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1431. [Article] A study of differentials related to renting and owning mobile home sites, Shasta County, California
The purpose of this thesis was to identify and compare the housing costs for two groups of mobile home households. The groups selected were households in mobile homes on individual sites and households ...Citation Citation
- Title:
- A study of differentials related to renting and owning mobile home sites, Shasta County, California
- Author:
- Sandoval, Lou Ann Hawes
The purpose of this thesis was to identify and compare the housing costs for two groups of mobile home households. The groups selected were households in mobile homes on individual sites and households in mobile homes on sites in mobile home parks. Interview schedules designed for collecting data for this study were used to interview 80 randomly selected mobile home households in southwestern Shasta County, California. The data collected identified the characteristics of the mobile home households and the mobile homes, and the economic factors related to the mobile homes and their site locations. The following hypotheses were tested: 1. that there will be no differences in demographic characteristics of mobile home households located on individual and mobile home park sites, 2. that there will be no differences in characteristics of the mobile homes located on individual and on mobile home park sites, and 3. that there will be no difference in housing costs of mobile homes located on individual and on mobile home park sites. All three hypotheses were partially rejected on the basis of the significant differences between those respondents on individual sites and on mobile home park sites. The basis for partially rejecting the first hypothesis was the significant difference in the ages and the income of the respondents on individual and mobile home park sites. The first hypothesis was partially accepted on the basis of the following similarities of the mobile home households on individual sites and mobile home park sites: household size, marital status, occupation, sources of family income, and educational attainment. Other similar characteristics of both groups were no movement of the mobile home during the preceding year, satisfaction with mobile home housing and no plan to live in a site-built home. The second hypothesis was partially rejected on the basis of differences in the statistical averages for the ages of the mobile homes on individual and mobile home park sites, for the differences in types of rooms and their arrangement, difference in types of additional storage facilities, and difference in acquisition of laundry equipment. A significant difference was shown in mobile home lengths for individual and mobile home sites. Partial acceptance of the second hypothesis was based on the similarities of the mobile homes on individual and on mobile home park sites: 11.8 feet wide, 630 square feet of floor space, the acquisition of current household equipment and furnishings other than laundry equipment, use of gas for heating and use of evaporative water cooling. The third hypothesis was partially rejected on the basis of the significant difference in utilities cost for those on individual and mobile home park sites. Differences in the statistical averages for moving costs, for site costs and the purchase of new or used mobile homes for respondents on individual sites and in mobile home parks contributed to this partial rejection. The third hypothesis was partially accepted on the basis of these similarities of the economic factors related to the mobile home and its site location: length of financing period to purchase mobile home, amount of down payment for purchase of mobile home, cash payment for total purchase of mobile home, amount of annual state license fee for the mobile home, and amount paid for annual mobile home insurance. When median housing costs were compared for those on individual sites and those on mobile home park sites, the data revealed that those respondents on individual sites who owned and had fully paid for their site and their mobile home paid monthly housing costs of $54.66, one-fourth of the $195.24 paid by those on individual sites who were financing both their site and home purchases, and one-third of the $154.24 paid by those in mobile home parks who were renting their site and financing their mobile home purchase. Those on individual sites who owned their site but were financing their mobile home purchase paid $10,737, double the total capital outlay of $5,393 paid by those in mobile home parks who were renting their site and financing their mobile home purchase. It was concluded from this study that differences do exist between those mobile home households who locate their mobile home on individual sites and those who locate within a mobile home park. The typical mobile home for this study was six years old, single width, 52 feet long, 630 square feet of floor space, had a separate living room, a kitchen-dining room combination, two bedrooms, and one bathroom and cost $5,774. Added storage facilities for both groups typically included a metal shed.
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1432. [Article] Distribution and life history of the spiny dogfish (Squalus acanthias) off the Oregon and Washington coasts
This study examines the spatial and temporal distribution and life history of the "offshore" component of the Northeastern Pacific spiny dogfish (Squalus acanthias) population. Distribution was examined ...Citation Citation
- Title:
- Distribution and life history of the spiny dogfish (Squalus acanthias) off the Oregon and Washington coasts
- Author:
- Richards, Jaclyn M.
