2,017 research outputs found

    Predictors and outcomes of crossover to surgery from physical therapy for meniscal tear and osteoarthritis a randomized trial comparing physical therapy and surgery

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    BACKGROUND: Arthroscopic partial meniscectomy (APM) combined with physical therapy (PT) have yielded pain relief similar to that provided by PT alone in randomized trials of subjects with a degenerative meniscal tear. However, many patients randomized to PT received APM before assessment of the primary outcome. We sought to identify factors associated with crossing over to APM and to compare pain relief between patients who had crossed over to APM and those who had been randomized to APM. METHODS: We used data from the MeTeOR (Meniscal Tear in Osteoarthritis Research) Trial of APM with PT versus PT alone in subjects ≥45 years old who had mild-to-moderate osteoarthritis and a degenerative meniscal tear. We assessed independent predictors of crossover to APM among those randomized to PT. We also compared pain relief at 6 months among those randomized to PT who crossed over to APM, those who did not cross over, and those originally randomized to APM. RESULTS: One hundred and sixty-four subjects were randomized to and received APM and 177 were randomized to PT, of whom 48 (27%) crossed over to receive APM in the first 140 days after randomization. In multivariate analyses, factors associated with a higher likelihood of crossing over to APM among those who had originally been randomized to PT included a baseline Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain Score of ≥40 (risk ratio [RR] = 1.99; 95% confidence interval [CI] = 1.00, 3.93) and symptom duration of <1 year (RR = 1.74; 95% CI = 0.98, 3.08). Eighty-one percent of subjects who crossed over to APM and 82% of those randomized to APM had an improvement of ≥10 points in their pain score at 6 months, as did 73% of those who were randomized to and received only PT. CONCLUSIONS: Subjects who crossed over to APM had presented with a shorter symptom duration and greater baseline pain than those who did not cross over from PT. Subjects who crossed over had rates of surgical success similar to those of the patients who had been randomized to surgery. Our findings also suggest that an initial course of rigorous PT prior to APM may not compromise surgical outcome. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence

    An case of extreme particulate matter concentrations over Central Europe caused by dust emitted over the southern Ukraine

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    On 24 March 2007, an extraordinary dust plume was observed in the Central European troposphere. Satellite observations revealed its origins in a dust storm in Southern Ukraine, where large amounts of soil were resuspended from dried-out farmlands at wind gusts up to 30 m s?1. Along the pathway of the plume, maximum particulate matter (PM10) mass concentrations between 200 and 1400 ?g m?3 occurred in Slovakia, the Czech Republic, Poland, and Germany. Over Germany, the dust plume was characterised by a volume extinction coefficient up to 400 Mm?1 and a particle optical depth of 0.71 at wavelength 0.532 ?m. In-situ size distribution measurements as well as the wavelength dependence of light extinction from lidar and Sun photometer measurements confirmed the presence of a coarse particle mode with diameters around 2?3 ?m. Chemical particle analyses suggested a fraction of 75% crustal material in daily average PM10 and up to 85% in the coarser fraction PM10?2.5. Based on the particle characteristics as well as a lack of increased CO and CO2 levels, a significant impact of biomass burning was ruled out. The reasons for the high particle concentrations in the dust plume were twofold: First, dust was transported very rapidly into Central Europe in a boundary layer jet under dry conditions. Second, the dust plume was confined to a relatively stable boundary layer of 1.4?1.8 km height, and could therefore neither expand nor dilute efficiently. Our findings illustrate the capacity of combined in situ and remote sensing measurements to characterise large-scale dust plumes with a variety of aerosol parameters. Although such plumes from Southern Eurasia seem to occur rather infrequently in Central Europe, its unexpected features highlights the need to improve the description of dust emission, transport and transformation processes needs, particularly when facing the possible effects of further anthropogenic desertification and climate change

    An episode of extremely high PM concentrations over Central Europe caused by dust emitted over the southern Ukraine

