4,021 research outputs found

    Identification and Characterization of the Lipid Transport System in the Tarantula Grammostola rosea

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    Lipids due to its hydrophobic nature are transported in the hemolymph mainly by lipoproteic fractions. In the present work we studied the lipoproteic fractions present in the hemolymph of the spider Grammostola rosea. Through ultracentrifugation two lipoproteic fractions are isolated, one of high density named Gr-HDL (δ = 1.13 - 1.15 g/ml) and the other of very high density called Gr-VHDL (δ = 1.24 - 1.27 g/ml) Gr-VHDL in hemolymph is majority in relation to Gr-HDL. In this sense Gr-VHDL fraction has 98.6% of hemolymphatic proteins, and 89.3% of lipids presents in the hemolymph. Both lipoproteic fractions possess phospholipids such as majority lipids (phosphatidylcholine and phosphatidylethanolamine) and 18:1, 16:0, 18:2 and 18:0 as the major fatty acids. In order to confirm the role played by lipoproteic fractions in vitro assays with different 14C-lipid were performed. It was observed that Gr-VHDL takes up mainly free fatty acids and triacylglycerols unlike that observed for Gr-HDL in relation to phosphatidylcholine. Through electrophoresis it was observed that Gr-VHDL has three proteins: a predominant band of 68 kDa and two others of 99 and 121 kDa. Gr-HDL displayed a predominant band of 93 kDa, and other minority of 249 kDa. In conclusion, this study reports lipid characterization of the lipoproteic fractions present in the hemolymph of the tarantula, G. rosea. The role of each lipoproteic fraction in relation to lipid up- take is sustained by in vitro assays. Similarities and differences are found when it is compared to lipoproteins of only the three species of spiders studied.Fil: Laino, Aldana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Cunningham, Monica Liliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Suarez, Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Garcia, Carlos Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; Argentin

    Photoproduction with a mini-jet model and Cosmic Ray showers

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    We present post-LHC updates of estimates of the total photo-production cross section in a mini-jet model with infrared soft gluon resummation, and apply the model to study Cosmic Ray shower development, comparing the results with those obtained from other existing models.Comment: 7 pages, 5 figures, presented at Photon 2017, 22-26 May 2017 CER

    ¿Cuál es el estilo parental óptimo para adolescentes con baja vs. alta autoeficacia? Autoconcepto, desajuste psicológico y rendimiento académico de los adolescentes en el contexto español