This study examines the spatial and temporal distribution and life history of the "offshore" component of the Northeastern Pacific spiny dogfish (Squalus acanthias) population. Distribution was examined in relation to latitude, depth, the Columbia River plume and large-scale climate changes. Fishery and survey data indicate that the Northeastern Pacific spiny dogfish population has a broad range along the Washington and Oregon coasts, with the highest abundance occurring off the northern Washington and central Oregon coasts. Catches, however, were patchy throughout the 37-year period of available survey data. In terms of depth, the greatest abundances of spiny dogfish were captured in shallow waters (55-184 m). An examination of the influence of the Columbia River plume using a generalized additive model (GAM) indicated that the fish were influenced significantly by the salinity, chlorophyll and surface temperature patterns associated with the plume, preferring the oceanic zone to the plume zone. In contrast, there was no indication that the catch-per-unit-effort of spiny dogfish was influenced by the Pacific Decadal Oscillation (PDO) or the El-Niño (ENSO) over 24-year period of the National Marine Fisheries (NMFS) triennial shelf groundfish survey (1977-2001). The multi-cohort age structure of the population, due to the spiny dogfish's late age at maturity and long lifespan, as well as the low fecundity make it difficult to detect the loss of a single cohort or two when examining abundance trends. Moreover, effects on abundance may be time-lagged, especially if, as is likely, the youngest cohort(s) is the most vulnerable life stage. Their absence would not become evident until they were large enough to have been captured by the survey gear. Sensitive abundance data and/or age-structured data would be needed to identify a pattern. I quantified the age, maturation and fecundity of the spiny dogfish and use these data to develop an age-structured matrix model to examine the sensitivity of the population's growth rate to changes in mortality (i.e. fishing). Female spiny dogfish in this population have an average age at 50% maturity of 28 years and males 20 years. Average length at 50% maturity was 85.0 cm for females and 71.5 cm for males. Female fecundity was extremely low, averaging eight pups per clutch biennially and ranging from four to 14. The number of pups increased with length, but not age. Using these data, a deterministic, female-based model was developed. Asymptotic population growth rate (λ) was determined to be very low, 1.01, and comparable to population growth rates calculated for "coastal" populations. When fishing mortality was incorporated into the model, the fishery was only sustainable when exploitation was low and strict size limits enforced. When fecundity was doubled, the population growth rate increased from 1% to 3% per year. This 33% increase in population growth was equivalent to the effect of a decrease in the age at first maturity of three years. Given that responses to changes in population demographics through shifts in fecundity or spawning frequency are likely constrained, responses would then seem likely to involve changes in age at maturity. These life history traits translate into a low potential population growth and as a consequence high susceptibility to overfishing. My findings indicate that the Northeastern Pacific spiny dogfish are relatively slow growing, late to mature, and have low fecundity and a patchy distribution, with large catches occurring off the northern Washington and central Oregon coasts in shallow waters (55-184 m). These life history traits and distributional patterns are useful in the development of population models to predict responses to environmental fluctuations or increased mortality and thus the management of the population. It is evident from my findings that periodic monitoring is necessary to track possible catch declines off the northern Washington and central Oregon coasts and prevent collapse of the population should it be targeted by a fishery and overfishing occur.
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1433. [Article] Nearshore distribution of barnacle and mussel larvae and oceanographic mechanisms of onshore transport and delivery
Recruitment of larvae from the plankton is an important determinant of community structure in marine systems. In populations of many marine species, recruitment determines the basic demographic parameters ...Citation Citation
- Title:
- Nearshore distribution of barnacle and mussel larvae and oceanographic mechanisms of onshore transport and delivery
- Author:
- Tyburczy, Joe
Recruitment of larvae from the plankton is an important determinant of community structure in marine systems. In populations of many marine species, recruitment determines the basic demographic parameters of immigration, emigration, and reproduction. Moreover, the effect of recruitment as an "ecological subsidy" can determine the strength of interactions among species and whether populations are limited by recruitment itself, or by competition or predation. For this reason, understanding the transport of larvae is essential for management and conservation. In Chapter 2, my coauthors and I investigated the vertical and cross-shelf distribution of barnacle and bivalve larvae with a series of paired day/night sampling cruises off the coast of central Chile. Barnacle larvae were generally found close to shore (within 1.5 km), and the cross-shelf distribution of all taxa varied little despite contrasting upwelling conditions. Since current velocities decrease quickly with proximity to shore, larvae distributed in the nearshore are less likely to be dispersed long distances. Further, the consistent cross-shelf distribution of larvae suggests that they are not necessarily swept on- or offshore by upwelling or relaxation. Depth distributions consistent with classical diel vertical migration (DVM; swimming deeper during the day, shallower at night) were found in barnacle nauplii, but not barnacle cyprids or in bivalve larvae. One potential advantage of DVM is that it may limit offshore transport and thereby increase the odds that larvae will reach suitable habitat when they are competent to settle. Another possible benefit of DVM is that it may increase feeding opportunity in shallow water at night when