Employment Grade Research Articles

Job insecurity and its association with health among employees in the Taiwanese general population

As employers respond to intensive global competition through the deregulation of labor, job insecurity has become a widespread problem. It has been shown to have significant health impacts in a growing number of workers, but less is known about its social distribution, the mechanisms through which it may act, and the moderating effects of gender, socioeconomic position, and company size. Utilizing data from a national survey of a representative sample of paid employees in Taiwan, we examined the prevalence of job insecurity and its associations with psychosocial work characteristics and health status. A total of 8705 men and 5986 women aged between 25 and 65 years old were studied. Information on perceived job insecurity, industrial and occupational types, psychosocial work characteristics as assessed by the Job Strain model, and various measures of health status were obtained by a self-administered questionnaire. The overall prevalence of job insecurity was high (50%). Job insecurity was more prevalent among employees with lower education attainment, in blue-collar and construction workers, those employed in smaller companies, and in older women. Insecure employees also reported lower job control, higher job demands, and poor workplace social support, as compared with those who held secure positions. Regression analyses showed that job insecurity was strongly associated with poor health, even with adjustment of age, job control, job demands, and work place social support. The deleterious effects of job insecurity appeared to be stronger in men than women, in women who held managerial or professional jobs than women in other employment grades, and in those working in larger companies than smaller ones. The findings of this study suggest that perceived job insecurity is an important source of stress, and it is accompanied with adverse psychosocial work conditions and poor health. High-risk groups were identified for further investigation.

A comparison of socio-economic differences in long-term sickness absence in a Japanese cohort and a British cohort of employed men

To compare the magnitude of socio-economic differences in sickness absence rates between a Japanese cohort and a British cohort. To assess the effects of self-rated health and behavioural risk factors on sickness absence in the two cohorts, and whether they explain socio-economic differences in sickness absence within and between cohorts. An 8 year follow up study of sickness absence in 2504 Japanese male employees in a factory in Japan and 6290 British male employees in civil service departments in London. The rates of first occurrences of long-term (>7 calendar days) sickness absence were determined and compared between these cohorts. Socio-economic status was measured with hierarchical employment grades. The first time sickness absence rates were about two times higher among British men as compared with Japanese men. The rate ratio of lower to higher employment grade was 1.2, 1.3 and 2.1 among Japanese white-collar, Japanese blue-collar and British white-collar employees respectively. Baseline self-rated health and smoking habit predicted sickness absence in both cohorts. After adjusting for these factors a significant difference between the Japanese and British cohorts, and between employment grades remained. The rate of long-term sickness absence was higher in the British cohort than the Japanese cohort.

Self-reported job insecurity and health in the Whitehall II study: potential explanations of the relationship

This paper examines the potential of demographic, personal, material and behavioural characteristics, other psychosocial features of the work environment and job satisfaction to explain associations between self-reported job insecurity and health in a longitudinal study of British white-collar civil servants. Strong associations were found between self-reported job insecurity and both poor self-rated health and minor psychiatric morbidity. After adjustment for age, employment grade and health during a prior phase of secure employment, pessimism, heightened vigilance, primary deprivation, financial security, social support and job satisfaction explained 68% of the association between job insecurity and self-rated health in women, and 36% in men. With the addition of job control, these factors explained 60% of the association between job insecurity and minor psychiatric morbidity, and just over 80% of the association with depression in both sexes.

Prospective study of social and other risk factors for incidence of type 2 diabetes in the Whitehall II study.

Social inequalities in the incidence of type 2 diabetes and the relation of health behaviors and psychosocial factors to the incidence of type 2 diabetes are not well established. Prospective occupational cohort study of 10 308 civil servants aged 35 to 55 years at baseline in phase 1 (1985-1988). Diagnosis of diabetes was ascertained by questionnaire at baseline and follow-up at phases 2 (1989), 3 (1992-1993), 4 (1995), and 5 (1997-1999) and glucose tolerance tests in phases 3 and 5. Participants working in the lower employment grades had a higher incidence of diabetes than those in higher employment grades (men: odds ratio [OR], 2.9; 95% confidence interval [CI], 1.9-4.4; women: OR, 1.7 [95% CI, 0.8-3.7]). Body mass index and other risk factors considered traditional for type 2 diabetes were found to be so in this cohort. In men, of the psychosocial risk factors examined, only effort-reward imbalance was related to incidence of diabetes (OR, 1.7 [95% CI, 1.0-2.8]). The General Health Questionnaire depression subscale was related to incidence of diabetes and impaired glucose tolerance (OR, 1.25 [95% CI, 1.0-1.6]). These associations remained after adjustment for other confounding factors. In men only, social difference in incidence of diabetes was reduced but still significant after adjustment for conventional risk factors. An inverse relationship exists between social position and incidence of diabetes that is partly explained by health behaviors and other risk factors. Effort-reward imbalance, which is reportedly associated with coronary heart disease, is also associated with type 2 diabetes.

