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We report optical B-band observations with the Large Binocular Telescope (LBT) of the isolated neutron star RBS1774. The stacked image with a total exposure of $2\fh5$reveals a candidate optical counterpart at mB= 26.96 ±0.20 at position $\alpha {\rm (2000)} = {\rm 21^h43^m03\fs40}$, $\delta{\rm (2000)} = +06\degr54^\prime17\farcs5$, within the joint Chandra and XMM-Newton error circles. We analyse archival XMM-Newton observations and derive revised spectral and positional parameters. The predicted optical flux from the extrapolated X-ray spectrum is likely twice as high as reported before. The measured optical flux exceeds the extrapolated X-ray spectral flux by a factor ${\sim}40$(15-60 at 1σconfidence). We interpret our detection and the spectral energy distribution as further evidence of a temperature structure over the neutron star's surface and present a pure thermal model reflecting both the SED and the pulsed fraction of the light curve.

Context.We present multi-wavelength observations of the bright quasar HS1603+3820: the optical data taken with the MMT and Keck telescopes, with the 40–50 km s-1resolution, and X-ray data taken by the Chandra X-ray Observatorysatellite.

The 'Gun Room' department in Guns & Ammo has always been informative and interesting. I was sorry to see that it had been shrunk to only three questions in your [...]

Impaction allograft is an established method of securing initial stability of an implant in arthroplasty. Subsequent bone integration can be prolonged, and the volume of allograft may not be maintained. Intermittent administration of parathyroid hormone has an anabolic effect on bone and may therefore improve integration of an implant.Using a canine implant model we tested the hypothesis that administration of parathyroid hormone may improve osseointegration of implants surrounded by bone graft. In 20 dogs a cylindrical porous-coated titanium alloy implant was inserted into normal cancellous bone in the proximal humerus and surrounded by a circumferential gap of 2.5 mm. Morsellised allograft was impacted around the implant. Half of the animals were given daily injections of human parathyroid hormone (1–34) 5 µg/kg for four weeks and half received control injections. The two groups were compared by mechanical testing and histomorphometry. We observed a significant increase in new bone formation within the bone graft in the parathyroid hormone group. There were no significant differences in the volume of allograft, bone-implant contact or in the mechanical parameters.These findings suggest that parathyroid hormone improves new bone formation in impacted morsellised allograft around an implant and retains the graft volume without significant resorption. Fixation of the implant was neither improved nor compromised at the final follow-up of four weeks.

Converging lines of behavioral and pharmacological evidence suggest that GABAergic synapses in the basolateral amygdala (BLA) may play an integral role in mediating the anxiolytic effects of ethanol (EtOH). Since anxiety is thought to play an important role in the development of, and relapse to, alcoholism, elucidating the mechanisms through which EtOH modulates GABAergic synaptic transmission in the BLA may be fundamental in understanding the etiology of this disease. A recent study in mice has shown that principal cells within the BLA receive inhibitory input from two distinct types of GABAergic interneurons: a loosely distributed population of local interneurons and a dense network of paracapsular (pcs) GABAergic cells clustered along the external capsule border. Here, we sought to confirm the presence of these two populations of GABAergic synapses in the rat BLA and evaluate their ethanol sensitivity. Our results suggest that rat BLA pyramidal cells receive distinct inhibitory input from local and pcs interneurons and that EtOH potentiates both populations of synapses, albeit via distinct mechanisms. EtOH enhancement of local inhibitory postsynaptic currents (IPSCs) was associated with a significant decrease in paired-pulse ratio (PPR) and was significantly potentiated by the GABA(B) receptor antagonist SCH 50911 [(+)-(S)-5,5-dimethylmorpholinyl-2-acetic acid], consistent with a facilitation of GABA release from presynaptic terminals. Conversely, EtOH enhancement of pcs IPSCs did not alter PPR and was not enhanced by SCH 50911 but was inhibited by blockade of noradrenergic receptors. Collectively, these data reveal that EtOH can potentiate GABAergic inhibitory synaptic transmission in the rat BLA through at least two distinct pathways.

We have investigated whether the presence of polyethylene (PE) alone is sufficient to cause an aggressive periprosthetic tissue response, or whether certain mechanical interface conditions can allow bone to grow while in the presence of PE. An experimental implant was loaded in the presence and absence of particulate PE under stable and unstable conditions.Bone with a thin, discontinuous fibrous membrane formed in both groups of stable implants, either in the presence or absence of PE. By contrast, a continuous fibrous membrane consistently formed in both groups of unstable implants. The membrane consisted of loose fibrous connective tissue when PE was absent, and dense connective tissue with macrophages and a synovial lining when PE was present. In this model, if the interface was stable, the presence of PE was not sufficient to prevent the formation of bone or to produce a phagocytic tissue response. Only when the interface was unstable did a fibrous membrane form, and only then in the presence of PE.

It is shown that the tetragonal phase can be stabilized in the sintered body of a partially stabilized zirconia (PSZ) containing low concentrations of yttria. Such sintered body containing the metastable phase undergoes stress-induced phase transformation by the absorption of thermal or mechanical stress and exhibits strengths in excess of 690 MPa (100ksi).

Visualisation of periacetabular osteolysis by standard anteroposterior (AP) radiographs underestimates the extent of bone loss around a metal-backed acetabular component. We have assessed the effectiveness of standard radiological views in depicting periacetabular osteolysis, and recommend additional projections which make these lesions more visible. This was accomplished using a computerised simulation of radiological views and a radiological analysis of simulated defects placed at regular intervals around the perimeter of a cadaver acetabulum. The AP view alone showed only 38% of the defects over all of the surface of the cup and failed to depict a 3 mm lesion over 83% of the cup. When combined with the AP view, additional 45° obturator-oblique and iliac-oblique projections increased the depiction, showing 81% of the defects. The addition of the 60° obturator-oblique view further improved the visualisation of posterior defects, increasing the rate of detection to 94%. Based on this analysis, we recommend using at least three radiographic views when assessing the presence and extent of acetabular osteolysis.

