28 research outputs found
Environmental Services Associated With The Reclamation Of Areas Degraded By Mining: Potential For Payments For Environmental Services
This paper discusses the potential of associating environmental services (ES) with techniques for reclaiming degraded areas (RDA) used in the mining sector, considering the current trends in payments for environmental services (PES) in Brazil. A literature review with content analysis generated results which identified the ES generated for eight cases of RDA in mining. As an example, ES related to soil enhancement were found. A more extended review of general RDA techniques confirmed the potential for associating other ES to RDA techniques used in mining, an example here is the enhancement of carbon stocks. Support for actions could come from existing PES schemes, particularly for cases where the ES identified as associated with an RDA technique are related to soil and water conservation. Concluding remarks indicate that there is a potential scenario for ES diversification in the reclamation stage of mining operations. A first step towards accomplishing this diversification envisages the creation of a PES scheme specific to the mining sector. Further studies are needed to develop criteria for fostering a PES scheme specifically for the reclamation phase of mining operations in Brazil.19213716
Replacing sodium bicarbonate with half amount of calcareous marine algae in the diet of beef cattle
This study evaluated the effects of feeding calcareous marine algae or sodium bicarbonate as rumen buffer on the performance, behaviour, in vitro diet digestibility, and meat quality of beef cattle. A total of 180 Charolaise bullocks (536-38 kg; 14-1 months of age) were divided into two homogeneous groups and fed a diet with a mineral mix containing 40% sodium bicarbonate or 20% calcareous marine algae (CMA) for the entire fattening period (130 days). Of the in vivo and in vitro parameters evaluated, CMA supplementation improved average daily gain and feed conversion ratio and reduced the prevalence of bloat and lameness. Bullocks fed CMA tended to exhibit a calmer behaviour while in the pen. Supplementation with CMA improved rumen pH and in vitro digestion. Meat from bullocks fed CMA showed a lower pH and higher lightness and tenderness. The results suggest that CMA is more effective than sodium bicarbonate in buffering beef cattle, with a positive impact on growth performance, feed efficiency, health, and meat quality
Aging-related predictive factors for oxygenation improvement and mortality in COVID-19 and acute respiratory distress syndrome (ARDS) patients exposed to prone position: A multicenter cohort study
Background: Elderly patients are more susceptible to Coronavirus Disease-2019 (COVID-19) and are more likely to develop it in severe forms, (e.g., Acute Respiratory Distress Syndrome [ARDS]). Prone positioning is a treatment strategy for severe ARDS; however, its response in the elderly population remains poorly understood. The main objective was to evaluate the predictive response and mortality of elderly patients exposed to prone positioning due to ARDS-COVID-19.
Methods: This retrospective multicenter cohort study involved 223 patients aged ≥ 65 years, who received prone position sessions for severe ARDS due to COVID-19, using invasive mechanical ventilation. The PaO2/FiO2 ratio was used to assess the oxygenation response. The 20-point improvement in PaO2/FiO2 after the first prone session was considered for good response. Data were collected from electronic medical records, including demographic data, laboratory/image exams, complications, comorbidities, SAPS III and SOFA scores, use of anticoagulants and vasopressors, ventilator settings, and respiratory system mechanics. Mortality was defined as deaths that occurred until hospital discharge.
Results: Most patients were male, with arterial hypertension and diabetes mellitus as the most prevalent comorbidities. The non-responders group had higher SAPS III and SOFA scores, and a higher incidence of complications. There was no difference in mortality rate. A lower SAPS III score was a predictor of oxygenation response, and the male sex was a risk predictor of mortality.
Conclusion: The present study suggests the oxygenation response to prone positioning in elderly patients with severe COVID-19-ARDS correlates with the SAPS III score. Furthermore, the male sex is a risk predictor of mortality
Chemical composition and antioxidant activity of geopropolis produced by Melipona fasciculata (Meliponinae) in flooded fields and cerrado areas of Maranhão State, northeastern Brazil
Extração e exportação de nutrientes pelo feijoeiro adubado com nitrogênio, em diferentes tempos de implantação do sistema plantio direto
Observation of inverse Compton emission from a long γ-ray burst.
Long-duration γ-ray bursts (GRBs) originate from ultra-relativistic jets launched from the collapsing cores of dying massive stars. They are characterized by an initial phase of bright and highly variable radiation in the kiloelectronvolt-to-megaelectronvolt band, which is probably produced within the jet and lasts from milliseconds to minutes, known as the prompt emission1,2. Subsequently, the interaction of the jet with the surrounding medium generates shock waves that are responsible for the afterglow emission, which lasts from days to months and occurs over a broad energy range from the radio to the gigaelectronvolt bands1-6. The afterglow emission is generally well explained as synchrotron radiation emitted by electrons accelerated by the external shock7-9. Recently, intense long-lasting emission between 0.2 and 1 teraelectronvolts was observed from GRB 190114C10,11. Here we report multi-frequency observations of GRB 190114C, and study the evolution in time of the GRB emission across 17 orders of magnitude in energy, from 5 × 10-6 to 1012 electronvolts. We find that the broadband spectral energy distribution is double-peaked, with the teraelectronvolt emission constituting a distinct spectral component with power comparable to the synchrotron component. This component is associated with the afterglow and is satisfactorily explained by inverse Compton up-scattering of synchrotron photons by high-energy electrons. We find that the conditions required to account for the observed teraelectronvolt component are typical for GRBs, supporting the possibility that inverse Compton emission is commonly produced in GRBs
Fauna invertebrada e atributos físicos e químicos do solo em sistemas de integração lavoura-pecuária
The Great Markarian 421 Flare of 2010 February: Multiwavelength Variability and Correlation Studies
We report on variability and correlation studies using multiwavelength observations of the blazar Mrk 421 during the month of 2010 February, when an extraordinary flare reaching a level of ∼27 Crab Units above 1 TeV was measured in very high energy (VHE) γ-rays with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) observatory. This is the highest flux state for Mrk 421 ever observed in VHE γ-rays. Data are analyzed from a coordinated campaign across multiple instruments, including VHE γ-ray (VERITAS, Major Atmospheric Gamma-ray Imaging Cherenkov), high-energy γ-ray (Fermi-LAT), X-ray (Swift, Rossi X-ray Timing Experiment, MAXI), optical (including the GASP-WEBT collaboration and polarization data), and radio (Metsahovi, Owens Valley Radio Observatory, University of Michigan Radio Astronomy Observatory). Light curves are produced spanning multiple days before and after the peak of the VHE flare, including over several flare "decline" epochs. The main flare statistics allow 2 minute time bins to be constructed in both the VHE and optical bands enabling a cross-correlation analysis that shows evidence for an optical lag of ∼25-55 minutes, the first time-lagged correlation between these bands reported on such short timescales. Limits on the Doppler factor (δ ⪆ 33) and the size of the emission region (δ-1RB≲ 3.8 × 1013cm) are obtained from the fast variability observed by VERITAS during the main flare. Analysis of 10 minute binned VHE and X-ray data over the decline epochs shows an extraordinary range of behavior in the flux-flux relationship, from linear to quadratic to lack of correlation to anticorrelation. Taken together, these detailed observations of an unprecedented flare seen in Mrk 421 are difficult to explain with the classic single-zone synchrotron self-Compton model.</p