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Background: Fatigue and sleep deprivation are important safety issues for long-haul truck drivers.Methods: We conducted round-the-clock electrophysiologic and performance monitoring of four groups of 20 male truck drivers who were carrying revenue-producing loads. We compared four driving schedules, two in the United States (five 10-hour trips of day driving beginning about the same time each day or of night driving beginning about 2 hours earlier each day) and two in Canada (four 13-hour trips of late-night-to-morning driving beginning at about the same time each evening or of afternoon-to-night driving beginning 1 hour later each day).Results: Drivers averaged 5.18 hours in bed per. day and 4.78 hours of electrophysiologically verified sleep per day over the five-day study (range, 3.83 hours of sleep for those on the steady 13-hour night schedule to 5.38 hours of sleep for those on the steady 10-hour day schedule). These values compared with a mean (+/-SD) self-reported ideal amount of sleep of 7.1+/-1 hours a day. For 35 drivers (44 percent), naps augmented the sleep obtained by an average of 0.45+/-0.31 hour. No crashes or other vehicle mishaps occurred. Two drivers had undiagnosed sleep apnea, as detected by polysomnography. Two other drivers had one episode each of stage 1 sleep while driving, as detected by electroencephalography. Forty-five drivers (56 percent) had at least 1 six-minute interval of drowsiness while driving, as judged by analysis of video recordings of their faces; 1067 of the 1989 six-minute segments (54 percent) showing drowsy drivers involved just eight drivers.Conclusions: Long-haul truck drivers in this study obtained less sleep than is required for alertness on the job. The greatest vulnerability to sleep or sleep-like states is in the late night and early morning. [ABSTRACT FROM AUTHOR]

The initiation of novices into research communities relies on the communication of tacit knowledge, behavioral norms and moral values. Much of this instruction happens informally, as messages subtly embedded in everyday interactions. Through participant-observation and interviews, I investigate how engineers socialize future engineers. Specifically, I study how undergraduate students who work in an engineering laboratory learn their research community's social and technical norms. I found that a key method of conveying knowledge about social behavior and technical practices is the narration of the experience of mistakes and failures. As a powerful tool of socialization, these 'disaster stories' contain messages of self-deprecation, humility, teamwork and mutual learning. They are most often told by the principal investigator or a graduate student to an undergraduate student, thus generously offering novices the opportunity to learn vicariously through more experienced engineers' errors. Disaster stories can reduce hierarchy, normalize learning through mistakes and build relationships among workers through the sharing of humbling personal struggles. The stories promote collaboration, a sense of belonging and the value of continuous learning for all the community's members. They demonstrate the power of storytelling in the acquisition of tacit social and technical knowledge.

A research community must share assumptions, such as about accepted knowledge, appropriate research practices, and good evidence. However, community members also hold some divergent assumptions, which they-and we, as analysts of science-tend to overlook. Communities with different assumed values, knowledge, and goals must negotiate to achieve compromises that make their conflicting goals complementary. This negotiation guards against the extremes of each group's desired outcomes, which, if achieved, would make other groups' goals impossible. I argue that this diversity, as a form of value pluralism, regularly influences scientific practice and can make scientific evidence and knowledge more useful and more reliable. As an example, I examine vertebrate paleontology laboratories, which house a variety of workers with different training and priorities, particularly about the meaning of time. Specifically, scientists want to study fully prepared fossils immediately, conservators want to preserve fossils for future use (such as by not preparing them), and preparators mediate between the other groups' conflicting goals. After all, one cannot study a fossil encased in rock, and one cannot remove that rock without removing information from that specimen. In response, these coworkers articulate their assumptions in everyday deliberations about how scientific evidence should be made and used. I argue that this exchange of assumptions is crucial for a research community to achieve mutually beneficial compromises that benefit current and future knowledge construction.

Laboratory technicians are typically portrayed as manual workers following routine procedures to produce scientific data. However, technicians in vertebrate paleontology laboratories often describe their work in terms of creativity and artistry. Fossil specimens undergo extensive preparation--including rock removal, damage repair, and reconstruction of missing parts--to become accessible to researchers. Technicians called 'fossil preparators' choose, apply, and sometimes invent these preparation methods. They have no formal training, no standard protocols, and few publications to consult on techniques. Despite the resulting diversity of people and practices, preparators and their work are usually absent from research publications, making them 'invisible technicians' in Steven Shapin's sense. But preparators reject the view of their work as predictable or simple; in particular, many preparators value art training, the aesthetics of prepared fossils, and the process of creative problem-solving in their work. Based on interviews and participant observation and drawing from literature in science studies, sociology of work, and anthropology of craft, I ask why these technicians compare themselves with artists and how this portrayal affects scientific practice and social order in laboratories. I argue that associating artistry and creativity with their work distances preparators from ideas of unskilled technical work and technicians' low status, thus improving their social role in the laboratory community and preserving their power over laboratory practices.

Osteoporosis, a disease of bone loss associated with aging and estrogen loss, can be crippling but is 'silent' (symptomless) prior to bone fracture. Despite its disastrous health effects, high prevalence, and enormous associated health care costs, osteoporosis lacked a universally accepted definition until 1992. In the 1980s, the development of more accurate medical imaging technologies to measure bone density spurred the medical community's need and demand for a common definition. The medical community tried, and failed, to resolve these differing definitions several times at consensus conferences and through published articles. These experts finally accepted a standard definition at an international consensus conference convened by the World Health Organization in 1992. The construction of osteoporosis as a disease of quantifiable risk diagnosed by medical imaging machines reflects contemporary trends in medicine, including the quantification of disease, the risk factor model, medical disciplinary boundaries, and global standardization of medical knowledge., (Copyright © 2010 Elsevier Ltd. All rights reserved.)