1,396 research outputs found
Individual Quality Explains Association between Plumage Colouration, Arrival Dates and Mate Acquisition in Yellow Warblers (Setophaga petechia)
Background
In many bird species colour traits influence social dominance and breeding success. In our study we first evaluated whether the colour of the basic plumage (tail feathers grown at the end of the breeding season), that provides an index of individual quality, influenced winter habitat use by yellow warblers. We then evaluated whether winter habitat use (inferred using δ13C and δ15N signatures of winter grown greater-coverts) influenced alternate plumage colouration, after controlling for individual quality using basic plumage colouration. Finally, we investigated whether basic and alternate plumage colouration influenced arrival dates, mate acquisition, breeding phenology and reproductive success of yellow warblers breeding in southern (Revelstoke, B.C.) and arctic (Inuvik, N.W.T.) Canada.
Results
The colour (chroma and hue) of tail feathers, grown on the breeding grounds, was not related to subsequent winter habitat use. Greater covert and tail feather colour (chroma and hue) were correlated, suggesting genetics and/or individual quality played a role in pigment deposition. After controlling for individual difference in tail colour, δ13C values did not explain any variation in greater covert colour, but birds with high δ15N signatures had greater coverts with higher chroma. Male arrival dates varied with tail chroma in Revelstoke and tail hue in Inuvik. Males that arrived early paired with older and/or more colourful mates that initiated clutches earlier, and at one site (Revelstoke) were more likely to fledge young. In addition, in Revelstoke (but not Inuvik) males with high tail hue also acquired more colourful mates. In contrast, after controlling for individual differences in tail colour, greater covert colour did not affect male arrival date, the quality of the mate obtained or reproductive success in either population.
Conclusions
Our results suggest that plumage colour effects on breeding phenology and mate acquisition result from differences in the intrinsic quality of individuals rather than a carry-over effect of winter habitat use
Evidence Is a Verb: A Relational Approach to Knowledge and Mastery in Coaching
This article provides a fresh look at the evidential needs in coaching by outlining important principles for the bases of evidence-based practice, the nature of evidence itself, the links between research and practice, the uses of evidence, the politics of evidence and the implications of evidence as a basis for coaching. The aim is to enhance our understanding of the “black box” of coaching, the body of knowledge specific to and foundational for coaching, and the development of shared guidelines for the use of evidence in coaching. Two models are introduced to support a new and relational view of evidence: one that identifies four domains of knowledge as the basis for mastery in coaching and the other that articulates a need for artistry as a way to draw on these domains in working with clients. Examples are offered to illustrate many of the key points and the article concludes with a vision for the future of evidence in coaching
Astrobiology and the Human Exploration of Mars
In March 2007, the Mars Exploration Program Analysis Group (MEPAG) chartered the Human Exploration of Mars Science Analysis Group (HEM-SAG), co-chaired by J. B. Garvin and J. S. Levine and consisting of about 30 Mars scientists from the U.S. and Europe. HEM-SAG was one of a half dozen teams charted by NASA to consider the human exploration of Mars. Other teams included: Mars Entry, Descent and Landing, Human Health and Performance, Flight and Surface Systems, and Heliospheric/Astrophysics. The results of these Mars teams and the development of an architecture for the human exploration of Mars were summarized in two recent publications: Human Exploration of Mars Design Reference Architecture 5.0, NASA Special Publication-2009-566 (B. G. Drake, Editor), 100 pages, July 2009 and Human Exploration of Mars Design Reference Architecture 5.0, NASA Special Publication-2009-566 Addendum (B. G. Drake, Editor), 406 pages, July 2009. This presentation summarizes the HEM-SAG conclusions on astrobiology and the search for life on Mars by humans
Assessment of Negative Economic Impacts from Deer in the Northeastern United States
We conducted a survey and literature review to identify affected stakeholders and gauge economic impacts from unwanted deer-human interactions in the northeastern United States. We estimated an annual economic impact from deer-vehicle collisions and deer depredation to select high-value agricultural, grain, and nursery crops, and residential and commercial landscaping for 13 northeastern United States at nearly $640 million. Our results can be used by Extension and wildlife professionals to inform and involve stakeholders participating in deer management decisions, tailor management strategies to mitigate deer-human conflicts, and assist policy makers when weighing the benefits against the negative impacts from deer
Do nest boxes in restored woodlands promote the conservation of hollow-dependent fauna?
