831 research outputs found

    Assets at risk:menstrual cycle variation in the envisioned formidability of a potential sexual assailant reveals a component of threat assessment

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    Abstract Situations of potential agonistic conflict demand rapid and effective deci-sion-making. The process of threat assessment includes assessments of relative fighting capacity, assessments of the likelihood of attack, and assessments of the extent to which one′s assets are at risk. The dimensions of physical size and strength appear to serve as key parameters in a cognitive representation summarizing multiple constituents of threat assessment. Here, we examine the thesis that this same representation summa-rizes asset risk. The fitness costs of sexual assault are in part a function of conception risk, as pregnancy due to assault compromises female choice and imperils existing and subsequent male investment. Prior research indicates that women′s attitudes and behaviors vary systematically across the menstrual cycle in a manner that would have reduced the likelihood of sexual assault during periods of greatest fertility in ancestral women. If the envisioned size and strength of a potential antagonist is used to represent asset risk, and if the threat that sexual assault poses to a woman′s reproductive assets is in part a product of her fertility, then the conceptualized size and strength of a potential sexual assailant should be a function of conception risk. We find support for thi

    Optimizing Photonic Nanostructures via Multi-fidelity Gaussian Processes

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    We apply numerical methods in combination with finite-difference-time-domain (FDTD) simulations to optimize transmission properties of plasmonic mirror color filters using a multi-objective figure of merit over a five-dimensional parameter space by utilizing novel multi-fidelity Gaussian processes approach. We compare these results with conventional derivative-free global search algorithms, such as (single-fidelity) Gaussian Processes optimization scheme, and Particle Swarm Optimization---a commonly used method in nanophotonics community, which is implemented in Lumerical commercial photonics software. We demonstrate the performance of various numerical optimization approaches on several pre-collected real-world datasets and show that by properly trading off expensive information sources with cheap simulations, one can more effectively optimize the transmission properties with a fixed budget.Comment: NIPS 2018 Workshop on Machine Learning for Molecules and Materials. arXiv admin note: substantial text overlap with arXiv:1811.0075

    Testing the affiliation hypothesis of homoerotic motivation in humans:the effects of progesterone and priming

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    The frequency of homoerotic behavior among individuals who do not identify as having an exclusively homosexual sexual orientation suggests that such behavior potentially has adaptive value. Here, we define homoerotic behavior as intimate erotic contact between members of the same sex and affiliation as the motivation to make and maintain social bonds. Among both male and female nonhuman primates, affiliation is one of the main drivers of homoerotic behavior. Correspondingly, in humans, both across cultures and across historical periods, homoerotic behavior appears to play a role in promoting social bonds. However, to date, the affiliation explanation of human homoerotic behavior has not been adequately tested experimentally. We developed a measure of homoerotic motivation with a sample of 244 men and women. Next, we found that, in women (n = 92), homoerotic motivation was positively associated with progesterone, a hormone that has been shown to promote affiliative bonding. Lastly, we explored the effects of affiliative contexts on homoerotic motivation in men (n = 59), finding that men in an affiliative priming condition were more likely to endorse engaging in homoerotic behavior compared to those primed with neutral or sexual concepts, and this effect was more pronounced in men with high progesterone. These findings constitute the first experimental support for the affiliation account of the evolution of homoerotic motivation in humans

    Molecular Theory of Hydrophobic Effects: ``She is too mean to have her name repeated.''

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    This paper reviews the molecular theory of hydrophobic effects relevant to biomolecular structure and assembly in aqueous solution. Recent progress has resulted in simple, validated molecular statistical thermodynamic theories and clarification of confusing theories of decades ago. Current work is resolving effects of wider variations of thermodynamic state, e.g. pressure denaturation of soluble proteins, and more exotic questions such as effects of surface chemistry in treating stability of macromolecular structures in aqueous solutionComment: submitted to Ann. Rev. Phys. Chem., 31 pages, 245 references, 2 figure

    Magnetism in one-dimensional metamaterials: Double hyperbolic media and magnetic surface states

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    Metamaterials with magnetic properties have been widely investigated with rather complex two- and three-dimensional resonant structures. Here we propose conceptually and demonstrate experimentally a mechanism for broadband optical magnetism in simpler one-dimensional systems. We experimentally demonstrate that alternating high-index dielectric/metal multilayer hyperbolic metamaterials can exhibit a strong magnetic response including variously µ>1 to µ<0. By engineering the electric permittivity as well, we reveal an epsilon and mu near zero regime. We show that modifications of internal metamaterial structure can lead to either type I or type II magnetic hyperbolic dispersion, thereby generalizing the notion of a hyperbolic metamaterial to encompass both TE and TM polarizations in simple multilayer geometries. Finally, we show that a negative magnetic response can give rise to TE interface-bound states, analogous to their TM counterparts, surface plasmon polaritons

    Advantages and trade-offs of introducing ethical issues in computing through a dedicated course or through modules in relevant content courses in the curriculum

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    We discuss two alternatives for introducing consideration of ethical questions in the computer science curriculum. These alternatives are 1) a selfcontained course on ethical issues in computing, and 2) introduction of modules devoted to ethical questions throughout the curriculum in content courses such as software engineering, databases, data mining, artificial intelligence, and systems. We discuss the advantages and the potential “hidden messages” involved in each of these approaches. By way of illustration, we list some of the pertinent points raised by two important case studies that are appropriate for inclusion in either a self-contained course or a course on software engineeringPresentado en el I ETHICOMP LatinoaméricaRed de Universidades con Carreras en Informática (RedUNCI

    A consideration of the lasting effects of a course introducing ethical issues in computing

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    We discuss the objectives of a course for computer science majors that introduces ethical issues in computing. In particular we are interested – as an exceptional matter – in the long term objectives. We pose and attempt to answer [or at least discuss] the following questions: What effects are we hoping such a course has on its participants five, ten, twenty years down the road? How can our contemplation of these issues inform our pedagogy? How can we design this course so that is has a lasting impact on the students?Eje: II ETHICOMP LatinoaméricaRed de Universidades con Carreras en Informática (RedUNCI

    High Spectral Resolution Plasmonic Color Filters with Subwavelength Dimensions

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    Rapid advances in image sensor technology have generated a mismatch between the small size of image sensor pixels and the achievable filter spectral resolution. This mismatch has prevented the realization of chip-based image sensors with simultaneously high spatial and spectral resolution. We report here a concept that overcomes this trade-off, enabling high spectral resolution (transmission FWHM <31 nm) filters with subwavelength dimensions operating at optical and near-infrared wavelengths. An inverse design methodology was used to realize a new type of plasmonic cavity that efficiently couples an in-plane Fabry–Perot resonator to a single plasmonic slit that supports surface plasmon polaritons. This design principle, combined with a new metal imprinting method that yields metallic nanostructures with both top and bottom surfaces that are extremely smooth, enabled demonstration of high spectral resolution transmission filters with smaller area than any previously reported
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