Abstract In this thesis a socio-cultural perspective of medical science education is adopted to argue the position that undergraduate medical scientists must be enculturated into the profession as knowledge workers and symbolic analysts who can interact with computers in complex analytical procedures, quality assurance and quality management. The cue for this position is taken from the transformations taking place in the pathology industry due to advances in automation, robotics and informatics. The rise of Evidence-Based Laboratory Medicine (EBLM) is also noted and the observation by higher education researchers, that knowledge systems are transforming in such a way that disciplines can no longer act in isolation. They must now collaborate with disparate fields in transdisciplinary knowledge systems such as EBLM, for which new skills must be cultivated in undergraduate medical scientists. This thesis aims to describe a theoretical basis for knowledge work by taking a semiotic perspective. This is because, semiotics, a theory of signs and representations, can be applied to the structure of transdisciplinary scientific knowledge, the logic of scientific practice and the rhetoric of scientific communications. For this purpose, a semiotic framework is first derived from a wide range of semiotic theories existent in the literature. Then the application of this semiotic framework to clinical chemistry knowledge, context, logic, and rhetoric is demonstrated. This is achieved by interpreting various clinical chemistry data sources, for example, course materials, laboratory spatial arrangements, instruments, printouts, and students' practical reports, collected from a teaching laboratory situation. The results of semiotic analysis indicate that the clinical chemist working in the computerised laboratory environment performs knowledge work, and the term is synonymous with symbolic analysis. It is shown that knowledge work entails the application of a systematic structure for clinical chemistry knowledge derived in terms of the validation procedures applied to laboratory, data, results and tests; the application of logic in the classification and selection of instruments, their rulegoverned- use, and in troubleshooting errors; pragmatic decisions based on availability of space, services and budgets; discrimination among values in laboratory test evaluations in EBLM, for the cost-effectiveness and relevance of pathology services; and the recognition of rhetorical strategies used to communicate laboratory test information in graphs, charts, and statistics. The role of the laboratory context is also explained through semiotics, in terms of its spatial arrangements and designs of laboratory instruments, as a place that constrains the knowledge work experience. This contextual analysis provides insights into the oppositional trend brought to wide attention by analysts of computerised professional work, that more skills are needed, but that there are fewer highly skilled positions available. The curriculum implications of these findings are considered in terms of the need to cultivate knowledge workers for highly complex symbolic analysis in computerised laboratories; and also the need to prepare medical science graduates for the transdisciplinary knowledge system of EBLM, and related venues of employment such as biomedical research and clinical medicine. In meeting the aims to define and demonstrate knowledge work from the semiotic perspective, this thesis makes an original contribution to knowledge by the application of semiotics to a field in which it has probably never been tested. It contributes to the scholarship of teaching in higher education by formulating a structure for transdisciplinary medical science knowledge, which integrates scientific with other forms of knowledge, and with real world practice.

Made available in DSpace on 2016-06-02T20:19:14Z (GMT). No. of bitstreams: 1 3279.pdf: 2107272 bytes, checksum: 76c57df00c9a0034d4eafd7654a5e1fb (MD5) Previous issue date: 2010-05-26 / Universidade Federal de Minas Gerais / The dissertation consisted of two works. The objective of the first study was to use linear and non-linear methods to investigate the cardiac autonomic modulation in elderly men and women in response to a postural change from the supine to the standing position. Fourteen men (66 ± 3.5 years) and ten women (65 ± 3.3 years) who did not use hormonal replacement therapy (HRT) were evaluated. All volunteers were apparently healthy. The RR intervals (RRi) and the beat-to-beat heart rate (HR) were recorded in the supine and standing positions. The HR variability (HRV) was studied by spectral analysis: low