东北西部草地建设经济技术对策的研究

东北西部的天然草地位于北纬 4 1°0 ～ 4 3°5 ,东经 117°0 ～ 12 7°5 ,分布于黑龙江省、吉林省和辽宁省西部地区的松花江、嫩江和辽河流域。大约在 130年前 ,该草原地区分布有富饶的草地资源 ,拥有 2 6 6 6 .6 6万公顷草地。自清朝末年以来 ,遭到 3次草地大破坏。到目前为止 ,该草地尚存 5 33.33万公顷草地 ,其中有 333.33万公顷是沙化、退化和盐碱化草地。文章的研究证实 ,以往任何时期无论草地破坏和草地修复都与当时社会的经济变革和经济体制 ,特别是与市场经济有关。目前 ,在草地建设中改良退化草原和建立人工草地主要采用下列农业经济技术对策 :1)退耕还牧的技术经济对策 ;2 )旨在封育沙化、退化和盐碱化草地的技术经济对策 ;3)发展草地农业和建立人工草地的技术经济对策。     

Detection of squamous cell carcinoma of presumed pancreatic origin and its metastasis in a spotted seal (Phoca largha) using ultrasonography and computed tomography

A 21-year-old female spotted seal (Phoca largha), with a swollen abdomen, had a five-month history of anorexia and vomiting. Ultrasonography revealed an extended mass with central necrotic foci in the right cranial abdomen. Computed tomography revealed an abdominal mass with a low-density central lumen and a pulmonary nodular lesion. Cytology of an abdominal specimen collected through fine-needle aspiration indicated a malignant tumor with round, atypical cells with large nuclei. Three days after diagnosis, necropsy revealed a 10-cm large, solid, whitish mass in the pancreatic parenchyma and multiple small nodules in the liver, spleen, mesentery, lungs, and mediastinal lymph nodes. Histopathological analysis showed prolific neoplastic cells with marked atypia and occasional keratinization. Immunohistochemistry revealed that the neoplastic cells were positive for cytokeratin AE1/AE3 antibody. Thus, the seal was diagnosed with squamous cell carcinoma, of presumed pancreatic origin, which had metastasized to multiple organs.     

日本以农协为主推进智慧农业发展经验及对中国的启示

日本农业面临严峻的农业人口老龄化与农业人口减少的问题,且以小型田块和山地耕地居多,农业劳作不便。为了解决上述问题,保障粮食供应,振兴地方经济,日本正大力发展智慧农业。日本农协协助制定了新的农业基本法以及农林水产信息化战略以支持农业的发展,并在农业机械自动化、农用信息系统、农村网络改造、农用航空、植物工厂等方面开展了大量的科技创新与应用,推动了日本现代农业的发展,日本以140.4万人且主体为老龄人口的核心农户实现了近1.3亿人口的主要粮食自给自足。日本农协多层级、多部门、全方位覆盖农业流程的服务,为智慧农业的落地助力。纵观日本智慧农业的发展历程与成效,借鉴其成功经验,对中国农业发展提出如下建议：应当创新农业体制机制,打通信息、人力、资源的流通渠道;优化农村营商环境,发挥好地方、高校、企业等不同主体的优势,立足乡村振兴角度对智慧农业技术进行长期的实证化研究;借鉴日本农协在农业生产、销售、推广、管理上的经验,因地制宜,积极探索,夯实根基,有助于推进中国乡村全面振兴,加快农业农村现代化和建设智慧农业强国。     

Virulence of infectious pancreatic necrosis virus is associated with the larger RNA segment (RNA segment A)

Abstract. Infectious pancreatic necrosis virus (IPNV) contains two segments of double- stranded RNA (the larger RNA segment, A; and a smaller RNA segment, B). The IPNV- Buhl isolate belongs to the VR299 serotype, and eel virus European (EVE) is serologically the same as the Ab serotype. IPNV-Buhl is virulent to rainbow trout fry, Oncorhynchus mykiss (Walbaum), whereas EVE is avirulent. To determine the genetic basis for the difference of the virulence, intertypic reassortants were made between IPNV-Buhl and EVE. The reassortants with the genotypes of P/E (segment A of IPNV-Buhl and segment B of EVE) and E/P (segment A of EVE and segment B of IPNV-Buhl) were studied for their pathogenicity to rainbow trout fry. The P/E reassortant was highly virulent, similar to the IPNV-Buhl parent (P/P), while the E/P reassortant was avirulent, as was the EVE parent (E/E). A high level of viral replication was observed in almost all organs of the fry infected with the P/E reassortant and the IPNV-Buhl parent. In contrast, viral replication was restricted to the epidermal cells of the fry infected with the E/P reassortant and the EVE parent. The results demonstrate that the larger RNA segment (RNA segment A) of IPNV is related to cell tropism in vivo and is responsible for virulence in rainbow trout fry.     

