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•Nine fruits commonly consumed in Manaus (Brazil) were comparatively studied.•Murici and cubiu displayed high reducing and antioxidant capacities.•Murici and cubiu also displayed the ...highest α-glucosidase inhibitions.•Breadfruit and soursop presented the lowest anti-glycation IC50 values.•Murici and cubiu showed the highest concentrations of antioxidant compounds.•139 VOCs were identified with a unique profile for each fruit.
Fruits are widely recognized as sources of biologically active metabolites, such as antioxidant compounds. In this context, fruits commonly consumed in the central Amazonia, especially in its biggest metropolis (Manaus – AM/Brazil), are attractive as potential sources of antioxidant compounds related to biological activities. Most of such fruits are still poorly studied and/or remain unknown outside the Amazon region. Therefore, this study aims to investigate nine fruits (abiu, cubiu, biribá, breadfruit, genipap, peach palm, murici, soursop, and umari) regarding their chemical composition (fixed and volatile), reducing capacity, antioxidant activity, enzyme inhibition, and cytotoxicity. Determination of small organic acids, hydroxycinnamic acids, flavan-3-ols and flavonoid aglycones was done by HPLC-MS/MS, whereas determination of volatile organic compounds (VOCs) was done by HS-SPME/GC–MS. Reducing capacity was determined by the Folin–Ciocalteu method, and antioxidant activities were evaluated by DPPH, ABTS, and H-ORACFL assays. In vitro activities regarding inhibition of enzymes were tested for α-glucosidase, lipase, and α-amylase, and anti-glycation activities were evaluated for methylglyoxal and fructose. Cytotoxicity of fruit extracts was evaluated by cell viability of human fibroblast cell line (MRC-5). A total of 16 antioxidant compounds and 139 VOCs were determined, whose profiles were unique for each studied fruit. Total phenolic contents as well as antioxidant activities found herein were similar or even higher than those reported for several traditional fruits. Some of fruit extracts were able to inhibit α-glucosidase and glycation in methylglyoxal and fructose models, whereas none of them was active for lipase and α-amylase. All of the fruit extracts showed to be non-cytotoxic to MRC-5 cell line.
•Differences in forest seasonal productivity cannot be explained by access to water or sunlight.•Equatorial climates benefit species that support high levels of dry-season photosynthesis.•PAR levels ...predicted the degree to which canopy photosynthetic capacity drives GEP.•Converted sites at Central Amazon show the disruption of the productivity cycle.
We investigated the seasonal patterns of Amazonian forest photosynthetic activity, and the effects thereon of variations in climate and land-use, by integrating data from a network of ground-based eddy flux towers in Brazil established as part of the ‘Large-Scale Biosphere Atmosphere Experiment in Amazonia’ project. We found that degree of water limitation, as indicated by the seasonality of the ratio of sensible to latent heat flux (Bowen ratio) predicts seasonal patterns of photosynthesis. In equatorial Amazonian forests (5° N–5° S), water limitation is absent, and photosynthetic fluxes (or gross ecosystem productivity, GEP) exhibit high or increasing levels of photosynthetic activity as the dry season progresses, likely a consequence of allocation to growth of new leaves. In contrast, forests along the southern flank of the Amazon, pastures converted from forest, and mixed forest-grass savanna, exhibit dry-season declines in GEP, consistent with increasing degrees of water limitation. Although previous work showed tropical ecosystem evapotranspiration (ET) is driven by incoming radiation, GEP observations reported here surprisingly show no or negative relationships with photosynthetically active radiation (PAR). Instead, GEP fluxes largely followed the phenology of canopy photosynthetic capacity (Pc), with only deviations from this primary pattern driven by variations in PAR. Estimates of leaf flush at three non-water limited equatorial forest sites peak in the dry season, in correlation with high dry season light levels. The higher photosynthetic capacity that follows persists into the wet season, driving high GEP that is out of phase with sunlight, explaining the negative observed relationship with sunlight. Overall, these patterns suggest that at sites where water is not limiting, light interacts with adaptive mechanisms to determine photosynthetic capacity indirectly through leaf flush and litterfall seasonality. These mechanisms are poorly represented in ecosystem models, and represent an important challenge to efforts to predict tropical forest responses to climatic variations.
