937 research outputs found
Negative forms and path space forms
We present an account of negative differential forms within a natural
algebraic framework of differential graded algebras, and explain their
relationship with forms on path spaces.Comment: 12 pp.; the Introduction has been rewritten and mention of cohomology
dropped in Proposition 3.2; material slightly reorganize
The Toll of Toxics: Investigating Environmental Contaminants
Two recent events [the Deepwater Horizon oil spill and the Asarco settlement] bring to the fore the work of wildlife toxicologists. Focusing on amphibians, reptiles, birds, and mammals, wildlife toxicology is a component of ecotoxicology--the study of toxic effects caused by natural or synthetic pollutants on living organisms and other constituents of ecosystems (Truhaut 1977). Now a distinct discipline within the wildlife profession-practiced by members of The Wildlife Society\u27s own Wildlife Toxicology Working Group, among others-wildlife toxicology has become increasingly important as human populations and industry have spread, causing contaminants to multiply.
Emerging Environmental Contaminants (EECs) include an array of chemicals and substances that are discharged into the environment. According to the U.S. Geological Survey Toxic Substances Hydrology Program (2006), EECs include veterinary and human antibiotics, human drugs, industrial and household wastewater products, and sex and steroidal hormones. Beyond these four groupings, some experts also include phthalates that are used as plasticizers, chemicals used for disinfection in homes and industries, flame retardants, and extremely small particulates or nanomaterials (GRAC 2008, Sadler et al. 2003).
Studies by wildlife toxicologists have only skimmed the surface of how the thousands of chemicals in the environment affect wildlife, and new regulations and novel applications of old laws are constantly changing how toxicologists approach their work. Recent lawsuits brought against the EPA by the Center for Biological Diversity, for example, note that pesticides used on the landscape may be impacting endangered species in violation of the ESA (CBD 2010). That\u27s really driving a lot of EPA attention right now, says Exponent\u27s Anne Fairbrother, and I think that\u27s likely to continue. Wildlife toxicologists will help determine the impacts on at-risk species. With so many questions to answer about the ecological effects of contaminants on wildlife, wildlife toxicologists have more than enough work for many decades of productive scientific research
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Depression among women of reproductive age in rural Bangladesh is linked to food security, diets and nutrition
Objective: To quantify the relationship between screening positive for depression and several indicators of the food and nutrition environment in Bangladesh.Design: We used cross-sectional data from the Food and Agricultural Approaches to Reducing Malnutrition (FAARM) trial in Bangladesh to examine the association of depression in non-peripartum (NPW) and peripartum women (PW) with food and nutrition security using multivariable logistic regression and dominance analysis.Setting: Rural north-eastern Bangladesh.Participants: Women of reproductive age.Results: Of 2599 women, 40 % were pregnant or up to 1 year postpartum, while 60 % were not peripartum. Overall, 20 % of women screened positive for major depression. In the dominance analysis, indicators of food and nutrition security were among the strongest explanatory factors of depression. Food insecurity (HFIAS) and poor household food consumption (FCS) were associated with more than double the odds of depression (HFIAS: NPW OR = 2·74 and PW OR = 3·22; FCS: NPW OR = 2·38 and PW OR = 2·44). Low dietary diversity (<5 food groups) was associated with approximately double the odds of depression in NPW (OR = 1·80) and PW (OR = 1·99). Consumption of dairy, eggs, fish, vitamin A-rich and vitamin C-rich foods was associated with reduced odds of depression. Anaemia was not associated with depression. Low BMI (<18·5 kg/m2) was also associated with depression (NPW: OR = 1·40).Conclusions: Depression among women in Bangladesh was associated with many aspects of food and nutrition security, also after controlling for socio-economic factors. Further investigation into the direction of causality and interventions to improve diets and reduce depression among women in low-and middle-income countries are urgently needed. © © The Authors 2020
Depression among women of reproductive age in rural Bangladesh is linked to food security, diets and nutrition