Establishment and characterization of primary canine hepatocellular carcinoma cell lines producing alpha-fetoprotein

A primary cultured cell line named CHKS was established from a hepatocellular carcinoma (HCC) of a dog showing a high level of serum alpha-fetoprotein (AFP). CHKS secreted a 66 KDD AFP into the growth medium regardless of the presence or absence of fetal bovine serum (FBS). Cloning CHKS with limiting dilution produced 4 clones, CHKS-1, -2, -3, and -4, which secreted 826, 471, 70, and less than 10 ng/ml, respectively, of AFP into the culture medium. In culture, these cell lines were similar in morphology and proliferation pattern to epithelial cells and positive to periodic acid-Schiff (PAS) staining. The presence of mRNA for canine albumin was demonstrated by nested PCR. The doubling times of the clone cell lines were 21, 45, 36, and 35 h, saturation densities 34, 18, 22, and 24 x 10(4)/cm(2), and plating efficiencies 18, 45, 46, and 45%, respectively. Chromosome analysis of these cell lines showed near triploidy. These results show that CHKS and its clones have hepatic cell functions and are useful for carcinogenetic and clinical studies of canine HCC.     

Association of Verticillium dahliae and Verticillium longisporum with Chinese cabbage yellows and their distribution in the main production areas of Japan

Chinese cabbage yellows caused by Verticillium dahliae and V. longisporum is one of the most economically important diseases in Japan. Verticillium isolates from infected Chinese cabbage in Japan were identified as V. dahliae and V. longisporum based on morphological characteristics and newly developed molecular genotyping methods using group I intron of 18S rDNA, mitochondrial-SSU rDNA and cob gene. Although the two species were equally virulent to Chinese cabbage in the greenhouse, V. longisporum was more virulent in the field compared with V. dahliae. Among the 67 Verticillium isolates from Chinese cabbage, 53 were V. longisporum and considered to be the major pathogen. The isolation frequency of V. longisporum was 98?% in Ibaraki and eastern Gunma where Chinese cabbage was cropped from autumn to winter. In contrast, the frequency was 48?% in Nagano and north to west Gunma where the plant was cropped in cool summer and highland conditions and the rests were V. dahliae. This is the first report to show the different geographical distribution of V. longisporum and V. dahliae in Chinese cabbage production area of Japan.     

Genomic characterization and distribution of bovine foamy virus in Japan

Bovine foamy virus (BFV) is distributed through worldwide cattle herds. Although the biological features of BFV are not well understood, appearance of clinical manifestation by superinfection with other microorganisms is inferred. In Japan, reports of genomic characterizations and epidemiology of this virus are limited. In this study, we performed whole genomic sequencing of BFV strains Ibaraki and No.43, which were isolated in this country. Additionally, we investigated BFV in geographically distant four daily farms in Japan, to estimate the distribution of BFV and its correlation to bovine leukemia virus (BLV). BFV was distributed throughout Japan; the average positive rate was 12.7%. The nucleotide sequence identities of the isolates were 99.6% when compared with BFV strain isolated in the USA. The phylogenetic tree using env gene sequence showed strains Ibaraki, No.43 and Kagoshima were sorted in the same cluster including the USA and Chinese strains, while Hokkaido strain was in the other cluster including European strains. Although no clear correlation between BFV and BLV could be found, BFV and BLV infections were likely to increase with ages. Our data on epidemiology and characteristics of BFV will provide important information to reveal biological features of BFV.     

Intraoperative acridine orange photodynamic therapy and cribriform electron-beam irradiation for canine intranasal tumors: A pilot study

Untreated canine intranasal tumors carry a poor prognosis. We retrospectively evaluated the efficacy of marginal tumor resection in combination with intraoperative acridine orange (AO) photodynamic therapy (PDT) and 1 fraction of 5 Gy megavoltage irradiation for canine intranasal malignant tumors. When cribriform plate invasion or turbinate destruction around the cribriform plate was present, an additional fraction of 20 Gy was delivered with an electron beam during surgery. The study included 6 dogs, 2 of which were classified as stage I, 1 as stage II, and 3 as stage IV. The median local disease-free survival time and overall survival after the treatment were 8.5 and 13 months, respectively. Recurrence was noted in 2 of the 6 dogs after 4 and 7 months. Adverse events were mild (subcutaneous emphysema in 1 case, and rhinitis in 3 cases). Combination AO therapy may increase the tumor control time of dogs with marginally resectable intranasal malignant tumors.