Investigating two−stage degradation of threshold voltage induced by off−state stress in AlGaN/GaN HEMTs

In this work, a two-step degradation phenomenon in D-mode Si3N4/AlGaN/GaN metal-insulator-semiconductor high−electron−transistors (MIS−HEMT) is discussed systematically. During off−state stress, threshold voltage shifts positively for a short duration, and is followed by a negative shift. In contrast, the off−state leakage continues to decrease throughout the entire stress. Results of varied measurement conditions indicate that carrier trapping at different regions dominates this phenomenon. It is interesting that under a large lateral electric field, electron−hole pairs are generated and will then be trapped at the gate dielectric layer. Furthermore, when increasing the stress temperature, impact ionization due to carriers from the gate electrode becomes more severe. Finally, devices with different gate insulator (GI) thicknesses are performed to verify the physical model of the degradation behavior.

Determining the Impacts of Educational Intervention based on PLST Extended Care on Caregiving Methods and Improved Exposure to Challenging Behaviors of People with Dementia (PWD): A mixed-methods study

BackgroundPsychological events in people with dementia (PWD) lead to behavioral disorders that require targeted planning for caregivers on how to adapt to these behaviors. A progressively lowered stress threshold (PLST) model provides effective interventions for caregivers to adapt to the behaviors of people with dementia (PWD). Therefore, this study aims to determine the impacts of educational intervention based on the progressively lowered stress threshold extended (PLSTE) model on the caregiving of people with dementia (PWD) in Isfahan, Iran.MethodsThis exploratory mixed methods study was initially conducted with a qualitative approach to content analysis type from May 2016 to June 2018. Data were collected in a qualitative stage through in-depth nonstructured interviews with 29 People with Dementia (PWD)'s caregivers using the "new comment" command and then analyzed. The researcher designed a multisectional questionnaire, including demographic characteristics, knowledge measurement, and monitoring the practice of caregivers. The validity of the questionnaire was verified by a panel of experts, and its reliability was confirmed using the Cronbach alpha coefficient (knowledge section 0.838 and practice section 0.802). To adjust the intervention program, the educational content based on the PLSTE model was used for 38 caregivers available at two elderly nursing centers in Isfahan. This educational intervention was designed and managed for the first time in our community. None of the caregivers agreed to refuse to receive the educational content, So the evaluation of the program lacks a randomized controlled group. The data were collected immediately and one month after the educational intervention using a questionnaire.ResultsAccording to the results of the qualitative section of this study, the researcher was able to add a cultural and belief class and then the related intervention method to the PLST model. In the quantitative part, paired t-test indicated that the mean scores of knowledge, caregiving practice, and exposure to Challenging Behaviors (CB) in all dimensions of practice immediately and one a month after intervention were significantly higher than the mean scores before intervention (P < 0.05).ConclusionConsidering the impacts of this intervention, educating caregivers with PLST extended the care model is recommended, with a specific focus on cultural and traditional issues of society, to improve the knowledge and practice of caregivers in caregiving skills and appropriate exposure to challenging behaviors people with dementia (CBPWD).Trial registration No. IRCT20180421039370N1 -2019-01-11-http://www.irct.ir

Determining The Impacts of Educational Intervention Based on PLST Extended Care On Caregiving Methods and Improved Exposure To Challenging Behaviors of People With Dementia (PWD): A Mixed-Methods Study

