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1.
The aim of this study was to gain additional knowledge about the asynchrony phenomenon in developmental dyslexia, especially when spatial selective attention is manipulated. Adults with developmental dyslexia and non-impaired readers underwent two experimental tasks, one including alphabetic stimuli (pre-lexical consonant–vowel syllables) and the other containing non-alphabetic stimuli (pictures and sounds of animals). Participants were instructed to attend to the right or left hemifields and to respond to all stimuli on that hemifield. Behavioral parameters and event-related potentials were recorded. The main finding was that the dyslexic readers demonstrated asynchrony between the auditory and visual modalities when alphabetic stimuli were presented on the right hemifield. These results suggest that intact reading is linked to a synchronized auditory and visual speed of processing even when spatial selective attention is manipulated. The findings of the current study are discussed in terms of asynchrony between modalities as a neurocognitive marker in developmental dyslexia.  相似文献   

2.
INTRODUCTION Telomeres are distinctive DNA-protein struc-tures that cap the ends of linear chromosomes.It is very important to keep the chromosomes stabilization.Telomerase activity is closely linked to attainment of cellular immortality,a step in carcinogenesis,while lack of such activity contributes to cellular senes-cence.Telomerase is activated in more than85%ofmalignant tumors(Hiayma et al.,1997).Human te-lomeric repeat binding factor1(TRF1)is a telomere associated with proteins a…  相似文献   

3.
In research in the cognitive and neurosciences, a co-occurrence between naming and reading disorders has been found in children and aphasic adults. Evidence from a completed cross-sectional study will be briefly summarized and an ongoing longitudinal study will be presented to suggest that factors disrupting specific stages of the naming process can impede the development of children’s reading in particular, perhaps predictable, ways. Based on the components of a neurolinguistic model of naming, a battery of naming and reading tests was administered to a longitudinal sample of 115 children before, during, and after reading acquisition. Preliminary trends indicate that poor readers are significantly different (p<.001) from average readers on all naming tests except those emphasizingreceptive vocabulary perception. Tests emphasizing retrieval rate are best able to predict patterns of naming performance and errors characterize specific subgroups of the dyslexias. The research was supported in part by funds from the Livingston Fellowship Foundation, Department of Social Psychiatry, Harvard Medical School and Biomedical Research Support Grants from Tufts University.  相似文献   

4.
Objective: To observe the difference of androgen and inflammatory cytokines level in atherosclerosis and analyse their relations. Method: Both carotid arteries and arteries of lower extremity were subjected to ultrasonic examination by Doppler's method. Those with much atheromatous plaque formation were ranged into case group, and those with normal result formed control group. Total, free testosterone and estradiol were assayed by radioimmunoassay. C reactive protein (CRP) was assayed by nepheloturbidity. Tumor necrosis factor-α (TNF-α), Interleukin-6 (IL-6), Interleukin-8 (IL-8), Interleukin-10 (IL-10), Interleukin-18 (IL-18), soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) were assayed by ELISA. The mean difference between two groups and the correlation between free testosterone and cytokines were analysed. Results: Free testosterone was (6.337±3.371) pg/L in case group and (11.375±4.733) pg/L in control group,P<0.01. No differences were found in total testosterone and estradiol. CRP was (27.294±10.238) mg/L in case group and (12.843±6.318) mg/L in control group,P<0.01. IL-6 was (41.700±31.385) pg/L in case group and (25.396±20.772) pg/L in control group,P<0.05. IL-8 was (89.249±58.357) pg/L in case group and (67.873±31.227) pg/L in control group,P<0.05. sICAM-1 was (470.491±134.078) pg/L in case group and (368.487±97.183) pg/L in control group,P<0.01.sVCAM-1 was (537.808±213.172) pg/L in case group and (457.275±157.273) pg/L in control group,P<0.05. There were no differences in TNF-α, IL-10 and IL-18. Correlation analysis showed that FT (free testosterone) had negative correlation with CRP, IL-6 and sICAM-1. Among them FT had well correlation with CRP, correlation index was −0.678. Conclusion: Free testosterone was in negative correlation with atherosclerosis in old-age male. Free testosterone may have the role of anti-atherosclerosis, and this effect was not achieved by its transformation to estradiol. Low free testosterone level was followed by increased level of inflammatory cytokines. Low free testosterones coexist with inflammation and they both affect the process of atherosclerosis in old-age male. Project (No. 2003B045) supported by the Health Bureau of Zhejiang Province, China  相似文献   

