487 research outputs found
Mesotocin influences pinyon jay prosociality
Many species exhibit prosocial behavior, in which one individual’s actions benefit another individual, often without an immediate benefit to itself. The neuropeptide oxytocin is an important hormonal mechanism influencing prosociality in mammals, but it is unclear whether the avian homologue mesotocin plays a similar functional role in birds. Here, we experimentally tested prosociality in pinyon jays (Gymnorhinus cyanocephalus), a highly social corvid species that spontaneously shares food with others. First, we measured prosocial preferences in a prosocial choice task with two different payoff distributions: Prosocial trials delivered food to both the subject and either an empty cage or a partner bird, whereas Altruism trials delivered food only to an empty cage or a partner bird (none to subject). In a second experiment, we examined whether administering mesotocin influenced prosocial preferences. Compared to choices in a control condition, we show that subjects voluntarily delivered food rewards to partners, but only when also receiving food for themselves (Prosocial trials), and administration of high levels of mesotocin increased these behaviors. Thus, in birds, mesotocin seems to play a similar functional role in facilitating prosocial behaviors as oxytocin does in mammals, suggesting an evolutionarily conserved hormonal mechanism for prosociality
The Role of Adolescent Behaviors in the Female–Male Disparity in Obesity Incidence in US Black and White Young Adults
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/93675/1/oby.2009.362.pd
Citi Email from Charles Price to Robert Druskin Re RevolutionMoney
Series of emails from 9/28/2007 to 10/2/2007
Cognitive mediators of the effect of peer victimization on loneliness
The impact of stress on psychological adjustment may be mediated by cognitive interpretations (i.e., appraisals) of events for individuals. Defining characteristics of loneliness suggest that appraisals of blame, threat, and perceived control may be particularly important in this domain. AIMS: To evaluate the extent to which cognitive appraisals (perceived control, threat, and blame) can mediate the effect of peer victimization on loneliness. SAMPLE: One hundred and ten children (54 boys, 56 girls) aged 8-12 years attending mainstream schools in Scotland. METHOD: Self-report measures of peer victimization, appraisal, and loneliness. RESULTS: Perceived control partially mediated the effects of peer victimization on loneliness, but neither blame nor threat were mediators. All three measures of control were significantly associated with loneliness at the bivariate level, but only perceived control was significant when the appraisals were entered as predictors in a hierarchical multiple linear regression. CONCLUSIONS: The results highlight the importance of research designs assessing multiple categories of appraisal. Furthermore, they suggest that intervention efforts aiming to combat feelings of loneliness within a peer victimization context should address children's appraisals of perceived control
Flute Studio Recital
Caine College of the Arts Department of Music presents Flute Studio Recital featuring the USU Flute Choir.https://digitalcommons.usu.edu/music_programs/1096/thumbnail.jp
The Murchison Widefield Array: Design Overview
The Murchison Widefield Array (MWA) is a dipole-based aperture array
synthesis telescope designed to operate in the 80-300 MHz frequency range. It
is capable of a wide range of science investigations, but is initially focused
on three key science projects. These are detection and characterization of
3-dimensional brightness temperature fluctuations in the 21cm line of neutral
hydrogen during the Epoch of Reionization (EoR) at redshifts from 6 to 10,
solar imaging and remote sensing of the inner heliosphere via propagation
effects on signals from distant background sources,and high-sensitivity
exploration of the variable radio sky. The array design features 8192
dual-polarization broad-band active dipoles, arranged into 512 tiles comprising
16 dipoles each. The tiles are quasi-randomly distributed over an aperture
1.5km in diameter, with a small number of outliers extending to 3km. All
tile-tile baselines are correlated in custom FPGA-based hardware, yielding a
Nyquist-sampled instantaneous monochromatic uv coverage and unprecedented point
spread function (PSF) quality. The correlated data are calibrated in real time
using novel position-dependent self-calibration algorithms. The array is
located in the Murchison region of outback Western Australia. This region is