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    The aim of this paper is to establish which parenting style is associated with optimum outcomes among adolescents of Spanish families considering adolescents with low vs. high self-efficacy. Although classical studies identify the authoritative parenting style (based on warmth and strictness) as the best parental strategy, emerging research seriously questions the benefits of parental strictness. Additionally, the impact of parenting on the adolescent’s psychosocial competence has been studied for years, but less is known about whether it might vary depending on individual characteristics of the adolescent (e.g., self-efficacy). Participants were 1029 Spanish adolescents, 453 males (44%), aged 12-17 years. Families were classified in one of the parenting styles groups (authoritative, authoritarian, indulgent, or neglectful), and adolescents were grouped by low vs. high self-efficacy. Adolescent psychosocial competence was examined through emotional and academic self-concept, psychological maladjustment (hostility/aggression, negative self-esteem, emotional responsivity, instability, and negative view of the world), and academic performance (grade point average and number of failing grades). Main and interaction effects of parenting style and adolescent self-efficacy were tested. Main effect results indicated that adolescents with low self-efficacy were always associated with the worst psychosocial competence. Consistently, the main effect findings indicated that adolescents from indulgent and authoritative families were associated with better results than those from neglectful and authoritarian families. However, the indulgent parenting style yielded the best results. The impact of parenting might not be the same for adolescents in all cultural contexts. Contrary to findings from classical studies, parental strictness seems to be unnecessary or even detrimental for adolescents with low and high self-efficacy.El objetivo de este estudio es identificar qué estilo parental se asocia con resultados óptimos entre los adolescentes de familias españolas considerando aquellos con baja vs. alta autoeficacia. Los participantes fueron 1029 adolescentes españoles, 453 varones (44%), de 12 a 17 años. Aunque los estudios clásicos identifican el estilo autorizativo (basado en el afecto y la severidad) como la mejor estrategia socializadora, las investigaciones emergentes cuestionan seriamente los beneficios de la severidad parental. Además, el impacto de la socialización parental en la competencia psicosocial del adolescente se ha estudiado durante años, pero se sabe menos sobre si podría variar en función de las características individuales del adolescente (e.g., la autoeficacia). Las familias fueron clasificadas por estilo parental (autorizativo, autoritario, indulgente o negligente), y los adolescentes por baja vs. alta autoeficacia. La competencia psicosocial se examinó a través del autoconcepto emocional y académico, el desajuste psicológico (hostilidad/agresión, autoestima negativa, irresponsividad emocional, inestabilidad emocional y visión negativa del mundo) y el rendimiento académico (nota media y número de cursos repetidos). Se comprobaron los efectos principales y de interacción de estilo parental y autoeficacia. Los resultados de los efectos principales indicaron que los adolescentes con baja autoeficacia presentaban siempre la peor competencia psicosocial. También que los adolescentes de familias indulgentes y autorizativas presentaron mejores resultados que los de familias negligentes y autoritarias. Sin embargo, el estilo parental indulgente se asoció a los mejores resultados. El impacto de la socialización parental podría no ser igual en todos los contextos culturales. Frente a los resultados de los estudios clásicos, la severidad parental parece ser innecesaria o incluso perjudicial para los adolescentes con baja y alta autoeficacia

    A presença social e a semipresencialidade nas disciplinas pedagógicas dos cursos de licenciatura nas áreas de Matemática e Ciências

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    O presente artigo apresenta uma discussão baseada em uma pesquisa de doutorado que objetiva discutir a semipresencialidade, nos cursos de licenciatura nas áreas de Ciências e Matemática. O enfoque está na análise e na avaliação da figura do professor tutor como mediador do processo de ensino e aprendizagem e facilitador da “Presença Social” em disciplinas oferecidas na modalidade a distância, que visam à formação pedagógica do futuro profissional da educação em uma Universidade privada da cidade de São Paulo. Alunos e professores, atualmente, estão diante de situações diferenciadas de ensino e aprendizagem; neste sentido é importante tentarmos entender como esses sujeitos do processo se comportam diante do novo paradigma. Faz-se necessário analisar e avaliar a importância do professor no processo de mediação, pois, no cenário atual, este passa a ocupar outro papel no exercício da profissão, não menos importante, mas diferenciado. Além de ser o responsável por criar situações de aprendizagem em um ambiente moderado pela tecnologia, cujo desafio é constante. Em contraponto a este cenário, observa-se o ensino presencial, em que o professor é valorizado pela sua presença física, no ambiente de ensino

    Kinetic and mechanistic analysis of azo dyes decolorization by ZVI-assisted Fenton systems: pH-dependent shift in the contributions of reductive and oxidative transformation pathways

