46 research outputs found

    Review: Formation and Metabolic Function of Coral Rubble Biofilms in the Reef Ecosystem

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    When coral dies, their calcareous skeletons constitute coral rubble in conjunction with the cementing activity of coralline algae and bacteria, creating a secondary reef structure which takes from years to decades to form. Healthy coral reefs differ from coral—rubble dominated reefs in microbial taxonomic composition and metabolic functional roles. The metabolisms of healthy reefs are dominated by autotrophic pathways, where carbon and nitrogen fixation dominate, while the metabolism of rubble—dominated reefs predominate in degradation of organic matter. Nitrogen fixation is 3 orders of magnitude lower in rubble—dominated reefs than in healthy reefs. Coral—rubble harbors a vast diversity of microbes that can precipitate carbonate through coupling several metabolic processes including photosynthesis, ureolysis, ammonification, denitrification, sulfate reduction, methane oxidation, and anaerobic sulfide oxidation. All these metabolic processes were found in rubble microbial communities, but ammonification and sulfate reduction were most prevalent. Anthropogenic and non—anthropogenic perturbations of healthy coral reefs in the past decades have led to the prevalence of rubble—dominated reefs in areas of the Caribbean where the ecological and functional shifts of the community still need further study

    A genome-wide association scan implicates DCHS2, RUNX2, GLI3, PAX1 and EDAR in human facial variation

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    We report a genome-wide association scan for facial features in B6,000 Latin Americans. We evaluated 14 traits on an ordinal scale and found significant association (P valueso5 10 8) at single-nucleotide polymorphisms (SNPs) in four genomic regions for three nose-related traits: columella inclination (4q31), nose bridge breadth (6p21) and nose wing breadth (7p13 and 20p11). In a subsample of B3,000 individuals we obtained quantitative traits related to 9 of the ordinal phenotypes and, also, a measure of nasion position. Quantitative analyses confirmed the ordinal-based associations, identified SNPs in 2q12 associated to chin protrusion, and replicated the reported association of nasion position with SNPs in PAX3. Strongest association in 2q12, 4q31, 6p21 and 7p13 was observed for SNPs in the EDAR, DCHS2, RUNX2 and GLI3 genes, respectively. Associated SNPs in 20p11 extend to PAX1. Consistent with the effect of EDAR on chin protrusion, we documented alterations of mandible length in mice with modified Edar funtion

    Latin Americans show wide-spread Converso ancestry and imprint of local Native ancestry on physical appearance

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    Historical records and genetic analyses indicate that Latin Americans trace their ancestry mainly to the intermixing (admixture) of Native Americans, Europeans and Sub-Saharan Africans. Using novel haplotype-based methods, here we infer sub-continental ancestry in over 6,500 Latin Americans and evaluate the impact of regional ancestry variation on physical appearance. We find that Native American ancestry components in Latin Americans correspond geographically to the present-day genetic structure of Native groups, and that sources of non-Native ancestry, and admixture timings, match documented migratory flows. We also detect South/East Mediterranean ancestry across Latin America, probably stemming mostly from the clandestine colonial migration of Christian converts of non-European origin (Conversos). Furthermore, we find that ancestry related to highland (Central Andean) versus lowland (Mapuche) Natives is associated with variation in facial features, particularly nose morphology, and detect significant differences in allele frequencies between these groups at loci previously associated with nose morphology in this sample.Instituto Multidisciplinario de BiologĂ­a Celula

    Latin Americans show wide-spread Converso ancestry and imprint of local Native ancestry on physical appearance

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    Historical records and genetic analyses indicate that Latin Americans trace their ancestry mainly to the intermixing (admixture) of Native Americans, Europeans and Sub-Saharan Africans. Using novel haplotype-based methods, here we infer sub-continental ancestry in over 6,500 Latin Americans and evaluate the impact of regional ancestry variation on physical appearance. We find that Native American ancestry components in Latin Americans correspond geographically to the present-day genetic structure of Native groups, and that sources of non-Native ancestry, and admixture timings, match documented migratory flows. We also detect South/East Mediterranean ancestry across Latin America, probably stemming mostly from the clandestine colonial migration of Christian converts of non-European origin (Conversos). Furthermore, we find that ancestry related to highland (Central Andean) versus lowland (Mapuche) Natives is associated with variation in facial features, particularly nose morphology, and detect significant differences in allele frequencies between these groups at loci previously associated with nose morphology in this sample.Instituto Multidisciplinario de BiologĂ­a Celula

