Twin Analyses of Fatigue

Abstract Prolonged fatigue equal to or greater than 1 month duration and chronic fatigue equal to or greater than 6 months duration are both commonly seen in clinical practice, yet little is known about the etiology or epidemiology of either symptom. Chronic fatigue syndrome (CFS), while rarer, presents similar challenges in determining cause and epidemiology. Twin studies can be useful in elucidating genetic and environmental influences on fatigue and CFS. The goal of this article was to use biometrical structural equation twin modeling to examine genetic and environmental influences on fatigue, and to investigate whether these influences varied by gender. A total of 1042 monozygotic (MZ) twin pairs and 828 dizygotic (DZ) twin pairs who had completed the University of Washington Twin Registry survey were assessed for three fatigue-related variables: prolonged fatigue, chronic fatigue, and CFS. Structural equation twin modeling was used to determine the relative contributions of additive genetic effects, shared environmental effects, and individual-specific environmental effects to the 3 fatigue conditions. In women, tetrachoric correlations were similar for MZ and DZ pairs for prolonged and chronic fatigue, but not for CFS. In men, however, the correlations for prolonged and chronic fatigue were higher in MZ pairs than in DZ pairs. About half the variance for both prolonged and chronic fatigue in males was due to genetic effects, and half due to individual-specific environmental effects. For females, most variance was due to individual environmental effects

Feeling Bad in More Ways than One: Comorbidity Patterns of Medically Unexplained and Psychiatric Conditions

Considerable overlap in symptoms and disease comorbidity has been noted among medically unexplained and psychiatric conditions seen in the primary care setting, such as chronic fatigue syndrome, low back pain, irritable bowel syndrome, chronic tension headache, fibromyalgia, temporomandibular joint disorder, major depression, panic attacks, and posttraumatic stress disorder

Regional brain response to visual food cues is a marker of satiety that predicts food choice

ABSTRACT Background: Neuronal processes that underlie the subjective experience of satiety after a meal are not well defined. Objective: We investigated how satiety alters the perception of and neural response to visual food cues. Design: Normal-weight participants (10 men, 13 women) underwent 2 fMRI scans while viewing images of high-calorie food that was previously rated as incompatible with weight loss and "fattening" and low-calorie, "nonfattening" food. After a fasting fMRI scan, participants ate a standardized breakfast and underwent reimaging at a randomly assigned time 15-300 min after breakfast to vary the degree of satiety. Measures of subjective appetite, food appeal, and ad libitum food intake (measured after the second fMRI scan) were correlated with activation by "fattening" (compared with "nonfattening") food cues in a priori regions of interest. Results: Greater hunger correlated with higher appeal ratings of "fattening" (r = 0.46, P = 0.03) but not "nonfattening" (r = 20.20, P = 0.37) foods. Fasting amygdalar activation was negatively associated with fullness (left: r = 20.52; right: r = 20.58; both P # 0.01), whereas postbreakfast fullness was positively correlated with activation in the dorsal striatum (right: r = 0.44; left: r = 0.45; both P , 0.05). After breakfast, participants with greater activation in 4 regions-medial orbital frontal cortex (r = 0.49, P , 0.05), left amygdala (r = 0.49, P , 0.05), left insula (r = 0.47, P , 0.05), and nucleus accumbens (right: r = 0.57, P , 0.01; left: r = 0.43, P , 0.05)-chose buffet foods with higher fat content. Conclusions: Postmeal satiety is shown in regional brain activation by images of high-calorie foods. Regions including the amygdala, nucleus accumbens, and dorsal striatum may alter perception of, and reduce motivation to consume, energy-rich foods, ultimately driving food choice. This trial was registered at clinicaltrials.gov as NCT01631045. Am J Clin Nutr 2012;96:989-99

Factors Affecting European Farmers’Participation in Biodiversity Policies

This article reports the major findings from an interdisciplinary research project that synthesises key insights into farmers’ willingness and ability to co-operate with biodiversity policies. The results of the study are based on an assessment of about 160 publications and research reports from six EU member states and from international comparative research.We developed a conceptual framework to systematically review the existent literature relevant for our purposes. This framework provides a common structure for analysing farmers’ perspectives regarding the introduction into farming practices of measures relevant to biodiversity. The analysis is coupled and contrasted with a survey of experts. The results presented above suggest that it is important to view support for practices oriented towards biodiversity protection not in a static sense – as a situation determined by one or several influencing factors – but rather as a process marked by interaction. Financial compensation and incentives function as a necessary, though clearly not sufficient condition in this process

A virtual power plant demonstration platform for multiple optimization and control systems

