3,206 research outputs found
Chronic Elevation of Liver Enzymes in Acute Intermittent Porphyria Initially Misdiagnosed as Autoimmune Hepatitis
Autoimmune hepatitis is a disease characterized by an elevation of liver enzymes, as well as specific autoantibodies. It is more common in women than men. We describe a 32-year-old woman with elevated transaminases, autoantibodies, and a liver biopsy result suggestive of autoimmune hepatitis. The indicated treatment was administered without showing a satisfactory response. The patient had a family history of acute intermittent porphyria (AIP) so we decided to begin treatment with hematin, achieving a complete remission of the symptoms. Acute intermittent porphyria is a rare condition characterized by neurovisceral symptoms, abdominal pain being the most common of them. The disease has a higher prevalence among young women and certain European countries such as Sweden, Great Britain, and Spain. A correct diagnosis and prompt treatment are essential because patients affected by AIP must have a strict followup due to the fatal outcome of the outbreaks
Deuteration around the ultracompact HII region Mon R2
The massive star-forming region Mon R2 hosts the closest ultra-compact HII
region that can be spatially resolved with current single-dish telescopes. We
used the IRAM-30m telescope to carry out an unbiased spectral survey toward two
important positions (namely IF and MP2), in order to studying the chemistry of
deuterated molecules toward Mon R2. We found a rich chemistry of deuterated
species at both positions, with detections of C2D, DCN, DNC, DCO+, D2CO, HDCO,
NH2D, and N2D+ and their corresponding hydrogenated species and isotopologs.
Our high spectral resolution observations allowed us to resolve three velocity
components: the component at 10 km/s is detected at both positions and seems
associated with the layer most exposed to the UV radiation from IRS 1; the
component at 12 km/s is found toward the IF position and seems related to the
molecular gas; finally, a component at 8.5 km/s is only detected toward the MP2
position, most likely related to a low-UV irradiated PDR. We derived the column
density of all the species, and determined the deuterium fractions (Dfrac). The
values of Dfrac are around 0.01 for all the observed species, except for HCO+
and N2H+ which have values 10 times lower. The values found in Mon R2 are well
explained with pseudo-time-dependent gas-phase model in which deuteration
occurs mainly via ion-molecule reactions with H2D+, CH2D+ and C2HD+. Finally,
the [H13CN]/[HN13C] ratio is very high (~11) for the 10 km/s component, which
also agree with our model predictions for an age of ~0.01-0.1 Myr. The
deuterium chemistry is a good tool for studying star-forming regions. The
low-mass star-forming regions seem well characterized with Dfrac(N2H+) or
Dfrac(HCO+), but it is required a complete chemical modeling to date massive
star-forming regions, because the higher gas temperature together with the
rapid evolution of massive protostars.Comment: 14 pages of manuscript, 17 pages of apendix, 7 figures in the main
text, accepted for publication in A&
Spatial distribution of small hydrocarbons in the neighborhood of the Ultra Compact HII region Monoceros R2
We study the chemistry of small hydrocarbons in the photon-dominated regions
(PDRs) associated with the ultra-compact HII region Mon R2. Our goal is to
determine the variations of the abundance of small hydrocarbons in a high-UV
irradiated PDR and investigate their chemistry. We present an observational
study of CH, CCH and c-CH in Mon R2 combining data obtained with the
IRAM 30m telescope and Herschel. We determine the column densities of these
species, and compare their spatial distributions with that of polycyclic
aromatic hydrocarbon (PAH). We compare the observational results with different
chemical models to explore the relative importance of gas-phase, grain-surface
and time-dependent chemistry in these environments. The emission of the small
hydrocarbons show different patterns. The CCH emission is extended while CH and
c-CH are concentrated towards the more illuminated layers of the PDR.
The ratio of the column densities of c-CH and CCH shows spatial
variations up to a factor of a few, increasing from
_3_2 in the envelope to a maximum of
towards the 8m emission peak. Comparing these results
with other galactic PDRs, we find that the abundance of CCH is quite constant
over a wide range of G, whereas the abundance of c-CH is higher in
low-UV PDRs. In Mon R2, the gas-phase steady-state chemistry can account
relatively well for the abundances of CH and CCH in the most exposed layers of
the PDR, but falls short by a factor of 10 to reproduce c-CH.
In the molecular envelope, time-dependent effects and grain surface chemistry
play a dominant role in determining the hydrocarbons abundances. Our study
shows that CCH and c-CH present a complex chemistry in which UV
photons, grain-surface chemistry and time dependent effects contribute to
determine their abundances.Comment: 18 pages, 11 figures, 7 tables. Proposed for acceptance in A&A.
Abstract abridge
Status and preliminary results of the ANAIS experiment at Canfranc
ANAIS (Annual Modulation with NaI's) is an experiment planned to investigate
seasonal modulation effects in the signal of galactic WIMPs using up to 107 kg
of NaI(Tl) in the Canfranc Underground Laboratory (Spain). A prototype using
one single crystal (10.7 kg) is being developed before the installation of the
complete experiment; the first results presented here show an average
background level of 1.2 counts/(keV kg day) from threshold (Ethr~4 keV) up to
10 keV.Comment: 3 pages, 2 figures, talk delivered at the 7th International Workshop
on Topics in Astroparticle and Underground Physics (TAUP 2001), September
2001, Laboratori Nazionali del Gran Sasso, Italy (to appear in the Conference
Proceedings, Nucl. Phys. B (Proc. Suppl.)
