Aim of research: to describe TV viewing trajectories from age 5 to 40 months

As virtual experiences are rapidly substituting a significant proportion of in-person interactions during the COVID pandemic, it is critical to monitor the effect of screen exposure time on developing children’s behavior and nervous system. Screen use boosts information accessibility and, therefore, may delay the development of the inhibitory control networks in children, who are vulnerable to immediate reward-orientated tendencies and not yet capable of controlling their impulsivity. Therefore, it was hypothesized that as children become more exposed to screens, the development of the inhibitory control network would be delayed and their reward sensitivity will be augmented. Using the ABCD Study Data Repository, 8,334 children’s behavioral and neural data (aged 9-11) were included. Robust mediation analysis and correlation analysis were used to investigate how Screen Time interacts with children’s reward-orientated tendency (e.g. Behavioral approach system, BAS) and the brain's inhibitory network. Intrinsic Frontoparietal Network-Striatum (FPN-Striatum) connectivity strength was used as neural indices of the inhibitory control quality in children. Results showed that Screen Time significantly mediated the relationship between BAS and both waves of the intrinsic inhibitory process. A higher BAS was linked to a longer Screen Time and weaker inhibitory network connectivity. This complete/full mediation model indicates that Screen Time negatively influenced the strength of FPN-Striatum connectivity. In conclusion, the study revealed specific behavioral and neural correlates of screen exposure using a large database, and suggested that increasing screen exposure time may impair the inhibitory capability and increase impulsivity in children. / M.S. / The current study explored the effect of daily screen exposure in pre-adolescent children to provide an important springboard for future work in protecting developing children against the negative impacts of screen use, which has increased significantly during the COVID-19 pandemic. Over 8,000 children’s data from the Adolescent Brain Cognitive Development (ABCD) project was included and found that an increased daily screen exposure time is linked to an inefficient inhibitory control system in the brain. As children’s inhibitory control systems are still developing, this negative effect further hinder the maturation of inhibitory-control systems two years later. Given that the virtual movement is irreversible, the results provide scientific evidence that a balance between screen time and non-screen activities is required for developing children.

Abstract Background: Prevalence of sleep disturbances, latency, and limited sleeping duration are highest during the adolescence phase. The possible cause is adoption of sedentary behavior that involves excessive screen time due to exposure to digital and electronic devices among adolescents. When the sleep quality is compromised it contributes to adverse health outcomes. Aim: The aim of this thesis is to explore the relationship between screen time and sleep quality among adolescents in Nordic countries Methods: The systematic literature review approach was considered in this research and a narrative synthesis was performed to determine whether there was a connection between screen time and sleep quality through the assessment of qualitative (n=4), quantitative (n=14), cross- sectional (n=9), and cohort (n=1) studies. A sample size of 28 articles was considered after the articles fulfilled the inclusion criterion standards. The population of the study comprised adolescents within the age bracket of 10 and 20 years in primary, high school, and university. The sleep quality outcomes that were measured include duration, latency, efficiency, and disturbances. Besides, the screen time outcomes that were measures are timing, type, and duration. Results: There is a significant association between sleep timing including daytime and nighttime use of digital and electronic devices with the sleep quality outcomes. Also, there is a positive relationship between duration of screen time and sleep quality outcomes among adolescents in Nordic countries. However, there was an insignificant relationship between type of digital devices either smartphone, tablet, computer, or television with the sleep quality outcomes of adolescents. 2Conclusions: The research outcomes showed that high screen time in regards to timing such as daytime and nighttime contributes to low quality sleep outcomes among adolescents in Nordic countries, but the type of devices is not important. There was significant evidence on prolonged screen time duration and low sleep quality. Insignificant relationships were found between the type of screen and screen time with sleep quality. Future researchers need to take a specific approach in regards to the topic by focusing on effects of high screen time on the sleep quality of adolescents. These findings might have positive implications in the public health context in consideration of increased digital devices across Nordic countries and the increased prevalence on low quality sleep among adolescents that is likely to increase their health risks. Keywords: Adolescents, screen time, sleep quality, Nordic region, Behavior, Health. / <p>This thesis uses a comprehensive literature review of 28 studies to investigate how screen time affects the quality of sleep that teenagers in Nordic countries get. Teenagers who use digital devices more often tend to have higher screen times, which contributes to their frequent sleep disruptions and poorer quality of sleep. In order to measure sleep length, latency, efficiency, and disruptions in connection to the timing, type, and duration of screen time, the study analysed qualitative, quantitative, cross-sectional, and cohort studies concentrating on teenagers aged 10 to 20. The results suggest that while the type of device used had no discernible effect, there are substantial connections between screen time—both during the day and at night—and poor sleep quality. These findings highlight the necessity for additional study on the relationship between screen time length and teenage sleep, which has significant ramifications for public health.</p>

