Effect of Gamma Radiation on the Wear Potential of Hybrid Ceramic to Tooth Enamel.

Hybrid ceramics exhibit low wear on antagonist tooth enamel, which may positively impact the oral rehabilitation of head-and-neck irradiated patients who experience alterations in tooth microstructure and wear resistance. This study aimed to evaluate the wear resistance of hybrid ceramics after gamma radiation exposure in contact with irradiated tooth enamel, as well as their mechanical and chemical properties. Notably, no previous studies focusing on the effects of radiation on hybrid ceramics were found in the literature.

The Hunga Tonga-Hunga Ha'apai volcanic barometric pressure pulse and meteotsunami travel recorded in several Antarctic stations.

The Hunga Tonga-Hunga/Hunga-Ha'apai eruption on January 15, 2022 sent off a plume of ash material up to the stratosphere and triggered a meteotsunami and barometric pressure pulse that rippled through the atmosphere and oceans all around the world. The nature of the volcanic event and its global impacts on the oceans, atmosphere, lithosphere and the cryosphere are a matter of debate. Here we present a first overview of the time travel of the sound atmospheric pressure wave through the Antarctic continent based on in situ measurements, which represented a unique event observed through the polar ice sheet during the instrumental meteorological era.

Amazon savannization and climate change are projected to increase dry season length and temperature extremes over Brazil.

Land use change and atmospheric composition, two drivers of climate change, can interact to affect both local and remote climate regimes. Previous works have considered the effects of greenhouse gas buildup in the atmosphere and the effects of Amazon deforestation in atmospheric general circulation models. In this study, we investigate the impacts of the Brazilian Amazon savannization and global warming in a fully coupled ocean-land-sea ice-atmosphere model simulation.

Using structural equation modeling to assess the genotoxic and mutagenic effects of heavy metal contamination in the freshwater ecosystems: A study involving Oreochromis niloticus in an urban river.

Chemical pollutants represent a leading problem for aquatic ecosystems, as they can induce genetic, biochemical, and physiological changes in the species of these ecosystems, thus compromising their adaptability and survival. The Capibaribe River runs through the state of Pernambuco, located in Northeastern Brazil, and passes through areas of agricultural cultivation, densely populated cities, and industrial centers, primarily textiles. Despite its importance, few ecotoxicological studies have been conducted on its environment, and knowledge about pollution patterns and their effects on its biota is still being determined.

Biofunctionalization of surfaces to minimize undesirable effects in cardiovascular assistance devices.

Background: The reactivity of blood with non-endothelial surface is a challenge for long-term Ventricular Assist Devices development, usually made with pure titanium, which despite of being inert, low density and high mechanical resistance it does not avoid the thrombogenic responses. Here we tested a modification on the titanium surface with Laser Induced Periodic Surface Structures followed by Diamond Like Carbon (DLC) coating in different thicknesses to customize the wettability profile by changing the surface energy of the titanium.

Methods: Four different surfaces were proposed: (1) Pure Titanium as Reference Material (RM), (2) Textured as Test Sample (TS), (3) Textured with DLC 0.

Earthworm species in native and planted forests in Brazil.

Over 150 species of earthworms are known from the Brazilian Atlantic rainforest, but many more are expected to live in this megadiverse biome. In the present study, we evaluated earthworm species occurrence and diversity in native and reforested areas in four National Forests in three Brazilian states: Três Barras National Forest (Santa Catarina), Irati and Piraí do Sul National Forests (Paraná) and Capão Bonito National Forest (São Paulo) using formalin and hand sorting methods. A total of 13 species were found, five exotic and eight natives (of which four were new, undescribed species), belonging to six genera and five families (Rhinodrilidae, Glossoscolecidae, Ocnerodrilidae, Benhamiidae, Megascolecidae).

Brazilian Amazon indigenous territories under deforestation pressure.

Studies showed that Brazilian Amazon indigenous territories (ITs) are efficient models for preserving forests by reducing deforestation, fires, and related carbon emissions. Considering the importance of ITs for conserving socio-environmental and cultural diversity and the recent climb in the Brazilian Amazon deforestation, we used official remote sensing datasets to analyze deforestation inside and outside indigenous territories within Brazil's Amazon biome during the 2013-2021 period. Deforestation has increased by 129% inside ITs since 2013, followed by an increase in illegal mining areas.

