Evolving weighting schemes for the Bag of Visual Words

The Bag of Visual Words (BoVW) is an established representation in computer vision. Taking inspiration from text mining, this representation has proved to be very effective in many domains. However, in most cases, standard term-weighting schemes are adopted (e.g., term-frequency or TF-IDF). It remains open the question of whether alternative weighting schemes could boost the performance of methods based on BoVW. More importantly, it is unknown whether it is possible to automatically learn and determine effective weighting schemes from scratch. This paper brings some light into both of these unknowns. On the one hand, we report an evaluation of the most common weighting schemes used in text mining, but rarely used in computer vision tasks. Besides, we propose an evolutionary algorithm capable of automatically learning weighting schemes for computer vision problems. We report empirical results of an extensive study in several computer vision problems. Results show the usefulness of the proposed method

In vitro wood decay of teak (Tectona grandis) by Rigidoporus cf. microporus (Meripiliaceae, Polyporales, Basidiomycota)

The use of exotic species like teak for industry demands has increased over the last decades in Central America, however its vulnerability to decay by saprophytic fungi has not been well studied. Among these fungi, Rigidoporus spp. have been described as white rotters of dead hardwoods and conifers worldwide. In Costa Rica, R. microporus has been found growing on teak stumps. The aim of this study was to determine the effects of this white rot fungus on the chemical, mechanical and physical properties of teak wood from trees of different ages. Six and ten year old sapwood and heartwood samples were used in the assays. Severe anatomical damage and the highest weight and resistance losses were observed on 6 yr. old sapwood samples. There was an increase in the quantity of soluble materials in 1% NaOH (relative values) and lignin content in all the samples analyzed, after 3 months exposure and up to the end of the experiment. Mass loss reduction and increased resistance of wood to compressive strength parallel to the grain were related to both the type of wood and the age of the tree. Knowledge of the potential damage that this fungus can cause to teak wood might help in a better selection of wood and developing more effective protection measures against decay in the field or in construction wood.El crecimiento lento y la escasez de especies nativas en Centro América, ha incrementado el uso de algunas especies exóticas, como teca y melina en las últimas décadas, dado su rápido crecimiento y la buena calidad de sus maderas. Un aspecto importante que no ha sido bien estudiado, es la vulnerabilidad de estas maderas, en especial la de teca, al ataque de hongos causantes de podredumbre de la madera utilizada en construcción. Varias especies del género Rigidoporus han sido comunicadas como causantes de podredumbre blanca en angiospermas y gimnospermas a nivel mundial. En Costa Rica, Rigidoporus microporus ha sido reportada en tocones y troncos caídos de teca en plantaciones, pero no se han realizado estudios a nivel de laboratorio sobre los efectos que puede causar en las diferentes propiedades de la madera. Esta investigación se llevó a cabo para determinar los cambios que este hongo puede causar en las propiedades anatómicas, físicas, mecánicas y químicas de la madera de teca. Para determinar si existían diferencias en la severidad del ataque con respecto al estado de desarrollo del árbol, se utilizaron muestras de maderas provenientes de árboles con diferentes edades (albura y duramen de árboles de 6 y 10 años). Se montaron 262 cámaras de podredumbre para realizar las diferentes pruebas, y muestras de madera se removieron cada mes durante 6 meses para estudiar los cambios en las diferentes propiedades a través del tiempo. Los cambios más severos en la anatomía, y las pérdidas de peso y de resistencia más altas fueron obtenidos en las muestras de albura de 6 años. Se observó un aumento en la cantidad de materiales solubles en 1% NaOH y en los contenidos de lignina en todas las muestras analizadas a partir del tercer mes y hasta el final de la prueba. La reducción en pérdida de masa y el aumento de la resistencia de la madera a la fuerza paralela de comprensión al grano, estuvieron relacionadas tanto al tipo de madera como a la edad del árbol de donde esta procedía. Se considera que el conocimiento de los daños potenciales que puede causar este hongo, puede ayudar a realizar una mejor selección de la madera y a desarrollar medidas de protección más efectivas en el campo o a nivel de construcción

Heterozygosity decrease in wild boar mating system. A case of outbreeding avoidance?

In sexually reproducing organisms, the specific combinations of parental alleles can have important consequences on offspring viability and fitness. Accordingly, genetic relationship between mates can be used as a criterion for mate choice. Here, we used microsatellite genetic markers to estimate the genetic relationship between mating pairs in the wild boar, Sus scrofa. Males, females and foetuses proceeding from Portugal, Spain and Hungary were genotyped using 14 microsatellite markers. The genetic relationship between mates was estimated using different measures of foetus heterozygosity. We found that the observed heterozygosity of foetuses was lower than that expected under random mating. This result occurred mainly when Sd2 (relatedness of parental genomes) was used as the heterozygosity measure. After simulations, we concluded that the observed low heterozygosity was possibly due to outbreeding avoidance. Outbreeding avoidance based on genetically different genomes might play an important role in species evolution and its genetic conservation

ESTUDIO DE LA FACTIBILIDAD TÉCNICO-ECONÓMICA PARA LA RECUPERACIÓN DE CALORES RESIDUALES EN LA EMPRESA MANUFACTURAS CAROLINA S.A.

