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1.
An Acad Bras Cienc ; 95(suppl 2): e20201533, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38126516

RESUMO

Mangroves occur in the tropics and subtropics. This region is constantly covered by clouds and therefore highly challenging to map and monitor. Technological advances in remote sensing have increased the flexibility of performing such analyses. In this study, mapping and change detection were carried out for mangrove areas of the South and Southeast regions of Brazil between 2008 and 2016 using multisensor data and geographical object-based image analysis (GEOBIA). The 823.03 km² mangrove areas in study site in 2008 were reduced to 789.00 km² in 2016, representing a net loss of ~34 km². A change detection analysis of the mangrove areas showed a total gain of 138.21 km², a total loss of 172.24 km² and no change for 650.79 km². The GEOBIA classification accuracy was assessed by performing a statistical analysis of confusion matrix: (2008): global accuracy = 0.92, Kappa index = 0.84 and Tau index = 0.84; and (2016): global accuracy = 0.93, Kappa index = 0.86 and Tau index = 0.86. These results demonstrate the effectiveness of the GEOBIA to map and analyze mangrove dynamics. The results exhibit an excellent accuracy. Furthermore, mangrove areas in the south and southeast Brazil were mapped from the same methodological approach.


Assuntos
Processamento de Imagem Assistida por Computador , Áreas Alagadas , Brasil , Geografia , Ecossistema
2.
An Acad Bras Cienc ; 95(2): e20210468, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37493710

RESUMO

Given the ecological and socioeconomic importance of the mangroves of the Brazilian Amazon coast, RapidEye satellite images were analyzed to recognize mangrove forest and salt flat changes to different land use through human activities. Results show that mangroves are still very well preserved, with less than 1% of the total converted to other uses, primarily urban areas and roads. These human activities have been the principal causes of use in the mangrove forest, driven by local anthropogenic pressures resulting from human settlements in the transition zone between the mainland and tidal flats. In contrast, aquaculture, the principal driver of the loss of mangroves in other regions of South America and in Asian countries, plays only a secondary role in habitat conversion on the Amazon coast. However, these human activities demand more attention and policies need to be supported by Brazilian legislation.


Assuntos
Ecossistema , Áreas Alagadas , Humanos , Brasil , Aquicultura , Atividades Humanas
3.
J Environ Manage ; 318: 115590, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-35949080

RESUMO

Due to the global magnitude of forest degradation and deforestation and the high cost of ecological restoration, several approaches have been used to prioritize conservation or restoration areas based on different objectives and criteria. The present work aims to develop a multicriteria approach to defining forest restoration priority areas in the Itacaiúnas River basin, eastern Amazon, that maximizes the criteria equitably. The selected criteria were: improve forest connectivity, provide climatic refuges for biodiversity, mitigate the impacts of deforestation on streamflow, and improve the probability of natural regeneration. A strong difference between selected areas was observed when the criteria of forest connectivity and mitigate the impact on streamflow were considered separately, but greater equity among the criteria was achieved using the multicriteria approach. The most priority areas were concentrated near protected areas. The method used provides a flexible framework, and different criteria or subarea selections can be applied for different purposes to facilitate adaptive management. Analyzing forest restoration prioritization on rural properties can provide guidance for conserving and restoring biodiversity at the landscape scale while complying with legal requirements.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Biodiversidade , Conservação dos Recursos Naturais/métodos , Florestas , Rios
4.
Environ Manage ; 69(2): 438-448, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35013793

RESUMO

Developing conservation strategies to mitigate cumulative impacts requires the understanding of historic land use and land cover changes at the regional scale. By using a multisensory and multitemporal approach, we identified the major changes driving cumulative impacts on native vegetation in northeastern Amazon. Comparing two regions, one with mining as the key driver and another where mining is associated with other industrial activities (cellulose), we explore the land use and land cover historic dynamics and derive implications for the assessment of cumulative impacts. Transitions of forest cover to pastureland, silviculture, and urban expansion were mapped in detail over a 20-year period, revealing that silviculture growth cleared more forests than pastureland expansion when associated with pulp mill activities and kaolin mining. In contrast, in a region with gold and iron mining, pastureland expansion was more relevant, clearing mainly areas surrounding new roads. This research shows that the interplay of major mining and industrial investments can produce cumulative losses of native vegetation, depending on the associated industries and infrastructure required for the project development. Our findings emphasize that the definition of spatial and temporal boundaries for the assessment of cumulative impacts must consider different trends in impact accumulation and changes in their spatial distribution over time.


