3,105 research outputs found
Theiler's murine encephalomyelitis virus-binding activity on neural and non-neural cell lines and tissues
Three categories of cell lines are described with respect to their activity in binding Theiler's murine encephalomyelitis virus (TMEV). High, medium and low densities of viral receptors can be detected on cell lines from different species and origins by using an immunological binding assay. Nevertheless, TMEV acts as a fastidious virus that only infects a few cell types productively. No correlation between virion binding and degree of permissiveness to infection could be detected. The presence of viral receptors in both susceptible and resistant strains of mice seemed to have a widespread tissue distribution, the thymus being an exception. When primary cerebral cultures, enriched in neurons, astrocytes or oligodendrocytes, were checked in the immunological assay, a higher density of viral receptors was detected in the neuronal population. The number of virus-binding sites in the BHK-21 cell line is reported here to be 5 x 103 per cell; approximately 15 x 103 and 2.5 x 103 are the estimates of binding sites per cultured neuron and macroglial cell, respectively.Peer Reviewe
Coastal zones and cities: relations between different territories in Las Palmas de Gran Canaria
El comienzo del siglo XXI constituye una etapa con profundas transformaciones en
el espacio urbano situado en el litoral de Las Palmas de Gran Canaria. En este entorno
costero se han producido múltiples acontecimientos sociales y económicos a lo largo del
siglo XX. Desde la ciencia geográfica se observan con gran interés estos aspectos del
funcionamiento de la ciudad, dadas sus implicaciones medioambientales, demográficas,
económicas y culturales. Se analiza la aparición de un nuevo territorio, a través de la
figura de los grandes proyectos urbanos y la planificación pública. En este discurso,
se valora la experiencia de esta ciudad en las estrategias de rehabilitación del espacio
urbano y el litoral.Le commencement du XXIéme siècle est une période des profundes transformatiòns
dans l’espace urbain situé dans le littoral de Las Palmas de Gran Canaria. Dans etendroit
de la cóte il se sont produit beancoup de phínomènes sociaux et économiquest out au long
du XXéme siècle. Dès la science de la géographie, on observe, avec beancoup d’intérêt ces
phénomines du fonctionnement de la cité, ses conséquences écologiques, démographiques,
économiques et culturelles. On analyse l’áparítion d’un nouveau territoire grâce à la figure
des grands proyects urbains et grâce, aussi, à la planification publique. Dans ce discours
on évalue l’expérience de cette cité en ce gui concerne aux stratégies dé réhabilitation de
l’espace urbain et du littoral
Coordinación sectorial y urbanística. Luces y sombras
El artículo aborda la problemática entre las determinaciones sectoriales con incidencia territorial y el marco urbanístico municipal. La prevalencia de lo sectorial sobre lo urbanístico se pone de manifiesto en el caso concreto de las infraestructuras públicas de comunicación y, en general, en la ordenación de las obras públicas de interés general o de interés autonómico.The article addresses the problem between sectoral determinations with territorial incidence and the municipal urban framework. The prevalence of the sectoral over the urban is evident in the specific case of public communication infrastructures and, in general, in the management of public works of general interest or of regional interest
Medios y soportes alternativos para una publicidad convencional: publicidad «off the line»
En el presente artículo se intenta realizar una reflexión sobre la aparición de nuevos medios para la difusión de mensajes publicitarios. Unos medios que, por otro lado, no pueden ser incluidos en la catalogación below the line o above the line y, después de la realización de esta trabajo, hemos considerado oportuno catalogarlos como off the line. Desde este punto de vista, se realizó una búsqueda de estos nuevos medios y se analizaron los anunciantes que se valían de estas vías «alternativas» de difusión de los mensajes, intentando establecer una relación entre medios y mensajes alternativos.In this paper we try to explain the reasons for the new advertising media growth. New advertising media can not be included within the concepts of media «below the line» or «above the line». After our research we concluded that we can name it like media «off the line». Keeping that in mind, we look for examples of new medias and try to establish the relation «advertiser–media». We are willing to know if alternative advertisements use alternative medias
Cálculo de la corrección topográfica a las observaciones gravimétricas en la Caldera del Teide obtenidas a partir del modelo topográfico digital de la Isla de Tenerife
