5,854 research outputs found
Comment on " A simple model for DNA denaturation"
The replacment of mutual avoidance of polymers by a long-range interaction of
the type proposed by Garel etal (Europhys. Lett. 55, 132 (2001),
cond-mat/0101058) is inconsistent with the prevalent renormalization group
arguments.Comment: 2 pages, Comment on Garel etal. Europhys. Lett 55, 132(2001)
cond-mat/0101058. Appeared in Europhys Let
Helicase activity on DNA as a propagating front
We develop a propagating front analysis, in terms of a local probability of
zipping, for the helicase activity of opening up a double stranded DNA (dsDNA).
In a fixed-distance ensemble (conjugate to the fixed-force ensemble) the front
separates the zipped and unzipped phases of a dsDNA and a drive acts locally
around the front. Bounds from variational analysis and numerical estimates for
the speed of a helicase are obtained. Different types of helicase behaviours
can be distinguished by the nature of the drive.Comment: 5 pages, 5 eps figures; replaced by the published versio
Frequency Dependent Viscosity Near the Critical Point: The Scale to Two Loop Order
The recent accurate measurements of Berg, Moldover and Zimmerli of the
viscoelastic effect near the critical point of xenon has shown that the scale
factor involved in the frequency scaling is about twice the scale factor
obtained theoretically. We show that this discrepancy is a consequence of using
first order perturbation theory. Including two loop contribution goes a long
way towards removing the discrepancy.Comment: No of pages:7,Submitted to PR-E(Rapid Communication),No of EPS
files:
Possible ferro-spin nematic order in NiGa2S4
We explore the possibility that the spin-1 triangular lattice magnet NiGa2 S4
may have a ferro-nematic ground state with no frozen magnetic moment but a
uniform quadrupole moment. Such a state may be stabilized by biquadratic spin
interactions. We describe the physical properties of this state and suggest
experiments to help verify this proposal. We also contrast this state with a
`non-collinear' nematic state proposed earlier by Tsunetsugu and Arikawa for
NiGa2S4
Critical Viscosity Exponent for Fluids: What Happend to the Higher Loops
We arrange the loopwise perturbation theory for the critical viscosity
exponent , which happens to be very small, as a power series in
itself and argue that the effect of loops beyond two is negligible.
We claim that the critical viscosity exponent should be very closely
approximated by .Comment: 9 pages and 3 figure
A hospital based study of scenerio of glaucoma patients in upper Assam, India
Background: Glaucoma can be defined as a chronic multifactorial optic neuropathy with a characteristic accelerated degeneration of retinal ganglion cells presenting as classical optic nerve head features and correlating visual field changes, which may or may not be associated with angle abnormality in the presence or absence of any cause for the disease.Methods: This was a prospective hospital based study of patients >40years with a suspicion of glaucoma attending the Outpatient Department of Ophthalmology, Assam Medical College, Dibrugarh, Assam, india. Patients were subjected to a comprehensive eye examination to diagnose and classify glaucoma.Results: In this study out of 1000 patients, 22 were diagnosed to have glaucoma (2.2%), most common age group >61years (50%), male patients were 73%, PACG accounted for 11 patients (50%). POAG in 7 cases (32%), LIG in 14%, Neovuscular in 1 cases (5%).Conclusions: Glaucoma prevalence, age and sex distribution was found to be similar to studies conducted in other parts of India. Most common type of glaucoma was PACG followed by POAG
Examples of Artificial Perceptions in Optical Character Recognition and Iris Recognition
This paper assumes the hypothesis that human learning is perception based,
and consequently, the learning process and perceptions should not be
represented and investigated independently or modeled in different simulation
spaces. In order to keep the analogy between the artificial and human learning,
the former is assumed here as being based on the artificial perception. Hence,
instead of choosing to apply or develop a Computational Theory of (human)
Perceptions, we choose to mirror the human perceptions in a numeric
(computational) space as artificial perceptions and to analyze the
interdependence between artificial learning and artificial perception in the
same numeric space, using one of the simplest tools of Artificial Intelligence
and Soft Computing, namely the perceptrons. As practical applications, we
choose to work around two examples: Optical Character Recognition and Iris
Recognition. In both cases a simple Turing test shows that artificial
perceptions of the difference between two characters and between two irides are
fuzzy, whereas the corresponding human perceptions are, in fact, crisp.Comment: 5th Int. Conf. on Soft Computing and Applications (Szeged, HU), 22-24
Aug 201
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