763 research outputs found
Ecological niche modeling: integrating patterns of species richness, factors shaping geographical range limits, and conservation planning
The concept of the niche has been a central theme of ecology for over half a century. With recent advances in Geographic Information Systems (GIS) and statistical procedures, the inferential method of ecological niche modeling (ENM) has emerged as an important tool for studies in ecology and evolutionary biology. This method consists of modeling species' distributions based on attributes of the environment that should be correlated with species' niche requirements. The models assume that geographic distribution and characteristics of the environment are related to the species niche, and therefore are tied to ecological niche theory. Over the past several years, ENM has been widely used to address numerous research questions in ecology, evolutionary biology, and conservation. Here I applied ENM in novel ways, focusing on central themes in Macroecology, Biogeography, and Conservation. First, I analyzed species richness in the Brazilian Cerrado, identifying areas of high richness and analyzing the relationship between richness and climatic variables to test predictions of large-scale hypotheses concerning determinants of species richness. Second, I assessed the performance of two ENM algorithms in predicting species richness and composition of an unsampled area of conservation interest in the Brazilian Cerrado. These analyses provided an overall assessment of the weaknesses and strengths of ENM for conservation planning. Lastly, I applied ENM to two different situations in an effort to understand and disentangle the relative contributions of abiotic factors, competition, dispersal barriers, and biotic interactions in determining species' range limits. Overall, I was able to show that by applying ENM techniques it is possible to gain insights into a vast number of ecological questions. These studies highlight the complexity of studying species range limits, but reiterate that an integrative approach is necessary to understand this phenomenon
Cytotoxicity evaluation of two root canal sealers and a commercial calcium hydroxide paste on THP1 cell line by Trypan Blue assay
OBJECTIVE: The aim of this investigation was to evaluate the cytotoxicity of two brands of root canal sealers, epoxy-resin based and zinc oxide-eugenol based, and one commercial calcium hydroxide paste on a monocyte cell line THP-1. MATERIAL AND METHODS: Undiluted (crude extract) and diluted extracts to 10%, 1%, 0.1%, 0.01%, 0.001% and 0.0001% of the sealers were tested for cytotoxicity to THP-1 cells using the trypan blue assay. Extracts were obtained according to ISO standard. Data were analyzed statistically by the Kruskal-Wallis and Mann-Whitney tests at 5% significance level. RESULTS: Crude extract of AH Plus and Fill Canal killed approximately 90% of THP-1 cells versus 36% of THP-1 cells killed by L&C crude extract (
A SERM increasing the expression of the osteoblastogenesis and mineralization-related proteins and improving quality of bone tissue in an experimental model of osteoporosis
Raloxifene is an antiresorptive drug, selective estrogen receptor modulator (SERM) used in the treatment of osteoporosis. Objective: To evaluate proteins related to bone repair at the peri-implant bone in a rat model of osteoporosis treated with raloxifene. Material and Methods: 72 rats were divided into three groups: SHAM (healthy animals), OVX (ovariectomized animals), and RLX (ovariectomized animals treated with raloxifene). Raloxifene was administered by gavage (1 mg/kg/day). Tibial implantation was performed 30 days after ovariectomy, and animals were euthanized at 14, 42, and 60 days postoperatively. Samples were collected and analyzed by immunohistochemical reactions, molecular analysis, and microtomographic parameters. Results: RLX showed intense staining of all investigated proteins at both time points except for RUNX2. These results were similar to SHAM and opposite to OVX, showing mild staining. The PCR gene expression of OC and ALP values for RLX (P<0.05) followed by SHAM and OVX groups. For BSP data, the highest expression was observed in the RLX groups and the lowest expression was observed in the OVX groups (P<0.05). For RUNX2 data, RLX and SHAM groups showed greater values compared to OVX (P<0.05). At 60 days postoperatively, microtomography parameters, related to closed porosity, showed higher values for (Po.N), (Po.V), and (Po) in RLX and SHAM groups, whereas OVX groups showed lower results (P<0.05); (BV) values (P=0.009); regarding total porosity (Po.tot), RLX group had statistically significant lower values than OVX and SHAM groups (P=0.009). Regarding the open porosity (Po.V and Po), the SHAM group presented the highest values, followed by OVX and RLX groups (P<0.05). The Structural Model Index (SMI), RLX group showed a value closer to zero than SHAM group (P<0.05). Conclusions: Raloxifene had a positive effect on the expression of osteoblastogenesis/mineralization-related proteins and on micro-CT parameters related to peri-implant bone healin
