Advancement in Textile Technology for Defence Application

The early development of textiles involved use of natural materials like cotton, wool and flax. The advent of the new technology revolutionized textiles which enables to develop synthetic fibers like lycra®, a segmented polyurethane-urea, which has exceptional elastic properties, Kevlar®, which has ultra high strength properties and is used as bulletproof vest. For the improvement of personal mobility, health care and rehabilitation, it requires to integrate novel sensing and actuating functions to textiles. Fundamental challenge in the development of smart textile is that drapability and manufacturability of smart textiles should not be affected. Textile fabrics embedded with sensors, piezoelectric materials, flame retardant materials, super hydrophobic materials, controlled drug release systems and temperature adaptable materials can play major role in the development of advanced and high-tech military clothes. Advancement in the textile materials has the capacity of improving comfort, mobility and protection in diverse hostile environment. In this study, the advancement in energy harvesting textiles, controlled release textiles and engineering textiles are presented.Defence Science Journal, 2013, 63(3), pp.331-339, DOI:http://dx.doi.org/10.14429/dsj.63.275

Evolution of HIV-1 subtype C gp120 envelope sequences in the female genital tract and blood plasma during acute and chronic infection

Philosophiae Doctor - PhDHeterosexual transmission of HIV-1 via the female genital tract is the leading route of HIV infection in sub-Saharan Africa. Viruses then traffic between the cervical compartment and blood ensuring pervasive infection. Previous studies have however reported the existence of genetically diverse viral populations in various tissue types, each evolving under separate selective pressures within a single individual, though it is still unclear how compartmentalization dynamics change over acute and chronic infection in the absence of ARVs. To better characterize intrahost evolution and the movement of viruses between different anatomical tissue types, statistical and phylogenetic methods were used to reconstruct temporal dynamics between blood plasma and cervico-vaginal lavage (CVL) derived HIV-1 subtype C gp120 envelope sequences. A total of 206 cervical and 253 blood plasma sequences obtained from four treatment naïve women enrolled in the CAPRISA Acute Infection study cohort in South Africa were evaluated for evidence of genotypic and phenotypic differences between viral populations from each tissue type up to 3.6 years post-infection. Evidence for tissue-specific differences in genetic diversity, V-loop length variation, codon-based selection, co-receptor usage, hypermutation, recombination and potential N-linked glycosylation (PNLG) site accumulation were investigated. Of the four participants studied, two anonymously identified as CAP270 and CAP217 showed evidence of infection with a single HIV-1 variant, whereas CAP177 and CAP261 showed evidence of infection by more than one variant. As a result, genetic diversity, PNLGs accumulation and the number of detectable recombination events along the gp120 env region were lowest in the former patients and highest in the latter. Overall, genetic diversity increased over the course of infection in all participants and correlated significantly with viral load measurements from the blood plasma in one of the four participants tested (i.e. CAP177). Employing a structured coalescent model approach, rates of viral migration between anatomical tissue types on time-measured genealogies were also estimated. No persistent evidence for the existence of separate viral populations in the cervix and blood plasma was found in any of the participants and instead, sequences generally clustered together by time point on Bayesian Maximum Clade Credibility (MCC) trees. Clades that were monophyletic by tissue type comprised mostly of low diversity or monotypic sequences from the same time point, consistent with bursts of viral replication. Tissue-specific monophyletic clades also generally contained few sequences and were interspersed among sequences from both tissue-types. Tree and distance-based statistical tests were employed to further evaluate the degree to which cervical and blood plasma viruses clustered together on Bayesian MCC trees using the Slatkin-Maddison (S-M), Simmonds Association index (AI), Monophyletic Clade (MC), Wright’s measure of population subdivision (FST) and Hudson’s Nearest Neighbour (Snn) statistics, in the presence and absence of monotypic and low diversity sequences. Statistical evidence for the presence of tissue-specific population structure disappeared or was greatly reduced after the removal of monotypic and low diversity sequences, except in CAP177 and CAP217, in 3/5 of longitudinal tree and distance-based tests. Analysis of phenotypic differences between viral populations from the blood plasma and cervix revealed inconsistent tissue-specific patterns in genetic diversity, codon-based selection, co-receptor usage, hypermutation, recombination, V-loop length variation and PNLG site accumulation during acute and chronic infection among all participants. There is therefore no evidence to support the existence of distinct viral populations within the blood plasma and cervical compartments longitudinally, however slightly constrained populations may exist within the female genital tract at isolated time points, based on the statistical findings presented in this study

