Reasonable Limits Research Articles

PERAN KOMUNIKASI KELUARGA DALAM MENGONTROL PENGGUNAAN GADGET PADA ANAK USIA DINI DI KECAMATAN PERCUT SEI TUAN

Family communication is inseparable from the relationship between parents and children. In a family, not only parents but also children use gadgets. In fact, almost the average parent associates the use of gadgets with early childhood. Of course this is a challenge in establishing good communication so that parents can control the use of these devices so that their use remains within reasonable limits. This study aims to determine the role of communication used by parents in controlling the use of gadgets in early childhood in Percut Sei Tuan District. In this study used a qualitative method with a phenomenological approach. Then the researcher obtained the data by using observation, interview and documentation techniques. The source of information in this research is Percut Sei Tuan's parents. Data analysis was carried out descriptively and variation techniques and reliability tests were used for validity. The results of this study indicate that in a family, parents control the decision-making process about what children do.

Prevention of Election Violations on The Money Political Mode Conducted by Candidate Members of the 2024 Legislative

Elections are instruments or means to implement democracy; in fact, many democratic countries make elections as a symbol as well as a benchmark for democracy. Direct general elections by the people are a means of realizing people's sovereignty in order to produce a democratic state government based on Pancasila and the 1945 Constitution. The 1945 Constitution in Article 1 paragraph (2) states that "sovereignty is in the hands of the people and implemented according to the 1945 Constitution." Constitution". Direct, public, free, confidential, honest and fair general elections can be realized if they are carried out by general election organizers who have integrity, professionalism and accountability. In the implementation of elections, the role of political participation is important because citizens have surrendered their right to power to political institutions through elections and must not lose their right to defend themselves against possible abuse of power. This approach method is carried out in order to be able to make changes or changes from various theories in the discipline of law through a scientific process. Normative juridical research is research conducted by examining library materials or primary legal materials. This information can be obtained from laws and regulations and articles. Then it is described and linked so that it can be presented in a more systematic writing, in order to answer the problems that have been formulated. The research specification used in this research is descriptive analytical method by explaining, describing, and correlating legal regulations and theories with the problems that occur. The results of the study show that efforts to prevent election violations related to the money politics mode committed by legislative candidates in 2024 can be carried out through several steps, including the government must strictly enforce the law against money politics violations. Increase public education and awareness about the dangers and negative effects of money politics. Improve oversight of expenditures and campaign funding of candidates for legislative members. Communities must be encouraged to actively report any money politics practices they encounter. Establish a reasonable and realistic maximum limit on campaign spending for legislative candidates. This can help reduce the financial gap between candidates and prevent unhealthy money politics practices. Establish an independent institution tasked with overseeing elections and handling violations related to money politics. Conducting education and training related to ethics and integrity to candidates for legislative members. Keywords: Prevention of Election, Money Political, Legislative

Direct Ammonia SOFC-Gas Turbine Hybrid Systems Modeling for Heavy-Duty Transportation Sector

Ammonia currently stands as being the second most produced chemical in the world [1]. While it is prominently used in the manufacturing of fertilizers, increase in production capacity through renewable sources such as green hydrogen and its potential as a carbon-neutral energy carrier make it a promising candidate to replace fossil fuels for power generation in the future [2]. Moreover, when compared to liquid hydrogen, ammonia can be stored at more practical temperatures (-253⁰C vs -33⁰C at 1 bar) and has a higher volumetric energy density (8.5 MJ/L vs 12.7 MJ/L) [3]. Though the toxicity of ammonia as a fuel is well known, there are well established safety and handling procedures for storage and transport, given its ubiquitous existence as an essential commodity required for agriculture.From a systems perspective, residual chemical exergy available in the SOFC anode gas exhaust can be utilized through a gas turbine to enable increased efficiency [4]. Direct ammonia SOFCs (DASOFCs) can eliminate the need for external cracking to hydrogen, thereby reducing system complexity. In addition, heat loss and thermal management in the stack periphery may be effectively managed via in-situ endothermic decomposition of ammonia [5]. Integration in a hybrid system is also beneficial to SOFCs due to the associated heat of compression for pressurized operation. The different physicochemical timescales of electrochemical fuel cells and mechanical turbomachinery are advantageous to dynamic operation which is important because of fluctuating power loads in a mobile application.In this work, the potential of an ammonia-based hybrid SOFC/GT system concept is assessed. A multiscale stack simulation using constitutive relations for heat, mass and charge transfer based on high power density SOFCs is integrated with turbomachinery and other auxiliary system components within the gPROMS process simulation framework. State variables for each point can then be defined to estimate the operating boundaries of the system.This presentation discusses the thermodynamics of SOFC operation and system concepts to utilize ammonia in a hybrid system for a kW-scale transportation application. This involves evaluation of system indicators such as thermodynamic efficiency, fuel utilization and specific power which can help determine optimal performance. The efficiency and specific power are dictated by the operating temperature of the fuel cell, preheating requirements and the relative utilization of fuel between the SOFC and gas turbine. The proposed system concept is shown to achieve LHV efficiencies of up to 60% (LHV) within reasonable operating limits. The presentation includes an examination of the prospects of ammonia as a power source for the mobility sector in comparison to contemporary and future renewable fuels, and concludes with practical challenges for deployment.

