Polarized Neutron Laue Diffraction on a Crystal Containing Dynamically Polarized Proton Spins

We report on a polarized-neutron Laue diffraction experiment on a single crystal of neodynium doped lanthanum magnesium nitrate hydrate containing polarized proton spins. By using dynamic nuclear polarization to polarize the proton spins, we demonstrate that the intensities of the Bragg peaks can be enhanced or diminished significantly, whilst the incoherent background, due to proton spin disorder, is reduced. It follows that the method offers unique possibilities to tune continuously the contrast of the Bragg reflections and thereby represents a new tool for increasing substantially the signal-to-noise ratio in neutron diffraction patterns of hydrogenous matter.Comment: 5 pages, 3 figure

Relationship Between Passion and Courage among the Experienced Male Soccer Players

Background: The nature of the relationship between passion and courage and its influence on soccer performance has yet to be revealed. Thus, the purpose of this study was to examine passion attributes (i.e. harmonious and obsessive inclinations) among male soccer players in relation to the level of courageous characteristics (i.e. mastery, determination, assertiveness, venturesome and sacrificial behaviour), other demographic and player characteristics. Methods: Data were collected from 278 male soccer players aged 13–38 years (mean [M] = 17.42 ± 4.36) with the number of competitive soccer experiences ranging from 1–28 years (M = 7.51 ± 4.23 years). Participants had at least a year of experience in the sport of soccer completed the validated passion scale, sports courage scale and demographic form. Results: Analyses revealed that soccer players with higher levels of total courage (P < 0.001), have more experience in soccer (P = 0.011), and their soccer level being professional (P < 0.001) had a significantly higher score in harmonious passion. There was no significant difference in obsessive passion among different level of total courage (P = 0.154). However, soccer players with more experience (P = 0.011) and higher soccer level being professional (P < 0.001) demonstrated a significant higher score in obsessive passion. Conclusion: In conclusion, soccer players with higher harmonious and obsessive passionate attributes had higher courage (except for mastery). In addition, the courageous and passionate traits of the soccer players played meaningful roles in indicating individual and performance variables.This research was partially funded by the Research University Individual Grant from Universiti Sains Malaysia (1001.PPSP.8012250)

Understanding the Relationship between Sport Courage and Female Soccer Performance Variables

The purpose of this study was to examine the relationships between female soccer players' courage and key performance variables (level of participation, injury past, being selected or non-selected by a national team, being starter or substitute). METHODS: The Sport Courage Scale-31, by Konter and Ng (2012) and key performance variables were collected from 210 female soccer players aged 12 to 27 (M = 17.97 ± 3.34 years old). Spearman correlations and Mann-Whitney U tests were used to analyse the collected data. RESULTS: The correlations between mastery (r = 0.196), determination (p = 0.239), assertiveness (r = 0.325), sacrifice behaviour (r = 0.182), total sport courage (r = 0.265) and age of female soccer players were found to be significant (p &lt; 0.05). Female soccer players who have sustained an injury in the past scored significantly higher on the venturesome scale (p = 0.006) than those who have not sustained an injury in the past. In comparison, female soccer players who have not sustained an injury in the past or who have not been substituted had significantly more mastery than female soccer players who have sustained an injury in the past or who have been substituted (p = 0.017, p = 0.002, respectively). CONCLUSIONS: This study indicates that sport courage is related to key performance variables among female soccer players. Mastery and age seem to be related to courageous behaviour, whereas increasing venturesomeness might cause injuries in female soccer. Some relevant implications for practitioners can be drawn from the present findings

Sports Courage in Malaysian Silat Athletes: Confirmatory Factor Analysis of the Malay Language Version

This article belongs to the Special Issue Physical and Sport Activity for Wellbeing, Lifestyle, Health Promotion and Chronic Diseases Prevention© 2020 by the authors. Sports courage is one of the most important attributes to help competitive athletes overcome anxiety, nervousness, and other psychological obstacles but this field of study is still being overlooked by most athletes and coaches. The purpose of this study is to validate the Malay language version of the Sports Courage Scale (SCS-M) for Silat athletes using confirmatory factor analysis (CFA). Data was collected during 9th UPSI International Pencak Silat Championship in Malaysia. A total of 258 competitors (male = 66.7%, female = 33.3%), with a mean age of 18 years (SD = 2.6) volunteered to participate in this study. The original SCS with 50 items underwent forward and backward translations into the Malay language and was pre-tested with ten martial arts athletes. Then, Silat athletes were asked to complete the translated SCS-M questionnaire. There were five factors in the SCS-M (i.e., mastery, determination, assertiveness, venturesome, and self27 sacrificial behaviour). The first hypothesised model with 50 items did not result in a good fit to the data (RMSEA = 0.06, CFI = 0.93, NFI = 0.87, NNFI = 0.93, RMR = 0.14, SRMR = 0.09). A total of 17 problematic items were identified and were removed iteratively. The final measurement model with 33 items fit the data well (RMSEA = 0.06, CFI = 0.94, NFI = 0.89, NNFI = 0.94, RMR = 0.05, SRMR = 0.07).The reliability of each subscale based on Cronbach’s alpha ranged from 0.64 to 0.76. The convergent and discriminant validity were achieved for the final measurement model. The revised version of SCS-M with 33 items was considered valid and reliable for measuring the sports courage in Silat athletes in Malaysia.This research was partially supported by the Research University’s Individual Grant (USM-RUI 1001/PPSP/812149) from Universiti Sains Malaysia (USM)

Time-resolved nuclear spin-dependent small-angle neutron scattering from polarised proton domains in deuterated solutions

