Heavy Quark Production at HERA

Heavy flavour production is one of the key components of the HERA II physics programme. While most of the results presented use leptons or the reconstruction of charmed mesons to identify heavy flavour production, both the H1 and ZEUS experiments now have working microvertex detectors that are being used more and more. In this talk I will summarise a selection of the recent results obtained by the two collaborations.Comment: 10 pages, 18 figures, to appear in the Proceedings of the 8th International Conference on Hyperons, Charm and Beauty Hadrons (BEACH2008), 22-28 June 2008, University of South Carolina, Columbi

Discovery of Four High Proper Motion L Dwarfs, Including a 10 pc L Dwarf at the L/T Transition

We discover four high proper motion L dwarfs by comparing the Wide-field Infrared Survey Explorer (WISE) to the Two Micron All Sky Survey (2MASS). WISE J140533.32+835030.5 is an L dwarf at the L/T transition with a proper motion of 0.85+/-0.02" yr^-1, previously overlooked due to its proximity to a bright star (V=12 mag). From optical spectroscopy we find a spectral type of L8, and from moderate-resolution J band spectroscopy we find a near-infrared spectral type of L9. We find WISE J140533.32+835030.5 to have a distance of 9.7+/-1.7 pc, bringing the number of L dwarfs at the L/T transition within 10 pc from six to seven. WISE J040137.21+284951.7, WISE J040418.01+412735.6, and WISE J062442.37+662625.6 are all early L dwarfs within 25 pc, and were classified using optical and low-resolution near-infrared spectra. WISE J040418.01+412735.6 is an L2 pec (red) dwarf, a member of the class of unusually red L dwarfs. We use follow-up optical and low-resolution near-infrared spectroscopy to classify a previously discovered (Castro & Gizis 2012) fifth object WISEP J060738.65+242953.4 as an (L8 Opt/L9 NIR), confirming it as an L dwarf at the L/T transition within 10 pc. WISEP J060738.65+242953.4 shows tentative CH_4 in the H band, possibly the result of unresolved binarity with an early T dwarf, a scenario not supported by binary spectral template fitting. If WISEP J060738.65+242953.4 is a single object, it represents the earliest onset of CH_4 in the H band of an L/T transition dwarf in the SpeX Library. As very late L dwarfs within 10 pc, WISE J140533.32+835030.5 and WISEP J060738.65+242953.4 will play a vital role in resolving outstanding issues at the L/T transition.Comment: 45 pages, 12 figures, accepted for publication in Ap

Experimental measurement of stress at a four-domain junction in lead zirconate titanate

A junction between two lamellar bands of ferroelectric domains in a lead zirconate titanate (PZT) ceramic is analysed using Kikuchi diffraction patterns in the transmission electron microscope. Indexing of the diffraction patterns allowed the determination of the 3D relative orientation of the 4 different domains at the junction and thus the characterisation of the domain boundaries. The local c/a ratio could also be determined from the misorientations at the domain boundaries. Analysis of the data showed that large stresses were concentrated at the junction, and that this is inevitable at such band junctions. Such stress concentrations could act as nuclei for cracking of the ceramic under additional loading in service, perhaps particularly as a consequence of extended electromechanical cycling. Moreover, the stresses would increase with increasing c/a making the issues all the more serious for Ti-rich compositions having larger c/a ratios

Is retrospective assessment of health-related quality of life valid?