Humanitarian bargains: private refugee sponsorship and the limits of humanitarian reason

ABSTRACT This article analyzes Canada's private sponsorship of refugees to explore the conceptual and practical limits of humanitarian reason. In private refugee sponsorship, sponsors channel their humanitarian impulse to resettle refugees in a time-limited partnership with both the state and the refugees they sponsor. To gain insight into how sponsors perform their role in this structurally and temporally bounded trajectory, we conducted a national online survey of 530 sponsors who volunteered to support Syrians resettled to Canada after November 2015. Our analysis draws primarily from written comments shared by survey respondents. We find that over time, sponsors resort to tacit ‘humanitarian bargains’ to mediate between their initial commitment to save refugees’ lives and their ongoing quotidian experiences of intervening in and shaping refugee lives. These bargains become visible when sponsors evaluate sponsorship by reference to a set of expectations and judgements about sponsored refugees, their fellow sponsors and the state. We suggest that the concept of the humanitarian bargain has explanatory force beyond refugee sponsorship.

Use of a handheld Doppler to measure brachial and femoral artery occlusion pressure.

Objective: Measurement of arterial occlusion pressure (AOP) is essential to the safe and effective use of blood flow restriction during exercise. Use of a Doppler ultrasound (US) is the "gold standard" method to measure AOP. Validation of a handheld Doppler (HHDOP) device to measure AOP could make the measurement of AOP more accessible to practitioners in the field. The purpose of this study was to determine the accuracy of AOP measurements of the brachial and femoral arteries using an HHDOP. Methods: We simultaneously measured AOP using a "gold standard" US and a HHDOP in the dominant and non-dominant arms (15 males; 15 females) and legs (15 males; 15 females). Results: There were no differences in limb circumference or limb volume in the dominant and non-dominant arms and legs between males and females or between the dominant and non-dominant arms and legs of males and females. The differences between US and HHDOP measures of AOP in the dominant and non-dominant arms and legs were either not significant or small (<10mmHg) and of little practical importance. There were no sex differences in AOP measurements of the femoral artery (p > 0.60). Bland-Altman analysis yielded an average bias (-0.65mmHg; -2.93mmHg) and reasonable limits of agreement (±5.56mmHg; ±5.58mmHg) between US and HHDOP measures of brachial and femoral artery AOP, respectively. Conclusion: HHDOP yielded acceptable measures of AOP of the brachial and femoral arteries and can be used to measure AOP by practitioners for the safe and effective use of blood flow restriction. Due to the potential differences in AOP between dominant and non-dominant limbs, AOP should be measured in each limb.

Development and validation of a mathematical model for evaluating shear-induced damage of von Willebrand factor

