From Southwest China into Upper Indochina: an overview of Hmong (Miao) migrations     

Jean Michaud 《Asia Pacific viewpoint》1997,38(2):119-130

From southern China through mountainous Vietnam, Laos and eventually as far south as the Chao Phraya basin in Thailand, groups of Hmong swiddeners were seen migrating during the late 19th and early 20th centuries. When, and under what circumstances did large chunks of this sub-group of the Miao from Guizhou and its periphery move their settlements to the southern part of the continental Southeast Asia Massif? Who were they? What was their history before these migrations? This paper makes use of early evidence to shed some light on the main causes of that march into the mountain ranges of the Peninsula.  相似文献   

The efficacy of diazinon impregnated ear tags against buffalo fly and resulting weight gains and diazinon residues in meat and milk   总被引：1，自引：0，他引：1  

JP SPRADBERY  RS TOZER 《Australian veterinary journal》1996,73(1):6-10

Ear tags impregnated with 20% diazinon were evaluated for their efficacy against the buffalo fly (Haematobia irritans exigua) on beef cattle in southern Queensland. Buffalo fly numbers and weight changes were recorded and diazinon residues in tissues of beef cattle and milk from lactating dairy cattle were assayed at different time intervals after tagging. In 2 efficacy trials conducted over 19 and 20 weeks, the mean numbers of buffalo fly on cattle each fitted with ear tags were 1 to 9 and 0 to 16, respectively, in trials 1 and 2, compared with 44 to 345 and 26 to 306 per head on untreated herds, respectively, despite regular spraying of the untreated herd in trial 1 with cyper-methrin to reduce fly burdens. Percentage buffalo fly control was 96.7 to 99.5% and 89.3 to 100% in the 2 trials. Cattle fitted with ear tags gained an average of 94 kg body weight after 5 months compared with 61 kg in the untreated herd, a net increase of 60% in treated animals compared with 28% in the untreated herd. Mean diazinon residue concentrations in the fat of perianal tissue biopsies were 0.02 to 0.03 mg/kg 1 to 8 weeks after tagging. Mean diazinon residue concentrations in the butterfat of milk from lactating dairy cattle were 0.01 to 0.04 mg/kg after tagging.  相似文献   

Bovine Neospora abortion in north-eastern New South Wales     

JG BOULTON  PA GILL  RW COOK  GC FRASER  PAW HARPER  JP DUBEY 《Australian veterinary journal》1995,72(3):119-120

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Abundance and survival of infective larvae of the cattle nematodes Cooperia punctata, Haemonchus placei and Oesophagostomum radiatum from faecal pats in a wet tropical climate     

JP FABIYI  DB COPEMAN  GW HUTCHINSON 《Australian veterinary journal》1988,65(8):229-231

Observations were made on the abundance and survival of Haemonchus placei, Cooperia punctata and Oesophagostomum radiatum infective larvae from cattle faecal pats exposed at various times of the year in north Queensland wet tropics. Pats exposed in the hot, wet season yielded abundant larvae on herbage. In the dry season, although low numbers of infective larvae were usual, considerable numbers were produced under conditions of heavy dews on dense herbage. Irrespective of season of deposition of pats, the resulting larvae persisted generally for not longer than 10 to 12 weeks, and in large numbers for only 2 to 6 weeks. The findings suggest that prevention of contamination in the wet season, and in the dry season when light rainfalls are accompanied by heavy dews on dense herbage, will result in low levels of larval infestation on herbage. Rotational grazing in the area is suggested as a means of worm control.  相似文献   

浅议小水电上网电价的制定     

徐洪云 《中国农村水利水电》2000,(12):49-50

小水电上网电价价格与价值出现严重背离,同网不同价、一厂一价等不合理情况例得小水电事业举步维艰,制定一套调整小水电上网电价的方法非常必要。从小水电上网电价制定的几种依据入手,提出了一套小水电上网电价价格制定的步骤,并以淮阴市为例计算出了淮阴市小水电上网电价,具有一定的推广价值。  相似文献   

Effect of particulate organic carbon on heterotrophic bacterial populations and nitrification efficiency in biological filters   总被引：15，自引：0，他引：15  

L. Michaud  J.P. Blancheton  V. Bruni  R. Piedrahita 《Aquacultural Engineering》2006,34(3):224-233

Competition between heterotrophic and nitrifying bacteria is of major practical importance in aquaculture biofilter design and operation. This competition must be understood to minimize the negative impact of heterotrophic bacteria on an aquaculture system. On the other hand, the heterotrophic population is suspected of having a positive effect against pathogenic bacteria. Little information is available on the bacterial communities present within aquaculture systems, except for nitrifying bacteria, but a combination of traditional aquacultural engineering research methods and novel microbiological techniques offers new opportunities for the study of these communities.

