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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. We performed the first experiment using this imager on a DT gas-filled hohlraum and successfully obtained the spatial distribution of neutron production in the hohlraum plasma. We will report on the design of the spindle, characterization of the detectors, and methodology of the image reconstruction. [ABSTRACT FROM AUTHOR]

Bermudagrasses (Cynodon spp.) grown in the U.S. transition zone and other regions with a similar climate undergo cold acclimation in fall and deacclimation in spring. Physiological mechanisms of cold acclimation and deacclimation are not well documented or understood. This study investigated changes in quality, photochemical efficiency, N metabolite (proline, total amino acid [AA], and protein) content, and dehydrin expression during cold acclimation and deacclimation in five bermudagrass entries. One ecotype (GA-851) and four cultivars (Patriot, Riviera, Tifway, and Princess-77) were subjected to cold acclimation at 8/4°C (day/night; 10-h photopenod) for 28 d and then deacclimation at 10/5, 21/7, 23/8, and 26/14°C sequentially (11-h photoperiod) for either 3 wk (standard deacclimation) or 1 wk (fast deacclimation treatment) at each temperature. In response to cold acclimation, turfgrass quality and photochemical efficiency declined, while proline, AA, protein, and abundance of 25 kDa dehydrin increased. Patriot and Riviera had higher levels of stolon proline, AA, protein, and abundance of 25 kDa dehydrin relative to Princess-77 at the end of cold acclimation. Significant deacclimation occurred as temperature changed from 21/7 to 23/8°C. Patriot, GA-851, and Tifway had greater turfgrass quality ratings and photochemical efficiency and also higher levels of N metabolites relative to Princess-77 and Riviera during deacclimation. A similar response was observed with fast deacclimation treatment. The results suggest that selection and use of entries with higher levels of N metabolites during cold acclimation and deacclimation could improve bermudagrass persistence and spring green-up in transition zone climates. [ABSTRACT FROM AUTHOR]

Bermudagrasses (Cynodon spp.) grown in the U.S. transition zone and other regions with a similar climate undergo cold acclimation in fall and deacclimation in spring. Physiological mechanisms of cold acclimation and deacclimation associated with freezing tolerance and spring green-up are not well documented. This study investigated changes in cytokinin (t-zeatin riboside [t-ZR]) and abscisic acid (ABA) during cold acclimation and deacclimation in five bermudagrass entries in growth chambers. One ecotype (GA-851) and four cultivars (Patriot, Riviera, Tifway, and Princess-77) were subjected to cold acclimation at 8/4°C (day/night) for 28 d and then deacclimation at 10/5, 21/7, 23/8, and 26/14°C for either 3 wk (standard deacclimation) or 1 wk (fast deacclimation treatment). Stolon t-ZR content declined while ABA content increased during cold acclimation. Patriot and Riviera had higher levels of stolon ABA relative to Princess-77 at the end of cold acclimation. During deacclimation, t-ZR increased as the temperature increased to 26/14°C, while ABA declined as the temperature increased from 10/5 to 21/7°C. Patriot, GA-851, and Tifway had higher levels of t-ZR relative to Riviera and Princess-77. Abscisic acid level during cold acclimation may be associated with freezing tolerance, while cytokinin level during deacclimation may be associated with rate of spring green-up of bermudagrass. The results suggest that selection and use of entries with higher levels of ABA during cold acclimation and cytokinin during deacclimation could improve bermudagrass winter survival and spring green-up in transition zone climates. [ABSTRACT FROM AUTHOR]

