1,720,959 research outputs found
Does Hermetia illucens recognize sibling mates to avoid inbreeding depression?
No full textManagement of genetic diversity in Hermetia illucens L. (Diptera: Stratiomyidae) commercial colonies is a key problem. Inbreeding depression can affect the maintenance and sustainability of insect farming, in particular small-scale mass-rearing, by reducing population fitness or causing colony collapse. In animals, kin recognition could play a role avoiding inbreeding and mating with sibling. To determine inbreeding impact in a H. illucens laboratory strain, the courtship and mating behaviour occurring between unrelated or full-sibling mates were compared in controlled crosses. Furthermore, selected lifetime parameters, including egg laying and fertility, developmental time, total fecundity, and sex ratio, were compared. Inbreeding depression can be observed by second generation of full-sibling mating, with a severe reduction of produced progeny (emerged adults per female, No-Sib: 234.9 ± 38.0 vs. Sib2: 64.3 ± 16.7). No differences attributable to kin recognition were noted in the pre-copula and post-copula behavioural sequences. However, copulation was prolonged in inbred mates (No-Sib:
35.5 ± 2.8 min vs. Sib2: 52.2 ± 6.4 min), probably due to the physiological characteristics of the mates. Nevertheless, a valuable restoring impact of backcross on several life-time parameters was also observed, mitigating the impact of inbreeding depression.
This research provides valuable information about inbreeding and mate selection to avoid population depression in H. illucens. Further studies are needed to investigate the occurrence of other selection mechanisms in this species, as well as the possible impact of outbreeding on population fitness
Bioactivity of Allium sativum essential oil-based nano-emulsion against Planococcus citri and its predator Cryptolaemus montrouzieri
No full textBotanical extracts, in particular essential oils (EOs), could be the ideal candidates for the development of bio-pesticides as an alternative to synthetic pesticides. However, some limitations of EOs (high flammability, vola-tility, degradability, poor solubility in water) prevent their use under real operational conditions. Nanotechnologies are useful tools to overcome the above-mentioned limitations of these natural substances. Furthermore, encapsulation in nano-delivery systems (nanoparticles and nano-emulsions) can improve the functional properties of EOs. In this context, this study aimed to develop a highly stable, concentrated garlic nano-emulsion (15%) and to evaluate the acute toxicity with different exposure routes towards Planococcus citri and its predator Cryptolaemus montrouzieri. First, garlic EO was used to develop a nano-emulsion (15% EO; 5% Tween 80; 80% water) using a high-pressure microfluidizer; then both the crude EO and EO in nano-emulsion were chemically investigated by Solid Phase Microextraction-Gas Chromatography-Mass Spectrometry (SPME-GC-MS) technique. The nano-emulsion was physically characterized by dynamic light scattering analysis over time (24 h, 3 months and 1 year after preparation) and used in bioassays involving both the target and non-target organisms. Results showed that the garlic EO consisted of over 95% sulphur compounds with diallyl disulphide as the most abundant component, and the developed nano-emulsion remained stable even after 1 year, with droplets' dimension within the nanometric range (221.4 nm). The nano-formulation was effective against the target pest after 48 h from the treatment (Direct: LC90 = 0.967%; Indirect: LC90 = 1.088%), while it had no effect on C. montrouzieri. These promising results highlight the potential of garlic-based nano-emulsion as effective and environmentally friendly insecticide for pest control
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
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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