166 research outputs found

    Der Einfluss Submesoskalischer Strömungen auf die Mesoskalische Agulhas Dynamik

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    Mesoscale eddies are central to the oceanic circulation and the global climate. Of particular importance, in this respect, are mesoscale eddies in the Agulhas region south of Africa, as they govern the inflow of warm and salty Indian Ocean waters into the Atlantic Ocean. In this dissertation, it is shown that these eddies are strengthened by submesoscale flows. This highlights the importance of including submesoscale effects for a realistic representation of the mesoscale dynamics in ocean models. First, a general circulation ocean model for the Agulhas region is improved with respect to the simulation of submesoscale dynamics by increasing the vertical and horizontal resolution and reducing the model diffusion and dissipation. Second, a model validation based on horizontal-wavenumber spectra computed from high-resolution satellite sea-surface temperature and sea-surface height measurements is performed. It demonstrates that the simulated submesoscale and mesoscale circulation in the Cape Basin are extraordinary well represented in this model. A comparison to two parallel model experiments, of which the first only resolves the largest and the second no submesoscale flows, reveals that the mesoscale spectral density of sea-surface height increases the more submesoscales are resolved. The results of an eddy detection algorithm show that this can be attributed to a strengthening of the mesoscale eddies. Third, a coarse-graining approach for the transfer of kinetic energy between spatial scales is applied to the model outputs. The results indicate that the mesoscale eddies are strengthened in spring or early summer by the absorption of submesoscale eddies resulting from baroclinic mixed-layer instability in winter. Fourth, this analysis complemented with the computation of the transfer of kinetic energy between temporal scales reveals that submesoscale eddies emerging from barotropic instabilities at the northern boundary of the Agulhas Current are important for the strength of shear-edge eddies and further of lee cyclones that propagate into the Cape Basin. The model comparison shows that the combination of both strengthening effects contributes to an increase of the surface mesoscale kinetic energy in the Cape Basin by 28 %, if submesoscale processes are resolved

