1,720 research outputs found

    Impact of climate change and bioenergy on nutrition

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    Food security has deteriorated since 1995 and reductions in child malnutrition are proceeding too slowly to meet the Millennium Development Goal (MDG) target for halving hunger by 2015. Three major challenges threaten to drastically complicate efforts to overcome food insecurity and malnutrition: climate change, the growing use of food crops as a source of fuel and soaring food prices. Food security has four dimensions: food availability, access to food, stability of supply and access and safe and healthy food utilization. It is a key factor in good nutrition, along with health, sanitation and care practices. Globally, one billion people are currently without access to safe water and over 2 billion lack adequate sanitation facilities. Present global food supplies are more than adequate to provide everyone with all the needed calories, if the food were equally distributed. But over 820 million people in developing countries have calorie-deficient diets; over 60 percent live in Sub-Saharan Africa and South Asia.Climate change, Bioenergy, Nutrition, food security, Food prices, Sustainable development,

    The Porcupine Survey: A Distributed Survey and WISE Followup

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    Spitzer post-cryogen observations to perform a moderate depth survey distributed around the sky are proposed. Field centers are chosen to be WISE brown dwarf candidates, which will typically be 160 µJy at 4.7 µm and randomly distributed around the sky. The Spitzer observations will give much higher sensitivity, higher angular resolution, and a time baseline to measure both proper motions and possibly parallaxes. The distance and velocity data obtained on the WISE brown dwarf candidates will greatly improve our knowledge of the mass and age distribution of brown dwarfs. The outer parts of the Spitzer fields surrounding the WISE positions will provide a deep survey in many narrow fields of view distributed around the sky, and the volume of this survey will contain many more distant brown dwarfs, and many extragalactic objects

    Incomplete Wood-Ljungdahl pathway facilitates one-carbon metabolism in organohalide-respiring Dehalococcoides mccartyi.

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    The acetyl-CoA "Wood-Ljungdahl" pathway couples the folate-mediated one-carbon (C1) metabolism to either CO2 reduction or acetate oxidation via acetyl-CoA. This pathway is distributed in diverse anaerobes and is used for both energy conservation and assimilation of C1 compounds. Genome annotations for all sequenced strains of Dehalococcoides mccartyi, an important bacterium involved in the bioremediation of chlorinated solvents, reveal homologous genes encoding an incomplete Wood-Ljungdahl pathway. Because this pathway lacks key enzymes for both C1 metabolism and CO2 reduction, its cellular functions remain elusive. Here we used D. mccartyi strain 195 as a model organism to investigate the metabolic function of this pathway and its impacts on the growth of strain 195. Surprisingly, this pathway cleaves acetyl-CoA to donate a methyl group for production of methyl-tetrahydrofolate (CH3-THF) for methionine biosynthesis, representing an unconventional strategy for generating CH3-THF in organisms without methylene-tetrahydrofolate reductase. Carbon monoxide (CO) was found to accumulate as an obligate by-product from the acetyl-CoA cleavage because of the lack of a CO dehydrogenase in strain 195. CO accumulation inhibits the sustainable growth and dechlorination of strain 195 maintained in pure cultures, but can be prevented by CO-metabolizing anaerobes that coexist with D. mccartyi, resulting in an unusual syntrophic association. We also found that this pathway incorporates exogenous formate to support serine biosynthesis. This study of the incomplete Wood-Ljungdahl pathway in D. mccartyi indicates a unique bacterial C1 metabolism that is critical for D. mccartyi growth and interactions in dechlorinating communities and may play a role in other anaerobic communities

    Misfit and milestones: structural elaboration and capability reinforcement in the evolution of entrepreneurial top management teams

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    We examine how "top management team (TMT) misfit," or discrepancies between the TMT's functional roles and the qualifications of the managers who fill those roles, affects the evolution of TMT composition and structure in a longitudinal study of entrepreneurial ventures. We distinguish two types of misfit--overqualification and underqualification-- and study how each is associated with TMT changes. We further consider the moderating effect of firm development. Results reveal that underqualified TMTs hire new managers to reinforce existing capabilities whereas overqualified TMTs elaborate their role structures. However, achieving developmental milestones (i.e., obtaining venture capital funding and staging an initial public offering) is a critical contingency to TMT change: absent these milestones, firms neither hire new managers nor add roles, even when they seemingly need to do so. These findings contribute to knowledge of how TMTs and new ventures evolve by underscoring the importance of simultaneously attending to TMT composition and structure

    Linkage and Referral to HIV and Other Medical and Social Services: A Focused Literature Review for Sexually Transmitted Disease Prevention and Control Programs

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    BACKGROUND: Sexually transmitted disease (STD) program and clinic staff play an important role in providing linkage and referrals to programs and services that address the complex medical and psychosocial needs of their clients. We synthesized recent published literature related to effective practices for linkage to care for HIV and referral to other medical and social services. METHODS: Three PubMed searches were conducted to identify relevant studies published since 2004 on (1) linkage to HIV care, (2) referral within STD clinical contexts, and (3) (review articles only) referral practices among all medical specialties. Systematic review procedures were not used. RESULTS: Thirty-three studies were included in this review. Studies highlight the limited value of passive referral practices and the increased effectiveness of active referral and linkage practices. Numerous studies on linkage to HIV care suggest that case management approaches, cultural-linguistic concordance between linkage staff and clients, and structural features such as colocation facilitate timely linkage to care. Integration of other medical and social services such as family planning and alcohol screening services into STD settings may be optimal but resource-intensive. Active referral practices such as having a written referral protocols and agreements, using information technology to help transfer information between providers, and making appointments for clients may offer some benefit. Few studies included information on program costs associated with linkage and referral. CONCLUSIONS: Recent literature provides some guideposts for STD program and clinical staff to use in determining their approach to helping link and refer clients to needed care. Much experience with these issues within STD services remains unpublished, and key gaps in the literature remain

    There are laterality effects in memory functioning in children/adolescents with focal epilepsy.

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    In a sample of individuals with childhood focal epilepsy, children/adolescents with left hemisphere foci outperformed those with right foci on both measures of nonverbal learning. Participants with left foci performed worse than controls on paired associate delayed recall and semantic memory, and they had greater laterality effects in IQ. Participants with right foci performed worse than controls on delayed facial recognition. Both groups displayed reduced focused attention and poor passage retention over time. Although participants with bilateral foci displayed poor learning and lower IQ than controls, they did not have worse impairment than those with a unilateral focus
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