Fortschreitendes Alter geht häufig mit Leistungsabnahmen in kognitiven Aufgaben einher. Eine steigende Anzahl Studien zeigt, dass regelmäßige körperliche Aktivität negativen Alterseffekten entgegenwirken kann und somit zur Erhaltung kognitiver und zerebraler Funktionen im Alter beiträgt. Die vorliegende Dissertation untersuchte im Rahmen eines Ausdauertrainings die Zusammenhänge zwischen Veränderungen in der körperlichen Fitness und Veränderungen in Gehirn und Verhalten bei älteren Erwachsenen. Studie I zeigt, dass zuvor gefundene Vergrößerungen des Hippocampus auf Änderungen der Mikrostruktur des zugrundeliegenden Gewebes zurückgeführt werden können. Die Probanden, die ihre Fitness am meisten verbesserten, zeigten auch die stärkste Verdichtung des Hippocampusgewebes. Die Verdichtung des Gewebes stand wiederum in positivem Zusammenhang mit der Veränderung im Hippocampusvolumen. Diese Ergebnisse weisen darauf hin, dass Veränderungen im Volumen aus einer Vermehrung der Zellmembranen resultieren und nicht aus der Ausdehnung bereits vorhandener Zellen. In Studie II hingen Veränderungen in der Fitness zusammen mit Veränderungen in der Mikrostruktur eines präfrontalen Traktes der weißen Substanz, nämlich dem Forceps minor. Gleichermaßen hingen die Veränderungen in der Mikrostruktur des Forceps minor mit Veränderungen in einem zusammengesetzten Maß fluider kognitiver Fähigkeiten zusammen. Dieses Ergebnis zeigt, dass Veränderungen in der Mikrostruktur der weißen Substanz möglicherweise zu den positiven Auswirkungen von körperlicher Aktivität auf kognitive Fähigkeiten beitragen. Studie III zeigt, dass Veränderungen der Fitness positiv mit Veränderungen der neuronalen Spezifität korrelieren, welches als indirektes Maß für dopaminerge Neuromodulation angenommen wird. Zusammenfassend erweitern die Ergebnisse dieser Dissertation die Literatur über positive Effekte von körperlicher Aktivität auf Alterungsprozesse und stärken den Kenntnisstand über zugrundeliegende Mechanismen. / Advanced age has been consistently linked to performance deterioration in cognitive tasks targeting the ability to mentally manipulate information. A growing body of literature suggests that regular physical exercise alleviates the adverse effects of age and helps to preserve cognitive and cerebral capacities in old age. The present dissertation investigated associations between changes in fitness and changes in cerebral and cognitive measures within a group of older adults who participated in an exercise intervention. Paper I shows that previously reported increases in hippocampal volume can be linked to exercise-induced changes in the underlying tissue microstructure. The participants who improved most in fitness showed most increments in hippocampal tissue density. Changes in tissue density were in turn positively associated with changes in hippocampal volume. This finding suggests that volumetric changes result from an increase in the bulk of cell membranes, and not from a mere dilation of existing cells. In Paper II, changes in fitness were associated with changes in the microstructure of a prefrontal white matter tract, namely the forceps minor. Likewise, changes in forceps minor microstructure were related to changes in a composite score of fluid cognitive abilities. This result indicates that changes in white matter microstructure may contribute to the beneficial effects of exercise on cognition. Paper III demonstrates that changes in fitness are positively correlated with changes in neural specificity, presumably an indirect marker of dopaminergic neuromodulation. In summary, findings from the present dissertation extend the literature on beneficial effects of exercise on age-related deterioration and add knowledge regarding the underlying mechanisms.

