Dynamic Response of Angle Ply Laminates with Uncertainties Using MARS,ANN-PSO,GPR and ANFIS

In the present work, for the first time, free vibration response of angle ply laminates with uncertainties is attempted using Multivariate Adaptive Regression Spline (MARS), Artificial Neural Network-Particle Swarm Optimization (ANN-PSO), Gaussian Process Regression (GPR), and Adaptive Network Fuzzy Inference System (ANFIS). The present approach employed 2D C⁰ stochastic finite element (FE) model based on the Third Order Shear Deformation Theory (TSDT) in conjunction with MARS, ANN-PSO, GPR, and ANFIS. The TSDT model used eliminates the requirement of shear correction factor owing to the consideration of the actual parabolic distribution of transverse shear stress. Zero transverse shear stress at the top and bottom of the plate is enforced to compute higher-order unknowns. C⁰ FE model makes it commercially viable. Stochastic FE analysis done with Monte Carlo Simulation (MCS) FORTRAN inhouse code, selection of design points using a random variable framework, and soft computing with MARS, ANN-PSO, GPR, and ANFIS is implemented using MATLAB in-house code. Following the random variable frame, design points were selected from the input data generated through Monte Carlo Simulation. A total of four-mode shapes are analyzed in the present study. The comparison study was done to compare present work with results in the literature and they were found in good agreement. The stochastic parameters are Young’s elastic modulus, shear modulus, and the Poisson ratio. Lognormal distribution of properties is assumed in the present work. The current soft computation models shrink the number of trials and were found computationally efficient as the MCS-based FE modelling. The paper presents a comparison of MARS, ANN-PSO, GPR, and ANFIS algorithm performance with the stochastic FE model based on TSDT.     

Nonlocal Strain Gradient Theory for the Bending of Functionally Graded Porous Nanoplates

Many investigators have become interested in nanostructures due to their outstanding mechanical, chemical, and electrical properties. Two-dimensional nanoplates with higher mechanical properties compared with traditional structural applications are a common structure of nanosystems. Nanoplates have a wide range of uses in various sectors due to their unique properties. This paper focused on the static analysis of functionally graded (FG) nanoplates with porosities. The nonlocal strain gradient theory is combined with four-variable shear deformation theory to model the nanoplate. The proposed model captures both nonlocal and strain gradient impacts on FG nanoplate structures by incorporating the nonlocal and strain gradient factors into the FG plate’s elastic constants. Two different templates of porosity distributions are taken into account. The FG porous nanoplate solutions are compared with previously published ones. The impact of nonlocal and strain gradient parameters, side-to-thickness ratio, aspect ratio, and porosity parameter, are analyzed in detail numerically. This paper presents benchmark solutions for the bending analysis of FG porous nanoplates. Moreover, the current combination of the nonlocal strain gradient theory and the four-variable shear deformation theory can be adapted for various nanostructured materials such as anisotropic, laminated composites, FG carbon nanotube reinforced composites, and so on.     

Blame and the couples dynamic

Guilt and blame are common in relationships in which one or both parties are HIV-positive; however, counseling may help these people manage their relationships better. One technique used by therapists is Control Mastery Theory, a cognitive, interpersonal, psychoanalytic approach that classifies behavior as either growth-promoting or pathogenic. Control Mastery Theory, designed to break the blame/rage cycle, is based on the theory that a person's beliefs are rooted in their childhood experiences. Therapists use the approach to help clients better understand their responses to their situation and to their partner. A case is presented of an HIV-serodiscordant couple who have years of mutual blaming. The therapist helps the couple explore the pathogenic beliefs underlying their behaviors so that they can gain greater control over their behaviors. To ease transitions during antiviral treatment success, therapists should pay attention to the unconscious, irrational beliefs underlying patient's behaviors.     

Effectiveness of theory-based diabetes self-care training interventions; a systematic review

BackgroundPermanent compliance of self-care behaviors is a challenging issue in managing chronic diseases like diabetes. The evidence supports theory-based intervention in promoting self-care behaviors. However, no systematic review was done to monitor these interventions and compare more effective constructs. This study was conducted to investigate the studies using self-care theories and introducing the most effective theories.MethodsThis is a systematic review study during which some scientific databases including Scopus, Elsevier, Google scholar and PubMed were searched by using some key words like self-care or self-management, diabetes, theory or model. English articles from the start of 2013 up to the end of November 2020 were monitored.Results20 articles were selected and studied based on eight theories which they used. These theories were: Social support theory, Health Belief Model, Heath Belief Model and Empowerment Theory, Empowerment Theory, Self-efficacy Theory, precede-proceed model, Self-regulation Theory, behavioral theory and Social Cognitive Theory.ConclusionFour theories appeared to be more effective for the target behavior of present research: Social Support Theory and the combination of Empowerment Theory and Health Belief Model, Social Cognitive Theory and Self Efficacy Theory. Taken together, the findings of this systematic review suggest that interventions that go beyond individual determinants (such as changing knowledge and attitudes) to determinants of upper cognitive, motor, and social levels (such as the development of skills and competencies) they have led to raised self-care outcomes.     