Objective: To quantify the relationship between screening positive for depression and several indicators of the food and nutrition environment in Bangladesh. Design: We used cross-sectional data from the Food and Agricultural Approaches to Reducing Malnutrition (FAARM) trial in Bangladesh to examine the association of depression in non-peripartum (NPW) and peripartum women (PW) with food and nutrition security using multivariable logistic regression and dominance analysis. Setting: Rural north-eastern Bangladesh. Participants: Women of reproductive age. Results:
Of 2599 women, 40 % were pregnant or up to 1 year postpartum, while 60 % were not peripartum. Overall, 20 % of women screened positive for major depression. In the dominance analysis, indicators of food and nutrition security were among the strongest explanatory factors of depression. Food insecurity (HFIAS) and poor household food consumption (FCS) were associated with more than double the odds of depression (HFIAS: NPW OR = 2·74 and PW OR = 3·22; FCS: NPW OR = 2·38 and PW OR = 2·44). Low dietary diversity (<5 food groups) was associated with approximately double the odds of depression in NPW (OR = 1·80) and PW (OR = 1·99). Consumption of dairy, eggs, fish, vitamin A-rich and vitamin C-rich foods was associated with reduced odds of depression. Anaemia was not associated with depression. Low BMI (<18·5 kg/m2) was also associated with depression (NPW: OR = 1·40). Conclusions: Depression among women in Bangladesh was associated with many aspects of food and nutrition security, also after controlling for socio-economic factors. Further investigation into the direction of causality and interventions to improve diets and reduce depression among women in low- and middle-income countries are urgently needed
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Food and agricultural approaches to reducing malnutrition (FAARM): Protocol for a cluster-randomised controlled trial to evaluate the impact of a Homestead Food Production programme on undernutrition in rural Bangladesh
Introduction Chronic undernutrition affects over 150 million children worldwide and has serious consequences. The causes are complex and include insufficient dietary diversity and poor hygiene practices. Systematic reviews of nutrition-sensitive agricultural interventions concluded that while these hold promise, there is insufficient evidence for their impact on child growth. The Food and Agricultural Approaches to Reducing Malnutrition (FAARM) project is a 1:1 cluster-randomised trial aiming to evaluate the impact of a Homestead Food Production (HFP) programme implemented by Helen Keller International on women's and children's undernutrition. Methods and analysis The HFP intervention comprises training of women's groups and asset distribution to support year-round home gardening, poultry rearing and improved nutrition and hygiene practices. Formal trainings are supplemented by behaviour change communication during household visits, and facilitated links between producer groups and market actors. The FAARM trial will examine if and how this complex intervention reduces undernutrition. In 2015, FAARM enrolled married women and their children (0-3 years) in 96 rural settlements of Habiganj district in Sylhet division, Bangladesh. Covariate-constrained randomisation was used to assign 48 settlements to receive a 3-year HFP intervention, with the other 48 acting as controls, targeting over 2700 women. To study impact pathways, a surveillance system collects data on all participants every 2 months. In late 2019, children 0-3 years of age (born during the intervention period) will be surveyed, thus capturing impact during the critical first 1000 days of life. Children's length/height-for-age z-scores will be compared between intervention and control arms using mixed-effects linear regression. Secondary outcomes include women's and children's micronutrient status, dietary intake, dietary diversity and other indicators of child growth, development and morbidity. Ethics and dissemination Ethical approval was received in Bangladesh and Germany. Results will be disseminated through peer-reviewed publications and presentations in Bangladesh and internationally. Trial registration number NCT02505711; Pre-results. © Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY. Published by BMJ
Food and Agricultural Approaches to Reducing Malnutrition (FAARM): protocol for a cluster-randomised controlled trial to evaluate the impact of a Homestead Food Production programme on undernutrition in rural Bangladesh
