120 research outputs found
Spatial and seasonal changes in benthic macrofauna from two dissipative sandy beaches in eastern Brazil)
Sandy beaches are dynamic ecosystems with strong interaction of sediments, waves and tidal energy, with marked effects on benthic assemblages. Although there are numerous efforts in understanding spatial-temporal variation of benthic macrofauna on sandy beaches along the southern and southeastern Marine Ecoregions in Brazil, there is poor sampling along beaches of the Eastern Marine Ecoregion (EME). Here we examined spatial and temporal scales of variability in benthic macrofauna (>; 500 µm) through a hierarchical sampling of two dissipative sandy beaches within the EME between two seasons (winter 2011 and summer 2012). We tested the hypothesis that spatial changes (i.e., meters to hundreds of meters scales) in the structure of benthic assemblages will be more pronounced compared to the weak seasonal fluctuations at this tropical region. We found weak temporal and spatial changes in sediment grain size and beach slope, but differences in macrofaunal assemblages were evident. Contrary to our hypothesis, hierarchical sampling indicated significant changes in macrofaunal composition and density at multiple local scales (meters to hundreds of meters) and on seasonal scales. The macrofauna density and composition was directly related to changes on the sediment organic matter and grain size.Praias arenosas são ambientes dinâmicos com interação entre sedimento, energia de ondas e marés, com marcantes efeitos sobre assembléias bentônicas. Existem numerosos esforços no entendimento da variação espaço-temporal da macrofauna bentônica em praias no Brasil, sendo a maioria concentrados na Ecorregião Marinha Sudeste e Rio Grande (20oS a 35oS), mas limitada amostragem em praias tropicais na Ecoregião Marinha Leste (EML). Este estudo examinou as escalas de variabilidade espaço-temporal da macrofauna bentônica (>; 500 µm) através de amostragem hierárquica em duas praias dissipativas dentro da EML em duas estações (inverno de 2011/verão de 2012). Testou-se a hipótese que mudanças espaciais (escala de metros a centenas de metros) na estrutura das assembléias bentônicas são menos pronunciadas em comparação com as fracas flutuações sazonais nesta região tropical. Foram encontradas pequenas mudanças espaço-temporais na granulometria e perfil de praia, mas com evidentes diferenças nas assembléias macrofaunais. Contrariando a hipótese deste estudo, a amostragem hierárquica indicou mudanças significativas na composição e densidade da macrofauna em múltiplas escalas locais (metros a centenas de metros) e em escalas temporais. A densidade e composição da macrofauna está relacionada com mudanças no teor de matéria orgânica do sedimento e tamanho do grão
Benthic estuarine communities in Brazil: moving forward to long term studies to assess climate change impacts
Estuaries are unique coastal ecosystems that sustain and provide essential ecological services for mankind. Estuarine ecosystems include a variety of habitats with their own sediment-fauna dynamics, all of them globally undergoing alteration or threatened by human activities. Mangrove forests, saltmarshes, tidal flats and other confined estuarine systems are under increasing stress due to human activities leading to habitat and species loss. Combined changes in estuarine hydromorphology and in climate pose severe threats to estuarine ecosystems on a global scale. The ReBentos network is the first integrated attempt in Brazil to monitor estuarine changes in the long term to detect and assess the effects of global warming. This paper is an initial effort of ReBentos to review current knowledge on benthic estuarine ecology in Brazil. We herein present and synthesize all published work on Brazilian estuaries that has focused on the description of benthic communities and related ecological processes. We then use current data on Brazilian estuaries and present recommendations for future studies to address climate change effects, suggesting trends for possible future research and stressing the need for long-term datasets and international partnerships.Estuários são ecossistemas costeiros que sustentam uma ampla variedade de serviços ambientais para a humanidade. Estuários abrigam muitos ambientes bentônicos com caracterÃsticas especÃficas e seriamente ameaçados globalmente. Manguezais, marismas e planÃcies de maré são amplamente impactados por poluentes domésticos e industriais, por atividades comerciais que levam à perda de habitat e pela sobrepesca. Os diversos impactos locais, associados a mudanças regionais e globais na hidromorfologia estuarina e potenciais efeitos de mudanças climáticas, colocam sérias ameaças a ecossistemas estuarinos. A rede Bentos foi criada para estudar o efeito de mudanças no clima em ecossistemas bentônicos costeiros brasileiros. Este trabalho faz parte dos esforços iniciais do Grupo de Trabalho Estuários em rever o conhecimento sobre comunidades bentônicas estuarinas no Brasil. Aqui apresentamos uma breve revisão crÃtica sobre os trabalhos realizados objetivando o estudo, em nÃvel de comunidades, do bentos estuarino e processos ecológicos associados. A partir do cenário atual, realizamos recomendações de estudo para responder questões cientÃficas sobre efeitos de mudanças climáticas em comunidades bentônicas estuarinas, e enfatizamos a necessidade de bases de dados contÃnuas e de longa duração e o estabelecimento de parcerias internacionais com foco especÃfico nos estuários brasileiros
