Specific ion channels contribute to key elements of pathology during secondary degeneration following neurotrauma

Background: Following partial injury to the central nervous system, cells beyond the initial injury site undergo secondary degeneration, exacerbating loss of neurons, compact myelin and function. Changes in Ca 2+ flux are associated with metabolic and structural changes, but it is not yet clear how flux through specific ion channels contributes to the various pathologies. Here, partial optic nerve transection in adult female rats was used to model secondary degeneration. Treatment with combinations of three ion channel inhibitors was used as a tool to investigate which elements of oxidative and structural damage related to long term functional outcomes. The inhibitors employed were the voltage gated Ca 2+ channel inhibitor Lomerizine (Lom), the Ca 2+ permeable AMPA receptor inhibitor YM872 and the P2X 7 receptor inhibitor oxATP. Results: Following partial optic nerve transection, hyper-phosphorylation of Tau and acetylated tubulin immunoreactivity were increased, and Nogo-A immunoreactivity was decreased, indicating that axonal changes occurred acutely. All combinations of ion channel inhibitors reduced hyper-phosphorylation of Tau and increased Nogo-A immunoreactivity at day 3 after injury. However, only Lom/oxATP or all three inhibitors in combination significantly reduced acetylated tubulin immunoreactivity. Most combinations of ion channel inhibitors were effective in restoring the lengths of the paranode and the paranodal gap, indicative of the length of the node of Ranvier, following injury. However, only all three inhibitors in combination restored to normal Ankyrin G length at the node of Ranvier. Similarly, HNE immunoreactivity and loss of oligodendrocyte precursor cells were only limited by treatment with all three ion channel inhibitors in combination. Conclusions: Data indicate that inhibiting any of a range of ion channels preserves certain elements of axon and node structure and limits some oxidative damage following injury, whereas ionic flux through all three channels must be inhibited to prevent lipid peroxidation and preserve Ankyrin G distribution and OPCs

Exploring EFL Teachers’ Competencies in Synchronous Telecollaborative Intercultural Communication Platforms

The purpose of this qualitative study was to explore how the competencies required of EFL (English as Foreign Language) teachers to foster collaboration in synchronous language classes can be developed. More precisely, the aim of the study was to deepen the understanding of teachers’ competencies in technology and intercultural communications as applied to their online teaching. The researcher conducted this study at Taif University, a government university in the Kingdom of Saudi Arabia, over the course of 8 weeks. The researcher utilized a design-based research approach. In this approach, the researcher recruited 14 EFL teachers, who provided qualitative data via reflective journals, educator videos, personal learning videos, discussion boards, and artifacts and videos from group activities. The major themes that arose from the data analysis included (a) knowledge on body language, posture, and gesture; (b) awareness on the cultural background of the students; (c) knowing the importance of when to use different types of communication; and (d) emphasizing the need for culturally sensitive communication. The thesis discusses these themes in conjunction with the data found through a strategic search of relevant literature

Thermal fluctuations and carrier localization induced by dynamic disorder in MAPbI3 described by a first-principles based tight-binding model

Halide perovskites are strongly influenced by large amplitude anharmonic lattice fluctuations at room temperature. We develop a tight binding model for dynamically disordered MAPbI$_3$ based on density functional theory (DFT) calculations to calculate electronic structure for finite temperature crystal structures at the length scale of thermal disorder and carrier localization. The model predicts individual Hamiltonian matrix elements and band structures with high accuracy, owing to the inclusion of additional matrix elements and descriptors for non-Coulombic interactions. We apply this model to electronic structure at length and time scales inaccessible to first principles methods, finding an increase in band gap, carrier mass, and the sub-picosecond fluctuations in these quantities with increasing temperature as well as the onset of carrier localization in large supercells induced by thermal disorder at 300 K. We identify the length scale $L^*= 5$ nm as the onset of localization in the electronic structure, associated with associated with decreasing band edge fluctuations, increasing carrier mass, and Rashba splitting approaching zero

Thermal fluctuations and carrier localization induced by dynamic disorder in MAPbI3 described by a first-principles based tight-binding model

