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Exploring the individual differences of the longitudinal growth of early numeracy (EN) in young children with Intellectual disabilities (IDs) prerequires the critical stage of exploring and validating the potential factor structure. Despite the fact that Relational Skills (RS), Counting Skills (CS) and Operations (O) are expected to constitute distinct domains of EN, there is not sufficient evidence to support either the above position or the position that they are different means of assessing a general-informal numeracy skill construct. This study was designed to shed light in the field through the evaluation of a measurement model describing the structure of RS, CS and O domains of EN and their interrelation. The sample included N = 155children with IDs, enrolled in special school classes, mentally aged between 5;02 (y;m)and 6;10 (M = 5.11, SD = 0.974).Confirmatory Factor Analysis indicated a “good fit” of the two-factor model (RS, CS + O) of EN in ID (RMSEA=.029 < 0.08, CFI = 0.98 ≥ 0.90 and SRMR = 0.000 < 0.08). No measurement invariance across gender was reported for the proposed two-factor model of EN. The nested EN models validated full measurement invariance across gender. Finally, educational implications are discussed.

The current study explores the parental perspectives of children with intellectual disabilities (ID) on the effectiveness of inclusive education in Greek mainstream schools. The participants were 83 parents, whose children had different degrees of ID and all of them were attending mainstream schools at the time of the study. They completed a questionnaire examining their perspectives with regard to (a) the most effective educational placement in mainstream schools (special class, mainstream class or co-teaching), (b) their satisfaction with the inclusive mainstream education, (c) their cooperation with the teachers, (d) the perceived benefits of their children’s educational placement and (e) their suggestions regarding the improvement of the inclusive educational model. Results indicated that most parents of children with ID would like their child to attend a mainstream class with a co-teaching arrangement. The perceived benefits are mostly related to the development of their children’s social skills. Significant considerations regarding cooperation with the teachers, lack of individualized information and guidance, administrative and organizational issues were expressed.

Written language is a difficult endeavour as the demands of transcription require self-regulatory skills from a motor, cognitive and attention perspective. The purpose of the present study was to investigate the relation between the Test of Writing Difficulties (Porpodas et al., 2007) and the Test of Detection and Investigation of Executive Functions (Simos et al., 2007) in a sample of 50 Greek-speaking, 5th-grade students with writing disabilities. The results of our study indicated that there were significant Pearson correlations ranging from .35 to .44 between executive functions and written expression. Furthermore, regression analysis showed that the subscales of the Test of Executive Functions had significant predictive power for spelling correctness and correction of jumbled sentences. Further implications of these findings for a school-based neuropsychological evaluation and planning of individualised educational interventions are discussed.

Written language is a difficult endeavour as the demands of transcription require self-regulatory skills from a motor, cognitive and attention perspective. The purpose of the present study was to investigate the relation between the Test of Writing Difficulties (Porpodas et al., 2007) and the Test of Detection and Investigation of Executive Functions (Simos et al., 2007) in a sample of 50 Greek-speaking, 5th-grade students with writing disabilities. The results of our study indicated that there were significant Pearson correlations ranging from .35 to .44 between executive functions and written expression. Furthermore, regression analysis showed that the subscales of the Test of Executive Functions had significant predictive power for spelling correctness and correction of jumbled sentences. Further implications of these findings for a school-based neuropsychological evaluation and planning of individualised educational interventions are discussed.

A lack of educational intervention programmes is noticed in the sexual education of all children and teenagers, regardless of whether they have intellectual disabilities (ID), or not. The purpose of the present study was to create an educational intervention programme in the sexual education of a pre-adolescent with Prader-Willi syndrome (PWS). The participant was a 13-year-old pre- adolescent boy who has been diagnosed with PW syndrome. Based on the data obtained, it was found that the educational intervention was very effective and that it could be applied to other teenagers with this specific cognitive profile.

The aim of this study was to explore the factors that are considered crucial by teachers for a successful intervention in managing of challenging behaviors of people with intellectual disabilities. We asked 177 Greek general and Special Educator teachers to prioritize, using a list of 24 factors, the 6 major that can contribute to the success of an intervention. Teachers chose the factor “knowledge and expertise, staff training” as the most important for the successful management of challenging behaviours. The x2test revealed no dependency relationships with teachers’ gender, working structure or Special Education expertise. The need of staff training in changing the way teachers understand challenging behaviors is also discussed.

