Superior capsular reconstruction: current evidence and limits

The treatment of rotator cuff tears (RCTs) has evolved. Nonsurgical treatment is adequate for many patients; however, for those for whom surgical treatment is indicated, rotator cuff repair provides reliable pain relief and good functional results. However, massive and irreparable RCTs are a significant challenge for both patients and surgeons. Superior capsular reconstruction (SCR) has become increasingly popular in recent years. It works by passively restoring the superior restriction of the humeral head, thus restoring the pair of forces and improving the kinematics of the glenohumeral joint. Early clinical results using fascia lata (FL) autograft were promising in terms of pain relief and function. The procedure has evolved, and some authors have suggested that FL autografts could be replaced by other methods. However, surgical techniques for SCR are highly variable, and patient indications remain undefined. There are concerns that the available scientific evidence does not support the popularity of the procedure. This review aimed to critically evaluate the biomechanics, indications, procedural considerations, and clinical outcomes associated with the SCR procedure.info:eu-repo/semantics/publishedVersio

Enhancing Biodiversity and Multifunctionality of an Organic Farmscape in California’s Central Valley

Organic farmers in the USA increasingly manage the margins of previously monocultured farmed landscapes to increase biodiversity, e.g. they restore and protect riparian corridors, plant hedgerows and construct vegetated tailwater ponds. This study attempts to link habitat enhancements, biodiversity and changes in ecosystem functions by: 1. inventorying the existing biodiversity and the associated belowground community structure and composition in the various habitats of an organic farm in California’s Central Valley; and 2. monitoring key ecosystem functions of these habitats. Two years of inventories show greater native plant diversity in non-cropped areas. While nematode diversity did not differ between habitats, functional groups were clearly associated with particular habitats as were soil microbial communities (phospholipid fatty acid analysis). Earthworm diversity did not differ between habitats, but biomass was higher in non-cropped areas. Habitats with woody vegetation stored 20% of the farmscape’s total carbon (C), despite their relatively small size (only 5% of the total farm). Two years of monitoring data of farmscape C and nitrogen (N) through emissions, run-off and leaching showed distinct tradeoffs in function associated with each habitat. Clearly habitat restoration in field margins will increase both landscape biodiversity and the multifunctionality of the farmscape as a whole

On the physics and technology of gaseous particle detectors

Despite an already long and fruitful history, gaseous elementary-particle detectors remain today an important mainstay of high-energy and nuclear physics experiments and of radiation detection in general. In here we briefly describe some of the gaseous detector's main technologies and applications, along with some unsolved gas-discharge physics aspects of practical relevance.Comment: Submitted to Plasma Sources in Science and Technolog

Comparative clinical and radiologic evaluation between patients undergoing standard reversed shoulder arthroplasty or bony increased offset

Background: Modifications of the medialized design of Grammont-type reverse shoulder arthroplasty (RSA) using a bony increased offset (BIO-RSA) has shown better clinical results and fewer complications. The aim of this study is to compare the clinical results, complications, and radiological outcomes between patients undergoing standard RSA and BIO-RSA. Methods: A retrospective review was performed of 42 RSA procedures (22 standard RSA and 20 BIO-RSA). With a minimum of 1 year of follow-up, range of motion (ROM), Constant shoulder score (CSS), visual analog scale (VAS), and subjective shoulder score (SSS) were compared. Radiographs and computed tomography (CT) scan were examined for scapular notching, glenoid and humeral fixation, and graft healing. Results: At a mean follow-up of 27.6 months (range, 12-48 months), a significant difference was found for active-internal rotation (P=0.038) and for passive-external rotation (P=0.013), with better results in BIO-RSA. No other differences were found in ROM, CSS (P=0.884), VAS score, and SSS. Graft healing and viability were verified in all patients with CT scan (n=34). The notching rate was 28% in the standard RSA group and 33% in the BIO-RSA group, but the standard RSA had more severe notching (grade 2) than BIO-RSA (P=0.039). No other significative differences were found in glenoid and humeral fixation. Conclusions: Bone-graft lateralization is associated with better internal and external rotation and with less severe scapular notching compared to the standard RSA. Integration of the bone graft occurs effectively, with no relevant changes observed on radiographic evaluation.info:eu-repo/semantics/publishedVersio

Investigation of the performance of an optimised MicroCAT, a GEM and their combination by simulations and current measurements

A MicroCAT (Micro Compteur A Trous) structure which is used for avalanche charge multiplication in gas filled radiation detectors has been optimised with respect to maximum electron transparency and minimum ion feedback. We report on the charge transfer behaviour and the achievable gas gain of this device. A three-dimensional electron and ion transfer simulation is compared to results derived from electric current measurements. Similarly, we present studies of the charge transfer behaviour of a GEM (Gas Electron Multiplier) by current measurements and simulations. Finally, we investigate the combination of the MicroCAT and the GEM by measurements with respect to the performance at different voltage settings, gas mixtures and gas pressures.Comment: 26 pages, 32 figure

Optical Relative Calibration and Stability Monitoring for the Auger Fluorescence Detector

