1,721,428 research outputs found
Wax production in the adults of the flatid planthopper Metcalfa pruinosa (Say) (Homoptera Fulgoroidea)
No full textSurfing the Web: the role of Social-Support in the adolescents’ Internet use
Full text linkThis research analyzes what predictors determine either a problematic internet use (PIU) or a functional Internet use (FIU) in 574 adolescents (303 females and 271 males). A cross-sectional study was proposed based on the compilation of an online questionnaire. It was hypothesized that Online Social-Support positively predicts PIU only when Offline Social-Support is low and Online Social-Support positively predicts FIU only when Offline Social-Support is high. Results show that Online Social-Support doesn't predict PIU, while, Offline Social-Support negatively affects It. FIU isn't affected by Offline Social-Support, while Online Social-Support predicts it. Gender differences occurs in PIU, Offline Social-Support and number of acquaintances in favor of males
Wax glands and cuticular pores in nymphs of Metcalfa pruinosa (Say) (Homoptera Flatidae): a light and scanning electron microscopy study
No full textDiversity and abundance of landing aphids in two areas of seed pota-to production in tunisia; relative to the incidence of potato viruses
No full textAphid flight activities were monitored in 2015 in two areas of seed potato production in Tunisia. Yellow water traps were used to investigate the diversity of aphidofauna and the incidence of aphids involved in potato virus transmission. A total of 9966 specimens belonged to 73 taxa were captured. The cumulative abundance recorded in Douala (first site) was much higher than in El Ogla (second site) (8768 vs 1189 specimens). The most prepon-derant species in Douala were Aphis spiraecola Patch (66.1%) and Aphis spp. group (13.5%). In El Ogla Rhopalosiphum padi (L.) comprised 58.9% of total catches, followed by Acyrthosiphon pisum (Harris) (12%) and Aploneura lentisci (Passerini) (10.4%). The highest values of diversity indices were recorded on April 23th [Shannon-Wiener index (H')=2.58; Simpson index (1-D)=0.88] in Douala and on May 12th (H'=1.70; 1-D=0.75) in El Ogla. The detection of viral infections by DAS-ELISA determined the predominance of Potato virus Y amongst five main potato viruses tested. Overall Chi-square analysis determined significant differences crossing all areas of seed and ware potatoes and season crops. The highest incidence of viruses was recorded in Douala (18.5%) while El Ogla was under the threshold value (4%). This might be attributed to the occurrence of aphids in early season known previously to be efficient vectors of PVY and to the characteristics of area including cli-matic conditions, altitude and landscape structure. These results provide new evidence for El Ogla as ideal site to produce healthy tubers while conversely Douala is favourable for the propagation of vectors and viruses
On the distribution in Italy of the neartic hopper Acanalonia conica (Say) Hemiptera: Acanaloniidae), with ecological notes
No full textGoing 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
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Wax Production in Adults of Planthoppers (Homoptera: Fulgoroidea) with Particular Reference to Metcalfa pruinosa (Flatidae)
No full textAlthough wax characteristics, wax-producing structures, and their probable functions
in planthopper juveniles have been summarized in recent articles, very little has been published
regarding the morphology of these structures in adults. In the Nearctic ßatid Metcalfa pruinosa (Say),
most wax is secreted on the forewings of both sexes and on the anal tube of females. There is also a
sparse powdery layer of wax that lightly covers most of the body. Along most of the body surface and
forewings many small glandular ring-shaped areas occur, delimiting a pore, from which single thin
Þlaments of wax emerge. Moreover, numerous moniliform glandular pore-plates are randomly scattered
on the surface of the forewings. On each plate, 8Ð50 subcircular pores are symmetrically
arranged in one or two lines around a long central sensory hair. An internally hollow cylindrical wax
ribbon emerges from each pore. In addition, many prominent glandular plates occupy the ventral
surface of the female anal tube. Each plate is nearly circular and is marginally perforated by seven to
eight pores from which long, hollow, cylindrical wax tubules emerge. These plates are not present on
the anal tube of the male. Although the function of the anal tube wax is unknown, the wax layer that
covers the body and forewings may play an important role in protection against abiotic factors and
prevent smearing the cuticle with honeydew
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