Como se expuso en otra comunicación, se ha desarrollado un modelo digital topográfico de la Isla de Tenerife, una de cuyas aplicaciones es el cálculo de la corrección topográfica de las observaciones grav~métricas efectuadas en la Caldera del Teide y en zonas próximas. El método clásico, que utiliza ábacos a cuyos compartimentos deben asignarse altitudes medias a partir de la cartografía existente, resulta enormemente lento, penoso y no exento de posibles errores personales. Para obtener mayor precisión el modelo d í gí t al de la Isla obtenido a partir del 50.000 del Servicio Geográfico del Ejército, se ha suplementado en la zona de la Caldera con el 25.000 de dicha zona. Se presenta en esta comunicación el método y los resultados obtenidos, para la corrección topográfica, y la comparación de dichos resultados con los que se calculan a partir de emplear el método de Hammer en la primera campaña de observación. Como conclusión podemos decir que las anomalías obtenidas a partir del calculo automático, basado en el modelo digital, son del mismo orden de magnitud que las que se obtuvieron por el método del ábaco pero con la enorme ventaja de ganancia en tiempo y disminución de errores personale
Las variaciones periódicas de la gravedad observadas en el túnel volcánico de la Cueva de los Verdes (Lanzarote)
En el marco de los proyectos de investigación que sobre Mareas Terrestres y Geodinámica en las Islas Canarias desarrolla el Instituto de Astronomía y Geodesia, se ha instalado en el interior del túnel volcánico del Volcán de la Corona en Lanzarote, en la zona llamada Cueva de los Verdes, una estación Geodinámica. Uno de los sensores,ya en funcionamiento desde mayo de 1987, es un gravimetro LaCoste Romberg mod. G modificado como instrumento de masa estática (Van Ruymbeke, 1985) con registro continuo, sobre sistema analógico, de las variaciones de la gravedad. En este trabajo se presentan los primeros resultados obtenidos y se discuten dichos resúltados teniendo en cuenta las singularidades de Lanzarote, isla con volcanismo reciente, con fuertes anomalías térmicas, con corteza no continental, etc. y del lugar de emplazamiento de la estación a menos de 3 km de la costa y por consiguiente con una importante infuencia oceánica
Genomic insights into drug resistance and virulence platforms, CRISPR-Cas systems and phylogeny of commensal E. Coli from wildlife
Commensal bacteria act as important reservoirs of virulence and resistance genes. However, existing data are generally only focused on the analysis of human or human-related bacterial populations. There is a lack of genomic studies regarding commensal bacteria from hosts less exposed to antibiotics and other selective forces due to human activities, such as wildlife. In the present study, the genomes of thirty-eight E. coli strains from the gut of various wild animals were sequenced. The analysis of their accessory genome yielded a better understanding of the role of the mobilome on inter-bacterial dissemination of mosaic virulence and resistance plasmids. The study of the presence and composition of the CRISPR/Cas systems in E. coli from wild animals showed some viral and plasmid sequences among the spacers, as well as the relationship between CRISPR/Cas and E. coli phylogeny. Further, we constructed a single nucleotide polymorphisms-based core tree with E. coli strains from different sources (humans, livestock, food and extraintestinal environments). Bacteria from humans or highly human-influenced settings exhibit similar genetic patterns in CRISPR-Cas systems, plasmids or virulence/resistance genes-carrying modules. These observations, together with the absence of significant genetic changes in their core genome, suggest an ongoing flow of both mobile elements and E. coli lineages between human and natural ecosystems.Funding: This work was partially supported by project SAF2016-76571-R and PID2019-106158RB-I00 from the Agencia Estatal de Investigación (AEI) of Spain and the Fondo Europeo de Desarrollo Regional (FEDER) of EU. During the experimental work of this study, Carla Andrea Alonso Alonso
had a predoctoral fellowship FPI from MINECO
Genes for asparagine metabolism in Lotus japonicus : differential expression and interconnection with photorespiration
Background:
Asparagine is a very important nitrogen transport and storage compound in plants due to its high
nitrogen/carbon ratio and stability. Asparagine intracellu
lar concentration depends on a balance between asparagine
biosynthesis and degradation. The main enzymes involved in
asparagine metabolism are as
paragine synthetase (ASN),
asparaginase (NSE) and serine-glyoxylate aminotransfera
se (SGAT). The study of the genes encoding for these enzymes
in the model legume
Lotus japonicus
is of particular interest since it has been proposed that asparagine is the principal
molecule used to transport reduced nitrogen within the plant in most temperate legumes.
