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991.
Giardia lamblia which parasitize humans belong to either of two genotypes, A or B, based on specific signature sequences in the 5' end of the small subunit (16S) ribosomal RNA (rRNA) gene. These two genotypes also were found in cysts from fecal samples of animal origin such as dogs, cats, some farm animals and wild animals. In addition, trophozoites recovered from cysts obtained from environmental samples belonged to these two genotypes as well, suggesting that the G. lamblia genotypes A and B are widespread and possibly zoonotic. Trophozoites were recovered from rats and these isolates might belong to another genotype of G. lamblia. Deer mice and one dog appeared to be parasitized by genotypes of Giardia with close affinity to G. microti. This species, therefore, also consists of a genotype complex.  相似文献   
992.
The acute single dose oral toxicity of carbophenothion (S-4-chlorophenylthiomethyl OO-diethyl phosphorodithioate) has been determined in Canada geese (Branta canadensis), pigeons (Columba livia) and Japanese quail (Coturnix coturnix japonica). At post mortem examination gross pathological changes were observed in Canada geese and pigeons and esterase levels were determined by conventional and electrophoretic methods on extracts of liver and brain from these two species. Carbophenothion residue levels were determined in liver, brain and gizzard contents from the geese and pigeons. The overall pattern of results suggests that esterase inhibition may not be the dominant factor in carbophenothion poisoning in geese. It is suggested that a brain carbophenothion residue level of 1 part/106 is indicative of death by poisoning in geese.  相似文献   
993.
A stable isotope dilution assay for quantification of pantothenic acid in sea buckthorn berries, juice, and concentrate using a four-fold labeled isotopologue of vitamin B5 as the internal standard was adopted using reversed phase liquid chromatography-mass spectrometry with electrospray ionization. Because of a rapid sample clean up procedure without the necessity of external calibration, this methodology permits the accurate analysis of a high number of samples within a short time. Sea buckthorn juice was stored at 25 and 40 degrees C for up to 7 days to determine the effects of storage temperature on the stability of pantothenic acid. Analysis of kinetic data suggested that the degradation follows a first-order model. The results of the experiments showed that storage of sea buckthorn juice for 7 days at ambient temperature (25 degrees C) already resulted in a significant degradation of pantothenic acid of about 18%. The processing effects of juice production and subsequent concentration revealed a decrease of about 6-7% in the juice and of 23% in the juice concentrate.  相似文献   
994.
995.
The occurrence and characteristics of chemically-based density stratification in portions of the Seneca and Oswego Rivers, downstream of ion-polluted Onondaga Lake, are described for seven different days in the summer and fall of 1978 and 1981, which covered a wide range of river flows. The results indicate that chemically-based density stratification occurs routinely in the Seneca River downstream of the lake inflow, in response to a continuous chemically-based density difference between the two systems of 0.0015 to 0.0030 g cm?3. The persistence of the phenomenon, and therefore the longitudinal range over which the river stratification occurred, was dependent on the velocity of river flow and the magnitude of the density gradient that bordered the upper river water and the lower released lake water. During the low flows common to summer the stratification extended approximately 14 km downstream to a dam, and 3 km upstream, of the lake outlet — river junction. Vertical mixing between the stratified layers increased as the flow in the Seneca River increased, and as the vertical density gradient decreased. A dimensionless group, $$\frac{D}{{V\left( {\frac{\rho }{{\Delta _\rho /\Delta _z }}} \right)}}$$ where: D = apparent vertical diffusion (m2 hr?1), V = average velocity of the overlying river flow (m hr?1 ), p = density at the interface between the stratified layers (g cm?3), and Ap/Az = density gradient between the stratified layers (g cm?3 m?1), was found to be constant for summer low flow conditions for a 6.5 km length of the Seneca River, thus quantifying the interaction between vertical mixing and the included influences for that portion of the river. The occurrence of chemical stratification in the river had dramatic implications on the corresponding distribution of dissolved oxygen (DO). The isolation of the organically enriched lake water in the lower layer enhanced the depletion of DO there, which resulted in the development of substantial (> 4.0 mg 1?1 ) DO stratification downstream of the discharge from the lake during summer low flow periods.  相似文献   
996.
997.
