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1.
An Acad Bras Cienc ; 95(suppl 3): e20230451, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38055512

RESUMO

Understand the origin, transport, and character of organic matter entering Antarctic fjords is essential as they are major components of the global carbon cycle and budget. Macromolecular pools of particulate organic matter, bulk organic geochemistry, major and trace elements in surface sediments from Collins Bay were analysed as source indicators. Oceanographic conditions, bathymetry (multibeam) and grain size were considered as environmental controlling factors. Sediment samples were taken with a van Veen grab, during the ANTAR XXV Peruvian expedition (February 2018), onboard the R/V "BAP Carrasco" from the Peruvian Navy. Biopolymeric composition revealed the predominance of fresh marine protein-rich organic matter in the seafloor of Collins Bay, denoting high quality food resource for marine benthic heterotrophs. Based on Igeo values (between 0 and 1) Collins Bay can be considered unpolluted with natural levels of As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn. Distribution of most of these elements with a gradient of decrease from the shallow inner fjord towards the outer deepest fjord, suggest their association with the deposition of detrital material and lithogenic particles supplied by Collins Glacier frontal ablation and runoff. This first comprehensive baseline information would assist in interpreting downcore sedimentary reconstructions and future climate-induce changes.


Assuntos
Metais Pesados , Oligoelementos , Poluentes Químicos da Água , Estuários , Regiões Antárticas , Oligoelementos/análise , Clima , Peru , Sedimentos Geológicos/química , Monitoramento Ambiental , Poluentes Químicos da Água/análise , Metais Pesados/análise
2.
Sci Total Environ ; 856(Pt 2): 159190, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36195141

RESUMO

Benthic indices have been widely used across different coastal ecosystems to assess ecological quality and detect anthropic impacts, but very few studies investigated their effectiveness on sandy beaches. Here, we evaluated and compared the efficacy of 12 assemblage-based benthic indices in assessing ecological quality in beaches, across a gradient of anthropic pressure and natural variability in 90 sandy beach sites. Overall, when sandy beaches were considered collectively, benthic indices had a poor performance in identifying decreases in ecological quality with increasing urbanization. However, when each morphodynamic type was evaluated separately, a few indices, especially those that were calibrated by reference conditions (i.e., M-AMBI, BAT, and BEQI-2), showed promising results for dissipative, and to a lesser extent, intermediate beaches. For reflective beaches, indices performed poorly, likely a reflection of the stronger natural disturbance these beaches are subjected to. Among functional indices, richness was found to be lower in urbanized beaches, but only in dissipative ones. Overall, our results show that benthic indices have the potential to be incorporated in sandy beach management and monitoring programs, especially for dissipative and intermediate beaches. For reflective beaches, given the early stage of studies with benthic indices in beaches, more research is needed to corroborate the observed patterns.


Assuntos
Ecossistema , Urbanização , Praias , Monitoramento Ambiental/métodos
3.
Mar Pollut Bull ; 184: 114101, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36095966

RESUMO

Changes in species composition and relative abundance caused by pollution might have an impact on the community dynamics and ecosystem functioning. Macrobenthos are widely used as indicators of marine environmental health due to their sensitive to disturbance. The present study aims to evaluate spatial and temporal variability of functional diversity of macrobenthos of the Montevideo and Canelones coastal zone along a pre-established pollution gradient, based on Biological Traits Analysis, and functional diversity indices. Body-size", "Feeding-mode", "Habitat", and "Indicator-role" were useful proxies to detect changes in environmental conditions in organically enriched habitats. FRic, FEve and FDis detected temporal variations but only FRic registered spatial variations. Differences among surveys would mainly reflect environmental variability caused by the 2009-2010 El Niño-Southern Oscillation event. Finally, negative correlations between FEve and FDis with AMBI suggest both indices as useful proxies of benthic environmental health, with potential to be used in monitoring and quality assessment programs.


