It takes a village : exploring African American women\u27s experiences with collective identity, racism, and well-being

This qualitative study sought to explore African American women\u27s understandings about collective identity in their lives and, specifically, in their encounters with racism that impacted their well-being. African American women hold rich traditions of healing that encompass their communities and are influenced by their early bonds of sisterhood. In the United States of America, these traditions of connectedness between Black folks have supported Black women, communities, and families against the pressures of racist domination. Ten self-identified African American women between the ages of 34 and 69 shared rich narratives about how they experienced a collective sense of self, racism, and well-being. This study\u27s findings were identified as they relate to participants\u27 lived experiences of and intersections between collective identity and the following: (a) racial pride and multiculturalism, (b) community as an important African American value that feels under threat, (c) protecting and proliferating Black female expression, (d) learning racism at a distance, and (e) the effects of bearing witness

Improved models of biological sequence evolution

Thesis (PhD)--Stellenbosch University, 2012.ENGLISH ABSTRACT: Computational molecular evolution is a field that attempts to characterize how genetic sequences evolve over phylogenetic trees – the branching processes that describe the patterns of genetic inheritance in living organisms. It has a long history of developing progressively more sophisticated stochastic models of evolution. Through a probabilist’s lens, this can be seen as a search for more appropriate ways to parameterize discrete state continuous time Markov chains to better encode biological reality, matching the historical processes that created empirical data sets, and creating useful tools that allow biologists to test specific hypotheses about the evolution of the organisms or the genes that interest them. This dissertation is an attempt to fill some of the gaps that persist in the literature, solving what we see as existing open problems. The overarching theme of this work is how to better model variation in the action of natural selection at multiple levels: across genes, between sites, and over time. Through four published journal articles and a fifth in preparation, we present amino acid and codon models that improve upon existing approaches, providing better descriptions of the process of natural selection and better tools to detect adaptive evolution.AFRIKAANSE OPSOMMING: Komputasionele molekulêre evolusie is ’n navorsingsarea wat poog om die evolusie van genetiese sekwensies oor filogenetiese bome – die vertakkende prosesse wat die patrone van genetiese oorerwing in lewende organismes beskryf – te karakteriseer. Dit het ’n lang geskiedenis waartydens al hoe meer gesofistikeerde waarskynlikheidsmodelle van evolusie ontwikkel is. Deur die lens van waarskynlikheidsleer kan hierdie proses gesien word as ’n soektog na meer gepasde metodes om diskrete-toestand kontinuë-tyd Markov kettings te parametriseer ten einde biologiese realiteit beter te enkodeer – op so ’n manier dat die historiese prosesse wat tot die vorming van biologiese sekwensies gelei het nageboots word, en dat nuttige metodes geskep word wat bioloë toelaat om spesifieke hipotesisse met betrekking tot die evolusie van belanghebbende organismes of gene te toets. Hierdie proefskrif is ’n poging om sommige van die gapings wat in die literatuur bestaan in te vul en bestaande oop probleme op te los. Die oorkoepelende tema is verbeterde modellering van variasie in die werking van natuurlike seleksie op verskeie vlakke: variasie van geen tot geen, variasie tussen posisies in gene en variasie oor tyd. Deur middel van vier gepubliseerde joernaalartikels en ’n vyfde artikel in voorbereiding, bied ons aminosuur- en kodon-modelle aan wat verbeter op bestaande benaderings – hierdie modelle verskaf beter beskrywings van die proses van natuurlike seleksie sowel as beter metodes om gevalle van aanpassing in evolusie te vind

Sensing a Bacillis anthracis biomarker with well-known OLED emitter EuTta3Phen

Dipicolinic acid (DPA) is a distinctive biomarker for bacterial spores. Here, we present the successful demonstration of dramatic Switch-OFF sensing of DPA using an easily synthesised Eu(III) phosphor applied primarily in light-emitting devices. The sensor in the presence of water and phosphate is also demonstrated to be effective

Aislamiento y caracterización de cepas de Bacillus asociadas al cultivo del arroz (Oryza sativa L.)

El presente trabajo muestra el aislamiento y la caracterización de bacterias del género Bacillus provenientes de la rizosfera del cultivo del arroz (Oryza sativa L.) variedad J-104 utilizando el modelo microcosmos. Se realizaron además aislamientos directos del suelo que se encontraba cultivado con la variedad INCA LP-5. Se llevó a cabo la caracterización fisiológica de 13 aislados en cuanto a la producción de compuestos indólicos, la determinación de antagonismo frente a hongos fitopatógenos Del arroz (Alternaria solani, Pyricularia grisea, Fusarium sp. y Curvularia sp.), la capacidad de solubilización de fosfatos y la determinación cualitativa de la fijación de nitrógeno. Teniendo en cuenta los resultados obtenidos se seleccionaron a través de un análisis de conglomerado (cluster), los aislados más promisorios para su identificación utilizando las pruebas morfológicas, tintoriales y bioquímicas propuestas por el Manual de Bergey y la secuenciación del ADN ribosómico 16S