It is noticed lack of vocational guidance tools for students with intellectual disabilities (ID), certified as to their reliability and validity. The purpose of the present study was to examine the psychometric characteristics of the “Reading - Free Vocational Interest Inventory” (R-FVII) of Becker (1981), which is one of the best non - verbal assessment tool of vocational preferences. The participants were 35 students with mild ID at the Training Schools for Persons with Special Needs in Western Macedonia and their teachers (N=34). Based on the data obtained, it was found that the tool has satisfactory levels of reliability and validity.

The study was designed to determine if spatial location of movement was automatically encoded in memory by children with intellectual disabilities (ID) and typically developing (TD) children. Each participant performed motor exercises at each of four selected locations on a 20X20 m field. The condition variable consisted of intentional position-intentional exercise, incidental position-intentional exercise, and incidental position-incidental exercise. The results indicated that spatial location of movement was not automatically encoded because intention resulted in better performance for TD children. Several critical issues related to intervention strategies in the field of ID are also discussed, considering the educational practices

Several researchers explored the impact of cognition, language and social understanding on theory of mind abilities in typically developing (TD) children and children with intellectual disabilities (ID) (either ID of genetic origin or non-specific ID). The aim of the present study was to determine the specificity of the theory of mind deficit to different groups of children with ID. The results are in accordance with the developmental approach of similar structure hypothesis (Zigler, 1969). The findings are discussed in terms of the specificity of the etiology-related theory of mind profiles of ID groups, considering the educational and social inclusion practices.

Bovine aortic endothelial cells (ECs) respond to nitric oxide (NO) donors by activating the redox-sensitive NF-E2-related factor 2/antioxidant response element pathway and up-regulating heme oxygenase (HO)-1 expression. EC exposure to steady laminar shear stress causes a sustained increase in NO, a transient increase in reactive oxygen species (ROS), and activation of the HO-1 gene. Because steady laminar flow increases the mitochondrial superoxide (O(2)(*-)) production, we hypothesized that mitochondria-derived ROS play a role in shear-induced HO-1 expression. Flow (10 dynes/cm(2), 6 h)-induced expression of HO-1 protein was abolished when BAECs were preincubated and sheared in the presence of either N(G)-nitro-L-arginine methyl ester or N-acetyl-L-cysteine, suggesting that either NO or ROS up-regulates HO-1. Ebselen and diphenylene iodonium blocked HO-1 expression, and uric acid had no effect. The mitochondrial electron transport chain inhibitors, myxothiazol, rotenone, or antimycin A, and the mitochondria-targeted antioxidant peptide, Szeto-Schiller (SS)-31, which scavenges O(2)(*-), hydrogen peroxide (H(2)O(2)), peroxynitrite, and hydroxyl radicals, markedly inhibited the increase in HO-1 expression. These data collectively suggest that mitochondrial H(2)O(2) mediates the HO-1 induction. MitoSOX and 2',7'-dichlorofluorescin (DCF) fluorescence showed that mitochondrial O(2)(*-) levels and intracellular peroxides, respectively, are higher in sheared ECs compared with static controls and, in part, dependent on NO. SS-31 significantly inhibited both the shear-induced MitoSOX and DCF fluorescence signals. Either phosphatidylinositol 3-kinase or mitogen-activated protein kinase cascade inhibitors blocked the HO-1 induction. In conclusion, under shear, EC mitochondria-derived H(2)O(2) diffuses to the cytosol, where it initiates oxidative signaling leading to HO-1 up-regulation and maintenance of the atheroprotective EC status.

The field dependence-independence of normally developing and mentally retarded boys of low and upper/middle socioeconomic status was examined. To test the cognitive style, the 96 young participants were subdivided into four groups (n= 24 per group) matched on mean mental age, using the Raven Colored Progressive Matrices. Two groups of mentally retarded boys (Groups A and B) and two groups of normally developing boys (Groups C and D). Groups A and C were matched on mental age at 5.6 yr.; Groups B and D were matched on mental age at 7.6 yr. Each pair of groups differed significantly in mean chronological age. Within each subgroup, 12 boys came from upper/middle socioeconomic status families and 12 from low socioeconomic status families. Analysis indicated absence of significant differences between Groups A and C on field dependence-independence, but there were statistically significant differences between Groups B and D. Moreover, analysis showed that boys from families of upper/middle socioeconomic status, both normally developing and mentally retarded, were consistently more field independent than boys from families of low socioeconomic status. Finally, conclusions were drawn concerning the empirical and theoretical benefits for psychology and education, which arise from the study of field dependence-independence of mentally retarded individuals.