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    International audienceOn 24 March 2007, the atmosphere over Central Europe was affected by an episode of exceptionally high mass concentrations of aerosol particles, most likely caused by a dust storm in the Southern Ukraine on the preceding day. At ground-based measurement stations in Slovakia, the Czech Republic, Poland and Germany PM10 mass concentrations rose to values between 200 and 1400 ?g m?3. An evaluation of PM10 measurements from 360 monitoring stations showed that the dust cloud advanced along a narrow corridor at speeds of up to 70 km h?1. According to lidar observations over Leipzig, Germany, the high aerosol concentrations were confined to a homogeneous boundary layer of 1800 m height. The wavelength dependence of light extinction using both lidar and sun photometer measurements suggested the dominance of coarse particles during the main event. At a wavelength of 532 nm, relatively high volume extinction coefficients (300?400 Mm?1) and a particle optical depth of 0.65 was observed. In-situ measurements with an aerodynamic particle sizer at Melpitz, Germany, confirmed the presence of a coarse particle mode with a mode diameter >2 ?m, whose maximum concentration coincided with that of PM10. A chemical particle analysis confirmed the dominance of non-volatile and insoluble matter in the coarse mode as well as high enrichments of Ti and Fe, which are characteristic of soil dust. A combination of back trajectory calculations and satellite images allowed to identify the dust source with confidence: On 23 March 2007, large amounts of dust were emitted from dried-out farmlands in the southern Ukraine, facilitated by wind gusts up to 100 km h?1. The unusual vertical stability and confined height of this dust layer as well as the rapid transport under dry conditions led to the conservation of high aerosol mass concentrations along the transect and thus to the extraordinary high aerosol concentrations over Central Europe. Our observations demonstrate the capacity of a combined apparatus of in situ and remote sensing measurements to characterise such a dust with a variety of aerosol parameters. As a conclusion, the description of dust emission, transport and transformation processes needs to be improved, especially when facing the possible effects of further anthropogenic desertification and climate change

    Indikatoren einer tiergerechten Mastputenhaltung unter den Bedingungen der ökologischen Geflügelmast

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    Ziel der Studie war eine Analyse der Häufigkeit und des Ausprägungsgrades tierschutzrelevanter Veränderungen bei Puten, die gemäß den Bedingungen der EU-Verordnung 889/2008 für den ökologischen Landbau gehalten wurden. In zwei Durchgängen wurden in neun Aufzucht- und 14 Mastbetrieben 32 Herden mit insgesamt 105.483 Tieren erfasst. Der Tiergesundheitsstatus der einzelnen Herden wurde stichprobenartig an fünf Zeitpunkten durch Beurteilung von 60 Einzeltieren dokumentiert. Bei jedem Bestandsbesuch wurden außerdem Einstreuproben entnommen und ihr Feuchtigkeitsgehalt thermogravimetrisch bestimmt. Die mittlere kumulierte Verlustrate in der Aufzuchtphase lag bei 3,3 % und in der 16. Lebenswoche bei 4,5%. Am Ende der Aufzuchtphase wiesen bis zu 44 % der untersuchten Tiere Epithelnekrosen an den Fußballen auf. Häufigkeit und Schweregrad von Ballenveränderungen nahmen im Verlauf der Mastphase weiter zu. So wurden in der 16. Lebenswoche bei über 80 % der untersuchten Puten Ballennekrosen festgestellt. Am Schlachthof erfolgte eine Aufnahme allgemeiner Daten zur Schlachtung und folgend die visuelle Beschau von 60 Puten je Herde. Der überwiegende Teil der Tiere (97,7%) wies zum Zeitpunkt der Schlachtung Veränderungen der Fußballen auf, während Brusthautveränderungen nur selten dokumentiert wurden. Vermehrt traten weiterhin Leberveränderungen, insbesondere Grünfärbungen auf, wobei deutliche Unterschiede zwischen verschiedenen Betrieben sowie zwischen den einzelnen Durchgängen festgestellt wurden. Auch Gelenksveränderungen waren häufige Befunde. Als ein maßgeblicher Faktor für die Gesunderhaltung eines Putenbestandes ist die Befähigung des bestandsbetreuenden Personenkreises anzusehen, gesundheitliche Probleme frühzeitig zu erkennen und zeitnah darauf zu reagieren. Neben der Qualität des Einstreusubstrates inklusive Beurteilung der Kotkonsistenz können Häufigkeit und Ausprägung von Ballenveränderungen wertvolle Hinweise für eine Einschätzung des Tierhaltungsstandards in einem Bestand liefern und sind als wichtige, einfach erfassbare Tierschutzindikatoren einzustufen . Auch Gelenks- und Leberveränderungen sind aufgrund hoher Prävalenzen als relevante Tiergesundheitsparameter zu betrachten, die im Rahmen eines Monitorings routinemäßig erfasst werden sollten