Comparison of coronary angiography findings in diabetic and non-diabetic women with non-ST-segment-elevation acute coronary syndrome
OBJECTIVE: Compare hemodynamic and angiographic patterns, as well as atherosclerotic lesion morphology, in diabetic and non-diabetic females with unstable angina or non-ST-segment-elevation myocardial infarction (UA/NSTEMI). METHODS: Two interventional cardiologists determined the presence of severe atherosclerotic lesion, defined as those > 70%; plaque morphology, according to the American Heart Association classification; collateral circulation; plus ventricular and aortic pressures. Ejection fraction was calculated by angiography or echocardiography. RESULTS: During eight and a half years, 645 coronary angiographies were performed in women with UA/NSTEMI. In the present study, 593 female patients were assessed (215 diabetic - 36%). This group differed from the non-diabetic in the following aspects: older age (61 ± 10.6 x 58.1 ± 11.4), higher prevalence of postmenopausal women and lower prevalence of the smoking habit. Severe three-vessel disease was significantly more frequent in diabetic patients (28% x 10%), as well as totally occluded vessels: 51 (23%) x 54 (14.3%), p 70%, a morfologia da placa, de acordo com a classificação da American Heart Association, a presença de circulação colateral e as pressões ventriculares e aórticas. A fração de ejeção foi calculada pela angiografia ou pelo ecocardiograma. RESULTADOS: Em oito anos e meio, foram realizados 645 coronariografias em mulheres com AI/IAMSS. Foram analisadas 593 pacientes (215 diabéticas - 36%). Este grupo diferiu das não-diabéticas nos seguintes aspectos: idade mais alta (61 ± 10,6 x 58,1 ± 11,4), prevalência maior de mulheres pós-menopausa e menor prevalência de tabagismo. Lesão grave em três vasos foi significativamente mais freqüente nas pacientes diabéticas (28% x 10%), assim como vasos totalmente ocluÃdos: 51 (23%) x 54 (14.3%), p < 0.005.Fração de ejeção < 50% foi mais comum nas diabéticas. CONCLUSÃO: Estes achados confirmam o acometimento difuso da doença aterosclerótica em pacientes diabéticas, assim como maior deterioração da função ventricular, que pode estar relacionada ao pior prognóstico dessa população em curto e em longo prazo.Universidade Federal de São Paulo (UNIFESP)Hospital Santa MarcelinaUNIFESPSciEL
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Comparative Composition, Diversity and Trophic Ecology of Sediment Macrofauna at Vents, Seeps and Organic Falls
Sediments associated with hydrothermal venting, methane seepage and large organic falls such as whale, wood and plant detritus create deep-sea networks of soft-sediment habitats fueled, at least in part, by the oxidation of reduced chemicals. Biological studies at deep-sea vents, seeps and organic falls have looked at macrofaunal taxa, but there has yet to be a systematic comparison of the community-level attributes of sediment macrobenthos in various reducing ecosystems. Here we review key similarities and differences in the sediment-dwelling assemblages of each system with the goals of (1) generating a predictive framework for the exploration and study of newly identified reducing habitats, and (2) identifying taxa and communities that overlap across ecosystems. We show that deep-sea seep, vent and organic-fall sediments are highly heterogeneous. They sustain different geochemical and microbial processes that are reflected in a complex mosaic of habitats inhabited by a mixture of specialist (heterotrophic and symbiont-associated) and background fauna. Community-level comparisons reveal that vent, seep and organic-fall macrofauna are very distinct in terms of composition at the family level, although they share many dominant taxa among these highly sulphidic habitats. Stress gradients are good predictors of macrofaunal diversity at some sites, but habitat heterogeneity and facilitation often modify community structure. The biogeochemical differences across ecosystems and within habitats result in wide differences in organic utilization (i.e., food sources) and in the prevalence of chemosynthesis-derived nutrition. In the Pacific, vents, seeps and organic-falls exhibit distinct macrofaunal assemblages at broad-scales contributing to ß diversity. This has important implications for the conservation of reducing ecosystems, which face growing threats from human activities
