Aspectos e reflexões conceituais sobre informação, sistemas e teoria de sistemas

Os conceitos de subordinação, emergência e autonomia afirmam-se nas ciências, após os anos 50. O mundo atual interconecta-se em “redes”, que se relacionam, direta ou indiretamente, aos sistemas, subsistemas e supersistemas. Este artigo aborda aspectos e reflexões conceituais sobre informação e sistemas de informação. Algumas visões dadas pelas teorias da complexidade e de sistemas, e pela semiótica, são usadas como referencias teóricos. O objetivo é visitar uma fração da literatura correspondente ao tema. A perspectiva de abordagem é a pesquisa bibliográfica. As conclusões principais são: a) o fenômeno “informação” suscita discussões e confusões, no que tange aos “conceitos” e “significados”; b) organização, articulação entre partes e hierarquização são os aspectos mais relevantes dos sistemas; c) instituições e serviços de informação desempenham papéis que particularizam e definem sua ação, consoante perspectivas, tendo em conta: subordinação, emergência e autonomia

Identification and analysis of seven effector protein families with different adaptive and evolutionary histories in plant-associated members of the Xanthomonadaceae.

The Xanthomonadaceae family consists of species of non-pathogenic and pathogenic γ-proteobacteria that infect different hosts, including humans and plants. In this study, we performed a comparative analysis using 69 fully sequenced genomes belonging to this family, with a focus on identifying proteins enriched in phytopathogens that could explain the lifestyle and the ability to infect plants. Using a computational approach, we identified seven phytopathogen-enriched protein families putatively secreted by type II secretory system: PheA (CM-sec), LipA/LesA, VirK, and four families involved in N-glycan degradation, NixE, NixF, NixL, and FucA1. In silico and phylogenetic analyses of these protein families revealed they all have orthologs in other phytopathogenic or symbiotic bacteria, and are involved in the modulation and evasion of the immune system. As a proof of concept, we performed a biochemical characterization of LipA from Xac306 and verified that the mutant strain lost most of its lipase and esterase activities and displayed reduced virulence in citrus. Since this study includes closely related organisms with distinct lifestyles and highlights proteins directly related to adaptation inside plant tissues, novel approaches might use these proteins as biotechnological targets for disease control, and contribute to our understanding of the coevolution of plant-associated bacteria

Trans-Arctic asymmetries, melting pots and weak species cohesion in the low-dispersal amphiboreal seaweed Fucus distichus

Amphiboreal taxa are often composed of vicariant phylogroups and species complexes whose divergence and phylogeographic affinities reflect a shared history of chronic isolation and episodic trans-Arctic dispersal. Ecological filters and shifting selective pressures may also promote selective sweeps, niche shifts and ecological speciation during colonization, but these are seldom considered at biogeographical scales. Here we integrate genetic data and Ecologic Niche Models (ENMs) to investigate the historical biogeography and cohesion of the polymorphic rockweed Fucus distichus throughout its immense amphiboreal range, focusing on trans-Arctic asymmetries, glacial/interglacial dynamics, and integrity of sympatric eco-morphotypes. Populations were sampled throughout the Pacific and the Atlantic, from southern rear-edges to the high-Arctic. They were genotyped for seven microsatellites and an mtDNA spacer, and genetic diversity and structure were assessed from global to local scales. ENMs were used to compare niche divergence and magnitude of post-glacial range shifts in Pacific versus Atlantic sub-ranges. Haplotypic and genotypic data revealed distinct and seemingly isolated Pacific vs Arctic/Atlantic gene-pools, with finer-scale regional sub-structuring pervasive in the Pacific. MtDNA diversity was highly structured and overwhelmingly concentrated in the Pacific. Regionally, Alaska showed the highest intra-population diversity but the lowest levels of endemism. Some sympatric/parapatric ecotypes exhibited distinct genotypic/ haplotypic compositions. Strikingly, niche models revealed higher Pacific tolerance to maximum temperatures and predicted a much more consolidated presence in the NE Atlantic. Glacial and modern ranges overlapped extensively in the Pacific, whereas the modern Atlantic range was largely glaciated or emerged during the Last Glacial Maximum. Higher genetic and ecogeographic diversity supports a primary Pacific diversification and secondary Atlantic colonization, also likely reflecting the much larger and more stable climatic refugia in the Pacific. The relic distribution and reduced ecological/morphological plasticity in the NE Atlantic are hypothesized to reflect functional trans-Arctic bottlenecks, recent colonization or competition with congeners. Within the Pacific, Alaska showed signatures of a post-glacial melting pot of eastern and southern populations. Genetic/ecotypic variation was generally not sufficiently discontinuous or consistent to justify recognizing multiple taxonomic entities, but support a separate species in the eastern Pacific, at the southern rear-edge. We predict that layered patterns of phylogeographic structure, incipient speciation and niche differences might be common among widespread low-dispersal amphiboreal taxa