Abstract
Understanding the complex interactions between water vapor fields and deep convection on the mesoscale requires observational networks with high spatial (kilometers) and temporal (minutes) ...resolution. In the equatorial tropics, where deep convection dominates the vertical distribution of the most important greenhouse substance—water—these mesoscale networks are nonexistent. Global Navigational Satellite System (GNSS) meteorological networks offer high temporal/spatial resolution precipitable water vapor, but infrastructure exigencies are great. The authors report here on very accurate precipitable water vapor (PWV) values calculated from a GNSS receiver installed on a highly nonideal Amazon rain forest flux tower. Further experiments with a mechanically oscillating platform demonstrate that errors and biases of approximately 1 mm (2%–3% of PWV) can be expected when compared with a stable reference GNSS receiver for two different geodetic grade receivers/antennas and processing methods GPS-Inferred Positioning System (GIPSY) and GAMIT. The implication is that stable fixed antennas are unnecessary for accurate calculation of precipitable water vapor regardless of processing techniques or geodetic grade receiver.
We investigated the seasonal patterns of water vapor and sensible heat flux along a tropical biome gradient from forest to savanna. We analyzed data from a network of flux towers in Brazil that were ...operated within the Large‐Scale Biosphere‐Atmosphere Experiment in Amazonia (LBA). These tower sites included tropical humid and semideciduous forest, transitional forest, floodplain (with physiognomies of cerrado), and cerrado sensu stricto. The mean annual sensible heat flux at all sites ranged from 20 to 38 Wm−2, and was generally reduced in the wet season and increased in the late dry season, coincident with seasonal variations of net radiation and soil moisture. The sites were easily divisible into two functional groups based on the seasonality of evaporation: tropical forest and savanna. At sites with an annual precipitation above 1900 mm and a dry season length less than 4 months (Manaus, Santarem and Rondonia), evaporation rates increased in the dry season, coincident with increased radiation. Evaporation rates were as high as 4.0 mm d−1 in these evergreen or semidecidous forests. In contrast, ecosystems with precipitation less than 1700 mm and a longer dry season (Mato Grosso, Tocantins and São Paulo) showed clear evidence of reduced evaporation in the dry season. Evaporation rates were as low as 2.5 mm d−1 in the transitional forests and 1 mm d−1 in the cerrado. The controls on evapotranspiration seasonality changed along the biome gradient, with evaporative demand (especially net radiation) playing a more important role in the wetter forests, and soil moisture playing a more important role in the drier savannah sites.
The interest in bioactive compounds from natural sources, such as marine organisms, has increased considerably in recent years. Among these compounds, sulfated polysaccharides from seaweed exhibit a ...broad spectrum of biological activities. Sulfated polysaccharides from green algae are still poorly investigated. For this reason, in this study, using unusual methodologies, such as extraction conditions, FACE, and RAMAN, we investigated the structural features of F50UL and F70UL sulfated polysaccharides from Ulva lactuca L. and their distinct in vitro anticoagulant and in vivo antithrombotic activities. Sulfated polysaccharides of U. lactuca were obtained by enzymatic proteolysis with ALCALASE® and fractionated by acetone precipitation. F50Ul and F70Ul sulfated polysaccharides with higher yield were partially chemically characterized by Fluorophore-assisted carbohydrate electrophoresis (FACE) and RAMAN spectroscopy analysis and submitted to an in vitro screening by APTT, PT, TT, and anti-factor Xa and IIa tests. The venae cavae ligature experimental model for the analysis of in vivo antithrombotic activity of F50Ul and F70Ul sulfated polysaccharides were also performed. The U. lactuca L. sulfated polysaccharides characterization by FACE and RAMAN showed a typical ulvans structure that contains as principal component rhamnose, but other monosaccharides (uronic acid, glucose, and galactose) are present. F50Ul (0.1–1.0 μg/μl) showed anticoagulant activity in vitro. However, F70Ul that has a similar composition did not present these effects. Also, only F50Ul sulfated polysaccharides (≥5 μg/g) showed a great in vivo antithrombotic concentration-dependent and time-dependent activity. In summary, we demonstrate the use of unusual extraction and characterization analysis procedures for U. lactuca L. sulfated polysaccharides and the ability of F50Ul to reduce the weight of thrombus in rats probably by the association with factors Xa and IIa inhibition. These results provide strong evidence of the anticoagulant potential of these sulfated polysaccharides isolated from Ulva lactuca L.
