149 research outputs found
Measuring trace element fingerprinting for cereal bar authentication based on type and principal ingredient
This paper introduces a method for determining the authenticity of commercial cereal bars based on trace element fingerprints. In this regard, 120 cereal bars were prepared using microwave-assisted acid digestion and the concentrations of Al, Ba, Bi, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Pb, Rb, Se, Sn, Sr, V, and Zn were later measured by ICP-MS. Results confirmed the suitability of the analyzed samples for human consumption. Multielemental data underwent autoscaling preprocessing for then applying PCA, CART, and LDA to input data set. LDA model accomplished the highest classification modeling performance with a success rate of 92%, making it the suitable model for reliable cereal bar prediction. The proposed method demonstrates the potential of trace element fingerprints in distinguishing cereal bar samples according to their type (conventional and gluten-free) and principal ingredient (fruit, yogurt, chocolate), thereby contributing to global efforts for food authentication.Fil: Pérez Rodríguez, Michael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; Argentina. Instituto Tecnologico de Monterrey. Escuela de Ingenieria y Ciencias.; MéxicoFil: Hidalgo, Melisa Jazmin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Mendoza, Alberto. Instituto Tecnologico de Monterrey. Escuela de Ingenieria y Ciencias.; MéxicoFil: González, Lucy T.. Instituto Tecnologico de Monterrey. Escuela de Ingenieria y Ciencias.; MéxicoFil: Longoria Rodríguez, Francisco. Centro de Investigacion En Materiales Avanzados; MéxicoFil: Goicoechea, Hector Casimiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Laboratorio de Desarrollo Analítico y Quimiometría; ArgentinaFil: Pellerano, Roberto Gerardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; Argentin
Plaskett's Star: Analysis of the CoRoT photometric data
The SRa02 of the CoRoT space mission for Asteroseismology was partly devoted
to stars belonging to the Mon OB2 association. An intense monitoring was
performed on Plaskett's Star (HD47129) and the unprecedented quality of the
light curve allows us to shed new light on this very massive, non-eclipsing
binary system. We particularly aimed at detecting periodic variability which
might be associated with pulsations or interactions between both components. We
also searched for variations related to the orbital cycle which could help to
constrain the inclination and the morphology of the binary system. A
Fourier-based prewhitening and a multiperiodic fitting procedure were applied
to analyse the time series and extract the frequencies of variations. We
describe the noise properties to tentatively define an appropriate significance
criterion, to only point out the peaks at a certain significance level. We also
detect the variations related to the orbital motion and study them by using the
NIGHTFALL program. The periodogram exhibits a majority of peaks at low
frequencies. Among these peaks, we highlight a list of about 43 values,
including notably two different sets of harmonic frequencies whose fundamental
peaks are located at about 0.07 and 0.82d-1. The former represents the orbital
frequency of the binary system whilst the latter could probably be associated
with non-radial pulsations. The study of the 0.07d-1 variations reveals the
presence of a hot spot most probably situated on the primary star and facing
the secondary. The investigation of this unique dataset constitutes a further
step in the understanding of Plaskett's Star. These results provide a first
basis for future seismic modelling. The existence of a hot region between both
components renders the determination of the inclination ambiguous.Comment: Accepted in A&A, 13 pages, 7 figures, 2 table
Usos de la glutamina en pediatría
ResumenLa glutamina, aminoácido “condicionalmente indispensable” tiene un rol clave en la respuesta del intestino delgado ante diferentes agresiones. Bajo ciertas condiciones de estrés clínico y quirúrgico ocurren cambios y atrofi a en la mucosa intestinal, originando diversos grados de desnutrición. Investigadores han demostrado que el intestino es el órgano de mayor actividad de la glutamina y que su epitelio es considerado como blanco en la captura de la glutamina; asignándole un papel especial en la recuperación del intestino delgado. Se revisaron los trabajos recientes sobre su utilidad en el área pediátrica, con énfasis en el metabolismo intestinal y nutrición. Concluyendo que la glutamina puede ser benefi ciosa y absolutamente necesaria durante las situaciones críticas.[Marante J, Rodríguez R, López KC, González LG, Flores LS, Villalobos DC, et al. Usos de la glutamina en pediatría. MedUNAB 2005; 8 (1 Supl 1):S37-S42]Palabras clave: Glutamina, pediatría, intestino, aminoácido, nutrición enteral
