250 research outputs found

    Contribution of discourse and morphosyntax skills to reading comprehension in Chinese dyslexic and typically developing children

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    This study aimed at identifying important skills for reading comprehension in Chinese dyslexic children and their typically developing counterparts matched on age (CA controls) or reading level (RL controls). The children were assessed on Chinese reading comprehension, cognitive, and reading-related skills. Results showed that the dyslexic children performed significantly less well than the CA controls but similarly to RL controls in most measures. Results of multiple regression analyses showed that word-level reading-related skills like oral vocabulary and word semantics were found to be strong predictors of reading comprehension among typically developing junior graders and dyslexic readers of senior grades, whereas morphosyntax, a text-level skill, was most predictive for typically developing senior graders. It was concluded that discourse and morphosyntax skills are particularly important for reading comprehension in the non-inflectional and topic-prominent Chinese system. © 2010 The Author(s).published_or_final_versionSpringer Open Choice, 21 Feb 201

    Syntactic skills in sentence reading comprehension among Chinese elementary school children

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    The present study examined the role of syntactic skills for reading comprehension in Chinese. Two hundred and seventy-two Chinese children were tested on their phonological processing, orthographic, morphological, syntactic, and literacy skills at Grades 1 and 2. Hierarchical multiple regression results showed that syntactic skills, in terms of word order, connective usage, and knowledge of morphosyntactic structure (measured by an oral cloze task) in Grade 1, significantly predicted sentence reading comprehension in Grade 2 after controlling for the children's age, IQ, and word level reading-related cognitive skills in Grade 1, and word reading in Grade 2. As in alphabetic languages, syntactic skills are essential for reading comprehension in Chinese. The unique roles of individual syntactic skills for understanding sentences in Chinese are discussed. © 2011 Springer Science+Business Media B.V.postprin

    Early rheumatoid arthritis is characterized by a distinct and transient synovial fluid cytokine profile of T cell and stromal cell origin

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    Pathological processes involved in the initiation of rheumatoid synovitis remain unclear. We undertook the present study to identify immune and stromal processes that are present soon after the clinical onset of rheumatoid arthritis ( RA) by assessing a panel of T cell, macrophage, and stromal cell related cytokines and chemokines in the synovial fluid of patients with early synovitis. Synovial fluid was aspirated from inflamed joints of patients with inflammatory arthritis of duration 3 months or less, whose outcomes were subsequently determined by follow up. For comparison, synovial fluid was aspirated from patients with acute crystal arthritis, established RA and osteoarthritis. Rheumatoid factor activity was blocked in the synovial fluid samples, and a panel of 23 cytokines and chemokines measured using a multiplex based system. Patients with early inflammatory arthritis who subsequently developed RA had a distinct but transient synovial fluid cytokine profile. The levels of a range of T cell, macrophage and stromal cell related cytokines ( e. g. IL-2, IL-4, IL-13, IL-17, IL-15, basic fibroblast growth factor and epidermal growth factor) were significantly elevated in these patients within 3 months after symptom onset, as compared with early arthritis patients who did not develop RA. In addition, this profile was no longer present in established RA. In contrast, patients with non-rheumatoid persistent synovitis exhibited elevated levels of interferon-gamma at initiation. Early synovitis destined to develop into RA is thus characterized by a distinct and transient synovial fluid cytokine profile. The cytokines present in the early rheumatoid lesion suggest that this response is likely to influence the microenvironment required for persistent RA

    T cell cytolytic capacity is independent of initial stimulation strength.

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    How cells respond to myriad stimuli with finite signaling machinery is central to immunology. In naive T cells, the inherent effect of ligand strength on activation pathways and endpoints has remained controversial, confounded by environmental fluctuations and intercellular variability within populations. Here we studied how ligand potency affected the activation of CD8+ T cells in vitro, through the use of genome-wide RNA, multi-dimensional protein and functional measurements in single cells. Our data revealed that strong ligands drove more efficient and uniform activation than did weak ligands, but all activated cells were fully cytolytic. Notably, activation followed the same transcriptional pathways regardless of ligand potency. Thus, stimulation strength did not intrinsically dictate the T cell-activation route or phenotype; instead, it controlled how rapidly and simultaneously the cells initiated activation, allowing limited machinery to elicit wide-ranging responses

