基于HP滤波法的菠萝价格波动分析——以北京丰台区新发地农产品批发市场为例

近年来,菠萝价格波动异常频繁,对消费者和生产者造成很大的影响。本文运用 2011年8月至2015年9月北京丰台区新发地农产品批发市场菠萝批发价格数据作为研究对象,剔除通货膨胀对菠萝价格的影响,分析菠萝价格波动主要特征;运用CensusX12季节调整模型和 HP 滤波分解模型将2011年8月～2015年9月的菠萝价格分离出趋势和循环序列,据此考察菠萝价格长期波动的趋势,并对短期波动的周期进行划分,以此剖析菠萝价格波动存在的内在规律。研究发现：菠萝的批发价格属于一种高峰型的波动并具有稳步上涨的长期趋势,但扩张能力正在逐渐下降;菠萝的批发价格很不稳定,变动的幅度很大,波动周期短,市场稳定性差、风险高容易受到其他因素的影响。     

外源寡糖对奶山羊免疫机能的影响

选用体况良好、年龄相近、体质量（32.80±2.45）kg、装有永久性瘤胃瘘管的崂山奶山羊6只,采用分期分组试验设计,分别饲喂添加1%（以有效含量计）甘露寡糖（MOS）、半乳甘露寡糖（GMOS）、果寡糖（FOS）、寡木糖（XOS）和异麦芽寡糖（IMO）的试验日粮,另设不添加寡糖的对照组。试验共分为4期,每期35d,其中预试期14d,正试期21d。结果表明：1）21d时,FOS组的血清碱性磷酸酶（AKP）含量显著升高（P〈0.05）,GMOS组的血清AKP、溶菌酶含量显著升高（P〈0.05）。2）21d时,FOS组、MOS组和GMOS组的血清免疫球蛋白A含量显著或极显著升高（P〈0.05或P〈0.01）;7、21d时,FOS组的血清免疫球蛋白G、M含量显著或极显著升高（P〈0.05或P〈0.01）;14、21d时,GMOS组的血清免疫球蛋白G、M含量显著或极显著升高（P〈0.05或P〈0.01）;7、14d时,MOS组的血清免疫球蛋白M含量极显著升高（P〈0.01）。3）7d时,FOS组血清白细胞介素-2、4、6含量显著或极显著升高（P〈0.05或P〈0.01）;7、21d时,GMOS组血清白细胞介素-2、6含量显著升高（P〈0.05）;14d时,FOS组和GMOS组血清白细胞介素-4含量显著升高（P〈0.05）。试验结果表明,不同外源寡糖对奶山羊有较好的免疫调节作用,其中,添加FOS和GMOS效果最好。     

Cytotoxic Effects of Serum from Equine Grass Sickness Cases on Neuro-2a and PC12 Tet-Off Cell Lines: Implication for Using In Vitro Methods as Antemortem Diagnostic Tools

A wide variety of clinical and paraclinical methods have been used for diagnosis of equine grass sickness (EGS), but none of them could absolutely confirm the diagnosis, and postmortem pathologic examination is still considered the final step in precise diagnosis of EGS. Use of in vitro cell toxicity caused by EGS serum on neuronal cell lines was investigated. Three well-known cytotoxic methods were used to investigate the cytotoxicity of EGS serum on neuro-2a and genetically engineered PC12 Tet-Off P53 cells. The results of alamar blue reduction as an index for mitochondrial activities and intracellular adenosine triphosphate content assays, but not neutral red uptake, indicate that the EGS serum may affect the mitochondrial function and cellular metabolism at up to 60% of the cases. The results of present study might be used for diagnosis of EGS cases. Further studies with high sample size may lead us to uncover the pathogenesis of EGS and to increase the sensitivity and applicability of in vitro techniques as diagnostic tools.     

浅议世界土壤酸化及其影响

该文主要综述了土壤酸化对土壤微生物、林业、基础设施、人类健康等方面的影响。     

鲤CYR61基因的克隆、表达及系统进化树的构建

中世纪是一个伟大的综合时代。相比较9世纪的加洛林文艺复兴,12世纪文艺复兴是中世纪的一次全面的学术复兴,是一次伟大的文化运动。城市的复兴和翻译运动催生了12世纪的文艺复兴。大学是中世纪留给后世最重要的遗产,它兴起于12世纪文艺复兴时代。城市的复兴为大学提供了物质和精神基础,诞生了知识分子阶层,城市中的工商业者的行会为汇聚在城市中的师生提供了自我组织的制度参照。翻译运动使古典知识重新返回欧洲,为大学中的师生提供了讨论和研究的材料。大学是教师和学生在与市民、城市当局和教会等势力斗争的过程中形成的,是学者的行会。12世纪至少自发形成了四所大学,其中波隆那大学作为学生型大学成为南欧大学的典范,巴黎大学作为教师型大学,成为北欧大学的典范。中世纪大学在本质上是师生的行会,并且具有国际性、教会性、特权性的特征。现代大学是中世纪大学的直系后裔。     

基于人类行为视角的低碳景观构建途径

解析了人类行为和低碳景观的内涵,根据行为学、心理学的相关理论,从人类行为的角度出发,探讨行为与低碳景观的内在关联,认为低碳景观与人类行为是相互联系、相互作用、互为前提而存在的,合理的景观环境承载着人们对自然的向往,不同景观带给人们的不同感受,表现出不同的行为特征。提出了从景观设计理念、景观设计方法、景观施工过程及景观后期管理等途径构建低碳景观,以期为倡导节能环保、创造绿色生态的低碳景观构建提供理论依据。     