5.
This follow-up study to van Kraayenoord and Schneider (1999) examined the performance in reading, metacognition and motivation related to reading of students in Grades 7 and 8. Results showed significant correlations between all of the variables. A multivariate analysis of variance showed that “good” and “poor” readers differed in reading self-concept and metacognitive measures related to reading and memory. A stepwise regression analysis suggested that the metacognitive variables were the best predictors of reading. Furthermore, a comparison of the results of the previous study with those of the current investigation revealed that the findings were stable over time. Since the period between the two studies is the time during which students make important decisions related to enrolment in one of three distinct school-types in Germany, we examined the results of various groups of students: those in “Gymnasium” (high educational track), “Realschule” (middle educational track), and “Hauptschule” (low educational track). Students in the Gymnasium scored significantly better than students in the other two groups on almost all variables related to reading. A re-analysis of the data from our first investigation found that the results of the Gymnasium students in the second study could be predicted from their results obtained during elementary school.  相似文献   

6.
The study investigates dyslexic and normal Hebrew readers’ perception of words containing a vowel letter in different orthographic and morphological contexts. In the first experiment, 72 undergraduate education students (half diagnosed with reading disabilities and half normal readers) were asked to judge pointed words with different morphological structures with and without the grapheme W. Half of the words had consistent (obligatory) W and half had inconsistent (optional) W. In the second experiment, the same procedure was repeated using the same words without pointing marks. Response latencies and accuracy were measured. In both experiments, dyslexic readers did less well than normal readers. They had lower scores on accurate lexical decisions and they took more time over these decisions. They also exhibited some deviant patterns, indicating that they cannot make use of orthographic and morphological cues that are available to normal readers, especially in the pointed experiment. Processing pointed words placed a heavier cognitive burden on the dyslexic readers. These findings are in line with other studies of adult dyslexic reader/writers, and support a reading / spelling processing model, which claims that internal orthographic representations of words are increasingly strengthened with each exposure during reading, but not all graphemes are strengthened equally. The general implication is that the ambiguities that exist in the relationships between orthography, phonology, and morphology underlie spelling knowledge, and are particularly difficult for dyslexic readers.  相似文献   

7.
In two experiments, visual and auditory memory was tested for good and for poor readers from the upper elementary grades. Under experimenter-blind conditions, no reading group differences existed for single mode presentation in recognition frequency or recognition latency. With a multimodal presentation, latencies for poor readers were similar to those for the single mode presentation. Good readers, however, had significantly faster latencies with multiple input. Generally, results supported dual coding and self-terminating memory search hypotheses for previously encoded stimuli. Implications of the latency differences between reader groups were discussed with respect to the reading process and reading theory.  相似文献   

8.
Classical eyeblink conditioning (EBC) has been widely used to probe cerebellar function in humans and nonhuman mammals. Although the neural pathways governing behavior in this task are well understood and fairly discrete, it remains unclear in the human literature how conditioned stimuli (CSs) of different modalities (e.g., visual and auditory) influence the exhibition of conditioned responses (CRs). In the present study, therefore, CRs to a visual CS and an auditory CS were examined with the single-cue delay EBC procedure. An initial experiment (N=61) was conducted to identify visual and auditory stimuli that had equal perceived intensities. Using these perceptually equivalent stimuli, a second group of 25 subjects completed auditory and visual EBC procedures in two testing sessions 5–8 days apart. Whereas the acquisition of CRs was similar between the CS modality conditions, the timing of the CRs differed such that earlier CR onset and peak latencies were associated with the visual CS. In addition, CR timing improved across testing sessions, as indicated by the later CR peak latencies exhibited during the second testing session, as compared with the first.  相似文献   

9.
Rats received pairings of two stimuli with reward noncontingently in the Skinner box. During noncontingent pairings, the bar was immobilized. For Group CC 100% of the presentations of both stimuli were rewarded (S1 ±, S2 ±), for Group PP 50% of the presentations of each stimulus were rewarded (S1, ±, S2±), and for Group PC one stimulus was followed by reward on 50% of its presentations, while the second stimulus was followed by reward on 100% of its presentations (S1 ±, S2 ±). A fourth group received the stimuli and reward nonpaired. In a subsequent rewarded test phase, the response facilitating effects of the stimuli were evaluated. In the test phase all groups that received reward paired with S1, and S2 performed better in the presence of S1 and S2 than the group for which the stimuli were not paired with reward. For groups that received the stimuli paired with reward, a difference due to schedule of reward occurred when schedule of reward was varied within Ss (Group PC), but not when varied between Ss (Group PP vs Group CC). The specific form of this finding was that Group PC’s performance in the presence of S2 ± was more vigorous than its performance in the presence of S1 ± and was more vigorous than the performance of Groups PP and CC to S2. Group PC’s performance to S1 ± did not differ from that of Groups PP and CC to S1.  相似文献   

