1,515 research outputs found
Rating assignments: Lessons from international banks
This paper estimates ordered logit and probit regression models for bank ratings which also include a country index to capture country-specific variation. The empirical findings provide support to the hypothesis that the individual international bank ratings assigned by Fitch Ratings are underpinned by fundamental quantitative financial analyses. Also, there is strong evidence of a country effect. Our model is shown to provide accurate predictions of bank ratings for the period prior to the 2007 – 2008 banking crisis based upon publicly available information. However, our results also suggest that quantitative models are not likely to be able to predict ratings with complete accuracy. Furthermore, we find that both quantitative models and rating agencies are likely to produce highly inaccurate predictions of ratings during periods of financial instability
Bank Efficiency, Productivity and Convergence in EU countries: A Weighted Russell Directional Distance Model
The objective of this study is three-fold. First we estimate and analyse bank efficiency and productivity changes in the EU28 countries with the application of a novel approach, a weighted Russell directional distance model. Second, we take a disaggregated approach and analyse the contribution of the individual bank inputs on bank efficiency and productivity growth. Third, we test for convergence in EU28 bank productivity as well as in the inefficiency of individual bank inputs. We find that bank efficiency has been undermined by the financial crisis in banks notably from the EU15 countries. We also argue that bank efficiency and productivity in EU countries vary across the banking sector with banks from the ‘old’ EU showing higher efficiency levels. Nonetheless, a noticeable catching up process is observed for banks from the ‘new’ EU countries. Consequently, we do not find evidence of group convergence for bank productivity but there is evidence of convergence in bank efficiency change and technical change among the EU28 countries throughout the period 2005-2014. The driving force seems to be convergent technical change from the old EU Member States’ banks. On the other hand, almost no convergence is detected for the banks’ individual inputs while the transition paths show heightened diversity during the crisis years
A new technique for elucidating -decay schemes which involve daughter nuclei with very low energy excited states
A new technique of elucidating -decay schemes of isotopes with large
density of states at low excitation energies has been developed, in which a
Broad Energy Germanium (BEGe) detector is used in conjunction with coaxial
hyper-pure germanium detectors. The power of this technique has been
demonstrated on the example of 183Hg decay. Mass-separated samples of 183Hg
were produced by a deposition of the low-energy radioactive-ion beam delivered
by the ISOLDE facility at CERN. The excellent energy resolution of the BEGe
detector allowed rays energies to be determined with a precision of a
few tens of electronvolts, which was sufficient for the analysis of the
Rydberg-Ritz combinations in the level scheme. The timestamped structure of the
data was used for unambiguous separation of rays arising from the
decay of 183Hg from those due to the daughter decays
Do evolutionary algorithms indeed require random numbers? Extended study
An inherent part of evolutionary algorithms, that are based on Darwin theory of evolution and Mendel theory of genetic heritage, are random processes. In this participation, we discuss whether are random processes really needed in evolutionary algorithms. We use n periodic deterministic processes instead of random number generators and compare performance of evolutionary algorithms powered by those processes and by pseudo-random number generators. Deterministic processes used in this participation are based on deterministic chaos and are used to generate periodical series with different length. Results presented here are numerical demonstration rather than mathematical proofs. We propose that a certain class of deterministic processes can be used instead of random number generators without lowering of evolutionary algorithms performance. © Springer International Publishing Switzerland 2013
Effect of particle properties of powders on the generation and transmission of raman scattering
Transmission Raman measurements of a 1 mm thick sulfur-containing disk were made at different positions as it was moved through 4 mm of aspirin (150-212 mu m) or microcrystalline cellulose (Avicel) of different size ranges (<38, 53-106, and 150-212 mu m). The transmission Raman intensity of the sulfur interlayer at 218 cm(-1) was lower when the disk was placed at the top or bottom of the powder bed, compared to positions within the bed and the difference between the sulfur intensity at the outer and inner positions increased with Avicel particle size. Also, the positional intensity difference was smaller for needle-shaped aspirin than for granular Avicel of the same size. The attenuation coefficients for the propagation of the exciting laser and transmitted Raman photons through the individual powders were the same but decreased as the particle size of Avicel increased; also, the attenuation coefficients for propagation through 150-212 mu m aspirin were almost half of those through similar sized Avicel particles. The study has demonstrated that particulate size and type affect transmitted Raman intensities and, consequently, such factors need to be considered in the analysis of powders, especially if particle properties vary between the samples
Clinical outcomes in a subpopulation of adults with Morquio A syndrome: results from a long-term extension study of elosulfase alfa
