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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Psychophysiologische Untersuchung mentaler Beanspruchung in simulierten Mensch-Maschine-Interaktionen

Ribback, Sven January 2003 (has links)
In der vorliegenden Untersuchung wurde ein arbeitspsychologisches Problem thematisiert, dass in Mensch-Maschine-Systemen auftritt. <br /> In Mensch-Maschine-Systemen werden Informationen in kodierter Form ausgetauscht. Diese inhaltlich verkürzte Informationsübertragung hat den Vorteil, keine lange Zustandsbeschreibung zu benötigen, so dass der Mensch auf die veränderten Zustände schnell und effizient reagieren kann. Dies wird aber nur dann ermöglicht, wenn der Mensch die kodierten Informationen (Kodes) vorher erlernten Bedeutungen zuordnen kann. Je nach Art der kodierten Informationen (visuelle, akustische oder alphanumerische Signale) wurden Gestaltungsempfehlungen für Kodealphabete entwickelt. <br /> Für Operateure resultiert die mentale Belastung durch Dekodierungsprozesse vor allem aus dem Umfang des Kodealphabetes (Anzahl von Kodezeichen), der wahrnehmungsmäßigen Gestaltung der Kodes und den Regeln über die Zuordnung von Bedeutungen zu Kodezeichen. <br /> <br /> Die Entscheidung über die Güte von Kodealphabeten geschieht in der Arbeitspsychologie in der Regel über Leistungsindikatoren. Dies sind üblicherweise die zur Dekodierung der Kodes benötigte Zeit und dabei auftretende Zuordnungsfehler. Psychophysiologische Daten werden oft nicht herangezogen.<br /> Fraglich ist allerdings, ob Zeiten und Fehler allein verlässliche Indikatoren für den kognitiven Aufwand bei Dekodierungsprozessen sind, da im hochgeübten Zustand bei gleichen Alphabetlängen, aber unterschiedlicher Kodezeichengestaltung sich häufig die mittleren Dekodierungszeiten zwischen Kodealphabeten nicht signifikant unterscheiden und Fehler überhaupt nicht auftreten. <br /> Die in der vorliegenden Arbeit postulierte Notwendigkeit der Ableitung von Biosignalen gründet sich auf die Annahme, dass mit ihrer Hilfe zusätzliche Informationen über die mentale Beanspruchung bei Dekodierungsprozessen gewonnen werden können, die mit der Erhebung von Leistungsdaten nicht erfasst werden. Denn gerade dann, wenn sich die Leistungsdaten zweier Kodealphabete nicht unterscheiden, können psychophysiologische Daten unterschiedliche Aspekte mentaler Beanspruchung erfassen, die mit Hilfe von Leistungsdaten nicht bestimmt werden können. <br /> Daher wird in Erweiterung des etablierten Untersuchungsansatzes vorgeschlagen, Biosignale als dritten Datenbereich, neben Leistungsdaten und subjektiven Daten mentaler Beanspruchung, abzuleiten, um zusätzliche Informationen über die mentale Beanspruchung bei Dekodierungsprozessen zu erhalten.<br /> Diese Annahme sollte mit Hilfe der Ableitung von Biosignalen überprüft werden. <br /> <br /> Der Begriff mentaler Beanspruchung wird in der bisherigen Literatur nur unzureichend definiert und differenziert. Daher wird zur Untersuchung dieses Konzepts, die wissenschaftliche Literatur berücksichtigend, ein erweitertes Modell mentaler Beanspruchung vorgestellt.<br /> Dabei wird die mentale Beanspruchung abgegrenzt von der emotionalen Beanspruchung. Mentale Beanspruchung wird weiterhin unterschieden in psychomotorische, perzeptive und kognitive Beanspruchung. Diese Aspekte mentaler Beanspruchung werden jeweils vom psychomotorischen, perzeptiven oder kognitiven Aufwand der zu bearbeitenden Aufgabe ausgelöst.<br /> <br /> In der vorliegenden Untersuchung wurden zwei zentrale Fragestellungen untersucht:<br /> Einerseits wurde die Analyse der anwendungsbezogenen Frage fokussiert, inwieweit psychophysiologische Indikatoren mentaler Beanspruchung über die Leistungsdaten (Dekodierungszeiten und Fehleranzahl) hinaus, zusätzliche Informationen zur Bestimmung der Güte von Kodealphabeten liefern. <br /> Andererseits wurde der Forschungsaspekt untersucht, inwieweit psychophysiologische Indikatoren mentaler Beanspruchung die zur Dekodierung notwendigen perzeptiven und kognitiven Aspekte mentaler Beanspruchung differenzieren können. Emotionale Beanspruchung war nicht Gegenstand der Analysen, weshalb in der Operationalisierung versucht wurde, sie weitgehend zu vermeiden. Psychomotorische Beanspruchung als dritter Aspekt mentaler Beanspruchung (neben perzeptiver und kognitiver Beanspruchung) wurde für beide Experimentalgruppen weitgehend konstant gehalten.<br /> <br /> In Lernexperimenten hatten zwei anhand eines Lern- und Gedächtnistests homogenisierte Stichproben jeweils die Bedeutung von 54 Kodes eines Kodealphabets zu erwerben. Dabei wurde jeder der zwei unahbhängigen Stichproben ein anderes Kodealphabet vorgelegt, wobei sich die Kodealphabete hinsichtlich Buchstabenanzahl (Kodelänge) und anzuwendender Zuordnungsregeln unterschieden. Damit differierten die Kodealphabete im perzeptiven und kognitiven Aspekt mentaler Beanspruchung.<br /> Die Kombination der Abkürzungen entsprach den in einer Feuerwehrleitzentrale verwendeten (Kurzbeschreibungen von Notfallsituationen). In der Lernphase wurden den Probanden zunächst die Kodealphabete geblockt mit ihren Bedeutungen präsentiert. <br /> Anschließend wurden die Kodes (ohne deren Bedeutung) in sechs aufeinanderfolgenden Prüfphasen randomisiert einzeln dargeboten, wobei die Probanden instruiert waren, die Bedeutung der jeweiligen Kodes in ein Mikrofon zu sprechen. <br /> Während des gesamten Experiments wurden, neben Leistungsdaten (Dekodierungszeiten und Fehleranzahl) und subjektiven Daten über die mentale Beanspruchung im Verlauf der Experimente, folgende zentralnervöse und peripherphysiologische Biosignale abgeleitet: Blutdruck, Herzrate, phasische und tonische elektrodermale Aktivität und Elektroenzephalogramm. Aus ihnen wurden zunächst 13 peripherphysiologische und 7 zentralnervöse Parameter berechnet, von denen 7 peripherphysiologische und 3 zentralnervöse Parameter die statistischen Voraussetzungen (Einschlusskriterien) soweit erfüllten, dass sie in die inferenzstatistische Datenanalyse einbezogen wurden.<br /> <br /> Leistungsdaten und subjektive Beanspruchungseinschätzungen der Versuchsdurchgänge wurden zu den psychophysiologischen Parametern in Beziehung gesetzt. Die Befunde zeigen, dass mittels der psychophysiologischen Daten zusätzliche Erkenntnisse über den kognitiven Aufwand gewonnen werden können.<br /> <br /> Als weitere Analyse wurden die Kodes post hoc in zwei neue Kodealphabete eingeteilt. Ziel dieser Analyse war es, die Unterschiede zwischen beiden Kodealphabeten zu erhöhen, um deutlichere reizbezogene psychophysiologische Unterschiede in den EEG-Daten zwischen den Kodealphabeten zu erhalten. Dazu wurde diejenigen, hinsichtlich ihrer Bedeutung, parallelen Kodes in beiden Kodealphabeten ausgewählt, die sich in der Dekodierungszeit maximal voneinander unterschieden. Eine erneute Analyse der EEG-Daten erbrachte jedoch keine Verbesserung der Ergebnisse.<br /> <br /> Drei Hauptergebnisse bezüglich der psychophysiologischen Parameter konnten festgestellt werden:<br /> Das erste Ergebnis ist für die psychophysiologische Methodik bedeutsam. Viele psychophysiologische Parameter unterschieden zwischen den Prüfphasen und zeigen damit eine hinreichende Sensitivität zur Untersuchung mentaler Beanspruchung bei Dekodierungsprozessen an. Dazu gehören die Anzahl der spontanen Hautleitwertsreaktionen, die Amplitude der Hautleitwertsreaktionen, das Hautleitwertsniveau, die Herzrate, die Herzratendifferenz und das Beta-2-Band des EEG. Diese Parameter zeigen einen ähnlichen Verlauf wie die Leistungsdaten. Dies zeigt, dass es möglich ist, die hier operationaliserte Art mentaler Beanspruchung in Form von Dekodierungsprozessen psychophysiologisch zu analysieren.<br /> <br /> Ein zweites Ergebnis betrifft die Möglichkeit, Unterschiede mentaler Beanspruchung zwischen beiden Gruppen psychophysiologisch abzubilden:<br /> Das Hautleitwertsniveau und das Theta-Frequenzband des Spontan-EEG zeigten Unterschiede zwischen beiden Stichproben von der ersten Prüfphase an. Diese Parameter indizieren unterschiedlichen kognitiven Aufwand in beiden Stichproben über alle Prüfphasen.