The Effectiveness of Hypertext Annotations on Learners' Vocabulary Learning: A Meta-analysis

CALL) programs have been incorporated into language classrooms over the past five decades, it has become more important to find a clear answer to questions such as to what extent, and under which moderator variables CALL programs can yield more effective outcomes as compared to traditional language instruction. The present meta-analysis is a comprehensive investigation to determine the extent of the effectiveness of hypertext annotations on the learners' vocabulary learning.  Moreover, the study aimed at identifying the moderator variables that influence the heterogeneity of the effect of various studies. Methods: The statistical population of the present study consisted of all the studies conducted in the past related to the effectiveness of hypertext annotations on learners' vocabulary learning. To this aim, an exhaustive research of the multiple electronic databases was carried out in order to identify all the studies examining the relative effectiveness of CALL on enhancing learners' vocabulary learning The main criterion for selecting the studies to be analyzed in the present research was their publication in journals or proceedings of conferences during the period between 1950 to 2014.  Concurrently, the experts in this area were also consulted for articles that had not been identified in the primary search. Eventually, the search process resulted in the identification of 132 articles of potential relevance to the present meta-analysis. In the next stage, all studies were investigated more carefully and examined based on the checklist which was the criterion for the final selection of those studies  that should be included in the present meta-analysis. Finally, a total sample of 36 studies met the required criteria and selected for the final analysis. Data analysis was performed using Comprehensive Meta-analysis Software (Version 2). Findings: With respect to the overall effect size of the hypertext annotations on the students’ vocabulary acquisition, the results of 36 study in the present meta-analysis revealed that hypertext annotations had a large, positive, significant effect on students' vocabulary. Acquisition (+140).  In addition, there was a highly significant heterogeneity in the distribution of the effect sizes in the meta-analysis under investigation. To further explore the sources of the heterogeneity between the effect sizes across studies, moderator analyses were administered in terms of six variables (research design, sample size, proficiency level, age, duration of the program, year of publication). It was found that the variable of  the sample size had significantly affected the inconsistency of the effect sizes across the studies under investigation to the extent that studies with a sample size of more than 60 individuals produced a large effect size, whereas studies with sample size of less than 60 individuals generated medium effect size. Another significant finding was that the mean of the effect sizes statistically differed across different duration levels  of the teaching program. That is, studies with a higher duration of teaching program had a larger mean effect size than those with a lower duration, indicating that the learners' vocabulary achievement enhances significantly as the length of the teaching program increases. Moreover, the results revealed that publication year was also a significant moderator variable so that the studies published in the recent years had a higher effect size as compared with those published in earlier years. Other findings revealed that the dissimilarity of the effect sizes in the present meta-analysis was not influenced by the differences among research design, proficiency level, and age of the language learners. Conclusion: Based on the findings of the present meta-analysis, it is necessary to integrate CALL into traditional language classes in order to reach better learning outcomes. With respect to future research, the researchers are recommended to provide more details of the study so that it could be possible to confirm or reject the factors that are effective in the role of computer in second language (L2) learning.  ===================================================================================== COPYRIGHTS  ©2021 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.  ====================================================================================

Retinoic acid effects on nuclear maturation of bovine oocytes in vitro

In the present study, the effect of all-trans retinoic acid (t-RA) administration during in vitro maturation (IVM) on bovine oocytes maturation was determined. Concentrations of t-RA (RA; 0, 0.25, 0.5 and 1 μM) and 0.1% ethanol (vehicle) were included in the maturation medium. Ovaries collected from the local abattoir were transported to the laboratory in in 0.9% NaCl with 100 IU/ml penicillin and 100 in vitro maturation (IVM) on bovine oocytes maturation was determined. Concentrations of t-RA (RA; 0, 0.25, 0.5 and 1 μM) and 0.1% ethanol (vehicle) were included in the maturation medium. Ovaries collected from the local abattoir were transported to the laboratory in in 0.9% NaCl with 100 IU/ml penicillin and 100  in vitro maturation (IVM) on bovine oocytes maturation was determined. Concentrations of t-RA (RA; 0, 0.25, 0.5 and 1 μM) and 0.1% ethanol (vehicle) were included in the maturation medium. Ovaries collected from the local abattoir were transported to the laboratory in in 0.9% NaCl with 100 IU/ml penicillin and 100 g/ml streptomycin at 30 - 35°C within 1-2 h after collection. The oocytes of antral follicles, 2 to 8 mm in diameter, were recovered by aspiration. After preliminary evaluation, the oocytes were selected and washed four times in HEPES-TCM 199 supplemented with 2% FBS, 0.2 mM sodium pyruvate, 100 IU/ml penicillin and 100 g/ml streptomycin. Then 10 cumulus-oocyte complexes (COCs) were subjected to each droplet of maturation medium and incubated at 38.5°C, 5% CO2 and 95% humidity for 24 h. Maturation medium was bicarbonate-buffered TCM199 supplemented with 10% FBS, 0.2 mM sodium pyruvate, 5 μg/ml bovine FSH, 0.01 IU/ml bovine LH, 100 IU/ml penicillin and 100 g/ml streptomycin. Results show different concentrations of t-RA have no effect on cumulus expansion. The rate of oocytes developing to the MII stage compared to control, vehicle, and 0.25 μM groups was significantly increased with 1 μM t-RA treatment (

