3,349 research outputs found
From rest-frame luminosity functions to observer-frame colour distributions: tackling the next challenge in cosmological simulations
Galaxy spectral energy distributions (SEDs) remain among the most challenging
yet informative quantities to reproduce in simulations due to the large and
complex mixture of physical processes that shape the radiation output of a
galaxy. With the increasing number of surveys utilising broadband colours as
part of their target selection criteria, the production of realistic SEDs in
simulations is necessary for assisting in survey design and interpretation of
observations. The recent success in reproducing the observed luminosity
functions (LF) from far-UV to far-IR, using the state-of-the-art semi-analytic
model \shark\ and the SED generator \prospect, represents a critical step
towards better galaxy colour predictions. We show that with \shark\ and
\prospect\ we can closely reproduce the optical colour distributions observed
in the panchromatic GAMA survey. The treatment of feedback, star formation,
central-satellite interactions and radiation re-processing by dust are critical
for this achievement. The first three processes create a bimodal distribution,
while dust attenuation defines the location and shape of the blue and red
populations. While a naive comparison between observation and simulations
displays the known issue of over-quenching of satellite galaxies, the
introduction of empirically-motivated observational errors and classification
from the same group finder used in GAMA greatly reduces this tension. The
introduction of random re-assignment of of centrals/satellites as
satellites/centrals on the simulation classification closely resembles the
outcome of the group finder, providing a computationally less intensive method
to compare simulations with observations.Comment: Accepted for publication in MNRAS after minor corrections (20 pages,
19 figures
Necrosis aséptica de astrágalo: presentación de un caso en la infancia
Se presenta un caso de necrosis aséptica de astrágalo en la infancia de origen
idiopático que, hasta donde sabemos, resulta único en la literatura mundial. Se trata
de una niña con un síndrome de Klippel-Trenaunay que debuta a la edad de 8 años con
un cuadro de dolor e inflamación intermitente en tobillo derecho. Se realiza estudio mediante
radiografías simples, RNM y gammagrafía con "Tc, llegando al diagnóstico de necrosis
avascular de astrágalo. Se trata mediante descarga del miembro durante 3 meses,
realizando la paciente vida normal con mínimas molestias a los 3 años del diagnósticoWe present one case of idiopathic avascular necrosis of the talus in a child.To our knowledge, this is the first case reported in the literature. The patient is a girl diagnosed of Klippel-Trenaunay syndrome of the ipsilateral limb. When she was 8 years old began with pain and swelling in the right ankle. Simple X-ray, isotopic bone scan and MRI were done, and she was diagnosed of avascular necrosis of the talar dome. The treatment was no weight bearing for three months. She has no sympthoms three years after diagnosis
Galaxy quenching timescales from a forensic reconstruction of their colour evolution
The timescales on which galaxies move out of the blue cloud to the red
sequence () provide insight into the mechanisms driving
quenching. Here, we build upon previous work, where we showcased a method to
reconstruct the colour evolution of observed low-redshift galaxies from the
Galaxy And Mass Assembly (GAMA) survey based on spectral energy distribution
(SED) fitting with ProSpect, together with a statistically-driven definition
for the blue and red populations. We also use the predicted colour evolution
from the SHARK semi-analytic model, combined with SED fits of our simulated
galaxy sample, to study the accuracy of the measured and
gain physical insight into the colour evolution of galaxies. In this work, we
measure in a consistent approach for both observations and
simulations. After accounting for selection bias, we find evidence for an
increase in in GAMA as a function of cosmic time (from
Gyr to Gyr in the lapse of
Gyr), but not in SHARK ( Gyr). Our
observations and simulations disagree on the effect of stellar mass, with GAMA
showing massive galaxies transitioning faster, but is the opposite in SHARK. We
find that environment only impacts galaxies below M in
GAMA, with satellites having shorter than centrals by
