Biological mechanisms of depression in chronic disease

Cross, Rebecca Lee University of California, Los Angeles 2007 해외박사(DDOD)

Depression is a common co-morbid condition among the medically ill, the incidence of which is particularly high among those with obstructive sleep apnea (OSA) and heart failure (HF). In many instances, the presence of depression can lead to an increase in morbidity and mortality when compared to those who are non-depressed. However, despite the high incidence of depression in common disorders such as OSA and HF, and the potential for poor outcomes, the biology of depression in these populations is poorly understood. Thus the purpose of this dissertation was to investigate biological mechanisms of depression in both OSA and HF patients. The dissertation is broken up into three manuscripts. The first manuscript reviews the literature on the state of the science regarding OSA and depression, and OSA and neuroimaging. A model in which neural injury caused by OSA may be in part related to depression is proposed. The second paper is a cross-sectional study in which we use structural brain magnetic resonance imaging to compare 40 OSA and 61 control subjects with and without depressive symptoms. Neural injury in OSA patients with depressive symptoms compared to OSA and control subjects without depressive symptoms emerged in a number of brain regions, including the mid- and anterior cingulate, insula, hippocampus, medial pre-frontal, parietal, and left ventrolateral temporal cortices, caudate, internal capsule, anterior thalamus, and medial pons. These findings suggest depressive symptoms may exacerbate injury accompanying OSA, or introduce additional neural damage. The third manuscript explores the relationships between inflammation, depressive symptoms, and HF in a group of 29 HF patients and 43 controls. Here we find that the presence of both depressive symptoms and HF is independently associated with elevations in three proinflammatory markers, soluble intercellular adhesion molecule(sICAM)-1, interleukin(IL)-6, and tumor necrosis factor-alpha. The elevations of these biomarkers in HF patients with depressive symptoms may be contributing to the increase in morbidity and mortality observed in this population. These manuscripts offer new knowledge regarding the contribution of depressive symptoms to the neural injury observed in OSA, and that sICAM-1 and IL-6 may have a role in depression and HF.

A measurement of the total photon-proton cross section at ZEUS

Cross, Richard Nelson The University of Wisconsin - Madison 2001 해외박사(DDOD)

The total photon-proton cross section has been measured for the photon-proton center-of-mass energy of 207 Gigaelectron volts in positron-proton collisions observed by the ZEUS detector at HERA. The data was taken in a dedicated, systematics-controlled run during 1996. The measured total cross section is 163 plus or minus 1 (statistical) plus 13 minus 12 (systematic) microbarns.

in elastic neutrino-nuclei scatterings

류웅렬 (The)cross section 高麗大學校 1990 국내석사

Essays in incomplete agricultural markets

Cross, Robin M Oregon State University 2005 해외박사(DDOD)

Agricultural revenues, the product of stochastic prices and yields, lead to markets which are incomplete, thereby entreating and complicating economic inquiry. The following three essays explore the incomplete nature of agricultural markets and consider the implications of incompleteness for a range of policy questions and economic tools. The first essay, "Cooperative Pricing Policy Under Stress: The Case of Tri Valley Growers," explores the incomplete contract markets that arise from unobservable yield processes. I formalize a common class of forward contracts, decompose them into a convex combination of yield derivatives, then derive the arbitrage-free forward price bounds. These bounds are used to show how the Board of Directors of a large agricultural cooperative, Tri Valley Growers, overstated earnings in order to liquidate financial equity. The second essay, "Adapting Cooperative Structure for the New Global Environment," follows up on the first by showing that the liquidating strategy Tri Valley's Board pursued was rational in terms of maximizing expected net present value of future cash flows. I derive a condition under which optimal equity retention is strictly greater for investor-owned than for cooperatively owned firms. Finally, I use ruin probabilities associated with the standard first-crossing-time problem, together with numerical integration methods, to verify that this condition held under the market conditions in which Tri Valley and its investor-owned rivals operated. The third essay, "DEA and The Law of One Price," explores the effect of variable prices on technical efficiency estimation. Data commonly are furnished in value, rather than factor terms. This raises the question of how value-based DEA models coincide with factor-based models. A sufficient condition for the two models to coincide is that all firms face the same set of prices. In practice, however, prices commonly vary across firms. I show that, unless an unreasonable restriction holds, the two models do not coincide. I decompose the resulting estimation error into its technology and firm-related components. Using Farrell's original 1957 data set to illustrate, the resulting estimation error is found to be both systematic and one-sided.