PurposeTo develop a mathematical model for predicting shear-induced von Willebrand factor (vWF) function modification which can be used to guide ventricular assist devices (VADs) design, and evaluate the damage of high molecular weight multimers (HMWM)-vWF in VAD patients for reducing clinical complications. MethodsMathematical models were constructed based on three morphological variations (globular vWF, unfolded vWF and degraded vWF) of vWF under shear stress conditions, in which parameters were obtained from previous studies or fitted by experimental data. Different clinical support modes (pediatric vs. adult mode), different VAD operating states (pulsation vs. constant mode) and different clinical VADs (HeartMate II, HeartWare and CentriMag) were utilized to analyze shear-induced damage of HMWM-vWF based on our vWF model. The accuracy and feasibility of the models were evaluated using various experimental and clinical cases, and the biomechanical mechanisms of HMWM-vWF degradation induced by VADs were further explained. ResultsThe mathematical model developed in this study predicted VAD-induced HMWM-vWF degradation with high accuracy (correlation with experimental data r2 > 0.99). The numerical results showed that VAD in the pediatric mode resulted in more HMWM-vWF degradation per unit time and per unit flow rate than in the adult mode. However, the total degradation of HMWM-vWF is less in the pediatric mode than in the adult mode because the pediatric mode has fewer times of blood circulation than the adult mode in the same amount of time. The ratio of HMWM-vWF degradation was lower in the pulsation mode than in the constant mode. This is due to the increased flushing of VADs in the pulsation mode, which avoids prolonged stagnation of blood in high shear regions. This study also found that the design feature, rotor size and volume of the VADs, and the superimposed regions of high shear stress and long residence time inside VADs affect the degradation of HMWM-vWF. The axial flow VADs (HeartMate II) showed higher degradation of HMWM-vWF compared to centrifugal VADs (HeartWare and CentriMag). Compared to fully magnetically suspended VADs (CentriMag), hydrodynamic suspended VADs (HeartWare) produced extremely high degradation of HWMW-vWF in its narrow hydrodynamic clearance. Finally, the study used a mathematical model of HMWM-vWF degradation to interpret the clinical statistics from a biomechanical perspective and found that minimizing the rotating speed of VADs within reasonable limits helps to reduce HWMW-vWF degradation. All predicted conclusions are supported by the experimental and clinical data. ConclusionThis study provides a validated mathematical model to assess the shear-induced degradation of HMWM-vWF, which can help to evaluate the damage of HMWM-vWF in patients implanted with VADs for reducing clinical complications, and to guide the optimization of VADs for improving hemocompatibility.

Analysis of MIMO methods for 5G and subsequent technologies: advantages and disadvantages

Formulation of the problem. The global bandwidth shortage in the wireless communications sector has prompted the study and research of wireless access technology, known as mass Multiple Input/output (MIMO) technology. Mass MIMO is one of the key technologies for next-generation networks, which combines antennas in both the transmitter and receiver to provide high spectral and energy efficiency using relatively simple processing. Gaining a better understanding of the massive MIMO system to overcome the fundamental challenges of this technology is vital for the successful deployment of 5G and higher networks to implement various intelligent sensor system applications. Thus, in this paper, fully digital, analog and hybrid structures are analyzed and the method of multilevel massive MIMO transmission is described in detail. Purpose. Analysis of the main technologies needed to meet the demand for data transmission expected for 5G and 6G networks, with the allocation of transmission methods necessary for the mass implementation of MIMO. Practical significance. Evaluation of the MIMO system bandwidth, hardware and computational complexity, as well as energy efficiency, it is shown that massive MIMO circuits can rely on asymptotic linear independence when designing signal processing, given the large number of antennas used. Classical MIMO methods are not able to meet the technical requirements, so hybrid architectures use a combination of analog and digital areas to use the spatial resolution provided by a large number of antenna elements, but at the same time the number of energy-consuming and expensive radio frequency circuits remains within reasonable limits, and computational complexity is controlled. It becomes clear that there is no single structure/algorithm that would provide the best compromise between complexity and performance in all possible scenarios, rather, there is a need to adapt them to the characteristics of the application and channel when designing the system. As for optimizing the energy efficiency of the RF power supply, this is achievable using solutions such as multilayer massive MIMO.

Marine and land economy–energy–environment systems forecasting by novel structural-adaptive fractional time-delay nonlinear systematic grey model

Rapid economic growth and rising energy consumption have inevitably led to environmental problems, which is a cutting-edge issue of sustainable development. To distinguish the internal structure of marine and land economy–energy–environment (3E) systems and the non-linear relationships between the variables, a novel structural-adaptive fractional time-delay nonlinear systematic grey prediction model (FTDNSGM(1,m)) is established. Additionally, the solving process of each layer model of FTDNSGM(1,m) is described in detail, and the derived models of underlying layer FBTDGM(1,1) and upper layer FBTDGM(1,N) are deduced respectively, which constitute the nested grey difference equations. Furthermore, combined with comparative analysis and Monte-Carlo simulation, optimal non-linear parameters are determined by Beluga Whale Optimization (BWO) algorithm with robustness. Empirically, based on five case datasets under the national–regional dimensions, the FTDNSGM(1,m) model is scientifically verified to have superlative validity and stability. The results demonstrate that the average MAPEs of the proposed model in training and test sets are 0.38%, 0.28%, 0.34%, 0.26%, 0.21%, and 0.38%, 0.88%, 0.47%, 1.36%, 0.67%. Ulteriorly, the proposed model is of applicability to assess the impact on 3E systems attributed to the COVID-19 pandemic in 2020 and 2021. Predictably, from 2022 to 2025, with sustained economic growth, marine and land energy consumption will rise within reasonable limits, while coastal water quality will continue to grow and NOx emissions will keep going down.

