Experimental assessment of Heliconia acuminata growth in a fragmented Amazonian landscape

1 Fragmentation severely alters physical conditions in forest understories, but few studies have connected these changes to demographic impacts on forest species using detailed experimental examination at the individual and population levels.2 Using a 32-month, reciprocal-transplant experiment, we show that individuals of the Amazonian understory herb Heliconia acuminata transplanted into forest fragments lost over 20% of their vegetative shoots, while those transplanted to continuous forest showed a slight gain. The leaf area of plants in fragments also increased at half the rate it did in continuous forest sites.3 It appears that the normal dry season stresses to which forest understorey plants are exposed are greatly exacerbated in fragments, causing plants to shed shoots and leaves.4 the observed shifts in size could help explain why populations in fragments are more skewed towards smaller demographic stage classes than those in continuous forest. These shifts in size structure could also result in reduced abundances of flowering plants, as reproduction in H. acuminata is positively correlated with shoot number.5 Fragmentation-related changes in growth rates resulting from abiotic stress may have significant demographic consequences.

Máxima Fase estável de lactato em ratos obesos de ambos os gêneros

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Recovery of rat growth and lipid profiles in adult rats subjected to fetal protein malnutrition with a fructose-rich diet

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Stretching Exercise Program Improves Gait in the Elderly

Background: Ageing is characterized by a number of physical changes that contribute to a decline in the ability to perform daily tasks. Stretching has been proposed to reduce hip flexion contracture and increase hip and pelvis range of motion, thus improving gait performance. Objective: The purpose of this study was to determine whether a supervised stretching program designed to improve the range of motion of the lower limbs alters gait kinematics in older adults. Methods: Twenty healthy older adult women (65.9 +/- 4.2 years old and BMI 24.9 +/- 3.5) were divided into 2 groups. The experimental group undertook 12 sessions of stretching exercises, whereas the control group did not engage in any physical activity. Gait performance was assessed at the beginning of the experiment and after the 4-week intervention period. Results: Those in the experimental group showed increased step length, higher velocity and reduced double support time after training. In addition, participants involved in the stretching program showed greater anterior and lateral pelvis tilt and also greater rotation (p < 0.05). Conclusions: Based on our results, we can suggest that a supervised stretching program is effective to alter a number of gait variables. Moreover, after the stretching protocol, aged participants displayed gait parameters which were similar to those reported in young healthy adults. Therefore, stretching can be used as an effective means to improve range of motion and reverse some age-related changes that influence gait performance. Copyright (C) 2009 S. Karger AG, Basel

Solar Radiation Effect on the Complexation Capacity of Aquatic Humic Substances with Metals

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise do equilíbrio em pacientes hemiparéticos após o treino com o programa Wii Fit

OBJETIVO: A hemiparesia é um comprometimento parcial do hemicorpo que altera o equilíbrio, sendo este essencial para as atividades funcionais. OBJETIVO: Avaliar o equilíbrio em pacientes hemiparéticos submetidos ao treino de equilíbrio com o programa Wii Fit, que atuou como um recurso de biofeedback visual. MÉTODO: Foram selecionados 12 pacientes hemiparéticos pós AVE, 5 do sexo masculino e 7 do sexo feminino, com idade média de 58 ± 12,57 anos, divididos aleatoriamente em dois grupos. Um deles realizou a fisioterapia convencional (GC) pelo período de uma hora, o outro realizou por trinta minutos e mais trinta minutos de treino de equilíbrio com auxílio do Wii Fit (GW), duas vezes por semana durante cinco semanas, completando dez sessões. O equilíbrio foi avaliado antes e após as intervenções, por meio da aplicação da Escala de Equilíbrio de Berg (EEB) e pela estabilometria, que mensura a oscilação do centro de pressão (COP), nos eixos ântero-posterior (AP) e médio-lateral (ML), por uma plataforma de pressão em duas condições: de olhos abertos (OA) e olhos fechados (OF). RESULTADOS: de acordo com a EEB, os pacientes, tanto do GC quanto o do GW, obtiveram maior controle do equilíbrio estático e dinâmico. Na avaliação do COP no eixo ML, os indivíduos do GC e do GW tiveram diminuição na oscilação ML após a intervenção proposta para cada grupo, nas condições de OA e OF. No eixo AP do COP, o GC não teve diminuição na oscilação AP de OA e OF, e o GW apresentou diminuição na oscilação AP de OA e OF. CONLUSÃO: O presente estudo demonstra que a fisioterapia associada ao treino de equilíbrio com o Wii Fit apresenta resultados significantes na reabilitação dos indivíduos hemiparéticos, obtendo, assim, mais um recurso terapêutico na fisioterapia.

