A Importância das Teleconexões para a Previsão Sazonal

http://dx.doi.org/10.5902/2179460X13155This study analyzes the performance of ensemble forecasts of the European Center for Medium-Range Weather Forecasting model (ECMWF) using the linear wave theory in order to check its performance and specific errors. Seasonal forecast composites for the period 1981 – 2002 were used as well as the ECMWF reanalysis (ERA40) for validation. The analysis of the total wavenumber (Ks) fields and some meridional profiles in selected longitudes indicated that the waveguide predicted by the model is similar to the reanalysis but there are some small but important differences, particularly related to the latitudinal displacement of the waveguides which in turn will affect Rossby wave propagation. Through the analysis of the ray tracing technique it is shown that the model is not able to correctly reproduce the atmosphere mean basic state in the seasonal forecast. Depending on the season or the wavelength propagation the remote impact may be very different, once the phase and energy of the wave will be displaced when compared to observations and therefore the possibility of, for instance, the model to predict rain (or no rain) in one specific region can be compromised.Este estudo analisa o desempenho das previsões por conjunto do modelo do European Center for Medium-Range Weather Forecast (ECMWF) utilizando a teoria linear das ondas, a fim de verificar seu desempenho e seus erros específicos. As composições sazonais da previsão foram para o período de 1981 a 2001 e a validação utilizou dados de reanálise do ECMWF (ERA40). Através das análises dos campos de  (numero de onda total) e perfis meridionais em algumas longitudes, observou-se que a previsão sazonal dos possíveis guias de onda apesar de semelhantes aos dados da reanálise possuem pequenos deslocamentos latitudinais o que irá afetar o posicionamento dos guias de onda e, consequentemente, a propagação das ondas de Rossby. As diferenças obtidas através da técnica do ray tracing (Traçado de Raios) demonstram que o modelo não é capaz de reproduzir corretamente o estado médio básico da atmosfera na previsão sazonal. Dependendo da época ou do comprimento de onda o impacto da propagação remota pode ser muito diferente, uma vez que a fase e a energia das ondas estão deslocadas em relação aos dados observacionais e, portanto, a possibilidade de ocorrer chuva ou não em uma região específica (previsão) pode ser comprometida

Chainlike Mesoporous SnO2 as a Well-Performing Catalyst for Electrochemical CO2 Reduction

In this Article, we present an easy, quick, and scalable route, based on anodic oxidation, for the preparation of mesoporous SnO2 as an efficient electrocatalyst for the CO2 reduction reaction (CO2RR). Crystallographically interconnected SnO2 nanocrystals with abundant grain boundaries, high specific surface area, and easily accessible porosity result to be active and selective for the CO2RR. This electrocatalyst shows faradaic efficiency (FE) of about 95% at-0.97 and-1.06 V versus reversible hydrogen electrode (RHE) toward the formation of predominant HCOOH and minor CO. A peak FE value of 82% for the HCOOH production is obtained at-1.06 V vs RHE. High HCOOH partial current densities of 10.2 and 15.3 mA cm-2 are observed at-0.97 and-1.15 V vs RHE, respectively. Thorough electrochemical characterizations demonstrate that the synthesized SnO2-based gas diffusion electrode allows efficient diffusion of CO2 even at high kinetics because of the highly open porous structure. The good understanding of the catalyst behavior is achieved also after the electrode testing, and it shows that the proposed preparation route results in a stable and durable material. The here reported promising results can be exploited for developing high-performance and sustainable electrocatalysts with a high potentiality to be implemented in real CO2 conversion devices

Cretaceous tetrapod tracks from Italy: a treasure trove of exceptional biodiversity

After about thirty years of investigation, the Cretaceous tetrapod track record from Italy has proved to be a ‘Rosetta Stone’ for improving understanding of the palaeogeographical and palaeoenvironmental evolution of the peri-Adriatic area. In the present contribution, we summarize current knowledge and diferent interpretations proposed on the basis of twelve ichnosites from northern, central and southern Italy. The tetrapod track record is represented by few ichnosites in the earliest Cretaceous, with the bulk of the record reported from carbonate platform deposits of the Aptian-Cenomanian interval and, in the Late Cretaceous, from a extensive-tracksite in Apulia preserving thousands of dinosaur footprints. On the whole, the ichnological diversity documented by the material indicates a high diversity of trackmakers, among which are sauropods, diferent kinds of theropods, ankylosaurs and hadrosaurs. The persistent occurrence of dinosaur footprints at diferent stratigraphic levels produced significant questions and constituted a dramatic constraint for the understanding of palaeogeographical and geodynamical evolution of the Mediterranean area during the Mesozoic, suggesting new and diferent interpretations that challenged previous reconstructions.Fil: Petti, Fabio Massimo. Museo Delle Scienze Di Trento; ItaliaFil: Antonelli, Mateo. Università di Roma; ItaliaFil: Citton, Paolo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; ArgentinaFil: Mariotti, Nino. Università di Roma; ItaliaFil: Petruzzelli, Marco. Università di Bari, Dipartimento di Scienze della Terra e Geoambientali; ItaliaFil: Pignatti, Johannes. Università di Roma; ItaliaFil: D’Orazi Porchetti, Simone. Università di Roma; ItaliaFil: Romano, Marco. Università di Roma; ItaliaFil: Sacchi, Eva. Università di Roma; ItaliaFil: Sacco, Enrico. Università di Roma; ItaliaFil: Wagensommer, Alexander. GRID (Gruppo di Ricerca sulle Impronte di Dinosauro), San Giovanni Rotondo; Itali

Multi-Center Randomized Phase II Clinical Trial on Remote Ischemic Conditioning in Acute Ischemic Stroke Within 9 Hours of Onset in Patients Ineligible to Recanalization Therapies (TRICS-9): Study Design and Protocol

Aim: To assess the efficacy of remote ischemic conditioning (RIC) in patients with ischemic stroke within 9 h of onset, that are not candidates for recanalization therapies.Sample Size Estimates: A sample size of 80 patients (40 in each arm) should yield 80% power to detect a 20% difference in early neurological improvement at 72 h at p = 0.05, two sided.Methods and Design: TRICS-9 is a phase II, multicenter, controlled, block randomized, open-label, interventional clinical trial. Patients recruited in Italian academic hospitals will be randomized 1:1 to either RIC plus standard medical therapy or standard medical therapy alone. After randomization, RIC will be applied manually by four alternating cycles of inflation/deflation 5 min each, using a blood pressure cuff around the non-paretic arm.Study Outcomes: The primary efficacy outcome is early neurological improvement, defined as the percent change in the National Institute of Health Stroke Scale (NIHSS) at 72 h in each arm. Secondary outcomes include early neurologic improvement at 24 and 48 h, disability at 3 months, rate of symptomatic intracerebral hemorrhage, feasibility (proportion of patients completing RIC), tolerability after RIC and at 72 h, blood levels of HIF-1 alpha, and HSP27 at 24 h and 72 h.Discussion/Conclusion: RIC in combination with recanalization therapies appears to add no clinical benefit to patients, but whether it is beneficial to those that are not candidates for recanalization therapies is still to be demonstrated. TRICS-9 has been developed to elucidate this issue