223 research outputs found
Zur Kontextabhängigkeit von behinderungsbezogenen Kategorien im Sportunterricht aus der Sicht von Lehrkräften – Theoretische und empirische Anhaltspunkte einer fachbezogenen Diskussion um die Dekategorisierung inklusiver Bildung
No full textRischke A, Braksiek M. Zur Kontextabhängigkeit von behinderungsbezogenen Kategorien im Sportunterricht aus der Sicht von Lehrkräften – Theoretische und empirische Anhaltspunkte einer fachbezogenen Diskussion um die Dekategorisierung inklusiver Bildung. In: Hartmann M, Laging R, Scheinert C, eds. Professionalisierung in der Sportlehrerbildung – Konzepte und Forschung im Rahmen der Qualitätsoffensive Lehrerbildung. Bewegungspädagogik. Vol 12. Hohengehren: Schneider; 2019
Antarctic gravity anomaly and height anomaly grids (AntGG2021)
No full textThese data sets form a major update and enhancement of a first data publication in 2016 (Scheinert et al. 2016: doi:10.1002/2015GL067439, PANGAEA: doi:10.1594/PANGAEA.848168). Ground-based and airborne gravity data were compiled in the frame of the International Association of Geodesy (IAG) SC2.4f Gravity and Geoid in Antarctica (AntGG). Since 2016 important data have been acquired, primarily applying the method of airborne gravimetry, to close existing data gaps, especially over the south polar region. These data were measured during different projects where a number of institutions underwent close cooperations to fund and to realize specific campaigns, among others, Alfred Wegener Institute (Germany), DTU Space (Denmark), British Antarctic Survey (United Kingdom), Norwegian Polar Institute (Norway), National Geospatial Intelligence Agency (USA), and European Space Agency. Important steps in the set-up and processing compared to the AntGG2016 solution include: increase in grid resolution from 10 to 5 km; usage of a high-resolution background gravity field model (SATOP-1); thorough treatment of the topography; processing adopting the remove-compute-restore method and using a partition-enhanced least-squares collocation (LSC) (Zingerle et al. 2021: doi:10.1007/s00190-021-01540-6). Applying the LSC also gives the advantage to provide more data sets (since they are treated as functionals of the disturbing potential) and an accuracy measure (standard deviation) for the inferred gravity anomalies. Thus, data sets provided include: gravity anomaly (at the surface), gravity disturbance (both at the surface and at constant height of 5,000 m), height anomaly (both at surface and at ellipsoid), second radial derivative of the disturbing potential, Bouguer anomaly, and the standard deviation of LSC for the gravity anomaly
Doppelte Professionalisierung von Sportlehrkräften – ein theoretischer Anspruch im Praxis(semester)test
No full textUkley N, Fast N, Bergmann F, et al. Doppelte Professionalisierung von Sportlehrkräften – ein theoretischer Anspruch im Praxis(semester)test. In: Hartmann M, Laging R, Scheinert C, eds. Professionalisierung in der Sportlehrerbildung – Konzepte und Forschung im Rahmen der Qualitätsoffensive Lehrerbildung. Bewegungspädagogik. Vol 13. Hohengehren: Schneider; 2019: 176-191
Regional Geoid and Gravity Field from a Combination of Airborne and Satellite Data in Dronning Maud Land, East Antarctica
No full textSummaryRecently, a variety of gravity observations in Antarctica has become available through extensive e orts of airbornesurveys. Aircrafts serving as multi-instrumentation platforms provide measurements on gravity, bedrocktopography, ice surface topography and ice thickness. Collected datasets are valuable in terms of resolution andhomogeneity, which make them suitable for studying regional geoid determination in selected Antarctic regions.Within this context the German joint project VISA provided an excellent database for improving the regionalgeoid by combining gravity and topographic data from aerogeophysical observations with long-wavelength informationfrom global gravity eld models. Using the remove-compute-restore technique in conjunction withleast-squares collocation a regional geoid for Dronning Maud Land, East Antarctica, will be presented. A signalthreshold of up to 6 m added to the global model that was used as a basis can be expected. The accuracy ofthe regional geoid will be estimated to be at the level of 15 cm.Citation: J. Muller, S. Riedel, M. Scheinert, M. Horwath, R. Dietrich, D. Steinhage, H. Anschutz, W. Jokat(2007), RegionalGeoid and Gravity Field from a Combination