383 research outputs found
Comparative Cytogenetic Analysis Of Four Species Of Dendropsophus (hylinae) From The Brazilian Atlantic Forest
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)We conducted a cytogenetic study of four hyline frog species (Dendropsophus elegans, D. microps, D. minutus and D. werneri) from southern Brazil. All species had 2n = 30 chromosomes, with interspecific and intraspecific variation in the numbers of metacentric, submetacentric, subtelocentric and telocentric chromosomes. C-banding and fluorochrome staining revealed conservative GC-rich heterochromatin localized in the pericentromeric regions of all species. The location of the nucleolus organizer regions, as confirmed by fluorescent in situ hybridization, differed between species. Telomeric probes detected sites that were restricted to the terminal regions of all chromosomes and no interstitial or centromeric signals were observed. Our study corroborates the generic synapomorphy of 2n = 30 chromosomes for Dendropsophus and adds data that may become useful for future taxonomic revisions and a broader understanding of chromosomal evolution among hylids.952349355Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Fundacao de Amparo a Pesquisa do Estado de Sao PauloCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP
NANOCIÊNCIA & NANOTECNOLOGIA
Nanomateriais vêm causando uma revolução na ciência, e sua aplicação na tecnologia está aumentando. Nanopartículas compreendem partículas entre 1 e 100 nanômetros (nm) de tamanho, mas este intervalo pode variar quando relativo à avaliação toxicológica. O uso extensivo e a consequente produção de resíduos de nanomateriais têm levado esses produtos químicos para o meio ambiente, o que causa possíveis contaminações. Portanto, como um assunto interdisciplinar, fez-se, aqui, uma breve revisão sobre alguns aspectos interessantes e contemporâneos da nanotecnologia, especialmente focados em ciências ambientais e da conservação.Palavras-chave: Nanomateriais. Nanotoxicologia. Ecotoxicologia. Dióxido de titânio
Piscine micronucleus test and the comet assay reveal genotoxic effects of Atrazine herbicide in the neotropical fish Rhamdia quelen
Atrazine (ATZ) is an herbicide extensively used around the world to kill weeds. Due to its applicability and benefits in farming, ATZ can easily reach the aquatic ecosystems and, therefore, represent risks for aquatic biota and human populations. The aim of this study was to evaluate the genotoxic effects of ATZ on Rhamdia quelen through the piscine micronucleus test (MNT) and the comet assay in erythrocytes (ECA) and gill cells (GCA), at three different concentrations (2, 10, and 100 μg L-1) in static (SB) and semi-static bioassays (SSB) during 96 hours. In the SB, we observed an increased frequency of nuclear morphological abnormalities at all concentrations and a dose-dependent effect of ATZ on DNA through the ECA. There was no difference among treatments in gills. In the SSB there was no significant difference in MNT, but the ECA showed an increase of DNA breakages at 10 μg L-1 treatment. GCA showed higher DNA damage on fish exposed to 2 and 100 μg L-1. Our results show a trend to dose-dependent genotoxic effect of ATZ, which causes damage to the DNA of Rhamdia quelen even in a concentration considered safe by regulatory agencies
Derivational Rules in Aphasia
Proceedings of the Eighteenth Annual Meeting of the Berkeley Linguistics
Society: General Session and Parasession on The Place of Morphology in
a Grammar (1992), pp. 435-44
Influence of silvere nanoparticles on Growth and Health of broiler chickens after infection with <em>Campylobacter jejuni</em>
Abstract Background Silver nanoparticles (AgNP) have gained much attention in recent years due to their biomedical applications, especially as antimicrobial agents. AgNP may be used in poultry production as an alternative to the use of antibiotic growth promoter. However, little is known about the impact of oral administration of AgNP on the gut microbiota and the immune system. The aim of the present study was to investigate the effects of AgNP on growth, hematological and immunological profile as well as intestinal microbial composition in broilers challenged with Campylobacter jejuni (C. jejuni). Results AgNP did not affect the intestinal microbial profile of birds. The body weight gain and the relative weights of bursa and spleen were reduced when supplemented with AgNP. There was no difference with respect to packed cell volume. However, the plasma concentrations of IgG and IgM were lower in birds receiving AgNP compared to the non-supplemented control group. The expression of TNF-α and NF-kB at mRNA level was significantly higher in birds receiving AgNP. Conclusions The application of AgNP via the drinking water in the concentration of 50 ppm reduced broiler growth, impaired immune functions and had no antibacterial effect on different intestinal bacterial groups, which may limit the applicability of AgNP against C. jejuni in broiler chickens
Tecnologias de informação e comunicação para a educação para cidadania global de enfermeiros
Faced with a globalized world, information and communication technologies are present in people's daily lives and, therefore, the media can also appear in the school context. UNESCO encourages a global Citizenship Education through teaching and learning practices that include media and information literacy. The method is qualitative, a case study, whose objective is to identify how media literacy is present in a Nursing Undergraduate course at a private Higher Education institution in the south of the country with a critical, creative and reflective theoretical framework. Interviews with principals, online questionnaires with students, and physical questionnaires with teachers were conducted. The data were analyzed following the Stake model. The information and communication technologies category for an ECG of nurses was created from the corpus, and subcategories: Internet as a global learning resource; Virtual environment as a learning management strategy; Virtual environment as a collaborative and dialogue space between teachers, students and coordination; Social media as resources in the teaching and learning process. The results indicate that education needs to create a favorable environment for learning to be in person or in cyberspace, with physical or virtual spaces with active learning strategies, or the use of virtual social media and / or other information