Incidence and regulatory implications of single Nucleotide polymorphisms among established ovarian cancer genes

Magister Scientiae - MScOVARIAN cancer research focuses on answering important questions related to the disease, determining whether new approaches are feasible to contribute towards improving current treatments or discovering new ones. This study focused on the transcriptional regulation of genes that have been implicated in ovarian cancer, based on the occurrences of single nucleotide polymorphisms (SNPs) within transcription factor binding sites (TFBSs). Through the application of several in silico tools, databases and custom programs, this research aimed to contribute toward the identification of potentially bio-medically important genes or SNPs for pre-diagnosis and subsequent treatment planning of ovarian cancer. A total of 379 candidate genes that have been experimentally associated with ovarian cancer were analyzed. This led to the identification of 121 SNPs that were found to coincide with putative TFBSs potentially influencing a total of 57 transcription factors that would normally bind to these TFBSs. These SNPs with potential phenotypic effect were then evaluated among several population groups, defined by the International HapMap consortium resulting in the identification of three SNPs present in five or more of the eleven population groups that have been sampled.South Afric

Temperature assisted in-situ small angle X-ray scattering analysis of Ph-POSS/PC polymer nanocomposite

Inorganic/organic nanofillers have been extensively exploited to impart thermal stability to polymer nanocomposite via various strategies that can endure structural changes when exposed a wide range of thermal environment during their application. In this abstraction, we have utilized temperature assisted in-situ small angle X-ray scattering (SAXS) to examine the structural orientation distribution of inorganic/organic nanofiller octa phenyl substituted polyhedral oligomeric silsesquioxane (Ph-POSS) in Polycarbonate (PC) matrix from ambient temperature to 180 °C. A constant interval of 30 °C with the heating rate of 3 °C/min was utilized to guise the temperature below and above the glass transition temperature of PC followed by thermal gravimetric, HRTEM, FESEM and hydrophobic analysis at ambient temperature. The HRTEM images of Ph-POSS nano unit demonstrated hyperrectangular structure, while FESEM image of the developed nano composite rendered separated phase containing flocculated and overlapped stacking of POSS units in the PC matrix. The phase separation in polymer nanocomposite was further substantiated by thermodynamic interaction parameter (χ) and mixing energy (Emix) gleaned via Accelrys Materials studio. The SAXS spectra has demonstrated duplex peak at higher scattering vector region, postulated as a primary and secondary segregated POSS domain and followed by abundance of secondary peak with temperature augmentation

Dynamic Analysis of Cracked Rotor in Viscous Medium and its Crack Diagnosis Using Intelligent Techniques

Fatigue cracks have high potential to cause catastrophic failures in the rotor which can lead to catastrophic failure if undetected properly and in time. This fault may interrupt smooth, effective and efficient operation and performance of the machines. Thereby the importance of identification of crack in the rotor is not only for leading safe operation but also to prevent the loss of economy and lives.The condition monitoring of the engineering systems is attracted by the researchers and scientists very much to invent the automated fault diagnosis mechanism using the change in dynamic response before and after damage. When the rotor with transverse crack immersed in the viscous fluid, analysis of cracked rotor is difficult and complex. The analysis of cracked rotor partially submerged in the viscous fluid is widely used in various engineering systems such as long spinning shaft used drilling the seabed for the extracting the oil, high-speed turbine rotors, and analysis of centrifuges in a fluid medium. Therefore, dynamic analysis of cracked rotor partially submerged in the viscous medium have been presented in the current study. The theoretical analysis has been performed to measure the vibration signatures (Natural Frequencies and Amplitude) of multiple cracked mild steel rotor partially submerged in the viscous medium. The presence of the crack in rotor generates an additional flexibility. That is evaluated by strain energy release rate given by linear fracture mechanics. The additional flexibility alters the dynamic characteristics of cracked rotor in a viscous fluid. The local stiffness matrix has been calculated by the inverse of local dimensionless compliance matrix. The finite element analysis has been carried out to measure the vibration characteristics of cracked rotor partially submerged in the viscous medium using commercially available finite element software package ANSYS. It is observed from the current analysis, the various factors such as the viscosity of fluid, depth and position of the cracks affect the performance of the rotor and effectiveness of crack detection techniques. Various Artificial Intelligent (AI) techniques such as fuzzy logic, hybrid BPNN-RBFNN neural network, MANFIS and hybrid fuzzy-rule base controller based multiple faults diagnosis systems are developed using the dynamic response of rotating cracked rotor in a viscous medium to monitor the presence of crack. Experiments have been conducted to authenticate the performance and accuracy of proposed methods. Good agreement is observed between the results

