210 research outputs found

    Variable Response of Kochia Accessions to Dicamba and Fluroxypyr in Western Kansas

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    The rapid development of glyphosate resistance in kochia has increased the use of auxinic herbicides (dicamba and fluroxypyr) in the US Great Plains, including Kansas. Increasing reliance on auxinic herbicides for controlling glyphosate-resistant (GR) kochia may also enhance the evolution of resistance to these herbicide chemistries. The main objectives of this research were to (1) investigate the variation in kochia response to dicamba and fluroxypyr, and (2) characterize the dicamba resistance levels among progeny of kochia accessions collected from western Kansas. Greenhouse experiments were conducted at the Kansas State University Agricultural Research Center near Hays, KS. Discriminate-dose studies with field-use rates of Clarity (dicamba) (16 fl oz/a) and Starane Ultra (fluroxypyr) (0.6 pt/a) indicated that progeny from individual kochia plants (accessions) collected near Garden City, KS, had 78 to 100% and 85 to 100% survivors when treated with dicamba and fluroxypyr herbicides, respectively, at 28 days after treatment (DAT). In separate dicamba dose-response experiments, two putative dicamba-resistant (DR) kochia accessions viz., DR-110 and DR-113 collected near Hays, KS, had about 5- and 3-fold resistance to dicamba, respectively, based on fresh weight reduction (I50) compared to a dicamba-susceptible (DS) accession. Based on plant dry weight response, the DR-110 and DR-113 accessions showed 9- and 6-fold resistance to dicamba, respectively. These results confirm the co-evolution of cross-resistance to dicamba and fluroxypyr in kochia accessions from Garden City, and moderate to high level resistance to dicamba in the Hays accessions. Growers should adopt stewardship programs for auxinic herbicides and utilize all available weed control tactics to prevent further evolution of auxinic resistance in kochia populations

    A direct association between amber and dinosaur remains provides paleoecological insights

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    This work is licensed under a Creative Commons Attribution 4.0 International License.Hadrosaurian dinosaurs were abundant in the Late Cretaceous of North America, but their habitats remain poorly understood. Cretaceous amber is also relatively abundant, yet it is seldom found in direct stratigraphic association with dinosaur remains. Here we describe an unusually large amber specimen attached to a Prosaurolophus jaw, which reveals details of the contemporaneous paleoforest and entomofauna. Fourier-transform Infrared spectroscopy and stable isotope composition (H and C) suggest the amber formed from resins exuded by cupressaceous conifers occupying a coastal plain. An aphid within the amber belongs to Cretamyzidae, a Cretaceous family suggested to bark-feed on conifers. Distinct tooth row impressions on the amber match the hadrosaur’s alveolar bone ridges, providing some insight into the taphonomic processes that brought these remains together

    Measurement of the neutron lifetime using an asymmetric magneto- gravitational trap and in situ detection

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    The precise value of the mean neutron lifetime, τn\tau_n, plays an important role in nuclear and particle physics and cosmology. It is a key input for predicting the ratio of protons to helium atoms in the primordial universe and is used to search for new physics beyond the Standard Model of particle physics. There is a 3.9 standard deviation discrepancy between τn\tau_n measured by counting the decay rate of free neutrons in a beam (887.7 ±\pm 2.2 s) and by counting surviving ultracold neutrons stored for different storage times in a material trap (878.5±\pm0.8 s). The experiment described here eliminates loss mechanisms present in previous trap experiments by levitating polarized ultracold neutrons above the surface of an asymmetric storage trap using a repulsive magnetic field gradient so that the stored neutrons do not interact with material trap walls and neutrons in quasi-stable orbits rapidly exit the trap. As a result of this approach and the use of a new in situ neutron detector, the lifetime reported here (877.7 ±\pm 0.7 (stat) +0.4/-0.2 (sys) s) is the first modern measurement of τn\tau_n that does not require corrections larger than the quoted uncertainties.Comment: 9 pages, 3 figures, 2 table

    Resolving dual binding conformations of cellulosome cohesin-dockerin complexes using single-molecule force spectroscopy

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    Receptor-ligand pairs are ordinarily thought to interact through a lock and key mechanism, where a unique molecular conformation is formed upon binding. Contrary to this paradigm, cellulosomal cohesin-dockerin (Coh-Doc) pairs are believed to interact through redundant dual binding modes consisting of two distinct conformations. Here, we combined site-directed mutagenesis and single-molecule force spectroscopy (SMFS) to study the unbinding of Coh:Doc complexes under force. We designed Doc mutations to knock out each binding mode, and compared their single-molecule unfolding patterns as they were dissociated from Coh using an atomic force microscope (AFM) cantilever. Although average bulk measurements were unable to resolve the differences in Doc binding modes due to the similarity of the interactions, with a single-molecule method we were able to discriminate the two modes based on distinct differences in their mechanical properties. We conclude that under native conditions wild-type Doc from Clostridium thermocellum exocellulase Cel48S populates both binding modes with similar probabilities. Given the vast number of Doc domains with predicteddual binding modes across multiple bacterial species, our approach opens up newpossibilities for understanding assembly and catalytic properties of a broadrange of multi-enzyme complexes

    Measurement of charged particle multiplicities in pppp collisions at s=7{\sqrt{s} =7}TeV in the forward region

