103 research outputs found

    Effects of Thrips (Pseudodendrothrips mori Niwa) Infested Mulberry Leaves on Silkworm Growth and Commercial Cocoon Parameters

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    In mulberry orchards in northern part of Iran, thrips is a dominant pest and causing a lot of damage to the mulberry. The effect of pest on bio-chemical parameters of mulberry leaf of two varieties viz. Kenmochi and Ichenoise and also the effect of feeding of infested leaves on rearing performances have been studied. For the study, six plots of 200 m2 area of both the varieties were selected and three of them, of each variety, were sprayed with 0.5% Metasystox at a peak period of occurrence of nymph population to obtain the good healthy leaf without thrips infestation. Another 3 plots were left without pesticide spray to obtain infested leaves so as effect of infestation on chemical parameters of leaf and effect of infested leaves on rearing performance could be studied. During rearing, larvae were fed with good quality of mulberry leaf while another lot were fed with infested leaves. The results showed that there was a decrease in nitrogen, phosphorus, potassium and protein contents of leaves by 2.5, 10.8, 18.7 and 12.5%, respectively due to infestation and the decrease in these parameters was more in Kenmochi. There was also a significant decrease in total co coon production, cocoon weight, pupal weight, and shell weight due to feeding of infested leaves. However, there was no significant difference in shell ratio between the lots fed with healthy and infested leaves

    Bio-Economic Changes Due to Long Time Treatment of Carbendazim on Mulberry Silkworm (Bombyx mori L.

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    The effect of fungicides on silkworm larvae was analyzed with regard to the fact that these beneficial insects are usually affected by fungicides, Daily feeding on 1 and 2g/liter of carbendazim, a systemic fungicide, did not have significant effects on larval and pupal mortality. However the weight of the treated larvae showed considerable weight decrease up to 37% weight.. All the economic traits of male and female adults treated with fungicide decreased but this decrease is not significant in cocoon shell weight and hatching percentage. The comparison of means using Tukey test at 5% confidence level did not show any effect related to the concentration

    Biological effects on silkworm larvae fed by mulberry leaves treated with carbendazim fungicide

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    The biological effects on silkworm larvae fed on mulberry leaves contaminated with 0.5 and 1 mg/ml carbendazim were analyzed in different periods. The fungicide was sprayed on trees with 0, 1, 2, 4 and 8 days intervals before the first feeding of second instar larvae. Carbendazim decreased the larval weight and the highest reduction was 4.5% decrease compared to control. One mg/ml of fungicide used immediately after treatment caused a significant decrease in female cocoon characteristics such as cocoon weight, pupa weight and shell weight by 8.4, 8.5 and 7.8, respectively. The rate of hatching had also decreased in some treatments. Economical traits of male insects and the number of laid eggs by females were not affected. In total, the mean of cocoon shell percentage in both sexes did not have any difference with control. Feeding from the leaves contaminated with carbendazim residue did not have significant effects on larval mortality and utilization of the leaves sprayed by this fungicide two days after application is recommended

    In vitro establishment of embryonic primary cultures of silkworm, Bombyx mori (Lep.: Bombycidae)

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    Since the use of insect cell lines for producing bio-pesticides and recombinant proteins is increasing, the establishment of new cell lines will help to enrich this industry. Therefore, several primary cultures were initiated from embryonic tissues of silkworm, Bombyx mori L. using both enzymatic and mechanical methods. The cultures were incubated in TC-100 medium supplemented with 10 and 20% concentrations of fetal bovine serum (FBS) at 27ºC. Among the methods used, homogenizing the embryonic tissue represented the best culture, which reached the confluence state sooner. Six different morphologies were distinguished in the embryonic primary cultures of silkworm including fibroblast-like cells with three sub-forms of A to C, spindle shaped cells, spherical cells and epithelial-like cells. Also, developing primary cultures from B. mori using enzymatic method is not recommended because of its low efficiency

    Deep sequencing-based transcriptome analysis of Plutella xylostella larvae parasitized by Diadegma semiclausum

