1,720,973 research outputs found
Development of sexing systems functional to mass production of Aedes albopictus Skuse sterile males
No full textMethods currently used to control Aedes albopictus Skuse are not only insufficient to ensure its reduction under acceptable sanitary threshold, but they are also sources of environmental pollution. For these reasons, over years many studies have been carried out to find alternative methods to control this insect vector able to transmit Dengue, Chikungunya, Zika and Yellow Fever viruses.
One of the possible environmentally friendly alternatives for the control of Ae. albopictus is the sterile insect technique (SIT) which involves the release of adult males, previously treated with ionizing radiations in order to induce sterility into the wild population. Continuous releases of sterile males, in combination with traditional control strategies could be a valuable tool to suppress or eradicate the wild population, especially in those areas where Ae. albopictus represents a newly imported invasive species that is not yet heavily spread into the territory.
However, the presence of females in the SIT release campaigns must be avoided or strongly reduced. In fact, even if completely sterilised, the females maintain their feeding activity and vectorial capacity. Moreover, their presence in the released insects can affect the dispersal and mating rates of the males, thus reducing the cost effectiveness of the SIT.
Sex separation of Ae. albopictus can be effectively achieved by exploiting different biological traits between males and females at either pupal or adult stage such as protandry, dimorphism or by investigating classical non transgenic genetic sexing strains.
Currently the available sexing methods are not mechanized and are based on manual procedures, therefore they are not capable to assure an effective separation and are strongly affected by operator procedures.
My PhD project, here presented, has the purpose to investigate new methods for an effective and reliable sex separation of Ae. albopictus at different stages in accordance with the European regulations, which limits the creation and use of genetic modified strains.
The implementation of a hyper-proterandry strain through a classical cross-breeding method and the production of an optical sexing system integrated with an artificial intelligence able to sort sexes at adult stage are the main lines of investigation during my current studies within the PhD in Health, Safety and Green Systems
Response of the European Ladybird Adalia bipunctata and the Invasive Harmonia axyridis to a Neonicotinoid and a Reduced-Risk Insecticide
No full textThe spread of the multicolored Asian lady beetle Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) in Europe
coincided with the decline of the native Adalia bipunctata (L.) (Coleoptera: Coccinellidae). Both species are predators
of aphids in orchards, and differential susceptibility to insecticides used to control fruit pests may contribute to
explain the competitive advantage of the invasive over the native species. In this study, the insecticidal activity
of imidacloprid and spinetoram was tested on third instars and adults of both ladybird species under laboratory
conditions. Insects were exposed to insecticide residues on potted peach plants that were sprayed with the
maximum recommended field doses (100 mg/liter for imidacloprid and 66.67 mg/liter for spinetoram). Mortality
was scored after short (2 d for both stages) and long (7 and 10 d for adults and larvae, respectively) exposure
periods. The susceptibility to the insecticides was very similar for H. axyridis and A. bipunctata. Imidacloprid caused
a significant increase in the mortality of both stages of the two species for every exposure period. On the other
hand, when exposed to spinetoram residues, larvae and adults of both ladybirds did not show higher mortality
than controls after short and long exposure periods. The pest suppression provided by ladybirds, which could be
severely hampered by the applications of nonselective pesticides, might be enhanced by the adoption of reducedrisk
insecticides, selective for these beneficial insects
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
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Probing behaviour of Myzus persicae on tomato plants containing Mi gene or BTH-treated evaluated by electrical penetration graph
No full textThe probing behaviour of the green peach aphid, Myzus persicae Sulzer (Rhynchota Aphididae) was evaluated by electrical penetration graph (EPG-DC) on the tomato (Solanum lycopersicum L. syn. Lycopersicon esculentum Mill.) cultivar Motelle, containing the Mi gene conferring resistance to the potato aphid, Macrosiphum euphorbiae (Thomas) (Rhynchota Aphididae), to test the resistance degree of the cultivar to M. persicae. The aphid probing behaviour was also evaluated on a susceptible (mi) tomato cultivar, Moneymaker, after treatment by a chemical plant resistance elicitor, benzo(1,2,3)thiadiazole-7-carbothioic acid S-methyl ester (benzothiadiazole or BTH). Concerning a possible antixenotic effect due to physical and chemical barriers, no significant differences were found between the two cultivars in the probing and phloem phases. However, a difference was detected between the preinfested and non-preinfested susceptible cultivar in the total duration of phloem ingestion. The lack of significant differences in the entire process of host feeding between resistant and susceptible cultivars is probably due to the fact that the resistant cultivar identifies only the specific elicitors produced by M. euphorbiae. By contrast, the BTH treatment apparently makes the susceptible cultivar less palatable to a generalist aphid like M. persicae: the main component of this induced resistance is the reduced phloem ingestion
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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