1,828 research outputs found
Neither internal nor external nasal dilation improves cycling 20-km time trial performance
Objectives: Research is equivocal regarding endurance performance benefits of external nasal dilators, and currently research focusing on internal nasal dilators is non-existent. Both devices are used within competitive cycling. This study examined the influence of external and internal nasal dilation on cycling economy of motion and 20-km time trial performance.
Design: The study utilized a randomized, counterbalanced cross-over design.
Methods: Fifteen trained cyclists completed three exercise sessions consisting of a 15min standardized warm up and 20-km cycling time trial while wearing either a Breathe RightÂź external nasal dilator, TurbineÂź internal nasal dilator or no device (control). During the warm up, heart rate, ratings of perceived exertion and dyspnea and expired gases were collected. During the time trial, heart rate, perceived exertion, and dyspnea were collected at 4-km intervals and mean 20-km power output was recorded.
Results: No differences were observed for mean 20-km power output between the internal (270. ±. 45. W) or external dilator (271. ±. 44. W) and control (272. ±. 44. W). No differences in the economy of motion were observed throughout the 15-min warm up between conditions.
Conclusions: The TurbineÂź and Breathe RightÂź nasal dilators are ineffective at enhancing 20-km cycling time trial performance
An interdisciplinary study of the extent of soil degradation in southern Africa
Non-Peer Reviewe
Longâterm effect of fertilizer microdosing on soil fertility in Sahelianwest Africa
Non-Peer Reviewe
Mass Suppression in Octet Baryon Production
There is a striking suppression of the cross section for production of octet
baryons in annihilation, as the mass of the produced hadron
increases. We present a simple parametrization for the fragmentation functions
into octet baryons guided by two input models: the SU(3) flavor symmetry part
is given by a quark-diquark model, and the baryon mass suppression part is
inspired by the string model. We need only eight free parameters to describe
the fragmentation functions for all octet baryons. These free parameters are
determined by a fit to the experimental data of octet baryon production in annihilation. Then we apply the obtained fragmentation functions to
predict the cross section of the octet baryon production in charged lepton DIS
and find consistency with the available experimental data. Furthermore, baryon
production in collisions is suggested to be an ideal domain to check the
predicted mass suppression.Comment: 20 pages, 5 figure
Direct comparison of sterile neutrino constraints from cosmological data, <i>Îœ</i><sub><i>e</i></sub> disappearance data and <i>Îœ</i><sub><i>ÎŒ</i></sub>â <i>Îœ</i><sub><i>e</i></sub> appearance data in a 3+1 model
Non-invasive laminar inference with MEG: comparison of methods and source inversion algorithms
Magnetoencephalography (MEG) is a direct measure of neuronal current flow; its anatomical resolution is therefore not constrained by physiology but rather by data quality and the models used to explain these data. Recent simulation work has shown that it is possible to distinguish between signals arising in the deep and superficial cortical laminae given accurate knowledge of these surfaces with respect to the MEG sensors. This previous work has focused around a single inversion scheme (multiple sparse priors) and a single global parametric fit metric (free energy). In this paper we use several different source inversion algorithms and both local and global, as well as parametric and non-parametric fit metrics in order to demonstrate the robustness of the discrimination between layers. We find that only algorithms with some sparsity constraint can successfully be used to make laminar discrimination. Importantly, local t-statistics, global cross-validation and free energy all provide robust and mutually corroborating metrics of fit. We show that discrimination accuracy is affected by patch size estimates, cortical surface features, and lead field strength, which suggests several possible future improvements to this technique. This study demonstrates the possibility of determining the laminar origin of MEG sensor activity, and thus directly testing theories of human cognition that involve laminar- and frequency-specific mechanisms. This possibility can now be achieved using recent developments in high precision MEG, most notably the use of subject-specific head-casts, which allow for significant increases in data quality and therefore anatomically precise MEG recordings
Contestable adulthood: variability and disparity in markers for negotiating the transition to adulthood
Recent research has identified a discreet set of subjective markers that are seen as characterizing the transition to adulthood. The current study challenges this coherence by examining the disparity and variability in young peopleâs selection of such criteria. Four sentence-completion cues corresponding to four differentcontexts in which adult status might be contested were given to 156 British 16- to 17-year-olds. Their qualitative responses were analyzed to
explore patterns whilst capturing some of their richness and diversity. An astonishing amount of variability emerged, both within and between cued contexts.The implications of this variability for how the transition to adulthood is experienced are explored. The argument is made that markers of the transition to adulthood are not merely reflective of the bioâpsychoâsocial development of
young people. Rather, adulthood here is seen as an essentially contested concept,located within the discursive interactional environment in which young people participate
Alternative job search strategies in remote rural and peri-urban labour markets: the role of social networks
This paper examines the importance of informal methods (especially social networking) to the job search strategies used by unemployed people. It compares three areas: a small rural town; a larger, more sparsely populated, remote rural area; and a centrally-located, peri-urban labour market. The analysis is based first on survey research undertaken with 490 job seekers across the study areas. Emerging issues were then followed up during a series of twelve focus groups. The survey research showed that job seekers in the rural study areas were significantly more likely to use social networks to look for work. However, those who had experienced repeated or long-term periods out of work, the unskilled and young people were significantly less likely to use such networks. Focus groups confirmed the perceived importance of social networking to the job search process in rural areas, in contrast to the more marginal role such methods appear to play in peri-urban settings. For many rural job seekers, formal job search activities conducted through Jobcentres were seen as largely symbolic, lacking the practical value of social networking. These results suggest that service providers seeking to assist unemployed people in rural areas need to address the problems faced by many disadvantaged job seekers who are currently caught between their lack of social network relations and the absence of local public employment service facilities in more remote communities
Polarization phenomena in open charm photoproduction processes
We analyze polarization effects in associative photoproduction of
pseudoscalar () charmed mesons in exclusive processes , , . Circularly polarized photons
induce nonzero polarization of the -hyperon with - and -components
(in the reaction plane) and non vanishing asymmetries and for polarized nucleon target. These polarization observables can be
predicted in model-independent way for exclusive -production processes
in collinear kinematics. The T-even -polarization and asymmetries for
non-collinear kinematics can be calculated in framework of an effective
Lagrangian approach. The depolarization coefficients , characterizing
the dependence of the -polarization on the nucleon polarization are also
calculated.Comment: 36 pages 13 figure
Discovery and Observations of ASASSN-13db, an EX Lupi-Type Accretion Event on a Low-Mass T Tauri Star
We discuss ASASSN-13db, an EX Lupi-type ("EXor") accretion event on the young
stellar object (YSO) SDSS J051011.01032826.2 (hereafter SDSSJ0510)
discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN). Using
archival photometric data of SDSSJ0510 we construct a pre-outburst spectral
energy distribution (SED) and find that it is consistent with a low-mass class
II YSO near the Orion star forming region ( pc). We present
follow-up photometric and spectroscopic observations of the source after the
5.4 magnitude outburst that began in September 2013 and ended
in early 2014. These data indicate an increase in temperature and luminosity
consistent with an accretion rate of yr,
three or more orders of magnitude greater than in quiescence. Spectroscopic
observations show a forest of narrow emission lines dominated by neutral
metallic lines from Fe I and some low-ionization lines. The properties of
ASASSN-13db are similar to those of the EXor prototype EX Lupi during its
strongest observed outburst in late 2008.Comment: 14 pages, 4 figures, 1 table. Updated May 2014 to reflect changes in
the final version published in ApJL. Photometric data presented in this
submission are included as ancillary files. For a brief video explaining this
paper, see http://youtu.be/yRCCrNJnvt
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