505 research outputs found

    (Anti-)de Sitter Black Hole Thermodynamics and the Generalized Uncertainty Principle

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    We extend the derivation of the Hawking temperature of a Schwarzschild black hole via the Heisenberg uncertainty principle to the de Sitter and anti-de Sitter spacetimes. The thermodynamics of the Schwarzschild-(anti-)de Sitter black holes is obtained from the generalized uncertainty principle of string theory and non-commutative geometry. This may explain why the thermodynamics of (anti-)de Sitter-like black holes admits a holographic description in terms of a dual quantum conformal field theory, whereas the thermodynamics of Schwarzschild-like black holes does not.Comment: 10 pages, revtex

    Sociosexual attitudes and quality of life in (non)monogamous relationships: the role of attraction and constraining forces among users of the Second Love web site

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    Research has typically shown that unrestricted sociosexuality is negatively associated with relationship quality and that relationship quality is positively associated with quality of life (QoL). However, these findings may be restricted to individuals in monogamous relationships, especially those with prior extradyadic interactions (i.e., non-consensual non-monogamous; NCNM). Indeed, individuals in consensual non-monogamous (CNM) relationships have more unrestricted sociosexuality and are also more satisfied with and committed to their relationships. Still, little research has examined whether both relationship agreements are associated differently with attraction forces (wanting to be) and constraining forces (having to be) in the relationship and how they are related to QoL. We conducted a cross-sectional study with 373 heterosexuals (73.2% men, Mage = 41.15, SD = 10.18) registered on Second Love, a dating Web site for romantically involved individuals. Results showed differences in the hypothesized model, according to relationship agreement. For individuals in CNM relationships, unrestricted sociosexuality was associated with stronger attraction forces, which were then associated with greater QoL. The opposite pattern was found for those in NCNM relationships. Furthermore, and regardless of relationship agreement, unrestricted sociosexuality was associated with weaker constraining forces, which were associated with greater QoL. These results make a novel contribution to the literature on relationship agreements and how they relate to QoL

    The effects of linguistic and cognitive factors on the L2 processing of oral input: a self-paced listening experiment

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    Listening comprehension is a real-time process, yet very little is known about the variables affecting real-time second language (L2) listening. The present study aimed at investigating the effects of syntactic complexity and word frequency on L2 listening. Furthermore, the role of the listener’s working memory capacity in listening comprehension was investigated. Fifty-three Dutch learners of French were tested using a working memory task and self-paced listening technique. Working memory scores and reaction times were collected as a measure of processing efficiency. Contrast analyses were run on the reaction times per variable. Correlation tests were run between the working memory scores and reaction times. The results showed that syntactic complexity affects L2 listening comprehension. However, no effect of word frequency on L2 listening and no correlation between working memory capacity and L2 listening in any of the conditions was found. We conclude that linguistic factors shown to affect offline L2 listening are not always generalizable to online L2 listening. We also conclude that working memory considered as a cognitive system separate from other cognitive processes involved in language comprehension does not explain individual differences in real-time L2 listening. Further research needs to be done to better understand (real-time) L2 listening comprehension

    Speeding up ecological and evolutionary computations in R; essentials of high performance computing for biologists

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    Computation has become a critical component of research in biology. A risk has emerged that computational and programming challenges may limit research scope, depth, and quality. We review various solutions to common computational efficiency problems in ecological and evolutionary research. Our review pulls together material that is currently scattered across many sources and emphasizes those techniques that are especially effective for typical ecological and environmental problems. We demonstrate how straightforward it can be to write efficient code and implement techniques such as profiling or parallel computing. We supply a newly developed R package (aprof) that helps to identify computational bottlenecks in R code and determine whether optimization can be effective. Our review is complemented by a practical set of examples and detailed Supporting Information material (S1–S3 Texts) that demonstrate large improvements in computational speed (ranging from 10.5 times to 14,000 times faster). By improving computational efficiency, biologists can feasibly solve more complex tasks, ask more ambitious questions, and include more sophisticated analyses in their research

