Die Bedeutung von experimentellem Paradigma und interindividuellen Unterschieden für die Interpretation von funktionellen MRT-Ergebnissen

Diese kumulative Dissertation umfasst drei Studien, die Einflüsse von experimentellem Paradigma und interindividuellen Unterschieden auf die Interpretation des resultierenden fMRT-Signals untersuchen. In der ersten Studie verglichen Kollegen und ich verschiedene, in fMRT-Studien eingesetzte, Paradigmen hinsichtlich ihrer Robustheit, ein bestimmtes Kriterium (Rechtslateralisation) zu erfüllen. Das robusteste Paradigma prüften wir weiterhin auf seine Test-Retest-Reliabilität. Die Untersuchungen verdeutlichen, dass sich gängige Paradigmen in der Erfüllung oftmals vorausgesetzter, aber nicht geprüfter, Kriterien (wie z.B. die Rekrutierung rechtslateralisierter Prozesse) unterscheiden. Außerdem kann sich die Reliabilität eines Paradigmas in Abhängigkeit von der jeweiligen Testgröße (z.B. ein einzelner Voxelwert vs. ein zusammengefasstes Maß wie der Lateralisationsindex) grundlegend ändern, was dazu führt, dass der Einsatz eines Paradigmas nur für getestete, umschriebene Zwecke empfohlen werden kann. In der zweiten Studie betrachteten Kollegen und ich neurale Aktivierungsmuster (im Rahmen von Pareidolie), anders als übliche fMRT-Untersuchungen, auf individueller Ebene. Dabei stellten sich die Unterschiede zwischen Probanden extremer dar als unter Annahme der Gauß‘schen Normalverteilung zu erwarten gewesen wäre. Bedeutende interindividuelle Unterschiede können im Rahmen von fMRT-Studien leicht unerkannt bleiben, da die Berichterstattung von Ergebnissen in der Regel lediglich auf der Basis von Gruppenstatistiken erfolgt. Gleichzeitig können diese Unterschiede die Interpretation der Studienergebnisse jedoch maßgeblich beeinflussen. In diesem Zusammenhang, sowie auch im Bezug auf die dritte Studie dieser Dissertation, diskutiere ich sowohl verschiedene Arten von interindividuellen Unterschieden als auch bestimmte Rahmenbedingungen, unter denen eine Berücksichtigung interindividueller Unterschiede in neuralen Prozessen von besonderer Bedeutung ist. In der dritten und aufwendigsten Studie dieser Dissertation beschäftigten Kollegen und ich uns mit den Einflüssen von in der fMRT besonders häufig vernachlässigten Verhaltensunterschieden: unter Einsatz von komplexem visuellen Stimulusmaterial ermittelten wir Effekte, die im Zusammenhang mit natürlichem Blickverhalten stehen. Zunächst zeigten wir, dass sich das Blickverhalten gesunder Probanden je nach Ausprägung einer bestimmten Persönlichkeitseigenschaft (Alexithymie) unterschied. Wir integrierten das Blickverhalten (in Form von individuellen Fixationszeiten) in unser Modell zur Analyse der fMRT-Daten und fanden – im Gegensatz zu einer vorherigen Studie – keine Unterschiede in den neuralen Prozessen der Probanden, die sich durch die Merkmalsausprägung per se erklären ließen. Es zeigten sich jedoch Unterschiede, die in Verbindung mit dem Blickverhalten der Probanden standen: je länger Probanden mit geringer Merkmalsausprägung bestimmte Stimulusaspekte fixierten, desto stärker stellte sich das neurale Signal in für den Prozess bedeutenden Hirnarealen dar. Bei den Probanden mit extremer Merkmalsausprägung beobachteten wir einen entgegengesetzten Zusammenhang (längere Fixation, abnehmendes Signal). Die Ergebnisse unserer Studie verdeutlichen den Mehrwert einer Berücksichtigung des Blickverhaltens im Rahmen von fMRT-Studien. Demnach ist die Kontrolle des Blickverhaltens einerseits notwendig, um eine Fehlinterpretation der neuralen Unterschiede zu vermeiden, die lediglich daraus resultieren, dass die Probanden auf verschiedene Stimulusaspekte achten. Andererseits können unterschiedliche kognitive Strategien identifiziert werden, die verschiedene Individuen bei der Verarbeitung derselben spezifischen Stimulusaspekte einsetzen. Anhand der beschriebenen drei Studien verdeutlicht meine Dissertation, dass bei fMRT-Studien, insbesondere im Hinblick auf die zum gegenwärtigen Zeitpunkt bestehende Replikationskrise, sowohl die Eignungsprüfung des experimentellen Paradigmas als auch die Berücksichtigung interindividueller Unterschiede erstrebenswert sind. Die Prüfung des Paradigmas kann anhand verschiedener Gütekriterien erfolgen und Empfehlungen sollten unter Beachtung der speziellen Prüfgrößen ausgesprochen werden. Des Weiteren kann eine verstärkte Berücksichtigung der verschiedenen Arten interindividueller Unterschiede perspektivisch zu einer Reduktion nicht aufgeklärter Varianzen führen und somit nicht nur die Replikation von Gruppenergebnissen erleichtern, sondern auch zur Aufklärung individueller neuraler Verarbeitungsmechanismen beitragen

