1,721,111 research outputs found
Struttura delle «aree sensoriali» antennali di alcuni Bostrichidi (Coleoptera)
No full textMost species of Bostrychidae exhibit specialized sensory organs which consist in dense groups of basiconic sensilla on each segment of their antennal club. These sensory organs cover either flat or concave surfaces. Observations have been carried out, in order to assess structural details on the antennal clubs of the following species: Bostrychus capucinus L., Lichenophanes varius Illig., Amphicerus bimaculatus (Ol.), Xylonites retusus (Ol.), Xylonites praeustus Germ., Scobicia chevrieri Villa, Sinoxylon sexdentatum (Ol.), Sinoxylon perforans Schr.
Three different arrangements of sensilla have been observed: l) flat fields; 2) longitudinal grooves; 3) subspherical pits.
The borders of the flat fields are either entirely or partially contoured. Both flat fields of certain species and the subspherical pits are concealed beneath a group of layered marginal setae. No sex dimorphism was found. The sensory areas occupy both faces of each antennal segment.They are usually two on each face, although their number may be higher in some species. With regard to the phylogenesis of these structures, it is suspected that both the longitudinal grooves and the subspherical pits originate from the flat fields by way of two separate evolutionary trends. Subsequently, they were masked by the marginal setae. Possibly, Bostrychidae use these organs to search for their host-plants
Dettagli strutturali dei chemiorecettori antennali in Carpophilus hemipterus (L.) e C.humeralis (F.) (Coleoptera, Nitidulidae)
No full textAs other species of Nitidulidae, adults of both sexes of Carpophilus humeralis (F.) and C. hemipterus (L.) exhibit two particular receptors in each antenna, respectively in the 10th and 11th segments.
Study by light-microscope, TEM and SEM gives data as follows:
i) Presence and shape of both receptors do not exhibit sex dimorphism.
ii) The receptor of the 11th segment is flask-like and opens through a very small pore (nearly 10 μm in diameter) on that segment face which is oriented downwards when the insect walks; it bears a number of transversal crests along its internai walls.
iii) The receptor of the 10th segment is a largely opened pit of the intersegmental face; it is deeper, partly vesicle-like, in C. humeralis.
iv) Both receptors include a few basiconic sensilla of the type MPG-conoid, sensu Zacharuk (1980).
v) No inlet of glandular cells was found in them.
Observations show a trend to both confining of the elementary sensilla and redundance of receptors, which are difficult to rel:lte to any function, due to the lack of behavioral knowledge
Contemporary treatment of Popliteal Artery Entrapment syndrome
No full textContemporary treatment of Popliteal Artery Entrapment syndrom
Tattismi inconsueti: spostamenti casuali o finalizzati? il caso di Corimalia tamarisci (Gyllenhal) (Coleoptera Apionidae)
No full textMetodo computerizzato di calcolo del volume di spermateche
No full textA method for computing the volume of spermathecae of Coleoptera is presented. It exploits a generai feature of these organs: their transversal sections are nearly circu- lar. This method consists in resolving the outline obtained by a drawing tube in a number of piane figures, each corresponding to the sections of a regular solid having one circular face at least. Single volumes of these solids can be easily computed, and their sum gives the total volume. The use of a personal computer, in order to make operations more careful and quick, is explained.
Key-words: Sitophilus granarius (L.), spermatheca, volume computing, method
The popliteal artery entrapment syndrome. Personal experience
No full textThe popliteal artery entrapment syndrome. Personal experienc
Ruolo di Psocotteri Ectopsocidi e Coleotteri Anticidi nella Diffussione di Spilocaea oleagina
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
- …