In a retrospective study, we investigated the results of 384 stapedectomies performed between 1962 and 1989. The purpose was to determine the possible influence of age on the postoperative functional result. The operative technique uniformly consisted of a total stapedectomy, seal of the oval window with perichondrium and replacement of the stapes by a free tragal cartilage graft. The audiometric data at 0.5, 1, 2, and 4 kHz were compared. The patients were divided into five groups based upon chronological age: under 30, 30-40, 41-50, 51-60, over 60 years. Although the preoperative airbone gap (ABG) increased with age at all frequencies, and thus the chance for surgery to improve the ABG, the youngest group showed the best improvement in ABGG ( P<0.05). Using a technique with total removal of the footplate, bone conduction thresholds improved in the frequencies up to 2 kHz. At 4 kHz, they deteriorated in the four oldest groups. The greatest improvement in bone conduction thresholds occurred in the youngest group of patients ( P<0.05), with a parallel decline in age and postoperative results occurring. The causes of these differences are not yet clear, although spontaneous recovery and greater resistance to operative trauma in the younger age groups might be of influence. [ABSTRACT FROM AUTHOR]

Neutron time of flight (nToF) detectors are fielded at the National Ignition Facility (NIF) to measure neutron yield, ion temperature, and downscattering in the cold fuel for D-T implosions. Anisotropically assembled cold fuel may generate different nToF data when measured by detectors located at the Target Chamber equator and poles. A collimated nToF line of sight has been fielded near the Target Chamber South Pole (SP) to examine any possible anisotropy in the cold fuel. The SP nToF detector is located in the lowest floor level of the NIF’s Target Bay and at a distance of ~ 18 m from the Target Chamber Center. The detector utilizes a solid bibenzyl scintillator and four photomultiplier tubes. The line of sight includes a port collimator that is attached to the Target Chamber and a bore hole collimator in the concrete floor above the detector. In addition, a beam line get lost hole is constructed in the Target Bay floor to minimize the backscattered radiation at the detector location. Initial measurements indicated the need for installation of additional shielding to eliminate gamma background during the period before arrival of the 14.1 MeV neutrons to the detector. A set of MCNP Monte Carlo simulations with the full Target Bay model were conducted to provide an estimate of the expected neutron and gamma backgrounds during D-T shots. A new shielding scheme is designed to reduce the gamma background by an order of magnitude.

The 35Cl(n,p) and 35Cl(n,α) cross sections at incident neutron energies between 2.42 and 2.74 MeV were measured using the Berkeley High Flux Neutron Generator. The cross sections for 35Cl(n,p) were more than a factor of 3 to 5 less than all of the values in the neutron absorption data libraries, while the 35Cl(n,α) cross sections are in reasonable agreement with the data libraries. The measured energy-differential cross section is consistent with a single resonance with a width of 293(46) keV. This result suggests that, despite the high incident neutron energy, any attempt to model (n,x) cross sections in the vicinity of the N=Z=20 shell gap requires a resolved resonance approach rather than a Hauser-Feshbach approach. [ABSTRACT FROM AUTHOR]

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., Methods: Sixteen individuals with PD and 15 healthy adults completed traditional motor, cognitive, and IADL assessments and the CC-VRS task. Group differences were evaluated using Welch's t-test., Results: There were no between-group differences in traditional performance measures of motor, cognitive, or IADL function. Regarding CC-VRS performance, participants in the PD group completed the task significantly slower than controls (690 vs. 523 sec, respectively). Participants with PD spent 25 % more time walking and turning and were stopped 46 % longer than controls. Average gait speed when viewing the shopping list, a measure of dual-task performance, was significantly slower in the PD group compared to controls (0.26 vs. 0.17 m/s, respectively)., Conclusion: Unlike traditional performance measures of motor, cognitive, and IADL function, the CC-VRS discriminated participants with PD from healthy older adults. For the PD group, motor and dual-task declines contributed to diminished CC-VRS performance. Identifying underlying contributors to IADL declines supports using ecological assessments, such as the CC-VRS, for the routine clinical evaluation of IADLs., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Jay L. Alberts and Anson B. Rosenfeldt have authored intellectual property related to the CC-VRS platform., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

