Geoquímica de elementos maiores de rochas-fonte, solo e sedimentos detríticos de parte da Bacia do Rio Piratini : contribuição aos estudos de proveniência sedimentar

O estudo dos processos sedimentares e da forma como a composição é modificada entre rocha, solo e sedimento, é fundamental para compreender os primeiros estágios da evolução dos sedimentos detríticos. Para compreender a inter-relação complexa entre os processos que geram todo o registro sedimentar, são necessários estudos em ambientes atuais. Para avaliar estes processos, foram amostradas rochas-fonte, perfis de alteração e sedimentos detríticos em drenagens do Arroio Santana, onde rochas graníticas pertences ao Batólito de Pelotas são expostas em clima subtropical úmido. As amostras foram separadas em oito intervalos granulométricos, variando de seixo a lama. A composição geoquímica destas amostras foi analisada por ICP-EOS. A composição química versus relações de tamanho de grão foi analisada por métodos estatísticos através de diagramas, gráficos de dispersão, análise dos componentes principais e avaliação da estrutura de covariância via análise biplot, está realiza a partir do tratamento dos dados, que consistiu fundamentalmente em transformações de razões log. Os resultados revelam um forte controle do tamanho do grão na composição dos solos e sedimentos, evidenciando a influência do fracionamento geoquímico. A partir do Índice Químico de Alteração foi possível verificar altos valores restritos às frações de grãos finos entre 60 e 86, e valores baixos a moderados entre 57 e 80 em frações finas. A análise forneceu uma descrição da composição e demais processos sedimentares e acredita-se que ela seja de grande valia para a construção de modelos abrangentes de geração de sedimentos em ambientes atuais.The study of sedimentary processes and how the composition is modified between rock, soil, and sediment is fundamental to understand the early stages of the debris sediment evolution. To understand the complex interrelationship between the processes that generate the entire sedimentary record, studies in today's environments are needed. To evaluate these processes, source rocks, alteration profiles and detrital sediments were sampled in drainages of Arroio Santana, where granitic rocks belonging to Pelotas Batholith are exposed in a humid subtropical climate. The samples were separated into eight particle size ranges, ranging from pebble to mud. The geochemical composition of these samples was analyzed by ICP-EOS. The chemical composition versus grain-size ratios was analyzed by statistical methods through diagrams, scatter plots, principal component analysis, and covariance structure evaluation via biplot analysis, it is based on the treatment of data, which consisted mainly of transformations, of log reasons. The results reveal a strong control of grain size in the composition of soils and sediments, showing the influence of geochemical fractionation. From the Chemical Index of Alteration it was possible to verify high values restricted to fine grain fractions between 60 and 86, and low to moderate values between 57 and 80 in fine fractions. The analysis provided a description of the composition and other sedimentary processes and is believed to be of great value for the construction of comprehensive sediment generation models in today's environments

Major elements composition in source-rock, soil and sediments derived from granitic rocks in humid subtropical climate: contribution to the sedimentary provenance studies

The study of the sedimentary processes and the modification of the detrital composition between source rock, soil, and sediment is crucial to understand the compositional fractionation in the first stages of the sedimentary cycle. Studies in current environments are needed to unravel the complex relations between the processes that generate all the detrital sediment composition spectrum. In this work, the influence of the sedimentary processes in the composition of the sediments was evaluated using samples of the source-rocks, soils, and detrital sediments in a hydrographic basin where granitic rocks are exposed in a humid subtropical environment. The samples were separated into eight granulometric intervals from pebble to mud. Inductively Coupled Emission Optical Spectroscopy — ICP-EOS — determined the geochemical composition. The relations between chemical composition and grain size was analyzed by statistical methods using diagrams, dispersion charts, main components analysis, and the evaluation of the covariance structure through biplot analysis. The results demonstrate the grain size control in the soil and sediments composition and imply for the understanding of weathering and transport in the geochemical fractionation. The analysis of the compositional relations between rock, soil, and sediment in actual environments contribute to the building of quantitative models that allow determining the effects of the sedimentary processes in the composition of siliciclastic rocks.O estudo dos processos sedimentares e da modificação da composição detrítica entre rocha, solo e sedimento é fundamental para compreender o fracionamento composicional nos primeiros estágios do ciclo sedimentar. Estudos em ambientes atuais são necessários para desvendar a inter-relação complexa entre os processos que geram todo o espectro composicional dos sedimentos detríticos. Neste trabalho, a influência dos processos sedimentares na composição dos sedimentos foi avaliada utilizando-se amostras de rochas fonte, solos e sedimentos detríticos em uma bacia hidrográfica na qual rochas graníticas estão expostas em clima subtropical úmido. As amostras foram separadas em oito intervalos granulométricos de seixo a lama. A composição geoquímica dessas amostras foi analisada por Inductively Coupled Emission Optical Spectroscopy — ICP-EOS. A relação entre a composição química e o tamanho de grão foi analisada por métodos estatísticos utilizando-se diagramas, gráficos de dispersão, análise dos componentes principais e avaliação da estrutura de covariância via análise biplot. Os resultados demonstram o controle do tamanho de grão na composição dos solos e sedimentos e têm implicação no entendimento da influência do intemperismo e do transporte no fracionamento geoquímico. A análise da relação entre a composição de rocha, solo e sedimento em ambientes atuais contribui para a construção e tem potencial para a construção de modelos quantitativos que permitam determinar o efeito dos processos sedimentares na composição das rochas siliciclásticas

