13,142 research outputs found
Female Mate Choice is Influenced by Male Sport Participation
Sexual selection theory argues that females invest more heavily in reproduction than males and thus tend to be choosier in terms of mate choice. Sport may provide a context within which females can gain information about male quality to inform this choice. Males may be able to display attractive traits such as athleticism, strength, and physique to females while participating in sport. We predicted that females would favor males that participated in team sports over individual sports and non-athletes because team sport athletes may be more likely to display qualities such as the ability to work well with others and role acceptance. We used a questionnaire, a photograph, and manipulated descriptions to gauge the effects of sport involvement, attractiveness, and status on 282 females’ willingness to participate in various types of relationships. Team sport athletes were perceived as being more desirable as potential mates than individual sport athletes and non-athletes. It is suggested that team sport athletes may have traits associated with good parenting such as cooperation, likeability, and role acceptance, and/or these athletes may be better able to assert dominance in a team setting. Results are discussed in terms of further implications and future research
Using the chromatic Rossiter-McLaughlin effect to probe the broadband signature in the optical transmission spectrum of HD 189733b
Transmission spectroscopy is a powerful technique for probing exoplanetary
atmospheres. A successful ground-based observational method uses a differential
technique based on high-dispersion spectroscopy, but that only preserves narrow
features in transmission spectra. Here we use the chromatic Rossiter-McLaughlin
(RM) effect to measure the Rayleigh-scattering slope in the transmission
spectrum of HD 189733b with the aim to show that it can be effectively used to
measure broadband transmission features. The amplitude of the RM effects
depends on the effective size of the planet, and in the case of an atmospheric
contribution therefore depends on the observed wavelength. We analysed archival
HARPS data of three transits of HD 189733b, covering a wavelength range of 400
to 700 nm. We measured the slope in the transmission spectrum of HD 189733b at
a significance. Assuming it is due to Rayleigh scattering and not
caused by stellar activity, it would correspond to an atmospheric temperature,
as set by the scale height, of , well in line with
previously obtained results. This shows that ground-based high-dispersion
spectral observations can be used to probe broad-band features in the
transmission spectra of extrasolar planets, by using the chromatic RM effect.
This method will be particularly interesting in conjunction with the new
echelle spectrograph ESPRESSO, which currently is under construction for ESOs
Very Large Telescope and will provide a gain in signal-to-noise ratio of about
a factor 4 compared to HARPS. This will be of great value because of the
limited and uncertain future of the Hubble Space Telescope and because the
future James Webb Space Telescope will not cover this wavelength regime.Comment: 8 pages, 7 figures, accepted for publication on Astronomy and
Astrophysic
Superconducting phase formation in random neck syntheses: a study of the Y-Ba-Cu-O system by magneto-optics and magnetometry
Magneto-optical imaging and magnetization measurements were applied to
investigate local formation of superconducting phase effected by a random neck
synthesis in Y-Ba-Cu-O system. Polished pellets of strongly inhomogeneous
ceramic samples show clearly the appearance of superconducting material in the
intergrain zones of binary primary particles reacted under different
conditions. Susceptibility measurements allows evaluation of superconducting
critical temperature, which turned out to be close to that of optimally doped
YBCO.Comment: 6 pages, 11 figure
Hadronic structure in tau- -> pi- pi- pi+ neutrino decays
A model-dependent analysis of the hadronic substructure in tau- -> pi- pi-
pi+ neutrino decay is reported. The decay is dominated by the process tau- ->
a1(1260)- + neutrino, in which a1(1260)- -> rho0 pi- in an S-wave decay.
Amplitudes involving a1(1260) decays into isoscalars, especially a_1(1260)- ->
f0(600)pi-, are large. tau- -> pi- pi- pi+ neutrino decays via the pseudoscalar
pi(1300)- are small. These results support the resonant substructure reported
in the previously reported analysis of tau- -> pi0 pi0 pi- neutrino decay mode
from the same CLEO II data sample.Comment: Invited talk at the Seventh International Workshop on Tau Lepton
Physics (TAU02), Santa Cruz, CA, USA, September 2002, 7 pages, LaTeX, 7 eps
figure
Sport Participation Influences Perceptions of Mate Characteristics
Sport provides a context in which mate choice can be facilitated by the display of athletic prowess. Previous work has shown that, for females, team sport athletes are more desirable as mates than individual sport athletes and non-participants. In the present study, the perceptions of males and females were examined regarding potential mates base on sport participation. It was predicted that team sport athletes would be more positively perceived than individual sport athletes and non-participants by both males and females. A questionnaire, a photograph, and manipulated descriptions were used to gauge perceptual differences with respect to team sport athletes, individual sport athletes, and extracurricular club participants for 125 females and 119 males from a Canadian university. Both team and individual sport athletes were perceived as being less lazy, more competitive, and healthier than non-participants by both males and females. Interestingly, females perceived male athletes as more promiscuous than non-athletes, which upholds predictions based on previous research indicating (a) athletes have more sexual partners than non-athletes, and (b) females find athletes more desirable as partners than nonparticipants. Surprisingly, only males perceived female team sport athletes as more dependable than non-participants, and both team and individual sport athletes as more ambitious. This raises questions regarding the initial hypothesis that male team athletes would be perceived positively by females because of qualities such as the ability to cooperate, likeability, and the acceptance of responsibilities necessary for group functioning. Future studies should examine similar questions with a larger sample size that encompasses multiple contexts, taking into account the role of the social profile of sport in relation to mate choice and perception
A wave function based ab initio non-equilibrium Green's function approach to charge transport
We present a novel ab initio non-equilibrium approach to calculate the
current across a molecular junction. The method rests on a wave function based
description of the central region of the junction combined with a tight binding
approximation for the electrodes in the frame of the Keldysh Green's function
formalism. In addition we present an extension so as to include effects of the
two-particle propagator. Our procedure is demonstrated for a dithiolbenzene
molecule between silver electrodes. The full current-voltage characteristic is
calculated. Specific conclusions for the contribution of correlation and
two-particle effects are derived. The latter are found to contribute about 5%
to the current. The order of magnitude of the current coincides with
experiments.Comment: 21 pages, 3 figure
Method for Flavor Tagging in Neutral B Meson Decays
A method is proposed for tagging the flavor of neutral mesons in the
study of CP-violating decay asymmetries. The method makes use of a possible
difference in interactions in or systems with isospins 1/2
and 3/2, and would be particularly clean if the systems can be
detected as ``'' resonances.Comment: Submitted to Phys. Rev. D. 11 pages, LaTeX, Technion-PH-92-40 / PITHA
92/39 / EFI 92-5
Fluctuation effects in the theory of microphase separation of diblock copolymers in the presence of an electric field
We generalize the Fredrickson-Helfand theory of the microphase separation in
symmetric diblock copolymer melts by taking into account the influence of a
time-independent homogeneous electric field on the composition fluctuations
within the self-consistent Hartree approximation. We predict that electric
fields suppress composition fluctuations, and consequently weaken the
first-order transition. In the presence of an electric field the critical
temperature of the order-disorder transition is shifted towards its mean-field
value. The collective structure factor in the disordered phase becomes
anisotropic in the presence of the electric field. Fluctuational modulations of
the order parameter along the field direction are strongest suppressed. The
latter is in accordance with the parallel orientation of the lamellae in the
ordered state.Comment: 16 page
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