Individual differences in tolerance to shiftwork: a review

Individual differences in the subjective health effects of shiftwork are reviewed. Circadian regulation and brain restitution (sleep) are the crucial mechanisms by which inter-individual factors can affect tolerance to shiftwork. On the other hand, shiftworkers can use different coping mechanisms by trying to schedule their lives and especially their sleeping habits to work at unusual hours. Individual factors related to shiftwork tolerance are discussed in two groups; first, the factors which affect primarily the circadian adjustment; and, second, the factors which mainly relate to the ability to sleep at unusual hours. The significance of circadian adjustment in shiftwork tolerance is outlined.     

Ageing, physical fitness and shiftwork tolerance

The effects of ageing and physical fitness on shiftwork tolerance are reviewed. Ageing is one of the most cited factors decreasing the health of shiftworkers. Although long-term prospective studies on ageing are few, shiftworkers over 40-45 years of age seem to sleep worse after night, but not after morning shifts. Sleepiness after successive night shifts is also decreased by age although older shiftworkers' ability to resist acute sleep loss seems to be even better. The reasons for the altered sleep and wakefulness of older shiftworkers are probably related to changes in circadian rhythms, especially higher 'morningness'. Sleep need may also decrease with age which could explain some of the differences found in sleep length. Physical fitness as a factor increasing tolerance to shiftwork is a recent finding. Although the effects of physical activity on sleep have been studied in detail, the relationship of physical fitness to sleep is still a controversial issue. In shiftworkers, moderate physical training has been shown to increase sleep length and night-time alertness. It has not been shown, however, that exercise would quicken the circadian adjustment to night work. It is recommended that work time arrangements should take account of the older workers' changing personal references. Continuous night work should be voluntary after 40 years of age. Moderate physical exercise a few hours before the main sleep period is recommended.     

Circadian characteristics influencing interindividual differences in tolerance and adjustment to shiftwork

The study was carried out to evaluate whether shiftworkers showing different long-term tolerance to shiftwork differ in their circadian adjustments and/or in some behavioural characteristics. Three groups of eight workers, engaged on three shifts in a graphic plant and matched for age and work experience, were selected according to the presence or not of complaints related to shiftwork: (1) no complaints; (2) nervous complaints (anxiety/depression, severe sleep disturbances); (3) digestive disorders (gastroduodenitis, peptic ulcer). They answered questionnaires on family conditions, health status, rigidity of sleeping habits, ability to overcome drowsiness, morningness, manifest anxiety. They also recorded several physiological parameters (oral temperature, grip strength, peak expiratory flow rate, pulse rate, sleep hours) during day and night-shifts. The data obtained indicate that the characteristics of flexibility of sleeping habits, ability to overcome drowsiness, and lower manifest anxiety, are associated with better tolerance to shiftwork. These characteristics do not seem to influence the adjustment of the circadian rhythm of oral temperature passing from day to night-shifts and vice versa. Conversely, morningness appeared to be unrelated to long-term tolerance, but did influence circadian adjustments and sleep behaviour. Among the groups, the subjects with digestive disorders showed a greater phase shift and a reduction of the amplitude on night-work, suggesting a possible relationship also between the short-term circadian adjustment and the long-term tolerance to shiftwork, as pointed out by other authors.     

Individual differences in circadian rhythm parameters and short-term tolerance to shiftwork: a follow-up study

The relationship between individual differences in the phase and amplitude of circadian rhythms and tolerance to shiftwork has been the subject of several studies. Those studies recorded circadian rhythms and shiftwork tolerance at approximately the same time. The present study aimed to examine the predictive relationships between the amplitude, phase, and mesor of 24 h rhythms obtained before exposure to shiftwork, and subsequent indices of tolerance measured after one and three years of shiftwork. The results revealed some stable relations between the various rhythm parameters and subsequent tolerance measures. Workers who had a higher mesor of positive moods, and a lower mesor of negative moods and fatigue, before entering shiftwork tended to tolerate shiftwork better. Further, those whose heart rate rhythm showed an earlier acrophase had better subsequent sleep quality scores, while those with a smaller amplitude of their temperature, negative mood and fatigue rhythms showed better night-shift tolerance.     

