A developmental approach to understanding Fragile X syndrome in females

The psychological phenotype of females with fragile X syndrome (FraX) is discussed, focusing primarily on empirical findings over the past decade and on studies of probands with the full mutation (FM). A developmental approach is used to help characterize specific patterns of cognitive, neuropsychological, social, emotional, and behavioral functioning across the lifespan of females with FraX. Approximately half of females with the syndrome present with cognitive abilities that fall in the borderline to mentally retarded range, and the remaining females with average intellectual functioning may experience relative deficits in math achievement and problems with attention and executive functioning. Reports of socio-emotional functioning are somewhat inconsistent, due in part, perhaps, to methodological differences in study design. To date, much of what we understand about the psychological phenotype of FraX is based on cross-sectional studies of girls and women with the disorder. Symptoms associated with shyness, and social anxiety and avoidance have been reported in some school-age, adolescent, and adult females with FraX. Only recently have efforts begun to identify the developmental trajectory of FraX in infants and toddlers. There is a void of information specific to these developmental periods. Identifying key deficits in cognitive and socio-emotional functioning has important implications for early detection and intervention for girls with FraX. Directions for future research are discussed.     

Cerebral growth in Fragile X syndrome: review and comparison with Down syndrome

Neuroimaging studies have shown selective changes in brain size in Fragile X syndrome (FraX), which include reductions in the posterior cerebellar vermis, age-dependent increases in hippocampal volume, and enlarged caudate nucleus and thalamus. Contrasting with these limbic and subcortical anomalies, much less is known about the neocortex in FraX. The present study attempted to examine cerebral and lobar-level volumetric changes in young males with FraX (2-7 years), by comparing groups of subjects with full mutation (FM) and mosaicism (Mos) with both age-matched controls and subjects with developmental language delay (DLD) and Down syndrome (DS). For this purpose, we used high resolution (i.e, SPGR) MRI scans and semi-automated methods for segmenting (tissue class) and parcellating (i.e., Talairach) the brain. In agreement with previous studies, we found no changes in overall brain or cerebrum size in FraX. Nevertheless, boys with FM FraX had relative reductions in temporal lobe volume (primarily gray matter) and relative preservation/enlargement of parietal white matter volume. While temporal lobe reductions were not specific, since they were also observed in DLD and DS subjects, parietal preservation/enlargement was only seen in FraX. The relevance of these preliminary findings was emphasized by comparisons between FraX groups, which revealed more marked changes in FM FraX than in Mos FraX (i.e., gene dosage). While cross-sectional analyses revealed marked age-dependent decreases in DS, a group showing marked global and lobar volumetric reductions, there were no changes over time in FraX. These neuroimaging data are discussed in the context of FraX neurobiology and other developmental disorders.     

Influence of stimulants on electrodermal studies in Fragile X syndrome

Attention Deficit Hyperactivity Disorder (ADHD) is seen in the majority of children with Fragile X Syndrome (FraX). Previous work has documented an enhanced sweat response to stimuli in children with FraX compared to controls utilizing electrodermal response (EDR) measures. The present study assesses the EDRs both on and off stimulants in 19 children with ADHD and FraX compared to 17 age- and IQ-matched control patients with ADHD and developmental delays. Although the baseline EDRs were comparable between FraX patients and controls, the patients with FraX had a significant decrease in EDR amplitude and number of peaks when treated with stimulants compared to controls. This suggests that patients with FraX are more responsive to the enhancement of inhibitory systems that occur with stimulant use for ADHD. The use of a quantifiable measure, such as EDR, is recommended in future studies of treatment efficacy.     

Effects of Fragile X syndrome and an FMR1 knockout mouse model on forebrain neuronal cell biology

The neurological deficits exhibited by patients with Fragile X syndrome (FraX) have been attributed to the absence of the Fragile X Mental Retardation Protein (FMRP), the product of the FMR1 gene, which is nonfunctional in these individuals. While a great deal has been learned about FraX using non-invasive techniques and autopsy tissue from humans, the limited availability of subjects and specimens severely restricts the rate at which such data can be collected and the types of experimental questions posed. In view of these limitations, a transgenic mouse model of FraX has been constructed in which the FMR1 gene is selectively knocked out (KO) [Bakker et al. (1994) Cell 78:23-33]. These mice show molecular, morphological, and behavioral alterations consistent with phenotypes observed in FraX patients, making them good models to study the absence of FMRP expression.     

