516 research outputs found

    Field Application of a Monoclonal Antibody Panel to Differentiate Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) Isolates

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    Porcine reproductive and respiratory syndrome (PRRS) is recognized as the most economically devastating disease of swine throughout the world. Nucleotide sequencing and serological studies have deomnstrated sustantial antigenic variation amoung PRRS virus (PRRSV) isolates (Murtaugh, et al., 1995; Nelson, et al., 1993, 1996). Recently, European-like PRRSV isolates have been identified in the US (Rossow, et al. 2000) and other new, highly virulent PRRSV isolates have appeared and affect sows at all stages of gestation causing mortality of adult pigs as well as young pigs (Epperson et al., 1997). Therefore, it is even more important to control the spread of these new strains. Clinical signs vary between herds, indicating that viruses may differ in pathogenicity. Furthermore, effective use of vaccines and management approaches to control PRRS has not always been successful

    First Results from the KMOS Lens-Amplified Spectroscopic Survey (KLASS): Kinematics of Lensed Galaxies at Cosmic Noon

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    We present the first results of the KMOS Lens-Amplified Spectroscopic Survey (KLASS), a new ESO Very Large Telescope (VLT) large program, doing multi-object integral field spectroscopy of galaxies gravitationally lensed behind seven galaxy clusters selected from the HST Grism Lens-Amplified Survey from Space (GLASS). Using the power of the cluster magnification we are able to reveal the kinematic structure of 25 galaxies at 0.7z2.30.7 \lesssim z \lesssim 2.3, in four cluster fields, with stellar masses 8log(M/M)118 \lesssim \log{(M_\star/M_\odot)} \lesssim 11. This sample includes 5 sources at z>1z>1 with lower stellar masses than in any previous kinematic IFU surveys. Our sample displays a diversity in kinematic structure over this mass and redshift range. The majority of our kinematically resolved sample is rotationally supported, but with a lower ratio of rotational velocity to velocity dispersion than in the local universe, indicating the fraction of dynamically hot disks changes with cosmic time. We find no galaxies with stellar mass <3×109M<3 \times 10^9 M_\odot in our sample display regular ordered rotation. Using the enhanced spatial resolution from lensing, we resolve a lower number of dispersion dominated systems compared to field surveys, competitive with findings from surveys using adaptive optics. We find that the KMOS IFUs recover emission line flux from HST grism-selected objects more faithfully than slit spectrographs. With artificial slits we estimate slit spectrographs miss on average 60% of the total flux of emission lines, which decreases rapidly if the emission line is spatially offset from the continuum.Comment: Accepted for publication in Ap

    Novel Ran-RCC1 inhibitory peptide-loaded nanoparticles have anti-cancer efficacy in vitro and in vivo

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    YesThe delivery of anticancer agents to their subcellular sites of action is a significant challenge for effective cancer therapy. Peptides, which are integral to several oncogenic pathways, have significant potential to be utilised as cancer therapeutics due to their selectivity, high potency and lack of normal cell toxicity. Novel Ras protein-Regulator of chromosome condensation 1 (Ran-RCC1) inhibitory peptides designed to interact with Ran, a novel therapeutic target in breast cancer, were delivered by entrapment into polyethylene glycol-poly (lactic-co-glycolic acid) PEG-PLGA polymeric nanoparticles (NPs). A modified double emulsion solvent evaporation technique was used to optimise the physicochemical properties of these peptide-loaded biodegradable NPs. The anti-cancer activity of peptide-loaded NPs was studied in vitro using Ran-expressing metastatic breast (MDA-MB-231) and lung cancer (A549) cell lines, and in vivo using Solid Ehrlich Carcinoma-bearing mice. The anti-metastatic activity of peptide-loaded NPs was investigated using migration, invasion and colony formation assays in vitro. A PEG-PLGA-nanoparticle encapsulating N-terminal peptide showed a pronounced antitumor and anti-metastatic action in lung and breast cancer cells in vitro and caused a significant reduction of tumor volume and associated tumor growth inhibition of breast cancer model in vivo. These findings suggest that the novel inhibitory peptides encapsulated into PEGylated PLGA NPs are delivered effectively to interact and deactivate Ran. This novel Ran-targeting peptide construct shows significant potential for therapy of breast cancer and other cancers mediated by Ran overexpression

    An Analytical Assessment of NASA's N+1 Subsonic Fixed Wing Project Noise Goal

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    The Subsonic Fixed Wing Project of NASA's Fundamental Aeronautics Program has adopted a noise reduction goal for new, subsonic, single-aisle, civil aircraft expected to replace current 737 and A320 airplanes. These so-called 'N+1' aircraft - designated in NASA vernacular as such since they will follow the current, in-service, 'N' airplanes - are hoped to achieve certification noise goal levels of 32 cumulative EPNdB under current Stage 4 noise regulations. A notional, N+1, single-aisle, twinjet transport with ultrahigh bypass ratio turbofan engines is analyzed in this study using NASA software and methods. Several advanced noise-reduction technologies are analytically applied to the propulsion system and airframe. Certification noise levels are predicted and compared with the NASA goal

    Consumption of bushmeat around a major mine, and matched communities, in Madagascar

