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Hyperinsulinism of infancy (HI) is a congenital defect in the regulated release of insulin from pancreatic beta-cells. Here we describe stimulus-secretion coupling mechanisms in beta-cells and intact islets of Langerhans isolated from three patients with a novel SUR1 gene defect. 2154+3 A to G SUR1 (GenBank accession number L78207) is the first report of familial HI among nonconsanguineous Caucasians identified in the U.K. Using patch-clamp methodologies, we have shown that this mutation is associated with both a decrease in the number of operational ATP-sensitive K+ channels (KATP channels) in beta-cells and impaired ADP-dependent regulation. There were no apparent defects in the regulation of Ca2+- and voltage-gated K+ channels or delayed rectifier K+ channels. Intact HI beta-cells were spontaneously electrically active and generating Ca2+ action currents that were largely insensitive to diazoxide and somatostatin. As a consequence, when intact HI islets were challenged with glucose and tolbutamide, there was no rise in intracellular free calcium ion concentration ([Ca2+]i) over basal values. Capacitance measurements used to monitor exocytosis in control and HI beta-cells revealed that there were no defects in Ca2+-dependent exocytotic events. Finally, insulin release studies documented that whereas tolbutamide failed to cause insulin secretion as a consequence of impaired [Ca2+]i signaling, glucose readily promoted insulin release. Glucose was also found to augment the actions of protein kinase C- and protein kinase A-dependent agonists in the absence of extracellular Ca2+. These findings document the relationship between SUR1 gene defects and insulin secretion in vivo and in vitro and describe for the first time KATP channel-independent pathways of regulated insulin secretion in diseased human beta-cells.

(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) Large samples of [Lambda], Σ(1385) and Ξ(1321) hyperons produced in the deep-inelastic muon scattering off a ^sup 6^LiD target were collected with the COMPASS experimental setup at CERN. The relative yields of Σ(1385)^sup +^, Σ(1385)^sup -^, ..., ..., Ξ(1321)^sup -^, and ... hyperons decaying into ... were measured. The ratios of heavy-hyperon to [Lambda] and heavy-antihyperon to ... were found to be in the range 3.8 % to 5.6 % with a relative uncertainty of about 10 %. They were used to tune the parameters relevant for strange particle production of the LEPTO Monte Carlo generator.

In the fragmentation of a transversely polarized quark several left-right asymmetries are possible for the hadrons in the jet. When only one unpolarized hadron is selected, it exhibits an azimuthal modulation known as Collins effect. When a pair of oppositely charged hadrons is observed, three asymmetries can be considered, a di-hadron asymmetry and two single hadron asymmetries. In lepton deep inelastic scattering on transversely polarized nucleons all these asymmetries are coupled with the transversity distribution. From the high statistics COMPASS data on oppositely charged hadron-pair production we have investigated for the first time the dependence of these three asymmetries on the difference of the azimuthal angles of the two hadrons. The similarity of transversity induced single and di-hadron asymmetries is discussed. A new analysis of the data allows to establish quantitative relationships among them, providing for the first time strong experimental indication that the underlying fragmentation mechanisms are all driven by a common physical process.

The COMPASS collaboration at CERN has investigated pion Compton scattering, \\(\\pi^-\\gamma\\rightarrow \\pi^-\\gamma\\), at centre-of-mass energy below 3.5 pion masses. The process is embedded in the reaction \\(\\pi^-\\mathrm{Ni}\\rightarrow\\pi^-\\gamma\\;\\mathrm{Ni}\\), which is initiated by 190\\,GeV pions impinging on a nickel target. The exchange of quasi-real photons is selected by isolating the sharp Coulomb peak observed at smallest momentum transfers, \\(Q^2<0.0015\\)\\,(GeV/\\(c\\))\\(^2\\). From a sample of 63\\,000 events the pion electric polarisability is determined to be \\(\\alpha_\\pi\\ =\\ (\\,2.0\\ \\pm\\ 0.6_{\\mbox{\\scriptsize stat}}\\ \\pm\\ 0.7_{\\mbox{\\scriptsize syst}}\\,) \\times 10^{-4}\\,\\mbox{fm}^3\\) under the assumption \\(\\alpha_\\pi=-\\beta_\\pi\\), which relates the electric and magnetic dipole polarisabilities. It is the most precise measurement of this fundamental low-energy parameter of strong interaction, that has been addressed since long by various methods with conflicting outcomes. While this result is in tension with previous dedicated measurements, it is found in agreement with the expectation from chiral perturbation theory. An additional measurement replacing pions by muons, for which the cross-section behavior is unambigiously known, was performed for an independent estimate of the systematic uncertainty.