Fluid shear of low magnitude increases growth and expression of TGFbeta1 and adhesion molecules in human bone cells in vitro.

Deformation of the bone matrix by mechanical strain causes fluid shifts within the osteocytic canaliculi which affect osteocytic cell metabolism. We applied low fluid shear (1 - 63 micro Pa for 10 - 48 h) to human osteoblastic cells (HOB) in vitro to study its impact on cell proliferation and differentiated functions. Proteins involved in translating the physical force into a cellular response were characterised. Low fluid shear stress stimulated proliferation of HOB 1.2-fold when stress was applied intermittently for 24 h. Shear stress also increased differentiated cellular properties such as alkaline phosphatase (ALP) activity (121 % of control), fibronectin (FN) and fibronectin receptor (FNR) expression (290 % and 200 %, respectively). Prostaglandin E (2) (PGE (2)) and TGFbeta1 release into the medium were significantly stimulated when shear stress was applied for 6 - 12 h and 24 - 48 h, respectively. TGFbeta1 + 2 neutralising antibodies or the presence of indomethacine inhibited the mitogenic effect of fluid shear and reduced ALP activity to its control level. Furthermore, TGFbeta treatment induced a dose-dependent increase in FN and FNR expression. Therefore, fluid shear stress of low magnitude (a) suffices to affect HOB metabolism and (b) regulates anchorage of HOB via FN and FNR by stimulating osteoblastic PGE (2) and TGFbeta secretion.     

The COVID-19 Pandemic Confronts the Motivation Fallacy within Pulmonary Rehabilitation Programs

Abstract

Social distancing and quarantines have been implemented worldwide to reduce the spread of Coronavirus Disease (COVID-19). However, social distancing has had far-reaching health consequences, considering that the COVID-19 pandemic has exposed people to the hazard of physical inactivity and sedentary behavior. For patients with Chronic Obstructive Pulmonary Disease (COPD), which is one of the main diseases at risk for COVID-19, the impact is even greater since outpatient pulmonary rehabilitation (PR) programs are temporarily closed. More than ever, patients’ behavior change to exercise calls for urgent debate. We propose a theoretical discussion in light of Self-Determination Theory, aiming to make PR a setting that supports autonomous forms of motivation. The scenario will not be changed in the short-term; but if other conditions hinder the development of PR in its most traditional form, the PR community will be better prepared to overcome the barriers to maintain physical exercise.     