Combined Digital Nudging to Leverage Public Transportation Use

The urgency of global climate change is becoming increasingly evident, but current mobility patterns in developed countries continue to cause severe environmental damage. Therefore, developed countries need to change their mobility patterns fundamentally, such as modal changes to public transportation instead of private car use. Digital nudging in IT-enabled mobility applications is a novel and promising way to influence modal changes to public transportation. In this study, we conduct an online experiment with 183 participants in which they are being nudged toward public transportation trip options. Our results show that combining two different digital nudges significantly affects the choice of public transportation options. By contrast, single nudges do not lead to significant changes in the choice of public transportation trips. With our findings, we contribute to the research stream of digital nudging and the transportation literature and provide insights for practice to address the adverse effects of current mobility patterns

Postponed pregnancies and risks of very advanced maternal age

QUESTIONS UNDER STUDY To evaluate pregnancy outcome in pregnant women aged ≥45 years, termed very advanced maternal age (VAMA). METHODS We retrospectively compared the outcome of pregnancies in VAMA patients with controls aged 30 years at time of delivery. Subgroups of singleton and multiple pregnancies were also analysed. Incidences of maternal and fetal adverse outcomes were measured. Statistical significance was set at p 7 days (37.8% vs 15.1%; OR 3.42) was found. Infant complications such as prematurity (44.9% vs 16.2%; OR 4.2) and low birthweight <5th percentile (11.0% vs 5.6%; OR 2.1) were also increased. CONCLUSION Pregnant women of very advanced maternal age (≥45 years) have significantly increased maternal and fetal risks. Women postponing pregnancy or planning a pregnancy in very advanced age should be informed about these risks, in particular before artificial reproductive technologies are applied or "social freezing"

Pressure study on the interplay between magnetic order and valence-change crossover in EuPd2_2(Si1−x_{1-x}Gex_x)2_2

We present results of the magnetic susceptibility on high-quality single crystals of EuPd$_2$(Si$_{1-x}$Ge$_x$)$_2$ for Ge concentrations 0 $\leq x \leq$ 0.105 performed under varying hydrostatic (He-gas) pressure 0 $\leq p \leq$ 0.5 GPa. The work extends on recent studies at ambient pressure demonstrating the drastic change in the magnetic response from valence-change-crossover behavior for $x$ = 0 and 0.058, to long-range antiferromagnetic (afm) order below $T_{\text{N}}$ = 47 K for $x$ = 0.105. The valence-change-crossover temperature $T'_{\text{V}}$ shows an extraordinarily strong pressure dependence of d$T'_{\text{V}}$/d$p$ = +(80 $\pm$ 10) K/GPa. In contrast, a very small pressure dependence of d$T_{\text{N}}$/d$p \leq$ +(1 $\pm$ 0.5) K/GPa is found for the afm order upon pressurizing the $x$ = 0.105 crystal from $p$ = 0 to 0.05 GPa. Remarkably, by further increasing the pressure to 0.1 GPa, a drastic change in the ground state from afm order to valence-change-crossover behavior is observed. Estimates of the electronic entropy, derived from analyzing susceptibility data at varying pressures, indicate that the boundary between afm order and valence-change crossover represents a first-order phase transition. Our results suggest a particular type of second-order critical endpoint of the first-order transition for $x$ = 0.105 at $p_{\text{cr}} \approx$ 0.06 GPa and $T_{\text{cr}} \approx$ 45 K where intriguing strong-coupling effects between fluctuating charge-, spin- and lattice degrees of freedom can be expected

Mapping established psychopathology scales onto the Hierarchical Taxonomy of Psychopathology (HiTOP)

The Hierarchical Taxonomy of Psychopathology (HiTOP) organizes phenotypes of mental disorder based on empirical covariation, offering a comprehensive organizational framework from narrow symptoms to broader patterns of psychopathology. We argue that established self-report measures of psychopathology from the pre-HiTOP era should be systematically integrated into HiTOP to foster cumulative research and further the understanding of psychopathology structure. Hence, in this study, we mapped 92 established psychopathology (sub)scales onto the current HiTOP working model using data from an extensive battery of self-report assessments that was completed by community participants and outpatients (N = 909). Content validity ratings of the item pool were used to select indicators for a bifactor-(S-1) model of the p factor and five HiTOP spectra (i.e., internalizing, thought disorder, detachment, disinhibited externalizing, and antagonistic externalizing). The content-based HiTOP scales were validated against personality disorder diagnoses as assessed by standardized interviews. We then located established scales within the taxonomy by estimating the extent to which scales reflected higher-level HiTOP dimensions. The analyses shed light on the location of established psychopathology scales in HiTOP, identifying pure markers and blends of HiTOP spectra, as well as pure markers of the p factor (i.e., scales assessing mentalizing impairment and suspiciousness/epistemic mistrust)

