The formation of voids in a universe with cold dark matter and a cosmological constant

A spherical Lagrangian hydrodynamical code has been written to study the formation of cosmological structures in the early Universe. In this code we take into account the presence of collisionless non-baryonic cold dark matter (CDM), the cosmological constant and a series of physical processes present during and after the recombination era, such as photon drag resulting from the cosmic background radiation and hydrogen molecular production. We follow the evolution of the structure since the recombination era until the present epoch. As an application of this code we study the formation of voids starting from negative density perturbations which evolved during and after the recombination era. We analyse a set of COBE-normalized models, using different spectra to see their influence on the formation of voids. Our results show that large voids with diameters ranging from 10h^{-1} Mpc up to 50h^{-1} Mpc can be formed in a universe model dominated by the cosmological constant (\Omega_\Lambda ~ 0.8). This particular scenario is capable of forming large and deep empty regions (with density contrasts \delta < -0.6). Our results also show that the physical processes acting on the baryonic matter produce a transition region where the radius of the dark matter component is greater than the baryonic void radius. The thickness of this transition region ranges from about tens of kiloparsecs up to a few megaparsecs, depending on the spectrum considered. Putative objects formed near voids and within the transition region would have a different amount of baryonic/dark matter when compared with \Omega_b/\Omega_d. If one were to use these galaxies to determine, by dynamical effects or other techniques, the quantity of dark matter present in the Universe, the result obtained would be only local and not representative of the Universe as a whole.Comment: MNRAS (in press); 9 pages, no figure

Toxicity of copaiba extracts to armyworm (Spodoptera frugiperda)

The objective of this study was to evaluate the effects of methanolic extracts from leaves, peels, seeds and pulps from fruits of Copaifera langsdorffii on Spodoptera frugiperda. Extracts derived from leaves and fruit peels were more toxic to S. frugiperda than the others. Hence, they were added to the artificial diet and used in further experiments with the second instar larvae of the insect, which presented larval growth reduction, prolonged period of development, increased mortality, and lower fertility and fecundity of adults. Lower egg viability was also observed when the insect was treated with extracts of leaves and fruit peels in the larvae stage. Moreover, when subjected to ultrastructural analysis under a scanning electron microscope, such eggs showed abnormalities in the aeropylar and micropylar regions. Both extracts also increased the excretion of protein in the insect feces and inhibited trypsin activity in the in vitro test. Consequently, C. langsdorffii presents potential to be used in the development of new products to control the fall armyworm.Key words: Copaifera langsdorffii, natural products, trypsin inhibitor, botanical insecticide

Ligação de dados espaço-temporais e textuais de mídias sociais com locais de interesse visitados / Linking space-time and textual data from social media with visited sites of interest

Dados de mídias sociais são gerados constantemente e representam uma relevante fonte de informação atualizada nos dias atuais. Todavia, mí- dias sociais incluem dados semi-estruturados (e.g. coordenadas geográ- ficas opcionais, indicação de local) e não estruturados (e.g. textos de postagens) que precisam ter sua semântica correta explicitada. Uma das formas de fazer isso é através de anotações semânticas que ligam porções relevantes de dados (e.g. um tweet inteiro, menções a entida- des nomeadas) a descrições com semântica bem definida em base de dados (e.g. locais de interesse do OpenStreetMap) ou de conhecimento (e.g. DBpedia, LinkedGeoData). Este trabalho se propõe a estudar, selecionar, desenvolver e testar algoritmos para ligar dados de mídias sociais que possuam coordenadas geográficas e texto (e.g. tweets ge- orreferenciados) a lugares de interesse visitados, descritos em bases de dados ou de conhecimento com semântica bem definida. Esta tarefa pode não ser tão simples em certas situações, porque coordenadas cos- tumam ter precisão limitada e pode haver uma grande quantidade de locais de interesse próximos à coordenada da postagem e até mesmo locais de interesse com coordenadas praticamente sobrepostas (e.g. em um edifício com vários andares). Desta forma, foi implementado um algoritmo para ligação de dados sobre movimento que considera dois raios distintos: um menor em que basta proximidade para ligar com confiança e outro maior em que se requer também menção ao local vi- sitado no texto para aumentar a confiabilidade da ligação. Em ambos os casos, ambiguidades são resolvidas escolhendo o local de interesse com rótulo lexicalmente mais similar ao local mencionado no texto da postagem.

Theorems on existence and global dynamics for the Einstein equations

This article is a guide to theorems on existence and global dynamics of solutions of the Einstein equations. It draws attention to open questions in the field. The local-in-time Cauchy problem, which is relatively well understood, is surveyed. Global results for solutions with various types of symmetry are discussed. A selection of results from Newtonian theory and special relativity that offer useful comparisons is presented. Treatments of global results in the case of small data and results on constructing spacetimes with prescribed singularity structure or late-time asymptotics are given. A conjectural picture of the asymptotic behaviour of general cosmological solutions of the Einstein equations is built up. Some miscellaneous topics connected with the main theme are collected in a separate section.Comment: Submitted to Living Reviews in Relativity, major update of Living Rev. Rel. 5 (2002)

Patients' perspective and lung function correlation:the importance of questionnaires in home mechanical ventilation

Classical physiological variables used to monitor respiratory function in patients under non-invasive ventilation (NIV), such as FEV1 or FVC, correlate poorly with reported impairment of physical function or overall health status and hence provide an incomplete picture of impaired health. Aim: to investigate the association between the Portuguese S3-non-invasive ventilation (S3-NIV) questionnaire score and objective measures of lung function. Consecutive adult patients with chronic respiratory failure, established on home NIV for at least 30 days were recruited in one outpatient clinic. Correlations between physiological variables and S3-NIV score were computed with Spearman rank coefficient. We studied 230 stable patients (126 male, 54.8%) with a mean age of 69.2 (± 11,0) years. Demographic and spirometry characteristics, and S3-NIV respiratory and total scores are presented on the table, according to disease groups. Spearman coefficient values are also presented. Neither the S3-NIV total score nor the respiratory symptoms subscore correlate with lung function impairment in any of the disease groups. This reinforces the notion that symptoms questionnaires and patient reported outcome measures must always be obtained directly from the patient and should be included in regular treatment monitoring

The course of specialization in public health in Rio de Janeiro, Brazil, from 1926 to 2006: lessons and challenges

<p>Abstract</p> <p>Background</p> <p>Public health, as a field of knowledge, depends on its professionals. Their education and training, therefore, is considered to be an important factor for the quality of health services. In Brazil, the Course of Specialization in Public Health of the National School of Public Health is one of the oldest in the country. The course has existed for over 80 years, during which it has had an eventful history, with modifications in its organization, interruptions in its delivery, threats to its survival and changes in the institutions hosting it, reflecting the wider transformation in Brazilian society and public life over that period.</p> <p>Methods</p> <p>In this article we analyse this course via its history, disciplines, organization and characteristics of the student body.</p> <p>Results</p> <p>Insights were gained into the advancement of public health in Brazil and the progress of education for professionals in this field was highlighted. The course has formed nearly 2000 specialists in public health.</p> <p>Conclusions</p> <p>An analysis of the course's history provides valuable lessons for other schools of public health trying to train professionals in developing countries.</p