10.
Different moderators/mediators of risk are involved in developmental dyslexia (DD), but data are inconsistent. We explored the prevalence of season of birth and its association with gender and age of school entry in an Italian sample of dyslexic children compared to an Italian normal control group. The clinical sample included 498 children (345 boys, mean age 10.3 ± 2.1 years) with DD, the control sample 1,276 children (658 boys, mean age 10.8 ± 2.2 years) from four elementary schools from the same urban area, and with the same socio-economic status level. A prevalence of birth in autumn was found among children with DD compared to controls (34% versus 24%, p < 0.0001). Children with DD were more frequently males (p < 0.0001) and had a lower mean age of school entry (p < 0.0001). Regarding the distribution of ages, 11.4% of children with DD, but none of the subjects in the control group, started school before 5.7 years. Therefore, greater risk of DD was related to age of school entry (OR = 2.72), gender (OR = 2.16), and season of birth (OR = 1.21). Significant interactions between boys with DD born in autumn, and correct school of entry (OR = 2.56) were joint predictors of higher risk of DD. The association between birth in autumn and DD may be explained by the earlier age of school entry, which may be a critical element in the youngest children with DD or at risk to DD. Whether Italian school policy is oriented to anticipate the school entry, a closer detection of early learning disorders and associated risk factors (familial load, specific language disorders, and attention deficit hyperactivity disorder) should be warranted.  相似文献   

11.
Several studies on children and adults with and without linguistic impairment have reported differences between verb and noun processing. The present study assessed whether noun and verb bases affect differently children’s reading of derived words. Thirty-six Italian good readers and 18 poor readers, all 4th or 5th graders, were asked to read aloud nouns derived from either a noun base (e.g., artista, artist) or a verb base (e.g., punizione, punishment). Word and base frequency affected latencies only for deverbal nouns, while an effect of word length emerged for denominal nouns and an inhibitory effect of suffix length was found for both types of stimuli. A high base frequency and a high whole-word frequency both led to higher levels of accuracy. Verb bases led to higher error rates than noun bases. Poor readers, although slower and less accurate than good readers, showed a pattern of results similar to that of typically developing readers. Data confirm that in 4th and 5th graders morphological decomposition may affect reading aloud of long complex words, and that the grammatical class of the base can modulate this effect.  相似文献   

12.
This study investigated the effects of medium of instructional practice, task difficulty, and gender on continuing motivation. A total of 139 fifth and sixth graders with previous computer experience completed an initial drill and practice learning task in one of the two media formats (computer or paper/pencil) at either a hard or easy difficulty level. Subjects' choice of practice medium for a second learning task was the measure of continuing motivation. Sixty-seven of the 69 computer subjects (97 percent) chose to return to practice on the computer, whereas only one of 70 paper/pencil subjects (one percent) chose to return to practice in the paper/pencil form. p<.001. Questionnaire data indicated that computer subjects also evaluated their own performance on the instructional practice task significantly more highly, reported the task to be significantly more interesting and easier, and had a greater desire to study more of the subject matter.  相似文献   

13.
This study examined the effects of dietary α-tocopheryl acetate supplementation on antioxidant enzyme activities and fillet quality in commercial-size Sparus macrocephalus. Three hundred fish [main initial weight （350±12） g] were divided into three groups （E250, E500 and El000） and reared in 9 cages. The fish were fed for 8 weeks with three diets containing different levels of dietary α-tocopheryl acetate （289, 553, 1069 mg/kg）. Over the experimental period, fish were fed to satiation and reached a final mean weight of （465±28） g without significant body weight difference and proximate composition difference. Fillet α-tocopherol was significantly （P〈0.05） different between groups, reaching levels of 14.2, 22.1, 30.9 pg/mg fillet for groups E250, E500 and El000, respectively. Total serum superoxide dismutase （SOD） activity increased significantly （P〈0.05） in fish fed the diets high in α-tocopheryl acetate, but serum glutathione peroxidase （GPX） activity was unaffected. In storage on ice, fillets of fish fed the diets high in α-tocopheryl acetate exhibited significantly lower （P〈0.05） levels of oxidation. These results suggested that increased dietary α-tocopheryl acetate could increase its flesh deposition, increase the activity of SOD and prevent lipid peroxidation ofSparus macrocephalus fillets in retail storage on ice.  相似文献   

