Evaluation of candidate genes for susceptibility to spina bifida

Neural tube defects (NTDs) are the most common severely disabling birth defects in the United States, with a frequency of approximately 1–2 of every 1,000 births. This text includes the identification and evaluation of candidate susceptibility genes that confer risk for the development of neural tube defects (NTDs). The project focused on isolated meningomyelocele, also termed spina bifida (SB). ^ Spina bifida is a complex disease with multifactorial inheritance, therefore the subject population (consisting of North American Caucasians and Hispanics of Mexicali-American descent) was composed of 459 simplex SB families who were tested for genetic associations utilizing the transmission disequilibrium test (TDT), a nonparametric linkage technique. Three categories of candidate genes were studied, including (1) human equivalents of genes determined in mouse models to cause NTDs, (2) HOX and PAX genes, and (3) the MTHFR gene involved in the metabolic pathway of folate. ^ The C677T variant of the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene was the first mutation in this gene to be implicated as a risk factor for NTDs. Our evaluation of the MTHFR gene provides evidence that maternal C677T homozygosity is a risk factor for upper level spina bifida defects in Hispanics [OR = 2.3, P = 0.02]. This observed risk factor is of great importance due to the high prevalence of this homozygous genotype in the Hispanic population. Additionally, maternal C677T/A1298C compound heterozygosity is a risk factor for upper level spina bifida defects in non-Hispanic whites [OR = 3.6, P = 0.03]. ^ For TDT analysis, our total population of 1128 subjects were genotyped for 54 markers from within and/or flanking the 20 candidate genes/gene regions of interest. Significant TDT findings were obtained for 3 of the 54 analyzed markers: d20s101 flanking the PAX1 gene (P = 0.019), d1s228 within the PAX7 gene (P = 0.011), and d2s110 within the PAX8 gene (P = 0.013). These results were followed-up by testing the genes directly for mutations utilizing single-strand conformational analysis (SSCA) and direct sequencing. Multiple variations were detected in each of these PAX genes; however, these variations were not passed from parent to child in phase with the positively transmitted alleles. Therefore, these variations do not contribute to the susceptibility of spina bifida, but rather are previously unreported single nucleotide polymorphisms. ^

Efficiency and Continuity in Public Finance: The Ottoman System of Taxation

Economic historians have recently emphasized the importance of integrating economic and historical approaches in studying institutions. The literature on the Ottoman system of taxation, however, has continued to adopt a primarily historical approach, using ad hoc categories of classification and explaining the system through its continuities with the historical precedent. This paper integrates economic and historical approaches to examine the structure, efficiency, and regional diversity of the tax system. The structure of the system made it possible for the Ottomans to economize on the transaction cost of measuring the tax base. Regional variations resulted from both efficient adaptations and institutional rigidities.

The Secret Life of Mundane Transaction Costs

Transaction costs, one often hears, are the economic equivalent of friction in physical systems. Like physicists, economists can sometimes neglect friction in formulating theories; but like engineers, they can never neglect friction in studying how the system actually does let alone should work. Interestingly, however, the present-day economics of organization also ignores friction. That is, almost single-mindedly, the literature analyzes transactions from the point of view of misaligned incentives and (especially) transaction-specific assets. The costs involved are certainly costs of running the economic system in some sense, but they are not obviously frictions. Stories about frictions in trade are not nearly as intriguing as stories about guileful trading partners and expensive assets placed at risk. But I will argue that these seemingly dull categories of cost what Baldwin and Clark (2003) call mundane transaction costs actually have a secret life. They are at least as important as, and quite probably far more important than, the more glamorous costs of asset specificity in explaining the partition between firm and market. These costs also have a secret life in another sense: they have a secret life cycle. I will argue that these mundane transaction costs provide much better material for helping us understanding how the boundaries among firms, markets, and hybrid forms change over time.