Im Mittelpunkt steht die Frage, was der Vorruhestand für die Ostdeutschen lebensbiographisch bedeutet und welche Funktion und Effekte dieser Aspekt des Institutionentransfers arbeits-markt- und sozialpolitisch hatte. Der Autor entwickelt zur Charakterisierung dieses Vorgangs den Begriff des "Verordneten Ruhestands". Eine theoretisch modellierte umfangreiche Empirie zeigt die subjektiv biographischen Erfahrung und Verarbeitung des "Verordneten Ruhestands" im Kontext der umfas-senden Probleme der deutschen Einigung. Die Darstellung macht deutlich, daß der Institutionentransfer im Zuge der Einigung zwar eine Einheit institutioneller Regeln, zugleich aber auch eine Differenz der Mentalitäten erzeugt und verstärkt hat. Im Ergebnis entwirft der Autor eine theoretisch begründete und empirisch differenzierte Typologie kultureller Handlungs- und Rückzugsmuster. Die Darstellung zeigt, wie differenziert Lebens- und Systemgeschichte zusammengehören. Unübersehbar, daß Probleme des Wohlfahrsstaates im Zuge fortschreitender Modernisierung von den Menschen Anstrengungen, Neuarrangements und Verantwortung verlangen. / This thesis focuses on the effect of early retirement on the lives of East Germans, the function of this aspect of institutional transfer and its consequences for the job market and socio-political structures. The term coined by the author to describe this process is "prescribed retirement". Comprehensive empirical analysis based on a theoretical model has been used to demonstrate in subjective, biographical terms how "prescribed retirement" is experienced and dealt with within the problematical context of German unification. This account shows clearly that, while generating a uniform set of institutional norms, the institutional transfer necessitated by unification has also served to produce and heighten differences in mentality between the respective citizens of the two former German states. In his conclusions, the author has set up a theoretically based and empirically differentiated typology of cultural patterns of action and withdrawal. His account demonstrates the many ways in which human lives can be linked with the history of the system. The obvious conclusion is that in view of the modernisation process, the problems of the welfare state will necessitate an increased contribution from its members in terms of effort, re-arrangement and responsibility.

Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2018-09-17T21:43:55Z No. of bitstreams: 1 Disserta??o de Grasiela Lima.pdf: 760680 bytes, checksum: d69d878c3209b5f032db528c284856ba (MD5) / Made available in DSpace on 2018-09-17T21:43:55Z (GMT). No. of bitstreams: 1 Disserta??o de Grasiela Lima.pdf: 760680 bytes, checksum: d69d878c3209b5f032db528c284856ba (MD5) Previous issue date: 2018-06-06 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / This dissertation presents the (auto)biographical narratives of four monitors and a monitor of the area of natural sciences. Through his memories, trajectories and life histories we investigate his being and become an alternating teacher, understood both as a field of study and as being able to alternate between different universes. Therefore, we have the objective of knowing the alternating life of the natural science monitors in the EFAs of the REFAISA network, during the construction of their being and becoming a professional of the field, based on their trajectories / stories of life. It is a qualitative research, based on the concepts of memory, (auto) biography, life history and narratives. Semi-structured interviews were carried out to collect data. For the analysis of the data generated, we tried to appropriate the idea of experience, Jorge Larrosa and Professorality, by Marcos Villela Pereira, and also wanted to listen to our participants, so we felt obliged to work all issues that somehow affect them. From the analysis of the data, we can conclude that much of this being and becoming a teacher is permeated by experiences that are touching him along his trajectories, whether personal or professional, which leads to the construction of a qualityality, which is the difference in itself, and even when and I want to follow models, to be equal to others, I can not, because I build myself the teacher / monitor that I can, and this achievement is linked to what affects me, what happens to me In the case of EFAs feel more comfortable as a teacher or monitor is connected to the trajectory, a history built in contact with the family, in school as a student and then as a teacher, in their initial and continued formation. Our life is an eternal game, where we are influenced by ideas, brands that we carry from our lives and often we want to be equal to people who are considered important, however, our differences project us to other ways, to be unique, to change, with that our life is unstable and as a teacher we need to eternally rebuild ourselves. / Esta disserta??o apresenta as narrativas (auto)biogr?ficas de quatro monitores e de uma monitora da ?rea de ci?ncias naturais. Por meio de suas mem?rias, trajet?rias e hist?rias de vida, investigamos o seu ser e tornar-se docente em altern?ncia, entendida tanto como campo de estudo quanto como poder alternar entre universos distintos. Por isso, temos o objetivo de conhecer a vida em altern?ncia dos monitores/as da ?rea de ci?ncias naturais, nas EFAs da rede REFAISA, durante a constru??o do seu ser e tornar-se profissional do campo, com base nas suas trajet?rias/hist?rias de vida. Trata-se de uma pesquisa qualitativa, embasada nos conceitos de mem?ria, (auto)biografia, hist?ria de vida e narrativas. Para a coleta de dados, foram realizadas entrevistas semi-estruturadas. Para a an?lise dos dados gerados, tentamos nos apropriar da ideia de experi?ncia, de Jorge Larrosa e de professoralidade, de Marcos Villela Pereira, e tamb?m quer?amos escutar os/as nossos/as participantes, por isso, sentimo-nos na obriga??o de trabalhar todas as quest?es que, de certa forma, lhes afetam. A partir da an?lise dos dados, conseguimos concluir que muito desse ser e tornar-se docente est? perpassado por experi?ncias que v?o lhe tocando ao longo das suas trajet?rias, sejam elas pessoais ou profissionais, o que levam a constru??o de uma professoralidade, que ? a diferen?a em si, e mesmo quando e quero seguir modelos, ser igual a outros/as, eu n?o consigo, pois eu construo em mim o/a professor/a-monitor/a que consigo, e esse conseguir est? ligado ao que me afeta, ao que me passa. No caso das EFAs, sentir-se mais confort?vel como professor/a ou monitor/a est? ligado ? trajet?ria, a uma hist?ria constru?da em contato com a fam?lia, na escola enquanto estudante e depois enquanto docente, na sua forma??o inicial e continuada. A nossa vida ? um eterno jogo, onde somos influenciados por ideias, por marcas que carregamos das nossas vidas; muitas vezes queremos ser iguais a pessoas que s?o tidas como importantes, no entanto, as nossas diferen?as nos projetam para outros caminhos, para sermos ?nicos, para mudarmos. Com isso, a nossa vida ? inst?vel e, enquanto docente, precisamos eternamente nos reconstruir.

