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PubMed1989

Risk factors in the psychosocial work environment for neck and shoulder pain in secretaries.

The relationship between psychologic work variables and reported neck and shoulder pain was examined among secretaries. A battery of questionnaires concerning the experienced psychologic work environment as well as musculoskeletal pain symptoms was completed by 420 secretaries at a large medical center. A relatively "poor" psychologic work environment was compared with an environment that was experienced as "good." A "poorly" experienced psychologic work environment was related to a higher frequency of neck and shoulder pain. The relative risk for frequent neck pain was 2.85 (95% confidence interval 1.28 to 6.32) and for frequent shoulder pain 3.32 (95% confidence interval 1.53 to 7.23). Furthermore, the subindexes of work content and social support at work were found to be related to pain, whereas no clear relationship was found for work demands. The results of this study demonstrate the possible importance of the psychologic work environment in the development of musculoskeletal pain disorders. Future investigations should replicate these findings as well as isolate specific mechanisms so that preventive measures may be instituted.

Adult↗

PubMed2001

Supportive work environments for nursing faculty.

Whereas most of the concern about increasingly stressful work environments has focused on acute-care hospitals, the academic healthcare environment is not immune. Faculty, staff, and students in schools of nursing report similar stressors. Pressures from managed care, personnel shortages, and unceasing change are affecting the academic environment and yielding stressful, dysfunctional, and occasionally abusive settings here as well. This article describes the role of the dean in creating a healthy work environment in which students can learn and faculty can teach and do research. Future nurses are introduced to critical care as students, and the learning environment significantly influences them. Graduate students in critical care can experience encounters that range from supportive to obstructive. Knowing what is reasonable to expect from a dean and faculty should help students in critical care sort out the issues if they are experiencing an abusive situation, and what options they might pursue.

Communication↗

PubMed2006

Factors in optimizing the learning environment for surgical training.

Today's surgeon is required to demonstrate a variety of professional competencies in an increasingly complex environment. Recently, the time available to train this surgeon has started to erode due to external pressures on administrators and faculty. This growing crisis has led to questions about how to optimize learning in the surgical environment. Clearly, to adequately train a competent surgeon in all the required aspects, multiple environments will be required. We must, therefore, look carefully at each environment to maximize its educational potential for each of the competencies. At the same time, however, we must ensure these educational environments and opportunities integrate into a coherent and systematic program of training that is flexible and adaptable to the individual needs of the trainees. This paper describes two broad areas that must be at the forefront of the community's thinking as we strive toward this goal: the irreplaceable value of a mentor and maximizing the potential of optimal challenge points in learning.

Humans↗

PubMed2002

Mutator dynamics in fluctuating environments.

Populations with high mutation rates (mutator clones) are being found in increasing numbers of species, and a clear link is being established between the presence of mutator clones and drug resistance. Mutator clones exist despite the fact that in a constant environment most mutations are deleterious, with the spontaneous mutation rate generally held at a low value. This implies that mutator clones have an important role in the adaptation of organisms to changing environments. Our study examines how mutator dynamics vary according to the frequency of environmental fluctuations. Although recent studies have considered a single environmental switch, here we investigate mutator dynamics in a regularly varying environment, seeking to mimic conditions present, for example, under certain drug or pesticide regimes. Our model provides four significant new insights. First, the results demonstrate that mutators are most prevalent under intermediate rates of environmental change. When the environment oscillates more rapidly, mutators are unable to provide sufficient adaptability to keep pace with the frequent changes in selection pressure and, instead, a population of 'environmental generalists' dominates. Second, our findings reveal that mutator dynamics may be complex, exhibiting limit cycles and chaos. Third, we demonstrate that when each beneficial mutation provides a greater gain in fitness, mutators achieve higher densities in more rapidly fluctuating environments. Fourth, we find that mutators of intermediate strength reach higher densities than very weak or strong mutators.

Adaptation, Physiological↗

PubMed1999

Fitting a regression model for genotype-by-environment data on heading dates in grasses by methods for nonlinear mixed models.

