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961.
Sicilian cultivars of prickly pear (Opuntia ficus indica) produce yellow, red, and white fruits, due to the combination of two betalain pigments, the purple-red betanin and the yellow-orange indicaxanthin. The betalain distribution in the three cultivars and the antioxidant activities of methanolic extracts from edible pulp were investigated. In addition, the reducing capacity of purified betanin and indicaxanthin was measured. According to a spectrophotometric analysis, the yellow cultivar exhibited the highest amount of betalains, followed by the red and white ones. Indicaxanthin accounted for about 99% of betalains in the white fruit, while the ratio of betanin to indicaxanthin varied from 1:8 (w:w) in the yellow fruit to 2:1 (w:w) in the red one. Polyphenol pigments were negligible components only in the red fruit. When measured as 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox) equivalents per gram of pulp, the methanolic fruit extracts showed a marked antioxidant activity. Vitamin C did not account for more than 40% of the measured activity. In addition, the extracts dose-dependently inhibited the organic hydroperoxide-stimulated red cell membrane lipid oxidation, as well as the metal-dependent and -independent low-density lipoprotein oxidation. The extract from the white fruit showed the highest protection in all models of lipid oxidation. Purified betanin and indicaxanthin were more effective than Trolox at scavenging the [2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)] diammonium salt cation radical. Cyclic voltammetric measurements show two anodic waves for betanin and indicaxanthin, and differential pulse voltammetry shows three anodic waves for betanin, with calculated peak potentials of 404, 616, and 998 mV, and two anodic waves for indicaxanthin, with peak potentials of 611 and 895 mV. Betanin underwent complex formation through chelation with Cu(2+), whereas indicaxanthin was not modified. These findings suggest that the above betalains contribute to the antioxidant activity of prickly pear fruits.  相似文献   
962.
The diversity of Oniscidea across a 1000-m altitudinal gradient comprising three distinct environments—the coastal plain, the highland slopes, and the highlands—was described and analysed. We employed 1 h-long exploratory manual sampling at 41 sites. Fourteen species were identified, of 818 individuals collected. Sampling-effort curves stabilised for all three environments; analytical estimates of species richness did not exceed the observed value. Abundance did not vary significantly among environments, and local species richness differed only marginally. However, the Shannon diversity index for local sites indicated highland slopes to be significantly more diverse than the coastal region; the same was true for bootstrap estimates at the regional level. Two species appeared in all three environments, comprising 72.7% of the abundance. The coastal region and highlands had one exclusive species each, and the highland slopes had three. The first two environments are more similar to each other than to the slopes, although they are not contiguous. The altitudinal gradient of diversity was hump-shaped, because the highland slopes were most diverse. The reasons for this pattern are not biogeographical; that is, the highland slopes are not a contact zone between the highlands and the coast. A complete explanation depends upon better understanding of the effect of soil type and terrain slope on the diversity of terrestrial isopods.  相似文献   
963.
An optimized method for the determination of protease activity in acid forest soils A method for the determination of protease activity was tested for its applicability to acid forest soils (O-horizon and mineral soil). The influences of the following parameters on the protease activity and its determination were investigated: incubation time, substrate concentration. pH-value of the incubation solution, buffer solution, sample matrix and storage of soil samples. In consequence of the results an optimized method is proposed. The application of this modified method to two forest sites with contrasting N-transformation indicates, that also in acid forest soils the determination of protease activity allows significant differentiations.  相似文献   
964.
Stopping the increase of atmospheric CO2 level is an important task and information on how to implement adjustments on tillage practices could help lower soil CO2 emissions would be helpful. We describe how rotary tiller use on a red latosol affected soil CO2 efflux. The impact of changing blade rotation speed and rear shield position on soil CO2 efflux was investigated. Significant differences among treatments were observed up to 10 days after tillage. Cumulative CO2 efflux was as much as 40% greater when blade rotation of 216 rpm and a lowered rear shield was compared to blade rotation of 122 rpm and raised shield. This preliminary work suggests that adjusting rotary tiller settings could help reduce CO2 efflux close to that of undisturbed soil, thereby helping to conserve soil carbon in tropical environments.  相似文献   
965.