<br /> <br /> Das wichtigste Ergebnis betrifft die Frage nach einem Informationsgewinn bei Einsatz psychophysiologischer Methoden zur Bewertung der Güte von Kodealphabeten: <br /> Einen tatsächlichen Informationsgewinn gegenüber den Leistungsdaten zeigte die Amplitude der elektrodermalen Aktivität und die Herzraten-Differenz an. Denn in den späteren Prüfphasen, wenn sich die Leistungsdaten beider Kodealphabete nicht mehr unterschieden, konnten unterschiedliche Ausprägungen dieser psychophysiologischen Parameter zwischen beiden Kodealphabeten verzeichnet werden. Damit konnten unterschiedliche Aspekte mentaler Beanspruchung in beiden Kodealphabeten in den späteren Prüfphasen erfasst werden, in denen sich die Leistungsdaten nicht mehr unterschieden. <br /> <br /> Alle drei Ergebnisse zeigen, dass es, trotz erheblichen technischen und methodischen Aufwands, sinnvoll erscheint, bei der Charakterisierung mentaler Belastungen und für die Gestaltung von Kodealphabeten auch psychophysiologische Daten heranzuziehen, da zusätzliche Informationen über den perzeptiven und kognitiven Dekodierungsaufwand gewonnen werden können. / In this study a problem from the work psychology was focussed, which appears in human-machine systems.<br /> In human-machine systems informations were exchanged as codes. Using this kind of shortened information transmission needs no long description of the system state, so that the operator can react to the changed system state in a quick and efficient way. This is possible only in this case, if the operator has learned the meaning of the codes before. For the different kinds of coded informations (visual, acoustic or alphanumeric signals) special recommendations for their design were developed.<br /> Mental workload caused by decoding processes resulting from the size of the code alphabet, the percepted design of the codes, and the rules about the allocation of code meanings.<br /> <br /> The decision about the validity of code alphabets in work psychology is normally made by indicators of performance, which are the decoding times and decoding mistakes. Nearly all studies do not refer to psychophysiological data. <br /> It is questioned, if times and mistakes alone are valid indicators for the cognitive cost, because in well learned state and for the same size of the code alphabet but different design of the codes, the decoding times between code alphabets are not significantly different, and mistakes do not appear.<br /> This study postulates a necessity for the registration of psychophysiological data, so that additionally informations, which are not included in the performance data, can be examined. If the performance data does not differ between two code alphabets, psychophysiological data measures different aspects of mental workload, which could not be detected by performance data. To enlarge the established approach, it is recommended to registrate biosignals as a third domain of data to get additional informations about decoding processes.<br /> These hypotheses should be verified by registration of biosignals.<br /> <br /> There are vague definitions and deficient differentiations of the concept of mental workload in the scientific publications. To examine mental workload an enlarged model of mental workload is presented. Mental workload is delimited from emotional strain. Furthermore mental workload is differentiated in psychomotoric, perceptive, and cognitive aspects. These aspects of mental workload are caused by the psychomotoric, perceptive, and cognitive cost, which are initiated by the assigned task.<br /> <br /> Two main questions were examined in this study. <br /> First question refers to applied research. Do psychophysiological indicators of mental workload provide more information about the validity of code alphabets than performance data?<br /> The second question refers to what extent psychophysiological indicators of mental workload necessary for the decoding process could differentiate the perceptive and cognitive aspects of mental workload. <br /> <br /> >The emotional strain was not the objective of this study, therefore it was excluded from the experimental design.<br /> Psychomotoric workload as the third aspect of mental workload was a constant value for both experimental samples.<br /> <br /> In two learning experiments two samples with identical habituational memory performance were instructed to learn the meaning of 54 codes of a code alphabet. Both samples was presented another code alphabet, which differed in the number of included letters and the allocation rules. Thus the two code alphabets differed in the perceptive and in the cognitive aspect of mental workload.<br /> The combination of abbreviations was comparable to those used in a fire station. In a learning phase the code alphabets were presented with their meanings. Afterwards the codes were presented without their meanings in six following tests phases. Subjects were instructed to answer in a microphone. <br /> During the whole experiment performance data, subjective data of perceived strain, and psychophysiological data were registrated. The psychophysiological data contained: blood pressure, heart rate, phasic and tonic electrodermal activity, and the EEG. Thirteen peripherphysiological and seven EEG parameters were extracted from these raw data. Seven peripherphysiological and three EEG parameters accomplished the statistical premises and were included to further statistical analysis.<br /> Performance data and subjective data were set in relation to the psychophysiological parameters. The outcomes showed that using psychophysiological data generate additional informations about the cognitive cost.<br /> <br /> For further analysis the code items were divided into two new code alphabets. The intention of this analysis was to maximize the difference between the two code alphabets to get more stimuli based psychophysiological differences in the EEG data. This analysis included those pairs of codes with identical meaning and maximum difference in their decoding time. This further analysis did not improve the outcomes. <br /> <br /> Three main outcomes in respect to the psychophysiological data were detected. <br /> The first one is an important outcome for psychophysiological methodology. Many psychophysiological parameters differ between the test phases and thus show a sufficient sensitivity to examine mental workload in decoding processes. The number of spontaneous electrodermal responses, the amplitude of electrodermal responses, the electrodermal level, the heart rate, the heart rate difference, and the beta-2 frequency band of the EEG belong to these parameters. These parameters show a similar distribution like performance data. This shows the possibility of the operationalized mental workload through decoding processes analysable with psychophysiological methods.<br /> A second outcome concerns the possibility to show differences in mental workload between both samples in psychophysiological parameters:<br /> The electrodermal level and the theta frequency band of the EEG showed differences between both samples beginning from the first test phase. These parameters indicate different cognitive cost in both samples in all test phases.<br /> <br /> The most important outcome regards to the profit of information by using psychophysiological methods to test the validity of code alphabets. The amplitude of the electrodermal responses and the heart rate difference shows a surplus of information compared to performance data. Thus in later test phases, in which the performance data did no longer differ, different characteristics of psychophysiological parameters between both code alphabets were registrated. Therefore different aspects of mental workload could be quantified.<br /> <br /> All three outcomes showed that, nevertheless of the considerable technical and methodological expenditure, it is reasonable to use psychophysiological data to design code alphabets, because it supplies additional information about the perceptional and cognitive cost of the decoding processes.
32