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., Methods: Fifteen young adults completed forward walk, 180° turn, and 360° turn tasks under three conditions: (1) overground, (2) on the Infinadeck ODT in a virtual environment without a handrail, and (3) on the ODT with a handrail. Kinematic data for all walking trials were gathered using 3D optical motion capture., Results: Overall, gait speed was slower during ODT walking than overground. When controlling for gait speed, ODT walking resulted in shorter steps and greater variability in step length. There were no significant differences in other spatiotemporal metrics between ODT and overground walking. Turning on the ODT required more steps and slower rotational speeds than overground turns. The addition of the stability handrail to the ODT resulted in decreased gait variability relative to the ODT gait without the handrail., Conclusion: Walking on an ODT resembles natural gait patterns apart from slower gait speed and shorter step length. Slower walking and shorter step length are likely due to the novelty of physically navigating a virtual environment which may result in a more conservative approach to gait. Future work will evaluate how older adults and those with neurological disease respond to ODT walking., (© 2023. The Author(s).)

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G&#95;{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G&#95;{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

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. An impediment to the adoption and scaling of VR in clinical neurology is VR-related sickness resulting from sensory inconsistencies between the visual and vestibular systems (i.e., locomotion problem). The Cleveland Clinic Virtual Reality Shopping (CC-VRS) platform attempts to solve the locomotion problem by coupling an omnidirectional treadmill with high-resolution VR content, enabling the user to physically navigate a virtual grocery store to simulate shopping. The CC-VRS consists of Basic and Complex shopping experiences; both require walking 150 m and retrieving five items. The Complex experience has additional scenarios that increase the cognitive and motor demands of the task to better represent the continuum of activities associated with real-world shopping. The CC-VRS platform provides objective and quantitative biomechanical and cognitive outcomes related to the user's IADL performance. Initial data indicate that the CC-VRS results in minimal VR-sickness and is feasible and tolerable for older adults and patients with Parkinson's disease (PD). The considerations underlying the development, design, and hardware and software technology are reviewed, and initial models of integration into primary care and neurology are provided.

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 0 , and ion temperature, T ion . We present the results of uncertainty analysis showing the significant reduction of the uncertainty in determining these quantities in the Cherenkov detector system recently deployed at NIF. The increased sensitivity to gamma radiation requires additional consideration of the effect of this background to the uncertainties in both t 0 and T ion .

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. Enzymatic degradation was used to specifically target proteoglycans alone, collagen alone and both cartilage components sequentially. The resulting degradation was evaluated using MRI imaging techniques (T 1 , T 2 , diffusion tensor imaging, and gadolinium enhanced T 1 ) and derived measures of water, glycosaminoglycan and collagen content. We compared the classification ability of full thickness averages of these parameters with zonal averages (superficial, medial, and deep). Finally, we determined minimum variables sets to identify the smallest number of variables that allowed for complete separation of all degradation groups and ranked them by impact on the separation. Zonal analysis was much more sensitive than full thickness averages and allowed perfect separation of all four groups. Superficial zone cartilage was more sensitive to enzymatic degradation than the medial or deep zone, or the full thickness average. Variable ranking consistently identified collagen content and organization as the most impactful variables in the classification algorithm. The aim of this study is to classify cartilage degradation using only non-invasive MRI parameters that could be applied to OA diagnosis. Our results highlight the importance of zonal variation in the diagnosis of cartilage degeneration. Our novel, non-invasive collagen content measurement was crucial for complete separation of degraded groups from control cartilage. These findings have significant implications for clinical cartilage MRI for disease diagnosis., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

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 40 Ar/ 39 Ar dating of geological materials produces nearly monoenergetic 2.45MeV neutrons at outputs of 10 8 n/s. The narrow energy range is advantageous relative to the 235 U fission spectrum neutrons due to (i) reduced 39 Ar recoil energy, (ii) minimized production of interfering argon isotopes from K, Ca, and Cl, and (iii) reduced total activity for radiological safety and waste generation. Calculations provided show that future conditioning at higher currents and voltages will allow for a neutron output of over 10 10 n/s, which is a necessary requirement for production of measurable quantities of 39 Ar through the reaction 39 K(n,p) 39 Ar. A significant problem encountered with increasing deuteron current was beam-induced electron backstreaming. Two methods of suppressing secondary electrons resulting from the deuterium beam striking the target were tested: the application of static electric and magnetic fields. Computational simulations of both techniques were done using a finite element analysis in COMSOL Multiphysics ® . Experimental tests verified these simulations. The most reliable suppression was achieved via the implementation of an electrostatic shroud with a voltage offset of -800V relative to the target., (Copyright © 2017. Published by Elsevier Ltd.)

