Search results for "Ciencia"
showing 10 items of 22911 documents
New national and regional bryophyte records, 36
2013
In the moss flora of Uruguay there are recorder ten species of genus Fissidens (Matteri, 2004). Three of them (F. macrobryoides, F. prionocheilos and F. vitreo-limbatus) are species incertae because the type material for the names not was located (Purssel, 2007). As part of project "Studies on Bryophytes in the Cone Sur (Systematic and Phylogeny)" some specimens recently collected in Uruguay were determinate as Fissidens asplenioides a no previously species recorded in this country. The presence of F. asplenioides in Uruguay complete the distribution range of the species in the cone Sur (is present in Argentina, Bolivia, Brazil, Chile and Paraguay). However, within the Neotropical region th…
Recuperación post-nihilista de la intimidad corporal y la persona humana a partir de Nietzsche y Conill
2020
El objetivo de este trabajo es poner en relación el núcleo crítico de la última obra de Je-sús Conill, Intimidad corporal y persona huma-na. De Nietzsche a Ortega y Zubiri1, con la pro-blemática del nihilismo, como estructura que pervive en nuestras sociedades contemporáneas, en especial, en el contexto de las neurociencias, la tecnología y nuestro modo de relación con am-bas. Tras bosquejar a modo de presentación las idea clave del libro, en especial su innovadora con-cepción de la intimidad corporal, recuperaré al-gunas aportaciones de la tematización nietzsche-ana del nihilismo, para mostrar, en tercer lugar, que tras la "muerte de Dios" otras instancias toman su lugar, y que las lógicas…
Genetic admixture despite ecological segregation in a North African sparrow hybrid zone (Aves, Passeriformes, Passer domesticus × Passer hispaniolens…
2019
Under different environmental conditions, hybridization between the same species might result in different patterns of genetic admixture. Particularly, species pairs with large distribution ranges and long evolutionary history may have experienced several independent hybridization events over time in different zones of overlap. In birds, the diverse hybrid populations of the house sparrow (Passer domesticus) and the Spanish sparrow (Passer hispaniolensis) provide a striking example. Throughout their range of sympatry, these two species do not regularly interbreed; however, a stabilized hybrid form (Passer italiae) exists on the Italian Peninsula and on several Mediterranean islands. The spa…
The "Tracked Roaming Transect" and distance sampling methods increase the efficiency of underwater visual censuses.
2018
Underwater visual census (UVC) is the most common approach for estimating diversity, abundance and size of reef fishes in shallow and clear waters. Abundance estimation through UVC is particularly problematic in species occurring at low densities and/or highly aggregated because of their high variability at both spatial and temporal scales. The statistical power of experiments involving UVC techniques may be increased by augmenting the number of replicates or the area surveyed. In this work we present and test the efficiency of an UVC method based on diver towed GPS, the Tracked Roaming Transect (TRT), designed to maximize transect length (and thus the surveyed area) with respect to diving …
Research priorities for freshwater mussel conservation assessment
2018
Freshwater mussels are declining globally, and effective conservation requires prioritizing research and actions to identify and mitigate threats impacting mussel species. Conservation priorities vary widely, ranging from preventing imminent extinction to maintaining abundant populations. Here, we develop a portfolio of priority research topics for freshwater mussel conservation assessment. To address these topics, we group research priorities into two categories: intrinsic or extrinsic factors. Intrinsic factors are indicators of organismal or population status, while extrinsic factors encompass environmental variables and threats. An understanding of intrinsic factors is useful in monitor…
Weak effects of geolocators on small birds: A meta-analysis controlled for phylogeny and publication bias
2020
Abstract Currently, the deployment of tracking devices is one of the most frequently used approaches to study movement ecology of birds. Recent miniaturization of light‐level geolocators enabled studying small bird species whose migratory patterns were widely unknown. However, geolocators may reduce vital rates in tagged birds and may bias obtained movement data. There is a need for a thorough assessment of the potential tag effects on small birds, as previous meta‐analyses did not evaluate unpublished data and impact of multiple life‐history traits, focused mainly on large species and the number of published studies tagging small birds has increased substantially. We quantitatively reviewe…
Los foros y las redes sociales ayudan a descubrir especies exóticas en Europa y monitorear su propagación: el caso de Exaireta spinigera (Wiedemann, …
2018
La mosca soldado Exaireta spinigera (Wiedemann, 1830) (Diptera, Stratiomyidae) es originaria de Australia y se introdujo en Hawái, América del Norte y se está extendiendo rápidamente por Europa. Comentamos el conocimiento sobre su presencia en Italia y publicamos los primeros registros de Sicilia. El conocimiento existente sobre la llegada y distribución de esta especie en Italia se fundamenta exclusivamente en datos proporcionados por ciudadanos a través de foros de internet y grupos de Facebook sobre biodiversidad, que así han demostrado ser una ayuda útil para la difícil detección de especies invasoras.
Cell interactions between a nonpathogenic Fusarium oxysporum strain and root tissues of Eucalyptus viminalis
2004
Nonpathogenic isolates of Fusarium oxysporum can be successful antagonists of pathogenic forms of the same fungal species that commonly attacks crop plants. The characteristics that distinguish nonpathogenic from pathogenic forms are not well understood. In this study, the mode of root colonization of Eucalyptus viminalis seedlings by a nonpathogenic F. oxysporum strain is described at the ultrastructural level. Root systems of E. viminalis plants were inoculated with nonpathogenic F. oxysporum strain Fo47 in an in vitro model system. Changes in the occurrence of nonesterified and methyl-esterified pectins in colonized E. viminalis roots were evaluated by in situ immunolabeling using two mo…
In vitro comparison of primary stability of two implant designs in D3 bone
2016
Background Primary stability (PS) is a key factor for implant survival rate and depends on implant design or bone quality. The aim of this study was to compare different thread designs implants, evaluating PS with periotest values (PV) and implant stability quotient (ISQ) values through resonance frequency analysis (RFA). Material and Methods A total of 60 implants (Radhex®, Inmet-Garnick S.A., Guadalajara, Spain) were placed in freshly bovine ribs in vitro. Two designs were used: 30 tapered body with single thread design (PHI) and 30 tapered body with double thread design implants (PHIA). Both designs were 4mm wide and 12mm long. Implants were placed according to manufacturer’s guidelines.…
Communication cost of channel estimation interpolation for group-based vehicular communications in cellular networks
2020
Las comunicaciones inalámbricas para aplicaciones vehiculares en sistemas celulares de quinta generación (5G) deben ser de baja latencia y alta fiabilidad. Entre otros factores, la cantidad de información de control que debe intercambiarse entre cada vehículo y la estación base puede penalizar la latencia de la comunicación. Varios casos de uso vehicular 5G implican comunicaciones dentro de grupos de vehículos, por ejemplo el pelotón de vehículos. Este trabajo se centra en explotar la estructura y características de este servicio vehicular particular basado en grupos para disminuir el intercambio de información de control relacionado con la etapa de estimación del canal necesaria para las c…