A sex difference in the context-sensitivity of dominance perceptions

Although dominance perceptions are thought to be important for effective social interaction, their primary function is unclear. One possibility is that they simply function to identify individuals who are capable of inflicting substantial physical harm, so that the perceiver can respond to them in ways that maximize their own physical safety. Another possibility is that they are more specialized, functioning primarily to facilitate effective direct (i.e., violent) intrasexual competition for mates, particularly among men. Here we used a priming paradigm to investigate these two possibilities. Facial cues of dominance were more salient to women after they had been primed with images of angry men, a manipulation known to activate particularly strong self-protection motivations, than after they had been primed with images of angry women or smiling individuals of either sex. By contrast, dominance cues were more salient to men after they had been primed with images of women than when they had been primed with images of men (regardless of the emotional expressions displayed), a manipulation previously shown to alter men's impressions of the sex ratio of the local population. Thus, men's dominance perceptions appear to be specialized for effective direct competition for mates, while women's dominance perceptions may function to maximize their physical safety more generally. Together, our results suggest that men's and women's dominance perceptions show different patterns of context-sensitivity and, potentially, shed new light on the routes through which violence and intrasexual competition have shaped dominance perceptions

PolyMorphine provides extended analgesic-like effects in mice with spared nerve injury.

AbstractMorphine is a well-characterized and effective analgesic commonly used to provide pain relief to patients suffering from both acute and chronic pain conditions. Despite its widespread use and effectiveness, one of the major drawbacks of morphine is its relatively short half-life of approximately 4 h. This short half-life often necessitates multiple administrations of the drug each day, which may contribute to both dependence and tolerance to morphine. Here, we tested the analgesic properties of a new polymer form of morphine known as PolyMorphine. This polymer has monomeric units of morphine incorporated into a poly(anhydride-ester) backbone that has been shown to hydrolyze into free morphine in vitro. Using an animal model of chronic pain, the spared nerve injury surgery, we showed that PolyMorphine is able to block spared nerve injury-induced hypersensitivity in mice for up to 24-h post-administration. Free morphine was shown to only block spared nerve injury-induced hypersensitivity for up to 2-h post-injection. PolyMorphine was also shown to act through the mu opioid receptor due to the ability of naloxone (a mu opioid receptor antagonist) to block PolyMorphine-induced analgesia in spared nerve injury animals pretreated with PolyMorphine. Additionally, we observed that PolyMorphine causes similar locomotor and constipation side effects as free morphine. Finally, we investigated if PolyMorphine had any effects in a non-evoked pain assay, conditioned place preference. Pretreatment of spared nerve injury mice with PolyMorphine blocked the development of conditioned place preference for 2-methyl-6-(phenylethynyl)pyridine (MPEP), a short-lasting mGluR5 antagonist with analgesic-like properties. Free morphine does not block the development of preference for MPEP, suggesting that PolyMorphine has longer lasting analgesic effects compared to free morphine. Together, these data show that PolyMorphine has the potential to provide analgesia for significantly longer than free morphine while likely working through the same receptor

Magnetoroton scattering by phonons in the fractional quantum Hall regime

Motivated by recent phonon spectroscopy experiments in the fractional quantum Hall regime we consider processes in which thermally excited magnetoroton excitations are scattered by low energy phonons. We show that such scattering processes can never give rise to dissociation of magnetorotons into unbound charged quasiparticles as had been proposed previously. In addition we show that scattering of magnetorotons to longer wavelengths by phonon absorption is possible because of the shape of the magnetoroton dispersion curve and it is shown that there is a characteristic cross-over temperature above which the rate of energy transfer to the electron gas changes from an exponential (activated) to a power law dependence on the effective phonon temperature.Comment: LaTex document, 3 eps figures. submitted to Phys Rev

Voice parameters predict sex-specific body morphology in men and women

Studies of several mammalian species confirm that formant frequencies (vocal tract resonances) predict height and weight better than does fundamental frequency (F0, perceived as pitch) in same-sex adults due to differential anatomical constraints. However, our recent meta-analysis (Pisanski et al., 2014, Animal Behaviour, 95, 89–99) indicated that formants and F0 could explain no more than 10% and 2% of the variance in human height, respectively, controlling for sex and age. Here, we examined whether other voice parameters, many of which are affected by sex hormones, can indicate additional variance in human body size or shape, and whether these relationships differ between the sexes. Using a cross-cultural sample of 700 men and women, we examined relationships among 19 voice parameters (minimum–maximum F0, mean F0, F0 variability, formant-based vocal tract length estimates, shimmer, jitter, harmonics-to-noise ratio) and eight indices of body size or shape (height, weight, body mass index, hip, waist and chest circumferences, waist-to-hip ratio, chest-to-hip ratio). Our results confirm that formant measures explain the most variance in heights and weights of men and women, whereas shimmer, jitter and harmonics-to-noise ratio do not indicate height, weight or body mass index in either sex. In contrast, these perturbation and noise parameters, in addition to F0 range and variability, explained more variance in body shape than did formants or mean F0, particularly among men. Shimmer or jitter explained the most variance in men's hip circumferences (12%) and chest-to-hip ratios (6%), whereas harmonics-to-noise ratio and formants explained the most variance in women's waist-to-hip ratios (11%), and significantly more than in men's waist-to-hip ratios. Our study represents the most comprehensive analysis of vocal indicators of human body size to date and offers a foundation for future research examining the hormonal mechanisms of voice production in humans and perceptual playback experiments

Fuel cycles in nuclear reactors

Series numbering from publisher's list"61"--stamped on cover"Unclassified. NYO-2131."Originally issued by the first author as an Sc. D. thesis, Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1959Contract AT(30-1)-207

Passage-time statistics of superradiant light pulses from Bose-Einstein condensates

We discuss the passage-time statistics of superradiant light pulses generated during the scattering of laser light from an elongated atomic Bose-Einstein condensate. Focusing on the early-stage of the phenomenon, we analyze the corresponding probability distributions and their scaling behaviour with respect to the threshold photon number and the coupling strength. With respect to these parameters, we find quantities which only vary significantly during the transition between the Kapitza Dirac and the Bragg regimes. A possible connection of the present observations to Brownian motion is also discussed.Comment: Close to the version published in J. Phys.

Sensory exploitation, sexual dimorphism, and human voice pitch

Selection for low male voice pitch is generally assumed to occur because it is a valid cue of formidability. Here we summarize recent empirical challenges to this hypothesis. We also outline an alternative account in which selection for low male voice pitch is a byproduct of sensory exploitation