Control design for UAV quadrotors via embedded model control

In this paper, a control system for unmanned aerial vehicles (UAVs) is designed, tested in simulation by means of a high-fidelity simulator, and then applied to a real quadrotor UAV. A novel approach is proposed for the control design, based on the combination of two methodologies: feedback linearization (FL) and embedded model control (EMC). FL allows us to properly transform the UAV dynamics into a form suitable for EMC; EMC is then used to control the transformed system. A key feature of EMC is that it encompasses a so-called extended state observer (ESO), which not only recovers the system state but also gives a real-time estimate of all the disturbances/uncertainties affecting the system. This estimate is used by the FL-EMC control law to reject the aforementioned disturbances/uncertainties, including those collected via the FL, allowing a robustness and performance enhancement. This approach allows us to combine FL and EMC strengths. Most notably, the entire process is made systematic and application oriented. To set-up a reliable UAV attitude observer, an effective attitude sensors fusion is proposed and also benchmarked with an enhanced complementary filter. Finally, to enhance the closed-loop performance, a complete tuning procedure, encompassing frequency requirements, is outlined, based on suitably defined stability and performance metrics

Luz solar e suicídio no trópico de Capricórnio, São Paulo, Brasil, 1996-2004

Estudos epidemiológicos têm confirmado que as taxas de suicídio apresentam variação sazonal relacionada às horas de insolação. O padrão de suicídios foi analisado na cidade de São Paulo, Brasil, no trópico de Capricórnio, de 1996 a 2004. A regressão de Poisson foi utilizada para estimar padrões de sazonalidade, bem como verificar a associação dia-a-dia entre duração da insolação e suicídio. Durante os nove anos houve 3.984 suicídios (76,9% homens; mediana de idade=38,7 anos). As médias de suicídio por estação do ano e por mês de suicídio foram similares. Segundo a regressão de Poisson, não houve associação entre insolação e suicídio (p=0,45) para ambos os sexos. Conclui-se que não houve padrão sazonal de suicídios na cidade de São Paulo.Several studies have confirmed seasonal variation in suicide rates according to hours of sunshine. The suicide pattern was assessed in São Paulo, southeastern Brazil, at the tropic of Capricorn from 1996 to 2004. Poisson regression was employed to estimate parameters of seasonality, as well as to verify associations for each day between daylight duration and suicide. During the nine-year study period, there were 3,984 suicides (76.9% in men; median age=38.7 years old). Seasonal averages of suicides were similar, as were monthly averages. Poisson regression did not reveal any association between suicide rates and hours of sunshine (p=0.45) for both sexes. In conclusion, no seasonal pattern was observed for suicides

Resultados de oito aplicações do Teste do Progresso na Faculdade de Medicina da Universidade de São Paulo

BACKGROUND: Progress testing is a longitudinal tool for evaluating knowledge gains during the medical school years. OBJECTIVES: (1) To implement progress testing as a form of routine evaluation; (2) to verify whether cognitive gain is a continuous variable or not; and (3) to evaluate whether there is loss of knowledge relating to basic sciences in the final years of medical school. METHODS: A progress test was applied twice a year to all students from 2001 to 2004. The mean percentage score was calculated for each school year, employing ANOVA with post hoc Bonferroni test evaluation for each test. RESULTS: Progress testing was implemented as a routine procedure over these 4 years. The results suggest a cognitive gain from first to sixth year in all eight tests, as a continuum (P for trend < .0001). Gain was found to be continuous for basic sciences (taught during the first 2 years), clinical sciences (P < .0001), and clerkship rotation (P < .0001). There was no difference between the performance of men and women. CONCLUSION: Progress testing was implemented as a routine, applied twice a year. Data suggest that cognitive gain during medical training appears to be a continuum, even for basic science issues.O Teste do Progresso foi introduzido na Faculdade de Medicina da Universidade de São Paulo em 2001. OBJETIVO: (1) Testar a viabilidade da aplicação rotineira do teste; (2) verificar se o ganho de conhecimentos era progressivo e contínuo durante a graduação; (3) determinar se esse ganho de conhecimento inclui também as disciplinas do curso básico. MÉTODOS: O teste foi aplicado duas vezes por ano entre 2001-2004. Em cada teste, calculou-se o escore médio de acertos por ano letivo usando-se ANOVA com correção de Bonferroni para múltiplas comparações. RESULTADOS: O Teste do Progresso foi implementado como rotina entre 2001-2004. Os resultados sugerem um ganho cognitivo contínuo e progressivo ao longo da graduação (P < 0,0001) nos oito testes aplicados até o momento. Esse ganho seria significativo mesmo para as disciplinas do curso básico (P < 0,05), curso clínico (P < 0.0001) e internato (P < 0.0001). Não houve diferença de performance em função do gênero. CONCLUSÃO: O Teste do Progresso foi implementado como rotina, sendo aplicado semestralmente. Os resultados sugerem que o ganho cognitivo parece ser contínuo e progressivo mesmo para as disciplinas do básico ao longo dos seis anos

