bluuebunny/crossref_metadata_2025 huggingface dataset:
Helt determines GABAergic over glutamatergic neuronal fate by repressing Ngn genes in the developing mesencephalon
Authors: Nakatani Tomoya , Minaki Yasuko , Kumai Minoru , Ono Yuichi
Published: July 2007

The mechanism underlying the determination of neurotransmitter phenotype in the developing mesencephalon, particularly GABAergic versus glutamatergic fate, remains largely unknown. Here, we show in mice that the basic helix-loop-helix transcriptional repressor gene Helt (also known as Megane and Heslike) functions as a selector gene that determines GABAergic over glutamatergic fate in the mesencephalon. Helt was coincidently expressed in all the progenitor domains for mesencephalic GABAergic neurons. In the mesencephalon of Helt-deficient embryos, GABAergic neurons were mostly absent and glutamatergic neurons emerged instead. Conversely, ectopically expressed Helt suppressed glutamatergic formation and induced GABAergic neurogenesis. However, the Helt mutants showed normal progenitor domain formation. In consequence, postmitotic expression of the homeodomain factor Nkx2.2, which was specifically expressed by GABAergic populations in wild-type embryos, was maintained despite the transmitter phenotype conversion from GABAergic to glutamatergic in the Helt mutants, suggesting that Helt is not involved in neuronal identity specification. Furthermore, we identified proneural genes Ngn1 and Ngn2, which were selectively expressed in glutamatergic progenitors in the developing mesencephalon and had the ability to confer the glutamatergic fate, as downstream target genes of Helt. These results suggest that Helt determines GABAergic over glutamatergic fate, at least in part, by repressing Ngn (Neurog) genes and that basic helix-loop-helix transcription factor networks involving Helt and Ngns are commonly used in the mesencephalon for determination of the GABAergic versus glutamatergic transmitter phenotype.
Elastic stresses and deflections of flat square plates under uniformly distributed normal pressure: A critical review
Authors: Penning R L
Published: July 2007

Published data on the maximum principal elastic stresses and deflections for thin, initially flat, square, isotropic plates under uniform normal pressure, supplemented by data provided by university and industrial sources, are correlated to produce design curves for four conditions of edge restraint. The trends disclosed by the correlation are discussed and the sources from which the data were obtained are briefly reviewed.
An investigation into the non-elastic behaviour of turbine rotor discs at high temperatures
Authors: Chubb E J
Published: July 2007

A simplified geometry has been used in the examination of the effects of temperature on a turbine rotor disc for steady and cyclic loading. For steady loading creep solutions have been obtained which show the effect of non-isothermal conditions and various commonly applied approximations.

For cyclic loading the effects of high transient stress during start-up and shutdown on the creep strain have been examined. The development of plastic strain and its effect on rotor creep are also considered.
Stress-concentration factors for shoulder fillets and grooves in plates
Authors: Wilson I H , White D J
Published: July 2007

Stress-concentration factors have been determined photoelastically for shoulder fillets and grooves in plates subjected to tension and bending. The parameters were mainly outside the range of previously published work which is also critically examined.

The validity of Neuber's analysis for grooved plates is confirmed. The new results on shouldered plates provide a useful extension to Engineering Sciences Data Unit item no. 69020 for small values of r/d and values of D/d from 1.01 to 1.5, where r is the fillet radius, D is the greater width, and d the smaller width of the plate.

These results for plates may be applied to shouldered shafts without the incurring of serious error.
Thermal stresses in a rotating, nonhomogeneous, anisotropic disk of varying thickness and density
Authors: Gurushankar G V
Published: July 2007

Closed form solution is obtained for stresses in a rotationally symmetric, nonhomogeneous, anisotropic, annular disk of varying thickness and density, subjected to thermal loading. Analysis is presented for a particular type of anisotropy, namely Polar Orthotropy, in which axes of anisotropy coincide with the principal axes of stresses at each point in the disk. The variations of homogenity, density and thickness are assumed to be hyperbolic. Numerical results in the form of graphs presented show the effect of nonhomogenity, density and degree of orthotropy on the stress distribution in a disk subjected to constant and varying temperature gradients. Homogeneous, varying density anisotropic rotating disk of varying thickness forms a special case of the analysis.
Elasto-plastic analysis of a rotating model conical turbine disc
Authors: Ginesu F , Picasso B , Priolo P
Published: July 2007

Results on the plastic collapse behaviour of an axisymmetric rotating shell, obtained by Limit Analysis and the Finite Element Method, are in good agreement with experimental data. The Finite Element Method, though computationally rather costly, permits, however, a more complete analysis of elasto-plastic behaviour. For the present case, the Limit Analysis has the advantage of greater computational simplicity and leads to a quite satisfactory forecast of collapse speed from the engineering point of view.
Experimental methods for fracture toughness measurement
Authors: Priest A H
Published: July 2007

Recommended methods for measuring fracture toughness parameters are discussed. The relevant Draft British Standards are: (a) Draft for Development 3:1971 ‘Methods for Plane Strain Fracture Toughness ( KI c) Testing’. (b) Draft for Development 19:1972 ‘Methods for Crack Opening Displacement (COD) Testing’.

