6,990 research outputs found
Some observations on lucifer Faxoni borradaile (Crustacea: Decapoda: Sergestidae) collected from a tidal estuary
A study of Lucifer faxoni conducted within the estuary of Potengi, Natal, Brazil, utilizing the pier of "Base Naval" showed that these planktonic organisms were present in the zooplankton samples
On-going and future research at the Sulcis site in Sardinia, Italy. Characterization and experimentation at a possible future CCS pilot
National Italian funding has recently been allocated for the construction of a 350 MWe coal-fired power plant / CCS
demonstration plant in the Sulcis area of SW Sardinia, Italy. In addition, the recently approved EC-funded ENOS project
(ENabling Onshore CO2 Storage in Europe) will use the Sulcis site as one of its main field research laboratories. Site
characterization is already ongoing, and work has begun to design gas injection experiments at 100-200 m depth in a fault. This
article gives an overview of results to date and plans for the future from the Sapienza University of Rome research group
Polymer quantum dynamics of the isotropic Universe in the Ashtekar-Barbero-Immirzi and in the volume variables
We analyze the semiclassical and quantum polymer dynamics of the isotropic
Universe in terms of both the standard Ashtekar-Barbero-Immirzi connection
together with its conjugate momentum and also of the new generalized coordinate
conjugate to the Universe volume. We study the properties of the resulting
bouncing cosmology that emerges in both the representations and we show that
the Big Bounce is an intrinsic cut-off on the cosmological dynamics only when
the volume variable is implemented, while in terms of the standard connection
the Universe critical density is fixed by the initial conditions on the
prepared wavepacket. Then, we compare the obtained results with what emerges in
Loop Quantum Cosmology, where the same difference in the nature of the Big
Bounce is associated to fixing a minimum area eigenvalue in a comoving or in a
physical representation. We conclude that the privileged character of the
Ashtekar-Barbero-Immirzi connection suggests that the natural scenario in the
polymer framework is a Big Bounce that is not a Universal cut-off. However, by
a parallelism between the polymer and LQC properties of the basic operators, we
also develop some considerations in favour of the viability of the
scheme of LQC on a semi-classical level.Comment: 11 pages, 8 figure
Reingeniería de "Presentes": una base de datos sobre el accionar del terrorismo de estado
"Presentes" es un software utilizado por el Archivo Provincial de la Memoria para la investigación del accionar del terrorismo de estado en la provincia de Córdoba. Este sistema informático contiene una base de datos que condensa y organiza información recopilada a lo largo de años de constante investigación.
El sistema no fue desarrollado mediante un proceso de producción de software adecuado y necesita un conjunto importante de modi caciones y extensiones. En consecuencia, en este trabajo proponemos realizar una reingeniería de "Presentes" teniendo en cuenta requerimientos relevados y planteados por el Archivo de la Memoria.
Como parte del proceso de reingeniería realizamos una ingeniería inversa de la base de datos existente, para esclarecer su funcionamiento actual, analizar sus falencias y proponer soluciones para ellas. Además, hicimos una migración de tecnología de base de datos a un motor más adecuado a los requisitos del sistema. Finalmente, diseñamos e implementamos una nueva base de datos utilizando conceptos de los modelos de bases de datos objeto-relacional y documental. En el proceso, mejoramos la calidad de los datos, eliminando inconsistencias y redundancias para adaptarlos a los cambios en la estructura y a las nuevas restricciones introducidas en cada etapa de la reingeniería.Trabajos finales.Sociedad Argentina de Informática e Investigación Operativa (SADIO
Effects of weed control practices on plant diversity in a homogenous olive-dominated landscape (South-east of Italy)
Olive groves represent an important economic, agro-ecological, and cultural resource in the Mediterranean Basin. Weed management plays a fundamental role in their sustainable management. The aim of this work was to characterize and assess the plant diversity associated with different weed control practices, in a homogeneous olive-dominated landscape in the South-East of Italy. Sixty-five vegetation plots were sampled in orchards treated with different weed control practices: mowing, tillage, and use of chemical herbicides. The multi-response permutation procedure was used to test the hypothesis of no difference among the treatments. The relationships between plots were visualized by means of non-metric multidimensional scaling ordination. A generalized linear mixed model was used to analyze the relationships between weed control practices and life forms, chorotypes, and diversity indexes. The results showed that the three weed control practices determined slightly different plant communities. Chemically weeded orchards showed an impoverished floristic composition and the lowest diversity, whereas mowing and tillage yielded similar values. These latter two treatments differed for the percentages of hemicryptophytes and therophytes. Moreover, different from other studies, we did not find plant species of particular concern for biodiversity conservation. We hypothesize that this result is due to the monotonous structure of the agro-landscape we investigated, where natural elements are almost lacking. From this point of view, a correct management of agro-districts should consider both the agronomic practices at the level of the individual olive groves and the structure of the agro-landscape
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