Cross-layer design of enhanced AMC with truncated ARQ protocols

Using a cross-layer approach, two enhancement techniques applied for adaptive modulation and coding (AMC) with truncated automatic repeat request (T-ARQ) are investigated, namely, aggressive AMC (A-AMC) and constellation rearrangement (CoRe). Aggressive AMC selects the appropriate modulation and coding schemes (MCS) to achieve higher spectral efficiency, profiting from the feasibility of using different MCSs for retransmitting a packet, whereas in the CoRe-based AMC, retransmissions of the same data packet are performed using different mappings so as to provide different degrees of protection to the bits involved, thus achieving mapping diversity gain. The performance of both schemes is evaluated in terms of average spectral efficiency and average packet loss rate, which are derived in closed-form considering transmission over Nakagami-m fading channels. Numerical results and comparisons are provided. In particular, it is shown that A-AMC combined with T-ARQ yields higher spectral efficiency than the AMC-based conventional scheme while keeping the achieved packet loss rate closer to the system's requirement, and that it can achieve larger spectral efficiency objectives than that of the scheme using AMC along with CoRe.

Discontinuous Galerkin methods for the p-biharmonic equation from a discrete variational perspective

We study discontinuous Galerkin approximations of the p-biharmonic equation for p∈(1,∞) from a variational perspective. We propose a discrete variational formulation of the problem based on an appropriate definition of a finite element Hessian and study convergence of the method (without rates) using a semicontinuity argument. We also present numerical experiments aimed at testing the robustness of the method.

Do the legs of magnetic clouds contain twisted flux-rope magnetic fields?

Magnetic clouds (MCs) are a subset of interplanetary coronal mass ejections (ICMEs) characterised primarily by a smooth rotation in the magnetic field direction indicative of the presence of a magnetic flux rope. Energetic particle signatures suggest MC flux ropes remain magnetically connected to the Sun at both ends, leading to widely used model of global MC structure as an extended flux rope, with a loop-like axis stretching out from the Sun into the heliosphere and back to the Sun. The time of flight of energetic particles, however, suggests shorter magnetic field line lengths than such a continuous twisted flux rope would produce. In this study, two simple models are compared with observed flux rope axis orientations of 196 MCs to show that the flux rope structure is confined to the MC leading edge. The magnetic cloud “legs,” which magnetically connect the flux rope to the Sun, are not recognisable as MCs and thus are unlikely to contain twisted flux rope fields. Spacecraft encounters with these non-flux rope legs may provide an explanation for the frequent observation of non-magnetic cloud ICMEs.

Microcystins -LA, -YR, and -LR action on neutrophil migration

Microcystins (MCs) produced by some freshwater cyanobacterial species possess potent liver toxicity as evidenced by acute neutrophil infiltration. Here, we investigate the ability of three structurally distinct toxins (MC-LA, MC-LR, and MC-YR) to evoke neutrophil recruitment per se and their effects on migration pathways. Intravital Microscopic Studies showed that topical application of only MC-LR enhanced the numbers of rolling and adhered leukocytes in the endothelium of postcapillary mesenteric venules. The latter effects may be dependent upon induction of the synthesis and expression Of L-selectin and beta(2)-integrin in neutrophils, as assessed by flow cytometry and RT-PCR, respectively. Conversely, the three toxins promoted direct locomotion of neutrophils and enhanced their migration in response to NO, as measured by Boyden chamber assays, and increased intracellular calcium, a messenger in the chemotaxic process. In conclusion, our results show that MCs act on specific pathways of neutrophil recruitment, indicating their potential effect on neutrophils activation. (C) 2009 Elsevier Inc. All rights reserved.

Transdural motor cortex stimulation reverses neuropathic pain in rats: A profile of neuronal activation

Motor cortex stimulation (MCS) has been used to treat patients with neuropathic pain resistant to other therapeutic approaches; however, the mechanisms of pain control by MCS are still not clearly understood. We have demonstrated that MCS increases the nociceptive threshold of naive conscious rats, with opioid participation. In the present study, the effect of transdural MCS on neuropathic pain in rats subjected to chronic constriction injury of the sciatic nerve was investigated. In addition, the pattern of neuronal activation, evaluated by Fos and Zif268 immunolabel, was performed in the spinal cord and brain sites associated with the modulation of persistent pain. MCS reversed the mechanical hyperalgesia and allodynia induced by peripheral neuropathy. After stimulation, Fos immunoreactivity (Fos-IR) decreased in the dorsal horn of the spinal cord and in the ventral posterior lateral and medial nuclei of the thalamus, when compared to animals with neuropathic pain. Furthermore, the MCS increased the Fos-IR in the periaqueductal gray, the anterior cingulate cortex and the central and basolateral amygdaloid nuclei. Zif268 results were similar to those obtained for Fos, although no changes were observed for Zif268 in the anterior cingulate cortex and the central amygdaloid nucleus after MCS. The present findings suggest that MCS reverts neuropathic pain phenomena in rats, mimicking the effect observed in humans, through activation of the limbic and descending pain inhibitory systems. Further investigation of the mechanisms involved in this effect may contribute to the improvement of the clinical treatment of persistent pain. (c) 2010 European Federation of International Association for the Study of Pain Chapters. Published by Elsevier Ltd. All rights reserved.