Selon la théorie de Jacobs (1988), l’expérience de dissociation est spécifique aux gens présentant une dépendance. D’autres auteurs, dont Bernstein et Putnam (1986), prétendent que la dissociation peut survenir dans la population normale. Le but de la individu pratique une activité qui le passionne. Pour ce faire, la dissociation est mesurée chez les trois groupes de personnes s’adonnant aux jeux de hasard et d’argent (N = 22), au cyclisme (N = 21) et à l’escalade (N = 20). Les participants reçoivent des questionnaires par la poste avec une enveloppe pré-affranchie. Par la suite, ils retournent cette enveloppe au chercheur. La Dissociative Expériences Scale (Bemstein & Putnam, 1986), adaptée pour la présente étude, a été utilisée pour mesurer la dissociation. Les résultats révèlent que les trois groupes ont rapporté de la dissociation. Le groupe de joueurs a obtenu des scores moyens de dissociation inférieurs à ceux des sportifs. Le concept du « flow » de Csikszentmihalyi (1975) permet certaines interprétations des résultats inattendus. Ces résultats suggèrent qu’il est possible de faire l’expérience de la dissociation lors de la pratique d’une activité qui nous passionne, et que cet état n’est pas spécifique aux gens qui éprouvent des problèmes de dépendances.

Submitted in partial compliance with the requirements for the Master’s Degree in Technology: Chiropractic,Durban University of Technology, 2014. / Background The Functional Movement Screen (FMSTM) is a pre-participation screen consisting of seven tests that rate a player’s functional movement. The screen may be used as an indicator for injury susceptibility in sports people. This may be implemented for preventative measures and improving or sustaining performance in sport. Objectives This research aimed to identify normative values on the FMSTM for female premier league hockey players and assess the association between FMSTM scores and incidence of seasonal injuries. Secondary to this, the research also undertook to assess dependence of the FMSTM on other risk factors identified in the study such as age, number of years playing hockey, height, weight, BMI and position. These risk measures were also tested for association to injury susceptibility. Method The research evaluated the FMSTM score in female premier league hockey players in KwaZulu-Natal prior to the commencement of the competitive season and then tracked the incidence, frequency and distribution of injuries that were sustained during the season. All nine teams in the KwaZulu-Natal female premier hockey league were approached and the players voluntarily participated provided that they fitted the inclusion criteria. In total 74 players between the ages of 18 and 35 were assessed. SPSS version 20 was used in the data analysis to test for statistical significance of the results. Results and conclusions The research sample revealed a mean FMSTM score of 14.39 with a standard deviation of 2.4. The difference in average FMSTM score between the 18 players who sustained non-contact injuries during the course of the season and the 56 players who did not was shown to not be statistically significant at a 95% confidence level. Therefore, this research shows that no association can be made between a low score on the Functional Movement ScreenTM and injury susceptibility. The FMSTM score was shown to be an independent metric when compared to the other injury risk measures identified in the study and the other risk measures were also found to not reliably indicate injury susceptibility. Having said this, the association of weight, FMSTM and BMI with injury susceptibility warrants further investigation as these measures indicated a degree of association. / M