14.
In this paper,we investigate the effect and the possible mechanism of high glucose levels on the calcification of human aortic smooth muscle cells (HASMCs).HASMCs were divided into four groups: normal glucose group (NG),osmolality control group (OC),high glucose group (HG,HASMCs culture medium containing 30 mmol/L glucose),and high glucose plus recombinant human Noggin protein (bone morphogenetic protein-2 (BMP-2) antagonist) group (HN).The mRNA levels and the protein expressions of BMP-2 and core binding factor alpha-1 (Cbfα-1) were measured by real-time quantitative polymerase chain reaction (PCR) and Western blot.After induced by 10 mmol/L β-glycerol phosphoric acid,cells were harvested for assessments of alkaline phosphatase (ALP) activities at Days 1,2,and 3,and intracellular calcium contents at Days 7 and 14,respectively.High glucose levels increased the mRNA levels and the protein expressions of BMP-2 and Cbfα-1 (P0.05).The expression of Cbfα-1 was partially blocked by Noggin protein (P0.05),while BMP-2 was not (P0.05).After being induced by β-glycerol phosphoric acid,high glucose levels increased the ALP activity [(48.63±1.03) vs.(41.42±2.28) U/mg protein,Day 3;P0.05] and the intracellular calcium content [(2.76±0.09) vs.(1.75±0.07) μmol/mg protein,Day 14;P0.05] in a time-dependent manner when compared with the NG group,while the ALP activity could not be blocked by Noggin protein [(48.63±1.03) vs.(47.37±0.97) U/mg protein,Day 3;P0.05].These results show that high glucose levels can evoke the calcification of HASMCs by inducing osteoblastic trans-differentiation and intracellular calcium deposition via the BMP-2/Cbfα-1 pathway,which can be partially blocked by Noggin protein.  相似文献   

15.
Reading performance of 46 poor readers was compared with that of 20 normal control readers. All subjects were second grade children. In Experiment 1 two matching word lists were presented under two conditions: one version of the test was read in the upright position and the other inverted. In Experiment 2 the eye movements of all subjects were recorded during reading of two meaningful sentences in the normal and inverted position. While the controls were negatively influenced by inversion of the text, the poor readers showed a variety of responses. Overall, the poor readers showed a slight tendency to be better at reading in the inverted position when the text must be scanned from right to left. An individual analysis of the data revealed that in 28.3% of the poor readers inverted reading improved performance at least 15 %, a phenomenon found in none of the controls.  相似文献   

16.
Objective: To demonstrate the validity and reliability of volumetric quantitative computed tomography (vQCT) with multi-slice computed tomography (MSCT) and dual energy X-ray absorptiometry (DXA) for hip bone mineral density (BMD) measurements, and to compare the differences between the two techniques in discriminating postmenopausal women with osteoporosis-related vertebral fractures from those without. Methods: Ninety subjects were enrolled and divided into three groups based on the BMD values of the lumbar spine and/or the femoral neck by DXA. Groups 1 and 2 consisted of postmenopausal women with BMD changes ＜-2SD, with and without radiographically confirmed vertebral fracture (n=11 and 33, respectively).Group 3 comprised normal controls with BMD changes ≥-1SD (n=46). Post-MSCT (GE, LightSpeed16) scan reconstructed images of the abdominal-pelvic region, 1.25 mm thick per slice, were processed by OsteoCAD software to calculate the following parameters: volumetric BMD values of trabecular bone (TRAB), cortical bone (CORT), and integral bone (INTGL) of the left femoral neck, femoral neck axis length (NAL), and minimum cross-section area (mCSA). DXA BMD measurements of the lumbar spine (AP-SPINE) and the left femoral neck (NECK) also were performed for each subject. Results: The values of all seven parameters were significantly lower in subjects of Groups 1 and 2 than in normal postmenopausal women (P＜0.05, respectively).Comparing Groups 1 and 2, 3D-TRAB and 3D-INTGL were significantly lower in postmenopausal women with vertebral fracture(s) [(109.8±9.61) and (243.3±33.0) mg/cm3, respectively] than in those without [(148.9±7.47) and (285.4±17.8) mg/cm3,respectively] (P＜0.05, respectively), but no significant differences were evident in AP-SPINE or NECK BMD. Conclusion: the femoral neck-derived volumetric BMD parameters using vQCT appeared better than the DXA-derived ones in discriminating osteoporotic postmenopausal women with vertebral fractures from those without, vQCT might be useful to evaluate the effect of osteoporotic vertebral fracture status on changes in bone mass in the femoral neck.  相似文献   

