999 resultados para exciton-longitudinal-optical-phonon


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O presente trabalho foi realizado com o propósito de estudar o efeito do aumento de velocidade sobre os valores da componente longitudinal do esforço tratório. Foi usado um arado de discos, de arrasto. Para a medição da componente longitudinal do esforço tratório foi utilizado um dispositivo de acoplamento na barra do trator, onde foi inserido um dinamômetro eletromecânico PIAB. Os ensaios foram realizados, em condições de campo, em um solo de classe textural areia. As velocidades de deslocamento foram em número de 4:2,86 km/h, 3,61 km/h, 4,74 km/h e 6,64 km/h. Nas condições em que foram realizados os ensaios, determinou-se a seguinte equação: K = 2,64 v + 62,88, sendo K = força específica média em kgf/dm² e v = velocidade de deslocamento em km/h.

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En aquest treball s’exposa l’estudi realitzat en un centre educatiu ordinari d’Educació Secundària Obligatòria. En aquest centre, el curs acadèmic 2002-2003 s’hi implanten dues unitats d’educació especial amb la finalitat d’aconseguir una escolarització amb un caràcter més normalitzat per als alumnes que les integren. Fruit d’aquesta implantació se’ns ofereix l’oportunitat de realitzar un estudi al voltant del funcionament d’aquest procés. Degut a la importància que tenen en els processos d’aquesta índole, entre d’altres motius, decidim decantar-nos per l’estudi de les actituds del professorat vers les pràctiques inclusives. Així doncs en aquest treball s’hi recullen quines són les actituds dels professorat d’aquest IES, en dos moments diferents al llarg del temps, al voltant de diferents aspectes relacionats amb les pràctiques inclusives, l’instrument dissenyat per a recollir aquestes actituds, així com també les pràctiques amb caràcter inclusiu que s’han dut a terme en aquest IES.

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Um estudo longitudinal clínico, radiológico e eletrocardiográfico do tipo caso-controle realizado no município de Virgem da Lapa, Minas Gerais, Brasil, com o acompanhamento de 124 chagásicos crônicos durante seis anos, revelou que 62,1% dos pacientes permaneceram com o quadro inicial inalterado, a maioria deles na forma indeterminada, 32,3% evoluíram com progressão da doença e 5,6% tiveram normalização do eletrocardiograma. Os resultados mencionados, quando comparados aos obtidos no grupo controle composto de pares não chagásicos da mesma idade e sexo, demonstraram uma progressão de 27,4% maior entre os pacientes com sorologia positiva, o que representa o excesso de risco ou componente exclusivamente chagásico na evolução da doença. Não houve diferença de progressão da doença em relação ao sexo, porém ela foi mais precoce e sete vezes mais freqüente em relação à cardiopatia do que ao megaesôfago, ambas ocorrendo na maioria das vezes em grau leve ou moderada. Em 192 chagásicos e 188 não chagásicos observados na área, no referido período, houve uma mortalidade 3,6 vezes maior entre os chagásicos, com uma letalidade pela cardiopatia de 8,9%, sem diferença entre os sexos, porém mais precoce no sexo masculino. A morte súbita foi mais freqüente do que a morte por insuficiência cardíaca. O prognóstico foi bom para os pacientes da forma indeterminada e digestiva e reservado para os casos de cardiopatia, principalmente os de graus mais elevados.

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Um estudo evolutivo do tipo caso-controle sobre a morbidade da doença de Chagas foi feito com indivíduos pareados por idade e sexo, utilizando-se duas avaliações, eletrocardiográficas e radiológicas com intervalo de dez anos. No primeiro estudo foram analizados 264 de indivíduos com sorologia positiva e outros tantos com sorologia negativa, e no último, foram obtidoas informações sobre 235 pacientes entre positivos e 216 entre os negativos dos quais foram reconstituídos e reexaminados 110 pares com a mesma metodologia inicial. A incidência da cardiopatia chagásica nos casos da forma inderteminada e o gravamento da forma cardíaca já instalada foi de 38,3 e 24%, respectivamente, no peíodo considerado. A evolução da doença como um todo foi progressiva em 34,5% dos casos, inalterada e, 57,3% e regressiva (normalização do ECG) em 8.2%. A mortalidade geral foi 23% no grupo chagásico e 10,6% no grupo controle, enquanto a letalidade por cardiopatia chagásica foi de 17% e por cardiopatias de outras etiologias no grupo controle foi de 2,3%. Não houve óbitos entre os 130 casos inicialmente na forma indeterminada nem entre seis casos de megaesôfogo. A mortalidade por doença de chagas foi duas vezes mais elevada no sexo masculino, com grande predominância no grupo etário de 30 a 59 anos de idade.

