507 research outputs found
Mid-infrared single- and multi-frequency coherent sources for high-resolution molecular spectroscopy
Thermal Transport in Chiral Conformal Theories and Hierarchical Quantum Hall States
Chiral conformal field theories are characterized by a ground-state current
at finite temperature, that could be observed, e.g. in the edge excitations of
the quantum Hall effect. We show that the corresponding thermal conductance is
directly proportional to the gravitational anomaly of the conformal theory,
upon extending the well-known relation between specific heat and conformal
anomaly. The thermal current could signal the elusive neutral edge modes that
are expected in the hierarchical Hall states. We then compute the thermal
conductance for the Abelian multi-component theory and the W-infinity minimal
model, two conformal theories that are good candidates for describing the
hierarchical states. Their conductances agree to leading order but differ in
the first, universal finite-size correction, that could be used as a selective
experimental signature.Comment: Latex, 17 pages, 2 figure
Acute pancreatitis associated with everolimus after kidney transplantation: a case report
Background: Acute pancreatitis (AP) following KT is a rare and often fatal complication of the early post-transplant period. Common causative factors for AP are rare after KT; anti-rejection drugs as CyA, prednisone and MMF have been implicated, although evidence is not strong and we found no reports on possible causative role for mTOR inhibitors. Case presentation: A 55-year-old Caucasian man with end-stage renal disease due to idiopathic membrano-prolipherative glomerulonephritis underwent single kidney transplantation (KT) from cadaveric donor. Anti-rejection protocol was based on Basiliximab induction followed by prednisone and mycophenolate mophetil (MMF) and Cyclosporine; Everolimus (Eve) was scheduled to substitute MMF at week 3. At day 1 he had an asymptomatic elevation of pancreatic enzymes, spontaneously resolved. The further course was unremarkable and on day 19 he started Eve, with following asymptomatic rise in pancreatic enzymes. At day 33 the patient presented with abdominal pain and a marked elevation in serum amylase (1383 U/l) and lipase (1015 U/l), normal liver enzymes and bilirubin, no hypercalcemia, mild elevation in triglycerids; RT-PCRs for Cytomegalovirus or Epstein-Barr virus were negative. The patient had no history of alcohol abuse; ultrasound, CT and MRI found no evidence of biliary lithiasis. CT scans showed a patchy fluid collection in the pancreatic head area, consistent with idiopathic necrotizing pancreatitis. The patient was treated medically and Eve was withdrawn 1 week after. Patient underwent guided drainage of the fluid collection, but developed bacterial sepsis; surgical intervention was required with debridement of necrotic tissue, lavage and drainage; immunosuppression was totally withdrawn. Following course was complicated with multiple systemic infection. Transplantectomy for acute rejection was performed, and patient entered hemodialysis. Conclusions: Our patient had a presentation that is consistent for a causative role of Eve. A predisposing condition (acute pancreatic insult during transplant surgery) spontaneously resolved, relapsed and evolved rapidly in AP after the initiation of treatment with Eve with a consistent time latency. None of the well-known common causative factors for AP was present. We discourage the use of Eve in patients with recent episodes of sub-clinical pancreatitis, since it may represent a precipitating factor or interfere with resolution
A universal conformal field theory approach to the chiral persistent currents in the mesoscopic fractional quantum Hall states
We propose a general and compact scheme for the computation of the periods
and amplitudes of the chiral persistent currents, magnetizations and magnetic
susceptibilities in mesoscopic fractional quantum Hall disk samples threaded by
Aharonov--Bohm magnetic field. This universal approach uses the effective
conformal field theory for the edge states in the quantum Hall effect to derive
explicit formulas for the corresponding partition functions in presence of
flux. We point out the crucial role of a special invariance condition for the
partition function, following from the Bloch-Byers-Yang theorem, which
represents the Laughlin spectral flow. As an example we apply this procedure to
the Z_k parafermion Hall states and show that they have universal non-Fermi
liquid behavior without anomalous oscillations. For the analysis of the
high-temperature asymptotics of the persistent currents in the parafermion
states we derive the modular S-matrices constructed from the S matrices for the
u(1) sector and that for the neutral parafermion sector which is realized as a
diagonal affine coset.Comment: 45 pages, LaTeX2e, 4 EPS figures, 1 table, for related color figures
see http://theo.inrne.bas.bg/~lgeorg/PF_k.htm
N=2 gauged WZW models and the elliptic genus
Witten recently gave further evidence for the conjectured relationship
between the series of the minimal models and certain Landau-Ginzburg
models by computing the elliptic genus for the latter. The results agree with
those of the minimal models, as can be calculated from the known
