Microstructural analysis of skeletal muscle force generation during aging.

Human aging results in a progressive decline in the active force generation capability of skeletal muscle. While many factors related to the changes of morphological and structural properties in muscle fibers and the extracellular matrix (ECM) have been considered as possible reasons for causing age-related force reduction, it is still not fully understood why the decrease in force generation under eccentric contraction (lengthening) is much less than that under concentric contraction (shortening). Biomechanically, it was observed that connective tissues (endomysium) stiffen as ages, and the volume ratio of connective tissues exhibits an age-related increase. However, limited skeletal muscle models take into account the microstructural characteristics as well as the volume fraction of tissue material. This study aims to provide a numerical investigation in which the muscle fibers and the ECM are explicitly represented to allow quantitative assessment of the age-related force reduction mechanism. To this end, a fiber-level honeycomb-like microstructure is constructed and modeled by a pixel-based Reproducing Kernel Particle Method (RKPM), which allows modeling of smooth transition in biomaterial properties across material interfaces. The numerical investigation reveals that the increased stiffness of the passive materials of muscle tissue reduces the force generation capability under concentric contraction while maintains the force generation capability under eccentric contraction. The proposed RKPM microscopic model provides effective means for the cellular-scale numerical investigation of skeletal muscle physiology. NOVELTY STATEMENT: A cellular-scale honeycomb-like microstructural muscle model constructed from a histological cross-sectional image of muscle is employed to study the causal relations between age-associated microstructural changes and age-related force loss using Reproducing Kernel Particle Method (RKPM). The employed RKPM offers an effective means for modeling biological materials based on pixel points in the medical images and allow modeling of smooth transition in the material properties across interfaces. The proposed microstructure-informed muscle model enables quantitative evaluation on how cellular-scale compositions contribute to muscle functionality and explain differences in age-related force changes during concentric, isometric and eccentric contractions

Investigating the Correlation between Force Output, Strains, and Pressure for Active Skeletal Muscle Contractions

Experimental observations suggest that the force output of the skeletal muscle tissue can be correlated to the intra-muscular pressure generated by the muscle belly. However, pressure often proves difficult to measure through in-vivo tests. Simulations on the other hand, offer a tool to model muscle contractions and analyze the relationship between muscle force generation and deformations as well as pressure outputs, enabling us to gain insight into correlations among experimentally measurable quantities such as principal and volumetric strains, and the force output. In this work, a correlation study is performed using Pearson's and Spearman's correlation coefficients on the force output of the skeletal muscle, the principal and volumetric strains experienced by the muscle and the pressure developed within the muscle belly as the muscle tissue undergoes isometric contractions due to varying activation profiles. The study reveals strong correlations between force output and the strains at all locations of the belly, irrespective of the type of activation profile used. This observation enables estimation on the contribution of various muscle groups to the total force by the experimentally measurable principal and volumetric strains in the muscle belly. It is also observed that pressure does not correlate well with force output due to stress relaxation near the boundary of muscle belly

Total Variation Regularization of Matrix-Valued Images

We generalize the total variation restoration model, introduced by Rudin, Osher, and Fatemi in 1992, to matrix-valued data, in particular, to diffusion tensor images (DTIs). Our model is a natural extension of the color total variation model proposed by Blomgren and Chan in 1998. We treat the diffusion matrix D implicitly as the product D = LLT, and work with the elements of L as variables, instead of working directly on the elements of D. This ensures positive definiteness of the tensor during the regularization flow, which is essential when regularizing DTI. We perform numerical experiments on both synthetical data and 3D human brain DTI, and measure the quantitative behavior of the proposed model

Empowering married young women and improving their sexual and reproductive health: Effects of the First-time Parents Project

The Population Council, in partnership with Child In Need Institute in Kolkata, Deepak Charitable Trust in Vadodara, and International Institute for Population Sciences, Mumbai, initiated the First-time Parents Project in India to develop and test an integrated package of health and social interventions to improve married young women’s reproductive and sexual health knowledge and practices, enhance their ability to act in their own interest, and expand their social support networks. The project was formulated on the hypothesis that the periods immediately following marriage and surrounding the first pregnancy and birth offer a unique and powerful entry point for improving the situation of married young women. Findings indicate that the intervention had a significant, positive net effect on most indicators reflecting married young women’s autonomy, social support networks, partner communication, and knowledge of sexual and reproductive health. However, the net effect of exposure to the intervention was mixed with regard to indicators related to gender role attitudes and attitudes toward domestic violence, as well as reproductive health practices. The experience of the intervention demonstrates that it is feasible to improve married young women’s reproductive health knowledge and practices, expand their sources of social support, and involve them in activities with peers in safe spaces outside the home, and through the process empower them in their marital and familial relationships. The report suggests that this model could also be integrated into existing NGO or government services, and could be tested for implementation on a larger scale