Assuntos
Ecossistema , Estuários , Monitoramento Ambiental , El Niño Oscilação Sul , Poluição Ambiental , Biodiversidade
4.
Sens Biosensing Res ; 37: 100513, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35958188

RESUMO

Recent outbreaks of infectious diseases such as Covid-19 that have fever as one of the symptoms drive the search for systems to track people with fever quickly and non-contact, also known as sanitary barriers. The use of non-contact infrared-based instruments, especially the infrared thermal imager, has widely spread. However, the screening process has presented low performance. This article addresses the choice of regions of interest on the human face for the analysis of the individual's fever, deals with the temperature thresholds used for this analysis, as well as the way to issue the recommendation to screen the person or not. The data collection and statistical analysis of temperatures of 198 volunteers allowed us to study and define the most appropriate face regions as targets for these barriers, as well as the temperature thresholds to be used for screening for each of these regions. Besides, the paper presents a probabilistic method based on the metrological quality of the sanitary barrier to the emission of recommendation for screening potentially febrile people. The developed method was tested in feverish and non-febrile volunteers, showing complete assertiveness in the tested cases.

5.
Bull Environ Contam Toxicol ; 100(4): 472-476, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29487956

RESUMO

Polychaetes that inhabit the sediments of estuaries are important prey to many species all around the world. Laeonereis acuta is a deposit feeder living in estuaries along the Atlantic coast of South America. Ragworms accumulate metals from the sediment, and represent a means of entry of sediment contaminants into the trophic network. The concentrations of Zn, Pb, Cu, Cr and Cd were determined in polychaetes and sediments (total and extractable) from six estuarine beaches of Río de la Plata. The associations between total and extractable concentrations in sediment and accumulated concentrations in L. acuta were analyzed. Sediments extracted by weak acid digestion appear to be a good proxy model of bioavailable metal fractions in the sediment. The association between metals in sediment and polychaetes denotes the role of L. acuta as an important link in metal trophic transfer from sediments to potential fish and bird predators of the worm.


Assuntos
Monitoramento Ambiental/métodos , Estuários , Sedimentos Geológicos/química , Metais Pesados/análise , Poliquetos/metabolismo , Oligoelementos/análise , Poluentes Químicos da Água/análise , Animais , Disponibilidade Biológica , Metais Pesados/metabolismo , Modelos Biológicos , Oligoelementos/metabolismo , Uruguai , Poluentes Químicos da Água/metabolismo
6.
Mar Pollut Bull ; 126: 438-448, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29421124

RESUMO

We investigated the relationship between the AMBI index and different contamination proxies in an urbanized bay in South America (SE Brazil), and the effect of (a) abundance data transformation and (b) exclusion of low-reliability sites (high SD; low N) on the index' performance. Poor ecological quality and opportunistic species were related to an increase in contaminants concentrations and mud content. Good ecological status and sensitive species (EG I) were mainly related to increased hydrodynamics. Data transformation caused minimal changes to the overall relationships, but exclusion of low-reliability sites improved the relationship between ecological groups and contamination proxies. Our results show that AMBI is robust in detecting effects of different contaminants in the area and reinforce the importance of the index as a tool for coastal management, but local joint efforts are needed to improve and adjust local species classification in ecological groups to improve the index' performance.


Assuntos
Monitoramento Ambiental/métodos , Animais , Baías , Brasil , Ecossistema , Reprodutibilidade dos Testes , Urbanização , Poluição da Água
7.
Clin Breast Cancer ; 18(1): e123-e133, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28927692