    Relativistic quantum dynamics in strong fields: Photon emission from heavy, few-electron ions

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    Recent progress in the study of the photon emission from highly-charged heavy ions is reviewed. These investigations show that high-ZZ ions provide a unique tool for improving the understanding of the electron-electron and electron-photon interaction in the presence of strong fields. Apart from the bound-state transitions, which are accurately described in the framework of Quantum Electrodynamics, much information has been obtained also from the radiative capture of (quasi-) free electrons by high-ZZ ions. Many features in the observed spectra hereby confirm the inherently relativistic behavior of even the simplest compound quantum systems in Nature.Comment: Version 18/11/0

    Geometric Approach to Pontryagin's Maximum Principle

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    Since the second half of the 20th century, Pontryagin's Maximum Principle has been widely discussed and used as a method to solve optimal control problems in medicine, robotics, finance, engineering, astronomy. Here, we focus on the proof and on the understanding of this Principle, using as much geometric ideas and geometric tools as possible. This approach provides a better and clearer understanding of the Principle and, in particular, of the role of the abnormal extremals. These extremals are interesting because they do not depend on the cost function, but only on the control system. Moreover, they were discarded as solutions until the nineties, when examples of strict abnormal optimal curves were found. In order to give a detailed exposition of the proof, the paper is mostly self\textendash{}contained, which forces us to consider different areas in mathematics such as algebra, analysis, geometry.Comment: Final version. Minors changes have been made. 56 page

    The regional aerosol-climate model REMO-HAM

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    REMO-HAM is a new regional aerosol-climate model. It is based on the REMO regional climate model and includes most of the major aerosol processes. The structure for aerosol is similar to the global aerosol-climate model ECHAM5-HAM, for example the aerosol module HAM is coupled with a two-moment stratiform cloud scheme. On the other hand, REMO-HAM does not include an online coupled aerosol-radiation nor a secondary organic aerosol module. In this work, we evaluate the model and compare the results against ECHAM5-HAM and measurements. Four different measurement sites were chosen for the comparison of total number concentrations, size distributions and gas phase sulfur dioxide concentrations: Hyytiälä in Finland, Melpitz in Germany, Mace Head in Ireland and Jungfraujoch in Switzerland. REMO-HAM is run with two different resolutions: 50 × 50 km2 and 10 × 10 km2. Based on our simulations, REMO-HAM is in reasonable agreement with the measured values. The differences in the total number concentrations between REMO-HAM and ECHAM5-HAM can be mainly explained by the difference in the nucleation mode. Since we did not use activation nor kinetic nucleation for the boundary layer, the total number concentrations are somewhat underestimated. From the meteorological point of view, REMO-HAM represents the precipitation fields and 2 m temperature profile very well compared to measurement. Overall, we show that REMO-HAM is a functional aerosol-climate model, which will be used in further studies

    Comprehensive assessment of meteorological conditions and airflow connectivity during HCCT-2010

