1,050 research outputs found

    Polymorphisms in ARMS2/HTRA1 and complement genes and age-related macular degeneration in India: findings from the INDEYE study.

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    PURPOSE: Association between genetic variants in complement factor H (CFH), factor B (CFB), component 2 (C2), and in the ARMS2/HTRA1 region with age-related macular degeneration (AMD) comes mainly from studies of European ancestry and case-control studies of late-stage disease. We investigated associations of both early and late AMD with these variants in a population-based study of people aged 60 years and older in India. METHODS: Fundus images were graded using the Wisconsin Age-Related Maculopathy Grading System and participants assigned to one of four mutually exclusive stages based on the worse affected eye (0 = no AMD, 1-3 = early AMD, 4 = late AMD). Multinomial logistic regression was used to derive risk ratios (RR) accounting for sampling method and adjusting for age, sex, and study center. RESULTS: Of 3569 participants, 53.2% had no signs of amd, 45.6% had features of early amd, and 1.2% had late amd. CFH (RS1061170), C2 (RS547154), OR CFB (RS438999) was not associated with early or late AMD. In the ARMS2 locus, RS10490924 was associated with both early (adjusted RR 1.22, 95% confidence interval [CI]: 1.13-1.33, P < 0.0001) and late AMD (adjusted RR 1.81, 95% CI: 1.15-2.86; P = 0.01); rs2672598 was associated only with early AMD (adjusted RR 1.12, 95% CI: 1.02-1.23; P = 0.02); rs10490923 was not associated with early or late AMD. CONCLUSIONS: Two variants in ARMS2/HTRA1 were associated with increased risk of early AMD, and for one of these, the increased risk was also evident for late AMD. The study provides new insights into the role of these variants in early stages of AMD in India

    Can HERA See an eu−−>ece u --> e c Signal of a Virtual Leptoquark?

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    Virtual leptoquarks could be detected at HERA through some nonstandard effects. Here we explore the possibility that virtual leptoquarks could be discovered via eu−−>ece u --> e c scattering, assuming integrated luminosity of 200 pb−1^{-1} and charm identification efficiency of 1%. We study the implications of low energy data for the leptoquarks couplings and find that the most relevant bound for the HERA cross sections comes from inclusive c−−>e+e− + anyc --> e^+e^-~+~any. This bound implies that the eu−−>ece u --> e c cross sections for virtual leptoquarks are just too small for observation of the signal. With an improvement by a factor of ~2 on the luminosity or on charm identification it could be possible to see virtual leptoquarks with {\it maximum couplings} up to ~1.5 - 2 TeV. However, the prospects for discovering the virtual particles if their couplings are somewhat below present bounds are very dim. We point out that this cross section could be very large for leptoquarks lighter than HERA's kinematical limit, and if such a leptoquark is discovered we recommend searching for a possible eu−−>ece u --> e c signal. Our results may also serve as an update on the maximum cross sections for leptoquark mediated eu−−>μce u --> \mu c scattering.Comment: 15 Pages (LaTeX), including 4 postscript figures at the end of the file. Feynman diagrams available by reques

    Trapping dust particles in the outer regions of protoplanetary disks

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    In order to explain grain growth to mm sized particles and their retention in outer regions of protoplanetary disks, as it is observed at sub-mm and mm wavelengths, we investigate if strong inhomogeneities in the gas density profiles can slow down excessive radial drift and can help dust particles to grow. We use coagulation/fragmentation and disk-structure models, to simulate the evolution of dust in a bumpy surface density profile which we mimic with a sinusoidal disturbance. For different values of the amplitude and length scale of the bumps, we investigate the ability of this model to produce and retain large particles on million years time scales. In addition, we introduced a comparison between the pressure inhomogeneities considered in this work and the pressure profiles that come from magnetorotational instability. Using the Common Astronomy Software Applications ALMA simulator, we study if there are observational signatures of these pressure inhomogeneities that can be seen with ALMA. We present the favorable conditions to trap dust particles and the corresponding calculations predicting the spectral slope in the mm-wavelength range, to compare with current observations. Finally we present simulated images using different antenna configurations of ALMA at different frequencies, to show that the ring structures will be detectable at the distances of the Taurus Auriga or Ophiucus star forming regions.Comment: Pages 15, Figures 14. Accepted for publication in Astronomy and Astrophysic