Background: Health-related quality of life (HRQoL) is a commonly used health outcome. For many acute conditions (e.g. fractures), retrospective measurement of HRQoL is necessary to establish pre-morbid health status. However, the validity of retrospective measurement of HRQoL following an intervening significant health event has not been established. The aim of this study was to test the validity of retrospective measurement (recall) of HRQoL by using a test-retest design to measure reliability and agreement between prospective and retrospective patient-reported HRQoL before and after an intervening health event (elective orthopaedic surgery). Method: Participants were recruited from the pre-admission clinic of a metropolitan hospital. Participants were assessed for their HRQoL using the EQ-5D-5L at two time-points; prospectively at 2 weeks prior to their date of surgery and then retrospectively (recalling their pre-operative health) following elective hip or knee joint replacement surgery. Prospective measurements were compared with retrospective measurements for the five domain scores (nominal data) using intra-class correlation and for the EQ-Index score and EQ-Visual Analogue Scale (VAS) score (continuous data), using Pearson’s correlation. Agreement was tested in continuous variables using Lin’s coefficient of concordance (pc) and Bland-Altman plots. Results: One hundred seventy-four patients consented to participate. Eighty-eight paired prospective and retrospective scores were collected and there was a median between-test period of 15 days. At a group level, the prospective measurements were similar to the retrospective measurements; the modes and means of the five domain scores were not different and the mean differences (MD) between the scores for EQ-Index (MD = 0.02, on a scale of 0–1) and EQ-VAS (MD = 0.53, on a scale of 1–100) were negligible. However, the correlation of paired scores was varied; the range of domain score correlations was 0.52 to 0.74, the concordance was substantial for the EQ-Index scores (pc = 0.76, 95% CI = 0.66, 0.84) and moderate for the EQ-VAS scores (pc = 0.46, 95% CI = 0.28, 0.61). Conclusion: Agreement between prospective and retrospective measurements was high at a group level and moderate to substantial at an individual level. Retrospective measurement of HRQoL using the EQ-5D-5L in an orthopaedic clinical context is a valid alternative to using reference data to estimate baseline or pre-morbid health status

Effectiveness of Surgery for Lumbar Spinal Stenosis : A Systematic Review and Meta-Analysis

Peer reviewedPublisher PD

Increased Clusterin Expression in Fuchs’ Endothelial Dystrophy

Purpose: To compare the relative expression of peroxiredoxin (Prx) proteins in normal human corneal endothelium with endothelium in corneas affected by Fuchs’ endothelial dystrophy (FED) and between normal human endothelium and epithelial/stromal tissue. Methods: Human corneal endothelial cell-Descemet’s membrane (HCEC-DM) complexes from normal and FED corneal buttons were dissected from the epithelium/stroma. For proteomic analysis, HCEC-DM protein extracts were separated by using two-dimensional gel electrophoresis. Relative differences in protein spot density was analyzed. Proteins of interest, including Prx isoforms, were identified by MALDI-TOF (matrix-assisted desorption ionization-time of flight) mass spectrometry. Western blot analysis compared the relative expression of Prx isoforms in normal and FED endothelium and between normal endothelium and normal epithelium/stroma. Expression of Prx-2 mRNA was compared by using real-time PCR. Results: Proteomic analysis identified differences in the relative expression of Prx isoforms between normal and FED endothelium. Western blot analysis confirmed that expression of Prx-2, −3, and −5 was significantly decreased (P \u3c 0.05) in FED cells. Normal HCECs expressed significantly (P \u3c 0.05) higher levels of Prx-2 and −3 than did the epithelium/stroma. Expression of Prx-5 was not significantly different (P \u3e 0.05) in the endothelium versus the epithelium/stroma. Real-time PCR analysis revealed that Prx-2 mRNA was significantly decreased (P = 0.027) in FED samples. Conclusions: Prx proteins were identified in human corneal endothelium. The fact that Prx-2 and −3 were expressed at significantly higher levels in HCEC-DM compared with the epithelium/stroma reflects the different physiologic activities of individual corneal cell types. Significantly decreased expression of Prx-2, −3, and −5 in FED may suggest an alteration in the ability of endothelial cells to withstand oxidant-induced damage and may be closely related to the pathogenesis of this disease

Properties of the mechanosensitive channel MscS pore revealed by tryptophan scanning mutagenesis

Funding This work was supported by a Wellcome Trust Programme grant [092552/A/10/Z awarded to I.R.B., S.M., J. H. Naismith (University of St Andrews, St Andrews, U.K.), and S. J. Conway (University of Oxford, Oxford, U.K.)] (T.R. and M.D.E.), by a BBSRC grant (A.R.) [BB/H017917/1 awarded to I.R.B., J. H. Naismith, and O. Schiemann (University of St Andrews)], by a Leverhulme Emeritus Fellowship (EM-2012-060\2), and by a CEMI grant to I.R.B. from the California Institute of Technology. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013 FP7/2007-2011) under Grant PITN-GA-2011-289384 (FP7-PEOPLE-2011-ITN NICHE) (H.G.) (awarded to S.M.).Peer reviewedPublisher PD

Pattern scaling using ClimGen: monthly-resolution future climate scenarios including changes in the variability of precipitation

