2,319 research outputs found
DESIGUALDADES SOCIAIS E ESPACIALIDADES DA COVID-19 EM REGIÕES METROPOLITANAS
The biggest Brazilian cities have undergone important changes in their social structure in recent years. It is an urban area marked by disputes, struggles, and conflicts that reveal the presence of precarious forms of life, work, and housing generated by the capitalist logic of space production. In this context, the COVID-19 pandemic built patterns of socio-territorial dissemination that evidenced the presence in cities of social groups of great vulnerability. This text analyzes the impacts of COVID-19 on income inequality and social vulnerability in the main Brazilian metropolitan regions. The Gini coefficient and the percentage of individuals living in households with monthly per capita income of up to ¼ of the minimum wage are considered as main indicators. The methodology includes a literature review of the concepts and categories analyzed and a statistical survey of socio-demographic and economic data sources.Las grandes ciudades brasileñas han experimentado importantes cambios en su estructura social en los últimos años. Es un espacio urbano marcado por disputas, luchas y conflictos, que revelan la presencia de formas precarias de vida, trabajo y vivienda generadas por la lógica capitalista de producción del espacio. En este contexto, la pandemia de la Covid-19 construyó patrones de diseminación socioterritorial que evidenciaron la presencia en las ciudades de grupos sociales de gran vulnerabilidad. Este texto analiza los impactos del Covid-19 en la desigualdad de ingresos y la vulnerabilidad social en las principales Regiones Metropolitanas de Brasil. Los principales indicadores para el análisis son el coeficiente de Gini y el porcentaje de personas que viven en hogares con un ingreso per cápita mensual de hasta ¼ del salario mínimo. La metodología incluye una revisión bibliográfica de los conceptos y categorías analizados y un levantamiento estadístico de datos sociodemográficos y económicos.Les grandes villes brésiliennes ont subi des importants changements dans leur structure sociale ces dernières années. C'est une zone urbaine marquée par des disputes, des luttes et des conflits, qui révèlent la présence de formes de vie, de travail et de logement précaires générées par la logique capitaliste de production spatiale. Dans ce contexte, la pandémie de COVID-19 a construit des schémas de diffusion socio-territoriale qui ont mis en évidence la présence dans les villes de groupes sociaux de grande vulnérabilité. Ce texte analyse les impacts du COVID-19 sur les inégalités de revenus et la vulnérabilité sociale dans les principales régions métropolitaines brésiliennes. Le coefficient de Gini et le pourcentage d'individus vivant dans des ménages dont le revenu mensuel par habitant ne dépasse pas ¼ du salaire minimum sont considérés comme des indicateurs principaux. La méthodologie comprend une revue de la littérature des concepts et des catégories analysés et une enquête statistique sur les sources de données sociodémographiques et économiques.As grandes cidades brasileiras passaram, nos últimos anos, por importantes transformações em sua estrutura social. Trata-se de um urbano marcado por disputas, lutas e conflitos que revelam a presença de formas precárias de vida, de trabalho e de habitação geradas pela lógica capitalista de produção do espaço. Nesse contexto, a pandemia da Covid-19 construiu padrões de disseminação socioterritorial que evidenciaram a presença nas cidades de grupos sociais de grande vulnerabilidade. Este texto analisa os impactos da Covid-19 sobre a desigualdade de renda e a vulnerabilidade social nas principais regiões metropolitanas brasileiras. Consideram-se como principais indicadores para a análise o Coeficiente de Gini e o percentual dos indivíduos vivendo em domicílios com rendimento per capita mensal de até ¼ de salário-mínimo. A metodologia contempla revisão bibliográfica dos conceitos e categorias analisados e levantamento estatístico de dados sociodemográficos e econômicos
Dexamethasone Treatment Reverses Cognitive Impairment but Increases Brain Oxidative Stress in Rats Submitted to Pneumococcal Meningitis
