972 resultados para Complement Fragments C5a


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This paper presents a solution to part of the problem of making robotic or semi-robotic digging equipment less dependant on human supervision. A method is described for identifying rocks of a certain size that may affect digging efficiency or require special handling. The process involves three main steps. First, by using range and intensity data from a time-of-flight (TOF) camera, a feature descriptor is used to rank points and separate regions surrounding high scoring points. This allows a wide range of rocks to be recognized because features can represent a whole or just part of a rock. Second, these points are filtered to extract only points thought to belong to the large object. Finally, a check is carried out to verify that the resultant point cloud actually represents a rock. Results are presented from field testing on piles of fragmented rock. Note to Practitioners—This paper presents an algorithm to identify large boulders in a pile of broken rock as a step towards an autonomous mining dig planner. In mining, piles of broken rock can contain large fragments that may need to be specially handled. To assess rock piles for excavation, we make use of a TOF camera that does not rely on external lighting to generate a point cloud of the rock pile. We then segment large boulders from its surface by using a novel feature descriptor and distinguish between real and false boulder candidates. Preliminary field experiments show promising results with the algorithm performing nearly as well as human test subjects.

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El trabajo releva la presencia de las universidades argentinas en la prensa de alcance nacional. Sistematizaremos la mención de ellas en la versión digital de los diarios para observar frecuencia de aparición y contenidos que se asocian. Partimos de la hipótesis de que los medios hegemónicos sólo registran los eventos de universidades del “interior del país” cuando se vinculan con hechos curiosos o violentos. Interesa indagar en qué casos particulares la referencia a dichas universidades se vincula con la producción y difusión académica del conocimiento científico, entre otras. Constituimos el corpus con fragmentos de textos periodísticos que permiten examinar estructuras gramaticales para develar las representaciones que la prensa naturaliza a través de esas formas. Seguimos consideraciones teórico-metodológicas de la Lingüística Crítica sobre el nivel sintáctico: cuando aparece una distorsión en la estructura superficial existe una manipulación ideológica del sentido. Incluimos parte de la teoría de las transformaciones: en el relato de un acontecimiento, cualquier alteración del esquema causa-consecuencia construye una ideología por la cual percibimos los hechos de otra manera. Asimismo, para establecer correlaciones semánticas en lo discursivo, analizaremos los términos en función de tipos de significado y valor eufórico/disfórico de la base léxica. Por otra parte, desde la Teoría de la Enunciación, distinguiremos palabras objetivas y subjetivas: los hechos enunciativos están constituidos por las huellas lingüísticas de la presencia del locutor en su enunciado, denominadas subjetivemas. Además de los pronombres, rasgos espaciales y temporales como marcas enunciativas, seleccionaremos unidades léxicas como sustantivos, adjetivos, verbos y adverbios. La existencia de los subjetivemas se fundamenta en que toda unidad léxica implica una interpretación del mundo, esto es, una ideología en el sentido que asumimos en nuestro trabajo desde el Análisis Crítico del Discurso. Como complemento de las perspectivas interpretativas mencionadas, realizaremos la cuantificación previa de referencias mediante el Análisis de Contenido como apoyo metodológico. A tal fin, el estudio prevé la utilización de una herramienta tecnológica diseñada ad hoc, para el conteo de frecuencia, relevamiento de contextos lingüísticos de aparición y asociaciones léxicas en la frase, como sistematización previa al trabajo cualitativo de valoración de estructuras léxico-semánticas y morfo-sintácticas. The research reflects the presence of Argentine universities in nationwide media. We will systematize their mention on online version of La Nación and Clarín newspapers to observe their frequency of appearance and the contents they are related to. With the hypothesis that hegemonic media only register events in universities from inside the country when they are related to curious or violent events, we will investigate in which particular cases the reference to such universities is related to the production and academic diffusion of scientific knowledge. We built up the corpus with fragments from articles which allow us to examine the deep grammatical structures to reveal the representation press naturalizes through these forms. We follow theoretical-methodological considerations of Critical Linguistics (CL) about the syntactical level: when a distortion in the superficial structure appears, there exists an ideological manipulation of meaning. Also, to establish semantic correlations on the discursive field, we will analyze terms as regards types of meaning and euphoric/disphoric value of lexical basis. From the Theory of Enunciation, we will distinguish between objective and subjective words (“subjectivemes”): lexical unit implies an interpretation of the world, that is, an ideology in the way we assume in our work from Critical Discourse Analysis (CDA). As a complement to CL and CDA, we will carry out a previous quantification using a technological tool designed ad hoc.

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L’ionomycine est un ionophore produit par la bactérie gram-positive streptomyces conglobatus. Sa synthèse représente un défi, car il possède plusieurs centres chiraux dans un motif polypropylène. De plus, la grande densité d’oxygène sur celui-ci oblige l’utilisation de plusieurs protections orthogonales. Notre stratégie divise l’ionomycine en quatre fragments, trois possédant le motif polypropylène, ainsi qu’un quatrième, bis-tétrahydrofuranne. Les trois premiers sont synthétisés en utilisant une méthodologie puissante développée dans le laboratoire du Pr Spino, qui utilise l’addition d’alkylcyanocuprates sur les carbonates allyliques dérivés de la menthone. Celle-ci permet l’introduction d’une unité propylène, avec un excellent contrôle du centre chiral introduit. Cette méthode est utilisée de manière itérative, afin d’introduire plusieurs unités propylènes. De plus, notre stratégie est hautement convergente, puisque des intermédiaires des fragments plus courts servent de produit de départ pour la synthèse des fragments plus longs. Le dernier fragment, bis-tétrahydrofuranne, a été fabriqué à partir de l’acétate de géranyle, par une polycyclisation d’un diépoxyde chiral, les époxydes ayant été introduits par une époxydation de Shi. Cette synthèse, si complétée, serait la plus courte publiée, avec 24 étapes pour la séquence linéaire la plus longue (51 au total).