Stigmergy,collective actions,and animal social spacing

Collective animal behavior studies have led the way in developing models that account for a large number of individuals, but mostly have considered situations in which alignment and attraction play a key role, such as in schooling and flocking. By quantifying how animals react to one another’s presence, when interaction is via conspecific avoidance rather than alignment or attraction, we present a mechanistic insight that enables us to link individual behavior and space use patterns. As animals respond to both current and past positions of their neighbors, the assumption that the relative location of individuals is statistically and history independent is not tenable, underscoring the limitations of traditional space use studies. We move beyond that assumption by constructing a framework to analyze spatial segregation of mobile animals when neighbor proximity may elicit a retreat, and by linking conspecific encounter rate to history-dependent avoidance behavior. Our approach rests on the knowledge that animals communicate by modifying the environment in which they live, providing a method to analyze social cohesion as stigmergy, a form of mediated animal–animal interaction. By considering a population of animals that mark the terrain as they move, we predict how the spatiotemporal patterns that emerge depend on the degree of stigmergy of the interaction processes. We find in particular that nonlocal decision rules may generate a nonmonotonic dependence of the animal encounter rate as a function of the tendency to retreat from locations recently visited by other conspecifics, which has fundamental implications for epidemic disease spread and animal sociality.Animals of the same species often are found either clustered together, e.g., in herds, or spread apart. Understanding the principles behind this heterogeneity is one of the central tenets in animal ecology with fundamental implications for population regulation, ecosystem functioning, and species evolution (1). Recent mechanistic modeling approaches (2) have produced landmark studies for the interpretation and analysis of animal spacing. Despite these fundamental advances, quantitative analyses often assume that individuals respond to one another’s presence instantaneously. Although computationally advantageous, such an approach may fail to capture the nonlocality, when present, of animal interactions. One such example occurs when individuals react to one another’s presence from a distance rather than only upon direct encounter. For this to occur, animals either use long-range communication, e.g., sound signals, or they acquire information about the past locations of other individuals. In the first case, the interaction is nonlocal in space, whereas in the second, the interaction is nonlocal in time. The latter is the focus of our investigation.How nonlocal individual interactions affect the spatial distribution of sedentary, i.e., neither nomadic nor migratory, animals remains an open question. Recent studies (3, 4) advocate the need to develop a general framework to explain the broad spectrum of spacing behavior we observe: from one extreme condition, with full territorial exclusion, to an intermediate situation, with overlapping home ranges, to the other extreme, with free-ranging animals that fully share the available space. Animals that deposit marks over the terrain represent a model animal system to develop such a framework. As individuals react to the encounter of foreign marks, they respond to the locations where other conspecifics have been in the past, making the interaction nonlocal in time. Recent studies on scent-marking animals (5–7) have taken into account nonlocal interactions, but they have investigated the formation of territorial patterns. Here, we move beyond that limitation by analyzing the collective emergence of spacing patterns resulting from animals’ avoidance. We chose to focus on the endogenous mechanisms of how patterns are generated rather than asking why animals do it, which depends on the resources they aim to defend (3).As with other collective movement phenomena, e.g., in herding (8) or schooling and flocking (9), the key to understanding the emerging dynamics is the interaction between individuals. Here, we consider the strength of the interaction as dependent on the degree of nonlocality, which we accomplish by having the probability of an individual to retreat from the encountered active foreign marks depending on how long ago the marks were deposited.     

Differentiating Between Precursor and Control Variables When Analyzing Reasoned Action Theories

This paper highlights the distinction between precursor and control variables in the context of reasoned action theory. Here the theory is combined with structural equation modeling to demonstrate how age and past sexual behavior should be situated in a reasoned action analysis. A two wave longitudinal survey sample of African-American adolescents is analyzed where the target behavior is having vaginal sex. Results differ when age and past behavior are used as control variables and when they are correctly used as precursors. Because control variables do not appear in any form of reasoned action theory, this approach to including background variables is not correct when analyzing data sets based on the theoretical axioms of the Theory of Reasoned Action, the Theory of Planned Behavior, or the Integrative Model.     

The theory of Rational Addiction

The Theory of Rational Addictions, by Gary Becker & Kevin Murphy (1988), was a rational choice model that became a standard tool for economists modeling addictive behavior. The approach differs from other theories of addiction by modeling addictive behavior as the gradual implementation of a rational, forward‐looking plan, where consumption at any point in time is partly motivated by the immediate payoff of consumption and partly by the effects this consumption has on the individual in the future. This makes addictive behavior a subset of rational behavior, requiring no more specific government policies or attention than any other consumption choice. Later work by economists extended the theory in different ways, allowing it to match an increasing number of consumption patterns, and searched for ways to test the forward‐looking assumption in different types of market data. While the work was successful as a contribution to rational choice theory, with possible statistical applications, there are several reasons to dismiss its usefulness as an explanation of real‐world addictive behavior and its ability to assess the welfare effects of addictions.     

Understanding behaviour: the key to successful health education

Effective health education requires an understanding of the factors which underlie a person's behavior. This paper describes "BASNEF," a simplified approach to understanding behavior, which is based on the PRECEDE model and on Value Expectancy Theory. Value Expectancy Theory holds that people will only perform a given behavior if they themselves see that it will provide benefits according to their perception of their situation and needs. Community beliefs and values may differ from those of health care workers. The perceived likelihood of different consequences of an act and the relative values of those outcomes determine the individual's attitude towards that act. The subjective norm consists of the net balance of the perceived attitudes of other people concerning the act. The person's attitude and the subjective norm must be balanced to arrive at the behavioral intention, the decision of whether or not to perform a behavior. Applying the BASNEF approach requires determining community perspectives regarding the behavior. The behavior must be defined as specifically as possible, and the materials and knowledge required for a motivated person to carry out the behavior must be considered. Some behaviors can be identified in which it is unrealistic to expect a change. The 1st priority must be toensure that all the enabling factors required for a motivated person to carry out the behavior, such as time, materials and education, are available. Social pressures must be addressed, particularly the opinions of influential persons. Changing the individual's beliefs and attitudes must come last. The proposed behavior may need to be modified to be acceptable. It is difficult to change beliefs which arise from direct experience, wider belief systems or which have been held for a long time. This BASNEF model can be used to design health education programs based on an understanding of the community.     

