A magnetic reconnection model for explaining the multi-wavelength emission of the microquasars Cyg X-1 and Cyg X-3

Recent studies have indicated that cosmic ray acceleration by a first-order Fermi process in magnetic reconnection current sheets can be efficient enough in the surrounds of compact sources. In this work, we discuss this acceleration mechanism operating in the core region of galactic black hole binaries (or microquasars) and show the conditions under which this can be more efficient than shock acceleration. In addition, we compare the corresponding acceleration rate with the relevant radiative loss rates obtaining the possible energy cut-off of the accelerated particles and also compute the expected spectral energy distribution (SED) for two sources of this class, namely Cygnus X-1 and Cygnus X-3, considering both leptonic and hadronic processes. The derived SEDs are comparable to the observed ones in the low and high energy ranges. Our results suggest that hadronic non-thermal emission due to photo-meson production may produce the very high energy gamma-rays in these microquasars.Comment: 17 pages and 7 figures. Accepted for publication in the Monthly Notices of the Royal Astronomical Society (MNRAS

Ultra-High-Energy Cosmic Ray Acceleration by Magnetic Reconnection in Newborn Accretion Induced Collapse Pulsars

We here investigate the possibility that the ultra-high energy cosmic ray (UHECR) events observed above the GZK limit are mostly protons accelerated in reconnection sites just above the magnetosphere of newborn millisecond pulsars which are originated by accretion induced collapse (AIC). We show that AIC-pulsars with surface magnetic fields $10^{12} G < B_{\star} \lesssim 10^{15}$ G and spin periods $1 ms \lesssim P_{\star} < 60 ms$, are able to accelerate particles to energies $\geq 10^{20}$ eV. Because the expected rate of AIC sources in our Galaxy is very small (\sim 10^{-5} yr^{-1}), the corresponding contribution to the flux of UHECRs is neglegible, and the total flux is given by the integrated contribution from AIC sources produced by the distribution of galaxies located within the distance which is unaffected by the GZK cutoff ($\sim 50$ Mpc). We find that the reconnection efficiency factor needs to be $\xi \gtrsim 0.1$ in order to reproduce the observed flux of UHECRs.Comment: Latex file, 16 pages, 2 figures, replaced with revised version accepted for publication in the ApJ letter

Herpes Zoster na Infância

O herpes zoster (HZ) surge por reactivação do vírus varicella zoster, latente na raiz dorsal dos gânglios sensoriais. A incidência aumenta com a idade, sendo raro na infância. São descritos os casos de duas crianças de dez e 16 meses,previamente saudáveis, internadas por exantema vesicular localizado, respectivamente, aos dermátomos T11-T12 e ramo oftálmico do trigémio. Foram medicadas com aciclovir com boa evolução e o estudo da imunidade efectuado não apresentava alterações. A aquisição precoce de HZ é rara e tem sido atribuída à imaturidade do sistema imunitário da criança e à interferência com os anticorpos maternos. Numa criança pequena, previamente saudável, o HZ é um diagnóstico possível e a exclusão de imunodeficiência subjacente não é obrigatória

Modeling the spectrum of gravitational waves in the primordial Universe

Recent observations from type Ia Supernovae and from cosmic microwave background (CMB) anisotropies have revealed that most of the matter of the Universe interacts in a repulsive manner, composing the so-called dark energy constituent of the Universe. The analysis of cosmic gravitational waves (GW) represents, besides the CMB temperature and polarization anisotropies, an additional approach in the determination of parameters that may constrain the dark energy models and their consistence. In recent work, a generalized Chaplygin gas model was considered in a flat universe and the corresponding spectrum of gravitational waves was obtained. The present work adds a massless gas component to that model and the new spectrum is compared to the previous one. The Chaplygin gas is also used to simulate a $\Lambda$-CDM model by means of a particular combination of parameters so that the Chaplygin gas and the $\Lambda$-CDM models can be easily distinguished in the theoretical scenarios here established. The lack of direct observational data is partialy solved when the signature of the GW on the CMB spectra is determined.Comment: Proc. of the Conference on Magnetic Fields in the Universe: from laboratories and stars to primordial structures, AIP(NY), eds. E. M. de Gouveia Dal Pino, G. Lugones & A. Lazarian (2005), in press. (8 pages, 11 figures