of Airborne and Satellite Data in Dronning Maud Land, East Antarctica { OnlineProceedings of the 10th ISAES, edited by A.K. Cooper and C.R. Raymond et al., USGS Open-File Report 2007-xxx, ExtendedAbstract yyy, 1-4.IntroductionThe new datasets provided by the satellite missions CHAMP, GRACE and GOCE (to be launched by theend of 2007) enable a homogeneous determination of the gravity eld. Furthermore, in the polar regions icesurface heights could be determined in a similar quality by ICESat. These new satellite data shall be validatedand densi ed by the German joint project VISA (Validation, Densi cation and Interpretation of Satellite Datafor the Determination of Magnetic Field, Gravity Field, Ice Mass Balance and Structure of the Earth Crust inAntarctica, uitilizing Airborne and Terrestrial Measurements) of TU Dresden and AWI Bremerhaven.For this purpose western and central Dronning Maud Land (DML), East Antarctica, were chosen as areaof investigation. Airborne as well as terrestrial observation campaigns were carried out to provide appropriatedatasets on height and height changes, gravity and gravity changes, magnetics, glaciology and seismology. Incombination with the satellite data these measurements will be applied to yield more detailed models of thegravity eld and the regional geoid, of the crustal structure and litosphere dynamics and of the dynamics andmass balance of the Antarctic ice sheet in the working area.Observation campaignsBetween 2001 and 2005 four airborne observation campaigns and two terrestrial observation campaigns werecarried out in western and central DML in order to conduct geodetic and geophysical measurements (Fig. 1,left). The scienti c program of the aerogeophysical campaigns for the observation of the gravity eld, magnetic eld, ice surface height and ice thickness (Radio Echo Sounding (RES)) contains more than 350 ight-hourswith a line-spacing between 10 and 20 kilometers. The terrestrial eld work took place at two di erent areas,during the season 2003/04 at Schirmacher Oasis - Potsdam Glacier - Wohlthat Mountains and one year later(season 2004/05) at Heimefrontfjella - Kirwanveggen. GPS and seismometer stations on bedrock were installed,kinematic GPS pro les, relative gravimetry on ice and ground penetrating radar (GPR) measurements werecarried out as well as samplings of rn cores and snow pits (Anschutz et al., 2007; Anschutz et al., 2006;Scheinert et al., 2005; Nixdorf et al., 2004).Regional Geoid ImprovementCombining satellite observations from CHAMP and GRACE with terrestrial data, high-resolution models ofthe Earth gravity eld have been obtained. Latest examples of these combination models are EIGEN-CG03C, EIGEN-GL04C (Forste et al., 2005; Forste et al., 2006) and GGM02C (Tapley et al., 2005). In Antarctica, thedetermination of the global gravity eld is problematic becausen due to the remoteness (often inaccessibility)and harsh conditions the terrestrial gravity data coverage features very large gaps. Only for a few smallerregions ground-based or airborne measured gravity was included into the combination. In order to improve theterrestrial gravity coverage and to determine the Antarctic geoid, the IAG Commission Project 2.4 "AntarcticGeoid" (chaired by M. Scheinert) was set into action, which is closely linked to SCAR Expert Group on GeodeticInfrastructure in Antarctica (GIANT) project 3 "Physical Geodesy". An overview on the situation is given in(Scheinert, 2005), and the strategy of regional geoid improvement is discussed in (Scheinert et al., 2007b) for thePrince Charles Mountains region, East Antarctica (PCMEGA), as well as for Palmer Land, Antarctic Peninsula(Scheinert et al., 2007a).Within this context, the VISA observation campaigns de-Figure 2: Free-air Anomalies (preliminary resultswith a spatial resolution of 14 kilometers)scribed above provide an excellent database for the validationof the gravity eld and, more importantly, for the determinationand improvement of the regional geoid. Fig. 2 showspreliminary results for the free-air anomalies derived from airbornemeasurements over the western and central DML witha resolution of 14 kilometer (Riedel and Jokat, 2007). Comparedwith the subglacial topography (Fig. 3, left panel) thestrong correlation between these two datasets is clearly visible.The right panel of Fig. 3 shows the ice surface heightin the area of investigation. The datasets of Fig. 3 a ord toderive the ice-thickness, which will be needed in addition