7,710 research outputs found

    Quiste óseo aneurismático postraumático

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    Se presenta un caso de quiste óseo aneurismático de localización superficial en la cara externa del húmero. El tumor fue tratado mediante la resección en bloque y relleno con hueso liofilizado. La evolución ha sido satisfactoria no habiéndose presentado recurrencia del tumor y considerándose el enfermo completamente curado a los tres años de realizado el tratamiento. Se establece una relación próxima en el tiempo con un episodio traumático, que se considera desencadenante del desarrollo tumoral y de la sintomatología.A case of aneurysmal bone cyst located at the lateral periosteal surface of the humeral diaphysis is presented. The patient was treated by in-bloc tumor resection and grafting of liophylized bone. The outcome has been satisfactory without tumor recurrence. Three years after surgery the patients remains free from disease. A relationship between previous trauma and the development of tumor could be found

    Fractura bipolar de clavícula

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    Se presenta un caso de fractura que afecta a ambos extremos de la clavícula. Fractura tipo II de Neer del fragmento distal y fractura del extremo esternal de la clavícula. Se realizó tratamiento quirúrgico mediante reducción abierta y osteosíntesis con agujas de Kirschner en ambas. El resultado a largo plazo ha sido satisfactorio cosmética y funcionalmente.A case of bipolar fracture affecting both ends of the clavicle is reported. The lesion consisted of a Neer type II fracture at the distal segment and a fracture close to the proximal joint with the sternum. Surgical treatment was carried out by open reduction and Kirschner wire fixation stabilizing both sides. At follow up, clinical and cosmetic results are satisfactories

    Tissue-Specific Transcriptomes Reveal Gene Expression Trajectories in Two Maturing Skin Epithelial Layers in Zebrafish Embryos.

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    Epithelial cells are the building blocks of many organs, including skin. The vertebrate skin initially consists of two epithelial layers, the outer periderm and inner basal cell layers, which have distinct properties, functions, and fates. The embryonic periderm ultimately disappears during development, whereas basal cells proliferate to form the mature, stratified epidermis. Although much is known about mechanisms of homeostasis in mature skin, relatively little is known about the two cell types in pre-stratification skin. To define the similarities and distinctions between periderm and basal skin epithelial cells, we purified them from zebrafish at early development stages and deeply profiled their gene expression. These analyses identified groups of genes whose tissue enrichment changed at each stage, defining gene flow dynamics of maturing vertebrate epithelia. At each of 52 and 72 hr post-fertilization (hpf), more than 60% of genes enriched in skin cells were similarly expressed in both layers, indicating that they were common epithelial genes, but many others were enriched in one layer or the other. Both expected and novel genes were enriched in periderm and basal cell layers. Genes encoding extracellular matrix, junctional, cytoskeletal, and signaling proteins were prominent among those distinguishing the two epithelial cell types. In situ hybridization and BAC transgenes confirmed our expression data and provided new tools to study zebrafish skin. Collectively, these data provide a resource for studying common and distinguishing features of maturing epithelia

    Markov chain Monte Carlo analyses of the flux ratios of B, Be and Li with the DRAGON2 code

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    Recent cosmic-ray measurements are challenging our models of propagation in the Galaxy. A good characterization of the secondary cosmic rays (B, Be, Li and sub-iron species) is crucial to constrain these models and exploit the precision of modern CR experiments. In this work, a Markov chain Monte Carlo analysis has been implemented to fit the experimental flux ratios between B, Be and Li and their flux ratios to the primary nuclei C and O. We have fitted the data using two different parametrizations for the spallation cross sections. The uncertainties in the evaluation of the spectra of these secondary cosmic rays, due to spallation cross sections, have been considered by introducing scale factors as nuisance parameters. We have also tested two different formulations for the diffusion coefficient, which differ in the origin of the high energy hardening of cosmic rays. Additionally, two different approaches are used to scale the cross sections, one based on a combined analysis of all the species ("combined" analysis) and the other reproducing the high energy spectra of the secondary-to-secondary flux ratios of Be/B, Li/B, Li/Be ("scaled" analysis). This allows us to make a better comparison between the propagation parameters inferred from the cross sections parametrizations tested in this work. This novel analysis has been successfully implemented using the numerical code DRAGON2 to reproduce the cosmic-ray nuclei data up to Z=14Z=14 from the AMS-02 experiment. It is found that the ratios of Li favor a harder spectral index of the diffusion coefficient, but compatible with the other ratios inside the observed 2σ2\sigma uncertainties. In addition, it is shown that, including these scale factors, the secondary-to-primary flux ratios can be simultaneously reproduced.Comment: 27 pages, 10 figures, 9 table

    Multivariate forecasting model to optimize management of grape downy mildew control

