36 research outputs found
Grid box-level evaluation of IMERG over Brazil at various space and time scales
This study evaluates the performance of the Integrated Multi-satellitE Retrievals for GPM (IMERG) Final Run product over Brazil by means of multi-temporal and -spatial analyses. The assessment of the IMERG Final Run product is based on six statistics obtained for the period between January-December 2016 (daily, monthly, and annual basis). The analysis consisted of comparing the satellite-based estimates against a ground-based gridded rainfall product created using daily records from 4,911 rain gauges distributed throughout Brazil. Overall, the results show that the IMERG product can effectively capture the spatial patterns of rainfall across Brazil. However, the IMERG product presents a slight tendency in overestimating the ground-based rainfall at all timescales. Furthermore, the performance of the satellite product varies throughout the region. The higher errors and biases are found in the North and Central-West regions, but the low density of rain gauges in those regions can be a source of large deviations between IMERG estimates and observations. A large underestimation of the IMERG data is evident along the coastal zone of the Northeast region, probably due to the inability of the passive microwave and infrared sensors to detect warm-rain processes over land. This study shows that the IMERG product can be a good source of rainfall data to complement the ground precipitation measurements in most of Brazil, although some uncertainties are found and need to be further studied
Whole-genome sequencing reveals host factors underlying critical COVID-19
Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2â4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genesâincluding reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)âin critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease
Diretriz da Sociedade Brasileira de Cardiologia sobre Diagnóstico e Tratamento de Pacientes com Cardiomiopatia da Doença de Chagas
This guideline aimed to update the concepts and formulate the standards of conduct and scientific evidence that support them, regarding the diagnosis and treatment of the Cardiomyopathy of Chagas disease, with special emphasis on the rationality base that supported it.
Chagas disease in the 21st century maintains an epidemiological pattern of endemicity in 21 Latin American countries. Researchers and managers from endemic and non-endemic countries point to the need to adopt comprehensive public health policies to effectively control the interhuman transmission of T. cruzi infection, and to obtain an optimized level of care for already infected individuals, focusing on diagnostic and therapeutic opportunistic opportunities.
Pathogenic and pathophysiological mechanisms of the Cardiomyopathy of Chagas disease were revisited after in-depth updating and the notion that necrosis and fibrosis are stimulated by tissue parasitic persistence and adverse immune reaction, as fundamental mechanisms, assisted by autonomic and microvascular disorders, was well established. Some of them have recently formed potential targets of therapies.
The natural history of the acute and chronic phases was reviewed, with enhancement for oral transmission, indeterminate form and chronic syndromes. Recent meta-analyses of observational studies have estimated the risk of evolution from acute and indeterminate forms and mortality after chronic cardiomyopathy. Therapeutic approaches applicable to individuals with Indeterminate form of Chagas disease were specifically addressed. All methods to detect structural and/or functional alterations with various cardiac imaging techniques were also reviewed, with recommendations for use in various clinical scenarios. Mortality risk stratification based on the Rassi score, with recent studies of its application, was complemented by methods that detect myocardial fibrosis.
The current methodology for etiological diagnosis and the consequent implications of trypanonomic treatment deserved a comprehensive and in-depth approach. Also the treatment of patients at risk or with heart failure, arrhythmias and thromboembolic events, based on pharmacological and complementary resources, received special attention. Additional chapters supported the conducts applicable to several special contexts, including t. cruzi/HIV co-infection, risk during surgeries, in pregnant women, in the reactivation of infection after heart transplantation, and others.
Finally, two chapters of great social significance, addressing the structuring of specialized services to care for individuals with the Cardiomyopathy of Chagas disease, and reviewing the concepts of severe heart disease and its medical-labor implications completed this guideline.Esta diretriz teve como objetivo principal atualizar os conceitos e formular as normas de conduta e evidĂȘncias cientĂficas que as suportam, quanto ao diagnĂłstico e tratamento da CDC, com especial ĂȘnfase na base de racionalidade que a embasou.
A DC no sĂ©culo XXI mantĂ©m padrĂŁo epidemiolĂłgico de endemicidade em 21 paĂses da AmĂ©rica Latina. Investigadores e gestores de paĂses endĂȘmicos e nĂŁo endĂȘmicos indigitam a necessidade de se adotarem polĂticas abrangentes, de saĂșde pĂșblica, para controle eficaz da transmissĂŁo inter-humanos da infecção pelo T. cruzi, e obter-se nĂvel otimizado de atendimento aos indivĂduos jĂĄ infectados, com foco em oportunização diagnĂłstica e terapĂȘutica.