Do haemodynamic responses to mental stress tests predict future blood pressure one year later? : prospective studies in the United Kingdom and Thailand

Yuenyongchaiwat, Kornanong January 2013 (has links)
This thesis explored whether haemodynamic responses to psychological stress test predict future blood pressure (BP) levels: the Reactivity Hypothesis. The research included a systematic review and two prospective cohort studies in the UK and Thai samples. In addition, the Blunted Reactivity Hypothesis, which posits that cardiovascular reactivity is inversely related to symptoms of anxiety and depression, was examined in cross-sectional analyses. A systematic review with meta-analysis and meta-regression with 41 prospective cohort studies (from 1950 to 2012) examined whether cardiovascular responses to psychological stress tests predict future BP levels, hypertension status, preclinical coronary heart disease (CHD) and cardiac events. Three possible moderators were included in analyses: type of task (active versus passive coping), age group (children versus adults), and duration of follow-up (short versus long-term follow-up). The review found that systolic BP reactions to psychological stress tests predict future systolic BP levels and that there was better prediction in child samples with shorter follow-up periods. Similarly, diastolic BP reactions to psychological stress predicted future diastolic BP levels. Cardiovascular reactions to psychological stress tests did not predict hypertension, preclinical CHD, or cardiac events. Cross-sectional analysis of two studies conducted in the UK and Thailand provided some evidence that anxiety and depressive symptoms were negatively associated with cardiovascular reactivity: these findings supported the Blunted Cardiovascular Hypothesis. However, these relationships were observed in the UK sample, but not in the Thai sample. Further, Thai participants responded to psychological stress task with large cardiovascular reactions, of a similar magnitude to the UK participants and observed in previous studies of Europeans and North Americans. Finally, prospective analyses revealed that systolic BP responses to mental arithmetic predict future systolic BP levels after one year of follow-up in both UK and Thai individuals, after controlling for baseline cardiovascular activity and traditional risk factors. In contrast, haemodynamic responses did not predict future BP. These results provide support for the “Reactivity Hypothesis” although the effect sizes were relatively small. However, responses to only one of the three stressors, mental arithmetic, predicted future BP implicating beta-adrenergically mediated cardiovascular responses. However, there was no physiologic evidence (i.e., cardiac output responses) that suggested beta-adrenergic mechanisms. Accordingly, future studies should examine alternate mechanisms (e.g., platelet aggregation and endothelial function) and cardiovascular responses in larger samples with a longer follow-up to further clarify the predictive value of reactivity in the development of hypertension, along with potential mechanisms.
33

