Multi-agent modeling and simulation of a stock market

The stock market represents complex systems where multiple agents interact. The complexity of the environment in the financial markets in general has encouraged the use of modeling by multi-agent platforms and particularly in the case of the stock market.In this paper, an agent-based simulation model is proposed to study the behavior of the volume of market transactions. The model is based on the case of a single asset and three types of investor agents. Each investor can be a zero intelligent trader, fundamentalist trader or traders using historical information in the decision making process. The goal of the study is to simulate the behavior of a stock market according to the different considered endogenous and exogenous variables

Does wet-cupping therapy improve repeated sprint ability, perceived wellness, and rating of perceived exertion in young active males?

Wet-cupping therapy (WCT) is one of the oldest known medical techniques, used as a traditional and complementary therapy with a wide application all around the world for general health. Research on the effects of WCT on sports performance are sparse and inconsistent. Thus, we aimed to explore the effects of WCT on repeated sprint ability, wellness, and exertion in young active males. Forty-nine active adult males (age: [28 ​± ​5] years; body height [177 ​± ​8] cm; body mass: [79 ​± ​7] kg; body mass index: [25.4 ​± ​1.8] kg/m2) were selected for the study. The participants performed a running-based sprint test on two separate occasions (Control and Post-WCT). WCT was performed 24 ​h before the testing session. They completed the Hooper questionnaire to assess their well-being (i.e., sleep, stress, fatigue, and soreness) before each session. The rating of perceived exertion (RPE) was collected after each testing session. A higher maximum power (p ​< ​0.05, effect size [ES] ​= ​0.6), mean power (p ​< ​0.01, ES ​= ​0.5) and minimum power (p ​< ​0.01, ES ​= ​0.6) were recorded post-WCT as compared to Control session along with a better perceived sleep (p ​< ​0.01, ES ​= ​0.85). Perceived stress (p ​< ​0.01, ES ​= ​0.6) and RPE (p ​< ​0.001; ES ​= ​1.1) were lower during the post-WCT compared to the Control session. The present findings demonstrated that WCT moderately enhanced repeated sprint ability and had positive effects on perceived sleep, stress, and exertion. WCT may be an effective ergogenic aid to improve repeated sprint ability and general well-being in young adult males. Future large-scale multicentric clinical studies are paramount to confirm the results of our study

The effects of exercise difficulty and time-of-day on the perception of the task and soccer performance in child soccer players

In soccer, accurate kicking skills are important determinants of successful performance. A successful kick must meet several criteria, including speed, accuracy, and timing. In fact, players who are able to kick the ball more accurately under various difficulties, such as time pressure, space constraints, the opponent’s pressure, and the distance between the kicking point and the goal, have a clear advantage during soccer games. The aim of the present study was to investigate the effect of exercise difficulty and time-of-day on perceived task difficulty and kicking performance. Accordingly, 32 boys (age: 11 ± 0.7 years; height: 1.45 ± 0.07 m; body-mass: 38.9 ± 7.8 kg) performed shooting accuracy tests under two difficulty levels (distance (long-distance (LD) vs. short-distance (SD)) and time pressure (Without-time-pressure (WTP) vs. With-time-pressure (TP)) at 08:00 h and 17:00 h. Absolute-error, variable-error, and constant-error were evaluated during the kicking tasks, in addition to ball velocity and shooting quality. Moreover, rating-of-perceived-exertion score (RPE), feeling-scale (FS), and perceived difficulty were completed immediately at the end of each test. The results showed that shooting quality was not affected by the time-of-day, but it was better in WTP vs. TP (p p p p < 0.05). In conclusion, specific soccer skills of boys were not time-of-day dependent, but they may be associated with time pressure and task difficulty

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance.

Investment in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing in Africa over the past year has led to a major increase in the number of sequences that have been generated and used to track the pandemic on the continent, a number that now exceeds 100,000 genomes. Our results show an increase in the number of African countries that are able to sequence domestically and highlight that local sequencing enables faster turnaround times and more-regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and illuminate the distinct dispersal dynamics of variants of concern-particularly Alpha, Beta, Delta, and Omicron-on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve while the continent faces many emerging and reemerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Reference quality density measurements and sorption behavior of binary CO2_2-rich mixtures

Vorliegend wurden Dichtemessungen an sieben binären kohlendioxidreichen Gemischen bestehend aus den drei Systemen (Kohlendioxid + Argon, Kohlendioxid + Wasserstoff, Kohlendioxid + Ethan) in einem Temperaturbereich von $\it T$ = (273 bis 323) K und bei Drücken bis zu $\it p$ = 9 MPa mithilfe einer Zwei-Senkkörper Gasdichtemessanlage durchgeführt. Die relative, kombinierte, erweitere Unsicherheit ($\it k$ = 2) wurde zwischen (0.03 und 0.07) % abgeschätzt. Um dem Ziel der genauen Messung von Taudichten näher zu kommen, wurden Sorptionseffekte, die die Messung von Taudichten anspruchsvoll machen, im Rahmen dieser Arbeit an nicht porösen Materialien untersucht. Hierzu wurden mehrere Verbesserungen an einer kommerziellen Magnetschwebewaage mit drei Schwebepositionen durchgeführt. Die relative, kombinierte, erweitere Unsicherheit ($\it k$ = 2) für die durchgeführten Dichtemessungen an reinem Ethan, reinem Kohlendioxid und einem Kohlendioxid und Ethan Gemisch wurden zwischen (0.08 und 0.15) % abgeschätzt