A morphometric study was conducted on the testis of the domestic quail Coturnix coturnix japonica to determine testicular kinetics. We investigated the variability along the year of testicular parameters such as seminiferous tubule diameter, germinal epithelium height and amount of meiotic figures of maturing spermatids in the seminiferous epithelium and of sperm in the tubular lumen. The results of morphometric analysis showed the occurrence of an annual testicular cycle defined by four distinct phases: a resting phase (at the end of summer), a recrudescence phase (in the fall), a proliferative phase (at the end of winter and beginning of spring), and a regression phase (spring and summer). We also observed that the testes of adult quails present elevated and maximal spermatogenic activity in fall-winter (short-day period) and at the beginning of spring, respectively, and lower values in spring and summer (long-day periods), with minimum values at the end of summer.  相似文献   
966.
OBJECTIVE: To evaluate pulmonary and cardiovascular effects of a recruitment maneuver (RM) combined with positive end-expiratory pressure (PEEP) during total intravenous anesthesia in ponies. ANIMALS: 6 healthy adult Shetland ponies. PROCEDURE: After premedication with detomidine (10 microg/kg, IV), anesthesia was induced with climazolam (0.06 mg/kg, IV) and ketamine (2.2 mg/kg, IV) and maintained with a constant rate infusion of detomidine (0.024 mg/kg/h), climazolam (0.036 mg/kg/h), and ketamine (2.4 mg/kg/h). The RM was preceded by an incremental PEEP titration and followed by a decremental PEEP titration, both at a constant airway pressure difference (deltaP) of 20 cm H2O. The RM consisted of a stepwise increase in deltaP by 25, 30, and 35 cm H2O obtained by increasing peak inspiratory pressure (PIP) to 45, 50, and 55 cm H2O, while maintaining PEEP at 20 cm H2O. Hemodynamic and pulmonary variables were analyzed at every step of the PEEP titration-RM. RESULTS: During the PEEP titration-RM, there was a significant increase in PaO 2 (+12%), dynamic compliance (+ 62%), and heart rate (+17%) and a decrease in shunt (-19%) and mean arterial blood pressure (-21%) was recorded. Cardiac output remained stable. CONCLUSIONS AND CLINICAL RELEVANCE: Although baseline oxygenation was high, Pa(O2) and dynamic compliance further increased during the RM. Despite the use of high PIP and PEEP and a high tidal volume, limited cardiovascular compromise was detected. A PEEP titration-RM may be used to improve oxygenation in anesthetized ponies. During stable hemodynamic conditions, PEEP titration-RM can be performed with acceptable adverse cardiovascular effects.  相似文献   
967.
OBJECTIVE: To identify qualitative and quantitative differences in cardiac mitochondrial protein expression in complexes I to V between healthy dogs and dogs with natural or induced dilated cardiomyopathy (DCM). SAMPLE POPULATION: Left ventricle samples were obtained from 7 healthy dogs, 7 Doberman Pinschers with naturally occurring DCM, and 7 dogs with DCM induced by rapid right ventricular pacing. PROCEDURES: Fresh and frozen mitochondrial fractions were isolated from the left ventricular free wall and analyzed by 2-dimensional electrophoresis. Protein spots that increased or decreased in density by 2-fold or greater between groups were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry or quadrupole selecting, quadrupole collision cell, time-of-flight mass spectrometry. RESULTS: A total of 22 altered mitochondrial proteins were identified in complexes I to V. Ten and 12 were found in complex I and complexes II to V, respectively. Five were mitochondrial encoded, and 17 were nuclear encoded. Most altered mitochondrial proteins in tissue specimens from dogs with naturally occurring DCM were associated with complexes I and V, whereas in tissue specimens from dogs subjected to rapid ventricular pacing, complexes I and IV were more affected. In the experimentally induced form of DCM, only nuclear-encoded subunits were changed in complex I. In both disease groups, the 22-kd subunit was downregulated. CONCLUSIONS AND CLINICAL RELEVANCE: Natural and induced forms of DCM resulted in altered mitochondrial protein expression in complexes I to V. However, subcellular differences between the experimental and naturally occurring forms of DCM may exist.  相似文献   
968.
