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The underlying pathophysiological triggers for equine acute laminitis are unknown, although digital vasoconstriction, ischaemia, hypoxia and reperfusion injury may be involved. The contractile responses of isolated equine digital arteries (EDAs), harvested from the hindlimbs of normal horses postmortem at an abattoir, were studied acutely (up to 3 h) under hyperoxic (95% oxygen, 5% CO2) and hypoxic (95% nitrogen, 5% CO2) conditions in organ baths. Phenylephrine (PHE; 10−6 m), 5-hydroxytryptamine (5-HT; 10−7 m) and high potassium (K+; 118 m m) caused contraction in EDAs which was significantly ( P < 0.0001) enhanced under hypoxic conditions. In contrast, contraction stimulated by 9,11-dideoxy-9α,11α-epoxymethanoprostaglandin F2α (U44069; 3 × 10−8 m) was not significantly enhanced by hypoxia ( P = 0.75). Hypoxia-enhanced contraction in response to K+ was greater ( P < 0.03) in vessels with a functional endothelium than in vessels in which the endothelium was removed by rubbing. Fasudil (10−6 to 10−5 m), a Rho kinase inhibitor, and apocynin (10−3 to 3 × 10−3 m), an NADPH oxidase inhibitor, significantly ( P ≤ 0.05) inhibited hypoxia-enhanced contraction in response to PHE and 5-HT. In conclusion, hypoxia-enhanced contraction occurred in EDAs. This appears to be partially mediated by reactive oxygen species produced by NAPDH oxidase, which activate Rho kinase to increase calcium sensitisation and enhance smooth muscle contraction. [ABSTRACT FROM AUTHOR]

Identification of ponies (Equus caballus) at increased risk of pasture-associated laminitis would aid in the prevention of the disease. Insulin resistance has been associated with laminitis and could be used to identify susceptible individuals. Insulin resistance may be diagnosed by feeding supplementary water-soluble carbohydrate (WSC) and measuring blood glucose and insulin concentrations. The aim of this study was to assess the glycemic and insulinemic responses of 7 normal (NP) and 5 previously laminitic (PLP), mixed breed, native UK ponies fed glucose, fructose, and inulin [ 1 g/(kg d) for 3 d] or no supplementary WSC (control) in spring and fall after a 7-d adaptation to a pasture or hay diet. Blood samples were taken for 12 h after feeding on each day, and baseline and peak concentrations and area under the curve (AUC) for glucose and insulin were recorded. Linear mixed models were used for statistical analysis. Differences between PLP and NP groups were most marked after glucose feeding with differences in peak glucose (P=0.02) and peak insulin (P- 0.016) concentrations. Season and diet adaptation also affected results. Peak concentrations of glucose and insulin occurred 2 to 4 h after WSC feeding. Peak insulin concentration was greater and more variable in fall, particularly in PLP adapted to fall pasture. Baseline glucose and insulin concentrations varied between individuals and with season and diet adaptation but were not greater in PLP than NP. Insulin AUC was greater in PLP than NP after feeding both glucose and fructose (P = 0.017), but there were no differences between PLP and NP in glucose AUC. Glycemic and insulinemic changes were less (P < 0.05) after feeding fructose than glucose, although differences between PLP and NP were still evident. Minimal changes in glucose and insulin concentrations occurred after inulin feeding. Measurement of peak insulin 2 h after feeding of a single dose of glucose (1 g/kg) may be a simple and practical way to aid identification of laminitis-prone ponies before the onset of clinical disease, particularly when ponies are adapted to eating fall pasture. [ABSTRACT FROM AUTHOR]

Abstract: The main task of the Target Tracker of the long baseline neutrino oscillation OPERA experiment, is to locate in which of the target elementary constituents, the lead/emulsion bricks, the neutrino interactions have occurred and also to give calorimetric information about each event. The technology used consists in walls of two planes of long plastic scintillator strips, one per transverse direction. Wavelength shifting fibres collect the light signal emitted by the scintillator strips and guide it to both ends where it is read by multi-anode photomultiplier tubes. The Target Tracker is composed of 62 scintillating walls of a total surface of about . Each wall is made by assembling 4 horizontal and 4 vertical modules of 64.7m long, scintillating strips. This detector has observed the first neutrino interactions during August 2006. In this paper we will describe all elements used for the construction and operation of this detector and we will also give its main characteristics. [Copyright &y& Elsevier]