IntroductionChronic undernutrition affects over 150 million children worldwide and has serious consequences. The causes are complex and include insufficient dietary diversity and poor hygiene practices. Systematic reviews of nutrition-sensitive agricultural interventions concluded that while these hold promise, there is insufficient evidence for their impact on child growth. The Food and Agricultural Approaches to Reducing Malnutrition (FAARM) project is a 1:1 cluster-randomised trial aiming to evaluate the impact of a Homestead Food Production (HFP) programme implemented by Helen Keller International on women’s and children’s undernutrition.Methods and analysisThe HFP intervention comprises training of women’s groups and asset distribution to support year-round home gardening, poultry rearing and improved nutrition and hygiene practices. Formal trainings are supplemented by behaviour change communication during household visits, and facilitated links between producer groups and market actors. The FAARM trial will examine if and how this complex intervention reduces undernutrition. In 2015, FAARM enrolled married women and their children (0–3 years) in 96 rural settlements of Habiganj district in Sylhet division, Bangladesh. Covariate-constrained randomisation was used to assign 48 settlements to receive a 3-year HFP intervention, with the other 48 acting as controls, targeting over 2700 women. To study impact pathways, a surveillance system collects data on all participants every 2 months. In late 2019, children 0–3 years of age (born during the intervention period) will be surveyed, thus capturing impact during the critical first 1000 days of life. Children’s length/height-for-age z-scores will be compared between intervention and control arms using mixed-effects linear regression. Secondary outcomes include women’s and children’s micronutrient status, dietary intake, dietary diversity and other indicators of child growth, development and morbidity.Ethics and disseminationEthical approval was received in Bangladesh and Germany. Results will be disseminated through peer-reviewed publications and presentations in Bangladesh and internationally.Trial registration numberNCT02505711; Pre-results.</jats:sec
mTORC1-independent Raptor prevents hepatic steatosis by stabilizing PHLPP2
Mechanistic target of rapamycin complex 1 (mTORC1), defined by the presence of Raptor, is an evolutionarily conserved and nutrient-sensitive regulator of cellular growth and other metabolic processes. To date, all known functions of Raptor involve its scaffolding mTOR kinase with substrate. Here we report that mTORC1-independent (‘free’) Raptor negatively regulates hepatic Akt activity and lipogenesis. Free Raptor levels in liver decline with age and in obesity; restoration of free Raptor levels reduces liver triglyceride content, through reduced β-TrCP-mediated degradation of the Akt phosphatase, PHLPP2. Commensurately, forced PHLPP2 expression ameliorates hepatic steatosis in diet-induced obese mice. These data suggest that the balance of free and mTORC1-associated Raptor governs hepatic lipid accumulation, and uncover the potentially therapeutic role of PHLPP2 activators in non-alcoholic fatty liver disease
Very Extended and at low levels, Gravity and Supergravity
We define a level for a large class of Lorentzian Kac-Moody algebras. Using
this we find the representation content of very extended and
(i.e. ) at low levels in terms of and
representations respectively. The results are consistent with the conjectured
very extended and symmetries of gravity and maximal supergravity
theories given respectively in hep-th/0104081 and hep-th/0107209. We explain
how these results provided further evidence for these conjectures.Comment: 16 pages, plain tex (equation 3.3 modified and one reference
expanded
Anti-self-dual conformal structures with null Killing vectors from projective structures
Using twistor methods, we explicitly construct all local forms of
four--dimensional real analytic neutral signature anti--self--dual conformal
structures with a null conformal Killing vector. We show that is
foliated by anti-self-dual null surfaces, and the two-dimensional leaf space
inherits a natural projective structure. The twistor space of this projective
structure is the quotient of the twistor space of by the group action
induced by the conformal Killing vector.
We obtain a local classification which branches according to whether or not
the conformal Killing vector is hyper-surface orthogonal in . We give
examples of conformal classes which contain Ricci--flat metrics on compact
complex surfaces and discuss other conformal classes with no Ricci--flat
metrics.Comment: 43 pages, 4 figures. Theorem 2 has been improved: ASD metrics are
given in terms of general projective structures without needing to choose
special representatives of the projective connection. More examples (primary
Kodaira surface, neutral Fefferman structure) have been included. Algebraic
type of the Weyl tensor has been clarified. Final version, to appear in
Commun Math Phy
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