925 resultados para neurocognitive deficits


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用盆栽对冬小麦不同生育阶段进行不同程度水分调亏试验结果表明 :拔节—孕穗期、抽穗—扬花期和灌浆—成熟 3个阶段内 RW上限为 4 0 %、5 0 %、60 %的水分亏缺均引起了产量的极显著下降 ,而且水分亏缺越严重 ,产量降低越大。在 3个生育阶段内进行 RW上限为 4 0 %的水分调亏减产幅度都很大 ,而且 3个生育阶段之间差异不明显 ;进行 5 0 %、60 %水分调亏 ,其减产程度则与生育期有关。灌浆—成熟期的减产程度大于前二个时期 ,这可能与前二个阶段复水后作物的补偿生长有关。不同生育期水分亏缺对冬小麦产量构成因素的影响也不同 ,拔节—扬花期水分亏缺主要减少了穗粒数 ,灌浆—成熟阶段的水分亏缺主要减少了千粒重

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Parkinson's disease is a neurodegenerative disorder of uncertain pathogenesis characterized by a loss of dopaminergic neurons in substantia nigra pars compacta, and can be modeled by the neurotoxin 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP). Oxidative stress may contribute to MPTP- and Parkinson's disease-related neurodegeneration. Fucoidan is a sulfated polysaccharide extracted from brown seaweeds which possesses a wide variety of biological activities including potent antioxidative effects. Here we investigated the effect of fucoidan treatment on locomoter activities of animals, striatal dopamine and its metabolites and survival of nigral dopaminergic neurons in MPTP-induced animal model of Parkinsonism in C57/BL mice in vivo and on the neuronal damage induced by 1-methyl-4-phenylpyridinium (MPP+) in vitro, and to study the possible mechanisms. When administered prior to MPTP, fucoidan reduced behavioral deficits, increased striatal dopamine and its metabolites levels, reduced cell death, and led to a marked increase in tyrosine hydroxylase expression relative to mice treated with MPTP alone. Furthermore, we found that fucoidan inhibited MPTP-induced lipid peroxidation and reduction of antioxidant enzyme activity. In addition, pre-treatment with fucoidan significantly protected against MPP+-induced damage in MN9D cells. Taken together, these findings suggest that fucoidan has protective effect in MPTP-induced neurotoxicity in this model of Parkinson's disease via its antioxidative activity. (C) 2009 Elsevier B.V. All rights reserved.

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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.

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Considerable studies find that developmental dyslexia is associated with deficits in phonological processing skills, especially phonological awareness. In order to explore the nature of phonological awareness deficits in dyslexia, researchers have begun to investigate the role of speech perception. The findings about speech perception abilities in dyslexics are inconsistent. The heterogeneity of dyslexia may be responsible for the inconsistency of findings. Considering the general suggestion that phonological awareness deficits in dyslexia are attributed to categorical perception deficits, it is more direct to examine whether children with phonological awareness difficulties or phonological dyslexia show speech categorization deficits consistently. The present study would investigate whether Chinese children with phonological awareness deficits or phonological dyslexia showed abnormal speech perception. The whole study consisted of two parts. Part I screened children with phonological-awareness deficits from Year 3 kindergartens and examined their abilities of perceiving native category continuum, nonnative category contrasts and non-speech sound series. Part II selected phonological dyslexics from an elementary school as participants, and further explored the relation between phonological deficits and speech perception. The first two experiments of Part II examined separately the abilities to label stimuli in native category continuum and brief stops in different contexts, the last experiment investigated the adaptation effects of different participant groups. The main conclusions are as follows: 1) Children with phonological dyslexia showed categorical perception deficits: they had lower consistency than controls when perceiving stimuli within phonetic categories, especially for the stimuli which were not natural sounds. 2) Children with phonological dyslexia exhibited a general difficulty of perceiving brief segments of stops from different contexts. 3) Children with phonological dyslexia did not show adaptation to repeatedly presented stimuli. Based on the present conclusions and the findings of previous studies, we suggested that the representations of sound stimuli in phonological dyslexics’ brains are different from those in normal children’s; the representations of sound stimuli in dyslexics’ cortical neural networks are more diffuse and inconsistent.