Abstract: This paper describes the recent development of a novel automatic computer-controlled manipulator for emulsion sheet placement and removal at the microscope object table (also called stage). The manipulator is designed for mass scanning of emulsions for the OPERA neutrino oscillation experiment and provides emulsion changing time shorter than 30s with an emulsion sheet positioning accuracy as good as RMS. [Copyright &y& Elsevier]

The NA60 experiment at the CERN SPS studies dimuon production in proton and heavy ion collisions. Its silicon pixel vertex telescope allows tracking of muon pairs in the vertex region, complementing the information from the muon spectrometer, and improving the mass resolution and signal-to-noise ratio. First results from the In-In data taking are shown for the light resonances and the J/ψ meson production. [Copyright &y& Elsevier]

The ORPHEUS dark matter detector is operating at our underground laboratory in Bern (70 m.w.e.). The detector relies on measuring the magnetic flux variation produced by weakly interacting massive particles (WIMPs) as they heat micron-sized superheated superconducting tin granules (SSG) and induce superconducting-to-normal phase transitions. In an initial phase, 0.45kg of tin granules in a segmented detector volume have been used. In this paper a general description of the experimental setup, overall performance of the detector, and first results are presented. [Copyright &y& Elsevier]

The ORPHEUS dark matter detector consists of 450 g superconducting tin granules with diameters of 28 and 36 μm. The detector has been operating in the shallow site of the underground laboratory in Bern (70 m.w.e). First preliminary results on WIMP detection sensitivity will be presented. [Copyright &y& Elsevier]

The cryogenic silicon Beam Tracker of NA60 is the first detector based on the Lazarus effect used in a high-energy physics experiment. It employs single-sided silicon strip sensors of 50 μm pitch operated at a temperature of 130 K. Two tracking stations determine the transverse coordinates of the interaction point at the target with 20 μm resolution, to improve the determination of the offset of secondary vertices. This impact parameter measurement allows NA60 to distinguish between prompt dimuons and muon pairs from D-meson decays. The detector concept and technical feasibility have been demonstrated in beam time periods between 1999 and 2002. [Copyright &y& Elsevier]

The NA60 experiment at the CERN SPS has measured muon pairs with unprecedented precision in 158 A GeV In–In collisions. A strong excess of pairs above the known sources is observed in the whole mass region 0.2< M<2.6 GeV. The mass spectrum for M<1 GeV is consistent with a dominant contribution from π+ π−→ ρ→ μ+ μ− annihilation. The associated ρ spectral function shows a strong broadening, but essentially no shift in mass. For M>1 GeV, the excess is found to be prompt, not due to enhanced charm production, with pronounced differences to Drell–Yan pairs. The slope parameter Teff associated with the transverse momentum spectra rises with mass up to the ρ, followed by a sudden decline above. The rise for M<1 GeV is consistent with radial flow of a hadronic emission source. The seeming absence of significant flow for M>1 GeV and its relation to parton–hadron duality is discussed in detail, suggesting a dominantly partonic emission source in this region. A comparison of the data to the present status of theoretical modeling is also contained. The accumulated empirical evidence, including also a Planck-like shape of the mass spectra at low p T and the lack of polarization, is consistent with a global interpretation of the excess dimuons as thermal radiation. We conclude with first results on ω in-medium effects. [ABSTRACT FROM AUTHOR]

The yield of muon pairs in the invariant mass region 1< M<2.5 GeV/ c2 produced in heavy-ion collisions significantly exceeds the sum of the two expected contributions, Drell-Yan dimuons and muon pairs from the decays of D meson pairs. These sources properly account for the dimuons produced in proton-nucleus collisions. In this paper, we show that dimuons are also produced in excess in 158 A GeV In-In collisions. We furthermore observe, by tagging the dimuon vertices, that this excess is not due to enhanced D meson production, but made of prompt muon pairs, as expected from a source of thermal dimuons specific to high-energy nucleus-nucleus collisions. The yield of this excess increases significantly from peripheral to central collisions, both with respect to the Drell-Yan yield and to the number of nucleons participating in the collisions. Furthermore, the transverse mass distributions of the excess dimuons are well described by an exponential function, with inverse slope values around 190 MeV. The values are independent of mass and significantly lower than those found at masses below 1 GeV/ c2, rising there up to 250 MeV due to radial flow. This suggests the emission source of thermal dimuons above 1 GeV/ c2 to be of largely partonic origin, when radial flow has not yet built up. [ABSTRACT FROM AUTHOR]