    Search for a Light Charged Higgs Boson Decaying to a W Boson and a CP-Odd Higgs Boson in Final States with eΌΌ or ΌΌΌ in Proton-Proton Collisions at √s=13  TeV

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    A search for a light charged Higgs boson (H+) decaying to a W boson and a CP-odd Higgs boson (A) in final states with eΌΌ or ΌΌΌ is performed using data from pp collisions at √s=13  TeV, recorded by the CMS detector at the LHC and corresponding to an integrated luminosity of 35.9  fb−1. In this search, it is assumed that the H+ boson is produced in decays of top quarks, and the A boson decays to two oppositely charged muons. The presence of signals for H+ boson masses between 100 and 160 GeV and A boson masses between 15 and 75 GeV is investigated. No evidence for the production of the H+ boson is found. Upper limits at 95% confidence level are obtained on the combined branching fraction for the decay chain, t→bH+→bW+A→bW+ÎŒ+Ό−, of 1.9×10−6 to 8.6×10−6, depending on the masses of the H+ and A bosons. These are the first limits for these decay modes of the H+ and A bosons.Peer reviewe

    Search for dark matter particles produced in association with a Higgs boson in proton-proton collisions at √s = 13 TeV

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    © 2020, The Author(s). A search for dark matter (DM) particles is performed using events with a Higgs boson candidate and large missing transverse momentum. The analysis is based on proton- proton collision data at a center-of-mass energy of 13 TeV collected by the CMS experiment at the LHC in 2016, corresponding to an integrated luminosity of 35.9 fb−1. The search is performed in five Higgs boson decay channels: h → b b ÂŻ , γγ, τ+τ−, W+W−, and ZZ. The results from the individual channels are combined to maximize the sensitivity of the analysis. No significant excess over the expected standard model background is observed in any of the five channels or in their combination. Limits are set on DM production in the context of two simplified models. The results are also interpreted in terms of a spin-independent DM-nucleon scattering cross section and compared to those from direct-detection DM experiments. This is the first search for DM particles produced in association with a Higgs boson decaying to a pair of W or Z bosons, and the first statistical combination based on five Higgs boson decay channels. [Figure not available: see fulltext.].SCOAP

    Automatic ear detection and feature extraction using Geometric Morphometrics and Convolutional Neural Networks