Molecular phenotype of Fragile X syndrome: FMRP,FXRPs, and protein targets

Fragile X syndrome (FraX) is one of the most prevalent genetic causes of mental retardation. FraX is associated with an unstable expansion of a polymorphism within the 5' untranslated region of the FMR1 gene. The main consequence of this mutation is a reduction in the levels of the gene product (FMRP). FMRP is an RNA-binding protein with multiple spliced variants (isoforms) and high levels of expression in a variety of tissues, including neurons. In the latter cells, it is localized not only to the perikaryon but also to dendrites and dendritic spines. FMRP belongs to a family of proteins that includes the Fragile X Related Proteins or FXRPs. FXRPs share high homology in their functional domains with FMRP, and also associate with mRNA and components of the protein synthesis apparatus. However, FXRPs do not have the same temporo-spatial pattern of distribution (and other properties) of FMRP. Immunochemical assays have confirmed that a functionally uncompensated FMRP deficit is the essence of the FraX molecular phenotype. Here, we report our preliminary study on FXRPs levels in leukocytes from FraX males. By immunoblotting, we found that a marked reduction in FMRP levels is associated with a modest increase in FXR1P and no changes in FXR2P levels. The consequences of this reduced FMRP expression on protein synthesis, in other words, the identification of FMRP targets, can be studied by different molecular approaches including protein interaction and proteomics methods. By two-dimensional gel electrophoresis, we showed that in FraX leukocytes there is a defect in acetylation that involves prominently the regulatory protein annexin-1. Extension of current studies of the molecular phenotype to more brain-relevant tissue samples, a wider range of proteomics-based methods, and correlative analyses of FMRP homologues and FMRP targets with multiple behavioral measures, will greatly expand our understanding of FraX pathogenesis and it will help to develop and monitor new therapeutic strategies.     

Instrumented toys for assessing spatial cognition in infants

This paper describes an interdisciplinary approach to the assessment on infants’ behavior, with a focus on the technology. The goal is an objective, quantitative analysis of concurrent maturation of sensory, motor and cognitive abilities in young children, in relation to the achievement of developmental milestones. An instrumented block-box toy specifically developed to assess the ability to insert objects into holes is presented. The functional specifications are derived from experimental protocols devised by neuroscientists to assess spatial cognition skills. Technological choices are emphasized with respect to ecological requirements. An ad hoc calibration procedure is also presented which is suitable to unstructured environments. Finally, preliminary tests carried out at a local day-care with 12–24 months old infants are presented which prove the in-field usability of the proposed technology.     

基于VB的单片机C语言延时程序各参数计算系统

基于C语言的单片机程序开发已经成为开发主流。而一些硬件系统需要使用非常精确的定时(例如:使用单片机驱动DS18B20时,其允许的误差为十几微秒,否则该器件便不可使用)。本文在详细分析汇编语言延时程序和C语言延时程序的基础上,得出了C语言延时程序延时时间计算公式。由于公式中包含四个参数,而通过人工确定四个参数,往往效率低下。因此,本文开发了基于VB的单片机C语言延时程序各参数自动计算系统。     

Fuzzy logic method for motor quality types on current waveforms

Fuzzy logic theory is widely adopted in various fields, such as speech recognition, image retrieval and pattern recognition. This study proposes a fuzzy logic approach to analyze current waveform for determining the motor’s quality types. Proper qualitative features of motor’s current waveforms are selected. Based on selected qualitative features, motor’s quality types are determined by using the fuzzy logic method. The accuracy of error rate is 7.377% (0.294%) for wrong judgment on defect (good) motor to be determined as good (defect). The right rate is 92.622% (99.705%) for right judgment on defect (good) motor to be determined as defect (good).     

Fragile X syndrome,the Fragile X related proteins,and animal models

The Fragile X syndrome (FraX), which is characterized among other physical and neurologic impairments by mental retardation, is caused by the absence of the product of the FMR1 gene. The Fragile X Mental Retardation Protein (FMRP) is a member of a novel family of RNA-binding proteins. The latter includes two other proteins highly homologous with FMRP: the fragile X related proteins 1 and 2 (FXRP1 and FXRP2). Characterization of FXRPs, including their interaction with FMRP, will provide critical information about the mechanisms of action of FMRP and the role of this group of proteins in FMRP-deficient conditions such as FraX. Genetic manipulations of FMRP and the FXRPs should also provide valuable tools for investigating pathophysiology and gene therapies in FraX. The present review summarizes the strategies used for identifying the FXRPs, their chromosomal localization, molecular structure, and tissue distribution. It also reviews interactions between different members of this family of RNA-binding proteins. Animal models, both knockout and transgenic, of FMRP and the FXRPs are discussed. Phenotypic features of the FMR1 knockout mouse, the FMR1 transgenic rescue mouse, and other novel strategies for manipulating and delivering FMRP and FXRPs to the brain and other tissues are described.     

基于语音识别及自然语言处理对话流的人机智能交互方法研究

提出了基于语音识别及自然语言处理的人机对话智能交互方法.分析了人工智能技术以及语音交互在电力系统中的应用和发展趋势.通过自然语言处理技术和基于具体应用语境的自然语言处理技术,提出人机智能语音交互的关键和重点.建立基于语音识别的人机交互模型,提出梯度提升、支持向量机和k最近邻等关键性算法,并搭建人机交互模型架构.提出自动语音识别算法,并说明语言模型和声学模型的具体交互原理.     