characters of the discrete series representations of the superconformal
algebra. The minimal models also have a Lagrangian representation as
supersymmetric gauged WZW models. We calculate the elliptic genera, interpreted
as a genus one path integral with twisted boundary conditions, for such models
and recover the previously known result.Comment: 11p, IASSNS-HEP-93/3
Reply to the letter of Dr Merdin
Dr Merdin kindly makes suggestions about the design of our study and asks for more information about the infectious and immunosuppressive history of our monoclonal Bâcell lymphocytosis (MBL) patients with monoclonal Bâcell lymphocytosis (MBL). In our study, we incidentally found the coexistence of five cases of MBL and monoclonal gammopathy of undetermined significance (MGUS) in a cohort of kidney transplant recipients at a median of 15 years after transplantation.1 MBL and MGUS are two preâmalignant lymphoproliferative disorders of terminally differentiated B cells. Clinically, MBL and MGUS share common features, such as an indolent course, a lateâonset age distribution, a low rate of progression and an increased susceptibility to infections. MBL and MGUS are also the precursor states of two hematologic malignancies: chronic lymphocytic leukemia (CLL) and multiple myeloma (MM), respectively
Revised taxonomy and early evolution of fasciculiths at the DanianâSelandian transition
Abstract. We present a taxonomic revision of the family Fasciculithaceae focused on forms that characterize the early evolution of this family group, which are currently included within the genera Gomphiolithus, Diantholitha, Lithoptychius and Fasciculithus. The investigation approach is based on a combined light microscope (LM) and scanning electron microscope (SEM) analysis of specimens from well-preserved ODPâDSDP site material (ODP Site 1209; Site 1262; ODP Site 1267; DSDP Site 356; DSDP Site 119) and outcrops (Bottaccione and Contessa, Italy; Qreiya, Egypt) across the DanianâSelandian transition. The direct LMâSEM comparison of the same individual specimen provides clarification of several taxa that were previously described only with the LM. One new genus (Tectulithus), five new combinations (Tectulithus janii, Tectulithus merloti, Tectulithus pileatus, Tectulithus stegastos and Tectulithus stonehengei) and six new species are defined (Diantholitha pilula, Diantholitha toquea, Lithoptychius galeottii, Lithoptychius maioranoae, Tectulithus pagodiformis and Fasciculithus realeae). The main characteristics useful to identify fasciculiths with the LM are provided, together with a 3Dâ2D drawing showing the main structural features. The accurate taxonomic characterization grants the development of an evolutionary lineage that documents a great fasciculith diversification during the late Danian and early Selandian. Four different well-constrained events have been documented: the lowest occurrence (LO) of Gomphiolithus, the paracme of Fasciculithaceae at the top of Chron C27r (PTC27r), the radiation of Diantholitha (LO Diantholitha), the paracme of Fasciculithaceae at the base of Chron C26r (PBC26r), the radiation of Lithoptychius (LO Lithoptychius) and the radiation of Tectulithus (lowest common occurrence of Tectulithus) that shows the biostratigraphic relevance of this group across the DanianâSelandian transition
Exact Consequences of the Trace Anomaly in Four Dimensions
The general form of the stress-tensor three-point function in four dimensions
is obtained by solving the Ward identities for the diffeomorphism and Weyl
symmetries. Several properties of this correlator are discussed, such as the
renormalization and scheme independence and the analogies with the anomalous
chiral triangle. At the critical point, the coefficients a and c of the
four-dimensional trace anomaly are related to two finite, scheme-independent
amplitudes of the three-point function. Off-criticality, the imaginary parts of
these amplitudes satisfy sum rules which express the total
renormalization-group flow of a and c between pairs of critical points.
Although these sum rules are similar to that satisfied by the two-dimensional
central charge, the monotonicity of the flow, i.e. the four-dimensional
analogue of the c-theorem, remains to be proven.Comment: 39 pages, 3 tables; published version, some misprints corrected;
Mathematica routines can be found at:
http://arturo.fi.infn.it/cappelli/papers/ttt
A new class of Matrix Models arising from the W-infinity Algebra
We present a new class of hermitian one-matrix models originated in the
W-infinity algebra: more precisely, the polynomials defining the W-infinity
generators in their fermionic bilinear form are shown to expand the orthogonal
basis of a class of random hermitian matrix models. The corresponding
potentials are given, and the thermodynamic limit interpreted in terms of a
simple plasma picture. The new matrix models can be successfully applied to the
full bosonization of interesting one-dimensional systems, including all the
perturbative orders in the inverse size of the system. As a simple application,
we present the all-order bosonization of the free fermionic field on the
one-dimensional lattice.Comment: 8 pages, 1 figur
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