1,721,433 research outputs found
Risorgimento, Marxismo, Keynesismo. Studi di storia del pensiero economico italiano in onore di Aurelio Macchioro
No full textIntroduction
No full textThis paper introduces the papers presented at the Siena Conference on the History of Economic Thought and selected for publication in this issue of History of Economic Idea
Further evidence of male antennal glands in Aphelinidae: the case of Aphytis melinus DeBach (Hymenoptera: Aphelinidae)
No full textVolume: 8Start Page: 109End Page: 11
Morfologia e ultrastruttura dei complessi ghiandolari antennali del coleottero mirmecofilo Paussus favieri (Carabidae, Paussinae, Paussini
No full textFine Structure of the Antennal Glands of the Ant Nest Beetle Paussus favieri (Coleoptera, Carabidae, Paussini).Corresponding author
No full textThe antennae of the ant nest beetle Paussus favieri are studied by using both SEM and TEM. In the myrmecophilous genus Paussus, these structures are composed of three joints: scape, pedicel and a wide third joint, the ‘‘antennal club’’, resulting from the fusion of antennomeres A3–A11 (flagellum). The antennal club shows an exceptional glandular activity, with the presence of pores mostly crowded in special hairless cuticular areas, surrounding the base of single setae, grouped at the base of tufts of setae, or positioned inside deep pockets that store the secretions, with filiform material arising from them. The surface of A1 and A3 are covered by mechanoreceptors, modified to spread the glandular exudates, while the chemoreceptors are restricted to the apex of the club. The fine structural analysis shows a great number of antennal glands, that can be referred to three main typologies: type A (GhA) bi-cellular, composed of a large secretory cell and a small duct cell, positioned close to the antennal surface; type B (GhB), tri-cellular, composed of two secretory cells and one duct cell, less frequent and positioned deep inside the antennal club; type C (GhC), rare, located deeply within the antennal lumen, in the vicinity of the trophocytes. This complexity indicates that more than one substance could be released from the antennae. Possible functional aspects of the secretions dealing with symbiotic interaction with the host ants are discussed
Sound production in Padogobius martensi (Günter) (Pisces, Gobiidae). A preliminary report.
No full text
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
First report of exocrine epithelial glands in oestroid flies: the tachinid sexual patches (Diptera: Calyptratae: Oestroidea: Tachinidae)
No full textCerretti, P., Di Giulio, A., Romani, R., Inclan, D.J., Whitmore, D., Di Giovanni, F.,
Scalici, M. andMinelli, A. 2014. First report of exocrine epithelial glands in oestroid
flies: The tachinid sexual patches (Diptera: Oestroidea: Tachinidae).—Acta Zoologica
(Stockholm) 00: 000–000.
Sexual patches are abdominal areas identifiable by modified setation, present in
the males of several groups of Tachinidae (Diptera). We comparatively studied
more than 40 species belonging to 24 genera representative of subfamilies known
to bear these organs, using light microscopy and scanning (SEM) and transmission
(TEM) electron microscopy. We provide a detailed characterization of the
fine structure of the setae and microtrichia composing these sexual patches and
of the underlying epithelium. Study of abdominal sections showed that, close to
the patch area, the epidermis forms a thick layer composed of numerous secretory
units of strictly associated cells, ending at the level of cuticular pores at the
base of the setae. We hypothesize a secretory function of these structures. The
segmental pattern of the sexual patches across the Tachinidae is defined and
predictable.We note that almost all the segmental patterns share the presence of
sexual patches on abdominal tergite 4, underscoring the diversity of male sexual
specializations that occur on the fourth abdominal segment of muscomorph flies
- …
