Symmetries in two-dimensional dilaton gravity with matter

The symmetries of generic 2D dilaton models of gravity with (and without) matter are studied in some detail. It is shown that $\delta_2$, one of the symmetries of the matterless models, can be generalized to the case where matter fields of any kind are present. The general (classical) solution for some of these models, in particular those coupled to chiral matter, which generalizes the Vaidya solution of Einstein Gravity, is also given.Comment: Minor changes have been made; the references have been updated and some added; 11 pages. To appear in Phys. Rev.

Pseudogenes as an alternative source of natural antisense transcripts

<p>Abstract</p> <p>Background</p> <p>Naturally occurring antisense transcripts (NATs) are non-coding RNAs that may regulate the activity of sense transcripts to which they bind because of complementarity. NATs that are not located in the gene they regulate (trans-NATs) have better chances to evolve than cis-NATs, which is evident when the sense strand of the cis-NAT is part of a protein coding gene. However, the generation of a trans-NAT requires the formation of a relatively large region of complementarity to the gene it regulates.</p> <p>Results</p> <p>Pseudogene formation may be one evolutionary mechanism that generates trans-NATs to the parental gene. For example, this could occur if the parental gene is regulated by a cis-NAT that is copied as a trans-NAT in the pseudogene. To support this we identified human pseudogenes with a trans-NAT to the parental gene in their antisense strand by analysis of the database of expressed sequence tags (ESTs). We found that the mutations that appeared in these trans-NATs after the pseudogene formation do not show the flat distribution that would be expected in a non functional transcript. Instead, we found higher similarity to the parental gene in a region nearby the 3' end of the trans-NATs.</p> <p>Conclusions</p> <p>Our results do not imply a functional relation of the trans-NAT arising from pseudogenes over their respective parental genes but add evidence for it and stress the importance of duplication mechanisms of genetic material in the generation of non-coding RNAs. We also provide a plausible explanation for the large transcripts that can be found in the antisense strand of some pseudogenes.</p

Identification of novel stem cell markers using gap analysis of gene expression data

A method for the detection of marker genes in large heterogeneous collections of gene expression data is described and applied to DNA microarray data generated from 83 mouse stem cell-related samples

El proceso de adaptación de las empresas de transporte internacional por carretera al transporte marítimo de corta distancia

Las empresas de transporte internacional por carretera se configuran como uno de los actores clave en el desarrollo del transporte marítimo de corta distancia. Si su deseo es operar de manera estable, utilizando la opción más eficiente –el transpor- te no acompañado– deben modificar su perfil con el propósito de obtener la máxima rentabilidad. El objetivo de este trabajo reside en analizar este proceso de cambio a partir del estudio de cinco empresas de transporte internacional por carretera que han desarrollado dicha adaptación para convertirse en operadores logísticos multi- modales. Los resultados de la investigación muestran cuatro áreas de cambio clave: reestructuración de la flota, reestructuración de la plantilla de conductores, cambios en el modelo de negocio y establecimiento de una estructura en el país de destinoInternational road haulage companies are seen to be one of the key players in the development of short-distance maritime transport. If they wish to operate in a stable manner, by using the most efficient option – unaccompanied transport – they must modify their profile with the aim of obtaining the greatest cost-effectiveness. The aim of this work is to analyse this process of change by studying five international road haulage companies that have undertaken such an adaptation in order to become multimodal logistics operators. The findings of the research show four key areas of change: restructuring of the fleet, restructuring of the workforce of drivers, changes in the business model, and setting up a structure in the destination countr

Blockade of the Interaction of Calcineurin with FOXO in Astrocytes Protects Against Amyloid-βInduced Neuronal Death

Astrocytes actively participate in neuro-inflammatory processes associated to Alzheimer’s disease (AD), and other brain pathologies. We recently showed that an astrocyte-specific intracellular signaling pathway involving an interaction of the phosphatase calcineurin with the transcription factor FOXO3 is a major driver in AD associated pathological inflammation, suggesting a potential new druggable target for this devastating disease. We have now developed decoy molecules to interfere with calcineurin/FOXO3 interactions, and tested them in astrocytes and neuronal co-cultures exposed to amyloid-β (Aβ) toxicity. We observed that interference of calcineurin/FOXO3 interactions exerts a protective action against A-induced neuronal death and favors the production of a set of growth factors that we hypothesize form part of a cytoprotective pathway to resolve inflammation. Furthermore, interference of the A-induced interaction of calcineurin with FOXO3 by decoy compounds significantly decreased amyloid-β protein precursor (AβPP) synthesis, reduced the AβPP amyloidogenic pathway, resulting in lower Alevels, and blocked the expression of pro-inflammatory cytokines TNFα and IL-6 in astrocytes. Collectively, these data indicate that interrupting pro-inflammatory calcineurin/FOXO3 interactions in astrocytes triggered by Aβ accumulation in brain may constitute an effective new therapeutic approach in AD. Future studies with intranasal delivery, or brain barrier permeable decoy compounds, are warranted

On The Reduced Canonical Quantization Of The Induced 2D-Gravity

The quantization of the induced 2d-gravity on a compact spatial section is carried out in three different ways. In the three approaches the supermomentum constraint is solved at the classical level but they differ in the way the hamiltonian constraint is imposed. We compare these approaches establishing an isomorphism between the resulting Hilbert spaces.Comment: 17 pages, plain LaTeX. FTUV/93-15, IFIC/93-10, Imperial-TP/93-94/1

Transporte marítimo de corta distancia entre España e Italia: perfil de las empresas usuarias

El Transporte Marítimo de Corta Distancia (TMCD) ha sido catalogado por la Comisión Europea como el único modo de transporte que ofrece posibilidades reales de lograr un transvase de carga desde la carretera, mejorando además la competitividad y reduciendo los costes ambientales. En los últimos años se han llevado a cabo diversos estudios donde se han tratado de identificar líneas de TMCD con un potencial de futuro importante. Sin embargo, no se han abordado trabajos donde se evalúe el perfil de las empresas de transporte internacional por carretera que hacen uso de esta modalidad de transporte. Con el propósito de cubrir este déficit, en el presente trabajo se procede, sobre una muestra de 81 empresas de transporte internacional por carretera (41 españolas, 3 portuguesas y 37 italianas) que hacen uso de las líneas de TMCD entre España e Italia, a delimitar el perfil de dichas empresas, a la vez que a analizar ciertos elementos inherentes a la relación que mantienen con las navieras con las que trabaja

Amplification of the Gene Ontology annotation of Affymetrix probe sets

BACKGROUND: The annotations of Affymetrix DNA microarray probe sets with Gene Ontology terms are carefully selected for correctness. This results in very accurate but incomplete annotations which is not always desirable for microarray experiment evaluation. RESULTS: Here we present a protocol to amplify the set of Gene Ontology annotations associated to Affymetrix DNA microarray probe sets using information from related databases. CONCLUSION: Predicted novel annotations and the evidence producing them can be accessed at Probe2GO: . Scripts are available on demand