1,060 research outputs found
Generalized Linear Models for Geometrical Current predictors. An application to predict garment fit
The aim of this paper is to model an ordinal response variable in terms
of vector-valued functional data included on a vector-valued RKHS. In particular,
we focus on the vector-valued RKHS obtained when a geometrical object (body) is
characterized by a current and on the ordinal regression model. A common way to
solve this problem in functional data analysis is to express the data in the orthonormal
basis given by decomposition of the covariance operator. But our data present very important differences with respect to the usual functional data setting. On the one
hand, they are vector-valued functions, and on the other, they are functions in an
RKHS with a previously defined norm. We propose to use three different bases: the
orthonormal basis given by the kernel that defines the RKHS, a basis obtained from
decomposition of the integral operator defined using the covariance function, and a
third basis that combines the previous two. The three approaches are compared and
applied to an interesting problem: building a model to predict the fit of childrenâs
garment sizes, based on a 3D database of the Spanish child population. Our proposal
has been compared with alternative methods that explore the performance of other
classifiers (Suppport Vector Machine and k-NN), and with the result of applying
the classification method proposed in this work, from different characterizations of
the objects (landmarks and multivariate anthropometric measurements instead of
currents), obtaining in all these cases worst results
Who receives treatment for alcohol use disorders in the European Union? A cross-sectional representative study in primary and specialized health care
Background
Alcohol use disorders (AUDs) are highly prevalent in Europe, but only a minority of those affected receive treatment. It is therefore important to identify factors that predict treatment in order to reframe strategies aimed at improving treatment rates.
Methods
Representative cross-sectional study with patients aged 18\u201364 from primary health care (PC, six European countries, n = 8476, data collection 01/13\u201301/14) and from specialized health care (SC, eight European countries, n = 1762, data collection 01/13\u201303/14). For descriptive purposes, six groups were distinguished, based on type of DSM-IV AUD and treatment setting. Treatment status (yes/no) for any treatment (model 1), and for SC treatment (model 2) were main outcome measures in logistic regression models.
Results
AUDs were prevalent in PC (12-month prevalence: 11.8%, 95% confidence interval (CI): 11.2\u201312.5%), with 17.6% receiving current treatment (95%CI: 15.3\u201319.9%). There were clear differences between the six groups regarding key variables from all five predictor domains. Prediction of any treatment (model 1) or SC treatment (model 2) was successful with high overall accuracy (both models: 95%), sufficient sensitivity (model 1: 79%/model 2: 76%) and high specificity (both models: 98%). The most predictive single variables were daily drinking level, anxiety, severity of mental distress, and number of inpatient nights during the last 6 months.
Conclusions
Variables from four domains were highly predictive in identifying treatment for AUD, with SC treatment groups showing very high levels of social disintegration, drinking, comorbidity and functional losses. Earlier intervention and formal treatment for AUD in PC should be implemented to reduce these high levels of adverse outcomes
Treatment of alcohol use disorders in patients with alcoholic liver disease.
