区域旅游资源的整体性与旅游资源开发 --以重庆市巴南区东温泉景区为例

从旅游资源的整体性出发探讨区域旅游资源开发的基本原则和建设内容,并以重庆市巴南区东温泉景区为例,实证分析"区域整体"之效应.认为在原有的"区域美"基础上创造新型市场条件下的"区域美",将促进区域整体吸引功能形成或得到增强,并具有持久性.     

等价电子组态nlN光谱项的推求法

从等价电子组态的"自旋因式化"出发,导出了nsN～nhN组态的Lα、Lβ取值规则,给出了推求等价电子组态光谱项的简易方法.     

贵州岩溶山区旱地灌溉方式研究

贵州借助前人、同仁和本课题研究工作 ,对旱地灌溉方式问题进行几种不同的研究 ,向社会公诸一个解决贵州岩溶山区旱地灌溉的一种新思维方式 ,并提供旱地灌溉的一种最佳模式。即 :喷灌 +雨养模式 ,以此推荐一个 2 1世纪岩溶山区旱地农业产业化的基本模式 ,为推动旱地高效节水思路尽快转化为生产力服务。     

A natural allele of Nxf1 suppresses retrovirus insertional mutations

Endogenous retroviruses have shaped the evolution of mammalian genomes. Host genes that control the effects of retrovirus insertions are therefore of great interest. The modifier-of-vibrator-1 locus (Mvb1) controls levels of correctly processed mRNA from genes mutated by endogenous retrovirus insertions into introns, including the Pitpn(vb) tremor mutation and the Eya1(BOR) model of human branchiootorenal syndrome. Positional complementation cloning identifies Mvb1 as the nuclear export factor Nxf1, providing an unexpected link between the mRNA export receptor and pre-mRNA processing. Population structure of the suppressive allele in wild Mus musculus castaneus suggests selective advantage. A congenic Mvb1(CAST) allele is a useful tool for modifying gene expression from existing mutations and could be used to manipulate engineered mutations containing retroviral elements.     

Dysregulation of TGF-beta activation contributes to pathogenesis in Marfan syndrome

Marfan syndrome is an autosomal dominant disorder of connective tissue caused by mutations in fibrillin-1 (encoded by FBN1 in humans and Fbn1 in mice), a matrix component of extracellular microfibrils. A distinct subgroup of individuals with Marfan syndrome have distal airspace enlargement, historically described as emphysema, which frequently results in spontaneous lung rupture (pneumothorax; refs. 1-3). To investigate the pathogenesis of genetically imposed emphysema, we analyzed the lung phenotype of mice deficient in fibrillin-1, an accepted model of Marfan syndrome. Lung abnormalities are evident in the immediate postnatal period and manifest as a developmental impairment of distal alveolar septation. Aged mice deficient in fibrillin-1 develop destructive emphysema consistent with the view that early developmental perturbations can predispose to late-onset, seemingly acquired phenotypes. We show that mice deficient in fibrillin-1 have marked dysregulation of transforming growth factor-beta (TGF-beta) activation and signaling, resulting in apoptosis in the developing lung. Perinatal antagonism of TGF-beta attenuates apoptosis and rescues alveolar septation in vivo. These data indicate that matrix sequestration of cytokines is crucial to their regulated activation and signaling and that perturbation of this function can contribute to the pathogenesis of disease.     

实时数据通讯的方法及应用

介绍了在Windows98环境下,通过Modem和公用电话网(PSTN),利用设置好的"拨号网络",实现PC机系统之间的实时数据传输的方法。讨论了运用VB语言,调用WindowsAPI所提供的远程访问函数,设计了一个专用于"拨号网络"通讯的类,并详细介绍了该类的功能和用法。     

时滞多变量时变系统的最优控制混合仿真研究

应用最优控制理论的极小值原理和参数优化理论 ,叙述了具有常数时滞的多变量时变系统的最优控制算法 ,基于该算法 ,提出了这类系统的数模混合仿真方法和实践方法。混合结果表明 :提出的算法是收敛的 ,且收敛速度优于全数字仿真结果。