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In recent years, the deficit of inhibition has become an important reason for explaining addiction. Response inhibition resembles the compulsive drug seeking behavior and it is the basement of addiction inhibition deficits. However, there were no enough evidence for the relationship between addiction and response inhibition deficits and the results of the neuro mechanisms studies remains unclear. Few studies has focused on the exploring the heroin users. Among those paradigms for study response inhibition deficits, stop signal is a very suitable model for the representation of compulsive drug seeking, but only a few researches has worked on this paradigm. In this study, we selected about 100 heroin abusers and had behaviour and neuro imaging scannings for investigating the response inhibition deficits. The behaviour researches found: first, the chronic heroin users had longer reaction time than control group and this reaction time were not affected by stop signals in heroin users. Second, heroin users had less waiting time than control group and they were more impulsive but less flexibility. Their erro monitoring and flexibale adjustment ability decreased. Third, the SSRT of heroin users was significantly longer than control group. These results suggested that the inhibition of heroin users were impaired. Further investigation showed that the SSRT of heroin users had positive correlation of four factor scores of ASI and the macro correlation coefficient was factor three of drug use. This correlation suggested that drug use was the main reason of inhibition deficits. fMRI results mainly focused on the ANOVA analysis for group difference. First, there was no intensity difference in M1 and SMA brain areas between the two groups. Second, heroin users had less activation in right dorsalateral prefrontal cortex, right inferior prefrontal cortex and anterior cingulated cortex, while in bilateral striatum and amygdala, heroin users had more activation than control group. The right prefrontal cortex was indentified as the main inhibition brain area. The anterior cingulated cortex has relationship with erro monitoring and amygdale was an important brain area for impulsivity and emotion control. The network of these brain areas was envovled in impulsivity and inhibition and it was suggested the mainly damaged network for heroin users’ disinhibition. We also investigated the gray matter changes of heroin users and found that chonic heroin use made their gray matter density decreased in prefrontal cortex (including bilateral dorsalateral prefrontal cortex, obital frontal cortex, inferior prefrontal cortex) and anterior cingulated cortex. The gray matter density in these brain regions had negative correlation with drug use duration. In conclusion, we indentified the disinhibition of heroin users and its neuro mechanism. Their compulsivity brain areas had more activation than control group and their inhibition brain areas had less activation than normal control. On the other side, the biological mechanism of this activation changes was the gray matter density decrease in these brain areas.

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Schizophrenia is a heritable disorder. However, molecular genetics and related research area have not unmasked the nature and mechanisms of this disorder. Therefore, many researchers begin to explore the pathology mechanism from other approaches. High-risk study is one of the promising approaches. In this study, we mainly focused on facial emotion perception in schizophrenia and their non-psychotic first-degree relatives, and attempted to explore whether facial emotion perception is the potential biological marker of schizophrenia. This dissertation comprises 4 studies. In the first study, we conducted a meta-analysis on behavioral data of facial emotion perception in schizophrenia. Our findings showed that patients demonstrated general deficits in both facial emotion perception and facial processing tasks. In the second study, sixty-nine patients with schizophrenia and 56 of their first-degree relatives (33 parents and 23 siblings), and 92 healthy controls (67 younger and 25 older healthy controls) completed a set of facial emotion perception tasks. The results validated that patients with schizophrenia displayed general deficits in facial emotion perception. Study two also demonstrated that siblings of patients performed equally well compared to the corresponding younger healthy controls in all the facial emotion perception tasks, while the parents of patients behaved significantly worse than the corresponding older healthy controls in the composite index of facial emotion perception tasks. The results suggest that relatives of patients display more severely declining in facial emotion perception with the increasing of age. In the third study, we used an automated voxel-wise technique, activation likelihood estimation (ALE) to provide an objective, quantitative evaluation of facial emotion processing in schizophrenia. Our findings demonstrated a marked under-recruitment of the amygdala, accompanied by a substantial limitation in activation in schizophrenia throughout a ventral temporal-basal ganglia-prefrontal cortex ‘social-brain’ system may be central to the difficulties patients experience when processing facial emotion. In the last study, we did an fMRI study about facial emotion perception in 12 patients with schizophrenia, 12 non-psychotic siblings of patients and 12 healthy controls. The results suggest that siblings of patients demonstrate abnormal activation in a variety of brain areas, including prefrontal gyrus, insula, parahippocampal gyrus and superior temporal gyrus. Taken together, the current findings suggest facial emotion perception may be a potential biological marker of schizophrenia.

