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1511. [Article] Polyunsaturated fatty acid metabolism in broiler chickens : effects of maternal diet
Three experiments were conducted in broiler hens to study the influence of dietary n-3 polyunsaturated fatty acids (PUFA) on egg quality, antioxidant status in progeny, and eicosanoid production in tissue. The ...Citation Citation
- Title:
- Polyunsaturated fatty acid metabolism in broiler chickens : effects of maternal diet
- Author:
- Bautista Ortega, Jaime
Three experiments were conducted in broiler hens to study the influence of dietary n-3 polyunsaturated fatty acids (PUFA) on egg quality, antioxidant status in progeny, and eicosanoid production in tissue. The objective of experiment 1 was to determine the effect of hen age and dietary n-3 PUFA on egg quality and hatchability. Two-hundred-twenty breeder chicks (males and females) (Cobb Breeders) were raised until 20 weeks of age following the company guidelines. At this age, 3 groups of birds (24 breeder hens and 3 roosters) were randomly allocated to one of the following dietary treatments: 3.5% sunflower oil (Low n-3 diet), 1.75% sunflower oil + 1.75% fish oil (Medium n-3 diet) or 3.5% fish oil (High n-3 diet). Egg quality was evaluated at 29, 37 and 45 weeks of age by determining total egg weight, its components (albumen, yolk and shell) and shell thickness. Total fat content in the yolk and its fatty acid profile was also determined. Egg production was recorded daily. Breeder hens fed the High n-3 diet laid lighter eggs with lighter yolks, albumens and shells than those fed the Medium and Low n-3 diets (p<0.05). Eggs laid by hens fed the Medium n-3 diet had thicker shells than those laid by hens fed the Low n-3 diet (p<0.05). Egg weight, yolk weight, albumen weight, shell weight and shell thickness increased significantly with hen age (p<0.05). Total fat content in the yolk was significantly higher in the eggs laid by 37-week-old and 45-week-old hens than in those laid by 29-week-old hens. Hens fed the high n-3 diet laid eggs with significantly higher n-3 PUFA and lower n-6 PUFA content than hens from the other treatments (p<0.05). Hen age did not affect the n-3 or n-6 PUFA content. Fertility and hatchability were not affected by maternal diet. Total egg weight, yolk weight, albumen weight and shell weight was decreased by feeding n-3 PUFA to breeder hens. The decreased n6:n3 ratio brought about by maternal dietary n-3 PUFA was further investigated in connection with possible effects on antioxidant and eicosanoid status in newly hatched chicks. The objective of experiment 2 was to determine the effect of maternal diet (Low, Medium and High n-3) on the antioxidant and eicosanoid status, tissue fatty acid profile and lipid peroxidation in the newly hatched chick. Two-hundred-ninety-eight eggs were collected from the 29-week-old breeder hens mentioned in experiment 1. After incubation, day-old chicks were randomly selected from a pool of eggs laid by hens fed the three experimental diets. Antioxidant status was established by measuring activity of antioxidant enzymes (glutathione peroxidase, glutathione reductase, superoxide dismutase and catalase) and the content of total glutathione. Hatchability and total fat content in the tissues were not affected by maternal diet. n-3 PUFA content increased and n-6 PUFA decreased significantly in chick’s tissue (p<0.05) hatched from hens fed the fish-oil supplemented diet compared to those hatched from hens fed the Low n-3 diet (p<0.05). Total glutathione and antioxidant enzyme activity was not affected by maternal diet, except for catalase, whose activity was significantly lower in chicks hatched from hens fed the High n-3 and the Medium n-3 diets than in those hatched from hens fed the Low n-3 diets (p<0.05). Malondialdehyde, a measure of lipid peroxidation, was significantly lower in the liver of chicks hatched from eggs laid by hens fed the High n-3 diet than in those hatched from hens fed the Medium n-3 diet. Maternal dietary n-3 PUFA was successfully transferred to the newly hatched chicks without compromising their antioxidant status. The decreased n-6/n-3 ratio observed in chicks hatched from hens fed the fish-oil supplemented