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Dati sulla biologia di due specie di formiche mietitrici (Messor wasmanni e M.minor) nella Tenuta presidenziale di Castelporziano
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Preliminary studies of Formica pratensis Retz. at Collelungo (Rieti) (Hymenoptera Formicidae).
No full textLaboratory study of the orientation mechanisms of f. pratensis retz. (hymenoptera, formicidae).
No full textAnts are able to repeatedly reach a fixed point in the environment by means of external and/or internal orientation references.
The orientation mechanisms of workers of F. pratensis was studied in laboratory controlled conditions.
The video-recorded experiment involved a base configuration in which the workers associated the position of the food source with that of a visual signal. The experimental sessions involved a change of some variables (food source, visual and chemical signals) and measurement of the number of ants arriving at two platforms associated with the visual signals. The data were analysed by the χ2-test.
Our study shows that chemical signal is an information able to change the behaviour of F. pratensis workers. To better understand the importance of visual and idiothetic information instead, further investigation will be necessary
Laboratory study on the orientation mechanisms of Formica pratensis Retz. (Hymenoptera, Formicidae).
No full textChemical soil properties of the nesting sites of two syntopic harvester ants: Messor wasmanni,M.minor.
No full textMulti-set indicators to assess environmental quality using soil micro arthropods, plants and humus.
No full textThe present study used a multi-set indicator approach to evaluate environmental quality in complex ecosystem. The simultaneous analysis of information deriving from different ecosystem scales and/or taxonomic groups was used to achieve a better understanding of the interconnected above- and below-ground ecosystem com-ponents. Three indicator sets were utilized in eight sampling sites representative of the main habitats of a Mediterranean area in Central Italy, the Castelporziano Presidential Estate:(1) plant indicators derived from Ellenberg and Hemeroby models; (2) fauna indicators from soil microarthropods; and (3) humus forms and soil parameters from direct measure-ments. Principal component analysis and Spearman corre-lation test were performed on the data indicators/parameters matrix to evaluate the agreement of the multi-set in describing environmental quality. Results highlighted sig-nificant correlations among the different indicators/parameters. In particular, vascular plants and soil microar-thropods represent two independent gradients in assessing ecosystem functioning, whilst humus forms provided sim-ilar information on habitat characteristics
Competizione e distribuzione spaziale: analisi preliminari su specie simpatriche di formiche mietitrici del genere Messor.
No full textProceeding
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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