3,109 research outputs found
The history of a surface in a single laser shot: from ultrafast carriers excitation to plasma emission, fading, and beyond
Laser ablation is currently a powerful tool in a wide range of aplications, concerning from removing several atoms from a surface to mechanical drilling. Despite all this applications are described by complex physico-chemical processes, they have in common the absorption of laser light into energy which heats the matter. If certain temperature is achieved by the heated sample, it can vaporized and even emit light, and its emission spectrum can be recorded.
The development of ultrashort lasers have resulted in several advantages compared to laser with longer pulses, as the ablation dynamics processes can be separated in time.
In this dissertation femtosecond pum-probe microscopy and LIBS are combined to relate the morphological dynamics induced during laser ablation and its further evolution into plasma emission, and describe a complete history of a surface in a single laser shot
Shannon entropy and particle decays
We deploy Shannon's information entropy to the distribution of branching
fractions in a particle decay. This serves to quantify how important a given
new reported decay channel is, from the point of view of the information that
it adds to the already known ones. Because the entropy is additive, one can
subdivide the set of channels and discuss, for example, how much information
the discovery of a new decay branching would add; or subdivide the decay
distribution down to the level of individual quantum states (which can be
quickly counted by the phase space). We illustrate the concept with some
examples of experimentally known particle decay distributions.Comment: 12 pages, 18 plots; to appear in Nuclear Physics
Naufragio del buque «Isla de Hierro» en el puerto de Málaga
La Sentencia del Tribunal Supremo, Sala 3ª, Sección 6ª, de 9 de abril de 2002 (Ar. 3461, La Ley 5565), ponente Agustín Puente Prieto, resuelve un caso de responsabilidad patrimonial del Estado por el naufragio del buque "Isla de Hierro" tras tratar de esquivar dos pateras que se encontraban en la entrada del puerto de Málaga
Initiation codon selection is accomplished by a scanning mechanism without crucial initiation factors in sindbis virus subgenomic mRNA
Translation initiation of alphavirus subgenomic mRNA (sgmRNA) can occur in the absence of several initiation factors (eIFs) in infected cells; however, the precise translation mechanism is still poorly understood. In this study, we have examined the mechanism of initiation and AUG selection in Sindbis virus (SINV) sgmRNA. Our present findings suggest that sgmRNA is translated via a scanning mechanism, since the presence of a hairpin structure before the initiation codon hampers protein synthesis directed by this mRNA. In addition, translation is partially recovered when an in-frame AUG codon is placed upstream of this hairpin. This scanning process takes place without the participation of eIF4A and active eIF2. These results, combined with our findings through modifying the SINV sgmRNA leader sequence, do not support the possibility of a direct initiation from the start codon without previous scanning, or a shunting mechanism. Moreover, studies carried out with sgmRNAs containing two alternative AUG codons within a good context for translation reveal differences in AUG selection which are dependent on the cellular context and the phosphorylation state of eIF2α. Thus, initiation at the additional AUG is strictly dependent on active eIF2, whereas the genuine AUG codon can start translation following eIF2α inactivation. Collectively, our results suggest that SINV sgmRNA is translated by a scanning mechanism without the potential participation of crucial eIFs. A model is presented that explains the mechanism of initiation of mRNAs bearing two alternative initiation codonsThis work was supported by a DGICYT (Dirección General de Investigación Científica y Técnica. Ministerio de Economía y Competitividad, Spain) grant BFU2012-31861. M.G.-M. is holder of a FPI (Formación de Personal Investigador) fellowship. The Institutional Grant awarded to the Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM) by the Fundación Ramón Areces is acknowledge
A Viral mRNA Motif at the 3′-Untranslated Region that Confers Translatability in a Cell-Specific Manner. Implications for Virus Evolution
