A Simulated Shift Work Schedule Does Not Increase DNA Double-Strand Break Repair by NHEJ in the Drosophila Rr3 System

Long-term shift work is widely believed to increase the risk of certain cancers, but conflicting findings between studies render this association unclear. Evidence of interplay between the circadian clock, cell cycle regulation, and DNA damage detection machinery suggests the possibility that circadian rhythm disruption consequent to shift work could alter the DNA double-strand break (DSB) repair pathway usage to favor mutagenic non-homologous end-joining (NHEJ) repair. To test this hypothesis, we compared relative usage of NHEJ and single-strand annealing (SSA) repair of a complementary ended chromosomal double-stranded break using the Repair Reporter 3 (Rr3) system in Drosophila between flies reared on 12:12 and 8:8 (simulated shift work) light:dark schedules. Actimetric analysis showed that the 8:8 light:dark schedule effectively disrupted the rhythms in locomotor output. Inaccurate NHEJ repair was not a frequent outcome in this system overall, and no significant difference was seen in the usage of NHEJ or SSA repair between the control and simulated shift work schedules. We conclude that this circadian disruption regimen does not alter the usage of mutagenic NHEJ DSB repair in the Drosophila male pre-meiotic germline, in the context of the Rr3 system.

A Study on the Subculture of Working Students in Call Centers

Employing the descriptive qualitative research method, this study drew on the Functional Theory of Talcott Parsons which espouse that subculture develop out of its adaptation from the dominant culture. It aimed to describe and analyze the subculture of working students in call centers in Metro Manila and its influence on their family relations, health, recreational activities, consumption behavior and academic performance. Results showed that the norms and values in the call center as reflected on the social environment influenced the values of the working students. The subculture in the call center produced positive and negative effects to the participants. The night shift work schedule led to health problems, less contact time with their family and peers, and less time on studying. Thus, there is a need for call center companies and schools to provide the necessary remediation to improve working students’ productivity in work and performance in school.

Association between Shift Work and Reflux Esophagitis: The Kangbuk Samsung Health Study

This cross-sectional study investigated the relationship between shift work and reflux esophagitis verified by endoscopic findings. Participants underwent a comprehensive health examination and esophagogastroduodenoscopy between January 2011 and December 2018. We examined endoscopic findings and performed multivariate-adjusted regression analysis of the association between shift work and reflux esophagitis using multiple demographic and clinical factors. Among the 247,450 participants, 49,767 (20.1%) had reflux esophagitis; Los Angeles (LA)-M (31,132, 12.6%) was most common, followed by LA-A (16,213, 6.6%), LA-B (2333, 0.9%), and ≥LA-C (89, 0.04%). The multivariate-fully adjusted odds ratio (OR) of overall reflux esophagitis for shift work compared to fixed day work was 1.15 (95% confidence interval [CI]: 1.11–1.19). When classified according to shift work type and severity of reflux esophagitis, the ORs of LA-A for regular day and night, and irregular shifts compared to fixed day works were 1.14 (95% CI: 1.03–1.26) and 1.26 (95% CI: 1.11–1.44), respectively. However, there was no significant association between any shift work schedule and ≥LA-B. Overall, we demonstrated the cross-sectional association between shift work (especially rotating and irregular shifts) and mild reflux esophagitis (≤LA-A) compared with daily fixed time shifts.

Insomnies of medical staff: theoretical aspects (literature review)

More and more medical staff is involved in work in a continuous mode, and therefore the study of their health problems becomes more and more relevant and practically significant. In the article, we summarized domestic and foreign data of the problem of sleep disorders in employees with shift work, gave modern approaches to the classification and diagnosis of insomnia. We have described the adverse physiological effects of the daily and night schedule on the body of medical staff. Analyzing the literary sources, we came to the conclusion that the state of health and the violation of circadian rhythms due to the shift work schedule are directly related. To date, there is no undisputed curative and preventive doctrine of insomnia. Scheduling nursing staff according to circadian rhythms, maximizing schedule stability and adhering to a healthy lifestyle can minimize most of the problems caused by shift work.

Cyclical Nurse Scheduling in Shah Alam Hospital Using Goal Programming

A shift work schedule is extremely important to obtain the optimum result of work allocation since it involves 24 hours of continuous services. Every nurse could not avoid shift work schedule since their services are very important towards the patients in the hospital. The major objective of the study is to propose a cyclical nurse scheduling in the Coronary Care Unit (CCU) at Shah Alam hospital using Goal Programming. It is to help the head nurse to spend less effort on building new schedules periodically and increase the satisfaction among nurses by providing fairness towards their schedules. There were nine hard constraints and three soft constraints for the nurse scheduling model. The results presented the optimal solution where all goals were achieved thus, it provided a fair schedule for 15 nurses in 15 days. Then, the schedule pattern was rotated among nurses based on the 15 schedules set in 225 days. The first schedule set will be used by the nurse for the first 15 days, then will be continuously rotated for another 15 days until all the nurses reached and experienced every 15 sets of the schedule. The schedule was generated using LINGO software which it took a short time to solve the problem.

