Modelação, simulação e implementação de agitação acústica para aplicações em microfluídica

Tese de Doutoramento (Programa Doutoral em Engenharia Biomédica)

O papel do transporte público nos padrões de mobilidade no acesso a um campus universitário

Dissertação de mestrado integrado em Engenharia Civil

Treinamento Físico Aeróbico como Tratamento não Farmacológico da Síncope Neurocardiogênica

Fundamento: Caracterizada por perda súbita e transitória da consciência e do tônus postural, com recuperação rápida e espontânea, a síncope é causada por uma redução aguda da pressão arterial sistêmica e, por conseguinte, do fluxo sanguíneo cerebral. Os resultados insatisfatórios com o uso de fármacos permitiu que o tratamento não farmacológico da síncope neurocardiogênica fosse contemplado como primeira opção terapêutica. Objetivos: Comparar, em pacientes com síncope neurocardiogênica, o impacto do Treinamento Físico Aeróbico (TFA) de moderada intensidade e de uma intervenção controle, na positividade do Teste de Inclinação Passiva (TIP) e no tempo de tolerância ortostática. Métodos: Foram estudados 21 pacientes com história de síncope neurocardiogênica recorrente e TIP positivo. Esses foram aleatorizados em: Grupo Treinado (GT), n = 11, e Grupo Controle (GC), n = 10. O GT foi submetido a 12 semanas de TFA supervisionado, em cicloergômetro, e o GC, a um procedimento controle que consistia na realização de 15 minutos de alongamentos e 15 minutos de caminhada leve. Resultados: O GT apresentou efeito positivo ao treinamento físico, com aumento significativo do consumo de oxigênio-pico. Já o GC não apresentou nenhuma mudança estatisticamente significante, antes e após a intervenção. Após o período de intervenção, 72,7% da amostra do GT apresentou resultado negativo ao TIP, não apresentando síncope na reavaliação. Conclusão: O programa de treinamento físico aeróbico supervisionado por 12 semanas foi capaz de reduzir o número de TIP positivos, assim como foi capaz de aumentar o tempo de tolerância na posição ortostática durante o teste após o período de intervenção.

Pequena contribuição à história natural de alguns Fringillidae do Brasil (Passeriformes)

A short contribution to the Natural History of some Brazilian Frigillidae The following species of Brazilian Fringillidae are mentioned here, the first of which being more deeply studied: 1 - Oryzoborus angolensis angolensis (Linnaeus). 2 - Oryzoborus crassirostris maximiliani Cabanis. 3 - Cyanocompsa cyanea sterea Oberholser. 4 - Coryphospingus cucullatus rubescens (Swainson). About each one of the referred species, the Author gives native names, some datas and observations on its reproduction and behaviour under captivity, as well as on its natural alimentation. Some considerations about the geographical races of Oryzoborus angolensis: O. a. angolensis (Linnaeus) and 0. a. torridus (Scopoli) -are also made. Both the races occur in Brasil and, according to the Author's opinion, they are not satisfactorily caracterized.

Contribuição a história natural do «Pararu» Scardafella squammata squammata(Lesson) (1)

The main wild doves of the region of Piracicaba (State of S. Paulo, Brazil) are Columba cayennensis sylvestris Vieillot, Oreopeleia montana montana (L.), Leptotila verreauxi decipiens Salvadori, Columbigallina talpacoti talpacoti. (Temminck) and Scardafella squammata squammata (Lesson). The last one is well known for the beauty of the coloration of its feathers and for the characteristic sounds produced when flying up. Of common occurrence around the local farms, that species can easily be recognized not only for the mentioned peculiarities as for the voice of the adults, which was translated into the Brazilian onomatopoeia by the expression "fogo-apagou". S. squammata's biology being not well known, the Author presents some notes on its nidification, behaviour of both sexes and of the young birds. The data were gotten in nature and with specimens kept in captivity, where the reproduction took place. In such a situation, the male dove used thin and small wooden shavings to build the nest, an artificial material unknown by him when in nature. This fact may be considered as another proof of the plasticity of the instinctive conduct of birds, not so marked as the one given by SCHIRCH (1931) concerning Synallaxis sp. (Furnariidae), which made use of wire pieces and also barbed wires in confectioning the nest. The copulation was sometimes verified, being preceded by the phenomena well known in other Columbidae species. The nest had its building ready just on the day in which the first egg was laid. As it generally happens amongst doves, the nest was not carefully made - a simple and shallow bowl (diameter = 10 cm), where two entirely white eggs were put.. .. ..(22,5-24,5 x 18,0-19,0 mm). The eclosion took place 14 days after the laying of the last egg. As soon as the young doves (at least the male one) can feed by themselves, they try to produce the characteristic species sounds. "Pararu", a common name oly applied to another species - Claravis godefrida (Temminck) - is reported, which is preferably used by people in this region to call the studied dove. No differences between the coloration of the fathers of the two sexes were observed. The female dove seemed to be a little thinner than the male. In addition, the slight differences between the sounds produced by the male and female are pointed out.