The association between maternal use of spermicides, condoms, intra-uterine devices or progesterone and major structural birth defects

Birth defects occur in 1 of every 33 babies born in the United States, and are the leading cause of infant death. Mothers using contraceptives that become pregnant may continue to use their contraceptives after their first missed menstrual period, thus exposing their baby in utero to the contraceptive product. Progesterone is also sometimes prescribed during the first trimester of pregnancy to mothers with a history of miscarriages or infertility problems. To ensure the safety of these products, it is important to investigate whether there is an increased occurrence of babies born with birth defects to mothers using various contraceptive methods or progesterone in early pregnancy. Using data from the National Birth Defects Prevention Study (NBDPS), an ongoing multi-state, population based case-control study, this study assessed maternal exposures to IUDs, spermicides, condoms and progesterone in early pregnancy. ^ Progesterone used for threatened miscarriage during the first three months of pregnancy was associated with an increased occurrence of hypoplastic left heart (adjusted odds ratios (OR) 2.24, 95% CI 1.13-4.21), perimembranous ventricular septal defects (OR 1.64, 95% CI 1.10-2.41), septal associations (OR 2.52, 95% CI 1.45-4.24), esophageal atresia (OR 1.82, 95% CI 1.04-3.08), and hypospadias (OR 2.12, 95% CI 1.41-3.18). Mothers using progesterone for injectable contraception had increased (OR > 2.5), but insignificant odds ratios for anencephaly, septal associations, small intestinal atresias and omphalocel. Progesterone used for fertility was not associated with an increased occurrence of any birth defects examined. ^ Mothers using progesterone for fertility assistance and threatened miscarriage were very similar with respect to their demographics and pregnancy history. They also both reported similar types of progesterone. Thus, if progesterone was a causal risk factor for birth defects we would have expected to observe similar increases in risk among mothers using progesterone for both indications. Because we predominantly observed increased associations among mothers using progesterone for threatened miscarriage but not fertility assistance, it is possible the increased associations we observed were confounded by indication (i.e. progesterone was administered for vaginal bleeding which occurred as a sequelae to the formation of a congenital anomaly. ^ No significant increased associations were observed between maternal spermicide use during pregnancy and 26 of 27 types of structural malformations. While multiple statistical tests were performed we observed first trimester maternal spermicide use to be associated with a significant increased occurrence of perimembranous ventricular septal defects (OR 2.21, 95% CI 1.16-4.21). A decreased occurrence (OR < 1.0) was observed for several categories of birth defects among mothers who conceived in the first cycle after discontinuing the use of spermicides (22 of 28) or male condoms (23 of 33). ^ Overall the percent of IUD use was similar between mothers of controls and mothers of all cases in aggregate (crude OR 1.05, 95% CI 0.61-1.84). Power was limited to detect significant associations between IUD use and birth defects, however mothers using an IUD in the month immediately prior to conception or during pregnancy were not associated with an increase of birth defects. Limb defects and amniotic band sequence previously reported to be associated with IUD use during pregnancy were not found to occur among any mothers reporting the use of an IUD during pregnancy.^

A review of the effects of Transcendental Meditation on cardiovascular disease

Cardiovascular disease (CVD) is the single greatest cause of death in the United States, accounting for nearly 2400 deaths each day. It is estimated that 79.4 million American adults have some form of the disease, and CVD mortality rates are greater than those of cancer, chronic lower respiratory diseases, accidents and diabetes mellitus combined. Psychosocial stress is a nontraditional risk factor for CVD, and can contribute to the clustering of traditional risk factors as well as to vascular manifestations of the disease. The Transcendental Meditation (TM) technique has been researched as a cost effective intervention aimed at decreasing psychosocial stress. This literature review attempts to analyze randomized controlled clinical trials of TM on cardiovascular disease outcomes. Eleven studies met inclusion criteria and are described below, with statistically significant positive outcomes observed in each study. Studies are grouped by primary outcome reported in the categories of cardiovascular function, blood pressure, and exercise tolerance. The TM intervention significantly decreased insulin resistance, heart rate variability, and carotid intima media thickness and improved exercise tolerance compared to control groups. Seven studies also reported significant decreases in blood pressure among hypertensive and normotensive subjects. Five studies focused solely on African American subjects, a population that has disproportionately higher rates of CVD and hypertension, and found significant improvements in CVD outcomes. Further research is recommended to establish the efficacy of TM on CVD outcomes. Future trials should include larger sample populations, wider ethnic distributions of subjects, and longer follow-up to ascertain the impact of this particular stress reduction technique on cardiovascular disease.^

