Saccadic suppression by way of retinal image processing

Humans make eye movements such as saccades four times every second. Saccades disrupt the visual flow on the retina; however, visual perception remains a stable and coherent process. This is a striking achievement of the visual system. Visual stability around the time of these eye movements is partially associated with a reduction in visual sensitivity, a phenomenon known as saccadic suppression. While saccadic suppression has been extensively characterized at the perceptual and neural levels, its underlying mechanisms remain elusive. According to the favored view, eye-movement related signals play a central role in the genesis of saccadic suppression. Despite extensive efforts to substantiate these claims, the neural origin of such signals has not been established. In this dissertation, we challenge the dominant view that saccadic suppression is triggered by eye-movement related signals. Instead, using electrophysiology in mouse, pig, and macaque retina, 2-photon calcium imaging, computational modeling, and human psychophysics we show evidence that visual mechanisms starting at the retina account for perceptual saccadic suppression. Cellular and circuit level descriptions of these retinal mechanisms are presented in detail. Most notably, we find a novel retinal processing motif underlying retinal saccadic suppression, “dynamic reversal suppression”, which is triggered by sequential stimuli containing contrast reversals. This motif does not involve inhibition but relies on nonlinear transformation of the inherently slow responses of cone photoreceptors by downstream retinal pathways. We also found that eye-movement related signals act to shorten the suppression resulting from visual mechanisms - a diametrically opposite involvement of eye movement signals than proposed in the literature. Overall, our results establish a neural locus of saccadic suppression, and provide detailed mechanistic insights underlying it. These findings resolve a long-standing open question concerning the origin of saccadic suppression. Given that the retinal saccadic suppression is triggered by sequential visual stimulation, our results also describe retinal processing of dynamic stimuli

Predictive Factors of Suicide Attempt and Non-Suicidal Self-Harm in Emergency Department

Introduction: Suicide is the third cause of mortality in America, second leading cause of death in developed countries, and one of the major health problems. Self-harm is self-inflicted damage to one’s self with or without suicidal intent. In the present study, the predictive factors of suicide attempt and non-suicidal self-harm were evaluated in patients referred to emergency department (ED) with these problem. Methods: The total number of 45 patients with suicide attempt or self-harm admitted to ED were included. Clinical symptoms, thoughts and behaviors of suicidal, and non-suicidal self-harm in these patients were evaluated at baseline. Suicidality, suicidal intent and ideation, non-suicidal self-injury, social withdrawal, disruptive behavior, and poor family functions were evaluated at admission time. Brief clinical visits were scheduled for the twelfth weeks. In the twelfth week, patients returned for their final visit to determine their maintenance treatment. Finally data were analyzed using chi-squared and multiple logistic regression. Results: Forty five patients were included in the study (56.1% female). The mean age of patients was 23.3±10.2 years (range: 15-75; 33.3% married). Significant association of suicide and self-injury was presented at the baseline and in the month before attempting (p=0.001). The most important predictive factors of suicide and self-harm based on univariate analysis were depression (suicidal and non-suicidal items of Hamilton depression rating scale), anxiety, hopelessness, younger age, history of non-suicidal self-harm and female gender (p<0.05). The participants’ quality of life analysis showed a significant higher quality in physical component summary (p=0.002), mental component summary (p=0.001), and general health (p=0.001) at follow up period. Conclusion: At the time of admission in ED, suicide attempt and non-suicidal self-harm are subsequent clinical markers for the patient attempting suicide again. The most independent predictive factors of suicide attempt and self-harm were poor family function, hopelessness, non-suicidality items of Hamilton depression rating scale, history of non-suicidal self-harm, and anxiety disorders

Biophysical neural adaptation mechanisms enable artificial neural networks to capture dynamic retinal computation

Adaptation is a universal aspect of neural systems that changes circuit computations to match prevailing inputs. These changes facilitate efficient encoding of sensory inputs while avoiding saturation. Conventional artificial neural networks (ANNs) have limited adaptive capabilities, hindering their ability to reliably predict neural output under dynamic input conditions. Can embedding neural adaptive mechanisms in ANNs improve their performance? To answer this question, we develop a new deep learning model of the retina that incorporates the biophysics of photoreceptor adaptation at the front-end of conventional convolutional neural networks (CNNs). These conventional CNNs build on 'Deep Retina,' a previously developed model of retinal ganglion cell (RGC) activity. CNNs that include this new photoreceptor layer outperform conventional CNN models at predicting male and female primate and rat RGC responses to naturalistic stimuli that include dynamic local intensity changes and large changes in the ambient illumination. These improved predictions result directly from adaptation within the phototransduction cascade. This research underscores the potential of embedding models of neural adaptation in ANNs and using them to determine how neural circuits manage the complexities of encoding natural inputs that are dynamic and span a large range of light levels

