5,827 research outputs found
Temporal variability of spawning site selection in the frog Rana dalmatina: consequences for habitat management
We evaluated whether R. dalmatina females laid their eggs randomly within a pond or preferred particular microhabitats. The same measures were performed in the same area in two consecutive years to determine whether the pattern remained constant over time. In 2003, we observed a significant selection for areas with more submerged deadwood and vegetation, presence of emergent ground and low water depth. However, these results were not confirmed in the subsequent year when none of the microhabitat features measured had a significant effect. Although microhabitat features can strongly influence tadpoles, the temporal variability of habitat at this spatial scale suggests that habitat management could be more effective if focused on a a wider spatial scale
Variabilidad temporal en la elección de los lugares de freza de la rana ágil Rana dalmantina: consecuencias para la gestión del hábitat
We evaluated whether R. dalmatina females laid their eggs randomly within a pond or preferred particular microhabitats. The same measures were performed in the same area in two consecutive years to determine whether the pattern remained constant over time. In 2003, we observed a significant selection for areas with more submerged deadwood and vegetation, presence of emergent ground and low water depth. However, these results were not confirmed in the subsequent year when none of the microhabitat features measured had a significant effect. Although microhabitat features can strongly influence tadpoles, the temporal variability of habitat at this spatial scale suggests that habitat management could be more effective if focused on a a wider spatial scale.Evaluamos si las hembras de R. dalmantina ponÃan sus huevos al azar en una charca o preferÃan microhábitats particulares. Durante dos años consecutivos se realizaron las mismas mediciones en la misma área, para determinar si el patrón era constante a través del tiempo. En el año 2003 observamos una selección significativa de áreas con mayor cantidad de ramas muertas y otra vegetación sumergidas, con zonas del fondo emergentes y aguas más someras. Sin embargo, estos resultados no fueron confirmados al año siguiente, en el cual ninguna de las caracterÃsticas del microhábitat medidas tuvo un efecto significativo. A pesar de que las caracterÃsticas del microhábitat pueden tener gran influencia sobre los renacuajos, la variabilidad temporal del hábitat a esta escala espacial sugiere que la gestión del hábitat podrÃa ser más efectiva si fuera proyectada según una escala espacial mayor
"All on short" prosthetic-implant supported rehabilitations
Objectives. Short implants are increasing their popularity among clinicians who want to fulfill the constant demanding of fixed prosthetic solutions in edentulous jaws. The aim of this report was to propose a new possibility to project and realize an occlusal guided implant cross-arch prosthesis supported by ultra-short implants, describing it presented an edentulous mandible case report. Methods. A 61-year-old, Caucasian, female patient who attended the dental clinic of the University of L’Aquila presented with edentulous posterior inferior jaw and periodontitis and periimplantitis processes in the anterior mandible. The remaining tooth and the affected implant were removed. Six 4-mm-long implants were placed to support a cross-arch metal-resin prosthesis. Results. At 1-year follow-up clinical and radiological assessment showed a good osseointegration of the fixtures and the patient was satisfied with the prosthesis solution. Conclusion. The method, even if it requires further validation, seems to be a valid aid in solving lower edentulous clinical cases, and appears less complex and with more indications of other proposals presented in the current clinical literature. Our case report differs from the current technique All-on-Four, which uses four implants in the mandible to support overdenture prosthesis, assuring a very promising clinical resul
System dynamics modeling as a circular process: The smart commons approach to impact management
Low delta-V near-Earth asteroids: A survey of suitable targets for space missions
In the last decades Near-Earth Objects (NEOs) have become very important
targets to study, since they can give us clues to the formation, evolution and
composition of the Solar System. In addition, they may represent either a
threat to humankind, or a repository of extraterrestrial resources for suitable
space-borne missions. Within this framework, the choice of next-generation
mission targets and the characterisation of a potential threat to our planet
deserve special attention. To date, only a small part of the 11,000 discovered
NEOs have been physically characterised. From ground and space-based
observations one can determine some basic physical properties of these objects
using visible and infrared spectroscopy. We present data for 13 objects
observed with different telescopes around the world (NASA-IRTF, ESO-NTT, TNG)
in the 0.4 - 2.5 um spectral range, within the NEOSURFACE survey
