329 research outputs found
Wheezing in infants: frequency, clinical characteristics and treatment
OBJECTIVE: To estimate the frequency and describe the clinical characteristics and respective treatments of previous history of wheezing. METHODS: Infants aged 6-23 months with upper respiratory tract complaints and reporting previous wheezing were followed-up retrospectively. Data were registered on a validated standardized form. RESULTS: Out of 451 infants, 164 (36.4%; 95%CI: 31.9-41.0) had a report of prior history of wheezing, 148 (32.8%; 95%CI: 28.5-37.4) during the first year of life. The mean age at the first episode of wheezing was 5.3±3.9 months. Among those who had had their first episode before 12 months of age, 38.5% reported 3 to 6 episodes and 14.2% > 6 episodes. Mean age at first episode was lower for those with > 3 episodes in comparison with those with seis episódios. A média da idade no primeiro episódio foi menor para os que apresentaram > três episódios em comparação aos que apresentaram até dois episódios (3,2±2,7 versus 5,7±2,5 meses, p < 0,001). CONCLUSÃO: Um terço dos lactentes apresentou chiado no primeiro ano de vida. Quanto mais cedo ocorre o primeiro episódio, mais frequente é a recorrência do chiado.Fundação de Amparo à Pesquisa do Estado da Bahia (FAPESB)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal da Bahia Faculdade de Medicina da Bahia Programa de Pós-Graduação em Ciências da SaúdeUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de PediatriaUniversidade de São Paulo Faculdade de Saúde Pública Departamento de EpidemiologiaEscola Bahiana de Medicina e Saúde PúblicaUFBAUFBA Faculdade de Medicina da Bahia Departamento de Anatomia Patológica e Medicina LegalUFBA Faculdade de Medicina da Bahia Departamento de PediatriaUNIFESP, EPM, Depto. de PediatriaSciEL
New Materials to Solve Energy Issues through Photochemical and Photophysical Processes: The Kinetics Involved
Kinetic rates of energy production are extremely controlled by the competing processes that occur in systems capable of energy transfer. Besides organic and inorganic compounds already known as electronically actives, supramolecular systems can be thought to form energy transfer complexes to efficiently convert, for instance, light into electricity and the mechanisms for that can be of any kind. Photophysical and photochemical processes can simultaneously occur in such systems to provide energy conversion, by competing mechanisms or collaborative ones. Thus, to investigate the kinetic rates of each process and to understand the dynamics of the electronic excited states population and depopulation in strategically structured materials, can offer important tools to efficiently make use of this not always so evident power of supramolecular materials. In this chapter, we present the state-of-the-art of the use of photophysical processes and photochemical changes, presented by new materials and devices to provide a control of energy transfer processes and enable distinct applications, since energy conversion to sensing and imaging techniques to material characterization
A pervasive approach to a real-time intelligent decision support system in intensive medicine
The decision on the most appropriate procedure to provide to the
patients the best healthcare possible is a critical and complex task in Intensive
Care Units (ICU). Clinical Decision Support Systems (CDSS) should deal with
huge amounts of data and online monitoring, analyzing numerous parameters
and providing outputs in a short real-time. Although the advances attained in
this area of knowledge new challenges should be taken into account in future
CDSS developments, principally in ICUs environments. The next generation of
CDSS will be pervasive and ubiquitous providing the doctors with the
appropriate services and information in order to support decisions regardless the
time or the local where they are. Consequently new requirements arise namely
the privacy of data and the security in data access. This paper will present a
pervasive perspective of the decision making process in the context of INTCare
system, an intelligent decision support system for intensive medicine. Three
scenarios are explored using data mining models continuously assessed and
optimized. Some preliminary results are depicted and discussed.Fundação para a Ciência e a Tecnologia (FCT
First bounds on the very high energy gamma-ray emission from Arp 220
Using the Major Atmospheric Gamma Imaging Cherenkov Telescope (MAGIC), we
have observed the nearest ultra-luminous infrared galaxy Arp 220 for about 15
hours. No significant signal was detected within the dedicated amount of
observation time. The first upper limits to the very high energy -ray
flux of Arp 220 are herein reported and compared with theoretical expectations.Comment: Accepted for publication in Ap
Implementation of the Random Forest Method for the Imaging Atmospheric Cherenkov Telescope MAGIC
The paper describes an application of the tree classification method Random
Forest (RF), as used in the analysis of data from the ground-based gamma
telescope MAGIC. In such telescopes, cosmic gamma-rays are observed and have to
be discriminated against a dominating background of hadronic cosmic-ray
particles. We describe the application of RF for this gamma/hadron separation.