The stability of the fluorescence telescopes of the Pierre Auger Observatory is monitored with the optical relative calibration setup. Optical fibers distribute light pulses to three different diffuser groups within the optical system. The total charge per pulse is measured for each pixel and compared with reference calibration measurements. This allows monitoring the short and long term stability with respect of the relative timing between pixels and the relative gain for each pixel. The designs of the LED calibration unit (LCU) and of the Xenon flash lamp used for relative calibration, are described and their capabilities to monitor the stability of the telescope performances are studied. We report the analysis of relative calibration data recorded during 2004. Fluctuations in the relative calibration constants provide a measure of the stability of the FD.Comment: 4 pp. To appear in the proceedings of 29th International Cosmic Ray Conference (ICRC 2005), Pune, India, 3-11 Aug 200

Performances of multi-gap timing RPCs for relativistic ions in the range Z=1-6

We present the performance of Multi-gap timing RPCs under irradiation by fully stripped relativistic ions (gamma*beta=2.7, Z=1-6). A time resolution of 80 ps at high efficiency has been obtained by just using standard `off the shelf' 4-gap timing RPCs from the new HADES ToF wall. The resolution worsened to 100 ps for ~ 1 kHz/cm2 proton flux and for ~ 100 Hz/cm2 Carbon flux. The chambers were operated at a standard field of E=100 kV/cm and showed a high stability during the experiment, supporting the fact that RPCs are a convenient choice when accommodating a very broad range of ionizing particles is needed. The data provides insight in the region of very highly ionizing particles (up to x 36 mips) and can be used to constrain the existing avalanche and Space-Charge models far from the usual `mip valley'. The implications of these results for the general case of detection based on secondary processes (n, gamma) resulting in highly ionizing particles with characteristic energy distributions will be discussed, together with the nature of the time-charge correlation curve.Comment: 31 pages, 19 figures, submitted to JINS

The ground state of the Lithium atom in strong magnetic fields

The ground and some excited states of the Li atom in external uniform magnetic fields are calculated by means of our 2D mesh Hartree-Fock method for field strengths ranging from zero up to 2.35 10^8 T. With increasing field strength the ground state undergoes two transitions involving three different electronic configurations: for weak fields the ground state configuration arises from the field-free 1s^22s configuration, for intermediate fields from the 1s^22p_{-1} configuration and in high fields the 1s2p_{-1}3d_{-2} electronic configuration is responsible for the properties of the atom. The transition field strengths are determined. Calculations on the ground state of the Li+ ion allow us to describe the field-dependent ionization energy of the Li atom. Some general arguments on the ground states of multi-electron atoms in strong magnetic fields are provided.Comment: 11 pages, 6 figures, submitted to Physical Review

The ground state of the carbon atom in strong magnetic fields

The ground and a few excited states of the carbon atom in external uniform magnetic fields are calculated by means of our 2D mesh Hartree-Fock method for field strengths ranging from zero up to 2.35 10^9 T. With increasing field strength the ground state undergoes six transitions involving seven different electronic configurations which belong to three groups with different spin projections S_z=-1,-2,-3. For weak fields the ground state configuration arises from the field-free 1s^2 2s^2 2p_0 2p_{-1}, S_z=-1 configuration. With increasing field strength the ground state involves the four S_z=-2 configurations 1s^22s2p_0 2p_{-1}2p_{+1}, 1s^22s2p_0 2p_{-1}3d_{-2}, 1s^22p_0 2p_{-1}3d_{-2}4f_{-3} and 1s^22p_{-1}3d_{-2}4f_{-3}5g_{-4}, followed by the two fully spin polarized S_z=-3 configurations 1s2p_02p_{-1}3d_{-2}4f_{-3}5g_{-4} and 1s2p_{-1}3d_{-2}4f_{-3}5g_{-4}6h_{-5}. The last configuration forms the ground state of the carbon atom in the high field regime \gamma>18.664. The above series of ground state configurations is extracted from the results of numerical calculations for more than twenty electronic configurations selected due to some general energetical arguments.Comment: 6 figures,acc. Phys.Rev.

A Monte Carlo simulation of ion transport at finite temperatures

We have developed a Monte Carlo simulation for ion transport in hot background gases, which is an alternative way of solving the corresponding Boltzmann equation that determines the distribution function of ions. We consider the limit of low ion densities when the distribution function of the background gas remains unchanged due to collision with ions. A special attention has been paid to properly treat the thermal motion of the host gas particles and their influence on ions, which is very important at low electric fields, when the mean ion energy is comparable to the thermal energy of the host gas. We found the conditional probability distribution of gas velocities that correspond to an ion of specific velocity which collides with a gas particle. Also, we have derived exact analytical formulas for piecewise calculation of the collision frequency integrals. We address the cases when the background gas is monocomponent and when it is a mixture of different gases. The developed techniques described here are required for Monte Carlo simulations of ion transport and for hybrid models of non-equilibrium plasmas. The range of energies where it is necessary to apply the technique has been defined. The results we obtained are in excellent agreement with the existing ones obtained by complementary methods. Having verified our algorithm, we were able to produce calculations for Ar$^+$ ions in Ar and propose them as a new benchmark for thermal effects. The developed method is widely applicable for solving the Boltzmann equation that appears in many different contexts in physics.Comment: 14 page