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-01-16T11:04:51Z No. of bitstreams: 1 2015 - Maiza Gabrielle Ribeiro Pereira.pdf: 1027889 bytes, checksum: b3b63a440a6fc35f9a0001062c6b903a (MD5) / Made available in DSpace on 2017-01-16T11:04:51Z (GMT). No. of bitstreams: 1 2015 - Maiza Gabrielle Ribeiro Pereira.pdf: 1027889 bytes, checksum: b3b63a440a6fc35f9a0001062c6b903a (MD5) Previous issue date: 2015-11-12 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The reflection made in the research base of this dissertation deals with the issue of formation of subjects of rural areas through educational experiences that build the Rural Education. Precisely, this focuses on the Pedagogy of Alternation by CEFFA, training of young people and adults do Campo, it usually serves a pedagogical approach that emphasizes the link between education and work, preparing the subject to life. This reflection dialogues with local / rural development settings, pointing successful points of the Pedagogy of Alternation, public policy. also shows the socio-historical perspective, as a method of criticism of collective social imagination, which combines the countryside and those who live in it, as something underdeveloped and "late", which for better characterization, then we use the image of "Fabiano" book character "Vidas Secas" of Graciliano Ramos. To better understand the problem, the research is divided into two parts. The first raises a discussion of the relationship of the subjects that are established in the field of literary production in Brazil prior to the period of expansion and technification of agriculture to the present day, weaving social history under the influence of "racial theories" in the composition of class division, which subjugated and subdues the farmer as a class unprepared to live in a new society provided with a new social standard and reformulated in new technology bases. The second stage of the research, portrays the new experiences of promotion of Rural Education, highlighting the CEFFA as part of the field enhancement process in support of local / rural development. Thus describes and contextualizes these experiences and their educational practices of sociocultural relations originating from public investment policies, new ruralities and local / rural development of the North Capixaba. / A reflex?o feita na pesquisa, base desta disserta??o, trata sobre a problem?tica da forma??o de sujeitos do meio rural por meio de experi?ncias pedag?gicas que constroem a Educa??o do Campo. Precisamente, esta focaliza a Pedagogia da Altern?ncia pelo CEFFA, na forma??o de jovens e adultos do Campo, pois geralmente atende a uma proposta pedag?gica que prioriza a articula??o entre a escolariza??o e o trabalho, preparando o sujeito para a vida. Essa reflex?o dialoga com defini??es de desenvolvimento local/rural, apontando pontos exitosos da Pedagogia da Altern?ncia, pol?ticas p?blicas. Aponta ainda a perspectiva s?cio-hist?rica, como m?todo da cr?tica ao imagin?rio social coletivo, que associa o campo e quem nele vive, como algo subdesenvolvido e ?atrasado?, que para melhor caracteriza??o, ent?o, utiliza-se a imagem do ?Fabiano?, personagem do livro ?Vidas Secas? de Graciliano Ramos. Para melhor compreens?o da problem?tica, a pesquisa se divide em dois momentos. O primeiro levanta uma discuss?o das rela??es dos sujeitos que est?o estabelecidas no campo da produ??o liter?ria do Brasil, anterior ao per?odo de expans?o e tecnifica??o da agricultura at? os dias de hoje, tecendo a hist?ria social sob a influ?ncia das ?teorias raciais? na composi??o da divis?o de classes, que subjugou e subjuga o homem do campo como sendo uma classe despreparada, para viver em uma nova sociedade provida de um novo padr?o social e reformulada em bases de novas tecnologias. O segundo momento da pesquisa, retrata as novas experi?ncias de promo??o da Educa??o do Campo, evidenciando o CEFFA como parte do processo de valoriza??o do campo em prol do desenvolvimento local/rural. Dessa maneira descreve e contextualiza essas experi?ncias e suas pr?ticas educativas das rela?oes socioculturais origin?rias das pol?ticas p?blicas de investimentos, em novas ruralidades e desenvolvimento local/rural do norte Capixaba