Advanced deep learning comparisons for non-invasive tunnel lining assessment from ground penetrating radar profiles
Innovative, automated, and non-invasive techniques have been developed by scientific community to indirectly assess structural conditions and support the decision-making process for a worthwhile maintenance schedule. Nowadays, machine learning tools are in the spotlight because of their outstanding capabilities to deal with data coming from even heterogeneous sources and their ability to extract information from the structural systems, providing highly effective, reliable, and efficient damage classification tools. In the current study, a supervised multi-level damage classification strategy has been developed regarding Ground Penetrating Radar (GPR) profiles for the assessment of tunnel lining conditions. In previous research, the authors firstly considered a convolutional neural network (CNN), adopting the quite popular ResNet-50, initialized through transfer learning. In the present work, further enhancements have been attempted by adopting two configurations of the newest state-of-art advanced neural architectures: the neural transformers. The foremost is the original Vision Transformer (ViT), whose core is an encoder entirely based on the innovative self-attention mechanism and does not rely on convolution at all. The second is an improvement of ViT which merges convolution and self-attention, the Compact Convolution Transformer (CCT). In conclusion, a critical discussion of the different pros and cons of adopting the above-mentioned different architectures is finally provided, highlighting the actual powerfulness of these technologies in the future civil engineering paradigm nevertheless
MRI/US fusion prostate biopsy in men on active surveillance: Our experience.
Aim: The upgrading or staging in men with prostate cancer (PCA) undergoing active surveillance (AS), defined as Gleason score (GS) ≥ 3+4 or more than 2 area with cancer, was investigated in our experience using the software-based fusion biopsy (FB). Methods: We selected from our database, composed of 620 biopsies, only men on AS according to criteria of John Hopkins Protocol (T1c, < 3 positive cores, GS = 3+3 = 6). Monitoring consisted of PSA measurement every 3 months, a clinical examination every 6 months, confirmatory FB within 6 months and then annual FB in all men. The suspicious MRI lesions were scored according to the Prostate Imaging Reporting and Data System (PI-RADS) classification version 2. FB were performed with a transrectal elastic free-hand fusion platform. The overall and clinically significant cancer detection rate was reported. Secondary, the diagnostic role of systematic biopsies was evaluated. Results: We selected 56 patients on AS with mean age 67.4 years, mean PSA 6.7 ng/ml and at least one follow-up MRI-US fusion biopsy (10 had 2 or 3 follow-up biopsies). Lesions detected by MRI were: PIRADS-2 in 5, PIRADS-3 in 28, PIRADS-4 in 18 pts and PIRADS-5 in 5 patients. In each MRI lesion, FB with 2.1 ± 1.1 cores were taken with a mean total cores of 13 ± 2.4 including the systematic cores. The overall cancer detection rate was 71% (40/56): 62% (25/40) in target core and 28% (15/40) in systematic core. The overall significant cancer detection rate was 46% (26/56): 69% (18/26) in target vs 31% (8/26) in random cores. Conclusions: The incidence of clinical significant cancer was 46% in men starting active surveillance, but it was more than doubled using MRI/US Target Biopsy 69% (18/26) rather than random cores (31%, 8/26). However, 1/3 of disease upgrades would have been missed if only the targeted biopsies were performed. Based on our experience, MRI/US fusion target biopsy must be associated to systematic biopsies to improve detection of significant cancer, reducing the risks of misclassification
Laparoscopic and robotic ureteral stenosis repair: a multi-institutional experience with a long-term follow-up
The treatment of ureteral strictures represents a challenge due to the variability of aetiology, site and extension of the stricture; it ranges from an end-to-end anastomosis or reimplantation into the bladder with a Boari flap or Psoas Hitch. Traditionally, these procedures have been done using an open access, but minimally invasive approaches have gained acceptance. The aim of this study is to evaluate the safety and feasibility and perioperative results of minimally invasive surgery for the treatment of ureteral stenosis with a long-term follow-up. Data of 62 laparoscopic (n\uc2 =\uc2 36) and robotic (n\uc2 =\uc2 26) treatments for ureteral stenosis in 9 Italian centers were reviewed. Patients were followed according to the referring center\ue2\u80\u99s protocol. Laparoscopic and robotic approaches were