3,050 research outputs found

    Parâmetros genéticos para a conservação de Hymenaea courbaril L. na Amazônia Sul-Ocidental.

    Get PDF
    A perda de diversidade em regiões tropicais tem sido pauta em diversas discussões governamentais e não governamentais, com foco principalmente na fragmentação e destruição de ecossistemas naturais. No entanto, tomadas de decisões sobre a conservação de recursos genéticos precisam ser pautadas em parâmetros genéticos populacionais, especialmente para as espécies com interesse econômico que são alvo de maior interferência humana. Este trabalho teve como objetivo definir e avaliar parâmetros genéticos para a conservação de populações de jatobá (Hymenaea courbaril) na região sul-ocidental da Amazônia brasileira. A espécie é uma das que possuem madeira mais valiosa e é uma das mais intensamente exploradas na Amazônia brasileira. O estudo foi realizado em três áreas de florestas preparadas para a exploração madeireira, segundo plano de manejo sustentável. Calculou-se, com uso de oito locos de marcadores microssatélites, a diversidade genética, os estimadores para a conservação da espécie e a divergência entre as populações. As populações com menor densidade populacional (< 0,08 ind.ha-1) apresentaram maior diversidade genética e índice de fixação elevado. A população com maior densidade populacional (0,25 ind.ha-1) foi a que apresentou menor diversidade genética e ausência de endogamia. A Área Mínima Viável para conservação da espécie foi compatível com a realidade do local de estudo, com uma ressalva de uma das populações onde há necessidade de uma área muito maior em relação às demais. A divergência genética foi elevada (G'ST = 0,344) e as populações foram classificadas como Unidades Independentes para o Manejo

    First Report of Alphacoronavirus Circulating in Cavernicolous Bats from Portugal

    Get PDF
    The emergence of novel coronaviruses (CoVs) has emphasized the need to understand their diversity and distribution in animal populations. Bats have been identified as crucial reservoirs for CoVs, and they are found in various bat species worldwide. In this study, we investigated the presence of CoVs of four cavernicolous bats in six locations in the centre and south of Portugal. We collected faeces, anal, and buccal swab samples, as well as air samples from the locations using a Coriolis air sampler. Our results indicate that CoVs were more readily detected in faecal samples compared to anal and buccal swab samples. No CoVs were detected in the air samples. Phylogenetic analysis showed that the detected viruses belong to the Alphacoronavirus genus. This study represents the first report of Alphacoronaviruses circulating in bats in Portugal and highlights the importance of continuous surveillance for novel CoVs in bat populations globally. Ongoing surveillance for CoVs in bat populations is essential as they are a vital source of these viruses. It is crucial to understand the ecological relationships between animals, humans, and the environment to prevent and control the emergence and transmission of infectious diseases. Further ecological studies are needed to investigate the factors contributing to the emergence and transmission of zoonotic viruses.Mahima Hemnani thanks Fundacao para a Ciencia e a Tecnologia (FCT) for the financial support of her PhD work under the Maria de Souza scholarship contract number 2021.09380.BD. This work was also funded by FCT, under the projects UIDB/04750/2020, LA/P/0064/2020, UIDP/00772/2020 and LA/P/0059/2020

    Processo de desenvolvimento de um site utilizando Web Mapping para o laboratório de geoprocessamento geosolos.

    Get PDF
    Em virtude dos avanços técnico-científicos, observa-se nos dias atuais o aumento expressivo na disponibilização de dados na Internet, de modo a facilitar o acesso aos mais diversos tipos de dados, tendo em vista as inovações proporcionadas com as novas e modernas ferramentas tecnológicas, que têm beneficiado o incremento e o uso de novos instrumentos (MOREIRA, 2010). Além dos avanços expressivos no campo informacional e tecnológico, como destaca Medeiros et al. (2010), podemos referenciar o geoprocessamento e os Sistemas de Informações Geográficas ? SIG?s que, aliados à Internet, tornaram-se tecnologias ainda mais robustas para divulgar os mais diversos tipos de informações. O uso da web como um meio de divulgação para os mapas pode ser considerado como um grande avanço na cartografia e abre muitas novas oportunidades, tais como mapas em tempo real, com divulgação mais barata e atualizações mais freqüentes, contendo mapas personalizados e interativos. O objetivo deste trabalho foi justamente a criação de um ambiente web, que propiciasse a divulgação dos mapas e trabalhos de pesquisa realizados pela equipe do laboratório de geoprocessamento da EPAMIG - GeoSolos, que utiliza geotecnologias para, entre outras coisas, mapear e caracterizar o café em grandes regiões produtoras de Minas Gerais. O público-alvo deste portal são todos os integrantes da cadeia produtiva do café, pesquisadores da área e pessoas interessadas nestas geotecnologias e na aplicação destas para o mapeamento do café

    Liberação de nutrientes durante a decomposição da biomassa de culturas de cobertura em solo do Cerrado no sistema plantio direto.

