3,594 research outputs found
Cerebrospinal Fluid Leaks and Encephaloceles
Encephaloceles and cereberospinal fluid (CSF) leaks of the ventral skull base resulting from trauma (surgical and non-surgical), neoplasm, congenital, and spontaneous are a complex problem typically managed by rhinologists/skull base surgeons. Conservative management is often the first step in managing these complex problems. Endoscopic repair of CSF leaks and encephaloceles has greatly evolved with the evolution of endoscopic visualization and instrumentation. Endoscopic repairs of CSF leaks are effective and offer decreased morbidity compared to open approaches with comparative success rates. Meticulous technique is key to success in repair of skull base defects. Materials used are often less important than quality of repair
An Extended Conceptual Framework for Transformative Service Research
Transformative service research (TSR), a recently-envisioned branch of service science, is about understanding connections between service offerings and well-being. It has at the core of its conceptualization the goal of improving the well-being of individuals. A founding statement characterizes TSR as: âthe integration of consumer and service research that centers on creating uplifting changes and improvements in the well-being of consumer entities: individuals (consumers and employees), communities and the ecosystemâ (Anderson et al. 2013). It is also clear that service touches innumerable aspects of daily life. It is then natural that the field of service science explores mitigation of negative and enhancement of positive service experiences beyond the value co-creation and customer satisfaction paradigms. This is well summed up in the conversation between the switch from goods-dominant to service-dominant logic (Vargo et al. 2008)
Diffusive behavior for randomly kicked Newtonian particles in a spatially periodic medium
We prove a central limit theorem for the momentum distribution of a particle
undergoing an unbiased spatially periodic random forcing at exponentially
distributed times without friction. The start is a linear Boltzmann equation
for the phase space density, where the average energy of the particle grows
linearly in time. Rescaling time, the momentum converges to a Brownian motion,
and the position is its time-integral showing superdiffusive scaling with time
. The analysis has two parts: (1) to show that the particle spends
most of its time at high energy, where the spatial environment is practically
invisible; (2) to treat the low energy incursions where the motion is dominated
by the deterministic force, with potential drift but where symmetry arguments
cancel the ballistic behavior.Comment: 55 pages. Some typos corrected from previous versio
First observation of Li ground state
The ground state of neutron-rich unbound Li was observed for the first
time in a one-proton removal reaction from Be at a beam energy of 53.6
MeV/u. The Li ground state was reconstructed from Li and two
neutrons giving a resonance energy of 120 keV. All events
involving single and double neutron interactions in the Modular Neutron Array
(MoNA) were analyzed, simulated, and fitted self-consistently. The three-body
(Li+) correlations within Jacobi coordinates showed strong
dineutron characteristics. The decay energy spectrum of the intermediate
Li system (Li+) was described with an s-wave scattering length
of greater than -4 fm, which is a smaller absolute value than reported in a
previous measurement.Comment: Accepted for publication in Phys. Rev. C as a Rapid Communicatio
Beam Test Results of the BTeV Silicon Pixel Detector
The results of the BTeV silicon pixel detector beam test carried out at
Fermilab in 1999-2000 are reported. The pixel detector spatial resolution has
been studied as a function of track inclination, sensor bias, and readout
threshold.Comment: 8 pages of text, 8 figures, Proceedings paper of Pixel 2000:
International Workshop on Semiconductor Pixel Detectors for Particles and
X-Rays, Genova, June 5-8, 200
Performance of prototype BTeV silicon pixel detectors in a high energy pion beam
The silicon pixel vertex detector is a key element of the BTeV spectrometer.
Sensors bump-bonded to prototype front-end devices were tested in a high energy
pion beam at Fermilab. The spatial resolution and occupancies as a function of
the pion incident angle were measured for various sensor-readout combinations.
The data are compared with predictions from our Monte Carlo simulation and very
good agreement is found.Comment: 24 pages, 20 figure
A Taxometric Analysis Of Panic Disorder
Panic-related suffering is associated with high individual costs and strain on medical resource utilization. Cognitive-behavioral interventions for panic disorder are effective, but obtaining a diagnosis often precludes access to such treatments. Evidence-based models suggest that panic disorder is a multi-dimensional construct, yet panic disorder is diagnosed categorically (i.e., âyou have it, or you donâtâ) in modern diagnostic manuals. Taxometric analyses, which test the dimensional or categorical latent structure of constructs, have consistently revealed dimensional latent structures when applied to other anxiety disorders and panic-related processes, but these analyses have never been applied to panic disorder. In this study, seven theoretically-relevant indicators of panic disorder were subjected to three nonredundant taxometric procedures to test the latent structure of panic disorder, and simulated comparison plots and objective fit indices were evaluated. The collective results provided consistent empirical support for a dimensional model of panic disorder. The implications of these findings for the measurement, assessment, diagnosis, and treatment of panic disorder are discussed
Conditions for large non-Gaussianity in two-field slow-roll inflation
We study the level of primordial non-Gaussianity in slow-roll two-field
inflation. Using an analytic formula for the nonlinear parameter f_nl in the
case of a sum or product separable potential, we find that it is possible to
generate significant non-Gaussianity even during slow-roll inflation with
Gaussian perturbations at Hubble exit. In this paper we give the general
conditions to obtain large non-Gaussianity and calculate the level of
fine-tuning required to obtain this. We present explicit models in which the
non-Gaussianity at the end of inflation can exceed the current observational
bound of |f_nl|<100.Comment: 16 pages, 6 figures, 1 table, v2: typos corrected and references
added, matches version accepted by JCA
New periodic variable stars coincident with ROSAT sources discovered using SuperWASP
We present optical lightcurves of 428 periodic variable stars coincident with ROSAT X-ray sources, detected using the first run of the SuperWASP photometric survey. Only 68 of these were previously recognised as periodic variables. A further 30 of these objects are previously known pre-main sequence stars, for which we detect a modulation period for the first time. Amongst the newly identified periodic variables, many appear to be close eclipsing binaries, their X-ray emission is presumably the result of RS CVn type behaviour. Others are probably BY Dra stars, pre-main sequence stars and other rapid rotators displaying enhanced coronal activity. A number of previously catalogued pulsating variables (RR Lyr stars and Cepheids) coincident with X-ray sources are also seen, but we show hat these are likely to be misclassifications. We identify four objects which are probable low mass eclipsing binary stars, based on
their very red colour and light curve morphology
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