Excess Demand Research Articles

Mathematical modeling of calcium homeostasis in female rats: An analysis of sex differences and maternal adaptations

Calcium plays a vital role in various biological processes, including muscle contractions, blood clotting, skeletal mineralization, and cell signaling. While extracellular calcium makes up less than 1% of total body calcium, it is tightly regulated since too high or too low extracellular calcium concentration can have dangerous effects on the body. Mathematical modeling is a well-suited approach to investigate the complex physiological processes involved in calcium regulation. While mathematical models have been developed to study calcium homeostasis in male rats, none have been used to investigate known sex differences in hormone levels nor the unique physiological states of pregnancy and lactation. Calcitriol, the active form of vitamin D, plays a key role in intestinal calcium absorption, renal calcium reabsorption, and bone remodeling. It has been shown that, when compared to age-matched male rats, females have significantly lower calcitriol levels. In this study we first seek to investigate the impact of this difference as well as other known sex differences on calcium homeostasis using mathematical modeling. Female bodies differ from male bodies in that during their lifetime they may undergo massive adaptations during pregnancy and lactation. Indeed, maternal adaptations impact calcium regulation in all mammals. In pregnant rodents, intestinal absorption of calcium is massively increased in the mother’s body to meet the needs of the developing fetus. In a lactating rodent, much of the calcium needs of milk are met by bone resorption, intestinal absorption, and renal calcium reabsorption. Given these observations, the goal of this project is to develop multi-scale whole-body models of calcium homeostasis that represents (1) how sex differences impact calcium homeostasis in female vs. male rats and (2) how a female body adapts to support the excess demands brought on by pregnancy and lactation. We used these models to quantify the impact of individual sex differences as well as maternal adaptations during pregnancy and lactation. Additionally, we conducted “what if” simulations to test whether sex differences in calcium regulation may enable females to better undergo maternal adaptations required in pregnancy and lactation than males.

A mechanistic account of visual discomfort.

Much of the neural machinery of the early visual cortex, from the extraction of local orientations to contextual modulations through lateral interactions, is thought to have developed to provide a sparse encoding of contour in natural scenes, allowing the brain to process efficiently most of the visual scenes we are exposed to. Certain visual stimuli, however, cause visual stress, a set of adverse effects ranging from simple discomfort to migraine attacks, and epileptic seizures in the extreme, all phenomena linked with an excessive metabolic demand. The theory of efficient coding suggests a link between excessive metabolic demand and images that deviate from natural statistics. Yet, the mechanisms linking energy demand and image spatial content in discomfort remain elusive. Here, we used theories of visual coding that link image spatial structure and brain activation to characterize the response to images observers reported as uncomfortable in a biologically based neurodynamic model of the early visual cortex that included excitatory and inhibitory layers to implement contextual influences. We found three clear markers of aversive images: a larger overall activation in the model, a less sparse response, and a more unbalanced distribution of activity across spatial orientations. When the ratio of excitation over inhibition was increased in the model, a phenomenon hypothesised to underlie interindividual differences in susceptibility to visual discomfort, the three markers of discomfort progressively shifted toward values typical of the response to uncomfortable stimuli. Overall, these findings propose a unifying mechanistic explanation for why there are differences between images and between observers, suggesting how visual input and idiosyncratic hyperexcitability give rise to abnormal brain responses that result in visual stress.

Controlling the Reactive Power Demand of a Distribution Grid by Coordinated Action of Electric Vehicle Chargers

Various factors, particularly an increasing share in underground cable lines, can lead to excessive reactive power demand of distribution grids to their respective transport grids and, thus, to the need of costly compensation measures. At the same time, the occurrence of battery-electric cars is considerably increasing. It is, therefore, conceivable to provide reactive power as an inexpensive “waste product” by the charging converters of the cars as a solution to the aforementioned problem. In this research work, the idea is examined for its feasibility by means of extensive time series simulation using the example of a real existing distribution grid. It was found that, with a realistic number of charging points—especially public ones with integrated converter electronics—not only can the reactive power demand be reduced to an acceptable level but also additional reactive power can be provided as a service to the transport grid.

