185 research outputs found

    Lorentz violation, Gravity, Dissipation and Holography

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    We reconsider Lorentz Violation (LV) at the fundamental level. We show that Lorentz Violation is intimately connected with gravity and that LV couplings in QFT must always be fields in a gravitational sector. Diffeomorphism invariance must be intact and the LV couplings transform as tensors under coordinate/frame changes. Therefore searching for LV is one of the most sensitive ways of looking for new physics, either new interactions or modifications of known ones. Energy dissipation/Cerenkov radiation is shown to be a generic feature of LV in QFT. A general computation is done in strongly coupled theories with gravity duals. It is shown that in scale invariant regimes, the energy dissipation rate depends non-triviallly on two characteristic exponents, the Lifshitz exponent and the hyperscaling violation exponent.Comment: LateX, 51 pages, 9 figures. (v2) References and comments added. Misprints correcte

    Improving breast cancer services for African-American women living in St. Louis

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    A mixed methods, community-based research study was conducted to understand how provider-level factors contribute to the African-American and white disparity in breast cancer mortality in a lower socioeconomic status area of North St. Louis. This study used mixed methods including: (1) secondary analysis of Missouri Cancer Registry data on all 885 African-American women diagnosed with breast cancer from 2000 to 2008 while living in the geographic area of focus; (2) qualitative interviews with a subset of these women; (3) analysis of data from electronic medical records of the women interviewed; and (4) focus group interviews with community residents, patient navigators, and other health care professionals. 565 women diagnosed with breast cancer from 2000 to 2008 in the geographic area were alive at the time of secondary data analysis; we interviewed (n = 96; 17 %) of these women. Provider-level obstacles to completion of prescribed treatment included fragmented navigation (separate navigators at Federally Qualified Health Centers, surgical oncology, and medical oncology, and no navigation services in surgical oncology). Perhaps related to the latter, women described radiation as optional, often in the same words as they described breast reconstruction. Discontinuous and fragmented patient navigation leads to failure to associate radiation therapy with vital treatment recommendations. Better integrated navigation that continues throughout treatment will increase treatment completion with the potential to improve outcomes in African Americans and decrease the disparity in mortality

    Child Care Time, Parents’ Well-Being, and Gender: Evidence from the American Time Use Survey

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    This study used data from the ‘Well Being Module’ of the 2010 American Time Use Survey (N = 1699) to analyze how parents experience child care time in terms of meaning and stress levels. Multivariate multilevel regressions showed clear differences by gender and the circumstances of child care activities. Mothers experienced child care time as more stressful than fathers, and fathers as slightly more meaningful. Interactive child care was experienced as more meaningful and less stressful than routine child care, whereas these differences were stronger among fathers than among mothers. Mothers experienced child care with a minor child as highly meaningful, and with an adolescent as particularly stressful. Fathers experienced child care with an infant as highly stressful, and with an offspring in middle childhood as disproportionally meaningful. The spouse’s presence was moderately associated with higher senses of meaning and lower levels of stress during child care, but these differences were modest, and only visible among fathers. Paid work hours increased mothers’ stress levels during child care activities, but reduced fathers’ stress levels. Meanwhile, nonemployed fathers reported child care time as less meaningful than non-employed mothers. Overall, this study has important scientific and practical implications for `understanding the gendered nature of parents’ child care time and well-being

    Efficacy of PermaNet® 2.0 and PermaNet® 3.0 against insecticide-resistant Anopheles gambiae in experimental huts in Côte d'Ivoire