The analysis of agricultural crop variety trials is usually complicated by the presence of genotype-by-environment interaction. A number of methods and models have been proposed to tackle this problem. One of the most common methods is the regression approach due to Yates and Cochran (1938, Journal of Agricultural Science 28, 556-580), in which performances of genotypes in the environments are regressed onto environmental means. The underlying regression model contains a multiplicative term with two unknown parameters (one for genotypes and one for environments). In the present paper, the model is modified by exchanging the role of genotypes and environments. Various diagnostic plots show that this modified model is adequate for a data set on heading dates in the grass species Dactylis glomerata. If environments are considered as a random factor while genotypes are taken as fixed, the model falls into the class of nonlinear mixed models. Recently, a number of procedures have been suggested for this class of models, which are based on first-order Taylor series expansion. Alternatively, the model can be estimated by maximum likelihood. This paper discusses the application of these methods for estimating parameters of the model.

Agriculture↗

PubMed2004

Evolution of Hsp90 expression in Tetrahymena thermophila (Protozoa, Ciliata) populations exposed to thermally variable environments.

Evolutionary consequences of thermally varying environments were studied in the ciliated protozoan Tetrahymena thermophila. Replicated lines were propagated for 60 days, a maximum of 500 generations, in stable, slowly fluctuating (red spectrum), and rapidly fluctuating (blue spectrum) temperatures. The red and blue fluctuations had a dominant period length of 15 days and two hours, respectively. The mean temperature of all time series was 25 degrees C and the fluctuating temperatures had the same minimum (10 degrees C), maximum (40 degrees C), and variance. During the experiment, population sizes and biomasses were monitored at three-day intervals. After the experiment, carrying capacity and maximum growth rate were measured at low (15 degrees C), intermediate (25 degrees C), and high (35 degrees C) temperatures for each experimental line. Physiological changes in the lines were assessed by measuring the expression of stress-induced heat shock protein Hsp90 at 25 degrees C, 35 degrees C, and 39 degrees C. Population sizes and biomasses showed no differences between stable, blue, or red temperature treatments during the experiment. Also, after the experiment, mean carrying capacities and maximum growth rates were comparable in the stable, blue, and red temperature treatments. The expression of Hsp90 was higher in lines from the blue environment than in lines from the stable environment. Lines from the red environment had an intermediate level of Hsp90 expression. This supports the hypothesis that inducible thermotolerance and expression of canalizing genes can evolve in response to rapidly varying environments. Furthermore, we found correlative evidence of benefits and disadvantages of high Hsp90 expression. Lines with high expression of Hsp90 had an increased growth rate at the highest temperature when food resources were not limiting growth. At low and intermediate temperatures the same lines had the lowest carrying capacities.

Analysis of Variance↗

PubMed2004

Trends in asthma, allergic rhinitis and eczema among Swedish conscripts from farming and non-farming environments. A nationwide study over three decades.

BACKGROUND: Asthma and allergies are less common in children who have been raised in farming environments. OBJECTIVES: To assess whether children who grow up in a farming environment have been protected against the general increase in atopic disorders in Sweden and whether other rural environments could also be protective. METHOD: Linkage at an individual level of three national registers in Sweden: The Swedish Military Service Conscription Register (MSCR), the Register of the Total Population (RTP) and the Population and Housing Censuses (PHC). Asthma, allergic rhinitis and eczema at conscription were analysed in relation to area of residence, parental occupation, maternal age, family size and being the first born for 1 309 652 male conscripts in three successive cohorts born between 1952 and 1981. RESULTS: Allergic rhinitis and eczema displayed a continuous increase throughout the study period, whereas the rise in asthma mainly occurred in conscripts born after 1961. Farming environments and rural living already provided protection from allergic rhinitis in conscripts born during the 1950s, but the protective effect was greater in later cohorts. An inverse association was observed between farm living and asthma, but mainly in conscripts born after 1970. The adjusted risk ratios for asthma in conscripts from farming vs. non-farming families were 1.00 (95% CI 0.93-1.07), 0.94 (95% CI 0.88-1.01) and 0.85 (95% CI 0.79-0.91) in conscripts born in 1952-1961, 1962-1971 and 1972-1981, respectively. Rural living per se had no effect on the occurrence of asthma. Eczema was less common in rural areas, but the time trend was similar in urban and rural areas. CONCLUSIONS: Our findings suggest that environmental changes affecting the whole of society have promoted an increase in asthma, allergic rhinitis and eczema in both farming and non-farming environments. A lower risk of allergic rhinitis in conscripts whose parents were involved in farming was observed in all birth cohorts, whereas the protective effect of growing up on a farm on the risk of asthma appears to be a fairly recent phenomenon.

Adolescent↗

PubMed2006

The general picture of supportive health environments for persons with intellectual disabilities among 121 disability welfare institutions in Taiwan.