The orchestration of disengagement.

In the clamor of many institutional and special interest "orchestras," it is possible to lose sight of their common object of concern-human welfare and dignity. In the sphere of scientific endeavor, this problem can show itself as a mistaken attempt to separate theory from technique and practice. Disclaimers that Disengagement Theory is "only a theory," not a policy statement, are regarded here as inaccurate and naive when the effects of the theory are examined. Other areas of criticism pertain to activity-passivity dynamics, the appreciation of coping behavior in later life, and, in general, the inadequate representation within Disengagement Theory of the full spectrum of experience, behavior, and dynamics, both personal and social, in the lives of elderly people.     

Terahertz Wave Propagation in a Nanotube Conveying Fluid Taking into Account Surface Effect

In nanoscale structure sizes, the surface-to-bulk energy ratio is high and the surface effects must be taken into account. Surface effect plays a key role in accurately predicting the vibration behavior of nanostructures. In this paper, the wave behaviors of a single-walled carbon nanotube (CNT) conveying fluid are studied. The nonlocal Timoshenko beam theory is used and the surface effect is taken into account. It is found that the fluid can flow at a very high flow velocity and the wave propagates in the terahertz frequency range. The surface effects can significantly enhance the propagating frequency. This finding is different from the classical model where the surface effect is neglected.     

Impact of Loading and Myocardial Mechanical Properties on Natural Shear Waves: Comparison to Pressure-Volume Loops

BackgroundShear wave elastography (SWE) has been proposed as a novel noninvasive method for the assessment of myocardial stiffness, a relevant determinant of diastolic function. It is based on tracking the propagation of shear waves, induced, for instance, by mitral valve closure (MVC), in the myocardium. The speed of propagation is directly related to myocardial stiffness, which is defined by the local slope of the nonlinear stress-strain relation. Therefore, the operating myocardial stiffness can be altered by both changes in loading and myocardial mechanical properties.ObjectivesThis study sought to evaluate the capability of SWE to quantify myocardial stiffness changes in vivo by varying loading and myocardial tissue properties and to compare SWE against pressure-volume loop analysis, a gold standard reference method.MethodsIn 15 pigs, conventional and high–frame rate echocardiographic data sets were acquired simultaneously with pressure-volume loop data after acutely changing preload and afterload and after inducting an ischemia/reperfusion (I/R) injury.ResultsShear wave speed after MVC significantly increased by augmenting preload and afterload (3.2 ± 0.8 m/s vs 4.6 ± 1.2 m/s and 4.6 ± 1.0 m/s, respectively; P = 0.001). Preload reduction had no significant effect on shear wave speed compared to baseline (P = 0.118). I/R injury resulted in significantly higher shear wave speed after MVC (6.1 ± 1.2 m/s; P < 0.001). Shear wave speed after MVC had a strong correlation with the chamber stiffness constant β (r = 0.63; P < 0.001) and operating chamber stiffness dP/dV before induction of an I/R injury (r = 0.78; P < 0.001) and after (r = 0.83; P < 0.001).ConclusionsShear wave speed after MVC was influenced by both acute changes in loading and myocardial mechanical properties, reflecting changes in operating myocardial stiffness, and was strongly related to chamber stiffness, invasively derived by pressure-volume loop analysis. SWE provides a novel noninvasive method for the assessment of left ventricular myocardial properties.     

Simultaneous hermaphroditism and sexual selection

Theory about the evolution of sexual behavior in dioecious species is based on the general assumption that egg production is limited by a female's ability to garner resources to make eggs, not by a lack of sperm to fertilize them. Reproductive success for males is thus limited by access to females (and their eggs). I suggest that egg production by simultaneous hermaphrodites also obeys this principle—that fertilized egg production by an individual is not limited by sperm availability, but by resources allocated to eggs. If true, this suggests that sperm competition (reproduction success through male function) and a form of male—female conflict have played important roles in the evolution of hermaphroditism.     

