1,290 research outputs found

    Identification and Functional Characterization of Toxoneuron nigriceps Ovarian Proteins Involved in the Early Suppression of Host Immune Response

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    The endophagous parasitoid Toxoneuron nigriceps (Viereck) (Hymenoptera, Braconidae) of the larval stages of the tobacco budworm Heliothis virescens (Fabricius) (Lepidoptera, Noctuidae) injects the egg, the venom, the calyx fluid, which includes a Polydnavirus (T. nigriceps BracoVirus: TnBV) and the Ovarian Proteins (OPs) into the host body during oviposition. The host metabolism and immune system are disrupted prematurely shortly after parasitization by the combined action of the TnBV, venom, and OPs. OPs are involved in the early suppression of host immune response, before TnBV infects and expresses its genes in the host tissues. In this work, we evaluated the effect of HPLC fractions deriving from in toto OPs. Two fractions caused a reduction in hemocyte viability and were subsequently tested to detect changes in hemocyte morphology and functionality. The two fractions provoked severe oxidative stress and actin cytoskeleton disruption, which might explain the high rate of hemocyte mortality, loss of hemocyte functioning, and hence the host\u2019s reduced hemocyte encapsulation ability. Moreover, through a transcriptome and proteomic approach we identify the proteins of the two fractions: eight proteins were identified that might be involved in the observed host hemocyte changes. Our findings will contribute to a better understanding of the secreted ovarian components and their role in parasitoid wasp strategy for evading host immune responses

    Solute Concentrations Influence Microbial Methanogenesis in Coal-bearing Strata of the Cherokee Basin, USA

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    Microorganisms have contributed significantly to subsurface energy resources by converting organic matter in hydrocarbon reservoirs into methane, the main component of natural gas. In this study, we consider environmental controls on microbial populations in coal-bearing strata of the Cherokee basin, an unconventional natural gas resource in southeast Kansas, USA. Pennsylvanian-age strata in the basin contain numerous thin (0.4-1.1 m) coalbeds with marginal thermal maturities (0.5-0.7% Ro) that are interbedded with shale and sandstone. We collected gas, water, and microbe samples from 16 commercial coalbed methane wells for geochemical and microbiological analysis. The water samples were Na-Cl type with total dissolved solids (TDS) content ranging from 34.9 to 91.3 g L?1. Gas dryness values [C1/(C2 + C3)] averaged 2640 and carbon and hydrogen isotope ratios of methane differed from those of carbon dioxide and water, respectively, by an average of 65 and 183%. These values are thought to be consistent with gas that formed primarily by hydrogenotrophic methanogenesis. Results from cultivation assays and taxonomic analysis of 16S rRNA genes agree with the geochemical results. Cultivable methanogens were present in every sample tested, methanogen sequences dominate the archaeal community in each sample (avg 91%), and few archaeal sequences (avg 4.2%) were classified within Methanosarcinales, an order of methanogens known to contain methylotrophic methanogens. Although hydrogenotrophs appear dominant, geochemical and microbial analyses both indicate that the proportion of methane generated by acetoclastic methanogens increases with the solute content of formation water, a trend that is contrary to existing conceptual models. Consistent with this trend, beta diversity analyses show that archaeal diversity significantly correlates with formation water solute content. In contrast, bacterial diversity more strongly correlates with location than solute content, possibly as a result of spatial variation in the thermal maturity of the coalbeds.Citation: Kirk MF, Wilson BH, Marquart KA, Zeglin LH, Vinson DS and Flynn TM (2015) Solute Concentrations Influence Microbial Methanogenesis in Coal-bearing Strata of the Cherokee Basin, USA. Front. Microbiol. 6:1287. doi: 10.3389/fmicb.2015.0128

    MetExplore: a web server to link metabolomic experiments and genome-scale metabolic networks

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    High-throughput metabolomic experiments aim at identifying and ultimately quantifying all metabolites present in biological systems. The metabolites are interconnected through metabolic reactions, generally grouped into metabolic pathways. Classical metabolic maps provide a relational context to help interpret metabolomics experiments and a wide range of tools have been developed to help place metabolites within metabolic pathways. However, the representation of metabolites within separate disconnected pathways overlooks most of the connectivity of the metabolome. By definition, reference pathways cannot integrate novel pathways nor show relationships between metabolites that may be linked by common neighbours without being considered as joint members of a classical biochemical pathway. MetExplore is a web server that offers the possibility to link metabolites identified in untargeted metabolomics experiments within the context of genome-scale reconstructed metabolic networks. The analysis pipeline comprises mapping metabolomics data onto the specific metabolic network of an organism, then applying graph-based methods and advanced visualization tools to enhance data analysis. The MetExplore web server is freely accessible at http://metexplore.toulouse.inra.fr

    Placenta-Like Structure of the Aphid Endoparasitic Wasp Aphidius ervi: A Strategy of Optimal Resources Acquisition

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    Aphidius ervi (Hymenoptera: Braconidae) is an entomophagous parasitoid known to be an effective parasitoid of several aphid species of economic importance. A reduction of its production cost during mass rearing for inundative release is needed to improve its use in biological control of pests. In these contexts, a careful analysis of its entire development phases within its host is needed. This paper shows that this parasitoid has some characteristics in its embryological development rather complex and different from most other reported insects, which can be phylogenetically very close. First, its yolkless egg allows a high fecundity of the female but force them to hatch from the egg shell rapidly to the host hemocoel. An early cellularisation allowing a rapid differentiation of a serosa membrane seems to confirm this hypothesis. The serosa wraps the developing embryo until the first instar larva stage and invades the host tissues by microvilli projections and form a placenta like structure able to divert host resources and allowing nutrition and respiration of embryo. Such interspecific invasion, at the cellular level, recalls mammal's trophoblasts that anchors maternal uterine wall and underlines the high adaptation of A. ervi to develop in the host body