The demonstration project Virtual Power Plant Neckar-Alb is constructing a Virtual Power Plant (VPP) demonstration site at the Reutlingen University campus. The VPP demonstrator integrates a heterogeneous set of distributed energy resources (DERs) which are connected to control the infrastructure and an energy management system. This paper describes the components and the architecture of the demonstrator and presents strategies for demonstration of multiple optimization and control systems with different control paradigms

Age at dieting onset, body mass index, and dieting practices. A twin study

•Nine-hundred and fifty adult female twins retrospectively reported age at first weight loss attempt.•Outcomes were self-reported adult BMI and dieting behaviors.•Early dieting was associated with higher adult BMI and more risky dieting behaviors.•These associations were not present in within-pair analyses.•Genetic/familial factors influence associations of early dieting with poor outcomes. Objective: Using a twin study design, we sought to determine whether an early age at dieting onset is a risk factor for higher adult body mass index (BMI) or use of risky dieting practices, independent of genetic and familial factors. Method: Female twins ages 18–60years (N=950) from the University of Washington Twin Registry completed 2 surveys an average of 3years apart. Analyses of individual twins and within-twin pairs tested associations of self-reported age at dieting onset with (1) adult BMI at baseline, (2) change in BMI between the two surveys and (3) risky dieting behaviors at baseline. Results: In analyses mimicking studies of unrelated individuals, an earlier age at dieting onset was associated with greater adult BMI (p=0.003), higher Restraint Scale scores (p<0.001), greater use of risky dieting behaviors (p=0.04) and more weight cycling episodes (p<0.001). In within-pair models that control for genetic and familial factors, the only significant association was between an earlier age at dieting onset and more weight cycling episodes (p=0.006). Discussion: Underlying genetic and familial factors may influence associations of early dieting with higher adult BMIs and risky dieting practices in women

Strategies to Understand the Weight‐Reduced State: Genetics and Brain Imaging

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/167080/1/oby23101.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/167080/2/oby23101_am.pd

The demonstration project Virtual Power Plant Neckar-Alb

Dezentrale Stromerzeugungsanlagen, Energiespeicher und Steuerungseinrichtungen für Erzeuger und Verbraucher sind die Grundbausteine eines virtuellen Kraftwerks, welches im Stromnetz der Zukunft, dem Smart Grid, eine wichtige Rolle spielt. Im Rahmen des Demonstrationsprojekts Virtuelles Kraftwerk Neckar-Alb soll an der Hochschule Reutlingen eine Demonstrationsanlage aufgebaut werden, die diese Grundbausteine vernetzt und funktional integriert. Damit entsteht eine flexible Testumgebung für Forschung und Lehre, in der sich das Zusammenspiel der Komponenten untersuchen lässt. Zudem wird eine Besichtigungsmöglichkeit für interessierte Unternehmen geschaffen. Damit sollen Akzeptanz und Verständnis für die Thematik gefördert werden.Distributed power generation, energy storage and control systems für producers and consumers of electrical energy are the building blocks of a virtual power plant (VPP) which is a central component of the future smart grid. The Demonstration Project Power Plant Neckar-Alb aims at building a demonstration site connecting and integrating those building blocks at the Reutlingen University campus. The VPP demonstrator provides a flexible environment for research and teaching to investigate interactions between the components. Additionally, the demonstrator's premises will be open to interested companies to increase acceptance for and improving understanding of VPP technology

Genetic and environmental influences on posttraumatic stress disorder symptoms and disinhibited eating behaviors.

Posttraumatic stress disorder (PTSD) and eating disorders (ED) frequently co-occur, but the mechanisms underlying this association remain unclear. EDs are characterized by features of maladaptive eating behaviors including disinhibited eating and cognitive dietary restraint. Identifying the genetic overlap between PTSD symptoms and maladaptive eating behaviors may elucidate biological mechanisms and potential treatment targets. A community sample of 400 same-sex twins (102 monozygotic and 98 dizygotic pairs) completed the PTSD Checklist-Civilian (PCL-C) for PTSD symptoms and the Three-Factor Eating Questionnaire-Reduced (TFEQ-R18) for eating behaviors (uncontrolled eating, emotional eating, and cognitive dietary restraint). We used biometric modeling to examine the genetic and environmental relationships between PCL-C and TFEQ-R18 total and subscales scores. Heritability was estimated at 48% for PTSD symptoms and 45% for eating behavior overall. Bivariate models revealed a significant genetic correlation between PTSD symptoms and eating behavior overall (rg&nbsp;=.34; CI:.07,.58) and Uncontrolled Eating (rg&nbsp;=.53; CI:.24,.84), and a significant environmental correlation between PTSD symptoms and Emotional Eating (re&nbsp;=.30; CI:.12,.45). These findings suggest the influence of common etiology. Future research and clinical efforts should focus on developing integrated treatments