(http://www.oa-roma.inaf.it/planet/NEOSurface.html). Objects are chosen from
among the more accessible for a rendez-vous mission. All of them are
characterised by a delta-V (the change in velocity needed for transferring a
spacecraft from low-Earth orbit to rendez-vous with NEOs) lower than 10.5 km/s,
well below the Solar System escape velocity (12.3 km/s). We taxonomically
classify 9 of these objects for the first time. 11 objects belong to the
S-complex taxonomy; the other 2 belong to the C-complex. We constrain the
surface composition of these objects by comparing their spectra with meteorites
from the RELAB database. We also compute olivine and pyroxene mineralogy for
asteroids with a clear evidence of pyroxene bands. Mineralogy confirms the
similarity with the already found H, L or LL ordinary chondrite analogues.Comment: 9 pages, 7 figures, to be published in A&A Minor changes by language
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Immunohistochemical analysis of adhesive papillae of Clavelina lepadiformis (Müller, 1776) and Clavelina phlegraea (Salfi, 1929) (Tunicata, Ascidiacea)
Almost all ascidian larvae bear three mucus secreting and sensory organs, the adhesive papillae, at the anterior end of the trunk, which play an important role during the settlement phase. The morphology and the cellular composition of these organs varies greatly in the different species. The larvae of the Clavelina genus bear simple bulbous papillae, which are considered to have only a secretory function. We analysed the adhesive papillae of two species belonging to this genus, C. lepadiformis and C. phlegraea, by histological sections and by immunolocalisation of β-tubulin and serotonin, in order to better clarify the cellular composition of these organs. We demonstrated that they contain at least two types of neurons: central neurons, bearing microvilli, and peripheral ciliated neurons. Peripheral neurons of C. lepadiformis contain serotonin. We suggest that these two neurons play different roles during settlement: the central ones may be chemo- or mechanoreceptors that sense the substratum, and the peripheral ones may be involved in the mechanism that triggers metamorphosis
Maize and grass integrated system fertilized with polyhalite and KCl.
Crop-livestock integrated systems (CLIS) have been used as a strategy of sustainable agricultural intensification which integrates annual crops and livestock activities on the same area and in the same season.Poster number 1143
THE COMMUNICATIVE ACTION TO HABERMAS: THE NECESSARY ADOPTION OF THE THEORY BY THE UN SECURITY COUNCIL
ABSTRACT Objective: The present study has as main objective to analyze whether the theory of communicative action proposed by Jürgen Habermas should be applied to the voting procedure of the United Nations Security Council.Methodology: The inductive methodology used is based on research on bibliography, legislation and United Nations Resolutions, as well as in doctrine, cases and articles published in specialized journals. Results: It was concluded that the theory proposed by Habermas identifies language as a means by which those involved in a discourse can influence one another in order to change their minds or conceive intentions that corroborate their purposes. It can be clearly said that the UN Security Council has, to a certain extent, the same objective, as its purpose is to create resolutions that have the power to guarantee international peace and security. Contributions: This study has as contribution the theory of communicative action proposed by Habermas which is explained by way of a concrete case.Keywords: Communicative action; living world; Security Council; veto power; United States of America. RESUMO Objetivo: O presente estudo tem como objetivo central analisar se a teoria do agir comunicativo proposta por Jürgen Habermas, deveria ser aplicada às normas de votação do Conselho de Segurança das Nações Unidas. Metodologia: A metodologia indutiva utilizada é baseada em pesquisas bibliográficas, legislativas e de resoluções das Nações Unidas, bem como em doutrina, casos e artigos publicados em periódicos especializados. Resultados: Concluiu-se que a adoção da teoria da ação comunicativa seria importante para alcançar os objetivos da Organização, a saber, paz e segurança global. A teoria proposta por Habermas identifica a linguagem como um meio pelo qual os envolvidos em um discurso podem influenciar-se mutuamente, a fim de mudar de ideia ou conceber intenções que corroborem seus propósitos. Diante disso, pode-se dizer claramente que o Conselho de Segurança da ONU tem, em certa medida, o mesmo objetivo, pois seu objetivo é criar resoluções que tenham o poder de garantir a paz e a segurança internacionais. Contribuições: Este estudo tem como contribuição a teoria da ação comunicativa proposta por Harbemas, que é explicada por meio de um caso concreto. Palavras-chave: Agir Comunicativo; mundo vivente; Conselho de Segurança; poder de veto; Estados Unidos da América
Produção de Paspalum regnellii em função da calagem e adubação com fósforo em três classes de solo.
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