82 research outputs found
Poor glycaemic control in Brazilian patients with type 2 diabetes attending the public healthcare system a cross-sectional study
Objectives: To describe the clinical profile of Brazilian patients with type 2 diabetes attending the public healthcare system and identify factors associated with poor glycaemic control.Design: Cross-sectional study.Setting: 14 centres in five regions of Brazil, including primary care units and outpatient clinics of University Hospitals.Participants: Patients with type 2 diabetes attending outpatient clinics of public healthcare system.Main outcome measured: Glycated haemoglobin (HbA1c), centrally measured by high-performance liquid chromatography (National Glycohemoglobin Standardization Program certified).Results: A total of 5750 patients aged 61 10 years, with 11 8 years of diabetes duration (66% women, 56% nonwhite, body mass index: 28.0 5.3 kg/m(2)) were analysed. Mean HbA1c was 8.6 +/- 2.2%, and median HbA1c was 8.1% (6.9% to 9.9%). HbA1c 8%.Conclusions: the majority of Brazilian patients with type 2 diabetes attending the public healthcare system had HbA1c levels above recommended targets. the recognition of Northeast residents and non-white patients as vulnerable populations should guide future policies and actions to prevent and control diabetes.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundo de Incentivo a Pesquisa (FIPE) of Hospital de Clinicas de Porto Alegre (HCPA)Pfizer PharmaceuticalHosp Clin Porto Alegre, Endocrine Div, Porto Alegre, RS, BrazilUniv Fed Rio Grande do Sul, Porto Alegre, RS, BrazilHosp Getulio Vargas, Endocrine Div, Manaus, Amazonas, BrazilUniv Fed Amazonas, Manaus, Amazonas, BrazilFed Univ Para, BR-66059 Belem, Para, BrazilUniversidade Federal de São Paulo, Endocrine Div, São Paulo, BrazilUniversidade Federal de São Paulo, Endocrine Div, São Paulo, BrazilWeb of Scienc
Modelling the Radiative Effects of Biomass Burning Aerosols on Carbon Fluxes in the Amazon Region
Every year, a dense smoke haze covers a large portion of South America originating from fires in the Amazon Basin and central parts of Brazil during the dry/biomass-burning season between August and October. Over a large portion of South America, the average aerosol optical depth at 550 nm exceeds 1.0 during the fire season while the background value during the rainy season is below 0.2. Biomass burning aerosol particles increase scattering and absorption of the incident solar radiation. The regional-scale aerosol layer reduces the amount of solar energy reaching the surface, cools the near surface air, and increases the diffuse radiation fraction over a large disturbed area of the Amazon rainforest. These factors affect the energy and CO2 fluxes at the surface. In this work, we applied a fully integrated atmospheric model to assess the impact of biomass burning aerosols in CO2 fluxes in the Amazon region during 2010. We address the effects of the attenuation of the global solar radiation and the enhancement of the diffuse solar radiation flux inside the vegetation canopy. Our results indicate that the biomass burning aerosols led to increases of about 27% of gross primary productivity of Amazonia, 10% of plant respiration and a decline in soil respiration of 3%. Consequently, in our model Amazonia, became a net carbon sink; net ecosystem exchange during September 2010 dropped from +101 to -104 TgC when the aerosol effects are considered, mainly due to the aerosol diffuse radiation effect. For the forest biome, our results point to a dominance of the diffuse radiation effect on CO2 fluxes, reaching a balance of 50% - 50% between the diffuse and direct aerosol effects for high aerosol loads. For C3 grasses and Savanna (cerrado), as expected, the contribution of the diffuse radiation effect is much lower, tending to zero with the increase of aerosol load. Taking all biomes together, our model shows the Amazon during the dry season, in the presence of high biomass burning aerosol loads, changing from being a source to being a sink of CO2 to the atmosphere
Levantamento fitossociológico em um fragmento de floresta estacional semidecídua, no município de São Carlos, SP
Oncocalyxone A: electrochemical, spectroscopic investigation and studies of its interaction with DNA, nucleobases and N-acetylcysteine
Infinitesimal Lyapunov functions for singular flows
We present an extension of the notion of infinitesimal Lyapunov function to
singular flows, and from this technique we deduce a characterization of
partial/sectional hyperbolic sets. In absence of singularities, we can also
characterize uniform hyperbolicity.
These conditions can be expressed using the space derivative DX of the vector
field X together with a field of infinitesimal Lyapunov functions only, and are
reduced to checking that a certain symmetric operator is positive definite at
the tangent space of every point of the trapping region.Comment: 37 pages, 1 figure; corrected the statement of Lemma 2.2 and item (2)
of Theorem 2.7; removed item (5) of Theorem 2.7 and its wrong proof since the
statement of this item was false; corrected items (1) and (2) of Theorem 2.23
and their proofs. Included Example 6 on smooth reduction of families of
quadratic forms. The published version in Math Z journal needs an errat
Native diversity buffers against severity of non-native tree invasions
Determining the drivers of non-native plant invasions is critical for managing native ecosystems and limiting the spread of invasive species. Tree invasions in particular have been relatively overlooked, even though they have the potential to transform ecosystems and economies. Here, leveraging global tree databases, we explore how the phylogenetic and functional diversity of native tree communities, human pressure and the environment influence the establishment of non-native tree species and the subsequent invasion severity. We find that anthropogenic factors are key to predicting whether a location is invaded, but that invasion severity is underpinned by native diversity, with higher diversity predicting lower invasion severity. Temperature and precipitation emerge as strong predictors of invasion strategy, with non-native species invading successfully when they are similar to the native community in cold or dry extremes. Yet, despite the influence of these ecological forces in determining invasion strategy, we find evidence that these patterns can be obscured by human activity, with lower ecological signal in areas with higher proximity to shipping ports. Our global perspective of non-native tree invasion highlights that human drivers influence non-native tree presence, and that native phylogenetic and functional diversity have a critical role in the establishment and spread of subsequent invasions
The global biogeography of tree leaf form and habit
Understanding what controls global leaf type variation in trees is crucial for comprehending their role in terrestrial ecosystems, including carbon, water and nutrient dynamics. Yet our understanding of the factors influencing forest leaf types remains incomplete, leaving us uncertain about the global proportions of needle-leaved, broadleaved, evergreen and deciduous trees. To address these gaps, we conducted a global, ground-sourced assessment of forest leaf-type variation by integrating forest inventory data with comprehensive leaf form (broadleaf vs needle-leaf) and habit (evergreen vs deciduous) records. We found that global variation in leaf habit is primarily driven by isothermality and soil characteristics, while leaf form is predominantly driven by temperature. Given these relationships, we estimate that 38% of global tree individuals are needle-leaved evergreen, 29% are broadleaved evergreen, 27% are broadleaved deciduous and 5% are needle-leaved deciduous. The aboveground biomass distribution among these tree types is approximately 21% (126.4 Gt), 54% (335.7 Gt), 22% (136.2 Gt) and 3% (18.7 Gt), respectively. We further project that, depending on future emissions pathways, 17-34% of forested areas will experience climate conditions by the end of the century that currently support a different forest type, highlighting the intensification of climatic stress on existing forests. By quantifying the distribution of tree leaf types and their corresponding biomass, and identifying regions where climate change will exert greatest pressure on current leaf types, our results can help improve predictions of future terrestrial ecosystem functioning and carbon cycling
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