    Affine equation of state from quintessence and k-essence fields

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    We explore the possibility that a scalar field with appropriate Lagrangian can mimic a perfect fluid with an affine barotropic equation of state. The latter can be thought of as a generic cosmological dark component evolving as an effective cosmological constant plus a generalized dark matter. As such, it can be used as a simple, phenomenological model for either dark energy or unified dark matter. Furthermore, it can approximate (up to first order in the energy density) any barotropic dark fluid with arbitrary equation of state. We find that two kinds of Lagrangian for the scalar field can reproduce the desired behaviour: a quintessence-like with a hyperbolic potential, or a purely kinetic k-essence one. We discuss the behaviour of these two classes of models from the point of view of the cosmological background, and we give some hints on their possible clustering properties.Comment: 9 pages, 6 figures. Minor updates, accepted by CQ

    Canine distemper virus ISCOMS induce protection in harbour seals (Phoca vitulina) against phocid distemper but still allow subsequent infection with phocid distemper virus-1.

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    A candidate canine distemper virus (CDV) ISCOM vaccine has been shown to be effective in protecting harbour seals (Phoca vitulina) from phocid distemper in 1988. However, of the 35 harbour seals receiving this vaccine upon admission to a seal rehabilitation and research centre (Pieterburen, The Netherlands) in 1989, six developed mild inflammatory symptoms of the respiratory tract. Phocid distemper virus-1 (PDV-1) could be isolated from three of these animals. This indicates that the vaccine affords protection from phocid distemper, but may still allow PDV-1 infection of the respiratory tract. Contacts with non-vaccinated seals should then be prevented until no more virus is excreted. It is speculated that this PDV-1 infection of the respiratory tract in CDV-ISCOM vaccinated seals is followed by a lifelong immunity

    A Host–parasite Model Explains Variation in Liana Infestation Among Co‐occurring Tree Species

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    Lianas are structural parasites of trees that reduce the growth, survival and reproduction of their hosts. Given that co‐occurring tree species differ strongly in the proportion of individuals that are infested by lianas (liana prevalence), lianas could differentially impact tree species and thereby influence tree community composition. Surprisingly, little is known about what governs variation in liana prevalence. Here, we apply an approach inspired by disease ecology to investigate the dynamics of liana prevalence over 11 years on Barro Colorado Island, Panama. We followed the fate of 1,938 individual trees from 21 tree species, recording deaths and change in liana infestation status. With these data, we fit species‐specific Markov chain models to estimate four rates: colonization by lianas (analogous to disease transmission), shedding or loss of lianas (analogous to host recovery), baseline mortality of uninfested trees (baseline mortality) and additional mortality of infested trees (parasite lethality). Models explained 58% of variation in liana prevalence among tree species, and revealed that host shedding of lianas and parasite lethality were the most important contributors to interspecific variation in liana prevalence at our site. These rates were also strongly related to shade tolerance, with light‐demanding species having greater rates of shedding and lethality, and lower rates of liana prevalence. An indirect path analysis with a structural equation model revealed that both greater rates of liana shedding and liana‐induced lethality contribute to the observed lower rates of liana prevalence for light‐demanding tree species. Synthesis. Our approach revealed that the prevalence of liana infestation among tree species is driven via indirect pathways operating on the rates of shedding and lethality, which relate to the ability (or inability) of trees to shed and/or tolerate lianas. Shade‐tolerant trees have greater proportions of trees infested by lianas because they are both less able to shed lianas and more able to tolerate infestation

    Elastic Tensor of Sr2_2RuO4_4

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    The six independent elastic constants of Sr2_2RuO4_4 were determined using resonant ultrasound spectroscopy on a high-quality single-crystal specimen. The constants are in excellent agreement with those obtained from pulse-echo experiments performed on a sample cut from the same ingot. A calculation of the Debye temperature using the measured constants agrees well with values obtained from both specific heat and M\"{o}ssbauer measurements.Comment: 4 pages, 2 figures, 2 tables, submitted to PR
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