14,924 research outputs found

    Effects of Aspen Phenolic Glycosides on Gypsy Moth (Lepidoptera: Lymantriidae) Susceptibility to \u3ci\u3eBacillus Thuringiensis\u3c/i\u3e

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    Performance of the gypsy moth, Lymantria dispar, on quaking aspen, Populus tremuloides, is strongly affected by foliar concentrations of phenolic glycosides. Because the microbial insecticide Bacillus thuringiensis is widely used against gypsy moths and has a mode of action similar to that of phenolic glycosIdes, we investigated the combined effects of the two toxins on gypsy moth larvae. The experimental design was a 2 x 2 factorial: two levels (0, +) of phenolicglycosides for each of two levels (0, +) of B. thuringiensis. The toxins were incorporated into artificial diets and bioassayed against first and fourth instars. Bacillus thuringiensis and phenolic glycosides ne~atively and addi· tively affected larval survival, growth and development tImes. Both agents slightly reduced consumption rates. In addition, B. thuringiensis reduced diet digestibility whereas phenolic glycosides decreased the efficiency with which food was converted to biomass. These results suggest that the efficacy of B. thuringiensis applications in aspen forests is likely to be affected by the allelo· chemical composition of foliage

    Available labor supply

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    Labor supply ; Employment

    Catalytic constructive deoxygenation of lignin-derived phenols: new C-C bond formation processes from imidazole-sulfonates and ether cleavage reactions

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    Funding: UK Engineering and Physical Sciences Research Council (EPSRC)As part of a programme aimed at exploiting lignin as a chemical feedstock for less oxygenated fine chemicals, several catalytic C-C bond forming reactions utilising guaiacol imidazole sulfonate are demonstrated. These include the cross-coupling of a Grignard, a non-toxic cyanide source, a benzoxazole, and nitromethane. A modified Meyers reaction is used to accomplish a second constructive deoxygenation on a benzoxazole functionalised anisole.Publisher PDFPeer reviewe

    Analogue Methods in Palaeoecology: Using the analogue Package

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    Palaeoecology is an important branch of ecology that uses the subfossil remains of organisms preserved in lake, ocean and bog sediments to inform on changes in ecosystems and the environment through time. The analogue package contains functions to perform modern analogue technique (MAT) transfer functions, which can be used to predict past changes in the environment, such as climate or lake-water pH from species data. A related technique is that of analogue matching, which is concerned with identifying modern sites that are floristically and faunistically similar to fossil samples. These techniques, and others, are increasingly being used to inform public policy on environmental pollution and conservation practices. These methods and other functionality in analogue are illustrated using the Surface Waters Acidification Project diatom:pH training set and diatom counts on samples of a sediment core from the Round Loch of Glenhead, Galloway, Scotland. The paper is aimed at palaeoecologists who are familiar with the techniques described but not with R.

    Tuberculosis in sub-Saharan Africa: opportunities, challenges, and change in the era of antiretroviral treatment.

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    Rapid scale-up of antiretroviral treatment programmes is happening in Africa, driven by international advocacy and policy directives and supported by unprecedented donor funding and technical assistance. This welcome development offers hope to millions of HIV-infected Africans, among whom tuberculosis is the major cause of serious illness and death. Little in the way of HIV diagnosis or care was previously offered to patients with tuberculosis, by either national tuberculosis or AIDS control programmes, with tuberculosis services focused exclusively on diagnosis and treatment of rising numbers of patients. Tuberculosis control in Africa has yet to adapt to the new climate of antiretroviral availability. Many barriers exist, from drug interactions to historic differences in the way that tuberculosis and HIV are perceived, but failure to successfully integrate HIV and tuberculosis control will threaten the viability of both programmes. Here, we review tuberculosis epidemiology in Africa and policy implications of HIV/AIDS treatment scale-up

    Swift observations of the 2015 outburst of AG Peg -- from slow nova to classical symbiotic outburst