visual predation risk is low, while providing refuge at depth during the day when visual predation in the upper water column is greater. In Chapter 3, my coauthors and I undertook a large-scale study in northern Monterey Bay, CA that integrated high-frequency physical and biological sampling to allow resolution of multiple different potential mechanisms of onshore larval transport and settlement. Depending on location within Monterey Bay, three processes were found to be associated with onshore barnacle settlement: regional upwelling, local diurnal upwelling driven by afternoon sea breezes, and the passage of an upwelling shadow front. Based on these findings we propose a novel conceptual model that encompasses oceanographic processes at multiple scales and reconciles apparent inconsistencies between empirical results and existing theories. In Chaper 4, my coauthors and I developed a simple larval transport model using data on currents, offshore flux of barnacle larvae, and onshore settlement of barnacles from the empirical study in Chapter 3. A parameter set was found that produced model settlement correlated with observed settlement. The fit of modeled and observed settlement was sensitive to model parameters. However, for all parameter sets examined, onshore transport of particles was much greater at depth. This result from the larval transport model is consistent with the conceptual model proposed in Chapter 3. Further, during intervals when onshore transport was observed, model particle trajectories clearly show onshore transport only at depth via two of the mechanisms identified in Chapter 3 (local diurnal upwelling and passage of the upwelling shadow front).
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1434. [Article] Identification of young homemakers' management problems related to resource limitations
This study was designed to identify young homemakers' management problems and to see if limitations of selected resources caused problems. Sources used for current homemaking information were also explored. The ...Citation Citation
- Title:
- Identification of young homemakers' management problems related to resource limitations
- Author:
- Koza, Mary Speckhart
This study was designed to identify young homemakers' management problems and to see if limitations of selected resources caused problems. Sources used for current homemaking information were also explored. The sample was composed of 50 married homemakers, age 30 or under, who were living with their husbands. Homemakers were randomly selected from a newsletter mailing list. Thirty of the homemakers were classified as full-time homemakers. Twelve were employed full-time and six on a part-time basis. Only two were currently enrolled as students taking credit courses. Their average age was 26 years and they had completed a mean of 14 years of education. All but seven had families ranging from one to four children. The family mean income was $10,500. All 17 tasks studied were carried out most often on a regular or sometimes basis by the homemakers. Tasks included: meal preparation, dishwashing, packing lunches, special food preparation, food preservation, regular house care, special house care, upkeep of the home, washing, ironing, sewing and mending, physical care of adults, physical care of children, financial planning, record keeping, marketing for food and marketing for clothing. Homemakers rated tasks on a scale ranging from very simple to very complex. Upkeep of the home was listed as most complex while dishwashing was named the least complex task. Hypothesis 1. Hypothesis 1, management problems of young homemakers will not differ with respect to: length of marriage, age, type of housing, place of residence, homemakers' education, homemakers' occupation, composition of family and income, was accepted since there was no indication of relationship at the 0.10 level of signficance between management problems expressed and the demographic variables. If tasks were complex, homemakers were asked if one or more of six resource limitations including: money, time, knowledge, equipment, energy or space caused the complexity. Chi-square tests indicated that resources were unevenly distributed among the tasks. Limitations causing the most difficulty were time followed by money and knowledge. Resource limitations were unevenly distributed for special food preparation, financial planning, record keeping, marketing for food, marketing for clothing and special house care at the 0.005 significance level. Limitations were unevenly distributed at the 0.01 signficance level for ironing, the 0.05 significance level for food preservation and 0.10 significance level for upkeep of the home. Hypothesis Z. Hypothesis 2, there will be no relationship between the expressed problem areas and the limitations of resources of time, money, knowledge, equipment, energy or space, was rejected for the tasks mentioned above due to the uneven distribution at the stated signficance levels. The task enjoyed most by homemakers was physical care of children even though it took the most time. Dishwashing was least enjoyed, while ironing and packing lunches were least time consuming. The most energy was spent on special house care while washing took the least amount. Sixty-two percent of the homemakers followed daily routines while three-fourths of the homemakers made spending plans regularly. Sixty-eight percent had monetary resources to cover expenditures on a regular basis. Appliances available to all homemakers included a refrigerator or refrigerator-freezer, range and vacuum cleaner. Two-thirds of the families owned or were buying their homes. Twenty-eight felt they could use additional living space. Of these 28, 17 specified the need for at least one additional bedroom. All homemakers received current homemaking information from the Oregon State University Cooperative Extension Service Young Homemaker Newsletter. They requested additional information on community resources, use of personal energy, time, money, household space and equipment via, the newsletter. The majority of homemakers were managing the tasks and resources discussed in this study effectively in terms of the homemakers' satisfactions. The homemakers appeared to place a high value on their dual roles as wife and mother and were willing to try new ideas to enhance their roles.