The reliability and stability of various individual difference and tolerance to shiftwork measures

The aim of the study was to evaluate the reliability and temporal stability of various individual difference and tolerance to shiftwork measures which were used in an extensive study on relationships between shiftworkers' features and tolerance to shiftwork. The study was conducted in a Croatian oil refinery where 604 male shift workers, working in a 2:2:3 continuous three-shift system were examined by means of various questionnaires. A subsample of 61 shift workers were re-examined using the same questionnaires and the same administration procedure nine years later. The questionnaires were: Jenkins Activity Survey, Eysenck Personality Inventory, Momingness-Eveningness Questionnaire, Behavioural Arousal Questionnaire, Orcadian Type Questionnaire and Inventory, Way of Life Questionnaire, Health Information Questionnaire, Sleep Quality Scale. The questionnaires were scored for 14 individual difference measures and eight tolerance to shiftwork measures. In addition to these scores sleep durations on night, morning, afternoon shifts, and on days off were used as tolerance to shiftwork measures. The reliability of each measure was determined by means of Cronbach alpha coefficients computed on a total of 604 shiftworkers and temporal stability by means of correlation coefficients between the scores obtained on two occasions on the subsample of 61 shiftworkers. The internal consistency coefficients for most of the measures ranged between moderate to high, and were considered to be satisfactory. The correlations between the scores obtained twice over a period of nine years proved both the individual difference and tolerance to shiftwork measures to be temporally stable. The only measure that had insignificant correlation was the sleep duration on days off.     

Cuckoo search: recent advances and applications

Cuckoo search (CS) is a relatively new algorithm, developed by Yang and Deb in 2009, and the same has been found to be efficient in solving global optimization problems. In this paper, we review the fundamental ideas of cuckoo search and the latest developments as well as its applications. We analyze the algorithm and gain insight into its search mechanisms and find out why it is efficient. We also discuss the essence of algorithms and its link to self-organizing systems, and finally, we propose some important topics for further research.     

Large-scale video compression: recent advances and challenges

The evolution of social network and multimedia technologies encourage more and more people to generate and upload visual information, which leads to the generation of large-scale video data. Therefore, preeminent compression technologies are highly desired to facilitate the storage and transmission of these tremendous video data for a wide variety of applications. In this paper, a systematic review of the recent advances for large-scale video compression (LSVC) is presented. Specifically, fast video coding algorithms and effective models to improve video compression efficiency are introduced in detail, since coding complexity and compression efficiency are two important factors to evaluate video coding approaches. Finally, the challenges and future research trends for LSVC are discussed.     

Parallel metaheuristics: recent advances and new trends

The field of parallel metaheuristics is continuously evolving as a result of new technologies and needs that researchers have been encountering. In the last decade, new models of algorithms, new hardware for parallel execution/communication, and new challenges in solving complex problems have been making advances in a fast manner. We aim to discuss here on the state of the art, in a summarized manner, to provide a solution to deal with some of the growing topics. These topics include the utilization of classic parallel models in recent platforms (such as grid/cloud architectures and GPU/APU). However, porting existing algorithms to new hardware is not enough as a scientific goal, therefore researchers are looking for new parallel optimization and learning models that are targeted to these new architectures. Also, parallel metaheuristics, such as dynamic optimization and multiobjective problem resolution, have been applied to solve new problem domains in past years. In this article, we review these recent research areas in connection to parallel metaheuristics, as well as we identify future trends and possible open research lines for groups and PhD students.     