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    Symbiotic stars often contain white dwarfs with quasi-steady shell burning on their surfaces. However, in most symbiotics, the origin of this burning is unclear. In symbiotic slow novae, however, it is linked to a past thermonuclear runaway. In June 2015, the symbiotic slow nova AG Peg was seen in only its second optical outburst since 1850. This recent outburst was of much shorter duration and lower amplitude than the earlier eruption, and it contained multiple peaks -- like outbursts in classical symbiotic stars such as Z And. We report Swift X-ray and UV observations of AG Peg made between June 2015 and January 2016. The X-ray flux was markedly variable on a time scale of days, particularly during four days near optical maximum, when the X-rays became bright and soft. This strong X-ray variability continued for another month, after which the X-rays hardened as the optical flux declined. The UV flux was high throughout the outburst, consistent with quasi-steady shell burning on the white dwarf. Given that accretion disks around white dwarfs with shell burning do not generally produce detectable X-rays (due to Compton-cooling of the boundary layer), the X-rays probably originated via shocks in the ejecta. As the X-ray photo-electric absorption did not vary significantly, the X-ray variability may directly link to the properties of the shocked material. AG Peg's transition from a slow symbiotic nova (which drove the 1850 outburst) to a classical symbiotic star suggests that shell burning in at least some symbiotic stars is residual burning from prior novae.Comment: Accepted by MNRAS 23 June 2016. Manuscript submitted in original form 5 April 201

    Developing site-specific guidelines for orchard soils based on bioaccessibility – Can it be done?

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    Horticultural land within the periurban fringe of NZ towns and cities increasingly is being developed for residential subdivision. Recent surveys have shown that concentrations of As, Cd, Cu, Pb, and ΣDDT (sum of DDT and its degradation products DDE and DDD) in such soils can exceed criteria protective of human health.¹ Soil ingestion is a key exposure pathway for non-volatile contaminants in soil. Currently in NZ, site-specific risk assessments and the derivation of soil guidelines protective of human health assume that all of the contaminant present in the soil is available for uptake and absorption by the human gastrointestinal tract. This assumption can overestimate health risks and has implications for the remediation of contaminated sites.² In comparison, the bioavailability of contaminants is considered when estimating exposure via dermal absorption and by ingestion of home-grown produce.³ Dermal absorption factors and plant uptake factors are included in the calculations for estimating exposures via these routes

    Forecasting inflation and output: comparing data-rich models with simple rules

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    There has been a resurgence of interest in dynamic factor models for use by policy advisors. Dynamic factor methods can be used to incorporate a wide range of economic information when forecasting or measuring economic shocks. This article introduces dynamic factor models that underlie the data-rich methods and also tests whether the data-rich models can help a benchmark autoregressive model forecast alternative measures of inflation and real economic activity at horizons of 3, 12, and 24 months ahead. The authors find that, over the past decade, the data-rich models significantly improve the forecasts for a variety of real output and inflation indicators. For all the series that they examine, the authors find that the data-rich models become more useful when forecasting over longer horizons. The exception is the unemployment rate, where the principal components provide significant forecasting information at all horizons.Inflation (Finance) ; Economic forecasting

    Near-optimal protocols in complex nonequilibrium transformations

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    The development of sophisticated experimental means to control nanoscale systems has motivated efforts to design driving protocols which minimize the energy dissipated to the environment. Computational models are a crucial tool in this practical challenge. We describe a general method for sampling an ensemble of finite-time, nonequilibrium protocols biased towards a low average dissipation. We show that this scheme can be carried out very efficiently in several limiting cases. As an application, we sample the ensemble of low-dissipation protocols that invert the magnetization of a 2D Ising model and explore how the diversity of the protocols varies in response to constraints on the average dissipation. In this example, we find that there is a large set of protocols with average dissipation close to the optimal value, which we argue is a general phenomenon.Comment: 6 pages and 3 figures plus 4 pages and 5 figures of supplemental materia

    Unemployment insurance claims and economic activity

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    Economic forecasters pay especially close attention to labor market indicators during periods of economic uncertainty. Labor market data are thought to provide early evidence about changes in the course of the economy. This article examines whether monthly changes in labor market indicators are useful for predicting real GDP. It then examines whether weekly changes in initial and continuing unemployment insurance claims are useful for helping to predict changes in important labor market indicators. Incoming monthly data on nonfarm payroll jobs and the index of aggregate weekly hours help predict changes in real GDP growth, but data on the civilian unemployment rate do not. The authors also find that unemployment insurance claims help to predict changes in monthly labor variables. As others have found, these predictions work best in periods of recession. However, this article shows that there was also some predictive ability during the 1990s expansion.Unemployment ; Labor market
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