tothe subglacial topography for the computation of an improvedgeoid. The high resolution of these datasets make them muchmore suitable than BEDMAP data (Lythe et al., 2000), whichwere a valuable source of information prior to the VISA radarobservations in DML.Especially in Antarctica problems occur when satellite observationsfrom CHAMP and GRACE up to a certain spherical harmonic degree (typically 120) should be combined with terrestrial data. Geophysically extrapolated gravity anomalies do not necessaily reect the actualgravity eld in Antarctica, though they are inevitable to provide a globally complete data coverage neededfor the solution of the closed surface integrals. For this reason, shorter wavelength information (higher thanspherical harmonic degree 120) is unreliable for most Antarctic areas (Fig. 1, right). This evinces when comparingthe gravity anomalies from EIGEN-GL04C for a harmonic window (degrees 121 to 360) (Fig. 1, right)with the free-air anomalies derived from VISA airborne measurements (Fig. 2). While a higher correlation canbe seen near the coastline, it diminishes in the southern part of DML.For the calculation of the regional geoid the remove-compute-restore technique (RCRT) was applied, whichis discussed in detail e.g. in (Forsberg and Tscherning, 1997) and (Sjoberg, 2005) and which was also usedin the PCMEGA case (Scheinert et al., 2007b). In the remove step, a long-wavelength part (predicted by aglobal gravity eld model) and a short-wavelength part (predicted by topography) are removed from the originalgravity data. In the compute step, the obtained band-pass ltered gravity anomalies are transformed into geoidheights, using least-squares collocation in this study. Least-squares collocation o ers the advantage of providingerror estimates for the resulting geoid. After having carried out the compute step, the long-wavelength part andthe short-wavelength part are restored in the geoid. For the computations, we could make use of the programpackage GRAVSOFT (Forsberg et al., 2003; Tscherning, 1974), which o ers a variety of tools for the geodeticgravity eld modelling.ConclusionCombining gravity and topographic data from VISA aerogeophysical campaigns with a global gravity eldmodel a regional geoid for Dronning Maud Land, East Antarctica, will be presented. Studies in other regionsof Antarctica (Scheinert et al., 2007a; Scheinert et al., 2007b) have shown that a signal threshold of up to 6 mto the global gravity eld model that was used as a basis can be expected when comparing the improved geoidwith the global model up to spherical harmonic degree 120. The accuracy of the regional geoid is estimated tobe at the level of 15 cm. Considering the current data situation in Antarctica, the accuracy level of 1 dm is arealistic and appropriate goal for this area of the world. The data coverage in Antarctica will most likely besubject to major improvements when further airborne surveys are carried out. The International Polar Year2007/ 2008 provides a reasonable framework for international and interdisciplinary cooperation in that eld.SCAR-GIANT project 3 "Physical Geodesy" and IAG Commission Project 2.4 "Antarctic Geoid" work towardsthe goal of closing the gaps in the gravity data coverage and at improving the geoid in Antarctica
Evaluation of the biodegradable peripheral Igaki-Tamai stent in the treatment of de novo lesions in the superficial femoral artery: the GAIA study.
No full textObjectives: This study sought to evaluate the safety and performance of the Igaki-Tamai (Igaki Medical Planning Company, Kyoto, Japan) biodegradable stent in patients with occlusive superficial femoral artery (SFA) disease.
Background: Poly-L-lactic acid (PLLA) biodegradable stents have been shown to be effective in the coronaries, but no data are available regarding their efficacy in the femoral artery.
Methods: A prospective, multicenter, nonrandomized study enrolled 30 patients with symptomatic de novo SFA disease undergoing implantation of Igaki-Tamai bioresorbable stents. Clinical examinations and duplex ultrasound were prospectively performed after 1, 6, 9, and 12 months. The main study endpoints were technical success, restenosis rate, rate of target lesion revascularization (TLR), changes in ankle-brachial index (ABI), and quality of life by evaluating the walking impairment questionnaire (WIQ). Safety was assessed by monitoring the occurrence of major adverse clinical events and serious adverse events.