Psychická zátěž u vysokoškoláků. / Mental stress in college students

BLECHOVÁ, Romana January 2016 (has links)
The thesis deals with an incidence of mental stress of college students. The thesis is not only focused on the present, but also on the degree of mental stress and the factors that affect the degree of stress. The first objective is to analyse the incidence and impact of mental stress at students of the faculty. A partial objective is to describe the relation of physical activity and mental load, as many authors state that physically active individuals are mentally more resistant. Furthermore, to determine how many students suffer from a particular degree of depression and whether students sought professional help. The practical part deals with the analysis of individual questions from the questionnaire, which are graphically presented in the form of graphs. In this section it is also stated the evaluation of standardized part of the questionnaire, the division of students into groups according to the SDS index and evaluation of hypotheses using statistical processing by method of multiple regression analysis by using the freely available Gretl program. For the purposes of the research two hypotheses were formulated: H1: Mental stress is present at the first-year students of bachelor's degree. H2: The degree of mental load varies among physically active and inactive students. These hypotheses were statistically evaluated using multiple regression analysis in freely available Gretl program and according to the results they were confirmed or disproved. The results of this thesis can be used for the needs of the faculty, which can obtain a comprehensive view on the impact of the faculty environment on the students' mental status. Studying at university is not only an instrument to gain professional knowledge and qualification in the field of study, but also the social environment where you can get a lot of contacts.
34

Problematika ošetřovatelské péče v traumacentrech České republiky / Nursing care in trauma centras in the Czech Republic

POLANOVÁ, Alena January 2010 (has links)
Abstract The thesis deals with the issues of nursing care in trauma centres in the Czech Republic. Injuries requiring complex and multidisciplinary treatment apart from surgery therapy are still more frequent nowadays. This is why trauma centres have been established in the Czech Republic. Their establishment increases demands for caring staff of non-physician fields. These increasing demands are of mental and physical character and of course demands for further education. The aim of the thesis was to find what opportunities nurses of trauma centres have in the field of further education, what are their biggest problems and how they cope with mental and physical stress in their work. The following hypotheses were set upon qualitative research in the form of unstructured interviews with nurses of trauma centres. Hypothesis 1: Nurses working in trauma centres prefer specialization education to tertiary education. Hypothesis 2: Nurses working in trauma centres cooperate with nurses from other clinical branches on provision of nursing care. Hypothesis 3: Nurses working in trauma centres get education not only in traumatology, but also in further clinical fields. Hypothesis 4: Nurses working in trauma centres cope with mental stress. Hypothesis 5: Nurses working in trauma centres cope with physical stress. Quantitative research in the form of questionnaires was applied on confirmation or refutation of the hypotheses. The research sample consisted of nurses working in trauma centres in the Czech Republic. Upon evaluation of the results hypotheses 1, 2 and 5 were confirmed and hypotheses 3 and 4 were refuted. The research results confirm that the work of nurses in trauma centres is hard in terms of mental and physical stress. There are still some reserves in further education of nurses not only on the part of the top managements but also on the part of the health care staff themselves. The thesis result may help in recruiting new staff to departments where the expected psychical and physical intensity might be an incentive to the care about an employee in the field of mental hygiene and improvement of interdisciplinary cooperation in trauma centres in the Czech Republic.
35

Avaliação da resposta vasodilatadora em crianças obesas portadoras de polimorfismo dos receptores beta 2-adrenérgico / Evaluation the muscle vasodilatory responses in obese children with beta 2-adrenoceptor

Alexandre Galvão da Silva 28 August 2007 (has links)
A obesidade é um dos maiores fatores de risco para o desenvolvimento de comprometimentos cardiovasculares. Essas alterações também são encontradas em crianças. Recentemente, estudos citam prejuízos cardiovasculares em crianças obesas. Estudos prévios in vitro e in vivo, sugeriram que alguns polimorfismos para o receptor beta 2-adrenérgico podem afetar de forma distinta as respostas à estimulação adrenérgica, levando a diferentes modulações cardiovasculares e metabólicas. No presente estudo, nós avaliamos a pressão arterial média, fluxo sangüíneo muscular e condutância vascular em resposta a estresse mental e exercício em crianças obesas homozigotas para Arg16 e Gln27 (Arg16/Gln27), Gly16 e Gln27 (Gly16/Gln27), e Gly16 e Glu27 (Gly16/Glu27) no receptor beta 2-adrenérgico. Inicialmente, foram pré-selecionadas 110 crianças obesas voluntárias do Ambulatório de Endocrinologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. Essas crianças foram genotipadas para os alelos Arg 16, Gly16, Glu27 e Gln27 do beta 2-adrenoreceptor. No estudo, foram detectadas 40 crianças obesas em homozigoze para os alelos 16 e 27 do receptor beta 2-adrenérgico. Vinte e três eram homozigotas para Arg16/Gln27, 7 para Gly16/Gln27 e 10 para Gly16/Glu27. Quando os três grupos foram comparados em condições basais, não houve diferenças nas variáveis antropométricas (idade, peso, IMC e Z-score), nos parâmetros metabólicos (glicemia, colesterol total, LDL - colesterol, HDL - colesterol, triglicérides, leptina, insulina, área de glicose e insulina e HOMA - IR) e nas variáveis hemodinâmicas (freqüência cardíaca, pressão arterial, fluxo sangüíneo muscular e condutância vascular). Durante o exercício, a resposta vasodilatadora foi maior nas crianças obesas homozigotas para Gly16 e Glu27 quando comparada às crianças obesas homozigotas para Gly16 e Gln27 e Arg16 e Gln27. Da mesma maneira, a resposta vasodilatadora ao estresse mental, foi maior nas crianças obesas homozigotas para Gly16 e Glu27 quando comparadas às crianças dos outros dois grupos. Pelos resultados, concluímos que a presença de homozigoze para Gly16 e Glu27 do receptor beta 2-adrenérgico favorece a melhor resposta vasodilatadora durante manobras fisiológicas. É razoável pensar que estas crianças estarão mais protegidas contra injúrias cardiovasculares. / Obesity is one major risk factor for development of vascular disorders. These alterations are also found in children, since recent studies reported vascular disorders in childhood obesity. Previous studies in vivo and in vitro, suggested that these variants of beta 2-adrenoceptors (ADRB2) may differently affect functional responses to adrenergic stimulation, leading to distinct modulations on cardiovascular and metabolic phenotypes. In the present investigation we report the mean blood pressure, forearm blood flow and forearm vascular conductance response during mental stress and exercise in obesity children who were homozygous for Arg16 and Gln27 (Arg16/Gln27), Gly16 and Gln27 (Gly16/Gln27), and Gly16 and Glu27 (Gly16/Glu27) of the beta 2-adrenoceptors. Initially, we screened one hundred and ten pre-selected obese children volunteers, from the Clinical Endocrinology Ambulatory Clinic of University of São Paulo. These children were genotyped for the Arg16, Gly16, Gln27, and Glu27 beta 2-adrenoceptor alleles. Forty subjects who were homozygous for the alleles 16 and 27 were involved in the study. Twentythree were homozygous for Arg16/Gln27, 7 for Gly16/Gln27, and 10 for Gly16/Glu27. When the three groups were compared, in basal conditions, there were no difference in terms of anthropometry (age, weight, height, BMI, Z-score), metabolic variables (glucose, cholesterol, LDL-cholesterol, HDLcholesterol, triglycerides, leptin, insulin, glucose area, insulin area and HOMA-IR) and hemodynamics variables (heart rate, blood pressure, forearm blood flow and forearm vascular conductance). During exercise, vasodilatory responsiveness was greater in obese children homozygous for Gly16 and Glu27 than in obese children homozygous for Gly 16 and Gln 27, and Arg 16 and Gln 27. Similarly, during mental stress vasodilatory responsiveness was greater in obese children homozygous for Gly 16 and Glu 27, than in obese children for Gly 16 and Gln 27, and Arg 16 and Gln 27. In conclusion, our results obtained in the obese children support the view that the homozygous for Gly16/Glu27 of the beta 2-adrenoceptor favors the greater vasodilatory response during physiological maneuvers; it is reasonable to think that they will be more protected against cardiovascular disorders.
36