Abstract: The main task of the Target Tracker detector of the long baseline neutrino oscillation OPERA experiment is to locate in which of the target elementary constituents, the lead/emulsion bricks, the neutrino interactions have occurred and also to give calorimetric information about each event. The technology used consists in walls of two planes of plastic scintillator strips, one per transverse direction. Wavelength shifting fibres collect the light signal emitted by the scintillator strips and guide it to both ends where it is read by multi-anode photomultiplier tubes. All the elements used in the construction of this detector and its main characteristics are described. [Copyright &y& Elsevier]

Multi-anode photomultipliers H7546 are used to readout signal from the OPERA Scintillator Tracker (CERN/SPSC 2000-028, SPSC/P318, LNGSP 25/2000; CERN/SPSC 2001-025, SPSC/M668, LNGS-EXP30/2001). A 32-channel front-end Read Out Chip prototype accommodating the H7546 has been designed at LAL. This device features a low-noise, variable gain preamplifier to correct for multi-anode non-uniformity, an auto-trigger capability 100% efficient at a 0.3 photo-electron, and a charge measurement extending over a large dynamic range [0–100] photo-electrons.In this article we describe the ASIC architecture that is being implemented for the Target Tracker in OPERA, with a special emphasis put on the designs and the measured performance. [Copyright &y& Elsevier]

Silicon microstrip detectors will provide the forward tracking in the TOTEM experiment at the LHC. To allow efficient tracking closest to the beam (&ap;1 mm) these detectors should be sensitive up to their physical edge (i.e. edgeless). Edgeless (without guard rings) microstrip planar detectors can be operated at cryogenic temperatures (about 130° K) where leakage currents due to the active edge are drastically reduced. A silicon microstrip prototype, cut perpendicular to the strips, has been tested with a pion beam at CERN to study its efficiency close to the edge by using reference tracks from a simple silicon telescope. Results indicate that the detector measures tracks with good efficiency up to the physical edge of the silicon. [Copyright &y& Elsevier]

This paper describes a novel technique to monitor high-intensity particle beams by means of a semiconductor detector. It consists of cooling a semiconductor detector down to cryogenic temperature to suppress the thermally generated leakage current and to precisely measure the integrated ionization signal. It will be shown that such a device provides very good linearity and a dynamic range wider than is possible with existing techniques. Moreover, thanks to the Lazarus effect, extreme radiation hardness can be achieved providing in turn absolute intensity measurements against precise calibration of the device at low beam flux. [Copyright &y& Elsevier]

We have designed and built a new hodoscope for heavy ion beams consisting of two tracking stations equipped with silicon microstrip detectors operated at 130 K. Preliminary results from tests performed in the high intensity CERN-SPS Pb ion beam show that we were able to detect and identify each incoming ion up to a beam intensity of ∼107 ions/s. The beam profile could be monitored on-line with 50 μm resolution. The detector performed satisfactory even after a dose of 90±40 Grad. [Copyright &y& Elsevier]

The NA60 experiment has studied low-mass muon pair production in proton–nucleus collisions with a system of Be, Cu, In, W, Pb and U targets, using a 400 GeV proton beam at the CERN SPS. The transverse momentum spectra of the ρ / ω and ϕ mesons are measured in the full p T range accessible, from p T = 0 up to 2 GeV/c . The nuclear dependence of the production cross sections of the η ω and ϕ mesons has been found to be consistent with the power law σ pA ∝ A α , with the α parameter increasing as a function of p T for all the particles, and an approximate hierarchy α η ≈ α ϕ > α ω . The cross section ratios σ η / σ ω σ ρ / σ ω and σ ϕ / σ ω have been studied as a function of the size A of the production target, and an increase of the η and ϕ yields relative to the ω is observed from p–Be to p–U collisions. [ABSTRACT FROM AUTHOR]