BACKGROUND: Little information is available on the provision of supportive health environments for persons with intellectual disabilities (ID) in institutions. The aim of this study was to present an overview of supportive environments for health in institutions in Taiwan. METHODS: A cross-sectional survey was conducted to examine the perceptions of 121 Taiwanese Institutional Directors on their setting's implementation of supportive healthy physical, social, and economic environments. RESULTS: Analyses showed that first-aid kits (97.5%) and medicine cabinets (85.5%) were the most common health facilities in institutions. Seventy-three per cent of institutions had set up specific areas to be used for rehabilitation practice, while only 43.1% thought their rehabilitation equipment/devices adequate for their real needs. Eighty-eight per cent of institutions implemented health promotion plans for people with ID, while 76.6% had appropriated specific health promotion plans. Sixty-three institutions (52.1%) reported employment of skilled nurses to serve people with ID, and these institutions showed statistically significant differences in implementation of each health facility. CONCLUSIONS: The present paper is the first to analyze supportive environments for health in disability institutions in Taiwan. An important focus of future research will be the extension of the present findings to consider the appropriateness of each area of supportive environments for improving the quality of institutional care for people with ID.

Attitude of Health Personnel↗

PubMed2004

Comparison of nurse competence in different hospital work environments.

AIM: This study examines nurses' perceptions of competence in different university hospital work environments. BACKGROUND: Nurses' self-recognition of own level of competence is essential in maintaining high standards of care. The demands for nurse competence may vary between work environments. However, there are very few studies that compare nurse competence in different hospital work environments. METHODS: We analysed self-assessments of competence of 593 Registered Nurses working in wards, emergency/outpatient or intensive care units or in operation rooms. The instrument used was a pretested 73-item questionnaire consisting of seven competence categories. The level of competence was assessed on a Visual Analogue Scale (VAS) scale of 0-100 and the frequency of using items of competencies in clinical practice was assessed on a four-point scale. RESULTS: Nurses reported their overall level of competence as good. They felt most competent in the categories of Managing situations, Diagnostic functions and Helping role (VAS-means 68-69), and least competent in Ensuring quality category (VAS-mean 56). Operation room nurses compared with other nurses reported lower level of competence and lower frequency of using items of competencies in several competence categories. In general, the self-assessed level of competence was greater the higher the frequency of using of competencies. Correlations between both age and length of work experience and the self-assessed overall level of competence were positive. CONCLUSIONS: Nurse competence profiles differed in both the level of and in frequency of using competencies between work environments. Context-specific knowledge of nurse competence from real work life situations provides direction on how to structure work environments and staff development interventions to provide qualified care.

Adult↗

PubMed2006

Male Drosophila melanogaster have higher mating success when adapted to their thermal environment.

Adaptation to new environments is a well-documented phenomenon. Individuals from populations maintained in a particular environment for multiple generations tend to be better able to survive and/or reproduce in that environment than their ancestors or other individuals adapted to alternative environments. A third major component of fitness, mating success, has not been well studied in replicated populations under selection in divergent environments. In this study, we used mating trials to compare the mating success of male Drosophila melanogaster adapted for 10 years to two different temperatures, 18 and 25 degrees C. In competition for female partners, males had significantly higher mating success at their adapted temperature compared with males adapted to a different temperature. These results are consistent with the notion that those mutations favoured by natural selection also tend to be favoured by sexual selection.

Adaptation, Physiological↗

PubMed1992

Characteristics of the infant thermal environment in the control population of a case-control study of SIDS.

This report examines the thermal environment during last sleep of a control population to investigate how the thermal environment of the infant's bedroom varies by season, external temperature and by certain maternal and infant characteristics. Two age-matched control infants were chosen for each case, one of which was also matched on birthweight. The home visits were not pre-arranged and were matched on climatic conditions, time of year and time period of day for the index case. The initial response rate for controls (n = 108) was 86%. Although there was a large amount of variation in the infant thermal environment, thermal insulation correlated with room temperature (r = -0.44, P = 0.0001) and external temperature (r = -0.30, P = 0.002). The thermal environment of the infant, as defined by excess thermal insulation for room temperature, did not vary by indoor or outdoor temperature, but higher average values were observed in teenage mothers (mean difference = 2.7 tog [95% Cl = 0.3, 5.2]), infants who slept in an adult bed (mean difference = 2.6 tog [-0.1, 5.4]) and infants with an illness (mean difference = 0.8 tog [-0.3, 1.9]). There was a tendency for the thermal environment of infants to be higher and more variable during winter, supporting previous hypotheses that paradoxical overheating may occur in some infants during winter. Further work is required to provide a set of recommendations on the optimal thermal conditions for post-neonatal infants.