Dual-channel snapshot imaging spectrometer with wide spectrum and high resolution.

The comprehensive analysis of dynamic targets brings about the demand for capturing spatial and spectral dimensions of visual information instantaneously, which leads to the emergence of snapshot spectral imaging technologies. While current snapshot systems face major challenges in the development of wide working band range as well as high resolution, our novel dual-channel snapshot imaging spectrometer (DSIS), to the best of our knowlledge, demonstrates the capability to achieve both wide spectrum and high resolution in a compact structure. By dint of the interaction between the working band range and field of view (FOV), reasonable limits on FOV are set to avoid spectral overlap. Further, we develop a dual-channel imaging method specifically for DSIS to separate the whole spectral range into two parts, alleviating the spectral overlap on each image surface, improving the tolerance of the system for a wider working band range, and breaking through structural constraints. In addition, an optimal FOV perpendicular to the dispersion direction is determined by the trade-off between FOV and astigmatism. DSIS enables the acquisition of 53×11 spatial elements with up to 250 spectral channels in a wide spectrum from 400 to 795nm. The theoretical study and optimal design of DSIS are further evaluated through the simulation experiments of spectral imaging.

Does fintech lending expansion disturb financial system stability? Evidence from Indonesia

Literature suggests two contradictory views regarding the impacts of fintech lending on banks. The competition-instability proponents believe that fintech lending expansion erodes bank market and threatens banks as traditional intermediaries, thereby intensifying bank risk-taking and potentially disturbing financial stability. In contrast, the competition-stability proponents believe fintech lending reduces asymmetric information in the credit market, thus reducing bank risk-taking and increasing bank resilience to a systematic shock. This paper aims to examine the impacts of fintech lending expansion on bank-risk taking, i.e., credit channeling activity and bank risk. This study utilizes the OLS, random effects, fixed effects, and two-step GMM regressions to test the conjectures. Consistent with the competition-stability hypothesis, our evidence indicates that shadow banking increases as banks actively seek channels to diversify their risks but are less likely to use fintech lending as a credit channel. This paper also corroborates the notion that fintech lending expansion encourages banks to diversify their risks. Pertaining to the relationship between fintech lending and bank risk, our results suggest that fintech lending expansion encourages banks to work more efficiently to improve their credit quality rather than to intensify bank risk-taking. These findings also indicate that synergy between fintech lending and banks would increase bank credit quality. This paper also examines the reasonable credit limits for fintech lending firms based on MSMEs’ characteristics. Employing the threshold regression, we find that IDR5 billion is the maximum credit provision to induce the profitability of MSMEs whereas IDR6 billion is the maximum credit provision to minimize the default risk of MSMEs.

Successful Repair Management for Urinary Bladder Perforation During Myomectomy on Cervical Myoma on Patients with Previous Cesarean Section: A Challenging Case Report

The 20-25% incidence of uterine myoma often experienced by women in childbearing age and 2% of these uterine myomas attach and grow in the uterine cervical area. The chief complain of cervical myom are lumps in the lower abdomen that are getting bigger and pressing on the urinary bladder cause difficulty in urinating and are accompanied by bloody urine, although the amount of menstrual blood is still within reasonable limits. Like uterine myomas, cervical myomas are not fused with the myometrial lining but are covered by thin connective tissue on the surface.The procedure of cervical myoma based on ACOG (American College of Obstetrics and Gynecology) is hysterectomy if the patient no longer wants to get pregnant, or myomectomy if the patient still wants to have children. Both of these actions have a very high risk in which vascularization in the pelvic area will be very complex, pressure on cervical myoma will have a high risk of injuring the urinary bladder mucosa and when setting aside the lower segment of the uterus there is a risk of injury. We present a 38-year-old woman with 30x 26 x 22 cm giant cervical myoma and secondary infertility that was treated with challenging laparotomi myomectomy in colaboration with urologist to preserve fertility. There was a tear in the upper part of the urinary bladder which was elongated with irregular edges measuring 12 x 5 cm after enucleation cervical myoma. The tear was repaired immediately and there are no complications in the form of vesico-vaginal fistulas or vesico-cervical postoperatively.

