1,813 research outputs found
Seascape genetics of the Atlantic Spotted Dolphin (Stenella frontalis) based on mitochondrial DNA
The Atlantic spotted dolphin (Stenella frontalis) is endemic to tropical, subtropical, and warm temperate waters of the Atlantic Ocean. Throughout its distribution, both geographic distance and environmental variation may contribute to population structure of the species. In this study, we follow a seascape genetics approach to investigate population differentiation of Atlantic spotted dolphins based on a large worldwide dataset and the relationship with marine environmental variables. The results revealed that the Atlantic spotted dolphin exhibits population genetic structure across its distribution based on mitochondrial DNA control region (mtDNA-CR) data. Analyses based on the contemporary landscape suggested, at both the individual and population level, that the population genetic structure is consistent with the isolation-by-distance model. However, because geography and environmental matrices were correlated, and because in some, but not all analyses, we found a significant effect for the environment, we cannot rule out the addition contribution of environmental factors in structuring genetic variation. Future analyses based on nuclear data are needed to evaluate whether local processes, such as social structure and some level of philopatry within populations, may be contributing to the associations among genetic structure, geographic, and environmental distance.info:eu-repo/semantics/acceptedVersio
Dose assessment by quantification of chromosome aberrations and micronuclei in peripheral blood lymphocytes from patients exposed to gamma radiation
Languages cool as they expand: Allometric scaling and the decreasing need for new words
We analyze the occurrence frequencies of over 15 million words recorded in millions of books published during the past two centuries in seven different languages. For all languages and chronological subsets of the data we confirm that two scaling regimes characterize the word frequency distributions, with only the more common words obeying the classic Zipf law. Using corpora of unprecedented size, we test the allometric scaling relation between the corpus size and the vocabulary size of growing languages to demonstrate a decreasing marginal need for new words, a feature that is likely related to the underlying correlations between words. We calculate the annual growth fluctuations of word use which has a decreasing trend as the corpus size increases, indicating a slowdown in linguistic evolution following language expansion. This ââcooling patternââ forms the basis of a third statistical regularity, which unlike the Zipf and the Heaps law, is dynamical in nature
The K+ Channel Opener 1-EBIO Potentiates Residual Function of Mutant CFTR in Rectal Biopsies from Cystic Fibrosis Patients
BACKGROUND: The identification of strategies to improve mutant CFTR function remains a key priority in the development of new treatments for cystic fibrosis (CF). Previous studies demonstrated that the Kâș channel opener 1-ethyl-2-benzimidazolone (1-EBIO) potentiates CFTR-mediated Clâ» secretion in cultured cells and mouse colon. However, the effects of 1-EBIO on wild-type and mutant CFTR function in native human colonic tissues remain unknown. METHODS: We studied the effects of 1-EBIO on CFTR-mediated Clâ» secretion in rectal biopsies from 47 CF patients carrying a wide spectrum of CFTR mutations and 57 age-matched controls. Rectal tissues were mounted in perfused micro-Ussing chambers and the effects of 1-EBIO were compared in control tissues, CF tissues expressing residual CFTR function and CF tissues with no detectable Clâ» secretion. RESULTS: Studies in control tissues demonstrate that 1-EBIO activated CFTR-mediated Clâ» secretion in the absence of cAMP-mediated stimulation and potentiated cAMP-induced Clâ» secretion by 39.2±6.7% (P<0.001) via activation of basolateral CaÂČâș-activated and clotrimazole-sensitive KCNN4 Kâș channels. In CF specimens, 1-EBIO potentiated cAMP-induced Clâ» secretion in tissues with residual CFTR function by 44.4±11.5% (P<0.001), but had no effect on tissues lacking CFTR-mediated Clâ» conductance. CONCLUSIONS: We conclude that 1-EBIO potentiates Clâ»secretion in native CF tissues expressing CFTR mutants with residual Clâ» channel function by activation of basolateral KCNN4 Kâș channels that increase the driving force for luminal Clâ» exit. This mechanism may augment effects of CFTR correctors and potentiators that increase the number and/or activity of mutant CFTR channels at the cell surface and suggests KCNN4 as a therapeutic target for CF
Baseline and Quality Reference Values for Natural Radionuclides in Soils of Rio de Janeiro State, Brazil
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Z boson production in Pb+Pb collisions at âSnn = 5.02 TeV measured by the ATLAS experiment
The production yield of Z bosons is measured in the electron and muon decay channels in Pb+Pb collisions at âS = 5.02 TeV with the ATLAS detector. Data from the 2015 LHC run corresponding to an integrated luminosity of 0.49 nb are used for the analysis. The Z boson yield, normalised by the total number of minimum-bias events and the mean nuclear thickness function, is measured as a function of dilepton rapidity and event centrality. The measurements in Pb+Pb collisions are compared with similar measurements made in proton-proton collisions at the same centre-of-mass energy. The nuclear modification factor is found to be consistent with unity for all centrality intervals. The results are compared with theoretical predictions obtained at next-to-leading order using nucleon and nuclear parton distribution functions. The normalised Z boson yields in Pb+Pb collisions lie 1-3Ï above the predictions. The nuclear modification factor measured as a function of rapidity agrees with unity and is consistent with a next-to-leading-order QCD calculation including the isospin effect. nn -
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