美国和加拿大的林业非政府组织建设

介绍了美国、加拿大4个重要林业非政府组织的概况、运作模式和管理制度, 对促进我国林业非政府组织的发展提出了建议。     

Prevalence of and factors associated with feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) in cats of the state of Santa Catarina,Brazil

A cross-sectional study was conducted in 274 cats for determination of FeLV antigenemia and FIV seropositivity and factors associated with those infections in cats presented at the Veterinary Hospital of the Santa Catarina State University - UDESC (Brazil). Apparent prevalence for sick cats at the hospital population was 28.41% (95%CI 21.88–34.94%) for FeLV, 7.65% (95%CI 3.71–11.50%) for FIV and 2.18% (95%CI 0.56–5.47%) for both viruses. For healthy cats, the apparent prevalence was 9.89% (95%CI 3.75–16.02%) for FeLV, 2.20% (95%CI 0.34–7.75%) for FIV by immunoassay (ELISA). Average age for FeLV- and FIV-positive individuals was 38.32 and 64.25 months, respectively. Behavior such as aggressiveness and sex (male) were both associated with increased odds of result positivity test for FeLV and FIV; older animals were also associated with FIV test results. A very small proportion of the animals were vaccinated against FeLV and none against FIV. Most of the animals were adopted from shelters or rescued from streets, living with multiple cats that had access to outdoors. The high prevalence of FeLV suggests a need for better control strategies against this disease.     

Mitogenic Equine Isolates of Streptococcus zooepidemicus From North America Host Superantigen Genes Similar to Those Hosted in Europe

Streptococcus equi subsp. zooepidemicus (Sz) is an important opportunist pathogen of the equine respiratory and reproductive tracts. It is highly variable with respect to sequence type and virulence factors including SzP and SzM. Recent studies in the UK have shown that many Sz strains host genes for mitogenic superantigens including szeF, szeN, szeP, seeI, seeL, and seeM. The aims of the present study were to estimate the prevalence of mitogenicity in equine Sz in North America and establish whether mitogenicity is more likely to be associated with isolates from a specific site of infection. Twenty-six percent (23/90) of strains randomly selected from over 600 Sz isolated in the United States from 1969 to 1994 were mitogenic for equine peripheral blood mononuclear cells. All but five of these mitogenic Sz encoded one or more of the superantigen genes szeF, szeN, szeP, seeI, seeL, and seeM. Homologues of seeH in S. equi were not detected in any Sz strain. Polymerase chain reaction analysis revealed the presence of seeI, szeF, szeN, or szeP in 91% (10/11) of isolates from lymph node abscesses confirming earlier reports of a significant association of superantigens with lymph node abscessation in the UK. In contrast, only 24% (4/17) of Sz isolates from the reproductive tract were mitogenic and/or hosted seeL, seeM, szeF, szeP, or szeN.     

美国HACCP体系法律法规建立与实施的研究

就美国HACCP体系的建立和实施、HACCP体系相关法律法规的建立和实施进行了研究,总结出对我国HACCP体系法律法规建立和实施有益经验。     

西洋参叶肉原生质体的游离与培养

[目的]为了探讨西洋参叶肉原生质体游离和培养的最佳条件。[方法]以5年生西洋参为材料,研究了纤维素酶的种类,酶的浓度和渗透压对西洋参叶肉原生质体游离的影响,并探讨了西洋参叶肉原生质体在KM8P、MS基本培养基中的分裂情况。[结果]在混合酶液其他组分相同的情况下,日本产R-10纤维素酶的游离效果最好。酶浓度为4%时,3 h后大部分叶片都被解离成原生质体。幼嫩叶片的原生质体产量最高,为4.8×105个/g。KM8P培养基适合于西洋参叶肉原生质体的培养,较高的2,4-D浓度可以促进分裂。[结论]用混合酶系统处理,能够获得大量(4.8×105个/g)有活性的原生质体。游离原生质体的酶浓度以1%～2%为宜。KM8P+2,4-D(2.0 mg/L)+6-BA(2.0 mg/L)+KT(0.7 mg/L)培养基适宜培养西洋参叶肉原生质体。     

美国生物技术产业带给我们的反思

生物技术产业必将成为21世纪的主导产业,其发展对中国经济社会发展具有极其重要的意义。总结了美国生物技术产业的成功经验,分析了我国生物技术产业在发展战略、投融资机制、人力资源、产业布局与结构等主要因素方面存在的不足。     