frequency (LF) and high frequency (HF) in absolute units (LF and HF) and normalized units (LFun and HFun) as well as the low frequency/high frequency (LF/HF) ratio. Symbolic analysis (0V%, 1V%, 2LV% and 2ULV% indexes) and Shannon entropy were also calculated for the HRV analysis. Men presented higher LF, LFnu and LF/HF ratio, and lower HFnu and 1V% symbolic index when compared to women in the supine position. Shannon entropy was higher among men than among women in the standing position. During the postural change there were a decrease in LF and an increase in Shannon entropy in the men s group. There was an increase in LFnu and LH/HF ratio as well as a decrease in HF, HFnu and 2LV% symbolic index due to the postural change from supine to standing position in the women s group. In conclusion, women presented a more appropriate response to the postural change than men in the age range studied, showing that the cardiac autonomic modulation may be better preserved in women than in men. Similarly, the objective of the second study was to investigate the HR autonomic modulation in elderly men and women HRT users and no-users by linear and nonlinear methods. So, 15 men (66 ± 3.4 years), 13 women without HRT (64 ± 3.5 years) and 7 women HRT users (61 ± 2.1 years), all of them apparently healthy, were evaluated. The RRi and the beat-to-beat HR were recorded in the supine position. The data analysis was carried out on the same methods described in the first study. The cardiac autonomic modulation analysis in the supine position shows that the women without HRT presented higher HFnu and lower LFnu, LF/HF ratio and 0V% symbolic index when compared to the men. No differences were observed in the comparison between the women who used and did not use HRT. We concluded that the women without HRT seem to have a higher cardiac vagal modulation and a lower cardiac sympathetic modulation when compared to the men. The use of HRT may not offer advantages to the cardiac autonomic modulation in elderly women. / A dissertação constou de 2 estudos descritos a seguir. O estudo I teve por objetivo verificar, por métodos lineares e não lineares, a modulação autonômica da freqüência cardíaca (FC) de idosos aparentemente saudáveis em resposta à mudança postural de supino para ortostatismo. Participaram deste estudo 14 homens (66 ± 3,5 anos) e 10 mulheres (65 ± 3,3 anos) sem uso de terapia de reposição hormonal (TRH). Os intervalos R-R (iR-R) e a FC batimento a batimento foram registrados nas posições supina e ortostática. A VFC foi analisada por meio dos índices espectrais de baixa freqüência (BF) e alta freqüência (AF) em unidades absolutas (BF e AF) e unidades normalizadas (BFun e AFun), da razão entre as bandas de baixa e alta freqüências (BF/AF). A análise simbólica da VFC (índices 0V%, 1V%, 2LV% e 2ULV%) e a entropia de Shannon também foram calculadas. Na análise da VFC em resposta à mudança postural, os homens apresentaram maiores valores de BF, BFun e razão BF/AF e menores valores de AFun e índice simbólico 1V% em comparação às mulheres, na posição supina. A entropia de Shannon foi maior no grupo de homens comparado ao grupo de mulheres na posição ortostática. Nos homens, a mudança postural levou à diminuição de BF e aumento da entropia de Shannon. Nas mulheres, houve aumento de BFun e da razão BF/AF e diminuição de AF, de AFun e do índice simbólico 2LV% devido à mudança de posição de supino para ortostatismo. Concluímos que, na faixa etária estudada, as mulheres apresentaram uma resposta mais adequada à mudança postural que os homens, mostrando que a modulação autonômica cardíaca nas mulheres parece estar mais preservada. Também foi realizado o estudo II, que teve por objetivo verificar, por métodos lineares e não lineares, a modulação autonômica da FC de homens e mulheres idosas com e sem o uso de TRH. Para isso, foram avaliados 15 homens (66 ± 3,4 anos), 13 mulheres sem TRH (64 ± 3,5 anos) e 7 mulheres com TRH (61 ± 2,1 anos), todos aparentemente saudáveis. Os iR-R e a FC batimento a batimento foram registrados na posição supina. A análise de dados foi realizada como descrito para o estudo I. A análise da modulação autonômica cardíaca na posição supina mostrou que as mulheres sem uso de TRH apresentaram maior AFun e menores BFun, razão BF/AF e índice 0V% comparadas aos homens. Nenhuma diferença foi observada na comparação entre as de mulheres sem TRH e as mulheres com TRH. Concluímos que as mulheres não usuárias de TRH parecem ter uma maior modulação vagal e uma menor modulação simpática cardíaca quando comparadas aos homens, sendo que o uso de TRH parece não oferecer vantagens com relação à modulação autonômica cardíaca de mulheres idosas.

