7,233 research outputs found

    Preliminary Observations of the Jovian 6190A Methane Band

    Get PDF
    Width of Jovian 6190A methane ban

    Evidence for an impact-induced biosphere from the δ34S signature of sulphides in the Rochechouart impact structure, France

    Get PDF
    The highly eroded 23 km diameter Rochechouart impact structure, France, has extensive evidence for post-impact hydrothermal alteration and sulphide mineralization. The sulphides can be divided into four types on the basis of their mineralogy and host rock. They range from pyrites and chalcopyrite in the underlying coherent crystalline basement to pyrites hosted in the impactites. Sulphur isotopic results show that δ34S values vary over a wide range, from -35.8‰ to +0.4‰. The highest values, δ34S -3.7‰ to +0.4‰, are recorded in the coherent basement, and likely represent a primary terrestrial sulphur reservoir. Sulphides with the lowest values, δ34S -35.8‰ to -5.2‰, are hosted within locally brecciated and displaced parautochthonous and autochthonous impactites. Intermediate δ34S values of -10.7‰ to -1.2‰ are recorded in the semi-continuous monomict lithic breccia unit, differing between carbonate-hosted sulphides and intraclastic and clastic matrix-hosted sulphides. Such variable isotope values are consistent with a biological origin, via bacterial sulphate reduction, for sulphides in the parautochthonous and autochthonous units; these minerals formed in the shallow subsurface and are probably related to the post impact hydrothermal system. The source of the sulphate is likely to have been seawater, penecontemporaneous to the impact, as inferred from the marginal marine paleogeography of the structure. In other eroded impact craters that show evidence for impact-induced hydrothermal circulation, indirect evidence for life may be sought isotopically within late-stage (≤120°C) secondary sulphides and within the shocked and brecciated basement immediately beneath the transient crater floor

    Stable Isotope Studies of the Rochechouart Impact Structure: Sources of Secondary Carbonates and Sulphides within Allochthonous and Parautochthonous Impactites

    Get PDF
    Hypervelocity impacts are among the most ubiquitous processes to affect solid bodies within our solar system [1, 2]. Although they are notoriously devastating, citing responsibility for mass extinction events and global climate perturbations, impacts can also create temporary environments which are favorable for life to thrive, if there is enough water present in the target, and sufficient energy is released as heat [1, 2]. One-third of impact structures on Earth contain fossil impact-initiated hydrothermal systems, and they are therefore being explored as potential “cradles of life” on other solid planets and satellites in our solar system [1].<p></p> We are presenting a case for the evaluation of the Mesozoic Rochechouart impact structure in France as a once-habitable environment. Initial δ 13C, δ18O and δ 34S isotope data collected in 2014 from hydrothermal carbonates and sulphides within monomict lithic impact breccia, collected from a site located 7.5km from the center of the structure at Champagnac quarry, supports our hypothesis of a warm, wet environment; we also found evidence for metabolically reduced sulphate [3]. Similar mineral assemblages can be found throughout the structure, including allochthonous breccias and low to unshocked target material. In order to explore our hypothesis further, a larger sample set was collected from various lithologies within the Champagnac site containing sulphide and carbonate mineralization for δ 13C, δ18O and δ34S isotope analysis in January 2015. These results will allow us to determine the relationships between the many hydrothermal mineral assemblages within this area of the structure, and ask whether the isotopic compositions recorded in secondary sulphides and carbonates of the impactites are inherited from the target, or possibly represent colonization by thermophilic microbes during the post-impact hydrothermal period.<p></p&gt

    La Iglesia, una y visible, en la vida y pensamiento de Newman

    Get PDF

    Livelihood, Exclusion and Opportunity: Socioeconomic Welfare among Gender and Sexuality Non-normative People in India

