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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Selection for hatchability of Japanese quail embryos incubated at 102 F

Colvin, Wendy R. 03 March 2005 (has links)
A genetic selection study to determine the effects on egg hatchability and subsequent chick performance of Japanese quail (Coturnix japonica) eggs incubated at 100 F dry bulb temperature (Control, Line C) when compared to other eggs incubated at 102 F (Selected, Line S) was conducted over 10 consecutive generations. Eggs from a randomly mated population (designated as Generation 0) of Japanese quail maintained at the Oregon Agricultural Experiment Station were randomly allocated to two treatment groups (Lines C and S) and incubated at the different temperatures in separate but identical Jamesway 252 machines. On day 14 of incubation all eggs were transferred to a common hatcher (98.5 F). Using family-based selection, the chicks that hatched from the two lines were subsequently used as breeders (25 paired matings per line) and the resulting eggs from each line incubated at their respective temperatures for 10 consecutive generations. Following the 10th generation percent egg fertility and percent hatch of fertile eggs were greater in Line C vs. Line S (p<O.O3 and p<O.0001, respectively). Embryo development time was shortened in Line S by 24 hours and mean 4- or 5- week body weights were greater (p<0.001) in Line S. Ten-day post-hatch mortality increased greatly in Line S vs. Line C after generation 6 (p<0.001) and hen-day egg production decreased after generation 4 in Line S vs. Line C (p<0.0001). The results indicate that embryo development time can be reduced by high temperature incubation, but at the expense of reproductive traits such as egg production, fertility, and hatchability of fertile eggs. / Graduation date: 2005
142

Fathers' perceptions of their impact on children's health and well-being : an exploratory study

Hill, Tisa Fontaine 14 March 2005 (has links)
Fathers play a critical role in child development and well-being, yet research on how men view their roles as fathers and their influence on their children's health is limited. The present study sought to answer the following questions: 1) What are men's expectations regarding fatherhood? 2) How have these expectations changed after becoming fathers? 3) What factors or role models shape and influence these expectations? and, 4) How do fathers perceive their impact on the health and well-being of their children? Data were collected via in-depth interviews with 20 fathers of pre-school aged children residing in two Oregon communities. Results suggest that role models, work schedule, mothers' roles, and their self-identity as fathers influenced participants' views of themselves as fathers and consequently their involvement in their children's lives. Fathers' sense of responsibility, either financial or emotional or both, appeared to heavily impact the ways they chose to engage with their children. While meeting physical needs of food, clothing, and shelter were discussed, for these fathers the primary indicator of children's health was happiness. They considered themselves responsible for creating a happy home environment in which to nurture their children's mental and emotional health. All the fathers engaged in caring for their children when they were sick, including sharing specific tasks such as doctors' visits, dispensing medicine, and staying at home with the children. Findings suggest that fathers view themselves as playing an important role in promoting and protecting the health of their children. / Graduation date: 2005
143

The relationship between morphology and ecology in the spatangoid urchin Brisaster latifrons

Brownell, Charles Lawrence 16 January 1970 (has links)
Graduation date: 1970
144

Seasonal variations in tidal dynamics, water quality, and sediments in the Coos Bay estaury

Arneson, Robert Jeffrey 29 May 1975 (has links)
Graduation date: 1976
145

Analysis of the administration of the health examination in the public schools of Oregon

Bech, Jack Karl 23 October 1954 (has links)
The school-age period is one in which the health status of the pupil must be constantly observed and appraised if optimal growth and development are to be realized. Therefore, Oregon laws provide that the State Board of Health shall have direct supervision of all matters pretaining to the preservation of the life and health of the people of the state. To achieve this purpose, the Superintendant of Public Instruction is given the duty to prescribe for, with the advice of the State Board of Health, the program of health examinations for pupils. The county and city school superintendants are made responsible for carrying out this program. These health examinations render a type of health service to children that develop understanding and action by parents and result in an improved health status of the child. In this study the questionnaire method was used and brought a fifty per cent return which was considered sufficient to make the study factual. Information for this study was collected from all areas of the state and included completed questionnaires from elementary, junior high and high schools. The total enrollment of the 125 schools returning the questionnaire came to a figure of 40,101 students. Of this total number only 36,455 were reported by the administrators as being in one of the nine categories available for health examination on the questionnaire. Of the 36,455 students recorded, only 23,378 were provided with health examinations, or 64 plus per cent. This figure is rather disappointing as it was hoped the percentage would be at least in the nineties. As was expected, the students participating in athletics are receiving a higher per cent of examinations than any other group of school-age children. Of the 8,894 athletes listed, 8,610 were given health examinations, or 97 per cent. The principals indicated that of the 4,765 pupils entering school for the first time, 4,101 received health examinations, or 87 per cent of the total. This group ranked second in the percentages, a full ten per cent behind the athletic participant group. There were 2,011 pupils referred for examination by the teacher or by the teacher-nurse screening. Of this number, 1,679 pupils were examined which indicates that 83 per cent of those referred were examined. This particular group ranked third in the over-all picture. Of the pupils entering the ninth grade and new to the school, 73 per cent are being examined according to the questionnaire. There were 6,647 pupils in this group and 4,848 received examinations. Of the 2,260 seventh grade pupils, 1,181 were given a health examination which gives a percentage figure of 52 plus per cent. Very little examining is done in the tenth or other grades according to the information gathered. Of the 961 students listed in this group, only 328 received examinations, or 34 per cent. Of the 10,917 students participating in the intramural and recreation program, only 1,631 were given a health examination, or 15 per cent. / Graduation date: 1955
146

