84 research outputs found
Exclusive electroproduction on the proton at CLAS
The reaction has been measured, using the 5.754
GeV electron beam of Jefferson Lab and the CLAS detector. This represents the
largest ever set of data for this reaction in the valence region. Integrated
and differential cross sections are presented. The , and
dependences of the cross section are compared to theoretical calculations based
on -channel meson-exchange Regge theory on the one hand and on quark handbag
diagrams related to Generalized Parton Distributions (GPDs) on the other hand.
The Regge approach can describe at the 30% level most of the features
of the present data while the two GPD calculations that are presented in this
article which succesfully reproduce the high energy data strongly underestimate
the present data. The question is then raised whether this discrepancy
originates from an incomplete or inexact way of modelling the GPDs or the
associated hard scattering amplitude or whether the GPD formalism is simply
inapplicable in this region due to higher-twists contributions, incalculable at
present.Comment: 29 pages, 29 figure
Molecular diagnosis of bird-mediated pest consumption in tropical farmland
Biodiversity loss will likely have surprising and dramatic consequences for human wellbeing. Identifying species that benefit society represents a critical first step towards predicting the consequences of biodiversity loss. Though natural predators prevent billions of dollars in agricultural pest damage annually, characterizing which predators consume pests has proven challenging. Emerging molecular techniques may illuminate these interactions. In the countryside of Costa Rica, we identified avian predators of coffeeâs most damaging insect pest, the coffee berry borer beetle (Coleoptera:Scolytidae Hypothenemus hampeii), by assaying 1430 fecal samples of 108 bird species for borer DNA. While feeding trials confirmed the efficacy of our approach, detection rates were low. Nevertheless, we identified six species that consume the borer. These species had narrow diet breadths, thin bills, and short wings; traits shared with borer predators in other systems. Borer predators were not threatened; therefore, safeguarding pest control necessitates managing species beyond those at risk of regional extinction by maintaining populations in farmland habitats. Generally, our results demonstrate potential for pairing molecular methods with ecological analyses to yield novel insights into species interactions. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/2193-1801-3-630) contains supplementary material, which is available to authorized users
Regional differences in portion size consumption behaviour: Insights for the global food industry
Abstract: Given the influence of globalization on consumer food behaviour across the world, the purpose of this paper is to contribute to the theoretical discourse around food portion size as a global consumption-related symbol and its underlying socio-economic drivers for food industry strategy. Overall, 25,000 global food consumers were surveyed across 24 countries to elicit insight on portion size consumption behaviour as well as consumer perception on eating and drinking small portion size within selected socio-economic classes. The data was quantitatively analysed to answer the pertinent research objectives. In 20 out of the 24 global markets surveyed, large food portion size was statistically established as a prevalent consumption-related symbol. The paper found that there are regional differences in portion size food consumption behaviour, and further disparities exist across age, gender and income status in 24 countries covering all regions, including Australia, China, Mexico, South Africa, United Kingdom and United States of America. The outlined food industry implications reveal that adaptation and standardisation strategies are still relevant in global food and nutrition strategy as revealed by the variations in the preference for food portion sizes across various countries of the world
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Continuous ultraviolet to blue-green astrocomb
Acknowledgements: The authors gratefully acknowledge grant funding from the UK Science and Technologies Facilities Council (ST/Y001273/1, ST/S001328/1, ST/V000403/1, ST/X002306/1, ST/N002997/1, and ST/V000918/1); the Royal Academy of Engineering (RCSRF1718639 and RCSRF2223-1678); and the Knut and Alice Wallenberg Scholarship 2021.AbstractCosmological and exoplanetary science using transformative telescopes like the ELT will demand precise calibration of astrophysical spectrographs in the blue-green, where stellar absorption lines are most abundant. Astrocombsâlasers providing a broadband sequence of regularly-spaced optical frequencies on a multi-GHz gridâpromise an atomically-traceable calibration scale, but their realization in the blue-green is challenging for current infrared-laser-based technology. Here, we introduce a concept achieving a broad, continuous spectrum by combining second-harmonic generation and sum-frequency-mixing in an MgO:PPLN waveguide to generate 390â520ânm light from a 1âGHz Ti:sapphire frequency comb. Using a Fabry-PĂ©rot filter, we extract a 30âGHz sub-comb spanning 392â472ânm, visualizing its thousands of modes on a high-resolution spectrograph. Experimental data and simulations demonstrate how the approach can bridge the spectral gap present in second-harmonic-only conversion. Requiring only
â
100 pJ pulses, our concept establishes a new route to broadband UV-visible generation at GHz repetition rates.</jats:p
Preliminary trial of an online acceptance-based behavioural treatment for military, police, and Veterans with chronic pain
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