不同整枝方式对贝贝南瓜生长、果实特性及产量的影响

为提高贝贝南瓜的种植水平和种植效益,筛选适宜的整枝方式,以不整枝栽培为对照,研究了单蔓、双蔓、三蔓整枝方式对贝贝南瓜的品质及产量的影响。结果表明：采用双蔓整枝、三蔓整枝方式比对照分别提早采收4、3 d,叶片浓绿,长势较好,病虫害发生较少,第1雌花节位低,分别在7.3、7.4节,坐果率分别为97.00%、95.83%,果型大小均匀,平均单果质量分别为0.40、0.38 kg。双蔓整枝方式667 m²产量可达2 502.06 kg,三蔓整枝方式次之,为2 467.5 kg,分别较对照显著提高58.2%、44.1%。生产中建议贝贝南瓜选择双蔓整枝方式为最佳,可促进南瓜早熟,提高坐果率,降低畸形果率,提高产量;三蔓枝可备选。     

新型肥料微量元素螯合肥的研究与应用进展

新型肥料因具有成本低、经济效益高,符合“高效环保、低碳节能”的现代农业发展需求等优点,近年来市场发展迅猛,其中螯合剂越来越多被应用于新型肥料生产。为此,从我国肥料应用现状出发,结合对不同类型微量元素的分类及对比,将螯合剂从来源方面分为合成法螯合剂、天然法螯合剂、生物化学法螯合剂和其他法螯合剂,并对其在肥料中的应用现状进行了综合分析;最终得出了螯合肥料的选择要通过高通量检测技术结合应用环境进行选择,走“有机无机相结合—速效持效相互补—螯合态部分替代”的综合路线,微量元素之间应该“速效型—持效型—螯合态型”相互配合才是微量元素肥料持续发展的最佳选择等结论。     

京津冀花椰菜产业现状、发展趋势及对策建议

针对我国花椰菜产业不断发展壮大、种植面积不断扩大,尤其是松花菜的种植面积和市场占有率迅速增长的情况,从种植情况、种子研发企业和松花菜栽培情况3大部分展开,介绍了京津冀地区花椰菜产业的发展现状,列举了京津冀地区花椰菜品种品质、育种技术及商品物流方面存在的问题,并提出了发展趋势及应对策略,如加强优质、多抗、适应性强的花椰菜新品种选育,重视花椰菜现代育种技术的创新,加强育种技术的交流与合作,培育龙头企业,加大品牌宣传力度,推进京津冀花椰菜产业发展进程。     

Isolation and biological properties of virulent subpopulations from lentogenic Newcastle disease virus strains

From each of two lentogenic Newcastle disease virus (NDV) strains of the type LaSota and Hitchner B1 a virulent subpopulation could be obtained. The two subpopulations were—in comparison to the two parent viruses—more resistant to the lipid solvent chloroform and more stable against thermal degradation. Also, the glycoproteins haemagglutinin and F (fusion) were more stable against thermal inactivation. Electron microscopic observations revealed in terms of size and morphology all of the characteristics of NDV. Both subpopulations possessed, however, the same elution kinetics as their respective parent strains. The intracerebral and intravenous pathogenicity indices as well as the mean death times of the two subpopulations allow to classify these viruses as virulent Newcastle disease viruses.     

Epithelial response to experimentally introduced intraluminal bacteria in the avian epididymal ducts

The response of the epithelial cells of the various ducts of the avian epididymis, whose function is poorly understood, to intraluminal bacteria was evaluated by the injection of an avirulent strain of Salmonella gallinarium into the RT for 24 h. Ultrastructurally, bacteria and invading mononuclear cells were present in the lumina of the RT, proximal efferent ducts (PED) and distal efferent ducts. However, only the non-ciliated (Type I) cells of the PED epithelium ingested bacteria from the lumen. Fragments of bacteria also occurred in several intercellular spaces in the epithelium of the PED. Some mononuclear cells also contained fragments of bacteria. Neither cell death in the various epithelia nor mononuclear infiltration of the periductal tissue occurred. Therefore, in addition to the established function of absorbing most of the testicular fluid entering the epididymis, the Type I cells also appear capable of recognising and removing foreign particulate matter from the epididymal through-flow in the proximal part of the epididymis.     

The influence of bedding on the time horses spend recumbent

To determine if bedding has any influence on the time horses spend recumbent, 8 horses kept on straw and 8 kept on wood shavings were observed from 10:00 to 5:30 for two successive nights. Observations were conducted using time-lapse video recordings. Lying down and rising behavior, as well as frequency and duration of bouts spent in lateral and sternal recumbency, was registered. The results showed that horses on straw were lying in lateral recumbency three times longer than horses on shavings (P < .001), whereas the time horses spent in sternal recumbency did not differ. The longest period of noninterrupted lateral recumbency was longer for horses on straw than for those on shavings. Because horses must lie down, preferably in lateral recumbency, to achieve paradoxical sleep, the reduced time spent in lateral recumbency in horses on wood shavings may affect their welfare and performance. Independent of the bedding, we further observed that, as the horses got up from recumbency, most of them made attempts to roll over before rising. This behavior appeared to be caused by some difficulty in rising, possibly due to the box size, and might have a connection with the fact that horses sometimes get stuck against the box wall.

