17 research outputs found

    Evolução da planície costeira das Praias do Sul e do Leste – Ilha Grande/RJ: implicações sobre a presença humana pre-histórica e contribuições para a reconstrução paleoambiental holocênica

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    A área de estudo deste trabalho possui ambientes lagunares bem preservados e sítios arqueológicos com idade de 3.000 anos AP. Dados altimétricos e análises de imagens aéreas permitiram a identificação de duas barreiras arenosas. Considerando a variação holocênica do nível relativo do mar, concluiu-se que a barreira interna possui idade pleistocênica. A externa, que inclui as praias atuais, formou-se durante a transgressão holocênica. Antigas desembocaduras fluvio-lagunares holocênicas apresentam-se nos extremos ocidental da Praia do Sul e oriental da Praia do Leste. O estabelecimento de um sítio arqueológico na barreira holocênica pode estar relacionado à antiga desembocadura na Praia do Leste. Neste caso, é possível que este sítio seja mais antigo do que o sítio do Ilhote, o qual pode ter sido ocupado somente a partir de 3.000 anos AP porque o nível do mar em rebaixamento teria facilitado o acesso. A sedimentação das lagoas tem sido investigada e apresentam-se resultados preliminares da análise de duas sondagens a percussão realizadas na Lagoa do Sul. A base do testemunho LS01 foi datada por 14C em 2.477 – 2.138 anos cal AP, a 116 cm, e do testemunho LS02, em 5.309 – 4.986 anos cal AP, a 136 cm. Os sedimentos lagunares são formados por lama orgânica de origem mista a terrestre, com camadas ricas em conchas e lentes arenosas de quartzo, interpretadas como resultado de episódios de enxurradas típicas da região, com alta pluviosidade. A sedimentação e a razão C:N indicam estabilidade ambiental com clima úmido nos últimos ~5.000 anos AP. Entre 1.394 – 1.174 e 795 – 481 anos cal AP ocorreu o intervalo mais úmido, com: (i) deposição concentrada de conchas e (ii) maior aporte de terrígenos. Maior quantidade de lentes arenosas foi depositada a partir de 3.066 – 2.647 anos cal AP, sugerindo maior frequência de chuvas intensas desde então

    Manoel Luiz Reefs morphology unveiled by high resolution satellite images (North Brazilian Continental Shelf)

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    The reefs of Manoel Luiz are located 100 nautical miles N from the city of São Luís, capital of the State of Maranhão - Brazil. The region is practically unconquerable, due to the great concentration of shallow reef pinnacles; it has never been possible to map the area by traditional methods, due to the dangers to navigate. The images acquired in June 2018, by programmed WorldView-3 satellite (30 cm resolution), revealed for the first time the real and exuberant reef formation with innumerable constructions, predominantly individual with circular, or linear and coalescent format. The reefs of Manoel Luiz are not constructed by corals. Drop-camera videos shows that sparse colonies of corals are fixed on hard structures formed (covered) by superimposed crusts of calcareous algae. The location of Manoel Luiz reefs remained almost 300 years unknown to navigators, since the year 1500, attributed to the discovery of Brazil, until 1820, when it was described by the French hydrographer Adm. Baron de Roussin, and another 198 years to be precisely georeferenced and mapped

    Environmental characterization of a dredging disposal site on the continental shelf of Espírito Santo, Brazil

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    Dredge material placement is among the major problems in coastal management. Sedimentation caused by dredge-spoil disposal presents a series of impacts, including the burial of benthos and the suffocation of filter-feeding benthic organisms. To minimize dredging impacts, studies in dredging disposal sites shall be performed to allow better approaches to adverse ecological risks. The goal of the present study was to map the sea bottom environment of a potential dredge disposal site by performing its geomorphology and ecology characterization, in the continental shelf of Espírito Santo state. Acoustic images were obtained using side scan sonar to characterize sediment texture and the geometry of deposits, along with a bathymetric survey. Additionally, underwater footage provided images and the description of the biota communities. The bathymetric survey revealed a relatively plain and homogenous bottom, with the presence of a paleochannel. Smooth elevations, with approximately 0.50m high, were found and characterized as calcareous biogenic concretions, among benthic and nektonic organisms. The organisms revealed a heterogeneous composition and a scattered distribution throughout the sampling stations, with the presence of a threatened species

    Biodegradação de matéria orgânica em lama sedimentada - definição de parâmetros na lagoa de piratininga, RJ: Biodegradation of organic matter in the sedimented mud - parameters definition at the piratininga lagoon, RJ

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    Entre março e julho/22, duas tecnologias complementares, EM® e Pulmão™, foram testadas para estudar a biorremediação na camada de lama da Lagoa de Piratininga, Niterói, RJ. Dados ortométricos, matéria orgânica, carbono orgânico, nitrogênio Kjeldahl total, fósforo e biopolímeros foram quantificados na superfície do sedimento. As concentrações crescentes de nitrogênio Kjeldahl indicaram aportes de esgoto doméstico ao sistema. O fósforo orgânico predominou sobre o total, pois foi consumido no processo de biorremediação. Ocorreram mudanças quali- quantitativas na composição da matéria orgânica lábil, com consumo de lipídio, molécula recalcitrante, e produção de proteínas e carboidratos. Os dados altimétricos indicaram maior tendência de consumo da lama na área que reuniu as tecnologias EM1®+Pulmão™, onde o aporte sedimentar foi praticamente anulado. Houve uma diminuição da espessura da lama, refletindo no aumento sutil de profundidade superficial da camada sedimentar. Estas modificações nas áreas experimentais indicam que o processo de restauração ambiental está ocorrendo

