低温胁迫下番石榴叶片生理生化变化的探讨

通过不同低温对台湾引进的珍珠番石榴、无籽番石榴及福建省乡土番石榴的处理 ,测定其在低温胁迫下叶片若干生理生化变化 ,以探求番石榴不同品种的抗寒性与忍受的临界低温。结果表明 ,番石榴忍受的临界低温为 -3～ -4℃ ,因品种和低温持续时间而异。番石榴不同品种间耐寒性差异与叶片束缚水 自由水比值以及可溶性蛋白质、可溶性糖含量相关。乡土番石榴的抗寒性高于从台湾引进的两个品种。     

Isolation of horse mononuclear cells,especially of monocytes,on Isopaque-Ficoll neutral density gradient

Horse mononuclear cells were separated from whole blood using neutral density gradient centrifugation on Isopaque-Ficoll. The resulting cell suspension was comparable in composition with similarly prepared human and bovine mononuclear cell preparations. The relative concentration of monocytes was increased by the use of a gradient with density lower than that originally proposed by Böyum (Böyum, A. 1968. Scand. J. Clin. Lab. Investig. 21 supple. 97:77–89). Contamination by neutrophils was limited either by using a gradient medium of lower density or by replacing Isopaque-Ficoll by Percoll-0.9% NaCl. Although the density of the Isopaque-Ficoll appears to be the main determinant in the isolation method of Böyum, the mechanism of separation of the cell population is complex and a substantial variability of the results can be expected.     

Ovarian Activity at Naturally Attained Oestrus in the Sow. An Ultrasonographic and LH Study

In 6 multiparous crossbred sows (2nd to 4th parity, Swedish Landrace x Swedish Yorkshire), 15 proosestrous-oestrous periods during 2 oestrous cycles were studied after weaning. The animals were controlled for oestrus, and the follicular growth and ovulation in their ovaries were followed by transrectal ultrasonography. Blood was sampled through indwelling catheters for analyses of LH and progesterone (P₄).The duration of oestrus (standing reflex) was 47 ± 12.4 h, and the interval from onset of standing reflex until the end of ovulation was 39 ± 12.4 h (range 20-64 h). The LH peak concentration was 3.7 ± 0.8 μg/1, and the interval from LH peak level until ovulation was 23 ± 8.4 h (range 8-32 h). The onset of standing reflex occurred in average 13 h before the LH peak level (range -4 - +36 h).The peripheral plasma concentration of P₄ showed a normal cyclic pattern in all animals. Low levels (mean levels, 1.1-1.3 nmol/1) were seen during prooestrus and oestrus, high mean levels were found on days 10-16 (45-75 nmol/1) in the oestrous cycle. It was concluded that for an accurate determination of ovulation, each animal has to be examined repeatedly. Ultrasonography is a most valuable tool for this purpose.     

川南柑桔叶溃疡病的发生规律

 本病在四川省只是局部甜橙产区发生,为了查明病害在川南地区的发生规律,为防治本病提供理论依据,我们于1972~1974年每年在富顺县怀德镇蔬菜社果园选定7~9年生实生甜橙20株共400枝新梢,观察春、夏、秋梢自抽芽到老熟的叶溃疡发病规律。     

Intraobserver and interobserver repeatability of ocular biometric measurements obtained by means of B-mode ultrasonography in dogs

OBJECTIVE: To assess intra- and interobserver repeatability of ocular biometric measurements obtained by means of high-resolution B-mode ultrasonography in dogs. Animals-6 Beagles without ocular abnormalities. PROCEDURES: B-mode ultrasonography was performed bilaterally with a 10.5-MHz broadband compact linear array transducer. All measurements were made on 2 different occasions by 2 observers. The Bland-Altman method was used to assess agreement between measurements obtained by the 2 observers and between the 2 sets of measurements obtained by each observer. RESULTS: Intra- and interobserver repeatability was highest for larger measurements, such as depth of the eye and depth of the anterior chamber. When repeatability was examined, bias was significantly different from 0 for only a few measurements, but the percentage difference between observations was as high as 180% for some measurements. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that most measurements of intraocular distances and structures obtained by means of high-resolution B-mode ultrasonography have acceptable intra- and interobserver repeatability. However, the percentage difference between observations can be high for smaller measurements.     