Background: This post hoc subanalysis examined outcomes in adult patients with Morquio A (mucopolysaccharidosis IVA) who received enzyme replacement therapy (ERT) with elosulfase alfa over a 120-weeks period. Patients ≥18 years of age evaluated in an open-label, long-term extension study of elosulfase alfa (modified per protocol [MPP], n = 32; intent-to-treat [ITT], n = 37; MOR-005; NCT01415427) were compared with the ≥18-year-old untreated population with 2-years follow-up from a Morquio A natural history study (n = 10; MorCAP; NCT00787995). The MOR-005 MPP population excluded patients who underwent orthopedic surgical procedures or were noncompliant with study protocol (defined as missing ≥20% of ERT infusions). No MorCAP patients underwent orthopedic surgical procedures during the relevant time period. Endurance was assessed by the 6-min walk test (6MWT) and 3-min stair climb test (3MSCT). Activities of daily living (ADLs) were assessed by the MPS Health Assessment Questionnaire (MPS HAQ). / Results: Least squares (LS) mean (SE) 6MWT distances increased by 34.9 (11.7) m (MPP) and 30.5 (10.8) m (ITT) by week 120; LS mean (SE) change in 3MSCT at week 120 was 6.7 (1.8) stairs/min (MPP) and 5.9 (1.7) stairs/min (ITT). MorCAP patients showed no improvement in 6MWT distance or 3MSCT over a similar period of time. Pulmonary function measures remained unchanged in both MOR-005 and MorCAP adults. All MPS HAQ domain scores improved in MOR-005 adults, whereas MorCAP adults had unchanged caregiver assistance and mobility outcomes and worsened self-care outcomes. / Conclusions: Long-term ERT in adult patients with Morquio A was associated with increased endurance and improvement in performance of ADLs. / Trial registration: Trial Registration NCT01415427. Name of registry: Long-Term Efficacy and Safety Extension Study of BMN 110 in Patients With Mucopolysaccharidosis IVA (Morquio A Syndrome). Registered 8 August 2011, retrospectively registered
Iron therapy substantially restores qEEG maturational lag among iron-deficient anemic infants
Objective: To use quantitative electroencephalography (qEEG) to assess the impact of iron-deficiency anemia on central nervous system maturation in the first year of life. Method: Twenty-five infants (3–12 months old) presenting ferropenic anemia (IDA) and 25 healthy controls (CTL1), matched by age/gender with the former, were studied in two stages. Electroencephalogram during spontaneous sleep was recorded from all participants; the fast Fourier transform was calculated to obtain absolute power (AP) and relative power (RP) qEEG measures. In the first stage, a qEEG comparison between CTL1 and IDA was performed. Second stage consisted in comparing qEEG of the IDA infants before and after supplementation with iron (IDA-IS group), and comparing qEEG of the IDA-IS group with another control age-matched group (CTL2). Non-parametric multivariate permutation tests (NPT) were applied to assess differences between CTL1 and IDA groups, as well as IDA vs. IDA-IS, and IDA-IS vs. CTL2. Results: More power in slow frequency bands and less power in fast frequency bands in 64% of IDA babies were observed. NPT evinced higher alpha AP and RP (P < 0.001), less theta AP, and less delta and theta RP in CTL1 than in IDA. After iron-restoration therapy, alpha AP and RP increased while theta AP and theta and delta RP decreased, reaching almost normal values. Discussion: This work reveals CNS developmental delay through the study of qEEG (less rapid and more slow frequencies) which recovered significantly with iron supplementation. It is concluded that IDA constitutes a high risk factor for a lag of CNS maturation.CONACYT-Project No. CO1/40257-A1
Impact of long-term elosulfase alfa treatment on respiratory function in patients with Morquio A syndrome
OBJECTIVE: To present long-term respiratory function outcomes from an open-label, multi-center, phase 3 extension study (MOR-005) of elosulfase alfa enzyme replacement therapy (ERT) in patients with Morquio A syndrome. METHODS: In part 1 of MOR-005, patients initially randomized to ERT in the 24-week pivotal study (MOR-004) remained on their regimen (2.0 mg/kg/week or every other week); placebo patients were re-randomized to one of the two regimens. During part 2, all patients received elosulfase alfa 2.0 mg/kg/week. Respiratory function was one of the efficacy endpoints evaluated in MOR-005. Change from MOR-004 baseline to 120 weeks of treatment for the combined population was determined and compared with results from untreated patients from a Morquio A natural history study (MorCAP). RESULTS: Maximum voluntary ventilation (MVV) improved up to week 72 and then stabilized; forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) increased continuously over 120 weeks. Mean increases in the modified per-protocol population was 9.2 % for FVC, 8.8 % for FEV1, and 6.1 % for MVV after 120 weeks. All patients ≤14 years showed respiratory improvements, presumably in part related to growth; however, these were greater in treated patients. For those >14 years, treated patients showed improvements, while deterioration occurred in untreated. Altogether, the improvements were significantly greater (P < 0.05) in treated patients. CONCLUSIONS: Long-term ERT is associated with sustained improvements in respiratory function in Morquio A. In younger patients (≤14 years), some improvement may be ascribed to growth. In older patients, other mechanisms, e.g., decreased glycosaminoglycan storage, are likely involved
Bregman Voronoi Diagrams: Properties, Algorithms and Applications
The Voronoi diagram of a finite set of objects is a fundamental geometric
structure that subdivides the embedding space into regions, each region
consisting of the points that are closer to a given object than to the others.
We may define many variants of Voronoi diagrams depending on the class of
objects, the distance functions and the embedding space. In this paper, we
investigate a framework for defining and building Voronoi diagrams for a broad
class of distance functions called Bregman divergences. Bregman divergences
include not only the traditional (squared) Euclidean distance but also various
divergence measures based on entropic functions. Accordingly, Bregman Voronoi
diagrams allow to define information-theoretic Voronoi diagrams in statistical
parametric spaces based on the relative entropy of distributions. We define
several types of Bregman diagrams, establish correspondences between those
diagrams (using the Legendre transformation), and show how to compute them
efficiently. We also introduce extensions of these diagrams, e.g. k-order and
k-bag Bregman Voronoi diagrams, and introduce Bregman triangulations of a set
of points and their connexion with Bregman Voronoi diagrams. We show that these
triangulations capture many of the properties of the celebrated Delaunay
triangulation. Finally, we give some applications of Bregman Voronoi diagrams
which are of interest in the context of computational geometry and machine
learning.Comment: Extend the proceedings abstract of SODA 2007 (46 pages, 15 figures
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