Geoquímica de elementos maiores de rochas-fonte, solo e sedimentos detríticos de parte da Bacia do Rio Piratini : contribuição aos estudos de proveniência sedimentar

O estudo dos processos sedimentares e da forma como a composição é modificada entre rocha, solo e sedimento, é fundamental para compreender os primeiros estágios da evolução dos sedimentos detríticos. Para compreender a inter-relação complexa entre os processos que geram todo o registro sedimentar, são necessários estudos em ambientes atuais. Para avaliar estes processos, foram amostradas rochas-fonte, perfis de alteração e sedimentos detríticos em drenagens do Arroio Santana, onde rochas graníticas pertences ao Batólito de Pelotas são expostas em clima subtropical úmido. As amostras foram separadas em oito intervalos granulométricos, variando de seixo a lama. A composição geoquímica destas amostras foi analisada por ICP-EOS. A composição química versus relações de tamanho de grão foi analisada por métodos estatísticos através de diagramas, gráficos de dispersão, análise dos componentes principais e avaliação da estrutura de covariância via análise biplot, está realiza a partir do tratamento dos dados, que consistiu fundamentalmente em transformações de razões log. Os resultados revelam um forte controle do tamanho do grão na composição dos solos e sedimentos, evidenciando a influência do fracionamento geoquímico. A partir do Índice Químico de Alteração foi possível verificar altos valores restritos às frações de grãos finos entre 60 e 86, e valores baixos a moderados entre 57 e 80 em frações finas. A análise forneceu uma descrição da composição e demais processos sedimentares e acredita-se que ela seja de grande valia para a construção de modelos abrangentes de geração de sedimentos em ambientes atuais.The study of sedimentary processes and how the composition is modified between rock, soil, and sediment is fundamental to understand the early stages of the debris sediment evolution. To understand the complex interrelationship between the processes that generate the entire sedimentary record, studies in today's environments are needed. To evaluate these processes, source rocks, alteration profiles and detrital sediments were sampled in drainages of Arroio Santana, where granitic rocks belonging to Pelotas Batholith are exposed in a humid subtropical climate. The samples were separated into eight particle size ranges, ranging from pebble to mud. The geochemical composition of these samples was analyzed by ICP-EOS. The chemical composition versus grain-size ratios was analyzed by statistical methods through diagrams, scatter plots, principal component analysis, and covariance structure evaluation via biplot analysis, it is based on the treatment of data, which consisted mainly of transformations, of log reasons. The results reveal a strong control of grain size in the composition of soils and sediments, showing the influence of geochemical fractionation. From the Chemical Index of Alteration it was possible to verify high values restricted to fine grain fractions between 60 and 86, and low to moderate values between 57 and 80 in fine fractions. The analysis provided a description of the composition and other sedimentary processes and is believed to be of great value for the construction of comprehensive sediment generation models in today's environments

Major elements composition in source-rock, soil and sediments derived from granitic rocks in humid subtropical climate: contribution to the sedimentary provenance studies

