24 research outputs found

    Silencing of ultradian rhythms and metabolic depression during spontaneous daily torpor in Djungarian hamsters

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    Ultradian rhythms of metabolism, body temperature and activity are attenuated or disappear completely during torpor in Djungarian hamsters, for all three ultradian periodicities (URsmall, URmedium and URlarge). URsmall and URmedium disappear during entrance into torpor, whereas URlarge disappear later or continue with a low amplitude. This suggests a tight functional link between torpor and the expression of ultradian rhythms, i.e. torpor is achieved by suppression of metabolic rate as well as silencing of ultradian rhythms. Spontaneous torpor is often initiated after an ultradian burst of activity and metabolic rate, beginning with a period of motionless rest and accompanied by a decrease of metabolic rate and body temperature. To extend previous findings on the potential role of the adrenergic system on torpor induction we analysed the influence of the ß3-adrenergic agonist Mirabegron on torpor in Djungarian hamsters, as compared to the influence of the ß-adrenergic antagonist Propranolol. Hamsters were implanted with 10 day release pellets of Mirabegron (0.06 mg day-1) or Propranolol (0.3 mg day-1). Mirabegron transiently supressed and accelerated ultradian rhythms but had no effect on torpor behaviour. Propranolol did not affect torpor behaviour nor the expression of ultradian rhythms with the dosage applied during this study

    Multiple ultradian rhythms of metabolism, body temperature and activity in Djungarian hamsters

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    Djungarian hamsters (Phodopus sungorus) living at constant 15 °C Ta in short photoperiod (8:16 h L:D) showed pronounced ultradian rhythms (URs) of metabolic rate (MR), body temperature (Tb) and locomotor activity. The ultradian patterns differed between individuals and varied over time. The period length of URs for MR, Tb and activity was similar although not identical. Wavelet analysis showed that three different URs are existing in parallel, URs of small amplitude and short duration (URsmall), URs of medium amplitude and medium duration (URmedium) and URs of large amplitude (URlarge), superimposed on each other. URlarge were accompanied by an increase in locomotor activity, whereas URsmall and URmedium were of metabolic origin with lacking or delayed responses of activity. An energetic challenge to cold which raised total energy requirements by about 50% did not accelerate the period length of URs, but extended the amplitude of URsmall and URmedium. URlarge corresponds with the URs of activity, feeding and drinking, sleep and arousal as described in previous studies, which are related to midbrain dopaminergic signalling and hypothalamic ultradian signalling. The cause and control of URmedium and URsmall is unknown. Their periods are similar to periods of central and peripheral endocrine ultradian signalling, suggesting a link with URs of metabolism

    Cross-cultural validation of the German and Turkish versions of the PHQ-9: an IRT approach

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    Background: The Patient Health Questionnaire’s depression module (PHQ-9) is a widely used screening tool to assess depressive disorders. However, cross-linguistic and cross-cultural validation of the PHQ-9 is mostly lacking. This study investigates whether scores on the German and Turkish versions of the PHQ-9 are comparable. Methods: Data from Germans without a migration background (German version, n = 1670) and Turkish immigrants in Germany (either German or Turkish version, n = 307) were used. Differential Item Functioning (DIF) was assessed using Item Response Theory (IRT) models. Results: Several items of the PHQ-9 were found to exhibit DIF related to language or ethnicity, e.g. ‘sleep problems’, ‘appetite changes’ and ‘anhedonia’. However, PHQ-9 sum scores were found to be unbiased, i.e., DIF had no notable impact on scale levels. Conclusions: PHQ-9 sum scores can be compared between Turkish immigrants and Germans without a migration background without any adjustments, regardless of whether they complete the German or the Turkish version.© The Author(s) 201

    Why is this happening to me? – a comparison of illness representations between Iranian and German people with mental illness

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    Background: Due to an increase in migration and globalization, cross-cultural encounters in health care are also becoming more frequent. As psychotherapy is grounded in a cultural context and must be congruent with the patient’s cultural beliefs of his or her illness in order to be effective, the consideration of cross-cultural differences in illness representations becomes increasingly important. Especially research on illness representations concerning mental disorders is scarce. Methods: The aim of the current study was to compare illness representations between Iranian (N = 87) and German (N = 90) patient samples as well as subclinical samples (Iranian N = 264, German N = 102) using a multivariate analysis of covariance (MANCOVA). Illness representations were measured using the Illness Perception Questionnaire Revised (IPQ-R). Initially, a factor analysis was conducted in order to ensure comparability of the IPQ-R between the Iranian and the German sample. Results: The factor analysis already revealed differences in item compositions of the IPQ-R subscales indicating differences of the conception of illness representations between the samples. Further, the Iranian samples showed a significantly higher amount of supernatural causal beliefs and emotional representation of the illness than the German samples. Surprisingly, the Iranian patient sample showed the highest amount of illness coherence. Conclusion: The current paper contributes to a deeper understanding of cross-cultural differences in illness representations regarding mental disorders. Nevertheless, further research is needed to confirm current findings and to further elaborate on the relationships found.© The Author(s) 201

