151 research outputs found
Domain Wall Dynamics of Phase Interfaces
The statics and dynamics of a surface separating two phases of a relativistic
quantum field theory at or near the critical temperature typically make use of
a free energy as a functional of an order parameter. This free energy
functional also affords an economical description of states away from
equilibrium. The similarities and differences between using a scalar field as
the order parameter versus the energy density are examined, and a peculiarity
is noted. We also point out several conceptual errors in the literature dealing
with the dynamical prefactor in the nucleation rate.Comment: 12 pages plus 5 figure
Effect of Intraduodenal Bile and Na-Taurodeoxycholate on Exocrine Pancreatic Secretion and on Plasma Levels of Secretin, Pancreatic Polypeptide, and Gastrin in Man
The effect of intraduodenally administered cattle bile (CB) and Na-taurodeoxycholate (TDC) on basal pancreatic secretion and plasma levels of secretin, pancreatic polypeptide (PP), and gastrin were investigated on two separate days in 10 fasting volunteers. Doses of 2-6 g CB and 20&600 mg TDC were given intraduodenally at 65-min intervals. Volume, bicarbonate, lipase, trypsin, amylase, and bilirubin were measured in 10-min fractions of duodenal juice, and GI peptides determined by radioimmunoassay. CB and TDC enhanced significantly and dose-dependently volume, bicarbonate and enzyme secretion, and plasma secretin and PP levels. In contrast, plasma gastrin showed only a marginal increase. We conclude that the hydrokinetic effect of intraduodenal CB and TDC is at least partially mediated by secretin. Gastrin could be ruled out as a mediator of the ecbolic effect, whereas other GI peptides, primarily CCK, and/or neural mechanisms must be considered possible mediators. Both pathways may also play a role in the PP release
Muons and emissivities of neutrinos in neutron star cores
In this work we consider the role of muons in various URCA processes relevant
for neutrino emissions in the core region of neutron stars. The calculations
are done for --stable nuclear matter with and without muons. We find
muons to appear at densities fm, slightly around the
saturation density for nuclear matter fm. The direct URCA
processes for nucleons are forbidden for densities below
fm, however the modified URCA processes with muons ), where is a
nucleon, result in neutrino emissivities comparable to those from
). This
opens up for further possibilities to explain the rapid cooling of neutrons
stars. Superconducting protons reduce however these emissivities at densities
below fm.Comment: 14 pages, Revtex style, 3 uuencoded figs include
Asymmetric nuclear matter and neutron star properties
In this work we calculate the total mass, radius, moment of inertia, and
surface gravitational redshift for neutron stars using various equations of
state (EOS). Modern meson-exchange potential models are used to evaluate the
-matrix for asymmetric nuclear matter. We calculate both a non-relativistic
and a relativistic EOS. Of importance here is the fact that relativistic
Brueckner-Hartree-Fock calculations for symmetric nuclear matter fit the
empirical data, which are not reproduced by non-relativistic calculations.
Relativistic effects are known to be important at high densities, giving an
increased repulsion. This leads to a stiffer EOS compared to the EOS derived
with a non-relativistic approach. Both the non-relativistic and the
relativistic EOS yield moments of inertia and redshifts in agreement with the
accepted values. The relativistic EOS yields, however, too large mass and
radius. The implications are discussed.Comment: Revtex, 16 pages, 6 figures include
Application of realistic effective interactions to the structure of the Zr isotopes
We calculate the low-lying spectra of the zirconium isotopes Z=40 with
neutron numbers from N=52 to N=60 using the 1p1/20g9/2 proton and
2s1d0g7/20h11/2 neutron sub-shells to define the model space. Effective
proton-proton, neutron--neutron and proton-neutron interactions have been
derived using 88Sr as closed core and employing perturbative many-body
techniques. The starting point is the nucleon-nucleon potential derived from
modern meson exchange models. The comprehensive shell-model calculation
performed in this work provides a qualitative reproduction of essential
properties such as the sub-shell closures in 96Zr and 98Zr.Comment: To appear in Phys Rev C, june 2000, 8 figs, Revtex latex styl
Superfluidity in beta-stable neutron star matter
In this work we present results for pairing gaps in --stable neutron
star matter with electrons and muons using a relativistic
Dirac--Brueckner--Hartree--Fock approach, starting with modern meson--exchange
models for the nucleon--nucleon interaction. Results are given for
superconducting protons and and neutron superfluids. A
comparison is made with recent non--relativistic calculations and the
implications for neutron star cooling are discussed.Comment: 7 pages, RevTex latex style, 3 figs include
Value of flow cytometry for MRD-based relapse prediction in B-cell precursor ALL in a multicenter setting
PCR of TCR/Ig gene rearrangements is considered the method of choice for minimal residual disease (MRD) quantification in BCP-ALL, but flow cytometry analysis of leukemia-associated immunophenotypes (FCM-MRD) is faster and biologically more informative. FCM-MRD performed in 18 laboratories across seven countries was used for risk stratification of 1487 patients with BCP-ALL enrolled in the NOPHO ALL2008 protocol. When no informative FCM-marker was available, risk stratification was based on real-time quantitative PCR. An informative FCM-marker was found in 96.2% and only two patients (0.14%) had non-informative FCM and non-informative PCR-markers. The overall 5-year event-free survival was 86.1% with a cumulative incidence of relapse (CIR5y) of 9.5%. FCM-MRD levels on days 15 (HzR 4.0, p 10(-4) associated with a CIR5y = 22.1%. In conclusion, FCM-MRD performed in a multicenter setting is a clinically useful method for MRD-based treatment stratification in BCP-ALL.Peer reviewe
Graph Regionalization with Clustering and Partitioning: an Application for Daily Commuting Flows in Albania
The paper presents an original application of the recently proposed spatial data mining
method named GraphRECAP on daily commuting flows using 2011 Albanian census data.
Its aim is to identify several clusters of Albanian municipalities/communes; propose a
classification of the Albanian territory based on daily commuting flows among
municipalities/communes. Starting from 373 local units, we first applied a spatial
clustering technique without imposing any constraining strategy. Based on the input
variables, we obtained 16 clusters. In the second step of our analysis, we impose a set of
constraining parameters to identify intermediate areas between the local level
(municipality/commune) and the national one. We have defined 12 derived regions (same
number as the actual Albanian prefectures but with different geographies). These derived
regions are quite different from the traditional ones in terms of both geographical
dimensions and boundarie
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