Fault diagnosis and protection of motors in coal shearer

Symmetrical components method is employed in analysis of the characteristic motor faults.Motor protection method is put forward based on detecting positive sequence,negative sequence and zero sequence current.And problems of lack of motor overload capacity in existing mining motor protection system,impact of dynamic current on stage and definite-time delay operation and inaccuracy of criterion phase failure protection are analyzed.The unbalanced faults protection and inverse-time overload protection,which can make protection time change with the current movement,are proposed.The above problems can be solved,and the reliability and intelligent of coal shearer are improved.     

纯电动汽车驱动电机选型方法研究与计算界面设计

驱动电机的正确选型对纯电动汽车整车动力性能的好坏有很大的影响,然而电机选型过程中间涉及到许多参数的输入与计算,为保证电机选型计算过程中参数输入正确,从而确保开发车型的动力性能满足目标要求.论文首先提出了一种驱动电机选型计算方法,然后基于Matlab/Gui设计开发了纯电动汽车驱动电机选型计算界面,通过开发车型的动力性能试验证明,论文提出的驱动电机选型计算方法及界面可以满足选型要求.     

电机产品研发的“蓝海战略”

通过当前国际形势及世界各国宏观政策上凸现出的新的社会发展态势,分析其对电机行业发展方向及产品市场结构未来趋势走向的影响,结合先进的"蓝海战略"理念,提出了几个符合我国电机生产制造企业自身发展的产品研发方向。并对现今广为流行的先进的"蓝海战略"理念进行了简要介绍。     

基于FIR优化滤波的旋转高频信号注入法及其应用

针对传统旋转高频信号注入法中信号处理精度低、延时时间长及过程复杂等缺陷,提出一种基于有限冲激响应(finite impulse response,FIR)优化滤波的改进旋转高频信号注入法.该方法采用等纹波最佳逼近FIR滤波器提取高频电流信号,实现高频电流信号提取误差最小.通过对高频电流作外差处理,提取转子位置误差信号,省去旋转高频信号注入法中的同步轴系滤波单元,降低系统的复杂性.通过线性相位补偿,实现转子速度与位置估计最小延迟.构建无轴承永磁同步电机无速度传感器矢量控制平台,验证算法的有效性.仿真实验结果表明:通过离线优化设计FIR滤波器及线性相位补偿,该方法在全速范围内能够准确估计转子的位置与速度,与卡尔曼滤波相比,其估计精度更高,鲁棒性更强.     

基于STC单片机的温控教学设备的设计

针对目前单片机教学设备的现状,介绍一种基于微控制器(STC12C5A60S2单片机)为控制核心的教学设备的开发。采用STC12C5A60S2单片机、按键、液晶显示器和温度传感器等完成系统的硬件设计;以KeiluVision4为软件开发环境,采用c语言完成系统的程序设计,控制单片机的温度采集电路获得当前温度值,将当前温度值和温度阈值比较,再经过温度控制电路控制温度。经实际运行,该系统实现了通过按键对温度阈值进行设定,LCD显示当前温度值,并能通过温度采集形成温度控制。     

摩托车车架强度分析系统的研究与开发

在总结摩托车车架强度有限元分析的基础上,应用Visual Basic 6.0和ANSYS分析软件二次开发工具APDL(ANSYS Parametric Design Language)开发出摩托车车架强度分析系统.系统主要包括模态分析、静强度分析、瞬态分析和疲劳强度分析四个模块.用此系统对一种摩托车车架进行实例分析计算,说明该系统满足工程实用的需要.     

自然语言理解在智能人机接口方面的应用

本文结合机械工程中广泛应用的自动化立体仓库及车间物流系统,着眼于操作人员以自然语言方式与计算机在限定语言范围中交互的研究方向,尝试着形成一种基于受限语言环境的自然语言理解方法;针对机械工程的生产物流作业,初步形成了基于自然语言的智能人机接口系统。该系统接收口语指令、将语音转化为文本、理解指令、最后按照指令的意义形成针对应用背景的三维动画演示系统的命令函数。     

语言管理网络与语音室建设

教育发展的现代化，对教学手段的现代化提出了更高的要求，就语言管理网络，及语音室建设、软件开发、管理模式进行研究旨在更好地为教学服务提出必要的保障。     

三相异步电机机械特性测试系统研究

针对高校电机教学实验中三相异步电机机械特性不稳定区不易测试的难点,对转速基于闭环控制的三相异步电机特性测试系统进行新的设计。该设计运用模糊控制算法,来实现实验台转矩的数字化控制,从而完成感应电机特性不稳定区的人工智能化测试。实验表明,新测试系统符合异步电机实验要求,并为全新智能化电机测试平台的开发提供依据。     

简单语音识别系统的设计与开发

提出一种基于矢量化VQ语音识别方法，在VC＋＋环境下模拟实现一个简单的小词汇量，孤立词语音识别系统，此系统有广阔的应用前景。