Shrapnel-Induced Mandibular Hypomobility

Mandibular hypomobility can develop from direct injury to, or as a result of disorders affecting, the supporting structures of the temporomandibular joint. This can be subdivided into intra-articular and extraarticular processes. Ankylosis is commonly associated with trauma (31% to 98%), followed by infections (10% to 49%) and systemic disease (10%). Temporomandibular joint ankylosis is an intra-articular process characterized by fibrous, fibro-osseous, or osseous obliteration of the joint space. Pseudoankylosis involves extracapsular causes of restricted jaw motion that include, but are not limited to, coronoid-zygomatic fusion, coronoid hypertrophy, and muscular fibrosis. Shrapnel injuries can be as devastating as high-velocity gunshot wounds, with functional and esthetic consequences, depending on the velocity, size, shape, and jagged edges of the fragments. Traumatic life support measures are paramount during the immediate postinjury setting. The airway and hemodynamic status must be maintained, because the oxygen-carrying capacity is essential for wound healing and the prevention of infection. A secure airway controlled with an endotracheal tube or tracheostomy needs early consideration because bleeding and edema can result in airway compromise. The securing of the airway should be followed by a comprehensive examination of the patient to reveal additional injuries

Phase fluctuations in superconductors: from Galilean invariant to quantum XY models

We analyze the corrections to the superfluid density due to phase fluctuations within both a continuum and a lattice model for $s$- and d-wave superconductors. We expand the phase-only action beyond the Gaussian level and compare our results with the quantum XY model both in the quantum and in the classical regime. We find new dynamic anharmonic vertices, absent in the quantum XY model, which are responsible for the vanishing of the correction to the superfluid density at zero temperature in a continuum (Galilean invariant) model. Moreover the phase-fluctuation effects are reduced with respect to the XY model by a factor at least of order $1/(k_F\xi_0)^2$.Comment: 4 pages; shorter version, accepted for publication on Phys. Rev. B Rapid Com

First results of meteor radar lower thermosphere wind measurements at Dixon, Arctic (73.5゜N, 80゜E)

Results of simultaneous wind measurements by the identical meteor radars at Dixon (73.5°N, 80°E) and Obninsk (55°N, 37°E) are presented for the time interval from November 12, 1999 to July 31, 2000. A number of features were observed which require comprehensive investigation on the basis of long-term wind measurements in the high-latitude lower thermosphere. The observed semidiurnal tide phases at Dixon are close to those published for Troms0, providing some evidence for predominance of the migrating semidiurnal tide for semidiurnal oscillations at this latitude. Highly coherent oscillations in tidal amplitudes and prevailing winds were also revealed, as well as time intervals with non-significant semidiurnal tide during which oscillations with periods different from but close to 12 h were observed

The summertime 12-h wind oscillation with zonal wavenumber <i>s</i> = 1 in the lower thermosphere over the South Pole

International audienceMeteor radar measurements of winds near 95 km in four azimuth directions from the geographic South Pole are analyzed to reveal characteristics of the 12-h oscillation with zonal wavenumber one (s=1). The wind measurements are confined to the periods from 19 January 1995 through 26 January 1996 and from 21 November 1996 through 27 January 1997. The 12-h s=1 oscillation is found to be a predominantly summertime phenomenon, and is replaced in winter by a spectrum of oscillations with periods between 6 and 11.5 h. Both summers are characterized by minimum amplitudes (5?10 ms?1) during early January and maxima (15?20 ms?1) in November and late January. For 10-day means of the 12-h oscillation, smooth evolutions of phase of order 4?6 h occur during the course of the summer. In addition, there is considerable day-to-day variability (±5?10 ms?1 in amplitude) with distinct periods (i.e., ~5 days and ~8 days) which suggests modulation by planetary-scale disturbances. A comparison of climatological data from Scott Base, Molodezhnaya, and Mawson stations suggests that the 12-h oscillation near 78°S is s=1, but that at 68°S there is probably a mixture between s=1 and other zonal wavenumber oscillations (most probably s=2). The mechanism responsible for the existence of the 12-h s=1 oscillation has not yet been identified. Possible origins discussed herein include in situ excitation, nonlinear interaction between the migrating semidiurnal tide and a stationary s=1 feature, and thermal excitation in the troposphere

Climatological lower thermosphere winds as seen by ground-based and space-based instruments

