| 1. |
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| 2. |
- Dahlgren, Anna, et al.
(författare)
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Day-to-day variation in saliva cortisol-Relation with sleep, stress and self-rated health.
- 2009
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Ingår i: Biological psychology. - : Elsevier BV. - 1873-6246 .- 0301-0511.
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Tidskriftsartikel (refereegranskat)abstract
- The objective was to examine the day-to-day variation in cortisol among healthy individuals and its relation to the time of saliva sampling, work, stress and fatigue. During 4 consecutive weeks, 14 office workers provided saliva samples (at awakening, 15min after awakening and at bedtime) and made diary ratings for each day. Results showed a variation in cortisol values between participants but also within individuals. After controlling for the individual differences, results showed that low cortisol levels in the morning were associated with sleepiness at awakening and anxiety, exhaustion, and poor health the day before. High evening levels of cortisol were associated with symptoms of stress and poor self-rated health. Further analysis of the cortisol awakening response (CAR) showed that all participants had a mixture of both a positive and negative responses. During mornings with a negative response participants stayed in bed for a longer time after the initial awakening, which might be a sign of snoozing, thus missing the awakening response.
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| 3. |
- Dahlgren, Anna, et al.
(författare)
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Different levels of work-related stress and the effects on sleep, fatigue and cortisol
- 2005
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Ingår i: Scandinavian Journal of Work, Environment and Health. - : Scandinavian Journal of Work, Environment and Health. - 0355-3140 .- 1795-990X. ; 31:4, s. 277-285
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Tidskriftsartikel (refereegranskat)abstract
- Objectives The aim of the study was to relate different levels of work stress to measures of sleep and the diurnal pattern of salivary cortisol and subjective sleepiness. Methods Thirty-four white-collar workers participated under two different conditions. One workweek with a relatively high stress level (H) and one with a lower stress level (L) as measured through self-rated stress during workdays. The workers wore activity monitors, filled out a sleep diary, gave saliva samples (for cortisol), and rated their sleepiness and stress during one workday and one free day. Results During the week with stress the number of workhours increased and total sleep time decreased. Sleepiness showed a significant interaction between weeks and time of day, with particularly high levels towards the evenings of the stress week. Cortisol also showed a significant interaction, with a more flattened pattern, probably due to increased evening levels during the stress week. Stress (restlessness) at bedtime was significantly increased during the stress week. Conclusion The results demonstrate that a workweek with a high workload and much stress increases sleepiness and workhours, impairs sleep, and affects the pattern of diurnal cortisol secretion.
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| 4. |
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| 5. |
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| 6. |
- Dahlgren, Anna, et al.
(författare)
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Individual differences in the diurnal cortisol response to stress
- 2004
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Ingår i: Chronobiology International. - 0742-0528 .- 1525-6073. ; 21:6, s. 913-922
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Tidskriftsartikel (refereegranskat)abstract
- The objectives of this study were to explore individual differences associated with diverse reactions in cortisol secretion under different stress levels. This study was part of a larger project concerning working hours and health. Thirty-four whitecollar workers participated under two different conditions; one work week with a high stress level (H) and one with a lower stress level (L) as measured through self-rated stress during workdays. Based on the morning cortisol concentration during a workday subjects were divided into two groups. One group consisted of subjects whose morning level of cortisol increased in response to the high-stress week, compared to their morning levels in the low-stress condition (Group 1). The other group consisted of subjects whose morning cortisol response was the opposite, with a lower level under the high stress condition (Group 2). Subjects wore actiwatches, completed a sleep diary, and rated their sleepiness and stress for one work week in each condition, i.e., high and low stress. Saliva samples for measures of cortisol were collected on a Wednesday. Group 2 reported higher workload, fatigue, and exhaustion during both weeks. Since there were no differences in perceived stress, neither within nor between groups, the data indicate that there are other factors influencing morning cortisol. The results suggest that one component modulating the cortisol response might be the level of exhaustion, probably related to work overload. Higher levels of stress in exhausted individuals might suppress morning cortisol levels.
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| 7. |
- Dahlgren, Anna, et al.