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•Sulfated polysaccharides from Ulvalactuca L. obtained by proteolytic procedures•Raman structural analysis of seaweed sulfated polysaccharides•U. lactuca sulfated polysaccharides were able to inhibit the coagulation Factor Xa.•In vivo inhibition of clot formation by sulfated polysaccharides from U.lactuca L.
Objectives
To assess the prevalence of elder abuse and to investigate potential sociodemographic, health behavior, and medical correlates.
Design
Cross‐sectional data were collected in face‐to‐face ...assessments.
Setting
São Paulo and Rio de Janeiro, Brazil.
Participants
Individuals aged 60 to 75.
Measurements
Information on elder abuse was obtained using the Brazil‐adapted, nine‐item Hwalek‐Sengstock Elder Abuse Screening Test. Sampling design–adjusted descriptive statistics and logistic regression were used in analyses.
Results
The overall prevalence of abuse was 14.4% (n = 46/259, 95% confidence interval (CI) = 9.82–20.61) in São Paulo and 13.3% (n = 27/197, 95% CI = 8.76–19.74) in Rio de Janeiro. Unadjusted analyses indicated that poor education, low physical activity, unemployment, heart disease, and psychiatric problems were associated with abuse, but in adjusted analyses, self‐reported elder abuse was significantly associated only with psychiatric problems (São Paulo: OR = 4.48, 95% CI = 1.75–11.45; Rio de Janeiro: OR = 21.61, 95% CI = 6.39–73.14).
Conclusion
Elder abuse is prevalent in São Paulo and Rio de Janeiro, but whether concomitants of abuse are cause, effect, or both is unclear because this was a cross‐sectional study. These findings highlight the importance of the problem, as well as the need to develop measures to increase awareness, facilitate prevention, and fight against abuse of elderly adults.
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•Raman spectroscopy to characterize sulfated polysaccharides from marine sponges.•Marine sponges: Polymastia janeirensis, Echinodictyum dendroides and Dragmacidon reticulatum.•Bands ...typical of sulfated polysaccharides at 1269cm−1 ν(SO3−), 1068cm−1 ν(SO3−) and 820–850cm−1 ν(COS) have been assigned from sponges.•The Raman characterization of sulfated polysaccharides can be relevant in terms of biotechnological application.
In this work sulfated polyssacharides from the marine sponges Polymastia janeirensis, Echinodictyum dendroides and Dragmacidon reticulatum have been analyzed by Raman spectroscopy as well as by biochemical analysis. The results showed that Raman spectroscopy can be applied as a screening method in monitoring the separation of ionic compounds such as sulfated polysaccharides in marine biological systems. The technique has been proven to be suitable in identifying sulfated polysaccharides rather than glycosaminoglycans from sponge tissues.
Atmospheric nitrous oxide (N
O) is a potent greenhouse gas thought to be mainly derived from microbial metabolism as part of the denitrification pathway. Here we report that in unexplored peat soils ...of Central and South America, N
O production can be driven by abiotic reactions (≤98%) highly competitive to their enzymatic counterparts. Extracted soil iron positively correlated with in situ abiotic N
O production determined by isotopic tracers. Moreover, we found that microbial N
O reduction accompanied abiotic production, essentially closing a coupled abiotic-biotic N
O cycle. Anaerobic N
O consumption occurred ubiquitously (pH 6.4-3.7), with proportions of diverse clade II N
O reducers increasing with consumption rates. Our findings show that denitrification in tropical peat soils is not a purely biological process but rather a 'mosaic' of abiotic and biotic reduction reactions. We predict that hydrological and temperature fluctuations differentially affect abiotic and biotic drivers and further contribute to the high N
O flux variation in the region.
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