During thrombolytic therapy and after recanalization is achieved, reduction in the volume of mural thrombi is desirable. Mural thrombi are known to contribute to rethrombosis and reocclusion. The lysis rate of mural thrombi has been demonstrated to increase with fluid flow in different experimental models, but the mechanisms responsible are unknown. An experimental and a theoretical study were developed to determine the contribution of outer convective transport to the lysis of mural fibrin clots. Normal human plasma containing recombinant tissue-type plasminogen activator (tPA; 0.5 μg/mL) was (re)perfused over mural fibrin clots with fluorescently labeled fibrin at low arterial, arterial, or higher wall shear stresses (4, 18, or 41 dyn/cm², respectively) and lysis was monitored in real time. Flow accelerated lysis, but significantly only at the highest shear stress: The average lysis front velocity was 3 × 10⁻⁵ cm/s at 41 dyn/cm² vs. almost half of that at the lower shear stresses. Confocal microscopy showed fibrin fibers dissolving only in a narrow region close to the surface when permeation velocity was predicted to be low. A heterogeneous transport-reaction finite element model was used to describe mural fibrinolysis. After scaling the effects of outer and inner convection, inner diffusion, and chemical reactions, a simplified inner diffusion/reaction model was used. Correlation to fibrin lysis data in purified systems dictated higher rates of plasmin(ogen) and tPA adsorption onto fibrin and a decreased catalytic rate of plasmin-mediated fibrin degradation, compared with published parameters. At each shear stress, the model predicted a temporal pattern of lysis of mural fibrin (similar to that observed experimentally), and protease accumulation in a narrow fibrin region and significant lysis inhibition by plasma α2-antiplasmin (according to the literature). Increasing outer convection accelerated mural fibrinolysis, but the model did not predict the big increase in lysis rate at the highest shear stress. At higher than arterial flows, additional mechanisms not accounted for in the current model, such as fibrin collapse at the fibrin front, may regulate the lysis of mural clots and determine the outcome of thrombolytic therapy. © 2002 John Wiley & Sons, Inc. Biotechnol Bioeng 77: 405–419, 2002; DOI 10.1002/bit.10127

This study compared the weight-discrimination sensitivity of 41 congenitally blind and 41 normally sighted adults. The superior weight-discrimination sensitivity of the congenitally blind subjects suggests that blindness from birth can cause compensatory adaptations within the cutaneous modality.

The Wisconsin Card Sorting Test, a standard test for the assessment of executive function and free of a motor component, was employed for the assessment of 37 nondemented patients with idiopathic Parkinson's Disease and 37 matched normal controls. The symptoms of the patients were clinically assessed by means of the Unified Parkinson's Disease Rating Scale, which yielded scores for the cardinal symptoms of the disease as well as a total motor score. The Wisconsin Card Sorting Test was administered in all subjects in its original form (128 cards), and it was scored to yield 16 measures according to the instruction of the Wisconsin Card Sorting Test revised manual. Patients with Parkinson's Disease had significantly lower scores on the following test variables: number of trials administered, perseverative responses, percent perseverative responses, and failure to maintain set. The correlations between the last three variables and total motor score were statistically significant. Of the four cardinal symptoms of the disease, only rigidity correlated significantly with the number of perseverative responses and percent perseverative responses. These findings provide a clue that the lower performance of these patients on certain variables of the Wisconsin Card Sorting Test may be related to the process of the disease.