Gyr, with SHARK only in qualitative agreement. Finally, we compare to
previous literature, finding consistency with timescales in the order of couple
Gyr, but with several differences that we discuss.Comment: 17 pages, 14 figures. Submitted to MNRAS. Updated to reflect changes
addressing the referee's comment
Vaccination of rabbits with immunodominant antigens from Sarcoptes scabiei induced high levels of humoral responses and pro-inflammatory cytokines but confers limited protection
Vaccination is an attractive ecological alternative to the use of acaricides for parasite control. However, effective anti-parasite vaccines against sarcoptic mange have not yet been developed. The purpose of this study was first to identify Sarcoptes scabiei immunodominant antigens and second to evaluate them as vaccine candidates in a rabbit/ S. scabiei var. cuniculi model. The S. scabiei Ssλ15 immunodominant antigen was selected by immunoscreening of a S. scabiei var. hominis cDNA. The full-length cDNA was sequenced and cloned into the pGEX vector and the recombinant protein expressed in BL21 (DE3) cells and purified. A vaccination trial was performed consisting of a test group (n = 8) immunised with recAgs (a mix of two recombinant antigens, Ssλ15 and the previously described Ssλ20∆B3) and a control group (n = 8) immunised with PBS. All analyses were performed with R Statistical Environment with α set at 0.050. The full-length open reading frame of the 1,821 nt cloned cDNA encodes a 64 kDa polypeptide, the sequence of which had 96 % identity with a hypothetical protein of S. scabiei. Ssλ15 was localised by immunostaining of skin sections in the tegument surrounding the mouthparts and the coxa in the legs of mites. Rabbit immunisation with recAgs induced high levels of specific IgG (P < 0.010) and increased levels of total IgEs. However, no significant clinical protection against S. scabiei challenge was detected. Unexpectedly, the group immunised with the recAgs mix had significantly higher lesion scores (P = 0.050) although lower mean mite densities than those observed in the control group. These results might indicate that the lesions in the recAgs group were due not only to the mites density but also to an exacerbated immunological response after challenge, which is in agreement with the specific high levels of pro-inflammatory cytokines (IL-1 and TNFα) detected after challenge in this group. The selected antigens delivered as recombinant proteins had no clinical protective efficacy against S. scabiei infestation although immunisation reduced mite density. However, these results pave the way for future studies on alternative production systems, adjuvants, delivery methods and combinations of antigens in order to manage stimulation of clinical protective immune responses. The online version of this article (doi:10.1186/s13071-016-1717-9) contains supplementary material, which is available to authorized users
Vaccination of rabbits with immunodominant antigens from Sarcoptes scabiei induced high levels of humoral responses and pro-inflammatory cytokines but confers limited protection
© 2016 The Author(s). Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.[EN]Background: Vaccination is an attractive ecological alternative to the use of acaricides for parasite control. However, effective anti-parasite vaccines against sarcoptic mange have not yet been developed. The purpose of this study was first to identify Sarcoptes scabiei immunodominant antigens and second to evaluate them as vaccine candidates in a rabbit/S. scabiei var. cuniculi model. Methods: The S. scabiei Ssλ15 immunodominant antigen was selected by immunoscreening of a S. scabiei var. hominis cDNA. The full-length cDNA was sequenced and cloned into the pGEX vector and the recombinant protein expressed in BL21 (DE3) cells and purified. A vaccination trial was performed consisting of a test group (n = 8) immunised with recAgs (a mix of two recombinant antigens, Ssλ15 and the previously described Ssλ20ΔB3) and a control group (n = 8) immunised with PBS. All analyses were performed with R Statistical Environment with α set at 0.050. Results: The full-length open reading frame of the 1,821 nt cloned cDNA encodes a 64 kDa polypeptide, the sequence of which had 96 % identity with a hypothetical protein of S. scabiei. Ssλ15 was localised by immunostaining of skin sections in the tegument surrounding the mouthparts and the coxa in the legs of mites. Rabbit immunisation with recAgs induced high levels of