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A two stage approach to performing ab initio calculations on medium and large sized molecules is described. The first step is to perform SCF calculations on small molecules or molecular fragments using the OPIT Program. This employs a small basis set of spherical and p-type Gaussian functions. The Gaussian functions can be identified very closely with atomic cores, bond pairs, lone pairs, etc. The position and exponent of any of the Gaussian functions can be varied by OPIT to produce a small but fully optimised basis set. The second stage is the molecular fragments method. As an example of this, Gaussian exponents and distances are taken from an OPIT calculation on ethylene and used unchanged in a single SCF calculation on benzene. Approximate ab initio calculations of this type give much useful information and are often preferable to semi-empirical approaches, since the nature of the approximations involved is much better defined.

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In the current study, we have developed a magnetic resonance imaging-based method for non-invasive detection of complement activation in placenta and foetal brain in vivo in utero. Using this method, we found that anti-complement C3-targeted ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles bind within the inflamed placenta and foetal brain cortical tissue, causing a shortening of the T2* relaxation time. We used two mouse models of pregnancy complications: a mouse model of obstetrics antiphospholipid syndrome (APS) and a mouse model of preterm birth (PTB). We found that detection of C3 deposition in the placenta in the APS model was associated with placental insufficiency characterised by increased oxidative stress, decreased vascular endothelial growth factor and placental growth factor levels and intrauterine growth restriction. We also found that foetal brain C3 deposition was associated with cortical axonal cytoarchitecture disruption and increased neurodegeneration in the mouse model of APS and in the PTB model. In the APS model, foetuses that showed increased C3 in their brains additionally expressed anxiety-related behaviour after birth. Importantly, USPIO did not affect pregnancy outcomes and liver function in the mother and the offspring, suggesting that this method may be useful for detecting complement activation in vivo in utero and predicting placental insufficiency and abnormal foetal neurodevelopment that leads to neuropsychiatric disorders.

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Photograph

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Squeeze, photographs and notes by A.E. Gordon

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Tese (doutorado)—Universidade de Brasília, Instituto de Ciências Humanas, Departamento de Geografia, Programa de Pós Graduação em Geografia, 2015.

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Low molecular weight fragments of sulfated galactans (Boc-5 and Boc-10) from the red algae Botryocladia occidentalis significantly inhibited Crotalus durissus cascavella sPLA2 enzymatic activity. Equimolar ratios of sPLA2 to Boc-5 or Boc-10 resulted in allosteric inhibition of sPLA2. Under the conditions tested, we observed that both Boc-5 and Boc-10 strongly decreased edema, myonecrosis, and neurotoxicity induced by native sPLA2.

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The objective of this study was to evaluate the methodology to establish the hemolytic activity of alternative complement pathway as an indicator of the innate immunity in Brazilian fish pacu (Piaractus mesopotamicus), in addition to verifying the influence of β-glucan as an immunostimulant. Fish were fed with diets containing 0, 0.1 and 1% β-glucan, during seven days, and then inoculated with Aeromonas hydrophila. Seven days after the challenge, they were bled for serum extraction. The methodology consisted of a kinetic assay that allows calculating the required time for serum proteins of the complement to promote 50% lysis of a rabbit red blood cell suspension. The method developed in mammals was successfully applied for pacu and determined that the hemolytic activity of the proteins of the complement system (alternative pathway) increased after the pathogen challenge, but was not influenced by the β-glucan treatment.

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Tuberculosis (TB) remains a pandemic affecting billions of people worldwide, thus stressing the need for new vaccines. Defining the correlates of vaccine protection is essential to achieve this goal. In this study, we used the wild boar model for mycobacterial infection and TB to characterize the protective mechanisms elicited by a new heat inactivated Mycobacterium bovis vaccine (IV). Oral vaccination with the IV resulted in significantly lower culture and lesion scores, particularly in the thorax, suggesting that the IV might provide a novel vaccine for TB control with special impact on the prevention of pulmonary disease, which is one of the limitations of current vaccines. Oral vaccination with the IV induced an adaptive antibody response and activation of the innate immune response including the complement component C3 and inflammasome. Mycobacterial DNA/RNA was not involved in inflammasome activation but increased C3 production by a still unknown mechanism. The results also suggested a protective mechanism mediated by the activation of IFN-γ producing CD8+ T cells by MHC I antigen presenting dendritic cells (DCs) in response to vaccination with the IV, without a clear role for Th1 CD4+ T cells. These results support a role for DCs in triggering the immune response to the IV through a mechanism similar to the phagocyte response to PAMPs with a central role for C3 in protection against mycobacterial infection. Higher C3 levels may allow increased opsonophagocytosis and effective bacterial clearance, while interfering with CR3-mediated opsonic and nonopsonic phagocytosis of mycobacteria, a process that could be enhanced by specific antibodies against mycobacterial proteins induced by vaccination with the IV. These results suggest that the IV acts through novel mechanisms to protect against TB in wild boar.