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Pervasive gaps in Amazonian ecological research

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    Diretriz da Sociedade Brasileira de Cardiologia sobre Diagnóstico e Tratamento de Pacientes com Cardiomiopatia da Doença de Chagas

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    This guideline aimed to update the concepts and formulate the standards of conduct and scientific evidence that support them, regarding the diagnosis and treatment of the Cardiomyopathy of Chagas disease, with special emphasis on the rationality base that supported it.  Chagas disease in the 21st century maintains an epidemiological pattern of endemicity in 21 Latin American countries. Researchers and managers from endemic and non-endemic countries point to the need to adopt comprehensive public health policies to effectively control the interhuman transmission of T. cruzi infection, and to obtain an optimized level of care for already infected individuals, focusing on diagnostic and therapeutic opportunistic opportunities.   Pathogenic and pathophysiological mechanisms of the Cardiomyopathy of Chagas disease were revisited after in-depth updating and the notion that necrosis and fibrosis are stimulated by tissue parasitic persistence and adverse immune reaction, as fundamental mechanisms, assisted by autonomic and microvascular disorders, was well established. Some of them have recently formed potential targets of therapies.  The natural history of the acute and chronic phases was reviewed, with enhancement for oral transmission, indeterminate form and chronic syndromes. Recent meta-analyses of observational studies have estimated the risk of evolution from acute and indeterminate forms and mortality after chronic cardiomyopathy. Therapeutic approaches applicable to individuals with Indeterminate form of Chagas disease were specifically addressed. All methods to detect structural and/or functional alterations with various cardiac imaging techniques were also reviewed, with recommendations for use in various clinical scenarios. Mortality risk stratification based on the Rassi score, with recent studies of its application, was complemented by methods that detect myocardial fibrosis.  The current methodology for etiological diagnosis and the consequent implications of trypanonomic treatment deserved a comprehensive and in-depth approach. Also the treatment of patients at risk or with heart failure, arrhythmias and thromboembolic events, based on pharmacological and complementary resources, received special attention. Additional chapters supported the conducts applicable to several special contexts, including t. cruzi/HIV co-infection, risk during surgeries, in pregnant women, in the reactivation of infection after heart transplantation, and others.     Finally, two chapters of great social significance, addressing the structuring of specialized services to care for individuals with the Cardiomyopathy of Chagas disease, and reviewing the concepts of severe heart disease and its medical-labor implications completed this guideline.Esta diretriz teve como objetivo principal atualizar os conceitos e formular as normas de conduta e evidências científicas que as suportam, quanto ao diagnóstico e tratamento da CDC, com especial ênfase na base de racionalidade que a embasou. A DC no século XXI mantém padrão epidemiológico de endemicidade em 21 países da América Latina. Investigadores e gestores de países endêmicos e não endêmicos indigitam a necessidade de se adotarem políticas abrangentes, de saúde pública, para controle eficaz da transmissão inter-humanos da infecção pelo T. cruzi, e obter-se nível otimizado de atendimento aos indivíduos já infectados, com foco em oportunização diagnóstica e terapêutica. Mecanismos patogênicos e fisiopatológicos da CDC foram revisitados após atualização aprofundada e ficou bem consolidada a noção de que necrose e fibrose sejam estimuladas pela persistência parasitária tissular e reação imune adversa, como mecanismos fundamentais, coadjuvados por distúrbios autonômicos e microvasculares. Alguns deles recentemente constituíram alvos potenciais de terapêuticas. A história natural das fases aguda e crônica foi revista, com realce para a transmissão oral, a forma indeterminada e as síndromes crônicas. Metanálises recentes de estudos observacionais estimaram o risco de evolução a partir das formas aguda e indeterminada e de mortalidade após instalação da cardiomiopatia crônica. Condutas terapêuticas aplicáveis aos indivíduos com a FIDC foram abordadas especificamente. Todos os métodos para detectar alterações estruturais e/ou funcionais com variadas técnicas de imageamento cardíaco também foram revisados, com recomendações de uso nos vários cenários clínicos. Estratificação de risco de mortalidade fundamentada no escore de Rassi, com estudos recentes de sua aplicação, foi complementada por métodos que detectam fibrose miocárdica. A metodologia atual para diagnóstico etiológico e as consequentes implicações do tratamento tripanossomicida mereceram enfoque abrangente e aprofundado. Também o tratamento de pacientes em risco ou com insuficiência cardíaca, arritmias e eventos tromboembólicos, baseado em recursos farmacológicos e complementares, recebeu especial atenção. Capítulos suplementares subsidiaram as condutas aplicáveis a diversos contextos especiais, entre eles o da co-infecção por T. cruzi/HIV, risco durante cirurgias, em grávidas, na reativação da infecção após transplante cardíacos, e outros.    Por fim, dois capítulos de grande significado social, abordando a estruturação de serviços especializados para atendimento aos indivíduos com a CDC, e revisando os conceitos de cardiopatia grave e suas implicações médico-trabalhistas completaram esta diretriz.&nbsp

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

    Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

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    Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt
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