These documents are being revized and updated for publishing as full British Standards and any significant additions and alterations are noted.

The situation with respect to non-standard tests is reviewed. The fracture toughness parameters under this heading include JI c, equivalent energy values, fracture propagation energy values and R-curve analysis. Particular attention is paid to the influence of strain rate on testing procedures and a crack monitoring technique is discussed.
Elastic stresses due to axial loading of a two-brace tubular k joint with and without overlap
Authors: Fessler H , Little W J G
Published: July 2007

The elastic stresses in non-overlapped and overlapped K joints under axial loading have been obtained by frozen stress photoelastic techniques. The models are representative of joints with stress-relieved, full penetration, ground welds and have brace angles of 45° and 135°. Results are compared with those of similarly shaped models analysed by other techniques (finite element and strain-gauged steel models) and with stress concentrations in joints with the same tube parameters but having different brace arrangements.
Comparison of finite element predictions of creep crack growth with experimental data
Authors: Hyde T H , Low K C , Webster J J
Published: July 2007

Five, pre-fatigued, compact tension specimens made from a model material, which exhibits similar macroscopic behaviour to some high temperature materials, have been subjected to steady loads. The results of these tests indicate that the ‘crack tip opening displacement’ governs the intiation of crack propagation. The subsequent creep crack growth rates are accurately predicted by the C∗ parameter.

‘Moving crack’ finite element calculations have shown that accurate predictions of creep crack growth rates are possible even with relatively coarse meshes. However, the predictions are very sensitive to both the critical crack tip opening displacement used for initiation and to the magnitude of the load. Also, although the C∗ parameter is strictly only applicable to stationary state stresses at stationary cracks, predictions of crack growth were found to be accurate when using C∗ under non-stationary stress and moving crack situations.
A comparison of two methods for predicting ductile crack growth instability
Authors: Gibson G P , Druce S G
Published: July 2007

One mode by which a structure can fail in an unstable manner is ductile crack propagation from a pre-existing defect. Two approaches have been suggested to predict the conditions for such an instability. These are the T approach of Paris et al. and the I approach of Turner. The Paris T approach is based on the stability of the equilibrium state between the applied value of the J integral and the J versus crack extension material resistance curve. Under linear elastic conditions instability may be interpreted as occurring when the second differential of available energy (with respect to crack extension exceeds that required for crack extension. In the elastic-plastic regime this interpretation is lost and the tearing modulus approach uses the J integral as a crack tip field characterising parameter. The Turner approach, on the other hand, is based on the balance between the energies available and required for crack extension. Under linear-elastic conditions instability occurs when the first differential of available energy exceeds that required for crack extension. Under elastic-plastic conditions the Turner approach continues to be an energy balance with the driving force being the elastic energy release rate, I, rather than the linear-elastic energy release rate, G. A comparison of the two approaches has been carried out by re-analysing the instability results of Paris et al., obtained using single-edge-notched, three-point bend specimens under conditions where the J integral can be considered as a crack tip field characterising parameter. Under these conditions both approaches, although based on different assumptions, are numerically similar and the predicted conditions for instability are in good agreement with experimental results. In addition, the two approaches are shown to be numerically similar for the case of centre-cracked tension specimens under limit load conditions. This agreement in two geometries of differing constraint gives tentative support for the generality of this result.
Crack length measurement: Analysis of the electropotential method using a finite element method
Authors: Pulle D W J
Published: July 2007

An evaluation of the electropotential method for deriving the crack length in a sheet metal specimen is carried out. Comparisons are made between an existing analytical and numerical method for calculating the relationship between electropotential and crack length. The numerical method allows an exact representation of the specimen geometry which enables the influence of asymmetrical crack growth on the electropotential to be examined. A case study to analyse this effect on the electropotential is discussed which indicates that underestimation of the crack length will occur which becomes increasingly significant as the voltage probes across which the electropotential is measured are placed closer to the crack. The paper shows that a compromise must be made with regard to voltage probe positioning between the desired sensitivity of the potential reading and tolerated vulnerability to asymmetric crack growth. Comparisons between experimental and theoretical derived potential crack length relationships indicate that limited crack length accuracy is obtained in case the latter is calculated on the basis of the measured electropotential.
Limit pressure for a spherical vessel with a circumferential slot at its junction with a radial cylindrical protruding branch
Authors: Robinson M , Lim C S , Kitching R
Published: July 2007

