Mobile hand-held communication device (smart phone) use is very prevalent and growing rapidly. In addition, there is empirical support for heavy use to be associated with musculoskeletal disorders. This study therefore addressed the physical demand and performance when using these devices. The natural texting style for 20 participants was identified and then participants performed standardized static and dynamic tasks on 4 different types of mobile hand-held devices; a touch screen device and 3 devices with different keyboard sizes and layout; a flip or clamshell design, a PDA style device and a phone with a pull out QWERTY keyboard. Participants rated the effort required to complete each task and for dynamic tasks, keystroke speed was also measured. The time history of angles of the carpometacarpal, metacarpophalangeal and interphalageal joints of the thumb as well as motion of the wrist were determined using small surface makers and an optoelectronic motion capture system. Thumb kinematics were normalized to the maximum range of motion of each joint. Statistically significant and substantial differences were found for the dynamic condition: The tasks which required the most motion in the flexion/extension axis of the thumb also required the most effort, and that there is an inverse relationship between effort and typing speed, namely that those tasks, or devices which required the highest effort resulted in the lowest typing speeds, and visa-versa. Similarly, results showed that those static tasks which required the most thumb flexion also required the most effort. Overall, use of the touch screen phone required the least effort for dynamic and static tasks, and also resulted in the highest typing speeds. This could be a result of having the lowest force required to engage the keys. The device which resulted in the lowest typing speed and highest required effort was the flip phone, which also had the highest required force to engage the keys. There was also a weak relationship between user thumb length and required effort, with longer thumb length necessitating a greater about of effort. Those subjects who used the texting style indentified as the slide style which used forearm rotation with a less flexed thumb reported significantly less effort for all tasks than those who used the claw style which used extreme flexion of the thumb joints. However, texting style had no significant effect on typing speed, indicating that someone could adopt the slide style to reduce muscular effort and potentially the risk of developing musculoskeletal disorders in the upper limbs and neck without sacrificing performance.

Mobile hand-held communication device (smart phone) use is very prevalent and growing rapidly. In addition, there is empirical support for heavy use to be associated with musculoskeletal disorders. This study therefore addressed the physical demand and performance when using these devices. The natural texting style for 20 participants was identified and then participants performed standardized static and dynamic tasks on 4 different types of mobile hand-held devices; a touch screen device and 3 devices with different keyboard sizes and layout; a flip or clamshell design, a PDA style device and a phone with a pull out QWERTY keyboard. Participants rated the effort required to complete each task and for dynamic tasks, keystroke speed was also measured. The time history of angles of the carpometacarpal, metacarpophalangeal and interphalageal joints of the thumb as well as motion of the wrist were determined using small surface makers and an optoelectronic motion capture system. Thumb kinematics were normalized to the maximum range of motion of each joint. Statistically significant and substantial differences were found for the dynamic condition: The tasks which required the most motion in the flexion/extension axis of the thumb also required the most effort, and that there is an inverse relationship between effort and typing speed, namely that those tasks, or devices which required the highest effort resulted in the lowest typing speeds, and visa-versa. Similarly, results showed that those static tasks which required the most thumb flexion also required the most effort. Overall, use of the touch screen phone required the least effort for dynamic and static tasks, and also resulted in the highest typing speeds. This could be a result of having the lowest force required to engage the keys. The device which resulted in the lowest typing speed and highest required effort was the flip phone, which also had the highest required force to engage the keys. There was also a weak relationship between user thumb length and required effort, with longer thumb length necessitating a greater about of effort. Those subjects who used the texting style indentified as the slide style which used forearm rotation with a less flexed thumb reported significantly less effort for all tasks than those who used the claw style which used extreme flexion of the thumb joints. However, texting style had no significant effect on typing speed, indicating that someone could adopt the slide style to reduce muscular effort and potentially the risk of developing musculoskeletal disorders in the upper limbs and neck without sacrificing performance.