    Get PDF
    In 2014, its 67th year as a sovereign country with a population of 1.21 billion (Government of India 2011a), India is the second most populous country in the world, the most populous democracy and has the longest written constitution among all sovereign countries. Its gross domestic product (GDP) is ranked tenth in the world (out of 184 countries) when measured through current prices (2014) and third on the basis of purchasing power parity (IMF 2014). In 1990, just before India embarked on an unprecedented economic liberalisation, the ranking by current prices was eleventh but by purchasing power parity it was ninth, indicating a significant jump forward in a 25-year period. Commensurate with the GDP growth (from around 5.5 per cent in the early 1990s to a peak of 10.3 per cent in 2010) (World Bank 2014), in spite of differences in poverty measurement between the Government of India, World Bank and the United Nations Development Programme, it is widely believed that there was significant reduction in poverty and that the government’s emphasis on economic growth was responsible for this (Aiyar 2011). Against this background, this case study explores the socioeconomic experiences of gender and sexuality minority peoples in India, especially in respect of ways in which sexual and gender ‘difference’ may be correlated to economic hardship and restricted opportunities for livelihood in the context of Indian socioeconomic ‘modernity’. Growth of economic opportunity through neoliberal models of economic expansion is typically achieved via the extension of economic opportunity for some people amidst the endurance of ongoing socioeconomic precarity for most others. In this report we consider these issues in the context of livelihood, poverty, economic opportunity and restraint in the lives of gender and sexuality non-conforming people in India, with a specific focus on the eastern Indian states of Odisha and Manipur. These sites were chosen because in the last five years they have been among the states that have witnessed a number of community, government, non-governmental organisation and donor-backed initiatives undertaken on economic inclusion for people with non-normative genders and sexualities.UK Department for International Developmen

    Legal Aid Services in Malawi

    Get PDF
    This Article will acquaint the reader with the organization and operation of legal aid services in Malawi. The discussion of the program will survey the economic, social, and legal context within which the program operates, the constitutional framework and the practical operation of the whole scheme, including the administration of the Legal Aid Department, the recruitment and functioning of the professional staff, and the kind of cases with which the Department deals

    Effects of Apolipoprotein E, Sex, and Estrogen on the Neuroplasticity of Olfactory Receptor Neurons in Mice Following Olfactory Bulbectomy

    Get PDF
    Apolipoprotein E (apoE) is well studied for its role in cholesterol transportation and metabolizing lipoproteins. ApoE is found in the olfactory system especially in the olfactory nerve and glomeruli of the olfactory bulb. Studies from our laboratory indicate that apoE is a required component for timely regeneration and olfactory receptor neuron maturation. The mechanism for which apoE contributes to neuron function and developing late onset Alzheimer\u27s disease is still being studied. A mutant form of apoE (apoE 4) is believed to be a prominent genetic risk factor for this neurodegenerative disease. Over sixty percent of Alzheimer\u27s disease patients in the United Sates are women. This revelation has concentrated more focus on the loss of estrogen as a potential risk factor. To better understand how apoE and estrogen may contribute to Alzheimer\u27s disease, this study utilizes apoE knockout mice and estradiol treatment. Using the olfactory system as a model, the right olfactory bulb was removed from all treatments of wild type (WT) and apoE knockout (KO) mice. Retrograde olfactory receptor neuron death and regeneration was observed between males and females of both genotypes in the olfactory epithelium. The results show massive olfactory receptor neuron death within days of olfactory bulb ablation in male mice compared to their female counter part. When estrogen was given at above the physiological dose, the duration of neuroprotection increased. However, when no estrogen was present olfactory receptor neurons died faster. Overall, mice treated with estrogen exhibited a more rapid rate of regeneration regardless of the presence of apoE. Animals without apoE illustrated similar results to those with apoE but the average data values were slightly lower for apoE knockout mice than WTmice, illustrating that apoE is required for proper olfactory epithelium maintenance. These results were fairly consistent 4 throughout the data; however data for estradiol treated animals varied among genotypes. To measure the rate of olfactory receptor neuron death olfactory epithelium thickness was measured at 3, 7 and 21 days following olfactory bulbectomy. To observe the rate of death of mature olfactory receptor neurons olfactory marker protein (OMP) immunohistochemistry was performed. To gauge the rate of globose basal (stem) cell division bromodeoxyuridine (BrdU) immunohistochemistry was performed. By removing the olfactory bulb, the target for olfactory receptor neuron which served as the signal transduction, the olfactory epithelium fails to return to its original thickness suggesting olfactory receptor neuron maturity is dependent on proper target connectivity

    Same-Sex Sexualities, Gender Variance, Economy and Livelihood in Nepal: Exclusions, Subjectivity and Development