Conformidad entre testigos oculares : efectos de falsas informaciones en testimonios criminales
Este estudo investigou como informações falsas fornecidas a testemunhas oculares podem afetar a fidedignidade de seus relatos. Os participantes foram divididos em duas condições experimentais. Todos assistiram ao vídeo de um crime e responderam a um questionário sobre informações nele descritas. Em uma condição, os participantes preencheram o questionário individualmente e, em seguida, discutiram suas respostas com um confederado, que fornecia informações falsas ao participante. Após discutirem tais informações, os participantes eram requisitados a fazer um novo relato. Em outra condição, os participantes realizaram todo o procedimento individualmente, sem receberem informações falsas. O número de erros na presença do confederado foi maior quando comparado com a condição sem o confederado. São discutidos possíveis fatores que envolvem a distorção da memória por meio de conformidade, assim como implicações práticas dos resultados encontrados.The current study investigated how misinformation presented to eyewitnesses can affect the reliability of their reports. An experiment was conducted with 54 participants, divided in two conditions. All participants watched a video of a crime scene, and then answered a questionnaire about the content of the video. In one condition participants filled the questionnaire individually and then discussed their answers with a confederate, instructed to provide misinformation to participants. After the discussion participants were required to provide a new report. In another condition participants made the whole procedure individually, without receiving any misinformation. Mistakes in the presence of the confederate were higher when compared to the condition with no confederate. Potential factors underlying the distortion of memories through conformity, as well as practical implications of the results are discussed.Este estudio investigó cómo información falsa proporcionada a testigos oculares puede afectar la veracidad de los testimonios. Los participantes fueron divididos en dos condiciones experimentales, y todos asistieron el video de un delito y luego respondieron a un cuestionario sobre la información contenida en el mismo. En un grupo los participantes completaron el cuestionario de forma individual y luego discutieron sus respuestas con un asociado que les proporcionaba informaciones falsas. Después de discutir esas informaciones se les solicitaba hacer un nuevo testimonio. En el otro grupo los participantes realizaron todo el procedimiento individualmente, sin recibir información falsa. El número de errores fue mayor en la presencia del asociado. Se discuten los posibles factores implicados en la distorsión de la memoria mediante la conformidad, así como las implicaciones prácticas de los resultados
OCORRÊNCIA DE SINTOMAS CLÍNICOS EM MULHERES CLIMATÉRICAS ASSISTIDAS EM UM SERVIÇO DE REFERÊNCIA EM SÃO LUÍS, MARANHÃO / SYMPTOMS OF OCCURRENCE IN CLINICAL WEATHER WOMEN IN SÃO LUIS, MARANHÃO, BRAZIL
Introdução: A Síndrome Climatérica (SC) é definida como o conjunto de sintomas que acompanham o Climatério, ou seja, atransição da mulher do seu período fértil para o período não-fértil, decorrentes da falência gradual da função ovariana. Vemacompanhada de sintomas vasomotores, psicológicos, sexuais e urogenitais que interferem fortemente na qualidade de vidada mulher. Objetivos: Avaliar a ocorrência dos sintomas em mulheres climatéricas no município de São Luís (MA). Método:Estudo descritivo transversal realizado com 153 mulheres na faixa etária ente 35 a 75 anos de idade, atendidas pelo serviço deGinecologia de Hospital de referencia no período de outubro de 2013 a julho de 2014. A coleta de dados foi realizada por meiode um questionário com questões sociodemográficas, ginecológicas e obstétricas, sintomas vasomotores, sintomas psicológicos,aspectos urinários, queixas intestinais e uso de terapia de reposição hormonal. Resultados: A média de idade foi de 50anos. Houve predomínio de mulheres na pré-menopausa (42,7%) e a idade média para menopausa natural foi de 44 anos. Foiobservada ocorrência de 63% de sintomas vasomotores e de 70% das mulheres apresentaram sintomas psicológicos. A queixaurogenital mais presente foi a de ressecamento vaginal (60%). Em relação aos aspectos sexuais, 57,5% das entrevistadas tinhamparceiro fixo, 60,3% referiram ter desejo sexual e 68,2% tinham vida sexual ativa. Conclusões: A maioria das mulheres nuncatinha feito uso de terapia de reposição hormonal e referiu algum sintoma vasomotor além de irritabilidade, nervosismo, tristeza,cefaleia e insônia. Poucas mulheres tinham conhecimento sobre a Síndrome Climatérica.Palavras-chave: Climatério, Menopausa, Saúde da Mulher.AbstractIntroduction: Climacteric Syndrome (CS) is defined as the set of symptoms that follows Climacteric, in other words, the woman'stransition from her fertile to non-fertile period, resulting from the gradual failure of ovarian