Resposta hemodinâmica durante o estresse mental em pacientes com cirrose hepática: influência do β-bloqueador

Guerrero, Rosa Virginia Diaz 26 March 2018 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2018-05-04T11:31:40Z No. of bitstreams: 1 rosavirginiadiasguerrero.pdf: 1157086 bytes, checksum: 8cdc3732c7d0fbf596e17da13771b8de (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-09-03T16:01:40Z (GMT) No. of bitstreams: 1 rosavirginiadiasguerrero.pdf: 1157086 bytes, checksum: 8cdc3732c7d0fbf596e17da13771b8de (MD5) / Made available in DSpace on 2018-09-03T16:01:40Z (GMT). No. of bitstreams: 1 rosavirginiadiasguerrero.pdf: 1157086 bytes, checksum: 8cdc3732c7d0fbf596e17da13771b8de (MD5) Previous issue date: 2018-03-26 / Introdução: Pacientes com cirrose hepática podem apresentar alterações hemodinâmicas em repouso, caracterizada por menores valores pressóricos. Além dessas alterações em repouso, esses pacientes também podem apresentar alterações durante situações que demandem maior exigência do sistema cardiovascular. Dentre essas situações o exercício físico e estresse mental ganham destaque. Com relação ao exercício físico, verificamos que pacientes com cirrose hepática apresentam resposta pressórica diminuída durante o exercício físico isométrico. Assim, é possível que esses pacientes também apresentem alterações hemodinâmicas frente ao estresse mental. Objetivo: Avaliar parâmetros hemodinâmicos durante o estresse mental em pacientes com cirrose hepática. Métodos: Foram avaliados 19 pacientes com cirrose hepática (13 Child A, 5 Child B e 1 Child C) divididos nos seguintes grupos: Pacientes sem uso de β-bloqueador (Grupo Sem β, n=11) e pacientes com uso de β-bloqueador (Grupo Com β, n=8). Adicionalmente, um grupo composto por 16 pessoas sem cirrose hepática (Grupo Controle), pareado por idade e sexo, foi avaliado. O estresse mental foi induzido pelo Stroop Color Word Conflict Test. Foram mesuradas as variáveis pressão arterial batimento a batimento (Finometer®), frequência cardíaca pelo eletrocardiograma (Biopac) e fluxo sanguíneo do antebraço pela pletismografia de oclusão venosa (Hokanson®) durante 3 minutos basais seguidos de 3 minutos de estresse mental. A condutância vascular periférica foi calculada dividindo o fluxo sanguíneo do antebraço pela pressão arterial média e reportada em unidades. Foi realizado test t para as variáveis em repouso e Anova de dois fatores para a resposta (Δ) ao estresse mental, considerado significativo p≤0,05. Resultados: Em repouso, não foram observadas diferenças entre os grupos Sem β e Controle para pressão arterial sistólica (135±18 vs. 132±13 mmHg p=0,58), pressão arterial diastólica (74±7 vs. 73±8 mmHg p=0,82), frequência cardíaca (64±8 vs. 69±10bpm p=0,16) e condutância vascular do antebraço (2,98±1,08 vs. 2,83±1,05unidades p=0,72), respectivamente. Durante o estresse mental, apesar do aumento significativo em relação ao basal efeito tempo p<0,01 dos grupos Sem β e Controle na pressão arterial sistólica (Δ1ºmin: 3±1 vs. 9±1; Δ2ºmin: 5±3 vs. 12±2; Δ3ºmin: 6±3 vs. 11±2 mmHg, respectivamente efeito interação p=0,09) e na pressão arterial diastólica (Δ1º min: 2±1 vs. 5±1; Δ2ºmin: 3±1 vs. 7±1; Δ3ºmin: 3±1 vs. 6±1 mmHg, respectivamente efeito da interação p=0,06), o grupo Sem β apresentou resposta significativamente deprimida em relação ao Controle efeito do grupo p=0,04 e p=0,03 respectivamente. A frequência cardíaca aumentou significativamente em relação ao basal efeito do tempo p=<0,01 e de forma semelhante entre os grupos Sem β e Controle (Δ1ºmin: 6±2 vs. 12±2; Δ2ºmin: 6±2 vs. 10±2; Δ3ºmin: 6±2 vs. 9±2 bpm, respectivamente efeito interação p=0,09). Por outro lado, apesar do aumento significativo em relação ao basal observado em ambos os grupos efeito do tempo p=<0,01, a resposta da condutância vascular periférica foi significativamente maior no grupo Sem β em relação ao grupo Controle (Δ1ºmin: 1,08±0,33 vs. 1,34±0,33; Δ2ºmin: 1,28±0,33 vs. 0,79±0,27; Δ3ºmin: 1,62±0,34 vs. 0,50±0,28 unidades, respectivamente efeito da interação p=0,01). Com relação ao grupo Com β, em repouso, a frequência cardíaca foi significativamente menor em relação ao grupo Controle (58±9 vs. 69±10bpm p=0,01). Os grupos Com β e Controle foram semelhantes em repouso para os valores de pressão arterial sistólica (132±16 vs. 132±13mmHg p=0,93), pressão arterial diastólica (69±6 vs. 73±8mmHg p=0,13) e condutância vascular periférica (2,38±0,66 vs. 2,83±1,05unidades p=0,21), respectivamente. Durante o estresse mental os grupos Com β e Controle apresentaram aumento significativo em relação ao basal efeito do tempo p<0,01 e de forma semelhante para pressão arterial sistólica (Δ1ºmin: 6±2 vs. 9±1; Δ2ºmin: 11±3 vs. 12±2; Δ3ºmin: 10±3 vs. 11±2 mmHg efeito da interação p=0,66), pressão arterial diastólica (Δ1ºmin: 4±1 vs. 5±1; Δ2ºmin: 6±2 vs. 7±1; Δ3ºmin: 5±2 vs. 6±1 mmHg efeito da interação p=0,93), frequência cardíaca (Δ1ºmin: 9±3 vs. 12±2; Δ2ºmin: 9±3 vs. 10±2; Δ3ºmin: 8±3 vs. 9±2 bpm efeito da interação p=0,55) e condutância vascular periférica (Δ1ºmin: 1,73±0,48 vs. 1,34±0,34; Δ2ºmin: 1,04±0,39 vs. 0,79±0,27; Δ3ºmin: 0,66±0,26 vs. 0,50±0,19 unidades efeito da interação p=0,83). Conclusão: Pacientes com cirrose hepática sem uso de β-bloqueador apresentam resposta deprimida da pressão