679 research outputs found

    Odorant binding proteins fromHermetia illucens: potential sensing elements for detecting volatile aldehydes involved in early stages of organic decomposition

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    Organic decomposition processes, involving the breakdown of complex molecules such as carbohydrates, proteins and fats, release small chemicals known as volatile organic compounds (VOCs), smelly even at very low concentrations, but not all readily detectable by vertebrates. Many of these compounds are instead detected by insects, mostly by saprophytic species, for which long-range orientation towards organic decomposition matter is crucial. In the present work the detection of aldehydes, as an important measure of lipid oxidation, has been possible exploiting the molecular machinery underlying odour recognition inHermetia illucens(Diptera: Stratiomyidae). This voracious scavenger insect is of interest due to its outstanding capacity in bioconversion of organic waste, colonizing very diverse environments due to the ability of sensing a wide range of chemical compounds that influence the choice of substrates for ovideposition. A variety of soluble odorant binding proteins (OBPs) that may function as carriers of hydrophobic molecules from the air-water interface in the antenna of the insect to the receptors were identified, characterised and expressed. An OBP-based nanobiosensor prototype was realized using selected OBPs as sensing layers for the development of an array of quartz crystal microbalances (QCMs) for vapour phase detection of selected compounds at room temperature. QCMs coated with four recombinantH. illucensOBPs (HillOBPs) were exposed to a wide range of VOCs indicative of organic decomposition, showing a high sensitivity for the detection of three chemical compounds belonging to the class of aldehydes and one short-chain fatty acid. The possibility of using biomolecules capable of binding small ligands as reversible gas sensors has been confirmed, greatly expanding the state-of the-art in gas sensing technology

    Rearing substrate impacts growth and macronutrient composition of Hermetia illucens (L.) (Diptera: Stratiomyidae) larvae produced at an industrial scale

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    Organic waste is a rapidly increasing problem due to the growth of the agricultural production needed to meet global food demands. Development of sustainable waste management solutions is essential. Black soldier fly, Hermetia illucens (L.) (Diptera: Stratiomyidae) (BSF), larvae are voracious consumers of a wide range of organic materials ranging from fruits and vegetables to animal remains, and manure. Thanks to this ability and considering the larval high protein and lipid content, BSF larvae are a useful additive in animal feeds and biodiesel production. Unfortunately, the feasibility of using the black soldier fly as a tool for waste valorization and feed production has primarily been investigated at the benchtop scale. Thus, mobilization of current practices to an industrial scale is challenging because scaling up from small laboratory studies to large industrial studies is not necessarily linear. The goal of this study was to demonstrate the ability of the BSF to recycle organic waste at an industrial scale. To accomplish this goal, three organic waste streams were used (e.g., apples, bananas, and spent grain from a brewery) to test six diet treatments (1) apple, (2) banana, (3) spent grain, (4) apple and banana, (5) apple and spent grain, and (6) banana and spent grain. Working at scale of 10,000 BSF larvae life history traits, waste valorization, protein and lipid profiles were measured for each diet treatment. Differences were recorded across all variables, except substrate conversion, for larvae fed on fruit and spent grain (alone or with fruit). Growth rate significantly differed across treatments; larvae reared on spent grain grew twice as fast as those fed apples alone, but those reared on the apple and spent grain mixture produced twice as much insect biomass. However, it should be noted that larvae resulting from the apple diet contained 50% more fat than larvae fed the fruit and spent grain mixtures. Commonly-available organic wastes were successfully used at an industrial scale to produce BSF larvae that have the potential to substitute other sources of protein and lipids in different industrial applications. Industrialization efforts are encouraged to assess these impacts when integrating diverse ingredients into larval diets as a means to more precisely predict output, such as larval development time and final larval biomass

    Effects of Low-stress Weaning on Calf Growth Performance and Carcass Characteristics

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    The objective of this study was to compare the influence of two low-stress weaning methods with conventional weaning on post-weaning performance and carcass characteristics of beef steers

    Cone dystrophy with "supernormal" rod ERG: psychophysical testing reveals comparable rod and cone temporal sensitivity losses with no gain in rod function

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    Purpose: We report a psychophysical investigation of five observers with the retinal disorder "cone dystrophy with supernormal rod ERG", caused by mutations in the gene KCNV2 that encodes a voltage-gated potassium channel found in rod and cone photoreceptors. We compare losses for rod- and for cone-mediated vision to further investigate the disorder and to assess whether the supernormal ERG is associated with any visual benefit. Methods: L-cone, S-cone and rod temporal acuity (critical flicker fusion frequency-cff) was measured as a function of target irradiance; L-cone temporal contrast-sensitivity was measured as a function of temporal frequency. Results: Temporal acuity measures reveal that losses for vision mediated by rods, S-cones and L-cones are roughly equivalent. Further, the gain in rod function implied by the supernormal ERG provides no apparent benefit to near-threshold rod-mediated visual performance. The L-cone temporal contrast-sensitivity function in affected observers is similar in shape to the mean normal function but only after the mean function has been compressed by halving the logarithmic sensitivities. Conclusions: The name of this disorder is potentially misleading because the comparable losses found across rod and cone vision suggest that the disorder is a generalized cone-rod dystrophy. Temporal acuity and temporal contrast-sensitivity measures are broadly consistent with the defect in the voltage-gated potassium channel producing a nonlinear distortion of the photoreceptor response but after otherwise normal transduction processes