北美农业合作社发展新动向及其启示王

在对国内外关于北美农业合作社的资料进行系统梳理、总结和分析的基础上,对北美农业合作社发展的新动向、新一代合作社和有限合作组织进行研究。结果表明：北美农业合作社通过一系列组织制度创新,延长了产业链条,增强了市场竞争力;合作社对基本原则进行了修正,允许外部投资者加入,并通过完善相关制度维护了惠顾者的利益。借鉴其经验,我国农民合作社应积极吸纳外部投资者加入合作社,增强合作社竞争力;向产业链下游延伸,提升合作社农产品增值能力;完善合作社的治理结构和盈余分配制度,协调好投资成员与惠顾成员间的关系。     

Fasciola hepatica infections in livestock flock, guanacos and coypus in two wildlife reserves in Argentina

Between autumn and spring 2006, a coprological survey was performed in two wildlife reserves located in the north of Argentine Patagonia to determine the prevalence of Fasciola hepatica and the number of parasite eggs per gram (epg) of feces in wild guanacos (Lama guanicoe), coypus (Myocastor coypus), and locally born and raised goats and sheep. Snails of the Family Lymnaeidae were collected in freshwater habitats, identified taxonomically and analyzed parasitologically.Prevalence of patent infection was 100% in sheep (n = 69) and coypus (n = 9), 84% in goats (n = 20) and 0.5% in guanacos (n = 224). No significant differences in epg were found among animals, but the median epg of coypus (160) and sheep (160) was higher than that of goats (80). For guanacos and goats, a negative binomial model estimating the population egg-count frequency could be fitted, while for coypus and sheep parasite egg-count frequencies trended toward a normal distribution, indicative of a more even, and much less aggregated distribution across sampled hosts. All snails (n = 175) were Lymnaea truncatula and none of them was found infected. This is the first report of fascioliasis in free-ranging guanacos in Argentina. Coypu appears to be a major wildlife reservoir of F. hepatica, which was presumably introduced locally by livestock.     

Fine-scale spatial and temporal variation in earthworm surface casting activity in agroforestry fields, western Honduras

Quantification of the spatial and temporal distribution patterns of soil fauna is a relatively new area of research, and has been proposed as the key to understanding the high diversity typical of soil fauna communities. Field research on the relationships among the spatial distribution patterns of trees, litter and earthworm surface casting was carried out in two agroforestry fields in a rugged area of western Honduras. Grid-based sampling at a scale of 2-20 m was employed to determine whether any spatial relationships existed among these variables at this fine scale. Each field was sampled twice at either 2 or 3 week intervals, to determine the short-term stability of spatial relationships. The spatial distribution of litter showed a strong pattern of aggregation, whereas earthworm cast distribution did not exhibit strong spatial autocorrelation. However, the spatial distribution patterns of each of these variables were well explained by the spatial arrangement of trees in both sites. Fitted model cross-semivariograms explained between 70% and 90% of the total variation in cross-semivariance between tree density and litter cover, and between tree density and earthworm cast weight. The results of the study suggest that farmers may be able to manipulate populations of earthworms indirectly by managing the spatial arrangement of trees within their crop fields. Planning the distribution of trees could allow farmers to create ‘patches’ of organic resources within fields, while minimising the negative effects of trees on crop growth due to competition for light, water and nutrients. Over the short time scale of the study, unusually heavy rainfall led to substantial changes in spatial distribution patterns of earthworm cast activity and litter cover, which may otherwise not have occurred. This result emphasises the need to take into account short-term temporal change during ecological studies at fine spatial scales.     

Sustaining sustainable agriculture: The rise and fall of the Fund for Rural America

Sustainable agriculture has lately madesignificant inroads into US agricultural policydiscourse. An examination of the ``life cycle' of theFund for Rural America, a component of the 1996 farmbill, provides an example of the complex and contestedways in which the goals of sustainable agriculture areadvocated, negotiated, and implemented at the level ofnational policy, in the context of the evolvingpolitical and institutional arrangements of Americanagricultural policy. The Fund, with its relativelylarge endowment of $100 million annually, and itsexplicit emphasis on alternative agriculture research,is emblematic of both the growing politicaleffectiveness of the alternative agriculture movementand the increasing institutionalization of alternativeagriculture representatives in Federal agencies. Theuntimely demise of the Fund in the appropriationsprocess, however, illustrates the extent to whichcertain key spaces within the state remain outsidesustainable agriculture's broadening sphere ofinfluence. This suggests that while some aspects ofthe movement's organizing strategy are indeedeffective, some may need to be rethought in light ofthe experience with the FRA.