Immobilization of primary cultures of insulin-releasing human pancreatic cells

Transplantation of pancreatic islets isolated from organ donors constitutes a promising alternative treatment for type 1 diabetes, however, it is severely limited by the shortage of organ donors. Ex vivo islet cell cultures appear as an attractive but still elusive approach for curing type 1 diabetes. It has recently been shown that, even in the absence of fibrotic over-growth, several factors, such as insufficient nutrition of the islet core, represent a major barrier for long-term survival of islets grafts. The use of immobilized dispersed cells may contribute to solve this problem due to conceivably easier nutritional and oxygen support to the cells. Therefore, we set out to establish an immobilization method for primary cultures of human pancreatic cells by adsorption onto microcarriers (MCs). Dispersed human islets cells were seeded onto Cytodex1 microcarriers and cultured in bioreactors for up to eight days. The cell number increased and islet cells maintained their insulin secretion levels throughout the time period studied. Moreover, the cells also presented a tendency to cluster upon five days culturing. Therefore, this procedure represents a useful tool for controlled studies on islet cells physiology and, also, for biotechnological applications.

Metoder och instrument för att mäta följsamheten till hygienföreskrifter : En litteraturöversikt

Syfte: Att genom vetenskaplig litteratur beskriva vilka metoder och instrument somanvänds inom hälso- och sjukvård för att mäta följsamheten tillhygienföreskrifter.Metod: Föreliggande studie har genomförts som en litteraturöversikt. Artiklar söktes viaCinahl, PubMed och Web Of Science.Resultat: Resultatet grundar sig på 14 artiklar. Fem kategorier av metoder beskrevs, medtio tillhörande instrument. I tio av studierna användes manuell observation sommätmetod. Två studier tog upp provtagning på ytor (ATP-mätning) för attutvärdera städrutiner. Även elektronisk observation, självskattning samt intervjubeskrevs. Instrumenten som beskrevs var fyra typer av observationsformulär, tvåtyper av ATP-mätare, två typer av enheter som registrerar elektroniska signaler,ett intervjuformulär samt ett självskattningsformulär.Slutsats: Att mäta följsamheten till hygienregler behöver inte vara svårt eller kostsamt,men kan hjälpa oss i arbetet mot en högre patientsäkerhet. Mätningar kan ge ossen bild av våra svaga punkter i följsamhet till hygienregler. I och med attsynliggöra svagheterna kan vi också arbeta med att förbättra dem.

Förväntningar på kompetens hos specialistsjuksköterskan inom psykiatrisk vård

Syfte: Denna studie undersöker uppfattningar och förväntningar på den specialistutbildadesjuksköterskan från övriga professioner inom det psykiatriska teamet.Metod: Strukturerad kvalitativ och kvantitativ enkätstudie utförd på två öppna psykiatriskakliniker. Data analyserades med en deskriptiv ansats.Resultat: Resultatet visade att knappt 50 procent av respondenterna uppger sig veta vad somskiljer i formell kompetens mellan en specialistutbildad och en grundutbildad sjuksköterska.Ändå uppger samtliga respondenter att det är viktigt att det finns specialistutbildadesjuksköterskor på arbetsplatsen. Nästa alla förväntar sig att den specialistutbildadesjuksköterskan har högre kompetens än den grundutbildade. Den ökade kompetens somförväntades gällde psykiatriska sjukdomar/diagnoser samt läkemedel. Inga skillnader iarbetsuppgifter rapporterades mellan den specialist- och den grundutbildade sjuksköterskan.En osäkerhet kring specialistsjuksköterskans roll och kompetens finns både utifrån och frånsjuksköterskan själv.Slutsats: För att särskilja arbetsuppgifter mellan grundutbildade och specialistutbildadesjuksköterskor bör kännedomen om skillnaderna klargöras menar författarna. För omverksamheten inte känner till kompetensen, uppskattas den inte och därmed används intekompetensen i det kliniska arbetet.Vidare behöver ett förtydligande göras av vilken kompetens som behövs i det kliniska arbetet.