Agouti Expression in Human Adipose Tissue: Functional Consequences and Increased Expression in Type 2 Diabetes

It is well recognized that the agouti/melanocortin system is an important regulator of body weight homeostasis. Given that agouti is expressed in human adipose tissue and that the ectopic expression of agouti in adipose tissue results in moderately obese mice, the link between agouti expression in human adipose tissue and obesity/type 2 diabetes was investigated. Although there was no apparent relationship between agouti mRNA levels and BMI, agouti mRNA levels were significantly elevated in subjects with type 2 diabetes. The regulation of agouti in cultured human adipocytes revealed that insulin did not regulate agouti mRNA, whereas dexamethasone treatment potently increased the levels of agouti mRNA. Experiments with cultured human preadipocytes and with cells obtained from transgenic mice that overexpress agouti demonstrated that melanocortin receptor (MCR) signaling in adipose tissue can regulate both preadipocyte proliferation and differentiation. Taken together, these results reveal that agouti can regulate adipogenesis at several levels and suggest that there are functional consequences of elevated agouti levels in human adipose tissue. The influence of MCR signaling on adipogenesis combined with the well-established role of MCR signaling in the hypothalamus suggest that adipogenesis is coordinately regulated with food intake and energy expenditure

Die rol van die kerk as ondersteuningsnetwerk: Die verwantskap tussen psigo-sosiale klimaat, kerklike betrokkenheid en sielkundige welsyn

The role of the church as a supportive network: The relationship between psycho-social climate, church involvement, and psychological well-being. The aim of the present study was to determine whether mere involvement in church activities is enough to perceive the church as supportive, or whether the church should possess certain qualities before it is experienced as being supportive. The concept of psycho-social climate was used as a conceptual frame of reference to study the characteristics of the church. Two hundred and fourteen members of 10 different congregations completed a battery of questionnaires designed to measure their involvement in the church, their perception of the psycho-social climate of the church, and their level of psychological well-being. No relationship between church involvement and psychological well-being could be found. On the other hand, the analysis of the relationship between the dimensions of church climate and psychological well-being produced a number of significant correlations. Step-wise multiple regression analysis confirmed that the psycho-social dimensions of order/clarity, social concern, stability, and activity were significant predictors of the level of psychological well-being. The obtained relationship was interpreted as confirmation of the impact that the psycho-social environment has on individual functioning

Comments on alternative calculations of the broadening of spectral lines of neutral sodium by H-atom collisions

With the exception of the sodium D-lines recent calculations of line broadening cross-sections for several multiplets of sodium by Leininger et al (2000) are in substantial disagreement with cross-sections interpolated from the tables of Anstee and O'Mara (1995) and Barklem and O'Mara (1997). The discrepancy is as large as a factor of three for the 3p-4d multiplet. The two theories are tested by using the results of each to synthesize lines in the solar spectrum. It is found that generally the data from the theory of Anstee, Barklem and O'Mara produce the best match to the observed solar spectrum. It is found, using a simple model for reflection of the optical electron by the potential barrier between the two atoms, that the reflection coefficient is too large for avoided crossings with the upper states of subordinate lines to contribute to line broadening, supporting the neglect of avoided ionic crossings by Anstee, Barklem and O'Mara for these lines. The large discrepancies between the two sets of calculations is a result of an approximate treatment of avoided ionic crossings for these lines by Leininger et al (2000).Comment: 18 pages, 5 ps figures included, to appear in J Phys B: At. Mol. Opt. Phy

Combining the in vivo comet and micronucleus assays: a practical approach to genotoxicity testing and data interpretation

Despite regulatory directives requiring the reduction of animal use in safety testing, recent modifications to genotoxicity testing guidelines now propose the use of two in vivo genotoxicity assays as a follow-up to an in vitro positive (International Conference on Harmonization Consensus Draft Guidance S2[R1] released March, 2008). To address both goals, the in vivo comet and micronucleus (MN) assays can be successfully combined into one informative study. Combining these two assays with such differences in sensitivity, endpoints measured and the type of data generated significantly improves upon the current standard capabilities for detecting genotoxicity without requiring additional animals. But to take full advantage of the benefits of incorporating the comet assay in safety testing, these same differences must be recognized and considered. Developed from over 15 years experience using the in vivo comet and MN assays in genotoxicity testing of chemicals and pharmaceuticals, this paper presents guidelines for the appropriate experimental design, dose selection and data interpretation for combined in vivo comet/MN assay studies. To illustrate the approach, data from combined assay studies are presented and discussed