130 research outputs found
Firm default and aggregate fluctuations
This paper studies the relation between macroeconomic fluctuations and corporate defaults while conditioning on industry affiliation and an extensive set of firm-specific factors. Using a logit approach on a panel data set for all incorporated Swedish businesses over 1990-2002, we find strong evidence for a substantial and stable impact of aggregate fluctuations. Macroeffects differ across industries in an economically intuitive way. Out-of-sample evaluations show our approach is superior to both models that exclude macro information and best fitting naive forecasting models. While firm-specific factors are useful in ranking firmsâ relative riskiness, macroeconomic factors capture fluctuations in the absolute risk level.Business failures
Etnicitet mellem produktion og skole
PÄ baggrund af et interview- og observationsstudie af produktionsskoleelever pÄ tre forskellige produktionsskoler vil vi i denne artikel pege pÄ, hvorledes praktiske arbejdsfÊllesskaber giver andre deltagelsesmuligheder for etniske minoritetselever sammenlignet med undervisningssituationer tilrettelagt pÄ mere traditionel skolastisk vis. Vi vil pege pÄ, at den traditionelle undervisning, hvor sproglig interaktion fungerer som det organiserende princip, ikke altid formÄr at matche etniske minoritetselevers dansksproglige forudsÊtninger, hvilket kan bidrage til at fremstille etniske minoritetselever som knapt sÄ intellektuelt velfungerende. Dette kommer bÄde til udtryk gennem undervisningsformerne og undervisningsmaterialerne. De mere praktiske arbejdsfÊllesskaber, som er dominerende pÄ produktionsskolerne, synes i hÞjere grad at positionere etniske minoritetselever som mere velfungerende, idet sprogbrugen her i hÞjere grad nÊrmer sig dagligdagssprog, og de etniske minoritetselever fÄr langt stÞrre muligheder for at bruge deres lÊringserfaringer fra andre kontekster end skolekontekster
Quantum Cosmology and Higher-Order Lagrangian Theories
In this paper the quantum cosmological consequences of introducing a term
cubic in the Ricci curvature scalar into the Einstein--Hilbert action are
investigated. It is argued that this term represents a more generic
perturbation to the action than the quadratic correction usually considered. A
qualitative argument suggests that there exists a region of parameter space in
which neither the tunneling nor the no-boundary boundary conditions predict an
epoch of inflation that can solve the horizon and flatness problems of the big
bang model. This is in contrast to the --theory.Comment: 13 pages, LaTeX, preprint FERMILAB-Pub-94/XXX-A, March 199
Home Non Invasive Ventilation (NIV) treatment for COPD patients with a history of NIV-treated exacerbation:a randomized, controlled, multi-center study
BACKGROUND: In chronic obstructive pulmonary disease, the prognosis for patients who have survived an episode of acute hypercapnic respiratory failure due to an exacerbation is poor. Despite being shown to improve survival and quality-of-life in stable patients with chronic hypercapnic respiratory failure, long-term noninvasive ventilation is controversial in unstable patients with frequent exacerbations, complicated by acute hypercapnic respiratory failure. In an uncontrolled group of patients with previous episodes of acute hypercapnic respiratory failure, treated with noninvasive ventilation, we have been able to reduce mortality and the number of repeat respiratory failure and readmissions by continuing the acute noninvasive ventilatory therapy as a long-term therapy. METHODS: Multi-center open label randomized controlled trial of 150 patients having survived an admission with noninvasive ventilatory treatment of acute hypercapnic respiratory failure due chronic obstructive pulmonary disease. The included patients are randomized to usual care or to continuing the acute noninvasive ventilation as a long-term therapy, both with a one-year follow-up period. The primary endpoint is time to death or repeat acute hypercapnic respiratory failure; secondary endpoints are one-year mortality, number of readmissions and repeat acute hypercapnic respiratory failure, exacerbations, dyspnea, quality of life, sleep quality, lung function, and arterial gases. DISCUSSION: Though previous studies of long-term noninvasive ventilation have shown conflicting results, we believe the treatment can reduce mortality and readmissions when applied in patients with previous need of acute ventilatory support, regardless of persistent hypercapnia. TRIAL REGISTRATION: clinicaltrials.org: NCT01513655 16-Jan-2012
Nordic research and development cooperation to strengthen nuclear reactor safety after the Fukushima accident
A comprehensive study of photon interaction features has been made for some alloys containing Pd and Ag content to evaluate its possible use as alternative gamma radiations shielding material. The mass attenuation coefficient (ÎŒ/Ï) of the present alloys was measured at various photon energies between 81 keV â 1333 keV utilizing HPGe detector. The measured ÎŒ/Ï values were compared to those of theoretical and computational (MCNPX code) results. The results exhibited that the ÎŒ/Ï values of the studied alloys are in same line with results of WinXCOM software and MCNPX code results at all energies. Moreover, Pd75/Ag25 alloy sample has the maximum radiation protection efficiency (about 53% at 81 keV) and lowest half value layer, which shows that Pd75/Ag25 has superior gamma radiation shielding performance among the compared other alloys. Keywords: Alloys, shielding material, MCNPX, photon, HPGe detecto