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    The charged particle production in proton-proton collisions is studied with the LHCb detector at a centre-of-mass energy of s=7{\sqrt{s} =7}TeV in different intervals of pseudorapidity η\eta. The charged particles are reconstructed close to the interaction region in the vertex detector, which provides high reconstruction efficiency in the η\eta ranges −2.5<η<−2.0-2.5<\eta<-2.0 and 2.0<η<4.52.0<\eta<4.5. The data were taken with a minimum bias trigger, only requiring one or more reconstructed tracks in the vertex detector. By selecting an event sample with at least one track with a transverse momentum greater than 1 GeV/c a hard QCD subsample is investigated. Several event generators are compared with the data; none are able to describe fully the multiplicity distributions or the charged particle density distribution as a function of η\eta. In general, the models underestimate the charged particle production

    Is the ADA/EASD algorithm for the management of type 2 diabetes (January 2009) based on evidence or opinion? A critical analysis

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    The ADA and the EASD recently published a consensus statement for the medical management of hyperglycaemia in patients with type 2 diabetes. The authors advocate initial treatment with metformin monotherapy and lifestyle modification, followed by addition of basal insulin or a sulfonylurea if glycaemic goals are not met (tier 1 recommendations). All other glucose-lowering therapies are relegated to a secondary (tier 2) status and only recommended for selected clinical settings. In our view, this algorithm does not offer physicians and patients the appropriate selection of options to individualise and optimise care with a view to sustained control of blood glucose and reduction both of diabetes complications and cardiovascular risk. This paper critically assesses the basis of the ADA/EASD algorithm and the resulting tiers of treatment options

    A cluster randomised trial, cost-effectiveness analysis and psychosocial evaluation of insulin pump therapy compared with multiple injections during flexible intensive insulin therapy for type 1 diabetes: the REPOSE Trial.

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    BACKGROUND: Insulin is generally administered to people with type 1 diabetes mellitus (T1DM) using multiple daily injections (MDIs), but can also be delivered using infusion pumps. In the UK, pumps are recommended for patients with the greatest need and adult use is less than in comparable countries. Previous trials have been small, of short duration and have failed to control for training in insulin adjustment. OBJECTIVE: To assess the clinical effectiveness and cost-effectiveness of pump therapy compared with MDI for adults with T1DM, with both groups receiving equivalent structured training in flexible insulin therapy. DESIGN: Pragmatic, multicentre, open-label, parallel-group cluster randomised controlled trial, including economic and psychosocial evaluations. After participants were assigned a group training course, courses were randomly allocated in pairs to either pump or MDI. SETTING: Eight secondary care diabetes centres in the UK. PARTICIPANTS: Adults with T1DM for > 12 months, willing to undertake intensive insulin therapy, with no preference for pump or MDI, or a clinical indication for pumps. INTERVENTIONS: Pump or MDI structured training in flexible insulin therapy, followed up for 2 years. MDI participants used insulin analogues. Pump participants used a Medtronic Paradigm(Âź) Veo(TM) (Medtronic, Watford, UK) with insulin aspart (NovoRapid, Novo Nordisk, Gatwick, UK). MAIN OUTCOME MEASURES: Primary outcome - change in glycated haemoglobin (HbA1c) at 2 years in participants whose baseline HbA1c was ≄ 7.5% (58 mmol/mol). Key secondary outcome - proportion of participants with HbA1c ≀ 7.5% at 2 years. Other outcomes at 6, 12 and 24 months - moderate and severe hypoglycaemia; insulin dose; body weight; proteinuria; diabetic ketoacidosis; quality of life (QoL); fear of hypoglycaemia; treatment satisfaction; emotional well-being; qualitative interviews with participants and staff (2 weeks), and participants (6 months); and ICERs in trial and modelled estimates of cost-effectiveness. RESULTS: We randomised 46 courses comprising 317 participants: 267 attended a Dose Adjustment For Normal Eating course (132 pump; 135 MDI); 260 were included in the intention-to-treat analysis, of which 235 (119 pump; 116 MDI) had baseline HbA1c of ≄ 7.5%. HbA1c and severe hypoglycaemia improved in both groups. The drop in HbA1c% at 2 years was 0.85 on pump and 0.42 on MDI. The mean difference (MD) in HbA1c change at 2 years, at which the baseline HbA1c was ≄ 7.5%, was -0.24% [95% confidence interval (CI) -0.53% to 0.05%] in favour of the pump (p = 0.098). The per-protocol analysis showed a MD in change of -0.36% (95% CI -0.64% to -0.07%) favouring pumps (p = 0.015). Pumps were not cost-effective in the base case and all of the sensitivity analyses. The pump group had greater improvement in diabetes-specific QoL diet restrictions, daily hassle plus treatment satisfaction, statistically significant at 12 and 24 months and supported by qualitative interviews. LIMITATION: Blinding of pump therapy was not possible, although an objective primary outcome was used. CONCLUSION: Adding pump therapy to structured training in flexible insulin therapy did not significantly enhance glycaemic control or psychosocial outcomes in adults with T1DM. RESEARCH PRIORITY: To understand why few patients achieve a HbA1c of < 7.5%, particularly as glycaemic control is worse in the UK than in other European countries. TRIAL REGISTRATION: Current Controlled Trials ISRCTN61215213. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 20. See the NIHR Journals Library website for further project information

    Measurement of charged particle multiplicities and densities in pp collisions root s=7 TeV in the forward region

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    Charged particle multiplicities are studied in proton-proton collisions in the forward region at a centre-of-mass energy of TeV with data collected by the LHCb detector. The forward spectrometer allows access to a kinematic range of in pseudorapidity, momenta greater than and transverse momenta greater than . The measurements are performed using events with at least one charged particle in the kinematic acceptance. The results are presented as functions of pseudorapidity and transverse momentum and are compared to predictions from several Monte Carlo event generators
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