Castes, migration, immunogenetics and infectious diseases in south India

It has been said that the grandest genetic experiment of nature has been conducted in south India in the name of the caste system. One can expect the frequency of an infectious disease to be equal to the product of the frequencies of various indicated loci/alleles, whether physiological, hormonal or immunological, in an endemic area. The sympatrically isolated caste and sub-caste populations of southern India, with differing origins, migration patterns and breeding habits, differ significantly in their HLA and other immune repertoire and are ideal models to study and test this hypothesis. The prevalence of a number of major infectious diseases, including TB and leprosy, are reviewed in different communities in the light of their genetic history.     

Prevalence of eNOS Glu298Asp polymorphism in healthy volunteers from a region of Northern India

OBJECTIVE: Endothelial nitric oxide synthase (eNOS) Glu298Asp polymorphisms are under extensive study worldwide due to their suggested role in cardiovascular disorders. This polymorphism had gained more attention since several reports suggest its association with hypertension and coronary artery disease (CAD). Asian Indians are highly susceptible to ischemic heart dis eases. We determined the prevalence of eNOS Glu298 Asp polymorphism in 139 healthy volunteers from Delhi and the surrounding areas. The subjects were recruited from those who willingly participated in this study in response to a publicized call and a standard questionnaire. Male to female ratio was 2.7:1 due to the larger number of male participants in this investigation. This, however, does not represent normal male to female distribution in the area. Despite the male bias, this investigation was justified. The prevalence of CAD in males is about 3 times higher in this region and no data had so far been available on the distribution of this polymorphism from India. METHOD: The eNOS Glu298Asp polymorphism was studied by PCR-RFLP. RESULTS: Distribution of genotype GG, GT and TT in the study subjects was found to be 71.22, 28.06 and 0.72%, respectively, and allele frequency was G,0.853;T,0.147. CONCLUSION: T allele had been described as susceptibility allele for CAD in several population studies. The frequency of the T allele was found to be two times higher in our subjects than that reported for Japanese and Korean populations. This study does not provide any direct evidence for eNOS gene disease associations but is the first report on the prevalence of eNOS Glu298Asp gene polymorphism in Indian subjects. Whether the observed pattern of eNOS Glu298Asp polymorphism contributes to the greater susceptibility of Asian Indians to CAD as compared to the other population groups, needs to be investigated.     

Understanding inherited disease through human migrations: a south-west Asian perspective

Mitochondrial DNA (mtDNA) and the Y chromosome are inherited in a haploid manner and have been used extensively to reconstruct human lineages. mtDNA and the majority of the Y chromosome lack recombination and show high rates of apparently neutral mutation. Here, we demonstrate how detailed analysis of these uniparental inherited markers can reveal general and more subtle population movements within south-west Asia. These include a major migration of modern humans from East Africa to western and southern Asia around 60,000 YBP, migrations of populations from the Fertile Crescent in south-western Iran to India approximately 8,000 YBP, and migrations of Indo-European speakers from Central and West Asia to India approximately 5,000 YBP. We highlight how the understanding of these, and other population movements, can be useful in tracing the dispersal of disease-causing mutant alleles, and how these data could be applied to predicting the segregation of mutant alleles within populations.     

Activities in experimental stress and strain analysis in some asian countries

Paper discusses the recent activities in the experimental stress and strain analysis (ESSA) fields in Asia, referring the information from Japan, Korea, China and India, for example. It includes a general view of the international interchange or cooperation among Asian countries, relating to organizations, publications, education, standardization, and the backgrounds and topics of research activity and demands for ESSA in each country. Regarding the present insufficient exchange of information among Asian countries and the recent rapid progress in engineering and science in these countries, the requirement for improvement is stressed. Paper was presented at Fourth SESA International Congress on Experimental Mechanics held in Boston, MA on May 25–30, 1980.     

Analysis of mechanical response of fistula plug for structure optimization

Anal fistula is one of the three greatest anorectal diseases with a high prevalence. The traditional treatments(e.g., surgery) for fistula have limitations due to damage to the internal anal sphincter of patients. With recent advances in biomaterials, treatments based on biomaterial filling (e.g., scleraprotein injection, fistula plug) have emerged as novel therapies for fistula. The anal fistula plug (e.g., based on small intestinal submucosa (SIS)) has attracted increasing attention because of short term healing rate and biocompatibility. However, challenges remain for this method such as plug falling as observed in clinics. To address this, this paper analyzes the case of SIS falling under physiological condition from mechanical point of view using ANSYS simulation. It then proposes three new geometrical structures for fistula plug and compares their mechanical behavior (e.g., axial stress, reaction of constraint) with that of clinically used structure (cone shape). Based on the simulation, it optimizes the geometric parameters of fistula plug. The approach developed here can help to improve the design of fistula plug for better clinical treatments.     

