Peer-to-Peer networking

Peer-to-Peer (P2P) networking in recent times has been touted as the ‘killer application’ that is poised to shape the Internet’s future. The purpose of this article is to define P2P and explain its working. We also describe various models of P2P and diverse applications of this innovative networking concept. U Ananth Kini and Samarth M Shetty are computer science BE graduates from Sri Jayachamarajendra College of Engineering, University of Mysore. They are currently doing a project on peer-to-peer networking at SERC, Indian Institute of Science, Bangalore. Their interests include networking, operating systems and embedded systems.     

Steven Vogel (1940–2015)

Steven Vogel was a pinoneer in applying principles of mechanics to diverse living systems. This article first provides a brief overview of his career. It then reviews the concepts of Péclet number and Reynolds number which are helpful in appreciating the Classics article by Vogel reproduced in this issue.     

Immuno-Modulatory Effect and Therapeutic Potential of <Emphasis Type="Italic">Brugia malayi</Emphasis> Cystatin in Experimentally Induced Arthritis

Helminths are known to modulate host’s immune system and understanding this modulation can help in identification of novel therapeutic agents for autoimmune diseases. In this study, we have assessed the immune-modulatory activity and the therapeutic effect of Brugia malayi recombinant cystatin (rBmCys) in methylated BSA (mBSA) induced arthritis using rodent model. Administration of rBmCys has suppressed the severity of mBSA-arthritis in mastomys by reducing paw swelling and other clinical disease parameters as evident from significantly decreased arthritic index. The anti-arthritic effect of rBmCys was also confirmed by decreased histopathological score for synovitis, bone erosion and fibrosis in the tissue sections of paws. Further, this therapeutic effect of cystatin was found to be associated with significantly decreased production of IFN-γ and TNF-α and increased release of IL-4 and IL-10 cytokines. These results implied that rBmCys treatment has alleviated mBSA-induced arthritis and thus can be a promising alternative agent for the treatment of arthritis.     

Salivary glycoproteins as indicators of oral diseases

The present study deals with the estimation of total carbohydrate, protein bound carbohydrate, bound fucose and sialic acid along with total protein in disease conditions like gingivitis, periodontitis and their comparison with the normals. The neutral hexose values in gingivitis (8.08±2.20mg/100mg protein) and periodontitis (12.5±2.16mg/ 100mg protein) decreased significantly when expressed per 100 mg protein compared to normals (19.8±1.89mg/100mg protein). This might be because of higher protein concentration in these two clinical conditions. The ethanol insoluble hexose values were significantly reduced in both these conditions compared to controls (3.71±1.64,5.91±1.63,7.65±0.86mg/100mg protein respectively). The ethanol soluble hexose values were also found to be drastically reduced. This decrease in saliva appears to be characteristic feature of oral diseases. In gingivitis and periodontitis fucose level was found to be increased compared to normals when expressed as a function of salivary volume. However in terms of protein concentration the values in gingivitis (2.95±1.59), periodontitis (3.26±0.98) and normals (3.20±0.50mg/100mg) were not different. Sialic acid in ethanol insoluble fraction of salivary samples mg/100mg protein was found to be significantly reduced in both gingivitis (0.78±0.33) and periodontitis (0.95±0.31) compared to controls (1.92±0.33)     

HPLC method for amino acids profile in biological fluids and inborn metabolic disorders of aminoacidopathies

Quantification of total and individual amino acids in biological fluids such as plasma, urine and cerebrospinal fluid has an important diagnostic implication in laboratory medicine. The present paper describes protocols for the assay of total amino acids by modified method based on dinitrophenyl and HPLC profile involving pre-column derivatization with o-pthalaldehyde (OPA) derivatization, respectively. The method, based on the alkylation of-SH groups prior to OPA derivatization of amino acids followed by reverse phase high performance liquid chromatography, provide a comprehensive profile of more than twenty amino acids (including-SH group containing) in a single run lasting about 45 minutes. The present study, apart from establishing the normal profile of amino acids in plasma of Indian sub population, also presents HPLC profile for some of the rare amino acidopathies.     