Parents' impressions of inappropriate television content for Hispanic preschool children

Rates of childhood obesity have increased three-fold in the last 20 years, and experts estimate that well over half of adolescents with a Body Mass Index at or above the 95th percentile become obese adults. These trends are even more pronounced in ethnic minority and lower income populations that are disproportionately impacted by obesity and its complications. It would be appropriate, then, to focus obesity interventions on Hispanic children. Television viewing, especially, has been shown to contribute to obesity by increasing caloric intake and decreasing physical activity. Parent involvement has proven to be a critical component in changing children’s health behaviors. In order to explore parents’ motivations for limiting their children’s television viewing, I qualitatively analyzed data from twenty-five interviews with Houston area Head Start parents. Using Grounded Theory, four main categories of concern emerged from the audio-recorded conversations: developmentally inappropriate content, the influence of television, poor health behaviors/outcomes, and general disapproval with television. Developmentally inappropriate content was the most frequently mentioned category with 119 mentions. This included violence, the most common sub-theme. In all, parents were more concerned with television content that produced proximate consequences such as modeling violent behavior or inappropriate language. Content that encouraged behaviors that led to obesity or other delayed consequences were of less concern to the parents. This suggests that future interventions aimed at encouraging Hispanic parents to reduce their children’s television viewing should draw motivation from parents’ concerns about developmentally inappropriate content, rather than focusing on deleterious health outcomes such as obesity. ^

A DESCRIPTION AND EVALUATION OF EDUCATIONAL PROGRAMS FOR HEALTH MANPOWER IN NIGERIA

A descriptive study of the current educational programs of selected health personnel in Nigeria was made in 1986. Data on the content of educational programs was obtained from personal communication with the Heads of the various institutions and from their published materials (catalogs, course outlines and program descriptions). Adequacy of these programs was judged in the light of current health problems and needs of the population. Evaluation was based on the following criteria: (a) Selection of students to maximize their usefulness in the provision of health care. (b) Relevance of the curriculum to the tasks the trainee will be called upon to perform. (c) Types of courses that focus on community health needs. Using official reports, the health situation in the country was described to give a relative priority of health services.^ Findings indicate the following: (1) Health conditions in Nigeria are related to a high prevalence of illness and disease, unsanitary living conditions, a high ratio of infant mortality and a shortage of public health services. Priority needs for improvement call for attitudinal and environmental changes. (2) All health training programs have improved the relevance of education to community health needs by strengthening practical field experience, and teaching those courses which focus on disease prevention. (3) Prospective nurses and community health workers are selected on the basis of a number of personal and intellectual characteristics, but academic performance alone is the criterion for medical students. (4) The curriculum in the medical school needs to be restructured to cut back on time devoted to enriching the medical "background". Basic sciences need better integration with hospital work. (5) Managerial and organization courses have been well incorporated into the nursing and community health workers' curricula. (6) There is a marked overlap in the tasks the community health workers are expected to perform. This causes some redundancy in having four separate categories of these health personnel. ^

HOUSE-TO-HOUSE SURVEY OF ACCESS TO AND USE OF PUBLIC HEALTH FACILITIES IN METROPOLITAN LAGOS, NIGERIA

One of the broad objectives of the Nigerian health service, vigorously being pursued at all levels of government, is to make comprehensive health care available and accessible to the population at the lowest possible cost, within available resources. Some state governments in the federation have already introduced free medical service as a practical way to remove financial barriers to access and in turn to encourage greater utilization of publicly funded care facilities.^ To aid health planners and decision makers in identifying a shorter corridor through which urban dwellers can gain access to comprehensive health care, a health interview survey of the metropolitan Lagos was undertaken. The primary purpose was to ascertain the magnitude of access problems which urban households face in seeking care from existing public facilities at the time of need. Six categories of illness chosen from the 1975 edition of the International Classification of Disease were used as indicators of health need.^ Choice of treatment facilities in response to illness episode was examined in relation to distance, travel time, time of use and transportation experiences. These were graphically described. The overall picture indicated that distance and travel time coexist with transportation problems in preventing a significant segment of those in need of health care from benefitting in the free medical service offered in public health facilities. Within this milieu, traditional medicine and its practitioners became the most preferred alternative. Recommendations were offered for action with regard to decentralization of general practitioner (GP) consultations in general hospitals and integration of traditional medicine and its practitioners into public health service. ^