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    Background: Parasitoid insects manipulate their hosts' physiology by injecting various factors into their host upon parasitization. Transcriptomic approaches provide a powerful approach to study insect host-parasitoid interactions at the molecular level. In order to investigate the effects of parasitization by an ichneumonid wasp (Diadegma semiclausum) on the host (Plutella xylostella), the larval transcriptome profile was analyzed using a short-read deep sequencing method (Illumina). Symbiotic polydnaviruses (PDVs) associated with ichneumonid parasitoids, known as ichnoviruses, play significant roles in host immune suppression and developmental regulation. In the current study, D. semiclausum ichnovirus (DsIV) genes expressed in P. xylostella were identified and their sequences compared with other reported PDVs. Five of these genes encode proteins of unknown identity, that have not previously been reported

    Archival search for historical atypical scrapie in sheep reveals evidence for mixed infections

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    Flaviviruses are arthropod-borne viruses found worldwide and are responsible for significant human and veterinary diseases, including dengue, Zika, and West Nile fever. Some flaviviruses are insect specific and replicate only in mosquitoes. We report a genetically divergent group of insect-specific flaviviruses from Anopheles mosquitoes that do not replicate in arthropod cell lines or heterologous Anopheles species, exhibiting unprecedented specialization for their host species. Determination of the complete sequences of the RNA genomes of three of these viruses, Karumba virus (KRBV), Haslams Creek virus, and Mac Peak virus (McPV), that are found in high prevalence in some Anopheles mosquito populations and detection of virus-specific proteins, replicative double-stranded RNA, and small interfering RNA responses in the host mosquito species provided strong evidence of a functional replicating virus in the mosquito midgut. Analysis of nucleotide composition in the KRBV and McPV sequences also revealed a pattern consistent with the virus evolving to replicate only in insects. These findings represent a significant advance in our knowledge of mosquito-borne flavivirus ecology, host restriction, and evolution

    Ionic liquids at electrified interfaces

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    Until recently, “room-temperature” (<100–150 °C) liquid-state electrochemistry was mostly electrochemistry of diluted electrolytes(1)–(4) where dissolved salt ions were surrounded by a considerable amount of solvent molecules. Highly concentrated liquid electrolytes were mostly considered in the narrow (albeit important) niche of high-temperature electrochemistry of molten inorganic salts(5-9) and in the even narrower niche of “first-generation” room temperature ionic liquids, RTILs (such as chloro-aluminates and alkylammonium nitrates).(10-14) The situation has changed dramatically in the 2000s after the discovery of new moisture- and temperature-stable RTILs.(15, 16) These days, the “later generation” RTILs attracted wide attention within the electrochemical community.(17-31) Indeed, RTILs, as a class of compounds, possess a unique combination of properties (high charge density, electrochemical stability, low/negligible volatility, tunable polarity, etc.) that make them very attractive substances from fundamental and application points of view.(32-38) Most importantly, they can mix with each other in “cocktails” of one’s choice to acquire the desired properties (e.g., wider temperature range of the liquid phase(39, 40)) and can serve as almost “universal” solvents.(37, 41, 42) It is worth noting here one of the advantages of RTILs as compared to their high-temperature molten salt (HTMS)(43) “sister-systems”.(44) In RTILs the dissolved molecules are not imbedded in a harsh high temperature environment which could be destructive for many classes of fragile (organic) molecules

    A global experiment on motivating social distancing during the COVID-19 pandemic

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    Finding communication strategies that effectively motivate social distancing continues to be a global public health priority during the COVID-19 pandemic. This cross-country, preregistered experiment (n = 25,718 from 89 countries) tested hypotheses concerning generalizable positive and negative outcomes of social distancing messages that promoted personal agency and reflective choices (i.e., an autonomy-supportive message) or were restrictive and shaming (i.e., a controlling message) compared with no message at all. Results partially supported experimental hypotheses in that the controlling message increased controlled motivation (a poorly internalized form of motivation relying on shame, guilt, and fear of social consequences) relative to no message. On the other hand, the autonomy-supportive message lowered feelings of defiance compared with the controlling message, but the controlling message did not differ from receiving no message at all. Unexpectedly, messages did not influence autonomous motivation (a highly internalized form of motivation relying on one’s core values) or behavioral intentions. Results supported hypothesized associations between people’s existing autonomous and controlled motivations and self-reported behavioral intentions to engage in social distancing. Controlled motivation was associated with more defiance and less long-term behavioral intention to engage in social distancing, whereas autonomous motivation was associated with less defiance and more short- and long-term intentions to social distance. Overall, this work highlights the potential harm of using shaming and pressuring language in public health communication, with implications for the current and future global health challenges