Standardization of blood specimen collection procedure for reference values*

This document has been prepared by an ICSH Task Force as a proposed ICSH Standard for Blood Specimen Collection for Reference Values. The procedures described are a model for standardization of blood specimen collection either for people confined to bed, or for those who are ambulant; they are intended for obtaining reference values using the principles described in the ICSH paper on the Theory of Reference Values (Clin. lab. Haemat. 3 , 369–373, 1981). The document is based on recommendations by the Committee on Reference Values of the Scandinavian Society for Clinical Chemistry and Clinical Physiology as published in Scand. J. clin. lab. Invest. ( 35 , Suppl. 144, 39–43, 1975); it has been prepared in collaboration with the Panel on the Theory of Reference Values of the Scientific Committee of the International Federation of Clinical Chemistry (IFCC). The responsible authorities of ICSH and IFCC have proposed that it should be the basis for joint recommendations by both organizations.     

A practical model for preventing type 2 diabetes in minority youth

PURPOSE: This article proposes a model grounded in behavioral theory and empirical evidence for use when developing a program to prevent type 2 diabetes in high-risk minority youth. METHODS: The model is based on key concepts of 4 behavioral theories: the Health Belief Model, Social Learning Theory, the Theory of Planned Behavior, and the Ecological Model. Determinants of behavior to target for change are selected based on their theoretical link to behavior change, their success in changing behavior in past programs, and through thorough formative research in the target community. RESULTS: Diabetes prevention in children requires modifying a complex set of behavior patterns. Social norms and the environment are especially important in children in whom cognitive processes have not fully developed. Family and community involvement is essential for developing a health program and providing a supportive environment in which to change behavior and ongoing reinforcement to maintain behavior changes. CONCLUSIONS: Behavioral theory informs the selection of factors to target in a behavioral intervention. Special considerations apply when working with children. A program to target risk must be based in behavioral theory, supported by practical data, and tailored to the needs and beliefs of the target community.     

Temperature Dependency on the Microscopic Mechanism in the Normal Direction of Wrought AZ31 Sheet under Dynamic Compressive Behavior

In order to analyze the competitive relationship of different deformation mechanisms in wrought AZ31 magnesium alloy, the dynamic compressive experiments were conducted by a Split Hopkinson Pressure Bar (SHPB) apparatus and a resistance-heated furnace in the range of temperature between 20 and 350 °C at the strain rate of 1000 s⁻¹. With the help of Electron Backscattered Diffraction (EBSD) observation, theoretical calculated Schmid Factor (SF), Critical Resolved Shear Stress (CRSS), and critical equivalent stress (σ0.2), the dynamic compressive deformation behavior and corresponding mechanism of wrought AZ31 magnesium alloy along the normal direction (ND) were revealed in the current study. The results demonstrate that the c-axis of grains are gradually reoriented parallel to the normal direction of wrought AZ31-ND sheet with the temperature increasing, except the dynamic recrystallization (DRX) mechanism was activated or grains grew up. The non-basal slip and 101¯2 tension twinning are respectively the predominant deformation mechanisms at lower temperatures (≤250 °C) and higher temperatures (≥250 °C). The predominant type of DRX mechanism of wrought AZ31-ND sheet is rotational dynamic recrystallization (RDRX), which is regarded as an obstacle for the kernel misorientation concentration region enhancement.     

Evaluation of common carotid hemodynamic forces. Relations with wall thickening.

The localization of atherosclerotic lesions is influenced by hemodynamic factors, namely, shear stress and tensive forces. The present study investigated the relationships between shear stress and circumferential wall tension and between these hemodynamic factors and the intima-media thickness (IMT) of the common carotid artery in healthy men. Fifty-eight subjects were studied. Shear stress was calculated as blood viscosityxblood velocity/internal diameter. Circumferential wall tension was calculated as blood pressurexinternal radius. Blood velocity, internal diameter, and IMT were measured by high-resolution echo-Doppler. Mean shear stress was 12.6+/-3.3 dynes/cm(2) (mean+/-SD; range, 4.8 to 20.4) and was inversely related with age, blood pressure, and body mass index (BMI). Mean circumferential wall tension was 3.4+/-0.6x10(4) dynes/cm (range 2.4 to 5.6) and was directly associated with age and BMI. IMT was inversely associated with shear stress (r=0.55, P<0. 0001) and directly associated with circumferential wall tension (r=0. 43, P<0.0001). Shear stress and circumferential wall tension were inversely correlated (r=0.66, P<0.0001). In multiple regression analysis, shear stress and (marginally) cholesterol were independently associated with IMT, whereas circumferential wall tension, age, and BMI were not. These findings confirm that common carotid shear stress varies among healthy individuals and decreases as age, blood pressure, and BMI increase. Our findings also demonstrate that circumferential wall tension is directly associated with wall thickness, age, and BMI and that shear stress is associated with common carotid IMT independent of other hemodynamic, clinical, or biochemical factors.