The intrinsic shape of galaxy bulges
The knowledge of the intrinsic three-dimensional (3D) structure of galaxy
components provides crucial information about the physical processes driving
their formation and evolution. In this paper I discuss the main developments
and results in the quest to better understand the 3D shape of galaxy bulges. I
start by establishing the basic geometrical description of the problem. Our
understanding of the intrinsic shape of elliptical galaxies and galaxy discs is
then presented in a historical context, in order to place the role that the 3D
structure of bulges play in the broader picture of galaxy evolution. Our
current view on the 3D shape of the Milky Way bulge and future prospects in the
field are also depicted.Comment: Invited Review to appear in "Galactic Bulges" Editors: Laurikainen
E., Peletier R., Gadotti D. Springer Publishing. 24 pages, 7 figure
How to distinguish starbursts and quiescently star-forming galaxies: The `bimodal' submillimetre galaxy population as a case study
In recent work (arXiv:1101.0002) we have suggested that the high-redshift (z
~ 2-4) bright submillimetre galaxy (SMG) population is heterogeneous, with
major mergers contributing both at early stages, where quiescently star-forming
discs are blended into one submm source (`galaxy-pair SMGs'), and late stages,
where mutual tidal torques drive gas inflows and cause strong starbursts. Here
we combine hydrodynamic simulations of major mergers with 3-D dust radiative
transfer calculations to determine observational diagnostics that can
distinguish between quiescently star-forming SMGs and starburst SMGs via
integrated data alone. We fit the far-IR SEDs of the simulated galaxies with
the optically thin single-temperature modified blackbody, the full form of the
single-temperature modified blackbody, and a power-law temperature-distribution
model. The effective dust temperature, T_dust, and power-law index of the dust
emissivity in the far-IR, \beta, derived can significantly depend on the
fitting form used, and the intrinsic \beta\ of the dust is not recovered.
However, for all forms used here, there is a T_dust above which almost all
simulated galaxies are starbursts, so a T_dust cut is very effective at
selecting starbursts. Simulated merger-induced starbursts also have higher
L_IR/M_gas and L_IR/L_FUV than quiescently star-forming galaxies and lie above
the star formation rate-stellar mass relation. These diagnostics can be used to
test our claim that the SMG population is heterogeneous and to observationally
determine what star formation mode dominates a given galaxy population. We
comment on applicability of these diagnostics to ULIRGs that would not be
selected as SMGs. These `hot-dust ULIRGs' are typically starburst galaxies
lower in mass than SMGs, but they can also simply be SMGs observed from a
different viewing angle.Comment: 21 pages, 11 figures. Accepted for publication in MNRAS. Minor
changes to text but otherwise identical to v
Planck 2013 results. XXII. Constraints on inflation
We analyse the implications of the Planck data for cosmic inflation. The Planck nominal mission temperature anisotropy measurements, combined with the WMAP large-angle polarization, constrain the scalar spectral index to be ns = 0:9603 _ 0:0073, ruling out exact scale invariance at over 5_: Planck establishes an upper bound on the tensor-to-scalar ratio of r < 0:11 (95% CL). The Planck data thus shrink the space of allowed standard inflationary models, preferring potentials with V00 < 0. Exponential potential models, the simplest hybrid inflationary models, and monomial potential models of degree n _ 2 do not provide a good fit to the data. Planck does not find statistically significant running of the scalar spectral index, obtaining dns=dln k = 0:0134 _ 0:0090. We verify these conclusions through a numerical analysis, which makes no slowroll approximation, and carry out a Bayesian parameter estimation and model-selection analysis for a number of inflationary models including monomial, natural, and hilltop potentials. For each model, we present the Planck constraints on the parameters of the potential and explore several possibilities for the post-inflationary entropy generation epoch, thus obtaining nontrivial data-driven constraints. We also present a direct reconstruction of the observable