Cervical cancer is an emerging public health problem in developing countries. Globally, it is the 3rd most common malignancy in women after breast and colorectal cancers and 4th most frequent cancer in women, with an estimated 570,000 new cases and 311,000 deaths in 2018. Cervical cancer screening in the developed countries is credited with the reductions in cervical cancer morbidity and mortality during the last 50 years. However, nearly 90% of cervical cancer deaths occur in less developed countries. Ghana has a cervical cancer rate of 26.4%. Further, it is the highest cancer incidence faced among women 25 to 44 years and has a mortality rate of 17.4% in this age group. Knowledge, culture, attitude, and beliefs are known to limit women's participation in Pap test screening programs. Guided by the health belief model, the purpose of this quantitative study was to examine how knowledge, attitude, culture, and religious beliefs affected intent to seek Pap test screening among adolescent girls in Accra, Ghana. A total of 155 participants ages 16 to 20 years completed a 30-item questionnaire. Descriptive frequencies were calculated. Correlation and Chi-square tests were also performed to assess associations with intent to screen with Pap test. Most girls (92%) had never heard about Pap test screening. There were statistically significant correlations between cervical cancer knowledge (p=0.032) and attitude (p=0.001) with intent to participate in Pap test screening. However, culture (p=0.049) and religious beliefs (p=0.529) were not significantly associated with screening intent. The implications for social change include informing practice and research on how cervical cancer prevention programs can be tailored to girls living in countries where different cultural and religious values are practiced.

Die vorliegende Arbeit befasst sich mit der Herstellung von porösen Membranen mit integrierter Stützstruktur, wobei ihre Membrandicke geringer als ihr Porendurchmesser ist. Derartige Membranen können unter dem Begriff Mikrosiebe zusammengefasst werden und versprechen ein hohes Anwendungspotential als Filtermedien in industriellen und medizinischen Bereichen. Für die Membranstabilisierung werden Gewebe, extrudierte Gitter und Gewirke eingesetzt und erforscht. Gleichzeitig erfolgt die Weiterentwicklung eines bestehenden Herstellungsverfahrens von Membranen, welche nach dem Prinzip der partikelassistierten Benetzung (PAB) hergestellt werden. Die verschiedenen Stützstrukturen werden direkt bei der Membranherstellung fest in diese integriert. Weiterhin werden verschiedene Herstellungsparameter, wie zum Beispiel das Membranmaterial, die Funktionalisierung der Porenbildner und die leichtflüchtige Komponente gezielt untersucht und optimiert. Somit können mechanisch stabilisierte Membranen hergestellt werden, welche einen Durchmesser von bis zu 10 cm aufweisen. Für die abschließende Charakterisierung werden Filtrationsversuche und Stabilitätsmessungen durchgeführt.

