Pinning down the Glue in the Proton

The latest measurements of $F_2$ at HERA allow for a {\it combination} of gluon and sea quark distributions at small $x$ that is significantly different from those of existing parton sets. We perform a new global fit to deep-inelastic and related data. We find a gluon distribution which is larger for x \lapproxeq 0.01, and smaller for $x \sim 0.1$, and a flatter input sea quark distribution than those obtained in our most recent global analysis. The new fit also gives $\alpha_s(M_Z^2) = 0.114$. We study other experimental information available for the gluon including, in particular, the constraints coming from fixed-target and collider prompt $\gamma$ production data.Comment: 8 pages, LATEX, 6 figs available as .uu fil

Impedance spectroscopy as a tool for moisture uptake monitoring in construction composites during service

This is a first study comparing dielectric spectroscopy and gravimetric measurements of moisture uptake in pultruded glass fibre reinforced polymers (FRPs). Specimens were subjected to sub-Tg hygrothermal aging for 224 days. Impedance spectra in the frequency range 0.1 Hz to 10 MHz were captured during exposure and compared with gravimetric measurements. Moisture concentration was found to increase the FRP\u27s dielectric permittivity monotonically and decrease bulk resistance. High quality dielectric data was obtained as moisture uptake is independent of inherent changes suggested by mass loss which compromise gravimetry. Dielectric measurements remained sensitive to moisture despite significant mass loss, which typically distorts the weight gain process complicating the commonly adopted gravimetric methodology. Real-time dielectric measurements were obtained from FRP specimens continuously immersed in water and without making use of any additional sensing elements. The novel approach adopted is of high commercial impact as moisture uptake control is recognized as a significant problem by industry

Natural language processing to extract symptoms of severe mental illness from clinical text: the Clinical Record Interactive Search Comprehensive Data Extraction (CRIS-CODE) project.

OBJECTIVES: We sought to use natural language processing to develop a suite of language models to capture key symptoms of severe mental illness (SMI) from clinical text, to facilitate the secondary use of mental healthcare data in research. DESIGN: Development and validation of information extraction applications for ascertaining symptoms of SMI in routine mental health records using the Clinical Record Interactive Search (CRIS) data resource; description of their distribution in a corpus of discharge summaries. SETTING: Electronic records from a large mental healthcare provider serving a geographic catchment of 1.2 million residents in four boroughs of south London, UK. PARTICIPANTS: The distribution of derived symptoms was described in 23 128 discharge summaries from 7962 patients who had received an SMI diagnosis, and 13 496 discharge summaries from 7575 patients who had received a non-SMI diagnosis. OUTCOME MEASURES: Fifty SMI symptoms were identified by a team of psychiatrists for extraction based on salience and linguistic consistency in records, broadly categorised under positive, negative, disorganisation, manic and catatonic subgroups. Text models for each symptom were generated using the TextHunter tool and the CRIS database. RESULTS: We extracted data for 46 symptoms with a median F1 score of 0.88. Four symptom models performed poorly and were excluded. From the corpus of discharge summaries, it was possible to extract symptomatology in 87% of patients with SMI and 60% of patients with non-SMI diagnosis. CONCLUSIONS: This work demonstrates the possibility of automatically extracting a broad range of SMI symptoms from English text discharge summaries for patients with an SMI diagnosis. Descriptive data also indicated that most symptoms cut across diagnoses, rather than being restricted to particular groups

Electromagnetic form factors of light vector mesons

The electromagnetic form factors G_E(q^2), G_M(q^2), and G_Q(q^2), charge radii, magnetic and quadrupole moments, and decay widths of the light vector mesons rho^+, K^{*+} and K^{*0} are calculated in a Lorentz-covariant, Dyson-Schwinger equation based model using algebraic quark propagators that incorporate confinement, asymptotic freedom, and dynamical chiral symmetry breaking, and vector meson Bethe-Salpeter amplitudes closely related to the pseudoscalar amplitudes obtained from phenomenological studies of pi and K mesons. Calculated static properties of vector mesons include the charge radii and magnetic moments: r_{rho+} = 0.61 fm, r_{K*+} = 0.54 fm, and r^2_{K*0} = -0.048 fm^2; mu_{rho+} = 2.69, mu_{K*+} = 2.37, and mu_{K*0} = -0.40. The calculated static limits of the rho-meson form factors are similar to those obtained from light-front quantum mechanical calculations, but begin to differ above q^2 = 1 GeV^2 due to the dynamical evolution of the quark propagators in our approach.Comment: 8 pages of RevTeX, 5 eps figure

Novel gonadal characteristics in an aged bovine freemartin

The gonads from a five year old freemartin Holstein animal were subjected to morphological analysis and to immunohistochemistry using antibodies against developmental and functional markers. We demonstrate, for the first time, the retention of anti-mullerian hormone (AMH) producing intratubular cells (Sertoli cells) in the context of abundant steroidogenic interstitial cells, and structures consistent with clusters of luteal cells. This novel report describes the clinical, gross and histological findings accompanying this newly described gonadal immunophenotype, and its implication in the understanding of freemartin development

“It's like giving him a piece of me.”: Exploring UK and Israeli women's accounts of motherhood and feeding