    Get PDF
    O objetivo deste trabalho foi avaliar o acúmulo e a liberação de macronutrientes da biomassa seca, da braquiária (Brachiaria brizantha) e do capim mombaça (Panicum maximum), utilizadas como cobertura de solo, no sistema de plantio direto, nas condições da região do Cerrado.FertBio 2010

    Nefrite Túbulo-Intersticial Hipocomplementémica Idiopática

    Get PDF
    Background: Tubulointerstitial nephritis (TIN) is a common cause of kidney injury typically seen in association with drug exposure, infection or autoimmune diseases. However, TIN with interstitial immune complex deposition, without glomerular injury, is rarely observed. Case: We report a case of a 64-yearold Indian woman admitted for dialysis-requiring renal failure, without involvement of other organs. Urinalysis showed blood 3+ and 24h proteinuria of 1.5 g. Renal ultrasound revealed normal sized kidneys with loss of parenchymal-sinus differentiation. Laboratory tests disclosed low C3, positive ANA but negative anti-dsDNA, SSA and SSB. Serum protein electrophoresis was normal. The renal biopsy showed tubulointerstitial nephritis with positive immunoglobulin staining involving the interstitium and tubular basement membrane with glomerular sparing. The patient started prednisolone (1mg/kg/day) without recovery of the renal function. Conclusion: Idiopathic hypocomplementaemic tubulointerstitial nephritis is a rare disease with few cases described in the literature. To our knowledge this is the first case reported in Portugal

    Modified Beer-Lambert law for blood flow

    Get PDF
    FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPWe develop and validate a Modified Beer-Lambert law for blood flow based on diffuse correlation spectroscopy (DCS) measurements. The new formulation enables blood flow monitoring from temporal intensity autocorrelation function data taken at single or multiple delay-times. Consequentially, the speed of the optical blood flow measurement can be substantially increased. The scheme facilitates blood flow monitoring of highly scattering tissues in geometries wherein light propagation is diffusive or non-diffusive, and it is particularly well-suited for utilization with pressure measurement paradigms that employ differential flow signals to reduce contributions of superficial tissues.51140534075FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2012/02500-82013/07559-3We gratefully acknowledge help from Marion Knaus and Victoria Pallett per preparing the pig, and we thank longtime collaborators Daniel Licht, John Detre, Emile Mohler, Thomas Floyd, Turgut Durduran, and Theresa Busch for valuable discussions. We acknowledge support from the National Institutes of Health (R01-NS060653, NHLBI-HL007915, 8P41-EB015893), the American Heart Association (ABP, 14POST20460161), the Thrasher Pediatric Research Foundation Early Career Award (DRB), and the Sao Paulo Research Foundation (RCM, 2012/02500-8, 2013/07559-3)

    Modified Beer-Lambert law for blood flow

    Get PDF
    FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOThe modified Beer-Lambert law is among the most widely used approaches for analysis of near-infrared spectroscopy (NIRS) reflectance signals for measurements of tissue blood volume and oxygenation. Briefly, the modified Beer-Lambert paradigm is a scheme to derive changes in tissue optical properties based on continuous-wave (CW) diffuse optical intensity measurements. In its simplest form, the scheme relates differential changes in light transmission (in any geometry) to differential changes in tissue absorption. Here we extend this paradigm to the measurement of tissue blood flow by diffuse correlation spectroscopy (DCS). In the new approach, differential changes of the intensity temporal auto-correlation function at a single delay-time are related to differential changes in blood flow. The key theoretical results for measurement of blood flow changes in any tissue geometry are derived, and we demonstrate the new method to monitor cerebral blood flow in a pig under conditions wherein the semi-infinite geometry approximation is fairly good. Specifically, the drug dinitrophenol was injected in the pig to induce a gradual 200% increase in cerebral blood flow, as measured with MRI velocity flow mapping and by DCS. The modified Beer-Lambert law for flow accurately recovered these flow changes using only a single delay-time in the intensity auto-correlation function curve. The scheme offers increased DCS measurement speed of blood flow. Further, the same techniques using the modified Beer-Lambert law to filter out superficial tissue effects in NIRS measurements of deep tissues can be applied to the DCS modified Beer-Lambert law for blood flow monitoring of deep tissues.The modified Beer-Lambert law is among the most widely used approaches for analysis of near-infrared spectroscopy (NIRS) reflectance signals for measurements of tissue blood volume and oxygenation. Briefly, the modified Beer-Lambert paradigm is a scheme to derive changes in tissue optical properties based on continuous-wave (CW) diffuse optical intensity measurements. In its simplest form, the scheme relates differential changes in light transmission (in any geometry) to differential changes in tissue absorption. Here we extend this paradigm to the measurement of tissue blood flow by diffuse correlation spectroscopy (DCS). In the new approach, differential changes of the intensity temporal auto-correlation function at a single delay-time are related to differential changes in blood flow. The key theoretical results for measurement of blood flow changes in any tissue geometry are derived, and we demonstrate the new method to monitor cerebral blood flow in a pig under conditions wherein the semi-infinite geometry approximation is fairly good. Specifically, the drug dinitrophenol was injected in the pig to induce a gradual 200% increase in cerebral blood flow, as measured with MRI velocity flow mapping and by DCS. The modified Beer-Lambert law for flow accurately recovered these flow changes using only a single delay-time in the intensity auto-correlation function curve. The scheme offers increased DCS measurement speed of blood flow. Further, the same techniques using the modified Beer-Lambert law to filter out superficial tissue effects in NIRS measurements of deep tissues can be applied to the DCS modified Beer-Lambert law for blood flow monitoring of deep tissues.9319123FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO2012/02500-8; 2013/07559-311. Conference on Optical Tomography and Spectroscopy of Tissue9 a 11 de Fevereiro de 2015San Francisco, CASPIE - International Society for Optical EngineeringAgências de fomento estrangeiras apoiaram essa pesquisa, mais informações acesse artig