    Get PDF
    This case study explores the relationship between socioeconomic opportunity and exclusion in relation to minority gender and sexualities in Nepal. The study, a component of a wider programme on Sexuality, Poverty and Law supported by the Department for International Development (DFID) and undertaken at the Institute of Development Studies (IDS), aims to advance empirically grounded insights and recommendations to address the socioeconomic conditions of sexuality and gender minority peoples, in respect of varied aspects of life experience, subjectivity, self-identity and livelihood. Based on fieldwork conducted in Kathmandu, Nepal, between November 2013 and June 2014 the case study recounts experiences of socioeconomic marginalisation and opportunity as encountered and created by people who experience themselves as being different from socially normative conventions of sexuality and gender; in respect of the present research this has specifically entailed focusing on the experiences of transgender people and people who practise same-sex sexualities (and in respect of an understanding that such genders and sexualities are experienced differently by different people and do not represent uniform or singular categorisations). Many of the people who participated in the research evidence a multifaceted array of livelihood strategies as being connected to sexuality and gender difference. Some of these strategies were found to have been taken forward in the context of community-based support projects (for example, associated with non-governmental organisations (NGOs) for sexual and gender minorities) while others were conceived as independent life choices, or experienced as arising out of lack of choice or economic opportunity. In each of these often interconnected circumstances, the relationship between sexuality, gender, economy and livelihood emerges as complex and ambivalent.UK Department for International Developmen

    Effects of Apolipoprotein E, Sex, and Estrogen on the Neuroplasticity of Olfactory Receptor Neurons in Mice Following Olfactory Bulbectomy

    Get PDF
    Apolipoprotein E (apoE) is well studied for its role in cholesterol transportation and metabolizing lipoproteins. ApoE is found in the olfactory system especially in the olfactory nerve and glomeruli of the olfactory bulb. Studies from our laboratory indicate that apoE is a required component for timely regeneration and olfactory receptor neuron maturation. The mechanism for which apoE contributes to neuron function and developing late onset Alzheimer\u27s disease is still being studied. A mutant form of apoE (apoE 4) is believed to be a prominent genetic risk factor for this neurodegenerative disease. Over sixty percent of Alzheimer\u27s disease patients in the United Sates are women. This revelation has concentrated more focus on the loss of estrogen as a potential risk factor. To better understand how apoE and estrogen may contribute to Alzheimer\u27s disease, this study utilizes apoE knockout mice and estradiol treatment. Using the olfactory system as a model, the right olfactory bulb was removed from all treatments of wild type (WT) and apoE knockout (KO) mice. Retrograde olfactory receptor neuron death and regeneration was observed between males and females of both genotypes in the olfactory epithelium. The results show massive olfactory receptor neuron death within days of olfactory bulb ablation in male mice compared to their female counter part. When estrogen was given at above the physiological dose, the duration of neuroprotection increased. However, when no estrogen was present olfactory receptor neurons died faster. Overall, mice treated with estrogen exhibited a more rapid rate of regeneration regardless of the presence of apoE. Animals without apoE illustrated similar results to those with apoE but the average data values were slightly lower for apoE knockout mice than WTmice, illustrating that apoE is required for proper olfactory epithelium maintenance. These results were fairly consistent 4 throughout the data; however data for estradiol treated animals varied among genotypes. To measure the rate of olfactory receptor neuron death olfactory epithelium thickness was measured at 3, 7 and 21 days following olfactory bulbectomy. To observe the rate of death of mature olfactory receptor neurons olfactory marker protein (OMP) immunohistochemistry was performed. To gauge the rate of globose basal (stem) cell division bromodeoxyuridine (BrdU) immunohistochemistry was performed. By removing the olfactory bulb, the target for olfactory receptor neuron which served as the signal transduction, the olfactory epithelium fails to return to its original thickness suggesting olfactory receptor neuron maturity is dependent on proper target connectivity

    A Variational Monte Carlo Study of the Current Carried by a Quasiparticle

    Full text link
    With the use of Gutzwiller-projected variational states, we study the renormalization of the current carried by the quasiparticles in high-temperature superconductors and of the quasiparticle spectral weight. The renormalization coefficients are computed by the variational Monte Carlo technique, under the assumption that quasiparticle excitations may be described by Gutzwiller-projected BCS quasiparticles. We find that the current renormalization coefficient decreases with decreasing doping and tends to zero at zero doping. The quasiparticle spectral weight Z_+ for adding an electron shows an interesting structure in k space, which corresponds to a depression of the occupation number k just outside the Fermi surface. The perturbative corrections to those quantities in the Hubbard model are also discussed.Comment: 9 pages, 9 figure
    corecore