Studies in the semantics of modality : Cross, Charles Byron

Cross, Charles Byron 1985 국내박사

The influence of television and family on children's leisure time reading

Hornby, Melinda Cross U.M.I. 1989 해외석사

The impact of college and university faculty collective bargaining on state appropriations to public higher education

Cross, Jeffrey Franklin University of Illinois at Urbana-Champaign 2004 해외박사(DDOD)

Many public college and university faculties have unionized since public employees gained the right to bargain collectively in several states. Most studies of the effects of faculty unionization have been at the institutional level and have included faculty compensation, workload, and other conditions of employment. Although results of these studies are mixed, unionized faculties at four-year institutions experience greater compensation increases in their early years of collective bargaining, but this early advantage subsequently tails off until there is no difference from nonunion counterparts. Conversely, nonunion faculties at two-year institutions experience greater compensation increases compared to union faculties. Few studies have investigated faculty unionization and institutional income in general or state allocations to public universities in particular. Increased institutional revenues are needed for faculty unions to successfully negotiate increases in compensation, and the largest source of current funds revenue for public colleges and universities is state appropriations. An analysis of the percentage changes in state higher education appropriations from 1990 through 1999 in the 50 states suggests that changes in state economic environment are more correlated with increased appropriations to public higher education than is faculty unionization. Results are presented for public higher education taken as whole and for both four-year and two year institutions. For all public higher education throughout the decade and for four-year public institutions during a portion of the decade characterized by stagnant or receding state economies, faculty unionization was negatively correlated with changes in state appropriations. The correlation was significant, but weak, and contrary to the premise of the study. Whether state higher education governance was centralized or decentralized was not correlated with changes in appropriations during any portion of the study period.

Redefining relationships: Non-marriage-based cohabitations among low-income urban mothers

Cross-Barnet, Caitlin The Johns Hopkins University 2010 해외박사(DDOD)

Cohabitation has become increasingly common, and dynamic societal changes have led to increasing variations within cohabitations. Although usually viewed as a precursor to, trial of, or alternative to marriage, cohabiting relationships, especially among the poor, may be driven by economic or parenting needs only loosely related to aspects of marriage such as stability, personal fulfillment, and romance. I argue that it may be better to view unstable, need-based cohabitations as distinct relationships not necessarily related to marriage. This dissertation uses longitudinal ethnographic data from the Three-City Study, a multi-method project studying post-welfare-reform lives of low-income mothers in Boston, Chicago, and San Antonio. Using methods based in grounded theory, I identified 60 African American, white and Latina mothers engaging in non-marriage-based cohabitations. Analyzing 812 interviews, I identified 5 areas that impacted mothers' cohabitation decisions: economics, relationships with men, social structures and networks, parenting, and cultural contexts. Rather than deriving long-term utility though exchanges within stable relationships, mothers practiced rotating utility, using resources including months of TANF eligibility, employment, family and social resources, and men. Mothers rotated among these resources depending on their current needs. In rotating men through their lives, mothers engaged in serial cohabitations (living with a series of men); intermittent cohabitations (living on-and-off with the same man); and living together apart cohabitations (LTAs), in which they lived with the father of their child(ren) but did consider the cohabitation a relationship. Men were useful when they provided income, childcare and household help, a sense of safety, or a male role model. However, their frequent criminal justice problems, spotty employment, and propensity for domestic abuse made them unacceptable long-term partners. Mothers could not find jobs that allowed them a reliable income or upward mobility, and TANF was time-limited. Mothers thus had to rotate among resources for survival. Despite problems with men, mothers found it difficult to permanently sever ties with children's fathers and frequently rotated them in and out of the household. Unstable cohabitations emphasized the primacy of parenting ties over partner ties, as couples remained "bound by children" even if they no longer wished to have a relationship.