arterial sistólica e diastólica e vasodilatação exacerbada durante o estresse mental agudo quando comparados aos indivíduos sem cirrose hepática. Além disso, sugere-se que essas respostas inadequadas sejam normalizadas com o uso do β-bloqueador. / Introduction: Patients with hepatic cirrhosis may show hemodynamic alterations at rest, marked by low values of blood pressure. Besides those alterations at rest, these patients also may show alterations in situations that demand a greater exigence from the cardiovascular system. Among those situations, physical exercise and mental stress are prominent. In regard to physical exercise, we noted that patients with hepatic cirrhosis show a low blood pressure response during isometric physical exercise. Thus, these patients are also likely to show hemodynamic alterations due to mental stress. Objective: Evaluate hemodynamic parameters during mental stress in patients with hepatic cirrhosis. Methods: Nineteen patients with hepatic cirrhosis were evaluated (13 Child A, 5 Child B and 1 Child C) distributed in the following groups: Patients without use of beta-blocker (Group Without β Adrenergic Receptor, n=11) and patients with use of β Adrenergic Receptor (Group with β, n=8). In addition, a group integrated by 16 people with no hepatic cirrhosis (Group Control), paired in age and gender, was evaluated. The mental stress was induced by Stroop Color Word Conflict Test. The blood pressure variables were measured beat by beat (Finometer®), the cardiac frequency by electrocardiogram (Biopac) and the blood flow of the forearm by plethysmograph of venous occlusion (Hokanson®) during 3 basal minutes followed by 3 minutes of mental stress. The peripheral vascular conductance was calculated dividing the blood flow of the forearm by the mean blood pressure and reported in unities. A T test was carried out on the at-rest variables and Anova of two factors for the response (Δ) to mental stress, considered significant p≤0,05. Results: At rest, there were not differences observed between the groups without β and Control for systolic blood pressure (135±18 vs. 132±13 mmHg p=0,58), diastolic blood pressure (74 ±7 vs. 73±8 mmHg p=0,82), cardiac frequency (64±8 vs. 69±10bpm p=0,16) and peripheral vascular conductance (2,98±1,08 vs. 2,83±1,05 unities p=0,72), respectively. During mental stress, despite the significant increase in regard to the basal time effect p<0,01 of the two groups Without β and Control in the systolic blood pressure (Δ1ºmin: 3±1 vs. 9±1; Δ2ºmin: 5±3 vs. 12±2; Δ3ºmin: 6±3 vs. 11±2 mmHg, respectively interaction effect p=0,09) and in the diastolic blood pressure (Δ1º min: 2±1 vs. 5±1; Δ2ºmin: 3±1 vs. 7±1; Δ3ºmin: 3±1 vs. 6±1 mmHg, respectively interaction effect p=0,06), the group Without β showed a significantly depressed response compared with the Group Control group effect p=0,04 e p=0,03 respectively. The cardiac frequency significantly increased in regard to the basal time effect p=<0,01 and in the same way among the groups Without β and Group Control (Δ1ºmin: 6±2 vs. 12±2; Δ2ºmin: 6±2 vs. 10±2; Δ3ºmin: 6±2 vs. 9±2 bpm, respectively interaction effect p=0,09). On the other hand, despite the significant increase in regard to the basal time effect p=<0,01 observed in both groups, the response of the peripheral vascular conductance was crucially greater in the group Without β compared with the Group Control (Δ1ºmin: 1,08±0,33 vs. 1,34±0,33; Δ2ºmin: 1,28±0,33 vs. 0,79±0,27; Δ3ºmin: 1,62±0,34 vs. 0,50±0,28 unities, respectively interaction effect p=0,01). In regard to the group With β, at rest, the cardiac frequency was significantly lower compared with the Group Control (58±9 vs. 69±10bpm p=0,01). The groups With β and Control were similar at rest in terms of systolic blood pressure values (132±16 vs. 132±13mmHg p=0,93), diastolic blood pressure (69±6 vs. 73±8mmHg p=0,13) and peripheral vascular conductance (2,38±0,66 vs. 2,83±1,05 unities p=0,21). During mental stress the groups With β and Control showed a significant increase in regard to basal time effect p<0,01 and, likewise, for systolic blood pressure (Δ1ºmin: 6±2 vs. 9±1; Δ2ºmin: 11±3 vs. 12±2; Δ3ºmin: 10±3 vs. 11±2 mmHg interaction effect p=0,66), diastolic blood pressure (Δ1ºmin: 4±1 vs. 5±1; Δ2ºmin: 6±2 vs. 7±1; Δ3ºmin: 5±2 vs. 6±1 mmHg interaction effect p=0,93), cardiac frequency (Δ1ºmin: 9±3 vs. 12±2; Δ2ºmin: 9±3 vs. 10±2; Δ3ºmin: 8±3 vs. 9±2 bpm interaction effect p=0,55), and peripheral vascular conductance (Δ1ºmin: 1,73±0,48 vs. 1,34±0,34; Δ2ºmin: 1,04±0,39 vs. 0,79±0,27; Δ3ºmin: 0,66±0,26 vs. 0,50±0,19 unities interaction effect p=0,83). Conclusion: Patients with hepatic cirrhosis without use of beta-blocker show a depressed response in the systolic and diastolic, as well as in the exacerbated vasodilation during acute mental stress when compared with individuals without hepatic cirrhosis. Besides that, those inadequate responses are suggested to be normalized with the use of beta-blocker.
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Resposta vascular durante o teste de estresse mental em adultos fisicamente ativos e sedentários com apneia obstrutiva do sono / Vascular response during the mental stress test in physically active and sedentary adults with obstructive sleep apnea

