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21.
Isodiagnosis of blood from Rio Grande wild turkeys from southern Texas revealed a small, intraerythrocytic rickettsia, Aegyptianella pullorum Carpano, 1928, in 24 of 300 samples. Identification of this first isolate from North America was made using both light and transmission electron microscopy. It is suggested that the translocation of wild turkeys from Texas to other states could spread this pathogen to both wild birds and domestic poultry. 相似文献
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介绍了原木蒸煮废水的处理方法,提出氧化塘法是小型木材加工厂处理该废水的最佳选择,并用实例简单介绍了氧化塘的设计选型问题. 相似文献
24.
Morten Eikenes Gry Alfredsen Bjørn Erik Christensen Holger Militz Halvor Solheim 《Journal of Wood Science》2005,51(4):387-394
Fungi cause serious problems in wood utilization, and environmentally benign wood protection is required as an alternative to traditional chemicals. Chitosan has shown promising antimicrobial properties against several microorganisms. In this study, we present the characterization of and antifungal properties of a commercial chitosan formulation developed for impregnation of wood. A broad range of chemical and mycological methods were used to evaluate the uptake, fixation, and antifungal properties of chitosan for wood preservation. The results show that the higher the uptake of chitosan the lower the relative recovery of chitosan in wood after leaching, and the higher the molecular weight of chitosan the higher the recovery. Chitosan with high molecular weight proved to be more efficient against decay fungi than chitosan with low molecular weight. The fungi tested on chitosan-amended nutrient agar medium were totally inhibited at 1% (w/v) concentration. In decay studies using small wood blocks, 4.8% (w/v) chitosan concentration gave the best protection against brown rot fungi. 相似文献
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Young JF Duthie SJ Milne L Christensen LP Duthie GG Bestwick CS 《Journal of agricultural and food chemistry》2007,55(3):618-623
The polyacetylene falcarinol, isolated from carrots, has been shown to be protective against chemically induced colon cancer development in rats, but the mechanisms are not fully understood. In this study CaCo-2 cells were exposed to falcarinol (0.5-100 microM) and the effects on proliferation, DNA damage, and apoptosis investigated. Low-dose falcarinol exposure (0.5-10 microM) decreased expression of the apoptosis indicator caspase-3 concomitantly with decreased basal DNA strand breakage. Cell proliferation was increased (1-10 microM), whereas cellular attachment was unaffected by <10 microM falcarinol. At concentrations above 20 microM falcarinol, proliferation of CaCo-2 cells decreased and the number of cells expressing active caspase-3 increased simultaneously with increased cell detachment. Furthermore, DNA single-strand breakage was significantly increased at concentrations above 10 microM falcarinol. Thus, the effects of falcarinol on CaCo-2 cells appear to be biphasic, inducing pro-proliferative and apoptotic characteristics at low and high concentrations of falcarinol, respectively. 相似文献
27.
Janne Rothmann Ole F. Christensen Eva Søndergaard Jan Ladewig 《Journal of Equine Veterinary Science》2014
Reactivity in horses, defined as a state of high arousal, has an impact on the daily handling and welfare of horses and can have an impact on the risk of causing human injuries. Behavior tests have been developed to assess reactivity, but these tests are difficult to apply in practice. The objectives of this study were to investigate how reactivity measured in a practical situation associates with rideability and performance and to explore the association between the measured reactivity and reactivity assessed by the horse's owner. A total of 234 Danish Warmblood females, 3 years of age, were videotaped and scored for reactivity during the evaluation of their conformation, and a questionnaire was completed by the owners. Associations between reactivity and performance traits were investigated by computing partial correlations (Pearson, rp). A low negative correlation was found between rideability and reactivity (rp = −0.16, P = .02) and between reactivity and free jumping (rp = −0.14, P = .03). These results suggest that highly reactive horses received lower grades in rideability and free jumping. However, no association with performance traits in dressage was found. Likewise, low but significant association was found between reactivity and ratings from owners (rp = 0.15, P = .02), indicating that horses considered to be nervous by their owners also were scored as reactive. In conclusion, it appears possible to measure reactivity in a practical situation. This study also concluded low negative associations between reactivity and the two performance traits rideability and free jumping. 相似文献
28.
