1,574 research outputs found
DERIVATIVE LOGIC AND THE BANKING SYSTEM
This paper tries to develop a fresh view of what it means to analyze the banking system. We use modern finance theory to disentangle the obvious. The view we put forward is suggestive and the idea is that by disentangling the language and transforming it into a language of finance, we realize what the liability side of a banks balance sheet consists of. In order to get going, we have to review both, the Merton model and the put-call parity. The technical details are less important than the generaĆ idea of what they convey [Merton, 1974]
Improved numerical approach for time-independent Gross-Pitaevskii nonlinear Schroedinger equation
In the present work, we improve a numerical method, developed to solve the
Gross-Pitaevkii nonlinear Schroedinger equation. A particular scaling is used
in the equation, which permits to evaluate the wave-function normalization
after the numerical solution. We have a two point boundary value problem, where
the second point is taken at infinity. The differential equation is solved
using the shooting method and Runge-Kutta integration method, requiring that
the asymptotic constants, for the function and its derivative, are equal for
large distances. In order to obtain fast convergence, the secant method is
used.Comment: 2 figure
Probing dipolar effects with condensate shape oscillation
We discuss the low energy shape oscillations of a magnetic trapped atomic
condensate including the spin dipole interaction. When the nominal isotropic
s-wave interaction strength becomes tunable through a Feshbach resonance (e.g.
as for Rb atoms), anisotropic dipolar effects are shown to be detectable
under current experimental conditions [E. A. Donley {\it et al.}, Nature {\bf
412}, 295 (2001)].Comment: revised version, submitte
Instantons and radial excitations in attractive Bose-Einstein condensates
Imaginary- and real-time versions of an equation for the condensate density
are presented which describe dynamics and decay of any spherical Bose-Einstein
condensate (BEC) within the mean field appraoch. We obtain quantized energies
of collective finite amplitude radial oscillations and exact numerical
instanton solutions which describe quantum tunneling from both the metastable
and radially excited states of the BEC of 7Li atoms. The mass parameter for the
radial motion is found different from the gaussian value assumed hitherto, but
the effect of this difference on decay exponents is small. The collective
breathing states form slightly compressed harmonic spectrum, n=4 state lying
lower than the second Bogolyubov (small amplitude) mode. The decay of these
states, if excited, may simulate a shorter than true lifetime of the metastable
state. By scaling arguments, results extend to other attractive BEC-s.Comment: 6 pages, 3 figure
Active Site Mapping of Xylan-Deconstructing Enzymes with Arabinoxylan Oligosaccharides Produced by Automated Glycan Assembly
Xylan-degrading enzymes are crucial for the deconstruction of hemicellulosic biomass, making the hydrolysis products available for various industrial applications such as the production of biofuel. To determine the substrate specificities of these enzymes, we prepared a collection of complex xylan oligosaccharides by automated glycan assembly. Seven differentially protected building blocks provided the basis for the modular assembly of 2-substituted, 3-substituted, and 2-/3-substituted arabino- and glucuronoxylan oligosaccharides. Elongation of the xylan backbone relied on iterative additions of C4-fluorenylmethoxylcarbonyl (Fmoc) protected xylose building blocks to a linker-functionalized resin. Arabinofuranose and glucuronic acid residues have been selectively attached to the backbone using fully orthogonal 2-(methyl)naphthyl (Nap) and 2-(azidomethyl)benzoyl (Azmb) protecting groups at the C2 and C3 hydroxyls of the xylose building blocks. The arabinoxylan oligosaccharides are excellent tools to map the active site of glycosyl hydrolases involved in xylan deconstruction. The substrate specificities of several xylanases and arabinofuranosidases were determined by analyzing the digestion products after incubation of the oligosaccharides with glycosyl hydrolases.Fil: Senf, Deborah. Max Planck Institut fĂŒr Kolloid und GrenzflĂ€chenforschung; Alemania. Freie UniversitĂ€t; AlemaniaFil: Ruprecht, Colin. Max Planck Institut fĂŒr Kolloid und GrenzflĂ€chenforschung; AlemaniaFil: de Kruijff, Goswinus H. M.. Max Planck Institut fĂŒr Kolloid und GrenzflĂ€chenforschung; Alemania. Freie UniversitĂ€t; Alemania. University Mainz. Institute of Institute of Organic Chemistry, Johannes Gutenberg; AlemaniaFil: Simonetti, SebastiĂĄn Osvaldo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de QuĂmica Rosario. Universidad Nacional de Rosario. Facultad de Ciencias BioquĂmicas y FarmacĂ©uticas. Instituto de QuĂmica Rosario; Argentina. Max Planck Institut fĂŒr Kolloid und GrenzflĂ€chenforschung; AlemaniaFil: Schuhmacher, Frank. Max Planck Institut fĂŒr Kolloid und GrenzflĂ€chenforschung; Alemania. Freie UniversitĂ€t; AlemaniaFil: Seeberger, Peter H.. Max Planck Institut fĂŒr Kolloid und GrenzflĂ€chenforschung; Alemania. Freie UniversitĂ€t; AlemaniaFil: Pfrengle, Fabian. Max Planck Institut fĂŒr Kolloid und GrenzflĂ€chenforschung; Alemania. Freie UniversitĂ€t; Alemani
Modulation of Variation by Response-Reward Spatial Proximity