Highly porous seeding-free boron-doped ultrananocrystalline diamond used as high-performance anode for electrochemical removal of carbaryl from water.

Boron-doped diamond (BDD) electrodes are regarded as the most promising catalytic materials that are highly efficient and suitable for application in advanced electrochemical oxidation processes targeted at the removal of recalcitrant contaminants in different water matrices. Improving the synthesis of these electrodes through the enhancement of their morphology, structure and stability has become the goal of the material scientists. The present work reports the use of an ultranano-diamond electrode with a highly porous structure (B-UNCD/TDNT/Ti) for the treatment of water containing carbaryl.

Applying the perturbative integral in aeromaneuvers around Mars to calculate the cost.

The perturbative integral method was applied to quantify the contribution of external forces during a specific interval of time in trajectories of spacecraft around asteroids and under the Luni-solar influence. However, this method has not been used to quantify the contributions of drag in aerocapture and aerobraking. For this reason, the planet Mars is selected to apply this method during an aerogravity-assisted maneuver.

Climate change could reduce and spatially reconfigure cocoa cultivation in the Brazilian Amazon by 2050.

Cocoa is a plant with origins in northwestern South America with high relevance in the global economy. Evidence indicates that cocoa is sensitive to a dry climate, under which crop production is reduced. Projections for future climate change scenarios suggest a warmer and drier climate in the Amazon basin.

Increased climate pressure on the agricultural frontier in the Eastern Amazonia-Cerrado transition zone.

Several large-scale drivers of both anthropogenic and natural environmental changes are interacting nonlinearly in the transition zone between eastern Amazonia and the adjacent Cerrado, considered to be another Brazilian agricultural frontier. Land-use change for agrobusiness expansion together with climate change in the transition zone between eastern Amazonia and the adjacent Cerrado may have induced a worsening of severe drought conditions over the last decade. Here we show that the largest warming and drying trends over tropical South America during the last four decades are observed to be precisely in the eastern Amazonia-Cerrado transition region, where they induce delayed wet-season and worsen severe drought conditions over the last decade.

Electrochemical oxidation of ciprofloxacin in different aqueous matrices using synthesized boron-doped micro and nano-diamond anodes.

The present work investigates the electrocatalytic performance of two different morphologies of boron doped-diamond film electrode (microcrystalline diamond - MCD, and nanocrystalline diamond - NCD) used in electrochemical oxidation for the removal of the antibiotic ciprofloxacin (CIP). A thorough study was conducted regarding the formation of the MCD and NCD films through the adjustment of methane in CH/H gas mixture, and the two films were compared in terms of crystalline structure, apparent doping level, and electrochemical properties. The physicochemical results showed that the NCD film had higher sp carbon content and greater doping level; this contributed to improvements in its surface roughness, as well as its specific capacitance and charge transfer, which consequently enhanced its electrocatalytic activity in comparison with the MCD.

Spiral SAR Imaging with Fast Factorized Back-Projection: A Phase Error Analysis.

This paper presents a fast factorized back-projection (FFBP) algorithm that can satisfactorily process real P-band synthetic aperture radar (SAR) data collected from a spiral flight pattern performed by a drone-borne SAR system. Choosing the best setup when processing SAR data with an FFBP algorithm is not so straightforward, so predicting how this choice will affect the quality of the output image is valuable information. This paper provides a statistical phase error analysis to validate the hypothesis that the phase error standard deviation can be predicted by geometric parameters specified at the start of processing.

Burning in southwestern Brazilian Amazonia, 2016-2019.

Fire is one of the most powerful modifiers of the Amazonian landscape and knowledge about its drivers is needed for planning control and suppression. A plethora of factors may play a role in the annual dynamics of fire frequency, spanning the biophysical, climatic, socioeconomic and institutional dimensions. To uncover the main forces currently at play, we investigated the area burned in both forested and deforested areas in the outstanding case of Brazil's state of Acre, in southwestern Amazonia.

Large-scale variations in the dynamics of Amazon forest canopy gaps from airborne lidar data and opportunities for tree mortality estimates.

