6,791 research outputs found
Business surveys modelling with Seasonal-Cyclical Long Memory models.
Business surveys are an important element in the analysis of the short-term economic situation because of the timeliness and nature of the information they convey. Especially, surveys are often involved in econometric models in order to provide an early assessment of the current state of the economy, which is of great interest for policy-makers. In this paper, we focus on non-seasonally adjusted business surveys relative to the Euro area released by the European Commission. We introduce an innovative way for modelling those series taking the persistence of the seasonal roots into account through seasonal-cyclical long memory models. We empirically prove that such models produce more accurate forecasts than classical seasonal linear models.Euro area ; business surveys ; seasonal ; long memory.
Thrombophilia and varicella zoster in children
From 2005 to 2011, 25 children of both sexes (13 boys and 12 girls, mean age 7.8 ± 2.5 years, 5-12.4 years) with acute varicella zoster virus (VZV) infection were selected. Five patients showed venous thromboembolism characterized by deep venous thrombosis (DVT). Comparison of activated partial thromboplastin time, antithrombin III, D-dimer, lupus anticoagulant, free S protein (PS), C protein, and antiphospholipid and PS antibodies was performed on children with acute VZV and DVT (group I), acute uncomplicated VZV (group II), and 30 healthy controls of both sexes (15 boys and 15 girls, mean age 7.5 ± 2.6 years, group III). Genetic thrombophilic mutations (Factor V Leiden, MTHFR C677T, and Prothrombin G20210A) were evaluated. Coagulation disorders and PS antibody were found in children with acute VZV (groups I and II). Significant differences were shown among the three groups (P0.05). Acute VZV infection could be associated with coagulation disorders and production of inhibitory PS antibodies in many uncomplicated cases
One-loop renormalisation of N=1/2 supersymmetric gauge theory with a superpotential
We construct a superpotential for the general N=1/2 supersymmetric gauge
theory coupled to chiral matter in the fundamental and adjoint representations,
and investigate the one-loop renormalisability of the theories.Comment: 67 pages, including 17 figures. Plain TeX. Uses Harvmac and epsf.
Combined and condensed version of hep-th/0607194 and hep-th/0607195 with some
added material including in particular a generalisation of the Lunin-Rey
classification of potentially divergent operator
Two-Centered Magical Charge Orbits
We determine the two-centered generic charge orbits of magical N = 2 and
maximal N = 8 supergravity theories in four dimensions. These orbits are
classified by seven U-duality invariant polynomials, which group together into
four invariants under the horizontal symmetry group SL(2,R). These latter are
expected to disentangle different physical properties of the two-centered
black-hole system. The invariant with the lowest degree in charges is the
symplectic product (Q1,Q2), known to control the mutual non-locality of the two
centers.Comment: 1+17 pages, 1 Table; v2: Eq. (3.23) corrected; v3: various
refinements in text and formulae, caption of Table 1 expanded, Footnote and
Refs. added. To appear on JHE
Effect on haematological and anthropometric parameters of iron supplementation in the first 2 years of life. Risks and benefits
Effects of iron supplementation (IS) on haematological and anthropometric parameters in a cohort of 121 healthy children, followed from 6 to 24 months of life, in the Paediatric Department, Second University of Naples, were evaluated. Children were randomly segregated in four groups: (1) exclusively breast feeding (BF) weaned with non-iron fortified (NIF) foods, (2) BF and iron fortified formulas (IFF) and foods, (3) exclusively IFF and foods, (4) BF and oral iron supplementation (OIS). Haematological parameters (Hb, MCV, Serum ferritin and transferrin saturation) in addition to anthropometric measurements (length and weight) were obtained. Results from the study at 6, 12, 18 and 24 months showed significantly lower values of haematological parameters in BF infants than other groups and in IFF infants than in those with OIS. In contrast children with OIS showed significant lower length. It appears that IS may be of limited or no benefit for growth in non-iron deficient children
On Central Charges and Hamiltonians for 0-brane dynamics
We consider general properties of central charges of zero branes and
associated duality invariants, in view of their double role, on the bulk and on
the world volume (quantum-mechanical) theory. A detailed study of the BPS
condition for the mass spectrum arising from toroidal compactifications is
given for 1/2, 1/4 and 1/8 BPS states in any dimensions. As a byproduct, we
retreive the U-duality invariant conditions on the charge (zero mode) spectrum
and the orbit classification of BPS states preserving different fractions of
supersymmetry. The BPS condition for 0-branes in theories with 16
supersymmetries in any dimension is also discussed.Comment: 23 pages, latex fil
Supersymmetric Sum Rules for Electromagnetic Multipoles
We derive model independent, non-perturbative supersymmetric sum rules for
the magnetic and electric multipole moments of any theory with N=1
supersymmetry. We find that in any irreducible N=1 supermultiplet the diagonal
matrix elements of the l-multipole moments are completely fixed in terms of
their off-diagonal matrix elements and the diagonal (l-1)-multipole moments.Comment: 10 pages, plain Te
Charge Orbits of Extremal Black Holes in Five Dimensional Supergravity
We derive the U-duality charge orbits, as well as the related moduli spaces,
of "large" and "small" extremal black holes in non-maximal ungauged
Maxwell-Einstein supergravities with symmetric scalar manifolds in d=5
space-time dimensions. The stabilizer groups of the various classes of orbits
are obtained by determining and solving suitable U-invariant sets of
constraints, both in "bare" and "dressed" charges bases, with various methods.
After a general treatment of attractors in real special geometry (also
considering non-symmetric cases), the N=2 "magic" theories, as well as the N=2
Jordan symmetric sequence, are analyzed in detail. Finally, the half-maximal
(N=4) matter-coupled supergravity is also studied in this context.Comment: 1+63 pages, 6 Table
Matrix Norms, BPS Bounds and Marginal Stability in N=8 Supergravity
We study the conditions of marginal stability for two-center extremal black
holes in N-extended supergravity in four dimensions, with particular emphasis
on the N=8 case. This is achieved by exploiting triangle inequalities satisfied
by matrix norms. Using different norms and relative bounds among them, we
establish the existence of marginal stability and split attractor flows both
for BPS and some non-BPS solutions. Our results are in agreement with previous
analysis based on explicit construction of multi-center solutions.Comment: 1+15 pages; v2: some new formulas added and misprints corrected; v3:
typos fixed, various refinements, Sec. 2.4 rewritten; to appear on JHE
On the Black-Hole/Qubit Correspondence
The entanglement classification of four qubits is related to the extremal
black holes of the 4-dimensional STU model via a time-like reduction to three
dimensions. This correspondence is generalised to the entanglement
classification of a very special four-way entanglement of eight qubits and the
black holes of the maximally supersymmetric N = 8 and exceptional magic N = 2
supergravity theories.Comment: 32 pages, very minor changes at the start of Sec. 4.1. Version to
appear in The European Physical Journal - Plu
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