Robustness area technique developing guidelines for power system restoration

This paper proposes a novel energy based technique called the Robustness Area (RA) technique that measures power system robustness levels, as a helper for planning Power System Restorations (PSRs). The motivation is on account of the latest blackouts in Brazil, where the local Independent System Operator (ISO) encountered difficulties related to circuit disconnections during the restoration. The technique identifies vulnerable and robust buses, pointing out system areas that should be firstly reinforced during PSR, in order to enhance system stability. A Brazilian power system restoration area is used to compare the guidelines adopted by the ISO with a more suitable new plan indicated by the RA tool. Active power and reactive power load margin and standing phase angle show the method efficiency as a result of a well balanced system configuration, enhancing the restoration performance. Time domain simulations for loop closures and severe events also show the positive impact that the proposed tool brings to PSRs

Public support for environmental organisations in BRIC countries

postprin

Los impactos de la crisis internacional en América Latina: ¿Hay margen para el diseño de políticas regionales?

La crisis internacional que se desencadenó en el segundo semestre de 2008 llevó a la adopción de medidas proteccionistas por parte de diversos países, principalmente para evitar problemas de balanza de pagos, potenciar el mercado interno como alternativa de crecimiento y lidiar con el aumento de la competencia en productos con excesivos inventarios en China y otros países de Asia. En muchos casos esas medidas adoptaron la forma de barreras no arancelarias, cuyo impacto es difícil de evaluar. Estas medidas restrictivas, de las que no estuvieron exentos los países de América Latina, agravaron los impactos de la crisis sobre los intercambios comerciales. Este libro examina las medidas de política comercial adoptadas por los países de América Latina y el Caribe en el contexto de la crisis internacional y evalúa en forma cuantitativa sus posibles impactos sobre las grandes variables macroeconómicas, la pobreza y la desigualdad. Asimismo, discute otras alternativas de política comercial aplicables en un contexto de crisis. De esta manera, se presenta a los hacedores de la política pública insumos para el debate con el objeto de poner en sus agendas instrumentos que permitan cuantificar los impactos de los cambios de políticas. El trabajo concluye que, pese a los impactos adversos de la crisis y de algunas medidas adoptadas por los países de la región sobre el producto, el comercio, el empleo y los indicadores sociales, hay espacios reales para la aplicación de políticas de mitigación de este tipo de efectos, así como oportunidades para una mayor coordinación de políticas en la región.international crisis, public policies

Narrativas de grafite e expressividade subalterna na pós-modernidade

Este trabalho visa explorar as maneiras pelas quais os grafites se enquadram nos modos de narração e construção de laços de sociabilidade e memória na pós-modernidade. Na esteira do pensamento de autores de filiação pós-moderna, voluntária ou não, propõe-se analisar as narrativas fragmentárias nas quais prevalecem histórias locais de grupos antes vistos como subalternos. Com um acesso ampliado às tecnologias de comunicação, parece haver uma emergência de vozes outrora silenciadas sob o status quo oficial, com uma crescente variedade de visões de mundo de tais grupos na pós-modernidade. A disseminação dessas vozes não mais favorece a história como um conjunto de fatos concretos estabelecidos por um saber legítimo, mas como um número de fábulas que animam uma renovada expressividade subalterna

Physical properties of Herschel selected galaxies in a semi-analytic galaxy formation model

[Abridged] We make use of a semi-analytic cosmological model that includes simple prescriptions for dust attenuation and emission to make predictions for the observable and physical properties of galaxies that may be detected by the recently launched Herschel Space Observatory in deep fields such as GOODS-Herschel. We compare our predictions for differential galaxy number counts in the PACS (100 & 160) and SPIRE (250, 350, and 500 micron) bands with available observations. We find very good agreement with the counts in the PACS bands, for the overall counts and for galaxies binned by redshift at z< 2. At z > 2 our model underpredicts the number of bright galaxies by a factor of ten. The agreement is much worse for all three SPIRE bands, and becomes progressively worse with increasing wavelength. We discuss a number of possible reasons for these discrepancies, and hypothesize that the effect of blending on the observational flux estimates is likely to be the dominant issue. We note that the PACS number counts are relatively robust to changes in the dust emission templates, while the predicted SPIRE number counts are more template dependent. We present quantitative predictions for the relationship between the observed PACS 160 and SPIRE 250 micron fluxes and physical quantities such as halo mass, stellar mass, cold gas mass, star formation rate, and total infrared (IR) luminosity, at different redshifts. We also present quantitative predictions for the correlation between PACS 160 micron flux and the probability that a galaxy has experienced a recent major or minor merger. Although our models predict a strong correlation between these quantities, such that more IR-luminous galaxies are more likely to be merger-driven, we find that more than half of all high redshift IR-luminous galaxies detected by Herschel are able to attain their high star formation rates without enhancement by a merger.Comment: Accepted for publication in MNRA

