Study on positive threshold voltage shift and DC characteristics of HEMTs using gate recess technique

In the present study, AlGaN/GaN high-electron-mobility transistors (HEMTs) were fabricated through metal–organic chemical vapor deposition. Gate recess etching, combined with inductively coupled plasma reactive ion etching, was adopted, and etching time was controlled to manipulate the threshold voltage [Formula: see text]. The DC characteristics of devices etched for 0–25 s were investigated. [Formula: see text] exhibited a 1.9-V positive shift in the device with the AlGaN layer etched for 25 s. The effect of an AlN buffer layer on the [Formula: see text] shift was also investigated. The [Formula: see text] of the HEMT etched for 25 s and without an AlN buffer layer exhibited a positive shift of 3.1 V.

Stochastic Spatial Heterogeneity in Activities of H+-ATP-ases in Electrically Connected Plant Cells Decreases Threshold for Cooling-Induced Electrical Responses

H+-ATP-ases, which support proton efflux through the plasma membrane, are key molecular transporters for electrogenesis in cells of higher plants. Initial activities of the transporters can influence the thresholds of generation of electrical responses induced by stressors and modify other parameters of these responses. Previously, it was theoretically shown that the stochastic heterogeneity of individual cell thresholds for electrical responses in a system of electrically connected neuronal cells can decrease the total threshold of the system (“diversity-induced resonance”, DIR). In the current work, we tested a hypothesis about decreasing the thresholds of generation of cooling-induced electrical responses in a system of electrically connected plant cells with increasing stochastic spatial heterogeny in the initial activities of H+-ATP-ases in these cells. A two-dimensional model of the system of electrically connected excitable cells (simple imitation of plant leaf), which was based on a model previously developed in our works, was used for the present investigation. Simulation showed that increasing dispersion in the distribution of initial activities of H+-ATP-ases between cells decreased the thresholds of generation of cooling-induced electrical responses. In addition, the increasing weakly influenced the amplitudes of electrical responses. Additional analysis showed two different mechanisms of the revealed effect. The increasing spatial heterogeneity in activities of H+-ATP-ases induced a weak positive shift of the membrane potential at rest. The shift decreased the threshold of electrical response generation. However, the decreased threshold induced by increasing the H+-ATP-ase activity heterogeneity was also observed after the elimination of the positive shift. The result showed that the “DIR-like” mechanism also participated in the revealed effect. Finally, we showed that the standard deviation of the membrane potentials before the induction of action potentials could be used for the estimation of thresholds of cooling-induced plant electrical responses. Thus, spatial heterogeneity in the initial activities of H+-ATP-ases can be a new regulatory mechanism influencing the generation of electrical responses in plants under actions of stressors.

The Geometry of Colors in Van Gogh’s Sunflowers

“Paintings fade like flowers”: van Gogh’s prediction on the impact of age on paintings came true for most of his paintings. We have studied the consequences of this aging on the Sunflowers in a vase with a yellow background series, namely its original, F454, and two replicates, F457 and F458, at the van Gogh’s museum in Amsterdam, which van Gogh painted using the original as a model. The background and flower renditions in those paintings have faded and turned brown, making them less vibrant that van Gogh had most likely intended. We have attempted to restore van Gogh’s intent using a computational approach based on data science. After identifications of regions of interest (ROI) within the three paintings F454, F457, and F458 that capture the flowers, stems of the flowers, and background, respectively, we studied the geometry of the color space (in RGB representation) occupied by those ROIs. By comparing those color spaces with those occupied by similar ROIs in photographs of real sunflowers, we identified shifts in all three color coordinates, R, G, and B, with the positive shift in the blue coordinate being the more salient. We have proposed two algorithms, PCR-1 and PCR-2, for correcting that shift in blue and generate representations of the paintings that aim to restore their original conditions. The reduction of the blue component in the yellow hues has lead to more vibrant and less brownish digital rendition of the three Sunflowers in a vase with a yellow background.