This thesis is mainly devoted to the investigation of speed control methods for three phase cage induction motors with particular emphasis being given to Direct Torque Control (DTC) improved techniques.Classical Direct Torque Control has inherent disadvantages such as: problems during starting resulting from the null states, the compulsory requirement of torque and flux estimators, and torque ripple. In the classical DTC induction motor drive a voltage vector is applied for the entire period, and this causes the stator current and electromagnetic torque exceeds its reference value early during the cycle, causing a high torque ripple. Switching cycles then follows this, in which the zero switching vectors are applied in order to reduce the electromagnetic torque to reference value. This thesis suggests a technique based on applying to the inverter the selected active states just enough time to achieve the torque and flux references values. The rest of the switching period a null state is selected which won't almost change both the torque and the flux. Therefore, a duty ratio has to be determined each switching time. By means of varying the duty ratio between its extreme values (0 up to 1) it is possible to apply any voltage to the motor. The optimum duty ratio per sampling period is a non-linear function of the electromagnetic torque error, the stator flux position and the working point, which is determined by the motor speed and the electromagnetic torque. It is obvious that it is extremely difficult to model such an expression since it is a different non-linear function per working point. Therefore, this thesis is focused on performing a fuzzy-logic-based duty-ratio controller, where the optimum duty ratio is determined every switching period. Additionally, this Fuzzy Controller is adaptive and may be applied to any induction motor.A stator flux reference optimum controller is also designed, which not only helps to achieve a smaller torque ripple, but also reduces the reactive power consumption of the drive taken from the main supply. This is achieved by changing the stator flux reference value with reference being made to the correspondent torque reference value. Therefore, the stator flux reference value chosen is to be just of sufficient value to produce the desired torque Simulated results are shown in order to compare the classical DTC and the Fuzzy Logic based DTC.The control algorithms have been implemented on a PC/DSP based board that facilitates the use of parallelism in software design. A 1.5kW, three-phase induction motor drive has been designed and experimental data obtained from it in order to verify the results achieved by simulation.

Striving for personal goals is one important aspect of composing one is life within a developmental context. In this realm, personal life investment (PLI) measures the amount of energy (action and thought) that people report investing in central life domains (e.g., health, family, leisure, independence). This study aimed at understanding the functional relations of PLI, its development between 70 and over 100 years, and its role for successful aging. Obligatory and optional PLI were distinguished to differentiate between life domains where older individuals need to invest energy to maintain a basis for their development and domains that allow for many more degrees of freedom as to where and when to invest. Cross-sectional and longitudinal data from the Berlin Aging Study (BASE) showed that optional PLI, in contrast to obligatory PLI, had only positive motivational and affective correlates, declined between age 80 and 90, and contributed to successful aging as long as older people had enough resources to invest in optional domains. / Das Streben nach persönlichen Zielen ist für die eigene Lebensgestaltung innerhalb eines veränderlichen Entwicklungskontextes zentral. Dabei erfasst das Konstrukt des persönlichen Lebensinvestments (PLI) einen Aspekt der Lebensgestaltung: das Ausmaß an Energie, das in Form von Handlungen und Gedanken in zentralen Lebensbereichen, wie z.B. Gesundheit, Familie, Freizeit oder Unabhängigkeit, investiert wird. Ziel der vorliegenden Studie war die Untersuchung der funktionalen Zusammenhänge des PLI, der Entwicklung von PLI zwischen 70 und über 100 Jahren und der Rolle des Investments beim erfolgreichen Altern. Hierbei wurde zwischen obligatorischem und optionalem PLI unterschieden, also PLI in Lebensbereichen, die im Alter Investment erfordern, um die Grundlagen für die eigene Entwicklung zu erhalten, und PLI in Lebensbereichen, die weitaus mehr Freiheitsgrade hinsichtlich des Ausmaßes und Zeitpunktes des Investments bieten. Analysen von Quer- und Längsschnittdaten der Berliner Altersstudie (BASE) zeigten, dass optionales PLI, im Gegensatz zu obligatorischem PLI, nur positive motivational-affektive Korrelate aufweist, zwischen 80 und 90 Jahren leicht reduziert wird und zum erfolgreichen Altern beitragen kann, sofern die betreffende ältere Person über ausreichende Ressourcen verfügt, um sie in optionalen Bereichen zu investieren.