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Developmental dyslexia (DD) is a common kind of learning disorder, which affects 5-18% of people. It seems important to explore the deficit in visual magnocellular pathway in Chinese developmental dyslexia, for many researches demonstrated that one of the core deficits of Chinese developmental dyslexia was orthographic deficit which was associated with the deficit in visual magnocellular pathway. Two studies were done to detect the differences among Chinese developmental dyslexics, average readers of the same chronological age (CA controls) and average readers of the same reading level (RL controls) in reaction time, accuracy and visual mismatch negativity (vMMN) elicited by the moving gratings responded by visual magnocellular pathway. There were two grating-conditions which were low contrast/low spatial frequency condition and high contrast/high spatial frequency condition respectively. In ERP study, a modified “cross-modal delayed response” paradigm was used to elicit the vMMN. The results showed that the developmental dyslexics responded slower than CA controls, had more errors than RL controls, and had smaller amplitudes of vMMNs than the two controls in visual magnocellular pathway condition, but not in control condition. That is to say, Chinese developmental dyslexics had deficits in visual magnocellular pathway.

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It is well established that memory functioning deteriorates with advancing age. However, research indicates that the magnitude of age-related memory deficits varies across different types of memory, and broad individual differences can be observed in the rate and timing of memory aging. The general aim of this study was to investigate the selectivity and variability of memory functioning in relation to anxiety. Firstly, memory effectiveness was assessed in episodic memory tasks with reality monitoring and external source monitoring paradigms, semantic memory tasks referred to general knowledge and word fluency, and perceptual priming task reflected in word completion. According to the scores on trait version of STAI, the high-trait and low-trait anxious subjects were screened respectively from young and old participants matched for educational level. Secondly, based on the results of the first part, concurrent primary and secondary tasks with probe technique assessing spare processing capacity were used to explore the relation between memory efficiency and anxiety. The first main findings were that: (a) there were no age-related differences in semantic memory assessed by general knowledge and PRS, whereas age effects were observed in episodic memory and semantic memory assessed by word fluency with stringent time restraints. (b) Furthermore, comparison of age-related deficits in source and item was not related to the presentation ways and encoding effort for source, but was affected by types of source. Specifically, memory was more sensitive to aging than item memory in external source monitoring processes involved in discriminating two external sources (i.e., female vs. male voices), but not in reality monitoring processes in discriminating between internal and external sources (i.e., acting vs. listening). The second main findings were that: (a) Anxiety had no effects on the effectiveness and efficiency of semantic memory in recall of general knowledge and PRS, but impaired those of semantic memory in word fluency. (b) The effects of anxiety on episodic memory were different between the old and the young. Both the effectiveness and the efficiency of episodic memory of the old were affected adversely by anxiety. More importantly, source recall in external source monitoring processes was observed to be more vulnerable to anxiety than item memory. The effectiveness of episodic memory of the young was relatively unrelated to anxiety, while anxiety might have adverse effect on their memory efficiency. These results indicated that: First, the selectivity of age-related memory deficits existed not only between memory systems, but also within episodic memory system. The tendency to forget the source even when the fact was retained in external source monitoring was suggested to be a specific feature of cognitive aging. Second, anxiety had adverse impact on the individual differences in memory aging, and mediated partial age-related differences in episodic memory performance.

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Introduction: Brazil is experiencing a nutritional transition characterized by a reduction in the prevalence of nutritional deficits and an increase in overweight and obesity, not only in adults but also in children and adolescents.Objectives: This study was designed to evaluate the factors associated with overweight and obesity in Brazilian 5-year-old preschoolers.Methods: A cross-sectional study of a cohort of 232 preschoolers born in Diamantina/Minas Gerais, Brazil, was undertaken. the data, including socioeconomic status, anthropometry, diet, previous history of the preschoolers and family history, were collected between July of 2009 and July of 2010. To identify the factors associated with overweight and obesity, a logistic regression and a hierarchical model were undertaken.Results: Overweight and obesity occurred in 17.2% of the preschoolers. After adjusting for mother's obesity, per capita income, protective food intake, weight gain at age 0-4 months and time spent playing, the factors associated with overweight and obesity that reached statistical significance were mother's obesity [OR = 3.12 (95% CI 1.41-6.91), P = 0.01], weight gain of more than 0.85 kg/month in the first four months of life [OR = 2.16 (95% CI 1.01-4.64), P = 0.041 and lower per capita income [OR = 0.32 (95 %CI 0.13-0.79), P = 0.01].Conclusion: the results show that more weight gain during the first four months of life and being born of mothers with obesity increased the odds of overweight/obesity in the preschoolers, while lower per capita income was a protective factor.