Attitudes of medical students to electroconvulsive therapy

AimsThis study explores the different attitudes among fourth year medical students in Queen's University Belfast to Electroconvulsive Therapy (ECT) and investigates whether these are influenced by teaching and exposure to ECT during their undergraduate psychiatry placement. In particular we sought to determine firstly, correlates of baseline attitudes to ECT and secondly, whether specific forms of ECT teaching improved attitudes to ECT during their placement.MethodThis study was conducted in Queen's University Belfast and agreed with their ethics committee. Participants completed a questionnaire at the beginning of their psychiatry placement and another questionnaire in the second half of their placement. The first questionnaire captured background information and baseline attitudes. The second questionnaire recorded the educational and clinical experience gained on ECT during placement (for example lectures, tutorials, informal teaching, observing ECT and interacting with ECT patients), in addition to attitudes to ECT at this timepoint. Attitudes to ECT were assessed on a 5-point Likert scale. A positive attitude to ECT was defined as scoring agree/strongly agree on a 5-point Likert scale to the statement “I would recommend ECT for a patient if clinically indicated”.Result187 students were interviewed at both time points. At the outset of the psychiatry placement 66% of students reported a positive attitude to ECT. Positive attitude was associated with age: 72% of students under 24 had a positive attitude to ECT vs 58% of students over 24 (χ2 = 3.5; P < 0.05). Of students who had previously attended a lecture on ECT (n = 117) 83% had a positive attitude to ECT vs 42% of those who had not previously attended a lecture (χ2 = 33.5; P < 0.001).Attitudes to ECT significantly improved during the placement (66% vs 94% positive; t = 7.97; P < 0.001). Students who attended a lecture on ECT during the psychiatry placement were more likely to have a positive shift in attitude (67% vs 49%; F = 6.0; P = 0.01). No other specific teaching modality was associated with a positive shift in attitude.ConclusionWe conclude that undertaking a Psychiatry placement and particularly having a lecture on ECT significantly improves attitudes of medical students to ECT. It is therefore important that lectures on ECT are included in the medical undergraduate curriculum to allow students to be accurately informed about this essential treatment for a number of psychiatric disorders.

Exploring Effectiveness of Online Nutrition-Related Diabetes Education Training for Interdisciplinary Healthcare Students at a Student-Run Free Clinic

Objectives The objective of this project was to explore the effectiveness of online nutrition-related diabetes education training for interdisciplinary healthcare students volunteering at a student-run free clinic (SRFC). Providing online nutrition-related diabetes education training to interdisciplinary healthcare students at a student-run free clinic may increase participants’ familiarity with and confidence in providing nutrition-related diabetes education to patients. Methods Student volunteers (n = 16) at a SRFC watched an online training video on nutrition-related diabetes education. Topics covered in the training video included the relationship between diet and type 2 diabetes, and the use of motivational interviewing and SMART goals to counsel patients with type 2 diabetes. Using a pre-test/post-test design with eight Likert-scaled (strongly disagree to strongly agree) items, students rated statements indicating familiarity with and confidence in providing nutrition-related diabetes education to patients. Wilcoxon signed-rank tests were conducted to test for statistically significant shifts in each Likert-scaled item pre- to post-test. Statistical significance was set at P ≤ 0.05. Results Results showed an overall positive shift in response ratings from the pre- to post-test for all Likert-scaled items. Seven of the eight sets of results had a statistically significant positive shift in response rating (P values &lt; 0.05). Conclusions Findings indicate that providing online nutrition-related diabetes education to interdisciplinary students volunteering at a SRFC has potential to increase their familiarity with and confidence in providing nutrition-related diabetes education to their patients with diabetes. Funding Sources No funding was received.

Reciprocal institutional visibility: Youth, peace and security and ‘inclusive’ agendas at the United Nations

Within the architecture of the United Nations (UN), formal recognition of the contributions of historically marginalised individuals and communities to peacebuilding denotes a positive shift in rhetoric and practice. Alongside broader institutional moves towards ‘sustaining peace’; the emergence of a ‘Youth, Peace and Security’ agenda since 2015 formalises attention to youth as positive contributors to peacebuilding and in responding to violence. This article situates the Youth, Peace and Security agenda within broader institutional and academic attention on ‘inclusive peace’. It considers the ongoing challenges in legitimising youth inclusion; and positions this emergent agenda in relation to the gains made by the Women, Peace and Security agenda, and the establishment of the UN’s sustaining peace agenda. These explorations demonstrate the value of considering the evolution of inclusive peace agendas together, while remaining mindful of their distinctive characteristics, to better understand the potential of inclusive approaches to peace. It argues that the Youth, Peace and Security agenda should be understood as a key element of shifts in UN peacebuilding practice towards inclusivity that enable visibility and legitimacy to a broader range of peace actors. We suggest that greater recognition of the contributions of youth to the broader ‘inclusive and sustaining peace’ mandates is needed.

Change in the volume of water crystallization as a result of exposure to a high-frequency electromagnetic field

The influence of a high-frequency electromagnetic field on the process of water crystallization has been stud-ied.Water irradiated by аfield at 30–200 MHz was kept from 0 to 21 days, then it was frozen. Volumes of ice at crystallization were compared for water irradiated and unirradiated by the field. Values located more or less symmetrically near zero; 2) values with a predominantly positive shift, and 3) values for which the shift is mostly negative. Positive shift was noted when combining 200 MHz and the exposure time up to 11 days. The maximum effect of relative volume increase almost two times was observed at 200 MHz and one day ex-posure time. The maximum compression of ice approximately three times compared to the unirradiated sam-ple occurred twice: after field effect at 90 MHz and exposure time of 11 days, and at 140 MHz and exposure time of 21 days. The similarity of time dependence at 170MHz with the dependence of thermal effect of glu-cose dissolution found in early works was noted.The data obtained confirm that field effect results in both strengthening and loosening of water structure