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    The chemical decolorization of the azo-dye Acid Black 1 (AB1) by ZVI-assisted Fenton systems was investigated for assessing the relative importance of reductive and oxidative pathways. To this end, system evolution was followed by UV–vis, HPLC, CG–MS, TOC and toxicity measurements. The effects of reaction conditions including initial pH, oxidants (O2 and H2O2) concentrations, ZVI loading, and the presence of SO42− were studied. Mechanistic issues were addressed by following H2O2, Fe(II), Fe(III) and pH profiles, as well as by performing experiments in the presence of iron-complexing agents (o-phenanthroline and EDTA) or reactive species scavengers (2-propanol and DMSO). Results show that AB1 reduction occurs through heterogeneous processes with moderate to low pH dependent rates, whereas AB1 oxidation is ruled by the Fenton reaction with significantly pH dependent rates. Mechanistic studies demonstrated that AB1 decolorization in ZVI-assisted Fenton systems involves both oxidative and reductive pathways, whose relative contributions significantly change as the initial pH is raised from 3 to 5. In acidic media, AB1 is mostly transformed by oxidative pathways linked to H2O2 consumption. In contrast, in circumneutral media, a rather inefficient H2O2 consumption leads to similar contributions of oxidative and reductive AB1 transformation pathways. A detailed analysis of the pH dependence of the key reactions involved suggests that the overall system behavior is ruled by a shift in the oxidation mechanism of Fe(II) species, as a consequence of the development of a thigh corrosion layer onto ZVI particles at circumneutral pH values.Fil: Donadelli, Jorge Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Carlos, Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación y Desarrollo en Ingeniería de Procesos, Biotecnología y Energías Alternativas. Universidad Nacional del Comahue. Instituto de Investigación y Desarrollo en Ingeniería de Procesos, Biotecnología y Energías Alternativas; ArgentinaFil: Arques, Antonio. Universidad Politécnica de Valencia; EspañaFil: Garcia Einschlag, Fernando Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentin

    Photoproduction models for total cross section and shower development

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    A model for the total photoproduction cross section based on the ansatz that resummation of infrared gluons limits the rise induced by QCD minijets in all the total cross-sections, is used to simulate extended air showers initiated by cosmic rays with the AIRES simulation program. The impact on common shower observables, especially those related with muon production, is analysed and compared with the corresponding results obtained with previous photoproduction models.Comment: 5 pages, 5 figures, to appear in Proceedings of ISVHCRI 201

    Los pastos en las fincas de Lugar Nuevo y Selladores-Contadores (Sª de Andújar, Jaén): tipología, calidad y distribución espacial

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    Las fincas del O. A. Parques Nacionales “Lugar Nuevo” y “Selladores-Contadero” están situadas en el Parque Natural de la Sierra de Andújar (Jaén). Su situación geográfica, y especialmente su historia de usos y propiedad han motivado que hoy sean ejemplo de una flora y vegetación con buen estado de conservación. En trabajos anteriores se han realizado catálogos florísticos de las dos fincas como estudios básicos para la planificación de la gestión y la compatibilidad de la conservación y el aprovechamiento de los recursos en los espacios naturales protegidos. En esta comunicación se realiza un análisis de los pastos herbáceos de las dos fincas que constituyen un recurso estratégico para la alimentación de las poblaciones de herbívoros instaladas en las mismas. Se analizan y cartografían las distintas formaciones de pastos reconocidos (10), su distribución espacial, palatabilidad y grado de utilizació

    Spectral Domain Optical Coherence Tomography in Diffuse Unilateral Subacute Neuroretinitis

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    Purpose. To describe the SD-OCT findings in patients with diffuse unilateral subacute neuroretinitis (DUSN) and evaluate CRT and RNFL thickness. Methods. Patients with clinical diagnosis of DUSN who were submitted to SD-OCT were included in the study. Complete ophthalmologic examination and SD-OCT were performed. Cirrus scan strategy protocols used were 200 × 200 macular cube, optic nerve head cube, and HD-5 line raster. Results. Eight patients with DUSN were included. Mean RNFL thickness was 80.25 μm and 104.75 μm for affected and normal eyes, respectively. Late stage had mean RNFL thickness of 74.83 μm compared to 96.5 μm in early stage. Mean CMT was 205.5 μm for affected eyes and 255.13 μm for normal fellow eyes. Conclusion. RNFL and CMT were thinner in DUSN eyes compared to normal eyes. Late-stage disease had more pronounced thinning compared to early-stage patients. This thinning in RNFL and CMT may reflect the low visual acuity in patients with DUSN
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