Low energy kaon photoproduction from nuclei

We study $K^+$-meson production in $\gamma{A}$ interaction at energies below the reaction threshold in free space. The Thomas-Fermi and spectral function approaches are used for the calculations of the production process. It is found that the measurement of the differential spectra may allow to reconstruct the production mechanism and to investigate the dispersion relations entering the production vertex. It is shown that the contribution from secondary pion induced reactions to the total kaon photoproduction is negligible for $E_\gamma{<}$1.2 GeV so that strangeness production at low energies is sensitive to the nuclear spectral function.Comment: 20 pages, espcrc1, including 12 figures, to appear in Nucl. Phys.

Anti-thrombogenicity by Layer-by-Layer

Anti-thrombogenic films with high durability were fabricated in a wet process. Anti-thrombogenicity was achieved with polyelectrolyte multilayer thin film prepared from poly(vinyl alcohol)-poly(acrylic acid)(PVA-PAA) blends, deposited in alternate layers with poly(allylamine hydrochloride) (PAH). Film durability, assessed by abrasion resistance and water resistance, was enhanced by forming crosslinks via amide bonds induced by heat treatment of the film. The film was found to be resistant to protein adsorption, as measured by the amount of fibrinogen adsorbed from an aqueous solution. Anti-thrombogenic efficacy was assessed in ex vivo experiments by the ability of stainless steel mesh, coated with the polyelectrolyte and inserted into a pig blood vessel, to inhibit thrombus formation. Mesh coated with the polyelectrolyte did not reduce blood flow over a period of 15 minutes, whereas with uncoated mesh blood flow stopped within 6 minutes because of blood vessel blockage by thrombus formation

The clock genes Period 2 and Cryptochrome 2 differentially balance bone formation

Background: Clock genes and their protein products regulate circadian rhythms in mammals but have also been implicated in various physiological processes, including bone formation. Osteoblasts build new mineralized bone whereas osteoclasts degrade it thereby balancing bone formation. To evaluate the contribution of clock components in this process, we investigated mice mutant in clock genes for a bone volume phenotype. Methodology/Principal Findings: We found that Per2Brdm1 mutant mice as well as mice lacking Cry2-/- displayed significantly increased bone volume at 12 weeks of age, when bone turnover is high. Per2Brdm1 mutant mice showed alterations in parameters specific for osteoblasts whereas mice lacking Cry2-/- displayed changes in osteoclast specific parameters. Interestingly, inactivation of both Per2 and Cry2 genes leads to normal bone volume as observed in wild type animals. Importantly, osteoclast parameters affected due to the lack of Cry2, remained at the level seen in the Cry2-/- mutants despite the simultaneous inactivation of Per2. Conclusions/Significance: This indicates that Cry2 and Per2 affect distinct pathways in the regulation of bone volume with Cry2 influencing mostly the osteoclastic cellular component of bone and Per2 acting on osteoblast parameters

Evidence for a narrow structure at W~1.68 GeV in eta photoproduction on the neutron

New results on quasi-free $\eta$ photoproduction on the neutron and proton bound in a deuteron target are presented. The $\gamma n \to \eta n$ quasi-free cross section reveals a bump-like structure which is not seen in the cross section on the proton. This structure may signal the existence of a relatively narrow ($M\sim 1.68$ GeV, $\Gamma \leq 30$ MeV) baryon state.Comment: Replaced with published versio

Clinical impairment in premanifest and early Huntington's disease is associated with regionally specific atrophy.