A doença de Chagas representa um importante problema para a Saúde Publica na América Latina, onde o tratamento é limitado principalmente na fase crônica. Mesmo controlando a replicação parasitária, a completa eliminação do parasita e a cura da doença não são observadas de forma consistente. A ativação do eixo adrenal-hipotálamo-hipófise possui um papel importante na supressão do sistema imune. Neste trabalho foram observados os efeitos do estresse repetitivo em ratos Wistar infectados com a cepa Y de Trypanosoma cruzi durante as fases aguda e crônica da doença experimental, através da exposição dos animais a vapores de éter por um minuto duas vezes ao dia. O estresse repetitivo provocou aumento do número de parasitas e a administração de DHEA reduziu significantemente a parasitemia durante a fase aguda. A resposta TH-1 foi mais vigorosa em animais submetidos à terapia com DHEA mesmo quando submetidos ao estresse repetitivo. Assim TNF-, IFN-, IL-2, NO e linfoproliferação mostraram concentrações mais elevadas quando comparadas aos animais não submetidos à terapia. A resposta TH-2 nos grupos sem suplementação com DHEA, IL-4 e IL-10 apresentaram valores reduzidos nos animais infectados e estressados submetidos à terapia com DHEA. A concentração de corticosterona mostrou-se elevada para animais estressados e infectados em relação aos animais submetidos a terapia com DHEA. A histopatologia apresentou redução no número de neurônios nas fases aguda e crônica para os animais estressados e infectados, os mesmos apresentaram desorganização tecidual cardíaca com aumento do número de ninhos de amastigotas e moderado processo inflamatório por células mononucleares. Estes resultados sugerem que o estresse repetitivo pode ser considerado como ii fator importante durante o desenvolvimento da doença de Chagas experimental, aumentando sua patogênese através de distúrbios do sistema imune do hospedeiro. / Chagas disease represents an important public health problem in Latin American, where the treatment is limited especially to chronic phase, besides the harmful side effects. Although controlling the parasite replication, the complete elimination of the etiologic agent still was not observed. Activation of the hypothalamuspituitaryadrenal axis plays a major role in the suppression of the immune system. We have investigated the effects of repetitive stress on Wistar rats infected with the Y strain of Trypanosoma cruzi during the acute and chronic phases of the experimental disease by the exposure to ether vapor for one minute twice a day. Repetitive stress resulted in an elevated number of circulating parasites and DHEA administration reduced significantly blood parasites during the acute phase. Several immunological parameters were evaluated. TH-1 response was more vigorous in animals submitted to DHEA therapy even those which underwent repetitive stress. So, TNF-, IFN-, IL-2, NO and lymphoproliferation displayed enhanced concentrations as compared to unsupplied animals. The TH-2 immune response in groups without DHEA supplementation, showed reduce values for IL-4 and IL-10 in groups infected and stressed submitted to DHEA therapy. Enhanced corticosterone concentration was a observed for infected and stressed animals. DHEA triggered reduced levels of corticosterone. The histopathology revealed that stressed animals showed a reduction in the number of neurons. Histological sections of heart smears from infected and stressed animals displayed deep tissue disorganization, increased parasite burdens and moderate diffused mononuclear inflammatory process. These results suggest that repetitive stress could be considered an iv important factor during development of experimental Chagas disease, enhancing pathogenesis through disturbance of the hosts immune system.

abstract: All too often, industrial designers face seemingly intractable obstacles as they endeavor to, as Simon (1996, p. 111) describes, devise "courses of action aimed at changing existing situations into preferred ones." These problems, described by Rittel and Webber (1973) as "wicked," are insurmountable due to the contradictory and changing nature of their requirements. I argue that that industrial design (ID) is largely subject to Rittel's quandary because of its penchant for producing single solutions for large populations; such design solutions are bound, in some senses, to fail due to the contradictory and changing nature of large and, thus, inherently diverse populations. This one-size-fits-all approach is not a necessary attribute of ID, rather, it is a consequence of the time in which it came into being, specifically, the period of industrial mass production. Fortunately, new, agile manufacturing techniques, inexpensive sensors, and machine learning provide an alternative course for ID to take, but it requires a new way of thinking and it requires a new set of methods, which I will elaborate in this thesis. According to Duguay, Landry, and Pasin (1997), we are entering an age where it will be feasible to produce individualized, one-off products from large-scale industrial manufacturing facilities in a way that is not only cost effective, but in many ways as cost effective as the existing techniques of mass production. By availing ourselves of these