diets needs was further investigated relative to its downstream modulatory effects in connection with fat metabolism. The objective of experiment 3 was to establish the effect of maternal diet on fatty acid accretion in heart tissue, and the production of eicosanoids by heart tissue homogenates and peripheral blood mononuclear cells (PBMNC) from broilers fed diet devoid of long-chain PUFA. Broilers were hatched from hens fed the Low, Medium or High n-3 diet. One-hundred-fortyfour 1-day-old chicks were weighed and randomly allocated to four pens housed in three rooms of similar dimensions. Temperature was controlled according to specifications by Cobb Breeders during the 42 days that the experiment lasted. A cardiac morphological study was conducted on a weekly basis starting at 14 days of age to assess the heart weight relative to body weight. Also, the ventricular weights index (right ventricular weight divided by the total ventricular weight) was determined weekly from 14 days onwards. Day-0 chicks hatched from hens fed the High n-3 diet were significantly lighter than those hatched from hens fed the Low n-3 diet. After accounting for age, chicks hatched from hens fed the Low n-3 diet were significantly heavier than those hatched from hens fed the High n-3 diet (p<0.05). Maternal diet did not affect heart weight, after accounting for age. The heart percentage (heart weight relative to body weight) was significantly higher in chicks hatched from hens fed the High n-3 diet than in those hatched from hens fed the Low n-3 diet (p<0.05). The ventricular weights index was not affected by maternal diet. At 7 and 14 days of age, arachidonic acid (AA) content in heart tissue was significantly lower in chicks hatched from hens fed the High n-3 diet than those hatched from hens fed the Low n-3 diet (p<0.05). At 7 days of age, AA content in the heart tissue of chicks hatched from hens fed the High n-3 diet was significantly lower than in those hatched from hens fed the Medium n-3 diet (p<0.05). At day 0, the heart tissue production of prostaglandin E2 (PGE2) was significantly higher in the chicks hatched from hens fed the Low n-3 diet than in those hatched from hens fed the Medium or High n-3 diets (p<0.05). At the same age, thromboxane A3 (TXA3) production was significantly lower in the heart tissue of chicks hatched from hens fed the Low n-3 diet than in that of chicks hatched from hens fed either the Medium or Low n-3 diets (p<0.05). At day 7, PBMNCs isolated from chickens hatched from hens fed the Low and Medium n-3 diets produced significantly higher PGE2 and TXA2 concentrations than those isolated from birds hatched from eggs laid by hens fed the High n-3 diet (p<0.05). At day 31, PBMNCs isolated from chickens hatched from hens fed the Medium and High n-3 diets produced significantly higher PGE2 and TXA2 concentrations than those isolated from chicks hatched from eggs laid by hens fed the Low n-3 diet (p<0.05). Chicks hatched from hens fed the High n-3 diet had a higher heart/body weight than those hatched from the Low n-3 diet. Thus, chicks hatched from hens fed the Low n-3 diet may be at higher risk of developing cardiovascular complications related to high AA concentrations in the heart and blood cells during the first week of age. Further research is encouraged in which the three subpopulations of broilers (i.e.hatched from hens fed the Low, Medium and High n-3 diets) are raised under commercial conditions to investigate how the economic loss, due to a reduction in body weight observed in the High n-3 chickens compares with the potential reduction in mortality during the first week of age. Finally, the mechanistic action of n-3 PUFA needs further investigation, especially molecular aspects related to modulatory effects on gene expression.
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1512. [Image] Ecology of kokanee salmon and rainbow trout in Crater Lake, a deep ultraoligotrophic caldera lake (Oregon)
ill.; Thesis (M.S.)-Oregon State University, 1988; Includes bibliographical references (leaves 74-80)Citation Citation
- Title:
- Ecology of kokanee salmon and rainbow trout in Crater Lake, a deep ultraoligotrophic caldera lake (Oregon)
- Author:
- Buktenica, M. W., (Mark W.)
