Neutron imaging of the deuterium-tritium tamping gas volume in an inertial confinement fusion hohlraum.

To benchmark the accuracy of the models and improve the predictive capability of future experiments, the National Ignition Facility requires measurements of the physical conditions inside inertial confinement fusion hohlraums. The ion temperature and bulk motion velocity of the gas-filled regions of the hohlraum can be obtained by replacing the helium tamping gas in the hohlraum with deuterium-tritium (DT) gas and measuring the Doppler broadening and Doppler shift of the neutron spectrum produced by nuclear reactions in the hohlraum. To understand the spatial distribution of the neutron production inside the hohlraum, we have developed a new penumbral neutron imager with a 12 mm diameter field of view using a simple tungsten alloy spindle.

An immersive virtual reality shopping task detects declines in instrumental activities of daily living in individuals with Parkinson's disease.

Introduction: Declines in instrumental activities of daily living (IADLs) have been proposed as a prodromal marker of Parkinson's disease (PD). The Cleveland Clinic Virtual Reality Shopping (CC-VRS) platform combines an omnidirectional treadmill with a virtual reality headset to create a virtual grocery store that a user physically walks through and completes a shopping task. The primary aim of this project was to determine the known-group validity of the CC-VRS platform in discriminating IADL performance and to characterize specific motor and cognitive declines responsible for PD-related IADL impairments.

Gait patterns during overground and virtual omnidirectional treadmill walking.

Background: Omnidirectional treadmills (ODTs) offer a promising solution to the virtual reality (VR) locomotion problem, which describes the mismatch between visual and somatosensory information and contributes to VR sickness. However, little is known about how walking on ODTs impacts the biomechanics of gait. This project aimed to compare overground and ODT walking and turning in healthy young adults.

The Immersive Cleveland Clinic Virtual Reality Shopping Platform for the Assessment of Instrumental Activities of Daily Living.

A decline in the performance of instrumental activities of daily living (IADLs) has been proposed as a prodromal marker of neurological disease. Existing clinical and performance-based IADL assessments are not feasible for integration into clinical medicine. Virtual reality (VR) is a powerful yet underutilized tool that could advance the diagnosis and treatment of neurological disease.

Design of the ion-optics for the MRSt neutron spectrometer at the National Ignition Facility (NIF).

A new Magnetic Recoil Spectrometer (MRSt) is designed to provide time-resolved measurements of the energy spectrum of neutrons emanating from an inertial confinement fusion implosion at the National Ignition Facility. At present, time integrated parameters are being measured using the existing magnet recoil and neutron time-of-flight spectrometers. The capability of high energy resolution of 2 keV and the extension to high time resolution of about 20 ps are expected to improve our understanding of conditions required for successful fusion experiments.

Top-level physics requirements and simulated performance of the MRSt on the National Ignition Facility.

The time-resolving Magnetic Recoil Spectrometer (MRSt) for the National Ignition Facility (NIF) has been identified by the US National Diagnostic Working Group as one of the transformational diagnostics that will reshape the way inertial confinement fusion (ICF) implosions are diagnosed. The MRSt will measure the time-resolved neutron spectrum of an implosion, from which the time-resolved ion temperature, areal density, and yield will be inferred. Top-level physics requirements for the MRSt were determined based on simulations of numerous ICF implosions with varying degrees of alpha heating, P2 asymmetry, and mix.

The five line-of-sight neutron time-of-flight (nToF) suite on the National Ignition Facility (NIF).

Measurement of the neutron spectrum from inertial confinement fusion implosions is one of the primary diagnostics of implosion performance. Analysis of the spectrum gives access to quantities such as neutron yield, hot-spot velocity, apparent ion temperature, and compressed fuel ρr through measurement of the down-scatter ratio. On the National Ignition Facility, the neutron time-of-flight suite has been upgraded to include five independent, collimated lines of sight, each comprising a high dynamic range bibenzyl/diphenylacetylene-stilbene scintillator [R.

Uncertainty analysis of response functions and -backgrounds on T and t measurements from Cherenkov neutron detectors at the National Ignition Facility (NIF).

Cherenkov radiators deployed to measure the neutron time-of-flight spectrum have response times associated with the neutron transit across the detector and are free from long time response tails characteristic of scintillation detectors. The Cherenkov radiation results from simple physical processes which makes them amenable to high fidelity Monte Carlo simulation. The instrument response function of neutron time-of-flight systems is a major contributor to both the systematic and statistical uncertainties of the parameters used to describe these spectra; in particular, the first and second moments of these distributions are associated with arrival time, t, and ion temperature, T.

Aperture design for the third neutron and first gamma-ray imaging systems for the National Ignition Facility.

The current construction of a new nuclear-imaging view at the National Ignition Facility will provide a third line of sight for hotspot and cold fuel imaging and the first dedicated line of sight for 4.4-MeV γ-ray imaging of the remaining carbon ablator. To minimize the effort required to hold and align apertures inside the vacuum chamber, the apertures for the two lines of sight will be contained in the same array.

A fused silica Cherenkov radiator for high precision time-of-flight measurement of DT and neutron spectra (invited).

A fused silica Cherenkov radiator has been implemented at the National Ignition Facility to provide a new high precision measurement of the time-of-flight spectrum of 14.1 MeV DT fusion neutrons. This detector enables a high precision (<30 ps) co-registered measurement of both a thresholded -ray and a neutron spectrum on a single record.

response functions for Cherenkov-based neutron detectors.