specific IgG (P < 0.010) and increased levels of total IgEs. However, no significant clinical protection against S. scabiei challenge was detected. Unexpectedly, the group immunised with the recAgs mix had significantly higher lesion scores (P = 0.050) although lower mean mite densities than those observed in the control group. These results might indicate that the lesions in the recAgs group were due not only to the mites density but also to an exacerbated immunological response after challenge, which is in agreement with the specific high levels of pro-inflammatory cytokines (IL-1 and TNFα) detected after challenge in this group. Conclusions: The selected antigens delivered as recombinant proteins had no clinical protective efficacy against S. scabiei infestation although immunisation reduced mite density. However, these results pave the way for future studies on alternative production systems, adjuvants, delivery methods and combinations of antigens in order to manage stimulation of clinical protective immune responses.SIThis work was partially funded by grant RTA11-00087-00-00 from the Spanish Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Fondo Europeo de Desarrollo Regional (FEDER), AGL2010-22200-C02-01 from Spanish Ministry (MINECO) and the Biotechnology and Biological Sciences Research Council (BBSRC) grant BBS/E/I/00002014
Medición de impedancia eléctrica en tejido biológico – revisión
El siguiente trabajo presenta una revisión de las propiedades eléctricas de los tejidos biológicos. Los tópicos incluidos en el trabajo son el estudio, caracterización y técnicas de medición. Se aborda el tema de las propiedades de conductividad (σ) y permitividad (ε) eléctrica de los tejidos y los modelos creados para su estimación y aproximación. Se presentan las características de los elementos de medición, ventajas y desventajas de los diferentes métodos creados y sus aplicaciones. Se mencionan algunos de los tipos de señales más utilizadas en cuanto a corriente y frecuencia de aplicación. Finalmente se presentan algunas recomendaciones a tener en cuenta al momento de realizar mediciones in vivo, para disminuir los errores debido a las múltiples fuentes fisiológicas. Esta revisión permitió obtener los lineamientos y condiciones de un trabajo de medición de impedancia de fémur que se encuentra en desarrollo.This paper presents a review of the electrical properties of biological tissues regarding their study, characterization, and measurement techniques. Electrical conductivity (σ) and permittivity (ε) property of tissues, and models developed for their estimation and approximation are mentioned. Measurement elements, advantages and disadvantages of different methods and their applications are presented. Some types of signals used in terms of current and frequency of application are described. Finally, some recommendations to consider for measurements in vivo to reduce errors produced by multiple physiological sources are done. This review permitted to obtain guidelines and conditions for impedance measurement work of femur, which one is doing
Fracturas de estrés en la infancia
Aportamos 13 casos de fracturas de estrés diagnosticadas en nuestro centro en los
últimos 5 años ocurridas en niños entre 4 y 15 años de edad. Encontramos una mayor incidencia
en el sexo masculino (9 de los 13 casos), así como un claro predominio de la localización en el tercio
proximal de la diáfisis tibial (7 casos), hallazgos que concuerdan con los referidos en la literatura.
Uno de los aspectos más interesantes de este tipo de fracturas es su similitud tanto clínica
como radiológica con procesos de origen infeccioso y neoplásico, por lo que la realización de un
correcto diagnóstico diferencial, apoyado en las radiografías simples, tomografías, gammagrafía,
TAC y, más recientemente, RMN, resulta crucial.We present 13 cases of stress fractures in children, collected in our center during
the last 5 years. The age of patients ranged from 4 to 15 years old. In agreement with literature,
we found a greater incidence on males (9 of 13 cases), and a predominant location on the proximal
shaft of the tibia (7 cases). One of the most interesting aspects of this type of fractures is their
clinical and radiological similarity with infections and tumors. Therefore, it is essential to achieve
a right diagnosis based on standard radiographs, tomography, radionuclide bone scan, CT-scan
and, most recently, MRI
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