THE RELATIONSHIP BETWEEN DEGREE OF BLOOD PRESSURE REDUCTION AND MORTALITY AMONG HYPERTENSIVES IN THE HYPERTENSION DETECTION AND FOLLOW-UP PROGRAM

The relationship between degree of diastolic blood pressure (DBP) reduction and mortality was examined among hypertensives, ages 30-69, in the Hypertension Detection and Follow-up Program (HDFP). The HDFP was a multi-center community-based trial, which followed 10,940 hypertensive participants for five years. One-year survival was required for inclusion in this investigation since the one-year annual visit was the first occasion where change in blood pressure could be measured on all participants. During the subsequent four years of follow-up on 10,052 participants, 568 deaths occurred. For levels of change in DBP and for categories of variables related to mortality, the crude mortality rate was calculated. Time-dependent life tables were also calculated so as to utilize available blood pressure data over time. In addition, the Cox life table regression model, extended to take into account both time-constant and time-dependent covariates, was used to examine the relationship change in blood pressure over time and mortality.^ The results of the time-dependent life table and time-dependent Cox life table regression analyses supported the existence of a quadratic function which modeled the relationship between DBP reduction and mortality, even after adjusting for other risk factors. The minimum mortality hazard ratio, based on a particular model, occurred at a DBP reduction of 22.6 mm Hg (standard error = 10.6) in the whole population and 8.5 mm Hg (standard error = 4.6) in the baseline DBP stratum 90-104. After this reduction, there was a small increase in the risk of death. There was not evidence of the quadratic function after fitting the same model using systolic blood pressure. Methodologic issues involved in studying a particular degree of blood pressure reduction were considered. The confidence interval around the change corresponding to the minimum hazard ratio was wide and the obtained blood pressure level should not be interpreted as a goal for treatment. Blood pressure reduction was attributed, not only to pharmacologic therapy, but also to regression to the mean, and to other unknown factors unrelated to treatment. Therefore, the surprising results of this study do not provide direct implications for treatment, but strongly suggest replication in other populations. ^

INFANT MORTALITY IN THE MEXICAN AMERICAN COMMUNITY: AN ANALYSIS OF DIFFERENTIALS IN INFANT, NEONATAL, AND POSTNEONATAL MORTALITY BY ETHNICITY AND PARENTAL NATIVITY, 1974-75 SINGLE LIVE BIRTH COHORT, HARRIS COUNTY, TEXAS

The paradoxically low infant mortality rates for Mexican Americans in Texas have been attributed to inaccuracies in vital registration and idiosyncracies in Mexican migration in rural areas along the U.S.-Mexico border. This study examined infant (IMR), neonatal (NMR), and postneonatal (PNMR) mortality rates of Mexican Americans in an urban, non-border setting, using linked birth and death records of the 1974-75 single live birth cohort (N = 68,584) in Harris County, Texas, which includes the city of Houston and is reported to have nearly complete birth and death registration. The use of parental nativity with the traditional Spanish surname criterion made it possible to distinguish infants of Mexican-born immigrants from those of Blacks, Anglos, other Hispanics, and later-generation, more Anglicized Mexican Americans. Mortality rates were analyzed by ethnicity, parental nativity, and cause of death, with respect to birth weight, birth order, maternal age, legitimacy status, and time of first prenatal care.^ While overall IMRs showed Spanish surname rates slightly higher than Anglo rates, infants of Mexican-born immigrants had much lower NMRs than did Anglos, even for moderately low birth weight infants. However, among infants under 1500 grams, presumably unable to be discharged home in the neonatal period, Mexican Americans had the highest NMR. The inconsistency suggested unreported deaths for Mexican American low birth weight infants after hospital discharge. The PNMR of infants of Mexican immigrants was also lower than for Anglos, and the usual mortality differentials were reversed: high-risk categories of high birth order, high maternal age, and late/no prenatal care had the lowest PNMRs. Since these groups' characteristics are congruent with those of low-income migrants, the data suggested the possibility of migration losses. Cause of death analysis suggested that prematurity and birth injuries are greater problems than heretofore recognized among Mexican Americans, and that home births and "shoebox burials" may be unrecorded even in an urban setting.^ Caution is advised in the interpretation of infant mortality rates for a Spanish surname population of Mexican origin, even in an urban, non-border area with reportedly excellent birth and death registration. ^

