1,730 research outputs found
Origin of spatial organization of DNA-polymer in bacterial chromosomes
In-vivo DNA organization at large length scales () is highly
debated and polymer models have proved useful to understand the principle of
DNA-organization. Here, we show that % cross-links at specific points in a
ring polymer can lead to a distinct spatial organization of the polymer. The
specific pairs of cross-linked monomers were extracted from contact maps of
bacterial DNA. We are able to predict the structure of 2 DNAs using Monte Carlo
simulations of the bead-spring polymer with cross-links at these special
positions. Simulations with cross-links at random positions along the chain
show that the organization of the polymer is different in nature from the
previous case.Comment: arXiv admin note: text overlap with arXiv:1701.0506
Polarisation dependence of magnetic Bragg scattering in YMnO
The polarisation dependence of the intensity of elastic magnetic scattering
from \ymno\ single crystals has been measured at 25 K in magnetic fields
between 1 and 9 T. A significant polarisation dependence was observed in the
intensities of magnetic satellite reflections, propagation vector
\pv=0.5,0,0.25 measured with both the [100] and [010] axes parallel to the
common polarisation and applied field direction. The intensity asymmetries
observed in sets of orthorhombicly equivalent reflections show systematic
relationships which allow the phase relationship between different components
of their magnetic interaction vectors to be determined. They fix the
orientation relationships between the small and moments on the \mnfp\
and \mntp\ sub-lattices and lend support to the structure reported by Kim et
al. It was found that that which suggests
that there is a small modulation of the nuclear structure which has the same
wave-vector as the magnetic modulation leading to a small nuclear structure
factor for the satellite reflections. The differences observed indicate shifts in the atomic positions of order 0.005 \AA
Access to Justice For Women: India's Response to Sexual Violence in Conflict and Social Upheaval
A 2014 report by the Special Rapporteur on Violence Against Women on gender-based crimes describes the female experience in India as consisting of a "continuum of violence...from the 'womb to the tomb.'" According to Indian government data, a woman is raped in the country approximately every twenty minutes. Women and girls are especially vulnerable to sexual violence during armed conflict and mass violence. Indeed, gender-based crime is a common feature of the armed conflict and mass violence that has marred India since independence.This report examines emblematic case examples from conflict zones and incidents of mass violence to understand how the Indian State responds to sexual violence against women and girls in these contexts. The goal of this report is to analyze the efforts of women victims of sexual violence and their allies to access justice in these contexts and to identify emblematic ways the Indian legal system succeeded or failed to provide effective redress
Multiferroic coupling in nanoscale BiFeO3
Using the results of x-ray and neutron diffraction experiments, we show that
the ferroelectric polarization, in ~22 nm particles of BiFeO3, exhibits a jump
by ~30% around the magnetic transition point T_N (~635 K) and a suppression by
~7% under 5T magnetic field at room temperature (<<T_N). These results confirm
presence of strong multiferroic coupling even in nanoscale BiFeO3 and thus
could prove to be quite useful for applications based on nanosized devices of
BiFeO3.Comment: 4 pages including 4 figures and supplementary data; accepted for
publication in Appl. Phys. Let
Weak ferromagnetism and magnetic phase transitions in GdCuO
We report a polarised neutron study of the magnetic structures and phase
trasitions in \gdc\ in low magnetic fields. These experiments have been
complemented by integrated intensity measurements with unpolarised neutrons in
zero field. Polarised neutron flipping ratio measurements have been made with
magnetic fields , 0.10 and 0.5 T in the temperature range 4-20 K.
These have enabled us to deduce that the anomalous temperature behaviour of the
coherent magnetic scattering from the Cu sublattice, which shows sharp
intensity minima at \Tcn1 K and \Tcn2 K, is due to
cross-overs in the sign of the interaction between strongly coupled, weakly
ferromagnetic, CuO layers. At \Tcn1\ the coupling changes from
ferromagnetic to anti-ferromagnetic and long-range order between layers is
temporarily lost. \Tcn2\ is the temperature at which the Gd moments order and a
further reorganisation of the interlayer order takes place. The weak
ferromagnetism of the CuO layers is found to be due to a small rotation of the
Cu moments in the same direction as that in which their coordinating oxygen
squares rotate in the tetragonal to orthorhombic distortion of the crystal
structure. Further analysis of the flipping ratio measurements has enabled us
to model the magnetic structures of the zero-field and the field-induced phases
of GdCuO
Magnetoelastic effects in Jahn-Teller distorted CrF and CuF studied by neutron powder diffraction
We have studied the temperature dependence of crystal and magnetic structures
of the Jahn-Teller distorted transition metal difluorides CrF and CuF
by neutron powder diffraction in the temperature range 2-280 K. The lattice
parameters and the unit cell volume show magnetoelastic effects below the
N\'eel temperature. The lattice strain due to the magnetostriction effect
couples with the square of the order parameter of the antiferromagnetic phase
transition. We also investigated the temperature dependence of the Jahn-Teller
distortion which does not show any significant effect at the antiferromagnetic
phase transition but increases linearly with increasing temperature for CrF
and remains almost independent of temperature in CuF. The magnitude of
magnetovolume effect seems to increase with the low temperature saturated
magnetic moment of the transition metal ions but the correlation is not at all
perfect
Detection of gravitational-wave bursts with chirplet-like template families
Gravitational Wave (GW) burst detection algorithms typically rely on the
hypothesis that the burst signal is "locally stationary", that is it changes
slowly with frequency. Under this assumption, the signal can be decomposed into
a small number of wavelets with constant frequency. This justifies the use of a
family of sine-Gaussian templates in the Omega pipeline, one of the algorithms
used in LIGO-Virgo burst searches. However there are plausible scenarios where
the burst frequency evolves rapidly, such as in the merger phase of a binary
black hole and/or neutron star coalescence. In those cases, the local
stationarity of sine-Gaussians induces performance losses, due to the mismatch
between the template and the actual signal. We propose an extension of the
Omega pipeline based on chirplet-like templates. Chirplets incorporate an
additional parameter, the chirp rate, to control the frequency variation. In
this paper, we show that the Omega pipeline can easily be extended to include a
chirplet template bank. We illustrate the method on a simulated data set, with
a family of phenomenological binary black-hole coalescence waveforms embedded
into Gaussian LIGO/Virgo-like noise. Chirplet-like templates result in an
enhancement of the measured signal-to-noise ratio.Comment: 8 pages, 6 figures. Submitted to Class. Quantum Grav. Special issue:
Proceedings of GWDAW-14, Rome (Italy), 2010; fixed several minor issue
Respiratory metabolism in Oreochromis mossambicus, Peters under different environmental conditions
Oxygen consumption in Oreochromis mossambicus, Peters (3-60g in weight) was measured under different stress conditions at a constant temperature of 20±1°C. The rate of oxygen consumption was significantly higher (0.170 ml gˉ¹hˉ¹)at a salinity of 30x10ˉ³ compared with that (0.132ml gˉ¹hˉ¹) in freshwater. The oxygen consumption was also found to be affected by changes in pH. Weight specific rate decreased significantly from 0.113 to 0.045 ml gˉ¹hˉ¹ with increasing body weight. A positive correlation was recorded between availability of dissolved oxygen and the rate of oxygen consumption by the fish. While copper sulphate and malachite green inhibited the respiratory metabolism, formaldehyde treatment raised it from 0.088 to 0.118ml gˉ¹hˉ¹
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