Summary: Salivary alpha-amylase: More than an enzyme - Investigating confounders of stress-induced and basal amylase activity (Dipl.-Psych. Jana Strahler) The hypothalamus-pituitary-adrenal (HPA) axis and the autonomic nervous system (ANS) are two of the major systems playing a role in the adaptation of organisms to developmental changes that threaten homeostasis. The HPA system involves the secretion of glucocorticoids, including cortisol, into the circulatory system. Numerous studies have been published that introduced salivary cortisol to assess HPA axis activity and therefore strengthens its role as an easy obtainable biomarker in stress research that can be monitored easily and frequently. Recent findings suggest a possible surrogate marker of autonomic activity due to autonomic innervation of salivary glands: salivary alpha-amylase (sAA). Up to date, additional methodological research is needed for a better understanding of the advantages and disadvantages of sAA activity in comparison to already established markers of ANS activity. The aim of the present thesis is to further our knowledge of confounders of sAA activity under basal and acute stress conditions and to strengthen the validity of this enzyme as an easy obtainable alternative for ANS testing. After introducing classical and modern stress concepts and stress system physiology (chapter 2), the reader is acquainted with anatomical basics of salivary gland innervation and secretion of salivary proteins, including sAA, due to autonomic innervation (chapter 3 and 4). Afterwards, a more nuanced review of methodological considerations of sAA determination shows gaps of knowledge concerning its usefulness as a marker of ANS activity (chapter 5). Given the fact that the integration of sAA into developmental and aging research is a relative recent phenomenon, several issues have to be addressed before a final conclusion could be drawn. Therefore, we conducted a series of studies incorporating these considerations regarding behavioral correlates of inter- and intraindividual differences in sAA activity with a special emphasis on older adults. Chapter 7 deals with sAA activity under psychological stress conditions in different age groups. Since vulnerability to disease and disease prevalence patterns change with age, it is important to investigate stress reactivity of people in different age groups. We therefore investigated children between 6 and 10 years, because childhood is a sensitive period of growth and development, and thus plays an important role for later life health. Young adults were included to represent the most studied human age group as a reference. Older adults between 59 and 61 years were investigated, because at this age the course is set for the further development of a person’s health in later life, and because autonomic stress responses in older age might be important determinants of cardiovascular and inflammatory aging. Our goal is to test for associations of sAA with more established stress system markers, i.e., salivary cortisol as outcome measurement of HPA reactivity, heart rate (HR) and heart rate variability (HRV) as markers for autonomic reactivity, and to directly compare these responses between different age groups across the life span. Secretion of sAA and cortisol was repeatedly assessed in 62 children, 78 young adults, and 74 older adults after exposure to a standardized psychosocial stressor, the Trier Social Stress Test. In addition, cardiovascular activity was measured in both adult groups. Older adults showed attenuated sAA, HR, and HRV responses. Furthermore, we found higher sAA but lower cortisol at baseline as well as lower sAA and cortisol responses in children. Age by sex interactions were observed only for cortisol with higher responses in older male participants. No associations between the parameters were found. Results in children and young adults confirm previous results. Overall, findings implicate sAA as an alternative or additional autonomic stress marker throughout the life span, with marked and rapid responsiveness to stress in three relevant age groups. The impact of age and chronic stress on basal sAA activity is the center of interest in chapter 8. We therefore assessed diurnal profiles of sAA and salivary cortisol in 27 younger and 31 older competitive ballroom dancers as well as 26 younger and 33 older age- and sex-matched controls. According to the Allostatic Load concept, repeated, non-habituating responses to social-evaluative conditions, which characterize the lives of competitive ballroom dancers, should be associated with stress system dysregulations. Furthermore, we expect to see an increased sympathetic drive associated higher overall alpha-amylase activity in older adults. Analyses revealed an elevated daily overall output of sAA in older adults while there was no effect of age on mean cortisol levels. Alterations of diurnal rhythms were only seen in younger male dancers showing a flattened diurnal profile of sAA and younger dancers and female older dancers showing a blunted diurnal rhythmicity of cortisol. Furthermore, we found a negative correlation between summary indices of basal sAA and the amount of physical activity. In conclusion, higher overall output of sAA in