Dynamic simulations in SixTrack
The DYNK module allows element settings in SixTrack to be changed on a
turn-by-turn basis. This document contains a technical description of the DYNK
module in SixTrack. It is mainly intended for a developer or advanced user who
wants to modify the DYNK module, for example by adding more functions that can
be used to calculate new element settings, or to add support for new elements
that can be used with DYNK.Comment: Submission to CERN yellow report / conference proceeding, the 2015
collimation tracking code worksho
Algoritmos Evolutivos para Descubrimiento de Reglas de Predicción en la Mejora de Sistemas Educativos Adaptativos basados en Web
Este artículo muestra la utilización de los algoritmos evolutivos para el descubrimiento de
reglas de predicción que se utilizarán en la mejora de Cursos Hipermedia Adaptativos basados en Web. Se
ha desarrollado una herramienta de minería de datos específica para descubrir relaciones entre los datos de
utilización recogidos durante las ejecuciones de los distintos alumnos. Esta información puede ser de gran
utilidad para el profesor o autor del curso, para la toma de decisiones sobre qué modificaciones son las más
adecuadas para mejorar el aprendizaje de los alumnos. Para la realización de la búsqueda de reglas de
predicción se ha utilizado programación genética basada en gramáticas multi-objetivo y se han comparado
con algoritmos clásicos de descubrimiento de reglas.In this paper we show the use of evolutionary algorithms for discovering prediction rules to
improve web-based adaptive hypermedia courses. We have developed a specific data mining tool to
discover relationship between the usage data pickup during the execution of different students. This
information can be very useful to the courseware author in order to make decisions about what are the most
appropriated modifications to improve the learning of the students. In order to do prediction rule
discovering we have used multi-objective grammar-based genetic programming and we have compared it
with other classic algorithm for rule discovering
Present status of IGEX dark matter search at Canfranc Underground Laboratory
One IGEX 76Ge double-beta decay detector is currently operating in the
Canfranc Underground Laboratory in a search for dark matter WIMPs, through the
Ge nuclear recoil produced by the WIMP elastic scattering. A new exclusion plot
has been derived for WIMP-nucleon spin-independent interactions. To obtain this
result, 40 days of data from the IGEX detector (energy threshold 4 keV),
recently collected, have been analyzed. These data improve the exclusion limits
derived from all the other ionization germanium detectors in the mass region
from 20 GeV to 200 GeV, where a WIMP supposedly responsible for the annual
modulation effect reported by the DAMA experiment would be located. The new
IGEX exclusion contour enters, by the first time, the DAMA region by using only
raw data, with no background discrimination, and excludes its upper left part.
It is also shown that with a moderate improvement of the detector performances,
the DAMA region could be fully explored.Comment: 3 pages, 3 figures, talk delivered at the 7th International Workshop
on Topics in Astroparticle and Underground Physics (TAUP 2001), September
2001, Laboratori Nazionali del Gran Sasso, Italy (to appear in the Conference
Proceedings, Nucl. Phys. B (Proc. Suppl.)
Caracterización mecánica de pistas deportivas fabricadas con materiales procedentes de neumáticos fuera de uso (NFU)
Congreso celebrado en la Escuela de Arquitectura de la Universidad de Sevilla desde el 24 hasta el 26 de junio de 2015.The European Framework Directive 2008/98/EC on waste established as priority reuse and recycling before other recovery alternatives. In this normative reference, one the main waste flows identified are the end-of-life tyres, as a material whose mechanical properties could provide advantage in the construction of new structures. This paper presents the mechanical characterization of a layer made with shredded tires out of use, inside a section of a sportive track which included a sand layer. The use of the shredded tires out of use provides special features related with elasticity and damping to the sportive surface. In order to do that, a new test based on UNE-14809 was designed. A number of tests were performed using different configuration of sand and shredded tires. From the results obtained, a numerical model was implemented in FEA software
Phase mapping of aging process in InN nanostructures: oxygen incorporation and the role of the zincblende phase
Uncapped InN nanostructures undergo a deleterious natural aging process at
ambient conditions by oxygen incorporation. The phases involved in this process
and their localization is mapped by Transmission Electron Microscopy (TEM)
related techniques. The parent wurtzite InN (InN-w) phase disappears from the
surface and gradually forms a highly textured cubic layer that completely wraps
up a InN-w nucleus which still remains from original single-crystalline quantum
dots. The good reticular relationships between the different crystals generate
low misfit strains and explain the apparent easiness for phase transformations
at room temperature and pressure conditions, but also disable the classical
methods to identify phases and grains from TEM images. The application of the
geometrical phase algorithm in order to form numerical moire mappings, and RGB
multilayered image reconstructions allows to discern among the different phases
and grains formed inside these nanostructures. Samples aged for shorter times
reveal the presence of metastable InN:O zincblende (zb) volumes, which acts as
the intermediate phase between the initial InN-w and the most stable cubic
In2O3 end phase. These cubic phases are highly twinned with a proportion of
50:50 between both orientations. We suggest that the existence of the
intermediate InN:O-zb phase should be seriously considered to understand the
reason of the widely scattered reported fundamental properties of thought to be
InN-w, as its bandgap or superconductivity.Comment: 18 pages 7 figure
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