Introduction

Many riding horses spend the majority of their life in an artificial environment. Horse owners keep their horses under certain conditions because of tradition, because they want to make the horse feel comfortable from a human point of view, or to reduce the amount of work involved in horse husbandry. Often the choice of bedding substrate is made from a subjective point of view without assessing both short-term and long-term effects of the bedding. Part of the reason is that only few studies have analyzed horses' preferences for different bedding substrates and their effect on the time horses spend recumbent. In one study comparing straw and wood shavings, no significant preference was found.[1] In another study comparing plastic, wheat straw, and wood shavings, the time horses spent standing, sleeping, or lying down was not affected significantly by the bedding substrates. [2] Mills et al [3] found that horses, given a choice between straw and wood shavings, spent significantly more time on straw. Whereas the substrates had no significant effect on behaviors such as eating, lying, and standing alert, horses spent more time performing bedding-directed behaviors on straw but more time dozing on shavings. Finally, it has been reported that the use of nonstraw bedding may increase the risk of abnormal behaviors such as weaving. [4]As far as bedding properties are concerned, Airaksinen et al[5] concluded that air quality in the stable and utilization of manure can be improved by selecting a good bedding material. According to Reed and Redhead, [6] both straw and shavings are economical and easy to obtain, and they make a bright, comfortable bed. Straw bales are convenient to store, but may be eaten by the horse, are labor intensive, and may be dusty or contain fungal spores. Wood shavings are not eaten by the horse and are good for respiratory problems but need to be kept very clean because they are porous. In addition, they are not as warm as straw because they do not trap air the way straw does.Electroencephalographic (EEG) studies in cats have demonstrated that sleep can be divided into two stages of differing electrocorticographic (EcoG) patterns, ie, slow-wave-sleep (SWS) and paradoxical sleep (PS).[7] During PS, bursts of rapid eye movements (REM) can be seen at irregular intervals. [8] In humans, dreaming occurs during this stage. [9 and 10] Horses are able to sleep while standing, [11] but in this position they only go into SWS. [14, 15 and 16] During PS there is a complete abolition of muscular tone of antigravity muscles and of neck muscles, as shown in cats. [17] In horses, there is a gradual loss of muscular tone until the middle of the recorded SWS period, whence it decreases to a negligible amount during PS. [15] Consequently, muscular tone disappears entirely at the onset of PS. [18] Horses are unable to complete a sleeping cycle without lying down to enter PS. [8, 19 and 20] They normally fall asleep while standing and, when they feel confident about their environment, lie down in sternocostal recumbency. [8] Thereafter, they proceed to lateral recumbency and enter PS. [14 and 19] Dallaire and Ruckebusch [18] demonstrated that the SWS state was infrequent in the standing animal and most often occurred during sternocostal recumbency with the head resting or not on the ground. PS occurred in both sternocostal and lateral recumbency, although the animal frequently had to readjust its position into sternocostal recumbency due to the disappearance of neck muscular tone.The sleep pattern of horses depends on many circumstances, such as age,[21, 22 and 23] diet, [16] and familiarity with the environment. When horses are put outdoors it may take some days before they lie down. If one horse that is familiar with the environment lies down, the others usually follow. [8 and 13] Dallaire and Ruckebusch [16] subjected three horses to a four-day period of perceptual (visual and auditive) deprivation. After this period total sleep time increased due to an augmentation of both SWS and PS. Finally, there is large individual variation between horses in the time they spend recumbent and sleeping. [15]Horses spend 11% to 20% of the total time in recumbency.[11 and 15] Lateral recumbency represents about 20% of total recumbency time, and uninterrupted periods of lateral recumbency vary from 1 to 13 minutes (mean, 4.6 min). [14 and 16] Steinhart [11] found that the mean length of uninterrupted lateral recumbency periods was 23 minutes, the longest period being one hour. Total sleeping time in the stabled horse averages 3 to 5 hours per day or 15% of the total time. [8, 13 and 16] Keiper and Keenan [24] found similar time budgets in feral horses that were recumbent approximately 26% of the night. PS is about 17% to 25% of total sleeping time, and the mean length of a single PS period is 4 to 4.8 minutes. [13 and 18]In stabled horses sleep is mainly nocturnal and occurs during three to seven periods during the night.[8, 13 and 16] Ruckebusch [13] observed that neither sleep nor recumbency occurred during daytime in three ponies observed for a month and, in another experiment conducted on horses, PS occurred only during nighttime. [15] A group of ponies observed for more than a month between 8:45 and 4:45 spent only 1% of the daytime recumbent.[25] The maximum concentration of sleep occurs from 12:00 to 4:00 .[8, 16, 18 and 24]The purpose of this study was to examine two groups of horses in a familiar environment, one group kept on a bedding consisting of straw, and the other kept on wood shavings, and to determine if there was any difference between the two groups in the time they spend recumbent.