Dynamical Model for Power Grid Frequency Fluctuations: Application to Islands With High Penetration of Wind Generation

We study the effects of a high share of wind generation on the frequency fluctuations of power grids on islands. We propose a dynamical model that includes conventional and variable renewable generation, as well as demand variations. Our model can assimilate load and generation data and reproduce frequency fluctuations with the current power mix with a high degree of accuracy, and it allows to simulate the frequency dynamics for different scenarios with a very high penetration of renewable energy. As a case study, we analyze the power grid of Gran Canaria island. We characterize the frequency fluctuations and propose a method to estimate the control needed to keep frequency deviations within reasonable limits.

Toward a New Neurobiology of Writing: Plasticity and the Feeling of Failure

This article will explore the potential of recent neuroscience to inform a writing pedagogy aimed at a habitus of plasticity and emotional intelligence. Arguing that our field has never fully realized the embodied pedagogy called for decades ago by compositionists such as Brand and McLeod, by placing affect theory in our field in conversation with neuroscience, the article theorizes the value of understanding the plasticity of embodied affects as meaningful in writing processes. It demonstrates that neuroscience offers advances in our understanding of the emotions involved in learning while providing practical resources to “recategorize” emotional experiences in ways that will enable students to persist in writing-related tasks and to better realize their rhetorical and social goals. Ultimately, addressing the limits of reason and metacognition, the article claims that our pedagogies must confront the new forms of woundedness and ossification that pose increasing challenges to learning today.

THE INFLUENCE OF THE GRAY ECONOMY ON THE ECONOMIC DEVELOPMENT OF BOSNIA AND HERZEGOVINA AND POTENTIAL MEASURES FOR BRINGING IT WITHIN REASONABLE LIMITS

&amp;lt;p style=&amp;quot;text-align: justify;&amp;quot;&amp;gt;&amp;lt;span lang=&amp;quot;BS-LATN-BA&amp;quot;&amp;gt;It is well known that the gray economy is a scourge of the modern global world, in which all positive and negative phenomena are quickly transferred from country to country. The gray economy is one of the greatest evils of today and leaves significant traces on the entire society. In this paper, we will present some of the negative consequences that the gray economy brings, starting with globalization and its impact on the deepening of the economic and financial crisis. We will also present the influence of the gray economy, especially illegal work, and the consequences that our economy and population suffer. In addition to the negative impact, if its analysis is carried out well and qualitatively, it can serve as an instrument for resetting the economy and society, thus becoming a new development opportunity for faster economic development in Bosnia and Herzegovina. We will present some potential measures that could bring the gray economy within reasonable limits and thereby help the state in the fight for the fastest possible recovery of the economy and its equal inclusion in contemporary economic flows.&amp;lt;/span&amp;gt;&amp;lt;/p&amp;gt;

Critical Review of Criminalization Policies in Law Number 1 of 2023 Concerning the KUHP

The Criminalization Policy in Law Number 1 of 2023 concerning the Criminal Code is First, criminalization is limited to determining an act as a criminal offense which is punishable by criminal sanctions. Second, criminalization is a complex problem because there are different types of acts that can be criminalized, differences in values and norms in society. Third, important principles that need to be considered in criminalization are the principle of legality, the principle of subsidiarity, and the principle of equality before the law. Finally, the criteria to consider in criminalization include: The application of the Criminalization Policy in Law Number 1 of 2023 concerning the Criminal Code is an example of Article 509 of Law Number 1/2023 of the Criminal Code which is contrary to the 1945 Constitution and has no binding legal force. Because within the limits of reasonable reasoning, criminal error in Article 509 of the National Criminal Code is on the informant (client), not on the advocate. So it is not right for an advocate to be convicted because of a client's false statement. Article 509 of the National Criminal Code contradicts: Article 1 paragraph (3) of the 1945 Constitution which states: The State of Indonesia is a State of Law.