One of the requirements of the two criteria method of safety assessment of a pressure vessel with a defect is an estimate of the plastic limit pressure. Here the defect is in a spherical shell close to its junction with a protruding radial cylindrical branch. The defect is assumed to be an axisymmetric circumferential slot of uniform depth on the outer surface of the shell. Lower bounds to the limit pressure are calculated for a wide range of geometries. The material is assumed to obey the von Mises yield criterion and a non-linear programming method is used to give optimum lower bounds. Data is supplied for spherical shell radius to thickness ratios from 25 to 100, nozzle radius to vessel radius ratios from 0 to 0.4, nozzle to vessel thickness ratios from 0.25 to 1.0 and ligament thickness to vessel thicknesses (ligament efficiencies) of 0 to 1. Slot widths vary from the significant to the infinitesimal, where it becomes a crack. Vessels of some proportions were shown to have their limit pressures reduced only a little by very low ligament efficiencies.
A method for the measurement of residual stresses using a fracture mechanics approach
Authors: Kang K J , Song J H , Earmme Y Y
Published: July 2007

A simple method for measuring residual stresses in a plate is described. In this method residual stresses are evaluated using a fracture mechanics approach, that is, the strains or displacements measured at a point on the edge of a plate as a crack is introduced and extended from the edge are used to deduce the state of stresses that existed in the uncracked plate. Through finite element analyses and experiments this method is shown to be valid and effective for measuring the two-dimensional residual stress distribution of a welded plate.
Cloud microphysics, radiation and vertical velocities in two‐ and three‐dimensional simulations of deep convection
Authors: Phillips Vaughan T. J. , Donner Leo J.
Published: July 2007

This study investigates the importance of dimensionality for the characteristics of simulations performed with cloud‐system resolving models (CSRMs). In addition to intrinsic questions related to dimensionality in CSRMs, the issue has gained added interest since CSRMs can be utilized instead of conventional cloud parametrizations to represent deep convection within global climate models. Such CSRMs may be either two‐ or three‐dimensional.

CSRM simulations of five observed cases of deep convection are performed in both two and three dimensions (2D and 3D) with the aim of elucidating the impact of dimensionality on overall cloud statistics. Observed profiles of the large‐scale average of advection of temperature and humidity are applied to initiate and maintain the convection. Two of the cases are from tropical oceanic regions. The other three cases are continental.

The average ascent rate in deep convective, cloudy updraughts is about 20–50% higher at mid‐levels of the troposphere in 3D than in 2D, for all cases. This corresponds to an increase by a similar percentage in the vertical mass flux of deep updraughts in the oceanic cases. Furthermore, the weak ascent (0.1<w<1 m s−1) outside the deep convective updraughts is much less prevalent in 3D than in 2D, with vertical velocities being about 20% lower for a given cumulative frequency and a lower vertical mass flux. Downdraughts are weaker in 3D, for most cases.

There is a substantial sensitivity of the vertical profiles of cloud liquid and cloud ice, and of other microphysical species, to dimensionality. This is consistent with the sensitivity of the dynamics of convection. Corresponding changes in radiative transfer, especially in the short‐wave band, result from the cloud–radiative interactions. In particular, the peak in domain‐averaged cloud liquid content in the melting layer is about 50% higher in most of the 2D simulations. The land cases display more sensitivity of the short‐wave radiative flux to the choice of orientation of the vertical plane of 2D simulations. Copyright © 2006 Royal Meteorological Society
Background error covariance functions for vector wind analyses using Doppler‐radar radial‐velocity observations
Authors: Xu Qin , Liu Shun , Xue Ming
Published: July 2007

A two‐dimensional form of cross‐covariance function between the radar radial‐ and tangential‐components (with respect to the direction of radar beam) of background wind errors is derived. Like the previously derived auto‐covariance function for the radial component, this cross‐covariance function is homogeneous but non‐isotropic in the horizontal. The auto‐ and cross‐covariance functions are used with the statistical interpolation technique to perform a vector wind analysis from Doppler radial‐velocity observations on a conical surface of low‐elevation radar‐scans. The structures of the two covariance functions are compared and interpreted in terms of the influence of a single‐point radial‐velocity observation on the analysed vector wind field. The utility and value of these covariance functions are demonstrated through analysis experiments that use either simulated radial‐velocity data from idealized flows or real radar observations. The results of the statistical interpolation scheme utilizing the proposed covariance functions are shown to be superior to the results of traditional VAD technique. The proposed technique can actually be considered a generalization of the traditional VAD technique. Copyright © 2006 Royal Meteorological Society
Modelling the influence of rimer surface temperature on the glaciation of intense thunderstorms: The rime–splinter mechanism of ice multiplication
Authors: Connolly Paul J. , Heymsfield Andrew J. , Choularton Thomas W.
Published: July 2007

A modelling study is presented to look at the potential importance of ice multiplication in a deep Cb cloud observed during the second Egrett Microphysics Experiment with Radiation, Lidar and Dynamics (EMERALD‐II). Simulations with both a cloud‐resolving model (CRM) and an explicit‐microphysics model (EMM) are used. The CRM has a two‐moment bulk microphysics scheme and resolved cloud dynamics, while the EMM has detailed size‐resolved microphysics, but is driven by the CRM cloud dynamics. The simulations consider the sensitivity of the storms to the rime‐splinter, secondary ice production mechanism (or Hallett–Mossop process).

