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

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

Noether's Symmetry Theorem for Variational and Optimal Control Problems with Time Delay

We extend the DuBois-Reymond necessary optimality condition and Noether's symmetry theorem to the time delay variational setting. Both Lagrangian and Hamiltonian versions of Noether's theorem are proved, covering problems of the calculus of variations and optimal control with delays.Comment: This is a preprint of a paper whose final and definite form will appear in the international journal Numerical Algebra, Control and Optimization (NACO). Paper accepted for publication 15-March-201

Transfer-Expanded Graphs for On-Demand Multimodal Transit Systems

This paper considers a generalization of the network design problem for On-Demand Multimodal Transit Systems (ODMTS). An ODMTS consists of a selection of hubs served by high frequency buses, and passengers are connected to the hubs by on-demand shuttles which serve the first and last miles. This paper generalizes prior work by including three additional elements that are critical in practice. First, different frequencies are allowed throughout the network. Second, additional modes of transit (e.g., rail) are included. Third, a limit on the number of transfers per passenger is introduced. Adding a constraint to limit the number of transfers has a significant negative impact on existing Benders decomposition approaches as it introduces non-convexity in the subproblem. Instead, this paper enforces the limit through transfer-expanded graphs, i.e., layered graphs in which each layer corresponds to a certain number of transfers. A real-world case study is presented for which the generalized ODMTS design problem is solved for the city of Atlanta. The results demonstrate that exploiting the problem structure through transfer-expanded graphs results in significant computational improvements.Comment: 9 pages, 4 figure

Parâmetros genéticos de caprinos da raça Saanen nascidos no Brasil de 1979 a 2009.

Resumo: A seleção permite que as características desejáveis sejam transmitidas para seus descendentes e que esses venham a produzir de forma eficiente, porém não existem trabalhos com dados oficiais no Brasil em que houvessem sido estimados os parâmetros genéticos das características biométricas e de tipo em caprinos. Foram avaliadas as características de 1243 caprinos da raça saanen, sendo 197 machos e 1046 fêmeas, nascidos de 1979 a 2009, com os seguintes parâmetros a serem estimados: perímetro torácico, comprimento corporal, altura na cernelha, altura, largura e comprimento da garupa, além das pontuações das principais características que definem o padrão racial e a aptidão do animal em uma escala de 0 a 100 pontos, incluindo a nota final e suas subdivisões, como característica racial, paleta e linha superior, membros e pés, tipo leiteiro, capacidade de corpo, úbere, ligamento traseiro e dianteiro, textura do úbere e tetos. Os componentes de variância foram estimados pelo método da Máxima Verossimilhança Restrita em análises multicaracterísticas incluindo todas as características simultaneamente. Foram encontrados valores de baixos a altos para as estimativas de herdabilidade das características morfofuncionais que variaram de 0,08 a 0,45 e correlações genéticas e fenotípicas de moderadas a altas, evidenciando a existência de variabilidade genética aditiva entre os animais e de possibilidade de resposta correlacionada. Genetic parameters of Saanen goats born in Brazil from 1979 to 2009. Abstract: The selection allows the desirable traits are transmitted to their offspring and that these will produce efficiently, but there are no jobs to official data in Brazil that had been estimated genetic parameters of biometric traits and type in goats. Were evaluated the traits of Saanen goats in 1243, being 197 males and 1046 females born from 1979 to 2009, with the following parameters to be estimated: heart girth, body length, wither height, height, width and length of rump addition to the scores of the main traits that define the breed standard and the suitability of the animal on a scale of 0 to 100 points, including the final score and its subdivisions, such as racial traits, shoulder and topline, limbs and feet, like dairy, capacity body, udder, linking front and rear, texture of the udder and teats. Variance components were estimated by Restricted Maximum Likelihood analyzes multicharacteristics including all features simultaneously. Values were found for low to high heritability estimates of morphological and functional traits that ranged from 0.08 to 0.45 and genetic and phenotypic correlations of moderate to high, showing the existence of additive genetic variability between animals and the possibility of response correlated

Insights into the role of three Endonuclease III enzymes for oxidative stress resistance in the extremely radiation resistant bacterium Deinococcus radiodurans

The extremely radiation and desiccation resistant bacterium Deinococcus radiodurans possesses three genes encoding Endonuclease III-like enzymes (DrEndoIII1, DrEndoIII2, DrEndoIII3). In vitro enzymatic activity measurements revealed that DrEndoIII2 is the main Endonuclease III in this organism, while DrEndoIII1 and 3 possess unusual and, so far, no detectable EndoIII activity, respectively. In order to understand the role of these enzymes at a cellular level, DrEndoIII knockout mutants were constructed and subjected to various oxidative stress related conditions. The results showed that the mutants are as resistant to ionizing and UV-C radiation as well as H2O2 exposure as the wild type. However, upon exposure to oxidative stress induced by methyl viologen, the knockout strains were more resistant than the wild type. The difference in resistance may be attributed to the observed upregulation of the EndoIII homologs gene expression upon addition of methyl viologen. In conclusion, our data suggest that all three EndoIII homologs are crucial for cell survival in stress conditions, since the knockout of one of the genes tend to be compensated for by overexpression of the genes encoding the other two

Numerical Modeling of Eta Carinae Bipolar Outflows

In this paper, we present two-dimensional gas dynamic simulations of the formation and evolution of the eta-Car bipolar outflows. Adopting the interacting nonspherical winds model, we have carried out high-resolution numerical simulations, which include explicitly computed time-dependent radiative cooling, for different possible scenarios of the colliding winds. In our simulations, we consider different degrees of non-spherical symmetry for the pre-outburst wind and the great eruption of the 1840s presented by the eta-Car wind. From these models, we obtain important differences in the shape and kinematical properties of the Homunculus structure. In particular, we find an appropriate combination of the wind parameters (that control the degree of non-spherical symmetry) and obtain numerical experiments that best match both the observed morphology and the expansion velocity of the eta-Car bipolar shell. In addition, our numerical simulations show the formation of a bipolar nebula embedded within the Homunculus (the little Homunculus) developed from a secondary eruptive event suffered by the star in the 1890s, and also the development of tenuous, high velocity ejections in the equatorial region that result from the impact of the eruptive wind of the 1840s with the pre-outburst wind and that could explain some of the high speed features observed in the equatorial ejecta. The models were, however, unable to produce equatorial ejections associated to the second eruptive event.Comment: 33 pages, 9 figures, accepted by the Astrophysical Journa