature decreased from 1981 to 1983 for all features with the exception of weatherstripping and caulking, while behavior change scores for respondents who did add the specific feature decreased for: 1) weatherstripping and caulking, 2) storm doors, 3) glass doors on fireplaces, and 4) wood-burning stoves. Third, energy saving behaviors of respondents increased when insulation related features were added. Fourth, a degree of lifestyle preservation by those who actually made structural changes was suggested by two observations: 1) energy conserving behaviors decreased following structural modifications, and 2) respondents selected energy conserving behaviors which required little or no changes to lifestyle and/or comfort. This study documents patterns of behaviors which emerged following residential structural modifications. A better understanding of residential energy consumption patterns is important to consumers, educators, researchers, utility companies, government officials and others who influence energy programs and policies as well as the housing environment. Knowledge of these behavior patterns may be used by professionals: 1) to educate consumers of indicated behavior patterns and 2) as a basis on which policy decisions can be made to facilitate energy conservation. Only with knowledge of behavior patterns can effective programs and education curricula be planned which sufficiently inform consumers of efficient (effective) energy conservation methods.
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A simulation model capable of execution on a programmable calculator was developed to study voluntary intake, liveweight change, and fertility of grade Zebu cows in the Llanos of Colombia. Organic nitrogen ...
Citation Citation
- Title:
- Computer simulation of beef cattle production systems in the Llanos of Columbia
- Author:
- Levine, Joel Martin
A simulation model capable of execution on a programmable calculator was developed to study voluntary intake, liveweight change, and fertility of grade Zebu cows in the Llanos of Colombia. Organic nitrogen in the diet and meta bolic weight were used to predict intake; age, liveweight, and energy concentration were the driving variables for the maintenance prediction equation. Energy concentration was calculated as a function of crude protein and digestible organic matter, and liveweight change was predicted as a function of intake, maintenance, liveweight, and energy concentration. Multiplicative correction factors were fitted from data obtained from cow-calf experiments to adjust intake and maintenance for the effects of burning the native savanna, compensatory gain, mineral deficiency, and lactation and gestation. The correction factors were .89 for intake after burning the native savanna, 1.05 and .95 for intake and maintenance during compensatory gain, and .90 for reduced intake due to mineral deficiency. Correction factors for physiological status were 1.20 for intake during early and late lactation, and 1.40, 1.32, and 1.05 for maintenance during early lactation, late lactation, and late gestation, respectively. The correction factors for burning and compensatory gain were fitted against data from dry cows of Herds 4-5 of the Herd Systems Experiment (HSE) and yielded a Pearsonian correlation coefficient of .95 (p<.001) between observed and simulated average daily gains. between March 1975 and June 1976. Correction factors for early lactation, late lactation, and late gestation were fitted with data from early lactation, late lactation, and late gestation cows from Herds 4-5, and correlation coefficients for observed vs. predicted daily gains computed. Results were .89, .83, and .84 (p<.01) for each physiological state, respectively. The correction factor for mineral deficiency was fitted against dry cows of Herds 2-3 and yielded a correlation coefficient of .90(p<.01). The first validation of the model performed against lactating and late gestating cows of Herds 2-3 and all cows from Herds 6-9 of the HSE yielded correlation coefficients between observed and predicted average daily gains for early lactating, late lactating, and late gestation cows from Herds 2-3 of .77 (p<.05), .75 (p<.05), and .62 (p<.10). Results obtained for Herds 6-7 were .93 (p .001), .73 (p<.05), .94 (p<.01), and .87 (p<.01) for dry, early lactation, late lactation, and late gestation cows, respectively. Results for the same categories of cows in Herds 8-9 were .90 (p<.01) .87 (p<.01), .88 (p<.01), and .93 (p<.001), respectively. Two cows selected at random from each herd of the HSE were simulated. Correlation coefficients between observed and predicted liveweights were calculated in each case. Results for Herds 2-3, 4-5, 6-7, and 8-9 were .89 (p<.01), .92 (p<.001), .20, and .12, respectively. Validations were performed against steer grazing data collected at Carimagua at the same time as the HSE. A distribution relating liveweight at breeding to probability of calving was developed. Results showed that less than 10% of conceptions occurred at breeding weights below 260 kg, 10% or more of conceptions occurred within each 20 kg weight interval from 260-380 kg and calving rates decreased at cow breeding weights greater than 380 kg. Results obtained for predicting the calving rate of each cow herd of the HSE were good. A validation of the calving rate predictions was conducted with independent data. Observed conceptions were 56 and 76% for two herds. Predicted calving rates were 53 and 68%, respectively. In an experiment with the model it was concluded that a maximum of 80% calving could be reached with an optimal combination of the inputs of the Herd Systems Experiment.