5,159 research outputs found
General CMB and Primordial Trispectrum Estimation
We present trispectrum estimation methods which can be applied to general
non-separable primordial and CMB trispectra. We present a general optimal
estimator for the connected part of the trispectrum, for which we derive a
quadratic term to incorporate the effects of inhomogeneous noise and masking.
We describe a general algorithm for creating simulated maps with given
arbitrary (and independent) power spectra, bispectra and trispectra. We propose
a universal definition of the trispectrum parameter , so that the
integrated bispectrum on the observational domain can be consistently compared
between theoretical models. We define a shape function for the primordial
trispectrum, together with a shape correlator and a useful parametrisation for
visualizing the trispectrum. We derive separable analytic CMB solutions in the
large-angle limit for constant and local models. We present separable mode
decompositions which can be used to describe any primordial or CMB bispectra on
their respective wavenumber or multipole domains. By extracting coefficients of
these separable basis functions from an observational map, we are able to
present an efficient estimator for any given theoretical model with a
nonseparable trispectrum. The estimator has two manifestations, comparing the
theoretical and observed coefficients at either primordial or late times. These
mode decomposition methods are numerically tractable with order
operations for the CMB estimator and approximately order for the general
primordial estimator (reducing to order in both cases for a special class
of models). We also demonstrate how the trispectrum can be reconstructed from
observational maps using these methods.Comment: 38 pages, 9 figures. In v2 Figures 4-7 are altered slightly and some
extra references are included in the bibliography. v3 matches version
submitted to journal. Includes discussion of special case
Uncomplicated term vaginal delivery following magnetic resonance-guided focused ultrasound surgery for uterine fibroids.
A 35 year-old para 1+0 underwent MRgFUS per study protocol for multiple uterine fibroids, the largest of which measured 5 cm. She conceived 10 months following the procedure. The patient was induced at 41+6 weeks and underwent a normal vaginal delivery
Oral contraceptives, hormone replacement therapy, thrombophilias and risk of venous thromboembolism: a systematic review The Thrombosis: Risk and Economic Assessment of Thrombophilia Screening (TREATS) Study
Combined oral contraceptives,oral hormone replacement therapy and thrombophilias are recognised risk factors for venous thromboembolism in women.The objective of this study was to assess the risk of thromboembolism among women with thrombophilia who are taking oral contraceptives or hormone replacement therapy, conducting a systematic review and metaanalysis. Of 201 studies identified, only nine met the inclusion criteria. Seven studies included pre-menopausal women on oral contraceptives and two studies included peri-menopausal women on hormone replacement therapy. For oral contraceptive use, significant associations of the risk of venous thromboembolism were found in women with factor V Leiden (OR 15.62; 95%CI 8.66 to 28.15); deficiencies of antithrombin (OR 12.60; 95%CI 1.37 to 115.79), protein C (OR 6.33; 95%CI 1.68 to 23.87), or protein S (OR 4.88; 95%CI 1.39 to 17.10), elevated levels of factor VIIIc (OR 8.80; 95%CI 4.13 to 18.75); and factor V Leiden and prothrombin G20210A (OR 7.85; 95%CI 1.65 to 37.41). For hormone replacement therapy, a significant association was found in women with factor V Leiden (OR 13.16; 95%CI 4.28 to 40.47).Although limited by the small number of studies, the findings of this study support the presence of interaction between thrombophilia and venous thromboembolism among women taking oral contraceptives. However, further studies are required to establish with greater confidence the associations of these, and other, thrombophilias with venous thromboembolism among hormone users
Remotely Supported Prehospital Ultrasound : Real-Time Communication Technology for Remote and Rural Communities
Highlands & Islands Enterprise, UK Technology Strategy Board’s Space and Life Sciences Catapult, University of Aberdeen’s dot.rural Digital Economy HubPeer reviewedPublisher PD
Molecular gas in NUclei of GAlaxies (NUGA) VII. NGC4569, a large scale bar funnelling gas into the nuclear region
This work is part of the NUGA survey of CO emission in nearby active
galaxies. We present observations of NGC4569, a member of the Virgo Cluster. We
analyse the molecular gas distribution and kinematics in the central region and
we investigate a possible link to the strong starburst present at the nucleus.
70% of the 1.1x10^9 Msolar of molecular gas detected in the inner 20" is found
to be concentrated within the inner 800 pc and is distributed along the large
scale stellar bar seen in near-infrared observations. A hole in the CO
distribution coincides with the nucleus where most of the Halpha emission and
blue light are emitted. The kinematics are modelled in three different ways,
ranging from the purely geometrical to the most physical. This approach allows
us to constrain progressively the physical properties of the galaxy and
eventually to emerge with a reasonable fit to an analytical model of orbits in
a barred potential. Fitting an axisymmetric model shows that the non-circular
motions must be comparable in amplitude to the circular motions (120 km/s).
Fitting a model based on elliptical orbits allows us to identify with
confidence the single inner Lindblad resonance (ILR) of the large scale bar.
Finally, a model based on analytical solutions for the gas particle orbits in a
weakly barred potential constrained by the ILR radius reproduces the
observations well. The mass inflow rate is then estimated and discussed based
on the best fit model solution. The gravitational torques implied by this model
are able to efficiently funnel the gas inside the ILR down to 300 pc, although
another mechanism must take over to fuel the nuclear starburst inside 100 pc.Comment: accepted for publication in A&
The medical licensing examination debate
National licensing examinations are typically large-scale examinations taken early in a career or near the point of graduation, and, importantly, success is required to subsequently be able to practice. They are becoming increasingly popular as a method of quality assurance in the medical workforce, but debate about their contribution to patient safety and the improvement of healthcare outcomes continues.
A systematic review of the national licensing examination literature demonstrates that there is disagreement between assessment experts about the strengths and challenges of licensing examinations. This is characterized by a trans-Atlantic divide between the dominance of psychometric reliability assurance in North America and the wider interpretations of validity, to include consequences, in Europe. We conclude that the debate might benefit from refocusing to what a national licensing examination should assess: to achieve a balance between assessing a breadth of skills and the capacity for such skills in practice, and focusing less on reproducibility
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