4,056 research outputs found

    Fifty per cent and all that: what Haldane actually said

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    In 1924, J. B. S. Haldane used the observation of increasing melanic frequencies in peppered moths (Biston betularia L.) to illustrate strong selection in a natural population. Since the phenomenon was first observed, there has been criticism and misinterpretation of work on industrial melanism in moths coming from a number of directions, increasingly on the Internet. Haldane’s calculation, its reception and his other interests in peppered moths are reviewed. An example of Internet comments attributing opinions to him, and their origin and background, are discussed

    Emerging HE cultures:Perspectives from CETL award holders in a partner college network.

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    Expansion of higher education (HE) into the further education (FE) sector has resulted in a renewed period of growth as colleges strive to create a culture and environment appropriate for HE. This article presents findings from interviews with lecturers delivering HE in FE within the University of Plymouth Partner College network and explores the perceived impact of HE expansion. Lecturers felt that expansion had a positive impact on their students, as raising the profile of HE within their colleges has encouraged internal progression. However, practitioners’ own experiences have been mixed. They felt there was limited recognition or understanding of the needs of HE from many of their FE colleagues, suggesting the presence of structural, education and managerial processes that may need to be considered in light of the emerging culture of HE. In our study, the emerging HE culture within colleges appears to reflect a combination of the FE profile of the college, the non-traditional nature of the student body, the HE processes instigated through collaboration with the university, and the emerging HE identity of lecturers

    Lack of Variation at Phosphoglucose Isomerase (Pgi) in Bumblebees: Implications for Conservation Genetics Studies

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    Assessing genetic variation underlying ecologically important traits is increasingly of interest and importance in population and conservation genetics. For some groups generally useful markers exist for examining the relative role of selection and drift in shaping genetic diversity e.g. the major histocompatibility complex in vertebrates and self-incompatibility loci in plants. For invertebrates there is no such generally useful locus. However, phosphoglucose isomerase (Pgi) has been proposed as a useful functional marker in the conservation genetics of invertebrates. Where thermal microclimate varies, balanced polymorphisms may be maintained due to trade-offs between thermally stable and kinetically advantageous allelic forms. We here report very low levels of Pgi variation in bumblebees rendering this locus to be of little use as an adaptive marker in a conservation genetics context in this group. Potential explanations for this lack of variation are considered

    Gitksan medicinal plants-cultural choice and efficacy

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    BACKGROUND: The use of plants for healing by any cultural group is integrally related to local concepts of the nature of disease, the nature of plants, and the world view of the culture. The physical and chemical properties of the plants themselves also bear on their selection by people for medicines, as does the array of plants available for people to choose from. I examine use of medicinal plants from a "biobehavioral" perspective to illuminate cultural selection of plants used for medicine by the Gitksan of northwestern British Columbia, Canada. METHODS: Consultant consensus, "intercultural consensus", independent use of the same plants by other cultural groups, and phytochemistry and bioassay results from the literature, were employed in analysis of probable empirical efficacy of plant uses. RESULTS: 70% of 37 Gitksan medicinal plants were used similarly by other cultures where direct diffusion is not known to have occurred; eleven plants, including the eight most frequently mentioned medicinal plants, also show active phytochemicals or bioassays indicating probable physiologically based therapeutic effects. CONCLUSION: Analysis of intercultural consensus revealed that the majority of cultures in the British Columbia region within the plant ranges use the same plants, or closely related species, in similar ways. The rigor of this analysis is effected by the lack of consistent data on all taxa of interest for all cultures within the region

    Mineral maturity and crystallinity index are distinct characteristics of bone mineral

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    The purpose of this study was to test the hypothesis that mineral maturity and crystallinity index are two different characteristics of bone mineral. To this end, Fourier transform infrared microspectroscopy (FTIRM) was used. To test our hypothesis, synthetic apatites and human bone samples were used for the validation of the two parameters using FTIRM. Iliac crest samples from seven human controls and two with skeletal fluorosis were analyzed at the bone structural unit (BSU) level by FTIRM on sections 2–4 lm thick. Mineral maturity and crystallinity index were highly correlated in synthetic apatites but poorly correlated in normal human bone. In skeletal fluorosis, crystallinity index was increased and maturity decreased, supporting the fact of separate measurement of these two parameters. Moreover, results obtained in fluorosis suggested that mineral characteristics can be modified independently of bone remodeling. In conclusion, mineral maturity and crystallinity index are two different parameters measured separately by FTIRM and offering new perspectives to assess bone mineral traits in osteoporosis

    Heritability of Lumbar Trabecular Bone Mechanical Properties in Baboons

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    Genetic effects on mechanical properties have been demonstrated in rodents, but not confirmed in primates. Our aim was to quantify the proportion of variation in vertebral trabecular bone mechanical properties that is due to the effects of genes. L3 vertebrae were collected from 110 females and 46 male baboons (6–32 years old) from a single extended pedigree. Cranio-caudally oriented trabecular bone cores were scanned with microCT then tested in monotonic compression to determine apparent ultimate stress, modulus, and toughness. Age and sex effects and heritability (h2) were assessed using maximum likelihood-based variance components methods. Additive effects of genes on residual trait variance were significant for ultimate stress (h2 = 0.58), toughness (h2 = 0.64), and BV/TV (h2 = 0.55). When BV/TV was accounted for, the residual variance in ultimate stress accounted for by the additive effects of genes was no longer significant. Toughness, however, showed evidence of a non-BV/TV-related genetic effect. Overall, maximum stress and modulus show strong genetic effects that are nearly entirely due to bone volume. Toughness shows strong genetic effects related to bone volume and shows additional genetic effects (accounting for 10% of the total trait variance) that are independent of bone volume. These results support continued use of bone volume as a focal trait to identify genes related to skeletal fragility, but also show that other focal traits related to toughness and variation in the organic component of bone matrix will enhance our ability to find additional genes that are particularly relevant to fatigue-related fractures

    The application of the sustainable livelihood approach to small scale-fisheries: The case of mud crab Scylla serrata in South west India

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    The sustainable livelihood approach is an analytical framework that helps identifying the assets that local communities rely on, the risks they are subjected to, organisations and institutions influence their daily lives and the strategies they undertake. This is a valuable approach in small-scale fisheries management as artisanal fisheries are exposed to uncertainty in terms of supply and demand, and fishing activities usually are influenced by social and institutional factors. However, in spite of its usefulness and the fact that this approach has been previously used in projects targeting small-scale fisher communities, it is still not widely applied to small-scale fisheries. In this study we applied the sustainable livelihood approach as an analytical tool to assess the potential of the mud crab Scylla serrata as a sustainable livelihood resource for the southwest Indian states such as Karnataka. As fishers worldwide face continuous pressure from industrial fishing fleets and decreased fish stocks and their productivity, we also identified what could be the potential barriers to small-scale mud crab farming for communities that are already are involved in mud crab fishing. Data were collected and analysed from a semi-structured questionnaire, two focus group discussions and key informant interviews conducted in Uttara Kannada district, Karnataka. The results indicated that though mud crab is perceived as a good source of income in this area, at present it is not recognised as a steady source of income due to the unpredictable fishery catches. Respondents were aware of mud crab farming yet stated the lack of land and financial resources as the main barriers and only the minority expressed any interest in undertaking such activity. The sustainable livelihood approach proved to be a valuable research tool for identifying matters of concern for local communities regarding their source of livelihoods and barriers to small-scale aquaculture.</p
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