Assuntos
Conservação dos Recursos Naturais , Florestas , Brasil , Mineração
5.
Int J Behav Nutr Phys Act ; 18(1): 69, 2021 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-34051796

RESUMO

BACKGROUND: Physical activity has been associated with reduced risk of seven types of cancer. It remains unclear, however, whether muscle-strengthening activities also reduce cancer incidence and mortality. METHODS: PubMed, Embase, Web of Science and Scopus were searched from inception to March 2020. Summary hazard ratio (HR) and 95% confidence intervals (CI) were estimated using random-effects models. RESULTS: Twelve studies (11 cohorts; 1 case-control), 6 to 25 years of follow-up, including 1,297,620 participants, 32,196 cases and 31,939 deaths, met inclusion criteria. Muscle-strengthening activities were associated with a 26% lower incidence of kidney cancer (HR for high vs low levels of muscle-strengthening activities: 0.74; 95% CI 0.56 to 0.98; I2 0%; 2 studies), but not with incidence of other 12 types of cancer. Muscle-strengthening activities were associated with lower total cancer mortality: HRs for high vs low levels of muscle-strengthening activities was 0.87 (95% CI 0.73 to 1.02; I2 58%; 6 studies); and HR for ≥2 times/week vs < 2 times/week of muscle-strengthening activities was 0.81 (95% CI 0.74 to 0.87; I2 0%; 4 studies). Regarding the weekly duration of muscle-strengthening activities, HR for total cancer mortality were 0.91 (95% CI 0.82 to 1.01; I2 0%; 2 studies) for 1-59 min/week and 0.98 (95% CI 0.89 to 1.07; I2 0%) for ≥60 min/week vs none. Combined muscle-strengthening and aerobic activities (vs none) were associated with a 28% lower total cancer mortality (HR 0.72; 95% CI 0.53 to 0.98; I2 85%; 3 studies). CONCLUSIONS: Muscle-strengthening activities were associated with reduced incidence of kidney cancer and total cancer mortality. Combined muscle-strengthening and aerobic activities may provide a greater reduction in total cancer mortality.


Assuntos
Neoplasias , Treinamento Resistido/estatística & dados numéricos , Humanos , Incidência , Neoplasias/epidemiologia , Neoplasias/mortalidade , Estudos Observacionais como Assunto
6.
PLoS One ; 15(3): e0230008, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32155195

RESUMO

Reliable estimates of biomass and carbon storage are essential for the understanding of the environmental drivers and processes that regulate the productivity of scrub forests. The present study estimated total (above-ground, AGB + below-ground, BGB) biomass and carbon storage of a scrub forest dominated by Avicennia germinans (L.) L. based on the existing allometric models for the AGB, while novel models were developed to estimate the BGB. Data collection followed a destructive approach by using the "sampling method", from 45 trees divided into three height classes. Tree height and diameter were used to estimate the BGB of these forests, providing more accurate estimates of their biomass. Our findings indicate the existence of a direct relationship with increasing topography and interstitial salinity, which result in an increase in the percentage contribution of the AGB. By contrast, increasing topography also led to reduction in tree height and contribution of the BGB, although this compartment represents approximately half of the total biomass of these forests. The contribution of BGB estimates increased from 43 to 49.5% from the lowest to the highest height class and the BGB and AGB values reached approximately 87 Mg ha-1 (48.6%) and 91.7 Mg ha-1 (51.4%), respectively. The estimates of the biomass and carbon stocks of scrub mangroves vary considerably worldwide, which reflects the uncertainties derived from the application of distinct sampling methods. Specific models developed for each height class should be considered instead generalist models to reduce the general uncertainties on the production and distribution of biomass and the storage of carbon. Overall, our results overcome a major lacuna in the development of allometric equations to estimate the production of BGB and the storage of carbon by scrub mangrove forests, contributing to the refinement of the total biomass estimates for this type of mangrove forest.


Assuntos
Biomassa , Carbono/análise , Florestas , Modelos Estatísticos , Salinidade , Incerteza
7.
PLoS One ; 14(6): e0217754, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31242200