The RF method often shows superior performance in comparison with traditional
semi-empirical techniques. Critical issues of the method and its implementation
are discussed. An application of the RF method for estimation of a continuous
parameter from related variables, rather than discrete classes, is also
discussed.Comment: 16 pages, 8 figure
Systematic search for VHE gamma-ray emission from X-ray bright high-frequency BL Lac objects
All but three (M87, BL Lac and 3C 279) extragalactic sources detected so far
at very high energy (VHE) gamma-rays belong to the class of high-frequency
peaked BL Lac (HBL) objects. This suggested to us a systematic scan of
candidate sources with the MAGIC telescope, based on the compilation of X-ray
blazars by Donato et al. (2001). The observations took place from December 2004
to March 2006 and cover sources on the northern sky visible under small zenith
distances zd < 30 degrees at culmination. The sensitivity of the search was
planned for detecting X-ray bright F(1 keV) > 2 uJy) sources emitting at least
the same energy flux at 200 GeV as at 1 keV. In order to avoid strong gamma-ray
attenuation close to the energy threshold, the redshift of the sources was
constrained to values z<0.3. Of the fourteen sources observed, 1ES 1218+304 and
1ES 2344+514 have been detected in addition to the known bright TeV blazars Mrk
421 and Mrk 501. A marginal excess of 3.5 sigma from the position of 1ES
1011+496 was observed and has been confirmed as a source of VHE gamma-rays by a
second MAGIC observation triggered by a high optical state (Albert et al.
2007). For the remaining sources, we present here the 99% confidence level
upper limits on the integral flux above ~200 GeV. We characterize the sample of
HBLs (including all HBLs detected at VHE so far) by looking for correlations
between their multi-frequency spectral indices determined from simultaneous
optical, archival X-ray, and radio luminosities, finding that the VHE emitting
HBLs do not seem to constitute a unique subclass. The absorption corrected
gamma-ray luminosities at 200 GeV of the HBLs are generally not higher than
their X-ray luminosities at 1 keV.Comment: 15 pages, 7 figures, 5 tables, submitted to ApJ (revised version
Upper limit for gamma-ray emission above 140 GeV from the dwarf spheroidal galaxy Draco
The nearby dwarf spheroidal galaxy Draco with its high mass to light ratio is
one of the most auspicious targets for indirect dark matter searches.
Annihilation of hypothetical DM particles can result in high-energy gamma-rays,
e.g. from neutralino annihilation in the supersymmetric framework. With the
MAGIC telescope a search for a possible DM signal originating from Draco was
performed during 2007. The analysis of the data results in a flux upper limit
of 1.1x10^-11 photons cm^-2 sec^-1 for photon energies above 140 GeV, assuming
a point like source. Furthermore, a comparison with predictions from
supersymmetric models is given. While our results do not constrain the mSUGRA
phase parameter space, a very high flux enhancement can be ruled out.Comment: Accepted for publication by Astrophysical Journa
MAGIC upper limits on the very high energy emission from GRBs
The fast repositioning system of the MAGIC Telescope has allowed during its
first data cycle, between 2005 and the beginning of year 2006, observing nine
different GRBs as possible sources of very high energy gammas. These
observations were triggered by alerts from Swift, HETE-II, and Integral; they
started as fast as possible after the alerts and lasted for several minutes,
with an energy threshold varying between 80 and 200 GeV, depending upon the
zenith angle of the burst. No evidence for gamma signals was found, and upper
limits for the flux were derived for all events, using the standard analysis
chain of MAGIC. For the bursts with measured redshift, the upper limits are
compatible with a power law extrapolation, when the intrinsic fluxes are
evaluated taking into account the attenuation due to the scattering in the
Metagalactic Radiation Field (MRF).Comment: 25 pages, 9 figures, final version accepted by ApJ. Changet title to
"MAGIC upped limits on the VERY high energy emission from GRBs", re-organized
chapter with description of observation, removed non necessaries figures,
added plot of effective area depending on zenith angle, added an appendix
explaining the upper limit calculation, added some reference
Observation of Pulsed Gamma-rays Above 25 GeV from the Crab Pulsar with MAGIC
One fundamental question about pulsars concerns the mechanism of their pulsed
electromagnetic emission. Measuring the high-end region of a pulsar's spectrum
would shed light on this question. By developing a new electronic trigger, we
lowered the threshold of the Major Atmospheric gamma-ray Imaging Cherenkov
(MAGIC) telescope to 25 GeV. In this configuration, we detected pulsed
gamma-rays from the Crab pulsar that were greater than 25 GeV, revealing a
relatively high cutoff energy in the phase-averaged spectrum. This indicates
that the emission occurs far out in the magnetosphere, hence excluding the
polar-cap scenario as a possible explanation of our measurement. The high
cutoff energy also challenges the slot-gap scenario.Comment: Slight modification of the analysis: Fitting a more general function
to the combined data set of COMPTEL, EGRET and MAGIC. Final result and
conclusion is unchange
First bounds on the high-energy emission from isolated Wolf-Rayet binary systems
High-energy gamma-ray emission is theoretically expected to arise in tight
binary star systems (with high mass loss and high velocity winds), although the
evidence of this relationship has proven to be elusive so far. Here we present
the first bounds on this putative emission from isolated Wolf-Rayet (WR) star
binaries, WR 147 and WR 146, obtained from observations with the MAGIC
telescope.Comment: (Authors are the MAGIC Collaboration.) Manuscript in press at The
Astrophysical Journal Letter
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