compared. All the procedures were completed successfully without open conversion. Average estimated blood loss in the two groups was 91.2\uc2 \uc2\ub1\uc2 71.9\uc2 cc for the laparoscopic and 47.2\uc2 \uc2\ub1\uc2 32.3\uc2 cc for the robotic, respectively (p\uc2 =\uc2 0.004). Mean days of hospitalization were 5.9\uc2 \uc2\ub1\uc2 2.4 for the laparoscopic group and 7.6\uc2 \uc2\ub1\uc2 3.4 for the robotic group (p\uc2 =\uc2 0.006). No differences were found in terms of operative time and post-operative complications. After a median follow-up of 27\uc2 months, the robotic group yielded 2 stenosis recurrence, instead the laparoscopic group shows no cases of recurrence (p\uc2 =\uc2 0.091). Minimally invasive approach for ureteral stenosis is safe and feasible. Both robotic and pure laparoscopic approaches may offer good results in terms of perioperative outcomes, low incidence of complications and recurrence
Importância da escola no conhecimento empÃrico sobre infecções sexualmente transmissÃveis e métodos contraceptivos: promoção da saúde na rede pública de ensino / Importance of the school in empirical knowledge about sexually transmitted infections and contraceptive methods: health promotion in the public school network
A sexualidade é um processo contÃnuo construÃdo pelo indivÃduo durante o desenvolvimento biológico, sendo influenciada por contextos sociais e culturais. A escola exerce papel fundamental na educação sexual dos discentes, sendo capaz de contribuir na construção do saber, refletindo na prevenção de Infecções Sexualmente TransmissÃveis (IST) e métodos contraceptivos. Diante disso, o objetivo do presente estudo foi identificar as dificuldades dos estudantes quanto ao conhecimento das IST e métodos contraceptivos. Após a identificação do conhecimento empÃrico dos alunos foram realizadas atividades de intervenção como meio de promoção e prevenção de complicações à saúde. Um questionário foi aplicado para realizar levantamento das dúvidas dos participantes sobre a temática. Além disso, as intervenções embasadas nas dúvidas foram realizadas por meio de palestras e atividade dinâmica lúdica. Evidenciamos que os alunos de ambos os sexos apresentam pouco conhecimento em relação à s IST, possuem mais conhecimento sobre HIV/AIDS e consideraram apenas os preservativos masculino e feminino como métodos contraceptivos. Em conjunto, esses dados revelam a importância da educação sexual na escola, principalmente, em relação à s IST que causam diversas complicações como infertilidade, doença inflamatória pélvica (DIP), disfunção sexual, câncer de colo de útero e outros agravamentos à saúde
Contamination and oxidative stress biomarkers in estuarine fish following a mine tailing disaster
Background The Rio Doce estuary, in Brazil, was impacted by the deposition of iron mine tailings, caused by the collapse of a dam in 2015. Based on published baseline datasets, the estuary has been experiencing chronic trace metal contamination effects since 2017, with potential bioaccumulation in fishes and human health risks. As metal and metalloid concentrations in aquatic ecosystems pose severe threats to the aquatic biota, we hypothesized that the trace metals in estuarine sediments nearly two years after the disaster would lead to bioaccumulation in demersal fishes and result in the biosynthesis of metal-responsive proteins. Methods We measured As, Cd, Cr, Cu, Fe, Mn, Pb, Se and Zn concentrations in sediment samples in August 2017 and compared to published baseline levels. Also, trace metals (As, Cd, Cr, Cu, Fe, Hg, Mn, Pb, Se and Zn) and protein (metallothionein and reduced glutathione) concentrations were quantified in the liver and muscle tissues of five fish species (Cathorops spixii, Genidens genidens, Eugerres brasilianus, Diapterus rhombeus and Mugil sp.) from the estuary, commonly used as food sources by local populations. Results Our results revealed high trace metal concentrations in estuarine sediments, when compared to published baseline values for the same estuary. The demersal fish species C. spixii and G. genidens had the highest concentrations of As, Cr, Mn, Hg, and Se in both, hepatic and muscle, tissues. Trace metal bioaccumulation in fish was correlated with the biosynthesis of metallothionein and reduced glutathione in both, liver and muscle, tissues, suggesting active physiological responses to contamination sources. The trace metal concentrations determined in fish tissues were also present in the estuarine sediments at the time of this study. Some elements had concentrations above the maximum permissible limits for human consumption in fish muscles (e.g., As, Cr, Mn, Se and Zn), suggesting potential human health risks that require further studies. Our study supports the high biogeochemical mobility of toxic elements between sediments and the bottom-dwelling biota in estuarine ecosystems
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