Development, testing and example applications of the pattern-scaling approach for generating future climate change projections are reported here, with a focus on a particular software application called “ClimGen”. A number of innovations have been implemented, including using exponential and logistic functions of global-mean temperature to represent changes in local precipitation and cloud cover, and interpolation from climate model grids to a finer grid while taking into account land-sea contrasts in the climate change patterns. Of particular significance is a new approach for incorporating changes in the inter-annual variability of monthly precipitation simulated by climate models. This is achieved by diagnosing simulated changes in the shape of the gamma distribution of monthly precipitation totals, applying the pattern-scaling approach to estimate changes in the shape parameter under a future scenario, and then perturbing sequences of observed precipitation anomalies so that their distribution changes according to the projected change in the shape parameter. The approach cannot represent changes to the structure of climate timeseries (e.g. changed autocorrelation or teleconnection patterns) were they to occur, but is shown here to be more successful at representing changes in low precipitation extremes than previous pattern-scaling methods

Decreased Expression of Peroxiredoxins in Fuchs’ Endothelial Dystrophy

Purpose: To compare the relative expression of peroxiredoxin (Prx) proteins in normal human corneal endothelium with endothelium in corneas affected by Fuchs’ endothelial dystrophy (FED) and between normal human endothelium and epithelial/stromal tissue. Methods: Human corneal endothelial cell-Descemet’s membrane (HCEC-DM) complexes from normal and FED corneal buttons were dissected from the epithelium/stroma. For proteomic analysis, HCEC-DM protein extracts were separated by using two-dimensional gel electrophoresis. Relative differences in protein spot density was analyzed. Proteins of interest, including Prx isoforms, were identified by MALDI-TOF (matrix-assisted desorption ionization-time of flight) mass spectrometry. Western blot analysis compared the relative expression of Prx isoforms in normal and FED endothelium and between normal endothelium and normal epithelium/stroma. Expression of Prx-2 mRNA was compared by using real-time PCR. Results: Proteomic analysis identified differences in the relative expression of Prx isoforms between normal and FED endothelium. Western blot analysis confirmed that expression of Prx-2, −3, and −5 was significantly decreased (P \u3c 0.05) in FED cells. Normal HCECs expressed significantly (P \u3c 0.05) higher levels of Prx-2 and −3 than did the epithelium/stroma. Expression of Prx-5 was not significantly different (P \u3e 0.05) in the endothelium versus the epithelium/stroma. Real-time PCR analysis revealed that Prx-2 mRNA was significantly decreased (P = 0.027) in FED samples. Conclusions: Prx proteins were identified in human corneal endothelium. The fact that Prx-2 and −3 were expressed at significantly higher levels in HCEC-DM compared with the epithelium/stroma reflects the different physiologic activities of individual corneal cell types. Significantly decreased expression of Prx-2, −3, and −5 in FED may suggest an alteration in the ability of endothelial cells to withstand oxidant-induced damage and may be closely related to the pathogenesis of this disease

Insulin-stimulated phosphorylation of endothelial nitric oxide synthase at serine-615 contributes to nitric oxide synthesis

Insulin stimulates endothelial NO (nitric oxide) synthesis via PKB (protein kinase B)/Akt-mediated phosphorylation and activation of eNOS (endothelial NO synthase) at Ser-1177. In previous studies, we have demonstrated that stimulation of eNOS phosphorylation at Ser-1177 may be required, yet is not sufficient for insulin-stimulated NO synthesis. We therefore investigated the role of phosphorylation of eNOS at alternative sites to Ser-1177 as candidate parallel mechanisms contributing to insulin-stimulated NO synthesis. Stimulation of human aortic endothelial cells with insulin rapidly stimulated phosphorylation of both Ser-615 and Ser-1177 on eNOS, whereas phosphorylation of Ser-114, Thr-495 and Ser-633 was unaffected. Insulin-stimulated Ser-615 phosphorylation was abrogated by incubation with the PI3K (phosphoinositide 3-kinase) inhibitor wortmannin, infection with adenoviruses expressing a dominant-negative mutant PKB/Akt or pre-incubation with TNFα (tumour necrosis factor α), but was unaffected by high culture glucose concentrations. Mutation of Ser-615 to alanine reduced insulin-stimulated NO synthesis, whereas mutation of Ser-615 to aspartic acid increased NO production by NOS in which Ser-1177 had been mutated to an aspartic acid residue. We propose that the rapid PKB-mediated stimulation of phosphorylation of Ser-615 contributes to insulin-stimulated NO synthesis