17,965 research outputs found
A comparison of the expected and actual pain experienced by women during insertion of an intrauterine contraceptive device.
Objective: To compare the expected and actual pain experienced with the insertion of intrauterine contraception in women, and to determine whether either of these are related to their personal circumstances, or affected their satisfaction with the procedure. Design: A convenience sample of 89 women aged 15-50 attending a sexual health clinic for same day intrauterine contraception insertion were given a questionnaire which they completed following the procedure. The women were asked to rate their expectation of pain prior to insertion and to rate the actual pain they experienced immediately after insertion, on a scale of 1 to 10 with 10 being severe pain. Information on the women’s circumstances and their level of satisfaction with the procedure was also obtained. Results: Overall, the median actual pain experienced by women during insertion (4) was significantly lower than the expected pain median (6) (p<0.001). For those women who had not had a previous vaginal delivery, actual pain was significantly higher compared with women who had a previous vaginal delivery (median [IQR] = 6 [3.5-7.5] and 3 [1-5], p<0.001), respectively), but there was no significant difference between expected and actual pain experiences. In women who had a previous vaginal delivery, actual pain was much lower than expected (p<0.001). Neither actual nor expected pain experiences were linked to any other socio-demographic reproductive health or service use factors. Conclusion: All women had a high expectation of pain prior to IUD insertion but, for those who had a previous vaginal delivery, this was significantly greater than that actually experienced. Satisfaction levels overall were high. Counselling of women should take into account their expected pain prior to IUD insertion and consideration should be given to alternative and additional methods of pain relief in women who had not had a previous vaginal delivery
Aerodynamic characteristics of forebody and nose strakes based on F-16 wind tunnel test experience. Volume 1: Summary and analysis
The YF-16 and F-16 developmental wind tunnel test program was reviewed. Geometrical descriptions, general comments, representative data, and the initial efforts toward the development of design guides for the application of strakes to future aircraft are presented
3-Body Dynamics in a (1+1) Dimensional Relativistic Self-Gravitating System
The results of our study of the motion of a three particle, self-gravitating
system in general relativistic lineal gravity is presented for an arbitrary
ratio of the particle masses. We derive a canonical expression for the
Hamiltonian of the system and discuss the numerical solution of the resulting
equations of motion. This solution is compared to the corresponding
non-relativistic and post-Newtonian approximation solutions so that the
dynamics of the fully relativistic system can be interpretted as a correction
to the one-dimensional Newtonian self-gravitating system. We find that the
structure of the phase space of each of these systems yields a large variety of
interesting dynamics that can be divided into three distinct regions: annulus,
pretzel, and chaotic; the first two being regions of quasi-periodicity while
the latter is a region of chaos. By changing the relative masses of the three
particles we find that the relative sizes of these three phase space regions
changes and that this deformation can be interpreted physically in terms of the
gravitational interactions of the particles. Furthermore, we find that many of
the interesting characteristics found in the case where all of the particles
share the same mass also appears in our more general study. We find that there
are additional regions of chaos in the unequal mass system which are not
present in the equal mass case. We compare these results to those found in
similar systems.Comment: latex, 26 pages, 17 figures, high quality figures available upon
request; typos and grammar correcte
Chaos in an Exact Relativistic 3-body Self-Gravitating System
We consider the problem of three body motion for a relativistic
one-dimensional self-gravitating system. After describing the canonical
decomposition of the action, we find an exact expression for the 3-body
Hamiltonian, implicitly determined in terms of the four coordinate and momentum
degrees of freedom in the system. Non-relativistically these degrees of freedom
can be rewritten in terms of a single particle moving in a two-dimensional
hexagonal well. We find the exact relativistic generalization of this
potential, along with its post-Newtonian approximation. We then specialize to
the equal mass case and numerically solve the equations of motion that follow
from the Hamiltonian. Working in hexagonal-well coordinates, we obtaining
orbits in both the hexagonal and 3-body representations of the system, and plot
the Poincare sections as a function of the relativistic energy parameter . We find two broad categories of periodic and quasi-periodic motions that we
refer to as the annulus and pretzel patterns, as well as a set of chaotic
motions that appear in the region of phase-space between these two types.