Aspectos da biologia reprodutiva de Bothrops jararaca em cativeiro (Serpentes, Viperidae)

The reproduction of Bothrops jararaca (Wied, 1824) in captivity in ordened to determine the intercourse period, births, number of neonates, proportion of males and females per litter were performed between 1989 and 1999. Fifty eight females were observed, 16 intercourses in captivity, 45 females arrived already fertilized from nature and 53 litters, resulting on the birth of 426 live neonates, 67 infertile egg masses, 18 stillborn neonates and 4 abnormal neonates. The intercourse period was from february to december and the births happened between february and may. From the two gestacional periods observed, the shortest one was 152 days and the longest 239. The average amount of live neonates per litter was 8,04. Among 323 neonates, 47,68% were males and 52,32% were females. During the first year of life, 75,71% of the females and 71,54% of the males died, and 2,31% of the females and 0,81% of the males reached the fifth year of life.

Ocorrência de híbridos não naturais entre Bothrops jararaca e B. neuwiedi (Serpentes, Viperidae)

In May 1987, a female of Bothrops jararaca (Wied, 1824), from Carazinho, Rio Grande do Sul (RS), Brazil, was placed in the same vivarium with a male of Bothrops neuwiedi Wagler, 1824 coming from Guaíba, RS. There, they stayed for aproximately ten months. In March 1988, it was observed a delivery of five live and two still born, among them six presented morphologic characteristics of B. neuwiedi and one of B. jararaca. After the female died, in April 1988, through necropsy, two fetusus were found, one near the cloaca and, both identified as B. neuwiedi. The morphologic analysis and the origin of the progenitors suggest the hypothesis that the litter was resulted of cross-breeding.

Comportamento alimentar e dieta de serpentes, gêneros Boiruna e Clelia (Serpentes, Colubridae)

Boiruna maculata Boulenger, 1896 and Clelia rustica (Cope, 1878) were observed in captivity feeding snakes and rodents, respectively. Both species have shown a similar procedure in relation to the prey. Major behavior differences among the two species were: rodents killed before being swallowed, and snakes were mostly swallowed alive; both species are able to find the rodents head faster than the snake one; the coils formed during constriction were also used to hold the prey, specially the last coil, while swallowing rodents. Informations on stomach contents was gathered by dissection of preserved specimens of Clelia clelia (Daudin, 1803) and C. plumbea (Wied, 1820) were also included in the dietary study. The majority of preys consisted on snakes and lizards. Other prey items were mammals and birds. Adult snakes prey relatively smaller animals than the juvenile snakes do.

Variação de peso e sobrevida de Micrurus corallinus sob diferentes condições de alimentação em biotério (Serpentes, Elapidae)

The weight variation in Micrurus corallinus (Merrem, 1820) during the first 60 days in laboratory animal rooms was very remarkable. This fact demonstrates the difficulty in adaptation of these animals to the captive environment. The weight loss was observed in animals under voluntary feeding as well as forced feeding. The survival rate was significantly higher in voluntarily fed animals. Sex differences were also observed with higher survival rates for males. Low survival rates were observed in both sexes under forced feeding.