Frequency of CYP2C9 genotypes among Omani patients receiving warfarin and its correlation with warfarin dose

OBJECTIVES: This study was conducted to determine the frequency of CYP2C9 alleles in Omani patients receiving warfarin and to correlate genotyping data with warfarin dosage. The Omani population has Asian and African ethnicities. METHODS: CYP2C9 genotypes were determined by the polymerase chain reaction restriction fragment length polymorphism method. Non-parametric Kruskal-Wallis test was used to compare groups of continuous data for significance differences. RESULTS: Genotyping data showed that 12.7 and 5.8% of the samples were heterozygous for the CYP2C9*2 and CYP2C9*3 alleles, respectively. The CYP2C9*2 allele frequency was 0.074 in our population. It was 0.029 for CYP2C9*3. CONCLUSION: This is the first report on the presence of CYP2C9*2 allele homozygocity in any Asian or African population.     

Rapid synthesis and growth of silver nanowires induced by vanadium trioxide particles

This study demonstrates a novel approach for rapid synthesis of silver (Ag) nanowires induced by vanadium trioxide (V₂O₃) particles in aqueous solution at room temperature. Silver nanowires have an average diameter of 20 nm and length up to a few micrometers by parametric optimization. The micro-structure of the silver nanowires was characterized by TEM, HRTEM, SEM, and XRD techniques. The optical property of the as-prepared product was measured by ultraviolet–visible (UV–vis) spectroscopy. The possible growth mechanism of Ag nanowires via oriented attachment of Ag nanocrystals was discussed. The present approach shows several unique features such as rapid (a few minutes), reproducible and high-yield reaction with no need of any modifiers. V₂O₃ rods were reported for the first time to be used for synthesis of silver nanowires, playing multiple roles as reducing agent, template, and catalyst. The silver nanowires produced are promising for optical applications (e.g., SERS) due to their rough surface.     

Mitigating impact/blast energy via a novel nanofluidic energy capture mechanism

To effectively mitigating intense impact and blast waves, a novel protection mechanism is proposed in this study where a significant amount of the incident energy can be temporarily captured as potential energy in a nonwetting liquid-nanoporous material system, thereby weakening the peak pressure and elongating the impact pulse. When the pressure of a compressive wave traveling in a liquid overcomes the capillary resistance, the liquid molecules quickly intrude into nanopores while retaining highly compressed form. The incident energy is thus captured (temporarily stored) in nanopores in the form of potential energy of intercalated water molecules, and then gradually released upon unloading (which makes the system reusable). Comparing with other energy absorption materials, the present system has the unique advantage of low activation pressure and high energy density. Using comprehensive molecular dynamics (MD) simulations, the effects of several key parameters (e.g., impact velocity, nanopore size, and pore composition) on energy capture are investigated, and the molecular mechanism is elucidated. The findings are qualitatively validated by a parallel blast experiment on a zeolite/water system.     

The essential self-adjointness of Schrödinger-type operators

The paper discusses conditions under which the formally self-adjoint elliptic differential operator in R ^m given by 1 $$\tau {\text{ }}u = \sum\limits_{j,{\text{ }}k = 1}^m {[i\partial _j + b_j (x)]} {\text{ }}a_{jk} (x){\text{ }}[i\partial _k + b_k (x)]{\text{ }}u + q(x){\text{ }}u$$ has a unique self-adjoint extension. The novel feature is that the major conditions on the coefficients have to be imposed only in an increasing sequence of shell-like regions surrounding the origin. On the other hand it is shown that if these shells are broken so as to allow a tube extending to infinity in which the conditions on the coefficients are too weak, then, regardless of the coefficients elsewhere, there may not be a unique self-adjoint extension. The mathematical theorems are linked to the quantum-mechanical interpretation of essential self-adjointness (in the case that τ is the Schrödinger operator), that there is a unique self-adjoint extension if the particle cannot escape to infinity in a finite time.     

从具体例子看惯性流形概念的推广

惯性流形的概念要求所有轨道指数收敛于唯一吸引子[5],这对于很多物理问题,例如sine-Gordon方程是很难满足的[4],本文中给出的人工例子建议了惯性流形的推广形式,这个推广形式去掉了整体吸引子是唯一的预先要求,该推广概念使用于sine-Gordon方程。     

Awareness of genetic testing for increased cancer risk in the year 2000 National Health Interview Survey

OBJECTIVES: This study explores factors associated with differential awareness of genetic tests for increased cancer risk in the US. METHODS: 27,405 respondents from the 2000 National Health Interview Survey, ages 25+, were asked if they had heard of these tests. RESULTS: 44.4% said 'yes', including 49.9% of whites, 32.9% of African-Americans, 32.3% of American Indians/Alaskan Natives, 28.0% of Asian/Pacific Islanders, and 20.6% of Hispanics. In multivariate analysis, test awareness was significantly associated with higher education, white race, age <60 years, female gender, private health insurance, personal or parent's history of certain cancers, physical activity, and vitamin/supplement use, among other factors. CONCLUSIONS: The survey showed which population subgroups may lack access to cancer genetics information and may therefore benefit from targeted strategies to ensure risk-appropriate utilization of genetic counseling and testing.     