RESUMO

INTRODUCTION: The objective of the present work was to evaluate the impact of the phenotype of both intratumoral mononuclear inflammatory cells (MICs) and cancer-associated fibroblast (CAFs), assessed as to their expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) on prognosis in different breast cancer subtypes. MATERIALS AND METHODS: A total of 247 tumors of patients with primary ductal invasive breast cancer were categorized into 1 of 4 major subtypes, using the 3 standard immunohistochemical markers (estrogen receptor [ER], progesterone receptor [PR], and human epidermal growth factor receptor/Neu 2 [HER2] receptor status). An immunohistochemical study was performed using tissue arrays and specific antibodies against MMP-9, MMP-11, and MMP-14, and TIMP-1 and TIMP-2. RESULTS: MMP-11 expression by MICs was significantly and strongly associated with prognosis in all breast cancer subtypes. There were other significant associations with poor prognosis in luminal A tumors: expressions of MMP-9, MMP-11, and TIMP-2 by CAFs, in luminal B tumors: MMP-14 expression by MICs and TIMP-2 expression by MICs, in HER-2-positive tumors: expression of MMP-9 by MICs, and in triple negative breast cancers: expression of TIMP-1 by MICs. CONCLUSION: Characterization of both tumor stromal CAFs and MICs, with regard to the expression of MMPs and TIMPs, improve the prognostic evaluation of all breast cancer subtypes.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/patologia , Fibroblastos Associados a Câncer/patologia , Carcinoma Ductal de Mama/patologia , Microambiente Tumoral , Mama/citologia , Mama/patologia , Neoplasias da Mama/mortalidade , Carcinoma Ductal de Mama/mortalidade , Feminino , Seguimentos , Humanos , Metaloproteinase 11 da Matriz/metabolismo , Metaloproteinase 14 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Pessoa de Meia-Idade , Prognóstico , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/metabolismo , Análise de Sobrevida , Análise Serial de Tecidos , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Inibidor Tecidual de Metaloproteinase-2/metabolismo
8.
Nanomaterials (Basel) ; 7(3)2017 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-28336895

RESUMO

Porous films of cobalt nanoparticles have been obtained by sputter gas aggregation and controllably oxidized by air annealing at 100 °C for progressively longer times (up to more than 1400 h). The magnetic properties of the samples were monitored during the process, with a focus on the exchange bias field. Air annealing proves to be a convenient way to control the Co/CoO ratio in the samples, allowing the optimization of the exchange bias field to a value above 6 kOe at 5 K. The occurrence of the maximum in the exchange bias field is understood in terms of the density of CoO uncompensated spins and their degree of pinning, with the former reducing and the latter increasing upon the growth of a progressively thicker CoO shell. Vertical shifts exhibited in the magnetization loops are found to correlate qualitatively with the peak in the exchange bias field, while an increase in vertical shift observed for longer oxidation times may be explained by a growing fraction of almost completely oxidized particles. The presence of a hummingbird-like form in magnetization loops can be understood in terms of a combination of hard (biased) and soft (unbiased) components; however, the precise origin of the soft phase is as yet unresolved.

11.
Phys Rev Lett ; 115(5): 057201, 2015 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-26274435

RESUMO

Thermal activation tends to destroy the magnetic stability of small magnetic nanoparticles, with crucial implications for ultrahigh density recording among other applications. Here we demonstrate that low-blocking-temperature ferromagnetic (FM) Co nanoparticles (T(B)<70 K) become magnetically stable above 400 K when embedded in a high-Néel-temperature antiferromagnetic (AFM) NiO matrix. The origin of this remarkable T(B) enhancement is due to a magnetic proximity effect between a thin CoO shell (with low Néel temperature, T(N), and high anisotropy, K(AFM)) surrounding the Co nanoparticles and the NiO matrix (with high T(N) but low K(AFM)). This proximity effect yields an effective antiferromagnet with an apparent T(N) beyond that of bulk CoO, and an enhanced anisotropy compared to NiO. In turn, the Co core FM moment is stabilized against thermal fluctuations via core-shell exchange-bias coupling, leading to the observed T(B) increase. Mean-field calculations provide a semiquantitative understanding of this magnetic-proximity stabilization mechanism.

13.
14.
Mar Pollut Bull ; 91(2): 461-75, 2015 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-25060626

RESUMO

Organic pollution was evaluated in surface sediments along the middle portion of the Río de la Plata Estuary, SW Atlantic. A multi-molecular marker approach was performed to identify major sources of organic compounds using diagnostic indices. The relative contribution of different sources of hydrocarbons was quantified by source apportionment employing Principal Component Analysis/Multiple Linear Regression (PCA/MLR) as chemometric technique. All molecular markers indicated high chronic organic pollution in the stations of Montevideo Bay. Main sources of aliphatic and polycyclic aromatic hydrocarbons were petroleum inputs and combustion, due to oil transport and refinement, harbour activities and vehicular emissions. Major sources of linear alkylbenzenes and steroids were industrial and domestic sewage. Although, significant anthropogenic inputs, a natural footprint of terrestrial higher plants contribution was recognized. Multi-molecular marker and comprehensive assessments can improve the establishment of more precise regulation actions to reduce pollution levels.