Recent literature on modelling this process in Cb clouds suggests that it is of low importance to the cloud glaciation in intense storms. However, until now, numerical simulations in the literature have investigated this process by either switching it on or off in the model microphysics scheme. We show that if the rate of splinter production is doubled from that proposed by Hallett and Mossop's experiment—a reasonable factor—then for this simulated model cloud, there is a large direct impact on anvil glaciation. The approximate net radiative impact of this calculated with the CRM is 10 W m−2. Similar, ‘nonlinear’ results can also be expected from other ice nucleating mechanisms. Simulations are performed for both continental and maritime cloud condensation nuclei concentrations. In stark contrast to previous literature, we find that the Hallett–Mossop process is more important in the continental (‘polluted’) case than in the maritime (‘clean’) case. This is because of the extremely warm cloud base for this particular storm and consequently—because of the rapid production of rain—the scarcity of small cloud droplets for riming in the clean case. Copyright © 2006 Royal Meteorological Society
Measuring forecast skill: is it real skill or is it the varying climatology?
Authors: Hamill Thomas M. , Juras Josip
Published: July 2007

It is common practice to summarize the skill of weather forecasts from an accumulation of samples spanning many locations and dates. In calculating many of these scores, there is an implicit assumption that the climatological frequency of event occurrence is approximately invariant over all samples. If the event frequency actually varies among the samples, the metrics may report a skill that is different from that expected. Many common deterministic verification metrics, such as threat scores, are prone to mis‐reporting skill, and probabilistic forecast metrics such as the Brier skill score and relative operating characteristic skill score can also be affected.

Three examples are provided that demonstrate unexpected skill, two from synthetic data and one with actual forecast data. In the first example, positive skill was reported in a situation where metrics were calculated from a composite of forecasts that were comprised of random draws from the climatology of two distinct locations. As the difference in climatological event frequency between the two locations was increased, the reported skill also increased. A second example demonstrates that when the climatological event frequency varies among samples, the metrics may excessively weight samples with the greatest observational uncertainty. A final example demonstrates unexpectedly large skill in the equitable threat score of deterministic precipitation forecasts.

Guidelines are suggested for how to adjust skill computations to minimize these effects. Copyright © 2006 Royal Meteorological Society
A time‐staggered semi‐Lagrangian discretization of the rotating shallow‐water equations
Authors: Staniforth Andrew , Wood Nigel , Reich Sebastian
Published: July 2007

A time‐staggered semi‐Lagrangian discretization of the rotating shallow‐water equations is proposed and analysed. Application of regularization to the geopotential field used in the momentum equations leads to an unconditionally stable scheme. The analysis, together with a fully nonlinear example application, suggests that this approach is a promising, efficient, and accurate alternative to traditional schemes. © Royal Meteorological Society, 2006. A. Staniforth's and N. Wood's contributions are Crown copyright material, reproduced with the permission of the Controller of Her Majesty's Stationery Office.
Föohn/cold‐pool interactions in the Rhine valley during MAP IOP 15
Authors: Flamant C. , Drobinski P. , Furger M. , Chimani B. , Tschannett S. , Steinacker R. , Protat A. , Richner H. , Gubser S. , Häberli C.
Published: July 2007

The föhn/cold‐pool interactions in the lower Alpine Rhine valley documented in the framework of the Intensive Observing Period (IOP) 15 of the Mesoscale Alpine Programme (MAP) on 5 November 1999 are analysed. The present study focuses on the water vapour mixing ratio measurements acquired with the airborne differential absorption lidar LEANDRE 2 which enabled detailed documentation of the along‐valley structure of the cold pool. LEANDRE 2 and microbarograph measurements revealed the presence of Kelvin–Helmholtz waves (KHW) at the top of the cold pool. The characteristics of the waves were different in the region of the cold‐ pool leading edge (the southernmost part of the cold pool) and in the vicinity of the Bodensee (Lake Constance), further to the north. Gravity waves were also observed above the cold pool in the in situ aircraft data acquired in the vicinity of the Bodensee. The gravity waves are suspected to be triggered by the KHW at the top of the cold pool. We also investigate the respective role of the three known processes likely to control the structure of the cold pool and its erosion along the Rhine valley, namely (i) convection within the cold pool, (ii) turbulent erosion at the top of the cold pool due to the presence of KHW, and (iii) dynamic displacement of the cold pool by föhn air. The former two processes are likely not to play a role in the erosion of the cold pool observed in the course of this IOP. Finally, the temporal evolution of the heat budget advection term in the lower Rhine valley was investigated using temperature profiles derived from balloon soundings acquired at two sites which were overpassed by the cold‐pool edge in the course of its displacement northwards during the early afternoon as the result of the action of the föhn, and then southwards in the late afternoon as the föhn weakened and cold air from the Bodensee area was filling the lower Rhine Valley. Copyright © 2006 Royal Meteorological Society
A study of the Elite Plus femoral component using radiostereometric analysis
Authors: Derbyshire B. , Porter M. L.
Published: July 2007

We performed a three-year radiostereometric analysis (RSA) study of the Elite Plus femoral component on 25 patients undergoing primary total hip replacement. Additional assessments and measurements from standard radiographs were also made.

