500 research outputs found

    Mistakes, Crises, and Research Independence: The Perils of Fieldwork as a form of Evidence

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    Drawing on examples from rural Ethiopia and Uganda, this research note highlights some of the difficulties experienced in fieldwork. These difficulties do not justify the reluctance of increasingly risk-averse universities and funders to support independent fieldwork in Africa, but they do show that the rationale for research and the features of its design can provoke animosity and tensions. They also show that our own failure on occasion to appreciate local political dynamics made the situation more difficult. Challenges and threats came not only from local political forces but also from multinational companies and Fairtrade organizations uncomfortable with our findings and with fully independent research. The research note argues that the details of our experience have a practical value for other researchers, and that at least some of them should be treated as substantive forms of evidence and insight, rather than simply as threats or failures. We conclude that some crude best-practice norms and pressures on academics to form partnerships to conduct policy-relevant work may undermine the potential for truly independent and intensive field research. However, crises should not necessarily be seen as an unwelcome interruption to smooth processes of research; they can illuminate the context and power relations that the research is trying to understand

    Fairtrade and Labour Markets in Ethiopia and Uganda

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    Drawing on four years of fieldwork in Ethiopia and Uganda, this paper addresses gaps in knowledge about the mechanisms linking agricultural exports with poverty reduction, the functioning of rural labour markets, and the relevance to the lives of the poorest people of Fairtrade. Statistical analysis of survey evidence, complemented by qualitative research, highlights the relatively poor payment and non-pay working conditions of those employed in research sites dominated by Fairtrade producer organizations. We conclude that Fairtrade is not an effective way to improve the welfare of the poorest rural people

    Catabolite repression of the citST two-component system in Bacillus subtilis

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    In Bacillus subtilis, expression of the citrate transporter CitM is under strict control. Transcription of the citM gene is induced by citrate in the medium mediated by the CitS-CitT two-component system and repressed by rapidly degraded carbon sources mediated by carbon catabolite repression (CCR). In this study, we demonstrate that citST genes are part of a bicistronic operon. The promoter region was localized in a stretch of 58 base pairs upstream of the citS gene by deletion experiments. Transcription of the operon was repressed in the presence of glucose by the general transcription factor CcpA. A distal consensus cre site in the citS-coding sequence was implicated in the mechanism of repression. Furthermore, this repression was relieved in Bacillus subtilis mutants deficient in CcpA or Hpr/Crh, components essential to CCR. Thus, we demonstrate that CCR represses the expression of the citST operon, which is responsible for the induction of citM, through the cre site located 1326 bp from transcriptional start site of citST

    LOW ENERGY SUPERSYMMETRY PHENOMENOLOGY

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    We summarize the current status and future prospects for low energy (weak scale) supersymmetry. In particular, we evaluate the capabilities of various e+ee^+e^-, ppˉp\bar p and pppp colliders to discover evidence for supersymmetric particles. Furthermore, assuming supersymmetry is discovered, we discuss capabilities of future facilities to dis-entangle the anticipated spectrum of super-particles, and, via precision measurements, to test mass and coupling parameters for comparison with various theoretical expectations. We comment upon the complementarity of proposed hadron and e+ee^+e^- machines for a comprehensive study of low energy supersymmetry.Comment: 74 page (Latex) file; a PS or uuencoded manuscript with embedded figures is available via anonymous ftp at ftp://hep.fsu.edu/preprints/baer/FSUHEP950401.ps or .uu . Contributed chapter to DPF study group on Electroweak Symmetry Breaking and Beyond the Standard Model

    Serum calprotectin levels correlate with biochemical and histological markers of disease activity in TNBS colitis

