771 research outputs found

    Exploring the Inner Edge of the Habitable Zone with Fully Coupled Oceans

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    The role of rotation in planetary atmospheres plays an important role in regulating atmospheric and oceanic heat flow, cloud formation and precipitation. Using the Goddard Institute for Space Studies (GISS) three dimension General Circulation Model (3D-GCM) we demonstrate how varying rotation rate and increasing the incident solar flux on a planet are related to each other and may allow the inner edge of the habitable zone to be much closer than many previous habitable zone studies have indicated. This is shown in particular for fully coupled ocean runs -- some of the first that have been utilized in this context. Results with a 100m mixed layer depth and our fully coupled ocean runs are compared with those of Yang et al. 2014, which demonstrates consistency across models. However, there are clear differences for rotations rates of 1-16x present earth day lengths between the mixed layer and fully couple ocean models, which points to the necessity of using fully coupled oceans whenever possible. The latter was recently demonstrated quite clearly by Hu & Yang 2014 in their aquaworld study with a fully coupled ocean when compared with similar mixed layer ocean studies and by Cullum et al. 2014. Atmospheric constituent amounts were also varied alongside adjustments to cloud parameterizations (results not shown here). While the latter have an effect on what a planet's global mean temperature is once the oceans reach equilibrium they do not qualitatively change the overall relationship between the globally averaged surface temperature and incident solar flux for rotation rates ranging from 1 to 256 times the present Earth day length. At the same time this study demonstrates that given the lack of knowledge about the atmospheric constituents and clouds on exoplanets there is still a large uncertainty as to where a planet will sit in a given star's habitable zone

    Social reward among juvenile mice

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    Mammalian social relationships, such as mother–offspring attachments and pair bonds, can directly affect reproductive output. However, conspecifics approach one another in a comparatively broad range of contexts, so conceivably there are motivations for social congregation other than those underlying reproduction, parental care or territoriality. Here, we show that reward mediated by social contact is a fundamental aspect of juvenile mouse sociality. Employing a novel social conditioned place preference (SCPP) procedure, we demonstrate that social proximity is rewarding for juvenile mice from three inbred strains (A/J, C57BL/6J and DBA/2J), while mice from a fourth strain (BALB/cJ) are much less responsive to social contact. Importantly, this strain-dependent difference was not related to phenotypic variability in exploratory behavior or contextual learning nor influenced by the genetic background associated with maternal care or social conditioning. Furthermore, the SCPP phenotype was expressed early in development (postnatal day 25) and did not require a specific sex composition within the conditioning group. Finally, SCPP responses resulted from an interaction between two specifiable processes: one component of the interaction facilitated approach toward environments that were associated with social salience, whereas a second component mediated avoidance of environmental cues that predicted social isolation. We have thus identified a genetically prescribed process that can attribute value onto conditions predicting a general form of social contact. To our knowledge, this is the first definitive evidence to show that genetic variation can influence a form of social valuation not directly related to a reproductive behavior

    The Intentional Use of Service Recovery Strategies to Influence Consumer Emotion, Cognition and Behaviour

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    Service recovery strategies have been identified as a critical factor in the success of. service organizations. This study develops a conceptual frame work to investigate how specific service recovery strategies influence the emotional, cognitive and negative behavioural responses of . consumers., as well as how emotion and cognition influence negative behavior. Understanding the impact of specific service recovery strategies will allow service providers' to more deliberately and intentionally engage in strategies that result in positive organizational outcomes. This study was conducted using a 2 x 2 between-subjects quasi-experimental design. The results suggest that service recovery has a significant impact on emotion, cognition and negative behavior. Similarly, satisfaction, negative emotion and positive emotion all influence negative behavior but distributive justice has no effect

    The Primordial Inflation Explorer (PIXIE): A Nulling Polarimeter for Cosmic Microwave Background Observations

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    The Primordial Inflation Explorer (PIXIE) is an Explorer-class mission to measure the gravity-wave signature of primordial inflation through its distinctive imprint on the linear polarization of the cosmic microwave background. The instrument consists of a polarizing Michelson interferometer configured as a nulling polarimeter to measure the difference spectrum between orthogonal linear polarizations from two co-aligned beams. Either input can view the sky or a temperature-controlled absolute reference blackbody calibrator. PIXIE will map the absolute intensity and linear polarization (Stokes I, Q, and U parameters) over the full sky in 400 spectral channels spanning 2.5 decades in frequency from 30 GHz to 6 THz (1 cm to 50 um wavelength). Multi-moded optics provide background-limited sensitivity using only 4 detectors, while the highly symmetric design and multiple signal modulations provide robust rejection of potential systematic errors. The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r < 10^{-3} at 5 standard deviations. The rich PIXIE data set will also constrain physical processes ranging from Big Bang cosmology to the nature of the first stars to physical conditions within the interstellar medium of the Galaxy.Comment: 37 pages including 17 figures. Submitted to the Journal of Cosmology and Astroparticle Physic

    Single coronary artery from the right sinus of Valsalva

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    We describe a case of a single coronary artery originating from the right coronary sinus and bifurcating into the left coronary artery (LCA) and right coronary artery (RCA) in a 74-year old woman, with a non-ST elevation acute myocardial infarction (NSTEMI). Diagnosis was made by coronary angiography which ruled out stenosis, and showed normal LCA and RCA branching. The connection path of LCA, with the opposite cusp, was defined retroaortic by multislice computed tomography (CT). The variants of this coronary anomaly, together with their clinical implications and pathophysiology of acute myocardial infarction (AMI) are discussed. Multislice CT is fundamental for clinical decision making