older adults was in line with the phenomenon of a “sympathetic overdrive” with increasing age. Furthermore, a lower output of sAA in people who are more physical active was in line with the hypothesis of an exercise-induced decrease of sympathetic activity. Taken together, results of chapter 7 and 8 show a clear impact of age on sAA activity, either under acute stress or basal conditions. One problem when integrating sAA into developmental and aging research is the use of adrenergic agonists and antagonists what is very common in older adults, i.e. antihypertensive drugs (AD). As well, the previously shown sympathetic overactivity that occurs with normal aging is associated with higher blood pressure (BP). Therefore, chapter 9 deals with a possible impact of high BP and AD on diurnal sAA activity in 79 older adults (33 normotensive adults, 16 medicated vs. 45 hypertensive adults, 34 medicated). Results showed a pronounced rhythm of sAA in all groups. Diurnal profiles differed significantly between men and women with men lacking the typical decrease of sAA in the morning and showing more pronounced alterations throughout the day. An effect of AD on sAA profiles and area under the curve values indicates that subjects not using AD´s show a heightened diurnal profile and a higher total output of sAA. Descriptively, this was also true for hypertensive older adults. Hypertensive subjects and those not using AD showed the highest diurnal output of sAA and the steepest slope. In sum, our results show an impact of antihypertensive medication and a difference between normotensive and hypertensive subjects on characteristics of diurnal sAA activity. Hence, findings are of particular interest in research using sAA as a prognostic indicator of pathological states and processes. Given the fact that hypertension was also shown to be associated with substantial changes of transmitters within the suprachiasmatic nucleus (SCN) - the “biological clock” that receives photic input from retinal glands via the retinohypothalamic pathway - and an altered output from the SCN to the sympathetic nervous system, we broaden the idea of a possible effect of different lighting conditions on morning sAA profiles in chapter 10. In a counterbalanced within-subjects design six men and 16 women of different ages collected sAA morning profiles on two consecutive days with leaving their shutters closed on the one day (= dark) and open their shutters on the other day (= bright). We were able to replicate earlier findings of light-induced changes of salivary cortisol with higher responses during the bright condition. On either day, women showed larger cortisol increases than men. Despite multisynaptic autonomic connections arising from the SCN projecting to multiple organs of the body, we could not find an effect of sunlight on sAA morning profiles. Evidence for circadian clock gene expression in human oral mucosa might account for this result and indicates that peripheral oscillators may act more like integrators of multiple different time cues, e.g. light, food intake, instead of a “master” oscillator (SCN). Results of chapter 7 to 10 provide clear evidence that sAA is heightened in states of autonomic arousal, i.e. stress, aging and hypertension, and that its circadian rhythmicity seems to be regulated rather integrative than directly via efferent input from hypothalamic SCN neurons. In chapter 11 this thesis tries to approach one central question: What is the biological meaning of the findings made? According to this enzyme´s anti-bacterial and digestive action short term changes might not have a biological meaning itself but rather reflect just a small part of multiple coordinated body responses to stressful stimuli. While the sympathetic branch of the ANS mainly stimulates protein secretion, the parasympathetic branch stimulates saliva flow. Acute stress responses might therefore be interpreted as reflecting predominant sympathetic activity together with parasympathetic withdrawal. The same mechanism could also be suitable for the finding of higher diurnal levels of sAA in older adults or hypertensive subjects reflecting a higher peripheral sympathetic tone in these groups. Diurnal profiles of sAA itself may reflect circadian changes in autonomic balance. Circadian rhythms are of great advantage since they enable individuals to anticipate. This pre-adaptation enables the individual to cope with upcoming demands and challenges. Our finding of a relationship between sAA and salivary cortisol what strengthens the relevance of glucocorticoids that were previously shown to be able to phase shift circadian rhythms in cells and tissue. Within a food-related context there is evidence that decreasing levels of sAA in the morning could reflect increases of feeling hungry since sAA systematically increases during food consumption and with the subjective state of satiety. So far, much more research is needed to identify underlying physiological mechanisms of circadian sAA rhythmicity. Taking the next step, future studies will have to focus on the integration of sAA assessment into longitudinal studies and different disease states to prove its applicability as a marker of sympathetic neural functioning in the genesis and prognosis of disease.