Two likely mechanisms for the initiation of arterial platelet thrombus formation under conditions of elevated fluid shear stresses are: (1) excessive adhesion and aggregation of platelets from rapidly flowing blood onto the exposed subendothelium of injured, atherosclerotic arteries; or (2) direct, fluid shear stress-induced aggregation of platelets in constricted arteries with intact endothelial cells. Mechanism (1) was simulated using a parallel plate flow chamber, fibrillar collagen type l-coated slides, and mepacrine-labeled (fluorescent) platelets in whole blood anticoagulated with citrate, hirudin, unfractionated porcine heparin, or low molecular weight heparin flowing for 1 to 2 minutes at wall shear rates of 100 to 3,000 seconds−1(4 to 120 dynes/cm2). The precise sequence of interactions among von Willebrand factor (vWF), glycoprotein (GP)lb, and GPIIb-IIIa during platelet adhesion and subsequent aggregation were resolved by direct real-time observation using a computerized epifluorescence video microscopy system. Adhesion at high shear rates was the result of the adsorption of large vWF multimers onto collagen and the binding of platelet GPIb to the insolubilized vWF. Aggregation occurred subsequently and required the binding of ligands, including vWF via its RGD binding domain, to GPIIb-IIIa. Mechanism (2) was modeled by producing shear stresses of 90 to 180 dynes/cm2in a rotational cone and plate viscometer, which aggregates platelets from platelet-rich-plasma (PRP) anticoagulated with citrate, hirudin, or either type of heparin in reactions that require large vWF multimers, Ca2+, adenosine diphosphate, and both GPIb and GPIIb-IIIa. Both vWF-mediated shear-aggregation in PRP and platelet-collagen adhesion in flowing whole blood (anticoagulated with citrate and hirudin) are inhibited by two potentially useful anti-arterial thrombotic agents: polymeric aurin tricarboxylic acid (ATA; 28.5 to 114 µg/mL), which binds to vWF and inhibits its attachment of GPIb, and a recombinant vWF fragment (rvWF445-733; 30 to 200 µg/mL) that binds to platelet GPIb (in the absence of any modulator) and blocks attachment of vWF multimers. Unfractionated heparin, but not low molecular weight heparin, apparently binds to rvWF445-733and counteracts the inhibitory effects of the vWF fragment in vitro on shear-aggregation and platelet-collagen adhesion.

In the present study, fifty-four subjects were tested; twenty-seven with idiopathic Parkinson's disease and twenty-seven normal controls matched in age, education, verbal ability, level of depression, sex and socio-economic status. The subjects were tested on eight tasks. Five of the tasks were the classic deductive reasoning syllogisms, modus ponens, modus tollendo tollens, affirming the consequent, denying the antecedent and three-term series problems phrased in a factual context (brief scripts). Three of the tasks were inductive reasoning, including logical inferences, metaphors and similes. All tasks were presented to subjects in a multiple choice format. The results, overall, have shown nonsignificant differences between the two groups in deductive and inductive reasoning, an ability traditionally associated with frontal lobes involvement. Of the comparisons performed between subgroups of the patients and normal controls concerning disease duration, disease onset and predominant involvement of the left and/or right hemisphere, significant differences were found between patients with earlier disease onset and normal controls and between bilaterally affected patients and normal controls, demonstrating an additive effect of lateralization to reasoning ability.

Visuospatial discrimination was evaluated longitudinally in 45 patients with idiopathic Parkinson's disease. 47 normal matched subjects served as controls. Visuospatial discrimination was assessed by means of a picture test with complex superimposed objects (Poppelreuter's test) at the beginning of the study as well as three years later. At initial evaluation the group with Parkinson's disease identified fewer objects than the control group and made more errors. Relations between performance on the visuospatial discrimination task and the main parameters of the disease were not statistically significant. At reevaluation, three years later on the same task, performance by the group with Parkinson's disease deteriorated. Longitudinal assessment of motor symptoms showed that disease progressed during the study period in 35 patients. Comparison of motor deterioration with performance on the visuospatial discrimination task showed no statistically significant relationship.