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Adiposity, low aerobic fitness and low levels of activity are all associated with clustered cardiovascular disease risk in children and their high prevalence represents a major public health concern. The aim of this study is to investigate the relationship of objectively measured physical activity (PA) with motor skills (agility and balance), aerobic fitness and %body fat in young children. This study is a cross-sectional and longitudinal analyses using mixed linear models. Longitudinal data were adjusted for baseline outcome parameters. In all, 217 healthy preschool children (age 4-6 years, 48% boys) participated in this study. PA (accelerometers), agility (obstacle course), dynamic balance (balance beam), aerobic fitness (20-m shuttle run) and %body fat (bioelectric impedance) at baseline and 9 months later. PA was positively associated with both motor skills and aerobic fitness at baseline as well as with their longitudinal changes. Specifically, only vigorous, but not total or moderate PA, was related to changes in aerobic fitness. Higher PA was associated with less %body fat at baseline, but not with its change. Conversely, baseline motor skills, aerobic fitness or %body fat were not related to changes in PA. In young children, baseline PA was associated with improvements in motor skills and in aerobic fitness, an important determinant of cardiovascular risk.

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Report for the scientific sojourn at the Department of Information Technology (INTEC) at the Ghent University, Belgium, from january to june 2007. All-Optical Label Swapping (AOLS) forms a key technology towards the implementation of All-Optical Packet Switching nodes (AOPS) for the future optical Internet. The capital expenditures of the deployment of AOLS increases with the size of the label spaces (i.e. the number of used labels), since a special optical device is needed for each recognized label on every node. Label space sizes are affected by the wayin which demands are routed. For instance, while shortest-path routing leads to the usage of fewer labels but high link utilization, minimum interference routing leads to the opposite. This project studies and proposes All-Optical Label Stacking (AOLStack), which is an extension of the AOLS architecture. AOLStack aims at reducing label spaces while easing the compromise with link utilization. In this project, an Integer Lineal Program is proposed with the objective of analyzing the softening of the aforementioned trade-off due to AOLStack. Furthermore, a heuristic aiming at finding good solutions in polynomial-time is proposed as well. Simulation results show that AOLStack either a) reduces the label spaces with a low increase in the link utilization or, similarly, b) uses better the residual bandwidth to decrease the number of labels even more.

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This paper considers the characterisation and measurement of income-related health inequality using longitudinal data. The paper elucidates the nature of the Jones and Lopez Nicholas (2004) index of “health-related income mobility” and explains the negative values of the index that have been reported in all the empirical applications to date. The paper further questions the value of their index to health policymakers and proposes an alternative index of “income-related health mobility” that measures whether the pattern of health changes is biased in favour of those with initially high or low incomes. We illustrate our work by investigating mobility in the General Health Questionnaire measure of psychological well-being over the first nine waves of the British Household Panel Survey from 1991 to 1999.

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This paper elaborates the approach to the longitudinal analysis of income-related health inequalities first proposed in Allanson, Gerdtham and Petrie (2010). In particular, the paper establishes the normative basis of their mobility indices by embedding their decomposition of the change in the health concentration index within a broader analysis of the change in “health achievement” or wellbeing. The paper further shows that their decomposition procedure can also be used to analyse the change in a range of other commonly-used incomerelated health inequality measures, including the generalised concentration index and the relative inequality index. We illustrate our work by extending their investigation of mobility in the General Health Questionnaire measure of psychological well-being over the first nine waves of the British Household Panel Survey from 1991 to 1999.