Consumer Purchasing decision: Choosing the Marketing Strategy to influence consumer decision making

The purpose of this study was to investigate the role that marketing strategy plays as a determining element in the decision-making process of consumers. The current study made use of the quantitative research approach by customizing a questionnaire based on information gleaned from academic sources. This particular study had a sample size of 162 participants, all of whom were selected at random throughout the selection process. According to the findings, penetration pricing exerts a substantial and beneficial impact on the decision-making process of consumers at the 5% level. According to the findings, price skimming has a substantial and favorable effect on the decision-making process of consumers at the 5% level. According to the findings, marketing sharing websites have a considerable beneficial impact on the decision-making process of consumers at the 5% level. The findings indicate that blogs have a considerable and beneficial effect on the decision-making process of consumers at the 5% level. According to the findings, competitive pricing has a substantial and favorable impact on the choice-making process of consumers at the 5% level. Furthermore, every beta value exceeds the.001 threshold. All of the models have extremely high adjusted R2, which indicates that the models are very capable of explaining the variance in consumer decision-making that is caused by the variation in the independent variables. The F-value demonstrates that the explanatory variables are jointly statistically significant in the model, and the Durbin-Watson (DW) statistics demonstrate that there is autocorrelation in the models. Both of these findings are supported by the model\u27s positive autocorrelation

Production Management: Analyzing the alignment of knowledge management with production management

The development of new information in the field of project management has had a significant effect on the manufacturing industry. As a result, it is critical that service development procedures be optimized in every project. The rise in cement manufacturing production was supposed to be accomplished through the utilization of knowledge management principles and knowledge management as a mediator, which was the purpose of this research. The research was carried out across a number of different cement-producing sites in the Kurdistan area of Iraq. The researchers looked at four different aspects of knowledge management in order to determine how much production could be increased by using knowledge management. These aspects were knowledge creation, knowledge storage management, knowledge sharing, and knowledge application, with knowledge management acting as a mediator. The researchers utilized a quantitative research methodology in the form of a survey in order to carry out the current analysis that is being presented. The questionnaire was handed out in a randomized fashion to around one hundred and forty administrative staff members working for a variety of cement production enterprises in the Kurdistan area. However, the researchers did manage to gather a total of 128 completed surveys. The study employed hierarchical multiple regression analysis as well as the Sobel test in order to evaluate the research hypotheses that had been created. According to the findings, each component of knowledge management—knowledge creation, knowledge storage development, knowledge sharing, and knowledge application—had a distinct and significant positive relationship with increased production at carpet manufacturers in the Kurdistan region of Iraq. This was the case regardless of which component of knowledge management was examined. In addition, the findings indicated that all knowledge management concepts with a mediator (a project management development program) had an indirect positive and significant relationship with increased production at cement manufacturing facilities in the Kurdistan region of Iraq. The mediator in this case was the project management development progra

Organizational effectiveness: Educational leadership and its impact on organizational effectiveness

This paper aims to explore the link between educational leadership and organizational effectiveness, Erbil was selected as the place to carry out the research at small and medium-sized businesses. current studies are assessing the impact of strategic absorbency (ability), capacity to adjust strategies, and managerial wisdom on small and medium-sized companies in the Kurdistan region of Iraq\u27s educational leadership a separate regression analysis was used to quantify the impact of each independent variable on organizational effectiveness in the researchers applied a straight line of reasoning to small and medium-sized businesses in the Kurdistan region of Iraq. this ended up being a total of 175 questionnaires that were completed, as 152 of the 152 participants answered them correctly The study discovered that the greatest impact was found in the absorptive capability, with regard to sustainability, but on the least effect in terms of management expertise

Rods progressively escape saturation to drive visual responses in daylight conditions

Rod and cone photoreceptors support vision across large light intensity ranges. Rods, active under dim illumination, are thought to saturate at higher (photopic) irradiances. The extent of rod saturation is not well defined; some studies report rod activity well into the photopic range. Using electrophysiological recordings from retina and dorsal lateral geniculate nucleus of cone-deficient and visually intact mice, we describe stimulus and physiological factors that influence photopic rod-driven responses. We find that rod contrast sensitivity is initially strongly reduced at high irradiances, but progressively recovers to allow responses to moderate contrast stimuli. Surprisingly, rods recover faster at higher light levels. A model of rod phototransduction suggests that phototransduction gain adjustments and bleaching adaptation underlie rod recovery. Consistently, exogenous chromophore reduces rod responses at bright background. Thus, bleaching adaptation renders mouse rods responsive to modest contrast at any irradiance. Paradoxically, raising irradiance across the photopic range increases the robustness of rod responses.Peer reviewe

Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries