Internal Variables Research Articles

Multi drug resistance in Colorectal Cancer- approaches to overcome, advancements and future success

A significant obstacle to treating cancer is multidrug resistance (MDR), which is the capacity of cancerous cells to develop resistance to both traditional and cutting-edge chemotherapeutic treatments. Following the initial discovery that cellular pumps reliant on ATP were the root of chemotherapy resistance, more research has revealed the involvement of additional mechanisms, including increased drug metabolism, reduced drug entry, and compromised apoptotic pathways. Numerous projects have focused on MDR, and innumerable research has been conducted to better understand MDR and develop methods to mitigate its consequences. Multidrug resistance (MDR) is a key challenge in treating cancer. 90% of cancer-related fatalities are brought on by tumor metastasis and recurrence, which is possible with MDR. Drug resistance in cancerous cells is influenced by diverse internal and extrinsic variables, including genetic and epigenetic changes, drug efflux systems, DNA repair mechanisms, apoptosis, and autophagy. In this review paper, we list the potential hazards associated with cancer therapy in general, primarily multidrug resistance developing a theory for colorectal cancer in particular. We discussed the unique instance of multidrug resistance in colorectal cancer in malignancies generally and 5-fluorouracil, curcumin, and lipids as viable therapy options for the condition. The use of nanotechnology (mainly nanoparticles) has facilitated better in vitro as well as in vivo efficacy during preclinical phases, summarized below, allowing for a more thorough investigation of colorectal cancers and pancreatic carcinomas with their translation to following clinical trials.

Derivations of the stress-strain relations for viscoanelastic media and the heat equation in irreversible thermodynamic with internal variables

Abstract By using a procedure of classical irreversible thermodynamics with internal variable (CIT-IV), some possible interactions among heat conduction and viscous-anelastic flows for rheological media are studied. In particular, we introduce as internal variables a second rank tensor ε α β ( 1 ) \varepsilon _{\alpha \beta }^{(1)} that is contribution to inelastic strain and a vector ξα that influences the thermal transport phenomena and we derive the phenomenological equations for these variables in the anisotropic and isotropic cases. The stress-strain equations, the general flows and the temperature equation in visco-anelastic processes are obtained and when the medium is isotropic, we obtain that the total heat flux J (q) can be split in two parts: a first contribution J (0), governed by Fourier law, and a second contribution J (1), obeying Maxwell-Cattaneo-Vernotte (M-C-V) equation.

Analysis of the Relationship between Internal and External Variables and the Level of Women's Participation in Development Planning in Lintongnihuta Subdistrict, Humbang Hasundutan Regency

This study delves into the multifaceted participation of women in Village Development Planning Deliberation (Musrenbangdes) within the Lintongnihuta District, analyzing the influence of various factors like age, education, occupation, income, and duration of residence. Employing an eight-question Likert scale, the research measures women's engagement and utilizes quantitative descriptive data analysis, including frequency tables. The study employs cross-tabulation analysis (chi-square test) and validity tests with the Pearson Product-Moment formula through SPSS v24 software to determine relationships between internal and external factors and their impact on women's participation. Findings underscore Musrenbangdes as a substantive platform for authentic expressions of women's aspirations, revealing significant positive correlations between participation and internal factors such as age, education, communication, and leadership. While all proposals are accepted, government scrutiny precedes execution. The study advocates enhancing women's involvement through targeted improvements, childcare support, and health education, offering valuable insights for a more inclusive and effective development planning process.

Circadian-based approach for improving physiological, phytochemical and chloroplast proteome in Spinacia oleracea under salinity stress and light emitting diodes

Salt stress is a recognized annihilating abiotic stress that has a significant impact on agricultural and horticulture crop productivity. Plant development faces three distinct dangers as a result of salt stress: oxidative stress, osmotic stress, and ionic toxicity. It has been shown that plants can forecast diurnal patterns using the circadian clock; moreover, they can manage their defensive mechanism for the detoxification of reactive oxygen species (ROS). Circadian rhythmicity in gene expression assembles transcription and translation feedback networks to govern plant shape, physiology, cellular and molecular activities. Both external and internal variables influence the systemic rhythm via input routes. The Malav Jyoti (MJ) and Delhi Green (DG) genotypes of spinach (Spinacia oleracea) were grown in the plant growth chamber. The chamber had an optimized temperature of 25 °C and humidity of 65% containing light emitting diode (LED) having Red: Blue: white (one side) and White fluorescent (other side) under salinity stress. The samples were collected on the basis of 4 h intervals of circadian hours (0 h, 4 h, 8 h and 12 h) during Day-10 and Day-20 of salt treatments. Under salt stress, the circadian and light-emitting diode-based strategy had a substantial influence on spinach's anti-oxidative responses, stomatal movement, CO2 assimilation, PS-I and II efficiency, phytochrome pigment efficiency, and photosynthesis. Based on the findings of the free radical scavenging enzyme tests, the photoperiodic hours for the proteome analysis were set to 11 am and 3 pm on Day-20. When compared to white fluorescent, this study found that LED has the capacity to influence the entrainment cues of the circadian clock in the cultivation of salt-sensitive spinach genotypes. According to our findings, changing the cellular scavenging mechanism and chloroplast proteome has increased the survival rate of spinach genotypes under LED when compared to white fluorescent.

Quantized dynamic event-triggered control for fixed/preset-time bipartite synchronization of memristor-based discontinuous multi-layer signed networks

This study addresses the fixed/preset-time bipartite synchronization (FTBS/PTBS) of memristor-based discontinuous multi-layer signed networks via quantized dynamic event-triggered control (ETC). Firstly, a memristor-based neural network model incorporating multi-layer coupling structures, signed networks and discontinuous activations is built. Subsequently, by designing two quantized dynamic ETC strategies without the linear feedback term, the FTBS and PTBS of the considered networks are discussed, and it is proved that Zeno behavior can be ruled out. In contrast to the previous static ETC mechanism, the introduced internal dynamic variable can significantly decrease the triggering times and further save communication resources. Lastly, three numerical examples are offered to verify the correctness and practicability of the theoretical analysis.

Determinants of open membership in brazilian credit unions

Purpose: To identify the determining factors of Open Membership in Brazilian credit unions between 2016 and 2020.
 Methodology: A logistic regression model was used to estimate these factors. The analysis considered both specific internal variables of the cooperatives (age, asset size, number of members, and affiliation to systems) and variables representing the macroeconomic environment in which these institutions operate (municipal development index, population size in municipalities with service points (PACs) and cooperative headquarters).
 Results: The main results indicate that a lower population size in the municipalities containing the cooperative headquarters and PACs increases the probability of Open Membership. Additionally, cooperatives with a larger number of members and assets also have a higher likelihood of adopting Open Membership.
 Contributions of the Study: The study highlights the predominance of cooperatives with Open Membership in smaller and less developed municipalities, reinforcing the role of these cooperatives in social inclusion, reduction of inequalities, and provision of financial services and credit to the population in these locations. Moreover, the results provide valuable insights for policymakers, financial institutions, and cooperatives interested in promoting socio-economic development and equity in underserved communities by the financial system.

Nonlocal interfaces accounting for progressive damage within continuum-kinematics-inspired peridynamics

In this work, we present a modeling approach to nonlocal material interfaces in the framework of continuum-kinematics-inspired peridynamics. The nonlocal model accounts for progressive damage within a finite-thickness interface, as opposed to the more common practice of abrupt bond breakage across a zero-thickness interface. Our approach is based on an overlap of the constituents within the interface. Interfacial bonds between initially overlapping partner points are governed by a constitutive law reminiscent of a traction-separation-law. The governing equations for continuum-kinematics-inspired peridynamics in the presence of an interface are derived using a rate-variational principle. The damage formulation is established using the classical concept of internal variables. Following the notion of a standard dissipative material, thermodynamic consistency of the constitutive laws and the evolution of the internal variables is ensured. The latter results in a straightforward evaluation of a damage function. We give details about the computational implementation comprising a peridynamic discretization and a Newton–Raphson scheme. A sound approach to approximate the interface normal during deformation is presented, which allows to penalize material penetration across the interface. The proposed model is explored in a series of numerical examples, i.e., classical peeling and shearing tests, for a variety of damage functions. A key feature of our interface model are the nonlocal characteristics that are assumed to play a role especially at small scales. We, first, observe that an increasing thickness of the nonlocal interface leads to stronger interfacial bonding and less damage. Second, an increase in horizon size results in stiffer material behavior. When studying the wrinkling and delamination behavior of a compressed bilayer, it is found that an increase in interface stiffness leads to a smaller wrinkling wavelength. Moreover, delamination due to progressive damage of interfacial bonds in the post-wrinkling regime is observed, which, to the best of our knowledge, has not been studied in a nonlocal model before.

Study on the Damage Characteristics and Internal Variable Modeling of Single-Fracture Sandstone under the Coupling Effect of Freeze–Thaw and Fatigue Load

The fractured rock mass in the western cold region is affected by freezing and thawing disasters and is prone to local damage and fracture along the fissures’ ends. The fatigue damage induced by repeated frost heave and traffic loads seriously endangers the stability of cold region roadbed. This paper selects sandstone as the research object. Firstly, 20 freeze–thaw cycles were performed on fractured sandstone samples with different inclination angles of 30°, 45°, 60°, and 90°. Subsequently, triaxial compression and triaxial fatigue loading tests were conducted to explore the mechanical properties and fracture morphology evolution mechanism during the compression process of freeze–thaw fractured sandstone. Nuclear magnetic resonance technology (NMR) was used to measure the H-containing fluid inside rock pores. The microscopic damage characteristics inside the rock were analyzed from the NMR T2 relaxation spectrum signal and pore size distribution characteristics. Based on the internal variable theory of continuum mechanics, a fatigue model of freeze–thaw fractured sandstone with different inclination angles was established. The results show that sandstone strength was negatively correlated with the fracture dip angle, and the axial deformation and shear failure angle were positively correlated with the fracture dip angle. The mechanical properties of the sandstone were deteriorated by fatigue loading. When the crack angle was 90°, the fatigue failure strength of the rock sample was the lowest. The T2 spectrum distribution of the fractured sandstone mainly had three peaks and the pore size was mainly medium and small pores. There was a small leftward shift after freeze–thaw cycles and fatigue loading. The T2 spectrum area was significantly affected by fatigue loading, with the highest rate of change at a crack angle of 30°. Through the fine correspondence between the axial residual deformation and the deformation modulus, a fatigue model with different crack inclination angles was established using the axial residual deformation as the internal variable, and the rationality of the model was verified by fatigue loading tests.

Interplay of a unit-speed constraint and time-delay in the flocking model with internal variables

<p>We studied the dynamics of thermodynamic Cucker–Smale (TCS) particles moving with a constant speed constraint. The TCS model describes the collective dynamics of the population of birds with a time varying internal variable, and it was first introduced as the generalization of the Cucker–Smale (CS) model. In this paper, we considered a modification of the TCS model in which each agent moves at a constant speed, such as the Vicsek model, and we additionally considered the effect of time-delays due to the finiteness of the information propagation speed between agents. Then, we presented several sufficient conditions in terms of initial data and system parameters to exhibit asymptotic flocking. We presented two kinds of results for this purpose. One was an estimate of the diameter of the velocity and temperature configuration, and the other was an estimate of the diameter of the configuration within the time-delay bound $ \tau $.</p>

A mathematical model for simulation of cardiovascular, renal, and hormonal responses to burn injury and resuscitation.

Treating extensive burn injury requires an individually tailored resuscitation protocol that includes hourly-titrated intravenous fluid infusion to avert both hypovolemic shock and edema. Due to the complexity of burn pathophysiology and significant variability in treatment protocols, there is an ongoing effort to optimize burn resuscitation. The goal of this work is to contribute to this effort by developing a mathematical model of burn pathophysiology and resuscitation for in silico testing of burn resuscitation protocols and decision-support systems. In our previous work, we developed and validated a mathematical model consisting of volume kinetics, burn-induced perturbations, and kidney function. In this work, we expanded our previous mathematical model to incorporate novel mathematical models of cardiovascular system and hormonal system (renin-angiotensin-aldosterone (RAAS) system and antidiuretic hormone) which affect blood volume and pressure regulation. We also developed a detailed mathematical model of kidney function to regulate blood volume, pressure, and sodium levels, including components for glomerular filtration rate, reabsorption rates in nephron tubules, Tubuglomerular feedback, and myogenic mechanisms. We trained and validated the expanded mathematical model using experimental data from 15 pigs and 9 sheep with extensive burns to quantitatively evaluate its prediction accuracy for hematocrit, cardiac output, mean arterial pressure, central venous pressure, serum sodium levels, and urinary output. We then trained and tested the mathematical model using a clinical dataset of 233 human burn patients with demographic data and urinary output measurements. The mathematical model could predict all tested variables very well, while internal variables and estimated parameters were consistent with the literature. To the best of our knowledge, this is the first mathematical model of burn injury and resuscitation which is extensively validated to replicate actual burn patients. Hence, this in silico platform may complement large animal pre-clinical testing of burn resuscitation protocols. Beyond its primary purpose, the mathematical model can be used as a training tool for healthcare providers delivering insight into the pathophysiology of burn shock, and offering novel mathematical models of human physiology which can be independently used for other purposes and contexts.

Investigating Students’ Behavioral Intentions towards a Smart Learning Platform Based on Machine Learning: A User Acceptance and Experience Perspective

This study investigated students’ behavioral intentions toward a smart learning platform. In order to evaluate and implement the adoption model within the context of Thai education, an empirical study was conducted. On a sample of 1,250 pupils from throughout Thailand, an analysis technique known as structural equation modeling was used to evaluate the proposed research model. Results from the study showed that the adoption of smart learning platforms by students was most significantly impacted by attitudes towards using them. This was followed by internal variables, namely the Perceived Ease of Use (PEU) and Perceived Usefulness (PU) of the platforms. In addition, Accessibility (AC), Personalization (PL), and Perceived System Quality (PSQ) are peripheral factors that increase understanding of smart learning platform adoption. The findings of this study align with other research, with the exception that only AC had a detrimental impact on PEU. Therefore, this study will provide valuable insights for scholars and researchers by filling a knowledge gap in the existing literature and demonstrating the concrete use of a proficient smart learning platform in the realm of academic success.

Presentation of a Causal Model of Relationships Between Metacognitive Beliefs, Need for Cognition, and Metacognitive Awareness: The Mediating Role of Goal Orientation and Self-Efficacy

Objective: Metacognitive beliefs have significant impacts on individual performance, and enhancing and altering these beliefs lead to meaningful changes in metacognitive awareness. The present study aims to present a causal model of the relationships between metacognitive beliefs, the need for cognition, and metacognitive awareness: exploring the mediating role of goal orientation and self-efficacy in the context of students taking a general English course at Payame Noor University, Fars Province, during the first semester of 2021. Methods and Materials: This is an applied study using a descriptive correlational research design through path analysis. The statistical population includes all undergraduate students at Payame Noor University, Fars Province, who enrolled in a general English course in the first semester of 2021, totaling approximately 3,422 students. A sample of 480 students was selected using stratified random sampling based on Morgan’s table. Data collection tools included the Bufora et al. (1998) goal orientation questionnaire, Wells’ (1997) metacognitive beliefs questionnaire, Sherer and Maddux’s (1997) self-efficacy scale, and the Cacioppo (1996) need for cognition questionnaire. Findings: The current study indicates that the indices of the conceptual model’s fit are in an acceptable condition. The four factors of metacognitive beliefs, need for cognition, goal orientation, and self-efficacy have a significant effect on students’ metacognitive awareness. Among the internal variables, self-efficacy had the most substantial effect (0.19), and metacognitive beliefs had the least (0.164). Conclusion: Overall, considering the goodness-of-fit indices and the overall examination of the model within the study group, the model exhibited appropriate fit and can be utilized in decision-making and policy-setting.

Infinite-memory classical wave-particle entities, attractor-driven active particles, and the diffusionless Lorenz equations.

A classical wave-particle entity (WPE) can materialize as a millimeter-sized droplet walking horizontally on the free surface of a vertically vibrating liquid bath. This WPE comprises a particle (droplet) that shapes its environment by locally exciting decaying standing waves, which, in turn, guides the particle motion. At high amplitude of bath vibrations, the particle-generated waves decay very slowly in time and the particle motion is influenced by the history of waves along its trajectory. In this high-memory regime, WPEs exhibit hydrodynamic quantum analogs where quantum-like statistics arise from underlying chaotic dynamics. Exploration of WPE dynamics in the very high-memory regime requires solving an integrodifferential equation of motion. By using an idealized one-dimensional WPE model where the particle generates sinusoidal waves, we show that in the limit of infinite memory, the system dynamics reduce to a 3D nonlinear system of ordinary differential equations (ODEs) known as the diffusionless Lorenz equations (DLEs). We use our algebraically simple ODE system to explore in detail, theoretically and numerically, the rich set of periodic and chaotic dynamical behaviors exhibited by the WPE in the parameter space. Specifically, we link the geometry and dynamics in the phase-space of the DLE system to the dynamical and statistical features of WPE motion, paving a way to understand hydrodynamic quantum analogs using phase-space attractors. Our system also provides an alternate interpretation of an attractor-driven particle, i.e., an active particle driven by internal state-space variables of the DLE system. Hence, our results might also provide new insights into modeling active particle locomotion.

Determining performance with accountability policy as a mediating factor in agricultural public service organizations

In Indonesia one of the big challenges of agricultural development is how the economic growth achieved can increase the income of farmers, most of whom own land of less than half a hectare. The Ministry of Agriculture is tasked with improving the welfare of farmers by increasing food security and agricultural competitiveness. The Ministry of Agriculture provides public services to the community, especially farmers in each district. The performance of public organizations is closely related to service quality. There are a number of variables that will affect how well public service providers function. Through the use of accountability policy, the impact of organizational elements on the performance of public service providers will be investigated in this study. Policies relating to accountability have a critical role. Maintaining quality is an important part of being able to give the greatest performance. Two hundred state public servants employed by the Ministry of Agriculture in the Indonesian participated in the study. The goal of this research is to investigate, both directly and indirectly, the elements that is management commitment and government policies influence public service performance through the use of flexible accountability policies. A quantitative approach using the Partial Least Square Structural Equation Model is employed. The results of this study show that the inclusion of a mediating variable accountability policy has a direct and indirect impact on performance due to both internal and external organizational variables.

Neural Network-Based Sliding Mode Control for Semi-Markov Jumping Systems With Singular Perturbation.

The primary focus of this article centers around the application of sliding mode control (SMC) to semi-Markov jumping systems, incorporating a dynamic event-triggered protocol (ETP) and singular perturbation. The underlying semi-Markov singularly perturbed systems (SMSPSs) exhibit mode switching behavior governed by a semi-Markov process, wherein the variation of this process is regulated by a deterministic switching signal. To simultaneously reduce the triggering rate and uphold the system performance, a novel parameter-based dynamic ETP is established. This protocol incorporates weight estimation of a radial basis function neural network (RBFNN) and introduces two internal dynamic variables. Following the Lyapunov's theory, sufficient criteria are established for ensuring the mean-square exponential stability of the resulting system. Additionally, an SMC scheme based on the convergence factor is designed to fulfill reachability conditions. Finally, two examples are carried out to validate the solvability and applicability of the attained control methodology.

Incentive contract design considering quotas production: A principal-agent perspective

The quality of primary products in a supply chain is determined by the agent and the principal. Simultaneously, there are quota production constraints on the principals. Our discourse centers on the design of incentive contracts for agents within these supply chains. We derived the parameters describing the contract, level of effort, profits for both sides, and the minimum requirements of the principal for the proportion of high-quality primary products. This study compares the decision-making paradigms of agents and principals in various contexts. The results show that decision-making mechanisms are strongly influenced by individual effort costs, various internal and external organizational variables, and the interplay of efforts on both sides. Using numerical experiments, we investigate the effects of different situations between clients and contractors on contracting and effort strategies. The results show that when the agent exerts unilateral effort, reasonable incentive contracts can spur the agent to increase effort and thus increase the proportion of high-quality primary products. In the case of bilateral efforts, a well-calibrated contract design benefits the agent (bearing less risk). For the principal, the expected profit increases in most cases. When considering the quota production, it is necessary to set an appropriate limit on the proportion of high-quality primary products.

A dislocation density-based meshfree computational framework for solid phase processing

This work proposes a computational modeling framework capable of predicting the behavior of materials when subject to solid phase processing (SPP). A macroscopic dislocation density based constitutive model with internal state variables correlated to microscopic dislocation densities is incorporated into a meshfree smoothed particle hydrodynamics (SPH) framework able to handle large deformations and high temperatures typical of what a material undergoes during SPP. Unlike phenomenological constitutive models that typically neglect material microstructural contributions to macroscale response, the dislocation density based constitutive model improves significantly the predictivity of our modeling framework in a wider range of conditions and allows the multiscale material responses to be simulated simultaneously. With dislocation density based model parameters calibrated to AA1100-O aluminum test data, the generality of the proposed framework is tested on two SPP techniques, namely friction extrusion (FE) and friction stir processing (FSP). Simulation results with different process parameters are systematically validated by experimental data for both cases. The validated models are then used to elucidate the inherent physics associated with SPP by revealing the distributions of temperature, strain, strain rate, and dislocation density, stick-slip contact conditions, and heat generation rates. Model-predicted high dislocation density regions in the processed AA1100-O also agree well with the dynamically recrystallized grain refinement zones observed from experiments.

Factors that Influence the Learning Achievement of Students Majoring in Accounting at the Institut Teknologi dan Bisnis Master Pekanbaru

This research aims to determine the influence of internal factors and external factors on the learning achievement of students majoring in accounting at the Master's Institute of Technology and Business. This research is expected to provide evidence that internal factors and external factors can influence whether or not the learning achievement of students majoring in accounting. The population of this research were all students majoring in accounting at the Pekanbaru Masters Institute of Technology and Business. This research method uses a quantitative method by collecting questionnaire data which is distributed to respondents. The sample for this research consisted of 57 respondents from students majoring in accounting at the Pekanbaru Master's Institute of Technology and Business. The data analysis technique used is multiple linear regression. The results of this research showed that the influence of internal factor variables on learning achievement in part obtained a coefficient value of -0.030 with a statistical t test value of -0.266 with a significance of 0.791. Based on the significance value of t, it shows that at the 5% level internal factors do not have a significant effect on the learning achievement of students majoring in accounting. External factors have a significant effect on student learning achievement with a coefficient of 0.598 with a t test of 5.330 and a significance of 0.000. Based on the significance value of t, it shows that at the 5% level external factors have a significant effect on the learning achievement of students majoring in accounting. Internal factors and external factors influence simultaneously, the higher the internal factors and external factors, the more they influence student learning achievement.

ОСНОВЫ ПРИМЕНЕНИЯ СИТУАЦИОННОГО ПОДХОДА К УПРАВЛЕНИЮ ПЕРЕВОЗОК

The authors of the article provide theoretical data on modern approaches to managing the processes of truck transportation based on a situational approach, which is based on the formation of a situational (transport) model that responds to input (situational) variables and uses internal (situational) variables.

Micro-Mechanism Relations Between Deformation and Damage Behavior of Materials at Elevated Temperature

Deformation of metallic materials at elevated temperatures occurs by the movement of atoms either individually or in a group by diffusion, grain boundary sliding, and the slip processes as facilitated by vacancy, dislocations, and grain boundaries. The constitutive relationship for deformation is developed based on the contributions of external test conditions like temperature and strain rate or stress applied and the internal conditions like chemical composition, phases present, and the length scale of microstructures. Deformation can occur coherently by synergisms of all participating mechanisms, failing to which becomes a source for initiating the damage in the material. The same mechanisms that were initially responsible for deformation to occur then become the facilitators for void nucleation and its growth, which then go through cavity coalescence, and crack formation on the way to cause ultimate fracture of materials. The constitutive relationships for damage mechanisms then take the form that promotes the removal of atoms from the damaged part to a farther site, which further enhances the act of material damage. In the present work, the micro-mechanisms responsible for deformation and failure will be examined to evolve a relationship towards establishing connectivity between these two processes by integrating the effects of internal and external variables for a range of materials.