Outbreak of acute bovine viral diarrhea in Brazilian beef cattle: clinicopathological findings and molecular characterization of a wild-type BVDV strain subtype 1b

When first described in 1946, bovine viral diarrhea (BVD) was characterized as an acute transmissible disease associated with severe leucopenia, high fever, depression, diarrhea, gastrointestinal erosions, and hemorrhages. Recently the severe acute form has been related only to some hypervirulent BVDV-2 strains. This article reports the detection of BVDV-1b associated with an acute and fatal outbreak of BVD in a Brazilian beef cattle herd. Depression, anorexia, watery diarrhea, sialorrhea, and weakness were observed in six steers. One of these animals was evaluated for laboratorial, clinical, and pathological alterations. Laboratory findings were non-specific; clinically, the animal was weak, with dehydration and erosive oral lesions. Pathological alterations were predominant at the tongue, esophagus, and rumen. A RT-PCR assay using primers to partially amplify the 5′ untranslated region (5′UTR) of the BVDV genome was performed and identified BVDV in all clinical samples analyzed. Phylogenetic analysis of BVDV derived from lymph node revealed that this strain was clustered within the BVDV subtype 1b. This differentiating was only possible to be performed by molecular characterization since both clinical presentation and pathologic findings were similar to BVDV-2 infection.     

Genetic diversity of Bangladeshi native chickens based on complete sequence of mitochondrial DNA D-loop region

ABSTRACT

1. The aim of this study was to explore genetic diversity and possible origin of Bangladeshi (BD) native chickens. The complete mtDNA D-loop region was sequenced in 60 chickens representing five populations; naked neck, full feathered, Aseel, Hilly and autosomal dwarf. The 61 reference sequences representing different domestic chicken clades in China, India, Laos, Indonesia, Myanmar, and other Eurasian regions were included. The mtDNA D-loop sequence polymorphism and maternal origin of five BD populations were analysed.

2. A total of 35 polymorphic sites, and 21 haplotypes were detected in 60 mtDNA D-loop sequences. The haplotype and nucleotide diversity of the five populations were 0.921 ± 0.018 and 0.0061 ± 0.0019, respectively. Both mtDNA network and phylogenetic analysis indicated four clades (four haplogroups) in BD populations (21 haplotypes) along with 61 reference haplotypes. Clade E contained the most individuals (20) and haplotypes (11) of BD chickens, followed by clade D (17, 6), clade C (12, 2) and clade F (11, 2), respectively.

3. The higher number of unique haplotypes found in Yunnan, China, suggested that the origin of BD chickens was in this region. The haplotypes from different haplogroups were introduced in Bangladeshi chickens from India, China and Myanmar. The phylogenetic tree showed a close relationship of BD chickens with the clusters from India, China, Myanmar and Laos, and indicated the dispersion of BD chickens from these sources. The phylogenetic information revealed high genetic diversity of BD chickens because of their origin from different lineages with high genetic variation and distance, which was determined from four cluster and neighbour-joining trees.

4. In conclusion, BD populations had high genetic diversity. The mtDNA network profiles and phylogenetic trees showed multiple maternal origins of BD chickens from India, China, Myanmar and Laos.     

甘肃省不同区域人工草地土壤肥力特征研究

以甘肃省不同区域人工草地土壤样品为研究对象,测定12个不同区域[民乐县(ML1、ML2)、安定区(AD)、通渭县(TW1、TW2、TW3、TW4)、宁县(NX1、NX2)、靖远县(JY1、JY2、JY3)]人工草地土壤的pH值、有机质、全氮、速效磷、速效氮、速效钾。结果表明:AD的p H值最大,JY3的pH值最小;TW2有机质含量最高,AD有机质含量最低,TW2较AD提高了78.95%,在TW2种植陇东苜蓿对土壤有机质影响大;TW2、TW3速效氮含量较高,约为AD速效氮含量的3倍,在TW2、TW3种植陇东苜蓿对土壤速效氮影响大;JY2速效钾含量是AD的3倍,TW2速效钾的含量最低,在JY2种植陇东苜蓿对速效钾影响大;ML1、ML2速效磷含量较高,NX1、NX2速效磷含量较小,在NX1、NX2种植陇东苜蓿对土壤速效磷影响小;TW2全氮含量最高,较AD提高了85.07%,在TW2种植陇东苜蓿对土壤全氮影响大。综合分析结果显示,TW2土样的关联度值最大(0.787 9),综合肥力最好,为最优土样;NX2土样的关联度最小(0.500 7),综合肥力最差。     