New combined PIC-MCC approach for fast simulation of a radio frequency discharge at low gas pressure

A new combined PIC-MCC approach is developed for accurate and fast simulation of a radio frequency discharge at low gas pressure and high density of plasma. Test calculations of transition between different modes of electron heating in a ccrf discharge in helium and argon show a good agreement with experimental data. We demonstrate high efficiency of the combined PIC-MCC algorithm, especially for the collisionless regime of electron heating.Comment: 6 paged, 8 figure

Generalized Uncertainty Principle and the Ramsauer-Townsend Effect

The scattering cross section of electrons in noble gas atoms exhibits a minimum value at electron energies of approximately 1eV. This is the Ramsauer-Townsend effect. In this letter, we study the Ramsauer-Townsend effect in the framework of the Generalized Uncertainty Principle.Comment: 11 pages, 3 figure

Entanglement study of the 1D Ising model with Added Dzyaloshinsky-Moriya interaction

We have studied occurrence of quantum phase transition in the one-dimensional spin-1/2 Ising model with added Dzyaloshinsky-Moriya (DM) interaction from bi- partite and multi-partite entanglement point of view. Using exact numerical solutions, we are able to study such systems up to 24 qubits. The minimum of the entanglement ratio R $\equiv$ \tau 2/\tau 1 < 1, as a novel estimator of QPT, has been used to detect QPT and our calculations have shown that its minimum took place at the critical point. We have also shown both the global-entanglement (GE) and multipartite entanglement (ME) are maximal at the critical point for the Ising chain with added DM interaction. Using matrix product state approach, we have calculated the tangle and concurrence of the model and it is able to capture and confirm our numerical experiment result. Lack of inversion symmetry in the presence of DM interaction stimulated us to study entanglement of three qubits in symmetric and antisymmetric way which brings some surprising results.Comment: 18 pages, 9 figures, submitte

Case report of MR perfusion imaging in Sinking Skin Flap Syndrome: growing evidence for hemodynamic impairment

<p>Abstract</p> <p>Background</p> <p>The syndrome of the sinking skin flap (SSSF) with delayed sensorimotor deficits after craniectomy is not well known and often neglected. Among various postulated causes, there is evidence that disturbed brain perfusion may be related to the observed symptoms, and that cranioplasty reliably alleviates these symptoms. We report a case of sinking skin flap syndrome (SSFS) with recovery from neurological sensorimotor deficits after cranioplasty correlated with pre- and postsurgical MR brain perfusion studies.</p> <p>Case Presentation</p> <p>A 42-year-old woman presented with slowly progressive sensorimotor paresis of her left arm after decompressive extensive craniectomy due to subarachnoid hemorrhage four months ago. Her right cranium showed a "sinking skin flap". After cranioplastic repair of her skull defect, the patient fully recovered from her symptoms. Before cranioplasty, reduced brain perfusion in the right central cortical region was observed in MR-perfusion images. After cranioplasty, a marked increase in brain perfusion was observed which correlated with objective clinical recovery.</p> <p>Conclusion</p> <p>There is increasing evidence that impaired blood flow is responsible for delayed motor deficits in patients with sinking skin flap syndrome in the area of compressed brain regions. Symptoms should be evaluated by brain perfusion imaging complementing surgical decision-making.</p