Subsidence of the stem occurred at the cement-stem interface. At 36 months the subsidence of the stem centroid was a mean of 0.30 mm (0.02 to 1.28), and was continuing at a slow rate. At the same time point, internal rotation and posterior migration of the femoral head had ceased. One stem migrated excessively and additional assessments suggested that this was probably due to high patient demand.

The failure rate of 4% in our study is consistent with data from arthroplasty registers but contrasts with poor results from another RSA study, and from some clinical studies. We believe that the surgical technique, particularly the use of high-viscosity cement, may have been an important factor contributing to our results.
Effect of progesterone on recovery from nerve injury during leg lengthening in rats
Authors: Hara Y. , Ochiai N. , Abe I. , Ichimura H. , Saijilafu  , Nishiura Y.
Published: July 2007

We investigated the effect of progesterone on the nerve during lengthening of the limb in rats. The sciatic nerves of rats were elongated by leg lengthening for ten days at 3 mm per day. On alternate days between the day after the operation and nerve dissection, the progesterone-treated group received subcutaneous injections of 1 mg progesterone in sesame oil and the control group received oil only. On the fifth, tenth and 17th day, the sciatic nerves were excised at the midpoint of the femur and the mRNA expression level of myelin protein P0 was analysed by quantitative real time polymerase chain reaction. On day 52 nodal length was examined by electron microscopy, followed by an examination of the compound muscle action potential (C-MAP) amplitude and the motor conduction velocity (MCV) of the tibial nerve on days 17 and 52. The P0 (a major myelin glycoprotein) mRNA expression level in the progesterone-treated group increased by 46.6% and 38.7% on days five and ten, respectively. On day 52, the nodal length in the progesterone-treated group was smaller than that in the control group, and the MCV of the progesterone-treated group had been restored to normal.

Progesterone might accelerate the restoration of demyelination caused by nerve elongation by activating myelin synthesis.
A computer model of the position of the combined component in the prevention of impingement in total hip replacement
Authors: Barsoum W. K. , Patterson R. W. , Higuera C. , Klika A. K. , Krebs V. E. , Molloy R.
Published: July 2007

Dislocation remains a major concern after total hip replacement, and is often attributed to malposition of the components. The optimum position for placement of the components remains uncertain. We have attempted to identify a relatively safe zone in which movement of the hip will occur without impingement, even if one component is positioned incorrectly. A three-dimensional computer model was designed to simulate impingement and used to examine 125 combinations of positioning of the components in order to allow maximum movement without impingement. Increase in acetabular and/or femoral anteversion allowed greater internal rotation before impingement occurred, but decreases the amount of external rotation. A decrease in abduction of the acetabular components increased internal rotation while decreasing external rotation. Although some correction for malposition was allowable on the opposite side of the joint, extreme degrees could not be corrected because of bony impingement.

We introduce the concept of combined component position, in which anteversion and abduction of the acetabular component, along with femoral anteversion, are all defined as critical elements for stability.
Fracture of the hydroxyapatite-ceramic-coated JRI-Furlong femoral component
Authors: Harvie P. , Haroon M. , Henderson N. , El-Guindi M.
Published: July 2007

We describe three cases of fracture of the titanium JRI-Furlong hydroxyapatite-ceramic (HAC)-coated femoral component. We have examined previous case reports of failure of this stem and conclude that fracture may occur in two places, namely at the neck-shoulder junction and at the conical-distal cylindrical junction. These breakages are the result of fatigue in a metallurgically-proven normal femoral component. All the cases of failure of the femoral component have occurred in patients with a body mass index of more than 25 in whom a small component, either size 9 or 10, had been used.

In patients with a body mass index above normal size 9 components should be avoided and the femoral canal should be reamed sufficiently to accept a large femoral component to ensure that there is adequate metaphyseal fixation.
Radiation-induced sarcomas of bone
Authors: Kalra S. , Grimer R. J. , Spooner D. , Carter S. R. , Tillman R. M. , Abudu A.
Published: July 2007

