4,508 research outputs found
Deep Learning for Cardiologist-level Myocardial Infarction Detection in Electrocardiograms
Myocardial infarction is the leading cause of death worldwide. In this paper,
we design domain-inspired neural network models to detect myocardial
infarction. First, we study the contribution of various leads. This systematic
analysis, first of its kind in the literature, indicates that out of 15 ECG
leads, data from the v6, vz, and ii leads are critical to correctly identify
myocardial infarction. Second, we use this finding and adapt the ConvNetQuake
neural network model--originally designed to identify earthquakes--to attain
state-of-the-art classification results for myocardial infarction, achieving
classification accuracy on a record-wise split, and
classification accuracy on a patient-wise split. These two results represent
cardiologist-level performance level for myocardial infarction detection after
feeding only 10 seconds of raw ECG data into our model. Third, we show that our
multi-ECG-channel neural network achieves cardiologist-level performance
without the need of any kind of manual feature extraction or data
pre-processing.Comment: Accepted to the European Medical and Biological Engineering
Conference (EMBEC) 202
The omega rho pi coupling in the VMD model revisited
We determine the value of the \omega -\rho- \pi mesons coupling
(g_{\omega\rho\pi}), in the context of the vector meson dominance model, from
radiative decays, the \omega \rightarrow 3\pi decay width and the e^+e^-
\rightarrow 3\pi cross section. For the last two observables we consider the
effect of either a heavier resonance (\rho'(1450)) or a contact term. A
weighted average of the results from the set of observables yields
g_{\omega\rho\pi} =14.7 \pm 0.1 GeV^{-1} in absence of those contributions, and
g_{\omega\rho\pi} =11.9 \pm 0.2 GeV^{-1} or g_{\omega\rho\pi} =11.7 \pm 0.1
GeV^{-1} when including the \rho' or contact term respectively. The inclusion
of these additional terms makes the estimates from the different observables to
lay in a more reduced range. Improved measurements of these observables and the
\rho'(1450) meson parameters are needed to give a definite answer on the
pertinence of the inclusion of this last one in the considered processes.Comment: 14 pages, 5 figures. Extended analysis including SND and CMD2 data.
References added. Matches published versio
Polarization-tuneable excitonic spectral features in the optoelectronic response of atomically thin ReS2
The low crystal symmetry of rhenium disulphide (ReS2) leads to the emergence
of dichroic optical and optoelectronic response, absent in other layered
transition metal dichalcogenides, which could be exploited for device
applications requiring polarization resolution. To date, spectroscopy studies
on the optical response of ReS2 have relied almost exclusively in
characterization techniques involving optical detection, such as
photoluminescence, absorbance, or reflectance spectroscopy. However, to realize
the full potential of this material, it is necessary to develop knowledge on
its optoelectronic response with spectral resolution. In this work, we study
the polarization-dependent photocurrent spectra of few-layer ReS2
photodetectors, both in room conditions and at cryogenic temperature. Our
spectral measurements reveal two main exciton lines at energies matching those
reported for optical spectroscopy measurements, as well as their excited
states. Moreover, we also observe an additional exciton-like spectral feature
with a photoresponse intensity comparable to the two main exciton lines. We
attribute this feature, not observed in earlier photoluminescence measurements,
to a non-radiative exciton transition. The intensities of the three main
exciton features, as well as their excited states, modulate with linear
polarization of light, each one acquiring maximal strength at a different
polarization angle. We have performed first-principles exciton calculations
employing the Bethe-Salpeter formalism, which corroborate our experimental
findings. Our results bring new perspectives for the development of ReS2-based
nanodevices
Bisphenol A exposure in Mexico City and risk of prematurity: a pilot nested case control study
Abstract Background Presence of Bisphenol A (BPA) has been documented worldwide in a variety of human biological samples. There is growing evidence that low level BPA exposure may impact placental tissue development and thyroid function in humans. The aim of this present pilot study was to determine urinary concentrations of BPA during the last trimester of pregnancy among a small subset of women in Mexico City, Mexico and relate these concentrations to risk of delivering prematurely. Methods A nested case-control subset of 60 participants in the Early Life Exposure in Mexico to ENvironmental Toxicants (ELEMENT) study in Mexico City, Mexico were selected based on delivering less than or equal to 37 weeks of gestation and greater than 37 weeks of gestation. Third trimester archived spot urine samples were analyzed by online solid phase extraction coupled with high performance liquid chromatography isotope dilution tandem mass