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    Accurate gathering of phenotypic information is a key aspect in several subject matters, including biometrics, biomedical analysis, forensics, and many other. Automatic identification of anatomical structures of biometric interest, such as fingerprints, iris patterns, or facial traits, are extensively used in applications like access control and anthropological research, all having in common the drawback of requiring intrusive means for acquiring the required information. In this regard, the ear structure has multiple advantages. Not only the earÂŽs biometric markers can be easily captured from the distance with non intrusive methods, but also they experiment almost no changes over time, and are not influenced by facial expressions. Here we present a new method based on Geometric Morphometrics and Deep Learning for automatic ear detection and feature extraction in the form of landmarks. A convolutional neural network was trained with a set of manually landmarked examples. The network is able to provide morphometric landmarks on earsÂŽ images automatically, with a performance that matches human landmarking. The feasibility of using ear landmarks as feature vectors opens a novel spectrum of biometrics applications.Fil: Cintas, Celia. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Centro Nacional PatagĂłnico; ArgentinaFil: Quinto Sanchez, Mirsha Emmanuel. Universidad Nacional AutĂłnoma de MĂ©xico; MĂ©xico. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; ArgentinaFil: Acuña,Victor. University College London; Estados UnidosFil: Paschetta, Carolina Andrea. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Centro Nacional PatagĂłnico; ArgentinaFil: de Azevedo, Soledad. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Centro Nacional PatagĂłnico; ArgentinaFil: Silva de Cerqueira, Caio Cesar. Estado de SĂŁo Paulo. SuperintendĂȘncia da PolĂ­cia TĂ©cnico-CientĂ­fica; BrasilFil: Ramallo, Virginia. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Centro Nacional PatagĂłnico; ArgentinaFil: Gallo, Carla. Universidad Peruana Cayetano Heredia; PerĂșFil: Poletti, Giovanni. Universidad Peruana Cayetano Heredia; PerĂșFil: Bortolini, Maria Catira. Universidade Federal do Rio Grande do Sul; BrasilFil: Canizales Quinteros, Samuel. Universidad Nacional AutĂłnoma de MĂ©xico; MĂ©xicoFil: Rothhammer, Francisco. Universidad de TarapacĂĄ; ChileFil: Bedoya, Gabriel. Universidad de Antioquia; ColombiaFil: Ruiz Linares, Andres. Fudan University; China. Aix Marseille UniversitĂ©; FranciaFil: GonzĂĄlez JosĂ©, Rolando. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Centro Nacional PatagĂłnico; ArgentinaFil: Delrieux, Claudio Augusto. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - BahĂ­a Blanca. Instituto Argentino de OceanografĂ­a. Universidad Nacional del Sur. Instituto Argentino de OceanografĂ­a; Argentina. Universidad Nacional del Sur; Argentin

    Facial asymmetry and genetic ancestry in Latin American admixed populations

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    Fluctuating and directional asymmetry are aspects of morphological variation widely used to infer environmental and genetic factors affecting facial phenotypes. However, the genetic basis and environmental determinants of both asymmetry types is far from being completely known. The analysis of facial asymmetries in admixed individuais can be of help to characterize the impact of a genome's heterozygosity on the deveiopmental basis of both fl.uctuating and directional asymmetries. Here we characterize the association between genetic ancestry and individual asymmetry on a sample of Latin-American admixed populations. To do so, three-dimensional (3D) facial shape attributes were explored on a sample of 4,104 volunteers aged between 18 and 85 years. Individual ancestry and heterozygosity was estimated using more than 730,000 genome-wide markers. Multivariate techniques applied to geometric morphometric data were used to evaluate the magnitude and significance of directional and ftuctuating asymmetry (FA), as well as correiations and multipie regressions aimed to estimate the relationship between facial FA scores and heterozygosity and a set of covariates. Resuits indicate that directional and FA are both signi:ficant, the former being the strongest expression of asymmetry in this sample. In addition, our analyses suggest that there are some specific patterns of facial asymmetries characterizing the different ancestry groups. Finally, we find that more heterozygous individuais exhibit lower leveis of asymmetry. Our results highlight the importance of including ancestry-admixture estimators, especially when the analyses are aimed to compare leveis of asymmetries on groups differing on socioeconomic leveis, as a proxy to estimate developmental noise

    Pancreatic islet cells: a model for calcium-dependent peptide release

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    In mammals the concentration of blood glucose is kept close to 5 mmol∕l. Different cell types in the islet of Langerhans participate in the control of glucose homeostasis. ÎČ-cells, the most frequent type in pancreatic islets, are responsible for the synthesis, storage, and release of insulin. Insulin, released with increases in blood glucose promotes glucose uptake into the cells. In response to glucose changes, pancreatic α-, ÎČ-, and ÎŽ-cells regulate their electrical activity and Ca2+ signals to release glucagon, insulin, and somatostatin, respectively. While all these signaling steps are stimulated in hypoglycemic conditions in α-cells, the activation of these events require higher glucose concentrations in ÎČ and also in ÎŽ-cells. The stimulus-secretion coupling process and intracellular Ca2+ ([Ca2+]i) dynamics that allow ÎČ-cells to secrete is well-accepted. Conversely, the mechanisms that regulate α- and ÎŽ-cell secretion are still under study. Here, we will consider the glucose-induced signaling mechanisms in each cell type and the mathematical models that explain Ca2+ dynamics
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