DIABETIC RETINOPATHY IN NON-INSULIN-DEPENDENT DIABETES MELLITUS IN BLACK WOMEN: A DESCRIPTIVE STUDY OF RISK FACTORS

This cross-sectional study examines the prevalence of selected potential risk factors by stage of diabetic retinopathy (DR) among Black American women with non-insulin-dependent diabetes mellitus (NIDDM) followed at a university diabetes clinic. DR was assessed by ophthalmoscopy and five-field retinography, and graded on counts of microaneurysms, hemorrhages and/or exudates, and presence of proliferative DR. Prevalence of other vascular diseases was assessed from medical records. Potential risk factors included age, known duration of diabetes, type of hypoglycemic treatment, concentrations of random capillary blood glucose, glycosylated hemoglobin, urine protein and fibrinogen, body mass index, and blood pressure. Prevalence of these risk factors is reported for three categories: No DR, mild background DR, severe background or proliferative DR (including surgically treated DR). Duration, age at diagnosis and treatment of diabetes, concentration of urine protein and average blood glucose, hypertension and cardiovascular disease were significantly associated with DR in univariate analysis. The covariance analysis employed stratification on duration, age at diagnosis and therapy of diabetes. The highest DR scores were calculated for those diagnosed before age 45, regardless of duration, therapy, or average blood glucose. Only individuals diagnosed before age 45 had high blood glucose concentrations in all categories of duration. These findings suggest that in this clinic population of Black women, those diagnosed with NIDDm before age 45 who eventually required insulin treatment were at the greatest risk of developing DR and that longterm poor glucose control is a contributing factor. These results suggest that greater emphasis be placed on this subgroup in allocating the limited resources available to improve the quality of glucose regulation, particularly through measures affecting compliance behavior.^ Findings concerning the association of DR with concentration of blood glucose and urine protein, blood pressure/hypertension and weight were compared with those reported from American Indian and Mexican American populations of the Southwestern United States where prevalence of NIDDM, hypertension and obesity is also high. Additional comparative analyses are outlined to substantiate the preliminary finding that there are systematic differences between these ethnic populations. ^

Characterization of fecal contamination targeting 16S rRNA bacteroides molecular markers in the Santa Cruz River, Arizona

Understanding the origins, transport and fate of contamination is essential to effective management of water resources and public health. Individuals and organizations with management responsibilities need to understand the risks to ecosystems and to humans from contact with contamination. Managers also need to understand how key contaminants vary over time and space in order to design and prioritize mitigation strategies. Tumacacori National Historic Park (NHP) is responsible for management of its water resources for the benefit of the park and for the health of its visitors. The existence of microbial contaminants in the park poses risks that must be considered in park planning and operations. The water quality laboratory at the Maricopa Agricultural Center (in collaboration with stakeholder groups and individuals located in the ADEQ-targeted watersheds) identified biological changes in surface water quality in impaired reaches rivers to determine the sources of Escherichia coli (E. coli); bacteria utilizing innovative water quality microbial/bacterial source tracking methods. The end goal was to support targeted watershed groups and ADEQ towards E. coli reductions. In the field monitoring was conducted by the selected targeted watershed groups in conjunction with The University of Arizona Maricopa Agricultural Center Water Quality Laboratory. This consisted of collecting samples for Bacteroides testing from multiple locations on select impaired reaches, to determine contamination resulting from cattle, human recreation, and other contributions. Such testing was performed in conjunction with high flow and base flow conditions in order to accurately portray water quality conditions and variations. Microbial monitoring was conducted by The University of Arizona Water Quality Laboratory at the Maricopa Agricultural Center using genetic typing to differentiate among two categories of Bacteroides: human and all (total). Testing used microbial detection methodologies and molecular source tracking techniques.^

The cost of insuring the uninsured in the U.S.