Long-term follow-up of renal transplantation in children: a Dutch cohort study.

Few data exist on long-term morbidity, overall survival, and graft survival of pediatric renal transplantation. The authors performed a long-term cohort study in all Dutch patients, born before 1979, with onset of end-stage renal disease (ESRD) between 1972 and 1992 at age 0 to 15 years. Data on graft survival and determinants of outcome were obtained by reviewing all medical charts. The health status was assessed by cross-sectional examination of surviving patients. Three hundred ninety-seven transplantations were performed in 231 of all 249 patients, of whom 25 died with a functioning graft. Cardiovascular disease was the most prominent cause of death. Graft survival estimates for all transplantations were 59.2%, 45.3%, 35.4%, and 30.3% at 5, 10, 15, and 20 years, respectively. In comparison with azathioprine, cyclosporine as the immunosuppressant was associated with increased graft survival in retransplantations but not in first transplantations. Cross-sectional examination was performed on 110 patients. In 44 patients, the most recent graft survival exceeded 15 years. Co-morbidity was found in 40% of all patients; motor, hearing, or visual disabilities were found in 19%. Bone disease, headaches, itching, and tremors were the most reported disabling problems. Cyclosporine use was associated with hypertension and a history of epilepsy. Compared with all age-matched Dutch inhabitants, the educational attainment was low, and unemployment and parental dependency were high. The authors' results emphasize the need for reducing cardiovascular disease and metabolic bone disease in pediatric ESRD, a policy toward less toxic antirejection therapy, a more strict treatment of hypertension, and more attention for schooling and social development toward independence.

Does access to cardiac investigation and treatment contribute to social and ethnic differences in coronary heart disease? Whitehall II prospective cohort study

Objective To determine whether access to cardiac procedures and drugs contributes to social and ethnic differences in coronary heart disease in a population setting.Design Prospective study with follow up over...

Psychosocial stressors in inter-human relationships and health at each life stage: A review

Currently, psychosocial stressors' impacts on health are increasing. Among these stressors, this review focused on inter-human relationships. Since social supports could be protective against ill health, consequences contributing to psychosocial stressors are discussed here in relation to social supports for each stage of childhood, adulthood and elderly status.For childhood, parental divorce/isolation, and child abuse/neglect appeared to be determinants of healthy development at either the initial or later stages. According to prospective studies, such stressors, especially those occurring until around 3 years of age, were associated with later adverse life quality in adulthood. Therefore, nationwide preventive strategies were developed in each country to monitor protective social programs.For adulthood, job strain was focused on Karasek's job strain model, effort-reward imbalance, employment grade and working hours. These psychosocial stressors were shown to affect not only the physical health but also the mental health of working people. These days, since Karoshi and even suicide related to excessive workloads are taking a toll on workplace organization, stress-coping abilities such as a sense of coherence were introduced from the individual-social interaction aspect.For elderly status, retirement, caring for the elderly, and spouse bereavement were discussed as psychosocial stressors. Some evidence indicates that these stressors could be determiants of health. Finally, social supports have been demonstrated to promote health and protect the elderly against diseases and death.

