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31.
Experimental studies about the recovery, survival and migration to pasture of cyathostomin infective larvae (L(3)) from fresh feces depositions were conducted from February 2005 to March 2007 in a tropical region of southeast Brazil. Grass and feces were collected weekly at 8 a.m., 1 and 5 p.m. and processed by the Baermann technique. Multivariate analysis (principal components method) showed the influence of time and environmental variables on the number of infective larvae recovered from the feces and pasture. In the rainy period (October-March), more infective larvae were recovered on the feces and grass apex. In contrast, in the dry period (April-September), the recovery was higher only on the grass base, as well as the L(3) survival on feces and grass. More larvae were recovered at 8 a.m., except from the grass apex, where the highest recovery was at 1 p.m. Few studies investigating the seasonal transmission of equine cyathostomin have been conducted in South American tropical climates. These results demonstrate that in tropical conditions L(3) are available on feces and pasture throughout the year. Knowledge of climatic influences on the development and survival of L(3) is crucial to designing integrated parasite control programs that provide effective protection while slowing the development of anthelmintic resistance.  相似文献   
32.
The aim of this study was to evaluate the correlation between the cerebral state index (CSI) and the estimated propofol plasma concentrations in dogs during induction of anaesthesia. Fifteen healthy dogs undergoing scheduled routine surgical procedures were enrolled in this study. Target controlled infusion (TCI) software, based on the pharmacokinetic model for propofol, was used to control the syringe pump and to estimate plasma propofol concentrations (PropCp) and the CSI values every five-seconds. Three electrodes placed in the centre of the forehead, on the left side of the forehead and on the left mastoid were used to collect the electroencephalographic (EEG) signal converted by the cerebral state monitor into the CSI. The cerebral electrical changes induced by increasing propofol concentrations appear to be detected by CSI monitoring in dogs. The negative correlation between CSI and PropCp demonstrates that the CSI could be used to assess electrical brain activity in dogs during the induction of anaesthesia with propofol.  相似文献   
33.
Elevations in cytosolic free calcium concentration ([Ca(2+)](cyt)) constitute a fundamental signal transduction mechanism in eukaryotic cells, but the molecular identity of Ca(2+) channels initiating this signal in plants is still under debate. Here, we show by pharmacology and loss-of-function mutants that in tobacco and Arabidopsis, glutamate receptor-like channels (GLRs) facilitate Ca(2+) influx across the plasma membrane, modulate apical [Ca(2+)](cyt) gradient, and consequently affect pollen tube growth and morphogenesis. Additionally, wild-type pollen tubes grown in pistils of knock-out mutants for serine-racemase (SR1) displayed growth defects consistent with a decrease in GLR activity. Our findings reveal a novel plant signaling mechanism between male gametophyte and pistil tissue similar to amino acid-mediated communication commonly observed in animal nervous systems.  相似文献   
34.
The lipid classes of Pavlova lutheri, cultivated in semicontinuous mode, were studied by thin-layer chromatography and gas chromatography in attempts to describe the distribution of fatty acid residues within its lipid pool, with special emphasis on eicosapentaenoic (C20:5n-3, EPA) and docosahexaenoic (C22:6n-3, DHA) acids. Neutral lipids and glycolipids were the major constituents and accounted for approximately 57 and 24% of the total fatty acid residues (TFA), respectively. Phospholipids accounted for approximately 10% of TFA. Two lipid classes, acylated steryl glycosides (SG) and diphosphatidylglycerols (DPG), were eventually identified in P. lutheri for the first time. The nonpolar fraction was mainly composed of triacylglycerol (TAG), whereas the polar fraction was mainly composed of monogalactosylacylglycerols (MGDG). The distribution of total EPA and DHA within the lipid pool was calculated in attempts to ascertain the quality of said microalgae as a feed source, as well as the possibility of enhancement of individual fatty acid production and extraction thereafter. EPA was especially concentrated in MGDG (approximately 45%) and TAG (approximately 33%); conversely, DHA was dispersed through various classes, especially within TAG (approximately 27%), DPG (approximately 22%), and betaine lipids (21%).  相似文献   
35.
An outbreak of necrotic enteritis caused by Clostridium perfringens type C was diagnosed in captive collared (Pecari tajacu) and white-lipped (Tayassu pecari) peccaries housed in the Laboratory of Applied Ethology of Universidade Estadual de Santa Cruz located in Ilhéus, State of Bahia, Brazil. Four collared peccaries and three white-lipped peccaries, all juveniles (25-105 days old), were affected. For all affected animals, lethargy and inappetance were followed by sudden death within 24 hours. Histopathology of intestinal wall, culture of C. perfringens type C, and the identification of beta-toxin from intestinal content confirmed the diagnosis.  相似文献   
36.
Genetic Resources and Crop Evolution - The development of segregating populations in papaya allows the development of new high fruit yield and excellent fruit quality pure line or hybrid cultivars....  相似文献   
37.
Microalgae as sources of carotenoids   总被引:1,自引:0,他引:1  
Marine microalgae constitute a natural source of a variety of drugs for pharmaceutical, food and cosmetic applications-which encompass carotenoids, among others. A growing body of experimental evidence has confirmed that these compounds can play important roles in prevention (and even treatment) of human diseases and health conditions, e.g., cancer, cardiovascular problems, atherosclerosis, rheumatoid arthritis, muscular dystrophy, cataracts and some neurological disorders. The underlying features that may account for such favorable biological activities are their intrinsic antioxidant, anti-inflammatory and antitumoral features. In this invited review, the most important issues regarding synthesis of carotenoids by microalgae are described and discussed-from both physiological and processing points of view. Current gaps of knowledge, as well as technological opportunities in the near future relating to this growing field of interest, are also put forward in a critical manner.  相似文献   
38.
There is a great demand for the development of novel wound dressings to overcome the time and costs of wound care performed by a vast number of clinicians, especially in the current overburdened healthcare systems. In this study, Cyanoflan, a biopolymer secreted by a marine unicellular cyanobacterium, was evaluated as a potential biomaterial for wound healing. Cyanoflan effects on cell viability, apoptosis, and migration were assessed in vitro, while the effect on tissue regeneration and biosafety was evaluated in healthy Wistar rats. The cell viability and apoptosis of fibroblasts and endothelial cells was not influenced by the treatment with different concentrations of Cyanoflan, as observed by flow cytometry. Moreover, the presence of Cyanoflan did not affect cell motility and migratory capacity, nor did it induce reactive oxygen species production, even revealing an antioxidant behavior regarding the endothelial cells. Furthermore, the skin wound healing in vivo assay demonstrated that Cyanoflan perfectly adapted to the wound bed without inducing systemic or local oxidative or inflammatory reaction. Altogether, these results suggest that Cyanoflan is a promising biopolymer for the development of innovative applications to overcome the many challenges that still exist in skin wound healing.  相似文献   
39.
The existence of daily rhythms under light/dark (LD) cycles in plasma cortisol, blood glucose and locomotor and self-feeding activities, as well as their persistence (circadian nature) under constant light (LL), was investigated in Senegalese sole (Solea senegalensis). For the cortisol and glucose rhythms study, 48 soles were equally distributed in 8 tanks and exposed to a 12:12 LD cycle and natural water temperature (experiment 1). After an acclimation period, blood was sampled every 3 h until a 24-h cycle was completed. Blood glucose levels were measured immediately after sampling, while plasma cortisol was measured later by ELISA. In experiment 2, the fish were exposed to LL for 11 days, and after this period, the same sampling procedure was repeated. For the study of locomotor and self-feeding rhythms (experiment 3), two groups of sole were used: one exposed to LD and the other to LL. Each group was distributed within 3 tanks equipped with infrared photocells for the record of locomotor activity, and self-feeders for feeding behavior characterization. The results revealed a marked oscillation in cortisol concentrations during the daily cycle under LD, with a peak (35.65 ± 3.14 ng/ml) in the afternoon (15:00 h) and very low levels during the night (5.30 ± 1.09 ng/ml). This cortisol rhythm persisted under LL conditions, with lower values (mean cortisol concentration = 7.12 ± 1.11 ng/ml) and with the peak shifted by 3 h. Both rhythms were confirmed by COSINOR analysis (p < 0.05). The synchronizing role of temperature and feeding schedule, in addition to light, is also discussed. Diel rhythms of glucose were not evident in LD or LL. As to locomotor and self-feeding activity, a very marked rhythm was observed under LD, with higher activity observed during the night, with acrophases located at 2:14 and 3:37 h, respectively. The statistical significance of daily rhythms was confirmed by COSINOR analysis. Under LL, both feeding and locomotor rhythms persisted, with an endogenous period (τ) around 22.5 h. In short, our findings described for the first time the existence of circadian cortisol and behavioral circadian rhythms in flat fish. Such results revealed the importance of taking into account the time of day when assessing stress responses and evaluating physiological indicators of stress in fish.  相似文献   
40.
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