An in vitrowhole blood reperfusion model was employed to quantify: (a) initial rates of lysis of mural platelet deposits from flowing blood onto fibrin-coated surfaces and (b) plasmin-mediated consumption of plasma plasminogen and fibrinogen, by recombinant tissue-type plasminogen activator (rt-PA) and two t-PA variants, KHRR 296–299 AAAA (K-tPA) and T103N, N117Q, KHRR 296–299 AAAA (TNK-tPA), at wall shear rates of either 500 or 1000 s−1. K- and TNK-tPA are more fibrin-specific than rt-PA, and are also resistant to inactivation by plasminogen activator inhibitor−1 (PAI−1). At 500 s−1, no agent showed significant lysis of mural platelet deposits on fibrin, even at concentrations as high as 10 μ g/ml of blood. At 1000 s−1, each agent demonstrated a dose-dependent lysis of mural platelet deposits, due to plasmin-mediated lysis of the fibrin substrate (fibrinolysis). The local concentration of thrombolytic agents close to the fibrin-coated surface is probably higher than the concentration of released PAI−1 from the adherent and activated platelets. Hence, the initial rates of lysis achieved by K- and TNK-tPA were not significantly different from that by rt-PA, when each agent was tested at either 1 or 10 μ g/ml of blood. However, TNK-tPA, at 1 μ g/ml,> caused the most extensive lysis at the end of the 50 min reperfusion period (50% vs 29% and 17% by rt-PA and K-tPA, respectively). K- and TNK-tPA, at concentrations as high as 10 μ g/ml of blood, caused plasminogen activation that was controlled by the natural plasmin inhibitors, and, thus, no proteolytic degradation of plasma fibrinogen (fibrinogenolysis). On the contrary, rt-PA at 1 μ g/ml revealed slight fibrinogenolysis that became extensive at 10 μ g/ml. This study demonstrates the potential use of an in vitromodel, that mimics the in vivohemodynamic environment, in evaluating the performance of thrombolytic agents. The data suggest that: (a) adequate flow must accompany fibrinolysis for successful embolization, and (b) the TNK variant may lyse annular thrombi after recanalization, at least as efficiently as rt-PA does, while causing lesser defect of systemic hemostasis. © 1998 Biomedical Engineering Society. PAC98: 8745Hw, 8790+y, 8380Lz, 8715Kg

Two likely mechanisms for the initiation of arterial platelet thrombus formation under conditions of elevated fluid shear stresses are: (1) excessive adhesion and aggregation of platelets from rapidly flowing blood onto the exposed sub-endothelium of injured, atherosclerotic arteries; or (2) direct, fluid shear stress-induced aggregation of platelets in constricted arteries with intact endothelial cells. Mechanism (1) was simulated using a parallel plate flow chamber, fibrillar collagen type I-coated slides, and mepacrine-labeled (fluorescent) platelets in whole blood anticoagulated with citrate, hirudin, unfractionated porcine heparin, or low molecular weight heparin flowing for 1 to 2 minutes at wall shear rates of 100 to 3,000 seconds-1 (4 to 120 dynes/cm2). The precise sequence of interactions among von Willebrand factor (vWF), glycoprotein (GP)Ib, and GPIIb-IIIa during platelet adhesion and subsequent aggregation were resolved by direct real-time observation using a computerized epifluorescence video microscopy system. Adhesion at high shear rates was the result of the adsorption of large vWF multimers onto collagen and the binding of platelet GPIb to the insolubilized vWF. Aggregation occurred subsequently and required the binding of ligands, including vWF via its RGD binding domain, to GPIIb-IIIa. Mechanism (2) was modeled by producing shear stresses of 90 to 180 dynes/cm2 in a rotational cone and plate viscometer, which aggregates platelets from platelet-rich- plasma (PRP) anti-coagulated with citrate, hirudin, or either type of heparin in reactions that require large vWF multimers, Ca2+, adenosine diphosphate, and both GPIb and GPIIb-IIIa. Both vWF-mediated shear- aggregation in PRP and platelet-collagen adhesion in flowing whole blood (anticoagulated with citrate and hirudin) are inhibited by two potentially useful anti-arterial thrombotic agents: polymeric aurin tricarboxylic acid (ATA; 28.5 to 114 micrograms/mL), which binds to vWF and inhibits its attachment of GPIb, and a recombinant vWF fragment (rvWF445–733; 30 to 200 micrograms/mL) that binds to platelet GPIb (in the absence of any modulator) and blocks attachment of vWF multimers. Unfractionated heparin, but not low molecular weight heparin, apparently binds to rvWF445–733 and counteracts the inhibitory effects of the vWF fragment in vitro on shear-aggregation and platelet-collagen adhesion.