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. The theory of transformational versus transactional leadership style guided this study. A cross-sectional mailed survey design was conducted. A convenience sample of 233 nursing faculty participated in this study. Idealized influence, intellectual stimulation, and contingent reward leadership styles significantly and positively predicted job satisfaction. However, active management-by-exception significantly and negatively predicted job satisfaction. Nursing leaders should implement effective leadership styles. Study implications for nursing education administration, limitations, and recommendations for future studies were discussed.

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. These courses follow up completion of required foundational clinical courses. Emphasis areas include all clinical areas offered within the nursing curriculum such as cardiovascular, critical care, and community health. Courses begin and end with 1-credit seminars and include one 3-credit clinical Practicum. In the latter course, students work with a clinical preceptor, following the preceptor's work hours for a minimum of 9 hours a week over the 15-week semester. Advantages of the Emphasis Courses are many: students develop an in-depth knowledge and clinical skills in a selected area of clinical practice. Potential employers have an opportunity to observe students in a preemployment setting and to evaluate the fit of skills and personal attributes to the specific setting. Students are provided with "value-added" knowledge and experience. The emphasis course model offers advantages to students transitioning into the workforce, to employers, and, ultimately, to clients served.

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. Significantly fewer single-object, view-specific occlusions were produced for end-to-end than for side-to-side alignments. Nevertheless, the former reveal that more children are able to use the vertical dimension to depict multiple objects in depth. Other comparisons suggest an interaction in multiple-object depictions of canonicality with spatial dimension and graphic complexity.

This study examined nursing faculty perceptions of the importance of adequate library facilities and their satisfaction with them. Library facilities ranked highest in importance among all job characteristics studied, with faculty who had been most productive in terms of publication assigning the highest value to them. A moderate level of satisfaction was found. Faculty most satisfied with library facilities were those teaching in large schools of nursing with graduate programs and open organizational climates and those who were less well educated and generally satisfied with their positions.

In this chapter, evaluation was defined as a decision-making process that leads to suggestions for action to maintain and/or improve effectiveness and efficiency of programs and participants. Purposes for evaluating nursing programs in education and service were explained. The principles that govern evaluation in nursing, which are the same as those that govern the evaluation of any programmatic endeavor, were presented. The unique and specific character of nursing and its settings, which must be taken into account when strategies and techniques for implementing these principles are designed and/or selected, were discussed. Of major concern was the selection of an approach to evaluating nursing programs. Models for evaluating programs that have served as prototypes for evaluation in a variety of settings and fields were presented. More specifically, the views addressed included: Tyler's Objective-Based Evaluation, Accreditation/Certification Evaluation, Stake's Client-Centered Evaluation, Stufflebeam's Decision-Oriented Evaluation, Taba's Experimental-Research Evaluation, and Scriven's Consumer-Oriented Evaluation. Also discussed was the Utilization-Focused Approach to Evaluation. However, while all prototypes contribute in some manner to the conditions necessary for conducting a comprehensive evaluation of nursing programs, none are complete or sufficient in this regard. An eclectic approach to evaluating nursing programs developed by Waltz in an attempt to incorporate the strengths of existing models, minimize limitations, and expand thinking to include additional components and concerns with particular relevance to nursing was discussed. Attention was given to definition of terms, purposes for the evaluation, what the focus of the evaluation is, how the evaluation should proceed, when evaluation should occur, and major audiences. Specific considerations that increase the likelihood that an evaluation will be comprehensive but cost-efficient were elaborated.