A New Method of Generating Exact Inflationary Solutions
The mechanism of the initial inflation of the universe is based on
gravitationally coupled scalar fields . Various scenarios are
distinguished by the choice of an {\it effective self--interaction potential}
which simulates a {\it temporarily} non--vanishing {\em cosmological
term}. Using the Hubble expansion parameter as a new ``time" coordinate, we
can formally derive the {\it general} Robertson--Walker metric for a {\em
spatially flat} cosmos. Our new method provides a classification of allowed
inflationary potentials and is broad enough to embody all known {\it exact}
solutions involving one scalar field as special cases. Moreover, we present new
inflationary and deflationary exact solutions and can easily predict the
influence of the form of on density perturbations.Comment: 32 pages, REVTeX, 9 postscript figures (or hardcopy) available upon
request, Cologne-thp-1994-H
Classification of Inflationary Einstein--Scalar--Field--Models via Catastrophe Theory
Various scenarios of the initial inflation of the universe are distinguished
by the choice of a scalar field {\em potential} which simulates a
{\it temporarily} non--vanishing {\em cosmological term}. Our new method, which
involves a reparametrization in terms of the Hubble expansion parameter ,
provides a classification of allowed inflationary potentials and of the
stability of the critical points. It is broad enough to embody all known {\it
exact} solutions involving one scalar field as special cases. Inflation
corresponds to the evolution of critical points of some catastrophe manifold.
The coalescence of its nondegenerate critical points with the creation of a
degenerate critical point corresponds the reheating phase of the universe. This
is illustrated by several examples.Comment: 12 pages, REVTeX, no figure
Integrable Multicomponent Perfect Fluid Multidimensional Cosmology II: Scalar Fields
We consider anisotropic cosmological models with an universe of dimension 4
or more, factorized into n>1 Ricci-flat spaces, containing an m-component
perfect fluid of m non-interacting homogeneous minimally coupled scalar fields
under special conditions. We describe the dynamics of the universe: It has a
Kasner-like behaviour near the singularity and isotropizes during the expansion
to infinity.
Some of the considered models are integrable, and classical as well as
quantum solutions are found. Some solutions produce inflation from "nothing".
There exist classical asymptotically anti-de Sitter wormholes, and quantum
wormholes with discrete spectrum.Comment: 28 pages, LaTeX, subm. to Gen. Rel. Gra
Maternal diet and human milk composition: an updated systematic review
CONTEXT: Exclusive breastfeeding for 6âmonths after birth provides infants with the best start for life. A review by Bravi et al. summarized the importance of maternal diet as a determinant of human milk composition based on data up to 2015, but evidence on nutrient intake level was limited. OBJECTIVE: We updated the review by Bravi et al., critically assessed differences in study designs and sampling methods, and graphically visualized trends and associations. DATA SOURCES: PubMed was systematically searched for articles published between January 2015 and March 2021. DATA EXTRACTION: Article screening, selection, and data extraction was done by two independent researchers, including a risk of bias assessment based on 11 criteria. Articles were eligible when including: quantitative information, commonly used effect estimates, healthy mother-infant dyads. RESULTS: Twenty seven observational and five intervention studies were identified ( n â=â7,138) and combined with results of Bravi et al. Fatty acids were still the most studied human milk components in relation to maternal diet ( n â=â17 studies) with maternal fish intake being predominantly positively associated with milk ALA ( r â=â0.28-0.42), DHA ( r â=â0.24-0.46), and EPA ( r â=â0.25-0.28) content. PUFAs from diet were generally positively correlated with their concentrations in milk, while SFA intake was negatively associated with several fatty acids in milk. Studies on associations with maternal diet and milk carbohydrates, proteins, vitamins and minerals were limited in number and varied in methods and results. CONCLUSION: This updated review shows that evidence on the association between maternal diet and human milk fatty acids is rapidly increasing, but still diversified in methodology and results. Further studies, preferably intervention studies, assessing diet and milk carbohydrates, proteins, vitamins and minerals are needed to be able draw conclusions on the importance of maternal diet for human milk composition as a whole
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