Teleradiology as a Foundation for an Enterprise-wide Health Care Delivery System

An effective, integrated telemedicine system has been developed that allows (a) teleconsultation between local primary health care providers (primary care physicians and general radiologists) and remote imaging subspecialists and (b) active patient participation related to his or her medical condition and patient education. The initial stage of system development was a traditional teleradiology consultation service between general radiologists and specialists; this established system was expanded to include primary care physicians and patients. The system was developed by using a well-defined process model, resulting in three integrated modules: a patient module, a primary health care provider module, and a specialist module. A middle agent layer enables tailoring and customization of the modules for each specific user type. Implementation by using Java and the Common Object Request Broker Architecture standard facilitates platform independence and interoperability. The system supports (a) teleconsultation between a local primary health care provider and an imaging subspecialist regardless of geographic location and (b) patient education and online scheduling. The developed system can potentially form a foundation for an enterprise-wide health care delivery system. In such a system, the role of radiologist specialists is enhanced from that of a diagnostician to the management of a patient’s process of care

Enteral Multiple Micronutrient Supplementation in Preterm and Low Birth Weight Infants: A Systematic Review and Meta-analysis

OBJECTIVES To assess effects of supplementation with 3 or more micronutrients (multiple micronutrients; MMN) compared to no MMN in human milk-fed preterm and low birth weight (LBW) infants. RESULTS Data on a subgroup of 414 preterm or LBW infants from 2 randomized controlled trials (4 reports) were included. The certainty of evidence ranged from low to very low. For growth outcomes in the MMN compared to the non-MMN group, there was a small increase in weight-for-age (2 trials, 383 participants) and height-for-age z-scores (2 trials, 372 participants); a small decrease in wasting (2 trials, 398 participants); small increases in stunting (2 trials, 399 participants); and an increase in underweight (2 trials, 396 participants). For neurodevelopment outcomes at 78 weeks, we found small increases in Bayley Scales of Infant Development, Version III (BISD-III), scores (cognition, receptive language, expressive language, fine motor, gross motor) in the MMN compared to the non-MMN group (1 trial, 27 participants). There were no studies examining dose or timing of supplementation. CONCLUSIONS Evidence is insufficient to determine whether enteral MMN supplementation to preterm or LBW infants who are fed mother's own milk is associated with benefit or harm. More trials are needed to generate evidence on mortality, morbidity, growth, and neurodevelopment.publishedVersio

Performance of supply chain collaboration – A simulation study

In the past few decades several supply chain management initiatives such as Vendor Managed Inventory, Continuous Replenishment and Collaborative Planning Forecasting and Replenishment (CPFR) have been proposed in literature to improve the performance of supply chains. But, identifying the benefits of collaboration is still a big challenge for many supply chains. Confusion around the optimum number of partners, investment in collaboration and duration of partnership are some of the barriers of healthy collaborative arrangements. To evolve competitive supply chain collaboration (SCC), all SC processes need to be assessed from time to time for evaluating the performance. In a growing field, performance measurement is highly indispensable in order to make continuous improvement; in a new field, it is equally important to check the performance to test conduciveness of SCC. In this research, collaborative performance measurement will act as a testing tool to identify conducive environment to collaborate, by the way of pinpointing areas requiring improvements before initializing collaboration. We use actual industrial data and simulation to help managerial decision-making on the number of collaborating partners, the level of investments and the involvement in supply chain processes. This approach will help the supply chains to obtain maximum benefit of collaborative relationships. The use of simulation for understanding the performance of SCC is relatively a new approach and this can be used by companies that are interested in collaboration without having to invest a huge sum of money in establishing the actual collaboration

Use of thiopurines in inflammatory bowel disease : an update

Inflammatory bowel disease (IBD), once considered a disease of the Western hemisphere, has emerged as a global disease. As the disease prevalence is on a steady rise, management of IBD has come under the spotlight. 5-Aminosalicylates, corticosteroids, immunosuppressive agents and biologics are the backbone of treatment of IBD. With the advent of biologics and small molecules, the need for surgery and hospitalization has decreased. However, economic viability and acceptability is an important determinant of local prescription patterns. Nearly one-third of the patients in West receive biologics as the first/initial therapy. The scenario is different in developing countries where biologics are used only in a small proportion of patients with IBD. Increased risk of reactivation of tuberculosis and high cost of the therapy are limitations to their use. Thiopurines hence become critical for optimal management of patients with IBD in these regions. However, approximately one-third of patients are intolerant or develop adverse effects with their use. This has led to suboptimal use of thiopurines in clinical practice. This review article discusses the clinical aspects of thiopurine use in patients with IBD with the aim of optimizing their use to full therapeutic potential.Peer reviewe