Gender differences in the relationship of partner's social class to behavioural risk factors and social support in the Whitehall II study

In most countries health inequality in women appears to be greater when their socio-economic position is measured according to the occupation of male partners or spouses than the women's own occupations. Very few studies show social gradients in men's health according to the occupation of their female partners. This paper aims to explore the reasons for the differences in social inequality in cardiovascular disease between men and women by analysing the associations between own or spouses (or partners) socio-economic position and a set of risk factors for prevalent chronic diseases. Study participants were married or cohabiting London based civil servants included in the Whitehall II study. Socio-economic position of study participants was measured according to civil service grade; socio-economic position of the spouses and partners according to the Registrar General's social class schema. Risk factors were smoking, diet, exercise, alcohol consumption, and measures of social support. In no case was risk factor exposure more affected by the socio-economic position of a female partner than that of a male study participant. Wives’ social class membership made no difference at all to the likelihood that male Whitehall participants were smokers, or took little exercise. Female participants’ exercise and particularly smoking habit was, in contrast, related to their spouse's social class independently of their own grade of employment. Diet quality was affected equally by the socio-economic position of both male and female partners. Unlike the behavioural risk factors, the degree of social support reported by women participants was in general not strongly negatively affected by their husband or partner being in a less advantaged social class. However, non-employment in the husband or partner was associated with relatively lower levels of positive, and higher negative social support, while men with non-working wives or partners were unaffected. Studying gender differences in health inequality highlights some of the problems in health inequality research more broadly. We are brought face to face with the fact that the development of conceptual models that can be applied consistently to aetiology in both men and women are still at an early stage of development. Closer attention is needed to the different processes behind material power and ‘emotional power’ within the household when investigating gender differences in health and risk factors.

The psychosocial work environment and alcohol dependence: a prospective study

Aims: To examine whether a stressful psychosocial work environment predicts alcohol dependence. Methods: Alcohol dependence of participants in the Whitehall II occupational cohort of London based civil servants (1985–88) was...

Socioeconomic gradient in body size and obesity among women: the role of dietary restraint, disinhibition and hunger in the Whitehall II study.

To examine the associations between three psychological eating behaviour variables--restraint, hunger and disinhibition--and body weight and size, and to assess their explanatory power for the employment grade gradients in body measurement. Cross-sectional analysis of self-report and clinical data. : In all, 1470 women (aged 45-68 y, mean 56.3, s.d. 6.0 y), body mass index (BMI) 26.3 (4.8) kg/m(2) at phase 5 (1997-98) of the Whitehall II study. Employment grade was measured in six bands ranging from clerical (lowest) to administrative (highest). Five measures of body size were examined: BMI, weight in kilograms, waist and hip measurement in centimetres and waist-hip ratio. The eating behaviour variables were measured using Stunkard and Messick's (1985) Three-Factor Eating Questionnaire (TFEQ). Disinhibition and hunger scores were strongly and directly associated with all measures of body weight and size. Restraint score was not directly associated with body size and weight. An interaction between restraint and disinhibition scores was found. The low-restraint-high-disinhibition group (based on median score splits) were the heaviest (BMI 28.5 kg/m(2)) and largest (waist 85.8 cm), while the low-restraint-low-disinhibition group were the lightest (BMI 24.2 kg/m(2)) and smallest (waist 76.3 cm). Employment grade gradients in body weight and size remained largely unchanged after adjustment for dietary restraint. Moderate attenuations were found for disinhibition scores (3.6-15.0%) and hunger (4.8-19.9%) on the five body-size measures. Among middle-aged women high scores on hunger and disinhibition, as measured by the TFEQ, are associated with greater body size. Restraint relates to body size through its interaction with disinhibition. Individuals with high disinhibition and any level of restraint are heavier and larger than those with low levels of disinhibition. High disinhibition coupled with low levels of restraint is associated with the greatest weight and size. Hunger and disinhibition explain a moderate amount of the gradient in body size across employment grade and may be useful concepts for future work on the socio-economic gradient in obesity and overweight.

Socioeconomic status and stress-induced increases in interleukin-6

Coronary artery disease (CAD) is more prevalent in people from a low socioeconomic background, and low socioeconomic status (SES) is associated with an increased exposure to psychological stress. The pro-inflammatory cytokine interleukin-6 (IL-6) plays a central role in CAD development. IL-6 is responsive to psychological stress and could potentially mediate the effect of psychosocial factors on CAD risk. Accordingly, we predicted that people of low SES would have greater and/or more sustained IL-6 responses to acute psychological stress. Based on previous findings, we also predicted that these people would have delayed post-stress cardiovascular recovery. Thirty-eight male civil servants were tested, with participants divided into high and low SES groups according to employment grade. There were no differences between the groups at baseline. However there were significant differences in IL-6 and heart rate responses to stress. Stress induced increases in plasma IL-6 in all participants. However, in the low SES group, IL-6 continued to increase between 75 min and 2 h post-stress, whereas IL-6 levels stabilised at 75 min in the high SES group. Heart rate increased to the same extent following stress in both groups, however by 2 h post-stress, it had returned to baseline in 75% of the high SES group compared with only 38.1% of the low SES group. These results suggest that low SES people are less able to adapt to stress than their high SES counterparts. Prolonged stress-induced increases in IL-6 in low SES groups represents a novel mechanism potentially linking socioeconomic position and heart disease.