Elektrische Maschinen werden heutzutage auf mannigfaltigen Gebieten eingesetzt. Sie verrichten ihre Aufgaben in leistungsstarken Industrieantrieben für Erzmühlen oder Stahlwalzen, als Synchrongeneratoren zur Elektroenergieerzeugung, in Fertigungsanlagen wie Backstraßen oder Fließbänder oder auch im Verkehr, in Zügen oder verstärkt nun auch in Automobilen. Sie erleichtern uns aber auch den Alltag an Stellen, wo sie oft gar nicht wahrgenommen werden. Sie ermöglichen nützliche Helferlein im Auto mithilfe von Servomotoren – Scheibenwischer, Fensterheber oder Seitenspiegelverstellung sind nur ausgewählte Beispiele. Aber auch Fensterrollläden, Klimaanlagen oder Fahrstühle benötigen elektrische Antriebe. Darüber hinaus verstecken sich sie sich als Klein- und Kleinstmaschinen in medizinischen Geräten wie dem Zahnarztbohrer oder in Pflegeprodukten des täglichen Bedarfs von der Haarschneidemaschine, über den Nasenhaartrimmer und Föhn bis hin zur elektrischen Zahnbürste. Da Elektromotoren also in immer mehr Geräten stecken, müssen auch immer größere Stückzahlen gefertigt werden, die am besten nichts kosten. Es besteht somit die große Herausforderung all die Bedürfnisse ressourcenschonend und kostengünstig zu bedienen. Aus diesem Gedanken heraus entstand am Lehrstuhl die Idee, Wicklungen elektrischer Kleinmaschinen zu drucken. Dies geschieht mithilfe der Siebdrucktechnik, wie es schon heute bei RFID-Chips die Regel ist. Es handelt sich also um ein erprobtes Verfahren, das eine günstige Fertigung großer Stückzahlen erlaubt. Erste Erfahrungen wurden bereits gesammelt, hier sei auf [10], [11] und [12] verwiesen. Im Rahmen dieser Diplomarbeit sollen diese Grundlagen nun ausgebaut, gefestigt, sowie erweitert werden. Um einen Eindruck und Überblick zu gewinnen, wird im Folgenden eine Reihe elektrischer Kleinmaschinen entworfen. Hierbei sollen Probleme ausfindig gemacht, Lösungen eruiert und Abweichungen zum konventionellen Entwurf aufgezeigt werden. Im Rahmen dessen werden Berechnungsvorschriften für siebgedruckte Wicklungen abgeleitet und diese schließlich zur Berechnung einer Maschinenreihe mit verschiedenen Außendurchmessern und Längen genutzt. Am Ende der Arbeit sollen ausgewählte Motoren aus der berechneten Reihe stehen, an denen Messungen stattfinden um die verwendeten Algorithmen zu verifizieren.

Developmental biology adresses how cells are organised into functional structures and eventually into a whole organism. It is crucial to understand the molecular basis for processes in development, by studying the expression and function of relevant genes and their relationship to each other. A gene function can be studied be creating loss-of-function situations, in which the change in developmental processes is examined in the absense of a functional gene product, or in gain-of-function studies, where a gene product is either intrinsically overproduced or ectopically upregulated. One approach for a loss-of-function situation is the creation of specific mutants in single genes, and the zebrafish (Danio rerio) has proven to be an excellent model organism for this purpose. In this thesis, I report on two forward genetic screens performed to find new mutants affecting brain development, in particular mutants defective in development and function of the midbrain-hindbrain boundary (MHB), an organiser region that patterns the adjacent brain regions of the midbrain and the hindbrain. In the first screen, I could identify 10 specific mutants based on morphology and the analysis of the expression patterns of lim1 and fgf8, genes functioning as early neuronal markers and as a patterning gene, respectively. Three of these mutants lacked an MHB, and by complementation studies, I identified these mutants as being defective in the spg locus. The second screen produced 35 new mutants by screening morphologically and with antibodies against acetylated Tubulin, which marks all axonal scaffolds, and anti-Opsin, which is a marker for photoreceptors in the pineal gland. According to their phenotype, I distributed the mutant lines into 4 phenotypic subgroups, of which the brain morphology group with 18 mutant lines was studied most intensively. In the last part of my thesis, I characterise one of these brain morphology mutants, broken heart. This mutant is defective in axonal outgrowth and locomotion, and shows a striking reduction of serotonergic neurons in the epiphysis and in the raphe nuclei in the hindbrain, structures involved in serotonin and melatonin production. Studies in other model organisms suggested a role of factors from the floor plate and the MHB in induction of the serotonergic neurons in the hindbrain, and using broken heart, I show that Fgf molecules such as Fgf4 and Fgf8 can restore partially the loss of serotonergic neurons in the mutant. I conclude that forward genetic screens are an invaluable tool to generate a pool of mutations in specific genes, which can be used to dissect complex processes in development such as brain development.

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