We identified 42 patients who presented to our unit over a 27-year period with a secondary radiation-induced sarcoma of bone. We reviewed patient, tumour and treatment factors to identify those that affected outcome. The mean age of the patients at presentation was 45.6 years (10 to 84) and the mean latent interval between radiotherapy and diagnosis of the sarcoma was 17 years (4 to 50). The median dose of radiotherapy given was estimated at 50 Gy (mean 49; 20 to 66). There was no correlation between radiation dose and the time to development of a sarcoma. The pelvis was the most commonly affected site (14 patients (33%)). Breast cancer was the most common primary tumour (eight patients; 19%). Metastases were present at diagnosis of the sarcoma in nine patients (21.4%). Osteosarcoma was the most common diagnosis and occurred in 30 cases (71.4%). Treatment was by surgery and chemotherapy when indicated: 30 patients (71.4%) were treated with the intention to cure. The survival rate was 41% at five years for those treated with the intention to cure but in those treated palliatively the mean survival was only 8.8 months (2 to 22), and all had died by two years. The only factor found to be significant for survival was the ability to completely resect the tumour. Limb sarcomas had a better prognosis (66% survival at five years) than central ones (12% survival at five years) (p = 0.009).

Radiation-induced sarcoma is a rare complication of radiotherapy. Both surgical and oncological treatment is likely to be compromised by the treatment received previously by the patient.
Open arthrolysis for post-traumatic stiffness of the elbow
Authors: Sharma S. , Rymaszewski L. A.
Published: July 2007

We present a retrospective study of 25 patients treated by open arthrolysis of the elbow for post-traumatic stiffness. The mean follow-up was for 7.8 years (5 to 10.8). The range of movement of the elbow, pain scores and functional outcomes were recorded pre- and postoperatively. An improvement in the mean range of movement from 55° (0° to 95°) to 105° (55° to 135°) was obtained in our patients at one year. This improvement was maintained over the mean follow-up period of 7.8 years (5 to 10.8). Improvement in pain, function and patient satisfaction was recorded in 23 of the 25 patients at final follow-up.

On the basis of this study, we believe that the results of open arthrolysis for post-traumatic stiffness of the elbow are durable over the medium term.
Survival and clinical outcome of SB Charité III disc replacement for back pain
Authors: Ross R. , Mirza A. H. , Norris H. E. , Khatri M.
Published: July 2007

Between January 1990 and December 2000 we carried out 226 SB Charité III disc replacements for lumbar disc degeneration in 160 patients. They were reviewed at a mean follow-up of 79 months (31 to 161) to determine the clinical and radiological outcome. The clinical results were collected by an independent observer, who was not involved in patient selection, treatment or follow-up, using a combination of outcome measures, including the Oswestry Disability Index. Pain was recorded using a visual analogue score, and the most recent radiographs were reviewed.

Survival of the device was analysed by the Kaplan-Meier method and showed a cumulative survival of 35% at 156 months when radiological failure was taken as the endpoint. The mean improvement in the Oswestry disability index scores after disc replacement was 14% (6% to 21%) and the mean improvement in the pain score was 1.6 (0.46 to 2.73), both falling below the clinically significant threshold. Removal of the implant was required in 12 patients, four because of implant failure.

These poor results indicate that further use of this implant is not justified.
One-stage operation for locked bilateral posterior dislocation of the shoulder
Authors: Ivkovic A. , Boric I. , Cicak N.
Published: July 2007

A man of 52 years of age had a grand mal seizure. He presented to our unit three months later with irreducible bilateral posterior dislocation of the shoulder. CT scans revealed large compression defects on the anteromedial aspect of the heads of both humeri. The defect on the right side was of more than 50% of the articular surface, and on the left side of 40%. He was treated by a one-stage operation with a hemiarthroplasty on one side and reconstruction of the head by an osteochondral autograft on the other. Three years later the clinical and radiological results were excellent.
Pin-track infection in HIV-positive and HIV-negative patients with open fractures treated by external fixation
Authors: Norrish A. R. , Lewis C. P. , Harrison W. J.
Published: July 2007

Patients infected with HIV presenting with an open fracture of a long bone are difficult to manage. There is an unacceptably high rate of post-operative infection after internal fixation. There are no published data on the use of external fixation in such patients. We compared the rates of pin-track infection in HIV-positive and HIV-negative patients presenting with an open fracture. There were 47 patients with 50 external fixators, 13 of whom were HIV-positive (15 fixators).

There were significantly more pin-track infections requiring pharmaceutical or surgical intervention (Checketts grade 2 or greater) in the HIV-positive group (t-test, p = 0.001). The overall rate of severe pin-track infection in the HIV-positive patients requiring removal of the external-fixator pins was 7%. This contrasts with other published data which have shown higher rates of wound infection if open fractures are treated by internal fixation.

