580 research outputs found
Evolutionary variation in the expression of phenotypically plastic color vision in Caribbean mantis shrimps, genus Neogonodactylus
Author Posting. © The Author(s), 2006. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Marine Biology 150 (2006): 213-220, doi:10.1007/s00227-006-0313-5.Many animals have color vision systems that are well suited to their local environments.
Changes in color vision can occur over long periods (evolutionary time), or over relatively short
periods such as during development. A select few animals, including stomatopod crustaceans,
are able to adjust their systems of color vision directly in response to varying environmental
stimuli. Recently, it has been shown that juveniles of some stomatopod species that inhabit a
range of depths can spectrally tune their color vision to local light conditions through spectral
changes in filters contained in specialized photoreceptors. The present study quantifies the
potential for spectral tuning in adults of three species of Caribbean Neogonodactylus
stomatopods that differ in their depth ranges to assess how ecology and evolutionary history
influence the expression of phenotypically plastic color vision in adult stomatopods. After 12
weeks in either a full-spectrum âwhiteâ or a narrow-spectrum âblueâ light treatment, each of the
three species evidenced distinctive tuning abilities with respect to the light environment that
could be related to its natural depth range. A molecular phylogeny generated using
mitochondrial cytochrome oxidase C subunit 1 (CO-1) was used to determine whether tuning
abilities were phylogenetically or ecologically constrained. Although the sister taxa N. wennerae
and N. bredini both exhibited spectral tuning, their ecology (i.e. preferred depth range) strongly
influenced the expression of the phenotypically plastic color vision trait. Our results indicate
that adult stomatopods have evolved the ability to undergo habitat-specific spectral tuning,
allowing rapid facultative physiological modification to suit ecological constraints.This research was funded partially by NSF
grant (IBN-0235820) to TWC and Sigma Xi Grants-in-Aid to AGC and by the National Coral
Reef Institute through a subaward to PHB and RL Caldwell through the NOAA Coastal Ocean
Program under award #NA16OA2413, to Nova Southeastern University
Examining the Relationships among the Coaching Climate, Life Skills Development and Well-Being in Sport
Using Benson and Saito's framework for positive youth development, we investigated the relationships between the coaching climate, young people's perceived life skills development within sport, and their psychological well-being. British youth sport participants (N=326, Mage=13.81, range=11â18 years) completed a survey assessing the coaching climate, participants' perceived life skills development (teamwork, goal setting, time management, emotional skills, interpersonal communication, social skills, leadership, and problem solving and decision making) and psychological well-being (self-esteem, positive affect, and satisfaction with life). In all analyses, the coaching climate was positively related to young peoples' perceived development of life skills within sport and their psychological well-being. Total life skills development (a summative score of all eight life skills scores) was positively related to all three psychological well-being indicators â providing support for the "pile-up" effect â and partially mediated the relationships between the coaching climate and participants' psychological well-being. Interpretation of the results indicated that coaches should foster the development of multiple life skills in youth sport participants, as they are associated with participants' psychological well-being. One way this can be achieved is through autonomy-supportive coaching behaviours
Combined Use of Ultrasound-Assisted Liposuction and Limited-Incision Platysmaplasty for Treatment of the Aging Neck
High Resolution In Vivo Bioluminescent Imaging for the Study of Bacterial Tumour Targeting
The ability to track microbes in real time in vivo is of enormous value for preclinical investigations in infectious disease or gene therapy research. Bacteria present an attractive class of vector for cancer therapy, possessing a natural ability to grow preferentially within tumours following systemic administration. Bioluminescent Imaging (BLI) represents a powerful tool for use with bacteria engineered to express reporter genes such as lux. BLI is traditionally used as a 2D modality resulting in images that are limited in their ability to anatomically locate cell populations. Use of 3D diffuse optical tomography can localize the signals but still need to be combined with an anatomical imaging modality like micro-Computed Tomography (ÎŒCT) for interpretation
Development and validation of a physical activity monitor for use on a wheelchair
Study design:
Keeping physically active is important for people who mobilize using a wheelchair. However, current tools to measure physical activity in the wheelchair are either not validated or limited in their application. The purpose of this study was to develop and validate a monitoring system to measure wheelchair movement.<p></p>
Methods:
The system developed consisted of a tri-axial accelerometer placed on the wheel of a wheelchair and an analysis algorithm to interpret the acceleration signals. The two accelerometer outputs in the plane of the wheel were used to calculate the angle of the wheel. From this, outcome measures of wheel revolutions, absolute angle and duration of movement were derived and the direction of movement (forwards or backwards) could be distinguished. Concurrent validity was assessed in comparison with video analysis in 14 people with spinal cord injury using their wheelchair on an indoor track and outdoor wheelchair skills course. Validity was assessed using intraclass correlation coefficients (ICC(2,1)) and BlandâAltman plots.<p></p>