Abstract: Radiation hardness up to 1016 n eq/cm2 is required in the future HEP experiments for most inner detectors. However, 1016 n eq/cm2 fluence is well beyond the radiation tolerance of even the most advanced semiconductor detectors fabricated by commonly adopted technologies: the carrier trapping will limit the charge collection depth to an effective range of 20–30μm regardless of depletion depth. Significant improvement of the radiation hardness of silicon sensors has been taken place within RD39. Fortunately the cryogenic tool we have been using provides us a convenient way to solve the detector charge collection efficiency (CCE) problem at SLHC radiation level (1016 n eq/cm2). There are two key approaches in our efforts: (1) use of the charge/current injection to manipulate the detector internal electric field in such a way that it can be depleted at a modest bias voltage at cryogenic temperature range (⩽230K); and (2) freezing out of the trapping centers that affects the CCE at cryogenic temperatures lower than that of the LN2 temperature. In our first approach, we have developed the advanced radiation hard detectors using charge or current injection, the current injected diodes (CID). In a CID, the electric field is controlled by injected current, which is limited by the space charge, yielding a nearly uniform electric field in the detector, independent of the radiation fluence. In our second approach, we have developed models of radiation-induced trapping levels and the physics of their freezing out at cryogenic temperatures. In this approach, we intend to study the trapping effect at temperatures below LN2 temperature. A freeze-out of trapping can certainly help in the development of ultra-radiation hard Si detectors for SLHC. A detector CCE measurement system using ultra-fast picosecond laser with a He cryostat has been built at CERN. This system can be used to find out the practical cryogenic temperature range that can be used to freeze out the radiation-induced trapping levels, and it is ready for measurements on extremely heavily irradiated silicon detectors. Initial data from this system will be presented. [Copyright &y& Elsevier]

Abstract: There are two key approaches in our CERN RD 39 Collaboration efforts to obtain ultra-radiation-hard Si detectors: (1) use of the charge/current injection to manipulate the detector internal electric field in such a way that it can be depleted at a modest bias voltage at cryogenic temperature range (⩽150K), and (2) freezing out of the trapping centers that affects the CCE at cryogenic temperatures lower than that of the liquid nitrogen (LN2) temperature. In our first approach, we have developed the advanced radiation hard detectors using charge or current injection, the current injected diodes (CID). In a CID, the electric field is controlled by injected current, which is limited by the space charge, yielding a nearly uniform electric field in the detector, independent of the radiation fluence. In our second approach, we have developed models of radiation-induced trapping levels and the physics of their freezing out at cryogenic temperatures. [Copyright &y& Elsevier]

Abstract: The NA60 experiment studies the production of open charm and prompt dimuons in proton–nucleus and nucleus–nucleus collisions at the CERN SPS. The main goal of NA60 is the study of various possible signatures of the transition from hadronic to deconfined partonic matter, e.g. anomalous charmonium suppression, dimuons from thermal radiation and modifications of vector meson properties. Reaching these goals is facilitated by the use of new state-of-the-art silicon detectors in the vertex region. Downstream of the target and inside a 2.5T dipole magnetic field a pixel telescope measures the charged tracks originating from the collisions. The full pixel telescope consists of 16 planes with 96 ALICE1LHCb pixel detector assemblies in total. This paper describes the setup of the pixel telescope, results from tests as well as the expected implications of the operation of the silicon detectors in the harsh radiation environment of the NA60 experiment, with heavy-ion collisions. [Copyright &y& Elsevier]

Abstract: The CERN RD39 Collaboration is developing super-radiation hard cryogenic Si detectors for applications in experiments of the LHC and the future LHC Upgrade. Radiation hardness up to the fluence of 1016neq/cm2 is required in the future experiments. Significant improvement in the radiation hardness of silicon sensors has taken place during the past years. However, 1016neq/cm2 is well beyond the radiation tolerance of even the most advanced semiconductor detectors made by commonly adopted technologies. Furthermore, at this radiation load the carrier trapping will limit the charge collection depth to the range of 20–30μm regardless of the depletion depth. The key of our approach is freezing the trapping that affects Charge Collection Efficiency (CCE). [Copyright &y& Elsevier]

