Uma viagem “No Mundo da Ciência” (Folha de S. Paulo/ 1947 a 1958): a história de um suplemento de ciência

Para entendermos a divulgação científica que é realizada, atualmente, é importante ampliarmos os aspectos históricos de sua constituição como campo de estudo e prática. Para isso, analisamos os textos publicados, pelo biologista do Instituto Biológico, um dos fundadores da SBPC e patrono da divulgação científica no Brasil, José Reis (1909-2002), na seção permanente de ciência "No Mundo da Ciência" criada no, então, jornal Folha da Manhã (atual Folha de S. Paulo). A análise de 344 artigos, no período de 1947-1958, pode evidenciar como as iniciativas de divulgação científica de forma mais organizada visaram à formação de um público educado cientificamente e constituírem-se em uma tendência para a consolidação do caráter público da ciência. O período de análise dos textos (1947-1958) é particularmente significativo, pois foi marcado pela mobilização da comunidade científica com a criação da SBPC (na qual José Reis foi um dos fundadores e integrante de seu Conselho Científico), do CNPq, da ideia da Fapesp, entre outros. A ênfase no período histórico do pós-guerra é explicada pela importância da ação do Estado e da pressão da própria comunidade científica pela institucionalização e profissionalização da ciência. A tentativa de inscrever a divulgação científica dentro de uma perspectiva histórica não se encerra na atuação do cientista-divulgador e dos textos analisados, no entanto, fica evidente a importância de seu trabalho na constituição do campo da popularização da ciência e do jornalismo científico promovidos atualmente

Youngest dinocephalian fossils extend the Tapinocephalus Zone, Karoo Basin, South Africa.

The dinocephalians (Synapsida, Therapsida) were one of the dominant tetrapod groups of the Middle Permian (Guadalupian Epoch, ∼270-260 million years ago) and are most abundantly recorded in the Tapinocephalus Assemblage Zone (AZ) of the Main Karoo Basin, South Africa. Dinocephalians are thought to have become extinct near the top of the Abrahamskraal Formation of the Beaufort Group and their disappearance is one criterion used to define the base of the overlying Pristerognathus AZ. Because of the abundance of fossils in the Karoo, the Beaufort Group biozones form the biostratigraphic standard for later Permian terrestrial tetrapod ecosystems, so their stratigraphic delineation is of great importance to Permian palaeobiology. We report two new specimens of the rare tapinocephalid dinocephalian Criocephalosaurus from the lowermost Poortjie Member, which makes them the youngest dinocephalians known from the Main Karoo Basin and extends the Tapinocephalus AZ from the Abrahamskraal Formation up into the Teekloof Formation. The extension of the Tapinocephalus AZ relative to the lithostratigraphy potentially affects the biozone or biozones to which a fossil species can be attributed; this extension has implications for biostratigraphic correlations within the Main Karoo Basin as well as with other basins across Gondwana. These discoveries also indicate that a population of herbivorous tapinocephalids survived as rare constituents of the tetrapod fauna after most generic richness within the clade had already been lost.NCS201

QTc interval and ventricular action potential prolongation in the Mecp2Null/+ murine model of Rett syndrome

Rett Syndrome (RTT) is a congenital, X‐chromosome‐linked developmental disorder characterized by developmental delay, dysautonomia, and breathing irregularities. RTT is also associated with sudden death and QT intervals are prolonged in some RTT patients. Most individuals with RTT have mutations in the MECP2 gene. Whilst there is some evidence for QT prolongation in mouse models of RTT, there is comparatively little information on how loss of Mecp2 function affects ventricular action potentials (APs) and, to‐date, none on ventricular APs from female RTT mice. Accordingly, the present study was conducted to determine ECG and ventricular AP characteristics of Mecp2 ( Null/+ ) female mice. ECG recordings from 12–13 month old female Mecp2 ( Null/+ ) mice showed prolonged rate corrected QT (QTc) intervals compared to wild‐type (WT) controls. Although Mecp2 ( Null/+ ) animals exhibited longer periods of apnoea than did controls, no correlation between apnoea length and QT(c) interval was observed. Action potentials (APs) from Mecp2 ( Null/+ ) myocytes had longer APD(90) values than those from WT myocytes and showed augmented triangulation. Application of the investigational I(Na,Late) inhibitor GS‐6615 (eleclazine; 10 μM) reduced both APD(90) and AP triangulation in Mecp2 ( Null/+ ) and WT myocytes. These results constitute the first direct demonstration of delayed repolarization in Mecp2 ( Null/+ ) myocytes and provide further evidence that GS‐6615 may have potential as an intervention against QT prolongation in RTT