RESUMO

Mangroves play an essential ecological role in the maintenance of the coastal zone and are extremely important for the socioeconomics of coastal communities. However, mangrove ecosystems are impacted by a range of anthropogenic pressures, and the loss of this habitat can be attributed primarily to the human occupation of the coastal zone. In the present study, we analyzed the spatial patterns of land use in the mangrove of the Brazilian Amazon coast, and evaluated the anthropogenic drivers of this impact, using a remote sensing approach. We mapped the road network using RapidEye images, and human settlements using global data. The results of these analyses indicate that the Brazilian Amazon coast has a low population density and low rates of anthropogenic impact in most of the coastal microregions investigated, factors that contribute to the maintenance and conservation of the region's mangrove. The study also revealed that the paved road network is one of the principal drivers of land use in the mangrove, whereas other factors, such as population density, urban centers, and the number of settlements are much less important. While the region has 2024 km of paved highways, unpaved roads (17,496 km) facilitate access to the mangrove, with approximately 90% of anthropogenic impact being recorded within a 3 km radius of these roads. While the network of paved highways is relatively reduced in extension, preventive measures are urgently required to impede any major shift in the current scenario, caused by the expansion of major development programs. The results of the study indicate that biophysical, economic, and political factors may also contribute to the reduction, stability, and development of one of the world's largest areas of mangrove forest.


Assuntos
Conservação dos Recursos Naturais/métodos , Atividades Humanas , Áreas Alagadas , Brasil , Humanos
8.
PLoS One ; 14(1): e0211095, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30653607

RESUMO

The eastern Brazilian Amazon contains many isolated ferruginous savanna ecosystem patches (locally known as 'canga vegetation') located on ironstone rocky outcrops on the top of plateaus and ridges, surrounded by tropical rainforests. In the Carajás Mineral Province (CMP), these outcrops contain large iron ore reserves that have been exploited by opencast mining since the 1980s. The canga vegetation is particularly impacted by mining, since the iron ores that occur are associated with this type of vegetation and currently, little is known regarding the extent of canga vegetation patches before mining activities began. This information is important for quantifying the impact of mining, in addition to helping plan conservation programmes. Here, land cover changes of the Canga area in the CMP are evaluated by estimating the pre-mining area of canga patches and comparing it to the actual extent of canga patches. We mapped canga vegetation using geographic object-based image analysis (GEOBIA) from 1973 Landsat-1 MSS, 1984 and 2001 Landsat-5 TM, and 2016 Landsat-8 OLI images, and found that canga vegetation originally occupied an area of 144.2 km2 before mining exploitation. By 2016, 19.6% of the canga area was lost in the CMP due to conversion to other land-use types (mining areas, pasturelands). In the Carajás National Forest (CNF), located within the CMP, the original canga vegetation covered 105.2 km2 (2.55% of the CNF total area), and in 2016, canga vegetation occupied an area of 77.2 km2 (1.87%). Therefore, after more than three decades of mineral exploitation, less than 20% of the total canga area was lost. Currently, 21% of the canga area in the CMP is protected by the Campos Ferruginosos National Park. By documenting the initial extent of canga vegetation in the eastern Amazon and the extent to which it has been lost due to mining operations, the results of this work are the first step towards conserving this ecosystem.


Assuntos
Biodiversidade , Florestas , Pradaria , Ferro , Brasil , Conservação dos Recursos Naturais , Ferro/química , Ferro/metabolismo , Mineração
9.
Educ. revEduc. rev ; 34: e169378, 2018.
Artigo em Português | LILACS | ID: biblio-891262

RESUMO

RESUMO: Neste trabalho apresentamos a análise da trajetória de uma professora enquanto supervisora do Programa Institucional de Bolsas de Iniciação à Docência (PIBID). Por meio de uma análise narrativa, reconstruímos a história da professora no projeto, explicitando os principais aspectos de desenvolvimento profissional. Para tanto, nos apoiamos nas teorizações de Bernard Lahire sobre o conceito de disposições e sua articulação com as condições contextuais. Na análise da trajetória da professora inferimos disposições (participativa, reflexiva e à atualização) que foram mobilizadas ou atualizadas em determinadas características contextuais proporcionadas pelo PIBID. A mobilização dessas disposições, atravessadas por um contexto favorável, nos indicou aspectos de desenvolvimento profissional, como satisfação pessoal, reflexão sobre a própria prática, atualização teórica, entre outros. Os resultados evidenciam que é na confluência das condições contextuais com as maneiras pelas quais os sujeitos vivenciam essas condições, por meio de suas disposições, que o desenvolvimento profissional pode se dar de maneira efetiva.


ABSTRACT: In this work we present the analysis of the trajectory of a teacher as supervisor of the "Programa Institucional de Bolsas de Iniciação à Docência" (PIBID). Through a narrative analysis, we reconstructed the teacher story in the project, highlighting the main aspects of professional development. To this end, we rely on the theories of Bernard Lahire on the concept of dispositions and its articulation with the contextual conditions. In the analysis of the trajectory of the teacher we infer dispositions (participatory, reflective and to training) that were deployed or updated in certain contextual characteristics provided by PIBID. The mobilization of these dispositions, crossed by a favorable context, indicated aspects of professional development, such as personal satisfaction, reflect on their own practice, theoretical updates, among others. The results show that it is at the confluence of the contextual conditions with the ways in which individuals experience these conditions through its dispositions, that professional development can take place effectively.

