1,541 research outputs found
Sparse Linear Models applied to Power Quality Disturbance Classification
Power quality (PQ) analysis describes the non-pure electric signals that are
usually present in electric power systems. The automatic recognition of PQ
disturbances can be seen as a pattern recognition problem, in which different
types of waveform distortion are differentiated based on their features.
Similar to other quasi-stationary signals, PQ disturbances can be decomposed
into time-frequency dependent components by using time-frequency or time-scale
transforms, also known as dictionaries. These dictionaries are used in the
feature extraction step in pattern recognition systems. Short-time Fourier,
Wavelets and Stockwell transforms are some of the most common dictionaries used
in the PQ community, aiming to achieve a better signal representation. To the
best of our knowledge, previous works about PQ disturbance classification have
been restricted to the use of one among several available dictionaries. Taking
advantage of the theory behind sparse linear models (SLM), we introduce a
sparse method for PQ representation, starting from overcomplete dictionaries.
In particular, we apply Group Lasso. We employ different types of
time-frequency (or time-scale) dictionaries to characterize the PQ
disturbances, and evaluate their performance under different pattern
recognition algorithms. We show that the SLM reduce the PQ classification
complexity promoting sparse basis selection, and improving the classification
accuracy
Pseudo-Sylvester domains and skew laurent polynomials over firs
Building on recent work of Jaikin-Zapirain, we provide a homological criterion for a ring to be a pseudo-Sylvester domain, that is, to admit a division ring of fractions over which all stably full matrices become invertible. We use the criterion to study skew Laurent polynomial rings over free ideal rings (firs). As an application of our methods, we prove that crossed products of division rings with free-by-{infinite cyclic} and surface groups are pseudo-Sylvester domains unconditionally and Sylvester domains if and only if they admit stably free cancellation. This relies on the recent proof of the Farrell--Jones conjecture for normally poly-free groups and extends previous results of Linnell--L\"uck and Jaikin-Zapirain on universal localizations and universal fields of fractions of such crossed products
Multidisciplinary consensus on optimising the detection of NTRK gene alterations in tumours
Fusions de gens; Oncologia molecular; NeoplàsiaFusiones de genes; Oncología molecular; NeoplasiaGene fusions; Molecular oncology; NeoplasmThe recent identification of rearrangements of neurotrophic tyrosine receptor kinase (NTRK) genes and the development of specific fusion protein inhibitors, such as larotrectinib and entrectinib, have revolutionised the diagnostic and clinical management of patients presenting with tumours with these alterations. Tumours that harbour NTRK fusions are found in both adults and children; and they are either rare tumours with common NTRK fusions that may be diagnostic, or more prevalent tumours with rare NTRK fusions. To assess currently available evidence on this matter, three key Spanish medical societies (the Spanish Society of Medical Oncology (SEOM), the Spanish Society of Pathological Anatomy (SEAP), and the Spanish Society of Paediatric Haematology and Oncology (SEHOP) have brought together a group of experts to develop a consensus document that includes guidelines on the diagnostic, clinical, and therapeutic aspects of NTRK-fusion tumours. This document also discusses the challenges related to the routine detection of these genetic alterations in a mostly public Health Care System.SEOM, SEAP and SEHOP have received financial support for this project in the form of unrestricted collaboration in the logistics of expert meeting from Bayer and Roche
Correlation between capacitances of porous carbons in acidic and aprotic EDLC electrolytes
5 pages, 4 figures, 2 tables.-- Printed version published Jun 2007.A study based on a total of 41 nanoporous carbons shows that there exists a good correlation between the limiting gravimetric capacitances Co at low current densities j (1 mA cm−2) measured in aprotic (1 M (C2H5)4 NBF4 in acetonitrile) and in acidic (2 M aqueous H2SO4) electrolytes. The comparison of the surface-related capacitances (F m−2) of well characterized samples with the amount of thermodesorbed CO suggests a strong contribution of CO generating surface groups to charge storage in the acidic electrolyte, but a negligible contribution in the aprotic medium. It also appears that the decrease of the capacitance with current density is similar in both electrolytes. This confirms that the average micropore width and the CO2 generating surface groups are the main factors which limit the ionic mobility in both electrolytes.Peer reviewe
Datos sobre el tesorillo tardorromano de monedas de El Pedregal (Chantada, Lugo)
Se presentan los datos sobre el contexto de
aparición del Tesorillo Tardorromano de monedas de bronce de El Pedregal, descubierto
a raíz de unas obras de canalización.
