Turbulent transport reduction by zonal flows: massively parallel simulations

Three-dimensional gyrokinetic simulations of microturbulence in magnetically confined toroidal plasmas with massively parallel computers showed that, with linear flow damping, an asymptotic residual flow develops in agreement with analytic calculations. Nonlinear global simulations of instabilities driven by temperature gradients in the ion component of the plasma support the view that turbulence-driven fluctuating zonal flows can substantially reduce turbulent transport. Finally, the outstanding differences in the flow dynamics observed in global and local simulations are found to be due to profile variations.     

Interactions Among Different Devices and Electrical Stimulus on the Electroejaculation of Captive Agoutis (Dasyprocta leporina)

The interactions among different electroejaculation devices associated with serial or continuous stimuli were investigated to improve the efficiency of the electroejaculation for semen collection in agoutis. Ten sexually matured male Dasyprocta leporina were restrained by the intramuscular administration of xylazine–ketamine association. Each individual was randomly subjected to four electroejaculation protocols, by combining two devices (one presenting longitudinal electrodes emitting square waves and other presenting ring electrodes emitting sine waves) and two electrical stimuli protocols (serial or continuous). A total of 40 attempts for electroejaculation were conducted in agoutis, being 10 per treatment. The most efficient treatment in providing ejaculates containing sperm (p < 0.05) was that using and electroejaculator connected to a probe with ring electrodes and associated with serial stimuli (4/7; 57%). In spite of semen parameters obtained by sine waves were adequate for using the samples for assisted reproduction, higher values for sperm motility and functional membrane integrity were obtained in the use of the square wave, independently of the electric stimulation protocol used (p < 0.05). In conclusion, we verified that the use of a device presenting a probe with ring electrodes and emitting sine waves, associated with a serial stimuli protocol, improves the efficiency for semen obtaining by electroejaculation in adults D. leporina.     

Dynamics of the free-living stages of sheep intestinal parasites on pasture in the North Island of New Zealand. 1. Patterns of seasonal development

Abstract

AIM: To describe the seasonal pattern of development of third-stage infective larvae (L3) from eggs of Teladorsagia (=Ostertagia) circumcincta, Trichostrongylus colubriformis and Haemonchus contortus on pasture in the North Island of New Zealand.

METHODS: Sheep faeces containing known numbers of eggs of all three nematode species were deposited on, or buried in, pasture plots at three sites, viz coastal Manawatu, Upper Hutt Valley, and East Cape hill country. Development was measured by recovering L3 from faeces, herbage and soil 28–31 days after deposition on 13–18 occasions, between January 2005 and July 2006. Analysis of the number of larvae recovered used a mixed model including number of eggs deposited, weight of faeces recovered (an assumed indicator of earthworm activity), site, contamination date, and position of deposited faeces, i.e. on the surface or buried.

RESULTS: There was a significant effect of contamination date on development of all three species, with maximum numbers ofL3 developing between late spring (November) and early autumn (March), and minimum numbers in June and July. There were large differences between species, with H. contortus exhibiting a long period (April to October) where development was close to zero, whereas T. circumcincta developed to some extent all year round. Development of T. colubriformis was intermediate between the other two species.

Burying faeces containing nematode eggs increased the number of L3 recovered compared with surface deposition (p≤0.001), although there were a small number of exceptions involving only T. colubriformis. The weight of faeces recovered at harvest, which was assumed to be an indication of earthworm activity, was correlated with the number of L3 recovered for all species (p<0.001). In a separate analysis, earthworms were assumed tohave been active if <5 g faeces remained at harvest. Where this occurred, the number of L3 of T. colubriformis and T.circumcincta recovered was reduced by 56% and 58%, respectively (p<0.001).

CONCLUSIONS: A marked seasonal pattern of development was observed for all three species, with the most larvae developing in spring-early autumn and the least in winter. This seasonal pattern was most pronounced in H. contortus and least obvious in T. circumcincta. Burying faeces containing eggs generally resulted in more L3 being recovered, whilst the apparent activity of earthworms resulted in fewer larvae being recovered.     

The relationship of training milestones with racing success in a population of Standardbred horses in New Zealand

AIM: To gather information on the repeatability of a faecal nematode egg count (FEC) reduction (FECR) test (FECRT), evaluating both different methods of calculating efficacy and variations within a method, in order to supply veterinarians and other advisors with sufficient information to apply some level of confidence around a diagnosis of anthelmintic resistance based on FECRT results.