Abstract.: We have investigated the process of dynamic proton polarisation by means of time-resolved polarised small-angle neutron scattering (SANS) on frozen solutions of EHBA-CrV molecules in glycerol-water mixtures as a function of the concentration of EHBA-CrV and for different degrees of deuteration of the solvent. In the EHBA-CrV complex, the spins of the 20 protons which surround the paramagnetic CrV can be oriented using the method of dynamic nuclear polarisation (DNP), thereby offering the possibility to create locally a nuclear spin-dependent contrast for SANS. The time constants which describe the build-up of polarisation around the paramagnetic centre and the subsequent diffusion of polarisation in the solvent were determined by analysing the temporal evolution of the nuclear polarisation, which in turn was obtained by fitting a core-shell model to the time-dependent SANS curves. The results on the spin dynamics obtained using the scattering function of a core-shell could be independently confirmed by evaluating the integrated SANS intensity. A thermodynamic one-centre model is presented which is able to reproduce the observed dependence of the proton polarisation times on the proton concentration of the solven

Low Energy Analyzing Powers in Pion-Proton Elastic Scattering

Analyzing powers of pion-proton elastic scattering have been measured at PSI with the Low Energy Pion Spectrometer LEPS as well as a novel polarized scintillator target. Angular distributions between 40 and 120 deg (c.m.) were taken at 45.2, 51.2, 57.2, 68.5, 77.2, and 87.2 MeV incoming pion kinetic energy for pi+ p scattering, and at 67.3 and 87.2 MeV for pi- p scattering. These new measurements constitute a substantial extension of the polarization data base at low energies. Predictions from phase shift analyses are compared with the experimental results, and deviations are observed at low energies.Comment: 15 pages, 4 figure

Evidence for the return of subducted continental crust

Author Posting. © Nature Publishing Group, 2007. This is the author's version of the work. It is posted here by permission of Nature Publishing Group for personal use, not for redistribution. The definitive version was published in Nature 448 (2007): 684-687, doi:10.1038/nature06048.Substantial quantities of terrigenous sediments are known to enter the mantle at subduction zones, but little is known about their fate in the mantle. Subducted sediment may be entrained in buoyantly upwelling plumes and returned to the earth’s surface at hotspots, but the proportion of recycled sediment in the mantle is small and clear examples of recycled sediment in hotspot lavas are rare. We report here remarkably enriched 87Sr/86Sr and 143Nd/144Nd isotope signatures (up to 0.720830 and 0.512285, respectively) in Samoan lavas from three dredge locations on the underwater flanks of Savai’i island, Western Samoa. The submarine Savai’i lavas represent the most extreme 87Sr/86Sr isotope compositions reported for ocean island basalts (OIBs) to date. The data are consistent with the presence of a recycled sediment component (with a composition similar to upper continental crust, or UCC) in the Samoan mantle. Trace element data show similar affinities with UCC—including exceptionally low Ce/Pb and Nb/U ratios—that complement the enriched 87Sr/86Sr and 143Nd/144Nd isotope signatures. The geochemical evidence from the new Samoan lavas radically redefines the composition of the EM2 (enriched mantle 2) mantle endmember, and points to the presence of an ancient recycled UCC component in the Samoan plume

Impact of climate change on larch budmoth cyclic outbreaks

Periodic outbreaks of the larch budmoth Zeiraphera diniana population (and the massive forest defoliation they engender) have been recorded in the Alps over the centuries and are known for their remarkable regularity. But these have been conspicuously absent since 1981. On the other hand, budmoth outbreaks have been historically unknown in the larches of the Carpathian Tatra mountains. To resolve this puzzle, we propose here a model which includes the influence of climate and explains both the 8–9 year periodicity in the budmoth cycle and the variations from this, as well as the absence of cycles. We successfully capture the observed trend of relative frequencies of outbreaks, reproducing the dominant periodicities seen. We contend that the apparent collapse of the cycle in 1981 is due to changing climatic conditions following a tipping point and propose the recurrence of the cycle with a changed periodicity of 40 years – the next outbreak could occur in 2021. Our model also predicts longer cycles

Vailulu’u Seamount, Samoa: Life and death on an active submarine volcano

Submersible exploration of the Samoan hotspot revealed a new, 300-m-tall, volcanic cone, named Nafanua, in the summit crater of Vailulu’u seamount. Nafanua grew from the 1,000-m-deep crater floor in <4 years and could reach the sea surface within decades. Vents fill Vailulu’u crater with a thick suspension of particulates and apparently toxic fluids that mix with seawater entering from the crater breaches. Low-temperature vents form Fe oxide chimneys in many locations and up to 1-m-thick layers of hydrothermal Fe floc on Nafanua. High-temperature (81°C) hydrothermal vents in the northern moat (945-m water depth) produce acidic fluids (pH 2.7) with rising droplets of (probably) liquid CO₂. The Nafanua summit vent area is inhabited by a thriving population of eels (Dysommina rugosa) that feed on midwater shrimp probably concentrated by anticyclonic currents at the volcano summit and rim. The moat and crater floor around the new volcano are littered with dead metazoans that apparently died from exposure to hydrothermal emissions. Acid-tolerant polychaetes (Polynoidae) live in this environment, apparently feeding on bacteria from decaying fish carcasses. Vailulu’u is an unpredictable and very active underwater volcano presenting a potential long-term volcanic hazard. Although eels thrive in hydrothermal vents at the summit of Nafanua, venting elsewhere in the crater causes mass mortality. Paradoxically, the same anticyclonic currents that deliver food to the eels may also concentrate a wide variety of nektonic animals in a death trap of toxic hydrothermal fluids.KEYWORDS: habitats, hydrothermal, eels, currents, ventsThis is the publisher’s final pdf. The published article is copyrighted by the National Academy of Sciences of the United States of America and can be found at: http://www.pnas.org