The main characteristics of the COMPASS experimental setup for physics with hadron beams are described. This setup was designed to perform exclusive measurements of processes with several charged and/or neutral particles in the final state. Making use of a large part of the apparatus that was previously built for spin structure studies with a muon beam, it also features a new target system as well as new or upgraded detectors. The hadron setup is able to operate at the high incident hadron flux available at CERN. It is characterised by large angular and momentum coverages, large and nearly flat acceptances, and good two and three-particle mass resolutions. In 2008 and 2009 it was successfully used with positive and negative hadron beams and with liquid hydrogen and solid nuclear targets. This article describes the new and upgraded detectors and auxiliary equipment, outlines the reconstruction procedures used, and summarises the general performance of the setup.

Measurements of the Collins and Sivers asymmetries for charged pions and charged and neutral kaons produced in semi-inclusive deep-inelastic scattering of high energy muons off transversely polarised protons are presented. The results were obtained using all the available COMPASS proton data, which were taken in the years 2007 and 2010. The Collins asymmetries exhibit in the valence region a non-zero signal for pions and there are hints of non-zero signal also for kaons. The Sivers asymmetries are found to be positive for positive pions and kaons and compatible with zero otherwise.

A search for the exclusive production of the \\(Z_c^{\\pm}(3900)\\) hadron by virtual photons has been performed in the channel \\(Z_c^{\\pm}(3900)\\rightarrow J/\\psi \\pi^{\\pm}\\). The data cover the range from 7 GeV to 19 GeV in the centre-of-mass energy of the photon-nucleon system. The full set of the COMPASS data set collected with a muon beam between 2002 and 2011 has been used. An upper limit for the ratio \\(BR(Z_c^{\\pm}(3900)\\rightarrow J/\\psi \\pi^{\\pm} )\\times \\sigma_{ \\gamma~N \\rightarrow Z_c^{\\pm}(3900)~ N} /\\sigma_{\\gamma~N \\rightarrow J/\\psi~ N}\\) of \\(3.7\\times10^{-3}\\) has been established at the confidence level of 90%.

A measurement of the azimuthal asymmetry in dihadron production in deep-inelastic scattering of muons on transversely polarised proton (NH\\(_{3}\\)) targets are presented. They provide independent access to the transversity distribution functions through the measurement of the Collins asymmetry in single hadron production. The data were taken in the year \\(2010\\) with the COMPASS spectrometer using a \\(160\\,\\mbox{GeV}/c\\) muon beam of the CERN SPS, increasing by a factor of about three the available statistics of the previously published data taken in the year \\(2007\\). The measured sizeable asymmetry is in good agreement with the published data. An approximate equality of the Collins asymmetry and the dihadron asymmetry is observed, suggesting a common physical mechanism in the underlying fragmentation.

Spin-averaged asymmetries in the azimuthal distributions of positive and negative hadrons produced in deep inelastic scattering were measured using the CERN SPS muon beam at \\(160\\) GeV/c and a \\(^6\\)LiD target. The amplitudes of the three azimuthal modulations \\(\\cos\\phi_h\\), \\(\\cos2\\phi_h\\) and \\(\\sin\\phi_h\\) were obtained binning the data separately in each of the relevant kinematic variables \\(x\\), \\(z\\) or \\(p_T^{\\,h}\\) and binning in a three-dimensional grid of these three variables. The amplitudes of the \\(\\cos \\phi_h\\) and \\(\\cos 2\\phi_h\\) modulations show strong kinematic dependencies both for positive and negative hadrons.