Background: Psychological events in people with dementia (PWD) lead to behavioral disorders that require targeted planning for caregivers on how to adapt to these behaviors. A progressively lowered stress threshold (PLST) model provides effective interventions for caregivers to adapt to the behaviors of people with dementia (PWD). Therefore, this study aims to determine the impacts of educational intervention based on the progressively lowered stress threshold extended (PLSTE) model on the caregiving of people with dementia (PWD) in Isfahan, Iran.Methods: This exploratory mixed methods study was initially conducted with a qualitative approach to content analysis type from May 2016 to June 2018. Data were collected in a qualitative stage through in-depth nonstructured interviews with 29 People with Dementia (PWD)'s caregivers using the "new comment" command and then analyzed. The researcher designed a multisectional questionnaire, including demographic characteristics, knowledge measurement, and monitoring the practice of caregivers. The validity of the questionnaire was verified by a panel of experts, and its reliability was confirmed using the Cronbach alpha coefficient (knowledge section 0.838 and practice section 0.802). To adjust the intervention program, the educational content based on the PLSTE model was used for 38 caregivers available at two elderly nursing centers in Isfahan. The data were collected immediately and one month after the educational intervention using a questionnaire.Results: According to the results of the qualitative section of this study, the researcher was able to add a cultural and belief class and then the related intervention method to the PLST model. In the quantitative part, paired t-test indicated that the mean scores of knowledge, caregiving practice, and exposure to Challenging Behaviors (CB) in all dimensions of practice immediately and one a month after intervention were significantly higher than the mean scores before intervention (P < 0.05).Conclusion: Considering the impacts of this intervention, educating caregivers with PLST extended the care model is recommended, with a specific focus on cultural and traditional issues of society, to improve the knowledge and practice of caregivers in caregiving skills and appropriate exposure to challenging behaviors people with dementia (CBPWD).Trial registration No. IRCT20180421039370N1 -2019-01-11-http://www.irct.ir

Determining the Impacts of Educational Intervention based on PLST Extended Care model on Caregiving Methods and Improved Exposure to Challenging Behaviors of People with Dementia (PWD): A mixed-methods study

Background: Psychological events in People with Dementia (PWD) lead to behavioral disorders which require targeted planning for caregivers on how to adapt to these behaviors. Progressively lowered stress threshold (PLST) model provides effective interventions for caregivers to adapt to the behaviors of People with Dementia (PWD). Therefore, this study aims to determine the impacts of educational intervention based on the progressively lowered Stress threshold extended (PLSTE) model on the caregiving of People with Dementia (PWD) in Isfahan, Iran. Methods: This exploratory mixed methods study was initially conducted with a qualitative approach to content analysis type from May 2016 to June 2018. Data were collected in a qualitative stage through in-depth non-structured interviews with 29 People with Dementia (PWD)'s caregivers using the "new comment" command in a word and then analyzed. The researcher designed a multi-sectional questionnaire, including demographic characteristics, knowledge measurement, and monitoring the practice of caregivers. The validity of the questionnaire was verified by the panel of experts and its reliability was confirmed using the Cronbach alpha coefficient (knowledge section 0.838 and practice section 0.802). To adjust the intervention program, the educational content based on the PLSTE model was used for 38 caregivers available at two elderly nursing centers in Isfahan. The data were collected immediately and one month after the educational intervention using a questionnaire. Results: According to the results of the qualitative section of this study, the researcher was able to add a cultural and belief class, and then the related Intervention method to the PLST model. In the quantitative part, paired t-test indicated that the mean scores of knowledge, caregiving practice, and exposure to Challenging Behaviors (CB) in all dimensions of practice immediately and one a month after intervention were significantly higher than the mean scores before intervention (P < 0.05).Conclusion: Considering the impacts of this intervention, educating the caregivers with PLST extended the care model is recommended, with a specific focus on cultural and traditional issues of the society, to improve knowledge and practice of caregivers in caregiving skills and appropriate exposure to Challenging Behaviors People with Dementia (CBPWD).