The Prevalence of Physicians’ Burnout Syndrome in Ibrahim Malik Teaching Hospital, Khartoum, Sudan, 2020

Background: Burnout is described as exploratory and qualitatively as a state of emotional exhaustion due to excessive demands on energy, strength or sources in workplace. It is characterized by physical symptoms such as exhaustion, fatigue, frequent headache, and gastrointestinal disorders, sleeplessness and behavioral signs include frustration, anger, a suspicious attitude omnipotence or overconfidence, cynicism and signs of depression.
 Methods: This is a descriptive cross-sectional hospital-based study. The data was collected from 100 Physicians by a questionnaire specially prepared for the purposes of this study. Filling out the questionnaires was distributed by the research team in person. The questionnaire consisted of 27 questions, with 9 questions attributed to each of the 3 risk factors (Depersonalization, Emotional Exhaustion, and Personal Accomplishment). Data was analyzed by using SPSS program version 26 and the result was represented in tables and figures.
 Results: (72%) of the participant were females and (28 %) were males, age ranged between 2 and more than 51 years, age was categorized into three groups 20–30 (73%), 31–40 (20%) and 41–50 (5%) and more than 50 (2%). Participants were distributed in 6 different specialties with Pediatrics as the most represented specialty (18%). In the level of profession most of the participant were house officer (42%) followed by registrar (32%) and the least were specialist (4%). Levels of emotional exhaustion, depersonalization, (77 %) of the sample had a high level of (EE), (54%) had a high level of (DP), and (14 %) had a low level of (PA). (19%) of the residents included in this study had a high level of burnout in all three do- mains of the index, and (93%) had a high level in at least one of the three. The high level of each burnout components distributed according to the research different demographic variables and the results of the inferential statistical tests. Males had higher levels of EE (82.8%), and DP (55%), and lower levels of PA (14.9%) than females (71.6%), (54%), (12.1%) respectively.
 Conclusion: In conclusion, our study showed that burn out is highly prevalent among Ibrahim Malik hospital doctors, while female doctors had a higher degree burnout than males. Among the different professional levels, the highest percentage of burnout belonged to GPs and the lowest belonged to consultants .ER doctors suffered the most from burnout, whereas surgeons suffered the least. Several factors attributing to the burnout symptoms of these doctors have been identified.

Optimal Ordering Decisions in Portfolio Procurement Considering Spot Price Fluctuation

This paper studies a newsvendor’s optimal ordering decisions in portfolio procurement from long-term contracts and spot purchases. In portfolio procurement, the newsvendor can order commodities in a long-term contract to meet market demand, and the excess demands can be supplemented from the spot market. Firstly, the newsvendor’s optimal ordering quantity in long-term contracts to maximize the expected profits is achieved when the spot price fluctuation is not considered. Furthermore, the newsvendor’s optimal ordering quantity is derived when the spot price fluctuation is considered. The research will show that the newsvendor’s optimal ordering decisions change with market parameters. Spot price fluctuation has a significant influence on optimal ordering decisions in portfolio procurement. This research uses the method of relative fluctuation of spot price and long-term contract price, which is more applicable in practice. It is shown that the newsvendor’s optimal ordering quantity in a long-term contract increases with the spot price fluctuation, which implies that price fluctuation in the spot market leads to a greater order quantities in long-term contracts. Moreover, it is proven that the newsvendor’s expected profit obtained from portfolio procurement decreases with increasing spot price fluctuation. Finally, this is verified by numerical experiments, and several management insights are suggested.

A Scenario-based optimization model to design a hub network for covid-19 medical equipment management

The provision of medical equipment during pandemics is one of the most crucial issues to be dealt with by health managers. This issue has revealed itself in the context of the COVID-19 outbreak in many hospitals and medical centers. Excessive demand for ventilators has led to a shortage of this equipment in several medical centers. Therefore, planning to manage critical hospital equipment and transfer the equipment between different hospitals in the event of a pandemic can be used as a quick fix. In this paper, a multi-objective optimization model is proposed to deal with the problem of hub network design to manage the distribution of hospital equipment in the face of epidemic diseases such as Covid-19. The objective functions of the model include minimizing transfer costs, minimizing the destructive environmental effects of transportation, and minimizing the delivery time of equipment between hospitals. Since it is difficult to estimate the demand, especially in the conditions of disease outbreaks, this parameter is considered a scenario-based one under uncertain conditions. To evaluate the performance of the proposed model, a case study in the eastern region of Iran is investigated and sensitivity analysis is performed on the model outputs. The sensitivity of the model to changing the cost parameters related to building infrastructure between hubs and also vehicle capacity is analyzed too. The results revealed that the proposed model can produce justified and optimal global solutions and, therefore, can solve real-world problems.