Neutron time-of-flight diagnostics at the NIF were recently outfitted with Cherenkov detectors. A fused silica radiator delivers sub-nanosecond response time and is optically coupled to a microchannel plate photomultiplier tube with gain from ∼1 to 10. Capitalizing on fast time response and gamma-ray sensitivity, these systems can provide better than 30 ps precision for measuring first moments of neutron distributions.

Distribution of collected target debris using the large area solid debris radiochemistry collector.

A large area solid radiochemistry collector was deployed at the National Ignition Facility (NIF) with a collection efficiency for post-shot, solid target debris of approximately 1% of the total 4π solid angle. The collector consisted of a 20-cm diameter vanadium foil surrounded by an aluminum side-enclosure and was fielded 50 cm from the NIF target. The collector was used on two NIF neutron yield shots, both of which had a monolayer of U embedded in the capsule ablator 10 m from the inner surface.

Zonal variation of MRI-measurable parameters classifies cartilage degradation.

Osteoarthritis (OA) is a degenerative joint disease resulting in the deterioration of articular cartilage, a tissue with minimal ability to self-repair. Early diagnosis of OA with non-invasive imaging techniques such as magnetic resonance imaging (MRI) could provide an opportunity to intervene and slow or reverse this degeneration process. This study examines the classification of degradation states using MRI measurements.

Beam-induced back-streaming electron suppression analysis for an accelerator type neutron generator designed for Ar/Ar geochronology.

A facility based on a next-generation, high-flux D-D neutron generator has been commissioned and it is now operational at the University of California, Berkeley. The current generator designed for Ar/Ar dating of geological materials produces nearly monoenergetic 2.45MeV neutrons at outputs of 10n/s.

Use of genitourinary teaching associates (GUTAs) to teach nurse practitioner students: is self-efficacy theory a useful framework?

Self-efficacy theory guided an examination of the effect of an educational activity using genitourinary teaching associates (GUTAs) with beginning nurse practitioner students. Confidence in and comfort with learning and performing the examinations were evaluated prior to and immediately after the GUTA activity. Statistical analyses revealed significant increases in confidence following all activities with GUTAs, consistent with self-efficacy theory.

A QTL study of cattle behavioral traits in embryo transfer families.

Two behavioral traits, temperament and habituation, were measured in 130 calves from 17 full-sib families which comprise the Canadian Beef Cattle Reference Herd. Using variance components, heritability was calculated as 0.36 for temperament and 0.

Academic leadership style predictors for nursing faculty job satisfaction in Taiwan.

The purpose of this study was to examine the influence of nursing deans' and nursing directors' transformational and transactional leadership styles on nursing faculty job satisfaction in baccalaureate and associate degree nursing programs in Taiwan. The study provides a mechanism by which nursing deans or nursing directors can obtain feedback from nursing faculty about leadership styles. Such feedback can then serve as the basis for further development of academic nursing leadership potential in Taiwan.

Variability in vocal and behavioural responses to visual isolation between full-sibling families of beef calves.

In order to assess the value of vocal response as an indicator of welfare in cattle, it is necessary to investigate factors which influence vocal behaviour of individuals, that are independent of the specific environmental conditions to which they are exposed. The effect of parental differences, sex, age and weight on vocal responses of calves to visual isolation were examined. The relationship between vocal response and the amount of body movement during isolation were also evaluated.

Emphasis courses: preparing baccalaureate students for transition to the workforce.

In response to identified needs for stronger preparation of baccalaureate graduates to enter the workforce, the University of Maryland School of Nursing created, implemented, and evaluated the use of Clinical Emphasis Seminars and Practicum. A sequence of 3 courses was ultimately developed for students to take during the final year of their upper-division nursing curriculum. The courses, totaling 5 credits, allow students to develop their knowledge and experience in a focus area within 1 specific type of clinical nursing.

A neural network model for predicting pancreas transplant graft outcome.

Objective: To compare the results of a neural network versus a logistic regression model for predicting early (0-3 months) pancreas transplant graft survival or loss.

Research Design And Methods: This study was a cross-sectional, secondary analysis of demographic and clinical data from 117 simultaneous pancreas-kidney (SPK), 35 pancreas-after-kidney (PAK), and 8 pancreas-transplant-alone (PTA) patients (n = 160). The majority of patients were men (57%) and were white (90.

Assessing the outcomes of professional practice redesign. Impact on staff nurse perceptions.

There are many reports in the literature of management innovations to redesign nursing roles and care delivery systems in response to the dramatic changes taking place in the healthcare environment. Few of these innovations have been evaluated systematically in terms of the dynamics and effects of change at the work group level. The authors present results of a longitudinal study evaluating the work group outcomes of a professional practice model implemented in an academic medical center.

The effect of object alignment on the representation of depth in young children's drawings.

Light and Humphreys (1981, Journal of Experimental Child Psychology, 31, 521-530) provided evidence that young children's drawings, despite infrequently showing view-specific occlusion, do systematically reflect spatial relations within an array. The present research tested the hypothesis that young children's preferences for canonical "best views" interact with array-faithful tendencies to increase early uses of occlusion. Forty-three children between 4 and 7 years of age drew arrays like Light and Humphreys' end-to-end alignments, with end-on views of objects in depth, and arrays aligned side-to-side, with canonical side-views of objects in depth.