Absolute and convective instabilities of parallel propagating circularly polarized Alfven waves: Beat instability

Ruderman and Simpson [Phys. Plasmas 11, 4178 (2004)] studied the absolute and convective decay instabilities of parallel propagating circularly polarized Alfven waves in plasmas where the sound speed c(S) is smaller than the Alfven speed upsilon(A). We extend their analysis for the beat instability which occurs in plasmas with c(S)>upsilon(A). We assume that the dimensionless amplitude of the circularly polarized Alfven wave (pump wave), a, is small. Applying Briggs' method we study the problem analytically using expansions in power series with respect to a. It is shown that the pump wave is absolutely unstable in a reference frame moving with the velocity U with respect to the rest plasma if U-lU-r, the instability is convective. The signaling problem is studied in a reference frame where the pump wave is convectively unstable. It is shown that the spatially amplifying waves exist only when the signaling frequency is in two narrow symmetric frequency bands with the widths of the order of a(3). These results enable us to extend for the case when c(S)>upsilon(A) the conclusions, previously made for the case when c(S)<upsilon(A), that circularly polarized Alfven waves propagating in the solar wind are convectively unstable in a reference frame of any spacecraft moving with the velocity not exceeding a few tens of km/s in the solar reference frame. The characteristic scale of spatial amplification for these waves exceeds 1 a.u

Variações Longitudinais de Lipoproteínas de Baixa Densidade Oxidadas Associadas à Artéria "Culpada" no Enfarte do Miocárdio com Elevação ST - um Marcador Promissor?

The aim of the present study was to investigate variations in oxidized LDL (oxLDL) at the onset of acute myocardial infarction (AMI) and over the recovery period, exploring their relationship with coronary disease severity. A follow-up of 50 AMI patients was evaluated against 25 healthy volunteers (reference group). The AMI patients were evaluated at three time points: at admission before the administration of IIb/IIIa inhibitors and angioplasty, and two and 40 days after intervention. Plasma oxLDL concentrations were measured by ELISA. oxLDL was found to be significantly higher in AMI patients in the acute phase relative to reference levels, decreasing progressively over the recovery period. The results also demonstrated that oxLDL levels were decreased in patients with the left circumflex artery (LCX) as culprit vessel compared to the left anterior descending coronary (LAD) or right coronary artery (RCA). The results highlight a significant increase in oxLDL concentration related to coronary artery disease severity, as conditions such as LCX lesions are usually associated with a favorable prognosis, contrasting with LAD-associated conditions that can compromise large areas of myocardium. The results thus suggest that oxLDL may constitute a promising marker in assessment of AMI evolution

Impact of Euro-Atlantic blocking patterns in Iberia precipitation using a novel high resolution dataset

In this work we reassess the impacts of blocking patterns on precipitation regimes in the Iberian Peninsula, distinguishing between north Atlantic and European blocking. For this we take full advantage of the recently developed high-resolution datasets for the Iberian countries. Precipitation anomalies during blocking events obtained with this dataset allow a much finer regional characterization of the impacts in both average and extreme daily precipitation, particularly when compared to widely used low-resolution reanalysis datasets. Blocked patterns induce a negative-positive dipole of precipitation anomalies from northwest to southeast Iberia. Increases are widespread during Atlantic blocks and pronounced in southern and eastern areas of Iberia, while during European blocks they are more spatially restricted, with increases above 50 % in coastal Mediterranean areas, which represents a considerable fraction of the annual precipitation. Blocking impacts in precipitation are nearly opposite to those found during strong zonal flow situations, but there are also some asymmetries in the precipitation responses. A significant increase in cyclones and cut-off lows frequency southwards of blocking structures is related to precipitation excesses over southern and eastern areas, where dynamical factors and local processes play a crucial role. On the contrary, precipitation deficits in northwest Iberia during blocking episodes are better explained by a reduction in north Atlantic frontal activity and simultaneous decreases in large-scale moisture advection towards northern Iberia. We show that these anomalies during blocking result from changes in precipitation amount rather than from increases in rainy days, pointing to more extreme rainfall regimes, particularly in southeastern Iberia. Finally, an Extreme Value Analysis was performed, fitting Generalized Pareto Distributions to precipitation extremes. Results show that the different extreme precipitation regimes of northwest and Mediterranean regions are partially determined by opposite anomalies of the zonal flow. Thus, heavy precipitation events in Mediterranean areas are usually short-lived and frequently associated with blocking conditions, while in northwest Iberia the total accumulations during rainfall episodes are more important for triggering extreme events and they are mainly related to strong westerly flows.Peer reviewe

Spatial extremes of wildfire sizes: Bayesian hieralquical models for extremes

In Portugal, due to the combination of climatological and ecological factors, large wildfires are a constant threat and due to their economic impact, a big policy issue. In order to organize efficient fire fighting capacity and resource management, correct quantification of the risk of large wildfires are needed. In this paper, we quantify the regional risk of large wildfire sizes, by fitting a Generalized Pareto distribution to excesses over a suitably chosen high threshold. Spatio-temporal variations are introduced into the model through model parameters with suitably chosen link functions. The inference on these models are carried using Bayesian Hierarchical Models and Markov chain Monte Carlo methods

