森林资源可持续发展的两个基本条件

森林资源是林业生产和经营基础。本文讨论了实现森林资源可持续发展的两个基本条件；林内生物的多样性；限额采伐。     

The involvement of Fas/FasL interaction in porcine circovirus type 2 and porcine reproductive and respiratory syndrome virus co-inoculation-associated lymphocyte apoptosis in vitro

Lymphoid depletion of various lymphoid organs is one of the major lesions in pigs suffering from postweaning multisystemic wasting syndrome (PMWS). The co-existence of porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) in PMWS-affected pigs along with the more severe and wider range of lymphocyte depletion of lymphoid organs in PCV2 and PRRSV dually-inoculated pigs imply that PCV2 and PRRSV may interact in the pathogenesis of PMWS. The mechanism for the development of lymphoid depletion in PMWS-affected pigs remains controversial. The objective of the present study was to evaluate and compare the effects of inoculation of both viruses, singularly or in combination, on swine splenic macrophages (SMs) and co-cultured splenic (SLs) and peripheral blood (PBLs) lymphocytes in vitro. A significant reduction in the survival rate and increase in the apoptotic rate of the co-cultured SLs and PBLs and concurrent increase in the expression levels of Fas ligand (FasL) in SMs and Fas in co-cultured SLs and PBLs were demonstrated in PRRSV alone- and PCV2 and PRRSV dually-inoculated groups with the latter more prominent. The increased FasL was proven capable of inducing Fas/FasL-mediated apoptosis in co-cultured FasL-sensitive Jurkat T cells. The de novo expression and production of FasL in PCV2 and PRRSV dually-inoculated SMs and concurrently increased surface expression of Fas in co-cultured lymphocytes may contribute, at least partially, to lymphoid depletion in PMWS-affected pigs with PCV2 and PRRSV dual infection.     

Amyloid-producing odontogenic tumor and its immunohistochemical characterization in a Shih Tzu dog

A 10-year-old, male, Shih-Tzu dog presented with swelling of the right lower jaw caused by a mass arising from the right mandibular gingiva. Radiographic examination revealed bone lysis of the right wing of the mandible. Histopathologically, the growth was characterized by indistinctly lobulated nests, islands, and strands of proliferating odontogenic and squamous epithelial cells, intermingled in close association with large numbers of irregular extracellular deposits of amyloid and amorphous calcified substance. Immunohistochemically, both epithelial components stained strongly positive for cytokeratin (AE1/AE3); the squamous epithelial cells also reacted strongly with neuron-specific enolase (NSE) and S-100 protein, whereas the odontogenic epithelial cells displayed weak immunoreactivity to NSE and partial reactivity to S-100 protein. The amyloid deposits were AE1/AE3-negative. The growth was diagnosed as an amyloid-producing odontogenic tumor.     

精料补饲水平对暖季放牧牦牛瘤胃发酵和菌群结构的影响

为了研究精料补饲水平对暖季放牧牦牛瘤胃发酵和菌群结构的影响,试验选取体重相近、体况良好的公牦牛48头,随机分为4组,每组12头,以放牧为对照组,3个补饲组分别补饲0.5（Ⅰ）、1.5（Ⅱ）和2.5 kg·d^-1（Ⅲ）精料。预试期10 d,正式期60 d。结果表明：1）随着精料补饲水平的提高,瘤胃液pH值,乙酸浓度和乙酸/丙酸值呈线性和二次降低（P<0.05）;瘤胃总挥发性脂肪酸、丙酸、丁酸、异丁酸、戊酸和异戊酸浓度呈线性和二次提高（P<0.05）;其中补饲Ⅱ和Ⅲ组的微生物蛋白浓度显著高于其他两组（P<0.05）。2）4组共产生3138个OTU,其中共有OTU为1337个,占总OTU数目的42.61%,对照组与补饲Ⅲ组独有OTU分别为183和106个;瘤胃液细菌的物种数、Chao1指数和香农（Shannon）指数随精料补饲的提高呈线性和二次降低（P<0.05）。3）在门水平上,瘤胃拟杆菌门（Bacteroidetes）相对丰度呈线性和二次提高（P<0.05）;而厚壁菌门（Firmicutes）相对丰度随精料补饲水平提高呈线性和二次降低（P<0.05）;放线菌门（Actinobacteria）相对丰度随精料补饲水平的提高呈线性提高（P<0.05）。在属水平上,随精料补饲水平的提高,瘤胃普雷沃菌属_1（Prevotella_1）、克里斯滕森菌科_R-7（Christensenellaceae_R-7）及普雷沃氏菌科_UCG-001（Prevotellaceae_UCG-001）相对丰度呈线性和二次提高（P<0.05）;而解琥珀酸菌属（Succiniclasticum）和瘤胃球菌科_UCG-005（Ruminococcaceae_UCG-005）相对丰度随着精料补饲水平的提高呈线性和二次降低（P<0.05）。综上所述,适宜提高精料补饲水平能够促进暖季放牧牦牛瘤胃发酵,提高瘤胃部分淀粉相关降解菌的丰度。     