- Year:
- 1988, 2009
ill.; Thesis (M.S.)-Oregon State University, 1988; Includes bibliographical references (leaves 74-80)
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1513. [Article] Perceptions of "Dropouts" Recovered as Adults : A Life Course Case Study on Older High School Graduates
Research has established that poor outcomes are the future for those without a high school diploma--yet students continue to drop out and become members of that population. The purpose of this qualitative ...Citation Citation
- Title:
- Perceptions of "Dropouts" Recovered as Adults : A Life Course Case Study on Older High School Graduates
- Author:
- Bogen, Susan Lori
Research has established that poor outcomes are the future for those without a high school diploma--yet students continue to drop out and become members of that population. The purpose of this qualitative study was to investigate the experiences and perceptions of individuals who did not complete high school within the traditional age-graded time-frame, yet subsequently graduated from an adult high school program. Currently, in the United States, few secondary options exist for over-age dropouts. New Mexico and Indiana, however, are two states that allow public funding to pay for high school without imposing upper age limitations. For this case study, adult high school programs were identified in the aforementioned states, and purposive samples were selected. Eight participants were selected from the Gordon Bernell Charter School in New Mexico and 13 from Indiana’s Excel Centers. Of the 21 participants, 15 were female and six were male. Ages ranged from 21 to 70 years old. The study’s theoretical framework was anchored to Transformative Research, embedded in Social Constructivism, and analyzed through a Life Course Perspective. Life course examines complex interchanges and choices between individuals and their environments within time, socio-cultural, and economic constraints; and considers the effects of accumulated advantages and disadvantages. In this research, the themes that developed from interview responses were categorized and analyzed within the following five life course dimensions: a) time and place; b) linked lives; c) agency; d) timing; and e) life span development. A key finding revealed that changes in perspective had occurred over time--because the time and place changed--bringing participants to a new era in their lives. This change provided insight into past choices. Initial choices to drop out of school had become regret, but individuals were empowered to make different choices when given a new opportunity to finish high school. Timing also played into their decisions to return to high school when facing the needs of their growing children. Indications that people seek to grow and develop in positive and socially accepted ways over the life-span were evident in participants' diverse age groups and successes in graduating. These findings suggest that policies prohibiting public education beyond age 21 may need to be reviewed. Findings also implied that the cumulative disadvantages most of the participants had experienced in their youth had presented them with few perceived options regarding completion of high school. However, new opportunities allowed students to accumulate advantages that provided life-changing turning points and facilitated changes in life trajectories. Although results may not be generalizable to the greater population, sufficient insights exist to initiate a conversation around how adult high schools could help recover lost investments in secondary non-completers. Implications of this study have the potential to impact future policy and program development, inform adult education practitioners, and stimulate further research.
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1514. [Article] Paleoclimate, paleoventilation, and paleomagnetism as recorded in a 17kyr marine sediment record from the SE Alaska margin
The deglacial behavior of the sub-Arctic North Pacific is poorly constrained, with many published records suffering from limited age control due to extensive post- depositional biogenic carbonate dissolution. ...Citation Citation
- Title:
- Paleoclimate, paleoventilation, and paleomagnetism as recorded in a 17kyr marine sediment record from the SE Alaska margin
- Author:
- Davies, Maureen Helen
The deglacial behavior of the sub-Arctic North Pacific is poorly constrained, with many published records suffering from limited age control due to extensive post- depositional biogenic carbonate dissolution. Potential alternative dating methods could include the correlation of stable-isotopic and/or paleomagnetic secular variation records to an independently-dated regional template, however no such template currently exists. Cores EW0408-85JC (59°33.32'N, 144°9.21'W, 682 m water depth) and EW0408-79JC (59°33.32'N, 144°9.21'W, 682 m water depth) are located above the carbonate compensation depth on the Gulf of Alaska margin, affording an opportunity to inter- compare stable-isotopic and paleomagnetic variability from a single location, as well as to place observations of Northeast Pacific paleoclimate and paleomagnetic secular variation in a global context via an independent radiocarbon-based chronology. We evaluate three possible age models for core EW0408-85JC and their implications for North Pacific stable isotopic and paleoventilation behavior. These include calibrated planktonic and benthic foraminiferal radiocarbon dates, assuming constant reservoir ages, as well as a correlation of planktonic δ¹⁸O in foraminifera to δ¹⁸O in a layer-counted Greenland ice core (NGRIP). We conclude that the calibrated planktonic dates provide the most accurate chronology. Benthic foraminiferal radiocarbon dates evaluated on this age model indicate that intermediate-depth ventilation ages at the site increased to >2,670 ± 180 during Termination 1, implying reduced ventilation relative to the Holocene average of 1,740 ± 210 yr. The shift to lower ventilation ages occurs at ~10,500 cal ybp, coeval with the flooding of Beringia and the opening of the Bering Strait, suggesting that flooded shelves and net export of low- salinity surface waters enhanced ventilation of the North Pacific. Oxygen isotope data from planktonic and benthic foraminifera, interpreted on this age model, document surface freshening by 16,650 ± 170 cal ybp, likely due to freshwater input from retreating regional glaciers. A sharp transition to laminated hemipelagic sedimentation at 14,790 ± 380 cal ybp is coincident with abrupt warming and/or freshening of the surface ocean (i.e. additional δ¹⁸O reduction of 0.9 ‰), essentially coincident with the Bolling Interstade of Northern Europe and Greenland. Cooling and/or higher salinities returned during the Allerod interval, coeval with the Antarctic Cold Reversal and continuing until 11,740 ± 200 cal ybp, when the onset of warming coincides with the end of the Younger Dryas. This may indicate convolved Northern and Southern drivers of climate variability in the North Pacific. Two laminated opal-rich intervals record episodes of high productivity are observed from 14,790 ± 380 to 12,990 ± 190 cal ybp, and from 11,160 ± 130 to 10,750 ± 220 cal ybp. These events likely correlate to similar observations elsewhere on the margins of the North Pacific, and may be driven my remobilization of iron from newly inundated continental shelves during episodes of rapid sea-level rise. High-resolution paleomagnetic secular variation (PSV) records from the Gulf of Alaska constrain regional field behavior and provide information on larger scale geomagnetic dynamics. Both cores studied (EW0408-79JC and 85JC) preserve a generally strong and relatively stable (MAD <5°) magnetization for the period of overlap, though the quality of the magnetization at 85JC deteriorates beyond 8,000 cal ybp, in association with deglacial and early Holocene shifts in magnetic mineralogy. Component inclinations from both sites are consistent with historical reconstructions and consistent with a geocentric axial dipole (GAD), supporting spherical-harmonic attempts to model the Holocene field. Comparison with regional reconstructions suggest that even the earlier component of 85JC captures PSV fairly accurately, providing new information on this part of the record. Normalized remanence is reconstructed using NRM/ARM, though variability in the magnetic remanence carrier precludes us from interpreting these records as robust reflections of North Pacific relative paleointensity. The independently-dated directional records, however, are consistent with other regional reconstructions as well as those derived further afield in North America, suggesting that the concept of coherent North American flux lobe behavior through the majority of the Holocene can now be extended to the Gulf of Alaska.