We report large-scale estimates of Amazonian gap dynamics using a novel approach with large datasets of airborne light detection and ranging (lidar), including five multi-temporal and 610 single-date lidar datasets. Specifically, we (1) compared the fixed height and relative height methods for gap delineation and established a relationship between static and dynamic gaps (newly created gaps); (2) explored potential environmental/climate drivers explaining gap occurrence using generalized linear models; and (3) cross-related our findings to mortality estimates from 181 field plots. Our findings suggest that static gaps are significantly correlated to dynamic gaps and can inform about structural changes in the forest canopy.

Integrated terrestrial-freshwater planning doubles conservation of tropical aquatic species.

Conservation initiatives overwhelmingly focus on terrestrial biodiversity, and little is known about the freshwater cobenefits of terrestrial conservation actions. We sampled more than 1500 terrestrial and freshwater species in the Amazon and simulated conservation for species from both realms. Prioritizations based on terrestrial species yielded on average just 22% of the freshwater benefits achieved through freshwater-focused conservation.

Competition influences tree growth, but not mortality, across environmental gradients in Amazonia and tropical Africa.

Competition among trees is an important driver of community structure and dynamics in tropical forests. Neighboring trees may impact an individual tree's growth rate and probability of mortality, but large-scale geographic and environmental variation in these competitive effects has yet to be evaluated across the tropical forest biome. We quantified effects of competition on tree-level basal area growth and mortality for trees ≥10-cm diameter across 151 ~1-ha plots in mature tropical forests in Amazonia and tropical Africa by developing nonlinear models that accounted for wood density, tree size, and neighborhood crowding.

Mapping Atlantic rainforest degradation and regeneration history with indicator species using convolutional network.

The Atlantic rainforest of Brazil is one of the global terrestrial hotspots of biodiversity. Despite having undergone large scale deforestation, forest cover has shown signs of increases in the last decades. Here, to understand the degradation and regeneration history of Atlantic rainforest remnants near São Paulo, we combine a unique dataset of very high resolution images from Worldview-2 and Worldview-3 (0.

Temperature rising would slow down tropical forest dynamic in the Guiana Shield.

Increasing evidence shows that the functioning of the tropical forest biome is intimately related to the climate variability with some variables such as annual precipitation, temperature or seasonal water stress identified as key drivers of ecosystem dynamics. How tropical tree communities will respond to the future climate change is hard to predict primarily because several demographic processes act together to shape the forest ecosystem general behavior. To overcome this limitation, we used a joint individual-based model to simulate, over the next century, a tropical forest community experiencing the climate change expected in the Guiana Shield.

Vulnerability of Amazonian forests to repeated droughts.

Extreme droughts have been recurrent in the Amazon over the past decades, causing socio-economic and environmental impacts. Here, we investigate the vulnerability of Amazonian forests, both undisturbed and human-modified, to repeated droughts. We defined vulnerability as a measure of (i) exposure, which is the degree to which these ecosystems were exposed to droughts, and (ii) its sensitivity, measured as the degree to which the drought has affected remote sensing-derived forest greenness.

Atmosphere-Land Bridge between the Pacific and Tropical North Atlantic SST's through the Amazon River basin during the 2005 and 2010 droughts.

The present work uses a new approach to causal inference between complex systems called the Recurrence Measure of Conditional Dependence () based on the recurrence plots theory, in order to study the role of the Amazon River basin (AM) as a land-atmosphere bridge between the Niño 3.0 region in the Pacific Ocean and the Tropical North Atlantic. Two anomalous droughts in the Amazon River basin were selected, one mainly attributed to the warming of the Tropical North Atlantic (2005) and the other to a warm phase of El Niño-Southern Oscillation (2010).

Climate drivers of the Amazon forest greening.

Our limited understanding of the climate controls on tropical forest seasonality is one of the biggest sources of uncertainty in modeling climate change impacts on terrestrial ecosystems. Combining leaf production, litterfall and climate observations from satellite and ground data in the Amazon forest, we show that seasonal variation in leaf production is largely triggered by climate signals, specifically, insolation increase (70.4% of the total area) and precipitation increase (29.