    Driven Morse Oscillator: Model for Multi-photon Dissociation of Nitrogen Oxide

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    Within a one-dimensional semi-classical model with a Morse potential the possibility of infrared multi-photon dissociation of vibrationally excited nitrogen oxide was studied. The dissociation thresholds of typical driving forces and couplings were found to be similar, which indicates that the results were robust to variations of the potential and of the definition of dissociation rate. PACS: 42.50.Hz, 33.80.WzComment: old paper, 8 pages 6 eps file

    miRConnect 2.0: identification of oncogenic, antagonistic miRNA families in three human cancers

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    Abstract Background Based on their function in cancer micro(mi)RNAs are often grouped as either tumor suppressors or oncogenes. However, miRNAs regulate multiple tumor relevant signaling pathways raising the question whether two oncogenic miRNAs could be functional antagonists by promoting different steps in tumor progression. We recently developed a method to connect miRNAs to biological function by comparing miRNA and gene array expression data from the NCI60 cell lines without using miRNA target predictions (miRConnect). Results We have now extended this analysis to three primary human cancers (ovarian cancer, glioblastoma multiforme, and kidney renal clear cell carcinoma) available at the Cancer Genome Atlas (TCGA), and have correlated the expression of the clustered miRNAs with 158 oncogenic signatures (miRConnect 2.0). We have identified functionally antagonistic groups of miRNAs. One group (the agonists), which contains many of the members of the miR-17 family, correlated with c-Myc induced genes and E2F gene signatures. A group that was directly antagonistic to the agonists in all three primary cancers contains miR-221 and miR-222. Since both miR-17 ~ 92 and miR-221/222 are considered to be oncogenic this points to a functional antagonism of different oncogenic miRNAs. Analysis of patient data revealed that in certain patients agonistic miRNAs predominated, whereas in other patients antagonists predominated. In glioblastoma a high ratio of miR-17 to miR-221/222 was predictive of better overall survival suggesting that high miR-221/222 expression is more adverse for patients than high miR-17 expression. Conclusion miRConnect 2.0 is useful for identifying activities of miRNAs that are relevant to primary cancers. The new correlation data on miRNAs and mRNAs deregulated in three primary cancers are available at miRConnect.orghttp://deepblue.lib.umich.edu/bitstream/2027.42/112974/1/12864_2013_Article_4929.pd

    Caring for the collective: biopower and agential subjectification in wildlife conservation

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    types: ArticleCopyright © 2014 PionPost Print. Srinivasan, K. 2014. The definitive, peer-reviewed and edited version of this article is published in Environment and Planning D: Society and Space, Vol. 32, Issue 3, pp. 501 – 517 DOI:10.1068/d13101pThis paper explores turtle conservation in Odisha, India, to map the complicated ways in which animal well-being is pursued in the contemporary world. Using insights from Foucault’s work on biopolitics, it offers an account of conservation as population politics, questioning the entanglement of harm and care that infuses this space of more-than-human social change. In doing this, the paper elaborates the concept of agential subjectification in order to track the mechanisms that underlie the asymmetric circulation of biopower in human–animal interactions and to develop Foucauldian scholarship for the examination of present-day manifestations of the ‘will to improve’.RGS‑IBGCulture and Animals Foundatio

    A time-marching scheme for analyzing transient scattering from nonplanar doubly periodic structures

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    A novel marching-on-time (MOT) based scheme for solving a time domain integral equation (TDIE) was discussed. It was observed that the scheme was pertinent to the analysis of plane wave scattering from nonplanar doubly periodic structures with unit cells comprising perfect electrically conducting (PEC) elements and inhomogeneous dielectric volumes. This scheme aimed at rendering the solver applicable to the nonplanar structures. The resulted scheme was applied without any difficulty to nonplanar doubly periodic structures comprising PEC and sculptured dielectric substrates

    Naturally Light Leptoquarks

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    Light first generation leptoquarks are being hunted for in HERA and at FNAL and there are various proposals for further searches in future machines. Such leptoquarks are however problematic from a theoretical point of view: Low energy precision measurements imply strong constraints on the couplings of the leptoquarks, and up till now the fulfilment of these constraints seemed extremely unnatural. Here we show that horizontal symmetries, which are very conventional and widely used in the literature for completely different purposes, can suppress the unwanted couplings. Therefore light first generation leptoquarks can be natural.Comment: 12 pages LaTeX. WIS-94/27/Jul-P
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