The effect of Ramadan fasting on the morning-evening difference in team-handball-related short-term maximal physical performances in elite female team-handball players

The purpose of this study was to explore the effect of time of day (TD) on two types of exercise protocols [continuous (CP) versus alternated (AP)]. Eleven physical education students (mean ± SD: age = 24.4 ± 1.2 years, aerobic peak power (APP) = 290 ± 31.9 W) underwent four sessions. These sessions were performed at 08:00 (AM) and 18:00 (PM) and consisted of cycling exercises until voluntary exhaustion at 90% APP (CP) or 70%-105% APP (AP) with the order of testing randomly assigned. Time to exhaustion (time limit = Tlim) was measured from the start of the test to when voluntary exhaustion occurred. Heart rate (HR) was recorded at baseline (HRbaseline) and throughout the protocols to determine HR at exhaustion (HRpeak). Blood lactate ([La]) was measured at rest, immediately after exhaustion and at 2min30 post-exercise to determine [La]peak. A significantly higher means of Tlim (334 ± 57 s; 272 ± 59 s; p< 0.05), HRbaseline (72 ± 5 beats/min; 67 ± 5 beats/min; p< 0.01), HRpeak (186 ± 8 beats/min; 178 ± 9 beats/min; p< 0.01) and [La]peak (16.2 ± 2.1 mmol/l; 13.9 ± 1.9 mmol/l; p< 0.05) were observed in CP at the PM compared to the AM. In addition, a significant higher means of Tlim (380 ± 54 s; 312 ± 82 s; p< 0.05), HRbaseline (73.1 ± 5.5 beats/min; 67 ± 5.4 beats/min; p< 0.01), HRpeak (186 ± 8 beats/min; 180 ± 9 beats/min; p< 0.05) and [La]peak (17.9 ± 1.8 mmol/l; 14.7 ± 2.1 mmol/l; p< 0.01) were observed in AP at the PM compared to the AM. It is concluded that AP and CP are more appropriate in the late afternoon than in the morning for performing long-lasting exercises. The AP could be a novel strategy for increasing the engagement in physical activity. Copyright: © 2020 Souissi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.This study was supported by The Research Laboratory "Sports Performance Optimization" National Center of Medicine and Science in Sports (CNMSS).Scopu

Dynamic Modeling and Simulation of the Sulfur Combustion Furnace in Industrial Smelter

In industrial smelters, sulfuric acid is manufactured using the elemental sulfur in a series of three-unit operations: elemental sulfur oxidation, sulfur dioxide catalytic conversion, and sulfur trioxide absorption. The sulfur oxidation, which is the basic step in this process, is generally performed under a sulfur combustion furnace that ensures the production of the process gas stream, which will be the main supply stream to the other unit operations. In this paper, a dynamic model is developed based on the fundamental mass and energy balance, including the sulfur oxidation and the dynamic flow behavior aspects within the furnace. The obtained model is simulated in the Matlab/Simulink environment and data from an industrial plant were used to validate the model. The simulation results and the plant measurement comparison showed an accuracy of 96%, with a mean absolute error of 16.12 &deg;C and a root mean square error of 23.27 &deg;C. Afterwards, the effect of different operating conditions and disturbance parameters on the sulfur combustion furnace performance were studied. Finally, the relationship and a correlation between the temperature and sulfur dioxide molar fraction at the outlet of the furnace were investigated for industrial use

FIFA World Cup 2022: What can we learn from the inspiring Tokyo 2020 Olympic Games held in COVID-19 times?

Preparation for the FIFA World Cup 2022 (WC2022) comes in the time of the COVID-19 pandemic. This study aims were to (i) provide a brief overview of the 2020 Tokyo Olympic and Paralympic games in the context of the COVID-19 pandemic, and (ii) highlight the potential challenges and opportunities central to the hosting of the FIFA WC2022. The organisation, public health policies and prevention protocols of the postponed 2020 Olympic/Paralympic Games (Tokyo July-August 2021), the infection rates during the event, as well as the upcoming WC2022 and its related preparations and challenges, were analysed. An unparalleled International Olympic Committee (IOC) effort, together with the Japanese government and people’s perseverance and drive, enabled the safe delivery of the Tokyo Olympic/Paralympic Games, which left a legacy beyond sport. This has been aided by the collection of critical data and lessons learnt throughout the games. The stringent public health policies and especially the tight bubble system for players and their respective delegations have certainly been the key components that ensured the successful containment of COVID-19 within the targeted population. One of the most significant lessons learned from the Tokyo 2020 Olympics is the improvement made in controlling COVID-19 in the context of mass gathering events. Strict infection control strategies to prevent future COVID-19 transmission during the FIFA World Cup 2022 are an immediate priority in Qatar and are constantly being prepared. The planned measures and health care strategies appear to be well adjusted to the risk, especially for the large anticipated number of visitors, and can provide sufficient guarantees to conduct relatively “safe” mega sports events