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The prevalence of herbal supplement use by the elderly and factors that influence regular versus occasional use were investigated in a group of independent residents of a continuing care retirement community ...
Citation Citation
- Title:
- Herbal supplements and retirement facility residents : factors that predict usage
- Author:
- Weng, Yao-Lin
The prevalence of herbal supplement use by the elderly and factors that influence regular versus occasional use were investigated in a group of independent residents of a continuing care retirement community in Salem, Oregon. A nine-page questionnaire was delivered to 402 residents of Capital Manor; 318 questionnaires were usable (84% response rate). The majority of respondents were female (68%) and Caucasian (88%) with an age range of 65 to 100 (average 82.2 years). Twenty percent of all respondents (n=65) were herbal supplement users. Sixty-two percent of them were regular users and 39% were occasional users. The majority of users were female (68%), Caucasian (85%), and non-smokers (78%). Their age range was 65 to 91 years (mean of 79.6 years). Sixty-nine percent reported living with a spouse. They had more than a high school education (78%) and had annual household incomes above $50,000 (49%). "Books, newspapers, and magazines" (84%) were the information sources most frequently relied on for herbal supplement information, followed by "medical doctor/nurse" (72%). Forty-four percent of user households spent more than $10 per month on herbal supplements. Supermarkets (41%) and health food stores (41%) were the most popular places to purchase herbal supplements. The majority of herbal supplement users strongly agreed/agreed that taking herbal supplements would "make you feel less stress" (88%), "protect you from getting a cold" (81%), and "improve your memory" (81%). Fifty-two percent of users strongly agreed/agreed that "herbal supplements may cause side effects" and 24% strongly agreed/agreed that "herbal supplement shouldn't be taken with other medications". Gingko biloba was the most frequently used of eight herbal supplements (71% of respondents) followed by echinacea (39%) and ginseng (29%). Males were significantly more likely to use saw palmetto (claimed to prevent enlargement of the prostate gland). Eighty-three percent of herbal supplement users reported having some knowledge about possible benefits of ginkgo biloba (claimed to reduce memory loss). A belief that herbal supplements "improve your memory" was significantly associated with usage. Regular herbal supplement users were significantly more likely to agree that taking herbal supplements reduces severity of memory loss. Four factors were significantly related to herbal supplement use: age group (with age group of 75 to 84 years old more likely to be users than age groups of 65 to 74 years and age group of 85 years and over); living status (with those living with spouses being more likely to be users than those living alone), health status changes in the past year (with users being more likely to report their health status as "improved" than non-users); and physical exercise participation (with users being more likely to exercise than nonusers). The fundamental hypothesis of this study was that the frequency of use of herbal supplements among older adults would be mediated by several factors including: perceived susceptibility to and severity of chronic diseases (i.e., heart disease and cancer); perceived benefits of and barriers to herbal supplement usage; information sources; vitamin/mineral supplement usage; and perceived preventive lifestyle factors. Of these, only vitamin/mineral supplement usage was significantly associated with herbal supplement usage. Ninety-seven percent of herbal supplement users also used vitamin/mineral supplements. In addition, perception of control over health (a measure of self-efficacy) was significantly associated with herbal supplement use. The more control perceived, the more likely respondents were to be herbal supplement users. In general, the Health Belief Model did not predict frequency of herbal supplement usage (i.e., regular vs. occasional). Hence, further research is needed to focus on factors predicting herbal supplement use versus non-use. In addition, lack of awareness about risks and benefits of herbal supplement use suggests a need for education targeted at older adults.