Work stress, socioeconomic status and neuroendocrine activation over the working day

Socioeconomic status (SES) differences in cardiovascular and metabolic disease risk may be mediated in part by differential activation of neuroendocrine pathways. We have previously found that salivary cortisol levels over the working day are greater in lower than higher SES men, but that cortisol output is greater in higher than lower SES women. This study investigated the role of work stress in generating these patterns, analysing cortisol output in relation to job demands and job control. Participants were 97 men and 84 woman from the Whitehall II cohort, London, UK, recruited from higher and lower grades of employment. Saliva samples were obtained on waking and 30 min later to assess the cortisol waking responses, and at two hourly intervals over a typical working day. Cortisol responses to waking were positively associated with high job demands, but this effect was attenuated by higher SES. In women but not men, cortisol levels over the remainder of the day were elevated in lower SES participants who experienced high job demands, but depressed in lower status women who reported low job demands. Job control did not influence cortisol responses to waking, but in men cortisol levels over the remainder of the day were inversely related to job control. These cortisol differences were independent of age, smoking status and time of waking up. Subjectively, the most stress was reported by higher SES individuals who experienced low job control. We conclude that work stress and SES are related differently to cortisol responses to waking and cortisol output over the day. Job control may partly mediate SES differences in cortisol in men, while job demands are more relevant for women. Analyses of psychobiological pathways must take account of variations in exposure to chronic stressors as well as differences in responsivity to stressors.

Effects of socioeconomic indicators on coronary risk factors, self-rated health and psychological well-being among urban Japanese civil servants

In Japan, the effects of socioeconomic indicators on coronary risk factors and subjective well-being in an urban population have not been compared. The subjects of this study were 1361 civil servants (968 men and 393 women, aged 35–64 years) working in an urban area of Japan. Screening examinations were conducted from April 1997 to March 1998, and a questionnaire survey was conducted in February 1998. The effects of two socioeconomic indicators, education level (junior high school, high school and university education) and employment grade (manual, low-level nonmanual and high-level nonmanual work), on behavioral and biological coronary risk factors, self-rated health and affect balance were investigated using multivariate logistic regression analyses. Smoking was found to be inversely associated with level of education; compared to university graduates, the odds ratios for subjects who had only graduated from high school and those for subjects who had only graduated from junior high school were 1.96 and 2.07 in men and 3.44 and 5.48 in women, respectively. As for alcohol drinking and physical inactivity, relationships were inconsistent in terms of direction by the two indicators. Among biological risk factors, diabetes was inversely associated with education level in men. Self-rated health, however, was inversely associated with employment grade both in men and women, and affect balance was inversely associated with employment grade in men. In summary, different effects of two socioeconomic indicators, education and employment grade, were seen in some coronary risk factors and subjective well-being in an urban Japanese population. Our findings should contribute to the elucidation of mechanisms of the socioeconomic gradients of risk factors and mortality from coronary heart disease in Japan.

Psychosocial and socioeconomic factors associated with glycated hemoglobin in nondiabetic middle-aged men and women.

The authors tested associations between glycated hemoglobin (HbA1c; an index of glucose homeostasis and an indicator of cardiovascular disease risk in nondiabetic populations) and socioeconomic status (defined by grade of employment) and psychosocial factors in 234 British civil servants. HbA1c concentration was inversely related to grade of employment. Higher HbA1c was associated with greater waist-hip ratio, lower control at work, lower internal locus of control, lower active coping, and lower social support. Control at work, internal and chance locus of control, and active coping were also related to socioeconomic status. The association of social support but not other psychosocial factors with HbA1c was independent of socioeconomic status. HbA1c may complement measures of the metabolic syndrome and insulin resistance in studies of psychosocial factors in cardiovascular disease risk.

Social position and mortality from respiratory diseases in males and females.