Made available in DSpace on 2016-06-02T20:19:17Z (GMT). No. of bitstreams: 1 4130.pdf: 7746703 bytes, checksum: 425a15aa93496be6f1802d7a31fd28d2 (MD5) Previous issue date: 2012-02-29 / Financiadora de Estudos e Projetos / OBJECTIVE Evaluate the heart rate variability (HRV) of individuals with Type 2 diabetes, in the supine and in response to active postural maneuver from the supine to orthostatic position, by means of linear and non linear analysis and correlate these data. RESEARCH DESIGN AND METHODS Sixteen men with type 2 diabetes (DM) and sixteen control subjects (CG), age-range from 40 to 65 year were studied. The R-R intervals were recorded with a Polar RS800CX for 10 minutes in supine and 10 minutes in the orthostatic position. We assessed HRV using spectral (LFnu, HFnu and LF/HF), symbolic (0V%, 1V%, 2LV% and 2ULV%) analysis, Shannon (SE) and conditional entropy (complexity Index - CI and Normalized Complexity Index- NCI). RESULTS The DM presented higher sympathetic modulation (LFnu) in the supine position than the CG. In active postural maneuver for the variables LFnu and HFnu, DM showed no significant responses. Irrespective of position DM presented lower complexity than CG for SE. The same did not occur with conditional entropy, however, in both groups a reduction in values of entropies was observed with postural change. The reduction in complexity observed by SE was related to an increase in sympathetic modulation (0V%). CONCLUSION Our study showed that DM had higher sympathetic modulation in the supine position, which may be related to less complexity of HRV in this population. In addition, DM did not present the expected response of the autonomic nervous system to active postural maneuver for the variables LFnu and HFnu. / OBJETIVO Avaliar a variabilidade da frequência cardíaca (VFC) de indivíduos com diabetes mellitus tipo 2, na posição supina e em resposta a manobra postural ativa de supino para ortostático, por meio de análise linear e não linear e correlacioná-las. MÉTODOS Foram avaliados dezesseis homens com diabetes mellitus tipo 2 (DM) e dezesseis sujeitos controle (GC), na faixa etária de 40 a 65 anos. Os intervalos R-R (iRR) foram captados por um Polar RS800CX durante 10 minutos na posição supina e 10 minutos na posição ortostática. Avaliou-se a VFC utilizando análises espectral (BFun, AFun e BF/AF), simbólica (0V%, 1V%, 2LV% e 2ULV%), entropia de Shannon (ES) e condicional (índice de complexidade - IC e índice de complexidade normalizado - ICN). RESULTADOS O DM apresentou maior modulação simpática (BFun) na posição supina do que o GC. Na manobra postural ativa para as variáveis BFun e AFun o DM não mostrou resposta significativa. Independentemente da posição DM apresentou menor complexidade (menor ES) do que o GC. O mesmo não ocorreu com a entropia condicional, entretanto em ambos os grupos foi observada redução nos valores das entropias com a mudança postural. A redução da complexidade observada pela ES foi relacionada ao aumento da modulação simpática (0V%). CONCLUSÃO Nosso estudo mostrou que DM apresentou maior modulação simpática na posição supina, a qual pode estar relacionada com a menor complexidade da VFC nessa população. Além disso, DM não apresentou resposta esperada do sistema nervoso autonômico à manobra postural ativa para as variáveis BFun e AFun.

This essay studies the historical phenomenon of dog-headed men (cynocephaly) andSaint Christopher who is in eastern-orthodox iconography depicted as a dog headedman. The study argues that a symbolic and phenomenological perspective is preferredto understand mythical figures with “unnatural” depictions. In order to reach aconclusion about the symbolic meaning behind dog-headed men and SaintChristopher, the human experience of dogs and their role in our world is examined indetail to construct a theory concerning their symbolism. The theory is then applied todepictions of dogs and dog-headed men in religious stories and images as well ashistorical accounts to see if the theory fits the facts.The study concludes that dog-headed men and Saint Christopher symbolize a kind of“guardian of the border”. What it means to guard the border has different implicationsdepending on if the dog-headed man is depicted in a Christian or non-Christiancontext. When reading the story of Saint Christopher with this pattern in mind, thereason for his legendary depiction is revealed. The conclusion is supported bycomparing Saint Christopher to stories from the bible which symbolize “the rolewhich the border can play as a part of the whole”. The dog-headed men of history, thesaint and the biblical stories all reinforce the symbolism of each other, revealing thedeeper meaning behind the wild, peripheral side of Christianity.

