259 research outputs found

    Effect of photoperiod and host distribution on the horizontal transmission of Isaria fumosorosea (Hypocreales: Cordycipitaceae) in greenhouse whitefly assessed using a novel model bioassay

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    A model bioassay was used to evaluate the epizootic potential and determine the horizontal transmission efficiency of Isaria fumosorosea Trinidadian strains against Trialeurodes vaporariorum pharate adults under optimum conditions (25±0.5°C, ~100% RH) at two different photoperiods. Untreated pharate adults were arranged on laminated graph paper at different distributions to simulate varying infestation levels on a leaf surface. Four potential hosts were located 7, 14 and 21 mm away from a central sporulating cadaver simulating high, medium and low infestation levels, respectively. Percent hosts colonized were recorded 7, 12, 14 and 21 days post-treatment during a 16- and 24-h photophase. After 21 days, mean percent hosts colonized at the highest, middle and lowest infestation levels were 93 and 100%, 22 and 58%, 25 and 39% under a 16- and 24-h photophase, respectively. From the results, it was concluded that the longer the photophase, the greater the percentage of hosts colonized, and as host distance increased from the central sporulating cadaver, colonization decreased. The use of this novel model bioassay technique is the first attempt to evaluate the epizootic potential and determine the horizontal transmission efficiency of I. fumosorosea Trinidadian strains under optimal environmental conditions at different photoperiods. This bioassay can be used to assess horizontal transmission efficiency for the selection of fungi being considered for commercial biopesticide development

    Analyses of Sulfur and Iron in Waterlogged Archaeological Wood: The Case of Polyethylene-Glycol-Treated Yenikapı 12 Shipwreck

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    The Yenikapı (YK) 12 shipwreck is 1 of 37 shipwrecks found at Yenikapı, Istanbul. This merchantman has been dated to AD 672–876 by radiocarbon analyses. The conservation of YK 12, which was assembled with iron nails, was completed with the pre-impregnation of polyethylene glycol (PEG) and using vacuum freeze-drying processes. However, after conservation, dust formation was observed on some wooden parts of the shipwreck during storage. In this study, iron–sulfur-related problems detected in the woods of YK 12 were evaluated. We analysed samples taken from YK 12 to study the sulfur and iron content in woods from oak (Quercus), walnut (Juglans), and hornbeam (Carpinus), representing taxa with different wood properties. Fourier-transform infrared spectroscopy (FTIR) analyses, X-ray diffraction (XRD), and pH measurements were conducted on five samples. The results of these studies showed that the dust consisted of wood particles, PEG, and hydrated iron sulfates, such as FeSO4·4H2O and FeSO4·7H2O. Additionally, one sample included SiO2, whilst another exhibited a low pH value. These findings highlight the importance of optimum ambient conditions for the storage and display of these shipwrecks in order to prevent the irreversible degradation of YK 12 and other recovered shipwrecks

    A Gauge-Gravity Relation in the One-loop Effective Action

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    We identify an unusual new gauge-gravity relation: the one-loop effective action for a massive spinor in 2n dimensional AdS space is expressed in terms of precisely the same function [a certain multiple gamma function] as the one-loop effective action for a massive charged scalar in 4n dimensions in a maximally symmetric background electromagnetic field [one for which the eigenvalues of F_{\mu\nu} are maximally degenerate, corresponding in 4 dimensions to a self-dual field, equivalently to a field of definite helicity], subject to the identification F^2 \Lambda, where \Lambda is the gravitational curvature. Since these effective actions generate the low energy limit of all one-loop multi-leg graviton or gauge amplitudes, this implies a nontrivial gauge-gravity relation at the non-perturbative level and at the amplitude level.Comment: 6 page

    Regulation of epigenetic modifiers, including KDM6B, by interferon-γ and interleukin-4 in human macrophages

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    BACKGROUND: Interferon-γ (IFN-γ) or interleukin-4 (IL-4) drives widely different transcriptional programs in macrophages. However, how IFN-γ and IL-4 alter expression of histone-modifying enzymes involved in epigenetic regulation and how this affects the resulting phenotypic polarization is incompletely understood. METHODS AND RESULTS: We investigated steady-state messenger RNA levels of 84 histone-modifying enzymes and related regulators in colony-stimulating factor-1 differentiated primary human macrophages using quantitative polymerase chain reaction. IFN-γ or IL-4 treatment for 6–48 h changed 11 mRNAs significantly. IFN-γ increased CIITA, KDM6B, and NCOA1, and IL-4 also increased KDM6B by 6 h. However, either cytokine decreased AURKB, ESCO2, SETD6, SUV39H1, and WHSC1, whereas IFN-γ alone decreased KAT2A, PRMT7, and SMYD3 mRNAs only after 18 h, which coincided with decreased cell proliferation. Rendering macrophages quiescent by growth factor starvation or adenovirus-mediated overexpression of p27(kip1) inhibited expression of AURKB, ESCO2, SUV39H1, and WHSC1, and mRNA levels were restored by overexpressing the S-phase transcription factor E2F1, implying their expression, at least partly, depended on proliferation. However, CIITA, KDM6B, NCOA1, KAT2A, PRMT7, SETD6, and SMYD3 were regulated independently of effects on proliferation. Silencing KDM6B, the only transcriptional activator upregulated by both IFN-γ and IL-4, pharmacologically or with short hairpin RNA, blunted a subset of responses to each cytokine. CONCLUSION: These findings demonstrate that IFN-γ or IL-4 can regulate the expression of histone acetyl transferases and histone methyl transferases independently of effects on proliferation and that upregulation of the histone demethylase, KDM6B, assists phenotypic polarization by both cytokines

    Developing Participatory Methods to Consider the Ethics of Emerging Technologies for Children (Extended Abstract)

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    This SIG will provide child-computer interaction researchers and practitioners, as well as other interested CHI attendees, an opportunity to discuss topics related to developing participatory methods to consider the ethics of emerging technologies for children. While the community has extensively debated on ethical issues, we have not had ample discussion of methods to study the ethical implications of emerging technologies. Consequently, we have been largely reactive and have not made significant contributions to public discussions on these topics, leaving these largely to experts from other fields. Our community is well-placed to contribute unique perspectives by leveraging its expertise in participatory methods, combining expert views with those of stakeholders, including children
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