Genetic services in the new era: Native American perspectives

American Indians have arrived at a critical point in their more than 500-year history with the United States Government. With the advent of the new bio-revolution, a number of tribes have voiced vehement opposition to genetic patenting, creation of cell lines, transgenic experimentation and cloning. While many are opposed to the Human Genome Diversity Project, Human Genome Project and diversity research currently being conducted by the Indian Health Service, a few embrace the beneficial aspects of biomedical/biogenetic research. Moreover, an increasing number of Indians see the need for and are seeking genetic counseling and other services. This paper briefly describes some of the issues associated with developing and implementing effective genetic services within Native American communities. Problems of access, perception of services, previous experience with genetics and cultural and other barriers are discussed. Recommendations also are rendered to assist health professionals in the development of services.     

A micromechanical continuum model for the tensile behavior of shape memory metal nanowires

We have previously discovered a novel shape memory effect and pseudoelastic behavior in single-crystalline face-centered-cubic metal (Cu, Ni, and Au) nanowires. Under tensile loading and unloading, these wires can undergo recoverable elongations of up to 50%, well beyond the recoverable strains of 5-8% typical for most bulk shape memory alloys. This phenomenon only exists at the nanoscale and is associated with a reversible lattice reorientation driven by the high surface-stress-induced internal stresses. We present here a micromechanical continuum model for the unique tensile behavior of these nanowires. Based on the first law of thermodynamics, this model decomposes the lattice reorientation process into two parts: a reversible, smooth transition between a series of phase-equilibrium states and a superimposed irreversible, dissipative twin boundary propagation process. The reversible part is modeled within the framework of strain energy functions with multiple local minima. The irreversible, dissipative nature of the twin boundary propagation is due to the ruggedness of strain energy curves associated with dislocation nucleation, glide, and annihilation. The model captures the major characteristics of the unique behavior due to lattice reorientation and accounts for the size and temperature effects, yielding results that are in excellent agreement with the results of molecular dynamics simulations.     

Framework for non-coherent interface models at finite displacement jumps and finite strains

This paper deals with a novel constitutive framework suitable for non-coherent interfaces, such as cracks, undergoing large deformations in a geometrically exact setting. For this type of interface, the displacement field shows a jump across the interface. Within the engineering community, so-called cohesive zone models are frequently applied in order to describe non-coherent interfaces. However, for existing models to comply with the restrictions imposed by (a) thermodynamical consistency (e.g., the second law of thermodynamics), (b) balance equations (in particular, balance of angular momentum) and (c) material frame indifference, these models are essentially fiber models, i.e. models where the traction vector is collinear with the displacement jump. This constraints the ability to model shear and, in addition, anisotropic effects are excluded. A novel, extended constitutive framework which is consistent with the above mentioned fundamental physical principles is elaborated in this paper. In addition to the classical tractions associated with a cohesive zone model, the main idea is to consider additional tractions related to membrane-like forces and out-of-plane shear forces acting within the interface. For zero displacement jump, i.e. coherent interfaces, this framework degenerates to existing formulations presented in the literature. For hyperelasticity, the Helmholtz energy of the proposed novel framework depends on the displacement jump as well as on the tangent vectors of the interface with respect to the current configuration – or equivalently – the Helmholtz energy depends on the displacement jump and the surface deformation gradient. It turns out that by defining the Helmholtz energy in terms of the invariants of these variables, all above-mentioned fundamental physical principles are automatically fulfilled. Extensions of the novel framework necessary for material degradation (damage) and plasticity are also covered.     

