非言语学习不良青少年空间关系推理及其影响因素研究

It has reported that individuals with nonverbal learning disabilities (NLD) have deficits in visual-spatial organization and strengths in rote language abilities. At present, there are few studies on higher order cognitive abilities of adolescents with NLD, such as the reasoning about spatial relations. The study sampled three groups: a normal group (a control group, C), a nonverbal learning disabilities group (NLD), and a verbal learning disabilities group (VLD). The aim of this study was to examine spatial and nonspatial relation reasoning abilities in adolescents with NLD under figure and word conditions, and assessed the relative involvement of different working memory components in four types of reasoning tasks: reasoning about figure-spatial, figure-nonspatial, verbal-spatial, and verbal-nonspatial relations. Using the double-tasks methodology, visual, spatial, central-executive, and phonological loads were realized. We tried to find how working memory components impact on adolescents with NLD spatial and nonspatial reasoning. The main results of present research are as follows. (1) The NLD group didn’t differ from normal group on reasoning about figure-nonspatial relations. The NLD group scored lower than the C group in spatial problems. So, adolescents with NLD showed a dissociation between spatial and non-spatial relation reasoning. They scored higher in non-spatial problems than in spatial ones. Adolescents with VLD developed well in reasoning about figure-nonspatial relations, but showed deficits in other three tasks. (2) For each reasoning task, the difficult of four types of reasoning problem had different changing trend. For figure and verbal spatial problems, mental model approach can interpret performance of the four problems well. For verbal nonspatial problems, a logical rule approach can interpret performance of the four problems well. (3) Adolescents with NLD did not differ from adolescents with VLD and normal adolescents in phonological, central-executive, and visual dual tasks. But the NLD group had lower performance than the other two groups in spatial dual task. The results showed a dissociation between visual and spatial working memory in NLD group. The VLD group only experienced deficits in central-executive subsystem. (4) The studies found that spatial reasoning mainly loaded spatial working memory, whist the involvement of spatial resources in nonspatial reasoning was little. Visual working memory mainly involved in reasoning about spatial and figure-nonspatial relations, especially in figure-nonspatial problems, and had few impacts on verbal-nonspatial reasoning. Central executive system was involved in all reasoning tasks. The role of phonological loop in the reasoning tasks required further explored. (5) According to the findings, we concluded that the deficits in spatial working memory resulted in poor spatial reasoning abilities for teenagers with NLD, whist because of the limited central executive capability, teenagers with VLD showed poor reasoning abilities. (6) The three groups can used multiple strategies during the reasoning process. They didn’t differ from each other in reasoning strategies. They all used mental model strategy to solve figure and verbal spatial problems, and used logic rule strategy to solve verbal nonspatial problems.

空间及言语工作记忆任务的情绪效应：来自ERP/ fMRI的证据

In the present study, based on processing efficiency theory, we used the event-related potentials (ERP) and functional magnetic resonance image (fMRI) techniques to explore the underlying neutral mechanism of influences of negative emotion on three subsystems of working memory, phonological loop、 visuospatial sketh pad and the central executive. The modified DSMT (delayed matching-to-sample task) and n-back tasks were adopted and IAPS (International Affective Picture System) pictures were employed to induce the expected emotional state of subjects. The main results and conclusions obtained in the series of experiments are as the following: 1. In DSM tasks, we found P200 and P300 were reduced by negative emotion in both spatial and verbal tasks, however the increased negative slow wave were only observed in spatial tasks, not in verbal tasks. 2. In n-back tasks, the updating function of WM associated P300 was affected by negative emotion only in spatial tasks, not in verbal tasks. Current density analysis revealed strong current density in the fronto-parietal cortex only in the spatial tasks as well. 3. We adopted fMRI-block design and ROIs analysis, and found significant emotion and task effects in spatial WM-associated right superior parietal cortex; only emotion effect in verbal WM-associated Broca’s area; the interaction effect in attention-associated medial prefrontal area and bilateral inferior parietal cortex. These results implied the negative emotion mainly disturbed the spatial WM-related areas, and the attention control system play a key role in the interaction of spatial WM and negative emotion. 4. to further examine the effects of positive、negative and neutral emotion on tasks with different cognitive loads, the selective effect of emotion on the ERP components of spatial WM was only found in 2-back tasks, not in visual searching tasks. So, firstly the positive emotion as well as negative emotion selectively disturbed on spatial WM in light of the attention resource competition mechanism. Secondly, the selective influences based on the different WM systems, not the properties of spatial and verbal information. At last, the manner of the interaction of emotion and cognition is correlated with the cognitive load.

Flow pattern in chandler loop - the artificial thrombus formation

In this paper a hydrodynamic approach is used to analyse carefully the flow field inChandler loop--the artificial thrombus formation. The results obtained show that near thelower meniscus where the thrombus is formed, there is a back flow accompanied with asecondary flow and its mainflow is toward the meniscus, thus providing a favourable condi-tion for corpuscle aggregation. Our finding is valuable for studying the mechanism ofthrombus formation in artificial organ and in vivo.

