In this paper we propose an L 1/2 regularizer which has a nonconvex penalty. The L 1/2 regularizer is shown to have many promising properties such as unbiasedness, sparsity and oracle properties. A reweighed iterative algorithm is proposed so that the solution of the L 1/2 regularizer can be solved through transforming it into the solution of a series of L 1 regularizers. The solution of the L 1/2 regularizer is more sparse than that of the L 1 regularizer, while solving the L 1/2 regularizer is much simpler than solving the L 0 regularizer. The experiments show that the L 1/2 regularizer is very useful and efficient, and can be taken as a representative of the Lp(0 < p < 1) regularizer.

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In addition to staffing, nurses' work schedules are associated with patient mortality. This suggests that work schedule has an independent effect on patient outcomes.

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Night-shift workers are at high risk of drowsiness-related motor vehicle crashes as a result of circadian disruption and sleep restriction. However, the impact of actual night-shift work on measures of drowsiness and driving performance while operating a real motor vehicle remains unknown. Sixteen night-shift workers completed two 2-h daytime driving sessions on a closed driving track at the Liberty Mutual Research Institute for Safety: (i) a postsleep baseline driving session after an average of 7.6 ± 2.4 h sleep the previous night with no night-shift work, and (ii) a postnightshift driving session following night-shift work. Physiological measures of drowsiness were collected, including infrared reflectance oculography, electroencephalography, and electrooculography. Driving performance measures included lane excursions, near-crash events, and drives terminated because of failure to maintain control of the vehicle. Eleven near-crashes occurred in 6 of 16 postnight-shift drives (37.5%), and 7 of 16 postnight-shift drives (43.8%) were terminated early for safety reasons, compared with zero near-crashes or early drive terminations during 16 postsleep drives (Fishers exact: P = 0.0088 and P = 0.0034, respectively). Participants had a significantly higher rate of lane excursions, average Johns Drowsiness Scale, blink duration, and number of slow eye movements during postnight-shift drives compared with postsleep drives (3.09/min vs. 1.49/min; 1.71 vs. 0.97; 125 ms vs. 100 ms; 35.8 vs. 19.1; respectively, P < 0.05 for all). Night-shift work increases driver drowsiness, degrading driving performance and increasing the risk of near-crash drive events. With more than 9.5 million Americans working overnight or rotating shifts and one-third of United States commutes exceeding 30 min, these results have implications for traffic and occupational safety. drowsy driving | sleep | EEG | infrared oculography | fatigue

The objective of this study was to determine whether nurse staffing levels and modifiable characteristics of the nursing practice environment are associated with important quality indicators represented by the percentage of residents with pressure ulcers and numbers of deficiency citations in nursing homes. A cross-sectional design linked nurse survey data, aggregated to the facility level, with Nursing Home Compare, a publicly available federal database containing nursing home–level measures of quality. The facility sample consisted of 63 Medicare- and Medicaid-certified nursing homes in New Jersey, and the nurse survey sample comprised 340 registered nurses providing direct resident care. Characteristics of the practice environment were measured using the Practice Environment Scale of the Nursing Work Index, included in the nurse survey. The total number of deficiency citations, the percentage of residents with pressure ulcers, nurse staffing levels, and facility characteristics were extracted from the Nursing Home Compare database. Results indicated that a supportive practice environment was inversely associated with the percentage of residents with pressure ulcers and fully mediated the effect of profit status on this important outcome. The nursing practice environment and facility size explained 25% of the variance in quality deficiencies. There were no associations between staffing levels and quality indicators. Findings indicate that administrative initiatives to create environments that support nursing practice may hold promise for improving quality indicators in nursing homes.

The results inform the design of algorithms to monitor driver state that support real-time distraction mitigation systems.

When supported by their practice environments, nurses employ practices that can assist in interrupting medication errors before they reach the patients.