    Three consecutive generations of nephridia occur during development of Platynereis dumerilii (Annelida, Polychaeta)

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    Molecular data for nephridial development in polychaetes are not available yet. The scope of our work was to establish a reference system for future investigations using two markers for nephridial development: beta-tubulin as marker for cilia and alkaline phosphatase (AP) activity for secretory epithelia. The markers identified, unexpectedly, three consecutively forming generations of nephridia: (1) a transitory unciliated, but AP-positive head kidney, (2) a transitory larval nephridium, which undergoes a morphological transition from a protonephridium to a funnelled nephridium concomitant with the development of the coelomic cavity and finally, (3) the serially arranged metanephridia. The spatial arrangement of larval and definitive nephridia, revealed an up to now unknown developmental boundary between the synchronously forming larval and the serially proliferating definitive segments. Development of three consecutive sets of nephridia with different morphology and biochemical properties was unexpected and reveals an interesting multistep process in the development of excretory structures in Platynereis

    Thyroid Functioning and Fatigue in Women With Functional Somatic Syndromes – Role of Early Life Adversity

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    Objective: Fatigue is a core feature of functional somatic syndromes (FSS). Fatigue is also prominent in patients with thyroid diseases, which is unsurprising given the role of the hypothalamic-pituitary-thyroid (HPT) axis in regulating physiological energy demands. Research in healthy women has shown that early life adversity is linked with alterations in the HPT axis. In view of the substantial prevalence of early life adversity in patients with FSS, our aim was to investigate whether HPT functioning is related to (a) fatigue, and (b) early life adversity in these patients. Methods: N = 33 female patients with FSS and n = 30 age-matched controls were recruited. Fasting morning blood samples were taken to determine thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), and thyroxine (fT4). General, physical, and mental fatigue were measured via the multidimensional fatigue inventory (MFI). Early life adversity was measured using the childhood trauma questionnaire (CTQ). Results: Patients with FSS did not differ from controls in any thyroid parameters (all p > 0.672). However, the lower the patients’ TSH and the higher their fT4, the greater was their general (β = -0.32, p = 0.064; β = 0.35, p = 0.038) and physical (β = -0.47, p = 0.007; β = 0.32, p = 0.077) fatigue. In addition, emotional neglect (β = -0.32, p = 0.057), physical neglect (β = -0.60, p = 0.001), physical abuse (β = -0.47, p = 0.015), and sexual abuse (β = -0.40, p = 0.026) were linked with lower TSH. Conclusion: The lower TSH and the higher fT4, the more fatigue was reported by patients with FSS. In addition, lower TSH was linked with more early life adversity. Larger, prospective studies are warranted to determine whether HPT functioning may be a mediating pathway between early life adversity and fatigue in FSS.© 2018 Fischer, Markert, Strahler, Doerr, Skoluda, Kappert and Nate

    Humans represent the precision and utility of information acquired across fixations dataset

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    This dataset contrains the behavioural and eyetracking data for the paper: Stewart, E.E.M., Ludwig, C.J.H. & Schütz, A.C. Humans represent the precision and utility of information acquired across fixations. Sci Rep 12, 2411 (2022). https://doi.org/10.1038/s41598-022-06357-7 For results of the supplementary online experiment for this paper, as well as analysis of the images in the Amsterdam Library of Object Images (ALOI) dataset, please see the separate dataset: https://doi.org/10.5281/zenodo.6068096 This dataset also contrains a copy of the ALOI images used in the experiment, originally sourced from https://aloi.science.uva.nl/

    Music Listening and Stress in Daily Life—a Matter of Timing

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    Purpose: Despite increasing evidence suggesting that music listening in daily life has stress-reducing effects, studies mostly rely on subjective, retrospective data on music listening. Thus, the temporal dynamics underlying the stress-reducing effect of music listening remain unclear. Therefore, we aimed to examine the temporal dynamics of the associations between stress and music listening by assessing subjective and objective data on music in daily life. Design: An exploratory Ambulatory Assessment study examining a total of 60 participants (37 women), aged 18 to 34 years (M = 22.4 years, SD = 3.5) was conducted. Methods: For 1 week, participants answered questions on music listening and stress six times per day via an electronic diary device, which additionally objectively sampled the exact time point of music listening and its duration. Results: Self-reports on mere music listening were associated with lower stress reports, whereas objectively assessed data was not. However, concerning duration of music listening, both subjective and objective data on music listening showed associations between a minimum of 20 min of music listening and lower stress reports. Concerning the latency, objective data on music listening revealed that the association between stress reports and music listening occurs in a time-delayed manner. Conclusions: Although the study design does not allow for causal inferences, substantial associations among subjectively and objectively assessed data on music listening were found to differentially affect the experience of stress after music listening. In particular, when focusing on the temporal dynamics, objectively assessed data allowed for a more fine-grained analysis. In consequence, subjectively and objectively reported data on music listening should be assessed jointly when investigating effects of music listening on health. Experimental research with rigorous methodological control is required in order to corroborate our findings in a laboratory setting.© The Author(s) 201
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