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    This study presents a comprehensive assessment of the meteorological conditions and atmospheric flow dur- ing the Lagrangian-type “Hill Cap Cloud Thuringia 2010” experiment (HCCT-2010), which was performed in Septem- ber and October 2010 at Mt. Schmücke in the Thuringian Forest, Germany and which used observations at three measurement sites (upwind, in-cloud, and downwind) to study physical and chemical aerosol–cloud interactions. A Lagrangian-type hill cap cloud experiment requires not only suitable cloud conditions but also connected airflow condi- tions (i.e. representative air masses at the different measure- ment sites). The primary goal of the present study was to identify time periods during the 6-week duration of the ex- periment in which these conditions were fulfilled and there- fore which are suitable for use in further data examinations. The following topics were studied in detail: (i) the general synoptic weather situations, including the mesoscale flow conditions, (ii) local meteorological conditions and (iii) lo- cal flow conditions. The latter were investigated by means of statistical analyses using best-available quasi-inert trac- ers, SF6 tracer experiments in the experiment area, and re- gional modelling. This study represents the first applica- tion of comprehensive analyses using statistical measures such as the coefficient of divergence (COD) and the cross- correlation in the context of a Lagrangian-type hill cap cloud experiment. This comprehensive examination of local flow connectivity yielded a total of 14 full-cloud events (FCEs), which are defined as periods during which all connected flow and cloud criteria for a suitable Lagrangian-type ex- periment were fulfilled, and 15 non-cloud events (NCEs), which are defined as periods with connected flow but no cloud at the summit site, and which can be used as refer- ence cases. The overall evaluation of the identified FCEs provides the basis for subsequent investigations of the mea- sured chemical and physical data during HCCT-2010 (see http://www.atmos-chem-phys.net/special_issue287.html). Results obtained from the statistical flow analyses and regional-scale modelling performed in this study indicate the existence of a strong link between the three measurement sites during the FCEs and NCEs, particularly under condi- tions of constant southwesterly flow, high wind speeds and slightly stable stratification. COD analyses performed using continuous measurements of ozone and particle (49nm di- ameter size bin) concentrations at the three sites revealed, particularly for COD value

    Patellofemoral Syndrome

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    CLINICAL PRESENTATION & EXAM: Patellofemoral syndrome is a common cause of knee pain, particularly in young female athletes. Studies suggest that multiple factors contribute to its development, including patellar maltracking, imbalance between the vastus lateralis and vastus medialis, hip instability and weakness, hamstring imbalance and tightness, and rear-foot eversion. Patients typically present with anterior knee pain, especially during weight-bearing activities that involve knee flexion. The condition can also cause knee stiffness after prolonged sitting with the knee flexed and may lead to knee buckling due to quadriceps weakness. Pain often intensifies with squatting. Tight hamstrings have been linked to patellofemoral syndrome, as simultaneous contraction of the hamstrings and quadriceps increases force on the knee joint. Hamstring tightness may be observed during a passive knee extension test. ANATOMY & PATHOLOGY: The patellofemoral joint consists of the patella and the distal trochlea of the femur. The patella plays a crucial role in knee flexion, acting as a lever to enhance the efficiency of the quadriceps. It is connected to the quadriceps tendon and the patellar ligament. The patella is stabilized by surrounding muscles, including the rectus femoris, vastus lateralis, and vastus medialis obliquus. A Q angle exceeding 15-20 degrees is associated with an increased risk of patellofemoral syndrome. DIAGNOSTIC TESTING & CONSIDERATIONS: Diagnosing patellofemoral syndrome is based on a patient’s history and physical examination findings. Among manual maneuvers, the patellar tilt test has the highest likelihood ratio for identifying a true positive result. Additional tests, such as the patellar apprehension test or Clarke’s test, may also aid in evaluation. Gait analysis can reveal signs of patellofemoral syndrome, including exaggerated lumbar lordosis, asymmetric hip height, foot eversion, or quadriceps atrophy. Imaging may be useful for ruling out other conditions, such as osteoarthritis, fractures, or osteochondritis, if these are suspected based on the physical examination. TREATMENT & RETURN TO ACTIVITY: The treatment for patellofemoral syndrome is primarily non-operative, focusing on a conservative approach. Physical therapy is the most studied form of treatment, though no single exercise has been proven to be the most effective. Therapy should be individualized, with an emphasis on strengthening the hip, trunk, and knee muscles. Taping has shown success in addressing lateral patellar maltracking and patellar tilt. When combined with exercise, adhesive taping has demonstrated better results than exercise alone. The most commonly used taping technique is the McConnell method. Additionally, patellar braces can help manage patellar maltracking and pain levels
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