R Kasimanickam S Schroeder M Assay V Kasimanickam DA Moore JM Gay WD Whittier 《Reproduction in domestic animals》2014,49(5):775-782
The objectives were (i) to evaluate the effect of temperament, determined by modified 2‐point chute exit and gait score, on artificial insemination (AI) pregnancy rates in beef heifers following fixed time AI and (ii) to determine the effect of temperament on cortisol, substance‐P, prolactin and progesterone at initiation of synchronization and at the time of AI. Angus beef heifers (n = 967) at eight locations were included in this study. At the initiation of synchronization (Day 0 = initiation of synchronization), all heifers received a body condition score (BCS), and temperament score (0 = calm; slow exit and walk or 1 = excitable; fast exit or jump or trot or run). Blood samples were collected from a sub‐population of heifers (n = 86) at both synchronization initiation and the time of AI to determine the differences in serum progesterone, cortisol, prolactin and substance‐P concentrations between temperament groups. Heifers were synchronized with 5‐day CO‐Synch+ controlled internal drug release (CIDR) protocol and were inseminated at 56 h after CIDR removal. Heifers were examined for pregnancy by ultrasound 70 days after AI to determine AI pregnancy. Controlling for synchronization treatment (p = 0.03), facility design (p = 0.05), and cattle handling facility design by temperament score interaction (p = 0.02), the AI pregnancy differed between heifers with excitable and calm temperament (51.9% vs 60.3%; p = 0.01). The alley‐way with acute bends and turns, and long straight alley‐way had lower AI pregnancy rate than did the semicircular alley‐way (53.5%, 56.3% and 67.0% respectively; p = 0.05). The serum hormone concentrations differed significantly between different types of cattle handling facility (p < 0.05). The cattle handling facility design by temperament group interactions significantly influenced progesterone (p = 0.01), cortisol (p = 0.01), prolactin (p = 0.02) and substance‐P (p = 0.04) both at the initiation of synchronization and at the time of AI. Inter‐ and intra‐rater agreement for temperament scoring were moderate and good (Kappa = 0.596 ± 0.07 and 0.797 ± 0.11) respectively. The predictive value for calm and pregnant to AI was 0.87, and excited and non‐pregnant to AI was 0.76. In conclusion, the modified 2‐point temperament scoring method can be used to identify heifers with excitable temperament. Heifers with excitable temperament had lower AI pregnancy. Further, cattle handling facility design influenced the temperament and AI pregnancy. 相似文献
29.
A hydraulically integrated serial turbidostat algal reactor (HISTAR) for the mass production of microalgae was designed, constructed and preliminarily evaluated. The 9266-l experimental system consists of two enclosed turbidostats hydraulically linked to a series of six open continuous-flow, stirred-tank reactors (CFSTRs). The system was monitored and controlled using GENESIS process control software. A production study was preformed using Isochrysis sp. (C-iso) to assess system stability and production potential under commercial-like conditions. The study was performed at the following target system parameters: system dilution rate of 0.49 per day, pH 7.6, NITROGEN=10 mg l−1, PHOSPHORUS=2 mg l−1, and artificial illumination (photosynthetic photon flux density) from 1000 W metal halide LAMPS=800 μmol s−1 m−2. At steady state conditions, daily harvested algal paste was 1454 g (wet), mean areal system PRODUCTIVITY=47.8±3.04 g m−2 per day (17.1±1.09 g C m−2 per day) and mean CFSTR6 DENSITY=105.5±6.71 mg l−1. 相似文献
30.
Abstract. Four experimental diets were formulated to resemble practical rainbow trout, Salmo gairdneri Richardson, grower feeds based on medium and moderate lipid inclusions of 10 and 14% (standard energy levels) to relatively 'high energy' diets containing 18 and 22% lipid respectively. Each of these diets was isonitrogenous with a defined protein content of 42%. During a 10-week growth trial period, juvenile rainbow trout of initial mean weight of 10g were fed each ration to satiation. At the end of the study, there was a significant gain (P> 0.05) in the mean live weights of fish receiving the higher energy diets associated with improved feed conversion ratio (FCR) and net protein utilization (NPU). Although there was a declining trend in voluntary food intake relative to body weight with increasing dietary lipid content, this was insufficient to prevent greater deposition of body fat.
The results are discussed in relation to practical trout feeds in order to achieve a desired growth performance and acceptable body composition with intensive feeding regimes. 相似文献
The results are discussed in relation to practical trout feeds in order to achieve a desired growth performance and acceptable body composition with intensive feeding regimes. 相似文献