Logspace self-reducibility

A definition of self-reducibility is proposed to deal with logarithmic space complexity classes. A general property derived from the definition is used to prove known results comparing uniform and nonuniform complexity classes below polynomial time, and to obtain novel ones regarding nondeterministic nonuniform classes and reducibility to context-free languages.Peer ReviewedPostprint (published version

Objective novelty of association rules: measuring the confidence boost

On sait bien que la confiance des régles d’association n’est pas vraiment satisfaisant comme mésure d’interêt. Nous proposons, au lieu de la substituer par des autres mésures (soit, en l’employant de façon conjointe a des autres mésures), évaluer la nouveauté de chaque régle par comparaison de sa confiance par rapport á des régles plus fortes qu’on trouve au même ensemble de données. C’est á dire, on considère un seuil “relative” de confiance au lieu du seuil absolute habituel. Cette idée se précise avec la magnitude du “confidence boost”, mésurant l’increment rélative de confiance prés des régles plus fortes. Nous prouvons que nôtre proposte peut remplacer la “confidence width” et le blockage de régles employés a des publications précedentes.Postprint (author’s final draft

Learning definite Horn formulas from closure queries

A definite Horn theory is a set of n-dimensional Boolean vectors whose characteristic function is expressible as a definite Horn formula, that is, as conjunction of definite Horn clauses. The class of definite Horn theories is known to be learnable under different query learning settings, such as learning from membership and equivalence queries or learning from entailment. We propose yet a different type of query: the closure query. Closure queries are a natural extension of membership queries and also a variant, appropriate in the context of definite Horn formulas, of the so-called correction queries. We present an algorithm that learns conjunctions of definite Horn clauses in polynomial time, using closure and equivalence queries, and show how it relates to the canonical Guigues–Duquenne basis for implicational systems. We also show how the different query models mentioned relate to each other by either showing full-fledged reductions by means of query simulation (where possible), or by showing their connections in the context of particular algorithms that use them for learning definite Horn formulas.Peer ReviewedPostprint (author's final draft

Bacillus galliciensis sp. nov., isolated from faeces of wild seahorses (Hippocampus guttulatus)

4 páginas, 1 figura, 1 tablaA Gram-positive-staining, motile, rod-shaped, endospore-forming bacterium (BFLP-1T) was isolated from faeces of wild long-snouted seahorses (Hippocampus guttulatus) captured in northwest Spain (Toralla, Galicia). Strain BFLP-1T grew at 10–30 6C and pH 5.5–9 (optimally at 20 6C and pH 7.2) and with 0–7% (w/v) NaCl (optimally with 2% NaCl). The G+C content of the DNA was 48.1 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain BFLP-1T was a member of the genus Bacillus and was most closely related to Bacillus herbersteinensis D-1,5aT (96.6 %), B. shackletonii LMG 18435T (96.0 %) and B. isabeliae CVS-8T (95.9 %). Chemotaxonomic data (peptidoglycan type, meso-diaminopimelic acid; major menaquinone, MK-7; predominant fatty acids, anteiso-C15 : 0, anteiso-C17 : 0 and C16 : 1v11c; major polar lipids, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unknown aminoglycophospholipid) supported the affiliation of strain BFLP-1T to the genus Bacillus. Comparative analysis of 16S rRNA gene sequences and chemotaxonomic and phenotypic features indicated that strain BFLP-1T represents a novel species within the genus Bacillus, for which the name Bacillus galliciensis sp. nov. is proposed. The type strain is BFLP-1T (5DSM 21539T 5LMG 24668T).This study was financed by the Spanish Ministry of Science and Technology (Hippocampus CGL2005-05927-C03-01). J.L.B. was supported by a postdoctoral I3P contract from the Spanish Council for Scientific Research (CSIC).Peer reviewe

Mycobacterium hippocampi sp. nov., a rapidly growing scotochromogenic species isolated from a seahorse with tail rot

5 páginas, 3 figuras, 1 tablaA Gram-positive, aerobic, non-motile, non-sporulating, acid-fast, and rod-shaped bacterium (BFLP-6T), previously isolated from a seahorse (Hippocampus guttulatus) with tail rot, was studied using a polyphasic taxonomic approach. Growth occurred at 15–35 °C (optimum 25 °C), at pH 5.0–10.0 (optimum pH 7.0) and at NaCl concentrations between 0 and 6 % (w/v). The G+C content of DNA was 66.7 mol%. The predominant fatty acids were C18:1 ω9c, C16:0 and C16:1 ω6c. A mycolic acid pattern of alpha-mycolates and keto-mycolates was detected. Analysis of concatenated sequences (16S rRNA, rpoB, ssrA and tuf genes), and chemotaxonomic and phenotypic features indicated that strain BFLP-6T represents a novel species within the genus Mycobacterium, for which the name Mycobacterium hippocampi sp. nov. is proposed. The type strain is BFLP-6T (=DSM 45391T =LMG 25372T)This study was financed by the Spanish Min- istry of Science and Innovation (Projects CGL2005-05927-C03-01 and CGL2009-08386) and by the Regional Government Xunta de Galicia (09MDS022402PR). J.L.B. acknowledges receipt of an I3P postdoctoral contract from the Spanish National Research Council (CSIC), co-financed by the European Social Fund.Peer reviewe