(författare)
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Overtime work and its effects on sleep, sleepiness, cortisol and blood pressure in an experimental field study
- 2006
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Ingår i: Scandinavian Journal of Work, Environment and Health. - : Scandinavian Journal of Work, Environment and Health. - 0355-3140 .- 1795-990X. ; 32:4, s. 318-327
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Tidskriftsartikel (refereegranskat)abstract
- Objectives Previous studies of long workhours and their effects on stress, sleep, and health show inconclusive results. This inconclusiveness may be partly due to methodological problems such as the use of between-group designs or comparisons before and after reorganizations. In addition, stress is usually a confounder. A within-person design was used to examine the effects of working 8- or 12-hour shifts in the absence of additional stress. Methods In an experimental field study, 16 white-collar workers [9 women, mean age 45.9 (SD 15) years] undertook one workweek with normal workhours (8 hours) and 1 week of overtime with 4 extra hours of regular worktasks (12 hours). The participants wore actigraphs, rated sleepiness (Karolinska Sleepiness Scale) and stress throughout the day, and rated workload and how exhausted they felt. Saliva samples were collected on Mondays and Thursdays for cortisol analysis. On these days, ambulatory heart rate and blood pressure were also measured for 24 hours. Results Overtime was associated with higher levels of exhaustion. Sleepiness showed a significant interaction between conditions, with higher levels at the end of the workweek featuring overtime. Total sleep time was shorter in the overtime week. There were no significant differences between ratings of stress and workload. Cortisol showed a circadian variation but no main effect of condition. Conclusions One week of overtime work with a moderate workload produced no main effects on physiological stress markers. Nevertheless, sleep was negatively affected, with shorter sleeps during overtime work and greater problems with fatigue and sleepiness.
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| 8. |
- Dahlgren, Anna
(författare)
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Work stress and overtime work - effects on cortisol, sleep, sleepiness and health
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In Sweden the National Bureau of Statistics has reported an increase in stress-related disorders and sleep problems since the mid-1990’s. They also report that the number of hours of overtime worked has increased. Previous research on work-related stress and overtime work has demonstrated associations with altered physiological arousal, increased risk for stress related diseases, shorter sleep, greater fatigue and impaired performance. However, there is a lack of knowledge on the effects within individuals. The general aim of the thesis was to investigate the effect of overtime work and increased work stress on sleep, the diurnal pattern of cortisol, sleepiness and subjective stress in a within-subject design. In addition, it examined individual differences in the diurnal cortisol response to stress.We used a combination of methods – questionnaires, sleep and wake diaries, objective measures of sleep, stress hormones (salivary cortisol) and ambulatory measures of heart rate and blood pressure. Studies followed office workers during two different conditions of (I) high/low work stress and (II) overtime work respectively. The individual differences in the cortisol response to stress from study I prompted study III. In this study we examined two groups that showed different cortisol responses to stress.In conclusion, the results (I) demonstrated that a week with higher workload and stress affects physiological stress markers such as cortisol, and is associated with increased sleepiness and problems of unwinding at bedtime, shorter sleep duration and longer work hours. Furthermore (II) overtime work, under conditions of relatively low workload, was shown to be associated with modest effects on physiological markers of arousal. More pronounced effects were found on sleep and fatigue, with greater problems during overtime work. Study III indicated that individual differences in cortisol response to stress maybe related to fatigue and exhaustion.
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| 9. |
- Dahlgren, Hanna, et al.
(författare)
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Solar flares detected by the new narrowband VLF receiver at SANAE IV
- 2011
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Ingår i: South African Journal of Science. - : Academy of Science of South Africa. - 0038-2353 .- 1996-7489. ; 107:9-10, s. 39-46
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Tidskriftsartikel (refereegranskat)abstract
- A narrowband receiver was installed at the SANAE IV base in Antarctica to monitor specific very low frequency (VLF) radio signals from transmitters around the world. VLF waves propagating through the Earth-Ionosphere Waveguide are excellent probes of the varying properties of the lower region of the ionosphere. This paper describes the set-up of the narrowband system and demonstrates its capabilities with data from a set of solar flares on 08 February and 12 February 2010.
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| 10. |
- Edelfeldt, Stina, et al.