Halide perovskites are strongly influenced by large amplitude anharmonic lattice fluctuations at room temperature. We develop a tight binding model for dynamically disordered MAPbI$_3$ based on density functional theory (DFT) calculations to calculate electronic structure for finite temperature crystal structures at the length scale of thermal disorder and carrier localization. The model predicts individual Hamiltonian matrix elements and band structures with high accuracy, owing to the inclusion of additional matrix elements and descriptors for non-Coulombic interactions. We apply this model to electronic structure at length and time scales inaccessible to first principles methods, finding an increase in band gap, carrier mass, and the sub-picosecond fluctuations in these quantities with increasing temperature as well as the onset of carrier localization in large supercells induced by thermal disorder at 300 K. We identify the length scale $L^*= 5$ nm as the onset of localization in the electronic structure, associated with associated with decreasing band edge fluctuations, increasing carrier mass, and Rashba splitting approaching zero

Scheduling to the Rescue; Improving ML-Based Intrusion Detection for IoT

With their inherent convenience factor, Internet of Things (IoT) devices have exploded in numbers during the last decade, but at the cost of security. Machine learning (ML) based intrusion detection systems (IDS) are increasingly proving necessary tools for attack detection, but requirements such as extensive data collection and model training make these systems computationally heavy for resource-limited IoT hardware. This paper’s main contribution to the cyber security research field is a demonstration of how a dynamic user-level scheduler can improve the performance of IDS suited for lightweight and data-driven ML algorithms towards IoT. The dynamic user-level scheduler allows for more advanced computations, not intended to be executed on resource-limited IoT units, by enabling parallel model retraining locally on the IoT device without halting the IDS. It eliminates the need for any cloud resources as computations are kept locally at the edge. The experiments showed that the dynamic user-level scheduler provides several advantages compared to a previously developed baseline system. Mainly by substantially increasing the system’s throughput, which reduces the time until attacks are detected, as well as dynamically allocating resources based on attack suspicion

Trends and outcomes of combined percutaneous (TAVI+PCI) and surgical approach (SAVR+CABG) for patients with aortic valve and coronary artery disease: A National Readmission Database (NRD) analysis

Background: In patients with severe aortic stenosis (AS) and concomitant severe coronary artery disease (CAD), the relative merits of a combined percutaneous (transcatheter aortic valve implantation [TAVI] and percutaneous coronary intervention [PCI]] versus surgical approach (surgical aortic valve replacement [SAVR] and coronary artery bypass graft [CABG]) remain unknown. Aims: To determine the utility of combined percutaneous versus surgical approaches in patients with severe AS and CAD. Methods: The National Readmission Database (NRD) (2015-2019) was queried to identify all cases of TAVI+PCI and SAVR+CABG. The adjusted odds ratios (aOR) of mortality, stroke, and its composite (major adverse cardiovascular events [MACE]) were calculated using a propensity-score matched (PSM) analysis. Results: A total of 89,314 (5358 TAVI+PCI, 83,956 SAVR+CABG) patients were included in the crude analysis. There was a gradual increase in the utilization of TAVI+PCI from 2016 to 2019 by 2%-4% per year. Using PSM, a subset of 11,361 (5358 TAVI+PCI, 6003 SAVR+CABG) patients with a balanced set of demographics and baseline comorbidities was selected. During index hospitalization, the adjusted odds of MACE (aOR 0.72, 95% confidence interval [CI] 0.62-0.83), and all-cause mortality (aOR 0.68, 95% CI 0.57-0.81) were significantly lower in patients undergoing TAVI+PCI compared with SAVR+CABG. However, patients undergoing TAVI+PCI had a higher incidence of MACE (aOR 1.40, 95% CI 1.05-1.87), and mortality (aOR 1.75, 95% CI 1.22-2.50) at 30-days. The risk of index-admission (aOR 0.82, 95% CI 0.62-1.09) and 30-day (aOR 0.88, 95% CI 0.51-1.51) stroke was similar between the two groups. Conclusion: In selected patients with severe AS and concomitant CAD, a combined percutaneous approach (TAVR+PCI) compared with SAVR+CABG may confer a lower risk of MACE and mortality during index admission but a higher incidence of 30-day complications