1,844 research outputs found
The influence of leg-to-body ratio, arm-to-body ratio and intra-limb ratio on male human attractiveness.
Human mate choice is influenced by limb proportions. Previous work has focused on leg-to-body ratio (LBR) as a determinant of male attractiveness and found a preference for limbs that are close to, or slightly above, the average. We investigated the influence of two other key aspects of limb morphology: arm-to-body ratio (ABR) and intra-limb ratio (IR). In three studies of heterosexual women from the USA, we tested the attractiveness of male physiques that varied in LBR, ABR and IR, using figures that ranged from -3 to +3 standard deviations from the population mean. We replicated previous work by finding that the optimally attractive LBR is approximately 0.5 standard deviations above the baseline. We also found a weak effect of IR, with evidence of a weak preference for the baseline proportions. In contrast, there was no effect of ABR on attractiveness, and no interactions between the effects of LBR, ABR and IR. Our results indicate that ABR is not an important determinant of human mate choice for this population, and that IR may exert some influence but that this is much smaller than the effects of LBR. We discuss possible reasons for these results, including the limited variability in upper limb proportions and the potentially weak fitness-signal provided by this aspect of morphology
SN 2006bt: A Perplexing, Troublesome, and Possibly Misleading Type Ia Supernova
SN 2006bt displays characteristics unlike those of any other known Type Ia
supernova (SN Ia). We present optical light curves and spectra of SN 2006bt
which demonstrate the peculiar nature of this object. SN 2006bt has broad,
slowly declining light curves indicative of a hot, high-luminosity SN, but
lacks a prominent second maximum in the i band as do low-luminosity SNe Ia. Its
spectra are similar to those of low-luminosity SNe Ia, containing features that
are only present in cool SN photospheres. Light-curve fitting methods suggest
that SN 2006bt is reddened by a significant amount of dust; however, it
occurred in the outskirts of its early-type host galaxy and has no strong Na D
absorption in any of its spectra, suggesting a negligible amount of host-galaxy
dust absorption. C II is possibly detected in our pre-maximum spectra, but at a
much lower velocity than other elements. The progenitor was likely very old,
being a member of the halo population of a galaxy that shows no signs of recent
star formation. SNe Ia have been very successfully modeled as a one-parameter
family, and this is fundamental to their use as cosmological distance
indicators. SN 2006bt is a challenge to that picture, yet its relatively normal
light curves allowed SN 2006bt to be included in cosmological analyses. We
generate mock SN Ia datasets which indicate that contamination by similar
objects will both increase the scatter of a SN Ia Hubble diagram and
systematically bias measurements of cosmological parameters. However, spectra
and rest-frame i-band light curves should provide a definitive way to identify
and eliminate such objects.Comment: ApJ, accepted. 13 pages, 13 figure
The Low-Velocity, Rapidly Fading Type Ia Supernova 2002es
SN 2002es is a peculiar subluminous Type Ia supernova (SN Ia) with a
combination of observed characteristics never before seen in a SN Ia. At
maximum light, SN 2002es shares spectroscopic properties with the underluminous
SN 1991bg subclass of SNe Ia, but with substantially lower expansion velocities
(~6000 km/s) more typical of the SN 2002cx subclass. Photometrically, SN 2002es
differs from both SN 1991bg-like and SN 2002cx-like supernovae. Although at
maximum light it is subluminous (M_B=-17.78 mag), SN 2002es has a relatively
broad light curve (Dm15(B)=1.28 +/- 0.04 mag), making it a significant outlier
in the light-curve width vs. luminosity relationship. We estimate a 56Ni mass
of 0.17 +/- 0.05 M_sun synthesized in the explosion, relatively low for a SN
Ia. One month after maximum light, we find an unexpected plummet in the
bolometric luminosity. The late-time decay of the light curves is inconsistent
with our estimated 56Ni mass, indicating that either the light curve was not
completely powered by 56Ni decay or the ejecta became optically thin to
gamma-rays within a month after maximum light. The host galaxy is classified as
an S0 galaxy with little to no star formation, indicating the progenitor of SN
2002es is likely from an old stellar population. We also present a less
extensive dataset for SN 1999bh, an object which shares similar observed
properties. Both objects were found as part of the Lick Observatory Supernova
Search, allowing us to estimate that these objects should account for ~2.5% of
SNe Ia within a fixed volume. We find that current theoretical models are
unable to explain the observed of characteristics of SN 2002es.Comment: 19 pages, 15 figures, Submitted to Ap
Venous-right atrial bypass for superior vena cava thrombosis during orthotopic liver transplantation
Long-term Trends in Benthic Macroinvertebrate Populations in Lake Huron over the Past Four Decades
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