浅谈青海省农产品质量安全因素及建议

2005年青海省“两会”期间,代表、委员们关注较多的问题之一,就是农产品的质量安全问题,不少代表委员还写了议案和提案。解决农产品质量安全问题已成为各级政府和农业部门的当务之急。因此,面对农业发展的新形势、新要求,实施农产品质量安全保障工程,加快农产品质量建设,提高农产品质量安全水平,关系到人民的身体健康和生活质量,是一项民心工程。影响青海省农产品质量安全的因素很多,涉及到生产、加工、流通、技术、管理等方面。     

饲料厂配料仓设计方法

提出了一种以实际生产配方为基础,依据对基本配料仓的生产能力和协调性要求,确定饲料厂配料仓的仓容、规格与数目的设计方法,并进行了实例设计.     

我国森林采伐限额制度综述

森林采伐限额制度是国家依据合理经营和永续利用原则,规定林木采伐限额的一种最基本的管理制度,对实现森林资源永续增长具有重要意义。文中梳理了森林采伐限额制度的背景及发展历程,归纳了森林采伐限额制度的制度效果、存在问题和完善建议,指出现有研究在贯彻落实"放管服"改革、降低制度性交易成本、探索采伐权交易方面存在不足。未来森林采伐限额制度的优化研究可从政府主导与市场调节角度开展,具体可从以下4个方面改进:1)贯彻分类经营,落实商品林处置权;2)科学编制采伐限额,合理分配采伐指标;3)深入推进"放管服"改革,合理放权调整;4)落实三权分置,探索采伐权交易。     

秸秆还田配施氮肥改善土壤理化性状提高春玉米产量

为了探明秸秆还田配施氮肥耕层构造对春玉米产量及土壤物理性状的影响,2014-2015年在辽宁铁岭设置了秸秆0 kg/hm~2+纯N 0 kg/hm~2(S0F0),秸秆9 000 kg/hm~2+纯N 0 kg/hm~2(SN0),秸秆9 000 kg/hm~2+纯N 112.5 kg/hm~2(SN1),秸秆0 kg/hm~2+纯N 225 kg/hm~2(S0N2)(当地传统种植方式,CK),秸秆9 000 kg/hm~2+纯N 225 kg/hm~2(SN2),秸秆9 000 kg/hm~2+纯N 337.5 kg/hm~2(SN3)6个处理开展了研究。结果表明,秸秆还田配施氮肥耕层构造对春玉米产量、土壤物理性状、根系形态等指标影响显著(P0.05)。全量还田9 000 kg/hm~2和配施纯氮225 kg/hm~2产量最高,比秸秆不还田2 a增产1.10%~11.56%,但产量并未随着施氮量的增加而持续增加;群体生物产量随着施氮量的增加而增加,收获指数在0.46~0.59之间。秸秆还田配施氮肥耕层构造可显著提高土壤含水量,降低土壤容重,调节土壤三相比;秸秆还田配施氮肥耕层构造春玉米根数、根长、根体积、根干质量等根系形态指标均优于秸秆不还田,且随着氮肥施入量的增加,各项指标均表现越好。因此,综合分析认为,秸秆还田量9 000 kg/hm~2和配施氮肥225 kg/hm~2是辽北棕壤区比较理想的耕层构造模式和秸秆还田技术,在该区域农业发展中具有一定的应用价值。     

乙型肝炎与戊型肝炎病毒重叠感染者血清HBV标记物结果分析

目的：观察乙型肝炎病毒（ＨＢＶ）与戊型肝炎病毒（ＨＥＶ）重叠感染对ＨＢＶ复制的影响。方法：以血清ＨＢｓＡｇ和抗ＨＥＶ均阳性患者３６例作为重叠组,以单纯ＨＢＶ感染患者３６例作为对照组。两组病例抗ＨＡＶ－ＩｇＭ和抗ＨＣＶ均为阴性。采用ＥＬＩＳＡ法测定两组的ＨＢＶ－Ｍ。结果：重叠组血清ＨＢｅＡｇ的阳性率明显低于对照组（Ｐ＜０．００１）,抗ＨＢｅ阳性率明显高于对照组（Ｐ＜０．０５）。结论：ＨＢＶ与ＨＥＶ重叠感染后,ＨＢＶ的复制受到一定程度的抑制     

博优122连片免耕抛秧示范及高产创建栽培技术

2008年晚造,在广西浦北县小江镇长圹村进行博优122连片免耕抛秧高产创建栽培示范,项目采用适时早播种,科学杀灭稻桩、杂草,抛适龄小苗矮壮秧,合理密植,测土配方平衡施肥,科学管水和综合防治病虫害等配套栽培技术措施。博优122加权平均产量达9．03t／hm^2。