3,807 research outputs found
The Leggett-Garg inequality and Page-Wootters mechanism
Violation of the Leggett-Garg inequality (LGI) implies quantum phenomena. In
this light we establish that the Moreva \textit{et al.} \cite{moreva}
experiment demonstrating the Page-Wootter's mechanism \cite{wootters} falls in
the quantum domain. An observer outside a 2-photons world does not detect any
change in the photons state,i.e. there is no time parameter for the outside
observer. But an observer attached to one of the photons sees the other photon
evolving and this means there is an "internal" time. The LGI is violated for
the clock photon whose state evolves with the internal time as measured by the
system photon. Conditional probabilities in this 2-photons system are computed
for both sharp and unsharp measurements. The conditional probability increases
for entangled states as obtained by Page and Wootters for both ideal and also
unsharp measurements. We discuss how the conditional probabilities can be used
to distinguish between massless and massive gravitons. This is important in the
context of gravitational waves.Comment: 5 pages, Late
Modeling the Field Emission Current Fluctuation in Carbon Nanotube Thin Films
Owing to their distinct properties, carbon nanotubes (CNTs) have emerged as
promising candidate for field emission devices. It has been found
experimentally that the results related to the field emission performance show
variability. The design of an efficient field emitting device requires the
analysis of the variabilities with a systematic and multiphysics based modeling
approach. In this paper, we develop a model of randomly oriented CNTs in a thin
film by coupling the field emission phenomena, the electron-phonon transport
and the mechanics of single isolated CNT. A computational scheme is developed
by which the states of CNTs are updated in time incremental manner. The device
current is calculated by using Fowler-Nordheim equation for field emission to
study the performance at the device scale.Comment: 4 pages, 5 figure
MOLECULAR NETWORK CONTROLLING THE OVULE DEVELOPMENT IN ARABIDOPSIS THALIANA
Ovules are the essential organ for plant reproduction. Megasporogenesis, megagametogenesis, fertilization and embryogenesis take place within the ovule. In the ovule both sporophytic and gametophytic generation coexist. The analyses of this developmental process provides an excellent tool to understand the molecular mechanism involved in controlling the basic processes like primordia initiation, specification, cell division, expansion and differentiation. This system allows the study of basic developmental process as well as the evolutionary prospect in the same context. In my thesis I have used Arabidopsis thaliana as a model system.The aim of this project is to study the genetic and hormone network controlling ovule primordia formation. Reduction in number of ovule primordia was already described in the ant mutant (Baker et al., 1996). cuc1 and cuc2 single mutant display similar number of ovule primordia like wild type. Double mutant cuc1cuc2 shows defect in shoot apical meristem formation, two cotyledons fused along their margin to form a cup shaped structure (Aida et al., 1997). Normally it is difficult to get the double mutant plants from the fused cotyledon. Adventitious shoots regenerated from mutant calli form the double mutant flowers, which also display the reduction of number of ovule primordia (Ishida et al., 2000). The goal of this work was to investigate the interaction among ANT, CUC1, CUC2 genes to determine ovule primordia formation
IGVBrowser–a genomic variation resource from diverse Indian populations
The Indian Genome Variation Consortium (IGVC) project, an initiative of the Council for Scientific and Industrial Research, has been the first large-scale comprehensive study of the Indian population. One of the major aims of the project is to study and catalog the variations in nearly thousand candidate genes related to diseases and drug response for predictive marker discovery, founder identification and also to address questions related to ethnic diversity, migrations, extent and relatedness with other world population. The Phase I of the project aimed at providing a set of reference populations that would represent the entire genetic spectrum of India in terms of language, ethnicity and geography and Phase II in providing variation data on candidate genes and genome wide neutral markers on these reference set of populations. We report here development of the IGVBrowser that provides allele and genotype frequency data generated in the IGVC project. The database harbors 4229 SNPs from more than 900 candidate genes in contrasting Indian populations. Analysis shows that most of the markers are from genic regions. Further, a large fraction of genes are implicated in cardiovascular, metabolic, cancer and immune system-related diseases. Thus, the IGVC data provide a basal level variation data in Indian population to study genetic diseases and pharmacology. Additionally, it also houses data on ∼50 000 (Affy 50 K array) genome wide neutral markers in these reference populations. In IGVBrowser one can analyze and compare genomic variations in Indian population with those reported in HapMap along with annotation information from various primary data sources
IGVBrowser–a genomic variation resource from diverse Indian populations
The Indian Genome Variation Consortium (IGVC) project, an initiative of the Council for Scientific and Industrial Research, has been the first large-scale comprehensive study of the Indian population. One of the major aims of the project is to study and catalog the variations in nearly thousand candidate genes related to diseases and drug response for predictive marker discovery, founder identification and also to address questions related to ethnic diversity, migrations, extent and relatedness with other world population. The Phase I of the project aimed at providing a set of reference populations that would represent the entire genetic spectrum of India in terms of language, ethnicity and geography and Phase II in providing variation data on candidate genes and genome wide neutral markers on these reference set of populations. We report here development of the IGVBrowser that provides allele and genotype frequency data generated in the IGVC project. The database harbors 4229 SNPs from more than 900 candidate genes in contrasting Indian populations. Analysis shows that most of the markers are from genic regions. Further, a large fraction of genes are implicated in cardiovascular, metabolic, cancer and immune system-related diseases. Thus, the IGVC data provide a basal level variation data in Indian population to study genetic diseases and pharmacology. Additionally, it also houses data on ∼50 000 (Affy 50 K array) genome wide neutral markers in these reference populations. In IGVBrowser one can analyze and compare genomic variations in Indian population with those reported in HapMap along with annotation information from various primary data sources
Complete Break Up of Ortho Positronium (Ps)- Hydrogenic ion System
The dynamics of the complete breakup process in an Ortho Ps - He+ system
including electron loss to the continuum (ELC) is studied where both the
projectile and the target get ionized. The process is essentially a four body
problem and the present model takes account of the two centre effect on the
electron ejected from the Ps atom which is crucial for a proper description of
the ELC phenomena. The calculations are performed in the framework of Coulomb
Distorted Eikonal Approximation. The exchange effect between the target and the
projectile electron is taken into account in a consistent manner. The proper
asymptotic 3-body boundary condition for this ionization process is also
satisfied in the present model. A distinct broad ELC peak is noted in the fully
differential cross sections (5DCS) for the Ps electron corroborating
qualitatively the experiment for the Ps - He system. Both the dynamics of the
ELC from the Ps and the ejected electron from the target He+ in the FDCS are
studied using coplanar geometry. Interesting features are noted in the FDCS for
both the electrons belonging to the target and the projectile.Comment: 14 pages,7 figure
- …