and communication technologies. , with critical, creative, reflective and trained teachers prepared to teach and develop media and informational skills in their students.Ante un mundo globalizado, las tecnologías de la información y la comunicación están presentes en el día a día de las personas y, por ello, los medios también pueden aparecer en el contexto escolar. La UNESCO estimula una Educación para la ciudadanía global por medio de prácticas de enseñanza y aprendizaje en las que se encuentra la alfabetización mediática e informacional. El método es de tipo cualitativo, de estudio de caso, cuyo objetivo es identificar cómo la alfabetización mediática está presente en un curso de Graduación en Enfermería de una institución de Enseñanza Superior privada en el sur del país con referencial teórico crítico, creativo y reflexivo. Se realizaron entrevistas con directores, cuestionarios online con alumnos y cuestionarios físicos con profesores. Los datos fueron analizados siguiendo el modelo de Stake. A partir del corpus se creó la categoría tecnologías de información y comunicación para una ECG de enfermeros, y subcategorías: Internet como recurso global de aprendizaje; Entorno virtual como estrategia de gestión del aprendizaje; Entorno virtual como espacio colaborativo y de diálogo entre profesores, alumnos y coordinación; Medios sociales como recursos en el proceso de enseñanza y aprendizaje. Los resultados apuntan que la educación necesita crear un ambiente favorable para que el aprendizaje sea presencial o en ciberespacio, con espacios físicos o virtuales con estrategias activas de aprendizajes, o el uso de medios sociales virtuales y / o otras tecnologías de la información y la comunicación, con profesores capacitados críticos, creativos, reflexivos y preparados para enseñar y desarrollar habilidades mediáticas e informativas en sus alumnos.Diante de um mundo globalizado, as tecnologias de informação e comunicação estão presentes no cotidiano das pessoas e, portanto, a mídia também pode aparecer no contexto escolar. A UNESCO incentiva uma Educação para a Cidadania global por meio de práticas de ensino e aprendizagem que incluem a alfabetização midiática e informacional. O método é qualitativo, um estudo de caso, cujo objetivo é identificar como a alfabetização midiática está presente em um curso de Graduação em Enfermagem de uma instituição de Ensino Superior privada do sul do país com um referencial teórico crítico, criativo e reflexivo. Foram realizadas entrevistas com diretores, questionários online com alunos e questionários físicos com professores. Os dados foram analisados seguindo o modelo Stake. A partir do corpus foi criada a categoria de tecnologias de informação e comunicação para um ECG de enfermeiras e as subcategorias: Internet como recurso global de aprendizagem; Ambiente virtual como estratégia de gestão da aprendizagem; O ambiente virtual como espaço de colaboração e diálogo entre professores, alunos e coordenação; As redes sociais como recursos no processo de ensino e aprendizagem. Os resultados indicam que a educação precisa criar um ambiente favorável para que a aprendizagem seja presencial ou no ciberespaço, com espaços físicos ou virtuais com estratégias ativas de aprendizagem, ou com o uso de mídias sociais virtuais e / ou outras tecnologias de informação e comunicação. , com professores críticos, criativos, reflexivos e treinados, preparados para ensinar e desenvolver habilidades de mídia e informativa em seus alunos
Co-exposure effects of Titanium Dioxide Nanoparticles and Metals on antioxidant systems and DNA in the fish Hoplias intermedius
Metallic nanoparticles are one of the most produced and used engineered nanomaterial and their wide applications lead to environmental contamination. The aquatic environment is the major recipient of wastes containing nanoparticles and other co-occuring contaminants. We aimed to evaluate genotoxic and biochemical effects of acute exposure to nano-TiO2 in the fish Hoplias intermedius and the interaction to metals. Besides assessing the nanoparticles’ physical-chemical properties we performed an acute exposure with 0.1; 1; 10 μg g-1 nano-TiO2, alone and with lead (21 μgg-1) and aluminium (50 μgg-1). A set of biomarkers were evaluated in the liver such as genotoxicity by comet assay and biochemical biomarkers (SOD, CAT, GPx, GSH, EROD, GST). Most of the biomarkers were altered by the metals, and the nanoparticles caused decrease in SOD (0.1 and 1μg g-1), GSH (1μg g-1), and GST (0.1 μg g-1). In co-exposure, some metal effects were attenuated. There was an increase in EROD activity for most co-exposure groups. Nano-TiO2 was not genotoxic in the experimental conditions. We did not observe any increase in DNA breaks in co-exposure, although, nanoparticles changed the response of some biochemical biomarkers
Biochemical and genotoxicity assessment of a polluted urban river using the native fish Astyanax altiparanae Garutti & Britski (Teleostei, Characidae)
Agriculture residues and domestic effluents are contaminants that reach aquatic ecosystems leading to toxic effects to environment and human health. These contaminants impacting mainly developing countries, due to precarious treatment of effluents and lack of legislation in the use of pesticides. Perequê River (South of Brazil) is impacted by pesticides (mainly glyphosate) and domestic effluents. The aims of this study were to analyze the concentration of glyphosate in water and sediments of Perequê River; and to evaluate the sublethal effects of the river contamination in Astyanax altiparanae using biomarkers. A sampling of water, sediment and fish were carried out in Perequê River (November/2016). The samples were collected in two sites, site 1 (S1) that is located on agriculture area and water catchment point; and site 2 (S2) located on the area with a domestic effluents influence. Water and sediment samples were used to glyphosate quantification. Fish were collected and tissues (brain, muscle, liver) were used to biochemical and genetic biomarkers. Glyphosate were quantified in S1, which is impacted by agriculture. Alterations in the liver biomarkers were not observed between the sites. However, the decrease in the AChE activity was observed in the S2, showing that the mixture of contaminants (urban and agriculture contaminants) can lead to anticholinesterasic effects. The sublethal effects observed can be a threat of environmental and human health
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