Utility of serum lysosomal enzyme assay in the detection of cerebral sphingolipidoses in patients with progressive neurologic dysfunction

The cerebral sphingolipidoses which form part of a larger group of lysosomal disorders can be detected and conclusively confirmed by the demonstration of the relevent enzyme deficiency in easily available tissue samples like serum. We have assayed acid β-galactosidase, β-hexosaminidase and its isozymes hexosaminidase A and B, and arylsulfatase A in the serum of patients with progressive cerebral dysfunction and detected 18 patients with enzyme defects, thereby confirming the diagnosis of a specific type of cerebral lipidosis in these patients. The assay of serum lysosomal enzymes was of immense diagnostic use as it obviated the need for highly invasive techniques like a brain biopsy.     

Steam as coolant and lubricant in turning of metal matrix composites

Green cutting has become focus of attention in ecological and environmental protection. Steam is cheap, poilution-free and eco-friendly, and then is a good and economical coolant and lubricant. Steam generator and steam feeding system were developed to generate and feed steam. Comparative experiments were carried out in cutting AA6061-15 vol.% SiC （25 p.m particle size）, with cubic boron nitride （CBN） insert KB-90 grade under the conditions of compressed air, oil water emulsion, steam as coolant and lubricant, and dry cutting, respectively. The experimental results show that, with steam as coolant and lubricant, gradual reduction in the cutting force, friction coefficient, surface roughness and cutting temperature values were observed. Further, there was reduction in built up edge formation. It is proved that use of water steam as coolant and lubricant is environmentally friendly.     

Roll control using discrete-time robust sliding hyperplanes and fast output sampling

Robustness to unmatched parametric uncertainty is prime requirement of roll control algorithm, especially when it is modelled in discrete time domain and implemented through on-board processor. Sliding mode control is a well established nonlinear control technique, which ensures a robust performance in presence of matched uncertainties and disturbances. In case of the discrete version of sliding mode control, due to finite operational sampling frequency, the system trajectories cannot be forced to slide on the switching manifold. The trajectories remain confined to certain domain around the sliding surface and this is known as Quasi Sliding Mode (QSM) motion. The bound of QSM decides the accuracy and performance of the discrete version of sliding mode. By design, the discrete-time sliding modes are robust to the matched bounded perturbations, however, unmatched perturbations directly affect the boundary layer width and hence the performance of the system. In the present paper, discrete time Lyapunov inequality based sliding hyperplane is designed, which enables robustness to unmatched perturbations arising due to uncertain system matrix A. Further, the requirement of full state-vector for the design of control and sliding surface is met through the multi-rate output feedback (MROF). This control strategy is then demonstrated with application to roll position control of missile with a bandwidth limited actuator.     

Alkaline Phosphatase: An Overview

Alkaline phosphatase (ALP; E.C.3.I.3.1.) is an ubiquitous membrane-bound glycoprotein that catalyzes the hydrolysis of phosphate monoesters at basic pH values. Alkaline phosphatase is divided into four isozymes depending upon the site of tissue expression that are Intestinal ALP, Placental ALP, Germ cell ALP and tissue nonspecific alkaline phosphatase or liver/bone/kidney (L/B/K) ALP. The intestinal and placental ALP loci are located near the end of long arm of chromosome 2 and L/B/K ALP is located near the end of the short arm of chromosome 1. Although ALPs are present in many mammalian tissues and have been studied for the last several years still little is known about them. The bone isoenzyme may be involved in mammalian bone calcification and the intestinal isoenzyme is thought to play a role in the transport of phosphate into epithelial cells of the intestine. In this review, we tried to provide an overview about the various forms, structure and functions of alkaline phosphatase with special focus on liver/bone/kidney alkaline phosphatase.     

Electromagnetic field exposure as a plausible approach to enhance the proliferation and differentiation of mesenchymal stem cells in clinically relevant scenarios

Mesenchymal stem/stromal cell(MSC)-based therapy has been regarded as one of the most revolutionary breakthroughs in the history of modern medicine owing to its myriad of immunoregulatory and regenerative properties.With the rapid progress in the fields of osteo-and musculoskeletal therapies,the demand for MSC-based treatment modalities is becoming increasingly prominent.In this endeavor,researchers around the world have devised new and innovative techniques to support the proliferation of MSCs while minimizing the loss of hallmark features of stem cells.One such example is electromagnetic field(EMF)exposure,which is an alternative approach with promising potential.In this review,we present a critical discourse on the efficiency,practicability,and limitations of some of the relevant methods,with insurmountable evidence backing the implementation of EMF as a feasible strategy for the clinically relevant expansion of MSCs.