Efficacy of different dosages of ivermectin injectable against the Hypoderma spp. in yaks

A chemotherapy trial was conducted to determine the lowest dosage of injectable preparation of ivermectin against Hypoderma spp. infestation in yaks in Tibetan areas in Tianzhu county, Gansu province, in northwest of China. One hundred and sixty yaks were randomly divided into four groups of 40 yaks for the trial. The first three groups were treated by subcutaneous injection in the neck with 0.1% ivermectin (respectively, 1, 5, 10 microg/kg body weight). The fourth group was not treated and considered as control group. All the experiments were performed in November 2000 and the animals were examined for the presence of warbles in the next March and May. The results indicated that there was no warbles found on the back of treated animal while third stage larvae were palpated on back of some of the yaks in control group. It is concluded that dosage of 1 microg/kg ivermectin injectable was sufficient to kill or stop development of larvae of Hypoderma spp. in naturally infected yaks if administrated in November.     

Identification of a gonad-expression differential gene insulin-like growth factor-1 receptor (Igf1r) in the swamp eel (Monopterus albus)

In vertebrate species, the biopotential embryonic gonad differentiation is affected by many key genes and key steroidogenic enzymes. Insulin-like growth factor-1 receptor (Igf1r) has been considered as an important sex-differentiation gene in mammals and could mediate the biological action of Igf1, an important regulator of key steroidogenic enzymes. However, Igf1r gene is still unknown in the swamp eel, an economically important fish. In our study, we identified Igf1r gene in the swamp eel, which was a 2,148-bp open-reading frame encoding a protein of 716 amino acids. The alignment and the phylogenetic tree showed that Igf1r of the swamp eel had a conservative sequence with other vertebrates, especial fishes. Western blotting of Igf1r showed that Igf1r expressed much more in ovotestis and testis than in ovary, indicating an important role of Igf1r during gonad differentiation. We analyzed ubiquitination of Igf1r by co-immunoprecipitation and found the amount of ubiquitinated Igf1r was increased from ovary, ovotestis to testis, which was reversely to the trend of Hsp10 expression during gonadal transformation. It was possible that Hsp10 could suppress Igf1r ubiquitination during gonadal development of the swamp eel.     

农村饮水安全的实践经验与社会效益

长治市"十五"期间,累计投资2.14亿元,建成各类饮水解困工程1270处,解决了61.52万农村人口的饮水困难。2006年,全市投资6871万元,建成各类饮水安全工程269处,解决饮水安全人口16.86万人。饮水安全工程建设,促进了农村社会稳定和精神文明建设,解放了大批劳动力,加快了农村经济发展,促进了群众脱贫致富,改善了生态环境,提高了农民健康水平,社会效益显著。实践证明:加强组织领导、科学规划设计、多方筹集资金、严把施工质量、创新建管机制等措施,是保证工程建设和正常运行的重要环节。     

Fine-scale spatial genetic structure of sycamore maple (<Emphasis Type="Italic">Acer pseudoplatanus</Emphasis> L.)

Knowledge of SGS in plants is vital to understand the ecological and evolutionary dynamics of populations and to plan conservation strategies. Some of the major factors that can affect spatial genetic structure (SGS) in plants are the level of gene flow, spatial arrangement and life stages of individuals within populations. Applying six highly variable microsatellite markers, we investigated the effect of these factors on spatial genetic structure selecting two natural populations of sycamore maple, which is an insect-pollinated, autotetraploid and an indigenous hardwood species in Germany and in other central European countries. The two study populations had different shapes (“compact” and “elongated”) and tree densities. Significant SGS extended to ~180 m in the elongated population and to ~35 m in the compact population. Juvenile plants of the compact population showed significant SGS up to 40 m. Estimate of Sp statistic in high-density population was almost double of that in the population with low density. Gene dispersal distance in the low-density population was about 9 times higher than in the population with high density. The similar level of significant SGS in both adult and juvenile plants suggested minimal or no effect of life stages of individuals on SGS in the sycamore maple population. The data presented in this study can provide guidelines for seed collection and to establish populations for the conservation and management of genetic resources of the species.     

