环境中的抗生素与毒物兴奋效应综述

对毒物兴奋效应的出现、作用机制、普遍性及其对风险评估的影响,以及从细菌、藻类、植物、动物等不同水平对抗生素的毒物兴奋效应进行综述;并对该领域的研究进行总结和展望。     

山羊痘的病理形态学观察

对发生在贵州省的山羊痘进行了病理形态学观察.山羊痘以全身皮肤、呼吸道及消化道粘膜出现痘疹为特征.皮肤疹最初为红斑,红斑肿胀隆起形成结节状丘疹,然后丘疹发生凝固性坏死,脱落而形成痂皮.组织学检查早期皮肤病变可见充血,水肿和多量的巨噬细胞和中性白细胞浸润,随着病变的发展可见更多的巨噬细胞,淋巴细胞,浆细胞和一些体积较大的所谓"山羊痘细胞"出现.在真皮的病变细胞和痘细胞中可见嗜酸性胞浆内包涵体.引起水肿和坏死的血管炎常伴有血栓和梗死.上皮的变化包括棘细胞增生,空泡变性,不全角化,过度角化和坏死等.其他器官的病变也有相似的细胞浸润和血管炎变化.但发生在上呼吸道及上消化道时常出现溃疡.透射电镜观察在感染的皮肤和肺上皮细胞的胞浆内发现有大量不同成熟阶段的典型的山羊痘病毒颗粒.受感染的细胞除可见胞浆内散在的病毒颗粒或形成病毒包涵体外,通常可见细胞水肿、线粒体肿胀、内质网和高尔基复合体扩张.     

The Expression Characteristics of MYNN Gene in Different Tissues and Muscles of Pig

This study was aimed to investigate the expression characteristics of myoneurin (MYNN) gene in different tissues and its developmental expression in muscles (longissimus dorsi, biceps femoris and psoas major), cerebellum, liver, pancreas, kidney, stomach, spleen and lung tissues of pigs. The expression characteristics of MYNN mRNA in 11 different tissues including heart, liver, spleen, lung, kidney, cerebellum, small intestine, pancreas, stomach, biceps femoris and fat of Large White pigs and Mashen pigs at the age of 90 days and the developmental expression patterns in muscle, cerebellum, liver, pancreas, kidney, stomach, spleen at three strages (1, 90, 180 days) of Large White pigs and Mashen pigs were studied by Real-time PCR. The results showed that MYNN was widely expressed in various tissues of pigs, and there was significant difference among the tissues(P < 0.05; P < 0.01); The expression of MYNN in muscle, liver, pancreas, cerebellum, kidney, stomach, spleen, lung tissues were significant difference at three development stages of Large White pigs and Mashen pigs(P < 0.05; P < 0.01), and also had a specific rule, which indicated that it may play an important role in these pig tissues. The expression of MYNN gene could related to the tissue, age and the genetic background of breeds. The results of this study provided a better understanding of the biological functions of pig MYNN. Further studies are required to determine its molecular mechanisms, especially in the regulation of skeletal muscle development.     

Soil properties, grassland management, and landscape diversity drive the assembly of earthworm communities in temperate grasslands

Earthworms are widespread soil organisms that contribute to a wide range of ecosystem services. As such, it is important to improve our knowledge, still scanty, of the factors that drive the assembly of earthworm communities. The aim of the present study was to conjointly evaluate the effects on the assembly of earthworm communities of i) soil properties (texture, organic matter content, and pH), ii) grassland management (grassland age, livestock unit, and type of fertilization), iii) landscape diversity (richness, diversity of surrounding habitats, and grassland plant diversity), and iv) presence of hedgerows. The study was conducted in temperate grasslands of Brittany, France. Earthworms were sampled in 24 grasslands and, in three of these grasslands, they were sampled near a hedgerow or near a ditch (control without a hedgerow). Soil properties explained the larger portion of the variation in the earthworm community parameters compared to grassland management or landscape diversity. The increase in soil organic matter content and pH were the most favorable factors for earthworm abundance and biomass, in particular for endogeic species. Regarding grassland management, the increase in the livestock unit was the most damaging factor for earthworm communities, in particular for the anecic earthworm biomass and endogeic species richness. Surprisingly, landscape diversity negatively affected the total earthworm abundance and epigeic earthworm biomass, but it was related to an increase in the epi-anecic species. At a finer scale, we also demonstrated that the presence of hedgerows surrounding grasslands enhanced earthworm species richness, especially within the epigeic and anecic ecological categories. This study highlights that the earthworm ecological categories respond specifically to environmental filters; further studies need to be conducted to elucidate the factors that drive the assembly of earthworm communities at this ecological category level. We recommend that policymakers should act on landscape management to favor earthworm diversity in order to improve the ecosystem services they drive.     

