Novel components of Acacia mearnsii

From Summary: From the complex mixture of flavonoid components present in the heartwood of the black wattle tree (Acacia mearnsii) four new compounds have been isolated. These include a novel dioxane-linked dimeric proanthocyanidin based on leucofisetinidin. This is the first proanthocyanidin of its type to be isolated from a natural source. I solation was achieved by standard counter current partition separation and preparative paper chromatographic techniques. The compound, which forms an anthocyanidin, was identified by micro-degradation, and n.m.r. and mass spectrometry. Comparison of the spin-spin coupling constants of the heterocylic rings' protons with those of authentic monomeric flavan-3, 4-diols showed that the heterocyclic rings of the two symmetrical flavan moeities have 2,3-trans-3,4-cis configurations. Dreiding models suggest that the central dioxane ring has a half-boat conformation while the heterocyclic rings of the two flavan units have five point coplanar conformations. Two possible absolute configurations have been propose

Feminist Life Stories: Twelve Journeys Come Together at a Women\u27s Center

This study explores the personal narratives of twelve self-proclaimed feminists who started a women\u27s center in a small conservative mid-west town. Our common herstories are not identical but reveal learning experiences imbedded in our social and cultural contexts. These social and cultural contexts, however varied, held common threads of the pedagogies we experienced in formal and informal settings. These pedagogies held traditions that are often passed on without question because we are not always aware of their presence. The stories allowed us to reflect on the traditions in our lives in order to come to terms with our past and present realities. As we each learned to be girls, women and feminists, we accepted the rewards of connection and acknowledged the struggle for self-definition. This research chronicles the learning journeys we each took as we came of age in the 50s, 60s, and 70s

A statistical model relating transcription factor concentrations to positional information in the early Drosophila embryo

The idea of morphogen gradients encoding positional information for a developing organism has long been discussed in the field of developmental biology, but only recently have quantitative models been proposed that relate measured transcription factor concentrations to enhancer activity. However, successful models are typically computationally time-consuming, thus limiting full exploration and interpretation of the data. This thesis addresses these problems using standard statistical techniques applied to a comprehensive data set with the even skipped (eve) locus as a test case. The first part of the thesis introduces the data set. This is the precellular Virtual Embryo from the Berkeley Drosophila Transcription Network project. It comprises expression measurements of almost 100 genes in more than 6,000 individual nuclei at six time points. Different modelling approaches are evaluated in the context of this data set leading to a justification of logistic regression and the methods used to prepare the data set for further analysis. The second part applies logistic regression to describe the response of the eve enhancers to known regulating transcription factors such as Hunchback. Predictions of behaviour under regulator perturbation are consistent with experimental results and the functional form is shown not to be arbitrarily flexible, both in terms of the regulators and regions of the embryo included. The third part uses the framework developed above to find minimal explanatory models in the context of statistical model selection. It is found that the best scoring models depend on well-known regulators. The model selection techniques are then extended by directing the process using previous biological observations to analyse the eve 2 and eve 3+7 enhancers. The results are consistent with published research, but suggest specific additional hypotheses for the enhancers’ regulation. Finally, the thesis concludes by proposing a general model of positional information and discussing the biological implications of the results. Overall, the results show how transcriptional control can be allocated to discrete enhancers and that characterising their activity in relatively simple terms is sufficient to explain their precise spatially-defined response to transcription factor concentrations

"On the Internet Nobody Knows You're an Expert": Social Influence in Computer Mediated Communication

The focus of this research is on the use of computers as a communication medium, specifically for social purposes, and considers how computer-mediated communication (CMC) might affect persuasion and attitude change processes. The studies are organised around the framework of the classical message learning approach to persuasion (the effects of the source, message, channel and recipient), and the process of persuasion is considered, as well as the final outcome (attitude change). In order to give a more complete view of the influence process, both quantitative and qualitative approaches were taken. Also, both laboratory-based and field-based studies were carried out, which gives greater ecological validity to the research. Five studies were carried out, considering different aspects of the influence process, ranging from examination of source characteristics to the effects of the computer based medium on discussions, and subsequent attitude change. Although some attitude change was found, the medium (computer-based or face-to-face) appeared to have no real effect. However, it was found that the different media had an effect on other aspects of the influence process, particularly on perceptions of the source, and the actual discussion content. An alternative theoretical approach is proposed, based on McGuire's reception yielding model, which provides an explanation of some inconsistencies in both the present and previous research. The reading of a CMC message follows a set sequence of stages, which allows it to be rejected without further processing at different points. Within this process, the information that is significant to the recipient changes, and acts as a weighting for following information. However, in a laboratory-based study this sequence is entered at different points, depending on the experimental focus, and so this process is altered or bypassed entirely, creating a bias towards different information. This would, therefore, need to be taken into account for the comparison of results