Rosyvaldo Ferreira Silva 30 October 2017 (has links)
O objetivo deste estudo foi comparar a resposta do vascular durante o teste de estresse mental em adultos sedentários (SED) e fisicamente ativos (FA) com apneia obstrutiva do sono (AOS). Os pacientes não tratados com AOS e sem outras comorbidades foram classificados em SED e FA de acordo com o Questionário Internacional de atividade física. A pressão sanguínea, a freqüência cardíaca, o fluxo sanguíneo do antebraço (FSA) (pletismografia) e a condutância vascular do antebraço (CVA = FSA/pressão sanguínea x 100) foram medidas continuamente em repouso (4 min), seguidas de 3 min do teste Stroop Color Word Test (SCWT) também conhecido como teste de estresse mental. Quarenta pacientes com AOS (homens = 24, idade = 50 ± 1 anos, índice de massa corporal = 29 ± 0,5 Kg/m2, índice de apneia hipopnéia = 39 ± 4 eventos/h) divididos em SED (n = 21) e FA (n = 19) apresentaram diferença significativa na quantidade de tempo gasto em atividade física (17 ± 9 vs. 245 ± 33 minutos/semana, respectivamente). Os grupos foram semelhantes em relação ao sexo, idade, índice de massa corporal, frequência cardíaca do nível educacional e pressão arterial média em repouso, bem como percepção de estresse no final do SCWT. Em contraste, FSA basal (1,7 ± 0,08 mL/min/100mL vs 2,5 ± 0,19 mL/min/100mL) e CVA (1,7 ± 0,07 vs 2,5 ± 0,2) foram significativamente menores no grupo SED quando comaprados a FA, respectivamente (p <0,05). A resposta de frequência cardíaca e pressão arterial ao SCWT foram semelhantes e aumentou em ambos os grupos. O FSA (3,5 ± 0,2 mL/min/100mL vs 2,4 ± 0,14 mL/min/100mL) e a CVA (3,5 ± 0,2 vs 2,3 ± 0,1) durante SCWT foi significativamente menor no grupo SED quando comparados ao grupo FA (P <0,05). Houve uma correlação significativa entre a atividade física no tempo de lazer e FSA (r = 0,57; P <0,05) e CVA (r = 0,48; P <0,05). Conclui-se, que, a resposta vascular nos pacientes com AOS é influenciada pelo nível de atividade física de lazer. O alto nível de atividade física pode proteger a disfunção cardiovascular em repouso e na condição de estresse mental em pacientes com AOS moderado a severo / The objective of this study was to compare a vascular response during the mental stress test in sedentary (SED) and physically active (PA) patients with obstructive sleep apnea (OSA). Patients not treated with OSA and without other comorbidities were classified in SED and PA according to the International Questionnaire of Physical Action. Blood pressure, heart rate, forearm blood flow (plethysmography) and forearm vascular conductance (FVC = FBF / blood pressure x 100) were measured continuously at rest (4 min), followed by 3 min of the test Stroop Color Word Test (SCWT) also known as mental stress test. Forty patients with OSA (men = 24, age = 50 ± 1 years, body mass index = 29 ± 0.5 kg / m2, apnea hypopnea index = 39 ± 4 events / h) divided in SED (n = 19) and PA (n = 19) presented a significant difference in the amount of time spent in physical activity (17 ± 9 vs. 245 ± 33 minutes / week, respectively). The groups are similar in relation to gender, age, body mass index, heart rate at educational level, and mean resting blood pressure, as well as perceived stress at the end of SCWT. In contrast, baseline FBF (1.7 ± 0.08 mL/min/100mL vs 2.5 ± 0.19 mL/min/100mL) and FVC (1.7 ± 0.07 U vs 2.5 ± 0.2 U) were significantly lower without SED group when compared to PA, respectively (p <0.05). The heart rate and blood pressure response to SCWT were similar and increased in both groups. The FBF (3.5 ± 0.2 mL/min/100mL vs 2.4 ± 0.14 mL/min/100mL) and the FVC (3.5 ± 0.2 U vs 2.3 ± 0.1 U) during SCWT was much lower in the SED group when compared to the group PA (P <0.05). There was a significant correlation between physical activity without leisure time and FBF (r = 0.57, P <0.05) and FVC (r = 0.48, P <0.05). In conclusion, the vascular response in OSA patients is influenced by the level of leisure physical activity. The high level of physical activity may protect a cardiovascular dysfunction at rest and mental stress condition in patients with moderate to severe OSA
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RFID inom pappersindustrin : Identitetsföljning av order från packning till kund

