国内外天然橡胶期现货价格波动关系研究

【目的】近年来,随着重要农产品保障战略的逐步实施,党和国家十分重视天然橡胶产业发展,天然橡胶等战略性农产品的供需形势及价格走势越来越受到社会各界的关注。尤其是新冠肺炎疫情暴发以来,构建国内国际双循环相互促进的新发展格局显得至关重要。天然橡胶作为国内重要的战略物资,期货市场发展日渐成熟,研究其国内外价格波动关系规律也就势在必行。【方法】利用2010年以来商务部对国内外天然橡胶的统计数据,采用单位根检验、格兰杰检验、脉冲响应模型、方差分析等经济学模型方法分析了国内外天然橡胶期现货价格波动规律及内在联系,并对未来天然橡胶供需走势进行了预测。【结果】天然橡胶国内期货价格影响着国内现货价格,也影响着国际期货价格变动,国内期货价格上涨会对国外期货和国内现货价格产生正向影响,但受国际期货价格影响的程度是国内期货价格影响的近10倍;国内期货价格的发现作用较强,价格辐射力越来越大。【结论】基于国内外天然橡胶期现货价格波动的关系,建议出台提升天然橡胶产业竞争力的优化天然橡胶生产保护区精准支持政策、对天然橡胶市场监测预警、强化天然橡胶产业链各环节建设等政策建议。     

物理学发现中灵感的特征与类型

通过对物理学发现的典型事例的分析，探讨了物理学发现中５种灵感特征及９种灵感思维的类型。     

基于读者信息行为规律的信息服务管理策略

论述了网络环境下,高校图书馆读者信息行为规律的变化及共性特征,并进行了实证分析研究。在此基础上,提出了图书馆多样化、多元化、个性化和一站式的信息服务管理策略。     

基于语义Web服务发现模型的农业信息化研究

针对现有多数语义Web服务发现方法应用实施难度大和对终端用户输入信息的完整性依赖度高的问题,提出一种基于简单查询语句的轻量级语义Web服务发现模型。该模型将用户输入的查询语句经过领域本体匹配、基于WordNet同义词典匹配等步骤,自动发现并调用相应的Web服务操作。实验结果表明,采用该服务发现模型能够有效提高服务发现的准确率和召回率,进而可推广应用到基于语义Web服务的农业信息化中。     

紫陀螺菌的形态特征及生长环境初报

本文首次报道了在中国三峡地区首次发现的野生食用蕈菌———紫陀螺菌Gomphuspurpuraceus (Iwade)Yokoyama的形态特征及生长环境     

Mode of Action of Diterpene and Characterization of Related Metabolites from the Soft Coral,Xenia elongata

Chemical and biological investigation of the cultured marine soft coral Xenia elongata led to the isolation of two new diterpenes (2, 3). Their structures were elucidated using a combination of NMR and mass spectrometry. Biological evaluations and assessments were determined using the specific apoptosis induction assay based on genetically engineered mammalian cell line D3 deficient in Bak and Bax and derived from a mouse epithelial cell. The diterpenes induce apoptosis in low micromolar concentrations. The results indicate that the previously isolated compound (1) affects cell in a manner similar to that of HSP90 and HDAC inhibitors and in a manner opposite of PI3 kinase/mTOR inhibitors. Compound (3) inhibits selectively HDAC6 in high micromolar concentrations.     

A Chemoinformatics Approach to the Discovery of Lead-Like Molecules from Marine and Microbial Sources En Route to Antitumor and Antibiotic Drugs

The comprehensive information of small molecules and their biological activities in the PubChem database allows chemoinformatic researchers to access and make use of large-scale biological activity data to improve the precision of drug profiling. A Quantitative Structure–Activity Relationship approach, for classification, was used for the prediction of active/inactive compounds relatively to overall biological activity, antitumor and antibiotic activities using a data set of 1804 compounds from PubChem. Using the best classification models for antibiotic and antitumor activities a data set of marine and microbial natural products from the AntiMarin database were screened—57 and 16 new lead compounds for antibiotic and antitumor drug design were proposed, respectively. All compounds proposed by our approach are classified as non-antibiotic and non-antitumor compounds in the AntiMarin database. Recently several of the lead-like compounds proposed by us were reported as being active in the literature.     

Deployment of wild relatives for genetic improvement in rice (Oryza sativa)

Rice is one of the most important crops in the world. The wild species of rice are expected to have novel beneficial alleles that have been lost from cultivated rice during the process of domestication. Therefore, wild species could be the potential source to induce lost genetic diversity in cultivated rice. Serving as an important reservoir of novel genes/QTLs, wild species, in general, are better adapted to different ecologies and can tolerate many biotic and abiotic stresses. Despite that, only a few wild species are studied and extensive characterization both at the molecular and morphological level is yet to be achieved. Several agronomically important genes/QTLs for improving biotic and abiotic stresses, resistance, productivity and grain quality traits were identified from AA genome donor wild species and were tagged with breeder friendly molecular markers for their transfer to elite genetic backgrounds. The present review provides information on the important wild rice species harbouring genes/QTLs for agriculturally important traits and their successful utilization in rice breeding programmes.     

Performance of shrimp futures markets as price discovery and hedging mechanisms

Abstract

Granger causality tests revealed leading indicators of shrimp futures prices, implying that futures prices do not reflect all available market information and potentially fail to be an exemplary price discovery mechanism. Trading simulations confirmed that the use of some leading indicators allowed profitable arbitrage in shrimp futures trading. Shrimp futures were deficient as a hedging tool, as well. Correlations between futures and wholesale cash prices were often low, and basis risk rivaled price risk. Lack of liquidity is a likely explanation for shrimp futures’ shortcomings as a hedging tool and price discovery mechanism.     

大豆分子育种研究进展

分子育种技术的研究和应用是近十余年来世界大豆生产发展的重要科技动力。2011年,国内外在大豆分子育种相关领域取得了新的进展。在分子标记开发与辅助育种方面,发掘出与产量、发育、品质、抗病和抗逆等性状相关的新的分子标记或QTL;在新基因挖掘方面,克隆了与光周期反应、共生固氮、品质及抗逆性相关的基因,并分析了其功能。在大豆转基因育种方面,遗传转化体系的优化取得了新的进展,转化效率有所提高,同时对一些功能基因(包括来自其它物种的一些基因)进行了功能评价和育种利用价值评估。转基因大豆继续保持良好的发展势头,并且出现一些新的发展方向。该文对这些研究进展进行了综述,并对今后的发展趋势进行了展望。