食野习俗与生物链缺失问题研究

探讨“食野习俗”及其引发的生物链缺失问题。“食野”是我国传统饮食文化中需要反思的一个组成部分,民间的一些“食疗”、“食补”的传闻助长了食野习俗,商家的过度宣传,媒体的不当炒作又对食野陋习起着推波助澜的作用。食野习俗引发的生态环境问题主要是生物链缺失,由于害虫的天敌减少,害虫因而更加猖獗;为了确保增产,农民不断增施化学农药,这样又加剧了生态环境恶化,由此形成恶性循环。最后就限制或摒弃食野习俗和加快生物链修复等方面提出几点对策建议。     

薄煤层野青复合顶板的支护技术研究

由于孙庄煤矿野青煤层的灰岩顶板条件各不相同,不同条件的灰岩顶板使用支护方式也会不尽相同,通过观测巷道顶板、断面变形的情况科学采用巷道顶板支护技术,有利于支护技术的完善。将综掘作业方式应用到施工的过程中,可有效减少因为掘进而致使的灰岩顶板破坏,有利于掘进单进、野青薄煤层开拓速度的提高,合理采掘薄煤层可有效缓解矿井产量不足的情况。     

巢式-多重RT-Realtime PCR检测马铃薯Y病毒脉坏死株系的方法

马铃薯Y病毒脉坏死株系（Potato virus Yvein necrosis strain,PVY^n）是马铃薯中一个非常重要的病毒病害。本研究根据PVYn基因组中RNA依赖的RNA聚合酶（RNA dependentRNA polymerase,RDRP）基因序列保守区域,设计合成了两对巢式PCR引物和一条TaqMAN荧光探针,建立了巢式-多重RT-Real-time PCR检测PVY^n的新方法。该方法采用E.Z.N.ATM快速提取植物总RNA,并有机地结合了巢式PCR、多重PCR和探针检测技术。实验结果表明,本方法检测的准确性、灵敏度比巢式PCR、单重Real time PCR等方法高。该方法检测灵敏度可达3 fg/μL植物总RNA。利用四对引物和一条TaqMAN探针对PCR阳性产物进行确认,检测的准确性比其它方法高。     

黄河三角洲湿地(东营)药用植物群落调查

为有效保护黄河三角洲滨海湿地,构建近海岸生态系统修复作用的复合人工林带,应用中药资源调查的方法,对东营市河口区40万亩柽柳林场的药用植物群落进行了综合调查,共调查了16个样地,65个样方.调查范围涉及植物物种及野外分布、群落结构和蕴藏量等.本区植被主要为柽柳-盐地碱蓬群落、盐地碱蓬群落和"柽柳群落";优势植物的蕴藏量为...     

透明颤菌血红蛋白基因克隆及在紫色非硫细菌中的表达

构建了含有透明颤菌血红蛋白基因的可转化大肠杆菌-紫色非硫细菌穿梭质粒(pHSG-MG-vgb),将其转化到紫色非硫细菌(Rhodopseudo palustns),获得了基因工程菌EPB01。经SDS-PAGE和CO示差分光光谱分析证明,重组菌株表达了有活性的透明颤菌血红蛋白,通过低溶解氧诱导后,基因工程菌EPB01的菌体密度较对照菌增加了24%~32%。     

Are Some Forecasters Really Better than Others? A Note*

In this paper, we use bootstrap approach to test the null hypothesis that all forecasters in the U.S. Surveys of Professional Forecasters (SPF) have equal ability. Our bootstrap procedure captures any potential cross-sectional and serial correlation in the forecast errors while preserving the unbalanced nature of the panel data. Once we account for the presence of cross-sectional and serial correlation in the forecast errors while resampling, we find convincing evidence that some individuals really are better than others—this is in sharp contrast to the findings of D'Agostino et al. (2012).     

Exploring household financial strain dynamics

Rising energy and food prices are causing living standards to fall across Europe and straining household budgets. The longer-term outlook for households is unclear as the dynamics of financial strain are not well understood. We address four important research questions on financial strain dynamics by applying a dynamic random coefficients probit model with duration and occurrence dependence to De Nederlandsche Bank (DNB) Household Survey panel data. We find no evidence that households become habituated or sensitised to financial strain over time unlike in studies of responses to stress. Entry into household financial strain is less likely when the household can cope by increasing earnings from work or by borrowing from family and friends but not by the economically inactive entering employment. Our third result is that the persistence of financial strain can be explained by a mutually-enforcing negative cycle through worse health but not through marital conflict or more short-sighted and risk averse decision-making. Finally, we find that neither income or wealth shocks affect financial strain in contrast to other studies. Further research into understanding the experience of financial hardship is warranted in the light of the economic challenges caused by the current cost of living crisis.