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    Mining can have serious biodiversity consequences and many mining operations take steps to mitigate their impacts. Evaluating their success poses a significant challenge because appropriate counterfactuals (what would have happened in the absence of the mine) are often unavailable. We aimed to estimate the effects of education and enforcement measures carried out by a large mine in eastern Madagascar on local consumption of illegal bushmeat. We adopt a quasi-experimental approach and use an interview technique designed to reduce sensitivity biases to compare levels of consumption amongst mine employees and people living within the mine�s intervention area with those of statistically matched control groups, and to relate differences to respondents� knowledge of relevant wildlife laws. Consumption was lower, and awareness of the law higher, amongst mine employees and those living in the mine�s intervention area. However caution should be applied in interpreting these results as evidence of the effectiveness of anti-bushmeat efforts by the mine due to potential confounding factors: for example abundance of bushmeat species may vary between the study areas, and our method may not have completely removed the sensitivity of questions about illegal consumption. This illustrates the challenges of evaluating conservation impacts. We highlight the low level of understanding of wildlife laws, including among mine employees, and suggest better communication of these laws, as part of an education programme, could be a useful first step towards reducing illegal hunting

    Time-delayed model of immune response in plants

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    In the studies of plant infections, the plant immune response is known to play an essential role. In this paper we derive and analyse a new mathematical model of plant immune response with particular account for post-transcriptional gene silencing (PTGS). Besides biologically accurate representation of the PTGS dynamics, the model explicitly includes two time delays to represent the maturation time of the growing plant tissue and the non-instantaneous nature of the PTGS. Through analytical and numerical analysis of stability of the steady states of the model we identify parameter regions associated with recovery and resistant phenotypes, as well as possible chronic infections. Dynamics of the system in these regimes is illustrated by numerical simulations of the model

    Higher moments of nucleon spin structure functions in heavy baryon chiral perturbation theory and in a resonance model

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    The third moment d2d_2 of the twist-3 part of the nucleon spin structure function g2g_2 is generalized to arbitrary momentum transfer Q2Q^2 and is evaluated in heavy baryon chiral perturbation theory (HBChPT) up to order O(p4){\mathcal{O}}(p^4) and in a unitary isobar model (MAID). We show how to link d2d_2 as well as higher moments of the nucleon spin structure functions g1g_1 and g2g_2 to nucleon spin polarizabilities. We compare our results with the most recent experimental data, and find a good description of these available data within the unitary isobar model. We proceed to extract the twist-4 matrix element f2f_2 which appears in the 1/Q21/Q^2 suppressed term in the twist expansion of the spin structure function g1g_1 for proton and neutron.Comment: 30 pages, 7 figure

    On the role of the magnetic dipolar interaction in cold and ultracold collisions: Numerical and analytical results for NH(3Σ^3\Sigma^-) + NH(3Σ^3\Sigma^-)

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    We present a detailed analysis of the role of the magnetic dipole-dipole interaction in cold and ultracold collisions. We focus on collisions between magnetically trapped NH molecules, but the theory is general for any two paramagnetic species for which the electronic spin and its space-fixed projection are (approximately) good quantum numbers. It is shown that dipolar spin relaxation is directly associated with magnetic-dipole induced avoided crossings that occur between different adiabatic potential curves. For a given collision energy and magnetic field strength, the cross-section contributions from different scattering channels depend strongly on whether or not the corresponding avoided crossings are energetically accessible. We find that the crossings become lower in energy as the magnetic field decreases, so that higher partial-wave scattering becomes increasingly important \textit{below} a certain magnetic field strength. In addition, we derive analytical cross-section expressions for dipolar spin relaxation based on the Born approximation and distorted-wave Born approximation. The validity regions of these analytical expressions are determined by comparison with the NH + NH cross sections obtained from full coupled-channel calculations. We find that the Born approximation is accurate over a wide range of energies and field strengths, but breaks down at high energies and high magnetic fields. The analytical distorted-wave Born approximation gives more accurate results in the case of s-wave scattering, but shows some significant discrepancies for the higher partial-wave channels. We thus conclude that the Born approximation gives generally more meaningful results than the distorted-wave Born approximation at the collision energies and fields considered in this work.Comment: Accepted by Eur. Phys. J. D for publication in Special Issue on Cold Quantum Matter - Achievements and Prospects (2011

    Charm-anticharm baryon production asymmetries in photon-nucleon interactions

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    We report measurements of the charm-anticharm production asymmetries for Λc+\Lambda_c^+, Σc++\Sigma_c^{++}, Σc0\Sigma_c^0, Σc++\Sigma_c^{++*}, Σc0\Sigma_c^{0*}, and Λc+(2625)\Lambda_c^+(2625) baryons from the Fermilab photoproduction experiment FOCUS (E831). These asymmetries are integrated over the region where the spectrometer has good acceptance. In addition, we have obtained results for the photoproduction asymmetries of the Λc\Lambda_c baryons as functions of pLp_L, pT2p_T^2, and xFx_F. The integrated asymmetry for Λc+\Lambda_c^+ production, (σΛc+σΛc)/(σΛc++σΛc)(\sigma_{\Lambda_c^+} - \sigma_{\Lambda_c^-}) / (\sigma_{\Lambda_c^+} + \sigma_{\Lambda_c^-}), is 0.111±0.018±0.0120.111 \pm 0.018 \pm 0.012, significantly different from zero. The asymmetries of the excited states are consistent with the Λc\Lambda_c asymmetry.Comment: 12 pages, 9 figures, 1 tabl
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