The Effect Of Using Metalinguistic Awareness On Developing English Reading Skills For The Primary School Pupils With Dyslexia

The current study was conducted to investigate the effectiveness of  using Metalinguistic Awareness on developing English reading skills for the primary school pupils with dyslexia. A pre- post experimental group design was designed to achieve the study objectives, as the researcher used the explicit teaching by promoting metalinguistic awareness activities in a classroom to develop reading skills for dyslexic pupils. Twenty dyslexic pupils were inentionaly chosen for the experimental group and twenty for the control group from the fifth primary dyslexic pupils. Pupils were trained to develop their reading skills by using metalinguistic awareness activities while the control group used usual instruction. Instruments of the study included metalinguistic awareness checklist and reading skills checklist to determine metalinguistic awareness skills and reading  skills that were mostly needed by the fifth primary pupils, a pre-posttest in reading skills.  Some lessons were reformed by promoting metalinguistic awareness activities and teaching them by explicit teaching by the researcher to develop reading skills for the sample of the study. Analysis of data obtained by dyslexic pupils revealed that the experimental group significantly achieved higher on the post reading  test as the difference in the mean scores of the two administrations was statistically significant in favor of the experimental group. . Discussion of these findings, recommendations and suggestions for further research are presented                                                 &nbsp

Cytotoxic effect on lymphocytes of Tat from human immunodeficiency virus (HIV-1)

AbstractThe human immunodeficiency virus type 1 (HIV-1) genome codes for trans-activator Tat, an 86-residue protein whose expression is critical for viral replication. Full-length Tat and Tat peptides from HIV-1 were chemically synthesized using optimized solid phase technique. Synthetic Tat2 in86, was found not only to inhibit antigen-induced human peripheral blood lymphocyte (PBL) proliferation in vitro, as described by Viscidi et al. [1989, Science 246, 1606-1608], but also mitogen-induced PBL proliferation, with 50% inhibition obtained at 0.9 and 8 μ;M, respectively. To assess the mechanism by which Tat exert its inhibitory effect, we analysed its interaction and effect on CD4+-cells. Direct fluorescence and indirect immunofluorescence assays analysed by flow cytometry showed that fluorescein isothiocyanate-labeled and -unlabeled Tat interact (>0.2 μ;M) with CD4-expressing lymphoid cells (CEM cell line). Experiments of chromium-51 release and Trypan blue exclusion on these tumor cells in vitro have demonstrated the capacity of Tat to modify cellular membrane permeability and cell viability, in a dose-dependent manner. The use of Tat peptides revealed that those containing the Tat basic region from 49 to 57 were able to bind to the cell membrane and to exhibit a cytotoxic activity on lymphocytes. Together, the data suggest that the potential cytotoxicity of Tat on lymphocytes could be directly implicated in virus-induced immune dysfunction observed in HIV-1 infected patients

Securing Untrusted RF-EH Relay Networks Using Cooperative Jamming Signals

We propose a new scheme to secure a wireless-powered untrusted cooperative-communication network, where a legitimate source node (Alice) transmits her information messages to a legitimate destination node (Bob) through the multiple amplify-and-forward untrusted relays. The relay nodes are assumed to be honest but curious nodes; hence, they are trusted at the service level but are untrusted at the information level. To reduce the energy consumption of the network, only one relay node is selected in each time slot to forward Alice's information signal. We assume a power-splitting-based energy-harvesting scheme, where each relay node splits its received signal into information and energy streams. Since the relay nodes are assumed to be untrusted at the information level, they attempt to decode the information intended to Bob while harvesting energy at the same time. When the relaying mode is selected, the scheme is realized over two non-overlapping time phases. To prevent any information leakage to the untrusted relay nodes, Bob and a cooperative jammer (John) inject jamming (artificial noise) signals during the first phase. During the second phase, the untrusted relay nodes that will not be forwarding the information signal must harvest energy to accumulate more energy to help Alice in future time slots. Moreover, the cooperative jammer will jam the untrusted relays to further power their batteries and prevent them from decoding the information-forwarding relay signal in case they decided to cheat and decode it. We model the battery state transitions at each relay as a finite-state Markov chain and analyze it. Our numerical results show the security gains of our proposed scheme relative to two benchmark schemes.This work was supported by NPRP from the Qatar National Research Fund (a member of Qatar Foundation) under Grant 8-627-2-260. The statements made herein are solely the responsibility of the authors.Scopu