Made available in DSpace on 2016-06-02T20:18:23Z (GMT). No. of bitstreams: 1 6236.pdf: 2944020 bytes, checksum: dcbf2b2eaca77c3425524a77887f4d6b (MD5) Previous issue date: 2014-06-06 / Universidade Federal de Minas Gerais / The aging process affects many systems of the human body, including: autonomic nervous system, which can be assessed by heart rate variability (HRV); cellular structures, such as telomere length; and mechanisms of regulation of the inflammatory process, which can be evaluated by inflammatory markers such as high-sensitivity C-reactive protein (hsCRP). The combined analysis of these variables enables the study of the aging process in a multidimensional way. Additionally, the effects of hormone replacement therapy (HRT) on HRV are contradictory. In this way, we conducted the study I, which aimed to investigate the effects of HRT on HRV in healthy postmenopausal women. Two groups were evaluated: Group 1 (G1): 20 women who did not use HRT (60 ± 5.89 years) and group 2 (G2): 20 women undergoing HRT (59 ± 5.70 years). The electrocardiogram was recorded in supine position for 10 min. Spectral analysis included low and high frequency in absolute (LF and HF) and normalized (LFnu and HFnu) units. LF/HF ratio was also calculated. Symbolic analysis (0V%, 1V%, 2LV% e 2UV%), Shannon and conditional entropy were calculated. LF, LFnu and LF/HF ratio were higher, whereas HFnu was lower in G2 than in G1. Correlations between complexity indices and HFnu were significant and positive only in G1. We conclude that women undergoing HRT had higher cardiac sympathetic modulation and reduced cardiac vagal modulation compared to women not using HRT. Moreover, the expected positive relationship between cardiac vagal modulation and HRV complexity was found only in the group not undergoing HRT, indicating that vagal modulation in women under therapy drop below a minimum value necessary to the association to become apparent, suggesting an unfavorable cardiac autonomic modulation in spite of HRT. Considering the findings of the study I, we chose to adopt the use of the therapy as an exclusion criterion for the study II. Thus, the study II aimed to examine the aging effect on heart rate variability in supine and standing, on serum hsCRP and leukocyte telomere length, as well as to verify the age at which the changes caused by aging process are accentuated. One hundred and ten volunteers were divided into five groups according to age: G21-30 years, G31-40 years, G41-50 years, G51-60 years, and G61-70 years. Venous blood samples were collected for measurements of serum hsCRP and telomere length. ECG signals were recorded in rest supine and standing (15 min in each posture). HRV was assessed by spectral analysis in low and high frequencies in absolute (LF e HF) and normalized (LFnu e HFnu) units; symbolic analysis (0V%, 1V%, 2LV% e 2UV%); Shannon entropy; and complexity index (CI) and normalized CI (NCI) from conditional entropy. The main results were: 1) HF and 2UV% reduction (vagal modulation) in G51-60, and 0V% increase (sympathetic modulation) and NCI reduction (complexity) in G61-70, in supine; 2) less efficient response to postural change from supine to standing with advancing age; 3) hsCRP increase in G51-60; 4) telomere shortening in G61-70; 5) in supine, HRV indices showed stronger relationship with the principal component of most relevance from the multivariate principal component analysis, compared to hsCRP and telomere length. Considering that HRV indices in supine had a stronger association with the aging process, we can conclude that the decrease in cardiac vagal modulation may have influenced the increase in serum hsCRP (although normal values), in G51-60, since this effect is described by the cholinergic anti-inflammatory pathway. Decreased cardiac vagal modulation and increased hsCRP may have contributed to the telomere shortening identified in the following decade (G61-70). In this way, we must consider the importance of preventive actions prior to the onset of aging effects, particularly in the 41-50 age range, in an attempt to attenuate the natural effects of senescence. / O envelhecimento exerce influência sobre vários sistemas do corpo humano, dentre eles: sistema nervoso autonômico, que pode ser avaliado pela variabilidade da frequência cardíaca (VFC); estruturas celulares, como o comprimento de telômeros; e mecanismos reguladores de processos inflamatórios, que podem ser avaliados por marcadores inflamatórios, como a proteína C-reativa ultra sensível (PCRus). A análise conjunta dessas variáveis permitiria o estudo do processo de envelhecimento de forma multidimensional. Adicionalmente, são