14,571 research outputs found
Conserved Charges and Supersymmetry in Principal Chiral Models
We report on investigations of local (and non-local) charges in bosonic and
supersymmetric principal chiral models in 1+1 dimensions. In the bosonic PCM
there is a classically conserved local charge for each symmetric invariant
tensor of the underlying group. These all commute with the non-local Yangian
charges. The algebra of the local charges amongst themselves is rather more
subtle. We give a universal formula for infinite sets of mutually commuting
local charges with spins equal to the exponents of the underlying classical
algebra modulo its Coxeter number. Many of these results extend to the
supersymmetric PCM, but with local conserved charges associated with
antisymmetric invariants in the Lie algebra. We comment briefly on the quantum
conservation of local charges in both the bosonic and super PCMs.Comment: 18 pages, LaTeX. Revised and up-dated version based on conference
talks by JME and NJ
Scale-free network topology and multifractality in weighted planar stochastic lattice
We propose a weighted planar stochastic lattice (WPSL) formed by the random
sequential partition of a plane into contiguous and non-overlapping blocks and
find that it evolves following several non-trivial conservation laws, namely
is independent of time , where
and are the length and width of the th block. Its dual on the
other hand, obtained by replacing each block with a node at its center and
common border between blocks with an edge joining the two vertices, emerges as
a network with a power-law degree distribution where
revealing scale-free coordination number disorder since
also describes the fraction of blocks having neighbours. To quantify the
size disorder, we show that if the th block is populated with then its distribution in the WPSL exhibits multifractality.Comment: 7 pages, 8 figures, To appear in New Journal of Physics (NJP
USF binding sequences from the HS4 insulator element impose early replication timing on a vertebrate replicator
The nuclear genomes of vertebrates show a highly organized program of DNA replication where GC-rich isochores are replicated early in S-phase, while AT-rich isochores are late replicating. GC-rich regions are gene dense and are enriched for active transcription, suggesting a connection between gene regulation and replication timing. Insulator elements can organize independent domains of gene transcription and are suitable candidates for being key regulators of replication timing. We have tested the impact of inserting a strong replication origin flanked by the β-globin HS4 insulator on the replication timing of naturally late replicating regions in two different avian cell types, DT40 (lymphoid) and 6C2 (erythroid). We find that the HS4 insulator has the capacity to impose a shift to earlier replication. This shift requires the presence of HS4 on both sides of the replication origin and results in an advance of replication timing of the target locus from the second half of S-phase to the first half when a transcribed gene is positioned nearby. Moreover, we find that the USF transcription factor binding site is the key cis-element inside the HS4 insulator that controls replication timing. Taken together, our data identify a combination of cis-elements that might constitute the basic unit of multi-replicon megabase-sized early domains of DNA replication
Theory of low transitions in CO discharge lasers
A self consistent theoretical model which couples the electron and heavy particle finite rate kinetics with the optical and fluid dynamic processes has been employed to identify the various parameters and explain the mechanism responsible for producing low lying transitions in slow flowing CO lasers. It is found that lasing on low lying transitions can be achieved at low temperatures for low pressures (or low flow rates) together with high partial pressures of the He and N2. The role of N2 has been identified as an additive responsible for reducing the electron temperature to a range where the transfer of electrical power to the lower vibrational modes of CO is optimum
Geriatric Challenges - Tackling With Innovative Measures
is a natural process. India has 77 million elderly people and is expected to have 177 million by 2025. By the year 2050, one fifth of total population will be graying. Ninety percent of the elderly are from unorganized sector with no social security. Over 73 percent of 60 plus are illiterate and dependent on physical labour. Forty percent people live below the povertyline. Recent studies have shown that 89.62 percent of elderly population has multiple morbidities. The leading symptoms or group of symptoms in both males and females pertain to visual impairment / diminished vision (65% & 56.2% respectively). Other problems include heart diseases, respiratory diseases, joints pains, hearing problems etc.Many innovative experimental studies have been done to reverse the biochemical and pathological changes that occur during ageing by using chemicals and drugs. In various studies it has been established that the use of Ca2 (+) antagonists leads to reversal of atherosclerotic process, similarly 2 - mercapto propionly glycine (MPG) and oxidized MPG improve heart functioning. Centrophenoxine considered as an ageing reversal drug is regarded as neuroenergeticum in human therapy. Ginkgo biloba extract can improve the cerebral function. Topically applied all-trans retionic acid can repair and probably prevent photo ageing
Hadron Production in Neutrino-Nucleon Interactions at High Energies
The multi-particle production at high energy neutrino- nucleon collisions are
investigated through the analysis of the data of the experiment CERN-WA-025 at
neutrino energy less than 260GeV and the experiments FNAL-616 and FNAL-701 at
energy range 120-250 GeV. The general features of these experiments are used as
base to build a hypothetical model that views the reaction by a Feynman diagram
of two vertices. The first of which concerns the weak interaction between the
neutrino and the quark constituents of the nucleon. At the second vertex, a
strong color field is assumed to play the role of particle production, which
depend on the momentum transferred from the first vertex. The wave function of
the nucleon quarks are determined using the variation method and relevant
boundary conditions are applied to calculate the deep inelastic cross sections
of the virtual diagram.Comment: 6 pages PDF forma
An interconnected duplicated femoral vein and its clinical significance
Anatomical variations in the femoral vein are of great clinical importance especially in cases of deep vein thrombosis (DVT). Knowledge of the variable anatomy of the femoral vein is important to minimise false-negative findings on ultrasound examination in patients with DVT and help to explain the ‘silent’ DVT.Furthermore, the presence of a duplicated femoral vein itself is associated with higher incidence of DVT. These venous anomalies are usually due to the truncular venous malformation. In the present study, while dissecting the right lower limb, we found a case of variation of the femoral vein. In this case, besides a duplicated femoral vein, we also noticed a 3rd interconnecting channel near the apex of the femoral triangle joining the two veins. This variation has not been reported previously by other authors. Considering its uniqueness and clinical importance,we decided to report this case
Model Development of Children Under Mortality Rate with Group Method of Data Handling
In this research we examine aspects of the interdependence between economic development and the use of environmental and natural resources assets from global data published by united nations. for that purpose, we use data mining techniques.data mining techniques applied in this paper were: 1) group method of data handling (gmdh), originally from engineering, introducing principles of evolution - inheritance, mutation and selection - for generating a network structure systematically to develop the automatic model, synthesis, and its validation; 2) step wise regression were also applied for some cases.data sets for this research consist of one sets integration data of air quality data and macroeconomic data of the cross-country data of world development indicator 2003 (wdi 2003). the result shows that the mortality rate of children under five years old is dependent on sanitation and water facilities obtained from gmdh results. however, the results from step-wise regression shows that mortality rate was dependent on annual deforestation, particulate matter, nationally protected area, with the big contribution was from annual deforestation
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