Assuntos
Monitoramento Ambiental/estatística & dados numéricos , Estuários , Sedimentos Geológicos/química , Poluentes Químicos da Água/análise , Monitoramento Ambiental/métodos , Hidrocarbonetos/análise , Modelos Lineares , Petróleo/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Análise de Componente Principal , Esgotos/química , Uruguai , Emissões de Veículos/análise
15.
Mar Pollut Bull ; 91(2): 454-60, 2015 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-25455787

RESUMO

Indices based on macrobenthic responses to disturbance remain to be adequately tested for the detection of spatial variability by robust sampling designs. We present herein a congruence test to real-world data of the widely used indices AMBI, M-AMBI and BENTIX in tidal flats of a subtropical estuary. We used a hierarchical sampling design to evaluate the spatial variability of the indices in response to distinct levels of sewage contamination. Indices were then tested for correlations with chemical proxies of contamination and for the similarity of responses. BENTIX and M-AMBI produced over- and underestimations of ecological status. We found a low degree of similarity among indices as an expression of the spatial variation of macrofaunal assemblages on their performances. Only AMBI varied at the contamination scale (10(3)m) and was congruent with physical-chemical proxies. Ambiguous responses indicated effects of natural inputs of organic matter rather than environmental quality associated to sewage.


Assuntos
Ecossistema , Monitoramento Ambiental/métodos , Estuários , Invertebrados/fisiologia , Esgotos , Poluição da Água/análise , Animais , Brasil , Monitoramento Ambiental/normas , Análise Espacial
16.
Mar Pollut Bull ; 73(1): 102-14, 2013 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-23790447

RESUMO

We evaluated benthic habitat quality along a presumed contamination gradient in the Mar del Plata port (Southwestern Atlantic) by coupling biological and chemical proxies in a multidisciplinary approach. Organic matter and photosynthetic pigment contents were higher in silty-clay bottoms of the inner port sites. Levels of all fecal steroids decreased from the inner sites to the port inlet. High concentrations of coprostanol in the inner sites seemed to derive from a permanent population of sea lions rather than from sewage outfalls due to coprostanol/epicoprostanol ratio (IV) values <2.5. PAHs levels were also higher in the inner sector, related to both biomass combustion and petroleum combustion associated to local marine traffic. High disturbance and low ecological status were reflected in low benthic diversity and high AMBI values in the inner sites.


Assuntos
Ecossistema , Monitoramento Ambiental/métodos , Água do Mar/química , Poluentes Químicos da Água/análise , Animais , Biodiversidade , Invertebrados/classificação , Invertebrados/crescimento & desenvolvimento , Hidrocarbonetos Policíclicos Aromáticos/análise , Esgotos/análise , Esgotos/estatística & dados numéricos
17.
Biota neotrop. (Online, Ed. port.) ; 10(4): 205-213, Oct.-Dec. 2010. graf, mapas, tab
Artigo em Inglês | LILACS | ID: lil-578500

RESUMO

In Uruguay, as well as in other regions of the world, IAS cause negative impacts on natural and managed ecosystems. The use of databases is a helpful tool to elaborate different strategies for prevention and control, and to develop policies and scientific analyses related to IAS. The database of IAS in Uruguay (InBUy) was developed during two time periods (2006-2007 and 2009-2010). It currently contains information on 33 specialists of different taxonomic groups, 14 research projects, 185 references, 351 species and 4,715 records, with vascular plants having both the highest number of species and records. Among vascular plants, herbaceous life forms are the most strongly represented, followed by trees and shrubs. Within animals, the fishes and mollusks are the most important groups. Analysis of the native distribution areas of IAS showed that most are indigenous from Europe, followed by Asia and Oceania. Data showed that introductions of IAS into Uruguay are mainly intentional (67 percent), so efforts should be focused on policies and rules in order to control the entrance of exotic organisms and prevent new invasions. The geography of the compiled dataset shows the main impact is along the coastline, where the highest exotic species richness and records occurs, and also the most biological invasions. The InBUy database is up-to-date and has successfully contributed to the creation of an official IAS list for Uruguay and both a National and a Coastal Geographic Information System. It has also been used for developing consciousness about this important threat to biodiversity, at both national and regional scales.


