18,412 research outputs found

    Gender Diversity around the World: The Role of Country Legal Regulations and Culture

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    The goal of this project is to analyze the factors that contribute to the gender discrepancy in labor force participation rates around the world. This paper will explore potential drivers of the gender disparity phenomenon through the analyzation of country-specific elements to detect related impacts that may be imposed on a country’s composition of labor force as it relates to gender. More specifically, I interpret the degree to which specific factors can directly influence the proportion of female presence in labor forces around the world. My empirical results suggest that the societal factors, legal regulations, culture, total fertility rate (births per woman) are all determinants of female labor force participation rates by country. My results confirm theoretical and economic theories, as well as findings from existing literature. It is of upmost importance to study these relationships as they explain much of the labor force participation rates around the world

    Chimpanzee hunting behavior

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    The pursuit, capture and consumption of small-and medium-sized vertebrates, appears to be typical of all chimpanzee (Pan troglodytes) populations, although large variation exists. Red colobus monkeys (Piliocolobus sp.) appear to be the preferred prey but intensity and frequency of hunting varies from month to month and between populations. Hunting is a predominately male activity and is typically opportunistic, although there is some evidence of searching for prey. The degree of cooperation during hunting, as well as prey selection, varies between East and West African populations and may be related to the way the kill is divided: in West Africa, hunters often collaborate, with kills tending to be shared according to participation, whereas in East Africa, the kill is typically divided tactically by the male in possession of the carcass, trading meat with females in return for sex or with other males to strengthen alliances, and cooperation in hunting is more limited. The adaptive function of chimpanzee hunting is not well understood, although it appears that it may be both a means to acquire a nutritionally valuable commodity that can then be traded and as a means for males to display their prowess and reliability to one another

    The structure of the leaf and peristome of Holomitriopsis laevifolia (Broth.) H. Robins : illustrated with scanning electron microscopy

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    The vegetative and sporophytic features of Holomitriopsis that distinguish this genus from Schistomitrium and from Leucobryum are discussed and illustrated using scanning electron microscopy

    Study of ice accretion on icing wind tunnel components

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    In a closed loop icing wind tunnel the icing cloud is simulated by introducing tiny water droplets through an array of nozzles upstream of the test section. This cloud will form ice on all tunnel components (e.g., turning vanes, inlet guide vanes, fan blades, and the heat exchanger) as the cloud flows around the tunnel. These components must have the capacity to handle their icing loads without causing significant tunnel performance degradation during the course of an evening's run. To aid in the design of these components for the proposed Altitude Wind Tunnel (AWT) at NASA Lewis Research Center the existing Icing Research Tunnel (IRT) is used to measure icing characteristics of the IRT's components. The results from the IRT are scaled to the AWT to account for the AWT's larger components and higher velocities. The results show that from 90 to 45 percent of the total spray cloud froze out on the heat exchanger. Furthermore, the first set of turning vanes downstream of the test section, the FOD screen and the fan blades show significant ice formation. The scaling shows that the same results would occur in the AWT

    Bystanders, parcelling, and an absence of trust in the grooming interactions of wild male chimpanzees

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    The evolution of cooperation remains a central issue in socio-biology with the fundamental problem of how individuals minimize the risks of being short-changed (‘cheated’) should their behavioural investment in another not be returned. Economic decisions that individuals make during interactions may depend upon the presence of potential partners nearby, which o ers co operators a temptation to defect from the current partner. The parcelling model posits that donors subdivide services into parcels to force cooperation, and that this is contingent on opportunities for defection; that is, the presence of bystanders. Here we test this model and the e ect of bystander presence using grooming interactions of wild chimpanzees. We found that with more bystanders, initiators gave less grooming at the beginning of the bout and were more likely to abandon a grooming bout, while bouts were less likely to be reciprocated. We also found that the groomer’s initial investment was not higher among frequent groomers or stronger reciprocators, suggesting that contrary to current assumptions, grooming decisions are not based on trust, or bonds, within dyads. Our work highlights the importance of considering immediate social context and the in uence of bystanders for understanding the evolution of the behavioural strategies that produce cooperation

    Sets with few distinct distances do not have heavy lines

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    Let PP be a set of nn points in the plane that determines at most n/5n/5 distinct distances. We show that no line can contain more than O(n43/52polylog(n))O(n^{43/52}{\rm polylog}(n)) points of PP. We also show a similar result for rectangular distances, equivalent to distances in the Minkowski plane, where the distance between a pair of points is the area of the axis-parallel rectangle that they span

    Nitrogen removal during summer and winter in a primary facultative WSP pond: preliminary findings from 15N-labelled ammonium tracking techniques

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    Nitrogen removal mechanisms and pathways within WSP have been the focus of much research over the last 30 years. Debates and theories postulated continue to refine our knowledge regarding the cycling and removal pathways for this important nutrient, but a succinct answer has yet to be provided for holistic nitrogen removal. In this study, two experimental runs using labelled 15N as a stable isotope tracking technique were conducted on a pilot-scale primary facultative WSP in the UK; one in the summer of 2006, and the other in the winter of 2007. An ammonium chloride (15NH4Cl) spike was prepared as the slug for each experimental run, which also contained rhodamine WT to act as a dye tracer enabling the hydraulic characteristics of the pond to be mapped. Initial results from the study are reported here, and findings are compared and contrasted. Preliminary findings reveal that a greater proportion of 15N is incorporated into the algal biomass by assimilation and subsequent release as soluble organic nitrogen in summer than in winter. 15N ammonium passes out of the system much sooner and in a much higher proportion in the winter than in summer

    A data storage, retrieval and analysis system for endocrine research

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    This retrieval system builds, updates, retrieves, and performs basic statistical analyses on blood, urine, and diet parameters for the M071 and M073 Skylab and Apollo experiments. This system permits data entry from cards to build an indexed sequential file. Programs are easily modified for specialized analyses

    Preparing Undergraduates for Research Careers: Using Astrobites in the Classroom

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    Because undergraduate participation in research is a longstanding and increasingly important aspect of the career path for future scientists, students can benefit from additional resources to introduce them to the culture and process of research. We suggest the adoption of the web resource Astrobites as a classroom tool to increase the preparation of undergraduate physics and astronomy students for careers in research. We describe the content and development of the website, discuss previous university courses that have made use of Astrobites, and suggest additional strategies for using Astrobites in the classroom.Comment: Published in the Astronomy Education Revie
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