Quiz Games as a model for Information Hiding

We present a general computation model inspired in the notion of information hiding in software engineering. This model has the form of a game which we call quiz game. It allows in a uniform way to prove exponential lower bounds for several complexity problems of elimination theory.Comment: 46 pages, to appear in Journal of Complexit

Conceptual Maps: A Resource for the Supported Learning in Technologies

Se describen las características fundamentales de los mapas conceptuales, se resalta su importancia como instrumento para la organización y sistematización de ideas y conocimientos y se ofrecen propuestas para su elaboración, especialmente vinculándolos al diseño y producción de materiales didácticos que sirvan de apoyo a diferentes modalidades de aprendizaje apoyadas en las tecnologías de la información y la comunicación.This paper describes the fundamental characteristics of conceptual maps, highlights its importance as an instrument for organization and sistematization of ideas and knowledge, and makes proposals for its construction, specially in connection with the design and production of educational stuff aimed at several information-technology supported learning modalities

Cytogenetic characterization of “Donax trunculus” (Bivalvia: Donacidae) by means of karyotyping, fluorochrome banding and fluorescent “in situ” hybridization

[Abstract]: The chromosomes of “Donax trunculus” were analysed by means of Giemsa staining, chromomycin A3 (CA3), DAPI and fluorescent “in situ” hybridization (FISH) with an 18S-5.8S-28S rDNA probe. The diploid number is 38 chromosomes and the karyotype consists of nine pairs of metacentric chromosomes, two pairs of submetacentric-metacentric, seven pairs of submetacentric and one pair of telocentric chromosomes. CA3-positive bands are located on eight chromosome pairs and DAPI treatment resulted in uniform staining. Major ribosomal clusters 18S-5.8S-28S are located on the short arm of one submetacentric chromosome pair.Xunta de Galicia; XUGA 10306B9

Genetic divergence detected by ISSR markers and characterization of microsatellite regions in "Mytilus" mussels

[Abstract] The wide distribution of microsatellites in mussels of the Mytilus edulis complex (Mytilidae) enables the analysis of inter-simple-sequence repeat (ISSR) markers. The aim of this investigation was to assess genetic differentiation in six sampling localities distributed along the European Atlantic coast to expose the potential of these markers in genetic studies requiring the detection of low polymorphism and as a source of sequences for developing microsatellite markers. We detected low genetic structuring within each member of the Mytilus edulis complex. Nei and Li distances and AMOVA clustered the individuals studied into two groups. On the basis of these results two sampling localities coming from the M. edulis × M. galloprovincialis mosaic hybrid zone in Western Europe were assigned to one species. On the other hand, mussels of a sampling locality in the Baltic Sea were not significantly different from a pure M. edulis locality supporting an extensive introgression of M. edulis in these individuals. Finally, 148 microsatellites were found in the sequences of 51 ISSR markers, and two polymorphic microsatellite markers were developed.Xunta de Galicia; PGIDT10PX110304P

Discerning the interactions between environmental parameters reflected in d13C and d18O of recent fluvial tufas: Lessons from a Mediterranean climate region

d13C and d18O of recent, continuous tufa records, obtained during a monitoring period spanning 3 to 13 years, are compared with the corresponding, known environmental conditions. Three rivers in NE Iberia (located along a 200-km N–S transect) are used for this comparison. The isotopic variations through space and time are discussed in terms of the environmental and geological parameters that operate on different scales, focusing on discerning the interactions between these parameters and providing examples of possible misinterpretation of climatic conditions, which is important to past climate studies based on isotopic data. The calculation of the actual isotopic fractionation coefficients, and the comparison with the literature-derived coefficients, demonstrates that the studied tufa formation was close to isotopic equilibrium to reflect the water temperature. The difference between mean measured water temperature (Tw) and mean calculated Tw (based on d18Ocalcite and measured d18Owater) is less than 2.7 °C. Tendencies of these calculated Tw are similar to the regional air temperature (Tair) tendencies through time, in particular in the case of the 13-year record, although certain deviations exist over shorter time spans. The best agreement between measured and calculated Tw and between d18Ocalcite-based Tw tendencies and Tair tendencies corresponds to the tufa stromatolite facies. Differences between the d18Ocalcite records of the three rivers cannot be attributed to temperature changes, but to the varying influences of groundwater inputs and isotopic rainfall composition in each river.Without considering these parameters, d18Ocalcite-based Tw calculations yield inaccurate results when comparing the study sites. d13Ccalcite values do not exhibit distinct patterns over time, and d13Ccalcite variations are likely caused by local processes that do not reflect general environmental changes. These findings underscore the significance of accounting for both groundwater behaviour and rainfall stable isotope composition when interpreting climate parameters in carbonate systems, particularly when differences between the isotopic signatures of deposits exist in the same region

