23,172 research outputs found
Electrostatic contribution to DNA condensation - application of 'energy minimization' in a simple model in strong Coulomb coupling regime
Bending of DNA from a straight rod to a circular form in presence of any of
the mono-, di-, tri- or tetravalent counterions has been simulated in strong
Coulomb coupling environment employing a previously developed energy
minimization simulation technique. The inherent characteristics of the
simulation technique allow monitoring the required electrostatic contribution
to the bending. The curvature of the bending has been found to play crucial
roles in facilitating electrostatic attractive potential energy. The total
electrostatic potential energy has been found to decrease with bending which
indicates that bending a straight DNA to a circular form or to a toroidal form
in presence of neutralizing counterions is energetically favorable and
practically is a spontaneous phenomenon
Number-conserving theory of nuclear pairing gaps: a global assessment
We study odd-even mass staggering of nuclei, also called pairing gaps, using
a Skyrme self-consistent mean-field theory and a numerically exact treatment of
the pairing Hamiltonian. We find that the configuration-space Monte Carlo
method proposed by Cerf and Martin offers a practical computational procedure
to carry out the numerical solutions in large-dimensional model spaces.
Refitting the global strength of the pairing interaction for 443 neutron
pairing gaps in our number-conserving treatment, we find the correction to the
pairing correlation energies and pairing gaps to have rms values of 0.6 MeV and
0.12 MeV, respectively. The exact treatment provides a significant improvement
in the fit to experimental gaps, although it is partially masked by a larger
rms error due to deficiencies in other aspects of the theory such as the
mean-field energy functional.Comment: 11 pages, 9 figure
Safe abortion – Still a neglected scenario: A study of septic abortions in a tertiary hospital of Rural India
Background and Aims: In spite abortion has been legalized in India over three decades, unsafe abortion continues to be a significant contributor of maternal mortality and morbidity. The aim of the present study is to assess the magnitude of septic abortion in a tertiary care hospital over a period of three years with a special emphasis on maternal mortality and morbidity and various surgical complications. Settings and Design: Retrospective study of patients who were admitted with unsafe abortions over a three year period from 2005 to 2008 in a tertiary teaching Hospital of Rural India. Materials and Methods: Hospital records of the patients who were admitted with unsafe abortion in three years (2005-2008) were reviewed to evaluate the demographic and clinical profile in relation to age, parity, marital status, indication of abortion , the methods of abortion ,qualification of abortion provider complications and maternal mortality. Results: Unsafe abortion constitutes 11.6% ( n=132) of total abortion cases admitted over 3 years. Majority of women (70.45%) were in their thirties, married (89%).Sixty percent wanted abortion for birth spacing. Abortion methods included various primitive methods (30%) but majority by dilatation and evacuation. About 60% of abortionists were unqualified. Majority of women admitted with serious complications like peritonitis (70%), visceral injuries (60%), hemorrhagic and septic shock, renal failure (17.4%), and life threatening conditions like DIC, hepatic failure and encephalopathy. A total of 231 women died of unsafe abortion making it 12.55% of total maternal mortality in our institution. Out of 73 women requiring laparotomy, 22% were done within 24 hours of admission and majority (49%) were performed beyond 24-48 hours. Interestingly no women died when early aggressive surgery was done. Conclusion: The present study confirms that unsafe abortion is a great neglected health care problem leading to a considerable loss of maternal lives. Education and accessibility of contra caption, readily available, quality abortion services by trained abortion providers remain the key to limit mortality and morbidity arising from unsafe abortion
Universality of TMD distribution functions of definite rank
Transverse momentum dependent (TMD) distribution and fragmentation functions
are described as Fourier transforms of matrix elementscontaining nonlocal
combinations of quark and gluon fields. These matrix elements also contain a
gauge link operator with a process dependent path, of which the process
dependence that can be traced back to the color flow in the process. Expanding
into irreducible tensors built from the transverse momenta p_\st, we can
define a universal set of TMD correlators of definite rank with a well-defined
operator structure.Comment: 6 pages, to be published in proceedings of the Third Worshop on the
QCD Structure of the Nucleon (QCD N'12), Bilbao, Spain, 22-26 October 201
Universality of TMD correlators
In a high-energy scattering process with hadrons in the initial state, color
is involved. Transverse momentum dependent distribution functions (TMDs)
describe the quark and gluon distributions in these hadrons in momentum space
with the inclusion of transverse directions. Apart from the (anti)-quarks and
gluons that are involved in the hard scattering process, additional gluon
emissions by the hadrons have to be taken into account as well, giving rise to
Wilson lines or gauge links. The TMDs involved are sensitive to the process
under consideration and hence potentially nonuniversal due to these Wilson line
interactions with the hard process; different hard processes give rise to
different Wilson line structures. We will show that in practice only a finite
number of universal TMDs have to be considered, which come in different linear
combinations depending on the hard process under consideration, ensuring a
generalized universality. For quarks this gives rise to three Pretzelocity
functions, whereas for gluons a richer structure of functions arises.Comment: 6 pages, presented by the first author at the 4th International
Workshop on Transverse Polarization Phenomena in Hard Processes (Transversity
2014), June 9-13, 2014, Chia, Italy. To appear in EPJ Web of Conference
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