The Two-Dimensional Stringy Black-Hole: A New Approach and a Pathology

The string propagation in the two-dimensional stringy black-hole is investigated from a new approach. We completely solve the classical and quantum string dynamics in the lorentzian and euclidean regimes. In the lorentzian case all the physics reduces to a massless scalar particle described by a Klein-Gordon type equation with a singular effective potential. The scattering matrix is found and it reproduces the results obtained by coset CFT techniques. It factorizes into two pieces : an elastic coulombian amplitude and an absorption part. In both parts, an infinite sequence of imaginary poles in the energy appear. The generic features of string propagation in curved D-dimensional backgrounds (string stretching, fall into spacetime singularities) are analyzed in the present case. A new physical phenomenon specific to the present black-hole is found : the quantum renormalization of the speed of light. We find c_{quantum} = \sqrt{{k\o{k-2}}}~c_{classical}, where $k$ is the integer in front of the WZW action. This feature is, however, a pathology. Only for $k \to \infty$ the pathology disappears (although the conformal anomaly is present). We analyze all the classical euclidean string solutions and exactly compute the quantum partition function. No critical Hagedorn temperature appears here.Comment: 32 pages, uses phyzz

Antagonistic effect of Trichoderma harzianum VSL291 on phytopathogenic fungi isolated from cocoa (Theobroma cacao L.) fruits

In this study we evaluated the antagonism in vitro of Trichoderma harzianum strain VSL291 against 18 pathogens of cocoa fruits in dual culture. T. harzianum VSL291 inhibited the growth of the phytopathogenic fungi tested between 10.54 and 85.43%. The mycoparasitism of Moniliophthora roreri by T. harzianum VSL291 was studied by light and scanning electron microscopy. T. harzianum VSL291 hyphae grew in parallel with the hyphae of M. roreri and in some places these were united with the hyphae of the cocoa pathogen through small structures like apresorious that tangled in the pathogenic fungus preventing its growth. T. harzianum VSL291 produced lytic enzymes: β-1,3-glucanases, chitinases, proteases, xylanases and lipases, when grown in minimal medium, with fungal cell walls as the sole carbon source. The highest proteolytic activities detected in T. harzianum VSL291 broth with M. roreri, Penicillium expansum and Byssochlamys spectabilis cell walls appear to be associated with increased activities of β-1,3 glucanases, chitinases, lipases, proteases and xylanases and biocontrol index derived from the experiments of confrontation. These results suggest that proteolytic enzymes according to their degree of induction could participate in the antagonistic effect of T. harzianum VSL291 against the fungi tested.Key words: Antagonism, Trichoderma harzianum, mycoparasitism, phytopathogenic fung

Formación docente : un ámbito de encuentro entre la educación formal y la educación no formal

Los propósitos que dieron marco a la propuesta se vincularon con: El fortalecimiento de los procesos educativos en el sistema Formal, a partir de la gestión de proyectos interinstitucionales ; El reconocimiento de la Alfabetización Científica como instancia democratizadora del conocimiento lo cual permite enlazar el mundo de la ciencia con prácticas, hábitos, lenguajes y producciones sociales ; El desarrollo de estrategias didácticas que orientan hacia la problematización y complejización de los contenidos curriculares. Se utilizó una metodología cualitativa con organización de colectivos docentes. Las conclusiones obtenidas nos permiten manifestar que este trabajo de articulación es altamente significativo; si bien se requiere extender el período de colectivo para fortalecer el intercambio de los diferentes actores y lograr mejores resultados

Searching for galactic sources in the Swift GRB catalog

Since the early 1990s Gamma Ray Bursts have been accepted to be of extra-galactic origin due to the isotropic distribution observed by BATSE and the redshifts observed via absorption line spectroscopy. Nevertheless, upon further examination at least one case turned out to be of galactic origin. This particular event presented a Fast Rise, Exponential Decay (FRED) structure which leads us to believe that other FRED sources might also be Galactic. This study was set out to estimate the most probable degree of contamination by galactic sources that certain samples of FREDs have. In order to quantify the degree of anisotropy the average dipolar and quadripolar moments of each sample of GRBs with respect to the galactic plane were calculated. This was then compared to the probability distribution of simulated samples comprised of a combination of isotropically generated sources and galactic sources. We observe that the dipolar and quadripolar moments of the selected subsamples of FREDs are found more than two standard deviations outside those of random isotropically generated samples.The most probable degree of contamination by galactic sources for the FRED GRBs of the Swift catalog detected until February 2011 that do not have a known redshift is about 21 out of 77 sources which is roughly equal to 27%. Furthermore we observe, that by removing from this sample those bursts that may have any type of indirect redshift indicator and multiple peaks gives the most probable contamination increases up to 34% (17 out of 49 sources). It is probable that a high degree of contamination by galactic sources occurs among the single peak FREDs observed by Swift.Comment: Published to A&A, 4 pages, 5 figures, this arXiv version includes appended table with all the bursts considered in this stud

Performance optimization in switched reluctance motor drives

In this paper, switched reluctance motors (SRM) are proposed as an alternative for electric power assisted steering (EPAS) applications. A prototype machine has been developed as very attractive design for a steering electric motor, both from a cost and size perspective. A fourphase 8/6 SRM drive is designed for a rack type EPAS which should provide a maximum force of 10 kN. Two-dimension finite element analysis is used to validate the design

Biotecnología microbiana para la agricultura en Producción Integrada: Buscando nuevos biofertilizantes para patata

Póster presentado en la Feria del Sector Agropecuario Salamaq 14N

Strategies for proteomic analysis of blood glycated proteins

Comunicaciones a congreso

Assessing the existence of a semantic space to express action tendencies

[EN] There is an abundance of literature showing that action tendencies measure can help in improving prediction of people final behaviour in different fields. Applying action tendencies in combination with differential semantics could be useful in understanding the relationship between product design and people final decision making. In this regard, a questionnaire including a reduced set of action tendencies would be desirable. The present research applies differential semantics to assess the existence of a semantic space of action tendencies people use to express their intention to react. One hundred volunteers reported to which extent 19 images prompted them to react in 37 different ways. They also selected the emotion and meaning they most associated to each image. Results show that there exists a semantic space with 11 axis people use to express their intention to react. The semantic space is little sensitive to the sample of people in the experiment. The observed relationship of semantic axes with emotions and meanings, and the comparison of the resulted axis with previous literature, evidence that they correspond to action tendencies.Alcantara, E.; Ruescas-Nicolau, M.; Artacho Ramírez, MÁ.; Sánchez-Sánchez, ML.; Dueñas, L. (2022). Assessing the existence of a semantic space to express action tendencies. International Journal of Industrial Ergonomics. 90:1-15. https://doi.org/10.1016/j.ergon.2022.1033171159