2,193 research outputs found

    Fast detector/first responder : interactions between the superior colliculus-pulvinar pathway and stimuli relevant to primates

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    Primates are distinguished from other mammals by their heavy reliance on the visual sense, which occurred as a result of natural selection continually favoring those individuals whose visual systems were more responsive to challenges in the natural world. Here we describe two independent but also interrelated visual systems, one cortical and the other subcortical, both of which have been modified and expanded in primates for different functions. Available evidence suggests that while the cortical visual system mainly functions to give primates the ability to assess and adjust to fluid social and ecological environments, the subcortical visual system appears to function as a rapid detector and first responder when time is of the essence, i.e., when survival requires very quick action. We focus here on the subcortical visual system with a review of behavioral and neurophysiological evidence that demonstrates its sensitivity to particular, often emotionally charged, ecological and social stimuli, i.e., snakes and fearful and aggressive facial expressions in conspecifics. We also review the literature on subcortical involvement during another, less emotional, situation that requires rapid detection and response—visually guided reaching and grasping during locomotion—to further emphasize our argument that the subcortical visual system evolved as a rapid detector/first responder, a function that remains in place today. Finally, we argue that investigating deficits in this subcortical system may provide greater understanding of Parkinson's disease and Autism Spectrum disorders (ASD)

    Asparagopsis armata exudate cocktail: the quest for the mechanisms of toxic action of an invasive seaweed on marine invertebrates

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    The seaweed Asparagopsis armata exhibits a strong invasive behavior, producing halogenated compounds with effective biological effects. This study addresses the biochemical responses to sublethal concentrations of A. armata exudate on the marine snail Gibbula umbilicalis whole body and the shrimp Palaemon elegans eyes and hepatopancreas. Antioxidant defenses superoxide dismutase (SOD) and glutathione-S-transferase (GST), oxidative damage endpoints lipid peroxidation (LPO) and DNA damage, the neuronal parameter acetylcholinesterase (AChE), and the fatty acid profile were evaluated. Results revealed different metabolic responses in both species. Despite previous studies indicating that the exudate affected G. umbilicalis’ survival and behavior, this does not seem to result from oxidative stress or neurotoxicity. For P. elegans, the inhibition of AChE and the decrease of antioxidant capacity is concomitant with the increase of LPO, suggesting neurotoxicity and oxidative stress as contributor mechanisms of toxicity for this species. Fatty acid profile changes were more pronounced for P. elegans with a general increase in polyunsaturated fatty acids (PUFAs) with the exudate exposure, which commonly means a defense mechanism protecting from membrane disruption. Nonetheless, the omega-3 PUFAs arachidonic acid (ARA) and docosapentaenoic acid (DPA) increased in both invertebrates, indicating a common regulation mechanism of inflammation and immunity responsesinfo:eu-repo/semantics/publishedVersio

    Use of the Hospital Anxiety and Depression Scale (HADS) in a Cardiac Emergency Room – Chest Pain Unit

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    OBJECTIVE: To determine the prevalence of anxiety and depression in patients complaining of chest pain who seek a chest pain unit attendance. INTRODUCTION: Patients arriving at a Chest Pain Unit may present psychiatric disorders not identified, isolated or co-morbid to the main illness, which may interfere in the patient prognosis. METHODOLOGY: Patients were assessed by the "Hospital Anxiety and Depression Scale" as a screening instrument wile following a systematized protocol to rule out the diagnosis of acute coronary syndrome and other potentially fatal diseases. Patients with 8 or more points in the scale were considered "probable case" of anxiety or depression. RESULTS: According to the protocol, 59 (45.4%) of 130 patients studied presented Chest Pain of Determined Cause, and 71 (54.6%) presented Chest Pain of Indefinite Cause. In the former group, in which 43 (33.1%) had acute coronary syndrome, 33.9% were probable anxiety cases and 30.5% depression cases. In the second group, formed by patients without acute coronary syndrome or any clinical conditions involving greater morbidity and mortality risk, 53.5% were probable anxiety cases and 25.4% depression. CONCLUSION: The high anxiety and depression prevalence observed may indicate the need for early and specialized approach to these disorders. When coronary arterial disease is present, this may decrease complications and shorten hospital stay. When psychiatric disorder appears isolated, is possible to reduce unnecessary repeated visits to emergency room and increase patient's quality of life

    IdentificaciĂłn de maderas colombianas utilizando el Xylotron: Prueba de concepto de una colaboraciĂłn internacional