Phase-sensitive atom localization in a loop Lambda-system

The behaviour of the Lambda-system has been studied theoretically in the context of atom localization. In addition to the probe field and the standing wave driving field, a microwave field is introduced to couple the two lower states, and as a result our Lambda-system forms a closed loop. Therefore phase-sensitive atom localization is expected. Indeed by appropriate choice of the relative phase between three fields, an improvement by a factor of 2 has been found in the detection probability of atoms within the sub-wavelength domain of the standing wave. The effect of other parameters is also investigated.

Trypsin inhibitory loop is an excellent lead structure to design serine protease inhibitors and antimicrobial peptides

The disulfide-bridged hendecapeptide ( CWTKSIPPKPC) loop, derived from an amphibian skin peptide, is found to have strong trypsin inhibitory capability. This loop, called the trypsin inhibitory loop ( TIL), appears to be the smallest serine protease inhib

云南保山猪线粒体DNA D loop区序列初步分析

为了解云南保山猪(Baoshan pig)的遗传多样性及其遗传背景，我们测定了19个个体线粒体DNA Dloop高变区1 1 5 363 - 1 5 801片段序列438帅。检测到1。种单倍型，包括8个多态位点，其中5次T/ C转换、1次G/ A转换、1次G/ C颠换和1次A/ T颠换，其A.T.GX碱基的平均含量分别为35.4%.26.9%.13.2%和24.5 %,A+ T含量(62 .3)明显高于G+ C含量(37 .7 %)。对于保山猪的保种及其持续利用有着重要的理论指导意义。

Genetic diversity and origin of Chinese cattle revealed by mtDNA D-loop sequence variation

To determine the origin and genetic diversity of Chinese cattle, we analyzed the complete mtDNA D-loop sequences of 84 cattle from 14 breeds/populations from southwest and west China, together with the available cattle sequences in GenBank. Our results sh

Dynamics of RNA with A6 bulge loop

In order to understand the behavior of RNAs with large bulges In solution, molecular dynamics was performed on the RNA molecule in water with A6 bulge. The result of simulation showed that nonstacked conformation Is the main conformation in large bulges, and the backbone of large bulge is of great conformational flexibility, but bulges-induced bends are relatively rigid. The fluctuation in bulge has little influence on the bend angle of RNAs.

Statistical correlation between protein secondary structure and messenger RNA stem-loop structure

Anew integrated sequence-structure database, called IADE (Integrated ASTRAL-DSSP-EMBL), incorporating matching mRNA sequence, amino acid sequence, and protein secondary structural data, is constructed. It includes 648 protein domains. Based on the IADE database, we studied the relation between RNA stem-loop frequencies and protein secondary structure. It was found that the alpha-helices and beta-strands on proteins tend to be preferably "coded" by mRNA stem region, while the coils on proteins tend to be preferably "coded" by mRNA loop region. These tendencies are more obvious if we observe the structural words (SWs). An SW is defined by a four-amino-acid-fragment that shows the pronounced secondary structural (alpha-helix or beta-strand) propensity. It is demonstrated that the deduced correlation between protein and mRNA structure can hardly be explained as the stochastic fluctuation effect. (C) 2003 Wiley Periodicals, Inc.

线粒体D-loop序列变异与东方鲀属鱼类系统发育

东方鲀属的红鳍东方鲀(Takifugu rubripes)是后基因组时代的一种重要模式生物。本研究中,利用东方鲀属11种鱼类(18尾)的D-loop基因序列,对东方鲀属鱼类的系统发育关系进行研究。经序列比对排定后,分析中D-loop序列有841个位点,其中395个位点为可变位点,267个位点为系统发育信息位点。分别采用邻接法(NJ)、最大简约法(MP)、最大似然法(ML)和贝叶斯方法构建了分子系统树。研究结果表明:(1)东方鲀属鱼类为一单系类群;(2)由横纹东方鲀(T. oblongus)和铅点东方鲀(T

线粒体DNA d-loop序列变异与鳅鮀亚科鱼类系统发育

对鳅鮀亚科(Gobiobotinae)2个属8个种10个个体线粒体控制区d-loop全序列进行了测定.以(鱼丹)亚科斑马鱼为外类群,对鳅鮀及鲤科(Cyprinidae)一些亚科代表种鱼类进行了系统发育分析.结果显示,鳅鮀鱼类是一个单系类群,与鮈和细鲫有较近的亲缘关系.从系统发育的角度看,鳅鮀亚科应归属于鮈亚科(Gobioninae).研究结果支持鳅鮀亚科分为异鳔鳅鳅属(Xenophyso-gobio)和鳅鮀属(Gobiobtia).