Self-efficacy in non-concussed youth: a normative study.

OBJECTIVE: In pediatric concussion, there has been a shift to consider how pre-injury profiles, such as self-efficacy, affect the recovery trajectory. The aim of this study was to investigate normal ranges of self-efficacy (overall, academic, social, emotional) in youth and to explore its relationship with the effects of daily stressors, operationalized as concussion-like symptoms, demographic factors, pre-injury/learning related factors, and concussion history. METHODS: A cross-sectional study of 1300 uninjured youth 13-18 years old (1111 males, 189 females) was conducted by secondary analysis of clinical pre-injury/baseline concussion data. Demographic information, concussion-like symptoms (Post-concussion Symptom Inventory), and self-efficacy (Self-efficacy Questionnaire for Children) were self-reported. RESULTS: The most reported concussion-like symptoms were common stress symptoms and there was a strong negative relationship with self-efficacy. Males reported higher self-efficacy than females, but no age effects were observed. Pre-injury factors including learning disability, ADHD, special education, IEP, mental health challenges, history of headaches/migraines, and concussion history were associated with significantly lower overall self-efficacy. CONCLUSIONS: These normative ranges and predictive model can be used to provide a benchmark of self-efficacy to indicate how youth may respond to a concussion, and to inform clinical care during recovery.

High-Brightness Continuous-Wave Electron Beams from Superconducting Radio-Frequency Photoemission Gun.

Continuous-wave photoinjectors operating at high accelerating gradients promise to revolutionize many areas of science and applications. They can establish the basis for a new generation of monochromatic x-ray free electron lasers, high-brightness hadron beams, or a new generation of microchip production. In this Letter we report on the record-performing superconducting rf electron gun with CsK_{2}Sb photocathode. The gun is generating high charge electron bunches (up to 10 nC/bunch) and low transverse emittances, while operating for months with a single photocathode. This achievement opens a new era in generating high-power beams with a very high average brightness.

Health-Related Quality of Life in Non-Concussed Children: A Normative Study to Inform Concussion Management.

Purpose: There has been a shift to consider pediatric concussion recovery beyond symptom management by considering how health-related quality of life (HRQoL) affects recovery. This study investigated normative ranges of HRQoL in children and explored its relationship with common pediatric concussion variables. Methods: A cross-sectional study of 1,722 non-concussed children 8-12 years old (M = 10.52 ± 1.23 years; 1,335 males, 387 females) was conducted by secondary analysis of clinical baseline concussion data. Demographic information, concussion-like symptoms (PCSI-C), and HRQoL (KIDSCREEN-10 Index) were self-reported. Results: The most reported concussion-like symptoms were common stress symptoms and were significantly negatively correlated with HRQoL. Premorbid histories of attention deficit hyperactivity disorder, mental health challenges, headaches/migraines, and concussion significantly lowered HRQoL. The number of diagnosed concussions and PCSI-C scores were significantly negatively correlated with HRQoL. Conclusions: The normative ranges and model can indicate HRQoL levels to inform clinicians how children may respond to concussion and streamline care beyond traditional assessment models.

Experimental Demonstration of Hadron Beam Cooling Using Radio-Frequency Accelerated Electron Bunches.

Cooling of beams of gold ions using electron bunches accelerated with radio-frequency systems was recently experimentally demonstrated in the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. Such an approach is new and opens the possibility of using this technique at higher energies than possible with electrostatic acceleration of electron beams. The challenges of this approach include generation of electron beams suitable for cooling, delivery of electron bunches of the required quality to the cooling sections without degradation of beam angular divergence and energy spread, achieving the required small angles between electron and ion trajectories in the cooling sections, precise velocity matching between the two beams, high-current operation of the electron accelerator, as well as several physics effects related to bunched-beam cooling. Here we report on the first demonstration of cooling hadron beams using this new approach.

Association between pigs with high caecal Salmonella loads and carcass contamination.

Contaminated pork is a significant source of foodborne Salmonella infections. Pork is contaminated at the slaughterhouse; however, the mechanisms driving Salmonella contamination of carcasses are still poorly understood. The aim of this study was to investigate whether the amount of Salmonella carried by slaughtered pigs in their guts has an influence on carcass contamination. On that account, we tested whether the number of carcasses contaminated during a slaughter day was associated with the prevalence of highly contaminated pigs (HCP: Salmonella caecal loads ≥3log/g), or with the prevalence of pigs that simply carry Salmonella spp. in their guts. Three hundred and six pigs were sampled in a slaughterhouse from Central Italy. Salmonella loads in the caecum and on the carcass of each pig were estimated by the most probable number (MPN) technique. The overall prevalence of Salmonella was 34.64% and 7.19% for the caeca and carcasses, respectively. S. Derby and Salmonella enterica 4,[5],12:i:- were the most frequently isolated serovars. The prevalence of HCP was 11.44%. We found a higher number of contaminated carcasses on days of high prevalence of HCP than on days of low prevalence of HCP (p=0.0011). Conversely, carcass contamination did not vary with the prevalence of pigs that simply carried Salmonella spp. in their guts (p=0.7970). Therefore, the prevalence of HCP, but not the prevalence of pigs carrying Salmonella spp., was related to carcass contamination. Taken together, these findings suggest that reduction of Salmonella loads in the guts of slaughtered pigs would result in fewer contaminated carcasses, and consequently, help to minimise the risk of human infection due to the consumption of contaminated pork.