function. It comes with vasomotor,psychological, sexual and urogenital symptoms, interfering heavily in women's life quality. Objective: To assess the prevalenceof these symptoms in women in São Luís, Maranhão, Brazil. Method: Cross-sectional descriptive study conducted with 153women attending the Gynecology service from University Hospital of Federal University of Maranhão from October 2013 to July2014. There were included women aged above 35 years and there were no criteria for exclusion. Data were analyzed using Epi-Info 7.1.5. Results: Mean age was 50 years. There was a predominance of premenopausal women (42.7%) and the average agefor natural menopause was 44 years. It was observed a 63% prevalence for vasomotor symptoms and 70% for the psychologicalsymptoms. The main urogenital complaint was vaginal dryness (60%). Regarding the sexual aspects, 57.5% of respondents hada steady partner, 60.3% reported to have sexual desire and 68.2% were sexually active. Conclusions: Most of the women hadnever used hormone replacement therapy and reported some vasomotor symptoms besides irritability, nervousness, sadness,headache and insomnia. Few women knew about Climacteric Syndrome.Keywords: Climacteric, Menopause, Women's Health
Monitoramento terapêutico do bussulfano em paciente pediátrico com diagnóstico de mucopolissacaridose I submetido ao transplante de células-tronco hematopoéticas
Doença do refluxo gastroesofágico: métodos diagnósticos e manejo terapêutico
A Doença do Refluxo Gastroesofágico (DRGE) é uma patologia gastrointestinal que ocorre após o refluxo da secreção ácida presente no estômago em direção ao esôfago. Trata-se de uma patologia que afeta cerca de 20% dos adultos nas sociedades ocidentais. Nos Estados Unidos, até 20% dos habitantes relatam sintomas de DRGE, algo que representa um grande problema de saúde. No que se refere a fisiopatologia da doença, sabe-se que a exposição crônica da mucosa do esôfago ao conteúdo ácido é responsável por causar os sintomas clássicos da doença: pirose e regurgitação, além de favorecer o processo de metaplasia ou displasia epitelial. Ademais, essa acidificação da mucosa esofágica distal pode estar diretamente relacionada com algumas manifestações extra esofágicas da DRGE. Entre os sintomas da DRGE a pirose é o mais frequente. A regurgitação é outro sintoma clássico e ocorre quando o refluxo do conteúdo gástrico atinge a cavidade oral podendo gerar gosto amargo. O diagnóstico da DRGE, na maior parte das vezes, pode ser feito de forma exclusivamente clínica. Deve-se lançar mão dos exames complementares somente na presença de sinais de alarme ou sintomas atípicos, que podem nos fazer pensar em complicações da doença. Dentre os exames complementares, para melhor avaliação de possíveis complicações da doença, pode-se realizar a Endoscopia digestiva alta, a Phmetria de 24h (com ou sem impedanciometria), esofagomanometria e a esofagografia baritada. O tratamento clínico para a DRGE está baseado na redução dos sintomas resultantes do refluxo gastrointestinal, por meio da diminuição da secreção ácida, todavia, o tratamento cirúrgico pode ser uma opção para os pacientes em que a terapêutica clínica foi ineficaz, que têm formas complexas de DRGE ou aqueles que requerem uso contínuo de medicação
Desenvolvimento e validação de metodologia bioanalítica para monitoramento terapêutico do bussulfano
Amazon hydrology from space : scientific advances and future challenges
As the largest river basin on Earth, the Amazon is of major importance to the world's climate and water resources. Over the past decades, advances in satellite-based remote sensing (RS) have brought our understanding of its terrestrial water cycle and the associated hydrological processes to a new era. Here, we review major studies and the various techniques using satellite RS in the Amazon. We show how RS played a major role in supporting new research and key findings regarding the Amazon water cycle, and how the region became a laboratory for groundbreaking investigations of new satellite retrievals and analyses. At the basin-scale, the understanding of several hydrological processes was only possible with the advent of RS observations, such as the characterization of "rainfall hotspots" in the Andes-Amazon transition, evapotranspiration rates, and variations of surface waters and groundwater storage. These results strongly contribute to the recent advances of hydrological models and to our new understanding of the Amazon water budget and aquatic environments. In the context of upcoming hydrology-oriented satellite missions, which will offer the opportunity for new synergies and new observations with finer space-time resolution, this review aims to guide future research agenda toward integrated monitoring and understanding of the Amazon water from space. Integrated multidisciplinary studies, fostered by international collaborations, set up future directions to tackle the great challenges the Amazon is currently facing, from climate change to increased anthropogenic pressure
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