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1435. [Article] A comparative analysis of factors influencing smoking behaviors of college students, 1963-1987
Cigarette smoking continues to be one of the country's major health concerns. It has been defined as the single largest preventable cause of disease and death in the United States. Although research has ...Citation Citation
- Title:
- A comparative analysis of factors influencing smoking behaviors of college students, 1963-1987
- Author:
- Gray, Nancy L.
Cigarette smoking continues to be one of the country's major health concerns. It has been defined as the single largest preventable cause of disease and death in the United States. Although research has indicated that overall cigarette consumption has decreased in the nation over the past decades, cigarette smoking remains a significant problem among young people in the United States. This fact, coupled with studies indicating that cigarette smoking increases with age into the early twenties suggests that research should be conducted to determine those variables that encourage smoking behavior of late adolescents and young adults. The purpose of the study was to compare the relationship between selected predisposing factors and subsequent smoking behaviors exhibited in 1963 and 1987 respectively. Assessments of smoking behaviors of college students in Oregon in 1963-64 and 1986-87 were conducted to determine relationships between students smoking behaviors and selected socio-demographic variables. Comparisons were made between the resulting data for students in the 1963-64and 1986-87 studies. Aquestionnaire relating to smoking behavior was developed and administered to 3,786 college students attending introductory personal health classes during the 1963-64 school year at four selected colleges in the state of Oregon. During the 1986-87 school year a modified version of the questionnaire was developed and administered to college students attending introductory personal health classes at three of the same four universities that were utilized in the 1963-64 study. Stepwise logistic regression, chi square and descriptive statistics were used to analyze the data. Results indicated that there were significantly more smokers in 1963-64 and their daily consumption rates were significantly higher when compared to 1986-87 data. Although a larger percentage of females were smokers in the total population surveyed in 1963-64, there were more female smokers in the population of smokers in 1986-87. Whereas males consumed significantly more cigarettes per day than did females in 1963-64, there was no significant difference between male and female consumption rates in 1986-87. Significant numbers of smokers in 1986-87 started smoking at an earlier age than did smokers in 1963-64. When separating by gender, this was significant for females but not for males. Peer smoking was listed as the number one reason for starting to smoke by more than half of the respondents in 1986-87 as compared to 40% who listed curiosity in 1963-64. Physical reasons were indicated as the main reason for quitting by ex-smokers in 1963-64 and in 1986-87, over one half of the respondents indicated that they quit because of a concern for their physical health. Stepwise logistic regression equations were used to determine the set of variables that best accounted for smoking status in 1963-64 and 1986-87. Results indicated that the variables which predisposed individuals toward subsequent smoking behavior did differ when comparing the two studies. In 1963-64, an individual with the highest probability of smoking was one who had one or more older sisters who smoked, both parents smoked, father was a high school non-graduate and was from an urban setting. The individual with the lowest probability of smoking in 1963-64 had no older sisters who smoked, mother and father did not smoke, father was a high school graduate and lived in a rural setting. In 1986-87, the only variable to significantly increase the probability of an individual smoking was one or more older brothers who smoked. The following data were collected only for the 1986-87 population of students because questions relating to these issues were not included on the 1963-64 questionnaire. Use of alcohol, marijuana and smokeless tobacco by cigarette smokers was not significantly different when compared to non-smokers. Illicit substance use (cocaine, crack, heroin, quaaludes, etc) was significantly different for cigarette smokers and non-smokers. Smokers were more likely to use illicit substances than were non-smokers. The largest number of smokeless tobacco users were males in the 18-19 age category. Use of alcohol, marijuana and other illicit substances were significantly different for smokeless tobacco users than for non-users. Smokeless tobacco users were more likely to consume more alcohol on a weekly basis and use marijuana and illicit substances on an occasional and regular basis than were non-users of smokeless tobacco.