Results:
The monitoring system demonstrated excellent validity for wheel revolutions, absolute angle and duration of movement (ICC(2,1)>0.999, 0.999, 0.981, respectively) in both manual and powered wheelchairs, when the wheelchair was propelled forwards and backwards, and for movements of various durations.<p></p>
Conclusion:
This study has found this monitoring system to be an accurate and objective tool for measuring detailed information on wheelchair movement and manoeuvring regardless of the propulsion technique, direction and speed
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Nonperturbative transverse-momentum-dependent effects in dihadron and direct photon-hadron angular correlations in p+p collisions at s =200 GeV
Dihadron and isolated direct photon-hadron angular correlations are measured in p+p collisions at s=200 GeV. The correlations are sensitive to nonperturbative initial-state and final-state transverse momenta kT and jT in the azimuthal nearly back-to-back region ÎÏâŒÏ. To have sensitivity to small transverse momentum scales, nonperturbative momentum widths of pout, the out-of-plane transverse-momentum component perpendicular to the trigger particle, are measured. In this region, the evolution of pout can be studied when several different hard scales are measured. These widths are used to investigate possible effects from transverse-momentum-dependent factorization breaking. When accounting for the longitudinal-momentum fraction of the away-side hadron with respect to the near-side trigger particle, the widths are found to increase with the hard scale; this is qualitatively similar to the observed behavior in Drell-Yan and semi-inclusive deep-inelastic scattering interactions, where factorization is predicted to hold. The momentum widths are also studied as a function of center-of-mass energy by comparing to previous measurements at s=510 GeV. The nonperturbative jet widths also appear to increase with s at a similar xT, which is qualitatively consistent to similar measurements in Drell-Yan interactions. Future detailed global comparisons between measurements of processes where transverse-momentum-dependent factorization is predicted to hold and be broken will provide further insight into the role of color in hadronic interactions
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Nonperturbative-transverse-momentum broadening in dihadron angular correlations in sNN =200 GeV proton-nucleus collisions
The PHENIX collaboration has measured high-pT dihadron correlations in p+p, p+Al, and p+Au collisions at sNN=200 GeV. The correlations arise from inter- and intrajet correlations and thus have sensitivity to nonperturbative effects in both the initial and final states. The distributions of pout, the transverse-momentum component of the associated hadron perpendicular to the trigger hadron, are sensitive to initial- and final-state transverse momenta. These distributions are measured multidifferentially as a function of xE, the longitudinal momentum fraction of the associated hadron with respect to the trigger hadron. The near-side pout widths, sensitive to fragmentation transverse momentum, show no significant broadening between p+Au, p+Al, and p+p. The away-side nonperturbative pout widths are found to be broadened in p+Au when compared to p+p; however, there is no significant broadening in p+Al compared to p+p collisions. The data also suggest that the away-side pout broadening is a function of Ncoll, the number of binary nucleon-nucleon collisions, in the interaction. The potential implications of these results with regard to initial- and final-state transverse-momentum broadening and energy loss of partons in a nucleus, among other nuclear effects, are discussed
Risk reduction through community-based monitoring:the vigĂas of Tungurahua, Ecuador
Since 2000, a network of volunteers known as vigĂas has been engaged in community-based volcano monitoring, which involves local citizens in the collection of scientific data, around volcĂĄn Tungurahua, Ecuador. This paper provides the first detailed description and analysis of this well-established initiative, drawing implications for volcanic risk reduction elsewhere. Based on 32 semi-structured interviews and other qualitative data collected in June and July 2013 with institutional actors and with vigĂas themselves, the paper documents the origins and development of the network, identifies factors that have sustained it, and analyses the ways in which it contributes to disaster risk reduction. Importantly, the case highlights how this community-based network performs multiple functions in reducing volcanic risk. The vigĂas network functions simultaneously as a source of observational data for scientists; as a communication channel for increasing community awareness, understanding of hazard processes and for enhancing preparedness; and as an early warning system for civil protection. Less tangible benefits with nonetheless material consequences include enhanced social capital â through the relationships and capabilities that are fostered â and improved trust between partners. Establishing trust-based relationships between citizens, the vigĂas, scientists and civil protection authorities is one important factor in the effectiveness and resilience of the network. Other factors discussed in the paper that have contributed to the longevity of the network include the motivations of the vigĂas, a clear and regular communication protocol, persistent volcanic activity, the efforts of key individuals, and examples of successful risk reduction attributable to the activities of the network. Lessons that can be learned about the potential of community-based monitoring for disaster risk reduction in other contexts are identified, including what the case tells us about the conditions that can affect the effectiveness of such initiatives and their resilience to changing circumstances
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