Vegetation restoration is considered an important strategy for reversing biodiversity decline in agricultural areas. However, revegetated areas often lack key vegetation attributes like large old hollow-bearing trees. As these trees take a long time to develop, artificial cavities such as nest boxes are sometimes provided to address lag effects. We conducted a 3-year experiment using 150 nest boxes with four designs to quantify patterns of occupancy within 16 replanted areas and 14 patches of remnant old growth eucalypt woodland. We quantified patterns of occupancy of nest boxes in physically connected versus isolated remnants and plantings, and multiple covariate effects on nest box occupancy at the nest box, tree, patch and landscape levels. Our analyses revealed a lower probability of nest box occupancy within remnants (versus plantings) for two of the six response variables examined: any species, and the Feral Honeybee. Nest boxes in connected remnants and plantings were more likely to be occupied than those in isolated plantings and remnants by any mammal and the Common Brushtail Possum. Nest boxes in restored woodlands are used by some hollow-dependent fauna, but principally already common species, and not taxa of conservation concern. Nest boxes also were used by pest species. A key management consideration must be to create connected habitat to facilitate colonization of nest boxes by mammals. Approximately 15% of the cavity-dependent vertebrates within the study area used next boxes, possibly because the diverse requirements of the array of other species were not met by the range of nest boxes deployed
Transits and secondary eclipses of HD 189733 with Spitzer
We present limits on transit timing variations and secondary eclipse depth
variations at 8 microns with the Spitzer Space Telescope IRAC camera. Due to
the weak limb darkening in the infrared and uninterrupted observing, Spitzer
provides the highest accuracy transit times for this bright system, in
principle providing sensitivity to secondary planets of Mars mass in resonant
orbits. Finally, the transit data provides tighter constraints on the
wavelength- dependent atmospheric absorption by the planet.Comment: 7 pages, 7 figures, submitted to proceedings of IAU Symposium No. 253
"Transiting Planets
Social and family characteristics of Hispanics with epilepsy
AbstractThe purpose of this study is to determine how acculturation, social support, family emotional involvement, perceived family criticism and stigma are associated with epilepsy self-efficacy and depression. A principal components analysis (PCA) was used to describe the salience of these characteristics within a sample of Hispanics with epilepsy.A total of 50 Hispanic adults of Mexican descent identified in our Epilepsy Clinic participated in this study. The PCA identified four distinct types, two were relatively culture-free, and two were distinctly culturally oriented. The first non-culture affiliated type described a well-adjusted group of individuals that tended to be males with moderate self-efficacy, who received social support, and who were unlikely to have depression or feel stigmatized. The second non-culture affiliated type described a dimension in which family emotional involvement tended to co-occur with perceived criticism. The Anglo-oriented group had a family environment that did not appear to criticize the individual with epilepsy and had good self-efficacy. The Mexican-oriented group had high self-efficacy and was unlikely to have depression. Results suggest that acculturation variables must be taken into consideration among ethnic groups because social, psychological and acculturation variables interact in complex ways. Additionally, it is clear that a diagnosis of epilepsy does not automatically lead to poor quality of life, stigma, or depression
A Kerr-microresonator optical clockwork
Kerr microresonators generate interesting and useful fundamental states of
electromagnetic radiation through nonlinear interactions of continuous-wave
(CW) laser light. Using photonic-integration techniques, functional devices
with low noise, small size, low-power consumption, scalable fabrication, and
heterogeneous combinations of photonics and electronics can be realized. Kerr
solitons, which stably circulate in a Kerr microresonator, have emerged as a
source of coherent, ultrafast pulse trains and ultra-broadband
optical-frequency combs. Using the f-2f technique, Kerr combs support
carrier-envelope-offset phase stabilization for optical synthesis and
metrology. In this paper, we introduce a Kerr-microresonator optical clockwork
based on optical-frequency division (OFD), which is a powerful technique to
transfer the fractional-frequency stability of an optical clock to a lower
frequency electronic clock signal. The clockwork presented here is based on a
silicon-nitride (SiN) microresonator that supports an optical-frequency
comb composed of soliton pulses at 1 THz repetition rate. By electro-optic
phase modulation of the entire SiN comb, we arbitrarily generate
additional CW modes between the SiN comb modes; operationally, this
reduces the pulse train repetition frequency and can be used to implement OFD
to the microwave domain. Our experiments characterize the residual frequency
noise of this Kerr-microresonator clockwork to one part in , which
opens the possibility of using Kerr combs with high performance optical clocks.
In addition, the photonic integration and 1 THz resolution of the SiN
frequency comb makes it appealing for broadband, low-resolution liquid-phase
absorption spectroscopy, which we demonstrate with near infrared measurements
of water, lipids, and organic solvents
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