The Consistency dimension and distribution-dependent learning from queries

We prove a new combinatorial characterization of polynomial learnability from equivalence queries, and state some of its consequences relating the learnability of a class with the learnability via equivalence and membership queries of its subclasses obtained by restricting the instance space. Then we propose and study two models of query learning in which there is a probability distribution on the instance space, both as an application of the tools developed from the combinatorial characterization and as models of independent interest.Postprint (published version

Closed-set-based discovery of representative association rules revisited

The output of an association rule miner is often huge in practice. This is why several concise lossless representations have been proposed, such as the “essential” or “representative” rules. We revisit the algorithm given by Kryszkiewicz (Int. Symp. Intelligent Data Analysis 2001, Springer-Verlag LNCS 2189, 350–359) for mining representative rules. We show that its output is sometimes incomplete, due to an oversight in its mathematical validation, and we propose an alternative complete generator that works within only slightly larger running times.Postprint (author’s final draft

Immunity and simplicity in relativizations of probabilistic complexity classes

The existence of immune and simple sets in relativizations of the probabilistic polynomial time bounded classes is studied. Some techniques previously used to show similar results for relativizations of P and NP are adapted to the probabilistic classes. Using these results, an exhaustive settling of all possible strong separations among these relativized classes is obtained.On étudie les relativisations des classes de complexité probabiliste polynômiale. On adapte aux classes probabilistes des techniques déjà utilisées pour établir des résultats similaires pour les relativisations de P et NP. On obtient à partir de ces résultats une classification de toutes les propriétés de séparation forte pour ces classes relativisées.Peer ReviewedPostprint (published version

Diseño de un proceso para la obtención de pulpa de pitahaya (Hylocereus triangularis) en la Asociación de productores y comercializadores de pitahaya y otros productos Palora.

El objetivo del presente trabajo de titulación fue diseñar un proceso para obtención de pulpa de pitahaya (Hylocereus triangularis) en la asociación de productores y comercializadores de pitahaya y otros productos “Palora”. La primera parte se basó en la caracterización de la fruta según la norma NTE INEN 2003:2015, el diseño se realizó en fundamento a pruebas piloto de simulación llevadas a cabo en las instalaciones del laboratorio de Procesos Industriales de la ESPOCH. Los datos obtenidos se tomaron como base para los cálculos correspondientes, a nivel industrial, de los equipos que intervienen en el proceso, el diseño de la planta se realizó contemplando las consideraciones de diseño y necesidades dispuestas por la Asociación. La validación del proceso diseñado se basó en la norma NTE INEN 2337:2008, que señala los parámetros físico-químicos y microbiológicos que debe cumplir el producto final para el consumo humano, los resultados reflejaron que el producto cumple con la norma. La planta se diseñó para 300 kg de carga verificándose un rendimiento del 41,63 % con una duración del proceso de 4 h; 16,02 min, el mismo incluye selección y clasificación de la materia prima, lavado -desinfección, escaldado, corte y pelado, despulpado, homogeneizado, envasado -sellado y almacenado. El producto será almacenado a: 21,2 Bx; 5,14 potencial de hidrogeno; densidad 1,0861 g/ml y viscosidad 54,2 cP. Así también se diseñó el tanque de escaldado, despulpadora, homogeneizador y mesas de trabajo. Se realizó el análisis financiero concluyendo que el proyecto es económicamente rentable y la inversión para su implementación se recuperara en 1 año y un mes de trabajo.The objective of the present titration work was a process to obtain pitahaya pulp (Hylocereus triangularis) in the associations of producers and marketers of pitahaya and other "Palora" products. The first part is based on the characterization of the fruit according to the NTE INEN 2003: 2015 standard, the design was made in a pilot fund simulation tests carried out in the facilities of the Industrial Processes Laboratory of the ESPOCH. The data is included as a basis for the corresponding calculations, an industrial level, the teams involved in the process, the design of the plant is made the contemplation of the design and the needs of the association. The validation of the process was based on the NTE INEN 2337: 2008 standard, it indicates the physical-chemical and microbiological parameters that the final product must fulfill for human consumption, the results reflected that the product complies with the standard. The plant was designed for 300 kg of load, verifying a yield of 41,63% with a duration of the process of 4 h; 16,02 min, it includes selection and classification of the raw material, washing-disinfection, blanching, cutting and peeling, pulping, homogelling, packaging-sealing and storage. The product will be stored at: 21,2 Bx; 5,14 hydrogen potential; density 1,0861 g / ml and viscosity 54,2 cP. The scalding tank, pulper, homogenizer and work tables were also designed. The financial analysis is carried out and it is concluded that the project is economically profitable and the investment for its implementation is recovered in 1 year and month of work