Interconnection of shift work and sleep disorders in nursing specialists

Aim. To study the prevalence, structure, causes of sleep disorders of nurses, working in shifts. Materials and methods. Analytical; questioning survey; statistical with processing results using Microsoft Excel. Results. Studies have shown that 85% of nurses working in shifts have a decrease in the quality of sleep, 60% of those surveyed associate sleep problems with their occupation. Daily work significantly increases the time to fall asleep, worsens the quality and duration of sleep, leads to frequent awakenings, and also negatively affects daytime performance. The development of sleep disorders depends on the length of service. The existing health problems of half of the respondents do not motivate nurses to switch to non-shift work. Thus, the shift work is not a factor that significantly reduces the quality of life. Conclusions. Recommendations of the program for the prevention and rehabilitation of insomnia, it is necessary to develop in three directions: for chief nurses, for senior nurses and directly for nurses with a shift work schedule.

Physiologically assessing the functional state of the body of doctors in children's medical organizations

Introduction. Increased nervous and emotional loads in doctors of children's medical organizations are caused by frequent stressful effects, shift work mode. The study of the features of the formation of the functional state of the body of surgeons will make it possible to scientifically justify measures to prevent overstrain to preserve the health of employees. The aim of study is to research the functional state of the body of doctors of children's medical organizations with a shift work schedule to justify and develop measures for physiological and hygienic optimization of work. Materials and methods. Complex physiological and hygienic studies included occupational analysis of labor activity, physiological studies of the state of the Central nervous system (CNS) and the cardiovascular system with the study of the features of response to functional loads (ECG recording on a 12-channel electrocardiograph and continuously using Holter monitoring). Results. The study of the features and degree of adequacy of the cardiovascular system's response to dosed physical activity revealed the tension of the regulatory mechanisms of the circulatory system with a pronounced increase in heart activity in surgeons during night hours. Conclusions. Stable indicators of CNS functions (concentration of attention, etc.) were established during various shifts, due to the requirements of the work itself, adverse changes in the cardiovascular system, more pronounced during the night shift, deterioration of ECG changes to functional load, which indicates a decrease in the functional capabilities of the myocardium.

0284 The Effects of a Circadian-Aligned Watchbill Shift Work Schedule on Sleep Quality and Quantity in U.S. Navy Submarine Personnel

Introduction Prior to 2014, the U.S. Navy Submarine Force operated on a non-circadian-aligned watchbill shift work schedule (18-hour day-length) that resulted in insufficient sleep. For instance, prior research reported that submariners received insufficient sleep on this schedule, and modest sleep restrictions can adversely affect performance, alertness, and, ultimately, negatively impact mission outcomes. Thus, the present study characterized sleep patterns of submariners operating on a newer, circadian-aligned 24-hour day-length watchbill. Methods Submariners (n=58; 27.8±5.9 years) of various ranks volunteered from a U.S. Navy submarine. Submariners wore a research-grade actigraphy watch over a 30-day underway mission, for objective sleep measurement of time in bed (TIB), total sleep time (TST), and sleep efficiency (SE). Subjective sleep was measured from questionnaires (Pittsburgh Sleep Quality Index [PSQI], Insomnia Severity Index [ISI], Profile of Mood States [POMS-fatigue subscale]) that were taken pre- and post-underway. Results Compared with pre-underway, at post-underway submariners reported significantly higher scores on the ISI, PSQI global sleep quality, and POMS-fatigue (all p<0.05, indicating worse sleep and fatigue ratings). According to actigraphy, submariners acquired on average 6.7±1.0 hours TST, 7.5±1.1 hours TIB, and 88.9±3.9 % SE per day throughout the underway mission. Actigraphy-determined TIB and TST were variable compared with PSQI self-reported TIB and TST. Conclusion Study results indicate that submariners experience modest sleep restriction on a newly implemented 24-hour watchbill, which is an improvement in sleep relative to prior assessments of the former standard 18-hour watchbill. However, submariners endorsed lower sleep quality and higher fatigue levels from a month-long underway mission. This study is one of the first examinations of sleep under the 24-hour watchbill mandate that was instated in 2014. Future studies should further evaluate sleep and test fatigue mitigation strategies in different shift configurations of the 24-hour watchbill. Support Joint Program Committee-5 Fatigue Mechanisms and Countermeasures Working Group

The influence of shift work on metabolic health

Recently, the world literature has been actively discussing the effect of circadian rhythm and sleep disturbances on human metabolic health. One of the most socially significant causes of circadian disorders is the shift work schedule. Shift work schedules began to occur more often due to the high demand for flexibility and labor productivity in modern society. Shift work is characteristic of medical personnel, law enforcement officials, rescue services, transport, the media and others. Shift workers make up about 17% of all workers in Europe. Globally, approximately 2.5 billion people work in shifts. Shift work was identified as an important professional risk. The connection between work with rotation of day and night shifts with overweight and obesity, with circadian rhythms and sleep disorders was proved. The review systematizes information regarding the role of the shift chart in the development of obesity and the metabolic syndrome, and considers mechanisms that mediate its effect on the regulation of energy balance.