Despite the high degree of non-linearity in the relativistic system, we find
that the the global structure of its phase space remains qualitatively the same
as its non-relativisitic counterpart for all values of that we could
study. However the relativistic system has a weaker symmetry and so its
Poincare section develops an asymmetric distortion that increases with
increasing . For the post-Newtonian system we find that it experiences a
KAM breakdown for : above which the near integrable regions
degenerate into chaos.Comment: latex, 65 pages, 36 figures, high-resolution figures available upon
reques
Intermediate left-right gauge symmetry, unification of couplings and fermion masses in SUSY
If left-right gauge theory occurs as an intermediate symmetry in a GUT then,
apart from other advantages, it is possible to obtain the see-saw scale
necessary to understand small neutrino masses with Majorana coupling of order
unity. Barring threshold or non-renormalizable gravitational effects, or
assumed presence of additional light scalar particles of unprescribed origin,
all other attempts to achieve manifest one-loop gauge coupling unification in
SUSY SO(10) with left-right intermediate symmetry have not been successful so
far. Attributing this failure to lack of flavor symmetry in the GUT, we show
how the spontaneous symmetry breaking of leads to such
intermediate scale extending over a wide range, GeV
to GeV. All the charged fermion masses are fitted at the see-saw
scale, GeV which is obtained with
Majorana coupling . Using a constrained parametrization in which
CP-violation originates only from quark sector, besides other predictions made
in the neutrino sector, the reactor mixing angle is found to be which is in the range accessible to ongoing and
planned experiments. The leptonic Dirac phase turns out to be radians with Jarlskog invariant .Comment: Minor clarification and few references added to match the published
versio
Higher Dimensional Taub-NUTs and Taub-Bolts in Einstein-Maxwell Gravity
We present a class of higher dimensional solutions to Einstein-Maxwell
equations in d-dimensions. These solutions are asymptotically locally flat,
de-Sitter, or anti-de Sitter space-times. The solutions we obtained depend on
two extra parameters other than the mass and the nut charge. These two
parameters are the electric charge, q and the electric potential at infinity,
V, which has a non-trivial contribution. We Analyze the conditions one can
impose to obtain Taub-Nut or Taub-Bolt space-times, including the
four-dimensional case. We found that in the nut case these conditions coincide
with that coming from the regularity of the one-form potential at the horizon.
Furthermore, the mass parameter for the higher dimensional solutions depends on
the nut charge and the electric charge or the potential at infinity.Comment: 11 pages, LaTe
Recommended from our members
Prisoners’ perceptions of care and rehabilitation from prison officers trained as 5 minute interventionists: analytical summary
The Five Minute Intervention (FMI) project trained prison officers to turn everyday conversations into rehabilitative opportunities using skills such as Socratic questioning, active listening, and affirmation. Webster and Kenny (2015) reported on the experiences of prison officers involved in the FMI pilot. This research reports on the experiences of ten male prisoners who participated in FMI conversations with prison officers. FMI training now forms part of the national training programme for prison staff
Classical predictability and coarse-grained evolution of the quantum baker's map
We investigate how classical predictability of the coarse-grained evolution
of the quantum baker's map depends on the character of the coarse-graining. Our
analysis extends earlier work by Brun and Hartle [Phys. Rev. D 60, 123503
(1999)] to the case of a chaotic map. To quantify predictability, we compare
the rate of entropy increase for a family of coarse-grainings in the decoherent
histories formalism. We find that the rate of entropy increase is dominated by
the number of scales characterising the coarse-graining.Comment: 28 pages, 1 figur
Accurate determination of the Lagrangian bias for the dark matter halos
We use a new method, the cross power spectrum between the linear density
field and the halo number density field, to measure the Lagrangian bias for
dark matter halos. The method has several important advantages over the
conventional correlation function analysis. By applying this method to a set of
high-resolution simulations of 256^3 particles, we have accurately determined
the Lagrangian bias, over 4 magnitudes in halo mass, for four scale-free models
with the index n=-0.5, -1.0, -1.5 and -2.0 and three typical CDM models. Our
result for massive halos with ( is a characteristic non-linear
mass) is in very good agreement with the analytical formula of Mo & White for
the Lagrangian bias, but the analytical formula significantly underestimates
the Lagrangian clustering for the less massive halos $M < M_*. Our simulation
result however can be satisfactorily described, with an accuracy better than
15%, by the fitting formula of Jing for Eulerian bias under the assumption that
the Lagrangian clustering and the Eulerian clustering are related with a linear
mapping. It implies that it is the failure of the Press-Schechter theories for
describing the formation of small halos that leads to the inaccuracy of the Mo
& White formula for the Eulerian bias. The non-linear mapping between the
Lagrangian clustering and the Eulerian clustering, which was speculated as
another possible cause for the inaccuracy of the Mo & White formula, must at
most have a second-order effect. Our result indicates that the halo formation
model adopted by the Press-Schechter theories must be improved.Comment: Minor changes; accepted for publication in ApJ (Letters) ; 11 pages
with 2 figures include
Dynamical N-body Equlibrium in Circular Dilaton Gravity
We obtain a new exact equilibrium solution to the N-body problem in a
one-dimensional relativistic self-gravitating system. It corresponds to an
expanding/contracting spacetime of a circle with N bodies at equal proper
separations from one another around the circle. Our methods are
straightforwardly generalizable to other dilatonic theories of gravity, and
provide a new class of solutions to further the study of (relativistic)
one-dimensional self-gravitating systems.Comment: 4 pages, latex, reference added, minor changes in wordin
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