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. The layout, ion-optics, and specifications of the MRSt will be presented.

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. Synthetic MRSt data were subsequently generated for different configurations using Monte-Carlo methods to determine its performance in relation to the requirements. The system was found to meet most requirements at current neutron yields at the NIF. This work was supported by the DOE and LLNL.

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. Hatarik et al., Plasma Fusion Res. 9, 4404104 (2014)] and high-speed fused silica Cherenkov detectors [A. S. Moore et al., Rev. Sci. Instrum. 89, 10I120 (2018)].

A fused silica Cherenkov radiator for high precision time-of-flight measurement of DT γ 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 γ-ray and a neutron spectrum on a single record. Other methods typically require γ and neutron signals to be co-registered via other diagnostics and/or dedicated timing experiments. Analysis of the co-registered γ and neutron signals allows precise extraction of the mean neutron energy and bulk hot-spot velocity, both of which were not possible with prior scintillator technologies. Initial measurements demonstrate the feasibility of this measurement and indicate that combined detection of neutrons and γ-rays on multiple lines-of-sight should enable the bulk vector velocity of the implosion hot-spot to be determined to ≈5 km/s and reduced uncertainty in the spectral width ≈0.1 keV.

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. In this work, we discuss the system requirements for neutron and γ-ray imaging and the resulting aperture array design.

Uncertainty analysis of response functions and γ -backgrounds on Tion and t0 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, t0, and ion temperature, Tion. 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 t0 and Tion.

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 238U embedded in the capsule ablator 10 µm from the inner surface. Fission and activation products produced in the 238U were collected, and subsequent analyses via gamma spectroscopy indicated that the distribution of fission products was not uniform, with peak and valley fission products preferentially collected on the vanadium and low- and high-mass fission products primarily located on the aluminum side-enclosure. The results from these shots will be used to design future nuclear data experiments at NIF.

Ab initio 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 104. 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. Generation of ab initio instrument response functions (IRFs) is critical to meet the <1% uncertainty needed. A combination of Monte Carlo modeling, benchtop characterization, and in situ comparison is employed. Close agreement is shown between the modeled IRFs and in situ measurements using the NIF's short-pulse advanced radiographic capability beams. First and second moments of neutron spectra calculated using ab initio IRFs agree well with established scintillator measurements. Next-step designs offer increased sensitivity and time-response.

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 0.46 for habituation. Genotyping of 162 microsatellites at approximately 20 cM intervals allowed the detection of six quantitative trait loci (QTL) for behavior traits on cattle chromosomes 1, 5, 9, 11, 14, 15.

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. 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.

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.Seventeen full-sibling families of beef calves (N=130) were created by breeding five sires with 13 superovulated dams. Embryos were transferred into unrelated cows, which reared the calves to weaning age. Vocal response of calves and body movement were measured on four occasions, while they were visually isolated for 1min on a single animal scale platform. The first two observations were made on the day of weaning (mean age 166 days) and the following day. At the third and fourth observations their average ages were 278 and 350 days, respectively. On the four occasions 33.3, 34.8, 27.8 and 38.6% of calves, respectively, vocalized. Both sire and family had a significant influence on the number of vocalizations and acoustic properties of the sounds. Electronically-measured movement while on the scale was also influenced by sire and family, but there was no relationship between vocal responses and body movement. There was a tendency (P=0.08) for older and therefore heavier calves to produce longer vocalizations. In the final observing session, age and weight were positively correlated with fundamental frequency and the sound pressure level at the frequency of greatest intensity, and negatively correlated with the loudest harmonic. At the last two observations, significantly more heifer calves than bull calves vocalized. There was little difference between the acoustic properties of heifers' and bulls' vocalizations.The considerable individual variability in vocal response within a group of identically-treated calves is partly due to parental genetic influences that are independent of rearing and early experience. Other endogenous characteristics such as sex, age and weight also influence vocal response. But there is no clear relationship between individual temperament (as assessed by the amount of body movement during isolation) and characteristics of vocal response.

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. 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.

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 (90.1%), with a mean age of 39 +/- 8.09 years. Of the patients, 23 (14.4%) experienced early graft loss, which included any loss owing to technical or immunological causes, and death with a functional graft. Data were analyzed with a logistic regression model for multivariate analysis and a backpropagation neural network (BPNN) model. RESULTS: A total of 12 predictor variables were chosen from literature and transplant surgeon recommendations. A logistic model with all predictor variables included correctly classified 93.53% of cases. Model sensitivity was 35.71%; specificity was 100% (pseudo-R2 0.24). Of the predictors, history of alcohol abuse (odds ratio [OR] 32.39; 95% CI 1.67-626.89), having a PAK or PTA (OR 13.6; 95% CI 2.20-84.01), and use of a nonlocal organ procurement center (OPO) (OR 4.51; 95% CI 0.78-25.96) were most closely associated with early graft loss. The BPNN model with the same 12 predictor variables correctly predicted 92.50% of cases (R2 0.71). Model sensitivity was 68%; specificity was 96%. Of the predictors, the three variables most closely associated with graft outcome in this model were recipient/donor weight difference >50 lb, having a PAK or PTA, and use of a nonlocal OPO. CONCLUSIONS: First, the BPNN model correctly predicted 92.5% of graft outcomes versus the logistic model (93.53%). Second, the BPNN model rendered more accurate predictions (>0.70 = loss; <0.30 = survival) versus the logistic model (>0.50 = loss; <0.50 = survival). Third, the BPNN model was more sensitive (68%) than the logistic model (35.71%) to graft failures and demonstrated an almost threefold increase in explained variance (R2 = 0.71 vs. 0.24). These results suggest that the BPNN model is a more powerful tool for predicting early pancreas graft loss than traditional multivariate statistical models.

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 strategy of integrating ongoing data collection and feedback into a process of continuous change also are presented.

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. 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.

Evaluating the program.

This chapter presents a discussion of the specific steps undertaken when the Waltz approach is employed for the evaluation of nursing programs. Discussion is organized in terms of: (1) who is responsible for the evaluation; (2) why the evaluation is conducted, (3) what is evaluated, (4) how judgments are made on the basis of findings, (5) how the evaluation proceeds, (6) when evaluation occurs, (7) reporting and recording findings and results, and (8) evaluating the evaluation. Specific strategies and techniques for developing and implementing the Master Plan for Evaluation and for managing the conduct of the ongoing evaluation are described. Specific topics regarding "who" include the following: establishing and maintaining the internal evaluator role, operationalizing the internal evaluator role, ethical and political aspects of the role, essential characteristics of internal evaluators, maintaining an outsider perspective in the insider role, and determining significant others to be involved. In the section on "why," attention is given to explaining the purposes for the evaluation and identifying the potential audiences for results. Regarding "what," the focus is on examining program inputs, processes, outcomes, and the setting in which the evaluation occurs, rendering goals and objectives measurable, and explicating questions of concern to the respective audiences. Attention in the section on "how" emphasizes the following: establishing a procedure for decision making, constructing a variable matrix, categorizing evaluation activities, assigning responsibility for evaluation activities using responsibility charting, determining the cost of evaluation activities via engineering cost analysis, and establishing priorities. Gantt Charts are discussed in terms of "when," and essential components and considerations in reporting and recording are elaborated. Meta-evaluation, evaluating the evaluation, is discussed as it relates to the Master Plan, the implementation of specific activities, and strategies and techniques for managing the evaluation.

Program evaluation.

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.