COVID-19 Crisis and the State of Emergency: Analyzing Impacts, Paradoxes, and Recommendations

This scientific article examines the exceptional situation that emerged during the COVID-19 pandemic and the subsequent imposition of states of emergency, which raised concerns about potential abuses of power by governments. Employing analytical and comparative approaches, the research explores the connection between the pandemic and its effects on human rights and freedoms, particularly regarding movement and assembly restrictions. The study highlights the diverse implementation of states of emergency across countries during the crisis. The findings reveal international gaps in preparedness, the violation of human rights, and the potential exploitation of emergencies for other purposes. Recommendations include enhancing international cooperation, reevaluating intellectual property rights related to combating epidemics, establishing a global health cooperation fund, setting reasonable limits for emergency measures, and implementing internal monitoring committees to ensure the proportionality of restrictions. These insights have significant implications for global health security, human rights protection, and international collaboration in response to future health emergencies.Highlights:&#x0D; &#x0D; &#x0D; Impact of state of emergency: Examining the repercussions of COVID-19 pandemic emergency measures on human rights.&#x0D; &#x0D; &#x0D; Global health challenges: Assessing health system effectiveness in confronting COVID-19 and its impact on human rights.&#x0D; &#x0D; &#x0D; Recommendations for action: Proposing measures for international cooperation, intellectual property rights reconsideration, establishing a health cooperation fund, setting reasonable emergency limits, and implementing monitoring committees.&#x0D; &#x0D; &#x0D; Keywords: COVID-19, state of emergency, human rights, global health, recommendations.&#x0D;

Vector Autoregression for Forecasting the Number of COVID-19 Cases and Analyzing Behavioral Indicators in the Philippines: Ecologic Time-Trend Study.

Traditional surveillance systems rely on routine collection of data. The inherent delay in retrieval and analysis of data leads to reactionary rather than preventive measures. Forecasting and analysis of behavior-related data can supplement the information from traditional surveillance systems. We assessed the use of behavioral indicators, such as the general public's interest in the risk of contracting SARS-CoV-2 and changes in their mobility, in building a vector autoregression model for forecasting and analysis of the relationships of these indicators with the number of COVID-19 cases in the National Capital Region. An etiologic, time-trend, ecologic study design was used to forecast the daily number of cases in 3 periods during the resurgence of COVID-19. We determined the lag length by combining knowledge on the epidemiology of SARS-CoV-2 and information criteria measures. We fitted 2 models to the training data set and computed their out-of-sample forecasts. Model 1 contains changes in mobility and number of cases with a dummy variable for the day of the week, while model 2 also includes the general public's interest. The forecast accuracy of the models was compared using mean absolute percentage error. Granger causality test was performed to determine whether changes in mobility and public's interest improved the prediction of cases. We tested the assumptions of the model through the Augmented Dickey-Fuller test, Lagrange multiplier test, and assessment of the moduli of eigenvalues. A vector autoregression (8) model was fitted to the training data as the information criteria measures suggest the appropriateness of 8. Both models generated forecasts with similar trends to the actual number of cases during the forecast period of August 11-18 and September 15-22. However, the difference in the performance of the 2 models became substantial from January 28 to February 4, as the accuracy of model 2 remained within reasonable limits (mean absolute percentage error [MAPE]=21.4%) while model 1 became inaccurate (MAPE=74.2%). The results of the Granger causality test suggest that the relationship of public interest with number of cases changed over time. During the forecast period of August 11-18, only change in mobility (P=.002) improved the forecasting of cases, while public interest was also found to Granger-cause the number of cases during September 15-22 (P=.001) and January 28 to February 4 (P=.003). To the best of our knowledge, this is the first study that forecasted the number of COVID-19 cases and explored the relationship of behavioral indicators with the number of COVID-19 cases in the Philippines. The resemblance of the forecasts from model 2 with the actual data suggests its potential in providing information about future contingencies. Granger causality also implies the importance of examining changes in mobility and public interest for surveillance purposes.

Defining Biliary Hyperkinesia and the Role of Cholecystectomy.