O estudo dos processos sedimentares e da modificação da composição detrítica entre rocha, solo e sedimento é fundamental para compreender o fracionamento composicional nos primeiros estágios do ciclo sedimentar. Estudos em ambientes atuais são necessários para desvendar a inter-relação complexa entre os processos que geram todo o espectro composicional dos sedimentos detríticos. Neste trabalho, a influência dos processos sedimentares na composição dos sedimentos foi avaliada utilizando-se amostras de rochas fonte, solos e sedimentos detríticos em uma bacia hidrográfica na qual rochas graníticas estão expostas em clima subtropical úmido. As amostras foram separadas em oito intervalos granulométricos de seixo a lama. A composição geoquímica dessas amostras foi analisada por Inductively Coupled Emission Optical Spectroscopy — ICP-EOS. A relação entre a composição química e o tamanho de grão foi analisada por métodos estatísticos utilizando-se diagramas, gráficos de dispersão, análise dos componentes principais e avaliação da estrutura de covariância via análise biplot. Os resul-tados demonstram o controle do tamanho de grão na composição dos solos e sedimentos e têm implicação no entendimento da influência do intemperismo e do transporte no fracionamento geoquímico. A análise da relação entre a composição de rocha, solo e sedimento em ambientes atuais contribui para a construção e tem potencial para a construção de modelos quantitativos que permitam determinar o efeito dos processos sedimentares na composição das rochas siliciclásticas.The study of the sedimentary processes and the modification of the detrital composition between source rock, soil, and sediment is crucial to understand the compositional fractionation in the first stages of the sedimentary cycle. Studies in cur-rent environments are needed to unravel the complex relations between the processes that generate all the detrital sediment composition spectrum. In this work, the influence of the sedimentary processes in the composition of the sediments was evaluated using samples of the source-rocks, soils, and detrital sediments in a hydrographic basin where granitic rocks are exposed in a humid subtropical environment. The samples were separated into eight granulometric intervals from pebble to mud. Inductively Coupled Emission Optical Spectroscopy — ICP-EOS — determined the geochemical composition. The relations between chemical composition and grain size was analyzed by statistical methods using diagrams, disper-sion charts, main components analysis, and the evaluation of the covariance structure through biplot analysis. The results demonstrate the grain size control in the soil and sediments composition and imply for the understanding of weathering and transport in the geochemical fractionation. The analysis of the compositional relations between rock, soil, and sediment in actual environments contribute to the building of quantitative models that allow determining the effects of the sedimentary processes in the composition of siliciclastic rocks

Neotropical freshwater fisheries : A dataset of occurrence and abundance of freshwater fishes in the Neotropics

The Neotropical region hosts 4225 freshwater fish species, ranking first among the world's most diverse regions for freshwater fishes. Our NEOTROPICAL FRESHWATER FISHES data set is the first to produce a large-scale Neotropical freshwater fish inventory, covering the entire Neotropical region from Mexico and the Caribbean in the north to the southern limits in Argentina, Paraguay, Chile, and Uruguay. We compiled 185,787 distribution records, with unique georeferenced coordinates, for the 4225 species, represented by occurrence and abundance data. The number of species for the most numerous orders are as follows: Characiformes (1289), Siluriformes (1384), Cichliformes (354), Cyprinodontiformes (245), and Gymnotiformes (135). The most recorded species was the characid Astyanax fasciatus (4696 records). We registered 116,802 distribution records for native species, compared to 1802 distribution records for nonnative species. The main aim of the NEOTROPICAL FRESHWATER FISHES data set was to make these occurrence and abundance data accessible for international researchers to develop ecological and macroecological studies, from local to regional scales, with focal fish species, families, or orders. We anticipate that the NEOTROPICAL FRESHWATER FISHES data set will be valuable for studies on a wide range of ecological processes, such as trophic cascades, fishery pressure, the effects of habitat loss and fragmentation, and the impacts of species invasion and climate change. There are no copyright restrictions on the data, and please cite this data paper when using the data in publications

Effects of pre-operative isolation on postoperative pulmonary complications after elective surgery: an international prospective cohort study an international prospective cohort study