The intake and feeding value for young beef cattle of two cultivars of tetraploid Italian ryegrass when grazed or conserved by artificial dehydration or ensilage

Two experiments were carried out to determine whether the differences in intake and feeding value previously shown between two grass cultivars when offered to ruminants as chopped artificially dehydrated (dried) material could also be demonstrated when the grasses were offered in other forms. Two cultivars of tetraploid Italian ryegrass ( Lolium multiflorum ), Sabalan and Tetila, were established in the same field in 1975. In 1976 they were grazed and conserved (two cuts of primary growth) as dried material or as silage.
The composition of the herbage selected at pasture and conserved showed higher concentrations of normal detergent fibre and acid detergent fibre in the dry matter for Tetila than for Sabalan, but differences between cultivars in digestibility were small. In both grazing and winter feeding trials differences in voluntary intake between the two cultivars were not significant, but at pasture young beef cattle spent less time grazing and tended to spend more time ruminating on Tetila than Sabalan. There was no measure of animal performance at pasture but liveweight gain was 15% higher for Sabalan than Tetila when both were offered to young beef cattle as the sole feed of dried grass or of silage. The voluntary intakes of the three forms of feed were very similar, which in part reflected a similarity in digestibility. However, gains were lower for calves given silage than those given dried grass. This may have been due to a lower efficiency in the utilization of the nitrogeneous components of silage for tissue growth than those of dried grass.     

Habitat use and demography of Mus musculus in a rural landscape of Argentina

The main goal of the paper was to determine the habitat distribution of the house mouse (Mus musculus) within a rural landscape of Buenos Aires province, Argentina. We also studied the seasonal variation in abundance and reproductive activity. The habitats studied were poultry farms, human houses in a small village, cropfields, pastures, cropfield and pasture edges, riparian habitats (streams), railway embankments and woodlots. We captured 817 M. musculus and 690 individuals of 5 native rodent species. M. musculus was captured in poultry farms, houses, riparian habitats, cropfield and borders, but it showed a significantly higher abundance in poultry farms compared to the other habitats. Its presence outside poultry farms was significantly related to the distance to streams and poultry farms. The mean trapping success index of M. musculus did not show significant variations between periods, but the proportion of active males was significantly higher in the spring–summer period than in the autumn–winter period. All captures of M. musculus in cropfields, borders and riparian habitats occurred in the spring–summer period. The capture of M. musculus in many types of habitats suggests that it can disperse outside poultry farms, and streams may be used as corridors.     

鸡球虫病发病机理及综合调控技术研究进展

球虫病是鸡群中危害最大的一类疾病,给养鸡业造成了巨大的经济损失。本文主要阐述了鸡球虫病的发病机制及调控技术,为有效防治及控制鸡球虫病的发生提供依据。     

Incidence of lymphoma in a captive-bred colony of hamadryas baboons (Papio hamadryas)

Objective   To assess the incidence of lymphoma and wasting-related deaths in the National Baboon Colony of Australia and relate it to the presence of simian T-cell lymphotrophic virus 1 (STLV-1) infection.
Design and procedure   The records of all animals that had died since establishment of the National Baboon Colony in Australia were reviewed retrospectively. The clinical signs and histopathological findings were recorded and assessed to determine the involvement of lymphoma in the deaths. The presence of STLV-1 was recorded if known and correlated with the STLV-1 status of the colony.
Results   Of the deaths from disease or illness, 53% were diagnosed as or suspected to be lymphoma, occurring in mature animals with no sex predisposition. The most common presentation was rapidly occurring generalised lymphadenomegaly.
Conclusions   This study has described a relatively high prevalence of lymphoma in a colony of captive-bred baboons, and it is evident that STLV-1 may play a role in the disease. Management practices in baboon colonies need to take into account the possible presence of STLV-1 and aim to reduce the transmission of the virus by preventing sexual contact between positive and negative animals. Lymphoma needs to be considered as one of the more common causes of wasting and death.     

转基因抗病棉花品系密度与肥料互作效应研究

在田间试验条件下 ,研究了转基因抗病棉品系 960 9不同密度与不同肥料的互作效应。结果表明 :以N2 62 D1 65处理时叶面积系数变化合理 ,单株干物质积累增加 ,并利于向生殖器官的分配 ,产量高 ;同一施肥水平 ,密度的增产效应为 3 .8%～ 1 9.8% ,同一密度下 ,肥料的增产效应为 5.2 %～ 3 1 .5% ,肥料的增产效应大于密度的增产效应。