Towards the bridging of molecular genetics data across Xenopus species

Indexación: ScopusBackground: The clawed African frog Xenopus laevis has been one of the main vertebrate models for studies in developmental biology. However, for genetic studies, Xenopus tropicalis has been the experimental model of choice because it shorter life cycle and due to a more tractable genome that does not result from genome duplication as in the case of X. laevis. Today, although still organized in a large number of scaffolds, nearly 85 % of X. tropicalis and 89 % of X. laevis genomes have been sequenced. There is expectation for a comparative physical map that can be used as a Rosetta Stone between X. laevis genetic studies and X. tropicalis genomic research. Results: In this work, we have mapped using coarse-grained alignment the 18 chromosomes of X. laevis, release 9.1, on the 10 reference scaffolds representing the haploid genome of X. tropicalis, release 9.0. After validating the mapping with theoretical data, and estimating reference averages of genome sequence identity, 37 to 44 % between the two species, we have carried out a synteny analysis for 2,112 orthologous genes. We found that 99.6 % of genes are in the same organization. Conclusions: Taken together, our results make possible to establish the correspondence between 62 and 65.5 % of both genomes, percentage of identity, synteny and automatic annotation of transcripts of both species, providing a new and more comprehensive tool for comparative analysis of these two species, by allowing to bridge molecular genetics data among them.https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-016-2440-

The sovereign yield curve and credit ratings in GIIPS

© 2020 International Review of Finance Ltd. 2020 This paper studies the impact of sovereign credit rating and outlook changes on the shape of the sovereign yield curve using data for five European countries, namely, Greece, Ireland, Italy, Portugal, and Spain, known as the GIIPS for the period of 2001–2016. We use the dynamic Nelson–Siegel model to estimate the level, slope, and curvature of the yield curve. Subsequently, we employ the vector autoregressive model to estimate the effect of sovereign rating and outlook changes on the sovereign yield curve. We find a significant effect of rating downgrades and an insignificant effect of rating upgrades in all five countries; however, the results for the effect of changes in outlook status are mixed. Our results remain robust to various sensitivity tests

Comprehensive phylogenomic time tree of bryophytes reveals deep relationships and uncovers gene incongruences in the last 500 million years of diversification

Premise: Bryophytes form a major component of terrestrial plant biomass, structuring ecological communities in all biomes. Our understanding of the evolutionary history of hornworts, liverworts, and mosses has been significantly reshaped by inferences from molecular data, which have highlighted extensive homoplasy in various traits and repeated bursts of diversification. However, the timing of key events in the phylogeny, patterns, and processes of diversification across bryophytes remain unclear. Methods: Using the GoFlag probe set, we sequenced 405 exons representing 228 nuclear genes for 531 species from 52 of the 54 orders of bryophytes. We inferred the species phylogeny from gene tree analyses using concatenated and coalescence approaches, assessed gene conflict, and estimated the timing of divergences based on 29 fossil calibrations. Results: The phylogeny resolves many relationships across the bryophytes, enabling us to resurrect five liverwort orders and recognize three more and propose 10 new orders of mosses. Most orders originated in the Jurassic and diversified in the Cretaceous or later. The phylogenomic data also highlight topological conflict in parts of the tree, suggesting complex processes of diversification that cannot be adequately captured in a single gene-tree topology. Conclusions: We sampled hundreds of loci across a broad phylogenetic spectrum spanning at least 450 Ma of evolution; these data resolved many of the critical nodes of the diversification of bryophytes. The data also highlight the need to explore the mechanisms underlying the phylogenetic ambiguity at specific nodes. The phylogenomic data provide an expandable framework toward reconstructing a comprehensive phylogeny of this important group of plantsFunding was provided by the NSF collaborative project “Building a Comprehensive Evolutionary History of Flagellate Plants” (DEB #1541506 to J.G. Burleigh, E.C. Davis, S.F. McDaniel, and E.B. Sessa, and #1541545 to M von Konrat). B.G. acknowledges DEB‐1753811. J.C.V.A. acknowledges the Canada Research Chair (950‐232698); the CRNSG‐RGPIN 05967–2016 and the Canadian Foundation for Innovation (projects 36781, 39135). The authors thank the two anonymous reviewers and the Associate Editor for their constructive comments on previous versions of the manuscrip