No description available.

Der Einsatz von digitalen Menschmodellen erlaubt neben einer frühzeitigen ergonomischen Analyse die Gestaltung von Arbeitsprozessen und stellt ein hilfreiches Werkzeug in der Produkt- und Prozessgestaltung dar. Im Rahmen dieses Beitrages soll auf ausgewählte Schwerpunkte der Entwicklung des digitalen Menschmodells „The Smart Virtual Worker“ eingegangen werden. Das Forschungsprojekt soll einen Beitrag zur Lösung, der mit dem demografischen Wandel der Gesellschaft einhergehenden Herausforderungen leisten. Die daraus resultierenden Forschungsschwerpunkte liegen insbesondere in der Einbeziehung von Alterungs- und psychischen Faktoren in die Bewegungsgenerierung des Menschmodells und der Modellierung von Umweltbedingungen. In Umsetzung des Projektes wurde ein erstes Arbeitsszenario erarbeitet, auf dessen Basis die vorgenannten Forschungsaufgaben interdisziplinär gelöst werden sollen.

Altersassoziiert entwickeln Hunde eine Erkrankung, die in vielen Aspekten der Alzheimer-Krankheit des Menschen ähnelt. Das canine kognitive Dysfunktionssyndrom äußert sich klinisch u.a. durch Desorientierung in vertrauter Umgebung, Vergessen von Kommandos und einen gestörten Schlaf-Wach-Rhythmus. Aus der Literatur ist bekannt, dass in den Gehirnen von alten Hunden regelmäßig Aβ- und selten Tauablagerungen zu beobachten sind. Allerdings erfolgte bisher kein Nachweis des hochgradig zytotoxischen und modifizierten pE3Aβ. Auch Veränderungen der mikroglialen Morphologie wurden bisher nicht beschrieben. Insgesamt lagen in dieser Studie 24 euthanasierte Rasse- und Mischlingshunde verschiedenen Alters vor. Fünf dieser Tiere besaßen ein durchschnittliches Alter von 2,1 Jahren und dienten als Kontrollgruppe. Die anderen 19 Hunde waren 8 bis 19 Jahre alt und wurden entsprechend ihrer Größe und des Gewichts in die drei Kategorien kleine (≤ 10 kg), mittelgroße (10 – 25 kg) und große Hunde (> 25 kg) unterteilt. Die Gehirne wurden aus den Schädeln präpariert und in 4 % Paraformaldehyd fixiert. Anschließend erfolgte die Präparation des frontalen und entorhinalen Kortex sowie der Hippokampusformation, die in 30%iger Saccharoselösung vitrifiziert und mittels Methylbutan bei -80 °C eingefroren wurden. Von den Regionen wurden Kryoschnitte mit einer Dicke von 40 µm angefertigt und diese anhand immunhistologischer Färbungen auf das Vorhandensein von Ablagerungen, bestehend aus den Amyloidsubtypen Aβ8-17 und pE3Aβ, sowie aus hyperphosphorylierten Tau, untersucht. Die Morphologie und das Aktivitätsstadium der Mikroglia wurden mit Antikörpern gegen Iba1 und TAL.1B5 analysiert. Zusätzlich erfolgte eine Untersuchung anhand des Filament Tracer. Stereologische Analysemethoden wurden zur Quantifizierung der Aβ-Ablagerungen und der Mikroglia angewandt. Disseminierte Plaques fanden sich bereits ab 9 Jahren. In den untersuchten Gehirnregionen von alten Hunden zeichnete sich ein progressiver Verlauf der Ablagerungen ab. Da insbesondere kleinere Hunde ein höheres Alter erreichten als mittelgroße und große Hunde konnten in dieser Kategorie vermehrt Plaques beobachtet werden. Den alten Tieren gemein war, dass in den untersuchten Gehirnregionen pE3Aβ-Plaques häufiger vorlagen als Plaques, die aus Aβ8-17 bestanden. Kleinere parenchymale und meningeale Gefäße des frontalen Kortex schienen besonders anfällig gegenüber pE3Aβ-Ablagerungen zu sein. Im entorhinalen Kortex von kleinen Hunden war die Menge an gefäßassoziierten Aβ8-17- und pE3Aβ-Ablagerungen annähernd gleich. Bei mittelgroßen und großen Hunden dominierte im entorhinalen Kortex und ventralen Hippokampus die Anzahl an gefäßassoziierten Aβ8-17-Ablagerungen. Bei kleinen Hunden existierten im ventralen Hippokampus signifikant mehr gefäßassoziierte Aβ8-17- als pE3Aβ-Ablagerungen. Hyperphosphoryliertes Tau fand sich in der Hippokampusformation von drei Hunden im Alter von 11 bzw. 15 Jahren. Der Schweregrad war unterschiedlich ausgeprägt, sodass nur ein Hund eine hochgradige Pathologie mit NFTs und neuritischen Plaques aufwies. Einhergehend mit dem Alter und einer assoziierten Proteinpathologie fanden sich Veränderungen der mikroglialen