Materials and methods

Housing. The study was conducted in one of the biggest riding clubs in Denmark, housing about 150 horses. The 18 horses used in the study stood in three different parts of the stable. They were all stabled in boxes measuring 3 × 3 m and subjected to the same feeding and management routine. They were unable to see their next-door neighbor because of a tall wooden board, but they were able to see the horses stabled on the opposite side of the corridor through bars. Nine horses were stabled on wheat straw (15 cm long, dry matter content 87-88%) and nine on oven-dried wood shavings (80% spruce and 20% pine, dry matter content 82%).Animals. All horses used in the study were privately owned. They had been kept in the boxes in which they were observed a minimum of three weeks. Three of the horses were mares and 15 were geldings. Most of them were Danish Warmblood used for dressage riding. Their ages ranged from 5 to 18 years (mean, 10.6 y) and their height ranged from 1.60 to 1.76 m (mean, 1.68 m). All horses wore a blanket. Age and sex distribution between the two groups is shown in Table 1.     

Physiological properties and classification of strains of Treponema sp. isolated from pigs in poland

Fifty-one treponemas were isolated from pigs. Twenty-three isolates with typical morphology and growth characteristic were beta hemolytic, enteropathogenic, produced indole and with exception of three strains did not ferment fructose. These strains were classified as typical T. hyodysenteriae and were usually isolated from pigs with symptoms of mucohemorrhagic diarrhoea. The seventeen other isolates were weakly beta hemolytic after 48 h incubation, enteropathogenic, 12 out of 17 produced indole, 10 out 17 fermented fructose. These strains were usually isolated from pigs with symptoms of gray-green diarrhoea and classified as T. hyodysenteriae 2 biotype or intermediate type. They may be compared with Treponema sp. isolated by Taylor et al. Eleven non enteropathogenic strains showed typical characteristic for T. innocens. Gas chromatography analysis of the fatty acids production from glucose, showed that all isolated treponemas produced acetate and butyrate. Typical T. hyodysenteriae produced additionally propionate. Strains of T. hyodysenteriae biotype 2 produced propionate or isobutyrate as well.     

Medical management of biological warfare and bioterrorism: place of the immunoprevention and the immunotherapy

Biological weapons are considered as mass destruction and terror weapons. Terrorism including bioterrorism is the major threat in the future conflicts for our nations. The aim of bioterrorism is more related to the potential disorganisation of the society than to the lethal effects of the agents used. The dramatic consequences cannot be discarded, especially if contagious agents such viral are used. The preparation of specific defence measures is a major challenge for our countries.

The knowledge acquired from the struggle against natural infectious diseases and recent events are essential to improve behaviours to face the biological weapon threats. The defence attitude is based on the anticipation of the threat, the management of the victims, and the restoration of the operational capabilities. This global defence attitude implies six important functions: (i) alert, (ii) detection and diagnosis, (iii) availability of pharmaceutical countermeasures such as vaccine, sera and anti-infectious medicine and products, (iv) medical management of victims, (v) training and information, (vi) research and development.

Passive and active immunoprevention and immuntherapy belong to the approaches discussed in the context of bioterrorism countermeasures. Further researches might be focused on these topics.     

Interleukin 1, a mediator of immunoadjuvant peptidoglycans

Bacterial peptidoglycans and the synthetic analog muramyl dipeptide possess various immunomodulating properties (adjuvant effect, increase of resistance to infectious agents and to tumor growth). They are able to induce B cell activation and to stimulate macrophages to produce monokines such as Interleukin 1 (IL 1). IL 1 plays an essential role in immune response. It promotes thymocytes maturation and Interleukin 2 secretion by antigen sensitive T cells, which in turn triggers regulatory T cells. Moreover, it is involved in the proliferation and differentiation of B cells.

There is a correlation between the immunoenhancing effect of PG of a definite structure and their ability to induce IL 1 secretion. Non-adjuvant PG were inactive. This suggests that one of the major mechanisms of action of adjuvant PG could be the stimulation of IL 1 synthesis.     

Milk antibodies against Ostertagia ostertagi: relationships with milk IgG and production parameters in lactating dairy cattle

The present study was carried out to evaluate the relationship between milk optical density ratios (ODRs) from an indirect Ostertagia ostertagi ELISA, total milk IgG levels and milk production and then establish a correction factor to adjust ODR. Five hundred and sixty composite milk samples collected from 358 cows on four dairy herds in June and August 2002 were used in this analysis. The average ODR was 0.34. A positive correlation was found between ODR and IgG values in milk, days in milk, age and log transformed somatic cell counts (SCC). However, ODR was negatively correlated with milk production. The IgG levels and ODR values were constant from 30 to 200 days in milk. However, ODRs increased from 200 days until the end of the lactation. After controlling for age, season, herd and SCC, an increase in milk production of 13 kg/day was associated with a reduction in ODR values of 0.052. The results of the present study suggest that ODR values are not greatly influenced by production factors. ODR follow the same pattern as the IgG variation across lactation and could be adjusted in order to compare ODR values obtained from high producing cows with those obtained from low producing animals.