Temporal Comparisons on the Genetic Variation of the Dusky Gopher Frog (Lithobates sevosus)

Monitoring temporal changes in genetic diversity within populations can provide vital information on future viability. The dusky gopher frog, Lithobates sevosus, exists in isolation with an estimated population size of 100-200 individuals, and previous research has shown that low genetic variability exists as a consequence of isolation and population size reduction. However, the temporal changes in genetic variation are not known. Therefore, my objectives were to (1) determine temporal trends in population genetic variation and implications for long-term viability of L. sevosus and (2) estimate effective population size. To accomplish these objectives, egg samples collected from 1997 to 2014 were genotyped for nine microsatellite loci. Observed and expected heterozygosity, allelic richness, and Wright\u27s inbreeding coefficient were calculated for each year and differences between sample years were assessed. Additionally, overall and pair-wise FST values were calculated to test for temporal genetic structuring. To estimate effective population size, two single-sample estimators (Tallmon et al. 2008; Waples and Do 2008) and two temporal estimators (Waples 1989; Wang 2001) were used. The results show a stable, but low, level of genetic variation. Weak genetic structure (FST = 0.023 (95% CI 0.006-0.043)) was found among years, which can be attributed to the increased effects of genetic drift in small populations. L. sevosus currently has an estimated effective population size between 32.99-58.6 individuals. The ratios of effective size to census size per year are fairly large (~0.5) and exhibit an increasing trend over time, which could possibly be explained by genetic compensation--or the lessening of genetic variation reduction in times with low population numbers. This research indicates the current management programs in place for L. sevosus have been effective at maintaining the genetic diversity present in the population; however, additional strategies need to be implemented to increase genetic diversity

Morrison, Bambara, Silko : fractured and reconstructed mythic patterns in Song of Solomon, The salt eaters, and Ceremony

Cette thèse explique le développement de la théorie critique des mythes (myth criticism) de Northrop Frye et veut démontrer que l'examen critique des mythes est un paradigme approprié pour analyser le développement des conventions littéraires anglaises et la communication d'archétypes dans des œuvres littéraires postmodernes. En examinant, à la lumière d'archétypes bibliques, de rites religieux provenant d'Afrique de l'ouest, de folklore amérindien et du mythe monomythique de la perte d'identité, trois romans afro-américains et amérindiens, je suggère que la théorie de Frye est applicable aux œuvres postmodernes amérindiennes et afro-américaines autant qu'elle l'est aux œuvres du canon traditionnel. Cette étude retrace les origines de la théorie de Frye et met en lumière la présence d'archétypes et de structures bibliques dans la fiction afro-américaine et amérindienne ainsi que la communication d'archétypes africains continentaux à la culture afro-américaine par un mélange d'ancienne religion africaine et d'archétypes bibliques. Ainsi, puisqu'il s'agit d'une application de la théorie de Frye, cette thèse enrichira notre compréhension du développement des conventions littéraires et de la portée de cette théorie, et permettra une remise en question de notre conception de la littérature afro-américaine et amérindienne

How effective is the early support program Babylotse-Plus for psychosocially burdened mothers and their infants? A comparative intervention study

Objectives: Our aim was to examine the effects of an early perinatal prevention program offered to mothers and families suffering from significant psychosocial burden. Methods: All mothers giving birth in a Berlin university hospital during Jan-Aug 2013 were screened with a standardized 27-item questionnaire by trained staff. Mothers with a screening-score ≥ 3, who were not enrolled in other public support programs, were defined as psychosocially burdened. They received a detailed needs assessment and were followed up with counseling. When necessary, affected mothers were voluntarily guided through to specialized 'early support' institutions during the 12-month-intervention period. The historical control group (care-as-usual) consisted of children born at the same hospital the year before.At 12 months postnatally, we interviewed mothers in both groups to assess their stress burden and coping skills by Parenting Stress Index and assessed the current childcare condition. Differences between the groups were compared by multivariable logistic regression analyses adjusting for potential confounders. Results: The intervention group and the control group included 225 and 157 families, respectively. After 12-months, mothers in the 'early support' intervention group had significantly less often depression (adjusted odds ratio 0.25, 95%-confidence interval 0.07-0.94), less often a disturbed relationship with the parenting partner (0.34, 0.10-1.14) and reported reduced stress due to the child's demands (0.40, 0.15-1.10) compared to the control group. Childcare indicators did not differ between the 2 groups. Conclusions: In mothers at high psychosocial risk, the 'early support' intervention program Babylotse-Plus seemed to reduce the occurrence of depression and several stress indicators in the first postnatal year

