170 research outputs found
Evaluating Frequency, Diagnostic Quality, and Cost of Lyme Borreliosis Testing in Germany: A Retrospective Model Analysis
Background. Data on the economic impact of Lyme borreliosis (LB) on European health care systems is scarce. This project focused on the epidemiology and costs for laboratory testing in LB patients in Germany. Materials and Methods. We performed a sentinel analysis of epidemiological and medicoeconomic data for 2007 and 2008. Data was provided by a German statutory health insurance (DAK) company covering approx. 6.04 million members. In addition, the quality of diagnostic testing for LB in Germany was studied. Results. In 2007 and 2008, the incident diagnosis LB was coded on average for 15,742 out of 6.04 million insured members (0.26%). 20,986 EIAs and 12,558 immunoblots were ordered annually for these patients. For all insured members in the outpatient sector, a total of 174,820 EIAs and 52,280 immunoblots were reimbursed annually to health care providers (cost: 2,600,850€). For Germany, the overall expected cost is estimated at 51,215,105€. However, proficiency testing data questioned test quality and standardization of diagnostic assays used. Conclusion. Findings from this study suggest ongoing issues related to care for LB and may help to improve future LB disease management
Relativistic Nucleus-Nucleus Collisions: from the BEVALAC to RHIC
I briefly describe the initial goals of relativistic nuclear collisions
research, focusing on the LBL Bevatron/Bevalac facility in the 1970's. An early
concept of high hadronic density fireball formation, and subsequent isentropic
decay (preserving information as to the high density stage) led to an outline
of physics observables that could determine the nuclear matter equation of
state at several times nuclear ground state matter density. With the advent of
QCD the goal of locating, and characterizing the hadron-parton deconfinement
phase transformation suggested the need for higher , the research
thus moving to the BNL AGS and CERN SPS, finally to RHIC at BNL. A set of
physics observables is discussed where present data span the entire
domain, from Bevalac and SIS at GSI, to top RHIC energy. Referring,
selectively, to data concerning bulk hadron production, the overall
evolution of directed and radial flow observables, and of pion pair
Bose-Einstein correlation are discussed. The hadronization process is studied
in the grand canonical statistical model. The resulting hadronization points in
the plane T vs. converge onto the parton-hadron phase boundary
predicted by finite lattice QCD, from top SPS to RHIC energy. At lower
SPS and top AGS energy a steep strangeness maximum occurs at which the
Wroblewski parameter 0.6; a possible connection to the QCD
critical point is discussed. Finally the unique new RHIC physics is addressed:
high hadron suppression and jet "tomography".Comment: 19 pages, 11 figure
A realistic pattern of fermion masses from a five-dimensional SO(10) model
We provide a unified description of fermion masses and mixing angles in the
framework of a supersymmetric grand unified SO(10) model with anarchic Yukawa
couplings of order unity. The space-time is five dimensional and the extra flat
spatial dimension is compactified on the orbifold ,
leading to Pati-Salam gauge symmetry on the boundary where Yukawa interactions
are localised. The gauge symmetry breaking is completed by means of a rather
economic scalar sector, avoiding the doublet-triplet splitting problem. The
matter fields live in the bulk and their massless modes get exponential
profiles, which naturally explain the mass hierarchy of the different fermion
generations. Quarks and leptons properties are naturally reproduced by a
mechanism, first proposed by Kitano and Li, that lifts the SO(10) degeneracy of
bulk masses in terms of a single parameter. The model provides a realistic
pattern of fermion masses and mixing angles for large values of . It
favours normally ordered neutrino mass spectrum with the lightest neutrino mass
below 0.01 eV and no preference for leptonic CP violating phases. The right
handed neutrino mass spectrum is very hierarchical and does not allow for
thermal leptogenesis. We analyse several variants of the basic framework and
find that the results concerning the fermion spectrum are remarkably stable.Comment: 30 pages, 7 figures, 4 table
A short-term in vivo model for giant cell tumor of bone
<p>Abstract</p> <p>Background</p> <p>Because of the lack of suitable <it>in vivo </it>models of giant cell tumor of bone (GCT), little is known about its underlying fundamental pro-tumoral events, such as tumor growth, invasion, angiogenesis and metastasis. There is no existing cell line that contains all the cell and tissue tumor components of GCT and thus <it>in vitro </it>testing of anti-tumor agents on GCT is not possible. In this study we have characterized a new method of growing a GCT tumor on a chick chorio-allantoic membrane (CAM) for this purpose.</p> <p>Methods</p> <p>Fresh tumor tissue was obtained from 10 patients and homogenized. The suspension was grafted onto the CAM at day 10 of development. The growth process was monitored by daily observation and photo documentation using <it>in vivo </it>biomicroscopy. After 6 days, samples were fixed and further analyzed using standard histology (hematoxylin and eosin stains), Ki67 staining and fluorescence <it>in situ </it>hybridization (FISH).</p> <p>Results</p> <p>The suspension of all 10 patients formed solid tumors when grafted on the CAM. <it>In vivo </it>microscopy and standard histology revealed a rich vascularization of the tumors. The tumors were composed of the typical components of GCT, including (CD51+/CD68+) multinucleated giant cells whichwere generally less numerous and contained fewer nuclei than in the original tumors. Ki67 staining revealed a very low proliferation rate. The FISH demonstrated that the tumors were composed of human cells interspersed with chick-derived capillaries.</p> <p>Conclusions</p> <p>A reliable protocol for grafting of human GCT onto the chick chorio-allantoic membrane is established. This is the first <it>in vivo </it>model for giant cell tumors of bone which opens new perspectives to study this disease and to test new therapeutical agents.</p