    Qualidade de Vida e Atitudes dos Idosos Face à Velhice

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    A problemática do envelhecimento tem assumido, nos últimos anos, uma crescente importância na consciência coletiva da população, tornando-se cada vez mais importante compreender a população idosa e a sua realidade. Posto isto, foi realizado um estudo quantitativo e correlacional, que teve como objectivo avaliar a qualidade de vida e atitudes face à velhice de idosos, bem como a relação entre estas e as variáveis sociodemográficas e familiares. Foram inquiridos 100 idosos, com mais de 65 anos e sem deficit cognitivo . Para a recolha de dados utilizou-se uma entrevista estruturada, constituída dados sóciodemográficos do idoso, WHOQOL-AGE (Caballero, Miret, Power, Chatterji, Tobiasz-Adamczyk, Koskinen, Leonardi, Olaya, Haro &Ayuso-Mateos, 2013) e o AAQ ( Laidlaw, Power, Schmidt and the WHOQOL-OLD Group, 2007). Dos resultados destacamos os seguintes: A amostra é constituída por 52% de idosos do sexo masculino tendo uma média de idades de 74,7 (DP=6,8). È no fator Perdas Psicossociais e no Desenvolvimento Psicológico que os idosos têm uma melhor atitude face ao envelhecimento. É no item “Tem dinheiro suficiente para satisfazer as suas necessidades?” que os idosos apresentam uma menor qualidade de vida. Não ter doença diagnosticada e ser do sexo masculino permitem ter melhores atitudes face ao envelhecimento. A Qualidade de Vida está relacionada com a idade, com o estado de saúde e com a intensidade de preocupação da família. Constatou-se que os idosos que não estão institucionalizados apresentam uma melhor qualidade de vida e uma melhor atitude face à velhice. Quem não precisa de ajudas técnicas para se movimentar apresenta uma melhor qualidade de vida. Diferenças nas atitudes face ao envelhecimento consoante a residência onde habita são significativas nas mudanças físicas e no desenvolvimento psicológico sendo que os idosos que não vivem em lares têm uma atitude mais positiva em ambos os fatores. / Over the past few years the issue of aging has played a growing importance in the population`s collective consciousness becoming increasingly important to understand the elderly population and this reality. Therefore a quantitative correlational study was performed to assess the quality of life of seniors and their attitudes towards old age, and the relationship between these and the socio-demographic and family factors. 100 seniors with more than 65 years and without cognitive deficit were surveyed. For data collection we used a structured interview consisting of sociodemographic data of the elderly, WHOQOL-AGE (Caballero Miret Power Chatterji Tobiasz-Adamczyk Koskinen Leonardi Olaya Ayuso-Mateos & Haro 2013) and AAQ (Laidlaw Power Schmidt and the WHOQOL-OLD Group 2007). We highlight: The sample is composed of 52% of males with a mean age of 74.7 (SD = 6.8). It is in the factor Psychosocial Losses and Psychological Development that elderly people have a better attitude towards aging. It is in the item "Do you have enough money to meet your needs?" that seniors show less quality of life. Not having illness and being male allows having better attitudes towards aging. Quality of Life is related to age, health condition and the intensity of family concerns. It was observed that the elderly who are not institutionalized have a better quality of life and a better attitude towards old age. Who does not need assistive devices to move around has a better quality of life. Differences in attitudes towards aging, according to residency, are significant in physical changes and psychological development, thus verifying that elderly who do not live in nursing homes have a more positive attitude in both factors

    Signatures of Baryon non-conserving Yukawa couplings in a supersymmetric theory

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    Renormalization effects of large baryon-nonconserving Yukawa couplings λijkUiDjDk\lambda^{\prime\prime}_{ijk} \overline{U_i} \overline{D_j} \overline{D_k} lower the right handed squark masses keeping the left-handed squark masses virtually untouched at the lowest order. At low energy they enhance the mass-splitting between left and right handed squarks of the same generation as well as intergenerational mass splitting among squarks, potentially detectable in future colliders or in rare decays. The predicted mass of the lightest stop squark becomes lower than the experimental bound for larger ranges of parameter space than that of the Baryon-conserving case, hence, further constraining the parameter space of a supersymmetric theory when baryon violation is included.Comment: 16 pages, six figures, captions.sty include

    An axiomatization of cumulative prospect theory

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    This paper presents a method for axiomatizing a variety of models for decision making under uncertainty, including Expected Utility and Cumulative Prospect Theory. This method identifies, for each model, the situations that permit consistent inferences about the ordering of value differences. Examples of rankdependent and sign-dependent preference patterns are used to motivate the models and the tradeoff consistency axioms that characterize them. The major properties of the value function in Cumulative Prospect Theory—diminishing sensitivity and loss aversion—are contrasted with the principle of diminishing marginal utility that is commonly assumed in Expected Utility

    Lorentz breaking Effective Field Theory and observational tests

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    Analogue models of gravity have provided an experimentally realizable test field for our ideas on quantum field theory in curved spacetimes but they have also inspired the investigation of possible departures from exact Lorentz invariance at microscopic scales. In this role they have joined, and sometime anticipated, several quantum gravity models characterized by Lorentz breaking phenomenology. A crucial difference between these speculations and other ones associated to quantum gravity scenarios, is the possibility to carry out observational and experimental tests which have nowadays led to a broad range of constraints on departures from Lorentz invariance. We shall review here the effective field theory approach to Lorentz breaking in the matter sector, present the constraints provided by the available observations and finally discuss the implications of the persisting uncertainty on the composition of the ultra high energy cosmic rays for the constraints on the higher order, analogue gravity inspired, Lorentz violations.Comment: 47 pages, 4 figures. Lecture Notes for the IX SIGRAV School on "Analogue Gravity", Como (Italy), May 2011. V.3. Typo corrected, references adde
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