Effects of cerebral lateral,ventricular infusions of phloridzin on feeding and body weight in Gallus domesticus (L.)

Summary Contrary to earlier findings in rats, cerebral lateral ventricular infusions of 1×10^–3 M or 2×10^–3 M solutions of phloridzin at a rate of 2.5 l/min for 90 min had no significant stimulating effects on food intake and weight gain in hens and cocks. These different responses to intraventricular phloridzin might reflect a difference of sensitivity to the inhibitory action of phloridzin on glucose transport in cerebral cells or certain peculiarities of mechanisms controlling food intake in chickens.     

Effects of elevation on litter-size variation among lizard populations in the Sceloporus grammicus complex (Phrynosomatidae) in Mexico

We examined the effect of elevation on litter-size variation in viviparous lizards of the Sceloporus grammicus complex in 10 states of Mexico. Female snout–vent length (SVL) decreased with increasing elevation, and absolute litter size based on embryos also tended to de crease with increasing elevation. However, after controlling for variation in female body size, we found that litter sizes tended to be relatively larger at higher elevation. Elevation therefore appears to influence litter size in these lizards; however, relatively little of the variation is explained by elevation; thus, other factors are likely making substantial contributions to the observed litter-size variation. The S. grammicus complex appears to be a good model system for examining the underlying causes of geographic and elevational variation in lizard life histories. Examinamos el efecto del altitud en la variación del tamaño de camada de las lagartijas vivíparas del complejo Sceloporus grammicus en 10 estados de México. La LHC de las hembras disminuyó con la altitud, y el tamaño absoluto de camada, calculado con base en el número de embriones, también tendió a disminuir. No obstante, después de controlar la variación en el tamaño corporal de las hembras, encontramos que los tamaños de camada tendieron a ser relativamente más grandes en altitudes mayores. La altitud, por tanto, parece influir en el tamaño de camada de estas lagartijas; sin embargo, la altitud explica relativamente poco de la variación, por lo que, es probable que otros factores contribuyan substancialmente a la variación observada en el tamaño de camada. El complejo S. grammicus parece ser un buen sistema para estudiar las causas fundamentales de la variación geográfica y altitudinal en la historia de vida de las lagartijas.     

投资学专业实验教学改革探讨

实验教学对于投资学专业课程的学习具有重要的意义。针对投资学专业实验教学过程中存在师资队伍不足、实验室建设滞后、实验课程开设过少等问题,提出从增加投入改善实验教学的软硬件环境、加强实验教学师资队伍建设、增加实验教学的比重、将实验教学和实践教学相结合、开放实验室等方面对投资学专业实验教学进行改革。     

高校科技保密与国家安全利益

高校在科学技术研究的活动中,已成为国家主力.科技保密已成为国家安全和国家利益的重要方面.本文在对科技保密重要性和必要性认识的基础上,分析了高校科技保密中存在的问题,提出搞好高校科技保密工作的相应对策.     

快速分析香料槟榔片的挥发性组分

采用顶空固相微萃取气质联用(HS-SPME-GC/MS)法分析检测香料槟榔片的挥发性香味组分,探讨萃取时间和萃取温度对所鉴定出的化合物数量及其质量分数的影响,确定固相微萃取的优化条件为:萃取时间30 min,萃取温度60℃。此时槟榔色谱共分离得到35种化合物,可鉴别出29种物质,其主要组分是反式茴香醚(w=25.573%)、己酸(w=17.227%)、肉桂醛(w=11.658%)、4-甲氧基安息香醛(w=4.513%)、十二烷酸(w=4.463%)和己醛(w=3.459%)等。     

The novel Cer-like protein Caronte mediates the establishment of embryonic left-right asymmetry.

In the chick embryo, left-right asymmetric patterns of gene expression in the lateral plate mesoderm are initiated by signals located in and around Hensen's node. Here we show that Caronte (Car), a secreted protein encoded by a member of the Cerberus/Dan gene family, mediates the Sonic hedgehog (Shh)-dependent induction of left-specific genes in the lateral plate mesoderm. Car is induced by Shh and repressed by fibroblast growth factor-8 (FGF-8). Car activates the expression of Nodal by antagonizing a repressive activity of bone morphogenic proteins (BMPs). Our results define a complex network of antagonistic molecular interactions between Activin, FGF-8, Lefty-1, Nodal, BMPs and Car that cooperate to control left-right asymmetry in the chick embryo.     

经济可持续发展与平顶山市科技发展战略

本文论述了经济可持续发展与科技发展的关系，认为平顶山市科技发展战略的模式包括优势技术战略和适用技术战略两个部分。     

对大学生学习武术动机的研究

本文主要分析了大学生在武术课教学过程中学习动机的类型和学习动机对学习成绩及身体素质的影响．研究表明，具有问接远景性学习动机的学生比具有直接近景性学习动机的学生的学习成绩和身体素质有明显的提高．所以，学习动机对学生学习成绩和身体素质的提高起着重要的作用．     

氟离子选择电极法测啤酒中的氟

本文采用氟离子电极法测定啤酒中的氟 ,测量溶液的酸度为PH5— 6,用总离子强度调节缓冲液 ,消除干扰离子及酸度的影响 ,方法回收率 96.1 2 %～ 99.2 4 % ,线性范围为 1 0 - 1 mol/L～ 5× 1 0 - 7mol/L ,最低检出浓度 0 .0 1 μg/ml,本法操作简单、快速 ,适合作常规测定 .     

《河南植物志》虎耳草科补遗

报道了《河南植物志》中未记录的虎耳草科植物9种5变种(均采有标本)。