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    Field deployable computer vision wood identification systems can play a key role in combating illegal logging in the real world. This work used 764 xylarium specimens from 84 taxa to develop an image data set to train a classifier to identify 14 commercial Colombian timbers. We imaged specimens from various xylaria outside Colombia, trained and evaluated an initial identification model, then collected additional images from a Colombian xylarium (BOFw), and incorporated those images to refine and produce a final model. The specimen classification accuracy of this final model was ~ 97%, demonstrating that including local specimens can augment the accuracy and reliability of the XyloTron system. Our study demonstrates the first deployable computer vision model for wood identification in Colombia, developed on a timescale of months rather than years by leveraging international cooperation. We conclude that field testing and advanced forensic and machine learning training are the next logical steps.Sistemas de identificaciĂłn automatizada de maderas pueden fortalecer la lucha contra el trĂĄfico ilegal de maderas. Este trabajo utilizĂł 764 especĂ­menes de xilotecas, correspondientes a 84 taxones, para desarrollar un modelo de identificaciĂłn para 14 especies comerciales de Colombia. Se comenzĂł colectando imĂĄgenes de especĂ­menes provenientes de xilotecas fuera de Colombia, que se utilizaron para entrenar y evaluar un modelo inicial. Se colectaron imĂĄgenes adicionales provenientes de una xiloteca Colombiana (BOFw), que se utilizaron para refinar y producir el modelo final. La capacidad de reconocimiento de este modelo fue del ~97%, demostrando que incluir muestras locales aumenta la precisiĂłn y confiabilidad del sistema [XyloTron]. Este estudio presenta el primer modelo de vision computarizada para identificaciĂłn de maderas en Colombia, desarrollado en una escala de tiempo corta y bajo cooperaciĂłn internacional. Concluimos que pruebas en campo y capacitaciĂłn forense y en aprendizaje automatizado, son los siguientes pasos lĂłgicos a seguir

    GLUT1 expression in malignant tumors and its use as an immunodiagnostic marker

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    OBJECTIVE: To analyze glucose transporter 1 expression patterns in malignant tumors of various cell types and evaluate their diagnostic value by immunohistochemistry. INTRODUCTION: Glucose is the major source of energy for cells, and glucose transporter 1 is the most common glucose transporter in humans. Glucose transporter 1 is aberrantly expressed in several tumor types. Studies have implicated glucose transporter 1 expression as a prognostic and diagnostic marker in tumors, primarily in conjunction with positron emission tomography scan data. METHODS: Immunohistochemistry for glucose transporter 1 was performed in tissue microarray slides, comprising 1955 samples of malignant neoplasm from different cell types. RESULTS: Sarcomas, lymphomas, melanomas and hepatoblastomas did not express glucose transporter 1. Fortyseven per cent of prostate adenocarcinomas were positive, as were 29% of thyroid, 10% of gastric and 5% of breast adenocarcinomas. Thirty-six per cent of squamous cell carcinomas of the head and neck were positive, as were 42% of uterine cervix squamous cell carcinomas. Glioblastomas and retinoblastomas showed membranous glucose transporter 1 staining in 18.6% and 9.4% of all cases, respectively. Squamous cell carcinomas displayed membranous expression, whereas adenocarcinomas showed cytoplasmic glucose transporter 1 expression. CONCLUSION: Glucose transporter 1 showed variable expression in various tumor types. Its absence in sarcomas, melanomas, hepatoblastomas and lymphomas suggests that other glucose transporters mediate the glycolytic pathway in these tumors. The data suggest that glucose transporter 1 is a valuable immunohistochemical marker that can be used to identify patients for evaluation by positron emission tomography scan. The function of cytoplasmic glucose transporter 1 in adenocarcinomas must be further examined

    Inequality and violent crime: evidence from data on robbery and violent theft

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    This article argues that the link between income inequality and violent property crime might be spurious, complementing a similar argument in prior analysis by the author on the determinants of homicide. In contrast, Fajnzylber, Lederman & Loayza (1998; 2002a, b) provide seemingly strong and robust evidence that inequality causes a higher rate of both homicide and robbery/violent theft even after controlling for country-specific fixed effects. Our results suggest that inequality is not a statistically significant determinant, unless either country-specific effects are not controlled for or the sample is artificially restricted to a small number of countries. The reason why the link between inequality and violent property crime might be spurious is that income inequality is likely to be strongly correlated with country-specific fixed effects such as cultural differences. A high degree of inequality might be socially undesirable for any number of reasons, but that it causes violent crime is far from proven

    Automatic 3D pulmonary nodule detection in CT images: a survey

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    This work presents a systematic review of techniques for the 3D automatic detection of pulmonary nodules in computerized-tomography (CT) images. Its main goals are to analyze the latest technology being used for the development of computational diagnostic tools to assist in the acquisition, storage and, mainly, processing and analysis of the biomedical data. Also, this work identifies the progress made, so far, evaluates the challenges to be overcome and provides an analysis of future prospects. As far as the authors know, this is the first time that a review is devoted exclusively to automated 3D techniques for the detection of pulmonary nodules from lung CT images, which makes this work of noteworthy value. The research covered the published works in the Web of Science, PubMed, Science Direct and IEEEXplore up to December 2014. Each work found that referred to automated 3D segmentation of the lungs was individually analyzed to identify its objective, methodology and results. Based on the analysis of the selected works, several studies were seen to be useful for the construction of medical diagnostic aid tools. However, there are certain aspects that still require attention such as increasing algorithm sensitivity, reducing the number of false positives, improving and optimizing the algorithm detection of different kinds of nodules with different sizes and shapes and, finally, the ability to integrate with the Electronic Medical Record Systems and Picture Archiving and Communication Systems. Based on this analysis, we can say that further research is needed to develop current techniques and that new algorithms are needed to overcome the identified drawbacks

