8,912 research outputs found
Fitting Constrained Continuous Spline Curves.
Fitting a curve through a set of planar data which represents a positive quantity requires that the curve stays above the horizontal axis, The more general problem of designing parametric and non-parametric curves which do not cross the given constraint boundaries is considered. Several methods will be presented
Kinetic Equation for a Plasma and Its Application to High-frequency Conductivity
Kinetic equation for inhomogenious nonisotropic plasma and application to high frequency conductivit
Applicability of the National Comprehensive Cancer Network/Multinational Association of Supportive Care in Cancer Guidelines for Prevention and Management of Chemotherapy-Induced Nausea and Vomiting in Southeast Asia: A Consensus Statement.
A meeting of regional experts was convened in Manila, Philippines, to develop a resource-stratified chemotherapy-induced nausea and vomiting (CINV) management guideline. In patients treated with highly emetogenic chemotherapy in general clinical settings, triple therapy with a serotonin (5-hydroxytryptamine-3 [5-HT3]) antagonist (preferably palonosetron), dexamethasone, and aprepitant is recommended for acute CINV prevention. In resource-restricted settings, triple therapy is still recommended, although a 5-HT3 antagonist other than palonosetron may be used. In both general and resource-restricted settings, dual therapy with dexamethasone (days 2 to 4) and aprepitant (days 2 to 3) is recommended to prevent delayed CINV. In patients treated with moderately emetogenic chemotherapy, dual therapy with a 5-HT3 antagonist, preferably palonosetron, and dexamethasone is recommended for acute CINV prevention in general settings; any 5-HT3 antagonist can be combined with dexamethasone in resource-restricted environments. In general settings, for the prevention of delayed CINV associated with moderately emetogenic chemotherapy, corticosteroid monotherapy on days 2 and 3 is recommended. If aprepitant is used on day 1, it should be continued on days 2 and 3. Prevention of delayed CINV with corticosteroids is preferred in resource-restricted settings. The expert panel also developed CINV management guidelines for anthracycline plus cyclophosphamide combination schedules, multiday cisplatin, and chemotherapy with low or minimal emetogenic potential, and its recommendations are detailed in this review. Overall, these regional guidelines provide definitive guidance for CINV management in general and resource-restricted settings. These consensus recommendations are anticipated to contribute to collaborative efforts to improve CINV management in Southeast Asia
Transport phenomenology for a holon-spinon fluid
We propose that the normal-state transport in the cuprate superconductors can
be understood in terms of a two-fluid model of spinons and holons. In our
scenario, the resistivity is determined by the properties of the holons while
magnetotransport involves the recombination of holons and spinons to form
physical electrons. Our model implies that the Hall transport time is a measure
of the electron lifetime, which is shorter than the longitudinal transport
time. This agrees with our analysis of the normal-state data. We predict a
strong increase in linewidth with increasing temperature in photoemission. Our
model also suggests that the AC Hall effect is controlled by the transport
time.Comment: 4 pages, 1 postscript figure. Uses RevTeX, epsf, multico
Memory function approach to the Hall constant in strongly correlated electron systems
The anomalous properties of the Hall constant in the normal state of
high- superconductors are investigated within the single-band Hubbard
model. We argue that the Mori theory is the appropriate formalism to address
the Hall constant, since it aims directly at resistivities rather than
conductivities. More specifically, the frequency dependent Hall constant
decomposes into its infinite frequency limit and a memory function
contribution. As a first step, both terms are calculated perturbatively in
and on an infinite dimensional lattice, where is the correlation strength.
If we allow to be of the order of twice the bare band width, the memory
function contribution causes the Hall constant to change sign as a function of
doping and to decrease as a function of temperature.Comment: 35 pages, RevTex, 3 ps figures include
Effect of dead space on avalanche speed
The effects of dead space (the minimum distance travelled by a carrier before acquiring enough energy to impact ionize) on the current impulse response and bandwidth of an avalanche multiplication process are obtained from a numerical model that maintains a constant carrier velocity but allows for a random distribution of impact ionization path lengths. The results show that the main mechanism responsible for the increase in response time with dead space is the increase in the number of carrier groups, which qualitatively describes the length of multiplication chains. When the dead space is negligible, the bandwidth follows the behavior predicted by Emmons but decreases as dead space increase
Reactive Hall constant of Strongly Correlated Electrons
The zero-temperature Hall response within tight-binding models of correlated
electrons is studied. Using the linear response theory and a linearization in
the magnetic field B, a general relation for the reactive (zero frequency) Hall
constant in the fast (transport) limit is derived, involving only matrix
elements between the lowest excited states at B=0; for noninteracting fermions,
the Boltzmann expression is reproduced. For a Fermi liquid with a well defined
Fermi surface and linear gapless excitations an analogous expression is found
more generally. In the specific case of quasi-one-dimensional correlated
systems a relation of to the charge stiffness D is recovered. Similar
analysis is performed and discussed for D and the compressibility.Comment: 8 pages, submitted to Phys.Rev.
Electromagnetic radiative corrections in parity-violating electron-proton scattering
QED radiative corrections have been calculated for leptonic and hadronic
variables in parity-violating elastic ep scattering. For the first time, the
calculation of the asymmetry in the elastic radiative tail is performed without
the peaking-approximation assumption in hadronic variables configuration. A
comparison with the PV-A4 data validates our approach. This method has been
also used to evaluate the radiative corrections to the parity-violating
asymmetry measured in the G0 experiment. The results obtained are here
presented.Comment: 12 pages, 11 figure
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