Determining the Impacts of Educational Intervention based on PLST Extended Care model on Caregiving Methods and Improved Exposure to Challenging Behaviors of People with Dementia (PWD): A mixed-methods study

Background: Psychological events in People with Dementia (PWD) lead to behavioral disorders which require targeted planning for caregivers on how to adapt to these behaviors. Progressively lowered stress threshold (PLST) model provides effective interventions for caregivers to adapt to the behaviors of People with Dementia (PWD). Therefore, this study aims to determine the impacts of educational intervention based on the progressively lowered Stress threshold extended (PLSTE) model on the caregiving of People with Dementia (PWD) in Isfahan, Iran. Methods: This exploratory mixed methods study was initially conducted with a qualitative approach to content analysis type from May 2016 to June 2018. Data were collected in a qualitative stage through in-depth non-structured interviews with 29 People with Dementia (PWD)'s caregivers using the "new comment" command in a word and then analyzed. The researcher designed a multi-sectional questionnaire, including demographic characteristics, knowledge measurement, and monitoring the practice of caregivers. The validity of the questionnaire was verified by the panel of experts and its reliability was confirmed using the Cronbach alpha coefficient (knowledge section 0.838 and practice section 0.802). To adjust the intervention program, the educational content based on the PLSTE model was used for 38 caregivers available at two elderly nursing centers in Isfahan. The data were collected immediately and one month after the educational intervention using a questionnaire. Results: According to the results of the qualitative section of this study, the researcher was able to add a cultural and belief class, and then the related Intervention method to the PLST model. In the quantitative part, paired t-test indicated that the mean scores of knowledge, caregiving practice, and exposure to Challenging Behaviors (CB) in all dimensions of practice immediately and one a month after intervention were significantly higher than the mean scores before intervention (P < 0.05).Conclusion: Considering the impacts of this intervention, educating the caregivers with PLST extended the care model is recommended, with a specific focus on cultural and traditional issues of the society, to improve knowledge and practice of caregivers in caregiving skills and appropriate exposure to Challenging Behaviors People with Dementia (CBPWD). Trial registration No. IRCT20180421039370N1 -2019-01-11-http://www.irct.ir

Determination of Fatigue Damage Initiation in Short Fiber-Reinforced Thermoplastic through Acoustic Emission Analysis

This study investigates the damage initiation in short glass fiber-reinforced polyamide 6.6 under fatigue loading using acoustic emission analysis. An optimized specimen geometry was developed to meet the specific requirements of this testing method, at the same time allowing further micromechanical studies. Specimens were preloaded with tensile–tensile fatigue loading, varying the maximum stress and the number of load cycles. Subsequently, the acoustic emission signals in residual strength tests were compared to those of undamaged specimens. The idea behind this approach is that only the damage that has not already occurred under fatigue load can be recorded in the residual strength tests. Using the analysis of acoustic energy, a stress threshold for damage initiation was identified. Furthermore, with tension–tension fatigue tests, the SN curve of the material was determined to estimate the lifetime for the identified stress threshold. The presented approach allows us to estimate a so-called endurance limit of short glass fiber-reinforced polyamide 6.6.

A Paradigm for Post-Covid-19 Fatigue Syndrome Analogous to ME/CFS

A significant proportion of COVID-19 patients are suffering from prolonged Post-COVID-19 Fatigue Syndrome, with characteristics typically found in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). However, no clear pathophysiological explanation, as yet, has been provided. A novel paradigm for a Post-COVID-19 Fatigue Syndrome is developed here from a recent unifying model for ME/CFS. Central to its rationale, SARS-CoV-2, in common with the triggers (viral and non-viral) of ME/CFS, is proposed to be a physiologically severe stressor, which could be targeting a stress-integrator, within the brain: the hypothalamic paraventricular nucleus (PVN). It is proposed that inflammatory mediators, released at the site of COVID-19 infection, would be transmitted as stress-signals, via humoral and neural pathways, which overwhelm this stress-center. In genetically susceptible people, an intrinsic stress-threshold is suggested to be exceeded causing ongoing dysfunction to the hypothalamic PVN's complex neurological circuitry. In this compromised state, the hypothalamic PVN might then be hyper-sensitive to a wide range of life's ongoing physiological stressors. This could result in the reported post-exertional malaise episodes and more severe relapses, in common with ME/CFS, that perpetuate an ongoing disease state. When a certain stress-tolerance-level is exceeded, the hypothalamic PVN can become an epicenter for microglia-induced activation and neuroinflammation, affecting the hypothalamus and its proximal limbic system, which would account for the range of reported ME/CFS-like symptoms. A model for Post-COVID-19 Fatigue Syndrome is provided to stimulate discussion and critical evaluation. Brain-scanning studies, incorporating increasingly sophisticated imaging technology should enable chronic neuroinflammation to be detected, even at a low level, in the finite detail required, thus helping to test this model, while advancing our understanding of Post-COVID-19 Fatigue Syndrome pathophysiology.