    Small RNA Profiling in Dengue Virus 2-Infected Aedes Mosquito Cells Reveals Viral piRNAs and Novel Host miRNAs

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    Contains fulltext : 171518.PDF (publisher's version ) (Open Access)In Aedes mosquitoes, infections with arthropod-borne viruses (arboviruses) trigger or modulate the expression of various classes of viral and host-derived small RNAs, including small interfering RNAs (siRNAs), PIWI interacting RNAs (piRNAs), and microRNAs (miRNAs). Viral siRNAs are at the core of the antiviral RNA interference machinery, one of the key pathways that limit virus replication in invertebrates. Besides siRNAs, Aedes mosquitoes and cells derived from these insects produce arbovirus-derived piRNAs, the best studied examples being viruses from the Togaviridae or Bunyaviridae families. Host miRNAs modulate the expression of a large number of genes and their levels may change in response to viral infections. In addition, some viruses, mostly with a DNA genome, express their own miRNAs to regulate host and viral gene expression. Here, we perform a comprehensive analysis of both viral and host-derived small RNAs in Aedes aegypti Aag2 cells infected with dengue virus 2 (DENV), a member of the Flaviviridae family. Aag2 cells are competent in producing all three types of small RNAs and provide a powerful tool to explore the crosstalk between arboviral infection and the distinct RNA silencing pathways. Interestingly, besides the well-characterized DENV-derived siRNAs, a specific population of viral piRNAs was identified in infected Aag2 cells. Knockdown of Piwi5, Ago3 and, to a lesser extent, Piwi6 results in reduction of vpiRNA levels, providing the first genetic evidence that Aedes PIWI proteins produce DENV-derived small RNAs. In contrast, we do not find convincing evidence for the production of virus-derived miRNAs. Neither do we find that host miRNA expression is strongly changed upon DENV2 infection. Finally, our deep-sequencing analyses detect 30 novel Aedes miRNAs, complementing the repertoire of regulatory small RNAs in this important vector species

    A global experiment on motivating social distancing during the COVID-19 pandemic

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    Significance Communicating in ways that motivate engagement in social distancing remains a critical global public health priority during the COVID-19 pandemic. This study tested motivational qualities of messages about social distancing (those that promoted choice and agency vs. those that were forceful and shaming) in 25,718 people in 89 countries. The autonomy-supportive message decreased feelings of defying social distancing recommendations relative to the controlling message, and the controlling message increased controlled motivation, a less effective form of motivation, relative to no message. Message type did not impact intentions to socially distance, but people’s existing motivations were related to intentions. Findings were generalizable across a geographically diverse sample and may inform public health communication strategies in this and future global health emergencies. Abstract Finding communication strategies that effectively motivate social distancing continues to be a global public health priority during the COVID-19 pandemic. This cross-country, preregistered experiment (n = 25,718 from 89 countries) tested hypotheses concerning generalizable positive and negative outcomes of social distancing messages that promoted personal agency and reflective choices (i.e., an autonomy-supportive message) or were restrictive and shaming (i.e., a controlling message) compared with no message at all. Results partially supported experimental hypotheses in that the controlling message increased controlled motivation (a poorly internalized form of motivation relying on shame, guilt, and fear of social consequences) relative to no message. On the other hand, the autonomy-supportive message lowered feelings of defiance compared with the controlling message, but the controlling message did not differ from receiving no message at all. Unexpectedly, messages did not influence autonomous motivation (a highly internalized form of motivation relying on one’s core values) or behavioral intentions. Results supported hypothesized associations between people’s existing autonomous and controlled motivations and self-reported behavioral intentions to engage in social distancing. Controlled motivation was associated with more defiance and less long-term behavioral intention to engage in social distancing, whereas autonomous motivation was associated with less defiance and more short- and long-term intentions to social distance. Overall, this work highlights the potential harm of using shaming and pressuring language in public health communication, with implications for the current and future global health challenges
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