Presentación de las actividades que lleva a cabo el grupo ORIÓN de investigación del área de óptica de la Universidad de Extremadura

Per ser conseqüents amb la nostra línia de treball d'innovació en l’ensenyament de la física i amb la línia editorial d'aquesta revista, aquest article sobre els treballs d'innovació i investigació educativa del nostre grup Orión d’investigació, es presenta en forma de mapa conceptual. La millor manera de llegir-lo és, si es té instal·lat el CmapTools a l'ordinador, visitar el lloc Cmap Universitat d'Extremadura (Espanya) i entrar a la carpeta Investigaciones del Grupo Orión. Encara que d'una forma una mica més limitada (no es podran obrir els Post-its aclaridors que hi apareixen), també pot llegir-se anant a l'adreça web: <http://grupoorion.unex.es:8001> i entrant a la carpeta indicada. Per qualsevol d'aquests dos procediments s'arriba al mapa conceptual que apareix més endavant i que resumeix les activitats del nostre grup. En aquest mapa apareixen multitud de vincles que porten als resultats dels diferents treballs duts a terme.Para resultar consecuentes con nuestra línea de trabajo de Innovación en la Enseñanza de la Física y con la línea editorial de esta revista, este artículo sobre los trabajos de Innovación e Investigación Educativa de nuestro Grupo Orión de Investigación, se presenta en forma de Mapa Conceptual. La mejor forma de leerlo es, si se tiene instalado CmapTools en el ordenador, visitar el Sitio Cmap “Universidad de Extremadura (España)” y entrar en la carpeta “Investigaciones del Grupo Orión”. Aunque de una forma algo más limitada (no se podrán abrir los post-it aclaratorios que aparecen), también puede leerse yendo a la dirección Web: http://grupoorion.unex.es:8001 y entrando en la carpeta antes indicada. Por cualquiera de estos 2 procedimientos se llega al mapa conceptual que aparece más adelante y que resume las actividades de nuestro grupo. En dicho mapa aparecen multitud de vínculos que llevan a los resultados de los diferentes trabajos llevados a cabo

Detection of Triacetone Triperoxide in air combining SnO2 sensor e-nose enhanced with a kinetic model

In the domain of high-temperature semiconductor arrays for electronic noses (e-noses), Metal Oxide Sensors (MOS) have a pivotal role despite their non-linear response to chemical vapors. A prevalent approach to enhance the identification algorithm's performance involves implementing mathematical models during the MOS signal processing. However, certain models rely solely on mathematical goodness-of-fit, overlooking crucial features that render practical e-nose applications ineffective. This paper introduces a theoretical model for the qualitative analysis of MOS signals, focusing on two primary diffusion processes: analyte migration to the sensor's surface and the subsequent dispersion of some of these molecules within the MOS bulk. Additionally, this work discusses a model validation using an ad-hoc e-nose, built with SnO2 gas sensors, and six organic chemicals, detailing main data processing steps. Finally, disclosed results showcase a high success rate for Triacetone Triperoxide (TATP) identification, one of the most significant threats among homemade explosives (HME). The presented conclusions underscore the enhanced efficacy of the proposed signal model for e-nose vapors identification and its practical utility in strengthening pre-emptive HME identification to enhance public safety

SPHERES, J\"ulich's High-Flux Neutron Backscattering Spectrometer at FRM II

SPHERES (SPectrometer with High Energy RESolution) is a third-generation neutron backscattering spectrometer, located at the 20 MW German neutron source FRM II and operated by the Juelich Centre for Neutron Science. It offers an energy resolution (fwhm) better than 0.65 micro-eV, a dynamic range of +-31 micro-eV, and a signal-to-noise ratio of up to 1750:1.Comment: 12 pages, 7 figures, 2 tables. Supplemental material consists of 3 pages, 2 figures, 2 table