Sindbis virus (SINV) mRNAs contain several motifs that participate in the regulation of their translation. We have discovered a motif at the 3′ untranslated region (UTR) of viral mRNAs, constituted by three repeated sequences, which is involved in the translation of both SINV genomic and subgenomic mRNAs in insect, but not in mammalian cells. These data illustrate for the first time that an element present at the 3′-UTR confers translatability to mRNAs from an animal virus in a cell-specific manner. Sequences located at the beginning of the 5′-UTR may also regulate SINV subgenomic mRNA translation in both cell lines in a context of infection. Moreover, a replicon derived from Sleeping disease virus, an alphavirus that have no known arthropod vector for transmission, is much more efficient in insect cells when the repeated sequences from SINV are inserted at its 3′-UTR, due to the enhanced translatability of its mRNAs. Thus, these findings provide a clue to understand, at the molecular level, the evolution of alphaviruses and their host rangeThis work was supported by a DGICYT (Dirección General de Investigación Científica y Técnica. Ministerio de Economía y Competitividad, Spain) grant BFU2012-31861. The Institutional Grant awarded to the Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM) by the Fundación Ramón Areces is acknowledge
Halobacterium identification in saltworks of Gran Canaria (Canary Islands, Spain)
This work analyzes bacterial communities present in evaporation ponds of solar salterns of Gran Canaria and reveals specific organisms through molecular techniques. Solar salterns are protected areas in Canary Islands where salt is produced from sea water by solar and wind powered evaporation. Salt was an important product for ancient islanders who used it for a broad field of purposes, but also has a great importance in recent time for its implications in the island economy.Based on amplifications with specific primers for 16S ribosomal DNA (16S rDNA) and subsequent nested-PCR approaches, different amplicons were obtained, and analyzed in silico. A taxonomic classification was carried out through phylogenetic trees.Results revealed different bacteria according to the evaporation grade of crystallizer ponds in saline works. It is worthstanding the presence of the genus Halobacterium in all crystallizer ponds. This opens an interesting framework for further studies and continuative molecular characterization approaches of bacterial communities in solar salterns of Gran Canaria
Desarrollo e implementación de algoritmos para escalado de melodías flamencas
El estudio de las medidas de la similitud melódica es de vital importancia en los sistema de recuperación
de información musical. En este proyecto usamos técnicas de concordancia geométrica para medir la similitud entre dos melodías. Proponemos un algoritmo eficiente para un problema de optimización inspirado en la operación melódica del escalado lineal.
En el problema de escalado, una melodía de consulta es escalada hacia adelante hasta que la similitud
melódica entre la consulta y la referencia sea mínima. La métrica de similitud melódica utilizada es el área
comprendida entre dos contornos melódicos.Melodic similarity is of key importance in Music Information Retrieval. In this project, we use geometric
matching techniques to measure the similarity between two melodies. We propose an efficient algorithm for
an optimization problem inspired in the operation of linear scaling on melodies. In the scaling problem, an
incoming query melody is scaled forward until the similarity measure between the query and the reference
melody is minimized. The similarity measure used is the area between two melodic contours.Universidad de Sevilla. Grado en Ingeniería de Tecnologías Industriale
Programes 3D en l'aprenentatge de Cicles Formatius de la família de Tèxtil, confecció i pell. Estudi d'implementació i viabilitat
Les noves tecnologies cada cop estan més presents i treballar amb programes 3D de moda resultaria interessant i útil per l'alumnat dels cicles formatius de la família de Tèxtil, confecció i pell. L'objectiu d'aquest estudi és investigar l'ús de programes 3D de moda en aquests cicles formatius en centres catalans, i valorar l'interès i la viabilitat que podria tenir la incorporació d'aquest tipus de programes per a complementar l'aprenentatge en aquests cicles en els centres d'estudi. Es tracta d'un estudi quantitatiu transversal. Es va entrevistar a professorat i alumnat de dos centres catalans amb aquest tipus d'estudis, seleccionats per conveniència, mitjançant uns qüestionaris estructurats autoemplenats enviats per correu electrònic a través d'un enllaç. Els participants van manifestar tenir un interès i una necessitat en la implementació d'aquest tipus de programes, a més de considerar-la viable. A partir dels resultats obtinguts, es considera necessària i viable la implementació de programes 3D de tèxtil i moda en l'aprenentatge dels cicles formatius de la família de Tèxtil, confecció i pell. Altrament, es podria dur a terme en qualsevol dels grups d'aquests cicles, preferentment als graus superiors, assenyalant CLO 3D com a programa més adient
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