Hexabromocyclododecane decreases tumor-cell-binding capacity and cell-surface protein expression of human natural killer cells

Hexabromocyclododecane (HBCD) is a flame retardant that decreases the lytic function of human natural killer (NK) cells. NK cells defend against tumor cells and virally infected cells. Thus, HBCD has the potential to increase cancer incidence and viral infections. NK cells must bind to their targets for lysis to occur. Thus, concentrations of HBCD that decrease lytic function were examined for their ability to alter NK binding to tumor targets. Levels of HBCD that caused a loss of binding function were examined for effects on expression of cell surface proteins needed for binding. NK cells exposed to HBCD for 24 h, 48 h or 6 days or to HBCD for 1 h followed by 24 h, 48 h or 6 days in HBCD-free media were examined for binding function and cell surface protein expression. The results indicated that exposure of NK cells to 10 μM HBCD for 24 h (which caused a greater than 90% loss of lytic function) caused a very significant decrease in NK cell binding function (70.9%), and in CD16 and CD56 cell-surface protein expression (57.8 and 24.6% respectively). NK cells exposed to 10 μM HBCD for 1 h followed by 24 h in HBCD-free media (which caused a 89.3% loss of lytic function) showed decreased binding function (79.2%), and CD 16 expression (48.1%). Results indicate that HBCD exposures decreased binding function as well as cell-surface marker expression in NK cells and that these changes may explain the losses of lytic function induced by certain HBCD exposures

Hexabromocyclododecane decreases the lytic function and ATP levels of human natural killer cells

This study investigates the effect of hexabromocyclododecane (HBCD) on the lytic function of human natural killer (NK) cells and on ATP levels in NK cells. NK cells are capable of lysing tumor cells, virally infected cells, and antibody-coated cells. HBCD is a brominated cyclic alkane used primarily as an additive flame retardant. If HBCD interferes with NK cell function, this could increase risk of tumor development and/or viral infection. NK cells were exposed to various concentrations of HBCD for 24 and 48 h and 6 days before determining lytic function and ATP levels. ATP levels and lytic function were also determined in NK cells that were exposed to HBCD for 1 h followed by 24 and 48 h, and 6 days in HBCD-free media. The results indicated that exposure of NK cells to 10 µm HBCD for 24 h causes a very significant decrease in both NK cell lytic function and ATP levels (93.5 and 90.5%, respectively). Exposure of NK cells to 10 µm HBCD for 1 h followed by 24 h in HBCD-free media showed a progressive and persistent loss of lytic function (89.3%) as well as a decrease in ATP levels (46.1%). The results indicate that HBCD exposures decreased lytic function as well as ATP levels. However, a decrease in lytic function was not necessarily accompanied by a similar decrease in ATP. Importantly, these results also indicate that a brief (1 h) exposure to HBCD causes a progressive loss of lytic function over a 6 day period

Disability and the Young Adult Reader: How Has the Portrayal of Disability Changed in the Last Fifty Years?

Literature offers an opportunity to share in the lived experiences of others, experiences that as readers we may otherwise never personally encounter. Disability in our society is a reality, yet one that has not been fully embraced--not unlike issues with race, gender, age, or sexual orientation. Individuals begin to encounter many of these matters early in life, but as impressionable adolescents, a time when they begin to understand and navigate the world, often times they meet these experiences in books. Since books are an especially important part of how thoughts and attitudes are shaped, this paper seeks to analyze a selection of texts geared towards young readers to understand whether the view of disability has remained static since the 1950s and to understand how disability is being used in more current texts for young adult readers. Stoner & Spaz by Ron Koertge, Freak the Mighty by Rodman Philbrick and Flowers for Algernon by Daniel Keyes will be the representative artifacts for this analysis. How these texts respond to important questions about language, representations of disability, the lived experiences of people with disabilities, and the power differentials which exist will be examined. | 45 page