共表达鸡IL-6和H5亚型禽流感病毒HA基因重组鸡痘病毒的遗传稳定性研究

为评价共表达鸡IL-6和H5亚型禽流感病毒HA基因重组鸡痘病毒(rFPV-AH5AIL6)的遗传稳定性,本研究将其接种CEF,绘制生长曲线.结果显示,该重组病毒与亲本病毒的生长速度及蚀斑大小一致;在CEF 连续培养20代,取第0代、5代、10代、20代重组病毒PCR扩增HA和Ⅱ-6基因进行鉴定,显示HA基因无核苷酸突变,IL-6基因在第20代时有1个氨基酸发生突变,但不影响该蛋白的功能区;间接免疫荧光试验证明所选代次病毒均能够表达HA蛋白,RT-PCR试验表明各代次病毒均可以表达鸡IL-6基因;通过蓝斑鉴定重组病毒纯度,结果显示所有蚀斑均为蓝斑.因此,该重组鸡痘病毒具有良好的遗传稳定性,符合兽医生物制品的生产要求.     

阿拉善地区不同植被生境中鼠类栖息地选择的特性

2002～2007年,在阿拉善荒漠区选择开垦区、轮牧区、过牧区和禁牧区四种植被生境,采用标志重捕法研究不同植被生境中鼠类栖息地选择的特性。结果表明:6个年度中啮齿动物群落的优势种群在四种不同植被生境中各不相同,各个群落的组成种类和主要种类的数量有较大变化;6年中不同植被生境中啮齿动物群落组成种的年平均种数为轮牧区=过牧区=禁牧区>开垦区。不同植被生境中主要组成种变化较大:开垦区为长爪沙鼠、黑线仓鼠;轮牧区为子午沙鼠、小毛足鼠;过牧区为三趾跳鼠、五趾跳鼠;禁牧区为小毛足鼠。长爪沙鼠在开垦区与其他三种干扰区间有极显著差异(P<0.01),而在其他三种干扰区间无差异;三趾跳鼠在过牧区与其他三种干扰区间有极显著差异(P<0.01)。     

Effect of ginkgolide B on cholesterol content in PC12 cells under high cholesterol culture

AIM: To explore the effect of ginkgolide B (GB) on high cholesterol-induced dysfunction in PC12 cells. METHODS: The rat brain microvascular endothelial cells and astrocytes were used to establish the blood-brain barrier (BBB) model by in vitro co-culture in the Transwell device with PC12 cells. Cholesterol at the concentration of 40 μmol/L was added into the side of brain microvascular endothelial cells of the Transwell. Various concentrations of GB were applied to deal with the culture system. The morphological changes of the cells were observed under microscope. The safe doses of GB were screened by MTT assay. The level of cholesterol in the PC12 cells was determined by the high-performance liquid chromatography. RESULTS: The morphology of PC12 cells in control group was normal,with round,short spindle or triangle shape,cytoplasm extension,two-pole short processes,good refraction and obvious nucleus.The doses of GB determined by MTT assay were 1 μmol/L for low dose,5 μmol/L for middle dose and 25 μmol/L for high dose. Compared with control group, the cholesterol obviously increased in model group with statistical difference (P<0.05). GB at dose of 25 μmol/L for 16 h exposure had the optimum results to decrease the cholesterol level in PC12 cells. However, no significant difference between GB high dose group and simvastatin group was observed (P>0.05). CONCLUSION: The active monomer of ginkgo leaf, GB, may effectively reduce the cholesterol content in PC12 cells with the condition of BBB in vitro.     

Lipoxin A4 reduces lipopolysaccharide-induced expression of cyclooxygenase 2 and prostaglandin E2 in human bronchial epithelial cells

AIM: To explore the effects of lipoxin A₄ on the expression of cyclooxygenase 2 (COX-2) in human bronchial epithelial cells (HBECs). METHODS: HBECs were incubated with various concentrations (0.1, 1 and 10 mg/L) of lipopolysaccharide(LPS) for 9 h, or 1 mg/L LPS for different time (3 h, 6 h and 9 h). The levels of COX-2 mRNA in HBECs and prostaglandin E₂ (PGE₂) in the culture supernatant were measured. In addition, the HBECs were exposed to lipoxin A₄ at concentration of 0, 100 and 400 μmol/L after stimulated with LPS at concentration of 1 mg/L for 9 h, and the supernatant of the culture cells was collected for determining the content of PGE₂ by ELISA. The cells were also harvested, and the mRNA and protein levels of COX-2 were analyzed by RT-PCR and Western blotting, respectively. RESULTS: LPS increased the mRNA expression of COX-2 and production of PGE₂ in a dose and time dependent manners in HBECs. Induction of COX-2 mRNA and protein by LPS were inhibited by lipoxin A₄ in a dose-dependent manner. Lipoxin A₄ also significantly decreased LPS-induced production of PGE₂. CONCLUSION: Lipoxin A₄ down-regulates LPS-induced expression of COX-2 and consequently inhibits the production of PGE₂ in HBECs.