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    Background and aim: Serum calprotectin is elevated in patients with inflammatory bowel disease (IBD). Whether it correlates other markers of disease activity is unknown. the aim of this study was to correlate serum calprotectin with biochemical and histological measures of intestinal inflammation.Materials and methods: TNBS colitis was induced in wistar rats, and serial blood samples were collected at 0, 3, and 12 days. Animals were subsequently sacrificed for pathological evaluation at day 12. Serum calprotectin and cytokines were measured by ELISA. Pathologic changes were classified at the macroscopic and microscopic levels.Results: TNBS colitis induced elevated serum calprotectin, TNF and IL-6 within 24 h. Levels of serum calprotectin remained elevated in parallel to persistence of loose stool and weight loss to day 12. Serum calprotectin levels correlated with serum levels of TNF-alpha, and IL6 (p < 0.001), but not CRP. Animals with liquid stool had significantly higher levels of serum calprotectin than control animals. There was a correlation between macroscopic colitis scores, and levels of serum calprotectin.Conclusion: Serum calprotectin levels correlate with biochemical and histological markers of inflammation in TNBS colitis. This biomarker may have potential for diagnostic use in patients with IBD. (C) 2013 Elsevier Inc. All rights reserved.NIHUniversidade Federal de São Paulo, UNIFESP EPM, Dept Gastroenterol, São Paulo, BrazilUniversidade Federal de São Paulo, UNIFESP EPM, Dept Nephrol, Basic Res Lab, São Paulo, BrazilHarvard Univ, Beth Israel Hosp, Sch Med, Ctr Inflammatory Bowel Dis, Boston, MA USAUniversidade Federal de São Paulo, UNIFESP EPM, Dept Gastroenterol, São Paulo, BrazilUniversidade Federal de São Paulo, UNIFESP EPM, Dept Nephrol, Basic Res Lab, São Paulo, BrazilNIH: K23DK084338Web of Scienc

    Gene expression profiling of the short-term adaptive response to acute caloric restriction in liver and adipose tissues of pigs differing in feed efficiency

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    Residual feed intake (RFI) is a measure of feed efficiency, in which low RFI denotes improved feed efficiency. Caloric restriction (CR) is associated with feed efficiency in livestock species and to human health benefits, such as longevity and cancer prevention. We have developed pig lines that differ in RFI, and we are interested in identifying the genes and pathways that underlie feed efficiency. Prepubertal Yorkshire gilts with low RFI (n = 10) or high RFI (n = 10) were fed ad libitum or fed at restricted intake of 80% of maintenance energy requirements for 8 days. We measured serum metabolites and hormones and generated transcriptional profiles of liver and subcutaneous adipose tissue on these animals. Overall, 6,114 genes in fat and 305 genes in liver were differentially expressed (DE) in response to CR, and 311 genes in fat and 147 genes in liver were DE due to RFI differences. Pathway analyses of CR-induced DE genes indicated a dramatic switch to a conservation mode of energy usage by down-regulating lipogenesis and steroidogenesis in both liver and fat. Interestingly, CR altered expression of genes in immune and cell cycle/apoptotic pathways in fat, which may explain part of the CR-driven lifespan enhancement. In silico analysis of transcription factors revealed ESR1 as a putative regulator of the adaptive response to CR, as several targets of ESR1 in our DE fat genes were annotated as cell cycle/apoptosis genes. The lipid metabolic pathway was overrepresented by down-regulated genes due to both CR and low RFI. We propose a common energy conservation mechanism, which may be controlled by PPARA, PPARG, and/or CREB in both CR and feed-efficient pigs

    Fairtrade and Labour Markets in Ethiopia and Uganda

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    Drawing on four years of fieldwork in Ethiopia and Uganda, this paper addresses gaps in knowledge about the mechanisms linking agricultural exports with poverty reduction, the functioning of rural labour markets, and the relevance to the lives of the poorest people of Fairtrade. Statistical analysis of survey evidence, complemented by qualitative research, highlights the relatively poor payment and non-pay working conditions of those employed in research sites dominated by Fairtrade producer organizations. We conclude that Fairtrade is not an effective way to improve the welfare of the poorest rural people

    Gene expression in hypothalamus, liver, and adipose tissues and food intake response to melanocortin-4 receptor agonist in pigs expressing melanocortin-4 receptor mutations