Perceptions of family held by older adolescents in non-relative foster care placement

Cross, Sharon Danine Virginia Commonwealth University 2005 해외박사(DDOD)

This qualitative study provides information about older adolescents in foster care and their perceptions of family and expands the literature on this sub-population of foster care recipients. Twenty-two female and male youth (ages 15-20) participated in four focus groups; they were asked about their views and perceptions of family while they were still in care. All but one of the youth was residing in group home care at the time of the study. The participants in the study were two-thirds female, predominantly youth of color, and had been in foster care for at least two and a half years at the time of the interview. The focus groups were audio taped and field notes were taken to capture nonverbal expressions. Data analysis was conducted using constant comparison methods and several themes emerged from the data. Participants in this study fell into two main categories, trusting and mistrustful adolescents. Those who were trusting of others reported positive perceptions of family, were able to connect with others with whom they lived, allowed themselves to be more vulnerable, displayed feelings of caring and gratitude, and considered biologically-related and non-biological persons as family. The mistrustful adolescents reported negative perceptions of family, had difficulty connecting to and being more vulnerable with others with whom they lived, displayed feelings of anger towards others, and considered only biologically-related persons as family. Future research on foster care adolescents' perceptions of family must be aware of the difficulty with recruitment. It is important to be respectful of the youth and include appropriate incentives. Social work educators instruct and train future child welfare workers, and may assist in developing perceptions that social work students may have of this population. It is important for social workers in the field to have knowledge of adolescents in foster care, since social workers may encounter the youth in various social work arenas.

Early marine growth and consumption demand of juvenile pink salmon in Prince William Sound and the northern coastal Gulf of Alaska

Cross, Alison Danielle University of Washington 2006 해외박사(DDOD)

Although early marine growth has repeatedly been correlated with overall survival for Pacific salmon (Oncorhynchus spp.), we currently lack a mechanistic understanding of the timing, magnitude, and source of stage-specific mortality periods. Pink salmon (O. gorbuscha) are a key plankton consumer in Prince William Sound and the Gulf of Alaska, and hatchery production significantly increases their abundance in this region. This study combined within-season back-calculations of growth and bioenergetics techniques to examine interannual variability in the growth performance and consumption demand of the average hatchery, average wild, and surviving hatchery juvenile pink salmon during the first summer at sea in Prince William Sound and the northern coastal Gulf of Alaska among years corresponding to low marine survival (3% in 2001 and 2003) and high marine survival (9% in 2002, 8% in 2004). Juvenile pink salmon were consistently larger throughout the summer and early fall of 2002 and 2004 than in 2001 and 2003, indicating that larger, faster-growing juvenile pink salmon experienced higher survival. All cohorts ate a larger proportion of their theoretical maximum consumption and consumed more prey during 2002 than during 2001 and 2003 while feeding predominantly on the pteropod Limacina helicina. Unmarked "wild" juvenile pink salmon were significantly larger than hatchery fish during low-survival years, but no significant difference was observed during high-survival years. Pink salmon that survived to adulthood were larger at circuli, grew faster, and consumed more prey than the average juvenile. The localized standing stock biomass of key prey exceeded the daily consumption demand of juvenile pink salmon during July--August; however, estimated prey biomass was not enough to sustain the high level of consumption required to satisfy observed growth. The high percentage of prey biomass consumed, low feeding rates during May--July, a mid-summer decrease in circulus spacing and growth efficiency, and the fact that growth and consumption rates were much higher for all cohorts in high-survival years and for surviving cohorts in all years indicate that pink salmon are food limited in Prince William Sound and the coastal Gulf of Alaska during their first summer at sea.