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A preliminary study was conducted to establish baseline data for emu artificial egg incubation and emu chick growth and management. Three experiments examined factors affecting hatchability of emu eggs ...
Citation Citation
- Title:
- Preliminary investigation of artificial incubation of emu eggs, and alternative feeds and management techniques for emu chicks up to ten weeks of age
- Author:
- Allen, Carol Ann
A preliminary study was conducted to establish baseline data for emu artificial egg incubation and emu chick growth and management. Three experiments examined factors affecting hatchability of emu eggs that occur prior to and during artificial incubation. Characteristics analyzed were egg storage duration, hen age, egg weight, egg index, shell thickness, incubation temperature, incubator type, and egg weight loss. The six treatments among the three incubation experiments consisted of two AVN incubators with temperatures maintained at 36.0 C and 35.8 C, and four Jamesway 252 incubators maintained at 36.0 C, 36.6 C, 36.5 C, and 36.7 C. Three subsequent experiments involved six treatments with hatched chicks to test the effects of diet and pen size on chick weight gain, and growth of the beak, middle toe, and tarsometatarsus up to eight and ten weeks of age. Sand, grass clippings, and pine shavings substrates were also tested. Analysis of duration of egg storage indicated that an increase in pre-incubation storage time was associated with a decrease in hatchability. The highest percent hatch (63.8%) occurred for eggs held ≤7 days and decreased for each additional week stored. Analysis revealed evidence that as emu hen age increased, fertility increased (p<0.05). Also, as hen age increased, egg size increased (p<0.05). Age often did not influence (p>0.05) egg index or shell thickness. There was no indication that egg index had an effect on hatch. An inverse relationship was observed between hatchability and egg shell thickness. Higher incubation temperatures were associated with a decrease in hatchability. Temperatures ≤36.0 C resulted in an average hatchability of 64.3%, while temperatures ≥36.0 C resulted in only 47.2%. Incubation temperatures ≤36.0 C were observed to increase chick quality compared to temperatures >36.0 C. Eggs having weight loss of 11%-14.9% during incubation had higher percentage hatch than eggs with losses out of this range. The pattern for embryonic mortality was observed to be similar to the pattern in other domestic avian species; high mortality peaks at the beginning and end of incubation. However, a higher than expected mortality occurred between the two peaks. Chicks fed a 21.4% protein broiler starter diet (BS) had higher weight gain (p<0.05) than chicks fed a 20.1% protein chick starter diet (CS). Feed conversion among chicks consuming the BS was significantly better (p<0.05) than the chicks consuming the CS. In a 2 X 3 factorial design experiment, chicks were raised in two different pen sizes, 0.9 m X 3.0 m and 1.8 m X 11.0 m, and fed three different commercial diets; an 18% protein all-in-one diet (AIO), a 23% protein emu diet (EMU), and a 28% protein turkey-gamebird starter diet (TG). Chicks showed no evidence (p>0.05) of interaction between pen size and diet for weight gain, feed conversion, or growth of the beak, middle toe, and tarsometatarsus. However, chicks fed EMU consumed significantly more feed (p<0.05) than chicks fed TG. Pine shavings substrate was determined to be the least labor intensive and provided the best footing for the chicks among the three substrates tested. According to this investigation, for farmers to achieve maximum production for artificial incubation of emu eggs, they should use breeder hens ~4 years old, store eggs no longer than 7 days, and incubate eggs at temperatures ranging from 35.5 C-36.0 C. Until nutrition requirements are established for emu, there is no advantage to feeding emu chicks through 10 weeks of age a commercial emu diet compared to other commercial domestic bird diets.