Examining the Relationship Between Academic Burnout and the University Student's Engagement: A Cross-Sectional Study on the Return to Face-to-Face Classes

Objective: Academic burnout is considered a psychological condition that students present and is characterized by low motivation and a feeling of failure due to the inability to cope with academic stress or excessive academic demands. In this sense, the objective of the present investigation was to determine if academic burnout is related to the university student's engagement in the Peruvian Amazon to return to face-to-face classes. Method: The approach was quantitative, the design was non-experimental and the type was descriptive - correlational, cross-sectional. The sample consisted of 342 students who were administered the Maslach Burnout Inventory Student Survey and the UWES-S Scale, instruments with adequate levels of validity and reliability. Likewise, to identify the relationship between the study variables, Pearson correlation coefficient was used. Results: The preliminary results indicate that the students were characterized by presenting moderate levels of academic burnout and engagement. On the other hand, it was determined that the Pearson correlation coefficient between both variables was -0.722 (p<0.05). Significant correlations were also reported between academic burnout and the dimensions vigor (r= -0.701, p<0.05), dedication (r= -0.712, p<0.05) and absorption (r= -0.694, p<0.05). In the same way, significant correlations were found between student engagement and the dimensions emotional exhaustion (r= -0.711, p<0.05), cynicism (r= -0.700, p<0.05) and inefficacy (r= -0.687, p <0.05). On the other hand, the β coefficients indicate that academic burnout (β= 0.204), emotional exhaustion (β= 0.259), cynicism (β= 0.196) and inefficacy (β= 0.337) significantly predicted student engagement. Conclusions: It was concluded that there is an inverse and significant relationship between academic burnout and the university student's engagement in the Peruvian Amazon to return to face-to-face classes.

Influence of psychosocial safety climate on occupational health and safety: a scoping review

BackgroundCreating a healthy, decent and safe workplace and designing quality jobs are ways to eliminate precarious work in organisations and industries. This review aimed at mapping evidence on how psychosocial safety climate (PSC) influence health, safety and performance of workers.MethodsA literature search was conducted in four main databases (PubMed, Scopus, Central and Web of Science) and other online sources like Google Scholar. A reference list of eligible studies was also checked for additional papers. Only full-text peer-reviewed papers published in English were eligible for this review.ResultsA search in the databases produced 13,711 records, and through a rigorous screening process, 93 papers were included in this review. PSC is found to directly affect job demands, job insecurity, effort-reward imbalance, work-family conflict, job resources, job control and quality leadership. Moreover, PSC directly affects social relations at work, including workplace abuse, violence, discrimination and harassment. Again, PSC has a direct effect on health, safety and performance outcomes because it moderates the impact of excessive job demands on workers’ health and safety. Finally, PSC boosts job resources’ effect on improving workers’ well-being, safety and performance.ConclusionManagers’ efforts directed towards designing quality jobs, prioritising the well-being of workers, and fostering a bottom-up communication through robust organisational policies, practices, and procedures may help create a high organisational PSC that, in turn, promotes a healthy and decent work environment.

Including Public Realism in Determining New Pricing Scheme for Sanitary Landfill in Malaysia

Financial restriction and excessive demand for solid waste disposal is a press-ing issue in developing countries. Neglecting this problem can worsen environmental damage and endanger public health. To address this challenge, this study investigated the influence of social factors on the willingness to pay for a sanitary landfill in Malaysia using choice modelling. Focusing on neighbouring districts, Kota Bharu and Bachok, where households share a crude-dumping landfill, the study collected data from 624 respondents. The findings revealed a common preference among respondents for a sanitary landfill attribute related to controlled disease vectors, with willingness to pay ranging from RM10.66 to RM13.33 per month. Interestingly, despite experiencing adverse effects from the crude-dumping landfill, respondents from Bachok still showed a preference for it. This preference could be influenced by lower mean incomes among Bachok residents who live closer to the landfill site compared to respondents in Kota Bharu. To address these dynamics, implementing cross-subsidies by charging higher prices to households in Kota Bharu and lower prices to households in Bachok could facilitate the successful implementation of the sanitary landfill. These results can inform other developing countries by highlighting the importance of considering the local social context when designing sustainable solid waste policies.

