germ cell-less Acts to Repress Transcription during the Establishment of the Drosophila Germ Cell Lineage

AbstractPreviously, it has been shown that, during early Drosophila and C. elegans development, the germ cell precursors undergo a period of transcriptional quiescence [1–4]. Here, we report that Germ cell-less (GCL), a germ plasm component necessary for the proper formation of “pole cells,” the germ cell precursors in Drosophila[5, 6], is required for the establishment of this transcriptional quiescence. While control embryos silence transcription prior to pole cell formation in the pole cell-destined nuclei, this silencing does not occur in embryos that lack GCL activity. The failure to establish quiescence is tightly correlated with failure to form the pole cells. Furthermore, we show that GCL can repress transcription of at least a subset of genes in an ectopic context, independent of other germ plasm components. Our results place GCL as the earliest gene known to act in the transcriptional repression of the germline. GCL's subcellular distribution on the nucleoplasmic surface of the nuclear envelope [7] and its effect on transcription suggest that it may act to repress transcription in a manner similar to that proposed for transcriptional silencing of telomeric regions

germ cell-less Is Required Only during the Establishment of the Germ Cell Lineage of Drosophila and Has Activities Which Are Dependent and Independent of Its Localization to the Nuclear Envelope

AbstractThe germ cell precursors of Drosophila (pole cells) are specified by maternally supplied germ plasm localized to the posterior pole of the egg. One component of the germ plasm, germ cell-less (gcl) mRNA, encodes a novel protein which specifically localizes to the nuclear envelope of the pole cell nuclei. In addition to its maternal expression, gcl is zygotically expressed through embryonic development. In this report, we have characterized a null allele of germ cell-less to determine its absolute requirement during development. We have found that gcl activity is required only for the establishment of the germ cell lineage. Most embryos lacking maternal gcl activity fail to establish a germline. No other developmental defects were detected. Examination of germline development in these mutant embryos revealed that gcl activity is required for proper pole bud formation, pole cell formation, and pole cell survival. Using this null mutant we have also assayed the activity of forms of Gcl protein with altered subcellular distribution and found that localization to the nuclear envelope is crucial for promoting pole cell formation, but not necessary to initiate and form proper pole buds. These results indicate that gcl acts in at least two different ways during the establishment of the germ cell lineage

3rd Annual Federal Practice Institute

Outline of speakers\u27 presentations from the 3rd Annual Federal Practice Institute held by UK/CLE on September 23, 1988

A pragmatic cluster randomised trial evaluating three implementation interventions

Background Implementation research is concerned with bridging the gap between evidence and practice through the study of methods to promote the uptake of research into routine practice. Good quality evidence has been summarised into guideline recommendations to show that peri-operative fasting times could be considerably shorter than patients currently experience. The objective of this trial was to evaluate the effectiveness of three strategies for the implementation of recommendations about peri-operative fasting. Methods A pragmatic cluster randomised trial underpinned by the PARIHS framework was conducted during 2006 to 2009 with a national sample of UK hospitals using time series with mixed methods process evaluation and cost analysis. Hospitals were randomised to one of three interventions: standard dissemination (SD) of a guideline package, SD plus a web-based resource championed by an opinion leader, and SD plus plan-do-study-act (PDSA). The primary outcome was duration of fluid fast prior to induction of anaesthesia. Secondary outcomes included duration of food fast, patients' experiences, and stakeholders' experiences of implementation, including influences. ANOVA was used to test differences over time and interventions. Results Nineteen acute NHS hospitals participated. Across timepoints, 3,505 duration of fasting observations were recorded. No significant effect of the interventions was observed for either fluid or food fasting times. The effect size was 0.33 for the web-based intervention compared to SD alone for the change in fluid fasting and was 0.12 for PDSA compared to SD alone. The process evaluation showed different types of impact, including changes to practices, policies, and attitudes. A rich picture of the implementation challenges emerged, including inter-professional tensions and a lack of clarity for decision-making authority and responsibility. Conclusions This was a large, complex study and one of the first national randomised controlled trials conducted within acute care in implementation research. The evidence base for fasting practice was accepted by those participating in this study and the messages from it simple; however, implementation and practical challenges influenced the interventions' impact. A set of conditions for implementation emerges from the findings of this study, which are presented as theoretically transferable propositions that have international relevance. Trial registration ISRCTN18046709 - Peri-operative Implementation Study Evaluation (POISE

Current Issues in Environmental Law

Materials from the Current Issues in Environmental Law seminar held by UK/CLE in April 1995