Functional gallbladder disorder is most commonly defined by biliary colic and low ejection fraction (EF) on cholescintigraphy. Biliary hyperkinesia is a controversial type of functional gallbladder disorder, and its definition and the role of cholecystectomy in treating functional gallbladder disorder remains unclear. We conducted a retrospective review of patients who underwent cholecystokinin-stimulated cholescintigraphy and cholecystectomy at 3 Mayo Clinic sites between 2007 and 2020. Eligible patients were 18 years or older, presented with symptoms of biliary disease, had an EF greater than 50%, underwent cholecystectomy, and had no evidence of acute cholecystitis or cholelithiasis on imaging. We used receiver operating characteristics curve analysis to identify the optimal cutoff value that predicted symptom resolution within 30 days of cholecystectomy. A total of 2,929 cholecystokinin-stimulated cholescintigraphy scans were performed during the study period; the average EF was 67.5% and the median EF was 77%. Analyzing those with EFs greater than or equal to 50% yielded 1,596 patients with 141 (8.8%) going on to have cholecystectomy. No significant differences were found in age, sex, BMI, final pathology between patients with and without pain resolution. Using a cutoff EF of 81% was significantly associated with pain resolution after cholecystectomy (78.2% for EF greater than or equal to 81% vs 60.0% for EF less than 81%, p = 0.03). Chronic cholecystitis was found in 61.7% of the patients on final pathology. We determined that an EF cutoff of 81% is a reasonable upper limit of normal gallbladder EF. Patients with biliary symptoms and an EF greater than 81% but no evidence of biliary disease on ultrasound or scintigraphy can be classified as having biliary hyperkinesia. Based on our findings, we recommend cholecystectomy for this patient population.

Evaluation of Submission Limits and Regression Penalties to Improve Student Behavior with Automatic Assessment Systems

Objectives . Automatic assessment systems are widely used to provide rapid feedback for students and reduce grading time. Despite the benefits of increased efficiency and improved pedagogical outcomes, an ongoing challenge is mitigating poor student behaviors when interacting with automatic assessment systems including numerous submissions, trial-and-error, and relying on marking feedback for problem solving. These behaviors negatively affect student learning as well as have significant impact on system resources. This research quantitatively examines how utilizing submission policies such as limiting the number of submissions and applying regression penalties can reduce negative student behaviors. The hypothesis is that both submission policies will have a significant impact on student behavior and reduce both the number of submissions and regressions in student performance. The research questions evaluate the impact on student behavior, determine which submission policy is the most effective, and what submission policy is preferred by students. Participants . The study involved two course sections in two different semesters consisting of a total of 224 students at the University of British Columbia, a research-intensive university. The students were evaluated using an automated assessment system in a large third year database course. Study Methods . The two course sections used an automated assessment system for constructing database design diagrams for assignments and exams. The first section had no limits on the number of submissions for both assignments and exams. The second section had limits for the exams but no limits on assignments. On the midterm, participants were randomly assigned to have either a restriction on the total number of submissions or unlimited submissions but with regression penalties if a graded answer was lower than a previous submission. On the final exam, students were given the option of selecting their submission policy. Student academic performance and submission profiles were compared between the course sections and the different submission policies. Findings. Unrestricted use of automatic grading systems results in high occurrence of undesirable student behavior including trial-and-error guessing and reduced time between submissions without sufficient independent thought. Both submission policies of limiting maximum submissions and utilizing regression penalties significantly reduce these behaviors by up to 85%. Overall, students prefer maximum submission limits, and demonstrate improved behavior and educational outcomes. Conclusions . Automated assessment systems when used for larger problems related to design and programming have benefits when deployed with submission restrictions (maximum attempts or regression penalty) for both improved student learning behaviors and to reduce the computational costs for the system. This is especially important for summative assessment but reasonable limits for formative assessments are also valuable.

Frequency Fluctuation Mitigation in a Single-Area Power System Using LQR-Based Proportional Damping Compensator

To maintain the stability of the power system, frequency fluctuations must be reduced in the shortest possible timeframe. Load frequency control (LFC) plays a critical role in achieving this objective by regulating the system frequency and the desired demand or output power in an interconnected network, thereby enabling the system to adapt the load disturbances. In order to effectively mitigate the frequency fluctuation caused by load variation in a single-area power system, a new control strategy integrating a linear quadratic regulator (LQR), a proportional controller, and a damping compensator is proposed in this paper. The proposed controller is named as the LQR-based proportional damping compensator which mitigates the frequency fluctuation of a single-area power system. MATLAB/Simulink simulation is conducted on a single-area power system to demonstrate the efficacy of the proposed control technique. The simulation results demonstrate that the proposed method successfully reduces frequency variations, maintains system frequency within reasonable limits, and substantially reduces the settling time as compared to other existing control techniques. Apart from the simulation analysis, to experimentally validate the performance of the proposed controller, a hybrid multiprocessor-based processor-in-loop (PIL) technique is also introduced in the paper. Both the simulation and experimental results prove the promising performance of the proposed controller for mitigating the frequency fluctuation of a single-area power system.