Relative intensity noise in the LISA Pathfinder interferometer - experiments on ground and in space

LISA Pathfinder war eine Satellitenmission der ESA mit dem Ziel der Demonstration der Messgenauigkeit der lokalen Messung der Position und Orientierung einer Testmasse, zur Vorbereitung auf den Gravitationswellendetektor LISA. LISA Pathfinder enthält vier Heterodyninterferometer, mit der gemessenen Phase können Positionsänderungen der Testmasse errechnet werden, um die wirkenden Kräfte zu untersuchen. In dieser Arbeit wird die Kopplung von Rauschen in der relativen Laserintensität zur Phasenmessung untersucht. Dazu werden Daten die während der aktiven Zeit des LPF Satelliten gemessen wurden verwendet, diese werden durch Daten von Experimenten von einem ähnlichen Aufbau im Labor ergänzt.LISA Pathfinder was a satellite mission of the European Space Agency with the aim to demonstrate the Precision of the local measurement of the position and orientation of a test mass, in preparation of the gravitational wave detector LISA. LISA Pathfinder consists of four heterodyne interferometers, with the measured phase signals changes in the position of the test mass can be calculated. This data is then used to investigate the forces acting on the test mass. In this thesis the coupling of relative intensity noise to the measured phase is investigated. Used is data measured during the operation of the LPF satellite, for further investigation data measured in a similar system on a ground based laboratory is used

Noise Investigation on the LISA-Pathfinder Optical Bench Ground Setup

The subject of this thesis is noise investigations on the LISA Pathfinder OMS ground setup. LISA Pathfinder (LPF) is a planned ESA technology demonstration space- mission, the LPF spacecraft features an optical measurement system similar to the LISA mission. LISA is a planned triangular laser telescope with a million kilometres arm length on an orbit around the sun. Distance fluctuations between two free falling test masses per arm are measured with heterodyne interferometry. The LPF flight model features two test masses about 0.38m apart. Test mass motion on earth is realised with piezoelectric actuators. During this thesis the noise dependence on different test mass positions was investigated. The test masses of the flight model (FM) are placed in a housing in the spacecraft, the implications of which on the interferometer performance were simulated with a housing mockup

Changes in the prevalence, treatment and control of hypertension in Germany? : a clinical-epidemiological study of 50.000 primary care patients

INTRODUCTION: Medical societies have developed guidelines for the detection, treatment and control of hypertension (HTN). Our analysis assessed the extent to which such guidelines were implemented in Germany in 2003 and 2001. METHODS: Using standardized clinical diagnostic and treatment appraisal forms, blood pressure levels and patient questionnaires for 55,518 participants from the cross-sectional Targets and Essential Data for Commitment of Treatment (DETECT) study (2003) were analyzed. Physician's diagnosis of hypertension (HTN(doc)) was defined as coding hypertension in the clinical appraisal questionnaire. Alternative definitions used were physician's diagnosis or the patient's self-reported diagnosis of hypertension (HTN(doc,pat)), physician's or patient's self-reported diagnosis or a BP measurement with a systolic BP≥140 mmHg and/or a diastolic BP≥90 (HTN(doc,pat,bp)) and diagnosis according to the National Health and Nutrition Examination Survey (HTN(NHANES)). The results were compared with the similar German HYDRA study to examine whether changes had occurred in diagnosis, treatment and adequate blood pressure control (BP below 140/90 mmHg) since 2001. Factors associated with pharmacotherapy and control were determined. RESULTS: The overall prevalence rate for hypertension was 35.5% according to HTN(doc) and 56.0% according to NHANES criteria. Among those defined by NHANES criteria, treatment and control rates were 56.0% and 20.3% in 2003, and these rates had improved from 55.3% and 18.0% in 2001. Significant predictors of receiving antihypertensive medication were: increasing age, female sex, obesity, previous myocardial infarction and the prevalence of comorbid conditions such as coronary heart disease (CHD), hyperlipidemia and diabetes mellitus (DM). Significant positive predictors of adequate blood pressure control were CHD and antihypertensive medication. Inadequate control was associated with increasing age, male sex and obesity. CONCLUSIONS: Rates of treated and controlled hypertension according to NHANES criteria in DETECT remained low between 2001 and 2003, although there was some minor improvement

Physical activity and prevalence and incidence of mental disorders in adolescents and young adults

ABSTRACT Background Although positive effects of physical activity on mental health indicators have been reported, the relationship between physical activity and the development of specific mental disorders is unclear. Method A cross-sectional (12-month) and prospective-longitudinal epidemiological study over 4 years in a community cohort of 2548 individuals, aged 14-24 years at outset of the study. Physical activity and mental disorders were assessed by the DSM-IV Composite International Diagnostic Interview (CIDI) with an embedded physical activity module. Multiple logistic regression analyses controlling for age, gender and educational status were used to determine the cross-sectional and prospective associations of mental disorders and physical activity. Results Cross-sectionally, regular physical activity was associated with a decreased prevalence of any and co-morbid mental disorder, due to lower rates of substance use disorders, anxiety disorders and dysthymia. Prospectively, subjects with regular physical activity had a substantially lower overall incidence of any and co-morbid mental disorder, and also a lower incidence of anxiety, somatoform and dysthymic disorder. By contrast, the incidence of bipolar disorder was increased among those with regular physical activity at baseline. In terms of the population attributable fraction (PAF), the potential for preventive effects of physical activity was considerably higher for men than for women. Conclusions Regular physical activity is associated with a substantially reduced risk for some, but not all, mental disorders and also seems to reduce the degree of co-morbidity. Further examination of the evidently complex mechanisms and pathways underlying these associations might reveal promising new research targets and procedures for targeted preventio