Valores como predictores de satisfacción con la vida en los jóvenes

Numa perspectiva funcionalista, os valores são uma expressão cognitiva das necessidades humanas, princípios que orientam o comportamento para metas mais pessoais, sociais ou gerais de vida, cujo impacto psicossocial merece mais investigação. Neste estudo, analisou-se em que medida o tipo de orientação dos valores prediz a satisfação com a vida de 562 jovens portugueses (n = 303, 53,9% mulheres), com idades entre 14 e 22 anos (M = 16,9, DP = 1,71), que frequentam o ensino médio: via profissionalizante (63,7%) e regular (36,3%). Os jovens completaram o Questionário de Valores Básicos e a Escala de Satisfação com a Vida. Os resultados da análise de regressão linear indicam que a orientação dos valores explica menos de um quarto da variabilidade da satisfação com a vida, o que suscita a necessidade de se analisar o seu poder explicativo em conjunto com outras variáveis, por exemplo, de personalidade e sociocognitivas.In a functionalist perspective, values are a cognitive expression of human needs as well as principles that guide behaviors to personal, social or general life goals, whose psychosocial impact deserves more investigation. This study aimed to analyze whether the type of values orientation predicts life satisfaction in 562 Portuguese youths (n = 303, 53.9% women) aged 14 to 22 years (M = 16.9; SD = 1.71), attending high school studies, being 63.7% technical and (36.3%) regular high school.Students completed the Basic Values Survey and the Satisfaction With Life Scale. The results of the linear regression analyzes indicate that the values orientation explains less than a quarter of life satisfaction variability, which indicated the need to further analyze its explanatory power together with other variables, such as, personality and socio-cognitive.Desde el punto de vista funcional, los valores son una expresión cognitiva de las necesidades humanas, principios que orientan el comportamiento hacia metas más personales, sociales o generales de vida, cuyo impacto psicosocial necesita más investigación. En este estudio se analizó en qué medida el tipo de orientación de los valores predice la satisfacción con la vida de 562 jóvenes portugueses (n = 303, 53.9% mujeres), con edades entre 14 y 22 años ( = 16.9, P = 1.71) que frecuentan Enseñanza Secundaria: profesional (63.7%) y normal (36.3%). Los jóvenes completaron el Cuestionario de Valores Básicos y la Escala de Satisfacción con la Vida. Los resultados del análisis de regresión lineal indican que la orientación de los valores explica menos de una cuarta parte de la variabilidad de satisfacción con la vida, lo que plantea la necesidad de analizar su poder explicativo, junto con otras variables, por ejemplo, de personalidad y socio-cognitivas.(undefined)info:eu-repo/semantics/publishedVersio

Foster families: A systematic review of intention and retention factors

Background: Compared to residential care, family foster care is the preferable type of alternative care for neglected or abused children as it provides a familiar context that supports children’s developmental needs. New foster families are needed to care for these children. Objective: This systematic review aims to provide a critical analysis of the literature, identifying factors that explain the intention to become and to continue as a foster family. This review was performed following the PRISMA checklist and guidelines, through a search conducted in the following databases (no restrictions were made): PsycArticles, PsycInfo, Psychology and Behavioral Sciences Collection, Academic Search Complete, ERIC, Scopus, and Web of Science. Study eligibility: The review includes empirical quantitative and/or qualitative studies in English, Portuguese, and Spanish, with community and/or foster parents’ samples and explores the factors for becoming and/or retention of foster parents. Results: Forty-nine studies were included. The results revealed that the intention to become a foster parent is largely influenced by motivational factors, personal and family characteristics, individual values and beliefs, social context influences, and perceived familiarity with the child protection system. The retention of foster families is closely related to factors within the child protection system, personal or family characteristics, foster child characteristics, and placement challenges. The relationship with agencies and professional support stands out as the most important factors. Limitations and Implications: This review did not include studies focused on children with specific needs and characteristics, and future research should consider the particular challenges of fostering this group. Practice implications of these findings for the recruitment, selection, and retention of foster families will be discussed.info:eu-repo/semantics/acceptedVersio

Hodgkin's Disease in HIV Patients: Two Clinical Case Reports

Os autores apresentam dois casos de febre prolongada em doente com infecção VIH. O seu estudo conduziu ao diagnóstico de Doença de Hodgkin

Alvenaria armada : soluções inovadoras em Portugal

Neste trabalho pretende-se abordar aspectos relacionados com as tipologias de paredes de alvenaria estrutural e com a concepção de edifícios em alvenaria. Além disso, são apresentadas duas principais soluções em alvenaria armada que têm vindo a ser objecto de estudo na Universidade do Minho. Discutem-se aspectos de concepção e tipologias e complementarmente os resultados experimentais obtidos na validação experimental de ambas as soluções

PSICOLOGIA SOCIAL COMO CIÊNCIA E PRÁTICA:: O QUE PENSAM PESQUISADORES BRASILEIROS?

This study aimed to gain knowledge regarding the way Brazilian Social Psychology researchers conceivetheir field, considering the science-practice dichotomy. Participants were 100 representatives of research groups of thisdiscipline. They answered an online questionnaire with five parts: conceptions of social psychology, area representatives,reference journals, attitudes toward the discipline as basic and applied sciences and demographic questions. Social psychologywas conceived as socio-historical-critical, polarizing between Silvia Lane and Aroldo Rodrigues. The journal Psicologia &amp;Sociedade was considered the most appropriate for publications in this area, while internationally the Journal of Personalityand Social Psychology was highlighted. Participants’ attitudes characterized this discipline as applied rather than basic science.In conclusion, the abrapsian perspective is predominant in Brazil, diverging some researchers of the classic social psychology.O objetivo deste estudo foi conhecer como pesquisadores da Psicologia Social brasileira a concebem, considerando a dicotomia ciência-prática. Participaram 100 representantes de grupos de pesquisa desta disciplina. Estes responderam questionário online com cinco partes: concepções da psicologia social, representantes da área, periódicos de referência, atitudes frente à disciplina como ciência aplicada e básica e informações demográficas. A psicologia social foi concebida como sócio-histórico-crítica, polarizando entre Silvia Lane e Aroldo Rodrigues. Considerou-se Psicologia &amp; Sociedade como mais apropriada para publicações desta área, destacando-se internacionalmente o Journal Personality and Social Psychology. As atitudes dos participantes a caracterizaram como mais aplicada. Concluindo, predomina a perspectiva abrapsiana no Brasil, divergindo alguns pesquisadores da psicologia social clássica