range of the inflaton potential. Unless a quartic term is allowed in the potential, we find results consistent with second-order slow-roll predictions. We also investigate whether the primordial power spectrum contains any features. We find that models with a parameterized oscillatory feature improve the fit by __2 e_ _ 10; however, Bayesian evidence does not prefer these models. We constrain several single-field inflation models with generalized Lagrangians by combining power spectrum data with Planck bounds on fNL. Planck constrains with unprecedented accuracy the amplitude and possible correlation (with the adiabatic mode) of non-decaying isocurvature fluctuations. The fractional primordial contributions of cold dark matter (CDM) isocurvature modes of the types expected in the curvaton and axion scenarios have upper bounds of 0.25% and 3.9% (95% CL), respectively. In models with arbitrarily correlated CDM or neutrino isocurvature modes, an anticorrelated isocurvature component can improve the _2 e_ by approximately 4 as a result of slightly lowering the theoretical prediction for the ` <_ 40 multipoles relative to the higher multipoles. Nonetheless, the data are consistent with adiabatic initial conditions
Mismatches in scale between highly mobile marine megafauna and marine protected areas
Marine protected areas (MPAs), particularly large MPAs, are increasing in number and size around the globe in part to facilitate the conservation of marine megafauna under the assumption that large-scale MPAs better align with vagile life histories; however, this alignment is not well established. Using a global tracking dataset from 36 species across five taxa, chosen to reflect the span of home range size in highly mobile marine megafauna, we show most MPAs are too small to encompass complete home ranges of most species. Based on size alone, 40% of existing MPAs could encompass the home ranges of the smallest ranged species, while only < 1% of existing MPAs could encompass those of the largest ranged species. Further, where home ranges and MPAs overlapped in real geographic space, MPAs encompassed < 5% of core areas used by all species. Despite most home ranges of mobile marine megafauna being much larger than existing MPAs, we demonstrate how benefits from MPAs are still likely to accrue by targeting seasonal aggregations and critical life history stages and through other management techniques.Fil: Conners, Melinda G.. University of Washington; Estados Unidos. State University of New York. Stony Brook University; Estados UnidosFil: Sisson, Nicholas B.. Old Dominion University; Estados UnidosFil: Agamboue, Pierre D.. Wildlife Conservation Society; GabónFil: Atkinson, Philip W.. British Trust For Ornithology; Reino UnidoFil: Baylis, Alastair M. M.. Macquarie University; Australia. South Atlantic Environmental Research Institute; Reino UnidoFil: Benson, Scott R.. Noaa National Marine Fisheries Service Southwest Regional Office; Estados Unidos. Moss Landing Marine Laboratories; Estados UnidosFil: Block, Barbara A.. University of Stanford; Estados UnidosFil: Bograd, Steven J.. Noaa National Marine Fisheries Service Southwest Regional Office; Estados UnidosFil: Bordino, Pablo. Mote Marine Laboratory; Estados UnidosFil: Bowen, W.D.. Bedford Institute Of Oceanography, Fisheries And Oceans Canada; Canadá. Dalhousie University Halifax; CanadáFil: Brickle, Paul. South Atlantic Environmental Research Institute; Reino Unido. University of Aberdeen; Reino Unido. University Of Aberdeeen; Reino UnidoFil: Bruno, Ignacio Matias. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: González Carman, Victoria. Instituto Nacional de Investigaciones y Desarrollo Pesquero; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Champagne, Cory D.. University of Washington; Estados UnidosFil: Crocker, Daniel E.. Sonoma State University; Estados UnidosFil: Costa, Daniel P.. University of California; Estados UnidosFil: Dawson, Tiffany M.. University Of Central Florida; Estados Unidos. Old Dominion University; Estados UnidosFil: Deguchi, Tomohiro. Yamashina Institute For Ornithology; JapónFil: Dewar, Heidi. Noaa National Marine Fisheries Service Southwest Regional Office; Estados UnidosFil: Doherty, Philip D.. University of Exeter; Reino UnidoFil: Eguchi, Tomo. Noaa National Marine Fisheries Service Southwest Regional Office; Estados UnidosFil: Formia, Angela. Wildlife Conservation Society; Gabón. African Aquatic Conservation Fund; Estados UnidosFil: Godley, Brendan J.. University of Exeter; Reino UnidoFil: Graham, Rachel T.. Maralliance; PanamáFil: Gredzens, Christian. Padre Island National Seashore; Estados UnidosFil: Hart, Kristen M.. United States Geological Survey; Estados UnidosFil: Hawkes, Lucy A.. University of Exeter; Reino UnidoFil: Henderson, Suzanne. Scottish Natural Heritage; Reino UnidoFil: Henry, Robert William. Groundswell Coastal Ecology; Estados UnidosFil: Hückstädt, Luis A.. University of Exeter; Reino Unido. University of California; Estados Unido