Abstract: The effect of flow-induced shear stress on membrane K+ permeability was investigated by measuring86Rb+ efflux in cultured calf pulmonary artery endothelial cells. Cells were subjected to step changes in shear stress from 1 dyn/cm2 to 2.4, 4.8, or 10 dyn/cm2 in a parallel-plate flow chamber. Increasing shear stress produced a graded, transient increase in86Rb+ efflux which peaked within 1 min and subsequently declined rapidly toward pre-stimulus levels. Upon returning shear stress to 1 dyn/cm2,86Rb+ efflux initially decreased, but returned slowly to basal values. In contrast, application of bradykinin at a constant shear stress of 1 dyn/cm2 produced a transient increase in86Rb+ efflux that was followed by a sustained elevated phase during which time efflux gradually returned to pre-stimulus levels. In order to exclude the possibility that the transient increase in86Rb+ efflux with shear stress simply reflects a flow-dependent change in the washout of radiotracer, the transient convection-diffusion equation was solved using finite element simulation. When the flux of86Rb+ from the cell monolayer was assumed to be constant with time, the mathematical model predicted an increase in efflux rate coefficients upon step increases in flow that were only 7–19% of that observed experimentally. The numerical predictions correlated well with the experimentally obtained peaks when the flux of86Rb+ from the cell monolayer was simultaneously increased with flow to a new steady value. These simulations however, could not predict the transient nature of the response to increased shear stress. The results from the computer modeling suggest that the transient increase in86Rb+ efflux does not reflect a washout phenomenon and supports the hypothesis that shear stress produces a graded, transient increase in the K+ permeability of vascular endothelial cells.

Two hundred seventy children of school age, 135 of whom were left-handed and an equivalent number of whom were right-handed, have been examined in the present study using a test battery of nine language ability measures: Vocabulary, Similarities, Comprehension (WISC-R), Deductive Reasoning, Inductive Reasoning, Sentence Completion, Comprehension of Sentential Semantics, Comprehension of Syntax, and Text Processing. The data analysis has indicated that: (1) One-factor solution applies both to the right- and left-handed population according to Standard Error Scree Method (Zoski & Jurs, 1996) with regard to language ability measures. (2) Handedness discriminates between right-handers (superior) and left-handers (inferior) in language ability. (3) There have been subgroups of left-handed children who differ in language ability distribution compared with right-handed children according to Hierarchical Cluster Analysis. (4) Extreme versus mild bias to hand preference and hand skill do not differentiate performance subgroups neither within the left-handed nor within the right-handed main group. (5) Sex and familial sinistrality do not affect performance. The results are discussed in relation to (a) “human balanced polymorphism” theory advocated by Annett (mainly Annett, 1985, 1993a; Annett & Manning, 1989), (b) potential pathology (mainly Bishop, 1984, 1990a; Coren & Halpern, 1991; Satz, Orsini, Saslow & Henry, 1985) and “developmental instability” (Yeo, Gangestad & Daniel, 1993), and delay of left-hemisphere maturation in left-handed individuals (Geschwind & Galaburda, 1985a,b, 1987), by pointing out the strength and weaknesses of these theoretical approaches in accounting for the present data.

Calcium (Ca2+) transport by mitochondria is an important component of the cell Ca2+homeostasis machinery in metazoans. Ca2+uptake by mitochondria is a major determinant of bioenergetics and cell fate. Mitochondrial Ca2+uptake occurs via the mitochondrial Ca2+uniporter (MCU) complex, an inner mitochondrial membrane protein assembly consisting of the MCU Ca2+channel, as its core component, and the MCU complex regulatory/auxiliary proteins. In this review, we summarize the current knowledge on the molecular nature of the MCU complex and its regulation by intra- and extramitochondrial levels of divalent ions and reactive oxygen species (ROS). Intracellular Ca2+concentration ([Ca2+]i), mitochondrial Ca2+concentration ([Ca2+]m) and mitochondrial ROS (mROS) are intricately coupled in regulating MCU activity. Here, we highlight the contribution of MCU activity to vascular endothelial cell (EC) function. Besides the ionic and oxidant regulation, ECs are continuously exposed to haemodynamic forces (either pulsatile or oscillatory fluid mechanical shear stresses, depending on the precise EC location within the arteries). Thus, we also propose an EC mechanotransduction-mediated regulation of MCU activity in the context of vascular physiology and atherosclerotic vascular disease.