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1436. [Article] A National Five-Year Exploratory and Descriptive Analysis of Two-Year Public College Graduation Rates at Branch Compared to Non-Branch Campuses
Branch campuses play an important part in postsecondary degree attainment by providing place-bound students from diverse socioeconomic backgrounds in different geographical regions access to education ...Citation Citation
- Title:
- A National Five-Year Exploratory and Descriptive Analysis of Two-Year Public College Graduation Rates at Branch Compared to Non-Branch Campuses
- Author:
- Harrison, Faimous J.L.
Branch campuses play an important part in postsecondary degree attainment by providing place-bound students from diverse socioeconomic backgrounds in different geographical regions access to education that is convenient. Their heterogeneousness structures, including enrollment size, communities, and populations served, are not accurately reflected in the majority of the research. Currently, there is minimal performance assessment research for branch campuses. Only a small percentage of the institutions report their individual survey results to the Integrated Postsecondary Education Data System (IPEDS) separately, or to other reporting agencies. The limited research available does not provide educators, researchers, policymakers, and community stakeholders the opportunity to assess performance, or make the most appropriate data-driven decisions. The purpose of this study was to determine if there is a relationship between two-year public college graduation rates at branch compared to non-branch campuses. Also, to determine if institutional size, geographic region, or student gender have an effect. This quantitative five-year exploratory and descriptive analysis were conducted utilizing the Statistical Package for the Social Sciences (SPSS) of an IPEDS dataset from the academic reporting periods that include 2008-2012. There were 1052 institutions that represented 5171 schools over the five years. Graduation rates were calculated at three years, 150% of normal time to graduate from a two-year college. The statistical procedures included a crosstabulation tested at the .05 level of significance. The contingency tables provided a platform to display the patterns of the relationship between the categorical data in a meaningful way. The P-values were set at 0.01 level of significance to control for Type 1 errors. The tests rejected the null hypothesis. A second chi-square test for homogeneity between the observed and expected frequencies of the variables was conducted. The graduations rates classified by school and enrollment size demonstrated greater success among the branch compared to the non-branch campus when the enrollment numbers were equal to or lower than 10,000 students. However, if the school had more than 10,000 students, the non-branch campus graduation rates were higher. The graduation rates classified by the school and geographic region demonstrated that Midwest branch campuses outperformed all campuses in every region. Furthermore, the results of the graduation rates classified by schools and gender of student showed that a male was more likely to graduate at a branch campus than a female. Whereas a female was more likely to graduate at non-branch campus than a male. The findings suggest there is a relationship between two-year public college graduation rates at branch compared to non-branch campuses. Additionally, institutional size, geographic region, and student gender did have an effect. Given the pervasive nature of performance outcomes in higher education, including graduation rates, time-to-degree completion, transparency, accountability, and the increasing demand for persistence, retention, and attainment, the results demonstrates the need for additional branch campus research to expand upon this study. This study advocates for mandatory, accurate, and transparent reporting of branch campus data separately to IPEDS and other reporting agencies. (Contains 166 references).
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1437. [Article] An analysis of ecological indices and leisure participation with selected dimensions of self-concept among the elderly
The primary focus of this investigation was to assess whether or not selected ecological indices and leisure preferences demonstrated statistically significant relationships with the aged's self-concept. Gerontology, ...Citation Citation
- Title:
- An analysis of ecological indices and leisure participation with selected dimensions of self-concept among the elderly
- Author:
- Guadagnolo, Frank Bernard, 1940-
The primary focus of this investigation was to assess whether or not selected ecological indices and leisure preferences demonstrated statistically significant relationships with the aged's self-concept. Gerontology, a relatively embryonic discipline, has only recently begun to examine the impact of demographic, physical and socio-psychological stresses upon the geron's self-concept. Even less attention has been given to exploring the potential of the elderly's leisure patterns towards the reduction, maintenance or enhancement of self-concept. It was this sparsity of; evidence that served as the impetus for this present investigation. Subjects for this study involved both men and women who were members of Little House, a senior citizen activity center located in Menlo Park, California. Among the members randomly selected, a total of 112 senior citizens completed all test instruments. A profile of the sample clearly suggests that the homogeneity of the sample neutralizes certain extraneous variables, while, at the same time, reducing any possible generalizations from the findings. The data were collected through the administration of two test instruments: the Ecological Indices Leisure Participation questionnaire (EILP), specifically developed for this study and the Tennessee Self Concept Scale (TSCS). Through the use of the EILP, a composite of several instruments, data were gathered on ecological indices currently considered as possible influences upon levels of selfconcept. The administration of the TSCS--a 100 item, self-descriptive instrument--served to establish a profile of the selected dimensions of self-concept. For purposes of this study, the dimensions of self-concept were limited to the instrument's major external references of Physical Self, Moral-Ethical Self, Personal Self, Family Self, Social Self, Total Self and Self Criticism. Using multiple regression analysis and t-tests as the primary statistical models, it was possible to establish a regression model for each of the seven dimensions of self-concept. In addition, statistical