Exclusive tensor meson photoproduction

We study tensor meson photoproduction outside of the resonance region, at beam energies of few GeVs. We build a model based on Regge theory that includes the leading vector and axial exchanges. We consider two determinations of the unknown helicity couplings, and fit to the recent a2 photoproduction data from CLAS. Both choices give a similar description of the a2 cross section, but result in different predictions for the parity asymmetries and the f2 photoproduction cross section. We conclude that new measurements of f2 photoproduction in the forward region are needed to pin down the correct production mechanism. We also extend our predictions to the 8.5 GeV beam energy, where current experiments are running.Comment: 13 pages, 7 figures, 3 tables. Version accepted for publication on Phys.Rev.

Sulphide donors affect the expression of mucin and sulphide detoxification genes in the mucosal organs of Atlantic salmon (Salmo salar)

Hydrogen sulphide (H2S) is a gas that affects mucosal functions in mammals. However, its detrimental effects are less understood in fish despite being known to cause mass mortality. Here we used explant models to demonstrate the transcriptional responses of Atlantic salmon (Salmo salar) mucosa to the sulphide donor sodium hydrosulphide (NaHS). The study focused on two groups of genes: those encoding for sulphide detoxification and those for mucins. Moreover, we performed pharmacological studies by exposing the organ explants to mucus-interfering compounds and consequently exposed them to a sulphide donor. Exposure to NaHS significantly affected the expression of sulphide:quinone oxidoreductase (sqor1, sqor2) and mucin-encoding genes (muc5ac, muc5b). The general profile indicated that NaHS upregulated the expression of sulphide detoxification genes while a significant downregulation was observed with mucins. These expression profiles were seen in both organ explant models. Pharmacological stimulation and inhibition of mucus production used acetylcholine (ACh) and niflumic acid (NFA), respectively. This led to a significant regulation of the two groups of marker genes in the gills and olfactory rosette explants. Treatment of the mucosal organ explants with the mucus-interfering compounds showed that low dose NFA triggered more substantial changes while a dose-dependent response could not be established with ACh. Pharmacological interference demonstrated that mucins played a crucial role in mucosal protection against H2S toxicity. These results offer insights into how a sulphide donor interfered with mucosal responses of Atlantic salmon and are expected to contribute to our understanding of the least explored H2S-fish interactions—particularly at the mucosa.Sulphide donors affect the expression of mucin and sulphide detoxification genes in the mucosal organs of Atlantic salmon (Salmo salar)publishedVersio

Determination of the pole position of the lightest hybrid meson candidate

Mapping states with explicit gluonic degrees of freedom in the light sector is a challenge, and has led to controversies in the past. In particular, the experiments have reported two different hybrid candidates with spin-exotic signature, pi1(1400) and pi1(1600), which couple separately to eta pi and eta' pi. This picture is not compatible with recent Lattice QCD estimates for hybrid states, nor with most phenomenological models. We consider the recent partial wave analysis of the eta(') pi system by the COMPASS collaboration. We fit the extracted intensities and phases with a coupled-channel amplitude that enforces the unitarity and analyticity of the S-matrix. We provide a robust extraction of a single exotic pi1 resonant pole, with mass and width 1564 +- 24 +- 86 MeV and 492 +- 54 +- 102 MeV, which couples to both eta(') pi channels. We find no evidence for a second exotic state. We also provide the resonance parameters of the a2(1320) and a2'(1700).Comment: 6 pages + 3 pages of supplemental material. Version to appear on Phys.Rev.Let

Nucleon resonance contributions to unpolarised inclusive electron scattering

The first CLAS12 experiments will provide high-precision data on inclusive electron scattering observables at a photon virtuality $Q^2$ ranging from 0.05 GeV$^2$ to 12 GeV$^2$ and center-of-mass energies $W$ up to 4 GeV. In view of this endeavour, we present the modeling of the resonant contributions to the inclusive electron scattering observables. As input, we use the existing CLAS electrocoupling results obtained from exclusive meson electroproduction data off protons, and evaluate for the first time the resonant contributions based on the experimental results on the nucleon resonance electroexcitation. The uncertainties are given by the data and duly propagated through a Monte Carlo approach. In this way, we obtain estimates for the resonant contributions, important for insight into the nucleon parton distributions in the resonance region and for the studies of quark-hadron duality

Validation of a multiplex-tandem RT-PCR for the detection of bovine respiratory disease complex using Scottish bovine lung samples

The welfare and economic impact of bovine respiratory disease complex (BRDC), and its associated antibiotic usage, are major challenges to cattle rearing and beef cattle finishing industries. Accurate pathogen diagnosis is important to undertake appropriate treatment and long-term management strategies, such as vaccine selection. Conventional diagnostic approaches have several limitations including high costs, long turnaround times and difficulty in test interpretation, which could delay treatment decisions and lead to unnecessary animal losses. We describe the validation of a multiplex-tandem (MT) reverse transcription-polymerase chain reaction (RT-PCR) for the detection of seven common pathogens associated with BRDC. This test has the potential to advance pathogen identification and to overcome many of the limitations of current testing methods. It requires a single sample and results are obtained quickly and not influenced by prior antimicrobial therapy or overgrowth of contaminating organisms. We demonstrated a test specificity of 100% and sensitivity ranging from 93.5% to 100% for these seven common pathogens. This test will be a useful addition to advance BRDC investigation and diagnosis.</p

CLIMATE CHAGE IMPACTS OF RURAL SOCIETIES: STAKEHOLDERS PERCEPTIONS AND ADAPTATION STRATEGIES IN BUENOS AIRES, ARGENTINA

N° ISBN - 978-2-7380-1284-5International audienceHeavily dependent on agriculture, Argentinean stakeholders must prepare to adapt their activities to a different climate. However, the country does not have an agricultural adaptation plan. A space of joint discussion and participatory planning among farmers, scientific researchers, firm managers and government representatives can increase the preparedness to cope with the impacts of climate change. This research uses individual and group interviews to identify perceptions about climate change and possible adaptation strategies suitable for different types of stakeholders of the district of Balcarce. Relatively homogeneous groups of stakeholders perceive an array of weather changes and identify a range of adaptation strategies. This rich set of perceptions and strategies constitute an excellent starting point to define priorities in research and in policy making to implement national, regional, or firm- level adaptation strategies. Genetic techniques, specific scientific knowledge and land-use planning are viewed as promising sources of adaptation and coordination mechanisms. One common request from stakeholders is the coordination between, and within, public and private organizations. Effective adaptation strategies require the implementation multi-level governance and policy integration. However, these integrations will generate benefits in any type of future climate

Strong magnetic response of submicron Silicon particles in the infrared

High-permittivity dielectric particles with resonant magnetic properties are being explored as constitutive elements of new metamaterials and devices in the microwave regime. Magnetic properties of low-loss dielectric nanoparticles in the visible or infrared are not expected due to intrinsic low refractive index of optical materials in these regimes. Here we analyze the dipolar electric and magnetic response of loss-less dielectric spheres made of moderate permittivity materials. For low material refractive index there are no sharp resonances due to strong overlapping between different multipole contributions. However, we find that Silicon particles with refractive index 3.5 and radius approx. 200nm present a dipolar and strong magnetic resonant response in telecom and near-infrared frequencies, (i.e. at wavelengths approx. 1.2-2 micrometer). Moreover, the light scattered by these Si particles can be perfectly described by dipolar electric and magnetic fields, quadrupolar and higher order contributions being negligible.Comment: 10 pages, 5 figure