Objective The present study explored how Israeli and UK mothers integrate feeding into their conceptualisations of mothering 2–6 months post-partum. Background The nature and importance of motherhood is subject to differential contextual, cultural, political and historical influences. We set out to compare experiences of motherhood and feeding between these two countries using a qualitative approach. Methods Forty one women (mean age 36.4 ± 2.7 years) from Israel and the UK, mostly married or in a committed relationship were interviewed about their experience of pregnancy, motherhood and feeding. Data were analysed thematically. Results The experience of motherhood in the early postnatal period was dominated, for all mothers, by the experience of breastfeeding and clustered around three representations of mothering, namely; 1) a devoted mother who ignores her own needs; 2) a mother who is available for her infant but acknowledges her needs as well; and 3) a struggling mother for whom motherhood is a burden. Such representations existed within both cultural groups and sometimes coexisted within the same mothers. UK women described more struggles within motherhood whereas a tendency towards idealising motherhood was observed for Israeli women. Conclusion There are similarities in the ways that UK and Israeli women experienced motherhood and feeding. Where family life is strongly emphasized, mothers reported extremes of idealism and burden and associated an “ideal” mother with a breastfeeding mother. Where motherhood is represented as just one of many roles women take up, they are more likely to represent a “good enough” approach to mothering. Understanding the experience of motherhood and feeding in different cultural settings is important to provide the context for postnatal care specifically where mothers are reluctant to share problems or difficulties encountered

Nonperturbative renormalization group approach to frustrated magnets

This article is devoted to the study of the critical properties of classical XY and Heisenberg frustrated magnets in three dimensions. We first analyze the experimental and numerical situations. We show that the unusual behaviors encountered in these systems, typically nonuniversal scaling, are hardly compatible with the hypothesis of a second order phase transition. We then review the various perturbative and early nonperturbative approaches used to investigate these systems. We argue that none of them provides a completely satisfactory description of the three-dimensional critical behavior. We then recall the principles of the nonperturbative approach - the effective average action method - that we have used to investigate the physics of frustrated magnets. First, we recall the treatment of the unfrustrated - O(N) - case with this method. This allows to introduce its technical aspects. Then, we show how this method unables to clarify most of the problems encountered in the previous theoretical descriptions of frustrated magnets. Firstly, we get an explanation of the long-standing mismatch between different perturbative approaches which consists in a nonperturbative mechanism of annihilation of fixed points between two and three dimensions. Secondly, we get a coherent picture of the physics of frustrated magnets in qualitative and (semi-) quantitative agreement with the numerical and experimental results. The central feature that emerges from our approach is the existence of scaling behaviors without fixed or pseudo-fixed point and that relies on a slowing-down of the renormalization group flow in a whole region in the coupling constants space. This phenomenon allows to explain the occurence of generic weak first order behaviors and to understand the absence of universality in the critical behavior of frustrated magnets.Comment: 58 pages, 15 PS figure

Electron Scattering From High-Momentum Neutrons in Deuterium

We report results from an experiment measuring the semi-inclusive reaction $d(e,e'p_s)$ where the proton $p_s$ is moving at a large angle relative to the momentum transfer. If we assume that the proton was a spectator to the reaction taking place on the neutron in deuterium, the initial state of that neutron can be inferred. This method, known as spectator tagging, can be used to study electron scattering from high-momentum (off-shell) neutrons in deuterium. The data were taken with a 5.765 GeV electron beam on a deuterium target in Jefferson Laboratory's Hall B, using the CLAS detector. A reduced cross section was extracted for different values of final-state missing mass $W^{*}$, backward proton momentum $\vec{p}_{s}$ and momentum transfer $Q^{2}$. The data are compared to a simple PWIA spectator model. A strong enhancement in the data observed at transverse kinematics is not reproduced by the PWIA model. This enhancement can likely be associated with the contribution of final state interactions (FSI) that were not incorporated into the model. A ``bound neutron structure function'' $F_{2n}^{eff}$ was extracted as a function of $W^{*}$ and the scaling variable $x^{*}$ at extreme backward kinematics, where effects of FSI appear to be smaller. For $p_{s}>400$ MeV/c, where the neutron is far off-shell, the model overestimates the value of $F_{2n}^{eff}$ in the region of $x^{*}$ between 0.25 and 0.6. A modification of the bound neutron structure function is one of possible effects that can cause the observed deviation.Comment: 33 pages RevTeX, 9 figures, to be submitted to Phys. Rev. C. Fixed 1 Referenc

Measurement of the Neutron Spin Structure Function g1ng_1^n with a Polarized ^3He Target

Results are reported from the HERMES experiment at HERA on a measurement of the neutron spin structure function $g_1^n(x,Q^2)$ in deep inelastic scattering using 27.5 GeV longitudinally polarized positrons incident on a polarized $^3$He internal gas target. The data cover the kinematic range $0.023<x<0.6$ and $1 (GeV/c)^2 < Q^2 <15 (GeV/c)^2$. The integral $\int_{0.023}^{0.6} g_1^n(x) dx$ evaluated at a fixed $Q^2$ of $2.5 (GeV/c)^2$ is $-0.034\pm 0.013(stat.)\pm 0.005(syst.)$. Assuming Regge behavior at low $x$, the first moment $\Gamma_1^n=\int_0^1 g_1^n(x) dx$ is $-0.037\pm 0.013(stat.)\pm 0.005(syst.)\pm 0.006(extrapol.)$.Comment: 4 pages TEX, text available at http://www.krl.caltech.edu/preprints/OAP.htm

A measurement of the tau mass and the first CPT test with tau leptons

We measure the mass of the tau lepton to be 1775.1+-1.6(stat)+-1.0(syst.) MeV using tau pairs from Z0 decays. To test CPT invariance we compare the masses of the positively and negatively charged tau leptons. The relative mass difference is found to be smaller than 3.0 10^-3 at the 90% confidence level.Comment: 10 pages, 4 figures, Submitted to Phys. Letts.