opportunities, we can tame the problem, not by defeating Rittel's logic, rather by reducing the extent to which his theories are appropriate to the domain of ID. This thesis also describes a test study: an experiment whose design was guided by the proposed design methodologies. The goal of the experiment was to determine the feasibility of a noninvasive system for measuring the health of the forearm muscles. Such a tool would provide the basis for assessing the true impact and possible pathogeny of the manual use of products or modifications to products. Previously, it was considered impossible to use surface electromyography (as opposed to needle or wire based electromyography) to assess muscular activity and muscular health due to the complexity of the arrangement of muscles in the forearm. Attempts to overcome this problem have failed because they have tried to create a single solution for all people. My hypothesis is that, by designing for each individual, a solution may be found. Specifically, I show that, for any given individual, there is a high correlation between the EMG signal and the movements of the fingers that, ostensibly, those muscles control. In other words, by knowing, with great accuracy, the position and the motion of the hand then it would become possible to disambiguate the mixed signals coming from the complex web of muscles in the forearm and enable the assessment of the forearm's health by non-invasive means. / Dissertation/Thesis / M.S.D. Design 2012

A doença de Chagas representa um importante problema para a Saúde Publica na América Latina, onde o tratamento é limitado principalmente na fase crônica. Mesmo controlando a replicação parasitária, a completa eliminação do parasita e a cura da doença não são observadas de forma consistente. A ativação do eixo adrenal-hipotálamo-hipófise possui um papel importante na supressão do sistema imune. Neste trabalho foram observados os efeitos do estresse repetitivo em ratos Wistar infectados com a cepa Y de Trypanosoma cruzi durante as fases aguda e crônica da doença experimental, através da exposição dos animais a vapores de éter por um minuto duas vezes ao dia. O estresse repetitivo provocou aumento do número de parasitas e a administração de DHEA reduziu significantemente a parasitemia durante a fase aguda. A resposta TH-1 foi mais vigorosa em animais submetidos à terapia com DHEA mesmo quando submetidos ao estresse repetitivo. Assim TNF-, IFN-, IL-2, NO e linfoproliferação mostraram concentrações mais elevadas quando comparadas aos animais não submetidos à terapia. A resposta TH-2 nos grupos sem suplementação com DHEA, IL-4 e IL-10 apresentaram valores reduzidos nos animais infectados e estressados submetidos à terapia com DHEA. A concentração de corticosterona mostrou-se elevada para animais estressados e infectados em relação aos animais submetidos a terapia com DHEA. A histopatologia apresentou redução no número de neurônios nas fases aguda e crônica para os animais estressados e infectados, os mesmos apresentaram desorganização tecidual cardíaca com aumento do número de ninhos de amastigotas e moderado processo inflamatório por células mononucleares. Estes resultados sugerem que o estresse repetitivo pode ser considerado como ii fator importante durante o desenvolvimento da doença de Chagas experimental, aumentando sua patogênese através de distúrbios do sistema imune do hospedeiro. / Chagas disease represents an important public health problem in Latin American, where the treatment is limited especially to chronic phase, besides the harmful side effects. Although controlling the parasite replication, the complete elimination of the etiologic agent still was not observed. Activation of the hypothalamuspituitaryadrenal axis plays a major role in the suppression of the immune system. We have investigated the effects of repetitive stress on Wistar rats infected with the Y strain of Trypanosoma cruzi during the acute and chronic phases of the experimental disease by the exposure to ether vapor for one minute twice a day. Repetitive stress resulted in an elevated number of circulating parasites and DHEA administration reduced significantly blood parasites during the acute phase. Several immunological parameters were evaluated. TH-1 response was more vigorous in animals submitted to DHEA therapy even those which underwent repetitive stress. So, TNF-, IFN-, IL-2, NO and lymphoproliferation displayed enhanced concentrations as compared to unsupplied animals. The TH-2 immune response in groups without DHEA supplementation, showed reduce values for IL-4 and IL-10 in groups infected and stressed submitted to DHEA therapy. Enhanced corticosterone concentration was a observed for infected and stressed animals. DHEA triggered reduced levels of corticosterone. The histopathology revealed that stressed animals showed a reduction in the number of neurons. Histological sections of heart smears from infected and stressed animals displayed deep tissue disorganization, increased parasite burdens and moderate diffused mononuclear inflammatory process. These results suggest that repetitive stress could be considered an iv important factor during development of experimental Chagas disease, enhancing pathogenesis through disturbance of the hosts immune system.