Comparisons are made between climatological dynamic fields obtained from ground-based (GB) and space-based (SB) instruments with a view towards identifying SB/GB intercalibration issues for TIMED and other future aeronomy satellite missions. SB measurements are made from the High Resolution Doppler Imager (HRDI) instrument on the Upper Atmosphere Research Satellite (UARS). The GB data originate from meteor radars at Obninsk, (55° N, 37° E), Shigaraki (35° N, 136° E) and Jakarta (6° S, 107° E) and MF spaced-antenna radars at Hawaii (22° N, 160° W), Christmas I. (2° N, 158° W) and Adelaide (35° S, 138° E). We focus on monthly-mean prevailing, diurnal and semidiurnal wind components at 96km, averaged over the 1991-1999 period. We perform space-based (SB) analyses for 90° longitude sectors including the GB sites, as well as for the zonal mean. Taking the monthly prevailing zonal winds from these stations as a whole, on average, SB zonal winds exceed GB determinations by ~63%, whereas meridional winds are in much better agreement. The origin of this discrepancy remains unknown, and should receive high priority in initial GB/SB comparisons during the TIMED mission. We perform detailed comparisons between monthly climatologies from Jakarta and the geographically conjugate sites of Shigaraki and Adelaide, including some analyses of interannual variations. SB prevailing, diurnal and semidiurnal tides exceed those measured over Jakarta by factors, on the average, of the order of 2.0, 1.6, 1.3, respectively, for the eastward wind, although much variability exists. For the meridional component, SB/GB ratios for the diurnal and semidiurnal tide are about 1.6 and 1.7. Prevailing and tidal amplitudes at Adelaide are significantly lower than SB values, whereas similar net differences do not occur at the conjugate Northern Hemisphere location of Shigaraki. Adelaide diurnal phases lag SB phases by several hours, but excellent agreement between the two data sources exists for semidiurnal tidal phases throughout the year. These results are consistent with phase retardation effects in the MF radar technique that are thought to exist above about 90km. Prevailing and tidal amplitudes from Shigaraki track year-to-year variations in SB fields, whereas in the Southern Hemisphere poorer agreement exists. The above hemispheric differences are due in part to MF vs. meteor radar techniques, but zonal asymmetries and day-to-day variability, combined with inadequate sampling, may also be playing a role. Based on these results, some obvious recommendations emerge that are relevant to combined GB/SB studies as part of TIMED and other future aeronomy missions.J. M. Forbes, Yu. I. Portnyagin, W. Skinner, R. A. Vincent, T. Solovjova, E. Merzlyakov, T. Nakamura, and S. Pal

Troposphere-Thermosphere Tidal Coupling as Measured by the SABER Instrument on TIMED during July-September, 2002

Coupling between the troposphere and lower thermosphere due to upward-propagating tides is investigated using temperatures measured from the SABER instrument on the TIMED satellite. The data analyzed here are confined to 20-120 km altitude and +/-40 deg latitude during 20 July 20 September, 2002. Apart from the migrating (sun-synchronous) tidal components, the predominant feature seen (from the satellite frame) during this period is a wave-4 structure in longitude with extrema of up to +/-40-50 K at 110 km. Amplitudes and longitudes of maxima of this structure evolve as the satellite precesses in local time, and as the wave(s) responsible for this structure vary with time. The primary wave responsible for the wave-4 pattern is the eastward-propagating diurnal tide with zonal wavenumber s=3 (DE3). Its average amplitude distribution over the interval is quasi-symmetric about the equator, similar to that of a Kelvin wave, with maximum of about 20 K at 5 deg S and 110 km. DE3 is primarily excited by latent heating due to deep tropical convection in the troposphere. It is demonstrated that existence of DE3 is intimately connected with the predominant wave-4 longitude distribution of topography and land-sea difference at low latitudes, and an analogy is drawn with the strong presence of DE1 in Mars atmosphere, the predominant wave-2 topography on Mars, and the wave-2 patterns that dominate density measurements from the Mars Global Surveyor (MGS) spacecraft near 130 km. Additional diurnal, semidiurnal and terdiurnal nonmigrating tides are also revealed in the present study. These tidal components are most likely excited by nonlinear interactions between their migrating counterparts and the stationary planetary wave with s=1 known to exist in the Southern Hemisphere during this period just prior to the austral mid-winter stratospheric warming of 2002