En Uruguay, al igual que en otras partes del mundo, las EEI han causado impactos negativos sobre los sistemas naturales y productivos. El uso de bases de datos a nivel mundial es una herramienta útil para elaborar estrategias de prevención y control, y para desarrollar políticas y análisis científicos en relación a las EEI. La base de datos de EEI en Uruguay (InBUy) fue desarrollada durante dos períodos (2006-2007 y 2009-2010). Actualmente contiene información de 33 especialistas de diferentes grupos taxonómicos, 14 proyectos de investigación, 185 referencias bibliográficas, 351 especies y 4715 registros, donde las plantas vasculares presentan el mayor número de especies y registros. Entre las plantas vasculares, las herbáceas son la forma de vida más representada, seguida por árboles y arbustos. Dentro de los animales, los peces y moluscos son los grupos más importantes. El origen geográfico de las EEI muestra que la mayoría son nativas de Europa, seguido por Asia y Oceanía. Los datos recabados muestran que la introducción de EEI a Uruguay es mayormente intencional (67 por ciento), por tanto los esfuerzos deberían ser focalizados en políticas y reglamentaciones para controlar el ingreso de organismos exóticos y prevenir nuevas invasiones biológicas. Por otra parte, los datos muestran un impacto mayor sobre los ambientes costeros, donde fue registrado el mayor número de especies y registros, así como el mayor número de invasiones biológicas. Hasta la fecha, la base de datos InBUy ha contribuido exitosamente en la conformación de una lista oficial de EEI para Uruguay, y en la construcción de un Sistema Geográfico de Información Nacional y Costero. Asimismo, ha contribuido a la concientización a través de políticas de divulgación acerca de esta importante amenaza sobre la conservación de la biodiversidad, tanto a escala nacional como regional.

19.
Mar Pollut Bull ; 52(1): 61-73, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16194551

RESUMO

A study of foraminiferal assemblages was carried out in 24 sediment samples collected from the Montevideo coastal zone (south-eastern coastal region of South America) to assess the response of the benthic foraminifera to the polluted sediments. The area is affected by different pollutants such as sewage, hydrocarbons and heavy metals derived from different sources. Biological data were analyzed with multivariate techniques of cluster analysis and a principal component analysis (PCA) was performed for abiotic factors. The results allowed the recognition of different species assemblages corresponding to different sub-environments, which reflected the prevalent ecological conditions. The Montevideo Bay, particularly, its inner part showed an extremely poor foraminiferal fauna-including a totally azoic station-and high percentages of abnormal tests, when compared with the adjacent Punta Carretas and Punta Yeguas zones. Mean faunal density showed a strong relationship with organic matter, oxygen and heavy metal concentrations, as well as redox potential and pH values of each sub-environment. Although the adjacent zones presented a moderate pollution degree, it was noticed that a positive effect on the foraminiferal density specially on Ammonia tepida, caused by the sewage pipe located in Punta Carretas, a pure organic contamination. Differences among foraminiferal assemblages seemed to be related to the combined action of the several kinds of pollutants and the natural abiotic variables, like the rapid salinity changes that occurred in this area.


Assuntos
Meio Ambiente , Eucariotos/fisiologia , Sedimentos Geológicos/química , Poluição da Água , Animais , Biodiversidade , Cromo/análise , Análise por Conglomerados , Eucariotos/classificação , Eucariotos/efeitos dos fármacos , Eucariotos/ultraestrutura , Chumbo/análise , Filogenia , Densidade Demográfica , Análise de Componente Principal , Esgotos , Uruguai , Poluição Química da Água
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