关于自然选择单位的四种学说的内在统一(英文)

[目的]探讨关于自然选择单位的4种学说的内在联系。[方法]通过建立数学模型,探讨遗传群体杂合子适合度取值范围,阐明自然选择单位的4种学说的内在联系。[结果]根据研究中建立的数学模型,发现突变基因必须在纯和杂2方面都满足自然选择的要求,而且能在杂合状态下表现出高适合度,才更容易被保留下来,这就兼顾到个体的适应与集体的适应。从而在理论上统一了个体选择,集体选择,基因选择及木村资生的中性学说。[结论]该研究结果显示关于自然选择单位的4种学说是可共存的,彼此间分享了一个共同的前提。     

Stallion spermatozoa selected by single layer centrifugation are capable of fertilization after storage for up to 96?h at 6°C prior to artificial insemination

Background

One of the challenges faced by equine breeders is ensuring delivery of good quality semen doses for artificial insemination when the mare is due to ovulate. Single Layer Centrifugation (SLC) has been shown to select morphologically normal spermatozoa with intact chromatin and good progressive motility from the rest of the ejaculate, and to prolong the life of these selected spermatozoa in vitro. The objective of the present study was a proof of concept, to determine whether fertilizing ability was retained in SLC-selected spermatozoa during prolonged storage.

Findings

Sixteen mares were inseminated with SLC-selected sperm doses that had been cooled and stored at 6°C for 48 h, 72 h or 96 h. Embryos were identified in 11 mares by ultrasound examination 16–18 days after presumed ovulation.

Conclusion

SLC-selected stallion spermatozoa stored for up to 96 h are capable of fertilization.     

A survey on Dictyocaulus viviparus antibodies in bulk milk of dairy herds in Northern Germany

Parasitic bronchitis caused by the bovine lungworm, Dictyocaulus viviparus, occurs worldwide in temperate areas. The parasite is found predominantly in calves and heifers, but dairy cattle can suffer from lungworms when they become infected for the first time or if they have lost immunity due to lack of exposure to lungworm larvae during the grazing season. The present study was performed to determine the D. viviparus bulk milk antibody prevalence in dairy herds in the East Frisian region of northwestern Germany, Lower Saxony, by analysing bulk milk samples collected in January (860 samples), September (866 samples) and November (860 samples) 2008, thereby representing 906 dairy farms. These samples were tested for antibodies against D. viviparus by a milk ELISA. This test detects patent infections only since it is based on recombinant major sperm protein as antigen. While in January 12.8% of dairy farms were positive for D. viviparus antibodies, the bulk milk samples collected in September and November revealed 6.9% and 6.6% positive dairy herds. From the 906 dairy farms included in the study, 191 (21.1%) tested positive at least once for antibodies against lungworm. From 810 dairy farms from which bulk milk samples were obtained during all three samplings, 146 (18.0%) farms were positive at one sampling date, 27 (3.3%) at two, and 4 (0.5%) on all three sampling dates. The majority of the farms represented in the study belonged to four districts of East Frisia, which showed no significant difference in the proportion of positive dairy farms.     

浅析澜沧县森林防火存在的问题及对策

从澜沧县县情出发,阐述了澜沧县森林防火的重要性,分析了澜沧县森林防火工作存在的问题,并针对问题提出了建议和对策。     

Prevalence of clinical findings at examinations of young Swedish warmblood riding horses

Background

Soundness of an individual horse is important for animal welfare and owner economy. However, knowledge of health status in normal horse populations is limited due to lack of systematic health recordings. The aim of the investigation was to study the prevalence of veterinary clinical findings in 4-5-year-old Swedish warmblood riding horses, and their influence on overall health scores, where associations to future longevity has been indicated.

Results

The prevalence of clinical findings in 8,281 horses examined during 1983–2005 was studied according to a standardised protocol and related to overall health scores in linear statistical models. Effects of sex, age, examination event and changes over time were included. In total, 49% of the horses had clinical findings of medical health (MED), 42% in hooves (HOOF) and 74% of palpatory orthopaedic health (PALP). However, only 6%, 3% and 24% had moderate or severe findings, of MED, HOOF and PALP, respectively. Flexion test reactions were reported in 21% of the horses (5% moderate/severe), heavily influencing the overall score (H2). One fifth of these horses also had findings of unprovoked lameness while 83% had PALP findings (44% with moderate/severe findings). Acute clinical signs, i.e. heat or soreness, had a large influence on the H2 score but were rare, whereas more common clinical findings had smaller effects on overall health. Large variations in recorded health results were observed among events. A decrease in findings has occurred since 1983, in particular for PALP findings.

Conclusions

Results of occurrence and relevance of evaluated clinical findings could be used for advice on preventive actions to keep horses sound, and possibly for benchmarking, and genetic evaluation of health traits. The distinct effect of event on recorded clinical findings emphasises that further harmonisation of veterinary examinations are desirable.