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This paper develops an accounting framework to consider the effect of deaths on the longitudinal analysis of income-related health inequalities. Ignoring deaths or using inverse probability weights (IPWs) to re-weight the sample for mortality-related attrition can produce misleading results, since to do so would be to disregard the most extreme of all health outcomes. Incorporating deaths into the longitudinal analysis of income-related health inequalities provides a more complete picture in terms of the evaluation of health changes in respect to socioeconomic status. We illustrate our work by investigating health mobility in Quality Adjusted Life Years (QALYs) as measured by the SF6D from 1999 till 2004 using the British Household Panel Survey (BHPS). We show that for Scottish males explicitly accounting for the dead, rather than using IPWs to account for mortality-related attrition, changes the direction of the relationship between relative health changes and initial income position, while for other population groups it increases the strength of this relationship by up to 14 times. When deaths are explicitly incorporated into the analysis it is found that over this five year period for both Scotland and England & Wales the relative health changes were significantly regressive such that the poor experienced a larger share of the health losses relative to their initial share of health and a large amount of this was related to mortality.

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Regression-based decomposition procedures are used to both standardise the concentration index and to determine the contribution of inequalities in the individual health determinants to the overall value of the index. The main contribution of this paper is to develop analogous procedures to decompose the income-related health mobility and health-related income mobility indices first proposed in Allanson, Gerdtham and Petrie (2010) and subsequently extended in Petrie, Allanson and Gerdtham (2010) to account for deaths. The application of the procedures is illustrated by an empirical study that uses British Household Panel Survey (BHPS) data to analyse the performance of Scotland in tackling income-related health inequalities relative to England & Wales over the five year period 1999 to 2004.

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A 28-month-old boy was referred for acute onset of abnormal head movements. History revealed an insidious progressive regression in behaviour and communication over several months. Head and shoulder 'spasms' with alteration of consciousness and on one occasion ictal laughter were seen. The electroencephalograph (EEG) showed repeated bursts of brief generalized polyspikes and spike-wave during the 'spasms', followed by flattening, a special pattern which never recurred after treatment. Review of family videos showed a single 'minor' identical seizure 6 months previously. Magnetic resonance imaging was normal. Clonazepam brought immediate cessation of seizures, normalization of the EEG and a parallel spectacular improvement in communication, mood and language. Follow-up over the next 10 months showed a new regression unaccompained by recognized seizures, although numerous seizures were discovered during the videotaped neuropsychological examination, when stereotyped subtle brief paroxysmal changes in posture and behaviour could be studied in slow motion and compared with the 'prototypical' initial ones. The EEG showed predominant rare left-sided fronto-temporal discharges. Clonazepam was changed to carbamazepin with marked improvement in behaviour, language and cognition which has been sustained up to the last control at 51 months. Videotaped home observations allowed the documentation of striking qualitative and quantitative variations in social interaction and play of autistic type in relation to the epileptic activity. We conclude that this child has a special characteristic epileptic syndrome with subtle motor and vegetative symptomatology associated with an insidious catastrophic 'autistic-like' regression which could be overlooked. The methods used to document such fluctuating epileptic behavioural manifestations are discussed.

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Purpose: Organ transplantation is a biological and psychological challenge and graft acceptance is an important achievement for patients. Patients' concerns toward the deceased donor and the organ may contribute to this process. Method: Forty-seven patients involved in heart (N=9), liver (N=8), lung (N=14) and kidney (N=16) transplantation participated in IRB-approved longitudinal semi-structured interviews: (T1) registered on the waiting-list, (T2) six months and (T3) twelve months after transplantation. Qualitative pattern analysis (QUAPA) was carried out on the verbatim transcripts and concerns about the donor and the organ were then analysed. Results: - Donor's representation: At T1, patients were reluctant to talk about the donor: 27% expressed culpability and 19% accepted the clause of anonymity. At T2, intense emotions were associated with the reminiscing about the donor and 45% highlighted the generosity of his/her act. In addition, heart, lung and kidney recipients were concerned about the donor's identity: 42% challenged the clause of anonymity. Liver recipients complained about anonymity, but could nevertheless cope with it. At T3, 47% of heart, lung and kidney recipients thought daily of the donor and 33% were still looking for information about him/her. Liver recipients rarely have thoughts about the donor. - Organ representation: At T1, organ descriptions were biomedical (49% of the interviewees) and more rarely, mainly heart candidates, referred to the symbolic meaning of the organ. After transplantation (T2-T3), function was underlined. Acceptance and organ integration were associated with post-operative outcomes (23%) and psychological well-being (45%). Some patients (32%) inferred the donor's personality from the organ quality and felt privileged having received an organ in such a good state. Conclusion: Donor's representations should be explored during the transplantation process as they play an important role in the psychological acceptance of the graft.