Culturally Appropriate Adaptation of an Evidence-Based HIV Prevention Program for Latinas in North Carolina

The purpose of this paper is to discuss the results of a literature review of culturally appropriate HIV prevention programs for Latinas, and provide recommendations for implementation of such a program in North Carolina. Latinas in North Carolina are disproportionately affected by HIV/AIDS. (2) Currently in the state of North Carolina no programs exist to meet the priorities and HIV/AIDS prevention needs of recently arrived and less acculturated immigrant Latinas who are settling and making North Carolina home.Master of Public Healt

Mathematics and physical science choices made by pupils in selected Eastern Cape high schools: an investigation into the factors influencing the different choice patterns of boys and girls

The disparate numbers of boys and girls who elect to continue with mathemalics and/or physical science in the higher slandards of the school system has recently attracted much research atlention and the complexity of the interrelaledness of causal factors has become obvious. The broad aim of the study was to investigale the significant drop-out rate of girls at the end of the junior secondary phase of education (approximate age of fourteen lo fifteen). This was to be carried out for mathematics and physical science and undertaken using a cross-sectional and a longitudinal study. The cross-sectional study entailed administering mathematics and physical science attitude questionnaires to 3531 standard six, seven and eight pupils from 4 co-educational, 2 allgirls' and 2 all-boys' schools, from middle and upper socioeconomic communities with similar language and cultural backgrounds . The longitudinal study involved pupils from two coeducational schools and one all-girls' school. It was a progressively-focused study starting with questionnaires administered to 358 standard six girls and boys, narrowing down to questionnaires and interviews used with 50 girls and 28 boys in standard seven and finally to interviews with 10 girls from standard eight. The parents of these ten girls were interviewed at the end of the study. The attilude questionnaires yielded strong sex differences which favoured the boys in both subjects for all the attitudes measured and also pointed to a progressive deterioralion of altitudes over the three-standard span. They also established significant differences in attitudes which favoured the pupils from Single-sex schools. It was further concluded that the girls were more strongly guided by their attitudes when making their subject-choice decisions. In the longitudinal study, reasons were suggested for pupils either taking or dropping mathematics and physical science. The introduction of algebra in the first year of high school presented a problem to pupils. In physical science, electricity was singled out as giving the subject a male bias. Socialization influences in the home were the main issue dealt with from the parent interviews . Sex-roles and stereotypes were dealt with in depth. Recommendations were made involving classroom strategies, curriculum possibilities, school policies and further researc

Evaluation of the Site Investigation and Construction Related Aspects of the Milwaukee\u27s Crosstown Deep Tunnel

The excavation of the 21,300 foot long, 32.33 foot diameter Crosstown Phase I Tunnel was completed by tunnel boring machine at an average rate of 108 feet per 3 shift day. No geologic conditions were encountered which were sufficiently adverse to impede the work. The geotechnical report combined with contract provisions prevented the unusual conditions encountered from becoming issues that delayed the work. It is probable that the monetary aspects related to these unusual conditions can be equitably resolved using the geotechnical data “base line” portrayed in the geotechnical report

Finding cell-specific expression patterns in the early Ciona embryo with single-cell RNA-seq

Single-cell RNA-seq has been established as a reliable and accessible technique enabling new types of analyses, such as identifying cell types and studying spatial and temporal gene expression variation and change at single-cell resolution. Recently, single-cell RNA-seq has been applied to developing embryos, which offers great potential for finding and characterising genes controlling the course of development along with their expression patterns. In this study, we applied single-cell RNA-seq to the 16-cell stage of the Ciona embryo, a marine chordate and performed a computational search for cell-specific gene expression patterns. We recovered many known expression patterns from our single-cell RNA-seq data and despite extensive previous screens, we succeeded in finding new cell-specific patterns, which we validated by in situ and single-cell qPCR