618 research outputs found
1167-208 Relationship between QRS duration and left ventricular dyssynchrony in patients with end stage heart failure
Iliolumbar membrane, a newly recognised structure in the back
Despite intensive research in the anatomical sciences for the last two centuries,
some structures of the human body still remain controversial or incompletely
described.
We describe a new membranous fascial anatomical entity, which we refer to as
the iliolumbar membrane (ILM). During the 2004-2005 academic semesters at
the American University of the Caribbean School of Medicine we dissected
40 human cadavers fixed in formalin-alcohol-phenol solution. Iliolumbar membrane
is a thick connective tissue structure, deep to the skin, originating from
the fibres of the thoracolumbar fascia at the lateral border of the erector spinae.
It runs inferior to the superior border of the iliac crest, lateral to the posterior
superior iliac spine, overlying the iliac crest at the level of the 4th lumbar vertebra.
Iliolumbar membrane terminates within subcutaneous fat, where it divides
into multiple layers. All cadavers showed considerable variation in the blending
of the membrane’s multiple layers with the subcutaneous fat. However, all specimens
consistently showed a uniform appearance of ILM at the point of origin.
Iliolumbar membrane could be demonstrated objectively by ultrasound examination
with a frequency of 7.5 MHz and also with a Stryker endoscope. A hypothesis
is put forth, conjecturing that this new structure may have relevance in
creating a natural barrier between the musculature of the back and the muscles
of the gluteal region, similar to Scarpa’s fascia of the anterior abdominal wall
Slowing polar molecules using a wire Stark decelerator
We have designed and implemented a new Stark decelerator based on wire
electrodes, which is suitable for ultrahigh vacuum applications. The 100
deceleration stages are fashioned out of 0.6 mm diameter tantalum and the
array's total length is 110 mm, approximately 10 times smaller than a
conventional Stark decelerator with the same number of electrode pairs. Using
the wire decelerator, we have removed more than 90% of the kinetic energy from
metastable CO molecules in a beam.Comment: updated version, added journal referenc
Population Monte Carlo algorithms
We give a cross-disciplinary survey on ``population'' Monte Carlo algorithms.
In these algorithms, a set of ``walkers'' or ``particles'' is used as a
representation of a high-dimensional vector. The computation is carried out by
a random walk and split/deletion of these objects. The algorithms are developed
in various fields in physics and statistical sciences and called by lots of
different terms -- ``quantum Monte Carlo'', ``transfer-matrix Monte Carlo'',
``Monte Carlo filter (particle filter)'',``sequential Monte Carlo'' and
``PERM'' etc. Here we discuss them in a coherent framework. We also touch on
related algorithms -- genetic algorithms and annealed importance sampling.Comment: Title is changed (Population-based Monte Carlo -> Population Monte
Carlo). A number of small but important corrections and additions. References
are also added. Original Version is read at 2000 Workshop on
Information-Based Induction Sciences (July 17-18, 2000, Syuzenji, Shizuoka,
Japan). No figure
Different value of coronary calcium score to predict obstructive coronary artery disease in patients with and without moderate chronic kidney disease.
published_or_final_versio
Effect of physical exercise on cognitive function and brain measures after chemotherapy in patients with breast cancer (PAM study): protocol of a randomised controlled trial
Plasma natriuretic peptide levels reflect changes in heart failure symptoms, left ventricular size and function after surgical mitral valve repair
Background and aim: N-terminal pro-B-type natriuretic peptide (NT-proBNP) has diagnostic and prognostic value in patients with heart failure. The present prospective study was designed to assess whether changes in NT-proBNP levels after surgical mitral valve repair reflect changes in heart failure symptoms an
Numerical Investigation of Wind Turbine Airfoils under Clean and Dusty Air Conditions
This paper focuses on the simulation of the airflow around wind turbine airfoils (S809 and S814) under both clean and dusty air conditions by using Computational Fluid Dynamics (CFD). The physical geometries of the airfoils and the meshing processes are completed in the ANSYS Mesh package ICEM. The simulation is done by ANSYS FLUENT. For clean air condition, Spalart– Allmaras (SA) model and realizable k-ε model are used. The results are compared with the experimental data to test which model agrees better. For dusty air condition, simulation of the two-phase flow is operated by realizable k-ε model and discrete phase model (DPM) in different concentration of dust particles (1% and 10% in volume). The results are compared with the data of clean air to illustrate the effect of dust contamination on the lift and drag characteristics of the airfoil
A review of Monte Carlo simulations of polymers with PERM
In this review, we describe applications of the pruned-enriched Rosenbluth
method (PERM), a sequential Monte Carlo algorithm with resampling, to various
problems in polymer physics. PERM produces samples according to any given
prescribed weight distribution, by growing configurations step by step with
controlled bias, and correcting "bad" configurations by "population control".
The latter is implemented, in contrast to other population based algorithms
like e.g. genetic algorithms, by depth-first recursion which avoids storing all
members of the population at the same time in computer memory. The problems we
discuss all concern single polymers (with one exception), but under various
conditions: Homopolymers in good solvents and at the point, semi-stiff
polymers, polymers in confining geometries, stretched polymers undergoing a
forced globule-linear transition, star polymers, bottle brushes, lattice
animals as a model for randomly branched polymers, DNA melting, and finally --
as the only system at low temperatures, lattice heteropolymers as simple models
for protein folding. PERM is for some of these problems the method of choice,
but it can also fail. We discuss how to recognize when a result is reliable,
and we discuss also some types of bias that can be crucial in guiding the
growth into the right directions.Comment: 29 pages, 26 figures, to be published in J. Stat. Phys. (2011
Observing Supermassive Black Holes across cosmic time: from phenomenology to physics
In the last decade, a combination of high sensitivity, high spatial
resolution observations and of coordinated multi-wavelength surveys has
revolutionized our view of extra-galactic black hole (BH) astrophysics. We now
know that supermassive black holes reside in the nuclei of almost every galaxy,
grow over cosmological times by accreting matter, interact and merge with each
other, and in the process liberate enormous amounts of energy that influence
dramatically the evolution of the surrounding gas and stars, providing a
powerful self-regulatory mechanism for galaxy formation. The different
energetic phenomena associated to growing black holes and Active Galactic
Nuclei (AGN), their cosmological evolution and the observational techniques
used to unveil them, are the subject of this chapter. In particular, I will
focus my attention on the connection between the theory of high-energy
astrophysical processes giving rise to the observed emission in AGN, the
observable imprints they leave at different wavelengths, and the methods used
to uncover them in a statistically robust way. I will show how such a combined
effort of theorists and observers have led us to unveil most of the SMBH growth
over a large fraction of the age of the Universe, but that nagging
uncertainties remain, preventing us from fully understating the exact role of
black holes in the complex process of galaxy and large-scale structure
formation, assembly and evolution.Comment: 46 pages, 21 figures. This review article appears as a chapter in the
book: "Astrophysical Black Holes", Haardt, F., Gorini, V., Moschella, U and
Treves A. (Eds), 2015, Springer International Publishing AG, Cha
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