17.
Objective: To study the stereoselective glucuronidation of carvedilol (CARV) by three Chinese liver microsomes. Methods: The metabolites of CARV were identified by a hydrolysis reaction with β-glucuronidase and HPLC-MS/MS. The enzyme kinetics for CARV enantiomers glucuronidation was determined by a reversed phase-high pressure liquid chromatogra-phy (RP-HPLC) assay using (S)-propafenone as internal standard after precolumn derivatization with 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosylisothiocyanate. Results: Two CARV glucuronides were found in three Chinese liver microsomes incubated with CARV. The non-linear regression analysis showed that the values of Km and Vmax for (S)-CARV and (R)-CARV enantiomers were (118±44) μmol/L, (2 500±833) pmol/(min·mg protein) and (24±7) μmol/L, (953±399) pmol/(min·mg protein), respectively. Conclusion: These results suggested that there was a significant (P<0.05) stereoselective glucuronidation of CARV enantiomers in three Chinese liver microsomes, which might partly explain the enantioselective pharmacokinetics of CARV.  相似文献   

18.
Objectives: To directly compare the quality of harmonic imaging (HI) and fundamental imaging (FI) in fetal echocardiography and to determine any differences in image quality between the two modalities. Methods: Fetal echocardiograms were performed with the use of FI and HI in 58 fetuses, image quality and visualization of left and right atria, left and right ventricles, mitral and tricuspid valves, aortic and pulmonary valves, left and right ventricular outflow tracts were evaluated and compared between FI and HI. Results: Mean HI scores were higher than mean FI scores (2.73±0.43 vs 2.16±0.69, P<0.001)for all the cardiovascular structures evaluated. Compared with FI, HI improved the image quality and visualization of fetal cardiac structures in subjects with both good (2.73±0.43 vs 2.88±0.32, P<0.001) and suboptimal (1.65±0.41 vs 2.58±0.47, P<0.001) echocardiographic windows. The interobserver correlation coefficient for the grading scores was 0.74 (P<0.001). Conclusions: harmonic imaging enhances and improves the image quality of fetal echocardiography; and has important potential role in cardiac imaging in the fetus.  相似文献   

19.
This study primarily examined the effects of thematic fantasy play on the perspective-taking ability of preschool children. A secondary investigation addressed the effects of play on the spontaneous play behaviour of young children. Based on the pretest-posttest control group design, 54 children (mean age=5.0 years) from two intact classes (n=27) of a private kindergarten were administered measures representing three areas of perceptual, cognitive and affective perspective-taking. Results of analysis of covariance indicated that subjects in the thematic fantasy play condition performed significantly better than the control group on total and perceptual perspective-taking measures (p<.05). In addition, chi-square analysis indicated that changes in spontaneous play was significant for the experimental group (p<.05) Findings were discussed in terms of their practical implications for curriculum design and teacher training, and further research to ascertain the permanency of play effects was recommended.  相似文献   

20.
Objective: To assess the occurrence of stressful life events in the year before the initiation of systemic sclerosis. Methods: A consecutive series of 40 patients with systemic sclerosis (mean age (56.3~ 11.9) years, mean disease duration (4.3±3.1) years; 32 females and 8 males), including 28 with diffuse cutaneous scleroderma and 12 with limited cutaneous scleroderma, were evaluated. A control group of 40 healthy subjects free of systemic sclerosis also was included. Socioeconomic status was inves-tigated and Paykel's interview for recent life events (a semi-structured research interview covering 64 life events) was conducted. Results: Patients with systemic sclerosis showed higher percentages of lower education (72.5%) and working class (82.5%), and reported more stressful life events (P＜0.05), such as exits (P＜0.05), undesirable events (P＜0.01), and uncontrolled events (P＜0.001), when compared with the control. More events that had an objective negative impact (P＜0.001) were also reported in systemic sclerosis patients than in the control. These results are in accordance with a muitifactorial model of pathogenesis in systemic sclerosis. Conclusion: We reported a strong relationship between stressful life events and the initiation of systemic sclerosis. Our findings are consistent with current understanding of the extensive links of behavioral responses to stress with neurophysiological and biochemical processes.  相似文献   

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