1,271 research outputs found
A summary of research relating to second and third grade reading
Thesis (Ed.M.)--Boston UniversityPURPOSE: To discover the reliability of the adjustment scale using two raters. This study was conducted to help determine whether the instrument used in this study gives a reliable measure of classroom adjustment.
PROCEDURE: The teacher checklist of classroom adjustment devised at Boston University School of Education was the instrument used. The instrument was built to follow the activities of a normal classroom day [TRUNCATED
How auditory experience differentially influences the function of left and right superior temporal cortices
To investigate how hearing status, sign language experience and task demands influence functional responses in the human superior temporal cortices (STC) we collected fMRI data from deaf and hearing participants (male and female), who either acquired sign language early or late in life. Our stimuli in all tasks were pictures of objects. We varied the linguistic and visuospatial processing demands in three different tasks that involved decisions about (1) the sublexical (phonological) structure of the British Sign Language (BSL) signs for the objects; (2) the semantic category of the objects; and (3) the physical features of the objects.
Neuroimaging data revealed that in participants who were deaf from birth, STC showed increased activation during visual processing tasks. Importantly, this differed across hemispheres. Right STC was consistently activated regardless of the task whereas left STC was sensitive to task demands. Significant activation was detected in the left STC only for the BSL phonological task. This task, we argue, placed greater demands on visuospatial processing than the other two tasks. In hearing signers, enhanced activation was absent in both left and right STC during all three tasks. Lateralisation analyses demonstrated that the effect of deafness was more task-dependent in the left than the right STC whereas it was more task-independent in the right than the left STC. These findings indicate how the absence of auditory input from birth leads to dissociable and altered functions of left and right STC in deaf participants
How auditory experience differentially influences the function of left and right superior temporal cortices
To investigate how hearing status, sign language experience and task demands influence functional responses in the human superior temporal cortices (STC) we collected fMRI data from deaf and hearing participants (male and female), who either acquired sign language early or late in life. Our stimuli in all tasks were pictures of objects. We varied the linguistic and visuospatial processing demands in three different tasks that involved decisions about (1) the sublexical (phonological) structure of the British Sign Language (BSL) signs for the objects; (2) the semantic category of the objects; and (3) the physical features of the objects.Neuroimaging data revealed that in participants who were deaf from birth, STC showed increased activation during visual processing tasks. Importantly, this differed across hemispheres. Right STC was consistently activated regardless of the task whereas left STC was sensitive to task demands. Significant activation was detected in the left STC only for the BSL phonological task. This task, we argue, placed greater demands on visuospatial processing than the other two tasks. In hearing signers, enhanced activation was absent in both left and right STC during all three tasks. Lateralisation analyses demonstrated that the effect of deafness was more task-dependent in the left than the right STC whereas it was more task-independent in the right than the left STC. These findings indicate how the absence of auditory input from birth leads to dissociable and altered functions of left and right STC in deaf participants.SIGNIFICANCE STATEMENTThose born deaf can offer unique insights into neuroplasticity, in particular in regions of superior temporal cortex (STC) that primarily respond to auditory input in hearing people. Here we demonstrate that in those deaf from birth the left and the right STC have altered and dissociable functions. The right STC is activated regardless of demands on visual processing. In contrast, the left STC is sensitive to the demands of visuospatial processing. Furthermore, hearing signers, with the same sign language experience as the deaf participants, did not activate the STCs. Our data advance current understanding of neural plasticity by determining the differential effects that hearing status and task demands can have on left and right STC function
Investigation into the Ultrasonic Setting of Glass Ionomer Cements : Part II Setting Times and Compressive Strengths
The ultrasonic setting of glass ionomer cements (GIC) was discussed. It was observed that the ultrasonic setting resulted in improvements of compressive strength. An increase in the PAA molecular weight from PAA50 to PAA200 resulted in an increase in the strength, but with a further increase in the PAA molecular weight to PAA450, there was a reduction in the strength. Results show that the strength of the ultrasonically set materials after 1 day were close to the values for the 7 days chemically set samples
Stochastic modelling of reaction-diffusion processes: algorithms for bimolecular reactions
Several stochastic simulation algorithms (SSAs) have been recently proposed
for modelling reaction-diffusion processes in cellular and molecular biology.
In this paper, two commonly used SSAs are studied. The first SSA is an
on-lattice model described by the reaction-diffusion master equation. The
second SSA is an off-lattice model based on the simulation of Brownian motion
of individual molecules and their reactive collisions. In both cases, it is
shown that the commonly used implementation of bimolecular reactions (i.e. the
reactions of the form A + B -> C, or A + A -> C) might lead to incorrect
results. Improvements of both SSAs are suggested which overcome the
difficulties highlighted. In particular, a formula is presented for the
smallest possible compartment size (lattice spacing) which can be correctly
implemented in the first model. This implementation uses a new formula for the
rate of bimolecular reactions per compartment (lattice site).Comment: 33 pages, submitted to Physical Biolog
Assessing the reliability and accuracy of nurse triage ratings when using the South African Triage Scale in the Emergency Department of District Headquarter Hospital of Timergara, Pakistan
ObjectiveTo assess inter and intra-rater reliability, as well as accuracy of nurse triage ratings when using the South African Triage Scale (SATS) in the Emergency Department (ED) of District Headquarter (DHQ) Hospital of Timergara, Pakistan.MethodsThis is a cross-sectional study using 42 previously validated paper based vignettes. Fifteen ED nurses assigned triage ratings to each of the 42 vignettes under classroom conditions. Validation of the SATS was done using the vignettes as a reference standard. Graphical displays portrayed rating distribution and validation measures of sensitivity, specificity, overtriage and undertriage across different acuity levels.ResultsThe estimated Quadratically weighted Kappa (QWK) and Interclass Correlation was found to be substantial at 0.77(CI 0.69–0.85). Intra-rater reliability with exact agreement was shown to be 87% (CI 67–100) with one category discrepancy showing 100% agreement. An average sensitivity, 70%; specificity, 97%; overtriage, 14.7% and undertriage, 21.6% was shown. The Graphical displayed showed that Very Urgent, Urgent and routine acuity levels had acceptable levels of overtriage and undertriage.ConclusionThe SATS has been shown to be a reliable triage scale for a developing country such as Pakistan. With accuracy being acceptable in the context of Timergara, we would suggest further validation studies looking at simple ways of validating the triage scale bearing in mind the challenges facing a developing country ED
Heterogeneity in ess transcriptional organization and variable contribution of the Ess/Type VII protein secretion system to virulence across closely related <em>Staphylocccus aureus </em>strains
The Type VII protein secretion system, found in Gram-positive bacteria, secretes small proteins, containing a conserved W-x-G amino acid sequence motif, to the growth medium. Staphylococcus aureus has a conserved Type VII secretion system, termed Ess, which is dispensable for laboratory growth but required for virulence. In this study we show that there are unexpected differences in the organization of the ess gene cluster between closely related strains of S. aureus. We further show that in laboratory growth medium different strains of S. aureus secrete the EsxA and EsxC substrate proteins at different growth points, and that the Ess system in strain Newman is inactive under these conditions. Systematic deletion analysis in S. aureus RN6390 is consistent with the EsaA, EsaB, EssA, EssB, EssC and EsxA proteins comprising core components of the secretion machinery in this strain. Finally we demonstrate that the Ess secretion machinery of two S. aureus strains, RN6390 and COL, is important for nasal colonization and virulence in the murine lung pneumonia model. Surprisingly, however, the secretion system plays no role in the virulence of strain SA113 under the same conditions
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