Results: The mean age of the patients was 67.7 years, and 77% were male. The mean lesion length was 5.9 cm. Mean diameter stenosis was reduced from 89.9% to 6.2%, after stent implantation. Technical success was 96.7%. Binary restenosis rate for the 6 and 12 months follow-up was 39.3% and 67.9%, respectively. The TLR rate was 25.0% after 6 months and 57.1% after 12 months. All TLR were successful; the secondary patency rate after 1 year was 89.3%. Between baseline and 12 months, ABI increased in 53.6% of patients. Functional endpoints (WIQ), even if affected by a relatively high reintervention rate, showed improvement in most of the patients.
Conclusions: The GAIA (Evaluation of the Biodegradable Peripheral Igaki-Tamai Stent in the Treatment of De Novo Lesions in the Superficial Femoral Artery) study shows that when using biodegradable PLLA stents (Igaki-Tamai), the immediate angiographic results are comparable to the results of metal stents, achieving a high secondary patency rate after 1 year. Modifications of stent characteristics and technical modifications are needed with the goal to reduce the restenosis rate during the reabsorption period
INCRAFT Stent-Graft System: One-year outcome of the INNOVATION trial
No full textAim: Endovascular repair has surpassed open surgical treatment as the most common procedure in patients with abdominal aortic aneurysms (AAA), yet its applicability remains limited to those with aortoiliac anatomy suitable for the introduction and deployment of the devices. The current study was performed to assess the safety and efficacy of INCRAFT® (Cordis Corporation, Bridgewater, NJ), an ultra-low-profile device for the treatment of AAA. Methods: The INNOVATION study is a first in human prospective, multicenter trial involving 6 centers in Europe. From March 2010 to June 2011 60 patients with asymptomatic AAA were treated with the INCRAFT® bifurcated Stent-Graft System. The main inclusion criteria were a proximal aortic neck of 15 mm or more in length and up to 27 mm in diameter; iliac landing zones greater than 10 mm in length and between 9 and 18 mm in diameter; an access vessel large enough to accept the 14F outer diameter of the delivery system; and an aortic bifurcation >18 mm in diameter. The primary endpoint was technical success at one-month; one-year safety endpoints included the absence of device-or procedure-related major adverse events; absence of type I or III endoleaks; and maintenance of device integrity through one year of follow-up. Results: Among 60 patients treated at six centers, the primary endpoint was met in 56 of 58 patients (97%; 95% CI, 88-100%) who came back for one month follow-up, two patients did not come back for their one month follow-up assessments but remained enrolled in the study. Fifty-six had one-year follow-up data showing 100% freedom from aneurysm enlargement with absence of type I and III endoleaks in all patients. There were two patients (3.6%) with a type la endoleak which was successfully treated with secondary endovascular intervention in both occasions. Core laboratory evaluation of the postoperative imaging studies documented absence of endograft migration, stent fracture, or limb occlusion. A single patient (1.8%) died within one year due to sepsis unrelated to the AAA. Conclusion: The results of the INNOVATION study with the INCRAFT® Stent-Graft are encouraging, with satisfactory clinical outcome and device durability through one-year of follow-up. The INCRAFT® device is a novel ultra-low-profile endograft that holds promise to broaden the patient population eligible for endovascular aneurysm repair
Assimilation of geodetic dynamic ocean topography using ensemble based Kalman filter
No full textEstimation of ocean circulation is investigated via assimilation of satellite measurements of the dynamic ocean topography (DOT) into the global finite-element ocean model (FEOM). The DOT was obtained by means of a geodetic approach from carefully cross-calibrated multi-mission altimeter data and GRACE gravity fields. The spectral consistency was achieved by consistently filtering both, the sea surface and the geoid. The filter length is determined by the spatial resolution of the gravity field and corresponds to approximately 241 km half width for the GRACE-based gravity field model ITG-Grace03s.