Alterações na atividade da peroxidase e do conteúdo de carboidratos em mandioca cultivada in vitro sob estresse salino

A influência de estresse induzido por cloreto de sódio (75 e 150 mM) sobre o conteúdo de carboidratos solúveis e atividade da peroxidase, foi estudada em plântulas de mandioca cultivadas in vitro. Os resultados mostraram que a atividade da peroxidase diminuiu gradualmente durante o crescimento de plântulas em todos os tratamentos. O conteúdo de açúcares redutores foi menor em plântulas submetidas a 75 mM de NaCl, nas fases mais adiantadas do desenvolvimento, em comparação com a dose mais elevada do sal (150 mM de NaCl) ou sua omissão. Os resultados obtidos indicaram que o NaCl alterou o metabolismo de carboidratos, atividade da peroxidase e o crescimento de plântulas cultivadas in vitro.

Sugarcane silage production treated with additives at different times post burning

Objetivou-se estudar a ação do tempo após a queima do canavial e o uso de aditivos sobre as características fermentativas, as perdas e a composição química de silagens de cana-de-açúcar. A cultivar utilizada foi a IAC 86-2480 colhida em cinco tempos (1, 4, 7, 10 e 14 dias) pós-queima. Os aditivos utilizados foram controle, sem aditivos, Lactobacillus buchneri, cal virgem micropulverizada e Lactobacillus buchneri + cal virgem micropulverizada. Antes da ensilagem em cada tempo, foram determinadas as populações de leveduras presentes na cana-de-açúcar. Decorridos 56 dias após a ensilagem, os silos experimentais foram abertos. O delineamento experimental utilizado foi o inteiramente casualizado em esquema fatorial, considerando os fatores aditivos e tempo pós-queima. Houve recontaminação da cana-de-açúcar pelas leveduras, elevando a população de 5,04 para 6,48 log ufc/g de forragem. Os teores de matéria seca (MS) após a abertura do silo reduziram em média 7,6 unidades percentuais em comparação aos observados na ensilagem. As silagens controle e com Lactobacillus buchneri tiveram menores recuperações da matéria seca (613 e 631 g/kg, respectivamente), em comparação às observadas nas silagens com cal e com a combinação Lactobacillus buchneri + cal (807 g/kg e 832 g/kg, respectivamente), fato que pode ser justificado pelo controle de levedura pela cal. Após a queima, as maiores variações foram na produção de gás e na recuperação de matéria seca: a produção de gás foi maior nos primeiros dias e diminuiu com o tempo após a queima, consequentemente, a recuperação de MS foi menor nos primeiros dias e aumentou com o tempo após a queima. O tempo após a queima altera o valor nutritivo da cana-de-açúcar fresca e das suas silagens, assim como a magnitude das perdas no processo de ensilagem.

Synthesis and sintering of PZT ceramics

Lead zirconate powder, with Zr/Ti ratio of 50/50 was prepared by polymeric precursor method and doped with 3, 5 and 7 mol% of Sr+2 Or Ba+2, as well as by 0.2 to 5 mol% of Nb+5. The powder was calcined at 750 degrees C by 4 hours and milled during 1.5 h in isopropilic alcohol. Powders were characterized by surface area measurements (BET method), by infrared spectroscopy and by X-ray diffraction to characterize the crystal structure. Isostatically pressed samples were sintered in a dilatometer furnace by using a constant heating rate of 10 degrees C/min from ambient to 1200 degrees C. Synthetic air and air with water vapor were used as atmospheres. Both Sr+2 and Ba+2 substitute Pb+2 and favor the formation of rhombohedral phase. Otherwise, Nb+5 substitute preferentially Zr+4 favoring tetragonal phase. The concentration of dopants and the atmosphere influence the densification and the microstructure of the PZT, which alters the dielectric and piezoelectric properties of the ceramics.

The Lactate Minimum Test protocol provides valid measures of cycle ergometer VO2 peak

Aim. The aim of the present study was to investigate the validity of the Lactate Minimum Test (LMT) for the determination of peak VO2 on a cycle ergometer and to determine the submaximal oxygen uptake (VO2) and pulmonary ventilation (VE) responses in an incremental exercise test when it is preceded by high intensity exercise (i.e., during a LMT).Methods. Ten trained male athletes (triathletes and cyclists) performed 2 exercise tests in random order on an electromagnetic cycle ergometer: 1) Control Test (CT): an incremental test with an initial work rate of 100 W, and with 25 W increments at 3-min intervals, until voluntary exhaustion; 2) LMT: an incremental test identical to the CT, except that it was preceded by 2 supramaximal bouts of 30-sec (similar to120% VO(2)peak) with a 30-sec rest to induce lactic acidosis. This test started 8 min after the induction of acidosis.Results. There was no significant difference in peak VO2 (65.6+/-7.4 ml.kg(-1).min(-1); 63.8+/-7.5 ml.kg(-1).min(-1) to CT and LMT, respectively). However, the maximal power output (POmax) reached was significantly higher in CT (300.6+/-15.7 W) than in the LMT (283.2+/-16.0 W).VO2 and VE were significantly increased at initial power outputs in LMT.Conclusion. Although the LMT alters the submaximal physiological responses during the incremental phase (greater initial metabolic cost), this protocol is valid to evaluate peak VO2, although the POmax reached is also reduced.