Pneumococcal meningitis is associated with a significant mortality rate and neurologic sequelae. The animals received either 10 μL of saline or a S. pneumoniae suspension and were randomized into different groups: sham: placebo with dexamethasone 0.7 mg/kg/1 day; placebo with dexamethasone 0.2 mg/kg/7 days; meningitis groups: dexamethasone 0.7 mg/kg/1 day and dexamethasone 0.2 mg/kg/7 days. Ten days after induction we evaluated memory and oxidative stress parameters in hippocampus and cortex. In the step-down inhibitory avoidance task, we observed memory impairment in the meningitis group with dexamethasone 0.2 mg/kg/7 days. The lipid peroxidation was increased in hippocampus in the meningitis groups with dexamethasone and in cortex only in the meningitis group with dexamethasone 0.2 mg/kg/7 days. The protein carbonyl was increased in hippocampus in the meningitis groups with dexamethasone and in cortex in the meningitis groups with and without dexamethasone. There was a decrease in the proteins integrity in hippocampus in all groups receiving treatment with dexamethasone and in cortex in all groups with dexamethasone (0.7 mg/kg/1 day). The mitochondrial superoxide was increased in the hippocampus and cortex in the meningitis group with dexamethasone 0.2 mg/kg/7 days. Our findings demonstrate that dexamethasone reverted cognitive impairment but increased brain oxidative stress in hippocampus and cortex in Wistar rats ten days after pneumococcal meningitis induction
Leishmanicidal activity of fractions rich in aporphine alkaloids from Amazonian Unonopsis species
In vitro evaluation of alkaloidal fractions of twigs, barks and leaves from two Unonopsis species, Unonopsis guatterioides R.E. Fr. and Unonopsis duckei R.E. Fr., Annonaceae, against promastigote forms of Leishmania amazonensis revealed these species as sources of substances with promising leishmanicidal potential. All alkaloidal fractions from twigs, barks and leaves of U. guatterioides were classified as highly active, with IC50 1.07, 1.90, and 2.79 mg/mL, respectively. Only the alkaloidal fraction from the twigs of U. duckei was classified as inactive.2261368137
Role of atrial tissue remodeling on rotor dynamics an in vitro study
The objective of this article is to present an in vitro model of atrial cardiac tissue that could serve to study the mechanisms of remodeling related to atrial fibrillation (AF). We analyze the modification on gene expression and modifications on rotor dynamics following tissue remodeling. Atrial murine cells (HL-1 myocytes) were maintained in culture after the spontaneous initiation of AF and analyzed at two time points: 3.1 +/- 1.3 and 9.7 +/- 0.5 days after AF initiation. The degree of electrophysiological remodeling (i.e., relative gene expression of key ion channels) and structural inhomogeneity was compared between early and late cell culture times both in nonfibrillating and fibrillating cell cultures. In addition, the electrophysiological characteristics of in vitro fibrillation [e.g., density of phase singularities (PS/cm2), dominant frequency, and rotor meandering] analyzed by means of optical mapping were compared with the degree of electrophysiological remodeling. Fibrillating cell cultures showed a differential ion channel gene expression associated with atrial tissue remodeling (i.e., decreased SCN5A, CACN1C, KCND3, and GJA1 and increased KCNJ2) not present in nonfibrillating cell cultures. Also, fibrillatory complexity was increased in late- vs. early stage cultures (1.12 +/- 0.14 vs. 0.43 +/- 0.19 PS/cm(2), P < 0.01), which was associated with changes in the electrical reentrant patterns (i.e., decrease in rotor tip meandering and increase in wavefront curvature). HL-1 cells can reproduce AF features such as electrophysiological remodeling and an increased complexity of the electrophysiological behavior associated with the fibrillation time that resembles those occurring in patients with chronic AF.This work was supported in part by grants from the Spanish Ministry of Science and Innovation (PLE2009-0152), the Instituto de Salud Carlos III (Ministry of Economy and Competitiveness, Spain: PI13-01882, PI13-00903, and TEC2013-50391-EXP), and the Red de Investigacion Cardiovacular (RIC) from Instituto de Salud Carlos III (Ministry of Economy and Competitiveness, Spain).Climent, A.; Guillem Sánchez, MS.; Fuentes, L.; Lee, P.; Bollensdorff, C.; Fernandez-Santos, M.; Suarez-Sancho, S.... (2015). Role of atrial tissue remodeling on rotor dynamics an in vitro study. AJP - Heart and Circulatory Physiology. 309(11):H1964-H1973. doi:10.1152/ajpheart.00055.2015SH1964H197330911Allessie, M. (2002). 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Efficiency of light-emitting diode and halogen units in reducing residual monomers
In this in-vitro study, we aimed to compare the residual monomers in composites beneath brackets bonded to enamel, using a light-emitting diode (LED) or a halogen unit, and to compare the residual monomers in the central to the peripheral areas of the composite
An Intracellular Arrangement of Histoplasma capsulatum Yeast-Aggregates Generates Nuclear Damage to the Cultured Murine Alveolar Macrophages