spectrometry. Results BPA was detected in 80.0% (N = 48) of the urine samples; total concentrations ranged from < 0.4 μg/L to 6.7 μg/L; uncorrected geometric mean was 1.52 μg/L. The adjusted odds ratio of delivering less than or equal to 37 weeks in relation to specific gravity adjusted third trimester BPA concentration was 1.91 (95%CI 0.93, 3.91, p-value = 0.08). When cases were further restricted to births occurring prior to the 37th week (n = 12), the odds ratio for specific-gravity adjusted BPA was larger and statistically significant (p < 0.05). Conclusions This is the first study to document measurable levels of BPA in the urine of a population of Mexican women. This study also provides preliminary evidence, based on a single spot urine sample collected during the third trimester, that pregnant women who delivered less than or equal to 37 weeks of gestation and prematurely (< 37 weeks) had higher urinary concentrations of BPA compared to women delivering after 37 weeks.http://deepblue.lib.umich.edu/bitstream/2027.42/78251/1/1476-069X-9-62.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78251/2/1476-069X-9-62.pdfPeer Reviewe
Herschel FIR counterparts of selected Ly-alpha emitters at z~2.2. Fast evolution since z~3 or missed obscured AGNs?
Ly-alpha emitters (LAEs) are seen everywhere in the redshift domain from
local to z~7. Far-infrared (FIR) counterparts of LAEs at different epochs could
provide direct clues on dust content, extinction, and spectral energy
distribution (SED) for these galaxies. We search for FIR counterparts of LAEs
that are optically detected in the GOODS-North field at redshift z~2.2 using
data from the Herschel Space Telescope with the Photodetector Array Camera and
Spectrometer (PACS). The LAE candidates were isolated via color-magnitude
diagram using the medium-band photometry from the ALHAMBRA Survey, ancillary
data on GOODS-North, and stellar population models. According to the fitting of
these spectral synthesis models and FIR/optical diagnostics, most of them seem
to be obscured galaxies whose spectra are AGN-dominated. From the analysis of
the optical data, we have observed a fraction of AGN or composite over source
total number of ~0.75 in the LAE population at z~2.2, which is marginally
consistent with the fraction previously observed at z=2.25 and even at low
redshift (0.2<z<0.45), but significantly different from the one observed at
redshift ~3, which could be compatible either with a scenario of rapid change
in the AGN fraction between the epochs involved or with a non detection of
obscured AGN in other z=2-3 LAE samples due to lack of deep FIR observations.
We found three robust FIR (PACS) counterparts at z~2.2 in GOODS-North. This
demonstrates the possibility of finding dust emission in LAEs even at higher
redshifts.Comment: 11 pages (including Appendices), 6 figures. Accepted for publication
in Astronomy & Astrophysics Letters (two references added
Layer-by-layer technique to developing functional nanolaminate films with antifungal activity
The layer-by-layer (LbL) deposition method was used to build up alternating layers (five) of different polyelectrolyte solutions (alginate, zein-carvacrol nanocapsules, chitosan and chitosan-carvacrol emulsions) on an aminolysed/charged polyethylene terephthalate (A/C PET) film. These nanolaminated films were characterised by contact angle measurements and through the determination of water vapour (WVTR) and oxygen (O2TR) transmission rates. The effect of active nanolaminated films against the Alternaria sp. and Rhizopus stolonifer was also evaluated. This procedure allowed developing optically transparent nanolaminated films with tuneable water vapour and gas properties and antifungal activity. The water and oxygen transmission rate values for the multilayer films were lower than those previously reported for the neat alginate or chitosan films. The presence of carvacrol and zein nanocapsules significantly decreased the water transmission rate (up to 40 %) of the nanolaminated films. However, the O2TR behaved differently and was only improved (up to 45 %) when carvacrol was encapsulated, i.e. nanolaminated films prepared by alternating alginate with nanocapsules of zein-carvacrol layers showed better oxygen barrier properties than those prepared as an emulsion of chitosan and carvacrol. These films containing zein-carvacrol nanocapsules also showed the highest antifungal activity (30 %), which did not significantly differ from those obtained with the highest amount of carvacrol, probably due to the controlled release of the active agent (carvacrol) from the zein-carvacrol nanocapsules. Thus, this work shows that nanolaminated films prepared with alternating layers of alginate and zein-carvacrol nanocapsules can be considered to improve the shelf-life of foodstuffs.The authors acknowledge financial support from
FP7 IP project BECOBIOCAP^. M. J. Fabra is recipients of a Juan de la
Cierva contract from the Spanish Ministry of Economy and
Competitivity. Maria L. Flores-López thanks Mexican Science and Technology
Council (CONACyT, Mexico) for PhD fellowship support
(CONACyT Grant Number 215499/310847). The author Miguel A.