Prevalência de doenças da tireóide em idosos: resultados do São Paulo Ageing & Health Study

This study aimed to estimate prevalence of thyroid disorders in the São Paulo Ageing & Health Study, an epidemiological study addressing several health-adverse outcomes among elderly people living in a poor area of São Paulo, Brazil. All participants answered a questionnaire and had a blood sample collected to assess levels of tireotropic hormone and free-thyroxine. Among 1,373 people (60.8% women), prevalence rates (95% confidence interval) for thyroid dysfunction (%) were: overt hyperthyroidism, 0.7% (0.2-1.1)[women: 0.8% (0.2-1.5); men: 0.4% (0.01-0.9)]; overt hypothyroidism, 5.7% (4.5-6.9) [women: 5.9% (4.3-7.5); men: 5.4% (3.5-7.3)]; subclinical hyperthyroidism, 2.4% (1.6-3.2) [women: 2.8% (1.6-3.9); men: 1.9% (0.7-3.0)]; and subclinical hypothyroidism, 6.5% (5.2-7.8) [women: 6.7% (5.0-8.4); men: 6.1% (4.1-8.2)]. There was no difference in prevalence rates according to gender, but almost 40% of women were diagnosed and under treatment compared to 9% of men. The burden of thyroid disorders in this sample is high and most participants were not aware of them.O objetivo da pesquisa foi avaliar a prevalência de doenças da tireóide no São Paulo Ageing & Health Study, estudo epidemiológico focado em desfechos de saúde adversos em amostra de idosos moradores de São Paulo, Brasil. Todos os participantes responderam a questionário e colheram sangue para dosagem de hormônio tireotrópico e tiroxina-livre. Entre os 1.373 participantes (60,8% mulheres), a prevalência (intervalo de 95% de confiança) de hipertireoidismo clínico foi de 0,7% (0.2-1,1) [mulheres: 0,8% (0,2-1,5); homens: 0,4% (0,01-0,9)]; hipotireoidismo clínico, 5,7% (4,5-6,9) [mulheres: 5,9% (4,3-7,5); homens: 5,4% (3,5-7,3)]; hipertireoidismo subclínico, 2,4% (1,6-3,2) [mulheres: 2,8% (1,6-3,9); homens: 1,9% (0,7-3,0)]; e hipotireoidismo subclínico, 6,5% (5,2-7,8) [mulheres: 6,7% (5,0-8,4); homens: 6,1% (4,1-8,2)]. Não houve diferença na prevalência de doenças da tireóide por sexo. Quarenta por cento das mulheres tinham diagnóstico e estavam tratando, comparadas a 9% dos homens. A prevalência de disfunção tireoidiana foi elevada e a maioria dos participantes desconhecia o diagnóstico.(FAPESP) São Paulo Research Foundatio

The influence of the day of the week of hospital admission on the prognosis of stroke patients

This study aimed to evaluate the weekday and weekend distribution of stroke case hospital admissions and their respective prognosis based on a sample from the Estudo de Mortalidade e Morbidade do Acidente Vascular Cerebral (EMMA), a cohort of stroke patients admitted to a community hospital in the city of São Paulo, Brazil. We ascertained all consecutive cases of first-time strokes between April 2006 and December 2008 and performed a subsequent one-year follow-up. No association was found between frequency of hospital admissions due to ischemic and hemorrhagic strokes and the specific day of the week on which the admission occurred. However, ten-day and twelve-month case-fatality was higher in hemorrhagic stroke patients admitted at the weekend. We also found that intracerebral hemorrhage patients admitted on weekends had a worse survival rate (50%) compared with those admitted during weekdays (25.6%, P log-rank = 0.03). We found a multivariate hazard ratio of 2.49 (95%CI: 1.10-5.81, P trend = 0.03) for risk of death at the weekend compared to weekdays for intracerebral hemorrhage cases. No difference in survival was observed with respect to the overall sample of stroke or ischemic stroke patients