FTY720 prevents renal T-Cell infiltration after ischemia/reperfusion injury

Ischemia/reperfusion (I/R) injury, a common early feature in renal transplantation, results from both free radical species generation and local inflammatory responses that attract different types of cells. The interaction with infiltrating leukocytes could promote damage and death of resident renal cells contributing to worsening of renal function. It has been shown that depletion of host T cells protects against kidney damage after I/R injury, although the mechanism is not fully understood. FTY720, a synthetic analog of a natural product extracted from Isaria sincclairii has shown modulatory properties in experimental models of autoimmune disease, transplantation, and I/R injury. FTY720 alters lymphocyte responses to chemokine homing signals, thereby decreasing the number of lymphocytes in inflammatory sites. We evaluated renal function in mice at 3, 5, and 7 days after I/R injury in the presence or absence of FTY720 treatment. FTY720 treatment promoted earlier recovery of renal function associated with a lower number of renal-infiltrating lymphocytes. These findings confirm previous results showing a protective effect of FTY720 in I/R injury models.

The influence of temperature on the color of TiO2:Cr pigments

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effects of prenatal exposure to deltamethrin on forced swimming behavior, motor activity, and striatal dopamine levels in male and female rats

The effects of prenatal exposure of rat pups to 0.08 mg/kg deltamethrin (DTM) on physical, reflex and behavioral developmental parameters, on forced swimming and open-field behaviors, and on striatal monoamine levels at 60 days of age were observed. Maternal and offspring body weight, physical and reflex development were unaffected by the exposure to the pesticide. At 21 days of age, open-field locomotion frequency and immobility duration of male and female offspring were not different between control and exposed animals. However, male rearing frequency was increased in experimental animals. A decreased immobility latency to float and in general activity after the swimming test in male offspring was observed at adult age; no interference was detected in the float duration during the swimming test. In addition, these animals presented higher striatal 3,4-dihydroxyphenylacetic acid (DOPAC) levels without modification in dopamine (DA) levels and an increased DOPAC/DA ratio. These data indicate a higher activity of the dopaminergic system in these animals. Noradrenaline (NA) levels were increased, while MHPG levels were not detectable in the system studied. Serotonin (5-HT) and 5-hydroxyindolacetic acid (5-HIAA) levels, as well as the homovanillic acid (HVA)/DA ratio, were not modified by the exposure to the pesticide. No changes were observed in swimming and open-field behaviors nor were there any changes in striatal monoamines or their metabolites in the female experimental group. In relation to the pesticide formula, the present data showing that prenatal exposure to DTM alters latency to float and the activity of striatal dopaminergic system might reflect a persistent effect of the pesticide on animal motor activity, mainly in males. on the other hand, the decrease in general activity observed in experimental male rats suggests higher levels of emotionality induced by previous exposure to the swimming behavior test in relation to control animals. Data gathered in the present study may be important for the assessment of the safety of pyrethroid insecticides. (C) 2001 Elsevier B.V. All rights reserved.

Microstructural development of ZnO varistor during reactive liquid phase sintering

The microstructural evolution, grain growth and densification for the varistor systems ZnO-Bi2O3 (ZB), ZnO-Bi2O3-Sb2O3 (ZBS), ZnO-Bi2O3-Sb2O3-MnO-Cr 2O3-CoO (ZBSCCM) were studied using constant heating rate sintering, scanning electron microscopy (SEM) and in situ phase formation measurement by high temperature X-ray diffraction (HT-XRD). The results showed that the densifying process is controlled by the formation and decomposition of the Zn2Bi3Sb3O14 pyrochlore (PY) phase for the ZBS and ZBSCCM systems. The addition of transition metals (ZBSCCM system) alters the formation and decomposition reaction temperatures of the pyrochlore phase and the morphology of the Zn7Sb2O12 spinel phase. Thus, the spinel grains act as inclusions and decrease the ZnO grain growth rate. Spinel grain growth kinetics in the ZBSCCM system showed an n value of 2.6, and SEM and HT-XRD results indicate two grain growth mechanisms based on coalescence and Ostwald ripening. © 1996 Chapman & Hall.

Morphology of the ventral lobe of the prostate and seminal vesicles in an ethanol-drinking strain of rats (UChA and UChB)

Chronic alcoholism alters reproduction and therefore may be responsible for alterations of prostate and seminal vesicles, which are the subject of this analysis in UCh ethanol-drinking rats. The prostate and seminal vesicles of 20 animals were submitted to macroscopic, light microscopy, electron microscopy and morphometric analysis. The UCh rats showed atrophy of the epithelium and reduction of the weight of the prostate and seminal vesicle, liver hypertrophy and fat infiltration and alterations of the hypothalamus-pituitary axis. Ethanol induces changes in the weight and in the epithelium of prostate and seminal vesicles and hypothalamus-pituitary axis of UCh rats.