(författare)
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Age-Independent Adult Mortality in a Long-Lived Herb
- 2019
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Ingår i: Diversity. - : MDPI AG. - 1424-2818. ; 11:10
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Tidskriftsartikel (refereegranskat)abstract
- Relative to mammals and birds, little is known about the mortality trajectories of perennial plants, as there are few long-term demographic studies following multiple yearly cohorts from birth to death. This is particularly important because if reproductively mature individuals show actuarial senescence, current estimations of life spans assuming constant survival would be incorrect. There is also a lack of studies documenting how life history trade-offs and disturbance influence the mortality trajectories of plants. We conducted Bayesian survival trajectory analyses (BaSTA) of a 33-year individual-based dataset of Pulsatilla vulgaris ssp. gotlandica. Mortality trajectories corresponded to Type III survivorship patterns, with rapidly decreasing annual mortality rates for young plants, but with constant mortality for reproductively mature individuals. We found trade-off effects resulting in a cost of growth for non-reproductive plants but no apparent cost of reproduction. Contrarily to our expectation, young plants that had previously shrunk in size had a lower mortality. However, accounting for trade-offs and disturbance only had minor effects on the mortality trajectories. We conclude that BaSTA is a useful tool for assessing mortality patterns in plants if only partial age information is available. Furthermore, if constant mortality is a general pattern in polycarpic plants, long-term studies may not be necessary to assess their age-dependent demography.
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| 11. |
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| 12. |
- Gjessing, Kristian, 1967-
(författare)
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Impact of medical and non-medical Factors on Quality and Costs in Primary Care : A Conscious Look at Subconcious Processes
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background / IntroductionPhysicians and patients may be influenced by more than just the medical facts of the situation at hand. The physician is a part of the sociocultural environment and is under influence of this. The physician could be afraid of making mistakes and thus choose the safest option. In addition, economic considerations may apply. The perceived continuity or quality of the communication may also influence medical decision-making. Patients may not think about what allergens they are exposed to. Differences in socioeconomy or perceived morbidity may influence the patient's or their family’s desire to see the doctor or to use medications like antibiotics.Material and MethodsIn Paper 1, referrals from two Primary Healthcare centers in Norway were compared to each other and to the other referrals that were received by the local hospital. In Paper 2, Influenza-Like Illness (ILI) for children 2-12 years old was monitored for 7 years, and costs of treatment and parental absence due to ill children were calculated using real numbers. In Paper 3, the number of antibiotic prescriptions was compared to the patient’s socioeconomic background, to investigate possible inequalities. Paper 4 compares asthma and atopy incidence to the number of antibiotic prescriptions, to investigate if asthma patients are more often treated with antibiotics than nonasthma patients are. The analyses are based on regional healthcare data and the prospective ABIS study.ResultsPaper 1 showed that locum doctors and regular General Practitioners had the same referral rates, but the locum doctors had a distribution of diagnoses that differed significantly from the regular GPs and from the other referrals.Paper 2 showed that parental absence due to children with ILI follows the seasonal influenza pattern closely. The main burden of consultations and costs is carried by Primary Care.Paper 3 showed that parent-reported infectious morbidity at age 5, is associated with a higher number of antibiotic prescriptions in later childhood (5-14 years). Family income is a factor, where children from Q1 (wealthiest) receive significantly fewer antibiotics than children from Q3-Q5.Paper 4 found that asthma/ fur allergy at age 5 was associated with more antibiotic prescriptions in later childhood, but that wide-spectrum antibiotics are rarely used. Doctors seem to adhere to national and regional guidelines.ConclusionsPrimary care physicians seem to be affected by their grade of continuity and length of employment in their referral diagnosis distribution. Influenza-like illness in children carries a substantial cost in terms of loss of production, healthcare encounters, and personal suffering for vulnerable individuals. Parents’ perceptions of morbidity seem to influence antibiotic demand in children, along with socioeconomic factors. Children with asthma or airway allergies seem to receive more antibiotic prescriptions, possibly due to increased infectious vulnerability or to allergic exposure unknown to the doctor.
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| 13. |
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| 14. |
- Jormeus, Anders, et al.
(författare)
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Doubling of Water Intake Increases Daytime Blood Pressure and Reduces Vertigo in Healthy Subjects
- 2010
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Ingår i: CLINICAL AND EXPERIMENTAL HYPERTENSION. - : Informa Healthcare. - 1064-1963 .- 1525-6006. ; 32:7, s. 439-443
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Tidskriftsartikel (refereegranskat)abstract
- We studied the effect of increased water intake on ambulatory blood pressure (BP) in healthy individuals. Blood pressure was recorded after 2 weeks of either regular (RWI) or extra water intake (EWI, an additional 30 ml water/kg body weight per day) in 20 healthy subjects (10 males, 10 females). The extra water intake (RWI: 1.7 +/- 0.59 l, EWI: 3.7 +/- 0.84 l, respectively, p andlt; 0.0001, i.e., an increase of 2 liters) induced an increase in mean arterial daytime BP from 89.0 +/- 5.5 mmHg during RWI to 91.4 +/- 6.4 mmHg during the EWI phase (p = 0.005), while night-time BP was unchanged by the intervention. The visual-analogue-scale (VAS, maximum score of 10) score corresponding to the statement "I often experience vertigo" was 3.1 +/- 2.6 during RWI and decreased to 2.1 +/- 2. 1 during EWI phase (p = 0.008). In conclusion, two liters of extra water intake for 2 weeks significantly increased daytime blood pressure and reduced a sense of vertigo in healthy individuals.