comparisons were made among members displaying contrasting leisure patterns. A total of 11 factors, measured by the EILP, were statistically significant (.05) in explaining increased or decreased mean scores on the seven TSCS scales. Perceived health, income, confinement to bed, frequency of visits with neighbors and relatives and the member's activity level at Little House each appeared in two or more of the final regression models. Other significant variables, appearing less frequently, were: age, marital status, employment status of the respondent's spouse and involvement in community activities. Upon examining the contrasting leisure patterns of subjects, only one factor exceeded the .05 confidence level. Specifically, new members of one year or less demonstrated significantly higher mean scores on Personal Self than their long-term counterparts of six years or more. Although the remaining comparisonsintensity of participation, contrasting activity areas and breadth of involvement--did not exceed the predetermined confidence levels, certain trends were noted. For example, subjects engaged in community or social activities consistently reflected higher mean scores when compared to the total sample population. Short-term members also accounted for higher TSCS mean scores when compared to the long-term members. In terms of intensity of activity, the more active Little House members displayed higher levels of self-concept than the less active member who attended Little House an average of less than one hour per week. Finally, the frequency distributions of several significant ecological indices, identified through regression analysis, were significantly different among groups displaying different leisure patterns. That is, higher TSCS means occurred among several groups even though their profiles suggested a reduced level of self-concept. Thus, controls for such influences, through the use of selective sampling procedures and larger sample populations, would allow for a more accurate appraisal of the relationship between the elderly's leisure preferences and patterns and his self-concept.
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1438. [Article] Exploring the Validity and Genetic Basis of Frailty
Frailty is a clinical syndrome characterized by decreased resilience to stressors, resulting from dysregulation across multiple physiological systems. Frailty is prevalent in elders and is associated with ...Citation Citation
- Title:
- Exploring the Validity and Genetic Basis of Frailty
- Author:
- Wu, Chenkai
Frailty is a clinical syndrome characterized by decreased resilience to stressors, resulting from dysregulation across multiple physiological systems. Frailty is prevalent in elders and is associated with a wide range of adverse outcomes including death, disability, hip fracture, and falls. In the absence of a gold standard, there is a lack of consensus on the operational definition of frailty. Fried and colleagues developed the physical frailty phenotype (PFP) scale using gait speed, grip strength, exhaustion, physical activity, and weight loss. Since its emergence, the PFP scale has been repeatedly validated and widely used in assessing frailty. The PFP scale, however, like all other frailty assessments, has limitations. First, precision is lost in the process of dichotomizing continuous indicators (e.g., gait speed). In addition, all five frailty indicators in the PFP scale are assumed to be of equal importance in measuring frailty. Moreover, the PFP scale is very effective in identifying the frailest elders but has limited ability to differentiate persons with low levels of frailty. This dissertation had two overarching goals. The first was to create a new continuous scale for assessing frailty and to comprehensively evaluate its construct and predictive validity as well as measurement properties. The second was to explore the genetic basis of frailty. First, I demonstrated the feasibility to construct a continuous frailty scale that had high construct validity and desirable measurement properties. Second, I showed that the new continuous frailty scale had high predictive validity for adverse health outcomes including mortality, disability, hip fracture, and falls among older adults. Third, the new scale could provide additional risk stratification for adverse outcomes above and beyond the categorical PFP scale, especially at the lower to middle end of the frailty continuum. Fourth, the new frailty scale was strongly associated with recovery of and improvement in activities of daily living function among elders who were newly disabled. Fifth, older persons with higher scores on the new frailty scale were more likely to have prolonged length of hospital stay after undergoing myocardial infarction and coronary artery bypass grafting. Additionally, frailer elders had higher mortality after experiencing myocardial infarction, heart failure, pneumonia, and coronary artery bypass grafting. Lastly, several genetic variants that have biological plausibility were suggestively associated with frailty. From a methodological perspective, the new continuous frailty scale frailty is a valid continuous construct with a unidimensional factor structure robust to nuanced differences in measurements and invariant across cohorts and demographics including age and sex. In addition, the new frailty scale has high predictive validity for multiple health outcomes including death, disability, hip fracture, and falls among community-dwelling older adults. Moreover, the new frailty scale could capture elders’ ability to recover from stressors (disability, medical events, and surgeries), which is considered one of the defining features of frailty. Findings from this dissertation could also have important public health and clinical implications. First, the new continuous frailty scale could further stratify risk of outcomes among robust and prefrail persons, suggesting these two subgroups were not homogeneous. Second, the new frailty scale was able to pinpoint frailty level in the early stage, which may be valuable for identifying at-risk persons who are not frail yet and offers opportunities for interventions that prevent or slow down the progression of frailty and maintain health and function. Third, assessment of frailty may help clinicians, public health professionals, and researchers better identify at-risk elders after experiencing disability and acute diseases and provide useful information in making informed decisions about surgical procedures. Fourth, the new continuous frailty scale, due to its continuous and sensitive nature, may be suitable to evaluate the effectiveness of interventions for frailty and track trajectories of frailty over time.