    Structural similarity-based predictions of protein interactions between HIV-1 and Homo sapiens

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    Abstract Background In the course of infection, viruses such as HIV-1 must enter a cell, travel to sites where they can hijack host machinery to transcribe their genes and translate their proteins, assemble, and then leave the cell again, all while evading the host immune system. Thus, successful infection depends on the pathogen's ability to manipulate the biological pathways and processes of the organism it infects. Interactions between HIV-encoded and human proteins provide one means by which HIV-1 can connect into cellular pathways to carry out these survival processes. Results We developed and applied a computational approach to predict interactions between HIV and human proteins based on structural similarity of 9 HIV-1 proteins to human proteins having known interactions. Using functional data from RNAi studies as a filter, we generated over 2000 interaction predictions between HIV proteins and 406 unique human proteins. Additional filtering based on Gene Ontology cellular component annotation reduced the number of predictions to 502 interactions involving 137 human proteins. We find numerous known interactions as well as novel interactions showing significant functional relevance based on supporting Gene Ontology and literature evidence. Conclusions Understanding the interplay between HIV-1 and its human host will help in understanding the viral lifecycle and the ways in which this virus is able to manipulate its host. The results shown here provide a potential set of interactions that are amenable to further experimental manipulation as well as potential targets for therapeutic intervention

    Brazilian adolescents' knowledge and beliefs about abortion methods: A school-based internet inquiry

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    Background: Internet surveys that draw from traditionally generated samples provide the unique conditions to engage adolescents in exploration of sensitive health topics.Methods: We examined awareness of unwanted pregnancy, abortion behaviour, methods, and attitudes toward specific legal indications for abortion via a school-based internet survey among 378 adolescents aged 12-21 years in three Rio de Janeiro public schools.Results: Forty-five percent knew peers who had undergone an abortion. Most students (66.0%) did not disclose abortion method knowledge. However, girls (aOR 4.2, 95% CI 2.4-7.2), those who had experienced their sexual debut (aOR1.76, 95% CI 1.1-3.0), and those attending a prestigious magnet school (aOR 2.7 95% CI 1.4-6.3) were more likely to report methods. Most abortion methods (79.3%) reported were ineffective, obsolete, and/or unsafe. Herbs (e.g. marijuana tea), over-the-counter medications, surgical procedures, foreign objects and blunt trauma were reported. Most techniques (85.2%) were perceived to be dangerous, including methods recommended by the World Health Organization. A majority (61.4%) supported Brazil's existing law permitting abortion in the case of rape. There was no association between gender, age, sexual debut, parental education or socioeconomic status and attitudes toward legal abortion. However, students at the magnet school supported twice as many legal indications (2.7, SE.27) suggesting a likely role of peers and/or educators in shaping abortion views.Conclusions: Abortion knowledge and attitudes are not driven simply by age, religion or class, but rather a complex interplay that includes both social spaces and gender. Prevention of abortion morbidity and mortality among adolescents requires comprehensive sexuality and reproductive health education that includes factual distinctions between safe and unsafe abortion methods

    The Chemotherapeutic Drug 5-Fluorouracil Promotes PKR-Mediated Apoptosis in a p53- Independent Manner in Colon and Breast Cancer Cells

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    The chemotherapeutic drug 5-FU is widely used in the treatment of a range of cancers, but resistance to the drug remains a major clinical problem. Since defects in the mediators of apoptosis may account for chemo-resistance, the identification of new targets involved in 5-FU-induced apoptosis is of main clinical interest. We have identified the ds-RNA-dependent protein kinase (PKR) as a key molecular target of 5-FU involved in apoptosis induction in human colon and breast cancer cell lines. PKR distribution and activation, apoptosis induction and cytotoxic effects were analyzed during 5-FU and 5-FU/IFNα treatment in several colon and breast cancer cell lines with different p53 status. PKR protein was activated by 5-FU treatment in a p53-independent manner, inducing phosphorylation of the protein synthesis translation initiation factor eIF-2α and cell death by apoptosis. Furthermore, PKR interference promoted a decreased response to 5-FU treatment and those cells were not affected by the synergistic antitumor activity of 5-FU/IFNα combination. These results, taken together, provide evidence that PKR is a key molecular target of 5-FU with potential relevance in the clinical use of this drug
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