10.
J Environ Manage ; 167: 175-84, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26686070

RESUMO

Long-term human-induced impacts have significantly changed the Amazonian landscape. The most dramatic land cover and land use (LCLU) changes began in the early 1970s with the establishment of the Trans-Amazon Highway and large government projects associated with the expansion of agricultural settlement and cattle ranching, which cleared significant tropical forest cover in the areas of new and accelerated human development. Taking the changes in the LCLU over the past four decades as a basis, this study aims to determine the consequences of land cover (forest and savanna) and land use (pasturelands, mining and urban) changes on the hydroclimatology of the Itacaiúnas River watershed area of the located in the southeastern Amazon region. We analyzed a multi-decadal Landsat dataset from 1973, 1984, 1994, 2004 and 2013 and a 40-yr time series of water discharge from the Itacaiúnas River, as well as air temperature and relative humidity data over this drainage area for the same period. We employed standard Landsat image processing techniques in conjunction with a geographic object-based image analysis and multi-resolution classification approach. With the goal of detecting possible long-term trends, non-parametric Mann-Kendall test was applied, based on a Sen slope estimator on a 40-yr annual PREC, TMED and RH time series, considering the spatial average of the entire watershed. In the 1970s, the region was entirely covered by forest (99%) and savanna (∼0.3%). Four decades later, only ∼48% of the tropical forest remains, while pasturelands occupy approximately 50% of the watershed area. Moreover, in protected areas, nearly 97% of the tropical forest remains conserved, while the forest cover of non-protected areas is quite fragmented and, consequently, unevenly distributed, covering an area of only 30%. Based on observational data analysis, there is evidence that the conversion of forest cover to extensive and homogeneous pasturelands was accompanied by systematic modifications to the hydroclimatology cycle of the Itacaiúnas watershed, thus highlighting drier environmental conditions due to a rise in the region's air temperature, a decrease in the relative humidity, and an increase in river discharge.


Assuntos
Conservação dos Recursos Naturais , Monitoramento Ambiental/métodos , Agricultura , Animais , Brasil , Bovinos , Meio Ambiente , Florestas , Humanos , Processamento de Imagem Assistida por Computador , Tecnologia de Sensoriamento Remoto , Rios , Clima Tropical
11.
J Pharm Pharmacol ; 67(12): 1682-95, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26256440

RESUMO

OBJECTIVES: The aim of this study was to investigate the cytotoxic effect of new 1,4-naphthoquinone- 1,2,3-triazoles, named C2 to C8 triazole derivatives, towards human cancer cell lines. METHODS: The effect on cell viability was assessed by MTT and propidium iodide assays. The cytotoxic effect of C2 and C3 in K562 and HL-60 cells were analyzed by flow cytometry, DNA fragmentation and reactive oxygen species (ROS) production. Western blot and q-PCR procedures were also performed. KEY FINDINGS: C2 and C3 inhibited both K562 and HL-60 cells growth in a concentration-dependent manner. C2 presented the highest cytotoxic activity with an IC50 of approximately 14 µm and 41 µm for HL-60 and K562 cells, respectively, while being less toxic to normal peripheral blood monocyte cells. Both derivatives induced cellular changes in HL-60 cells, characteristic of apoptosis, such as mitochondrial membrane depolarization, phosphatidylserine externalization, increasing sub-G1 phase, DNA fragmentation, downregulating Bcl-2 protein and upregulating Bax protein. In K562 cells, C2 and C3 induced S-phase arrest of cell cycle, which was associated with upregulation of p21. The effect of these derivatives in HL-60 cells can be related to the ROS intracellular level. CONCLUSION: Taken together our results showed that C2 and C3 triazole derivatives presented the best potential for drug design.


Assuntos
Antineoplásicos/farmacologia , Leucemia/tratamento farmacológico , Naftoquinonas/farmacologia , Triazóis/farmacologia , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Fragmentação do DNA , Relação Dose-Resposta a Droga , Células HL-60 , Humanos , Concentração Inibidora 50 , Células K562 , Leucemia/metabolismo , Leucemia/patologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Estrutura Molecular , Naftoquinonas/química , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Pontos de Checagem da Fase S do Ciclo Celular/efeitos dos fármacos , Relação Estrutura-Atividade , Triazóis/química
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