Delayed Ventricular Repolarization and Sodium Channel Current Modification in a Mouse Model of Rett Syndrome

Rett syndrome (RTT) is a severe developmental disorder that is strongly linked to mutations in the MECP2 gene. RTT has been associated with sudden unexplained death and ECG QT interval prolongation. There are mixed reports regarding QT prolongation in mouse models of RTT, with some evidence that loss of Mecp2 function enhances cardiac late Na current, I(Na,Late). The present study was undertaken in order to investigate both ECG and ventricular AP characteristics in the Mecp2(Null/Y) male murine RTT model and to interrogate both fast I(Na) and I(Na,Late) in myocytes from the model. ECG recordings from 8–10-week-old Mecp2(Null/Y) male mice revealed prolongation of the QT and rate corrected QT (QTc) intervals and QRS widening compared to wild-type (WT) controls. Action potentials (APs) from Mecp2(Null/Y) myocytes exhibited longer APD(75) and APD(90) values, increased triangulation and instability. I(Na,Late) was also significantly larger in Mecp2(Null/Y) than WT myocytes and was insensitive to the Nav1.8 inhibitor A-803467. Selective recordings of fast I(Na) revealed a decrease in peak current amplitude without significant voltage shifts in activation or inactivation V(0.5). Fast I(Na) ‘window current’ was reduced in RTT myocytes; small but significant alterations of inactivation and reactivation time-courses were detected. Effects of two I(Na,Late) inhibitors, ranolazine and GS-6615 (eleclazine), were investigated. Treatment with 30 µM ranolazine produced similar levels of inhibition of I(Na,Late) in WT and Mecp2(Null/Y) myocytes, but produced ventricular AP prolongation not abbreviation. In contrast, 10 µM GS-6615 both inhibited I(Na,Late) and shortened ventricular AP duration. The observed changes in I(Na) and I(Na,Late) can account for the corresponding ECG changes in this RTT model. GS-6615 merits further investigation as a potential treatment for QT prolongation in RTT

Avaliação do carvão produzido a partir de resíduos da produção de sementes de brachiária.

EVINCI. Resumo

Deficiency of GABAergic synaptic inhibition in the Kölliker-Fuse area underlies respiratory dysrhythmia in a mouse model of Rett syndrome

Life threatening breathing irregularity and central apnoeas are highly prevalent in children suffering from Rett syndrome. Abnormalities in inhibitory synaptic transmission have been associated with the physiopathology of this syndrome, and may underlie the respiratory disorder. In a mouse model of Rett syndrome, GABAergic terminal projections are markedly reduced in the Kölliker–Fuse nucleus (KF) in the dorsolateral pons, an important centre for control of respiratory rhythm regularity. Administration of a drug that augments endogenous GABA localized to this region of the pons reduced the incidence of apnoea and the respiratory irregularity of Rett female mice. Conversely, the respiratory disorder was recapitulated by blocking GABAergic transmission in the KF area of healthy rats. This study helps us understand the mechanism for generation of respiratory abnormality in Rett syndrome, pinpoints a brain site responsible and provides a clear anatomical target for the development of a translatable drug treatment

Balanço hidrológico da microbacia do córrego lageado, Município de Uberaba-MG, para o ano de 2012.

O manejo integrado em microbacia hidrográfica implementa uma nova maneira de se planejar e usar os recursos naturais, indo de encontro ao desenvolvimento sustentável. A compreensão do balanço hídrico, mesmo que de forma simplificada, é importante para o entendimento dos processos de degradação e conservação dos recursos naturais relacionados ao uso do solo e da água. Dentro deste contexto, o presente estudo teve por objetivo fazer o balanço hídrico da microbacia do córrego Lageado, situada no município de Uberaba, MG, para o ano de 2012. A escolha desta microbacia para este trabalho baseou-se na sua importância como terceiro maior manancial pertencente à APA (Área de Proteção Ambiental) do rio Uberaba e por estar parcialmente dentro do perímetro urbano. Nas últimas décadas, esta microbacia hidrográfica passou por intensas transformações relacionadas ao uso e à ocupação do solo