A multimodal neuroimaging classifier for alcohol dependence

With progress in magnetic resonance imaging technology and a broader dissemination of state-of-the-art imaging facilities, the acquisition of multiple neuroimaging modalities is becoming increasingly feasible. One particular hope associated with multimodal neuroimaging is the development of reliable data-driven diagnostic classifiers for psychiatric disorders, yet previous studies have often failed to find a benefit of combining multiple modalities. As a psychiatric disorder with established neurobiological effects at several levels of description, alcohol dependence is particularly well-suited for multimodal classification. To this aim, we developed a multimodal classification scheme and applied it to a rich neuroimaging battery (structural, functional task-based and functional resting-state data) collected in a matched sample of alcohol-dependent patients (N = 119) and controls (N = 97). We found that our classification scheme yielded 79.3% diagnostic accuracy, which outperformed the strongest individual modality - grey-matter density - by 2.7%. We found that this moderate benefit of multimodal classification depended on a number of critical design choices: a procedure to select optimal modality-specific classifiers, a fine-grained ensemble prediction based on cross-modal weight matrices and continuous classifier decision values. We conclude that the combination of multiple neuroimaging modalities is able to moderately improve the accuracy of machine-learning-based diagnostic classification in alcohol dependence

A multimodal neuroimaging classifier for alcohol dependence

With progress in magnetic resonance imaging technology and a broader dissemination of state-of-the-art imaging facilities, the acquisition of multiple neuroimaging modalities is becoming increasingly feasible. One particular hope associated with multimodal neuroimaging is the development of reliable data-driven diagnostic classifiers for psychiatric disorders, yet previous studies have often failed to find a benefit of combining multiple modalities. As a psychiatric disorder with established neurobiological effects at several levels of description, alcohol dependence is particularly well-suited for multimodal classification. To this aim, we developed a multimodal classification scheme and applied it to a rich neuroimaging battery (structural, functional task-based and functional resting-state data) collected in a matched sample of alcohol-dependent patients (N = 119) and controls (N = 97). We found that our classification scheme yielded 79.3% diagnostic accuracy, which outperformed the strongest individual modality - grey-matter density - by 2.7%. We found that this moderate benefit of multimodal classification depended on a number of critical design choices: a procedure to select optimal modality-specific classifiers, a fine-grained ensemble prediction based on cross-modal weight matrices and continuous classifier decision values. We conclude that the combination of multiple neuroimaging modalities is able to moderately improve the accuracy of machine-learning-based diagnostic classification in alcohol dependence

Transcriptome sequencing of the human pathogen Corynebacterium diphtheriae NCTC 13129 provides detailed insights into its transcriptional landscape and into DtxR-mediated transcriptional regulation

Wittchen M, Busche T, Gaspar AH, et al. Transcriptome sequencing of the human pathogen Corynebacterium diphtheriae NCTC 13129 provides detailed insights into its transcriptional landscape and into DtxR-mediated transcriptional regulation. BMC Genomics. 2018;19(1): 82.Background The human pathogen Corynebacterium diphtheriae is the causative agent of diphtheria. In the 1990s a large diphtheria outbreak in Eastern Europe was caused by the strain C. diphtheriae NCTC 13129. Although the genome was sequenced more than a decade ago, not much is known about its transcriptome. Our aim was to use transcriptome sequencing (RNA-Seq) to close this knowledge gap and gain insights into the transcriptional landscape of a C. diphtheriae tox+ strain. Results We applied two different RNA-Seq techniques, one to retrieve 5′-ends of primary transcripts and the other to characterize the whole transcriptional landscape in order to gain insights into various features of the C. diphtheriae NCTC 13129 transcriptome. By examining the data we identified 1656 transcription start sites (TSS), of which 1202 were assigned to genes and 454 to putative novel transcripts. By using the TSS data promoter regions recognized by the housekeeping sigma factor σA and its motifs were analyzed in detail, revealing a well conserved −10 but an only weakly conserved −35 motif, respectively. Furthermore, with the TSS data 5’-UTR lengths were explored. The observed 5’-UTRs range from zero length (leaderless transcripts), which make up 20% of all genes, up to over 450 nt long leaders, which may harbor regulatory functions. The C. diphtheriae transcriptome consists of 471 operons which are further divided into 167 sub-operon structures. In a differential expression analysis approach, we discovered that genetic disruption of the iron-sensing transcription regulator DtxR, which controls expression of diphtheria toxin (DT), causes a strong influence on general gene expression. Nearly 15% of the genome is differentially transcribed, indicating that DtxR might have other regulatory functions in addition to regulation of iron metabolism and DT. Furthermore, our findings shed light on the transcriptional landscape of the DT encoding gene tox and present evidence for two tox antisense RNAs, which point to a new way of transcriptional regulation of toxin production. Conclusions This study presents extensive insights into the transcriptome of C. diphtheriae and provides a basis for future studies regarding gene characterization, transcriptional regulatory networks, and regulation of the tox gene in particular

Stronger Prejudices Are Associated With Decreased Model-Based Control

Background: Prejudices against minorities can be understood as habitually negative evaluations that are kept in spite of evidence to the contrary. Therefore, individuals with strong prejudices might be dominated by habitual or “automatic” reactions at the expense of more controlled reactions. Computational theories suggest individual differences in the balance between habitual/model-free and deliberative/model-based decision-making. Methods: 127 subjects performed the two Step task and completed the blatant and subtle prejudice scale. Results: By using analyses of choices and reaction times in combination with computational modeling, subjects with stronger blatant prejudices showed a shift away from model-based control. There was no association between these decision-making processes and subtle prejudices. Conclusion: These results support the idea that blatant prejudices toward minorities are related to a relative dominance of habitual decision-making. This finding has important implications for developing interventions that target to change prejudices across societies