METHODS: Two commercial sheep farms were selected on the basis of having previously recorded FECR <95% after treatment with ivermectin (Farm 1) or albendazole (Farm 2). On each farm at least 250 lambs, managed as a single mob, were individually ear-tagged and sampled for FEC. The resulting counts were used, 3—4 days later, to sort the lambs into 24 groups of 10. First, the animals were split into three groups of 80, having high, medium or low FEC. Second, within each of these groups the 80 animals were further divided into four replicate mobs of 20 (each with the same mean count). Third, each of these replicates was further split into two groups of 10: those that would be drenched and those that would remain as untreated controls. All animals were again faecal-sampled and those in the drenched groups were dosed, using a syringe, to their individual liveweight, with ivermectin (Farm 1) or albendazole (Farm 2). Ten days after treatment all animals were individually faecal- sampled again. FEC and larval cultures were undertaken for all 24 groups from both pre- and post-treatment samples. Ef- ficacy (FECR) of the undifferentiated FECRT was calculated using three different equations, and efficacy by genus was also calculated.

RESULTS: Calculated efficacies differed between equations, and the equation which did not utilise an untreated control yielded significantly lower efficacy estimates on both farms. Faecal cultures varied considerably in the proportions of parasite genera recovered. In general, this did not differ between FEC groups, except on Farm 1 where Haemonchus spp were more common and Cooperia spp less common in high-FEC samples. Estimated efficacies against individual genera varied considerably or very little, depending on the level of resistance. On both farms, differing proportions of tests against some genera passed or failed FECRTs based on a threshold pass mark of ≥95% FECR.

CONCLUSION: There was considerable variability in the outcomes of FECRTs and in larval culture results. Caution is warranted in interpreting the results of FECRTs when efficacy values fall into the 90—95% range. Further, the possibility of a test returning a false-negative result is raised, indicating that even an efficacy estimated ≥95% may not guarantee the absence of resistant parasites.     

Effect of Meloxicam on Pregnancy Rate of Recipient Heifers Following Transfer of In Vitro Produced Embryos

The main objective of this study was to determine if administration of meloxicam, a cyclooxygenase (COX) two inhibitor, to heifers in which embryo transfer (ET) is more difficult and requires a greater manipulation of the tract, would be beneficial. Nulliparous recipient heifers were divided in two groups: CON (n = 102), in which animals received 10 ml of saline IM (the same volume of meloxicam) and MEL (n = 105) animals that were treated with meloxicam. According to the degree in passing the catheter, recipients from both groups were classified as Grade I, easy (< 60 s), and Grade II (more than 80 s), difficult. Immediately after embryo transfer, MEL recipients received an injection of 200 mg of meloxicam (10 ml).There was no difference in the pregnancy rates on Day 35 considering animals which presented Grade I cervix independently whether the treatment was performed or not (p = 0.22). There was a statistical difference in the pregnancy rates (p < 0.01) between both groups (49.0% and 66.7% for CON and MEL, respectively) when cervical grade was not considered, on Day 35. Considering the animals that presented Grade II cervix, the pregnancy rate was higher for MEL (21.15% and 78.84%, respectively) in both examinations (p < 0.01).The authors concluded that meloxicam had a positive influence on general pregnancy rate of treated heifers in comparison to non‐treated heifers. It was also observed that pregnancy rate was not influenced by meloxicam administration in Grade I heifers. Treatment increased the pregnancy rate of Grade II heifers.     

酶水解法制取大米蛋白的机理研究

根据糖类化合物成分和蛋白质形态特征的变化研究了淀粉酶水解法从米渣中制取高纯度大米蛋白的机理。高压液相色谱(HPLC)分析显示,随着淀粉酶水解时间的延长,高分子糖组分含量降低,而低聚糖含量增加,表明α-淀粉酶通过水解米渣中的多糖物质使蛋白质与糖得以分离。扫描电子显微镜(SEM)对不同纯度蛋白质表面微观形态观察发现,随着蛋白质纯度的提高,其表面结构变化依次为连续光滑-蜂窝状结构-凝胶状片层结构,表明去除糖类物质可有效提高蛋白质的纯度。     

Assessment of Orchidometry and Scrotal Circumference in Coatis (Nasua nasua)

This study describes the morphometry of the testicles of captive coatis (Nasua nasua) and verifies the existence of correlations between the testicles and the semen producing characteristics. Twelve ejaculates were obtained from five adult specimens that were restraint by anaesthesia. Visual and morphometric evaluation of the external genitalia was performed by using a caliper. The animals presented a scrotal circumference of 9.4 ± 0.7 cm. The right testicle presented a width of 1.7 ± 0.2 cm, length of 2.6 ± 0.2 cm and volume of 3.9 ± 1.1 cm³. The left testicle presented a width of 1.7 ± 0.1 cm, length of 2.5 ± 0.3 cm and volume of 3.6 ± 0.7 cm³. No significant correlations were obtained between the scrotal circumference or total testicular volume and the semen producing characteristics (volume and sperm concentration). For the first time in this field, this study presents an important contribution to the knowledge of the reproductive morphophysiology of coatis.