陕西省畜禽屠宰行业现状及发展对策

为全面了解畜禽屠宰行业发展现状,笔者对陕西省畜禽屠宰企业进行调研,分析了畜禽屠宰行业和监管现状,指出了畜禽屠宰监管不充分、生猪屠宰整体发展不均衡、牛羊屠宰发展相对落后、家禽规范化屠宰实施难等问题,针对性提出了持续强化畜禽屠宰监管、促进生猪屠宰企业转型升级、统筹规划牛羊屠宰产业、尽快规范家禽屠宰管理等策略,以期为陕西省畜禽屠宰高质量发展提供参考。     

花生芽组织块悬浮培养产辅酶Ｑ10的研究

【目的】建立花生芽组织块培养合成辅酶Q₁₀（CoQ₁₀）方法,为高效生产CoQ₁₀提供参考。【方法】以花生芽组织块为试验材料,考察培养温度、培养时间、蔗糖质量浓度、初始pH值对CoQ₁₀合成的影响。在单因素试验基础上,通过L₉（3⁴）正交试验优化培养条件。【结果】花生芽经悬浮培养后,其产CoQ₁₀的最优条件为：培养温度24 ℃,时间20 h,蔗糖质量浓度30 g/L,初始pH值6.0,在此条件下CoQ₁₀产量最高,为182.147 μg/g,比未经悬浮培养处理花生芽产CoQ₁₀含量提高了72.4%。【结论】建立了花生芽组织块悬浮培养产CoQ₁₀的最佳工艺,且这种工艺操作简便、周期短、成本低。     

榆林市“东桑西移”工程实施之我见

回顾了榆林市实施"东桑西移"工程所取得的主要成效,论述了"东桑西移"工程的社会影响和社会贡献,提出了项目实施过程中存在的问题,提出了几点建设性意见。     

Succession of soil bacterial and fungal communities of Caragana korshinskii plantation in a typical agro-pastoral ecotone in northern China over a 50-a period

Bacterial and fungal communities play critical roles in reestablishing vegetation structure, function and biodiversity in ecosystem restoration in arid and semi-arid areas. However, the long-term successional changes in bacterial and fungal communities that occur with artificial vegetation development are not fully understood. In this study, we investigated the successional changes in bacterial and fungal communities in Caragana korshinskii Kom. plantation over a period of 50 a (6, 12, 18, 40 and 50 a) and their relationships with key soil environmental factors in a typical agro-pastoral ecotone, northern China. The results showed that bacterial and fungal diversities (α- and β-diversity) were significantly affected by plantation age; moreover, the change in fungal community was more evident than that in bacterial community. Soil samples from 12 a plantation had the highest (P<0.05) bacterial and fungal α-diversity (i.e., abundance-based coverage estimator (ACE) and Chao1 index) at 0-10 cm depth compared with other samples. However, soil samples from plantation at the late recovery stage (40-50 a) had the highest α-diversity at 10-20 cm depth. Soil bacterial community was not significantly affected by plantation age at the genus level; but, soil fungal community was significantly affected at the genus level. Overall, Mortierella and Chaetomium were the dominant genera at natural recovery stage (0 a); Inocybe was the dominant genus at the early recovery stage (6-12 a); Inocybe and Mortierella were the dominant genera at the mid-recovery stage (12-40 a); And Mortierella, Cladosporium and Humicola were the dominant genera at the late recovery stage (40-50 a). Redundancy analysis (RDA) showed that β-glucosidase activity, total nitrogen and soil organic carbon were closely associated with bacterial community composition, while alkaline phosphatase, urease activity and total nitrogen were associated with fungal community composition, indicating that changes in enzyme activity and soil nutrients were the most important determinants of dominant genera. Furthermore, pathogenic microorganisms (Cladosporium and Humicola) were dominant in soils from 40-50 a plantation, which may affect plant growth, resulting in the decline of C. korshinskii plantation. Overall, the findings of this study improve the understanding of ecological patterns of bacterial and fungal communities in artificial vegetation and provide an important scientific basis for comprehensive ecological restoration management in arid and semi-arid areas.