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    Transcriptional profiling was used to identify genes and pathways that responded to intracerebroventricular injection of melanocortin-4 receptor (MC4R) agonist [Nle4, D-Phe7]-α-melanocyte stimulating hormone (NDP-MSH) in pigs homozygous for the missense mutation in the MC4R, D298 allele (n = 12), N298 allele (n = 12), or heterozygous (n = 12). Food intake (FI) was measured at 12 and 24 h after treatment. All pigs were killed at 24 h after treatment, and hypothalamus, liver, and back-fat tissue was collected. NDP-MSH suppressed (P \u3c 0.004) FI at 12 and 24 h in all animals after treatment. In response to NDP-MSH, 278 genes in hypothalamus (q ≤ 0.07, P ≤ 0.001), 249 genes in liver (q ≤ 0.07, P ≤ 0.001), and 5,066 genes in fat (q ≤ 0.07, P ≤ 0.015) were differentially expressed. Pathway analysis of NDP-MSH-induced differentially expressed genes indicated that genes involved in cell communication, nucleotide metabolism, and signal transduction were prominently downregulated in the hypothalamus. In both liver and adipose tissue, energy-intensive biosynthetic and catabolic processes were downregulated in response to NDP-MSH. This included genes encoding for biosynthetic pathways such as steroid and lipid biosynthesis, fatty acid synthesis, and amino acid synthesis. Genes involved in direct energy-generating processes, such as oxidative phosphorylation, electron transport, and ATP synthesis, were upregulated, whereas TCA-associated genes were prominently downregulated in NDP-MSH-treated pigs. Our data also indicate a metabolic switch toward energy conservation since genes involved in energy-intensive biosynthetic and catabolic processes were downregulated in NDP-MSH-treated pigs

    Boosting Efficiency in Light‐Driven Water Splitting by Dynamic Irradiation through Synchronizing Reaction and Transport Processes **

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    Abstract This work elaborates the effect of dynamic irradiation on light‐driven molecular water oxidation to counteract deactivation. It highlights the importance of overall reaction engineering to overcome limiting factors in artificial photosynthesis reactions. Systematic investigation of a homogeneous three‐component ruthenium‐based water oxidation system revealed significant potential to enhance the overall catalytic efficiency by synchronizing the timescales of photoreaction and mass transport in a capillary flow reactor. The overall activity could be improved by a factor of more than 10 with respect to the turnover number and a factor of 31 referring to the external energy efficiency by controlling the local availability of photons. Detailed insights into the mechanism of light driven water oxidation could be obtained using complementary methods of investigation like Raman, IR, and UV/Vis/emission spectroscopy, unraveling the importance of avoiding high concentrations of excited photosensitizers.Water splitting : Dynamic irradiation enables a significant increase in catalytic performance of a homogeneous three‐component system for light‐driven water oxidation. Lower irradiation intensities and higher flowrates in a flow‐through reactor minimize photosensitizer degradation and thus improve catalyst lifetime, yield, and overall efficiency of a catalytic system for artificial photosynthesis. imag

    Feeding the Worlth Healthily: the Challenge of Measuring the effects of Agriculture on Health

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    Agricultural production, food systems and population health are intimately linked. While there is a strong evidence base to inform our knowledge of what constitutes a healthy human diet, we know little about actual food production or consumption in many populations and how developments in the food and agricultural system will affect dietary intake patterns and health. The paucity of information on food production and consumption is arguably most acute in low- and middle-income countries, where it is most urgently needed to monitor levels of under-nutrition, the health impacts of rapid dietary transition and the increasing ‘double burden’ of nutrition-related disease. Food availability statistics based on food commodity production data are currently widely used as a proxy measure of national-level food consumption, but using data from the UK and Mexico we highlight the potential pitfalls of this approach. Despite limited resources for data collection, better systems of measurement are possible. Important drivers to improve collection systems may include efforts to meet international development goals and partnership with the private sector. A clearer understanding of the links between the agriculture and food system and population health will ensure that health becomes a critical driver of agricultural change
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