基于VAR模型的农村居民消费结构演进与经济增长关系分析

通过构造一个由消费结构、第二产业结构、第三产业结构和GDP四个变量组成的VAR模型,对中国农村居民的消费结构与经济增长相互作用的关系及其动态特征进行了实证研究.通过设定的模型、格兰杰因果检验、预测方差分解和协整检验,发现经济增长会影响农村居民消费结构演变,而经济增长对第二产业结构的影响存在双向因果关系.     

甘蔗与抗旱性相关差异蛋白质组分析

采用桶栽方式,对抗旱性强的F172和抗旱性弱的YL6甘蔗品种在苗期进行重度干旱胁迫处理后,应用蛋白质双向电泳技术进行差异蛋白质分析,分别找出差异显著的28和20个差异蛋白点,其中部分呈现上调表达,部分呈现下调表达,还有部分新增的蛋白点,因品种抗性不同而表现各异,F172叶片中的差异蛋白主要表现为上调表达,而YL6中大多表现为下调表达。在重度干旱胁迫下,抗旱性不同的甘蔗品种蛋白质丰度变化有显著差异。采用MALDI-TOF-TOF/MS鉴定所获得的差异蛋白,从YL6、F172中分别鉴定出18、14个蛋白的氨基酸序列,对所鉴定的蛋白质根据功能分为8类。YL6中参与自由基清除的2个,参与光合作用的6个,参与细胞生长和分裂的1个,参与基础代谢的6个,参与防卫反应的2个,未知功能蛋白1个。F172中参与自由基清除的1个,参与光合作用的2个,参与细胞生长和分裂的2个,参与基础代谢的4个,参与信号转导的2个,参与蛋白加工的1个,未知功能蛋白2个,其中22 k D干旱诱导蛋白的丰度明显提高,而在YL6中则检测不到此蛋白。这说明在干旱胁迫下抗旱性不同的甘蔗品种在蛋白质组成上有很大差异,推测这是不同甘蔗品种间抗旱性差异的重要分子基础。     

Husbandry Factors and the Resumption of Luteal Activity in Open and Zero‐Grazed Dairy Cows in Urban and Peri‐Urban Kampala,Uganda

The study investigated the influence of selected husbandry factors on interval to resumption of post‐partum cyclicity among dairy cows in urban and peri‐urban Kampala. A prospective study of 85 day post‐partum period of 59 dairy cows in open (n = 38) and zero grazing (n = 21) systems was conducted on 24 farms. Cows of parity 1–6 were recruited starting 15–30 days post‐partum. Progesterone (P4) content in milk taken at 10–12 day intervals was analysed using ELISA. The cow P4 profiles were classified into ‘normal’ (< 56 days), ‘delayed’ (> 56 days), ‘ceased’ or ‘prolonged’ (if started < 56 days but with abnormal P4 displays) resumption of luteal activity and tested for association with husbandry and cow factors. Of the 59 cows, luteal activity in 81.4% resumed normally and in 18.6%, delayed. Only 23.7% maintained regular luteal activity, while the others had ceased (10.2%), prolonged (37.3%) or unclear luteal activity (20.3%). There were no differences between open and zero‐grazed cows. Milk production was higher (p < 0.05) in zero than open grazing, in urban than peri‐urban and in cows fed on brew waste (p < 0.001) compared with mill products and banana peels. Results suggest that luteal activity resumes normally in a majority of cows, although only a minority experienced continued normal cyclicity once ovulation had occurred, in the two farming systems irrespective of feed supplements or water, and that supplementing with brew waste is beneficial for milk production.     

The Current State of Solar Modeling

Data from the Global Oscillation Network Group (GONG) project and other helioseismic experiments provide a test for models of stellar interiors and for the thermodynamic and radiative properties, on which the models depend, of matter under the extreme conditions found in the sun. Current models are in agreement with the helioseismic inferences, which suggests, for example, that the disagreement between the predicted and observed fluxes of neutrinos from the sun is not caused by errors in the models. However, the GONG data reveal subtle errors in the models, such as an excess in sound speed just beneath the convection zone. These discrepancies indicate effects that have so far not been correctly accounted for; for example, it is plausible that the sound-speed differences reflect weak mixing in stellar interiors, of potential importance to the overall evolution of stars and ultimately to estimates of the age of the galaxy based on stellar evolution calculations.     