Objectives: This study included two overarching objectives. Through a systematic review of the literature published between 1990 and 2012, the first objective aimed to assess whether insuring the uninsured would result in higher costs compared to insuring the currently insured. Studies that quantified the actual costs associated with insuring the uninsured in the U.S. were included. Based upon 2009 data from the Medical Expenditure Panel Survey (MEPS), the second objective aimed to assess and compare the self-reported health of populations with four different insurance statuses. The second part of this study involved a secondary data analysis of both currently insured and currently uninsured individuals who participated in the MEPS in 2009. The null hypothesis was that there were no differences across the four categories of health insurance status for self-reported health status and healthcare service use. The alternative hypothesis was that were differences across the four categories of health insurance status for self-reported health status and healthcare service use. Methods: For the systematic review, three databases were searched using search terms to identify studies that actually quantified the cost of insuring the uninsured. Thirteen studies were selected, discussed, and summarized in tables. For the secondary data analysis of MEPS data, this study compared four categories of health insurance status: (1) currently uninsured persons who will become eligible for Medicaid under the Patient Protection and Affordable Care Act (PPACA) healthcare reforms in 2014; (2) currently uninsured persons who will be required to buy private insurance through the PPACA health insurance exchanges in 2014; (3) persons currently insured under Medicaid or SCHIP; and (4) persons currently insured with private insurance. The four categories were compared on the basis of demographic information, health status information, and health conditions with relatively high prevalence. Chi-square tests were run to determine if there were differences between the four groups in regard to health insurance status and health status. With some exceptions, the two currently insured groups had worse self-reported health status compared to the two currently uninsured groups. Results: The thirteen studies that met the inclusion criteria for the systematic review included: (1) three cost studies from 1993, 1995, and 1997; (2) four cost studies from 2001, 2003, and 2004; (3) one study of disabilities and one study of immigrants; (4) two state specific studies of uninsured status; and (5) two current studies of healthcare reform. Of the thirteen studies reviewed, four directly addressed the study question about whether insuring the uninsured was more or less expensive than insuring the currently insured. All four of the studies provided support for the study finding that the cost of insuring the uninsured would generally not be higher than insuring those already insured. One study indicated that the cost of insuring the uninsured would be less expensive than insuring the population currently covered by Medicaid, but more expensive to insure than the populations of those covered by employer-sponsored insurance and non-group private insurance. While the nine other studies included in the systematic review discussed the costs associated with insuring the uninsured population, they did not directly compare the costs of insuring the uninsured population with the costs associated with insuring the currently insured population. For the MEPS secondary data analysis, the results of the chi-square tests indicated that there were differences in the distribution of disease status by health insurance status. As anticipated, with some exceptions, the uninsured reported lower rates of disease and healthcare service use. However, for the variable attention deficit disorder, the uninsured reported higher disease rates than the two insured groups. Additionally, for the variables high blood pressure, high cholesterol, and joint pain, the currently insured under Medicaid or SCHIP group reported a lower rate of disease than the two currently insured groups. This result may be due to the lower mean age of the currently insured under Medicaid or SCHIP group. Conclusion: Based on this study, with some exceptions, the costs for insuring the uninsured should not exceed healthcare-related costs for insuring the currently uninsured. The results of the systematic review indicated that the U.S. is already paying some of the costs associated with insuring the uninsured. PPACA will expand health insurance coverage to millions of Americans who are currently uninsured, as the individual mandate and insurance market reforms will require. Because many of the currently uninsured are relatively healthy young persons, the costs associated with expanding insurance coverage to the uninsured are anticipated to be relatively modest. However, for the purposes of construing these results, it is important to note that once individuals obtain insurance, it is anticipated that they will use more healthcare services, which will increase costs. (Abstract shortened by UMI.)^

Risk and protective factors associated with depression among racial and ethnic mothers of adolescents