Dynamical analysis of the infection status in diverse communities due to COVID-19 using a modified SIR model

In this article, we model and study the spread of COVID-19 in Germany, Japan, India and highly impacted states in India, i.e., in Delhi, Maharashtra, West Bengal, Kerala and Karnataka. We consider recorded data published in Worldometers and COVID-19 India websites from April 2020 to July 2021, including periods of interest where these countries and states were hit severely by the pandemic. Our methodology is based on the classic susceptible–infected–removed (SIR) model and can track the evolution of infections in communities, i.e., in countries, states or groups of individuals, where we (a) allow for the susceptible and infected populations to be reset at times where surges, outbreaks or secondary waves appear in the recorded data sets, (b) consider the parameters in the SIR model that represent the effective transmission and recovery rates to be functions of time and (c) estimate the number of deaths by combining the model solutions with the recorded data sets to approximate them between consecutive surges, outbreaks or secondary waves, providing a more accurate estimate. We report on the status of the current infections in these countries and states, and the infections and deaths in India and Japan. Our model can adapt to the recorded data and can be used to explain them and importantly, to forecast the number of infected, recovered, removed and dead individuals, as well as it can estimate the effective infection and recovery rates as functions of time, assuming an outbreak occurs at a given time. The latter information can be used to forecast the future basic reproduction number and together with the forecast on the number of infected and dead individuals, our approach can further be used to suggest the implementation of intervention strategies and mitigation policies to keep at bay the number of infected and dead individuals. This, in conjunction with the implementation of vaccination programs worldwide, can help reduce significantly the impact of the spread around the world and improve the wellbeing of people.

     

Flow dynamics and contact efficiency in a novel fast-turbulent fluidized bed with ring-feeder internals

The flow dynamics in a novel fast-turbulent fluidized bed(FTFB) with middle-upper expanding structure and two different ring-feeder internals(mixed and vortex ring-feeder) were studied to achieve a reduction in gasoline olefin production.Compared with a conventional circulating fluidized bed,the novel FTFB displayed unique characteristics and advantages.A higher solids holdup and more uniform solids holdup distribution existed in the diameter-expanding region,especially for the FTFB with vortex ring-feeder structure.A probability density distribution analysis indicated that the novel fluidized bed could reduce gas-solids segregation and enhance gas-solids interaction.A constant carbon dioxide tracer system was used to simulate the reactant gas distribution.The gas-solids contact efficiency was defined according to the solid dispersibility and the amount of gas covering the solid surface.Novel FTFB risers,especially those with vortex ring-feeders,have a much higher gas-solids contact efficiency than that of traditional risers.     

Design and development of planar reconfigurable motion generators

This article presents the concept of a new class of mechanical devices for multi-phase motion generation tasks. Reconfigurable Motion Generators are a new class of mechanical devices that are designed for a specific part family and their associated motion generation tasks. The research endeavors to realize a novel concept for Reconfigurable Motion Generators (RMGs) for multi-phase planar motion generation. Reconfigurable Motion Generators are capable of configuration changes according to variations in the motion generation requirements. Thus, Reconfigurable Motion Generators bridge the gap between the relative high flexibility and high cost of totally flexible devices (e.g., industrial robots) and the low flexibility and low cost of fully dedicated devices (e.g., cams and linkages). This paper introduces the concept of Reconfigurable Motion Generators that may be deployed in various automated manufacturing environments involving multi-phase motion generation tasks. The development, manufacturing, and testing of a prototype and the control system for a planar Reconfigurable Motion Generator based on a five-bar mechanism are discussed.     

Nonlinear kelvin-helmholtz instability

A non-linear analysis is presented with derivative expansion method for the interfacialstability of a liquid film adjacent to a subsonic gas flow under the influence of body force andsurface tension. The non-linear Rayleigh-Taylor instability is included as a special case.The gas and liquid are considered to be inviscid. Though Nayfeh (1971) gave considerationinto this case,there is something omitted in his third-order equation(e.g.p.213 expression(229)) and inconsistent with his solutions (e.g. the first-order solution(2.31)does notsatisfy his initial conditions(2.20)). Besides. in this paper, our solution near the cut-offwave number is extended to include the case of travelling waves and a new conclusion isdrawn.     

Flow dynamics and contact efficiency in a novel fast-turbulent fluidized bed with ring-feeder internals

The flow dynamics in a novel fast-turbulent fluidized bed (FTFB) with middle-upper expanding structure and two different ring-feeder internals (mixed and vortex ring-feeder) were studied to achieve a reduction in gasoline olefin production. Compared with a conventional circulating fluidized bed, the novel FTFB displayed unique characteristics and advantages. A higher solids holdup and more uniform solids holdup distribution existed in the diameter-expanding region, especially for the FTFB with vortex ring-feeder structure. A probability density distribution analysis indicated that the novel fluidized bed could reduce gas–solids segregation and enhance gas–solids interaction. A constant carbon dioxide tracer system was used to simulate the reactant gas distribution. The gas–solids contact efficiency was defined according to the solid dispersibility and the amount of gas covering the solid surface. Novel FTFB risers, especially those with vortex ring-feeders, have a much higher gas–solids contact efficiency than that of traditional risers.