The Acute-Phase Proteins Serum Amyloid A and C Reactive Protein in Transudates and Exudates

The distinction between exudates and transudates is very important in the patient management. Here we evaluate whether the acute-phase protein serum amyloid A (SAA), in comparison with C reactive protein (CRP) and total protein (TP), can be useful in this discrimination. CRP, SAA, and TP were determined in 36 exudate samples (27 pleural and 9 ascitic) and in 12 transudates (9 pleural and 3 ascitic). CRP, SAA, and TP were measured. SAA present in the exudate corresponded to 10% of the amount found in serum, that is, the exudate/serum ratio (E/S) was 0.10 ± 0.13. For comparison, the exudate/serum ratio for CRP and TP was 0.39 ± 0.37 and 0.68 ± 0.15, respectively. There was a strong positive correlation between serum and exudate SAA concentration (r = 0.764;p < 0.0001). The concentration of SAA in transudates was low and did not overlap with that found in exudates (0.02-0.21 versus 0.8–360.5 g/mL). SAA in pleural and ascitic exudates results mainly from leakage of the serum protein via the inflamed membrane. A comparison of the E/S ratio of SAA and CRP points SAA as a very good marker in discriminating between exudates and transudates

Divergent responses of serum testosterone and cortisol in athlete men after a marathon race

Physical exercise alters homeostasis, as it requires prompt mobilization of metabolic sources. In this study, we measured serum testosterone (T) and cortisol (C) levels and the muscle-wastage enzymes CK, CKMB and LDH in 20 healthy male athletes (ages 25 to 40 years) in response to a marathon race (42.2 km). Venous blood samples were drawn in 3 different periods: (i) in the morning, 48 h before the competition (control), (ii) at the end of the race (end), and (iii) in the next morning, 20 h after the race (recovery). At the end, T was significantly lower (from 673 to 303 ng/dl) and C higher (from 20.3 to 42.5 µg/dl) as compared to the control period. At recovery, both were virtually identical to control levels. CK, CKMB and LDH were significantly higher at the end of the competition and even higher in the recovering period (except for CKMB), characterizing muscle wastage. CK and LDH disclosed a significant negative correlation with T (-0.412 and -0.546, respectively), whereas CKMB correlated positively with C (0.4521). We conclude that the inverse correlation observed between T and C levels, and the pattern of CK, CKMB and LDH increase, allow us to confirm that a marathon race may cause a marked physical stress, resulting in a distinct hormonal imbalance and severe cellular damage.O exercício físico altera a homeostase, pois requer rápida mobilização de fontes metabólicas. Neste estudo, analisamos a resposta dos níveis séricos de testosterona (T) e cortisol (C) e das enzimas de desgaste muscular CK, CKMB e LDH, em 20 atletas masculinos sadios (25 a 40 anos), participantes de uma maratona (42,2 km). Coletas de sangue venoso foram feitas em 3 períodos: (i) pela manhã, 48 h antes da maratona (controle), (ii) logo após o término da corrida (final) e (iii) na manhã seguinte, 20 h após a realização da prova (recuperação). Ao final, T estava significantemente mais baixa (de 673 para 303 ng/dl) e C mais elevado (de 20,3 para 42,5 µg/dl) que no período controle. Na recuperação, ambos praticamente retornaram aos níveis basais. CK, CKMB e LDH estavam significantemente mais elevadas ao final da corrida e mais ainda na recuperação (exceto a CKMB), caracterizando o desgaste muscular. Enquanto CK e LDH apresentaram significante correlação negativa com a T (-0,412 e -0,546, respectivamente), CKMB correlacionou-se positivamente com o C (0,4521). Concluímos que a correlação inversa entre T e C, e o comportamento das enzimas CK, CKMB e LDH, permite comprovar que uma corrida de maratona causa intenso stress físico, provocando desequilíbrio hormonal e lesão celular severa.Universidade Federal de São Paulo (UNIFESP) Departamento de Medicina Centro de Medicina da Atividade Física e do EsporteUNIFESP, Depto. de Medicina Centro de Medicina da Atividade Física e do EsporteSciEL