Fine-Tuning Heat Stress Algorithms to Optimise Global Predictions of Mass Coral Bleaching

Increasingly intense marine heatwaves threaten the persistence of many marine ecosystems. Heat stress-mediated episodes of mass coral bleaching have led to catastrophic coral mortality globally. Remotely monitoring and forecasting such biotic responses to heat stress is key for effective marine ecosystem management. The Degree Heating Week (DHW) metric, designed to monitor coral bleaching risk, reflects the duration and intensity of heat stress events and is computed by accumulating SST anomalies (HotSpot) relative to a stress threshold over a 12-week moving window. Despite significant improvements in the underlying SST datasets, corresponding revisions of the HotSpot threshold and accumulation window are still lacking. Here, we fine-tune the operational DHW algorithm to optimise coral bleaching predictions using the 5 km satellite-based SSTs (CoralTemp v3.1) and a global coral bleaching dataset (37,871 observations, National Oceanic and Atmospheric Administration). After developing 234 test DHW algorithms with different combinations of the HotSpot threshold and accumulation window, we compared their bleaching prediction ability using spatiotemporal Bayesian hierarchical models and sensitivity–specificity analyses. Peak DHW performance was reached using HotSpot thresholds less than or equal to the maximum of monthly means SST climatology (MMM) and accumulation windows of 4–8 weeks. This new configuration correctly predicted up to an additional 310 bleaching observations globally compared to the operational DHW algorithm, an improved hit rate of 7.9%. Given the detrimental impacts of marine heatwaves across ecosystems, heat stress algorithms could also be fine-tuned for other biological systems, improving scientific accuracy, and enabling ecosystem governance.

Fine-tuning heat stress algorithms to optimise global predictions of mass coral bleaching

Increasingly severe marine heatwaves under climate change threaten the persistence of many marine ecosystems. Mass coral bleaching events, caused by periods of anomalously warm sea surface temperatures (SST), have led to catastrophic levels of coral mortality globally. Remotely monitoring and forecasting such biotic responses to heat stress is key for effective marine ecosystem management. The Degree Heating Week (DHW) metric, designed to monitor coral bleaching risk, reflects the duration and intensity of heat stress events, and is computed by accumulating SST anomalies (HotSpot) relative to a stress threshold over a 12-week moving window. Despite significant improvements in the underlying SST datasets, corresponding revisions of the HotSpot threshold and accumulation window are still lacking. Here, we fine-tune the operational DHW algorithm to optimise coral bleaching predictions using the 5km satellite-based SSTs (CoralTemp v3.1) and a global coral bleaching dataset (37,871 observations, National Oceanic and Atmospheric Administration). After developing 234 test DHW algorithms with different combinations of HotSpot threshold and accumulation window, we compared their bleaching-prediction ability using spatiotemporal Bayesian hierarchical models and sensitivity-specificity analyses. Peak DHW performance was reached using HotSpot thresholds less than or equal to Maximum Monthly Mean SST and accumulation windows of 4 - 8 weeks. This new configuration correctly predicted up to an additional 310 bleaching observations compared to the operational DHW algorithm, an improved hit rate of 7.9 %. Given the detrimental impacts of marine heatwaves across ecosystems, heat stress algorithms could also be fine-tuned for other biological systems, improving scientific accuracy, and enabling ecosystem governance.