We recommend the use of external fixation for the treatment of open fractures in HIV-positive patients.
The influence of lateral and anterior angulation of the proximal ulna on the treatment of a Monteggia fracture
Authors: Grechenig W. , Clement H. , Pichler W. , Tesch N. P. , Windisch G.
Published: July 2007

We have investigated the anatomy of the proximal part of the ulna to assess its influence on the use of plates in the management of fractures at this site. We examined 54 specimens from cadavers. The mean varus angulation in the proximal third was 17.5° (11° to 23°) and the mean anterior deviation 4.5° (1° to 14°). These variations must be considered when applying plates to the dorsal surface of the ulna for Monteggia-type fractures. A pre-operative radiograph of the contralateral elbow may also be of value.
Magnetic resonance imaging of the patella
Authors: Barnett A. J. , Gardner R. O. E. , Lankester B. J. A. , Wakeley C. J. , Eldridge J. D. J.
Published: July 2007

We retrospectively analysed the MR scans of 25 patients with patellofemoral dysplasia and ten control subjects, to assess whether there was any change in the morphology of the patella along its vertical length. Ratios were calculated comparing the size of the cartilaginous and subchondral osseous surfaces of the lateral and medial facets. We also classified the morphology using the scoring systems of Baumgartl and Wiberg. There were 18 females and seven males with a mean age of 20.2 years (10 to 29) with dysplasia and two females and eight males with a mean age of 20.4 years (10 to 29) in the control group.

In the patient group there was a significant difference in morphology from proximal to distal for the cartilaginous (Analysis of variance (ANOVA) p = 0.004) and subchondral osseous surfaces (ANOVA, p = 0.002). In the control group there was no significant difference for either the cartilaginous (ANOVA, p = 0.391) or the subchondral osseous surface (ANOVA, p = 0.526).

Our study has shown that in the dysplastic patellofemoral articulation the medial facet of the patella becomes smaller in relation to the lateral facet from proximal to distal. MRI is needed to define clearly the cartilaginous and osseous morphology of the patella before surgery is considered for patients with patellofemoral dysplasia.
Schwannoma of the posterior tibial nerve
Authors: Nawabi D. H. , Sinisi M.
Published: July 2007

Schwannomas are the most common tumours of the sheath of peripheral nerves. The clinical diagnosis is usually straightforward, but may be delayed for many years in a schwannoma of the posterior tibial nerve. The symptoms are often attributed to entrapment neuropathy or to lumbosacral radiculopathy.

We describe 25 patients with a schwannoma of the posterior tibial nerve. Only three were diagnosed within a year of presentation. The mean time to diagnosis was 86.5 months with a median of 48 months (2 to 360). All the patients complained of pain, which was felt specifically in the sole of the foot in 18. A Tinel sign was detected in all 25 patients. MRI confirmed the diagnosis in all the cases in which it had been undertaken. Surgical resection of the lesion abolished the neuropathic pain. In patients with a long history of neuropathic pain in the lower limb in whom lumbar and pelvic lesions have been excluded, a benign tumour of the sheath of a peripheral nerve may explain the symptoms. Surgical resection of the tumour is safe and effective.
Harry PottermeetsLe petit prince– On the usefulness of parallel corpora in crosslinguistic investigations
Authors: Stolz Thomas
Published: July 2007

This paper documents some of the experiences I have made in the course of my (areal) typological research projects. The empirical basis of these projects stems from the analysis of two large parallel literary corpora. The texts involved are original and translations of ANTOINE DE SAINT-EXUPÉRY'SLe petit princeand JOANNE ROWLING'SHarry Potterseries. The paper addresses a selection of issues touching upon methodo-logical, theoretical and practical problems of this kind of corpus-based linguistic research. Parallel corpora offer interesting possibilities for typological research. However, working with parallel literary corpora often imposes severe restrictions upon sample size and sample composition as there is a clear European bias in terms of available translations.
Demonstratives in parallel texts: a case study
Authors: da Milano Federica
Published: July 2007

The aim of this paper is to show the usefulness of parallel texts for typological inves-tigations. In order to analyze the way in which demonstrative systems of the European languages function, two kinds of data have been considered: first, the results of a questionnaire based on situations represented in 48 pictures, which will be necessarily discussed only in a summarized way here. Second, and this will be the main topic of this paper, a corpus of parallel texts: the translations, in different languages of Europe, of the book Harry Potter and the Chamber of Secrets. Parallel texts have been used to verify the generalizations based on the data elicited through the questionnaire.
Using Strong's Numbers in the Bible to test an automatic alignment of parallel texts
Authors: Cysouw Michael , Biemann Chris , Ongyerth Matthias
Published: July 2007

We describe a method for the automatic alignment of parallel texts using co-occurrence statistics. The assumption of this approach is that words which are often found together are linked in some way. We employ this assumption to automatically suggest links between words in different languages, using Bible verses as information units. The result is a word-by-word alignment between different translations of the Bible. The accuracy of our method is evaluated by using Strong's numbers as a benchmark. Overall, the performance is high, indicating that this approach can be used to give an approximate gloss of Bible verses.
From questionnaires to parallel corpora in typology
Authors: Dahl Östen
Published: July 2007