The assimilation of the geodetic DOT was performed by employing a local singular evolutive interpolated Kalman (SEIK) filter in combination with the method of weighting of observations. It is shown that this approach leads to a successful assimilation technique that reduced the RMS difference between the model and the data from 16 cm to 5 cm during one year of assimilation. The ocean model returns an optimized mean dynamic ocean topography. The effects of assimilation on transport estimates across several hydrographic World Ocean Circulation Experiment (WOCE) sections show improvements compared to the FEOM run without data assimilation. As a result of the assimilation, DOT estimates are available in the polar or coastal regions where the geodetic estimates from satellite data alone are not adequate. Furthermore, more realistic features of the ocean can be seen in these areas compared to those obtained using the filtered data fields
Subglacial Lake Vostok not expected to discharge water
No full textThe question whether Antarctica's largest lake, subglacial Lake Vostok, exchanges water is of interdisciplinary relevance but has been undecided so far. We present the potential pathway, outlet location, and threshold height of subglacial water discharge from this lake based on a quantitative evaluation of the fluid potential. If water left Lake Vostok, it would flow toward Ross Ice Shelf. Discharge would occur first to the east of the southern tip of the lake. At this location the bedrock threshold is 91 ± 23 m higher than the hydrostatic equipotential level of Lake Vostok. It is concluded that Lake Vostok is not likely to reach this level within climatic timescales and that no discharge of liquid water is to be expected. We show that in absence of the ice sheet the Lake Vostok depression would harbor a lake significantly deeper and larger than the present aquifer.Fil: Richter, Andreas Jorg. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Technische Universitat Dresden. Dresden; AlemaniaFil: Popov, Sergey V.. Polar Marine Geosurvey Expedition. Lomonosov; RusiaFil: Schroeder, Ludwig. Technische Universitat Dresden. Dresden; AlemaniaFil: Schwabe, Joachim. Technische Universitat Dresden. Dresden; AlemaniaFil: Ewert, Heiko. Technische Universitat Dresden. Dresden; AlemaniaFil: Scheinert, Mirko. Technische Universitat Dresden. Dresden; AlemaniaFil: Horwath, Martin. Technische Universitat Dresden. Dresden; AlemaniaFil: Dietrich, Reinhard. Technische Universitat Dresden. Dresden; Alemani
2-Year Results With a Sirolimus-Eluting Self-Expanding Stent for Femoropopliteal Lesions: The First-in-Human ILLUMINA Study
No full textObjectives: The aim of the study was to assess 24-month efficacy and safety of a novel drug-eluting stent (DES) for femoropopliteal interventions with an innovative stent design and abluminal reservoir technology releasing the amphilimus formulation (sirolimus plus fatty acid) for efficient drug transfer and optimized release kinetics. Background: DES releasing paclitaxel exhibited good patency rates after femoropopliteal interventions. No benefit has been reported when sirolimus or everolimus were used for antiproliferative stent coating. Methods: Within a multicenter, first-in-man, single-arm study, 100 patients with symptomatic femoropopliteal disease (Rutherford category 2-4, mean lesion length 5.8 ± 3.9 cm, 35.0% total occlusions) were treated with the NiTiDES stent (Alvimedica). Two-year follow-up included assessment of primary patency (defined as absence of clinically driven target lesion revascularization or binary restenosis with a peak systolic velocity ratio >2.4 by duplex ultrasound), safety, functional, and clinical outcomes. Results: At 24 months, Kaplan-Meier estimates of primary patency and freedom from clinically driven target lesion revascularization were 83.4% (95% CI: 73.9%-89.6%) and 93.1% (95% CI: 85.3%-96.9%), respectively. Over the study period, 3 deaths were reported with no major limb amputation. Functional and clinical benefits were sustained, as 82.1% of patients fell into Rutherford category 0 or 1 at 24 months, which was associated with preserved improvements in all walking disability questionnaire scores. Conclusions: The 2-year results of the ILLUMINA (Innovative siroLimus seLf expanding drUg-eluting stent for the treatMent of perIpheral disease: evaluation of safety aNd efficAcy) study demonstrate a sustained treatment benefit with a novel sirolimus-eluting stent that also compares favorably to other femoropopliteal intervention trials. Head-to-head comparisons of NiTiDES with a paclitaxel-based DES are warranted. (The ILLUMINA Study [ILLUMINA]; NCT03510676
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