OBJECTIVE: To evaluate the use of xylazine and ketamine for total i.v. anesthesia in horses. ANIMALS: 8 horses. PROCEDURE: Anesthetic induction was performed on 4 occasions in each horse with xylazine (0.75 mg/kg, i.v.), guaifenesin (75 mg/kg, i.v.), and ketamine (2 mg/kg, i.v.). Intravenous infusions of xylazine and ketamine were then started by use of 1 of 6 treatments as follows for which 35, 90, 120, and 150 represent infusion dosages (microg/kg/min) and X and K represent xylazine and ketamine, respectively: X35 + K90 with 100% inspired oxygen (O2), X35 + K120-(O2), X35 + K150-(O2), X70 + K90-(O2), K150-(O2), and X35 + K120 with a 21% fraction of inspired oxygen (ie, air). Cardiopulmonary measurements were performed. Response to a noxious electrical stimulus was observed at 20, 40, and 60 minutes after induction. Times to achieve sternal recumbency and standing were recorded. Quality of sedation, induction, and recovery to sternal recumbency and standing were subjectively evaluated. RESULTS: Heart rate and cardiac index were higher and total peripheral resistance lower in K150-(O2) and X35 + K120-air groups. The mean arterial pressure was highest in the X35 + K120-air group and lowest in the K150-(O2) group (125 +/- 6 vs 85 +/- 8 at 20 minutes, respectively). Mean Pa(O2) was lowest in the X35 + K120-air group. Times to sternal recumbency and standing were shortest for horses receiving K150-(O2) (23 +/- 6 minutes and 33 +/- 8 minutes, respectively) and longest for those receiving X70 + K90-(O2) (58 +/- 28 minutes and 69 +/- 27 minutes, respectively). CONCLUSIONS AND CLINICAL RELEVANCE: Infusions of xylazine and ketamine may be used with oxygen supplementation to maintain 60 minutes of anesthesia in healthy adult horses.  相似文献   
998.
999.
Italian ryegrass (Lolium multiflorum Lam. ssp. italicum Volkart ex Schinz et Keller) thrives well in permanent grassland in mild and moist regions of Switzerland. Ecotypes of Italian ryegrass from Swiss permanent meadows have often been used successfully as the base material of breeding programmes. However, their agronomic performance per se has never been studied in detail. Therefore, field trials were conducted to assess the potential of this semi-natural genetic resource for use in breeding. Twenty ecotype populations were collected in different geographical regions in 2003 and seed was increased. Plot trials with 20 ecotype populations were conducted 2005–2007 at three locations, supplemented by row trials at two additional locations, and including four currently recommended cultivars as controls. Average performance in terms of yield, vigour and resistance to snow mould of ecotypes was superior to the cultivars. Depending on the characteristic, between three and 16 of the 20 ecotypes performed significantly better than the cultivars mean. However, resistance against crown rust of all ecotypes was significantly poorer than that of the cultivars. Correlation and regression analysis showed that more eastern and more northern collecting sites harboured better performing ecotypes. However, the most consistent site related factor favouring performance of the ecotypes in terms of yield, vigour, snow mould and Xanthomonas resistance was a low abundance of species which are typical of Arrhenatheretum type meadows. Data from the plot trials were related to results obtained with spaced plants at a single site, either in a seedling nursery or in the greenhouse. Resistance against crown rust was extremely well predicted by spaced plant observations. Xanthomonas resistance observed after artificial inoculation in the greenhouse was also significantly, but less closely correlated with field observations. An early date of ear emergence as observed on spaced plants was associated with high annual yield in the plot trials. It is concluded that in intensively managed habitats, natural selection has resulted in ecotype populations of Italian ryegrass which are highly promising for use in breeding. Individual plant selection for resistance can be expected to efficiently reduce their high susceptibility to crown rust.  相似文献   
1000.
A study was conducted to determine the prevalence and possible significance of campylobacteria in pig abortions in Denmark. Surface-cauterised liver and kidney samples from 55 aborted pig fetuses submitted to the Danish Veterinary Laboratory were taken and a sensitive isolation procedure used to examine pooled tissue samples for Campylobacter, Arcobacter and Helicobacter spp. Routine microbiological, immunological, and histopathological examinations were also performed to identify concurrent infections or histopathological changes. The abortions tested negative for established abortifacient pathogens (Brucella, Leptospira, PPV, PRRSV), but Arcobacter spp. were recovered from 23/55 abortions. Co-infections with Streptococcus suis, Escherichia coli, and haemolytic streptococci were observed in 7/23 Arcobacter-positive fetuses, and in 4/32 Arcobacter-negative fetuses. Histopathological analyses identified placentitis, pneumonia, hepatitis and encephalitis among the study group. However, no obvious pathologic features were solely associated with Arcobacter-positive cases, nor were Arcobacter-like bacteria observed in tissue samples. Protein profile analyses of the 27 Arcobacter isolates identified 11 as A. cryaerophilus and 10 as A. skirrowii. Six strains could not be classified into any existing species and were phenotypically distinct, thus, potentially representing at least one new species. The identification results showed that multiple taxa could be found in a single fetus, and in distinct aborted fetuses from a single sow. The high prevalence of arcobacters in Danish pig abortions may account for at least some of the >90% of cases in which no established abortifacient agent is detected, but further studies are needed to define the role of each species, especially where co-infections with other bacteria are present.  相似文献   
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