Bedding and Linens↗

PubMed2006

Identifying interactions between genes and early environment in the mouse.

Interactions between genetic and early environmental factors are recognized to play a critical role in modulating susceptibility to disease, particularly mental illness. In order to better understand such mechanisms at the molecular level, we have developed a screening paradigm in mice that allows us to test the ability of targeted mutations in candidate genes to modify susceptibility to the long-term effects of different maternal environment. Offspring of genetically identical F1 hybrid dams produced by reciprocal breeding of C57BL/6 and BALB/c parents show alterations in anxiety-related behavior as a consequence of their different maternal environment. Introduction of targeted mutations into these offspring via the father allows for the identification of candidate genes that alter these maternal effects. Our strategy offers several advantages over other methods to study maternal effects, including the use of genetically identical parents, the ability to identify both prenatal and postnatal effects, the straightforward introduction of mutations and its adaptability to high-throughput screening. In order to test the utility of this paradigm to screen candidate genes, we tested for gene-environment interactions involving loss-of-function mutations in the serotonin 1A receptor gene. Our studies demonstrate that early gene-environment interactions can be successfully tested in the mouse. When combined with conditional gene targeting and other molecular genetic techniques available in the mouse, this approach has the potential to identify the molecular mechanisms underlying early gene-environment effects.

Animals↗

PubMed2006

Tryptophan hydroxylase 1 gene haplotypes modify the effect of a hostile childhood environment on adulthood harm avoidance.

We conducted a series of tests to determine whether there is any association between tryptophan hydroxylase 1 (TPH1) and temperament in adulthood. In addition to testing for main effects, we investigated whether TPH1 gene variation modifies the influence of childhood environment on temperament in adulthood. The subjects were 341 healthy adults whose childhood environment was assessed by their mothers in 1980 and who self-rated their temperaments twice, in 1997 and 2001. We found no association between the TPH1 gene and temperament; however, among women, the TPH1 gene modified a relationship between adverse childhood environment and harm avoidance in adulthood. This finding was confirmed in the same sample in another test setting 4 years later. The presence of the A/A haplotype of the TPH1 intron 7 A218A and A779C polymorphism predicted a high level of adulthood harm avoidance in the presence of a hostile childhood environment as defined in terms of emotional rejection, maternal neglect and harsh and inconsistent discipline. In addition, the findings suggest a gene-environment correlation for novelty seeking in men.

Adolescent↗

PubMed2001

Social environment effects on health and aging: integrating epidemiologic and demographic approaches and perspectives.

This paper provides an overview of epidemiological and demographic research linking social characteristics of both individuals and communities to differences in both morbidity and mortality risks. Evidence is presented linking three broad aspects of the social environment to health--the network of personal social relationships within which most of us live our lives, individual socioeconomic status (SES), and community-level social characteristics. Large and consistent bodies of literature from both epidemiology and demography provide clear evidence for the generally health-promoting effects of personal social relationships and SES. The bulk of the evidence relates to mortality although both fields have begun to examine other health outcomes, including aspects of physical and cognitive functioning as well as disease outcomes. A smaller but growing body of community-level data, reflecting both the socioeconomic/resource characteristics of these broader communities and, more specifically, social features of these environments, also point to health impacts from these more macro level social environment characteristics. Much remains to be elucidated, however, concerning the actual mechanisms through which something as complex and multifaceted as SES "gets under the skin." This necessarily includes consideration of external characteristics of the environments (both physical and sociocultural) where people live and work, and individual characteristics, as well as possible interactions between these in producing the observed SES gradients in health and mortality. These questions concerning links between social environment conditions and health may be a particularly fruitful area of future collaboration, drawing on the shared interest of demographers and epidemiologists in understanding how different social conditions promote variation in distributions of better versus worse health outcomes within a population.

Aging↗

PubMed2003

Survival of Helicobacter pylori in a natural freshwater environment.