Alcohol use disorders (AUDs) is one of the leading causes of disease and disability in almost all European countries. Among the alcohol-related diseases, alcoholic liver disease (ALD) is the most common. At present, alcohol is the most frequent cause of liver cirrhosis in the Western world. The cornerstone of treatment for ALD is achieving total alcohol abstinence and preventing relapse; medical and surgical treatments for ALD are limited when drinking continues. This narrative review summarizes current treatments for AUDs with a particular emphasis to the treatment of AUDs in patients with ALD. Medical management, psychosocial and pharmacological interventions are analyzed, underlying limits and options in AUD patients. Finally, this review discusses the most appropriate setting for the management of AUD patients with advanced liver disease as well as the indications for liver transplantation in AUD patients
The imitation game: Proca stars that can mimic the Schwarzschild shadow
Can a dynamically robust bosonic star (BS) produce an (effective) shadow that
mimics that of a black hole (BH)? The BH shadow is linked to the existence of
light rings (LRs). For free bosonic fields, yielding mini-BSs, it is known that
these stars can become ultra-compact - i.e., possess LRs - but only for
perturbatively unstable solutions. We show this remains the case even when
different self-interactions are considered. However, an effective shadow can
arise in a different way: if BSs reproduce the existence of an innermost stable
circular orbit (ISCO) for timelike geodesics (located at for
a Schwarzschild BH of mass M), the accretion flow morphology around BHs is
mimicked and an effective shadow arises in an astrophysical environment. Even
though spherical BSs may accommodate stable timelike circular orbits all the
way down to their centre, we show the angular velocity along such orbits may
have a maximum away from the origin, at ; this scale was recently
observed to mimic the BH's ISCO in some scenarios of accretion flow. Then: (i)
for free scalar fields or with quartic self-interactions,
only for perturbatively unstable BSs; (ii) for higher scalar self-interactions,
e.g. axionic, is possible for perturbatively stable BSs, but
no solution with was found in the parameter space explored;
(iii) but for free vector fields, yielding Proca stars (PSs), perturbatively
stable solutions with exist, and indeed for
a particular solution. Thus, dynamically robust spherical PSs can mimic the
shadow of a (near-)equilibrium Schwarzschild BH with the same M, in an
astrophysical environment, despite the absence of a LR, at least under some
observation conditions, as we confirm by comparing the lensing of such PSs and
Schwarzschild BHs.Comment: Abstract abridged due to arXiv length limit; 22 pages, 9 figure
Catalytically active membrane-like devices: ionic liquid-hybrid organosilicas decorated with palladium nanoparticles
Ionic liquid (IL)-hybrid organosilicas based on 1-n-butyl-3-(3-trimethoxysilylpropyl)-imidazolium cations associated with hydrophilic and hydrophobic anions decorated with well dispersed and similar sized (1.8â2.1 nm) Pd nanoparticles (Pd-NPs) are amongst the most active and selective catalysts for the partial hydrogenation of conjugated dienes to monoenes. The location of the sputter-imprinted Pd-NPs on different supports, as determined by RBS and HS-LEIS analysis, is modulated by the strength of the contact ion pair formed between the imidazolium cation and the anion, rather than the IL-hybrid organosilica pore size and surface area. In contrast, the pore diameter and surface area of the hybrid supports display a direct correlation with the anion hydrophobicity. XPS analysis showed that the Pd(0) surface component decreases with increasing ionic bond strength between the imidazolium cation and the anions (contact ion pair). The finding is corroborated by changes in the coordination number associated with the Pd-Pd scattering in EXAFS measurements. Hence, the interaction of the IL with the metal surface is found to occur via IL contact pairs (or aggregates). The observed selectivities of â„99% to monoenes at full diene conversion indicate that the selectivity is intrinsic to the electron deficient Pd-metallic surfaces in this ârestrictedâ ionic environment. This suggests that IL-hybrid organosilica/Pd-NPs under multiphase conditions (âdynamic asymmetric mixtureâ) operate akin to catalytically active membranes, i.e. far from the thermodynamic equilibrium. Detailed kinetic investigations show that the reaction rate is zero-order with respect to hydrogen and dependent on the fraction of catalyst surfaces covered by either the substrate and/or the product. The reaction proceeds via rapid inclusion and sorption of the diene to the IL/Pd metal surface saturated with H species. This is followed by reversible hydride migration to generate a Ï-allyl intermediate. The reductive elimination of this intermediate, the formal rate-determining step (RDS), generates the alkene that is rapidly expelled from the IL phase to the organic phase
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The Macroeconomic Consequences of Microeconomic Phenomena in the Housing and Labor Markets
This dissertation consists of three independent chapters, each of which use microeconomic data and methods to inform an analysis of macroeconomic models and questions. The first two chapters study the short-run dynamics of housing markets, while the last chapter studies fluctuations in labor markets.Economic
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