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This article is a continuation of a four-piece work describing the condition of soil in what has been broadly defined as central Poznań. This article presents the content of active forms of six chemical elements which tend to be absorbed by plants in biggest quantities. Relations between these chemical elements are discussed and indications are made of how to counteract the negative effects of deficits as well as overdoses of specific chemical elements in the substrate.

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Dissertação apresentada à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Psicologia Jurídica

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Trabalho de Projeto apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Terapêutica da Fala, área de especialização em Linguagem no Adulto

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A biomechanical model of the human oculomotor plant kinematics in 3-D as a function of muscle length changes is presented. It can represent a range of alternative interpretations of the data as a function of one parameter. The model is free from such deficits as singularities and the nesting of axes found in alternative formulations such as the spherical wrist (Paul, l98l). The equations of motion are defined on a quaternion based representation of eye rotations and are compact atnd computationally efficient.

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Irish literature on Acquired Brain Injury (ABI) is very scant and is mainly deficits and/or needs based. The focus is generally on how to manage the short term needs of the younger population with ABI. The starting position of my thesis is that people living long-term with ABI are important participants in developing knowledge about this social phenomenon, living with ABI while accepting that their brain injury does not determine them. Six mature adults with ABI and their six significant others participated in this longitudinal study. Using a narrative approach in interviews, over twenty months, five repeat individual interviews with each of the twelve participants was held. From this I gained an understanding of their lived experiences, their life-world and their experiences of our local public ABI/disability services, systems and discourse. Along with this new empirical data, theoretical developments from occupational therapy, occupational science, sociology, and disability studies were also used within a meta-narrative informed by critical theory and critical realism to develop a synthesis of this study. Social analysis of their narratives co-constructed with me, allowed me generate nuanced insights into tendencies and social processes that impacted and continues to impact on their everyday-everynight living. I discuss in some depth here, the relational attitudinal, structural, occupational and environmental supports, barriers or discrimination that they face(d) in their search for social participation and community inclusion. Personal recognition of the disabled participants by their family, friends and/or local community, was generally enhanced after much suffering, social supports, slow recovery, and with some form of meaningful occupational engagement. This engagement was generally linked with pre-injury interests or habits, while Time itself became both a major aid and a need. The present local ABI discourse seldom includes advocacy and inclusion in everyday/every night local events, yet most participants sought both peer-support or collective recognition, and social/community inclusion to help develop their own counter-discourse to the dominant ABI discourse. This thesis aims to give a broad social explanation on aspects of their social becoming, 'self-sameness' and social participation, and the status of the disabled participants wanting to live 'the slow life'. Tensions and dialectical issues involved in moving from the category of a person in coma, to person with a disability, to being a citizen should not demote the need for special services. While individualized short-term neuro-rehabilitation is necessary, it is not sufficient. Along with the participants, this researcher asks that community health and/or social care planners and service-providers rethink how ABI is understood and represented, and how people with ABI are included in their local communities

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The thesis was prompted by a simple clinical observation. Seriously ill children returning from Barretstown Holiday Camp appeared changed. Barretstown ‘magic’ confuses the issue but indicates real and clinically evident transformations. The project sought to understand the experience and place it in a recognisable framework. The data was collected by interviews, observations as camp Paediatrician, memberships of the Child Advisory Committee and the Association’s criteria assessment team, participation in volunteer training and visits to international camps. The research presents evidence that the concepts of rite of passage, graceful mimesis and salutogenesis clarify operative social processes. The passage stages of separation, transition and reaggregation can be identified. Passage rites reorder personal and social upsets to fresh arrangements that facilitate change. Interviews confirm the reordering impact of achievements in play activities. These are challenging experiences closely guided by their Masters of Ceremonies – the Caras. The Cara/camper relationship is crucial and compatible with Girard’s theory of external mimesis. Visits to four camps confirm an inspirational process in contrast to a reported camp with a predetermined formative influence. Charismatic Caras/Councillors inspire playful mimesis and salutogenic transformations. Health is more than correction of pathogenic deficits and restoration of homeostasis. Salutogenic health promotes heterostasis – a desire for optimal experiences underpinned by a sense of coherence and adequate resources. Some evidence is presented that children have an improved sense of coherence after camp, which enables them to cope better with the demands of ill health. The camps enable sick children to up regulate risk taking towards more heterostatic experiences rather than down regulate their expectations. The heterostatic impulse can explain the disability paradox of good quality of life in the presence of severe disability. The salutogenic power of Barretstown can trump the pathogenic effects of childhood cancer and other serious illnesses.