9,419 research outputs found
Steps toward a classifier for the Virtual Observatory. I. Classifying the SDSS photometric archive
Modern photometric multiband digital surveys produce large amounts of data
that, in order to be effectively exploited, need automatic tools capable to
extract from photometric data an objective classification. We present here a
new method for classifying objects in large multi-parametric photometric data
bases, consisting of a combination of a clustering algorithm and a cluster
agglomeration tool. The generalization capabilities and the potentialities of
this approach are tested against the complexity of the Sloan Digital Sky Survey
archive, for which an example of application is reported.Comment: To appear in the Proceedings of the "1st Workshop of Astronomy and
Astrophysics for Students" - Naples, 19-20 April 200
Steps towards a map of the nearby universe
We present a new analysis of the Sloan Digital Sky Survey data aimed at
producing a detailed map of the nearby (z < 0.5) universe. Using neural
networks trained on the available spectroscopic base of knowledge we derived
distance estimates for about 30 million galaxies distributed over ca. 8,000 sq.
deg. We also used unsupervised clustering tools developed in the framework of
the VO-Tech project, to investigate the possibility to understand the nature of
each object present in the field and, in particular, to produce a list of
candidate AGNs and QSOs.Comment: 3 pages, 1 figure. To appear in Nucl Phys. B, in the proceedings of
the NOW-2006 (Neutrino Oscillation Workshop - 2006), R. Fogli et al. ed
Media use during adolescence: the recommendations of the Italian Pediatric Society.
BACKGROUND: The use of media device, such as smartphone and tablet, is currently increasing, especially among the youngest. Adolescents spend more and more time with their smartphones consulting social media, mainly Facebook, Instagram and Twitter because. Adolescents often feel the necessity to use a media device as a means to construct a social identity and express themselves. For some children, smartphone ownership starts even sooner as young as 7 yrs, according to internet safety experts. MATERIAL AND METHODS: We analyzed the evidence on media use and its consequences in adolescence. RESULTS: In literature, smartphones and tablets use may negatively influences the psychophysical development of the adolescent, such as learning, sleep and sigh. Moreover, obesity, distraction, addiction, cyberbullism and Hikikomori phenomena are described in adolescents who use media device too frequently. The Italian Pediatric Society provide action-oriented recommendations for families and clinicians to avoid negative outcomes. CONCLUSIONS: Both parents and clinicians should be aware of the widespread phenomenon of media device use among adolescents and try to avoid psychophysical consequences on the youngest
Impact of antisecretory treatment on respiratory symptoms of gastroesophageal reflux disease in children.
Impacto social de las radiaciones no ionizantes y las políticas públicas
El objetivo del presente trabajo es fundamentar los beneficios de la contribución del asesoramiento profesional en la generación y transferencia del conocimiento, para la toma de decisiones en las políticas públicas que permita apropiarse de los avances y aplicaciones resultantes del trabajo científico desarrollado.Las Radiaciones No Ionizantes (RNI) son aquellas que no poseen la energía suficiente para ionizar la materia, pero que producen otro tipo de efectos, especialmente de tipo térmico. Sus efectos a largo plazo sobre la salud de los seres humanos aún es materia de discusión y es por esto que se genera en la ciudadanía una honda preocupación por el desconocimiento y falta de normativas a nivel municipal. El Grupo ITMA reúne un grupo interdisciplinario de profesionales con el objetivo de investigar el impacto de las RNI sobre el medio ambiente y los sistemas biológicos. Una de sus actividades es el asesoramiento a municipios y organismos públicos respecto de las RNI, en particular, el despliegue de antenas de telefonía móvil para generar ordenanzas municipales que contribuyan a la tranquilidad y mejora de la calidad de vida de la comunidad y contemplen los controles necesarios para preservar estas condiciones en el tiempo
Impact of the Rome II paediatric criteria on the appropriateness of the upper and lower gastrointestinal endoscopy in children.
BACKGROUND:
The demand for paediatric gastrointestinal (GI) endoscopy has increased, resulting in a significant rise of overall costs.
AIM:
To assess the clinical impact of the Rome II criteria for functional gastrointestinal disorders when selecting paediatric patients who underwent GI endoscopy.
METHODS:
The indications and findings of GI endoscopic procedures performed before and after the publication of the Rome II criteria were evaluated retrospectively.
RESULTS:
Upper GI endoscopy was performed in 1124 children, whereas colonoscopy was performed in 500 subjects. A total of 607 (54%) oesophago-gastro-duodenoscopies (OGDs) were positive and 517 (46%) were negative, whereas 306 (61.1%) colonoscopies were positive and 194 (38.9%) were negative. Of the 1624 procedures, 26% were considered inappropriate according to the Rome II criteria. Inappropriate procedures decreased significantly after publication of the Rome II criteria (OR, 3.7; 95% CI, 1.8-7.5). Of 1202 appropriate GI endoscopies, 502 OGD (62.7%) were significantly contributive, compared with only 105 (32.5%) of the 323 inappropriate procedures (OR, 3.5; 95% CI, 2.6-4.6), whereas 265 (65.8%) colonoscopies were significantly contributive, compared with only 41 (42.3%) of the 97 inappropriate procedures (OR, 2.6; 95% CI, 1.6-4.1).
CONCLUSIONS:
The use of the criteria for functional gastrointestinal disorders makes a significant positive impact, they should reduce unnecessary paediatric GI endoscopy
The use of neural networks to probe the structure of the nearby universe
In the framework of the European VO-Tech project, we are implementing new machine learning methods specifically tailored to match the needs of astronomical data mining. In this paper, we shortly present the methods and discuss an application to the Sloan Digital Sky Survey public data set. In particular, we discuss some preliminary results on the 3-D taxonomy of the nearby (z < 0.5) universe. Using neural networks trained on the available spectroscopic base of knowledge we derived distance estimates for ca. 30 million galaxies distributed over 8,000 sq. deg. We also use unsupervised clustering tools to investigate whether it is possible to characterize in broad morphological bins the nature of each object and produce a reliable list of candidate AGNs and QSOs
Consecutive occurrence of rhinoconjunctivitis, seronegative spondyloarthritis and pyoderma gangrenosum in a patient with ulcerative colitis.
Measurement of the proton and deuteron structure functions, F2p and F2d, and of the ratio sigma(L)/sigma(T)
The muon-proton and muon-deuteron inclusive deep inelastic scattering cross
sections were measured in the kinematic range 0.002 < x < 0.60 and 0.5 < Q2 <
75 GeV2 at incident muon energies of 90, 120, 200 and 280 GeV. These results
are based on the full data set collected by the New Muon Collaboration,
including the data taken with a small angle trigger. The extracted values of
the structure functions F2p and F2d are in good agreement with those from other
experiments. The data cover a sufficient range of y to allow the determination
of the ratio of the longitudinally to transversely polarised virtual photon
absorption cross sections, R= sigma(L)/sigma(T), for 0.002 < x < 0.12 . The
values of R are compatible with a perturbative QCD prediction; they agree with
earlier measurements and extend to smaller x.Comment: In this replacement the erroneously quoted R values in tables 3-6 for
x>0.12, and R1990 values in tables 5-6 for all x, have been corrected, and
the cross sections in tables 3-4 have been adapted. Everything else,
including the structure functions F2, remained unchanged. 22 pages, LateX,
including figures, with two .sty files, and three separate f2tab.tex files
for the F2-tables. Accepted for publication in Nucl.Phys.B 199
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