39 research outputs found
Measurement of the cosmic ray spectrum above eV using inclined events detected with the Pierre Auger Observatory
A measurement of the cosmic-ray spectrum for energies exceeding
eV is presented, which is based on the analysis of showers
with zenith angles greater than detected with the Pierre Auger
Observatory between 1 January 2004 and 31 December 2013. The measured spectrum
confirms a flux suppression at the highest energies. Above
eV, the "ankle", the flux can be described by a power law with
index followed by
a smooth suppression region. For the energy () at which the
spectral flux has fallen to one-half of its extrapolated value in the absence
of suppression, we find
eV.Comment: Replaced with published version. Added journal reference and DO
Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA) is part of the Pierre Auger
Observatory and is used to detect the radio emission of cosmic-ray air showers.
These observations are compared to the data of the surface detector stations of
the Observatory, which provide well-calibrated information on the cosmic-ray
energies and arrival directions. The response of the radio stations in the 30
to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of
the incoming electric field. For the latter, the energy deposit per area is
determined from the radio pulses at each observer position and is interpolated
using a two-dimensional function that takes into account signal asymmetries due
to interference between the geomagnetic and charge-excess emission components.
The spatial integral over the signal distribution gives a direct measurement of
the energy transferred from the primary cosmic ray into radio emission in the
AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air
shower arriving perpendicularly to the geomagnetic field. This radiation energy
-- corrected for geometrical effects -- is used as a cosmic-ray energy
estimator. Performing an absolute energy calibration against the
surface-detector information, we observe that this radio-energy estimator
scales quadratically with the cosmic-ray energy as expected for coherent
emission. We find an energy resolution of the radio reconstruction of 22% for
the data set and 17% for a high-quality subset containing only events with at
least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO
Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy
We measure the energy emitted by extensive air showers in the form of radio
emission in the frequency range from 30 to 80 MHz. Exploiting the accurate
energy scale of the Pierre Auger Observatory, we obtain a radiation energy of
15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV
arriving perpendicularly to a geomagnetic field of 0.24 G, scaling
quadratically with the cosmic-ray energy. A comparison with predictions from
state-of-the-art first-principle calculations shows agreement with our
measurement. The radiation energy provides direct access to the calorimetric
energy in the electromagnetic cascade of extensive air showers. Comparison with
our result thus allows the direct calibration of any cosmic-ray radio detector
against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI.
Supplemental material in the ancillary file
Utilidad de los probióticos en pediatría
Se define como probiótico al suplemento oral o a algún producto alimentario que contiene un número suficiente de microorganismos viables capaces de alterar la
microbiota intestinal del huésped y tiene el potencial de efectos benéficos a la salud. El sistema de defensa de la mucosa intestinal es una parte integral de una red
inmunorreguladora que incluye la microbiota. A continuación revisaremos la evidencia que existe hasta el momento sobre la utilidad de los probióticos en el ámbito de la prevención y tratamiento de enfermedades
en pacientes pediátricos. El hecho de que actualmente no se encuentre evidencia sobre la utilidad de un probiótico en determinada condición clínica no significa que futura
investigación clínica no pueda establecer beneficios clínicos significativos. Se han estudiado los probióticos en diarrea aguda infecciosa, diarrea asociada a antibióticos, enfermedad atópica, prevención de
enterocolitis necrosante en neonatos de bajo peso al nacer, tratamiento de erradicación para Helicobacter pylori, enfermedad inflamatoria intestinal, síndrome de
intestino irritable, dolor abdominal funcional, cólico del lactante, síndrome de intestino corto y enfermedades infecciosas extraintestinales
Hepatopatía crónica en enfermedades reumatológicas
Las enfermedades de la colágena son desórdenes mediados inmunológicamente, caracterizados por compromiso de múltiples órganos. Dentro de éstos pacientes, el incremento de las aminotransferasas
es un fenómeno común. No están bien descritas
las características del daño ni el signifi cado de la movilización de las aminotransferasas, ya sea en forma transitoria o intermitente, debido a que habitualmente éstos pacientes no
son monitoreados desde el punto de vista del
funcionamiento hepático y en consecuencia no
son completamente estudiados. Se han descrito
una variedad de alteraciones hepáticas asociadas a las colagenopatías como la arteritis y congestión hepática, así como también cambios asociados al uso de medicamentos hepatotóxicos, como son
el hígado graso e infl amación inespecífi ca. En algunos casos se han asociado a enfermedades hepáticas bien defi nidas como la cirrosis biliar primaria, hiperplasia nodular regenerativa del hígado, obliteración de la vena portal,
hepatitis autoinmune e infecciosa por virus
B y C. También se han descrito desórdenes
vasculares como el síndrome de Budd-Chiari.