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    Aim of this study was to develop a forecasting model for Plasmopara viticola to achieve rational disease management and to reduce the use of copper treatments in organic farming. Starting from meteo-climatic, agronomic and phytopathological data a partial least squares discriminant analysis was developed. Three different strategies were compared: treatments according to the established organic agricultural practice (standard); treatments according to the predictive model and untreated control where no fungicides against downy mildew were applied. The modelling approach was divided into three phases: 1) model calibration; 2) field testing and 3) a posteriori model performance evaluation. The prediction was separately considered and modelled for: i) disease onset and ii) disease progress. The results for phase 1 show a percentage of correct classification equal to 91.8 % for the disease onset with 3 days elapsed between the prediction of first potential attack and disease onset and to 91.23 % for disease progress. In field testing phase the percentage of correct classification was equal to about 81 % for both the analysed years (2009 and 2010). In the phase 3 the percentages were quietly higher for the 2009. The number of fungicide applications on the partial least squares discriminant analysis model was almost half compared with standard schedule both in 2009 and 2010. Finally this approach showed the possibility to reduce fungicidal treatments and to avoid applying copper not essential for disease control representing a first step in the model validation

    Quasiparticle dynamics and spin-orbital texture of the SrTiO3 two-dimensional electron gas

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    Two-dimensional electron gases (2DEGs) in SrTiO3_3 have become model systems for engineering emergent behaviour in complex transition metal oxides. Understanding the collective interactions that enable this, however, has thus far proved elusive. Here we demonstrate that angle-resolved photoemission can directly image the quasiparticle dynamics of the dd-electron subband ladder of this complex-oxide 2DEG. Combined with realistic tight-binding supercell calculations, we uncover how quantum confinement and inversion symmetry breaking collectively tune the delicate interplay of charge, spin, orbital, and lattice degrees of freedom in this system. We reveal how they lead to pronounced orbital ordering, mediate an orbitally-enhanced Rashba splitting with complex subband-dependent spin-orbital textures and markedly change the character of electron-phonon coupling, co-operatively shaping the low-energy electronic structure of the 2DEG. Our results allow for a unified understanding of spectroscopic and transport measurements across different classes of SrTiO3_3-based 2DEGs, and yield new microscopic insights on their functional properties.Comment: 10 pages including supplementary information, 4+4 figure

    Control of a two-dimensional electron gas on SrTiO3(111) by atomic oxygen

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    We report on the formation of a two-dimensional electron gas (2DEG) at the bare surface of (111) oriented SrTiO3. Angle resolved photoemission experiments reveal highly itinerant carriers with a 6-fold symmetric Fermi surface and strongly anisotropic effective masses. The electronic structure of the 2DEG is in good agreement with self-consistent tight-binding supercell calculations that incorporate a confinement potential due to surface band bending. We further demonstrate that alternate exposure of the surface to ultraviolet light and atomic oxygen allows tuning of the carrier density and the complete suppression of the 2DEG.Comment: 5 pages, 4 figure

    Non-pharmaceutical Interventions and the Infodemic on Twitter: Lessons Learned from Italy during the Covid-19 Pandemic

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    The COVID-19 pandemic changed expectations for information dissemination and use around the globe, challenging accepted models of communications, leadership, and social systems. We explore how social media discourse about COVID-19 in Italy was affected by the rapid spread of the virus, and how themes in postings changed with the adoption of social distancing measures and non-pharmaceutical interventions (NPI). We used topic modeling and social network analysis to highlight critical dimensions of conversations around COVID-19: 1) topics in social media postings about the Coronavirus; 2) the scope and reach of social networks; and 3) changes in social media content as the nation moved from partial to full social distancing. Twitter messages sent in Italy between February 11th and March 10th, 2020. 74,306 Tweets sent by institutions, news sources, elected officials, scientists and social media influencers. Messages were retweeted more than 1.2 million times globally. Non-parametric chi-square statistic with residual analysis to identify categories, chi-square test for linear trend, and Social Network Graphing. The first phase of the pandemic was dominated by social media influencers, followed by a focus on the economic consequences of the virus and placing blame on immigrants. As the crisis deepened, science-based themes began to predominate, with a focus on reducing the spread of the virus through physical distancing and business closures Our findings highlight the importance of messaging in social media in gaining the public’s trust and engagement during a pandemic. This requires credible scientific voices to garner public support for effective mitigation. Fighting the spread of an infectious disease goes hand in hand with stemming the dissemination of lies, bad science, and misdirection

    Efectos de un hidrocarburo aromático policíclico (ß naftoflavona) sobre biomarcadores de efecto en Corydoras paleatus en condiciones de campo y laboratorio

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    Polycyclic aromatic hydrocarbons (PAHs) are important anthropogenic sources of aquatic contamination. In this study, hepatic biomarker responses of Corydoras paleatus injected with one sublethal dose of a PAH (ß-naftoflavona, BNF) were assessed under laboratory and field conditions. Glutathion-S-transferase (GST) and catalase (CAT) hepatic activities, liver protein content (PC), condition factor (CF) and liver somatic index (LSI) were determined. Two bioassays were performed during winter time: laboratory (la) and field (ca). Fish were injected with 50 mg BNF/kg body weight dissolved in corn oil (ß-la y ßca); control fish received corn oil (C-la y C-ca). There were no differences between controls or in BNF injected fish in the assessed parameters. BNF provoked a tendency of increase in CAT and GST activities and lower values of CP; on the other hand, no differences were observed in the FC and IHS. In BNF field exposed fish (ß-ca) CAT activity was significantly stimulated vs. both field and laboratory controls; GST differences were detected both between ß-ca and ß-la and their respective controls. BNF exposure induced adverse effects principally in the enzymatic biomarkers of C. paleatus and those effects were modulated by the environmental conditions.Facultad de Ciencias Naturales y Muse
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