There has been a recent surge in the experimental investigation of the control of behavioral variability. Currently, it is understood that variability in behavior is predictably modulated by reinforcement parameters (e.g., a probability of reward delivery and reward magnitude). In two experiments, we investigated how spatial proximity between response and reward locations impacts the production of behavioral variability in both response rate and lever press duration. Rats were trained to lever press on two levers in a standard operant chamber that only differed from one another in their proximity to a food niche (i.e., Near vs. Far); a second experimental factor, the probability of reward, was signaled by an auditory cue. In Experiment 1, trials with a high-probability stimulus terminated with reward on 100% of trials, while trials with a low-probability stimulus terminated with reward 25% of the time. We used a similar procedure in Experiment 2, but reduced the likelihood of reward on low-probability trials to 10% and collected data in a post-acquisition extinction test. Overall, proximity and probability were inversely related to variation of response rate, whereas only the probability factor affected variation in lever press duration. Proximity also interacted with probability to influence variation in response rate. These findings extend the factors modulating behavioral variability to include the spatial proximity between a response and reward
Single Particle Tracking for Simultaneous Long and Short Electron Bunches in the BESSY II Storage Ring
A scheme where 1.5 ps and 15 ps long bunches rms can be stored simultaneously in the BESSY II storage ring has recently been proposed BESSYVSR . This paper presents simulations of single particle beam dynamics influenced by superconducting cavities used for the strong longitudinal beam focusing. The effect of RF jitter on very short bunches is investigated and results are discussed. Furthermore, possible effects on beam dynamics during ramp up and ramp down of the high gradient fields in the cavities are studied. The primary goal is to reveal preliminary design specifications for RF jitter on the basis of single particle dynamic
Order Parameter at the Boundary of a Trapped Bose Gas
Through a suitable expansion of the Gross-Pitaevskii equation near the
classical turning point, we obtain an explicit solution for the order parameter
at the boundary of a trapped Bose gas interacting with repulsive forces. The
kinetic energy of the system, in terms of the classical radius and of the
harmonic oscillator length , follows the law , approaching, for large , the
results obtained by solving numerically the Gross-Pitaevskii equation. The
occurrence of a Josephson-type current in the presence of a double trap
potential is finally discussed.Comment: 11 pages, REVTEX, 4 figures (uuencoded-gzipped-tar file) also
available at http://anubis.science.unitn.it/~dalfovo/papers/papers.htm
Frequency, syndrome specificity, influence of disease activity, long-term course, association with AQP4-IgG, and origin
Background Antibodies to myelin oligodendrocyte glycoprotein (MOG-IgG) have
been suggested to play a role in a subset of patients with neuromyelitis
optica and related disorders. Objective To assess (i) the frequency of MOG-IgG
in a large and predominantly Caucasian cohort of patients with optic neuritis
(ON) and/or myelitis; (ii) the frequency of MOG-IgG among AQP4-IgG-positive
patients and vice versa; (iii) the origin and frequency of MOG-IgG in the
cerebrospinal fluid (CSF); (iv) the presence of MOG-IgG at disease onset; and
(v) the influence of disease activity and treatment status on MOG-IgG titers.
Methods 614 serum samples from patients with ON and/or myelitis and from
controls, including 92 follow-up samples from 55 subjects, and 18 CSF samples
were tested for MOG-IgG using a live cell-based assay (CBA) employing full-
length human MOG-transfected HEK293A cells. Results MOG-IgG was detected in 95
sera from 50 patients with ON and/or myelitis, including 22/54 (40.7%)
patients with a history of both ON and myelitis, 22/103 (21.4%) with a history
of ON but no myelitis and 6/45 (13.3%) with a history of longitudinally
extensive transverse myelitis but no ON, and in 1 control patient with
encephalitis and a connective tissue disorder, all of whom were negative for
AQP4-IgG. MOG-IgG was absent in 221 further controls, including 83 patients
with AQP4-IgG-seropositive neuromyelitis optica spectrum disorders and 85 with
multiple sclerosis (MS). MOG-IgG was found in 12/18 (67%) CSF samples from
MOG-IgG-seropositive patients; the MOG-IgG-specific antibody index was
negative in all cases, indicating a predominantly peripheral origin of CSF
MOG-IgG. Serum and CSF MOG-IgG belonged to the complement-activating IgG1
subclass. MOG-IgG was present already at disease onset. The antibodies
remained detectable in 40/45 (89%) follow-up samples obtained over a median
period of 16.5 months (range 0â123). Serum titers were higher during attacks
than during remission (pâ<â0.0001), highest during attacks of simultaneous
myelitis and ON, lowest during acute isolated ON, and declined following
treatment. Conclusions To date, this is the largest cohort studied for IgG to
human full-length MOG by means of an up-to-date CBA. MOG-IgG is present in a
substantial subset of patients with ON and/or myelitis, but not in classical
MS. Co-existence of MOG-IgG and AQP4-IgG is highly uncommon. CSF MOG-IgG is of
extrathecal origin. Serum MOG-IgG is present already at disease onset and
remains detectable in the long-term course. Serum titers depend on disease
activity and treatment status
Influence of Transient Beam Loading on the Longitudinal Beam Dynamics at BESSY VSR
BESSY VSR, a scheme where 1.7 ps and 15 ps long bunches rms can be stored simultaneously in the BESSY II storage ring has recently been proposed [1]. The strong longitudinal bunch focusing is achieved by superconducting high gradient RF cavities. If the bunch fill pattern exhibits a significant inhomogeneity, e.g. due to gaps, transient beam loading causes a distortion of the longitudinal phase space which is different for each bunch. The result are variations along the fill pattern in synchronous phase, synchrotron fre quency and bunch shape. This paper presents investigations of transient beam loading and depicts the consequences on bunch length, phase stability and longitudinal multi bunch oscillations for the projected setup of BESSY VS
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