    Synthesis and characterization of push-pull bithiophene and thieno[3,2-b]thiophene derivatives bearing an ethyne linker as sensitizers for dye-sensitized solar cells

    Get PDF
    Five push-pull heterocyclic dyes 4-7, and 9 were synthesized and characterized in order to study the variations in the optical, electronic and photovoltaic properties induced by structural modifications, i.e. different spacer units and anchoring groups. The final push-pull conjugated dyes 6-7 and 9 are formed by a N,N-dimethylaniline donor moiety conjugated with bithiophene, ethynyl-bithiophene or ethynyl-thieno[3,2-b]thiophene spacers and cyanoacetic acid or rhodanine-3-acetic acid as anchoring group. The synthesis of the precursor aldehydes 4-5 was accomplished through a Sonogashira coupling, on the other hand, compound 8 was prepared by Suzuki coupling. Knoevenagel condensation of aldehydes 4, 5 and 8 with cyanoacetic acid or rhodamine-3-acetic acid afforded the final push-pull dyes 6, 7 and 9. Information on conformation, electronic structure and electron distribution was obtained by DFT and TDDFTcalculations. This multidisciplinary study regarding the evaluation of the optical, redox and photovoltaic properties of the dyes reveals that compound 7, bearing an ethynyl-bithiophene spacer conjugated with a cyanoacetic acid anchoring group, has the highest conversion efficiency (3.51 %) as dye sensitizer in nanocrystalline TiO2 solar cells. Co-adsorption studies were also performed for dyes 6-7 with N719 as co-adsorbent, and this enhanced dye efficiencies by 33-45 %. The best cell performance was obtained by co-adsorbing N719 and dye 7 (75/25 vol%) with 4.66 % efficiency.Laboratory for Advanced Computing at the University of CoimbraThanks are due to: Fundaçao para a Ci ~ encia e a Tecnologia for ^ PhD grants to S. S. M. Fernandes (SFRH/BD/87786/2012), and I. Mesquita (PD/BD/105985/2014) and a postdoctoral grant to L.L.G.Justino. (SFRH/BPD/97026/2013); FEDER-COMPETE for financial support through the CQ/UM PEst-C/QUI/UI0686/2013 (FCOMP- 01-0124-FEDER-037302); European Research Council (Contract no: 321315) for funding. H. D. Burrows are grateful for funding from Centro de Química de Coimbra, which is supported by the FC through the programmes UID/QUI/UI0313/2013 and COMPETE. The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network and was purchased within the framework of the National Program for Scientific Re-equipment, contract REDE/1517/ RMN/2005 with funds from POCI 2010 (FEDER) and FCT. The authors also thank the Laboratory for Advanced Computing at the University of Coimbra for providing computing resources that have contributed to the research results reported in this paper (URL http://www.lca.uc.pt). The authors would like also to acknowledge A. I. Pereira for sequential co-adsorption devices and Dr. D. Ivanou for IPCE experiments.info:eu-repo/semantics/publishedVersio

    Stokes' Drift of linear Defects

    Full text link
    A linear defect, viz. an elastic string, diffusing on a planar substrate traversed by a travelling wave experiences a drag known as Stokes' drift. In the limit of an infinitely long string, such a mechanism is shown to be characterized by a sharp threshold that depends on the wave parameters, the string damping constant and the substrate temperature. Moreover, the onset of the Stokes' drift is signaled by an excess diffusion of the string center of mass, while the dispersion of the drifting string around its center of mass may grow anomalous.Comment: 14 pages, no figures, to be published in Phys.Rev.
    corecore