En este artículo se presentan las metodologías de cálculo y diagnóstico para la evaluación de pérdidas y calores residuales, así como del potencial térmico disponible para recuperar éstos en la empresa Manufacturas Carolina S.A. Los potenciales de ahorro y de impacto ambiental tambien son presentados en este trabajo

Coloquio Nacional a diez años de la Ley Federal de Educación

Organizado por la Escuela de Ciencias de la Educación, la Secretaría de Extensión de la Facultad de Filosofía y Humanidades de la Universidad Nacional de Córdoba y el Equipo de Investigación de la Cátedra de Organización y Administración Educacional, se desarrolló un coloquio que nucleó a 250 investigadores de Universidades e Institutos de Formación Docente de todo el país, con el objetivo de realizar un balance de la implementación de la reforma educativa iniciada con la Ley Federal de Educación (LFE). Al cumplirse diez años de su sanción y poniendo entre signos de interrogación el lema que acompañó a la reforma: Mejor Educación para todos se expusieron gran cantidad de trabajos referidos a su implementación en las jurisdicciones. En general las presentaciones revistieron un tono crítico respecto a varias cuestiones básicas de la Ley y la Reforma

Measurement of the CKM angle γ from a combination of B±→Dh± analyses

A combination of three LHCb measurements of the CKM angle γ is presented. The decays B±→D K± and B±→Dπ± are used, where D denotes an admixture of D0 and D0 mesons, decaying into K+K−, π+π−, K±π∓, K±π∓π±π∓, K0Sπ+π−, or K0S K+K− final states. All measurements use a dataset corresponding to 1.0 fb−1 of integrated luminosity. Combining results from B±→D K± decays alone a best-fit value of γ =72.0◦ is found, and confidence intervals are set γ ∈ [56.4,86.7]◦ at 68% CL, γ ∈ [42.6,99.6]◦ at 95% CL. The best-fit value of γ found from a combination of results from B±→Dπ± decays alone, is γ =18.9◦, and the confidence intervals γ ∈ [7.4,99.2]◦ ∪ [167.9,176.4]◦ at 68% CL are set, without constraint at 95% CL. The combination of results from B± → D K± and B± → Dπ± decays gives a best-fit value of γ =72.6◦ and the confidence intervals γ ∈ [55.4,82.3]◦ at 68% CL, γ ∈ [40.2,92.7]◦ at 95% CL are set. All values are expressed modulo 180◦, and are obtained taking into account the effect of D0–D0 mixing

Grassroots Agency: Participation and Conflict in Buenos Aires Shantytowns seen through the Pilot Plan for Villa 7 (1971–1975)

open access articleIn 1971, after more than a decade of national and municipal policies aimed at the top-down removal of shantytowns, the Buenos Aires City Council approved the Plan Piloto para la Relocalización de Villa 7 (Pilot Plan for the Relocation of Shantytown 7; 1971–1975, referred to as the Pilot Plan hereinafter). This particular plan, which resulted in the construction of the housing complex, Barrio Justo Suárez, endures in the collective memory of Argentines as a landmark project regarding grassroots participation in state housing initiatives addressed at shantytowns. Emerging from a context of a housing shortage for the growing urban poor and intense popular mobilizations during the transition to democracy, the authors of the Pilot Plan sought to empower shantytown residents in novel ways by: 1) maintaining the shantytown’s location as opposed to eradication schemes that relocated the residents elsewhere, 2) formally employing some of the residents for the stage of construction, as opposed to “self-help” housing projects in which the residents contributed with unpaid labor, and 3) including them in the urban and architectural design of the of the new housing. This paper will examine the context in which the Pilot Plan was conceived of as a way of re-assessing the roles of the state, the user, and housing-related professionals, often seen as antagonistic. The paper argues that residents’ fair participation and state intervention in housing schemes are not necessarily incompatible, and can function in specific social and political contexts through multiactor proposals backed by a political will that prioritizes grassroots agency

Iberian red deer: paraphyletic nature at mtDNA but nuclear markers support its genetic identity

Red deer populations in the Iberian glacial refugium were the main source for postglacial recolonization and subspecific radiation in north-western Europe. However, the phylogenetic history of Iberian red deer (Cervus elaphus hispanicus) and its relationships with northern European populations remain uncertain. Here, we study DNA sequences at the mitochondrial control region along with STR markers for over 680 specimens from all the main red deer populations in Spain and other west European areas. Our results from mitochondrial and genomic DNA show contrasting patterns, likely related to the nature of these types of DNA markers and their specific processes of change over time. The results, taken together, bring support to two distinct, cryptic maternal lineages for Iberian red deer that predated the last glacial maximum and that have maintained geographically well differentiated until present. Haplotype relationships show that only one of them contributed to the northern postglacial recolonization. However, allele frequencies of nuclear markers evidenced one main differentiation between Iberian and northern European subspecies although also supported the structure of both matrilines within Iberia. Thus, our findings reveal a paraphyletic nature for Iberian red deer but also its genetic identity and differentiation with respect to northern subspecies. Finally, we suggest that maintaining the singularity of Iberian red deer requires preventing not only restocking practices with red deer specimens belonging to other European populations but also translocations between both Iberian lineages.This work was partly supported by project CGL2010-17163/BOS from the Spanish MInistry of Science and by Extremadura and Andalusian Regional Goverments