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1439. [Article] The influence of social structure and molecular evolution on genetic diversity in the sperm whale (Physeter macrocephalus)
The sperm whale (Physeter macrocephalus) shows some of the most derived characteristics of any mammal: a large body size, large brain, complex social organization and a capacity for deep foraging dives ...Citation Citation
- Title:
- The influence of social structure and molecular evolution on genetic diversity in the sperm whale (Physeter macrocephalus)
- Author:
- Alexander, Alana
The sperm whale (Physeter macrocephalus) shows some of the most derived characteristics of any mammal: a large body size, large brain, complex social organization and a capacity for deep foraging dives that few other marine mammals can match. Despite a history of exploitation that removed hundreds of thousands of individuals, the sperm whale population remains relatively abundant in comparison with other large whale species. Given this abundance, and the sperm whale's matrifocal social organization, it is surprising that previous research found that mitochondrial DNA control region (mtDNA CR) diversity in sperm whales is extremely low and population structure is relatively limited within oceans. This dissertation addresses several questions spanning evolutionary and ecological time scales, including whether the low levels of mtDNA CR diversity and differentiation seen in the sperm whale have been limited by sample size and geographic scope in previous studies; how sperm whale genetic diversity is partitioned at several hierarchical levels; and hypotheses explaining the low mtDNA CR diversity. To achieve this, I generated DNA profiles representing 557 individuals from circum-equatorial regions, strandings around the coasts of New Zealand, Samoa and Oregon, and biopsy samples from the Gulf of Mexico. DNA genotypes constructed from these samples (mtDNA CR, sex, 13 microsatellite loci), and mtDNA information from 1,167 previously published samples, indicated a high degree of mtDNA CR differentiation within the previously un-sampled Indian Ocean (FST 0.314, p < 0.001). The level of differentiation seen was similar to that found with the marginal seas of the Atlantic i.e. the Gulf of Mexico and the Mediterranean (FST 0.469, p < 0.001). In contrast, levels of mtDNA differentiation seen in the Pacific were much lower (FST 0.061, p < 0.001). Microsatellite differentiation was much less marked for all three oceans, consistent with tests indicating male-biased dispersal and gene flow. In addition to regional differentiation, significant differentiation was seen among social groups. However, the magnitude of this differentiation differed by ocean. Hierarchical mtDNA analyses showed that in the Pacific, 'social group' explained more variance than geographic region. In contrast, in the Indian Ocean, regions explained more variance than social group. In the Atlantic, the number of social groups within regions was too limited to make conclusions. Social group was the only level that explained significant variation in microsatellite allele frequencies in any ocean. Increased relatedness within social groups does not appear to explain the microsatellite differentiation. Instead, the likely explanation is different breeding males consorting with different female-dominated social groups. mtDNA differentiation seen among social groups appears to be driven by ‘lenient matrilineality', where 38% of groups were strictly matrilineal, and a further 25% of groups were comprised of more than one matriline, but fewer matrilines than expected by chance. However, the levels of matrilineality are too low to be consistent with the previously proposed hypothesis of a selective sweep linked with maternal cultural innovations as an explanation for low mtDNA diversity in the sperm whale. To examine alternative hypotheses for low mtDNA diversity, next-generation sequencing (454 and Illumina) was used to sequence mitogenomes for 17 Pacific Ocean sperm whale samples, with other cetacean mitogenomes compiled from the literature. Using these mitogenomes, no evidence of slow substitution rates were found in the mtDNA CR or protein-coding genes of the mitogenome that could explain the low diversity. In addition, the mtDNA CR had the highest diversity of the entire mitogenome and showed genealogical patterns concordant with the rest of the mitogenome. This discounts mtDNA CR-specific constraints as the cause of low mtDNA CR diversity. To investigate the remaining hypotheses of a selective sweep, population bottleneck or expansion, 8 nuclear loci (~12,000 bp) were sequenced for 22 sperm whales (Pacific and Gulf of Mexico), and compared to 10 New Zealand pygmy sperm whales (Kogia breviceps). The results were inconsistent with a selective sweep and showed instead low diversity across both mtDNA and nuclear DNA, in comparison to the higher levels of genetic diversity in the pygmy sperm whale and other cetacean species. Demographic reconstructions showed the sperm whale to have had a stable, but small, population size for much of historical time. This suggests a recent population expansion is responsible for the low mtDNA (and nuclear DNA) diversity in the sperm whale. The inferred timing of the expansion corresponds with expansions in squid species (the primary prey of the sperm whale), and explains shared mtDNA haplotypes between oceans. Since this expansion, the marked philopatry shown by female sperm whales at various hierarchical levels ranging from social groups (e.g. lenient matrilineality) to broader geographic scales, has led to maternally-mediated genetic drift driving striking differences in mtDNA haplotype frequencies between social groups, regions, and oceans.