Healthcare Recommendations from the Personalised ICT Supported Service for Independent Living and Active Ageing (PERSSILAA) Study

In the face of demographic ageing European healthcare providers and policy makers are recognising an increasing prevalence of frail, community-dwelling older adults, prone to adverse healthcare outcomes. Prefrailty, before onset of functional decline, is suggested to be reversible but interventions targeting this risk syndrome are limited. No consensus on the definition, diagnosis or management of pre-frailty exists. The PERsonalised ICT Supported Service for Independent Living and Active Ageing (PERSSILAA) project (2013-2016 under Framework Programme 7, grant #610359) developed a comprehensive Information and Communication Technologies (ICT) supported platform to screen, assess, manage and monitor pre-frail community-dwelling older adults in order to address pre-frailty and promote active and healthy ageing. PERSSILAA, a multi-domain ICT service, targets three pre-frailty: nutrition, cognition and physical function. The project produced 42 recommendations across clinical (screening, monitoring and managing of pre-frail older adults) technical (ICT-based innovations) and societal (health literacy in older adults, guidance to healthcare professional, patients, caregivers and policy makers) areas. This paper describes the 25 healthcare related recommendations of PERSSILAA, exploring how they could be used in the development of future European guidelines on the screening and prevention of frailty

Fire danger rating over Mediterranean Europe based on fire radiative power derived from Meteosat

We present a procedure that allows the operational generation of daily forecasts of fire danger over Mediterranean Europe. The procedure combines historical information about radiative energy released by fire events with daily meteorological forecasts, as provided by the Satellite Application Facility for Land Surface Analysis (LSA SAF) and the European Centre for Medium-Range Weather Forecasts (ECMWF). Fire danger is estimated based on daily probabilities of exceedance of daily energy released by fires occurring at the pixel level. Daily probability considers meteorological factors by means of the Canadian Fire Weather Index (FWI) and is estimated using a daily model based on a generalized Pareto distribution. Five classes of fire danger are then associated with daily probability estimated by the daily model. The model is calibrated using 13 years of data (2004–2016) and validated against the period of January–September 2017. Results obtained show that about 72 % of events releasing daily energy above 10 000 GJ belong to the extreme class of fire danger, a considerably high fraction that is more than 1.5 times the values obtained when using the currently operational Fire Danger Forecast module of the European Forest Fire Information System (EFFIS) or the Fire Risk Map (FRM) product disseminated by the LSA SAF. Besides assisting in wildfire management, the procedure is expected to help in decision making on prescribed burning within the framework of agricultural and forest management practices

ATRIBUTOS DETERMINANTES PARA COMPRA DE DEFENSIVOS AGRÍCOLAS: UM ESTUDO SOBRE O CAFEICULTOR NA REGIÃO DE PATROCÍNIO – MG

Neste artigo tem-se como objetivo principal analisar e descrever os atributos determinantes para a compra de defensivos agrícolas pelo produtor rural de café da região de Patrocínio/MG, verificando se a perspectiva teórica de Sheth, Mittal e Newman (2001) é adequada para tal. Elaborou-se inicialmente um instrumento de pesquisa que foi utilizado em um survey interseccional a partir dos pressupostos desse modelo. Os componentes individuais do instrumento foram divididos em cinco blocos, e em seguida utilizou-se a análise de cluster para obter um melhor agrupamento das variáveis contidas em cada bloco. Com o resultado dessa análise foi possível elaborar as hipóteses da pesquisa. Após essa fase, utilizou-se o teste qui-quadrado para julgar as hipóteses formuladas e validar a formação dos clusters. Para verificar o nível de similaridade contido nos atributos analisados na pesquisa foram feitas análises de correspondências simples e múltiplas. A partir desse procedimento estatístico, foi possível considerar adequado o modelo de Sheth, Mittal e Newman (2001). Como principal resultado pode-se identificar com base na classificação de Alpert (1971) os atributos determinantes para compra pelo produtor rural de café de Patrocínio/MG e região. ----- The article’s main goal’s to analyze and describe determining attributes for the purchase of agriculture defensives by coffee producers in the region of Patrocínio/MG, and also test if the theoretical perspective by Sheth, Mittal and Newman (2001) is suitable for this. Initially, it was elaborated a survey instrument that was used in an intersectional survey from the assumptions of this model. The individual components of the instrument were divided into five blocks, then used the cluster analysis to obtain a better grouping of the variables contained in each block. With the analysis results it was possible to elaborate the research hypothesis. Afterwards, it was used the qui-square test to judge formulated hypothesis and to valid the clusters formation. To verify the similarity level contained in the attributes analyzed on the research, simple and multiple correspondences analysis were done. Throughout this statistic procedure, it was possible to consider the model by Sheth, Mittal and Newman (2001) as being suitable. Therefore, as results of this research, based on Alpert rating scale (1971), it was possible to identify attributes for purchase by coffee producers in the region of Patrocínio/MG