1,720,995 research outputs found
Formulation and Safety Tests of a <i>Wickerhamomyces anomalus</i>–Based Product: Potential Use of Killer Toxins of a Mosquito Symbiotic Yeast to Limit Malaria Transmission
Full text linkWickerhamomyces anomalus strain WaF17.12 is a yeast with an antiplasmodial property based on the production of a killer toxin. For its symbiotic association with Anopheles mosquitoes, it has been proposed for the control of malaria. In an applied view, we evaluated the yeast formulation by freeze-drying WaF17.12. The study was carried out by comparing yeast preparations stored at room temperature for different periods, demonstrating that lyophilization is a useful method to obtain a stable product in terms of cell growth reactivation and maintenance of the killer toxin antimicrobial activity. Moreover, cytotoxic assays on human cells were performed, showing no effects on the cell viability and the proinflammatory response. The post-formulation effectiveness of the killer toxin and the safety tests indicate that WaF17.12 is a promising bioreagent able to impair the malaria parasite in vector mosquitoes
DETERMINATION OF THE IMMUNOSTIMULATORY ROLE OF ASAIA IN AEDES AEGYPTI: A POTENTIAL SYMBIONT-BASED CONTROL APPROACH?
No full textRecurring outbreaks of arboviruses such as dengue on a global scale, it is imperative to adopt multifaceted
strategies to limit the transmission of mosquito-borne diseases (MbDs). Insecticide and drug
resistance, coupled with the absence of effective vaccines, presents a significant obstacle in combating
MbDs. Recent years have seen a deeper understanding of mosquito microbiota, revealing its role in
different traits of the mosquito biology such as sexual reproduction, development, nutrition, and resistance
to pathogens. As a reflection of this new knowledge, exploitation of symbiotic bacteria of vector
mosquitoes has emerged as a potential control-strategy of MbDs. For instance, the symbiotic bacterium
Asaia has been shown to activate immune genes in different insect hosts including Anopheles where it
elicits an anti-plasmodium response (Gonnella et al., 2019. Front Physiol, 10:795; Cappelli et al., 2019.
Front Genet, 10:836). The present study investigates the effect of Asaia on the immune system of a
main vector of arboviruses such as Ae. aegypti. A laboratory strain of Ae. aegypti (New Orleans 2011)
was reared at standard conditions. The experimental set up included three groups of female mosquitoes
(a, b and c). Groups a and b received different dietary boosts of Asaia, respectively 105 cell/ml and
108 cells/mL while the control group c received a normal diet. Half of the mosquitoes per each group
were feed with blood meal and collected daily for 5 days post feeding. The Asaia amount was monitored
in all the tested samples by qPCR. The expression of transcription factors (Rel 1, Rel 2) and effectors
genes of IMD and Toll (Cecropin A, Defensin C, Gambicin and C-type Lectin) cascades together with
two genes (Heme peroxidase 7, Superoxide dismutase) codifying enzymes involved in the degradation
of Reactive oxygen Species (ROS) were evaluated by qPCR. Moreover, the effect of Asaia supplementation
on the microbiota composition was assessed through 16S MiSeq analysis. Outcomes suggest
that the analysed antimicrobial peptide genes and transcription factors are not affected by Asaia overloads,
nonetheless the expression of two ROS genes increased concurrently with the proliferation of
the bacterium on the second day post-blood meal. These observations need to be corroborated by further
analysis for quantifying specific metabolites associated with oxidative stress. Microbiota analysis
indicates a marked proliferation of Asaia following blood-feeding, emerging as the predominant bacterium.
Other symbiont such as pantoea exhibited a modest increase in abundance and pseudomonas
experienced a sharp decrease. Exploring the Asaia-Ae. aegypti system to investigate the influence of
symbiotic bacteria on stimulating the mosquito immune response against arboviruses, holds potential.
This could pave the way for the development of symbiotic-based interventions that can complement
existing approaches in the field
Deciphering symbiotic bacteria dynamics in mosquito thermal adaptation: implications for vector control E-poster viewing on screens: bacteria and climate change
No full textClimate changes significantly alters mosquito distribution and their role as disease vectors. Species like Aedes albopictus in Europe, and Anopheles stephensi in Africa rapidly adapt to climate changes, intensifying disease transmission
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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