Cartilage proteomics: Challenges, solutions and recent advances

The mammalian skeleton is largely composed of cartilage and bone. The major functions of cartilage are first to provide a transient template for development of the axial and appendicular skeleton and secondly to provide permanent articulating joint surfaces. The unique cartilage extracellular matrix (ECM) is essential for the load-bearing and viscoelastic properties of cartilage tissues. Maintained by the chondrocytes, the ECM contains a myriad of proteins and proteoglycans organized into precise networks. Many cartilage disorders result from genetic disruption of cartilage ECM components, their interactions and/or degradation. Although technically challenging, the proteomic analysis of cartilage in development and disease is now emerging as a clinically important research area. In this article, we will review progress in the proteomic characterization of cartilage-related samples.     

Industrial geometry: recent advances and applications in CAD

Industrial Geometry aims at unifying existing and developing new methods and algorithms for a variety of application areas with a strong geometric component. These include CAD, CAM, Geometric Modelling, Robotics, Computer Vision and Image Processing, Computer Graphics and Scientific Visualization. In this paper, Industrial Geometry is illustrated via the fruitful interplay of the areas indicated above in the context of novel solutions of CAD related, geometric optimization problems involving distance functions: approximation with general B-spline curves and surfaces or with subdivision surfaces, approximation with special surfaces for applications in architecture or manufacturing, approximate conversion from implicit to parametric (NURBS) representation, and registration problems for industrial inspection and 3D model generation from measurement data. Moreover, we describe a ‘feature sensitive’ metric on surfaces, whose definition relies on the concept of an image manifold, introduced into Computer Vision and Image Processing by Kimmel, Malladi and Sochen. This metric is sensitive to features such as smoothed edges, which are characterized by a significant deviation of the two principal curvatures. We illustrate its applications at hand of feature sensitive curve design on surfaces and local neighborhood definition and region growing as an aid in the segmentation process for reverse engineering of geometric objects.     

Influence of shift work in process industry on workers' occupational health,productivity, and family and social life: An ergonomic approach

Shift work is a major feature of modern work practices. It involves working at times considered unconventional for most workers, such as at night. Although the community often benefits from such work practices, shift work can be hazardous for both the workers and the community. There are increased risks for accidents and errors, increased sleepiness and fatigue due to difficulties sleeping, increased health problems, and disruptions to family and social life. More shift workers complained of sleep disturbance, poor sleep quality, tiredness at awakening, and sleepiness in work than did non‐shift workers. More shift workers also complained of gastrointestinal disturbances than did non‐shift workers. The aim of this article is to provide general information on shift work, work schedules, and the effects of work schedules on sleep, fatigue, performance, the health of the human operator, and productivity. © 2010 Wiley Periodicals, Inc.     

A survey on information visualization: recent advances and challenges

Information visualization (InfoVis), the study of transforming data, information, and knowledge into interactive visual representations, is very important to users because it provides mental models of information. The boom in big data analytics has triggered broad use of InfoVis in a variety of domains, ranging from finance to sports to politics. In this paper, we present a comprehensive survey and key insights into this fast-rising area. The research on InfoVis is organized into a taxonomy that contains four main categories, namely empirical methodologies, user interactions, visualization frameworks, and applications, which are each described in terms of their major goals, fundamental principles, recent trends, and state-of-the-art approaches. At the conclusion of this survey, we identify existing technical challenges and propose directions for future research.     

Model-based testing of software and systems: recent advances and challenges

Model-based testing is focused on testing techniques which rely on the use of models. The diversity of systems and software to be tested implies the need for research on a variety of models and methods for test automation. We briefly review this research area and introduce several papers selected from the 22nd International Conference on Testing Software and Systems (ICTSS).     

Scene text detection and recognition: recent advances and future trends

Text, as one of the most influential inventions of humanity, has played an important role in human life, so far from ancient times. The rich and precise information embodied in text is very useful in a wide range of vision-based applications, therefore text detection and recognition in natural scenes have become important and active research topics in computer vision and document analysis. Especially in recent years, the community has seen a surge of research efforts and substantial progresses in these fields, though a variety of challenges (e.g. noise, blur, distortion, occlusion and variation) still remain. The purposes of this survey are three-fold: 1) introduce up-to-date works, 2) identify state-of-the-art algorithms, and 3) predict potential research directions in the future. Moreover, this paper provides comprehensive links to publicly available resources, including benchmark datasets, source codes, and online demos. In summary, this literature review can serve as a good reference for researchers in the areas of scene text detection and recognition.     