Seroprevalence of Toxoplasma gondii IgG antibody in HIV/AIDS-infected individuals in Maputo, Mozambique
Remote sensing of lunar aureole with a sky camera: Adding information in the nocturnal retrieval of aerosol properties with GRASP code
The use of sky cameras for nocturnal aerosol characterization is discussed in this study. Two sky cameras are configured to take High Dynamic Range (HDR) images at Granada and Valladolid (Spain). Some properties of the cameras, like effective wavelengths, sky coordinates of each pixel and pixel sensitivity, are characterized. After that, normalized camera radiances at lunar almucantar points (up to 20° in azimuth from the Moon) are obtained at three effective wavelengths from the HDR images. These normalized radiances are compared in different case studies to simulations fed with AERONET aerosol information, giving satisfactory results. The obtained uncertainty of normalized camera radiances is around 10% at 533 nm and 608 nm and 14% for 469 nm. Normalized camera radiances and six spectral aerosol optical depth values (obtained from lunar photometry) are used as input in GRASP code (Generalized Retrieval of Aerosol and Surface Properties) to retrieve aerosol properties for a dust episode over Valladolid. The retrieved aerosol properties (refractive indices, fraction of spherical particles and size distribution parameters) are in agreement with the nearest diurnal AERONET products. The calculated GRASP retrieval at night time shows an increase in coarse mode concentration along the night, while fine mode properties remained constant.This work was supported by the Andalusia Regional Government (project P12-RNM-2409) and by the “Consejería de Educación, Junta de Castilla y León” (project VA100U14).Spanish Ministry of Economy and Competitiveness and FEDER funds under the projects CGL2013-45410-R, CMT2015-66742-R, CGL2016-81092-R.“Juan de la Cierva-Formación” program (FJCI-2014-22052).European Union's Horizon 2020 research and innovation programme through project ACTRIS-2 (grant agreement No 654109)
Interpretable surface-based detection of focal cortical dysplasias:a Multi-centre Epilepsy Lesion Detection study
One outstanding challenge for machine learning in diagnostic biomedical imaging is algorithm interpretability. A key application is the identification of subtle epileptogenic focal cortical dysplasias (FCDs) from structural MRI. FCDs are difficult to visualize on structural MRI but are often amenable to surgical resection. We aimed to develop an open-source, interpretable, surface-based machine-learning algorithm to automatically identify FCDs on heterogeneous structural MRI data from epilepsy surgery centres worldwide. The Multi-centre Epilepsy Lesion Detection (MELD) Project collated and harmonized a retrospective MRI cohort of 1015 participants, 618 patients with focal FCD-related epilepsy and 397 controls, from 22 epilepsy centres worldwide. We created a neural network for FCD detection based on 33 surface-based features. The network was trained and cross-validated on 50% of the total cohort and tested on the remaining 50% as well as on 2 independent test sites. Multidimensional feature analysis and integrated gradient saliencies were used to interrogate network performance. Our pipeline outputs individual patient reports, which identify the location of predicted lesions, alongside their imaging features and relative saliency to the classifier. On a restricted 'gold-standard' subcohort of seizure-free patients with FCD type IIB who had T1 and fluid-attenuated inversion recovery MRI data, the MELD FCD surface-based algorithm had a sensitivity of 85%. Across the entire withheld test cohort the sensitivity was 59% and specificity was 54%. After including a border zone around lesions, to account for uncertainty around the borders of manually delineated lesion masks, the sensitivity was 67%. This multicentre, multinational study with open access protocols and code has developed a robust and interpretable machine-learning algorithm for automated detection of focal cortical dysplasias, giving physicians greater confidence in the identification of subtle MRI lesions in individuals with epilepsy
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