An Android App Using Virtual Trial Room to Minimize Clothing Perceived Risks of Buyers

The world is moving on the clothing mobile application shopping applications, especially during the pandemic COVID 19 days there seems to be an excessive demand for online shopping. Online shopping applications that provide an approach to buying a product of your choice with the least effort also involve some of the risk factors, especially in the psychological environment of the developing county like Pakistan, where people have a minor trust factor and prefer to touch, use and see the personalized appearance before buying the item. This behavior seems to be more regressive when it comes to shopping in terms of clothing. People prefer to wear the items, match the colors, and check if it suits their personality. Online shopping seems to lack this customer approach, especially in developing countries like Pakistan. There has always been fear and, at the same time, a trust factor. A virtual trial room is an alternative approach where a user can virtually try the clothes on the body after providing the complete image to the system and then try different color combinations, different fabrics, and matching the contrast. Using an Image processing machine learning approach, a methodology is proposed to judge this behavior of the customer after trying the clothes on personal appearance virtually and evaluate the results after comparing them with buying behavior of the user in a simple online application and the online mobile application containing the virtual trial room model. Furthermore, studies have the Virtual trial room model as a productive model in the online shopping experience. Following the described methodology in mobile clothing mobile application, it is expected to gain the utmost trust after eliminating buying risks associated with online shopping

School and Intrapersonal Predictors and Stability of Rural Special Education Teacher Burnout

Special education teacher attrition is a significant and chronic problem that has worsened since the pandemic. A longitudinal survey of burnout was conducted with rural special education teachers ( N = 48) over four timepoints through the school year just prior to COVID-19. Both school and intrapersonal predictors of burnout obtained at the beginning of the school year were used to predict burnout at the end of the school year. Findings revealed that burnout is highly stable over the course of the school year. Furthermore, the strongest predictors of burnout at the end of the school year were baseline scores of burnout. Only one school factor—excessive work demands—and several teacher intrapersonal variables—coping, social support, and mindfulness skills—predicted at least one indicator of burnout. In a regression analysis, the baseline scores of each of the different domains of burnout (emotional exhaustion, depersonalization, personal accomplishment) accounted for the most variance in burnout reported at the end of the school year, except for passive avoidance. Passive avoidance accounted for unique variance with depersonalization. These findings suggest that burnout is stable and help identify teacher intrapersonal or school factors that might be useful targets for prevention or intervention research related to burnout.

Water desalination in Egypt; literature review and assessment

The increasing demand for water in urban and industrial areas in arid and semiarid coastal zones has led to the search for alternative nonconventional water resources.. Desalination plants are the most feasible solution to the huge water demand in arid regions, especially in Egypt, with its limited water resources of the Nile River and expected drought due to climate change and upstream dam construction. Many desalination technologies, such as thermal and membrane technologies, are used. Thermal desalination includes multistage flash desalination, multi-effect desalination, and desalination by vapor compression. Membrane desalination involves RO, forward osmosis, and electro dialysis. (RO) desalination plants are the most significant technique for desalinated water in Egypt. However, the treatment of brine wastewater is still a challenging problem. Hypersaline water effluent, as a byproduct of seawater desalination, has a negative impact on the marine ecosystem if it is discharged inadequately. In the past decade, Egypt has launched many large-scale projects along Red Sea and Mediterranean coasts to cope the recent economic growth. In this research a review of taxonomy of many related publications, and comparison has been made between the different seawater desalination techniques to determine the advantages and disadvantages of each of them, as well as to know the best technology that can be used in Egypt. The Egyptian state's plan to address the excessive demand for water resources as a result of the continuous population growth was reviewed by making a strategic plan for 30 years. It was divided into five-year plans, some parts of which have been completed, and the rest of the plan is being completed to present significant comparisons and enable the derivation of informative conclusions.

부동산 규제정책은 가격안정화에 성공하였는가?