Se ha realizado un estudio sobre una pequeña muestra entre las monedas mejor conservadas de las más de 10.000 monedas que lo componían, identificando la cronología y el metal empleado. En los análisis de composición se ha utilizado la técnica no destructiva de espectrometría por fluorescencia de rayos X.The paper deals with the archaeological
context of the hoard of Late Roman
bronze coins found in El Pedregal after
some public works. The hoard contains
more than ten thousand coins. A small
group choosen among the better preserved
coins has been studied to define
the chronology and the metal used.
Non-destructive x-ray fluorescence (XRF)
spectrometry was used for elemental
analysis
Asthma diagnosis is not associated with obesity in a population of adults from Madrid
Background: Several studies have suggested a relationship between asthma and obesity; however, this relationship is unclear when obesity
is compared with bronchial hyperresponsiveness to methacholine.
Aim: To determine whether obesity is associated with a diagnosis of asthma.
Methods: We conducted a cross-sectional study in a population of Spanish adults in the north of Madrid, Spain between 2003 and
2007. The patients included had experienced asthma symptoms during the previous year, but had a ratio of forced expiratory volume in
the fi rst second of expiration (FEV1) to forced vital capacity (FVC) of >70%. Diagnosis was confi rmed by the presence of symptoms and
demonstration of bronchial hyperresponsiveness to methacholine. Obesity was measured by body mass index (BMI). Adjusted odd ratios
(OR) were obtained by logistic regression.
Results: Of a total of 1424 patients included, 251 (17.6%) were diagnosed with asthma. These patients were younger (P<.001) and had
lower BMI (P<.001) and lung function parameters (FEV1 and FEV1/FVC ratio) than individuals without asthma (P<.001). After adjusting
the model for age, gender, baseline FEV1, and FEV1/FVC ratio, patients with overweight or obesity were not more frequently diagnosed
with asthma than those with normal weight (OR, 0.848 [95% confi dence interval (CI), 0.59-1.20]; and OR, 0.616 [95% CI, 0.38-0.99],
respectively). In addition, obese males were more frequently diagnosed with asthma than obese females (P<.041).
Conclusions: In this study, obesity and overweight were not associated with a diagnosis of asthma based on the presence of consistent
symptoms and demonstration of airway responsiveness to methacholineFundamento: Varios estudios sugieren que la obesidad es un factor de riesgo para padecer asma, lo que no siempre se confi rma cuando
se compara la obesidad con la hiperreactividad bronquial (HRB) en pacientes con síntomas de asma.
Objetivo: Determinar si la obesidad se asocia con el diagnóstico de asma, confi rmado por presencia de síntomas e HRB a metacolina.
Pacientes y Métodos: Se realizó un estudio transversal en población adulta del Área Norte de Madrid entre 2003 y 2007. Se incluyeron
sujetos que habían padecido síntomas de asma en el último año, con un FEV1/FVC>70% y que precisaban una prueba de metacolina
para confi rmar el diagnóstico. La obesidad se defi nió según el índice de masa corporal (IMC). Se aplicó un modelo de regresión logística
para calcular odd ratios (OR) ajustadas.
Resultados: Se estudiaron 1.424 sujetos y se diagnosticaron de asma 251 sujetos (17,6%) que, comparados con los 1.173 no diagnosticados
de asma, eran más jóvenes y presentaban un IMC y parámetros de función pulmonar (FEV1, FEV1/FVC) más bajos (p<0,001). Tras ajustar
el modelo por edad, sexo, FEV1 basal y FEV1/FVC el diagnóstico de asma no fue más prevalente en los sujetos obesos o con sobrepeso que
en los sujetos con peso normal (OR 0,848, IC95% 0,59-1,20 y OR 0,616, IC95% 0,38-0,99, respectivamente). El diagnóstico de asma
fue más frecuente en hombres obesos que en mujeres obesas (p=0,041).
Conclusiones: La obesidad y el sobrepeso no se asociaron con el diagnóstico de asma establecido por la presencia de síntomas e HRB a
metacolinaThis research project was carried out with a
grant from Fundación para la Investigación Biomédica del
Hospital Universitario La Paz (FIBHULP
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