Structural and thermal stability of polycarbonate decorated fumed silica nanocomposite via thermomechanical analysis and In-situ temperature assisted SAXS

The inorganic and organic nanocomposites have enticed wide interest in the field of polymer-based composite systems to augment their physiochemical properties like mechanical strength and electrical conductivity. Achieving interfacial interaction between inorganic filler and polymer matrix is a recurring challenge, which has significant implications for mechanical properties of nanocomposites. In this context, the effect of "interfacial zone" on structural and thermal attributes of the melt blended pristine polycarbonate and polycarbonate (PC) decorated fumed silica nanocomposite have been examined from ambient temperature to the glass transition temperature. Thermomechanical characterization and in-situ temperature assisted small angle X-ray scattering technique (SAXS) were used for contemplating quantitative and qualitative molecular dynamics of developed nanocomposites. Though, the FT-IR spectra have demonstrated some extent of interaction between inorganic and organic groups of composite, the reduced glass transition temperature and storage modulus was ascertained in DMA as well as in DSC, which has been further confirmed by in-situ temperature assisted SAXS. It is envisioned that the utilization of in-situ SAXS in addition to the thermomechanical analysis will render the qualitative and quantitative details about the interfacial zone and its effect on thermal and mechanical properties of nanocomposite at varying temperature conditions

Ten Simple Rules for Organizing a Virtual Conference—Anywhere

1 International Institute of Tropical Agriculture, Nairobi, Kenya, 2 Faculty of Life Sciences, The University of Manchester, Manchester, United Kingdom, 3 Department of Computer and Information Sciences, Covenant University, Ota, Nigeria, 4 Institute of Bioinformatics, Johannes Kepler University, Linz, Austria, 5 Moroccan Society for Bioinformatics Institute, Morocco, 6 South African National Bioinformatics Institute, University of the Western Cape, Bellville, South Africa, 7 University of Cape Town, Cape Town, South Africa, 8 University of Notre Dame, South Bend, Indiana, United States of America, 9 Biotechnology Unit, University of Buea, Buea, South West Region, Cameroon, 10 International Livestock Research Institute, Nairobi, Kenya, 11 Biosciences Eastern and Central Africa, Nairobi, Kenya, 12 International Center of Insect Physiology and Ecology, Nairobi, Kenya, 13 Bioinformatics Organization, Hudson, Massachusetts, United States of America, 14 Bioinformatics Team, Center for Development of Advanced Computing, Pune University Campus, Pune, India, 15 Harvard School of Public Health, Boston, Massachusetts, United States of Americ

Ten Simple Rules for Organizing a Virtual Conference—Anywhere

Etienne P. de Villiers and Sheila C. Ommeh are ILRI author

Ten Simple Rules for Organizing an Unconference

This is an open access article distributed under the terms of the Creative Commons Attribution License.Peer Reviewe

Nacre inspired polycarbonate based nanocomposite for high impact application

This study rendered to contemplate how structural bio-mimicking of mollusk structure in reinforced polycarbonate based nano composite system alter the inter and intra facial attributes under high impact dynamic loading. The findings demonstrated that the mechanical ability of polycarbonate can be modified by the virtue of hierarchical natural design architecture