    The contested and contingent outcomes of Thatcherism in the UK

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    The death of Margaret Thatcher in April 2013 sparked a range of discussions and debates about the significance of her period in office and the political project to which she gave her name: Thatcherism. This article argues that Thatcherism is best understood as a symbolically important part of the emergence of first-phase neoliberalism. It engages with contemporary debates about Thatcherism among Marxist commentators and suggests that several apparently divergent positions can help us now reach a more useful analysis of Thatcherism’s short- and long-term outcomes for British political economy. The outcomes identified include: an initial crisis in the neoliberal project in the UK; the transformation of the party political system to be reflective of the politics of neoliberalism, rather than its contestation; long-term attempts at the inculcation of the neoliberal individual; de-industrialisation and financial sector dependence; and a fractured and partially unconscious working class. In all long-term outcomes, the contribution of Thatcherism is best understood as partial and largely negative, in that it cleared the way for a longer-term and more constructive attempt to embed neoliberal political economy. The paper concludes by suggesting that this analysis can inform current debates on the left of British politics about how to oppose and challenge the imposition of neoliberal discipline today

    Tetrahydropyrazolo[1,5-a]Pyrimidine-3-Carboxamide and N-Benzyl-6′,7′-Dihydrospiro[Piperidine-4,4′-Thieno[3,2-c]Pyran] analogues with bactericidal efficacy against Mycobacterium tuberculosis targeting MmpL3

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    Mycobacterium tuberculosis is a major human pathogen and the causative agent for the pulmonary disease, tuberculosis (TB). Current treatment programs to combat TB are under threat due to the emergence of multi-drug and extensively-drug resistant TB. As part of our efforts towards the discovery of new anti-tubercular leads, a number of potent tetrahydropyrazolo[1,5-a]pyrimidine-3-ca​rboxamide(THPP) and N-benzyl-6′,7′-dihydrospiro[piperidine-4,​4′-thieno[3,2-c]pyran](Spiro) analogues were recently identified against Mycobacterium tuberculosis and Mycobacterium bovis BCG through a high-throughput whole-cell screening campaign. Herein, we describe the attractive in vitro and in vivo anti-tubercular profiles of both lead series. The generation of M. tuberculosis spontaneous mutants and subsequent whole genome sequencing of several resistant mutants identified single mutations in the essential mmpL3 gene. This ‘genetic phenotype’ was further confirmed by a ‘chemical phenotype’, whereby M. bovis BCG treated with both the THPP and Spiro series resulted in the accumulation of trehalose monomycolate. In vivo efficacy evaluation of two optimized THPP and Spiro leads showed how the compounds were able to reduce >2 logs bacterial cfu counts in the lungs of infected mice

    The transcriptional repressor protein NsrR senses nitric oxide directly via a [2Fe-2S] cluster

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    The regulatory protein NsrR, a member of the Rrf2 family of transcription repressors, is specifically dedicated to sensing nitric oxide (NO) in a variety of pathogenic and non-pathogenic bacteria. It has been proposed that NO directly modulates NsrR activity by interacting with a predicted [Fe-S] cluster in the NsrR protein, but no experimental evidence has been published to support this hypothesis. Here we report the purification of NsrR from the obligate aerobe Streptomyces coelicolor. We demonstrate using UV-visible, near UV CD and EPR spectroscopy that the protein contains an NO-sensitive [2Fe-2S] cluster when purified from E. coli. Upon exposure of NsrR to NO, the cluster is nitrosylated, which results in the loss of DNA binding activity as detected by bandshift assays. Removal of the [2Fe-2S] cluster to generate apo-NsrR also resulted in loss of DNA binding activity. This is the first demonstration that NsrR contains an NO-sensitive [2Fe-2S] cluster that is required for DNA binding activity

    Targeted redox inhibition of protein phosphatase 1 by Nox4 regulates eIF2a-mediated stress signaling

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    Source: doi: 10.15252/embj.201592394Phosphorylation of translation initiation factor 2α (eIF2α) attenuates global protein synthesis but enhances translation of activating transcription factor 4 (ATF4) and is a crucial evolutionarily conserved adaptive pathway during cellular stresses. The serine–threonine protein phosphatase 1 (PP1) deactivates this pathway whereas prolonging eIF2α phosphorylation enhances cell survival. Here, we show that the reactive oxygen species‐generating NADPH oxidase‐4 (Nox4) is induced downstream of ATF4, binds to a PP1‐targeting subunit GADD34 at the endoplasmic reticulum, and inhibits PP1 activity to increase eIF2α phosphorylation and ATF4 levels. Other PP1 targets distant from the endoplasmic reticulum are unaffected, indicating a spatially confined inhibition of the phosphatase. PP1 inhibition involves metal center oxidation rather than the thiol oxidation that underlies redox inhibition of protein tyrosine phosphatases. We show that this Nox4‐regulated pathway robustly enhances cell survival and has a physiologic role in heart ischemia–reperfusion and acute kidney injury. This work uncovers a novel redox signaling pathway, involving Nox4–GADD34 interaction and a targeted oxidative inactivation of the PP1 metal center, that sustains eIF2α phosphorylation to protect tissues under stress

    Protecting the environment through insect farming as a means to produce protein for use as livestock, poultry, and aquaculture feed

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    Securing protein for the approximate 10 billion humans expected to inhabit our planet by 2050 is a major priority for the global community. Evidence has accrued over the past 30 years that strongly supports and justifies the sustainable use of insects as a means to produce protein products as feed for pets, livestock, poultry, and aquacultured species. Researchers and entrepreneurs affiliated with universities and industries, respectively, from 18 nations distributed across North and South America, Europe, Asia, Africa and Australia contributed to the development of this article, which is an indication of the global interest on this topic. A brief overview of insects as feed for the aquaculture industry along with a review of the black soldier fly, Hermetia illucens (Diptera: Stratiomyidae), as a model for such systems is provided
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