Morphologie. Neben ramifizierten Mikroglia lagen in den untersuchten Gehirnregionen aktivierte Mikroglia vor. Einige Mikroglia wiesen Zeichen einer Seneszenz auf und waren insbesondere in den Gehirnen von Hunden mit einer hochgradigen Aβ- bzw. Tau-Pathologie vorhanden. Zusammenfassend ist festzustellen, dass mit dieser Studie eine nähere Charakterisierung des caninen kognitiven Dysfunktionssyndroms erfolgte. Die Befunde sind von hoher translationaler Bedeutung und fördern die Etablierung des Hundes als natürliches Modelltier zur Untersuchung von Alterungsprozessen des Gehirns und für die Erforschung des initialen Stadiums der Alzheimer-Krankheit. / Dogs develop an age-associated cognitive dysfunction syndrome with several aspects resembling Alzheimer\\\'s disease. Affected animals show signs of dis-orientation in their familiar surroundings, dementia, and a disturbed circadian rhythm. The underlying neurodegenerative disease is associated with patho-logic changes in the brain including regularly deposition of β-pleated amyloid and rarely hyperphosphorylated tau accumulation. However, there have been no reports of the highly cytotoxic and modified pE3Aβ in the canine brain. Equally, altered microglial morphology has not been documented so far. For this study 24 euthanized thoroughbred dogs and mongrels of different ages were available. Five of these animals had an average age of 2.1 years and served as control group. The remaining 19 dogs were 8 to 19 years old. Accor-ding to their height and weight these dogs were divided into 3 different categories including small (≤ 10 kg), medium (11 - 25 kg) and large dogs (> 25 kg). Brains were dissected from the skulls and fixed in 4 % paraformaldehyde. Afterwards the frontal and entorhinal cortex as well as the hippocampal for-mation were isolated, vitrificated in 30 % sucrose solution and frozen to -80 °C by methylbutane. These regions were sliced into 40 µm thick sections and subsequently stained by immunohistology in order to detect deposits of Aβ8-17, pE3Aβ and hyperphosphorylated tau, respectively. Antibodies against Iba1 and TAL.1B5 were used to analyze microglial morphology and activation status. Additionally further investigations were made with the Filament Tracer of Imaris software. Stereological analysis methods served for the quantification of Aβ depositions and microglia. Disseminated Aβ plaques were detected in dogs from 9 years on. Within the examined brain regions of elderly dogs a progressive course of Aβ depositions was observed. Especially small dogs had a longer lifespan than medium and large dogs with the result that more plaques were deposited in the brains of small dogs. Elderly dogs had in common that pE3Aβ-plaques where more often located in the examined brain regions than plaques containing Aβ8-17. Minor parenchymal and meningeal vessels seemed to be susceptible especially to pE3Aβ depositions. The amount of vessel-associated Aβ8-17 and pE3Aβ in the entorhinal cortex of small dogs was almost equal. Within the entorhinal cortex of medium and large dogs the amount of vessel-associated Aβ8-17 predominated. The ventral hippocampus of small dogs showed significantly more vessel-associated Aβ8-17 than pE3Aβ depositions. Hyperphosphorylated tau was present in the hippocampal formations of 3 dogs with an age of 11 and 15 years, respectively. The degree of severity varied with the result that only one dog showed a high-grade pathology with development of NFTs and neuritic plaques. Accompanied by age and associated protein pathology altered microglial morphology was detected. Alongside with ramified microglia, activated cells were identified in the examined brain regions. Several microglia showed signs of senescence and were present in the brains of dogs with severe Aβ and tau pathology. Summarizing, this study facilitated a further characterization of the canine cognitive dysfunction syndrome. The results are of highly translational importance and encourage the establishment of the dog as a natural animal model for studying age-associated processes and the initial stage of Alzheimer’s disease.