蓝狐MITF-M基因序列扩增及生物信息学分析

试验旨在研究蓝狐MITF-M基因核心启动子活性区、转录因子结合位点、基因编码蛋白结构及功能,为探究该基因的表达调控机制提供理论依据。从成年蓝狐背部皮肤组织中采集1 cm×1 cm样品,采用RT-PCR扩增及测序技术首次获得MITF-M基因序列3 880 bp（包括5'侧翼区2 262 bp、CDS区1 260 bp、3'侧翼区358 bp）,编码419个氨基酸残基。生物信息学分析结果显示,蓝狐MITF-M基因5'侧翼区存在潜在的启动子区域（-86~-336 bp）,且发现TATA框、CAAT框、GC框和CRE等调控元件及CREB、LSF和Sp1等多种转录因子。MITF-M基因编码的蛋白是定位于细胞核和细胞质的不稳定、可溶性亲水蛋白质。亚细胞定位结果提示该蛋白在细胞核、细胞质和线粒体的概率较高,分别为65.2%、17.4%和8.7%。DNAMAN软件对MITF-M基因编码蛋白的二级结构预测发现,该蛋白由α螺旋（33.66%）、β折叠（16.66%）和无规卷曲（49.68%）组成,且不存在跨膜区域和信号肽。蓝狐与其他物种MITF-M基因编码的氨基酸序列同源性对比和系统进化树分析均提示蓝狐与犬的遗传亲缘关系最近,与哺乳动物和禽类均具有较高的同源性（>89.1%）,说明MITF-M基因编码区在物种进化过程中较为保守。本研究为深入研究MITF-M基因调控狐狸被毛颜色的分子遗传机制奠定了理论基础。     

信阳市南湾水库库区森林植被调查分析

信阳市南湾水库库区森林植被南湾水库库区的水资源涵养和水土保持具有重要的作用。本文对水库加区的森林植被的环境,资源状况,类型进行了调查分析,并提出了保护管理的建议。     

黄河流域三倍体毛白杨区域生态经济发展战略

经过对黄河流域的社会、生态、经济和土地资源的全面考察和对三倍体毛白杨发展现状的分析,提出了绿化黄河、开发黄河三倍体毛白杨区域生态经济的发展战略。在区域生态经济产业化中,制定了以北京原种中心统一集中制种,黄河险工分区育苗,就地造林,定向收购加工利用的产业化模式;在林种结构上以三倍体毛白杨用材林为主,银杏、冬枣经济林为辅,大堤内配置适量的金丝垂柳和刺槐防浪林带,组成多功能、可持续发展的黄河区域生态经济林绿色长城,并带动黄河森林生态旅游和中国黄河历史文化经典旅游业的发展。     

太行山丘陵区旱地棉花综合措施优化组合筛选研究

通过对棉花播期、密度、行距和果枝数的复因子试验以及氮、磷、钾肥的单、复因子试验,确定了太行山丘陵区旱地棉花在干旱气候年型的播期和主要群体结构指标的优化组合,明确了该区旱地棉花氮、磷、钾肥的增产效应及最佳配比,提出了适合该区旱地棉花高产、稳产的技术路线。     

Producer services and growth management of a metropolitan region: the case of Kuala Lumpur,Malaysia

Producer services growth can change the character of a metropolitan region. Achieving that outcome may require the intervention of government, which is not necessarily a simple process as it creates tension between regulatory and developmental roles for government. This paper will address three interrelated issues in connection with the above-mentioned core idea in the context of the city of Kuala Lumpur, Malaysia: first, the extent to which the evolution of the Malaysian economy has been felt in the growth of the service sector; second, the way that evolution has led to change in the sectoral and spatial character of Kuala Lumpur; third, government’s responses in terms of spatial planning and management in order to accommodate producer services growth. The experience of the Kuala Lumpur region shows how global market forces and national development policies that influence producer service location and growth can reshape the spatial arrangement of a metropolitan region. Managing the growth of producer services calls for new approaches to manage metropolitan change. An ‘enabling’ model is proposed to replace the present ‘policing’ model of spatial planning.     

陕西省渭北、陕北粮食生产态势与定位

该文提出了确定区域粮食产量发展目标的“生产单元长时段产量动态分析法”,并根据黄土主原国家试验示范区粮食产量长期动态资料,提出渭北粮食近期８亿ｋｇ增产潜力。旱作粮食单产指标达到４０５０ｋｇ／ｈｍ＾２,其中小麦为３７５０ｋｇ／ｈｍ＾２,玉米为６７５０ｋｇ／ｈｍ＾２,并指出实现指标的３项指标。     

我国著名水土保持专家张信宝研究员

张信宝研究员,男,1946年生于江苏镇江,1967年南京大学地质系毕业后,分配至中科院、水利部成都山地灾害与环境研究所.1992年被中科院特聘为研究员,现任山地农业与侵蚀研究中心主任,兼任中科院西安黄土与第四纪地质国家重点实验室客座研究员,四川联合大学客座教授,中国水保学会滑坡泥石流专业委员会常委、小流域综合治理专业委员会委员,中国地理学会地貌专业委员会委员,中国土壤学会土壤侵蚀专业委员会委员,<土壤侵蚀与水土保持学报>、<第四纪研究>、<山地研究>和<长江水土保持>诸杂志编委.1983～1986年在新西兰森林研究所工作期间,被聘为一级地学科学家.