Head impact exposure in junior and adult Australian football players

Tis study measured and compared the frequency, magnitude, and distribution of head impacts sustained by junior and adult Australian football players, respectively, and between player positions over a season of games. Twelve junior and twelve adult players were tracked using a skin-mounted impact sensor. Head impact exposure, including frequency, magnitude, and location of impacts, was quantifed using previously established methods. Over the collection period, there were no signifcant diferences in the impact frequency between junior and adult players. However, there was a signifcant increase in the frequency of head impacts for midfelders in both grades once we accounted for player position. A comparable amount of head impacts in both junior and adult players has implications for Australian football regarding player safety and medical coverage as younger players sustained similar impact levels as adult players. Te other implication of a higher impact profle within midfelders is that, by targeting education and prevention strategies, a decrease in the incidence of sports-related concussion may result

Bootstrapping N=4\mathcal{N}=4 super-Yang-Mills on the conformal manifold

We combine supersymmetric localization results with numerical bootstrap techniques to compute upper bounds on the low-lying CFT data of ${\cal N} = 4$ super-Yang-Mills theory as a function of the complexified gauge coupling $\tau$. In particular, from the stress tensor multiplet four-point function, we extract the scaling dimension of the lowest-lying unprotected scalar operator and its OPE coefficient. While our method can be applied in principle to any gauge group $G$, we focus on $G = SU(2)$ and $SU(3)$ for simplicity. At weak coupling, the upper bounds we find are very close to the corresponding four-loop results. We also give preliminary evidence that these upper bounds become small islands under reasonable assumptions.Comment: 31 pages plus appendices, 11 figures, v2 references and OPE coefficient plot adde

Entangled Electronic States in Multiple Quantum-Dot Systems

We present an analytically solvable model of $P$ colinear, two-dimensional quantum dots, each containing two electrons. Inter-dot coupling via the electron-electron interaction gives rise to sets of entangled ground states. These ground states have crystal-like inter-plane correlations and arise discontinously with increasing magnetic field. Their ranges and stabilities are found to depend on dot size ratios, and to increase with $P$.Comment: To appear in Physical Review B (in press). RevTeX file. Figures available from [email protected]

Reporting on data monitoring committees in neonatal randomised controlled trials is inconsistent

Aim: To evaluate the reported use of Data Monitoring Committees (DMCs), the frequency of interim analysis, pre-specified stopping rules and early trial termination in neonatal randomised controlled trials (RCTs). Methods: We reviewed neonatal RCTs published in four high impact general medical journals, specifically looking at safety issues including documented involvement of a DMC, stated interim analysis, stopping rules and early trial termination. We searched all journal issues over an 11-year period (2003-2013) and recorded predefined parameters on each item for RCTs meeting inclusion criteria. Results: Seventy neonatal trials were identified in four general medical journals: Lancet, New England Journal of Medicine (NEJM), British Medical Journal and Journal of American Medical Association (JAMA). 43 (61.4%) studies reported the presence of a DMC, 36 (51.4%) explicitly mentioned interim analysis; stopping rules were reported in 15 (21.4%) RCTs and 7 (10%) trials were terminated early. The NEJM most frequently reported these parameters compared to the other three journals reviewed. Conclusion: While the majority of neonatal RCTs report on DMC involvement and interim analysis there is still scope for improvement. Clear documentation of safety related issues should be a central component of reporting in neonatal trials involving newborn infants

Statistical evolution of isotope composition of nuclear fragments

Calculations within the statistical multifragmentation model show that the neutron content of intermediate mass fragments can increase in the region of liquid-gas phase transition in finite nuclei. The model predicts also inhomogeneous distributions of fragments and their isospin in the freeze-out volume caused by an angular momentum and external long-range Coulomb field. These effects can take place in peripheral nucleus-nucleus collisions at intermediate energies and lead to neutron-rich isotopes produced in the midrapidity kinematic region.Comment: 14 pages with 4 figures. GSI preprint, Darmstadt, 200

Perinatal outcomes following Helping Babies Breathe training and regular peer-peer skills practice among village midwives in Sudan.