A 3-D skeleton model & SEMG approach for integrated neck and low back pain analysis test batteries.

Since several years our group is working on a project to merge into a full 3D reliable and detailed human skeleton representation various segmental biomechanical models presented in literature. The obtained 3D skeleton model is fully parametric and can be fitted to each subject anthropometric characteristics. A non-ionising approach based on 3D opto-electronic measurements of body landmarks labelled by passive markers has been chosen to build the 3D parametric biomechanical skeleton model. A special focus has been devoted to identify and model the spine with a correct degree of accuracy and reliability. In spine pain related pathologies is of major importance the evaluation of functional limitations associated. This requires to integrate morphological characteristics with information deriving from other measurements devices as force platform data, surface EMG, foot pressure maps. The aim of this study is to present a multi-factorial approach which integrates rachis morphological characteristics with full skeleton kinematic, dynamic and SEMG measurements to quantify spine function and mobility in particular for neck and low back pain. A set of clinical-biomechanical tests have been implemented. Static posture characteristics are first evaluated. After that, patient is asked to perform specific motion test batteries in order to fully measure the whole ROMs (spine angles ranges and spine shape modifications) for Axial rotations, forward-backward flexion-extension, lateral bendings per each spine functional units (Skull and neck, thoracic and lumbar districts). During forward bending also a digital Schober test is performed. Such data are correlated to simultaneous SEMG muscle activities recording to investigate motor co-ordination/dysfunction as well as the presence absence of flexion-relaxation phenomena associated to pain.

Epitaxially-grown Ge/Si avalanche photodiodes for 1.3 microm light detection.

We designed and fabricated Ge/Si avalanche photodiodes grown on silicon substrates. The mesa-type photodiodes exhibit a responsivity at 1310 nm of 0.54 A/W, a breakdown voltage thermal coefficient of 0.05%/ degrees C, a 3 dB-bandwidth of 10 GHz. The gain-bandwidth product was measured as 153 GHz. The effective k value extracted from the excess noise factor was 0.1.

A 10-Gbit/s EML link using detuned narrowband optical filtering.

In this paper, the effects of asymmetric narrowband optical filtering are investigated in a 10-Gbit/s optical communication link using integrated electro-absorption modulated lasers (EML). We investigate the effect of EML chirp on link performance as well as the optimal filter bandwidth and wavelength detuning. We show that both the phase response and the spectral narrowing of the filter will enable a longer distance transmission by interacting with the EML transient chirp and compensating for the fiber chromatic dispersion. Experimentally, an 8.75-GHz filter is shown to improve the link distance by 40 km from 65 to 105 km, when transmitting over standard single mode fiber.

Hyperventilation in normal subjects. A clinical, gas-analytic and EMG study.

Clinical (paresthesiae and Trousseau's sign), EMG, blood biochemical (lactic acid and total Ca2+) and gas-analytic (pH, PCO2, PO2, HCO3) changes were studied during and after 5 min voluntary hyperventilation (HV) in 15 normal subjects. Paresthesiae and spontaneous motor activity were common manifestations (87% and 67% respectively) in our test. They were significantly related only to changes in pH, PCO2 and PO2, with paresthesiae arising earlier and at milder gas-analytic changes than motor activity. Paresthesiae and motor activity induced by HV cannot be used as reliable indicators of pathology. Their presence simply reflects the degree of the blood gas-analytic changes (pH, PCO2 and PO2) which therefore should be carefully monitored before drawing any conclusion from an HV test.

F-wave normative studies in different nerves of healthy subjects.

F-wave main characteristics were investigated following stimulation of 8 different nerves (facial, axillary, radial, median, ulnar, femoral, deep peroneal, posterior tibial) in a population of normal healthy subjects. Additional studies compared different stimulation and recording techniques (stimulus intensity, stimulus duration, number of consecutive stimuli, facilitating maneuvers, type of recording electrodes). F-wave persistency varied markedly among the different nerves. Mean latencies were correlated to subjects' height, whereas conduction velocity was related to age. The optimal stimulation and recording parameters to obtain reliable information on F-wave studies were: stimulation duration of 0.2 msec with a strength adjusted 30% supramaximal to the direct M-response; administration of a train composed of 10 consecutive stimuli at rest and recording by concentric needle electrodes.