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The American Counseling Association's Code of Ethics states that counselors and counselor trainees must be competent providers of multicultural counseling, able to practice effectively with clients whose ...
Citation Citation
- Title:
- The Relationship Between Sexual Orientation Identity and Specific Health Behaviors
- Author:
- Muzacz, Arien K.
The American Counseling Association's Code of Ethics states that counselors and counselor trainees must be competent providers of multicultural counseling, able to practice effectively with clients whose identities differ from their own. Counseling students and trainees receive very little training around sexual orientation and how to work with clients who identify as members of a sexual minority group (i.e., LGB; lesbian, gay or bisexual). Counselors, counselor educators and pre-service counselors are also asked to seek out current, relevant research to provide a basis for the interventions and treatment offered to clients. Recent literature in public health has identified health disparities among individuals who identify as, or are identified as, sexual minorities. Higher rates of psychiatric disorders, substance use, heart disease, tobacco use, and obesity have been found in LGB samples as compared to heterosexual samples. However, existing articles are limited by: (a) sampling issues, including small sample sizes, (b) an overall lack of racial and ethnic diversity, and (c) the conflation of sexual behavior with identity. Additionally, counselors and counselor educators have not researched these differences in health behaviors and conditions. In the current study, the prevalence of harmful or potentially hazardous alcohol use and drug use among patients who self-identified as gay, lesbian, bisexual and heterosexual was compared in a diverse sample of patients visiting New York City STD clinics. Levels of alcohol and drug use were compared by sexual orientation identity using nonparametric analyses. Results showed that patients who identified as LGB reported higher rates of potentially harmful drug and alcohol use than patients who identified as heterosexual. Next, data collected from patients visiting New York City STD clinics for a physician visit were examined using binary logistic regression analyses. The aim of this study was to determine whether a relationship exists between sexual orientation identity and likelihood of diagnosis with a sexually transmitted infection (STI). In addition, known demographic and behavioral predictor variables were included in this regression analysis as covariates (i.e., race, ethnicity, age, gender identity, alcohol use, drug use, same-sex sexual behavior). Results showed that a relationship does exist between sexual orientation identity and likelihood of STI diagnosis, such that identifying as LGB increases an individual's odds of receiving a STI diagnosis. This predictor variable was found to increase the likelihood of diagnosis along with covariates including Black/African American racial identity, Hispanic ethnicity, same-sex sexual behavior, and drug use. Covariates that decreased the odds of STI diagnosis included female gender identity, transgender identity, and older age. The primary implication that emerged from the aforementioned research was that individuals who identify as sexual minorities (i.e., as LGB) have different relationships to health behaviors than individuals who identify as heterosexual. Therefore, LGB individuals should be given an opportunity to self-identify their sexual orientation upon intake and screened for quantity and frequency of substance use so that counselors can be aware of the individual’s risk of developing a substance use disorder. Individuals should also be asked discrete questions about sexual orientation identity as well as attraction and behavior, so that individuals who identify as LGB can be engaged in open discussion about sexual behaviors and safer sex practices as necessary, and not assumed to be engaging in behavior that places them at risk for STIs. More qualitative research is needed to determine why some LGB individuals engage in hazardous levels of alcohol and drug use while others do not, and to explore the relationship between LGB identity and engagement in sexual risk behaviors.