Signatures of Quark-Gluon-Plasma formation in high energy heavy-ion collisions: A critical review
A critical review on signatures of Quark-Gluon-Plasma formation is given and
the current (1998) experimental status is discussed. After giving an
introduction to the properties of QCD matter in both, equilibrium- and
non-equilibrium theories, we focus on observables which may yield experimental
evidence for QGP formation. For each individual observable the discussion is
divided into three sections: first the connection between the respective
observable and QGP formation in terms of the underlying theoretical concepts is
given, then the relevant experimental results are reviewed and finally the
current status concerning the interpretation of both, theory and experiment, is
discussed. A comprehensive summary including an outlook towards RHIC is given
in the final section.Comment: Topical review, submitted to Journal of Physics G: 68 pages,
including 39 figures (revised version: only minor modifications, some
references added
Fermion masses and mixing with tri-bimaximal in SO(10) with type-I seesaw
We study a class of models for tri-bimaximal neutrino mixing in SO(10) grand
unified SUSY framework. Neutrino masses arise from both type-I and type-II
seesaw mechanisms. We use dimension five operators in order to not spoil
tri-bimaximal mixing by means of type-I contribution in the neutrino sector. We
show that it is possible to fit all fermion masses and mixings including also
the recent T2K result as deviation from the tri-bimaximal.Comment: 13 pages, journal version, minor comments and reference adde
Predictions for the Leptonic Dirac CP Violation Phase: a Systematic Phenomenological Analysis
We derive predictions for the Dirac phase present
in the unitary neutrino mixing
matrix , where and are
unitary matrices which arise from the diagonalisation
respectively of the charged lepton and the neutrino mass matrices.
We consider forms of and allowing us to express
as a function of three
neutrino mixing angles,
present in ,
and the angles contained in .
We consider several forms of
determined by, or associated with, symmetries,
tri-bimaximal, bimaximal, etc.,
for which the angles in are
fixed. For each of these forms and forms of
allowing to reproduce the measured values of the neutrino
mixing angles,
we construct the likelihood function
for , using i) the latest results of the global
fit analysis of neutrino oscillation data,
and ii) the prospective sensitivities
on the neutrino mixing angles.
Our results, in particular, confirm the conclusion
reached in earlier similar studies
that the measurement of the Dirac phase
in the neutrino mixing matrix, together with an improvement
of the precision on the mixing angles,
can provide unique information about the
possible existence of symmetry
in the lepton sector
Constrains for non-standard statistical models of particle creations by identified hadron multiplicity results at LHC energies
We analyzed the identified hadron multiplicity predictions of the modified thermodynamical model of the multiparticle production processes with non-extensive statistic. The replacement of the standard Boltzmann exponential factor by the eventually much more slowly falling Tsallis one is suggested by the analysis of the transverse momentum distributions measured at high energies. The increase of high transverse momenta should accord with the abundance of heavy secondary particles, in particular multistrange baryons. The introduction to the thermodynamical model of suppression factors similar to the ones in quark jet fragmentation models is discussed
Different SO(10) Paths to Fermion Masses and Mixings
Recently SO(10) models with type-II see-saw dominance have been proposed as a
promising framework for obtaining Grand Unification theories with approximate
Tri-bimaximal (TB) mixing in the neutrino sector. We make a general study of
SO(10) models with type-II see-saw dominance and show that an excellent fit can
be obtained for fermion masses and mixings, also including the neutrino sector.
To make this statement more significant we compare the performance of type-II
see-saw dominance models in fitting the fermion masses and mixings with more
conventional models which have no built-in TB mixing in the neutrino sector.
For a fair comparison the same input data and fitting procedure is adopted for
all different theories. We find that the type-II dominance models lead to an
excellent fit, comparable with the best among the available models, but the
tight structure of this framework implies a significantly larger amount of fine
tuning with respect to other approaches.Comment: 24 pages, References and minor wording changes adde
Nonperturbative approach to Yang-Mills thermodynamics
An analytical and nonperturbative approach to SU(2) and SU(3) Yang-Mills
thermodynamics is developed and applied. Each theory comes in three phases: A
deconfining, a preconfining, and a confining one. We show how macroscopic and
inert scalar fields form in each phase and how they determine the ground-state
physics and the properties of the excitations. While the excitations in the
deconfining and preconfining phase are massless or massive gauge modes the
excitations in the confining phase are massless or massive spin-1/2 fermions.
The nature of the two phase transitions is investigated for each theory. We
compute the temperature evolution of thermodynamical quantities in the
deconfining and preconfining phase and estimate the density of states in the
confining phase. Some implications for particle physics and cosmology are
discussed.Comment: 92 pages, 35 figures, v4: more typos corrected, modification in
evolution equations for effective couplings, consequences thereof
implemented, there will be an erratum to the journal-published versio
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