Doublecortin-immunoreactive neuronal precursors in the dentate gyrus of spontaneously hypertensive rats at various age stages: comparison with Sprague-Dawley rats

Spontaneously hypertensive rats (SHRs) are widely accepted in medical research because this model has been used for studies in neurodegenerative diseases such as vascular dementia and stroke. In the present study, we observed newly generated neuronal precursors using doublecortin (DCX, a marker of neural proliferation and differentiation) in the subgranular zone of the dentate gyrus in SHRs compared to Sprague-Dawley rats (SDRs) at various age stages. DCX immunoreactivity, immunoreactive cell numbers and its protein level in the dentate gyrus of the SHRs were higher than those in the SDRs at postnatal month 1 (PM 1). At PM 8, DCX immunoreactivity, immunoreactive cell numbers and protein levels in both groups were markedly decreased compared to those at PM 1; however, they were higher than those in the SDRs. They were decreased in the both groups with age: DCX immunoreactive cells in the SDRs were few at PM 12. Our results indicate that newly generated neuronal precursors are more abundant in SHRs than in SDRs during their life.     

Formation of molecular chlorine from the photolysis of ozone and aqueous sea-salt particles

Halogen atoms from the reactions of sea-salt particles may play a significant role in the marine boundary layer. Reactions of sodium chloride, the major component of sea-salt particles, with nitrogen oxides generate chlorine atom precursors. However, recent studies suggest there is an additional source of chlorine in the marine troposphere. This study shows that molecular chlorine is generated from the photolysis of ozone in the presence of sea-salt particles above their deliquescence point; this process may also occur in the ocean surface layer. Given the global distribution of ozone, this process may provide a global source of chlorine.     

羊驼皮肤结构基因（原）胶原的表达特点

为了揭示羊驼皮肤胶原蛋白（Collagen）在皮肤结构发生中的分子机制,本研究通过构建羊驼皮肤cD—NA文库并进行大规模测序分析,结果表明：在羊驼皮肤内发现只有纤维类胶原表达,即typeⅠ,typeⅢ,typeⅤ collagen,其中typeⅠ表达最高,typeⅢ和typeⅤ表达低;然而,在羊驼皮肤内未发现各类collagen相对应的原胶原（procollagen）,其成员procollagentype Ⅰ,typeⅢ,typeⅣ,typeⅥ,typeⅦ,typeⅩⅧ在表达,且typeⅠ远远高于其他家族成员的表达,由此推断collagen和procollagentypeⅠ在羊驼皮肤结构发生中起主要作用,羊驼皮肤内的蛋白水解机制可能使procollagen产生不同类型的collagen。     

真空袋装储藏对荞麦品质影响的试验研究

本文针对荞麦在收获后到食用时品质下降过快的问题，在理论分析的基础上，采用真空袋装方法对荞麦米就储藏期间的品质保持问题进行了研究。试验结果表明：真空袋装能有效地抑制荞麦米储藏期间游离脂肪酸浓度的增长。真空度保持在80Kpa以上时，其游离脂肪酸浓度下降为同期常规储藏的42％左右：在荞麦米的色泽保持方面，避光条件下，真空袋装能很好地保持荞麦米原有色泽，但在光照条件下，它的护绿效果却很不明显，只略好于常规储藏。     

Impact of lower atmospheric carbon dioxide on tropical mountain ecosystems

Carbon-isotope values of bulk organic matter from high-altitude lakes on Mount Kenya and Mount Elgon, East Africa, were 10 to 14 per mil higher during glacial times than they are today. Compound-specific isotope analyses of leaf waxes and algal biomarkers show that organisms possessing CO2-concentrating mechanisms, including C4 grasses and freshwater algae, were primarily responsible for this large increase. Carbon limitation due to lower ambient CO2 partial pressures had a significant impact on the distribution of forest on the tropical mountains, in addition to climate. Hence, tree line elevation should not be used to infer palaeotemperatures.