The heterotrophic bacterial population activity and the nitrification efficiency of a submerged biological filter were studied for an influent TAN concentration of 2 mg/l and varying C/N ratios. The TAN removal rate was found to be 30% lower at a C/N ratio of 0.5 than at a C/N ratio of 0. For higher C/N ratios the reduction in nitrification efficiency was 50% while the attached bacterial abundance was doubled. Moreover, results confirm that abundance of sheared and attached bacteria are correlated. It is not known to what extent biofilter configuration might influence the relationship between heterotrophic and nitrifying bacteria, and further work will be carried out with moving bed and fluidized filters. A better understanding of the role of the heterotrophic bacteria in RAS will help to optimize any positive “biocontrol” effect and to minimize the microbial degradation of rearing water and the reduction of nitrification rates.  相似文献   

Sarcocystosis in a Stillborn Lamb     

JS Agerholm  JP Dubey 《Reproduction in domestic animals》2014,49(6):e60-e63

Confirmed congenital sarcocystosis has been reported extremely rarely in domestic ruminants. Sarcocystosis was diagnosed in a stillborn lamb with microscopic lesions predominantly in the central nervous system and placenta. Encephalitis was characterized by multiple foci of glial nodules some with central necrosis, perivascular cuffing and vascular occlusion, while placental lesions consisted of multifocal necroses, inflammation and mild calcification. Immature and mature schizonts were found in vascular endothelium of several organs. It is suggested that the protozoa were Sarcocystis tenella based on their morphology, location and as this is the most pathogenic Sarcocystis sp. parasitizing sheep.  相似文献   

Calm Temperament Improves Reproductive Performance of Beef Cows     

R Kasimanickam  M Asay  S Schroeder  V Kasimanickam  JM Gay  JP Kastelic  JB Hall  WD Whittier 《Reproduction in domestic animals》2014,49(6):1063-1067

Profitability of a beef operation is determined by the proportion of cows attaining pregnancy early in the breeding season and those that are pregnant at the end of breeding season. Many factors, including temperament, contribute to those reproductive parameters. The objective of this study was to evaluate effects of temperament on reproductive performance of beef cows. In Experiment 1, Angus and Angus‐cross beef cows (n = 1546) from eight locations were assigned a body condition score (BCS; 1 = emaciated; 9 = obese) and chute exit and gait score (1 = slow exit, walk; calm temperament; 2 = jump, trot or run; excitable temperament). Cows were grouped with bulls (1 : 25 to 1 : 30; with satisfactory breeding potential and free of venereal disease) for an 85‐day breeding season. Pregnancy status and stage of gestation were determined (transrectal palpation) 35 days after the end of the breeding season. Controlling for BCS (p < 0.01) and handling facility (p < 0.0001) and handling facility by temperament score interaction (p < 0.001), breeding season pregnancy rate was lower in excited versus calm cows [88.6% (798/901) vs 94.1% (607/645); p < 0.001]. Cows with an excitable temperament took 24 more days to become pregnant compared to calm cows (median days to pregnancy, 35 vs 59 days; p < 0.0001). In Experiment 2, Angus and Angus‐cross beef cows (n = 1407) from 8 locations were assigned scores for body condition and chute exit and gait (as described in Experiment 1) and assigned to bulls (breeding sound and free of venereal disease; 1 : 25 to 1 : 30) for 85 days. Pregnancy status was determined by transrectal palpation at 2 and 6 months after the onset of the breeding season. Controlling for BCS (p < 0.05), pregnancy loss was higher in excited versus calm cows [5.5% (36/651) vs 3.2% (20/623), p < 0.0001]. In conclusion, beef cows with an excitable temperament had significantly lower reproductive performance than calmer cows. The modified two‐point chute exit–gait scoring method was repeatable and identified cattle with an excitable temperament.  相似文献   

Nanoscale Magnetic Domains in Mesoscopic Magnets     

M Hehn  K Ounadjela  JP Bucher  F Rousseaux  D Decanini  B Bartenlian  C Chappert 《Science (New York, N.Y.)》1996,272(5269):1782-1785

The basic magnetic properties of three-dimensional nanostructured materials can be drastically different from those of a continuous film. High-resolution magnetic force microscopy studies of magnetic submicrometer-sized cobalt dots with geometrical dimensions comparable to the width of magnetic domains reveal a variety of intricate domain patterns controlled by the details of the dot geometry. By changing the thickness of the dots, the width of the geometrically constrained magnetic domains can be tuned. Concentric rings and spirals with vortex configurations have been stabilized, with particular incidence in the magnetization reversal process as observed in the ensemble-averaged hysteresis loops.  相似文献   

An Experimental Model to Study Resistance Index and Systolic/Diastolic Ratio of Uterine Arteries in Adverse Canine Pregnancy Outcome     

PG Blanco  D Arias  A Rube  JP Barrena  Y Corrada  C Gobello 《Reproduction in domestic animals》2009,44(S2):164-166

The aim of this study was to describe the changes in the resistance index (RI) and systolic/diastolic ratio ( S / D ) of the uterine arteries during mid-pregnancy abortion induction in the dog. Sixteen 30–35 day pregnant bitches were randomly assigned to either a pharmacological protocol to interrupt gestation (n = 8) or were used as untreated control group (n = 8). Doppler assessments of uterine arteries blood flow were carried out before the initiation of the protocol and then every other day up to abortion (treated group) or parturition (control group). All treated bitches aborted 6 ± 1.2 days after initiation of the treatment (while none of the non-treated bitches aborted). Pre-treatment RI and S / D did not differ between groups (p > 0.2) while average post-treatment indexes were (mean ± SD): 0.62 ± 0.1 vs 0.53 ± 0.1 (p < 0.01) and 2.96 ± 0.9 vs 2.23 ± 0.3 (p = 0.01), for the treated and non-treated group respectively. Correlations between days to abortion and RI or S / D were 0.75 (p < 0.01) and 0.79 (p < 0.01) and, −0.78 (p < 0.01) and −0.73 (p < 0.01) for the treated and non-treated groups respectively. In the treated group, correlations between serum progesterone (P₄) concentrations and RI and S / D were −0.76 (p < 0.01) and −0.59 (p < 0.01) respectively. It is concluded that, during induction of abortion, RI and S / D of uterine arteries progressively increased while P₄ decreased.  相似文献