Previsão da inadimplência bancária no Brasil através dos métodos FAVAR e FAVECM

O objetivo do presente trabalho é utilizar modelos econométricos de séries de tempo para previsão do comportamento da inadimplência agregada utilizando um conjunto amplo de informação, através dos métodos FAVAR (Factor-Augmented Vector Autoregressive) de Bernanke, Boivin e Eliasz (2005) e FAVECM (Factor-augmented Error Correction Models) de Baneerjee e Marcellino (2008). A partir disso, foram construídas previsões fora da amostra de modo a comparar a eficácia de projeção dos modelos contra modelos univariados mais simples - ARIMA - modelo auto-regressivo integrado de média móvel e SARIMA - modelo sazonal auto-regressivo integrado de média móvel. Para avaliação da eficácia preditiva foi utilizada a metodologia MCS (Model Confidence Set) de Hansen, Lunde e James (2011) Essa metodologia permite comparar a superioridade de modelos temporais vis-à-vis a outros modelos.

Rolezinho pelo funk ostentação: um retrato da identidade do jovem da periferia paulistana

Essa pesquisa explora a identidade do jovem da periferia paulistana retratada pelo movimento Funk Ostentação, que foi contextualizado e analisado sob a perspectiva teórica da Consumer Culture Theory (CCT), com foco nas teorias de identidade relacionadas ao consumo, como self estendido, self expandido, consumo aspiracional e consumo compensatório. Entrevistas e grupo de foco com jovens frequentadores de bailes funk (chamados funkeiros) somaram-se às transcrições de videoclipes de Funk Ostentação e programas com participação de MCs (cantores de funk) e foram analisados e codificados de forma livre, seguindo os preceitos de Strauss e Corbin (2008). Como resultado, foi desenvolvido um modelo teórico no qual os MCs expressam sua identidade por meio de marcas, objetos, lugares e pessoas (self estendido) e expandem aspectos de sua identidade para os funkeiros (self expandido), principalmente pelos videoclipes disponibilizados no YouTube. As relações de fama, admiração e inveja, encontradas nos videoclipes e reforçadas pelo discurso dos entrevistados, mostram aspectos da identidade dos MCs e funkeiros enquanto grupo. Enquanto para os MCs o consumo mostrado nos videoclipes é algo real, os funkeiros afirmam que consomem somente as roupas, acessórios e bebidas, sendo que automóveis, motos, joias e grandes casas fazem parte de suas aspirações de consumo. Foi encontrada diferença na expressão do self masculino e feminino, sendo que o consumo e exibição dos objetos de desejo estão relacionados à identidade masculina e as garotas apenas demonstram interesse em estar com rapazes que possuam os itens desejados, não em adquiri-los. Concluiu-se que o consumo e exibição dos objetos e marcas está relacionado ao consumo compensatório. Os jovens têm no consumo uma forma de preencher alguns aspectos frágeis de seu self e validar seu acesso a determinados locais que antes não se achavam aptos a frequentar, como shoppings centers. Nenhum deles mostrou interesse no consumo ou utilização de produtos não cantados pelo Funk Ostentação, ainda que relacionados ao entretenimento, como itens para prática de esportes e videogames, o que evidencia o consumo compensatório como substituto ao consumo de objetos não relacionados simbolicamente às fragilidades do self dos indivíduos. Também não demonstraram interesse em consumir outros itens que podem lhes trazer aumento de renda, como o investimento em educação, de forma que o consumo compensatório, que remedia os efeitos da exclusão social que sentem, parece substituir a real resolução do problema.

Modelo HJM com jumps: o caso brasileiro

Utilizando dados de mercado obtidos na BM&F Bovespa, este trabalho propõe uma possível variação do modelo Heath, Jarrow e Morton em sua forma discreta e multifatorial, com a introdução de jumps como forma de considerar o efeito das reuniões realizadas pelo Cômite de Políticas Monetárias (Copom). Através do uso da análise de componentes principais (PCA), é feita a calibração dos parâmetros do modelo, possibilitando a simulação da evolução da estrutura a termo de taxa de juros (ETTJ) da curva prefixada em reais via simulação de Monte Carlo (MCS). Com os cenários da curva simulada em vértices fixos (sintéticos), os resultados são comparados aos dados observados no mercado.