Perspectives on the Trypanosoma cruzi-host cell receptor interaction

Chagas disease is caused by the parasite Trypanosoma cruzi. The critical initial event is the interaction of the trypomastigote form of the parasite with host receptors. This review highlights recent observations concerning these interactions. Some of the key receptors considered are those for thromboxane, bradykinin, and for the nerve growth factor TrKA. Other important receptors such as galectin-3, thrombospondin, and laminin are also discussed. Investigation into the molecular biology and cell biology of host receptors for T. cruzi may provide novel therapeutic targets

Differences in bleeding behavior after endoscopic band ligation: a retrospective analysis

<p>Abstract</p> <p>Background</p> <p>Endoscopic band ligation (EBL) is generally accepted as the treatment of choice for bleeding from esophageal varices. It is also used for secondary prophylaxis of esophageal variceal hemorrhage. However, there is no data or guidelines concerning endoscopic control of ligation ulcers. We conducted a retrospective study of EBL procedures analyzing bleeding complications after EBL.</p> <p>Methods</p> <p>We retrospectively analyzed data from patients who underwent EBL. We analyzed several data points, including indication for the procedure, bleeding events and the time interval between EBL and bleeding.</p> <p>Results</p> <p>255 patients and 387 ligation sessions were included in the analysis. We observed an overall bleeding rate after EBL of 7.8%. Bleeding events after elective treatment (3.9%) were significantly lower than those after treatment for acute variceal hemorrhage (12.1%). The number of bleeding events from ligation ulcers and variceal rebleeding was 14 and 15, respectively. The bleeding rate from the ligation site in the group who underwent emergency ligation was 7.1% and 0.5% in the group who underwent elective ligation. Incidence of variceal rebleeding did not vary significantly. Seventy-five percent of all bleeding episodes after elective treatment occurred within four days after EBL. 20/22 of bleeding events after emergency ligation occured within 11 days after treatment. Elective EBL has a lower risk of bleeding from treatment-induced ulceration than emergency ligation.</p> <p>Conclusions</p> <p>Patients who underwent EBL for treatment of acute variceal bleeding should be kept under medical surveillance for 11 days. After elective EBL, it may be reasonable to restrict the period of surveillance to four days or even perform the procedure in an out-patient setting.</p

Flavonoids from Pterogyne nitens Inhibit Hepatitis C Virus Entry

Hepatitis C virus (HCV) is one of the leading causes of liver diseases and transplantation worldwide. The current available therapy for HCV infection is based on interferon-α, ribavirin and the new direct-acting antivirals (DAAs), such as NS3 protease and NS5B polymerase inhibitors. However, the high costs of drug design, severe side effects and HCV resistance presented by the existing treatments demonstrate the need for developing more efficient anti-HCV agents. This study aimed to evaluate the antiviral effects of sorbifolin (1) and pedalitin (2), two flavonoids from Pterogyne nitens on the HCV replication cycle. These compounds were investigated for their anti-HCV activities using genotype 2a JFH-1 subgenomic replicons and infectious virus systems. Flavonoids 1 and 2 inhibited virus entry up to 45.0% and 78.7% respectively at non-cytotoxic concentrations. The mechanism of the flavonoid 2 block to virus entry was demonstrated to be by both the direct action on virus particles and the interference on the host cells. Alternatively, the flavonoid 1 activity was restricted to its virucidal effect. Additionally, no inhibitory effects on HCV replication and release were observed by treating cells with these flavonoids. These data are the first description of 1 and 2 possessing in vitro anti-HCV activity