The purpose of this study is to empirically analyze the impact of real estate policies such as excess housing demand, financial regulations, and transaction restriction regulations on housing prices. Three policy indices were developed as variables to measure demand-side real estate policies, and empirical analysis was conducted using them as major explanatory variables. The financial regulation policy index (FRPI) was established by investigating financial regulations such as LTV, DTI, and DSR, and the transaction restriction policy index (TRPI) was organized in a time series by examining the details of transaction restrictions such as overheated speculation zones and speculative areas. In addition, the excess demand for housing, defined as the difference between the supply and demand of the real estate market, was estimated by monthly. The result of empirical showed that the effect of stabilizing housing prices of the FRPI and the TRPI was limited. On the other hand, excess housing demand was positively related to housing prices, and the increase in excess housing demand since the mid-2010s turned out to be a main background of the rise in housing prices.

The Buckingham’s π Theorem: Consequences for the Price Theory

The present article focuses on the possible interpretation of the pi theorem of physics in the field of the economics' general equilibrium analysis. The physical units of the exchanged goods are de ned as fundamental units and the neoclassical prices as dimensionless derived numbers. Thus, the general equilibrium does not need money metrics, unspeci ed money market and the complementing inappropriate incorporation of the Walras Law. Further, the main function of money is not that of a unit of account, but a means of exchange. If such type of a money market is introduced, the Walras symmetry holds but in the sense that the positive aggregate excess demand on the goods market matches the negative excess demand on the money market. Distinction is de ned between neoclassical, relative and monetary prices. Additional conditions must be met to allow for a closed monetary circulation.

The Probiotic Phaeobacter inhibens Provokes Hypertrophic Growth via Activation of the IGF-1/Akt Pathway during the Process of Metamorphosis of Greater Amberjack (Seriola dumerili, Risso 1810)

Metamorphosis entails hormonally regulated morphological and physiological changes requiring high energy levels. Probiotics as feed supplements generate ameliorative effects on host nutrient digestion and absorption. Thereby, the aim of the present research was to investigate the impact of the probiotic Phaeobacter inhibens as a water additive on cellular signaling pathways in the metamorphosis of greater amberjack (Seriola dumerili). Activation of insulin-like growth factor type 1 receptor (IGF-1R), protein kinase B (Akt), mitogen-activated protein kinases (MAPKs) and AMP-activated protein kinase (AMPK), induction of heat shock proteins (Hsps), and programmed cell death were assessed through SDS-Page/immunoblot analysis, while energy metabolism was determined through enzymatic activities. According to the results, greater amberjack reared in P. inhibens-enriched water entered the metamorphic phase with greater body length, while protein synthesis was triggered to facilitate the hypertrophic growth as indicated by IGF-1/Akt activation and AMPK inhibition. Contrarily, MAPKs levels were reduced, whereas variations in Hsps response were evident in the probiotic treatment. Apoptosis and autophagy were mobilized potentially for the structural remodeling processes. Furthermore, the elevated enzymatic activities of intermediary metabolism highlighted the excess energy demands of metamorphosis. Collectively, the present findings demonstrate that P. inhibens may reinforce nutrient utilization, thus leading greater amberjack to an advanced growth and developmental state.

Designing Traffic Management Strategies Using Reinforcement Learning Techniques

The future vision for traffic flow management is one that leverages advanced automation to assist human decision-makers in the identification of potential constraints and the development of resolution strategies. What makes this problem so challenging is the inherent uncertainty associated with forecasting these constraints, leaving human decision-makers reliant on experience to devise effective traffic management initiatives to mitigate demand in excess of resource capacity. This paper proposes to employ artificial intelligence-based methods to recommend traffic management initiatives under forecast uncertainty and to do so in a real-time planning context. The proposed algorithm consists of 1) a policy network that is generated offline using an Expert Iteration algorithm, 2) a statistical model that updates the likelihood of constraint futures based on observations, and 3) a Monte Carlo tree search algorithm that explores possible combinations of traffic management initiatives to identify the recommended actions for the current decision. The skill introduced by each of the algorithmic components is assessed for a case study focused on managing arrivals into the Atlanta Hartsfield–Jackson International Airport over 92 validation days.