Temporal variability of benthic macrofauna on Cassino beach, southernmost Brazil

The temporal variability of benthic macrofauna on Cassino beach, southernmost Brazil, was studied for a period of one year (June 2004 to May 2005) based on monthly sampling. Three sites were selected distant 50m from each other. At each site, 3 transects were established, 2m equidistant from one another. Each transect extended from the base of the primary dunes to the inner surf zone at approximately 1m in depth, with 7 or 8 sampling levels. Within transects, the distance between the levels was 20m until the upper swash zone, from which distance was 10m until the 1-meter isobath. The temporal variation in the abundance of benthic macrofauna observed in the present study can be attributed to (1) the positive effects of the recruitment peaks and migration of particular species to the swash zone and (2) negative effects of the migration of some species to deeper waters, as well (3) as mortality through natural causes (stranding and action of predators) and (4) human causes (harvesting and vehicle transit). We attribute the expressive abundance increase of benthic macrofauna to recruitment. The stranding, that is, the trapping of the organisms on the upper parts of the beach, is likely the main cause of abrupt drops in benthic macrofauna abundance.

Políticas de encaminamiento tolerantes a fallos

El uso intensivo y prolongado de computadores de altas prestaciones para ejecutar aplicaciones computacionalmente intensivas, sumado al elevado número de elementos que los componen, incrementan drásticamente la probabilidad de ocurrencia de fallos durante su funcionamiento. El objetivo del trabajo es resolver el problema de tolerancia a fallos para redes de interconexión de altas prestaciones, partiendo del diseño de polí­ticas de encaminamiento tolerantes a fallos. Buscamos resolver una determinada cantidad de fallos de enlaces y nodos, considerando sus factores de impacto y probabilidad de aparición. Para ello aprovechamos la redundancia de caminos de comunicación existentes, partiendo desde enfoques de encaminamiento adaptativos capaces de cumplir con las cuatro fases de la tolerancia a fallos: detección del error, contención del daño, recuperación del error, y tratamiento del fallo y continuidad del servicio. La experimentación muestra una degradación de prestaciones menor al 5%. En el futuro, se tratará la pérdida de información en tránsito.

Ecology and neurophysiology of sleep in two wild sloth species

Study Objectives: Interspecific variation in sleep measured in captivity correlates with various physiological and environmental factors, including estimates of predation risk in the wild. However, it remains unclear whether prior comparative studies have been confounded by the captive recording environment. Herein we examine the impact of predation pressure on sleep in sloths living in the wild. Design: Comparison of two closely related sloth species, one exposed to predation and one free from predation. Setting: Panamanian mainland rainforest (predators present) and island mangrove (predators absent). Participants: Mainland (Bradypus variegatus, 5 males and 4 females) and island (Bradypus pygmaeus, 6 males) sloths. Interventions: None. Measurements and Results: EEG and EMG activity were recorded using a miniature data logger. Although both species spent between 9 and 10 hours per day sleeping, the mainland sloths showed a preference for sleeping at night, whereas island sloths showed no preference for sleeping during the day or night. EEG activity during NREM sleep showed lower low-frequency power, and increased spindle and higher frequency power in island sloths when compared to mainland sloths. Conclusions: In sloths sleeping in the wild, predation pressure influenced the timing of sleep, but not the amount of time spent asleep. The preference for sleeping at night in mainland sloths may be a strategy to avoid detection by nocturnal cats. The pronounced differences in the NREM sleep EEG spectrum remain unexplained, but might be related to genetic or environmental factors.

Sustaining sleep spindles through enhanced SK2-channel activity consolidates sleep and elevates arousal threshold.

Sleep spindles are synchronized 11-15 Hz electroencephalographic (EEG) oscillations predominant during nonrapid-eye-movement sleep (NREMS). Rhythmic bursting in the reticular thalamic nucleus (nRt), arising from interplay between Ca(v)3.3-type Ca(2+) channels and Ca(2+)-dependent small-conductance-type 2 (SK2) K(+) channels, underlies spindle generation. Correlative evidence indicates that spindles contribute to memory consolidation and protection against environmental noise in human NREMS. Here, we describe a molecular mechanism through which spindle power is selectively extended and we probed the actions of intensified spindling in the naturally sleeping mouse. Using electrophysiological recordings in acute brain slices from SK2 channel-overexpressing (SK2-OE) mice, we found that nRt bursting was potentiated and thalamic circuit oscillations were prolonged. Moreover, nRt cells showed greater resilience to transit from burst to tonic discharge in response to gradual depolarization, mimicking transitions out of NREMS. Compared with wild-type littermates, chronic EEG recordings of SK2-OE mice contained less fragmented NREMS, while the NREMS EEG power spectrum was conserved. Furthermore, EEG spindle activity was prolonged at NREMS exit. Finally, when exposed to white noise, SK2-OE mice needed stronger stimuli to arouse. Increased nRt bursting thus strengthens spindles and improves sleep quality through mechanisms independent of EEG slow waves (<4 Hz), suggesting SK2 signaling as a new potential therapeutic target for sleep disorders and for neuropsychiatric diseases accompanied by weakened sleep spindles.