CÁNCER DE COLON Y EMBARAZO: REPORTE DE CASO Y REVISIÓN DE LA LITERATURA

El cáncer colorrectal asociado al embarazo es una patología extremadamente infrecuente. Se presenta el caso de una paciente de 38 años con antecedentes familiares de cáncer de colon, cursando un embarazo de 35 semanas en la que se diagnosticó un cáncer de colon derecho. Se efectúa una revisión de la literatura en relación al diagnóstico y manejo de esta rara entida

Technology Change: Sources and Impediments

There is little doubt that technology change, both in terms of its process and quality dimensions, represents the principal driving force to explain comparative economic performance at both micro and macro levels. This paper examines the sources of technology change and the impediments to the full realization of its opportunities, both abstractly and in the context of a comparison among six typologically diverse developing countries. Among the external sources, we examine the roles of trade, foreign patents and FDI; among the internal sources we examine the roles of investment, domestic R&D, domestic patents, S&T personnel and secondary education alternatives. Among impediments, we analyze certain public and private policy frameworks which tend to impede the realization of technological opportunities. We detect some reasons for the better TFP performance of the East Asian in comparison with the Latin American countries

Foreign direct investment and institutional reform : evidence and an application to Portugal

We examine the role of geographic, economic, and institutional factors in attracting Foreign Direct Investment (FDI) in Europe, using a cross-section of inward bilateral investments. We estimate and assess the expected benefits, the required reform efforts, and the efficiency of reform options corresponding to a con- vergence of Portuguese institutions to EU standards. We conclude that improving home institutions is likely to have a quantitatively very significant role in attracting FDI. Geographical and market size factors also play a role. Reforms promoting the independence of financial institutions and a leaner bureaucracy, lowering political risk and corruption, and improving the investment code may significantly affect the amount of bilateral inward FDI that is targeted to Portugal.info:eu-repo/semantics/publishedVersio

Potential use of fatty acid profiles of the adductor muscle of cockles (Cerastoderma edule) for traceability of collection site

Geographic traceability of seafood is key for controlling its quality and safeguarding consumers’ interest. The present study assessed if the fatty acid (FA) profile of the adductor muscle (AM) of fresh cockles (Cerastoderma edule) can be used to discriminate the origin of specimens collected in different bivalve capture/production areas legally defined within a coastal lagoon. Results suggest that this biochemical approach holds the potential to trace sampling locations with a spatial resolution <10 Km, even for areas with identical classification for bivalve production. Cockles further away from the inlet, i.e. in areas exposed to a higher saline variation, exhibited lower levels of saturated fatty acids, which are key for stabilizing the bilayer structure of cell membranes, and a higher percentage of polyunsaturated fatty acids, which enhance bilayer fluidity. Results suggest that the structural nature of the lipids present in the AM provides a stable fatty acid signature and holds potential for tracing the origin of bivalves to their capture/production areas

Trace element fingerprinting of cockle (Cerastoderma edule) shells can reveal harvesting location in adjacent areas

Determining seafood geographic origin is critical for controlling its quality and safeguarding the interest of consumers. Here, we use trace element fingerprinting (TEF) of bivalve shells to discriminate the geographic origin of specimens. Barium (Ba), manganese (Mn), magnesium (Mg), strontium (Sr) and lead (Pb) were quantified in cockle shells (Cerastoderma edule) captured with two fishing methods (by hand and by hand-raking) and from five adjacent fishing locations within an estuarine system (Ria de Aveiro, Portugal). Results suggest no differences in TEF of cockle shells captured by hand or by hand-raking, thus confirming that metal rakes do not act as a potential source of metal contamination that could somehow bias TEF results. In contrast, significant differences were recorded among locations for all trace elements analysed. A Canonical Analysis of Principal Coordinates (CAP) revealed that 92% of the samples could be successfully classified according to their fishing location using TEF. We show that TEF can be an accurate, fast and reliable method to determine the geographic origin of bivalves, even among locations separated less than 1 km apart within the same estuarine system. Nonetheless, follow up studies are needed to determine if TEF can reliably discriminate between bivalves originating from different ecosystems