The mode by which Helicobacter pylori, the causative agent of most gastric ulcers, is transmitted remains undetermined. Epidemiological evidence suggests these organisms are waterborne; however, H. pylori has rarely been grown from potential water sources. This may be due to the ability of this organism to rapidly enter the viable but nonculturable (VBNC) state. Our investigation examines the entrance of H. pylori into this state in laboratory cultures and a natural freshwater environment as well as the relationship between morphology and culturability. To this end, membrane diffusion chambers were utilized to expose the cells to the natural fluctuations of a freshwater stream. In both the laboratory and environment, samples were assayed for culturability using plate counts and stained using a LIVE/DEAD BacLight assay for viability and morphological determinations. Additionally, water samples were collected, six environmental parameters were measured, and resuscitation conditions were examined. H. pylori was observed to lose culturability in the laboratory and stream, although viability was maintained. While the results of our study agree with those of previous studies which suggested that there is a transition in morphology from rods to cocci as culturability is lost, the morphological distribution of cells did not change as culturability was lost in the environment. The majority of cells in the VBNC state in the laboratory are cocci; however, all morphological forms were present in the environment. The results of these studies suggest that H. pylori persists in laboratory cultures and the environment in the VBNC state and that cells in this state represent a public health hazard.

Bacteriological Techniques↗

PubMed2005

Multilevel modelling of built environment characteristics related to neighbourhood walking activity in older adults.

OBJECTIVE: To examine the relation between built environment factors (representing several dimensions of urban form of neighbourhoods) and walking activity at both the neighbourhood level and the resident level, in an older adult sample. DESIGN, SETTING, PARTICIPANTS: A cross sectional, multilevel design with neighbourhoods as the primary sampling unit and senior residents as the secondary unit. Five hundred and seventy seven residents (mean age = 74 years, SD = 6.3 years) participated in the survey, which was conducted among 56 city defined neighbourhoods in Portland, Oregon, USA. Neighbourhood level variables were constructed using geographical information systems. Resident level variables consisted of a mix of self reports and geocoded data on the built environment. MAIN OUTCOME MEASURE: Self reported neighbourhood walking. MAIN RESULTS: A positive relation was found between built environment factors (density of places of employment, household density, green and open spaces for recreation, number of street intersections) and walking activity at the neighbourhood level. At the resident level, perceptions of safety for walking and number of nearby recreational facilities were positively related to high levels of walking activity. A significant interaction was observed between number of street intersections and perceptions of safety from traffic. CONCLUSIONS: Certain neighbourhood built environment characteristics related to urban form were positively associated with walking activity in the neighbourhoods of senior residents. Public health promotion of walking activity/urban mobility and the design of interventions need to consider the contribution of neighbourhood level built environment influences.

Aged↗

PubMed2006

Impact of clinical environment on embolus detection: a comparison of automated and manual detection of Doppler embolic signals.

BACKGROUND: Transcranial Doppler ultrasound detection of weak embolic signals is inhibited by intrinsic limitations within the human auditory system. Psychoacoustics effects are likely to be exacerbated in a clinical environment, where automated embolus detection has potential to surpass manual detection. In this study we quantify the impact of clinical environment on manual detection of Doppler embolic signals following carotid surgery. We also discuss the implications of psychoacoustics considerations for the evaluation of automated detection systems. METHOD: Concurrent monitoring by vascular technologists and an automated embolus detection system were performed for 50 consecutive patients during postoperative recovery. Both detection methods were evaluated against a majority decision human expert panel analyzing under ideal conditions. RESULTS: Clinical environment reduced the overall sensitivity of manual monitoring by approximately 23%, mainly due to a approximately 2-dB increase in the lower threshold for detection. Clinical environment was also associated with a reduction in positive predictive value for manual detection of approximately 9% compared to ideal conditions. Automated monitoring, which is not affected by environment, was marginally more sensitive for detection of weaker embolic signals. CONCLUSIONS: One in 4 weak embolic signals was missed during routine clinical monitoring compared to ideal conditions. Automated detection (in this study) performed slightly better than human observers but did not approach the performance of the majority decision panel.

Aged↗

PubMed1986

Models for the joint effect of genotype and environment on liability to psychiatric illness.

The authors present three major models for the joint effect of genes and environment on liability to psychiatric illness: additive effects of genotype and environment, genetic control of sensitivity to the environment, and genetic control of exposure to the environment. Each model is illustrated by several examples, including a quantitative one. The authors attempt to demonstrate that genes and the environment can interact in several interesting and potentially subtle ways, that these interactions can be expressed in simple models from which clear empirical predictions can be generated, and that elucidation of the etiology of psychiatric disorders will require the consideration of both genetic and environmental risk factors.

Depressive Disorder↗