Aunque las enfermedades reumatológicas son raras en la población general pediátrica, se
deberá de sospechar compromiso hepático en
todo paciente con enfermedades reumatológicas
Latin American Considerations for Infant and Young Child Formulae
Infant formula is the only acceptable substitute for breastmilk from 0 to 6 months old when human milk cannot be provided in sufficient amounts. Manufacturers have developed options that intend to meet the changing needs of the child aged from six to twelve months (follow-on formulae) and after the age of one year (young child formulae). The international code for marketing breast milk substitute stipulates standards for marketing practices of these products. In Latin America there are local variations of marketing practices. Novel marketing strategies such as advertising through social media and influencers pose new threats for breastfeeding success in Latin America. This review aims to examine variations in local regulations for marketing of infant formulae and to analyze the emerging phenomenon of influencer advertising. We reviewed the local norms for Latin American countries and examined differences and possible gaps. Emerging evidence of influencer marketing was explored. The results indicate that national regulations differ among Latin American countries, particularly with respect to product labelling and the requirement to use a local native language, highlighting the cost of the product, and different regulations prohibiting certain messages and illustrations. Regarding new marketing strategies, there is limited evidence on advertising infant formula through social media influencers, where different categories of marketing strategies can be described. More transparent reporting of social marketing by formula providers and more independent research on novel marketing strategies are needed
Laminitis en una yegua Pura Raza Española en Tabasco, México: reporte de caso
Laminitis is a serious, highly prevalent disease, recognized as one of the most important clinical syndromes
in equines. The present study describes the case of a five-year-old Pura Raza Española mare diagnosed
with bilateral laminitis at approximately three months of age. The animal refused to walk, lying down all the
time. The degree of claudication, according to the Obel scale, was graded as 5; she also had an altered
palmar digital pulse. He was prescribed 30 days of anti-inflammatory therapy with 1.1mg/kg intravenous
(IV) of meglumine flunixin every 24 h, accompanied by omeprazole 2 mg/kg orally (O.V.). Additionally, hoof
trimming and corrective shoeing were recommended. After eight months of treatment, the mare showed a
remarkable improvement and gain in body condition, and a gestation was achieved. The anti-inflammatory
treatment, hoof trimming and corrective shoeing favored the growth and hardness of the hoof, being
successful in the treatment of laminitisLa laminitis es una enfermedad grave, de alta prevalencia, reconocida como uno de los síndromes clínicos
más importantes en equinos. En el presente estudio se describe el caso de una yegua Pura Raza Española
de cinco años de edad, con diagnóstico de laminitis bilateral de aproximadamente tres meses. El animal se
reusaba a caminar, manteniéndose echado todo el tiempo. El grado de claudicación, según la escala de
Obel, se calificó de 5; asimismo, presentaba pulso palmar digital alterado. Se receto terapia de 30 días con
antinflamatorios 1.1mg/kg intra venosa (IV) de flunixin de meglumine cada 24 h, acompañado de omeprazol
2 mg/kg vía oral (VO). Adicionalmente, se recomendó recorte de casco y herrajes correctivos. Después de
los ocho meses de tratamiento, la yegua presentó una notable mejoría y ganancia de condición corporal,
además, se logró una gestación. El tratamiento antiinflamatorio, recorte de casco y herrajes correctivos,
favorecieron el crecimiento y dureza del casco, teniendo éxito en el tratamiento de laminiti
Guidelines for the diagnosis and treatment of extrahepatic portal vein obstruction (EHPVO) in children
Introduction. Extrahepatic portal vein obstruction is an important cause of portal hypertension among children. The etiology is heterogeneous and there are few evidences related to the optimal treatment. Aim and methods. To establish guidelines for the diagnosis and treatment of EHPVO in children, a group of gastroenterologists and pediatric surgery experts reviewed and analyzed data reported in the literature and issued evidence-based recommendations.Results. Pediatric EHPVO is idiopathic in most of the cases. Digestive hemorrhage and/or hypersplenism are the main symptoms. Doppler ultrasound is a non-invasive technique with a high degree of accuracy for the diagnosis. Morbidity is related to variceal bleeding, recurrent thrombosis, portal biliopathy and hypersplenism. Endoscopic therapy is effective in controlling acute variceal hemorrhage and it seems that vasoactive drug therapy can be helpful. For primary prophylaxis of variceal bleeding, there are insufficient data for the use of beta blockers or endoscopic therapy. For secondary prophylaxis, sclerotherapy or variceal band ligation is effective; there is scare evidence to recommend beta-blockers. Surgery shunt is indicated in children with variceal bleeding who fail endoscopic therapy and for symptomatic hypersplenism; spleno-renal or meso-ilio-cava shunting is the alternative when Mesorex bypass is not feasible due to anatomic problems or in centers with no experience.Conclusions. Prospective control studies are required for a better knowledge of the natural history of EHPVO, etiology identification including prothrombotic states, efficacy of beta-blockers and comparison with endoscopic therapy on primary and secondary prophylaxis
Estudio multicéntrico sobre la epidemiologia de la Esofagitis Eosinofílica Pediátrica en América Latina
Objetivo: Evaluar las características epidemiológicas de un grupo depacientes pediátricos con esofagitis eosinofílica (EEo) y lasmodalidades de tratamiento empleadas en Latinoamérica. Pacientesy métodos: Estudio multicéntrico, observacional, transversal. Seaplicó una encuesta a 36 Centros de Gastroenterología y EndoscopiaPediátrica de 10 países latinoamericanos con la finalidad de obtenerinformación socio-demográfica y datos sobre el tratamiento utilizadopara el manejo de los casos evaluados durante el periodo 2014-2016. Resultados: 372 casos de EEo pediátrica fueron evaluadosdurante el periodo 2014-2016 y 108 casos (29%) correspondieron altrimestre Abril-Junio 2016. 46,72% de los casos pertenecían algrupo de edad escolar y 71,8% consultaron por disfagia. 87,2% delos pacientes fueron manejados con dieta, 55,3% esteroidesdeglutidos (12,8% en monoterapia) y 6% recibió montelukast. Nohubo reporte de pacientes en terapia con agentes biológicos.Conclusiones: los resultados sugieren un predominio del sexomasculino con una mayor incidencia de la enfermedad en la edadescolar y la adolescencia. Las manifestaciones clínicas másfrecuentes son disfagia, vómitos y síntomas de reflujogastroesofágico. El tratamiento más indicado por los especialistas enAmérica Latina es la dieta seguido del uso de esteroides deglutidos.Los IBP también son ampliamente utilizados como terapiacoadyuvante. Un estudio de prevalencia a nivel continental esnecesario para evaluar el comportamiento de la enfermedad endiferentes regiones de América Latina.