Influences of the Common FTO rs9939609 Variant on Inflammatory Markers Throughout a Broad Range of Body Mass Index

A recent study reported that the fatness associated A-allele of FTO rs9939609 increased plasma high sensitivity C-reactive protein (hs-CRP) levels independent of fatness. We aimed to investigate if this gene variant had fatness-independent effects on plasma hs-CRP and 10 additional circulating obesity-related adipokines throughout a broad range of body mass index (BMI) among Danish men.In a population of 362,200 young men, examined for military service between 1943 and 1977, two groups were identified: 1) a random 1% sample and 2) all obese men (BMI = 31.0 kg/m(2), all of whom were above the 99(th) percentile of this population). At an average age of 49 years (range: 39 through 65 years), 551 men, hereof 231 of the obese, were re-examined, including genotyping and measurement of the fasting circulating inflammatory markers hs-CRP, IL-1β, IL-6, IL-10, IL-18, mip1α, mip1β, sTNFα-R1, TGF-β, TNF-α and leptin. Men with known disease were excluded from the examination. All the inflammatory markers were log-transformed to approximate a normal distribution. Genotype-phenotype relationships were studied using linear regression analyses with the inflammatory markers as the response variable. Significant positive associations between hs-CRP, leptin and a broad range of BMI were observed, but the associations did not significantly differ across FTO rs9939609 genotype. There were no significant associations between the other inflammatory markers, FTO rs9939609 genotype or BMI, respectively.No fatness-independent effects of the FTO rs9939609 A-allele on a series of inflammatory markers were observed in this cohort of healthy middle-aged men representing a broad range of fatness

In Vivo Identification of Novel Regulators and Conserved Pathways of Phagocytosis in A. gambiae

SummaryAnopheles gambiae uses effective immune responses, including phagocytosis, to fight microbial infection. We have developed a semiquantitative phagocytosis test and used it in conjunction with dsRNA gene silencing to test the in vivo roles of 71 candidate genes in phagocytosis of Escherichia coli and Staphylococcus aureus. Here, we show that inactivation of 26 genes changes the phagocytic activity by more than 45% and that two pathways similar to those that mediate apoptotic cell removal in Caenorhabditis elegans are used in A. gambiae for phagocytosis of microorganisms. Simultaneous inactivation of the identified regulators of phagocytosis and conserved components defining each signaling pathway permitted provisional assignment of the novel regulators to one or the other pathway. Pathway inactivation enhances at least three times the ability of E. coli and S. aureus to proliferate in the mosquito. Interestingly, mosquito survival is not compromised even if both pathways are perturbed simultaneously

Einfluss der Fellbach-Wasserfälle auf das Fliessverhalten von Murgängen und auf mögliche Schutzmassnahmen

Aufsatz veröffentlicht in: "Wasserbau-Symposium 2021: Wasserbau in Zeiten von Energiewende, Gewässerschutz und Klimawandel, Zurich, Switzerland, September 15-17, 2021, Band 1" veröffentlicht unter: https://doi.org/10.3929/ethz-b-00049975

Heart rate sensor validation and seasonal and diurnal variation of body temperature and heart rate in domestic sheep

Advantages of low input livestock production on large pastures, including animal welfare, biodiversity and low production costs are challenged by losses due to undetected disease, accidents and predation. Precision livestock farming (PLF) enables remote monitoring on individual level with potential for predictive warning. Body temperature (Tb) and heart rate (HR) could be used for early detection of diseases, stress or death. We tested physiological sensors in free-grazing Norwegian white sheep in Norway. Forty Tb sensors and thirty HR sensors were surgically implanted in 40 lambs and 10 ewes. Eight (27%) of the HR and eight (20%) of the Tb sensors were lost during the study period. Two Tb sensors migrated from the abdominal cavity in to the digestive system. ECG based validation of the HR sensors revealed a measurement error of 0.2 bpm (SD 5.2 bpm) and correct measurement quality was assigned in 90% of the measurements. Maximum and minimum HR confirmed by ECG was 197 bpm and 68 bpm respectively. Mean passive HR was 90 bpm (SD=13 bpm) for ewes and 112 bpm (SD=13 bpm) for lambs. Mean Tb for all animals was 39.6°C (range 36.9 to 41.8°C). Tb displayed 24-hour circadian rhythms during 80.7 % but HR only during 41.0 % of the studied period. We established baseline values and conclude that these sensors deliver good quality. For a wide agricultural use, the sensor implantation method has to be further developed and real-time communication technology added

Heart Rate Logging In Free-Ranging Mammals

Sensors that measure heart rate and temeperature have been tested and validated on sheep on free ranging in Norwa