characterized by extremely low population density and a superbly radio-quiet
environment,allowing full exploitation of the instrumental capabilities.Comment: 9 pages, 5 figures, 1 table. Accepted for publication in Proceedings
of the IEE
A new layout optimization technique for interferometric arrays, applied to the MWA
Antenna layout is an important design consideration for radio interferometers
because it determines the quality of the snapshot point spread function (PSF,
or array beam). This is particularly true for experiments targeting the 21 cm
Epoch of Reionization signal as the quality of the foreground subtraction
depends directly on the spatial dynamic range and thus the smoothness of the
baseline distribution. Nearly all sites have constraints on where antennas can
be placed---even at the remote Australian location of the MWA (Murchison
Widefield Array) there are rock outcrops, flood zones, heritages areas,
emergency runways and trees. These exclusion areas can introduce spatial
structure into the baseline distribution that enhance the PSF sidelobes and
reduce the angular dynamic range. In this paper we present a new method of
constrained antenna placement that reduces the spatial structure in the
baseline distribution. This method not only outperforms random placement
algorithms that avoid exclusion zones, but surprisingly outperforms random
placement algorithms without constraints to provide what we believe are the
smoothest constrained baseline distributions developed to date. We use our new
algorithm to determine antenna placements for the originally planned MWA, and
present the antenna locations, baseline distribution, and snapshot PSF for this
array choice.Comment: 12 pages, 6 figures, 1 table. Accepted for publication in MNRA
Oxygen-limited thermal tolerance is seen in a plastron-breathing insect and can be induced in a bimodal gas exchanger.
Thermal tolerance has been hypothesized to result from a mismatch between oxygen supply and demand. However, the generality of this hypothesis has been challenged by studies on various animal groups, including air-breathing adult insects. Recently, comparisons across taxa have suggested that differences in gas exchange mechanisms could reconcile the discrepancies found in previous studies. Here, we test this suggestion by comparing the behaviour of related insect taxa with different gas exchange mechanisms, with and without access to air. We demonstrate oxygen-limited thermal tolerance in air-breathing adults of the plastron-exchanging water bug Aphelocheirus aestivalis. Ilyocoris cimicoides, a related, bimodal gas exchanger, did not exhibit such oxygen-limited thermal tolerance and relied increasingly on aerial gas exchange with warming. Intriguingly, however, when denied access to air, oxygen-limited thermal tolerance could also be induced in this species. Patterns in oxygen-limited thermal tolerance were found to be consistent across life-history stages in these insects, with nymphs employing the same gas exchange mechanisms as adults. These results advance our understanding of oxygen limitation at high temperatures; differences in the degree of respiratory control appear to modulate the importance of oxygen in setting tolerance limits
Interferometric imaging with the 32 element Murchison Wide-field Array
The Murchison Wide-field Array (MWA) is a low frequency radio telescope,
currently under construction, intended to search for the spectral signature of
the epoch of re-ionisation (EOR) and to probe the structure of the solar
corona. Sited in Western Australia, the full MWA will comprise 8192 dipoles
grouped into 512 tiles, and be capable of imaging the sky south of 40 degree
declination, from 80 MHz to 300 MHz with an instantaneous field of view that is
tens of degrees wide and a resolution of a few arcminutes. A 32-station
prototype of the MWA has been recently commissioned and a set of observations
taken that exercise the whole acquisition and processing pipeline. We present
Stokes I, Q, and U images from two ~4 hour integrations of a field 20 degrees
wide centered on Pictoris A. These images demonstrate the capacity and
stability of a real-time calibration and imaging technique employing the
weighted addition of warped snapshots to counter extreme wide field imaging
distortions.Comment: Accepted for publication in PASP. This is the draft before journal
typesetting corrections and proofs so does contain formatting and journal
style errors, also has with lower quality figures for space requirement
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