The NA60 experiment is taking place at the CERN SPS, to study the production of open charm and of prompt dimuons in collisions induced by proton and heavy ion beams on nuclear targets. In this paper we will present an overview of the detector concept, followed by a description of the newly developed silicon vertex telescope and its performance. Then we present some first results, including a dimuon mass spectrum obtained using the silicon vertex telescope. [Copyright &y& Elsevier]

RD39 collaboration develops new detector techniques for particle trackers, which have to withstand fluences up to 1016 cm−2 of high-energy particles. The work focuses on the optimization of silicon detectors and their readout electronics while keeping the temperature as a free parameter. Our results so far suggest that the best operating temperature is around 130 K. We shall also describe in this paper how the current-injected mode of operation reduces the polarization of the bulk silicon at low temperatures, and how the engineering and materials problems related with vacuum and low temperature can be solved. [Copyright &y& Elsevier]

The recovery of the charge collection efficiency (CCE) at low temperatures, the so-called ”Lazarus effect”, was studied in Si detectors irradiated by fast reactor neutrons, by protons of medium and high energy, by pions and by gamma-rays. The experimental results show that the Lazarus effect is observed: (a) after all types of irradiation; (b) before and after space charge sign inversion; (c) only in detectors that are biased at voltages resulting in partial depletion at room temperature. The experimental temperature dependence of the CCE for proton-irradiated detectors shows non-monotonic behaviour with a maximum at a temperature defined as the CCE recovery temperature. The model of the effect for proton-irradiated detectors agrees well with that developed earlier for detectors irradiated by neutrons. The same midgap acceptor-type and donor-type levels are responsible for the Lazarus effect in detectors irradiated by neutrons and by protons. A new, abnormal “zigzag”-shaped temperature dependence of the CCE was observed for detectors irradiated by all particles (neutrons, protons and pions) and by an ultra-high dose of γ-rays, when operating at low bias voltages. This effect is explained in the framework of the double-peak electric field distribution model for heavily irradiated detectors. The redistribution of the space charge region depth between the depleted regions adjacent to p+ and n+ contacts is responsible for the “zigzag”- shaped curves. It is shown that the CCE recovery temperature increases with reverse bias in all detectors, regardless of the type of radiation. [Copyright &y& Elsevier]

Presents a study of the modeling of the electric field distribution, which is controlled by injection and trapping of nonequilibrium carriers, in silicon (Si) detectors irradiated by high neutron influences. Calculation of electric field distribution; Effect of the dependence of the optimal temperature for the electric field distribution in highly irradiated Si detectors; Discussion of the approach for electric field manipulation by free carrier injection.

It has been recently observed that heavily irradiated silicon detectors, no longer functional at room temperature, “resuscitate” when operated at temperatures below 130 K. This is often referred to as the “Lazarus effect”. The results presented here show that cryogenic operation represents a new and reliable solution to the problem of radiation tolerance of silicon detectors. [Copyright &y& Elsevier]

An increasing interest in the behaviour of silicon detectors at cryogenic temperatures has been awakened by the discovery of the so-called Lazarus effect, namely the recovery of charge collection efficiency (CCE) by means of cryogenic cooling. We measured the CCEs of three single diodes previously irradiated with different neutron fluences. The current-voltage characteristic were measured at 300 and 77 K, showing that the low-temperature operation considerably decreases the steady-state current. This is also the case when a forward voltage bias is applied, which then becomes a suitable option. At 77 K, in the case of samples irradiated with 5 x 10[sup 14] neutrons cm[sup -2], the CCE is completely recovered. A third sample irradiated with 2 x 10[sup 15] neutrons cm[sup -2] shows a 60% CCE at 250 V forward bias. [ABSTRACT FROM AUTHOR]

The article presents the results of a study on the effects of tiletamine-zolazepam (TZ) to immobilise grey seals (Halichoerus grypus), particularly during the lactation period. Samples were obtained in three separate instances from thirty anaesthesised lactating female grey seals. Results indicated that TZ remains effective in immobilisation of female grey seals despite the variations in body weight estimates during lactation. Researchers comment, however, that supplementary analgesia may be required for more invasive procedures like blubber biopsy.