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    <p>Abstract</p> <p>Background</p> <p>Pyrethroid resistance in vectors could limit the efficacy of long-lasting insecticidal nets (LLINs) because all LLINs are currently treated with pyrethroids. The goal of this study was to evaluate the efficacy and wash resistance of PermaNet<sup>® </sup>3.0 compared to PermaNet<sup>® </sup>2.0 in an area of high pyrethroid in Côte d'Ivoire. PermaNet<sup>® </sup>3.0 is impregnated with deltamethrin at 85 mg/m<sup>2 </sup>on the sides of the net and with deltamethrin and piperonyl butoxide on the roof. PermaNet<sup>® </sup>2.0 is impregnated with deltamethrin at 55 mg/m<sup>2 </sup>across the entire net.</p> <p>Methods</p> <p>The study was conducted in the station of Yaokoffikro, in central Côte d'Ivoire. The efficacy of intact unwashed and washed LLINs was compared over a 12-week period with a conventionally-treated net (CTN) washed to just before exhaustion. WHO cone bioassays were performed on sub-sections of the nets, using wild-resistant <it>An. gambiae </it>and Kisumu strains. Mosquitoes were collected five days per week and were identified to genus and species level and classified as dead or alive, then unfed or blood-fed.</p> <p>Results</p> <p>Mortality rates of over 80% from cone bioassays with wild-caught pyrethroid-resistant <it>An. gambiae </it>s.s were recorded only with unwashed PermaNet<sup>® </sup>3.0. Over 12 weeks, a total of 7,291 mosquitoes were collected. There were significantly more <it>An. gambiae </it>s.s. and <it>Culex </it>spp. caught in control huts than with other treatments (P < 0.001). The proportion of mosquitoes exiting the huts was significantly lower with the control than for the treatment arms (P < 0.001). Mortality rates with resistant <it>An. gambiae </it>s.s and <it>Culex </it>spp, were lower for the control than for other treatments (P < 0.001), which did not differ (P > 0.05) except for unwashed PermaNet<sup>® </sup>3.0 (P < 0.001), which gave significantly higher mortality (P < 0.001).</p> <p>Conclusions</p> <p>This study showed that unwashed PermaNet<sup>® </sup>3.0 caused significantly higher mortality against pyrethroid resistant <it>An. gambiae s.s </it>and <it>Culex </it>spp than PermaNet<sup>® </sup>2.0 and the CTN. The increased efficacy with unwashed PermaNet<sup>® </sup>3.0 over PermaNet<sup>® </sup>2.0 and the CTN was also demonstrated by higher KD and mortality rates (KD > 95% and mortality rate > 80%) in cone bioassays performed with wild pyrethroid-resistant <it>An. gambiae s.s </it>from Yaokoffikro.</p

    Caenorhabditis elegans BAH-1 Is a DUF23 Protein Expressed in Seam Cells and Required for Microbial Biofilm Binding to the Cuticle

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    The cuticle of Caenorhabditis elegans, a complex, multi-layered extracellular matrix, is a major interface between the animal and its environment. Biofilms produced by the bacterial genus Yersinia attach to the cuticle of the worm, providing an assay for surface characteristics. A C. elegans gene required for biofilm attachment, bah-1, encodes a protein containing the domain of unknown function DUF23. The DUF23 domain is found in 61 predicted proteins in C. elegans, which can be divided into three distinct phylogenetic clades. bah-1 is expressed in seam cells, which are among the hypodermal cells that synthesize the cuticle, and is regulated by a TGF-β signaling pathway

    Cognitive skills and literacy performance of Chinese adolescents with and without dyslexia

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    The present study sought to identify cognitive abilities that might distinguish Hong Kong Chinese adolescents with dyslexia and to assess how these abilities were associated with Chinese word reading, word dictation, and reading comprehension. The cognitive skills of interest were morphological awareness, visual-orthographic knowledge, rapid naming, and verbal working memory. A total of 90 junior secondary school students, 30 dyslexic, 30 chronological age controls, and 30 reading level controls was tested on a range of cognitive and literacy tasks. Dyslexic students were less competent than the control students in all cognitive and literacy measures. The regression analyses also showed that verbal working memory, rapid naming, morphological awareness, and visual-orthographic knowledge were significantly associated with literacy performance. Findings underscore the importance of these cognitive skills for Chinese literacy acquisition. Overall, this study highlights the persistent difficulties of Chinese dyslexic adolescents who seem to have multiple causes for reading and spelling difficulties