The central paradigm linking disadvantaged social status and mental health has been the social stress model (Horwitz, 1999), the assumption being that individuals residing in lower social status groups are subjected to greater levels of stress not experienced by individuals from higher status groups. A further assumption is that such individuals have fewer resources to cope with stress, in turn leading to higher levels of psychological disorder, including depression (Pearlin, 1989). Despite these key assumptions, there is a dearth of literature comparing the social patterning of stress exposure (Hatch & Dohrenwend, 2007; Meyer, Schwartz, & Frost, 2008; Kessler, Mickelson, & Williams, 1999; Turner & Avison, 2003; Turner & Lloyd, 1999; Turner, Wheaton, & Lloyd, 1995), and the distribution and contribution of protective factors, posited to play a role in the low rates of depression found among African- and Latino-Americans (Alegria et al., 2007; Breslau, Aguilar-Gaxiola, Kendler, Su, Williams, & Kessler, 2006; Breslau, Borges, Hagar, Tancredi, Gilman, 2009; Gavin, Walton, Chae, Alegria, Jackson, & Takeuchi, 2010; Williams, & Neighbors, 2006). Thus, this study sought to describe both the distribution and contribution of risk and protective factors in relation to depression among a sample of African-, European-, and Latina-American mothers of adolescents, including testing a hypothesized mechanism through which social support, an important protective factor specific to women and depression, operates. ^ Despite the finding that the levels of depression were not statistically different across all three groups of women, surprising results were found in describing the distribution of both risk and protective factors, in that results reported among all women who were mothers when analyzed masked differences within each ethnic group when SES was assessed, a point made explicit by Williams (2002) regarding racial and ethnic variations in women's health. In the final analysis, while perceived social support was found to partially mediate the effect of social isolation on depression, among African-Americans, the direct effect of social isolation and depression was lower among this group of women, as was the indirect effect of social isolation and perceived social support when compared to European- and Latina-American mothers. Or, put differently, higher levels of social isolation were not found to be as associated with more depression or lower social support among African-American mothers when compared to their European- and Latina-American counterparts. ^ Women in American society occupy a number of roles, i.e., that of being female, married or single, mother, homemaker or employee. In addition, to these roles, ethnicity and SES also come into play, such that the intersection of all these roles and the social contexts that they occupy are equally important and must be taken into consideration when making predictions drawn from the social stress model. Based on these findings, it appears that the assumptions of the social stress model need to be revisited to include the variety of roles that intersect among individuals from differing social groups. More specifically, among women who are mothers and occupy a myriad of other roles, i.e., that of being female, married or single, African- or Latina-American, mother, homemaker or employee, the intersection of all the roles and the social contexts that women occupy are equally important and must be taken into consideration when looking at both the types and distribution of stressors across women. Predictions based on simple, mutually exclusive categories of social groups may lead to erroneous assumptions and misleading results.^

Dinoflagellate cysts abundance and events of ODP Hole 189-1168A sediments

Palynomorphs were studied in samples from Ocean Drilling Program (ODP) Leg 189, Hole 1168A (slope of the western margin of Tasmania; 2463 m water depth). Besides organic-walled dinoflagellate cysts (dinocysts), broad categories of other palynomorphs were quantified in terms of relative abundance. In this contribution, we provide an overview of the early late Eocene-Quaternary dinocyst distribution and illustrate main trends in palynomorph distribution. Dinocyst species throughout Hole 1168A are largely cosmopolitan with important contributions of typical low-latitude taxa and virtual absence of endemic Antarctic taxa. Dinocyst stratigraphic distribution broadly matches that known from the Northern Hemisphere and equatorial regions, although significant differences are noted. Selected potentially biochronostratigraphically useful events are summarized. The distribution of dinocysts in the middle-upper Miocene interval is rather patchy, probably due to prolonged exposure to oxygen. An important general aspect in the dinocyst assemblages is the near absence of Antarctic endemic species and the apparent influence of relatively warm waters throughout the succession at Site 1168. General palynomorph distribution indicates continued deepening from an initial shallow, even restricted, marine setting from late Eocene-Quaternary times. A curious massive influx of small skolochorate acritarchs is recorded throughout the late early-early middle Miocene; the significance of this signal is not yet understood. A general long-term oligotrophic nature of the surface waters influencing Site 1168 is suggested from the low abundance of (proto) peridinioid, presumably heterotrophic, species. The overall dinocyst distribution pattern corresponds to the long-term existence of a Leeuwin-like current influencing the region, including Site 1168, confirming results of earlier studies on other microfossil groups. The occasional influence of colder surface water conditions is, however, also apparent, notably during the late Pliocene-Quaternary, indicating the potential of high-resolution dinocyst analysis for future paleoceanographic studies.