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1517. [Article] Genetic and environmental differences in age at first estrus and in wool and lamb production of crossbred ewe lambs
Genetic and environmental factors affecting age of first estrus, wool production, reproduction and lamb production were examined in eight groups of crossbred ewe lambs from two birth years. The 399 ewe ...Citation Citation
- Title:
- Genetic and environmental differences in age at first estrus and in wool and lamb production of crossbred ewe lambs
- Author:
- Cedillo, Rose Mary
Genetic and environmental factors affecting age of first estrus, wool production, reproduction and lamb production were examined in eight groups of crossbred ewe lambs from two birth years. The 399 ewe lambs whose first year production was analyzed were from eight crossbred groups resulting from mating North Country Cheviot, Dorset, Finnsheep and Romney rams to Suffolk or whiteface Columbia-type range ewes. The ewe lambs were born January through March of both 1973 and 1974, and were raised to weaning on western Oregon hill pastures. They were summered and maintained through the breeding season on irrigated pastures. At the end of the breeding season each year, ewes within each of the eight groups were randomly divided between hill pasture and irrigated valley pasture management systems. After lambing in common facilities, they were returned to the appropriate management environment where they remained throughout lactation. Average age at first estrus for the 90 percent of ewes which did cycle their first fall was 205 days. Age at estrus between years differed by 18 days (P<.01). Sire breed and the sire x dam breed interaction were not significant effects, but ewes with Suffolk dams cycled ten days earlier than ewes with Columbia dams (P<.01). Also a greater proportion of ewes with Columbia dams failed to cycle their first fall (18 percent versus 2 percent for ewes with Suffolk dams). None of the birth year interactions was significant. The regression of age at estrus on birth date of ewe was -.85 days per day (P<.01). The regression of age at estrus on ewe weight at first estrus (estimated by interpolation between bracketing weights) was 0.39 days per pound (P<.01). The unexpected signs of the two regression coefficients probably resulted from shortened day length in the fall triggering estrus at a fairly constant calendar time but at varying ages and weights, depending upon when the lamb was born the previous spring lambing season. Breed of the ewe's dam significantly affected wool grade with Columbia crosses having finer wool. Staple length was longest and about equal for Finn and Romney sired ewes; Dorset crosses produced the shortest wool. Columbia cross wool was longer than Suffolk cross wool only in Finn and Dorset cross ewes. Grease fleece weight of Columbia crosses was consistently heavier than that of Suffolk crosses. Romney sired ewes had the heaviest fleeces followed by Cheviot, Dorset and Finn sired ewes. Observable medullation was most severe in the two Cheviot crossbred groups, with a tendency for slightly greater medullation in Suffolk than in Columbia crosses. Romney x Columbia ewes generated the most wool income, due to heavy fleece weight and high value per pound of clean wool. Ewes with Columbia dams generated higher wool income than did those with Suffolk dams. The reproductive performance of ewes with Finn sires was superior to that of ewes with Dorset, Cheviot or Romney sires, while ewes with Suffolk dams were superior to ewes with Columbia dams. Finn crossbreds had the greater percentage of ewes lambing per ewe bred (72 percent), while Romney x Columbia ewes were lowest (18 percent). Finn sired crossbred ewes averaged 1.62 lambs born per ewe lambing compared to 1.18 for the average of the other crosses. Finn cross ewes excelled for total weight of lamb weaned, followed by Dorset, Cheviot and Romney sired ewes. The greater lamb production of the Suffolk cross ewes more than compensated for their lower wool production. They generated $6.00 more total gross income than did Columbia crosses. Also for gross income, ewes with Finn sires were highest followed by Dorset, Cheviot and Romney sired ewes.
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1518. [Article] Temporal Evolution of Submarine Volcanoes and Seamount Trails
The spatial distribution and geologic histories of submarine volcanoes provide insight into submarine eruptive behavior, deep earth processes and plate tectonics. This dissertation examines the evolution ...Citation Citation
- Title:
- Temporal Evolution of Submarine Volcanoes and Seamount Trails
- Author:
- Schnur, Susan R.