Fredrikson, Oscar, Hansen, Sofie, Stenborg, Felice January 2024 (has links)
This qualitative case study focuses on investigating the benefits and challenges when applying Radio frequency identification (RFID) for identity tracking of products at manufacturing companies in the paper industry. This study has been designed from qualitative methods such as interviews and observations at the case company. A case study was chosen as it was considered most appropriate to answer the study’s purpose and questions. In the theoretical frame of reference, advantages, challenges, and limitations regarding the application of RFID technology in manufacturing companies emerge. In summary, there are several advantages to the application of RFID technology, including economic, technological, safety, and efficiency, for example improved traceability and reduced manual handling. The limitations and challenges that emerged during the theory are also financial, security, technological, and economic. The limitations focus on the technology itself while the challenges focus on the application of the technology. The results show that RFID technology offers advantages such as increased efficiency and accuracy in unloading and inventory, improved traceability, reduced risk of manual errors, and reduced mental stress. The challenges include the risk of technical errors, the need for security measures for information sharing, and issues regarding standardization and frequency regulation. There are solutions to some challenges, such as optimization of tag reading and collaboration with external parties. However, complex security issues and the need for standardization for a smooth transition to RFID technology remain. The study was limited to the application of RFID technology in the paper industry from packing out to the customer. During the study interesting information has emerged that has not been investigated further, partly because there was no room for further research, and it extended outside the scope of the study. This resulted in suggestions for further research, it would be interesting, among other things, to investigate the possibility of placing the reader in the gates of the magazines to see what advantages this gives or to investigate the possibility of attaching the RFID tag at an earlier stage of the production line. / Denna kvalitativa fallstudie har utförts på ett fallföretag och fokuserar på att undersöka fördelar och utmaningar vid en applicering av radiofrekvensidentifiering (RFID) för identitetsföljning av produkter hos företag inom pappersindustrin. Detta arbete har utformats från kvalitativa metoder som intervjuer och observationer på fallföretaget.  En fallstudie valdes då det ansågs mest lämpligt för att besvara arbetets syfte och frågeställningar. I den teoretiska referensramen framkommer fördelar, utmaningar och begränsningar gällande applicering av RFID-teknologin i tillverkande företag. Sammanfattningsvis finns det flera fördelar med applicering av RFID-teknologi, bland annat ekonomiska, teknologiska, säkerhetsmässiga och effektivitetsmässiga, exempelvis förbättrad spårbarhet och minskad manuell hantering. De begränsningar och utmaningar som framkommit under teorin är också ekonomiska, säkerhetsmässiga, teknologiska och ekonomiska. Begränsningarna fokuserar på själva tekniken medan utmaningarna fokuserar på appliceringen av teknologin. Resultatet visade att RFID erbjuder fördelar såsom ökad effektivitet och noggrannhet i utlastning och inventering, förbättrad spårbarhet, minskad risk för manuella fel samt minskad mental påfrestning. Utmaningarna inkluderar risk för tekniska fel, behov av säkerhetsåtgärder för informationsdelning samt frågor kring standardisering och frekvensreglering. Det finns lösningar på en del utmaningar, såsom optimering av taggavläsning och samarbete med externa parter. Dock kvarstår komplexa säkerhetsfrågor och behovet av standardisering för en smidig övergång till RFID-teknologi. Arbetet avgränsades till appliceringen av RFID-teknologin inom pappersindustrin från packning till kund. Under arbetet har det framkommit intressant information som inte har undersökts vidare, bland annat på grund av att det inte fanns utrymme att forskas vidare på och att det sträckte sig utanför avgränsningen för arbetet. Detta resulterade i förslag till vidare forskning, det hade bland annat varit intressant att undersöka möjligheten att placera läsaren i portarna på magasinen för att se vilka fördelar detta ger eller att undersöka möjligheten att fästa RFID-taggen i ett tidigare skede av produktionslinjen.
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Psychicky náročné momenty v práci sestry v intenzivní péči / Mentally challenging moments of intensive care's nurse

Myslivcová, Klára January 2016 (has links)
The profession of general intensive care nurse is specific in its high demands on physical, technical, ethical and mental abilities of each individual. The thesis focusses on the mental stress of the nurse, analyses potentially high-risk professional situations the nurse encounters and proposes methods for their management. The topic of mental stress and its handling has, and will, have important impact on the field. The goal of the thesis is to map the psychologically challenging situations that all of the 129 nurses approached in a smaller local medical facility considered as difficult to handle and thus have impact on their ability to cope with a demanding job. The situations are defined and evaluated using predefined hypotheses. The results of an anonymous quantitative questionnaire clearly show that the largest levels of stress and discomfort are caused by situations which are "directly connected to medical care provided by the general intensive care and accident and emergency nurse". The least discomfort is perceived in situations described as "indirectly connected to intensive care / A&E nurse duties", such as irregular working patterns and work during public holidays. The results are presented in a graphical form. We conclude by observing that unlike large-scales studies that commonly...
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仕事のストレス要因から評価した自覚的ストレスの妥当性、および自覚的ストレスと生活習慣との関連

Yatsuya, Hiroshi, OuYang, Pei, Sugiura, Kaichiro, Mitsuhashi, Hirotsugu, Hotta, Yo, Takefuji, Seiko, Matsushita, Kunihiro, Wada, Keiko, Morimoto, Yusuke, Tamakoshi, Koji, Toyoshima, Hideaki, Otsuka, Rei, 八谷, 寛, 歐陽, 蓓, 杉浦, 嘉一郎, 三橋, 弘嗣, 堀田, 洋, 竹藤, 聖子, 松下, 邦洋, 和田, 恵子, 森本, 祐介, 玉腰, 浩司, 豊嶋, 英明, 大塚, 礼 10 1900 (has links)
No description available.

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