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| 15. |
- Lindell, Torbjörn, et al.
(författare)
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Weather-driven demography and population dynamics of an endemic perennial plant during a 34-year period
- 2022
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Ingår i: Journal of Ecology. - : Wiley. - 0022-0477 .- 1365-2745. ; 110:3, s. 582-592
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Tidskriftsartikel (refereegranskat)abstract
- 1. Increased anthropogenic influence on the environment has accentuated the need to assess how climate and other environmental factors drive vital rates and population dynamics of different types of organisms. However, to allow distinction between the effects of multiple correlated variables, and to capture the effects of rare and extreme climatic conditions, studies extending over decades are often necessary.2. In this study, we used an individual-based dataset collected in three populations of Pulsatilla vulgaris subsp. gotlandica during 34 years, to explore the effects of variation in precipitation and temperature on vital rates and population dynamics.3. Most of the observed conspicuous variation in flowering among years was associated with differences in precipitation and temperature in the previous summer and autumn with a higher incidence of flowering following summers with high precipitation and low temperatures. In contrast, climatic variables had no significant effects on individual growth or survival.4. Although the weather-driven variation in flowering had only moderate absolute effects on the population growth rate, simulated persistent changes in average precipitation and temperature resulted in considerable reductions in population sizes compared with current conditions. Analyses carried out with subsets of data consisting of 5 and 10 years yielded results that strongly deviated from those based on the full dataset.5. Synthesis. The results of this study illustrate the importance of long-term demographic monitoring to identify key climatic variables affecting vital rates and driving population dynamics in long-lived organisms.
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| 16. |
- Stroeven, Arjen P., et al.
(författare)
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Importance of sampling across an assemblage of glacial landforms for interpreting cosmogenic ages of deglaciation
- 2011
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Ingår i: Quaternary Research. - : Cambridge University Press (CUP). - 0033-5894 .- 1096-0287. ; 76:1, s. 148-156
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Tidskriftsartikel (refereegranskat)abstract
- Deglaciation chronologies for some sectors of former ice sheets are relatively poorly constrained because of the paucity of features or materials traditionally used to constrain the timing of deglaciation. In areas without good deglaciation varve chronologies and/or without widespread occurrence of material that indicates the start of earliest organic radiocarbon accumulations suitable for radiocarbon dating, typically only general patterns and chronologies of deglaciation have been deduced. However, mid-latitude ice sheets that had warm-based conditions close to their margins often produced distinctive deglaciation landform assemblages, including eskers, deltas, meltwater channels and aligned lineation systems. Because these features were formed or significantly altered during the last glaciation, boulder or bedrock samples from them have the potential to yield reliable deglaciation ages using terrestrial cosmogenic nuclides (TCN) for exposure age dating. Here we present the results of a methodological study designed to examine the consistency of TCN-based deglaciation ages from a range of deglaciation landforms at a site in northern Norway. The strong coherence between exposure ages across several landforms indicates great potential for using TCN techniques on features such as eskers, deltas and meltwater channels to enhance the temporal resolution of ice-sheet deglaciation chronologies over a range of spatial scales.
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| 17. |
- Tagesson, Torbjörn, 1969-, et al.
(författare)
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The relationship between attitude towards harmonization and the internationalization of the corporation : a study of the attitude towards the implementation of IASB standards among Swedish listed companies
- 2003
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Harmonized accounting among European companies would contribute to creating better conditions for the free mobility of capital within the European Union. However, a harmonization of laws and standards does not necessarily lead to a de facto harmonization.The aim of this paper is to examine the attitude of financial managers in listed Swedish companies towards the implementation of IASB standards in Sweden from 2005. It analyzes whether there is a significant connection between attitude towards implementation of IASB standards and background variables such as share of foreign ownership, number of foreign subsidiary companies, number of stock exchanges on which the company is listed, and the proportion of sales exported. These are variables that we believe reflect a company’s extent of internationalization.The overall results show that financial managers of Swedish listed companies are cautiously positive towards the implementation of IASB standards. The study also shows that there is a significant connection between extent of internationalization and attitude towards the implementation of IASB standards. Financial managers of internationalized companies are generally more positive towards the implementation of IASB standards than their colleagues in less internationalized companies.