TRACK-HD is a multicentre longitudinal observational study investigating the use of clinical assessments and 3-Tesla magnetic resonance imaging as potential biomarkers for future therapeutic trials in Huntington's disease (HD). The cross-sectional data from this large well-characterized dataset provide the opportunity to improve our knowledge of how the underlying neuropathology of HD may contribute to the clinical manifestations of the disease across the spectrum of premanifest (PreHD) and early HD. Two hundred and thirty nine gene-positive subjects (120 PreHD and 119 early HD) from the TRACK-HD study were included. Using voxel-based morphometry (VBM), grey and white matter volumes were correlated with performance in four domains: quantitative motor (tongue force, metronome tapping, and gait); oculomotor [anti-saccade error rate (ASE)]; cognition (negative emotion recognition, spot the change and the University of Pennsylvania smell identification test) and neuropsychiatric measures (apathy, affect and irritability). After adjusting for estimated disease severity, regionally specific associations between structural loss and task performance were found (familywise error corrected, P < 0.05); impairment in tongue force, metronome tapping and ASE were all associated with striatal loss. Additionally, tongue force deficits and ASE were associated with volume reduction in the occipital lobe. Impaired recognition of negative emotions was associated with volumetric reductions in the precuneus and cuneus. Our study reveals specific associations between atrophy and decline in a range of clinical modalities, demonstrating the utility of VBM correlation analysis for investigating these relationships in HD

Backward pion-nucleon scattering

A global analysis of the world data on differential cross sections and polarization asymmetries of backward pion-nucleon scattering for invariant collision energies above 3 GeV is performed in a Regge model. Including the $N_\alpha$, $N_\gamma$, $\Delta_\delta$ and $\Delta_\beta$ trajectories, we reproduce both angular distributions and polarization data for small values of the Mandelstam variable $u$, in contrast to previous analyses. The model amplitude is used to obtain evidence for baryon resonances with mass below 3 GeV. Our analysis suggests a $G_{39}$ resonance with a mass of 2.83 GeV as member of the $\Delta_{\beta}$ trajectory from the corresponding Chew-Frautschi plot.Comment: 12 pages, 16 figure

The structural and geochemical evolution of the continental crust: Support for the oceanic plateau model of continental growth

The problem of the origin of the continental crust can be resolved into two fundamental questions: (1) the location and mechanisms of initial mantle extraction of the primitive crust and (2) the processes by which this primitive crust is converted into the continental crust that presently exists. We know that Archean continental crust is compositionally distinct from younger continental crust. Archean magmatism was dominantly bimodal, mafic thoeleiitic plus dacitic, heavy rare earth element depleted, in contrast to the dominantly unimodal, roughly andesitic calc-alkaline magmatism on younger crust [Taylor and McLennan, 1985; Condie, 1989]. The problem is whether these compositional differences are primarily due to different mechanisms of crustal extraction from the mantle or to different mechanisms of differentiation and alteration of newly formed continental crust

Integrating cancer survivors' experiences into UK cancer registries: design and development of the ePOCS system (electronic Patient-reported Outcomes from Cancer Survivors)

BACKGROUND: Understanding the psychosocial challenges of cancer survivorship, and identifying which patients experience ongoing difficulties, is a key priority. The ePOCS (electronic patient-reported outcomes from cancer survivors) project aims to develop and evaluate a cost-efficient, UK-scalable electronic system for collecting patient-reported outcome measures (PROMs), at regular post-diagnostic timepoints, and linking these with clinical data in cancer registries. METHODS: A multidisciplinary team developed the system using agile methods. Design entailed process mapping the system's constituent parts, data flows and involved human activities, and undertaking usability testing. Informatics specialists built new technical components, including a web-based questionnaire tool and tracking database, and established component-connecting data flows. Development challenges were overcome, including patient usability and data linkage and security. RESULTS: We have developed a system in which PROMs are completed online, using a secure questionnaire administration tool, accessed via a public-facing website, and the responses are linked and stored with clinical registry data. Patient monitoring and communications are semiautomated via a tracker database, and patient correspondence is primarily Email-based. The system is currently honed for clinician-led hospital-based patient recruitment. CONCLUSIONS: A feasibility test study is underway. Although there are possible challenges to sustaining and scaling up ePOCS, the system has potential to support UK epidemiological PROMs collection and clinical data linkage