Although social differences in respiratory diseases are considerable, few studies have focused on this disease entity using mortality as an outcome. Does mortality from respiratory disease, including chronic obstructive pulmonary disease (COPD) differ with social position measured by education, income, housing and employment grade? The study population consisted of 26,392 males and females from pooling of two population studies in the Copenhagen area. Data was linked with information from social registers in Statistics Denmark. The relationship between socioeconomic factors and risk of death from respiratory disease and COPD was assessed with an average duration of follow-up of 12 yrs. Education was strongly associated with respiratory mortality in both sexes. The association was stronger in later birth cohorts comparing the highest level of education (>11 yrs) with the lowest (<8 yrs). Although smoking rates were inversely associated with the level of education, the social gradient was not affected by adjustment for smoking. In males, but not in females, there was an additional effect of other indicators of social position, i.e. employment grade (white collar versus blue collar), household income, housing conditions (less than one person per room versus more), and cohabitation (cohabiting versus living alone). Similar results were found for mortality from COPD. The results confirm the existence of a strong social gradient in respiratory mortality and chronic obstructive pulmonary disease, which is independent of smoking and is stronger in males. Social disadvantage is a potentially avoidable cause of death from respiratory disease and further research is needed to explain the excess risk in the socioeconomically disadvantaged.

Socioeconomic status and stress-related biological responses over the working day.

The influence of low socioeconomic status on cardiovascular disease may be mediated in part by sustained activation of stress-related autonomic and neuroendocrine processes. We hypothesized that low socioeconomic status would be associated with heightened ambulatory blood pressure and cortisol output over the working day. One hundred eight men and 94 women from the Whitehall II epidemiological cohort participated. Blood pressure and heart rate were monitored every 20 minutes over a working day and evening, and salivary cortisol was sampled on waking up and at 2-hour intervals. Measures were also taken under resting laboratory conditions. Socioeconomic status was indexed by grade of employment. Resting blood pressure, heart rate, and cortisol did not differ by grade. Ambulatory systolic pressure was greater in the morning in the lower (128.9 +/- 15.7 mm Hg) than the intermediate (122.6 +/- 12.5 mm Hg) and higher grades (123.3 +/- 12.7 mm Hg) after adjustment for age, sex, smoking, and alcohol intake (p =.019). Heart rate was also raised in the morning in the lower grade participants. Differences in morning systolic pressure and heart rate were independent of concurrent physical activity. Cortisol concentration was greater in lower than higher grade men (9.54 +/- 4.1 vs. 7.38 +/- 2.8 nmol/liter, p =.008) but was more elevated in higher than lower grade women (7.84 +/- 2.5 vs. 6.35 +/- 1.9 nmol/liter, p =.014). Differences remained significant after adjustment for age, time of awakening, smoking, and alcohol intake. Socioeconomic differences in blood pressure and cortisol may reflect stress-related activation of biological pathways that contribute to variations in disease risk.

Socioeconomic status, C-reactive protein, immune factors, and responses to acute mental stress

Low socioeconomic status (SES) is associated with increased risk of coronary heart disease and immune-related disorders. We hypothesised that SES would be inversely associated with the acute phase reactant C-reactive protein (CRP) and with circulating lymphocyte levels, and that lymphocyte responses to acute psychological stress would also vary with SES. CRP was obtained from 226, and lymphocyte counts from 127 healthy volunteers from the Whitehall II cohort, and SES was defined primarily by grade of employment. CRP concentration was greater in lower compared with higher SES participants (1.18±0.75 vs. 0.75±0.8 mg/l, p=.002 ) independently of sex, age, body mass, waist/hip ratio, smoking, alcohol, and season of the year. Similar differences were evident when SES was defined by income and educational attainment. Higher SES was also associated with lower total lymphocyte ( p=.023), T-lymphocyte ( p=.024) and natural killer (NK) cell counts ( p=.006). Total, T- and B-lymphocyte, and NK cell counts increased with stress, but immune stress reactivity did not vary with SES. Post-stress recovery was delayed in women compared with men. The results suggest that moderate inflammation and immune activation may be processes through which lower SES increases disease risk.