Cerqueira is a recipient of a fellowship (SFRH/BPD/72753/2010) supported
by Fundação para a Ciência e Tecnologia, POPH-QREN and FSE
(FCT, Portugal). The authors also thank the FCT Strategic Project of UID/
BIO/04469/2013 unit, the project RECI/BBB-EBI/0179/2012 (FCOMP-
01-0124-FEDER-027462) and the project BBioInd - Biotechnology and
Bioengineering for improved Industrial and Agro-Food processes,^ REF.
NORTE-07-0124-FEDER-000028 Co-funded by the Programa
Operacional Regional do Norte (ON.2–O Novo Norte), QREN, FEDER.
The support of EU Cost Action FA0904 is gratefully acknowledged
Precise measurement of the top quark mass in the dilepton channel at D0
We measure the top quark mass (mt) in ppbar collisions at a center of mass
energy of 1.96 TeV using dilepton ttbar->W+bW-bbar->l+nubl-nubarbbar events,
where l denotes an electron, a muon, or a tau that decays leptonically. The
data correspond to an integrated luminosity of 5.4 fb-1 collected with the D0
detector at the Fermilab Tevatron Collider. We obtain mt = 174.0 +- 1.8(stat)
+- 2.4(syst) GeV, which is in agreement with the current world average mt =
173.3 +- 1.1 GeV. This is currently the most precise measurement of mt in the
dilepton channel.Comment: 7 pages, 4 figure
Double parton interactions in photon+3 jet events in ppbar collisions sqrt{s}=1.96 TeV
We have used a sample of photon+3 jets events collected by the D0 experiment
with an integrated luminosity of about 1 fb^-1 to determine the fraction of
events with double parton scattering (f_DP) in a single ppbar collision at
sqrt{s}=1.96 TeV. The DP fraction and effective cross section (sigma_eff), a
process-independent scale parameter related to the parton density inside the
nucleon, are measured in three intervals of the second (ordered in pT) jet
transverse momentum pT_jet2 within the range 15 < pT_jet2 < 30 GeV. In this
range, f_DP varies between 0.23 < f_DP < 0.47, while sigma_eff has the average
value sigma_eff_ave = 16.4 +- 0.3(stat) +- 2.3(syst) mb.Comment: 15 pages, 13 figure
Evidence for an anomalous like-sign dimuon charge asymmetry
We measure the charge asymmetry A of like-sign dimuon events in 6.1 fb(-1) of p (p) over bar collisions recorded with the D0 detector at a center-of-mass energy root s = 1.96 TeV at the Fermilab Tevatron collider. From A, we extract the like-sign dimuon charge asymmetry in semileptonic b-hadron decays: A(sl)(b) = -0.00957 +/- 0.00251 (stat) +/- 0.00146 (syst). This result differs by 3.2 standard deviations from the standard model prediction A(sl)(b)(SM) = (-2.3(0.6)(+0.5)) x 10(-4) and provides first evidence of anomalous CP violation in the mixing of neutral B mesons
Search for new fermions ("quirks") at the Fermilab Tevatron Collider
We report results of a search for particles with anomalously high ionization
in events with a high transverse energy jet and large missing transverse energy
in fb of integrated luminosity collected by the D0 experiment at
the Fermilab Tevatron collider. Production of such particles
(quirks) is expected in scenarios with extra QCD-like {\it SU(N)} sectors, and
this study is the first dedicated search for such signatures. We find no
evidence of a signal and set a lower mass limit of 107 ~GeV for the mass of a
charged quirk with strong dynamics scale in the range from 10 keV to
1 MeV.Comment: submitted to Phys. Rev. Letter
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