Over 80% of deliveries in Sudan occur in rural areas, attended by village midwives (VMWs). To determine the impact of Helping Babies Breathe training and regular peer-peer skills practice (HBBT(+RPPSP)) on VMW resuscitation practices and outcomes. In a prospective community-based intervention study, 71/82 VMWs, reporting to six East Nile rural medical centres, with previous experience in community health research, consented to HBBT(+RPPSP). Outcomes included changes in the resuscitation practices, fresh stillbirths (FSB) and early neonatal deaths <1 week (ENND). There were 1350 and 3040 deliveries before and after HBBT(+RPPSP), respectively, with no significant differences between the two cohorts regarding maternal age, education or area of birth. Drying of the newborn increased almost tenfold (8.4%, n=113 to 74.9%, n=1011) while suctioning of the mouth/nose decreased fivefold (80.3%, n=2442 to 14.4%, n=437) following HBBT(+RPPSP). Pre-HBBT(+RPPSP)9/18 (50%) newborns who had mouth-to-mouth ventilation died, compared with 13/119 (11%) who received bag-mask ventilation post-HBBT(+RPPSP). Excluding 11 macerated fetuses, there were 55 perinatal deaths: 14 FSB/18 ENND (6 months pre-HBBT(+RPPSP)) and 10 FSB/13 ENND (18 months post-HBBT(+RPPSP)). FSB rates decreased from 10.5 to 3.3 per 1000 births ((χ(2))=8.6209, p=0.003), while ENND rates decreased from 13.5 to 4.3 per 1000 live births ((χ(2))=10.9369, p=0.001) pre-HBBT(+RPPSP) and post-HBBT(+RPPSP), respectively. In a selected group of VMWs, HBBT(+RPPSP) was associated with improvements in newborn resuscitation and perinatal outcomes. HBBT(+RPPSP) could have immense benefits if propagated nationally to all 17 000 VMWs in Sudan.This study was funded by the Irish Aid Civil Society Grant scheme

Supercurrent through a single transverse mode in nanowire Josephson junctions

Hybrid superconductor-semiconductor materials are fueling research in mesoscopic physics and quantum technology. Recently demonstrated smooth $\beta$-Sn superconductor shells, due to the increased induced gap, are expanding the available parameter space to new regimes. Fabricated on quasiballistic InSb nanowires, with careful control over the hybrid interface, Sn shells yield critical current-normal resistance products exceeding temperature by at least an order of magnitude even when nanowire resistance is of order 10k$\Omega$. In this regime Cooper pairs travel through a purely 1D quantum wire for at least part of their trajectory. Here, we focus on the evolution of supercurrent in magnetic field parallel to the nanowire. Long decay up to fields of 1T is observed. At the same time, the decay for higher occupied subbands is notably faster in some devices but not in others. We analyze this using a tight-binding numerical model that includes the Zeeman, orbital and spin-orbit effects. When the first subband is spin polarized, we observe a dramatic suppression of supercurrent, which is also confirmed by the model and suggests an absence of significant triplet supercurrent generation

CHIMPS: the ¹³CO/C¹⁸O (<i>J</i> = 3 → 2) Heterodyne Inner Milky Way Plane Survey

We present the 13CO/C18O (J = 3 → 2) Heterodyne Inner Milky Way Plane Survey (CHIMPS) which has been carried out using the Heterodyne Array Receiver Program on the 15 m James Clerk Maxwell Telescope (JCMT) in Hawaii. The high-resolution spectral survey currently covers |b| ≤ 0.5° and 28° ≲ l ≲ 46°, with an angular resolution of 15 arcsec in 0.5 km s-1 velocity channels. The spectra have a median rms of ˜0.6 K at this resolution, and for optically thin gas at an excitation temperature of 10 K, this sensitivity corresponds to column densities of NH2 ˜ 3 × 1020 cm-2 and NH2 ˜ 4 × 1021 cm-2 for 13CO and C18O, respectively. The molecular gas that CHIMPS traces is at higher column densities and is also more optically thin than in other publicly available CO surveys due to its rarer isotopologues, and thus more representative of the three-dimensional structure of the clouds. The critical density of the J = 3 → 2 transition of CO is ≳104 cm-3 at temperatures of ≤20 K, and so the higher density gas associated with star formation is well traced. These data complement other existing Galactic plane surveys, especially the JCMT Galactic Plane Survey which has similar spatial resolution and column density sensitivity, and the Herschel infrared Galactic Plane Survey. In this paper, we discuss the observations, data reduction and characteristics of the survey, presenting integrated-emission maps for the region covered. Position-velocity diagrams allow comparison with Galactic structure models of the Milky Way, and while we find good agreement with a particular four-arm model, there are some significant deviations

Quantitative magneto-optical investigation of superconductor/ferromagnet hybrid structures

We present a detailed quantitative magneto-optical imaging study of several superconductor/ferromagnet hybrid structures, including Nb deposited on top of thermomagnetically patterned NdFeB, and permalloy/niobium with erasable and tailored magnetic landscapes imprinted in the permalloy layer. The magneto-optical imaging data is complemented with and compared to scanning Hall probe microscopy measurements. Comprehensive protocols have been developed for calibrating, testing, and converting Faraday rotation data to magnetic field maps. Applied to the acquired data, they reveal the comparatively weaker magnetic response of the superconductor from the background of larger fields and field gradients generated by the magnetic layer.Comment: 21 pages, including 2 pages of supplementary materia