A Review on the Impact of Workplace Culture on Employee Mental Health and Well-Being

Purpose: This review paper's objective is to look into how workplace culture affects the results of employee mental health and well-being. The review will cover the body of research on the subject and offer a thorough grasp of the elements that influence both healthy and unhealthy workplace cultures. Methodology: The systematic search and selection of pertinent studies on workplace culture and employee mental health and well-being will be the emphasis of this review study. Several peer-reviewed academic research examine and take into account the study's theoretical foundations. The majority of the information used in this article is taken from secondary sources. Journal articles and academic research publications provide secondary data. Findings: The findings demonstrate that organisational culture has a major impact on the mental health and wellbeing of employees. Through developing supportive leadership, social support, suitable job expectations, work-life balance, and effective regulations, healthy workplace cultures that promote employee mental health and well-being can be improved. The outcomes of employee mental health and well-being, however, can be negatively impacted by unfavourable workplace cultures, which are defined by unsupportive leadership, a lack of social support, excessive job demands, a lack of work-life balance, and insufficient policies. The study also discusses opportunities for future research, such as the need to look into the potential effects of workplace culture on certain mental diseases and the moderating effects of individual traits. Originality/Value: By offering an exhaustive synthesis of the body of research on the subject, this review paper makes a significant contribution to the body of knowledge on workplace culture and employee mental wellbeing and well-being. The study report will also offer useful recommendations for businesses, decision-makers, and practitioners on how to foster supportive work environments and enhance employee mental health and wellbeing. Overall, this review paper significantly contributes to our understanding of how workplace culture affects outcomes related to employee mental health and well-being. Paper Type: Literature Review

The Factors That Influence the Decision in Choosing Vocational Education of Students in Matthayom 3 in Eastern Economic Corridor Area (EEC) By Using Binary Logistic Regression Analysis

This research aimed to study the influential factors that influence students’ decision to choose vocational education after graduation among Matthayom 3 students whose schools are located EEC zone. The objectives of the research were to study their education choices (high school vs. vocational school), personal information, economic and social status including an awareness towards the demand for labors in the EEC area. This research was conducted among Matthayom 3 students who were in the last semester in the academic year of 2021 for 1,101 samples. The research tool was a survey questionnaire and the statistics used were the frequency, percentage as well as a Binary Logistic Regression for analyzing key influential factors that influence students’ decision to choose vocational education over high school. The research revealed that the majority of students chose high school for further education for 70%, vocational institution for 29% and only 1% chose not to study after graduation. For students who chose vocational education, the results showed that the positive factors that influenced the students’ decision were gender, GPA, average household income, the demand for labor in future industries, job opportunity after graduation, and dual degree program. The prediction accuracy for the students was 93.6%. These research findings can be used as a guideline to promote and encourage students to study further in vocational education that has already become an excessive demand in the EEC labor market.

The Factors That Influence the Decision in Choosing Vocational Education of Students in Matthayom 3 in Eastern Economic Corridor Area (EEC) By Using Binary Logistic Regression Analysis

This research aimed to study the influential factors that influence students’ decision to choose vocational education after graduation among Matthayom 3 students whose schools are located EEC zone. The objectives of the research were to study their education choices (high school vs. vocational school), personal information, economic and social status including an awareness towards the demand for labors in the EEC area. This research was conducted among Matthayom 3 students who were in the last semester in the academic year of 2021 for 1,101 samples. The research tool was a survey questionnaire and the statistics used were the frequency, percentage as well as a Binary Logistic Regression for analyzing key influential factors that influence students’ decision to choose vocational education over high school. The research revealed that the majority of students chose high school for further education for 70%, vocational institution for 29% and only 1% chose not to study after graduation. For students who chose vocational education, the results showed that the positive factors that influenced the students’ decision were gender, GPA, average household income, the demand for labor in future industries, job opportunity after graduation, and dual degree program. The prediction accuracy for the students was 93.6%. These research findings can be used as a guideline to promote and encourage students to study further in vocational education that has already become an excessive demand in the EEC labor market.

Instruments in general practice to identify and to measure (over)burden due to informal care for caring relatives: a scoping review protocol

IntroductionFamily caregivers provide by far the largest share of long-term, unpaid care for their primarily elderly and chronically ill relatives or friends. This is associated with a higher risk of...