The present study describes the morphological characteristics of black howler monkey (Alouatta caraya) ovarian follicles. One ovary of an adult healthy black howler monkey was collected and processed for light and electron microscopy. Primordial, primary, secondary, tertiary and pre-ovulatory follicles were evaluated for their morphometrical aspects. The ovary of black howler monkey presented a distinct conformation with a uniform distribution of the follicles mostly in the peripheric cortex. This black howler monkey ovary presented a total of 59 921 ovarian follicles. From this amount, 71.1% were classified as primordial, 18.9% as primary, 8.1% as secondary, 1.4% as tertiary and 0.5% as pre-ovulatory follicles. From all these developmental stages, the mean diameters of follicles, oocytes, oocytes nuclei and the mean number of granulosa cells are described. Moreover, primordial, primary and secondary follicles have been observed by electron microscopy.  相似文献   
969.
In the last 2 decades, the prevalence of Salmonella enterica serotype Enteritidis (Salmonella Enteritidis) has dramatically increased worldwide, becoming the leading cause of food-borne illnesses and an important public health issue. Many studies have suggested the role of the SEF14 fimbrial protein in the adhesion of Salmonella Enteritidis to the host. In the present study, the sefA gene, which encodes the main subunit of the SEF14 fimbrial protein, was cloned into a temperature-sensitive expression vector and transformed into a nonpathogenic, avirulent strain of Escherichia coli. The recombinant strain was used as a vaccine to elicit specific immune response against the SefA protein of Salmonella Enteritidis in 1-day-old chickens. The recombinant strain was reisolated from the intestines of treated birds for up to 21 days posttreatment, demonstrating its ability to colonize the intestinal tracts of 1-day-old chickens. In addition, immunoglobulin A (IgA) against the SefA protein was detected in intestinal secretions from treated birds at 7 days posttreatment and in bile samples from 14 to 21 days posttreatment by enzyme-linked immunosorbent assay. Nontreated birds did not show any evidence of intestinal colonization by the recombinant strain or anti-SefA IgA response in their bile or intestinal secretions. Preliminary evaluation of the recombinant strain showed a potential use of this strain to elicit protection against Salmonella Enteritidis infection in chickens. Further experiments are needed to study the ability of the recombinant strain to protect birds against Salmonella Enteritidis colonization.  相似文献   
970.
The teats of Brown Swiss and Austrian Simmental cows, divided into two groups, one milked by means of an automatic milking system, the other using a conventional milking parlour, were examined monthly by ultrasonography. Aim of the study was to compare the effects of two different milking machines upon the structures of the bovine teat canal and wall by ultrasonography and thereby evaluate ultrasonography as a research tool for visualisation of different influences on the bovine teat. Length and thickness of the teat canal and teat wall thickness were measured and analysed. During lactation, teat canal length and thickness increased in both groups, teat canal length decreased in conventional milked cows at the end of lactation. Shorter and narrower teat canals were observed in automatic milked cows. Differences between the groups in teat canal length and thickness were determined in early lactation. During lactation teat wall thickness showed a slight increase. Automatic milked cows displayed thinner teat walls than cows milked in the milking parlour. Teat morphology was influenced by the number and duration of lactations, milk yield, quarter of the udder and time and date of examination. It was concluded that the effect of the two different milking machines caused significant differences in bovine teat morphology and that ultrasonography proved to be an appropriate method for visualising influences of the milking technique on the bovine teat.  相似文献   
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