Transethnic analysis of the human leukocyte antigen region for ulcerative colitis reveals not only shared but also ethnicity-specific disease associations

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gut. Genetic association studies have identified the highly variable human leukocyte antigen (HLA) region as the strongest susceptibility locus for IBD, and specifically DRB1*01:03 as a determining factor for ulcerative colitis (UC). However, for most of the association signal such a delineation could not be made due to tight structures of linkage disequilibrium within the HLA. The aim of this study was therefore to further characterize the HLA signal using a trans-ethnic approach. We performed a comprehensive fine mapping of single HLA alleles in UC in a cohort of 9,272 individuals with African American, East Asian, Puerto Rican, Indian and Iranian descent and 40,691 previously analyzed Caucasians, additionally analyzing whole HLA haplotypes. We computationally characterized the binding of associated HLA alleles to human self-peptides and analysed the physico-chemical properties of the HLA proteins and predicted self-peptidomes. Highlighting alleles of the HLA-DRB1*15 group and their correlated HLA-DQ-DR haplotypes, we identified consistent associations across different ethnicities but also identified population-specific signals. We observed that DRB1*01:03 is mostly present in individuals of Western European descent and hardly present in non-Caucasian individuals. We found peptides predicted to bind to risk HLA alleles to be rich in positively charged amino acids such. We conclude that the HLA plays an important role for UC susceptibility across different ethnicities. This research further implicates specific features of peptides that are predicted to bind risk and protective HLA proteins

Craniectomy for Malignant Cerebral Infarction: Prevalence and Outcomes in US Hospitals

Randomized trials have demonstrated the efficacy of craniectomy for the treatment of malignant cerebral edema following ischemic stroke. We sought to determine the prevalence and outcomes related to this by using a national database.Patient discharges with ischemic stroke as the primary diagnosis undergoing craniectomy were queried from the US Nationwide Inpatient Sample from 1999 to 2008. A subpopulation of patients was identified that underwent thrombolysis. Two primary end points were examined: in-hospital mortality and discharge to home/routine care. To facilitate interpretations, adjusted prevalence was calculated from the overall prevalence and two age-specific logistic regression models. The predictive margin was then generated using a multivariate logistic regression model to estimate the probability of in-hospital mortality after adjustment for admission type, admission source, length of stay, total hospital charges, chronic comorbidities, and medical complications.After excluding 71,996 patients with the diagnosis of intracranial hemorrhage and posterior intracranial circulation occlusion, we identified 4,248,955 adult hospitalizations with ischemic stroke as a primary diagnosis. The estimated rates of hospitalizations in craniectomy per 10,000 hospitalizations with ischemic stroke increased from 3.9 in 1999-2000 to 14.46 in 2007-2008 (p for linear trend<0.001). Patients 60+ years of age had in-hospital mortality of 44% while the 18-59 year old group was found to be 24% (p = 0.14). Outcomes were comparable if recombinant tissue plasminogen activator had been administered.Craniectomy is being increasingly performed for malignant cerebral edema following large territory cerebral ischemia. We suspect that the increase in the annual incidence of DC for malignant cerebral edema is directly related to the expanding collection of evidence in randomized trials that the operation is efficacious when performed in the correct patient population. In hospital mortality is high for all patients undergoing this procedure

TET proteins regulate the lineage specification and TCR-mediated expansion of iNKT cells

TET proteins oxidize 5-methylcytosine in DNA to 5-hydroxymethylcytosine and other oxidation products. We found that simultaneous deletion of Tet2 and Tet3 in mouse CD4+CD8+ double-positive thymocytes resulted in dysregulated development and proliferation of invariant natural killer T cells (iNKT cells). Tet2-Tet3 double-knockout (DKO) iNKT cells displayed pronounced skewing toward the NKT17 lineage, with increased DNA methylation and impaired expression of genes encoding the key lineage-specifying factors T-bet and ThPOK. Transfer of purified Tet2-Tet3 DKO iNKT cells into immunocompetent recipient mice resulted in an uncontrolled expansion that was dependent on the nonclassical major histocompatibility complex (MHC) protein CD1d, which presents lipid antigens to iNKT cells. Our data indicate that TET proteins regulate iNKT cell fate by ensuring their proper development and maturation and by suppressing aberrant proliferation mediated by the T cell antigen receptor (TCR)