    Malaria vector research and control in Haiti: a systematic review

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    BACKGROUND: Haiti has a set a target of eliminating malaria by 2020. However, information on malaria vector research in Haiti is not well known. This paper presents results from a systematic review of the literature on malaria vector research, bionomics and control in Haiti. METHODS: A systematic search of literature published in French, Spanish and English languages was conducted in 2015 using Pubmed (MEDLINE), Google Scholar, EMBASE, JSTOR WHOLIS and Web of Science databases as well other grey literature sources such as USAID, and PAHO. The following search terms were used: malaria, Haiti, Anopheles, and vector control. RESULTS: A total of 132 references were identified with 40 high quality references deemed relevant and included in this review. Six references dealt with mosquito distribution, seven with larval mosquito ecology, 16 with adult mosquito ecology, three with entomological indicators of malaria transmission, eight with insecticide resistance, one with sero-epidemiology and 16 with vector control. In the last 15 years (2000–2015), there have only been four published papers and three-scientific meeting abstracts on entomology for malaria in Haiti. Overall, the general literature on malaria vector research in Haiti is limited and dated. DISCUSSION: Entomological information generated from past studies in Haiti will contribute to the development of strategies to achieve malaria elimination on Hispaniola. However it is of paramount importance that malaria vector research in Haiti is updated to inform decision-making for vector control strategies in support of malaria elimination

    Gene-Disease Network Analysis Reveals Functional Modules in Mendelian, Complex and Environmental Diseases

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    Scientists have been trying to understand the molecular mechanisms of diseases to design preventive and therapeutic strategies for a long time. For some diseases, it has become evident that it is not enough to obtain a catalogue of the disease-related genes but to uncover how disruptions of molecular networks in the cell give rise to disease phenotypes. Moreover, with the unprecedented wealth of information available, even obtaining such catalogue is extremely difficult. We developed a comprehensive gene-disease association database by integrating associations from several sources that cover different biomedical aspects of diseases. In particular, we focus on the current knowledge of human genetic diseases including mendelian, complex and environmental diseases. To assess the concept of modularity of human diseases, we performed a systematic study of the emergent properties of human gene-disease networks by means of network topology and functional annotation analysis. The results indicate a highly shared genetic origin of human diseases and show that for most diseases, including mendelian, complex and environmental diseases, functional modules exist. Moreover, a core set of biological pathways is found to be associated with most human diseases. We obtained similar results when studying clusters of diseases, suggesting that related diseases might arise due to dysfunction of common biological processes in the cell. For the first time, we include mendelian, complex and environmental diseases in an integrated gene-disease association database and show that the concept of modularity applies for all of them. We furthermore provide a functional analysis of disease-related modules providing important new biological insights, which might not be discovered when considering each of the gene-disease association repositories independently. Hence, we present a suitable framework for the study of how genetic and environmental factors, such as drugs, contribute to diseases. The gene-disease networks used in this study and part of the analysis are available at http://ibi.imim.es/DisGeNET/DisGeNETweb.html#Download

    Predicting environmental chemical factors associated with disease-related gene expression data

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    <p>Abstract</p> <p>Background</p> <p>Many common diseases arise from an interaction between environmental and genetic factors. Our knowledge regarding environment and gene interactions is growing, but frameworks to build an association between gene-environment interactions and disease using preexisting, publicly available data has been lacking. Integrating freely-available environment-gene interaction and disease phenotype data would allow hypothesis generation for potential environmental associations to disease.</p> <p>Methods</p> <p>We integrated publicly available disease-specific gene expression microarray data and curated chemical-gene interaction data to systematically predict environmental chemicals associated with disease. We derived chemical-gene signatures for 1,338 chemical/environmental chemicals from the Comparative Toxicogenomics Database (CTD). We associated these chemical-gene signatures with differentially expressed genes from datasets found in the Gene Expression Omnibus (GEO) through an enrichment test.</p> <p>Results</p> <p>We were able to verify our analytic method by accurately identifying chemicals applied to samples and cell lines. Furthermore, we were able to predict known and novel environmental associations with prostate, lung, and breast cancers, such as estradiol and bisphenol A.</p> <p>Conclusions</p> <p>We have developed a scalable and statistical method to identify possible environmental associations with disease using publicly available data and have validated some of the associations in the literature.</p
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