Os efeitos macroeconômicos das transferências sociais: uma abordagem de matriz de contabilidade social

Government transfers to individuals and families play a central role in the Brazilian social protection system, accounting for almost 14 per cent of GDP in 2009. While their fiscal and redistributive impacts have been widely studied, the macroeconomic effects of transfers are harder to ascertain. We constructed a Social Accounting Matrix (SAM) for 2009 and estimated short-term multipliers for seven different government monetary transfers . The SAM is a double-entry square matrix depicting all income flows in the economy. The data were compiled from the 2009 Brazilian National Accounts and the 2008/2009 POF, a household budget survey. Our SAM was disaggregated into 56 sectors, 110 commodities, 200 household groups and seven factors of production (capital plus six types of labor, according to schooling). Finally, we ran a set of regressions to separate household consumption into ‘autonomous’ (or ‘exogenous’) and ‘endogenous’ components. More specifically, we are interested in the effects of an exogenous injection into each of the seven government transfers outlined above. All the other accounts are thus endogenous. The so-called demand ‘leaks’ are income flows from the endogenous to exogenous accounts. Leaks—such as savings, taxes and imports—are crucial to determine the multiplier effect of an exogenous injection, as they allow the system to go back to equilibrium. The model assumes that supply is perfectly elastic to demand shocks. It assumes that the families’ propensity to save and consumption profile are fixed—that is, rising incomes do not provoke changes in behaviour. The multiplier effects of the on GDP corresponds to the growth in GDP resulting from each additional dollar injected into each transfer seven government transfers. If the government increased Bolsa Família expenditures by 1 per cent of GDP, overall economic activity would grow by 1.78 per cent, the highest effect. The Continuous Cash Benefit, comes second. Only three transfers— the private-sector and public servants’ pensions and FGTS withdrawals—had multipliers lower than unity. The multipliers for other relevant macroeconomic aggregates—household and total consumption, disposable income etc. —reveal a similar pattern. Thus, under the stringent assumptions of our model, we cannot reject the hypothesis that government transfers targeting poor households, such as the Bolsa Família, help foster economic expansion. Naturally, it should be stressed that the multipliers relate marginal injections into government transfers to short-term economic performance either real growth, or inflation if there is no idle capacity which is also useful to analyze. In the long term, there is no doubt that what truly matters is the growth of the country’s productive capacity.

Testando a superioridade preditiva do passeio aleatório em modelos de taxa de câmbio real efetiva

O estudo busca identificar quais variáveis são as mais relevantes para previsão da taxa de câmbio real efetiva e analisar a robustez dessas previsões. Foram realizados testes de cointegração de Johansen em 13 variáveis macroeconômicas. O banco de dados utilizado são séries trimestrais e os testes foram realizados sobre as séries combinadas dois a dois, três a três e quatro a quatro. Utilizando esse método, encontramos modelos que cointegravam entre si, para os países analisados. A partir desses modelos, foram feitas previsões fora da amostra a partir das últimas 60 observações. A qualidade das previsões foi avaliada por meio dos testes de Erro Quadrático Médio (EQM) e Modelo do Conjunto de Confiança de Hansen (MCS) utilizando um modelo de passeio aleatório do câmbio real como benchmark. Todos os testes mostram que, à medida que se aumenta o horizonte de projeção, o passeio aleatório perde poder preditivo e a maioria dos modelos são mais informativos sobre o futuro da taxa de câmbio real efetivo.

Avaliação dos efeitos de um extrato bruto de cianobactérias contendo microcistinas sobre o desempenho reprodutivo e a embriofetotoxicidade de ratos

The presence of cyanobacterial blooms in reservoirs intended for supply to the population can create public health problems for many species could produce potentially toxic compounds and these are not eliminated in the conventional procedures used in water treatment plants. So even in amounts less than the maximum allowable limit imposed by MS, cyanotoxins can be present in drinking water distributed to the population, creating a chronic exposure. There is little information about the long-term effects of oral exposure to cyanotoxins. This work aimed to show the exposure orally (v.o) of animals to a crude extract of cyanobacteria containing cyanotoxins to evaluate the reproductive performance of pregnant rats and their offspring and fertility of male rats. The presence of microcystins (MCs) in samples collected during the flowering processes in freshwater reservoirs in the Rio Grande do Norte, was analyzed by enzyme immunoassay and its variants have been identified and quantified by chromatographic methods. It was observed that by administration v.o. cyanobacterial extract containing MCs (40, 100 or 250 ng of MCs / kg / day) did not cause systemic toxicity in adult rats or effect on reproductive performance of male and female rats treated. It was also not observed any changes in skeletal study in the offspring of pregnant rats treated with the extract above. Because the solutions used contained MCs in a concentration equal to or greater than the tolerable daily intake for MCs, the results suggest, therefore, that the development of this work contributed to better assess public health risk as the oral exposure to cyanotoxins, increasing thus the credibility of the maximum allowable limit (LMP) of MCs in drinking water distributed to the population of several countries that use the LMP established by WHO in its legislation

Mineralogy of the clay fraction of alfisols in two slope curvatures: IV - spatial correlation with physical properties

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)