Histoplasma capsulatum is responsible for a human systemic mycosis that primarily affects lung tissue. Macrophages are the major effector cells in humans that respond to the fungus, and the development of respiratory disease depends on the ability of Histoplasma yeast cells to survive and replicate within alveolar macrophages. Therefore, the interaction between macrophages and H. capsulatum is a decisive step in the yeast dissemination into host tissues. Although the role played by components of cell-mediated immunity in the host's defense system and the mechanisms used by the pathogen to evade the host immune response are well understood, knowledge regarding the effects induced by H. capsulatum in host cells at the nuclear level is limited. According to the present findings, H. capsulatum yeast cells display a unique architectural arrangement during the intracellular infection of cultured murine alveolar macrophages, characterized as a formation of aggregates that seem to surround the host cell nucleus, resembling a crown. This extranuclear organization of yeast-aggregates generates damage on the nucleus of the host cell, producing DNA fragmentation and inducing apoptosis, even though the yeast cells are not located inside the nucleus and do not trigger changes in nuclear proteins. The current study highlights a singular intracellular arrangement of H. capsulatum yeast near to the nucleus of infected murine alveolar macrophages that may contribute to the yeast’s persistence under intracellular conditions, since this fungal pathogen may display different strategies to prevent elimination by the host's phagocytic mechanisms
Diversity and succession of pelagic microorganism communities in a newly restored Illinois River floodplain lake
While the success of restoration efforts frequently depends on reconstructing ecological communities, time series observations of community structure over the course of restoration are rare. Here, frequent sampling of bacterioplankton, phytoplankton, planktonic protozoa (ciliates and testaceans), and zooplankton was done along with measurements of select physical and chemical parameters during the first year of ecological restoration of Thompson Lake (TL), an Illinois River floodplain lake not connected to the river. The primary objective was to describe the microbial composition, diversity, and seasonal dynamics in TL and compare these results to similar measurements made in a nearby reference lake, river flood-pulsed Lake Chautauqua (LC). Strong seasonal patterns in bacterioplankton diversity were observed for both lakes. While TL phytoplankton diversity was lower and blooms more erratic than in LC, ciliate richness and abundance patterns were similar in both lakes. Rotifers and microcrustaceans were about 5× more abundant in TL than LC, with copepods and cladocerans exhibiting a fall abundance peak only in TL. When compared to temporal patterns of planktonic microorganisms in the reference lake (LC), the microbial dynamics in a lake recovering from decades of agriculture and drainage (TL) reflect the instability associated with early stages of ecological restoration.Ope
Conserving Ecosystem Diversity in the Tropical Andes
Documenting temporal trends in the extent of ecosystems is essential to monitoring their status but combining this information with the degree of protection helps us assess the effectiveness of societal actions for conserving ecosystem diversity and related ecosystem services. We demonstrated indicators in the Tropical Andes using both potential (pre-industrial) and recent (~2010) distribution maps of terrestrial ecosystem types. We measured long-term ecosystem loss, representation of ecosystem types within the current protected areas, quantifying the additional representation offered by protecting Key Biodiversity Areas. Six (4.8%) ecosystem types (i.e., measured as 126 distinct vegetation macrogroups) have lost >50% in extent across four Andean countries since pre-industrial times. For ecosystem type representation within protected areas, regarding the pre-industrial extent of each type, a total of 32 types (25%) had higher representation (>30%) than the post-2020 Convention on Biological Diversity (CBD) draft target in existing protected areas. Just 5 of 95 types (5.2%) within the montane Tropical Andes hotspot are currently represented with >30% within the protected areas. Thirty-nine types (31%) within these countries could cross the 30% CBD 2030 target with the addition of Key Biodiversity Areas. This indicator is based on the Essential Biodiversity Variables (EBV) and responds directly to the needs expressed by the users of these countries
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