The impact of shiftwork on work--home conflict, job attitudes and health

The present study was designed to test the impact of rotation and timing of shifts on work--home conflict, job attitudes, health and absenteeism among the military police. A total of 3122 employees participated in the study. Discriminant analysis was used to examine the relationships between rotation and timing of shifts on the one hand, and the outcome measures on the other. Whether employees had fixed dayshifts, fixed non-day shifts including weekends, or rotating shifts with or without weekends, could be predicted on the basis of the experienced work--home conflict, job attitudes, health and absenteeism. Each of the two parameters of shiftwork differentially affected the experience of the outcome measures. Rotation was most clearly related to unfavourable job attitudes (namely job satisfaction, cynicism, turnover intentions and professional efficacy), whereas timing was most clearly related to increased work--home conflict. The results suggest that fixed non-day shifts including weekends (i.e., during highly valuable times) should be avoided in order to minimize the conflict between work and home and that rotation rosters should be designed with a high degree of individualization and flexibility. These seem to be the most promising ways to reduce the negative consequences of shiftwork for employees, their families and organizations.     

Visual understanding by mining social media: recent advances and challenges

With the rapid increase in social websites that has dramatically increased the volume of social media, which includes the use of images and videos, visual understanding has attracted great interest in several areas such as multimedia, computer vision, and pattern recognition. Valuable auxiliary resources available on social websites, such as user-provided tags, aid in the tasks of visual understanding. Therefore, several methods have been proposed for exploring the auxiliary resources for tag refinement, image retrieval, and media summarization. This work conducts a comprehensive survey of recent advances in visual understanding by mining social media in order to discuss their merits and limitations. We then analyze the difficulties and challenges of visual understanding followed by several possible future research directions.     

Virtual cityscapes: recent advances in crowd modeling and traffic simulation

We survey our recent work on interactive modeling, generation, and control of large-scale crowds and traffic for simulating digital cities. These include multi-agent navigation, simulating large crowds with emerging behaviors as well as interactive simulation of traffic on large road networks. We also highlight their performance on different scenarios.     

Personality factors related to shift work tolerance in two- and three-shift workers

This study aimed to investigate whether different personality variables were associated with shift work tolerance, and whether these potential associations were moderated by various types of shift work. The sample comprised 1505 nurses who worked either two or three rotating shifts. Personality traits were measured in terms of morningness, flexibility, languidity and hardiness. Morningness reflects the tendency to be alert relatively early in the morning and sleepy relatively early in the evening. Flexibility denotes the ability to both work and sleep at odd times of the day, while languidity concerns the tendency to become tired/sleepy when cutting down on sleep. Hardiness relates to resilience to stressful life events. The dependent variables in this study comprised of measures of insomnia, sleepiness, depression and anxiety. Hierarchical regression analyses, which controlled for demographic variables and work load, revealed that Morningness was significantly and negatively related to insomnia. The Morningness by Shift type interaction was overall significant for depressive symptoms. Morningness was near significantly associated with lower levels of depressive symptoms in three-shift workers, but unrelated to depressive symptoms in two-shift workers. Flexibility was associated with higher levels of depressive symptoms. Flexibility by Shift type interaction was significant for insomnia, indicating that flexibility was negatively associated with insomnia for three-shift workers and unrelated with insomnia for two-shift workers. Languidity was associated with higher levels of sleepiness, depressive and anxiety symptoms. Hardiness was associated with lower levels of all four dependent variables.     

Virtual cityscapes: recent advances in crowd modeling and traffic simulation

We survey our recent work on interactive modeling, generation, and control of large-scale crowds and traffic for simulating digital cities. These include multi-agent navigation, simulating large crowds with emerging behaviors as well as interactive simulation of traffic on large road networks. We also highlight their performance on different scenarios.