Effects of maternal age on reproductive success in black rockfish, Sebastes melanops

Bobko, Stephen J. 02 May 2002 (has links)
From 1996 through 1998 I collected mature female black rockfish off Oregon and examined ovaries and otoliths to estimate weekly, age-specific larval production. In all reproductive seasons, older black rockfish extruded larvae earlier in the season, followed by progressively younger fish. Each year, beginning in May, I collected young-of-the-year (YOY) benthic juveniles that settled out in nearshore waters and determined their birthdates from counts of daily rings of lapillar otoliths. I compared the birthdate distribution of juvenile survivors to the age-specific temporal distribution of larval production to estimate the contribution of each adult female age group, ages 6-8, 9-11, 12-14, and 15+ to juvenile recruitment. The results from 1996 show a disproportionately greater contribution to benthic YOY recruitment by older fish. 1997 results show a relatively even contribution among maternal age groups. In 1998 most of the YOY recruits came from younger fish extruding larvae late in the season. I then examined larvae per recruit (LPR) models to evaluate the effects of fishing mortality on spawning potential of black rockfish, incorporating my estimates of age-specific maternal reproductive success. When it is evident that certain age groups are more successful at reproducing, as observed in black rockfish, changes in that population's age composition must be considered beyond simply reducing the estimate of total larval production. / Graduation date: 2003
147

Factors influencing the outcomes of public health legislation in the 2001 Oregon legislature

Wise, Kendra J. 16 April 2004 (has links)
Legislation can be an effective public health tool, and understanding the factors that influence legislative outcomes is advantageous for public health practitioners who propose and advocate for legislation. The literature indicates that the issues of personal freedoms, the presence or absence of strong coalition leadership, and political conditions and ideology have significant influences on the outcomes of public health legislation. The existing literature includes information about the factors that influence outcomes for legislation at the national level, and also discusses the factors that influence initiatives (particularly tobacco-related initiatives) at the state level. Little information is available, however, regarding the factors that influence the outcomes of public health legislation initiated through the Legislature at the state level in Oregon. The objective of the current research is to understand better which factors influenced the outcomes of public health legislation in the 2001 Oregon legislative session. To answer this question, I used a cross-sectional case study design to examine four pieces of public health legislation from the 2001 Oregon legislative session. The legislation and outcomes examined included 1) Senate Bill 734 / House Bill 2814, that would have allowed counties to opt out of providing family planning services to county public health clinics (in committee upon adjournment); 2) Senate Bill 99, that would have required water suppliers serving over 10,000 people to fluoridate their water (in committee upon adjournment); 3) Senate Bill 608 / House Bill 3312, that would have required insurance to cover prescription contraceptives at the same rate as are other prescriptions (in committee upon adjournment) and 4) Senate Bill 965 / House Bill 3659, that implemented a voluntary statewide health risk screening program for all firstborn children in Oregon (passed by the Legislature). Data sources for this research included the public legislative record, four Oregon newspapers (the Oregonian (Portland), the Statesman-Journal (Salem), the Herald (Baker City) and the Mail-Tribune (Medford), and tape-recorded telephone interviews with individuals involved with at least one piece of legislation. Two major and two minor factors were found to be influential in the outcomes of the legislation included in this research. The two major findings supported the existing literature, as major factors influencing outcomes were the issue of personal freedoms (expressed as an individual or local entity's right to self-determination) and the activities of effective political coalitions. Two minor factors influencing outcomes in Oregon also emerged from the research; these were the issues of economics (primarily in the State budget) and precedent (whether or not other, similar legislation or programs already existed in Oregon). The results of this research indicate that effective coalitions are necessary to a successful legislative effort, and that such coalitions operate within a broad social and political context. Future research should consider studying the development and progression of legislative efforts and coalitions prospectively over time to enable access to additional data sources such as radio and television coverage, and to prevent errors related to less-than-perfect recall of past legislation in individuals interviewed. / Graduation date: 2004
148