The spatial distribution and geologic histories of submarine volcanoes provide insight into submarine eruptive behavior, deep earth processes and plate tectonics. This dissertation examines the evolution of individual submarine volcanic edifices as well as linear trails of seamounts at three spatial and temporal scales. In order to understand constructive and destructive processes at submarine arc volcanoes on time scales of decades I present a study of the eruptive behavior and geology of NW Rota-1 seamount between 2004 and 2014. I use remotely operated vehicle (ROV) dive observations to develop geologic maps of the summit area (< 0.5 km2) in 2009 and 2010, before and after a significant landslide event. I combine these maps with repeat bathymetric surveys and hydrophone recordings to understand how changes in eruptive style affect the geology of the summit area and ultimately control the frequency and magnitude of landslides. At larger spatial and temporal scales, I consider the Tristan da Cunha island group (5,000 km2), which has a geologic history spanning less than 2 million years. Tristan da Cunha is one of the assumed hotspot locations for the Walvis Ridge, the highest-volume hotspot trail in the South Atlantic and one of the longest-lived primary hotspot trails in the world. However, Tristan da Cunha is much younger than surrounding seamounts and does not fit into the age progression of the Walvis Ridge. Based on 26 new 40Ar/39Ar ages I provide an updated maximum age for the island group of 1400.7 ± 8.1 ka and a median age of only 319.5 ± 17.8 ka, confirming that Tristan da Cunha is young and therefore an age outlier relative to nearby seamounts. Upper mantle convection models published by others suggest that plume material is being carried towards Tristan from the true plume center in the vicinity of Gough Island, located about 400 km away, which is often selected as a hotspot location for the Walvis Ridge. I therefore reject Tristan da Cunha as one of the Walvis hotspots and hypothesize instead that the true location of the second eruptive center in the Walvis system is located to the southwest, near Blue Seamount, the youngest seamount in the trail. At the largest scales I consider the 70-million-year history of the 1800 km long Young Walvis Ridge Guyot Province, a diffuse region of volcanism marking the young end of the Walvis Ridge hotspot trail. The Walvis Ridge is important as a key constraint on African plate motion but it is poorly understood due to its broad, bifurcated morphology, which differentiates it from other primary hotspot trails. I present 69 new high-quality 40Ar/39Ar ages for 30 previously-undated seamounts in the Guyot Province to show that this diffuse region of volcanism preserves an age progression, but that the spatial distribution of the seamounts does not always trace plate motion. The placement of seamounts at the young end of the trail is likely controlled by fracture zones extending from the nearby Mid-Atlantic Ridge, while the complex distribution of seamounts in the Guyot Province is a function of lithospheric thickness. The dual eruptive centers simultaneously generate volcanism on younger and older lithosphere, with melts under younger lithosphere rising to the surface directly from the underlying plume and melts under older lithosphere being forced to use fracture zones as conduits. Strikingly, all seamounts formed over the past ~30 million years are fracture zone-oriented, irrespective of lithospheric thickness. This appears to confirm that the Walvis plume is indeed waning, as suggested by a decrease in volume of volcanism along the trail. The diffuse nature of plume expression is likely a result of prevalent mantle flow patterns and proximity to the Mid-Atlantic Ridge, resulting in the drawback of material towards the ridge and transport of material to the northwest, dispersing plume material over a broad area. These three studies represent different perspectives on submarine volcanism and reflect the variety of spatial and temporal scales on which we study submarine volcanoes and seamount trails.
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1519. [Article] Dietary behavior and body composition parameters among self-reported exercising and non-exercising elderly women
The percentage of the American population who are 65 years old or older is rapidly increasing, especially the proportion of women. It is becoming crucial to encourage lifestyle behaviors that will enable ...Citation Citation
- Title:
- Dietary behavior and body composition parameters among self-reported exercising and non-exercising elderly women
- Author:
- Bell, Kathleen A.
The percentage of the American population who are 65 years old or older is rapidly increasing, especially the proportion of women. It is becoming crucial to encourage lifestyle behaviors that will enable senior women to remain in optimal health. Following the 1990 Dietary Guidelines' recommendations to limit fat intake and consume adequate amounts of dietary fiber has been shown to positively impact longevity and health status in the elderly by decreasing risk factors for chronic diseases. An expected outcome of engaging in regular exercise is a reduction in body fat, which is also associated with a lowered incidence of several chronic illnesses. However, the literature clearly indicates that nutritional quality of the diet and involvement in regular exercise decrease with increasing age. There is evidence that, with the adoption of one health enhancing behavior, there is a greater tendency to engage in other health promoting behaviors, but little data exist on the healthseeking behaviors of older adults. The purpose of this study was to ascertain if there were identifiable differences between self-defined exercising and self-defined non-exercising elderly women with respect to their nutrient intake, food sources of dietary fat and fiber, dietary change behavior, and body composition parameters, considering their age and education and income levels. The objective was to determine whether those women who had consciously undertaken a regular exercise program would also have higher micronutrient intakes, make lower fat and higher fiber food choices, report having made more dietary changes in the direction of the 1990 Dietary Guidelines, and have leaner body compositions than those who had not undertaken such a program. Thirty-three elderly women self-reported exercisers (mean age 74.1 years) and 30 self-reported non-exercisers (mean age 71.3 years) were enrolled in a 14 week study. Exercisers were defined as those who reported having engaged in a regular program of planned exercise a minimum of 15 minutes per session, 2 times