We aimed to determine the impact of pre-operative isolation on postoperative pulmonary complications after elective surgery during the global SARS-CoV-2 pandemic. We performed an international prospective cohort study including patients undergoing elective surgery in October 2020. Isolation was defined as the period before surgery during which patients did not leave their house or receive visitors from outside their household. The primary outcome was postoperative pulmonary complications, adjusted in multivariable models for measured confounders. Pre-defined sub-group analyses were performed for the primary outcome. A total of 96,454 patients from 114 countries were included and overall, 26,948 (27.9%) patients isolated before surgery. Postoperative pulmonary complications were recorded in 1947 (2.0%) patients of which 227 (11.7%) were associated with SARS-CoV-2 infection. Patients who isolated pre-operatively were older, had more respiratory comorbidities and were more commonly from areas of high SARS-CoV-2 incidence and high-income countries. Although the overall rates of postoperative pulmonary complications were similar in those that isolated and those that did not (2.1% vs 2.0%, respectively), isolation was associated with higher rates of postoperative pulmonary complications after adjustment (adjusted OR 1.20, 95%CI 1.05–1.36, p = 0.005). Sensitivity analyses revealed no further differences when patients were categorised by: pre-operative testing; use of COVID-19-free pathways; or community SARS-CoV-2 prevalence. The rate of postoperative pulmonary complications increased with periods of isolation longer than 3 days, with an OR (95%CI) at 4–7 days or ≥ 8 days of 1.25 (1.04–1.48), p = 0.015 and 1.31 (1.11–1.55), p = 0.001, respectively. Isolation before elective surgery might be associated with a small but clinically important increased risk of postoperative pulmonary complications. Longer periods of isolation showed no reduction in the risk of postoperative pulmonary complications. These findings have significant implications for global provision of elective surgical care. We aimed to determine the impact of pre-operative isolation on postoperative pulmonary complications after elective surgery during the global SARS-CoV-2 pandemic. We performed an international prospective cohort study including patients undergoing elective surgery in October 2020. Isolation was defined as the period before surgery during which patients did not leave their house or receive visitors from outside their household. The primary outcome was postoperative pulmonary complications, adjusted in multivariable models for measured confounders. Pre-defined sub-group analyses were performed for the primary outcome. A total of 96,454 patients from 114 countries were included and overall, 26,948 (27.9%) patients isolated before surgery. Postoperative pulmonary complications were recorded in 1947 (2.0%) patients of which 227 (11.7%) were associated with SARS-CoV-2 infection. Patients who isolated pre-operatively were older, had more respiratory comorbidities and were more commonly from areas of high SARS-CoV-2 incidence and high-income countries. Although the overall rates of postoperative pulmonary complications were similar in those that isolated and those that did not (2.1% vs 2.0%, respectively), isolation was associated with higher rates of postoperative pulmonary complications after adjustment (adjusted OR 1.20, 95%CI 1.05–1.36, p = 0.005). Sensitivity analyses revealed no further differences when patients were categorised by: pre-operative testing; use of COVID-19-free pathways; or community SARS-CoV-2 prevalence. The rate of postoperative pulmonary complications increased with periods of isolation longer than 3 days, with an OR (95%CI) at 4–7 days or ≥ 8 days of 1.25 (1.04–1.48), p = 0.015 and 1.31 (1.11–1.55), p = 0.001, respectively. Isolation before elective surgery might be associated with a small but clinically important increased risk of postoperative pulmonary complications. Longer periods of isolation showed no reduction in the risk of postoperative pulmonary complications. These findings have significant implications for global provision of elective surgical care

Global variation in postoperative mortality and complications after cancer surgery: a multicentre, prospective cohort study in 82 countries

© 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 licenseBackground: 80% of individuals with cancer will require a surgical procedure, yet little comparative data exist on early outcomes in low-income and middle-income countries (LMICs). We compared postoperative outcomes in breast, colorectal, and gastric cancer surgery in hospitals worldwide, focusing on the effect of disease stage and complications on postoperative mortality. Methods: This was a multicentre, international prospective cohort study of consecutive adult patients undergoing surgery for primary breast, colorectal, or gastric cancer requiring a skin incision done under general or neuraxial anaesthesia. The primary outcome was death or major complication within 30 days of surgery. Multilevel logistic regression determined relationships within three-level nested models of patients within hospitals and countries. Hospital-level infrastructure effects were explored with three-way mediation analyses. This study was registered with ClinicalTrials.gov, NCT03471494. Findings: Between April 1, 2018, and Jan 31, 2019, we enrolled 15 958 patients from 428 hospitals in 82 countries (high income 9106 patients, 31 countries; upper-middle income 2721 patients, 23 countries; or lower-middle income 4131 patients, 28 countries). Patients in LMICs presented with more advanced disease compared with patients in high-income countries. 30-day mortality was higher for gastric cancer in low-income or lower-middle-income countries (adjusted odds ratio 3·72, 95% CI 1·70–8·16) and for colorectal cancer in low-income or lower-middle-income countries (4·59, 2·39–8·80) and upper-middle-income countries (2·06, 1·11–3·83). No difference in 30-day mortality was seen in breast cancer. The proportion of patients who died after a major complication was greatest in low-income or lower-middle-income countries (6·15, 3·26–11·59) and upper-middle-income countries (3·89, 2·08–7·29). Postoperative death after complications was partly explained by patient factors (60%) and partly by hospital or country (40%). The absence of consistently available postoperative care facilities was associated with seven to 10 more deaths per 100 major complications in LMICs. Cancer stage alone explained little of the early variation in mortality or postoperative complications. Interpretation: Higher levels of mortality after cancer surgery in LMICs was not fully explained by later presentation of disease. The capacity to rescue patients from surgical complications is a tangible opportunity for meaningful intervention. Early death after cancer surgery might be reduced by policies focusing on strengthening perioperative care systems to detect and intervene in common complications. Funding: National Institute for Health Research Global Health Research Unit

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

© 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licenseBackground: Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide. Methods: A multimethods analysis was performed as part of the GlobalSurg 3 study—a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital. Findings: Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3·85 [95% CI 2·58–5·75]; p<0·0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63·0% vs 82·7%; OR 0·35 [0·23–0·53]; p<0·0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer. Interpretation: Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised. Funding: National Institute for Health and Care Research