A study of the policies with regard to postgraduate students in the Oregon high schools

Van Groos, Dorothy 06 1900 (has links)
Graduation date: 1934
149

Influence of cow age/experience and landscape thermal regimes on distribution and grazing patterns of cattle in northeastern Oregon mixed conifer forested rangelands

Wells, Micah 25 August 2003 (has links)
Two studies were conducted to determine the factors influencing distribution of cattle on northeastern Oregon mixed-conifer forested rangelands. The objective of the first study was the quantification of differences in distribution of cattle of different ages. Beginning in 1991, and continuing through 2001, radio telemetry collars were placed on a minimum of 30 cattle per year, prior to turnout. Cattle graze the forest from approximately 15 Jun until 15 Oct each year, and were grouped into four age classes: two and three year old cattle (group 1), four and five year old cattle (group 2), six and seven year old cattle (group 3), and cattle eight years of age and older (group 4). The objective of the second study was to determine differences in landscape thermal regimes between riparian and upland areas. Ambient and "black body" thermal probes were placed in a grid pattern in riparian and upland areas at a height of one meter (mid height of a cow), to encompass the entire pasture. For study 1, all groups of cattle preferred areas with shallow slopes (P<0.05), westerly aspects (P<0.05). All age classes of cattle also preferred areas farther from water than the mean distance to water in the pasture (P<0.05) as well as areas with higher quantities of forage (kg/ha) than the mean value of forage production for the pasture (P<0.05). Cattle in age classes two, three and four selected areas with lower percent canopy closure of trees greater than 12 cm diameter, breast height (dbh), than the mean value for the pasture (P<0.05) Cattle in age class one selected for areas of lower elevation and slightly steeper slopes than cattle in age class four (P<0.05). Cattle in age class two were not affected by slope or elevation in their distribution (P<0.05). Cattle in age class three were not influenced by elevation in their distribution, but selected areas of the pasture with shallower slopes (P<0.05). For the second study, the trial was conducted from 5 Aug to 25 Sep in 2001, and from 15 Jul to 1 Sep in 2002. Year was found to be significant (P<0.0001), therefore results from each year were analyzed separately. Each six week grazing period was divided into three-week intervals, and deemed early and late season for each year. Season was found to be highly significant (P<0.0001), and therefore analyzed separately within each year. Least significant means were utilized to determine differences in temperatures. Differences were considered significant at the P<0.05 level for all analysis. Thermal probes were divided into two types within two areas; ambient and blackball, within riparian and upland areas. Analysis conducted examined the differences between riparian and upland ambient and blackball thermal probes. Area and type of probe were both highly significant (P<0.0001) for all classifications, however, there was not an area by type interaction. / Graduation date: 2004
150

Clonal variation in Russet Norkotah and Umatilla Russet potato varieties

Brunick, Robert L. 15 March 2002 (has links)
These studies compared giant hill strains of Russet Norkotah and Umatilla Russet to the parent varieties. Selections were initially based on late maturity and increased vine vigor. Subsequent evaluations emphasized yield and quality parameters in comparison to the parent varieties. Giant hills were collected from the Columbia Basin and Central Oregon in 1999. Seed was tested and increased in a greenhouse during the winter of 1999 and in the field in 2000. Clones were inspected for viruses and other diseases in both years. Replicated performance trials were conducted at the Hermiston Agricultural Research and Extension Center in the Columbia Basin and at the Central Oregon Agricultural Research Center, near Madras, in 2001. Trials were grown using commercial management practices common to the areas. Tubers from the Madras trial were retained for use in future plantings. Relative yields of Russet Norkotah strains differed drastically between sites even though the growing seasons were similar in length. Several Russet Norkotah strains preformed better than the parent variety at Madras when the strains achieved good vine growth and the parent variety did not. Vine growth was subnormal at Madras in 2001 primarily due to delayed emergence and the subsequent short growing season. Few performance differences and no advantages were evident when Russet Norkotah strains were grown in the Columbia Basin under conditions with less environmental stress than usual. All strains of Umatilla Russet grown under a long season in the Columbia Basin out-yielded the parent variety; however, many strains also produced a high percentage of malformed tubers. In general, Umatilla Russet strains failed to produce adequate yields and tubers of acceptable size when delayed emergence shortened the growing season at Madras. At Madras, strains of Umatilla Russet with high biomass tended to have lower yields while strains of Russet Norkotah with high biomass tended to have high yields. Some strains performed better than the parent varieties at the two trial sites. Superior strains have been submitted to the Oregon Potato Variety Development Program and Oregon Foundation Potato Seed Project for further evaluation. / Graduation date: 2002

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