per week, for at least the last year, and non-exercisers were those who had not. They kept three, 7-day food records at 5 week intervals. Nutrient intake was estimated from 9 days of food records, 3 predetermined days from each recording period, using the Food Processor n software. Dietary intakes were analyzed for energy, macronutrients, dietary fiber, and selected micronutrients. Food sources of dietary fat and fiber were determined using a food categorization adapted from Popkin and coworkers (1989). Information concerning dietary change behavior, obtained from questionnaire responses, was compared between groups using chisquare tests. Body composition, assessed through repeat measurements during each dietary recording period, included determination of percent body fat through skinfolds, waist-to-hip-ratio and body mass index. Average 9-day nutrient intakes and anthropometric measures were compared between groups using t-tests or Mann- Whitney U tests. Both elderly women exercisers and non-exercisers had similar energy, macronutrient, and dietary fiber intakes based on 9-day means. Their total fat intakes, expressed in grams and as percentages of energy, were not significantly different. Both groups consumed a lower percentage of their daily kcalories as total fat (32%) compared with national surveys of women over 65 (36%). Exercisers consumed more total vitamin A (p=.03) and carotene (p=.00) than the non-exercising women. A great proportion of both groups did not meet 75 % of the Recommended Dietary Allowances for calcium and zinc. A larger proportion of the exercisers than the non-exercisers reported using lower fat cheese (p=.02) and green and yellow vegetables (p=.03), which partially explained their higher total vitamin A and carotene intakes. Exercisers obtained less of their total fat intake from lower fat milk (p=.02) and more of their fat intake from lower fat lunch meats (p=.04) than the non-exercisers. The categories of legumes (p=.02) and lower fiber vegetables (p=.05) supplied greater amounts of dietary fiber for the exercisers compared with the non-exercisers. When asked about dietary changes made over the past decade, a greater percentage of the exercisers than non-exercisers reported having decreased red meat intake (p=.05) and increased consumption of cereals (p=.05) and legumes (p=.00). Actual intake data showed that the legume food category contributed more dietary fiber to the diets of the exercisers than the non-exercisers (p=.02). No differences were found in body fat measures between the exercisers and non-exercisers. The lack of observed differences between the two groups reinforces what other researchers have found, that a large number of factors influence body composition, of which exercise is only one. More research is needed to distinguish the interactions of age, energy intake, and physical activity on the body fatness of elderly women, as well as the most accurate instruments for assessing body composition for this age group. Exercise participation among elderly women in this study appeared to be associated with several positive dietary behaviors. Elderly women exercisers compared to non-exercisers made food choices leading to higher total vitamin A and carotene intakes, and also reported making more changes in food consumption behaviors in the direction of current dietary recommendations. These observed outcomes provide support for designing health-promotion programs for elderly women which include both nutrition education and exercise components.
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1520. [Article] Lingual discrimination of two normal-speaking populations
The present investigation was undertaken to collect normative data on a teenage population and a young adult population in order to assess tongue sensitivity regarding the identification of various geometric ...Citation Citation
- Title:
- Lingual discrimination of two normal-speaking populations
- Author:
- Nesbitt, Janice Ellen Gould
- Year:
- 1974
The present investigation was undertaken to collect normative data on a teenage population and a young adult population in order to assess tongue sensitivity regarding the identification of various geometric shapes. The research, was conducted to answer the following questions: 1. Is there a significant difference between a teenage group and a young adult group regarding lingual discrimination? 2. What is the range and variability between and within the two groups? 3. Is the teenage group significantly better than the elementary school age group previously tested by Weiss (1973b)? There were 50 normal-speaking subjects in the teenage group ranging in age from 13 through 15 years, and 50 normal-speaking young adults ranging in age from 22 through 26 years. The subjects in the teenage group were volunteers from the public schools of Portland, Oregon, and Camas, Washington. The adults were from the same areas and were either employed in responsible jobs or were enrolled in graduate study programs. All subjects were administered a passive and an active test of lingual discrimination. Each test included 24 identifications of plexiglass geometric shapes. Selection of the shapes were made by the subject pointing to his choice on a response sheet, after the geometric shape had been removed from his mouth. The results were analyzed statistically to assess mean, range, and variability within and between the groups. A t-test was used to determine a significance of differences. The questions posed by this investigator were answered in the following manner: There was no significant difference in performance between a teenage group and a young adult group regarding lingual discrimination. This would appear to contraindicate the belief by some authorities (McDonald and Aungst, 1967) that lingual discrimination abilities continue to improve until the mid-teens. In discussing the results between the groups, the means of the active scores for both age groups were significantly greater than those achieved on the passive test. The variability on the passive test was significantly greater (p > .05) for the teenage group than for the adult group. The adults tended to be more variable on the active test. This would tend to indicate that both age groups were receiving more discriminative cues on the active test than on the passive test. 2. In comparing the teenage group to a group of 8 year-oIds previously tested by Weiss (1973b), it was found that the older group performed significantly better. These findings held true for both passive and active tests. This finding is not surprising in that one would expect maturation in this discrimination task over time as a result of human development.