    Lipophosphoglycan Polymorphisms Do Not Affect \u3cem\u3eLeishmania amazonensis\u3c/em\u3e Development in the Permissive Vectors \u3cem\u3eLutzomyia migonei\u3c/em\u3e and \u3cem\u3eLutzomyia longipalpis\u3c/em\u3e

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    Background: Lipophosphoglycan (LPG) is a dominant surface molecule of Leishmaniapromastigotes. Its species-specific polymorphisms are found mainly in the sugars that branch off the conserved Gal(ÎČ1,4)Man(α1)-PO4 backbone of repeat units. Leishmania amazonensis is one of the most important species causing human cutaneous leishmaniasis in the New World. Here, we describe LPG intraspecific polymorphisms in two Le. amazonensis reference strains and their role during the development in three sand fly species. Results: Strains isolated from Lutzomyia flaviscutellata (PH8) and from a human patient (Josefa) displayed structural polymorphism in the LPG repeat units, possessing side chains with 1 and 2 ÎČ-glucose or 1 to 3 ÎČ-galactose, respectively. Both strains successfully infected permissive vectors Lutzomyia longipalpis and Lutzomyia migonei and could colonize their stomodeal valve and differentiate into metacyclic forms. Despite bearing terminal galactose residues on LPG, Josefa could not sustain infection in the restrictive vector Phlebotomus papatasi. Conclusions: LPG polymorphisms did not affect the ability of Le. amazonensis to develop late-stage infections in permissive vectors. However, the non-establishment of infection in Ph. papatasi by Josefa strain suggested other LPG-independent factors in this restrictive vector

    Thermal stability of plasma-nitrided aluminum oxide films on Si

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    The effect of post-deposition rapid thermal annealing in vacuum and in dry O2 on the stability of remote plasma-assisted nitrided aluminum oxide films on silicon is investigated. The areal densities of Al, O, N, and Si were determined by nuclear reaction analysis and their concentration versus depth distributions by narrow nuclear reaction resonance profiling, with subnanometric depth resolution. Annealing in both vacuum and O2 atmospheres produced partial loss of N from the near-surface regions of the films and its transport into near-interface regions of the Si substrate. Oxygen from the gas phase was incorporated in the AlON films in exchange for O and N previously existing therein, as well as in the near-interface regions of the Si substrate, leading to oxynitridation of the substrate. Al and Si remained essentially immobile under rapid thermal processing, confirming that the presence of nitrogen improves the thermal stability characteristics of the AlON/ Si structures in comparison with non-nitrided Al2O3 /Si

    Proteome of the phytopathogen Xanthomonas citri subsp. citri: a global expression profile

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    <p>Abstract</p> <p>Background</p> <p>Citrus canker is a disease caused by <it>Xantomonas citri </it>subsp.<it>citri (Xac)</it>, and has emerged as one of the major threats to the worldwide citrus crop because it affects all commercial citrus varieties, decreases the production and quality of the fruits and can spread rapidly in citrus growing areas. In this work, the first proteome of <it>Xac </it>was analyzed using two methodologies, two-dimensional liquid chromatography (2D LC) and tandem mass spectrometry (MS/MS).</p> <p>Results</p> <p>In order to gain insight into the metabolism of <it>Xac</it>, cells were grown on two different media (<b>NB </b>- Nutrient Broth and <b>TSE </b>- Tryptone Sucrose broth enriched with glutamic acid), and proteins were proteolyzed with trypsin and examined by 2D LC-MS/MS. Approximately 39% of all predicted proteins by annotation of <it>Xac </it>were identified with their component peptides unambiguously assigned to tandem mass spectra. The proteins, about 1,100, were distributed in all annotated functional categories.</p> <p>Conclusions</p> <p>This is the first proteomic reference map for the most aggressive strain of <it>Xanthomonas </it>pathogen of all orange varieties. The compilation of metabolic pathways involved with bacterial growth showed that <it>Xac </it>expresses a complete central and intermediary metabolism, replication, transcription and translation machineries and regulation factors, distinct membrane transporters (ABC, MFS and pumps) and receptors (MCP, TonB dependent and metabolites acquisition), two-component systems (sensor and regulatory components) and response regulators. These data corroborate the growth curve <it>in vitro </it>and are the first reports indicating that many of these genome annotated genes are translated into operative in <it>Xac</it>. This proteomic analysis also provided information regarding the influence of culture medium on growth and protein expression of <it>Xac</it>.</p
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