Results:
A differential expression of genes encoding for seve
ral enzymes involved in asparagine metabolism was
detected in
L. japonicus
. ASN is encoded by three genes,
LjASN1
was the most highly expressed in mature leaves while
LjASN2
expression was negligible and
LjASN3
showed a low expression in this organ, suggesting that
LjASN1
is the main
gene responsible for asparagine synthesis in mature leaves. In young leaves,
LjASN3
was the only ASN gene expressed
although at low levels, while all the three genes encoding for NSE were highly expressed, especially
LjNSE1
.Innodules,
LjASN2
and
LjNSE2
were the most highly expressed genes, suggesting an important role for these genes in this organ.
Several lines of evidence support the connection between asparagine metabolic genes and photorespiration in
L.
japonicus
: a) a mutant plant deficient in
LjNSE1
showed a dramatic decrease in the expression of the two genes
encoding for SGAT; b) expression of the genes involved in asparagine metabolism is altered in a photorespiratory
mutant lacking plastidic glutamine synthetase; c) a clustering analysis indicated a similar pattern of expression among
several genes involved in photorespiratory and asparagine metabolism, indicating a clear link between
LjASN1
and
LjSGAT
genes and photorespiration.
Conclusions:
The results obtained in this paper indicate the exis
tence of a differential expression of asparagine
metabolic genes in
L. japonicus
and point out the crucial relevance of particular genes in different organs.
Moreover, the data presented establish clear links betw
een asparagine and photorespiratory metabolic genes in
this plant.Junta de Andalucía (P10-CVI- 6368)FEDER-Ministerio de Economía y Competitividad (AGL 2014 – 54413-R
EphA2-induced angiogenesis in ewing sarcoma cells works through bFGF production and is dependent on Caveolin-1
This is an open-access article distributed under the terms of the Creative Commons Attribution License.-- et al.Angiogenesis is the result of the combined activity of the tumor microenvironment and signaling molecules. The angiogenic switch is represented as an imbalance between pro- and anti-angiogenic factors and is a rate-limiting step in the development of tumors. Eph receptor tyrosine kinases and their membrane-anchored ligands, known as ephrins, constitute the largest receptor tyrosine kinase (RTK) subfamily and are considered a major family of pro-angiogenic RTKs. Ewing sarcoma (EWS) is a highly aggressive bone and soft tissue tumor affecting children and young adults. As other solid tumors, EWS are reliant on a functional vascular network for the delivery of nutrients and oxygen and for the removal of waste. Based on the biological roles of EphA2 in promoting angiogenesis, we explored the functional role of this receptor and its relationship with caveolin-1 (CAV1) in EWS angiogenesis. We demonstrated that lack of CAV1 results in a significant reduction in micro vascular density (MVD) on 3 different in vivo models. In vitro, this phenomenon correlated with inactivation of EphA2 receptor, lack of AKT response and downregulation of bFGF. We also demonstrated that secreted bFGF from EWS cells acted as chemoattractant for endothelial cells. Furthermore, interaction between EphA2 and CAV1 was necessary for the right localization and signaling of the receptor to produce bFGF through AKT and promote migration of endothelial cells. Finally, introduction of a dominant-negative form of EphA2 into EWS cells mostly reproduced the effects occurred by CAV1 silencing, strongly suggesting that the axis EphA2-CAV1 participates in the promotion of endothelial cell migration toward the tumors favoring EWS angiogenesis.This work was funded by the Fondo de Investigaciones Sanitarias-ISCIII-FEDER (CP06/00151; PI080259; PI110038; PI110018; RD09/0076/00028; RD06/0020/0059; RD06/0020/1038). LLT is funded by the Comissionat per a Universitats i Recerca (CUR) from Departament d’Innovació, Universitats i Empresa (DIUE) de la Generalitat de Catalunya i del Fons Social Europeu.Peer Reviewe
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