The Perceived Benefits of Height: Strength, Dominance, Social Concern, and Knowledge among Bolivian Native Amazonians

Research in industrial countries suggests that, with no other knowledge about a person, positive traits are attributed to taller people and correspondingly, that taller people have slightly better socioeconomic status (SES). However, research in some non-industrialized contexts has shown no correlation or even negative correlations between height and socioeconomic outcomes. It remains unclear whether positive traits remain attributed to taller people in such contexts. To address this question, here we report the results of a study in a foraging-farming society of native Amazonians in Bolivia (Tsimane’)–a group in which we have previously shown little association between height and socioeconomic outcomes. We showed 24 photographs of pairs of Tsimane’ women, men, boys, and girls to 40 women and 40 men >16 years of age. We presented four behavioral scenarios to each participant and asked them to point to the person in the photograph with greater strength, dominance, social concern, or knowledge. The pairs in the photographs were of the same sex and age, but one person was shorter. Tsimane’ women and men attributed greater strength, dominance, and knowledge to taller girls and boys, but they did not attribute most positive traits to taller adults, except for strength, and more social concern only when women assessed other women in the photographs. These results raise a puzzle: why would Tsimane’ attribute positive traits to tall children, but not tall adults? We propose three potential explanations: adults’ expectations about the more market integrated society in which their children will grow up, height as a signal of good child health, and children’s greater variation in the traits assessed corresponding to maturational stages

Space of Vulnerability in Poverty and Health: Political Ecology and Biocultural Analysis

In this article I present a political-ecological approach for biocultural analyses that attempts to synthesize perspectives from anthropological political economy and those from ecological anthropology and human adaptability approaches. The approach is used to examine contexts and consequences of vulnerability among Andean peoples in southern Peru, and specifically the ongoing and dialectical relationships between poverty, illness, and household production. Household demographic composition, class position, economic status, and interpersonal relations are all important in shaping their experience with illness, and coping capacity in dealing with the consequences of illness on household livelihood. I suggest that the contexts and consequences of vulnerability among rural producers in southern Peru contributed in part to the spread of the Sendero Luminoso revolutionary movement into the region in the late 1980s and early 1990s

Coca-colonization of diets in the Yucatan

Over the past three decades, tourism-based economic development has transformed social and economic conditions in the Yucatan Peninsula, Mexico. Mayan communities have become directly involved in the changing economy as the main source of inexpensive labor for construction and service jobs at tourism centers, and as sites of ecotourism and archeotourism. In this paper, we address how these macro-processes of change intersect locally with the commoditization of food systems, diets and nutrition in four Yucatec Mayan communities with differing relationships to the tourist economy. Yucatec Mayan diets have become increasingly dependent on purchased foods, and reflect a greater consumption of commercialized processed foods. Coca-Cola, an international icon of US culture, along with other local and internationally owned calorie-dense but nutrient-poor snack foods, is now a common element of Mayan diets, leading to what we call "coca-colonization." The consequences of this diet, likely exacerbated by the increased consumption of snack foods, include an apparent increase in overweight and obese adults as well as signs of growth stunting in children. The Maya we talked with recognize both the potential disruption that tourism brings to all aspects of their lives and the necessity of jobs that tourism creates to meet their families' basic needs.Maya Yucatan Tourism Food commoditization Dietary change Coca-colonization Mexico

Changes in stature, weight, and nutritional status with tourism-based economic development in the Yucatan

Over the past 40 years, tourism-based economic development has transformed social and economic conditions in the Yucatan Peninsula, Mexico. We address how these changes have influenced anthropometric indicators of growth and nutritional status in Yalcoba, a Mayan farming community involved in the circular migration of labor in the tourist economy. Data are presented on stature and weight for children measured in 1938 in the Yucatan Peninsula and from 1987 to 1998 in the Mayan community of Yalcoba. In addition, stature, weight and BMI are presented for adults in Yalcoba based on clinic records. Childhood stature varied little between 1938 and 1987. Between 1987 and 1998 average male child statures increased by 2.6 cm and female child statures increased by 2.7 cm. Yet, 65% of children were short for their ages. Between 1987 and 1998, average child weight increased by 1.8 kg. Child BMIs were similar to US reference values and 13% were considered to be above average for weight. Forty percent of adult males and 64% of females were overweight or obese. The anthropometric data from Yalcoba suggest a pattern of stunted children growing into overweight adults. This pattern is found elsewhere in the Yucatan and in much of the developing world where populations have experienced a nutrition transition toward western diets and reduced physical activity levels.Nutritional status Tourism Yucatan Mexico Nutrition transition