Colonic movements in healthy subjects as monitored by a Magnet Tracking System

Rapport de synthèse : Le Magnet Tracking System (MTS) est une technique peu invasive d'investigation de la motilité de l'entier du tube digestif. Elle repose sur le suivi de la progression d'un aimant par des senseurs externes en temps réel et dans les 3 dimensions. Dans cette étude, le MTS a été utilisé pour étudier les caractéristiques de propulsion propres aux différents segments coliques ainsi que pour comparer le transit de l'aimant permanent du MTS à celui de marqueurs radioopaques habituellement utilisés. Dix hommes et 10 femmes ayant un transit gastro-intestinal régulier ont ingéré simultanément un aimant de MTS et une capsule contenant 10 marqueurs radio-opaques, à 20h00. Les enregistrements se sont ensuite déroulés sur 2 matinées successives de 5 heures. L'analyse des données brutes recueillies a permis de réaliser une projection spatio-temporelle de la trajectoire de l'aimant dans le tube digestif ainsi qu'une description précise de l'origine, de la direction, de l'amplitude et de la vitesse des mouvements coliques. Des radiographies d'abdomen ont permis de comparer les positions respectives des marqueurs radio-opaques et de l'aimant du MTS. Durant 90% du temps d'enregistrement, l'aimant était immobile ou présentait des mouvements alternatifs de faible amplitude. Le reste des enregistrements consiste en activité propulsive dont 20% représentent des déplacements rétrogrades et une description très précise de 34 mouvements de masses. L'analyse des déplacements démontre une distribution bimodales des vitesses voisine de 1.5 et 50 cm /min, ce tant en direction orale que caudale. Deux tiers des distances parcourues le sont à vitesse rapide. L'analyse segmentaire confirme une progression horaire absolue supérieure dans le côlon gauche que droit. L'analyse détaillée par segment colique, reposant sur la description des déplacements enregistrés correspond aux rôles reconnus des différents segments, notamment de aire de stockage et de conditionnement du côlon ascendant ou de transit du côlon descendant. La comparaison des 2 sexes démontre un nombre plus important de mouvements, particulièrement de mouvements de masse chez l'homme. Les radiographies montrent une bonne corrélation entre la position de l'aimant et celle des marqueurs radio-opaques. Le MTS permet ainsi une description précise des caractéristiques propulsives des différents segments coliques, notamment par l'analyse détaillée des progressions à vitesses lente et rapide et leurs directions. Des distinctions peuvent également être notées en fonction du sexe. Ces investigations offrent de nouvelles perspectives pour l'étude des troubles de la motilité digestive.

Inhibition of gastric secretion by a water extract from Baccharis triptera, Mart

Baccharus triptera Mart, is a widespread Compositae used in Brazilian folk medicine to treat gastrointestinal disturbances, rheumatic disease, mild fever, diabetes and as an anti-helminthic. Water extract of small branches of the plant (WE) administered to mice and rats (0.1 to 2 g/Kg, p.o) did not alter spontaneous motor activity, sleeping time induced by barbiturates or the tailflick response in mice. The extract decreased by 40 por cento the number of writhings induced by 0.8 por cento scetic acid, i.p., but did not influence paw edema induced by carrageenan or dextran in rats WE (2g/Kg, p.o.) decreased the intestinal transit of charcoal in mice by 20//. Gastric secretion in pylorus ligated rats was reduced after treatment with WE (1 and 2 g/Kg. i.p. or intraduodenal and the gastric pH was raised. The extract (1 g/Kg, p.o.) prevented gastric ulcers induced in rats by immobilization at 4ºC, but not those induced by indomethacin (10 mg/Kg, s.c.). The results indicate that WE may relieve gastrointestinal disorders by reducing acid secretion and gastrointestinal hiperactivity. Neither analgesic nor anti-inflammatory activities were detectable.