Scale development to evaluate differences between concern about falling and fear of falling: the concern and fear of falling evaluation

PurposeIndividuals with multiple sclerosis (MS) experience fear of falling (FOF), which is associated with negative health and quality-of-life consequences. Prior research has used FOF and concern about falling (CAF) interchangeably, but persons with MS report that CAF and FOF represent separate constructs that lie on a continuum. Unfortunately, no scale exists to understand the differences between CAF and FOF. Therefore, we developed a novel questionnaire, the Concern and Fear of Falling Evaluation (CAFFE), in which respondents rank their CAF and FOF on a continuum across various activities. This study aims to describe the scale development process and examine its psychometric properties.MethodsIn a single online survey, MS participants responded to demographic questionnaires, indicated whether they experience CAF and FOF, and completed the CAFFE. Psychometric evaluation of the CAFFE involved internal consistency, split-half cross validation, exploratory factor analysis (EFA), and confirmatory factor analysis (CFA).ResultsOut of 1,025 respondents, 64.6% reported CAF and 47.2% reported FOF. The EFA yielded a two-factor solution encompassing activities in open (factor 1) and closed environments (factor 2). The CFA replicated this two-factor solution and the CAFFE demonstrated excellent internal consistency (α = 0.98).ConclusionThe 27-item CAFFE is a highly reliable and valid measure capturing the tipping point at which point CAF moves to FOF. Future research should seek to define the tipping point from the MS community, as CAF may be an adaptive mechanism, whereas FOF may be a maladaptive behavior

Itaconate Links Inhibition of Succinate Dehydrogenase with Macrophage Metabolic Remodeling and Regulation of Inflammation

Remodeling of the tricarboxylic acid (TCA) cycle is a metabolic adaptation accompanying inflammatory macrophage activation. During this process, endogenous metabolites can adopt regulatory roles that govern specific aspects of inflammatory response, as recently shown for succinate, which regulates the pro-inflammatory IL-1β-HIF-1α axis. Itaconate is one of the most highly induced metabolites in activated macrophages, yet its functional significance remains unknown. Here, we show that itaconate modulates macrophage metabolism and effector functions by inhibiting succinate dehydrogenase-mediated oxidation of succinate. Through this action, itaconate exerts anti-inflammatory effects when administered in vitro and in vivo during macrophage activation and ischemia-reperfusion injury. Using newly generated Irg1(−/−) mice, which lack the ability to produce itaconate, we show that endogenous itaconate regulates succinate levels and function, mitochondrial respiration, and inflammatory cytokine production during macrophage activation. These studies highlight itaconate as a major physiological regulator of the global metabolic rewiring and effector functions of inflammatory macrophages

Tensile strength and failure simulation of simplified spot weld models

A simple model for spot weld joints is desirable in body-in-white automotive structures which contains thousands of them. Hence, comparative performance and failure prediction study of six simplified spot weld models in terms of their geometric and constitutive properties are presented in this paper. The stiffness characteristics of these models under tensile loading condition were compared with the experimental results. It was found that the current spot weld modelling practice in the automotive industry predict the strength with 45.33% of error. To simulate the joint failure a material damage criterion correlating ultimate tensile strength of material was implemented in the developed models. The comparative study with respect to the accuracy was also related with the computational cost incurred by the different models. Hence, suitable modelling conditions to design a finite element model for spot welded joints are established which is very simple to develop, relatively cheap in terms of computational costs but yet predicts reasonably accurate results

Development of an FE model of a cricket ball

Studies of impact dynamics of cricket balls have the potential of significantly improving the development of cricket equipment and also contribute to improving the player's safety and performance. This work presents the development of a detailed multi-layer FE model for the structural analysis of cricket balls. The model was derived using experimental data obtained from tests developed for this purpose, including drop tests and high speed impact tests. The multi-layer, multi-material FE model was constructed using ABAQUS. Calibration of the model involves a multidisciplinary optimization technique. Comparison shows good agreement between experimental results and predictions from the refined model

Development of a fast-solving numerical model for the structural analysis of cricket balls

In cricket, high speed impacts occur between the cricket ball, the bat, players and their protective equipment. Improved understanding of impact dynamics has the potential to significantly improve the development of cricket equipment and also contribute to improving the player safety and performance. In particular, the development of high performance cricket balls with enhanced structural properties (e.g. improved durability) would benefit greatly from such insight. This article presents the development of two fast-solving numerical models as well as a universal FE model for the structural analysis of cricket balls. The models were developed using experimental data obtained from drop tests and high speed impact tests. These models predict impact characteristics with very little computing cost. A universal Finite Element (FE) ball model has also been developed using ABAQUS, which combines an FE model template and a material parameter selection tool based on an Artificial Neural Network (ANN) model. This approach allows for rapid model development while producing accurate results at different impact speeds. Comparison of results revealed good agreement between simulation and experimental results. The developed FE-ANN model can be used to predict the impact behaviour of different types of cricket balls under various dynamic conditions. This flexibility represents an advantage that can be utilized by sports equipment developers to rapidly develop different cricket ball models needed for inclusion in larger simulations involving impact of a cricket ball with other objects. This represents an invaluable tool for facilitating design, analysis and structural optimisation of cricket-related sport equipment

A comparative study of vent designs for effective ventilation in cricket helmets

It has been reported that wearing a protective helmet reduces airflow around the head and leads to an increase in heat-related stress and discomfort due to excessive sweat. The main objective of this study is to investigate vent designs in order to improve the air ventilation and heat dissipation in cricket helmets. An experiment was conducted in a research wind tunnel using a thermal manikin headfoam at a constant wind speed of 2.3m/s. Thermal comfort was measured in terms of heat dissipation and heat gain with ten K-type thermocouples. A comparison was made between four different helmets in terms of the vent design variations and temperature distributions. An increase in heat dissipation and a reduction in temperature in thermocouples were observed in the design incorporating suspension straps. The heat dissipation increases when there is an air gap between the head surface and the helmet shell/liners and where an air gap allows cooling air to circulate through the helmet. The thermal manikin experiment provided an efficient investigation of heat gain and/or loss for different vent designs, whereby its application is restricted to controlled experimental conditions

On the Move: Correlation of Impaired Mobility with Spatial Navigation Ability in Persons with Multiple Sclerosis

Spatial navigation ability is essential for independent living, and it relies on complex cognitive and motor processes that are vulnerable to decline in persons with multiple sclerosis (pwMS). The role of mobility in the physical act of navigation has been well documented; however, its association with cognitive processing that supports efficient navigation and recall of the environment is unknown. This study examined the relation between clinical mobility function and spatial navigation ability in pwMS. In a clinical sample of 43 individuals with relapsing-remitting MS (MPDDS = 2; age 25–67 years), we assessed spatial navigation ability in a virtual Morris water maze that allowed for active search by controlling a joystick while seated at a computer, and subsequent free recall of environment details. Individuals with worse mobility (measured by slower forward and backward walking) traveled less efficient virtual navigation routes to the goal location and recalled fewer accurate details of the environment. A stratified analysis by disability revealed moderate–strong correlations for those with a low level of disability, and effects were attenuated in individuals with a high level of disability. Given that the virtual navigation task was performed while seated, evidence of any correlation with mobility suggests differences in navigation ability that cannot be ascribed to general walking impairment, and instead suggests a role for mobility impairment to modify cognitive processing supporting navigation in pwMS