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| 18. |
- Tagesson, Torbjörn, et al.
(författare)
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The relationship between attitude towards harmonization and the internationalization of the corporation : a study of the attitude towards the implementation of IASB standards among Swedish listed companies
- 2003
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- Harmonized accounting among European companies would contribute to creating better conditions for the free mobility of capital within the European Union. However, a harmonization of laws and standards does not necessarily lead to a de facto harmonization. The aim of this paper is to examine the attitude of financial managers in listed Swedish companies towards the implementation of IASB standards in Sweden from 2005. It analyzes whether there is a significant connection between attitude towards implementation of IASB standards and background variables such as share of foreign ownership, number of foreign subsidiary companies, number of stock exchanges on which the company is listed, and the proportion of sales exported. These are variables that we believe reflect a company’s extent of internationalization. The overall results show that financial managers of Swedish listed companies are cautiously positive towards the implementation of IASB standards. The study also shows that there is a significant connection between extent of internationalization and attitude towards the implementation of IASB standards. Financial managers of internationalized companies are generally more positive towards the implementation of IASB standards than their colleagues in less internationalized companies.
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| 19. |
- Tucker, Philip, et al.
(författare)
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The impact of junior doctors' worktime arrangements on their fatigue and well-being
- 2010
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Ingår i: Scandinavian Journal of Work, Environment and Health. - : Scandinavian Journal of Work, Environment and Health. - 0355-3140 .- 1795-990X. ; 36:6, s. 458-465
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Tidskriftsartikel (refereegranskat)abstract
- Objective Many doctors report working excessively demanding schedules that comply with the European Working Time Directive (EWTD). We compared groups of junior doctors working on different schedules in order to identify which features of schedule design most negatively affected their fatigue and well-being in recent weeks. Methods Completed by 336 doctors, the questionnaires focused on the respondents’ personal circumstances, work situation, work schedules, sleep, and perceptions of fatigue, work–life balance and psychological strain. Results Working 7 consecutive nights was associated with greater accumulated fatigue and greater work–life interference, compared with working just 3 or 4 nights. Having only 1 rest day after working nights was associated with increased fatigue. Working a weekend on-call between 2 consecutive working weeks was associated with increased work–life interference. Working frequent on-calls (either on weekends or during the week) was associated with increased work–life interference and psychological strain. Inter-shift intervals of <10 hours were associated with shorter periods of sleep and increased fatigue. The number of hours worked per week was positively associated with work–life interference and fatigue on night shifts. Conclusion The current findings identify parameters, in addition to those specified in the EWTD, for designing schedules that limit their impact on doctors’ fatigue and well-being.
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| 20. |
- Wilhelmsson, Niklas, et al.
(författare)
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Phenomenographic study of basic science understanding-senior medical students' conceptions of fatigue
- 2013
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Ingår i: Education for Health. - : The Network:Towards Unity for Health. - 1357-6283 .- 1469-5804. ; 26:3, s. 156-163
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Helping students learn to apply their newly learned basic science knowledge to clinical situations is a long-standing challenge for medical educators. This study aims to describe how medical students' knowledge of the basic sciences is construed toward the end of their medical curriculum, focusing on how senior medical students explain the physiology of a given scenario. Methods A group of final-year medical students from two universities was investigated. Interviews were performed and phenomenographic analysis was used to interpret students' understanding of the physiology underlying the onset of fatigue in an individual on an exercise bicycle.RESULTS: Three categories of description depict the qualitatively different ways the students conceptualized fatigue. A first category depicts well integrated physiological and bio-chemical knowledge characterized by equilibrium and causality. The second category contains conceptions of finite amount of substrate and juxtaposition of physiological concepts that are not fully integrated. The third category exhibits a fragmented understanding of disparate sections of knowledge without integration of basic science and clinical knowledge.DISCUSSION: Distinctive conceptions of fatigue based with varying completeness of students' understanding characterized the three identified categories. The students' conceptions of fatigue were based on varying understanding of how organ systems relate and of the thresholds that determine physiological processes. Medical instruction should focus on making governing steps in biological processes clear and providing opportunity for causal explanations of clinical scenarios containing bio-chemical as well as clinical knowledge. This augments earlier findings by adding descriptions in terms of the subject matter studied about how basic science is applied by students in clinical settings.
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