Ocorrência do pepper yellow mosaic virus e cucumber mosaic virus em Capsicum chinense no estado do Amazonas, Brasil

The habanero chilli pepper, Capsicum chinense is an important crop in the Amazon Basin, mainly grown by small-scale producers. Capsicum chinense plants in an experimental field in the northern Brazilian state of Amazonas were found exhibiting characteristic symptoms of viral infection. Leaf sap from symptomatic plants examined under a transmission electron microscope revealed the presence of elongated flexuous particles and isometric particles. Using molecular assays, the viruses were identified as pepper yellow mosaic virus (PepYMV) and cucumber mosaic virus (CMV). Aphids, identified as Aphis gossypii, were found colonizing the C. chinense plants in the field and may be the vector for both PepYMV and CMV. We report the first occurrence of these viruses infecting C. chinense in the state of Amazonas.A pimenta-de-cheiro, Capsicum chinense é uma cultura importante na Bacia Amazônica, cultivada principalmente por pequenos produtores. Plantas de C. chinense em um campo experimental localizado no norte do estado brasileiro do Amazonas, foram encontradas apresentando sintomas característicos de infecção viral. Extratos de amostras de folhas sintomáticas examinados ao microscópio eletrônico de transmissão revelaram a presença de partículas alongadas e flexuosas e de partículas isométricas. Análises moleculares permitiram identificar a presença do pepper yellow mosaic virus (PepYMV) e do cucumber mosaic virus (CMV). Pulgões, identificados como Aphis gossypii foram encontrados colonizando pimenteiras-de-cheiro neste campo experimental e podem representar o provável vetor de PepYMV e CMV. Este trabalho relata a primeira ocorrência desses vírus infectando C. chinense no estado do Amazonas

Perfil epidemiológico dos pacientes em terapia renal substitutiva no Brasil, 2000-2004

