7 research outputs found

    Contributions To The Study Of Erosion Along The North Shore Of Lake Erie

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    Simultaneous observations of the phase-locked 2 day wave at Adelaide, Cerro Pachon, and Darwin

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    The Southern Hemisphere summer 2 day wave (TDW) is the most dramatic large-scale event of the upper mesosphere. The winds accelerate over _1 week, may attain \u3e 70 m/s, and are often accompanied by a near disappearance of the diurnal tide and stabilization of the period close to 48 h. We denote this as the phase-locked 2 day wave (PL/TDW). We have examined airglow and meteor radar (MR) wind data from the Andes Lidar Observatory (Cerro Pachon, Chile:30¡S, 289.3¡E), MR data from Darwin (12.5¡S, 131¡E) and airglow and medium frequency radar data from the University of Adelaide (34.7¡S, 138.6¡E) for the behavior of the TDW during the austral summers of 2010, 2012, and 2013. The Cerro Pachon and Adelaide sites are located at similar latitudes separated in longitude by about 120¡. We find a remarkable coincidence between the TDW oscillations at Chile and Adelaide for the period January-February 2010. The oscillations are nearly in phase in terms of local time and the minima and maxima repeat at nearly the same local time from cycle to cycle consistent with a phase-locked wave number 3 TDW. Data for this and other years (including Darwin) show that the amplitude of the diurnal tide decreases when the TDW is largest and that this occurs when the period is close to 48 h. These observations support the proposal that the PL/TDW is a subharmonic parametric instability wherein the diurnal tide transfers energy to a TDW that is resonant at nearly 48 h. ©2015. American Geophysical Union. All Rights Reserved

    The life cycle of instability features measured from the Andes Lidar Observatory over Cerro Pachon on 24 March 2012

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    The Aerospace Corporation\u27s Nightglow Imager (ANI) observes nighttime OH emission (near 1.6 μm) every 2 s over an approximate 73° field of view. ANI had previously been used to study instability features seen over Maui. Here we describe observations of instabilities seen from 5 to 8 UT on 24 March 2012 over Cerro Pachon, Chile, and compare them with previous results from Maui, with theory, and with Direct Numerical Simulations (DNS). The atmosphere had reduced stability because of the large negative temperature gradients measured by a Na lidar. Thus, regions of dynamical and convective instabilities are expected to form, depending on the value of the Richardson number. Bright primary instabilities are formed with a horizontal wavelength near 9 km and showed the subsequent formation of secondary instabilities, rarely seen over Maui, consistent with the primaries being dynamical instabilities. The ratio of the primary to secondary horizontal wavelength was greater over Chile than over Maui. After dissipation of the instabilities, smaller-scale features appeared with sizes in the buoyancy subrange between 1.5 and 6 km. Their size spectra were consistent with the model of Weinstock (1978) if the turbulence is considered to be increasing. The DNS results produce secondary instabilities with sizes comparable to what is seen in the images although their spectra are somewhat steeper than is observed. However, the DNS results also show that after the complete decay of the primary features, scale sizes considerably smaller than 1 km are produced and these cannot be seen by the ANI instrument

    Are joint and soft tissue injections painful? Results of a national French cross-sectional study of procedural pain in rheumatological practice

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    <p>Abstract</p> <p>Background</p> <p>Joint, spinal and soft tissue injections are commonly performed by rheumatologists in their daily practice. Contrary to other procedures, e.g. performed in pediatric care, little is known about the frequency, the intensity and the management of procedural pain observed in osteo-articular injections in daily practice.</p> <p>Methods</p> <p>This observational, prospective, national study was carried out among a French national representative database of primary rheumatologists to evaluate the prevalence and intensity of pain caused by intra-and peri-articular injections, synovial fluid aspirations, soft tissue injections, and spinal injections. For each physician, data were collected over 1 month, for up to 40 consecutive patients (>18-years-old) for whom a synovial fluid aspiration, an intra or peri-articular injection or a spinal injection were carried out during consultations. Statistical analysis was carried out in order to compare patients who had suffered from pain whilst undergoing the procedure to those who had not. Explanatory analyses were conducted by stepwise logistic regression with the characteristics of the patients to explain the existence of pain.</p> <p>Results</p> <p>Data were analysed for 8446 patients (64% female, mean age 62 ± 14 years) recruited by 240 physicians. The predominant sites injected were the knee (45.5%) and spine (19.1%). Over 80% of patients experienced procedural pain which was most common in the small joints (42%) and spine (32%) Pain was severe in 5.3% of patients, moderate in 26.6%, mild in 49.8%, and absent in 18.3%. Pain was significantly more intense in patients with severe pain linked to their underlying pathology and for procedures performed in small joints.</p> <p>Preventative or post-procedure analgesia was rarely given, only to 5.7% and 36.3% of patients, respectively. Preventative analgesia was more frequently prescribed in patients with more severe procedural pain.</p> <p>Conclusion</p> <p>Most patients undergoing intra-or peri-articular injections, synovial fluid aspirations and spine injections suffer from procedural pain. Most patients experience usually mild procedural pain and procedural pain management is uncommonly provided by physicians. Specific research and guidelines for the management of procedural pain related to rheumatologic care should be established to improve the quality of care provided by physicians.</p

    SURGICAL THERAPIES

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