Mecanismos patogĂȘnicos e fisiopatolĂłgicos da CDC foram revisitados apĂłs atualização aprofundada e ficou bem consolidada a noção de que necrose e fibrose sejam estimuladas pela persistĂȘncia parasitĂĄria tissular e reação imune adversa, como mecanismos fundamentais, coadjuvados por distĂșrbios autonĂŽmicos e microvasculares. Alguns deles recentemente constituĂram alvos potenciais de terapĂȘuticas.
A histĂłria natural das fases aguda e crĂŽnica foi revista, com realce para a transmissĂŁo oral, a forma indeterminada e as sĂndromes crĂŽnicas. MetanĂĄlises recentes de estudos observacionais estimaram o risco de evolução a partir das formas aguda e indeterminada e de mortalidade apĂłs instalação da cardiomiopatia crĂŽnica. Condutas terapĂȘuticas aplicĂĄveis aos indivĂduos com a FIDC foram abordadas especificamente. Todos os mĂ©todos para detectar alteraçÔes estruturais e/ou funcionais com variadas tĂ©cnicas de imageamento cardĂaco tambĂ©m foram revisados, com recomendaçÔes de uso nos vĂĄrios cenĂĄrios clĂnicos. Estratificação de risco de mortalidade fundamentada no escore de Rassi, com estudos recentes de sua aplicação, foi complementada por mĂ©todos que detectam fibrose miocĂĄrdica.
A metodologia atual para diagnĂłstico etiolĂłgico e as consequentes implicaçÔes do tratamento tripanossomicida mereceram enfoque abrangente e aprofundado. TambĂ©m o tratamento de pacientes em risco ou com insuficiĂȘncia cardĂaca, arritmias e eventos tromboembĂłlicos, baseado em recursos farmacolĂłgicos e complementares, recebeu especial atenção. CapĂtulos suplementares subsidiaram as condutas aplicĂĄveis a diversos contextos especiais, entre eles o da co-infecção por T. cruzi/HIV, risco durante cirurgias, em grĂĄvidas, na reativação da infecção apĂłs transplante cardĂacos, e outros.
Por fim, dois capĂtulos de grande significado social, abordando a estruturação de serviços especializados para atendimento aos indivĂduos com a CDC, e revisando os conceitos de cardiopatia grave e suas implicaçÔes mĂ©dico-trabalhistas completaram esta diretriz. 
Whole-genome sequencing reveals host factors underlying critical COVID-19
Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genesâincluding reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)âin critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease
A História da Alimentação: balizas historiogråficas
Os M. pretenderam traçar um quadro da HistĂłria da Alimentação, nĂŁo como um novo ramo epistemolĂłgico da disciplina, mas como um campo em desenvolvimento de prĂĄticas e atividades especializadas, incluindo pesquisa, formação, publicaçÔes, associaçÔes, encontros acadĂȘmicos, etc. Um breve relato das condiçÔes em que tal campo se assentou faz-se preceder de um panorama dos estudos de alimentação e temas correia tos, em geral, segundo cinco abardagens Ia biolĂłgica, a econĂŽmica, a social, a cultural e a filosĂłfica!, assim como da identificação das contribuiçÔes mais relevantes da Antropologia, Arqueologia, Sociologia e Geografia. A fim de comentar a multiforme e volumosa bibliografia histĂłrica, foi ela organizada segundo critĂ©rios morfolĂłgicos. A seguir, alguns tĂłpicos importantes mereceram tratamento Ă parte: a fome, o alimento e o domĂnio religioso, as descobertas europĂ©ias e a difusĂŁo mundial de alimentos, gosto e gastronomia. O artigo se encerra com um rĂĄpido balanço crĂtico da historiografia brasileira sobre o tema
Spatiotemporal distribution of precipitation and its characteristics under tropical atmospheric systems of Brazil : Insights from a large subâhourly database
Abstract The study of rainfall properties at various spatiotemporal scales is deeply important for understanding a large range of socioâenvironmental processes and variables (e.g., water resources, agriculture, socioâecosystemic services, natural risk assessment). However, such studies on rainfall characteristics, especially at subâhourly resolutions, are scarce in large areas of South America due to the lack of a highâresolution temporal database. The Brazilian National Centre for Monitoring and Early Warning of Natural Disasters (CEMADEN) has gradually implemented, starting in 2013, a subâhourly monitoring network composed of approximately 3500 automated rain gauges distributed across Brazil, enabling access to new hydrological studies in this vast tropical country featuring a range of biomes. This study analysed the characteristics of rainfall events for the whole of Brazil on subâdaily and subâhourly timescales, using 7âyears of data (from 2014 to 2021) provided by CEMADEN. Rainfall events were defined by the minimum interâevent time (MIT) and the minimum depth (1âmm). Seven MITs (30, 60, 120, 180, 360, 720, and 1440âmin) were considered to evaluate the behaviour of rainfall event characteristics and their relationships. The Gaussian mixture model method was applied to identify regions with similar rainfall patterns according to the MIT. Six groups with homogeneous characteristics were identified, evidencing the climatic diversity of Brazil. The results show that the MIT strongly influences precipitation properties (especially the dry time and the number of events). The highest number of events occurred in the Northâeast Coast region, which exceeded 200 events per year (MITâ<â60âmin), while the lowest number of events was observed in the Semiarid region, which reached only 38 events per year with an MIT of 1440âmin. Moreover, the events with the highest rainfall intensities were found in the Central region. The results found in this study provide a better understanding of precipitation and its characteristics in Brazil, highlighting the climatological diversity of this country
Dinùmica do uso e ocupação do solo em uma bacia hidrogråfica do semiårido brasileiro
As mudanças no uso e na ocupação do solo, provocadas pelas açÔes antrĂłpicas, tĂȘm gerado grandes impactos nas paisagens. Esses impactos podem ser mitigados atravĂ©s do monitoramento do uso e da cobertura do solo utilizando-se informaçÔes espaço-temporais das modificaçÔes ocorridas na paisagem. Este trabalho apresenta uma anĂĄlise espaço-temporal detalhada da dinĂąmica do uso e ocupação do solo da bacia hidrogrĂĄfica do riacho SĂŁo Paulo, localizada na regiĂŁo semiĂĄrida do Estado de Pernambuco, entre os anos de 1991 e 2010. Partindo da classificação de trĂȘs imagens de satĂ©lite dos anos de 1991, 2000 e 2010, foram utilizadas matrizes de transição, associadas Ă ĂĄlgebra de mapas e mĂ©tricas da paisagem. Os resultados mostraram que durante o perĂodo estudado as classes de uso e ocupação do solo passaram por uma grande transição, com a substituição progressiva das ĂĄreas de vegetação de caatinga aberta por ĂĄreas com pastagem/agricultura. Junto com o rĂĄpido crescimento da classe pastagem/agricultura, a paisagem predominante de vegetação nativa foi sendo substituĂda por uma paisagem cada vez mais devastada, heterogĂȘnea e fragmentada, como mostraram os Ăndices das mĂ©tricas da paisagem
Dynamic groundwater recharge simulations based on cosmicâray neutron sensing in a tropical wet experimental basin
none8siAlthough cosmic-ray neutron sensing (CRNS) is probably the most promising noninvasive proximal soil moisture measurement technique at the field scale, its application for hydrological simulations remains underexplored in the literature so far. This study assessed the use of CRNS to inversely calibrate soil hydraulic parameters at the intermediate field scale to simulate the groundwater recharge rates at a daily timescale. The study was conducted for two contrasting hydrological years at the Guaraira experimental basin, Brazil, a 5.84-km(2), a tropical wet and rather flat landscape covered by secondary Atlantic forest. As a consequence of the low altitude and proximity to the equator low neutron count rates could be expected, reducing the precision of CRNS while constituting unexplored and challenging conditions for CRNS applications. Inverse calibration for groundwater recharge rates was used based on CRNS or point-scale soil moisture data. The CRNS-derived retention curve and saturated hydraulic conductivity were consistent with the literature and locally performed slug tests. Simulated groundwater recharge rates ranged from 60 to 470 mm yr(-1), corresponding to 5 and 29% of rainfall, and correlated well with estimates based on water table fluctuations. In contrast, the estimated results based on inversive point-scale datasets were not in alignment with measured water table fluctuations. The better performance of CRNS-based estimations of field-scale hydrological variables, especially groundwater recharge, demonstrated its clear advantages over traditional invasive point-scale techniques. Finally, the study proved the ability of CRNS as practicable in low altitude, tropical wet areas, thus encouraging its adoption for water resources monitoring and management.noneBarbosa, LuĂs Romero; Coelho, Victor Hugo R.; Scheiffele, Lena M.; Baroni, Gabriele; Ramos Filho, Geraldo M.; Montenegro, Suzana M. G. L.; Almeida, Cristiano das N.; Oswald, Sascha E.Barbosa, LuĂs Romero; Coelho, Victor Hugo R.; Scheiffele, Lena M.; Baroni, Gabriele; Ramos Filho, Geraldo M.; Montenegro, Suzana M. G. L.; Almeida, Cristiano das N.; Oswald, Sascha E