OBJECTIVE: To describe the clinical and epidemiological profile of patients under renal replacement therapies, identifying risk factors for death. METHODS: This is a non-concurrent cohort study of data for 90,356 patients in the National Renal Replacement Therapies Database. A deterministic-probabilistic linkage was performed using the Authorization System for High Complexity/Cost Procedures and the Mortality Information System databases. All patients who started dialysis between 1/1/2000 and 12/31/2004 were included and followed until death or the end of 2004. Age, sex, region of residence, primary renal disease and causes of death were analyzed. A proportional hazards model was used to identify factors associated with risk of death. RESULTS: The prevalence of patients under renal replacement therapies increased an average of 5.5%, while incidence remained stable during the period. Hemodialysis was the predominant initial modality (89%). The patients were majority male with mean age 53 years, residents of the Southeast region and presented unknown causes as the main cause of chronic renal disease, followed by hypertension, diabetes and glomerulonephritis. Of these patients, 42% progressed to death and 7% underwent kidney transplantation. The patients on peritoneal dialysis were older and had higher prevalence of diabetes. The death rate varied from 7% among transplanted patients to 45% among non-transplanted patients. In the final Cox proportional hazards model, the risk of mortality was associated with increasing age, female sex, having diabetes, living in the North and Northeast region, peritoneal dialysis as a first modality and not having renal transplantation. CONCLUSIONS: There was an increased prevalence of patients on renal therapy in Brazil. Increased risk of death was associated with advanced age, diabetes, the female sex, residents of the North and Northeast region and lack of renal transplant.OBJETIVO: Describir el perfil epidemiológico y clínico de pacientes en terapia renal substitutiva, identificando factores asociados al riesgo de muerte. MÉTODOS: Estudio de observación, prospectivo no concurrente, a partir de datos de 90.356 pacientes de la Base Nacional en Terapias Renales Substitutivas, en Brasil. Fue realizado reracionamiento determinístico-probabilístico del Sistema de Información de Mortalidad. Fueron incluidos todos los pacientes incidentes que iniciaron diálisis entre 1/1/2000 y 31/12/2004, acompañados hasta la muerte o final de 2004. Edad, sexo, región de residencia, enfermedad renal primaria, causa del óbito fueron analizados. Se ajustó un modelo de riesgos proporcionales para identificar factores asociados al riesgo de muerte. RESULTADOS: Ocurrió un aumento promedio de 5,5% en la prevalencia de pacientes en terapia, con relación a la incidencia se mantuvo estable en el período. Hemodiálisis fue la modalidad inicial predominante (89%). La mayoría de los pacientes era del sexo masculino, con edad promedio de 53 años, residente en la región Sureste y presentaba causa indeterminada como principal causa básica de la enfermedad renal crónica, seguida de la hipertensión, diabetes y glomerulonefritis. De esos pacientes, 7% realizaron transplante renal y 42% evolucionaron a óbito. Los pacientes en diálisis peritoneal eran más ancianos y presentaban mayor prevalencia de diabetes. Entre los no transplantados, 45% fueron a óbito y, entre los transplantadas 7%. En el modelo final de riesgos proporcionales de Cox, el riesgo de mortalidad estuvo asociado con el aumento de la edad, sexo femenino, tener diabetes, residir en la región Norte y Noreste, diálisis peritoneal como modalidad de entrada y no haber realizado transplante renal. CONCLUSIONES: Hubo aumento de la prevalencia de pacientes en terapia renal en Brasil. Pacientes con edad avanzada, diabetes, del sexo femenino, residentes en la región Norte y Noreste y sin transplante renal presentan mayor riesgo de muerte.OBJETIVO: Descrever o perfil epidemiológico e clínico de pacientes em terapia renal substitutiva, identificando fatores associados ao risco de morte. MÉTODOS: Estudo observacional, prospectivo não concorrente, a partir de dados de 90.356 pacientes da Base Nacional em Terapias Renais Substitutivas, no Brasil. Foi realizado relacionamento determinístico-probabilístico do Sistema de Autorização de Procedimentos de Alta Complexidade/Custo e do Sistema de Informação de Mortalidade. Foram incluídos todos os pacientes incidentes que iniciaram diálise entre 1/1/2000 e 31/12/2004, acompanhados até a morte ou final de 2004. Idade, sexo, região de residência, doença renal primária, causa do óbito foram analisados. Ajustou-se um modelo de riscos proporcionais para identificar fatores associados ao risco de morte. RESULTADOS: Ocorreu um aumento médio de 5,5% na prevalência de pacientes em terapia enquanto a incidência manteve-se estável no período. Hemodiálise foi a modalidade inicial predominante (89%). A maioria dos pacientes era do sexo masculino, com idade média de 53 anos, residente na região Sudeste, e apresentava causa indeterminada como principal causa básica da doença renal crônica, seguida da hipertensão, diabetes e glomerulonefrites. Desses pacientes, 7% realizou transplante renal e 42% evoluiu para o óbito. Os pacientes em diálise peritoneal eram mais idosos e apresentavam maior prevalência de diabetes. Entre os não transplantados, 45% foi a óbito e, entre os transplantados, 7%. No modelo final de riscos proporcionais de Cox, o risco de mortalidade foi associado com o aumento da idade, sexo feminino, ter diabetes, residir nas regiões Norte e Nordeste, diálise peritoneal como modalidade de entrada e não ter realizado transplante renal. CONCLUSÕES: Houve aumento da prevalência de pacientes em terapia renal no Brasil. Pacientes com idade avançada, diabetes, do sexo feminino, residentes nas regiões Norte e Nordeste e sem transplante renal apresentam maior risco de morte

Carotid intima-media thickness and flow-mediated dilation do not predict acute in-hospital outcomes in patients hospitalized with COVID-19

Studies have suggested a potential role of endothelial dysfunction and atherosclerosis in the pathophysiology of COVID-19. Herein, we tested whether brachial flow-mediated dilation (FMD) and carotid intima-media thickness (cIMT) measured upon hospital admission are associated with acute in-hospital outcomes in patients hospitalized with COVID-19. A total of 211 patients hospitalized with COVID-19 were submitted to assessments of FMD and mean and maximum cIMT (cIMTmean and cIMTmax) within the first 72 h of hospital admission. Study primary outcome was a composite of intensive care unit admission, mechanical ventilation, or death during the hospitalization. These outcomes were also considered independently. Thrombotic events were included as a secondary outcome. Odds ratios (ORs) and confidence intervals (CIs) were calculated using unadjusted and adjusted multivariable logistic regression models. Eighty-eight (42%) participants demonstrated at least one of the composite outcomes. cIMTmean and cIMTmax were predictors of mortality and thrombotic events in the univariate analysis (cIMTmean and mortality: unadjusted OR 12.71 [95% CI 1.71–94.48]; P = 0.014; cIMTmean and thrombotic events: unadjusted OR 11.94 [95% CI 1.64–86.79]; P = 0.015; cIMTmax and mortality: unadjusted OR 8.47 [95% CI 1.41–51.05]; P = 0.021; cIMTmax and thrombotic events: unadjusted OR 12.19 [95% CI 2.03–73.09]; P = 0.007). However, these associations were no longer present after adjustment for potential confounders (P > 0.05). In addition, FMD% was not associated with any outcome. In conclusion, cIMT and FMD are not independent predictors of clinical outcomes in patients hospitalized with COVID-19. These results suggest that subclinical atherosclerosis and endothelial dysfunction may not be the main drivers of COVID-19 complications in patients hospitalized with COVID-19