    Lifetime determination of excited states in Cd-106

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    Two separate experiments using the Differential Decay Curve Method have been performed to extract mean lifetimes of excited states in 106 Cd. The inedium-spin states of interest were populated by the Mo-98(C-12, 4n) Cd-106 reaction performed at the Wright Nuclear Structure Lab., Yale University. From this experiment, two isomeric state mean lifetimes have been deduced. The low-lying states were populated by the Mo-96(C-13, 3n)Cd-106 reaction performed at the Institut fur Kernphysik, Universitat zu Koln. The mean lifetime of the I-pi = 2(1)(+) state was deduced, tentatively, as 16.4(9) ps. This value differs from the previously accepted literature value from Coulomb excitation of 10.43(9) ps

    Localisation of renin-angiotensin system (RAS) components in breast

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    Angiotensin II has mitogenic and angiogenic effects and its receptors are widespread, particularly in epithelial tissue. Tissue renin angiotensin systems (tRASs) may be a local source of angiotensin II that has specific paracrine functions. To investigate the presence of a tRAS in normal human breast and tumours. Immunocytochemistry, and quantitative RT–PCR was used to establish: (i) the presence and localisation of RAS components, (ii) the possibility of their involvement in cancer. (1) mRNA coding for angiotensinogen, prorenin, angiotensin converting enzyme (ACE), and both AT1 and AT2 receptors was demonstrated in normal and diseased breast tissues. (2) (pro)renin was identified in epithelial cells in both normal and diseased tissue, but in invasive carcinoma, its distribution was mostly confined to fibroblasts or could not be detected at all. (3) Angiotensin converting enzyme was shown in epithelial cells in both normal and malignant tissue. The results are consistent with the hypothesis that a tRAS is present in the breast, and is disrupted in invasive cancer

    A role for core planar polarity proteins in cell contact-mediated orientation of planar cell division across the mammalian embryonic skin

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    Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. © The Author(s) 2017. Supplementary information accompanies this paper at doi:10.1038/s41598-017-01971-2.The question of how cell division orientation is determined is fundamentally important for understanding tissue and organ shape in both healthy or disease conditions. Here we provide evidence for cell contact-dependent orientation of planar cell division in the mammalian embryonic skin. We propose a model where the core planar polarity proteins Celsr1 and Frizzled-6 (Fz6) communicate the long axis orientation of interphase basal cells to neighbouring basal mitoses so that they align their horizontal division plane along the same axis. The underlying mechanism requires a direct, cell surface, planar polarised cue, which we posit depends upon variant post-translational forms of Celsr1 protein coupled to Fz6. Our hypothesis has parallels with contact-mediated division orientation in early C. elegans embryos suggesting functional conservation between the adhesion-GPCRs Celsr1 and Latrophilin-1. We propose that linking planar cell division plane with interphase neighbour long axis geometry reinforces axial bias in skin spreading around the mouse embryo body.Peer reviewe

    Wave Propagation in Auxetic Tetrachiral Honeycombs

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    This paper describes a numerical and experimental investigation on the flexural wave propagation properties of a novel class of negative Poisson's ratio honeycombs with tetrachiral topology. Tetrachiral honeycombs are structures defined by cylinders connected by four tangent ligaments, leading to a negative Poisson's ratio (auxetic) behavior in the plane due to combined cylinder rotation and bending of the ribs. A Bloch wave approach is applied to the representative unit cell of the honeycomb to calculate the dispersion characteristics and phase constant surfaces varying the geometric parameters of the unit cell. The modal density of the tetrachiral lattice and of a sandwich panel having the tetrachiral as core is extracted from the integration of the phase constant surfaces, and compared with the experimental ones obtained from measurements using scanning laser vibrometers

    Blood levels of lead and dental caries in permanent teeth

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    ObjectivesThe purpose of this study was to determine whether there is an association between lead exposure within the ages of 1- 4- years and dental caries in the permanent dentition between ages 9- 17 among Mexican youth.MethodsData were collected for the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) cohort from a group of 490 children born and reared in Mexico City. Among ages 1- 4- years, blood lead levels were measured in micrograms of lead per deciliter of blood (μg/dL) and the presence of caries in adolescence was determined using the International Caries and Detection and Assessment System (ICDAS). The relationship between blood levels of lead and decayed, missing, or filled surfaces (DMFS) was examined using negative binomial regression. Covariates were selected based on previous studies and included age, gender, socioeconomic status, oral hygiene, body mass index, and diet. The nonlinear relationship between lead and DMFS was examined using smoothing splines.ResultsThe mean overall blood lead level (BLL) was 4.83- μg/dL (S.D. of 2.2). The mean overall caries level (DMFS) was 4.1. No statistically significant association was found between early childhood blood lead levels and dental caries in adolescence.ConclusionThis study shows a lack of association between exposure to lead between the ages of 1- 4- years of age and dental caries in permanent dentition later in life. Other covariates, such as age and sugar consumption, appeared to play a more prominent role in caries development.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163870/1/jphd12384.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163870/2/jphd12384_am.pd
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