Intimations of mortality: perceived age of leaving middle age as a predictor of future health outcomes within the Whitehall II study.

to determine the association between the subjective rate of ageing and future health outcomes. prospective cohort study (Whitehall II study). At the third phase of the study (1991-1993), participants were asked at what age they think most people leave middle age. Participants were followed until the end of phase 5 (1997-2000), so that mean length of follow-up was 7 years. London based office staff in 20 civil service departments. 5,262 male and 2,277 female civil servants aged 40-60. validated new cases of coronary heart disease and health function, measured by the SF-36 General Health Survey, at phase 5. perceived age of leaving middle age increased with age, self-rated health and grade of employment, and was higher in women. Adjusting for age and sex, people who believed middle age ends < or =60 years, compared to > or =70 years, were at higher risk for coronary heart disease (HR=1.43, 95% CI=1.05-1.94), fatal coronary heart disease and non-fatal myocardial infarction (HR=1.52, 0.95-2.42), and poor physical (OR=1.29, 1.10-1.50) and mental (OR=1.25, 1.07-1.45) functioning during follow-up. Adjustment for self-rated health, employment grade, health behaviours, social networks, control and baseline health status, respectively, did not eliminate these associations. the reported age at which middle age ends predicts future health outcomes. We hypothesise that perceived end of middle age acts as a general summary of the subjective rate of ageing.

Future uncertainty and socioeconomic inequalities in health: the Whitehall II study

Over the past 20 years, socioeconomic inequalities in mortality have widened, while job security and financial security have decreased. This paper examines the Whitehall II study, a longitudinal study of white-collar British civil servants. In the Whitehall II cohort socioeconomic gradients in morbidity and cardiovascular risk factors at Phase 5 (1997–99) were generally steeper than at Phase 1 (1985–88). We examine the contribution of job and financial insecurity to these at Phase 5 in 6770 women and men, all of whom were white-collar civil servants at Phase 1. Steep, inverse employment grade gradients were observed for all health measures at Phase 5, except cholesterol and systolic blood pressure in women. Gradients in the sub-population of non-employed participants tended to be steeper than gradients for participants in employment, although, with the exception of self-rated health and General Health Questionnaire (GHQ) score in men, differences were non-significant. Steep gradients in job insecurity were observed among employed participants ( p⩽0.01), and in financial insecurity among both employed and non-employed participants ( p⩽0.001), particularly non-employed men. With the exception of depression, adjustment for job insecurity had little effect on the employment grade gradients in morbidity. However, financial insecurity contributed substantially to gradients in self-rated health, longstanding illness, and depression in both employed and non-employed men, and additionally to GHQ score and diastolic blood pressure in the latter. Adjustment for financial insecurity in non-employed women substantially attenuated gradients in self-rated health, GHQ score and depression. These findings imply that the specific effects of job insecurity in this cohort may be less important than the more general effects of financial insecurity in determining inequalities in health.

Influence of socioeconomic status and job control on plasma fibrinogen responses to acute mental stress.

An elevation in plasma fibrinogen may be one of the pathways through which low socioeconomic status increases cardiovascular disease risk. This study assessed the influence of socioeconomic status, job control, and social isolation on fibrinogen responses to acute stress. The study was conducted with 125 white men and 96 white women aged 47 to 58 years, drawn from the Whitehall II cohort. Socioeconomic status was indexed by grade of employment, with 82 high, 75 intermediate, and 64 low grade participants. Plasma fibrinogen and hematocrit were assessed at baseline, immediately after performance of color-word and mirror tracing tasks, and 45 minutes later. Plasma fibrinogen increased from baseline to stress (from 2.85 +/- 0.57 to 2.92 +/- 0.58 g/liter), remaining elevated 45 minutes after stress (2.89 +/- 0.58 g/liter, p <.001). Fibrinogen concentration was greater in the low than in the high or intermediate employment grade groups, independently of sex, age, body mass index, smoking status, and hematocrit. Fibrinogen responses to acute stress did not differ across employment grades. Women had higher fibrinogen levels than men, but this pattern was abolished in women taking hormone replacement therapy. Men experiencing low job control showed greater fibrinogen responses to acute stress than did those with high job control (p =.003). Fibrinogen levels were greater in socially isolated individuals, but social isolation did not affect responses to acute stress. Socioeconomic status and acute stress had independent effects on the plasma fibrinogen level. Low job control may influence cardiovascular disease risk in men partly through provoking greater fibrinogen stress responses.