This rather programmatic paper discusses the use of parallel corpora in the typological study of grammatical categories. In the author's earlier work, tense-aspect categories were studied by means of a translational questionnaire, and cross-linguistic gramtypes were identified through their distribution in the questionnaire. It is proposed that a similar methodology could be applied to multilingual parallel corpora. The possibility of identifying grammatical markers by word-alignment methods is demonstrated with examples from Bible texts.
Species Concepts and Their Importance in Fisheries Management and Research
Authors: Wiley E. O.
Published: July 2007

Species concepts are important because adoption of a particular concept leads to decisions as to what species to name or recognize. The evolutionary species concept is the most general concept under a realist paradigm and leads to the recognition of species in nature that integrate well with current evolutionary theories of speciation. Aligning the nomenclature of species with the most relevant species concept available ensures that accessing the records associated with species' names will yield the most informative data possible given current understanding. Distributed information systems (systems of servers that permit access to biodiversity databases) now allow managers and fisheries biologists unprecedented access to biodiversity information in the form of collection data. This biodiversity information can be used to document known occurrences of species, prepare faunal lists for particular regions, and forecast potential distributions of both native and exotic species.
Cognitive Evaluation of Self‐Report Questions for Surveillance of Periodontitis
Authors: Miller Kristen , Eke Paul I. , Schoua‐Glusberg Alisu
Published: July 2007

This paper describes the cognitive testing of eight self‐report questions as part of a broader effort to evaluate and validate the use of these questions in estimating the prevalence of periodontitis in the United States population. This study examined how United States respondents understood and processed the proposed questions in English and Spanish, as well as identifying and correcting for possible response errors. The set of eight questions was selected by the Centers for Disease Control and Prevention Periodontal Disease Surveillance Workgroup for further testing after analytical assessments and field testing of an array of potential questions. Evaluation of these eight oral health questions was based on 40 in‐depth, semi‐structured cognitive interviews in English and Spanish. Results of this cognitive test study are presented. The recommendations from this cognitive testing evaluation served as the basis to improve the original questions in English and Spanish to be more inclusive and consistent and improve the estimation of periodontal disease in the United States population.
Naphthyl and Thionaphthyl End‐Capped Oligothiophenes as Organic Semiconductors: Effect of Chain Length and End‐Capping Groups
Authors: Tian H. K. , Shi J. W. , He B. , Hu N. H. , Dong S. Q. , Yan D. H. , Zhang J. P. , Geng Y. H. , Wang F. S.
Published: July 2007

Two series of oligothiophenes (OThs), NaTn and TNTn (n = 2–6 represents the number of thiophene rings), end‐capped with naphthyl and thionaphthyl units have been synthesized by means of Stille coupling. Their thermal properties, optical properties, single crystal structures, and organic field‐effect transistor performance have been characterized. All oligomers display great thermal stability and crystallinity. The crystallographic structures of NaT2, NaT3, TNT2, and TNT3 have been determined. The crystals of NaT2 and NaT3 are monoclinic with space group P21/C, while those of TNT2 and TNT3 are triclinic and orthorhombic with space groups P and P212121, respectively. All oligomers adopt the well‐known herringbone packing‐mode in crystals with packing parameters dependent on the structure of the end‐capping units and the number of thiophene rings. The shorter intermolecular distance in NaT3 compared to NaT2 indicates that the intermolecular interaction principally increases with increasing molecular length. X‐ray diffraction and atomic force microscopy (AFM) characterization indicate that the NaTn oligomers can form films with better morphology and high molecular order than TNTn oligomers with the same number of thiophene rings. The NaTn oligomers exhibit mobilities that are much higher than those for TNTn oligomers (0.028–0.39 cm2 V–1 s–1 versus 0.010–0.055 cm2 V–1 s–1, respectively). In particular, the NaTn oligomers with n = 4–6 all show a mobility higher than 0.1 cm2 V–1 s–1. This device performance is among the best in aryl end‐capped OThs, and indicates that naphthyl is an effectual building block for designing high‐performance organic semiconducting materials.
A query language for discovering semantic associations, Part I: Approach and formal definition of query primitives
Authors: Niemi Timo , Jämsen Janne
Published: July 2007

In contemporary query languages, the user is responsible for navigation among semantically related data. Because of the huge amount of data and the complex structural relationships among data in modern applications, it is unrealistic to suppose that the user could know completely the content and structure of the available information. There are several query languages whose purpose is to facilitate navigation in unknown structures of databases. However, the background assumption of these languages is that the user knows how data are related to each other semantically in the structure at hand. So far only little attention has been paid to how unknown semantic associations among available data can be discovered. We address this problem in this article. A semantic association between two entities can be constructed if a sequence of relationships expressed explicitly in a database can be found that connects these entities to each other. This sequence may contain several other entities through which the original entities are connected to each other indirectly. We introduce an expressive and declarative query language for discovering semantic associations. Our query language is able, for example, to discover semantic associations between entities for which only some of the characteristics are known. Further, it integrates the manipulation of semantic associations with the manipulation of documents that may contain information on entities in semantic associations.