Polycrystalline zirconia containing a high content of metastable tetragonal phase shows high strength (~ 700 MPa), high fracture toughness (Kc = 6 to 9 MN m-3/2) and small grain size (<0.3jµm). The strength and grain size remain nearly constant over a wide range of tetragonal phase content (100 to 30%). At a low concentration of tetragonal phase <30%, there is a rapid decrease in strength accompanied by a rapid increase in grain size. These results are explained by means of a stress-induced phase transformation in the metastable tetragonal phase.

The response of a premixed flame in stagnation-point flow with an imposed oscillating strain rate has been examined. This configuration is of fundamental interest and has potential application to turbulent combustion modelling. Of interest are flames which stand well clear of the front stagnation point of a bluff body. Under these conditions the flame can be treated as a surface of density discontinuity. A detailed solution is constructed in the burned and unburned gas regions and includes the flame response to the imposed fluctuations as well as the resulting displacement of the incident flow. Our analysis accounts for the full coupling between the flame and the underlying flow field and, unlike most previous studies, is not restricted to small-amplitude oscillations.

A model for the heating and ignition of a combustible solid by microwave energy is formulated and analysed in the limit of small inverse activation energy and small Biot number B. The high activation energy limit implies that the heating process is effectively inert until the temperature within the material reaches a critical ignition value, while the small Biot number limit implies that during this stage spatial variations in temperature throughout the material are always small. Analysis of the inert stage includes determination of the dynamics of inert hot-spots. As the ignition temperature is approached chemical energy is released rapidly in the form of heat, and the evolution then enters an ignition stage which develops on a fast time-scale. A reduced system is derived governing small-amplitude departures of the temperature from the inert value during the ignition stage under the significant scaling relation between the expansion parameters, which is shown to be ~ B. This reduced system recovers both of the familiar canonical systems describing (i) localized ignition by in-depth absorption of radiation and (ii) spatially homogeneous blow-up, in the limits of small and large values of µ = /B, respectively. Numerical integration of the reduced system in parameter regimes relevant to production of materials by combustion synthesis shows that ignition can occur either on the boundary or in the interior of a solid sample, and that there are regimes where the ignition site changes abruptly with variation of system parameters.

We compared joint proprioception in 12 hips in 12 patients with hemiarthroplasty after fracture of the hip, in 12 hips in 11 patients with total hip arthroplasty because of osteoarthritis and in a control group of 12 age-matched patients with no clinical complaints. There was no significant difference (p = 0.05) in joint proprioception in any of the groups. There was no decrease in joint proprioception in the group with total hip arthroplasty compared with the hemiarthroplasty group or with the control group.Other factors such as stretch receptors in the adjacent tendons and muscles may have a greater influence on proprioception in the hip than the intracapsular components.

Tensile properties of annealed molybdenum were investigated from 1000° to—200°C. In the vicinity of room temperature a well-defined transition in tensile properties occurs. Reduction in area decreases from over 80 pet to 0 pet and, simultaneously, the yield strength increases about 60,000 psi.

We used an experimental model producing a tissue response with a sclerotic endosteal neo-cortical rim associated with implant loosening in humans: a 6 mm PMMA cylinder pistoned 500 μm concentrically in a 7.5 mm hole, with polyethylene particles. At a second operation at eight weeks, the standard revision procedure removed the fibrous membrane in one knee, and the crack revision procedure was used to crack the sclerotic endosteal rim in the contralateral knee. Once stability was achieved following the revision procedures, loaded Ti plasma sprayed implants were inserted into the revision cavities of 8 dogs for an additional 4 weeks. Revision implant fixation (ultimate shear strength and energy absorption) was significantly enhanced by cracking the sclerotic endosteal rim. In conclusion, we demonstrated a simple technique of cracking the sclerotic endosteal rim as an additional method for improving revision fixation.

We have demonstrated retrograde transport of nerve growth factor to the dorsal root ganglia in the chicken embryo. Polyacrylamide gel pellets impregnated with 125I-labeled nerve growth factor were implanted subcutaneously in the leg of stage 36 (10-day) chicken embryos. The embryos were killed 8 hr after implantation and were processed for routine autoradiography. Examination revealed significant labeling of all lumbar dorsal root ganglia on the side of the implanted pellet. The lateral motor columns and ventral roots as well as the dorsal roots on both sides were unlabeled. These observations show that in the chicken embryo, during the period of sensory cell sensitivity to nerve growth factor, there is a selective uptake and retrograde transport of nerve growth factor from the target area to the dorsal root ganglia. These observations supplement reports from other laboratories in which selective retrograde transport of nerve growth factor in neonatal and adult rodents has been demonstrated.

Recently, Sheng and Hermann1reported the achievement of zero resistance at >100 K in the system Tl–Ca–Ba–Cu–O (TCBCO). Two superconducting phases were immediately identified2as Tl2CaBa2Cu2O8+δ(2122) and Tl2Ca2Ba2Cu3O10+δ(2223). Here we confirm that zero resistance is achievable above 100 K in 2122–TCBCO synthesized by a fast solid-state reaction, and report a small positive pressure dependence of the transition temperature, as in Bi2CaSr2Cu2O8+δ3.

The present status of superconductivity at very high temperatures, i.e. substantially higher than 100K, is summarized and examined. Possible future steps toward very high temperatures are suggested and discussed.