: Maurocalcine transduction into cells

International audienceMaurocalcine (MCa) is a 33-amino-acid residue peptide toxin isolated from the scorpion Scorpio maurus palmatus. External application of MCa to cultured myotubes is known to produce Ca2+ release from intracellular stores. MCa binds directly to the skeletal muscle isoform of the ryanodine receptor, an intracellular channel target of the endoplasmic reticulum, and induces long lasting channel openings in a mode of smaller conductance. Here we investigated the way MCa proceeds to cross biological membranes to reach its target. A biotinylated derivative of MCa was produced (MCa(b)) and complexed with a fluorescent indicator (streptavidine-cyanine 3) to follow the cell penetration of the toxin. The toxin complex efficiently penetrated into various cell types without requiring metabolic energy (low temperature) or implicating an endocytosis mechanism. MCa appeared to share the same features as the so-called cell-penetrating peptides. Our results provide evidence that MCa has the ability to act as a molecular carrier and to cross cell membranes in a rapid manner (1-2 min), making this toxin the first demonstrated example of a scorpion toxin that translocates into cells

Critical amino acid residues of maurocalcine involved in pharmacology, lipid interaction and cell penetration.

International audienceMaurocalcine (MCa) is a 33-amino acid residue peptide that was initially identified in the Tunisian scorpion Scorpio maurus palmatus. This peptide triggers interest for three main reasons. First, it helps unravelling the mechanistic basis of Ca(2+) mobilization from the sarcoplasmic reticulum because of its sequence homology with a calcium channel domain involved in excitation-contraction coupling. Second, it shows potent pharmacological properties because of its ability to activate the ryanodine receptor. Finally, it is of technological value because of its ability to carry cell-impermeable compounds across the plasma membrane. Herein, we characterized the molecular determinants that underlie the pharmacological and cell-penetrating properties of maurocalcine. We identify several key amino acid residues of the peptide that will help the design of cell-penetrating analogues devoid of pharmacological activity and cell toxicity. Close examination of the determinants underlying cell penetration of maurocalcine reveals that basic amino acid residues are required for an interaction with negatively charged lipids of the plasma membrane. Maurocalcine analogues that penetrate better have also stronger interaction with negatively charged lipids. Conversely, less effective analogues present a diminished ability to interact with these lipids. These findings will also help the design of still more potent cell penetrating analogues of maurocalcine

Evaluation of Laparoscopy Virtual Reality Training on the Improvement of Trainees' Surgical Skills.

Background and objectives: The primary objective was to evaluate the benefit of training with virtual reality simulation. The secondary objective was to describe the short-term skill acquisition obtained by simulation training and to determine the factors affecting its magnitude. Materials and Methods: We prospectively performed a three-stage evaluation: face, constructive, and predictive to evaluate the training with a laparoscopic simulator with haptic feedback. The participants (n = 63) were divided according to their level of experience into three groups: 16% residents; 46% specialists and 38% were consultants. Results: Face evaluation demonstrates the acceptance of the design and realism of the tasks; it showed a median score of eight (IQR 3) on a Likert scale and 54% of participants (n = 34) gave the tissue feedback a moderate rating. Constructive evaluation demonstrates the improvement of the participants in the training session and the ability of the designed task to distinguish the experienced from the inexperienced surgeon based on the performance score, at task I (transfer of pegs) and II (laparoscopic salpingectomy). There was an improvement in both tasks with a significant increase in score and reduction in time. The study showed that those with a high score at the pre-test recorded a high score post-test, showing a significant pair-wise comparison (Z) and correlation (p) showing a significant statistical significance (p < 0.001). The predictive evaluation demonstrates the beneficiary effect of training four weeks afterward on the practice of surgeons addressed with five questions. It showed an improvement regarding implementation into daily routine, performance of procedure, suturing, shortening of the operative time, and complication management. Conclusions: Virtual reality simulation established high ratings for both realism and training capacity, including clinical relevance, critical relevance, and maintaining training enthusiasm