controversos os efeitos da terapia de reposição hormonal (TRH) sobre a VFC. Assim, foi realizado o estudo I, o qual teve por objetivo investigar os efeitos da TRH na VFC em mulheres pós-menopáusicas saudáveis. Foram avaliados dois grupos: grupo 1 (G1): 20 mulheres que não faziam uso de TRH (60 ± 5,89 anos) e grupo 2 (G2): 20 mulheres submetidas à TRH (59 ± 5,70 anos). O eletrocardiograma foi registrado na posição supina por 10 min. A análise espectral incluiu a baixa e a alta frequência em unidades absolutas (BF e AF) e normalizadas (BFun e AFun). A relação BF/AF também foi calculada. A análise simbólica (0V%, 1V%, 2LV% e 2UV%), e entropias de Shannon e condicional também foram calculadas. BF, BFun e a razão BF/AF foram maiores, enquanto AFun foi menor no G2 do que no G1. As correlações entre índices de complexidade e AFun foram significativos e positivos apenas no G1. Concluímos que mulheres submetidas à TRH apresentaram maior modulação cardíaca simpática e menor modulação cardíaca vagal em comparação às que não faziam a terapia. Além disso, a relação positiva esperada entre modulação cardíaca vagal e a complexidade da VFC foi encontrada apenas no grupo não submetido à TRH, indicando que a modulação vagal em mulheres sob a terapia não atinge um valor mínimo necessário para a associação se tornar aparente, sugerindo uma modulação autonômica cardíaca desfavorável, apesar da TRH. A partir dos achados do estudo I, optou-se por adotar, como critério de exclusão para o estudo II, o uso da terapia. Assim, o estudo II teve por objetivo analisar o efeito do envelhecimento sobre a VFC nas posições supina e ortostática, os níveis séricos da PCRus e o comprimento de telômeros leucocitários, além de verificar em qual faixa etária se acentuam as alterações provocadas pelo processo de envelhecimento. Foram avaliados 110 voluntários, divididos em cinco grupos, de acordo com a idade: G21-30 anos, G31-40 anos, G41-50 anos, G51-60 anos e G61-70 anos. Amostras de sangue venoso foram coletadas para medidas de PCRus e comprimento de telômeros. Os sinais eletrocardiográficos foram registrados em repouso nas posições supina e ortostática (15 min em cada postura). A VFC foi avaliada por índices de baixa e alta frequências em unidades absolutas (BF e AF) e normalizadas (BFun e AFun) da análise espectral; índices 0V%, 1V%, 2LV% e 2UV% da análise simbólica; entropia de Shannon; e índice de complexidade (IC) e IC normalizado (ICN) da entropia condicional. Os principais resultados foram: 1) redução de AF e 2UV% (modulação vagal) em G51-60, além de aumento de 0V% (modulação simpática) e diminuição de ICN (complexidade) em G61-70 na posição supina; 2) resposta menos eficiente à manobra de mudança postural de supino para ortostatismo com o avanço da idade; 3) aumento da PCRus em G51-60; 4) encurtamento do comprimento de telômeros em G61-70; 5) na posição supina, os índices da VFC apresentaram relação mais alta com o componente principal de maior relevância, proveniente da análise multivariada por componentes principais, em comparação à PCRus e ao comprimento de telômeros. Considerando-se que os índices da VFC na posição supina apresentaram uma associação mais forte com o envelhecimento, podemos concluir que a diminuição da modulação cardíaca vagal possa ter contribuído para o aumento dos níveis séricos de PCRus (apesar dos valores estarem dentro de faixa de normalidade), na faixa etária de 51 a 60 anos, uma vez que este efeito é descrito pela via anti-inflamatória colinérgica. A diminuição da modulação cardíaca vagal e o aumento da PCRus podem ter contribuído para o encurtamento de telômeros, identificado na década seguinte, de 61 a 70 anos. Dessa maneira, torna-se importante a proposição de ações preventivas em faixas etárias anteriores ao início das alterações provocadas pelo envelhecimento, especialmente na década de 41 a 50 anos, na tentativa de atenuar os efeitos naturais da senescência.

Práce se zabývá metodami pro testování lineárních analogových obvodů v kmitočtové oblasti. Cílem je navrhnout efektivní metody pro automatické generování testovacího plánu. Snížením počtu měření a výpočetní náročnosti lze výrazně snížit náklady za testování. Práce se zabývá multifrekveční parametrickou poruchovou analýzou, která byla plně implementována do programu Matlab. Vhodnou volbou testovacích kmitočtů lze potlačit chyby měření a chyby způsobené výrobními tolerancemi obvodových prvků. Navržené metody pro optimální volbu kmitočtů byly statisticky ověřeny metodou MonteCarlo. Pro zvýšení přesnosti a snížení výpočetní náročnosti poruchové analýzy byly vyvinuty postupy založené na metodě nejmenších čtverců a přibližné symbolické analýze.