    Fußverletzungen bei PKW-Frontinsassen: Eine Analyse des GIDAS-Datenbestandes

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    Die Einrichtungen der Verkehrsunfallforschung Hannover und (ab 1999) Dresden registrierten 736 Beinverletzungen eines Schweregrades AIS ≄ 2 im Zeitraum von 1983 bis MĂ€rz 2007. 174 dieser Verletzungen (23,6 %) waren Frakturen und Luxationen des Fußes und des oberen Sprunggelenkes. Es waren 149 FĂŒĂŸe von 141 Frontinsassen (140 PKW) betroffen. Die Insassen untergliederten sich in 117 Fahrer und 24 Beifahrer. Das durchschnittliche Alter der Insassen betrug 38.5 ± 16.8 Jahre. Die hĂ€ufigste Verletzung war die Fraktur des oberen Sprunggelenkes (n=82; 80 Malleolarfrakturen, 2 Pilonfrakturen). 34 Frakturen und Luxationen betrafen den RĂŒckfuß (5 Talus- und 26 Calcaneusfrakturen, 2 subtalare Luxationen, 1 subtotale Amputation), 16 den Mittfuß (4 Navicularefrakturen, 5 Cuboidfrakturen, 3 Cuneiformefrakturen, 2 Chopart-Gelenksluxationen, 1 subtotale Amputation, 1 schweres Decollement) und 39 den Vorfuß (Metatarsalefrakturen). Offene Frakturen wurden nur in 3 FĂ€llen registriert (2 Malleolarfrakturen, 1 Metatarsalefraktur). In 10 FĂ€llen wurden beide FĂŒĂŸe verletzt. 33 Insassen (23,4 %) waren polytraumatisiert, davon starben 17. 81 % der Insassen waren angeschnallt. Die verunfallten PKW wurden in prĂ€- (Baujahr 1997 und Ă€lter) und post-EuroNCAP- (Baujahr 1998 und jĂŒnger) Fahrzeuge unterteilt. Die meisten Fußverletzungen fanden sich in prĂ€-EuroNCAP-Autos. Die meisten Insassen befanden sich in Fahrzeugen der unteren Mittelklasse (40 Fahrer und 9 Beifahrer) und der Mittelklasse (27 Fahrer und 7 Beifahrer). 49 der 140 UnfĂ€lle ereigneten sich auf Landes- bzw. Kreisstraßen, 26 auf Bundesstraßen und 13 auf Autobahnen. Es wurden ĂŒberwiegend FrontalzusammenstĂ¶ĂŸe beobachtet. Zwischen den verletzten Fußregionen fanden sich keine signifikanten Unterschiede hinsichtlich der Delta v- und EES-Werte, es ergab sich aber ein Trend zu höheren Delta v- und EES-Werten bei neueren PKW (post-EuroNCAP). Die HĂ€ufigkeit von Fußverletzungen stieg linear mit steigendem Delta v-Wert, oberhalb eines Delta v-Wertes von 55 km/h kam es nur noch in prĂ€-EuroNCAP-Autos zu einem weiteren linearen Anstieg, wĂ€hrend post-EuroNCAP-Fahrzeuge keinen weiteren Anstieg der VerletzungshĂ€ufigkeit zeigten. Die Fußraumintrusion zeigte keine signifikanten Unterschiede zwischen den einzelnen Fußregionen, jedoch zeigte sich in post-EuroNCAP-Fahrzeugen ein Trend zu höheren Intrusionswerten. Zwischen den einzelnen Fahrzeugklassen zeigten sich keine Unterschiede in der Fußraumintrusion. Nur 29 der 174 Frakturen und Luxationen des Fußes und des oberen Sprunggelenkes wurden in post-EuroNCAP-Fahrzeugen registiert, die ĂŒberwiegende Zahl dieser Verletzungen (n=145) ereignete sich in prĂ€-EuroNCAP-Fahrzeugen. Bei Betrachtung des AIS2008-assoziierten FCI (functional capacity index) fĂŒr die Fußregion zeigte sich eine geringere Wahrscheinlichkeit einer dauerhaften Behinderung in post-EuroNCAP-Fahrzeugen bei gleichem Delta v-Wert.:1. Einleitung zur Unfallforschung in Deutschland 6 2. Fragestellung 10 3. Patientengut und Methodik 13 4. Charakteristische Frakturen und zu Grunde liegende UnfĂ€lle 23 5. Auswertung 28 5.1 Erfasste Verletzungen 28 5.2 Charakterisierung der Fahrzeuge 32 5.2.1 Fahrzeugsegment 32 5.2.2 Unfallort 33 5.2.3 Aufprallrichtung 35 5.2.4 Verletzungsverursachendes Fahrzeugteil 36 5.3 Geschwindigkeitsparameter bei den beobachteten Verletzungen 37 5.4 Fußraumintrusion bei den beobachteten Verletzungen 41 5.5 HĂ€ufigkeit von Fußverletzungen 53 6. Diskussion 54 7. Zusammenfassung 67 8. Literaturverzeichnis 69 Danksagung 95 Thesen zur Dissertation 96The accident research of Hanover and (from 1999 on) Dresden registered 736 leg injuries (AIS ≄ 2) from 1983 to March 2007. 174 of these injuries (23.6 %) were fractures or dislocations of foot and ankle. 149 feet of 141 front seat car occupants in 140 cars were affected. Of these 117 were drivers, 24 were front seat passengers. The mean age of occupants was 38.5 ± 16.8 years. Ankle fractures were the most frequent injury (n = 82; 80 malleolar fractures, 2 pilon fractures). 34 fractures and dislocations affected the hindfoot (5 talus and 26 calcaneal fractures, 2 subtalar dislocations and 1 subtotal amputation) , 16 to midfoot (4 navicular fractures, 5 cuboid fractures, 3 fractures of cuneiformia, 2 dislocations of chopart joint, 1 subtotal amputation, and one severe decollement) and 39 the forefoot (metatarsal fractures). Open fractures were seldom seen (2 malleolar fractures, 1 metatarsal fracture). Both feet were injured in 10 cases. 33 occupants (23.4 %) were polytaumatic had a polytrauma, 17 of them died. 81 percent of the occupants were belted. The cars were divided in pre EuroNCAP (year of manufacture 1997 and older) and post EuroNCAP cars (year of manufacture 1998 and newer). Most of the foot injuries were seen in pre EuroNCAP cars. Most of the occupants sat in compact cars (40 drivers and 9 front seat passengers) and large family cars (27 drivers and 7 co-drivers). 49 of 140 accidents occurred on country roads, 26 on main roads and 13 on motorways. The crash direction was mostly frontal. Generally were found no differences of delta v- and EES-level between the injured foot regions, but divided into pre- and post-EuroNCAP cars there was a tendency to higher delta v- and EES-levels in newer cars. The frequency of foot injuries increased linearly with increasing delta v-level; but above delta v-level of 55 km/h the linear increase only was seen in pre-EuroNCAP cars, post-EuroNCAP cars showed no further increase of injuries. The footwell intrusion showed no difference between the injured foot regions but post-EuroNCAP cars had a tendency to higher footwell intrusion. There were no differences in footwell intrusion between the car types. Only 29 of 174 fractures or dislocations of foot and ankle were seen in post-EuroNCAP cars, the predominate number of these injuries (n = 145) were noticed in pre-EuroNCAP cars. A lower probability of long-term impairment was found in post-EuroNCAP cars for equal delta v levels, using the AIS2008 associated Functional Capacity Index (FCI) for the foot region.:1. Einleitung zur Unfallforschung in Deutschland 6 2. Fragestellung 10 3. Patientengut und Methodik 13 4. Charakteristische Frakturen und zu Grunde liegende UnfĂ€lle 23 5. Auswertung 28 5.1 Erfasste Verletzungen 28 5.2 Charakterisierung der Fahrzeuge 32 5.2.1 Fahrzeugsegment 32 5.2.2 Unfallort 33 5.2.3 Aufprallrichtung 35 5.2.4 Verletzungsverursachendes Fahrzeugteil 36 5.3 Geschwindigkeitsparameter bei den beobachteten Verletzungen 37 5.4 Fußraumintrusion bei den beobachteten Verletzungen 41 5.5 HĂ€ufigkeit von Fußverletzungen 53 6. Diskussion 54 7. Zusammenfassung 67 8. Literaturverzeichnis 69 Danksagung 95 Thesen zur Dissertation 9

    Validity and reliability on three European language versions of the Safety Organizing Scale

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    Background The Safety Organizing Scale (SOS) offers a reliable snapshot of nurses' engagement in unit-level safety behaviors in hospitals. As no comparable questionnaire exists in German, French and Italian, we explored the psychometric properties of SOS translations into each of those languages. Design and Methods The psychometric properties of the nine-item SOS were tested according to American Educational Research Association guidelines. Subjects and Setting Between October 2009 and June 2010, 1633 registered medical and/or surgical nurses in 35 Swiss hospitals completed translated SOS questionnaires. Results For each translation, psychometric evaluation revealed evidence based on content (scale-content validity index >0.89), response patterns (e.g. average of missing values across all items = 0.80%), internal structure (e.g. comparative fit indices >0.90, root mean square error of approximation 0.79). We differentiated the scale regarding one related concept (implicit rationing of nursing care). Higher SOS scores correlated with supportive leadership and lower nurse-reported medication errors, but not with nurse-reported patient falls. Conclusions The SOS offers a valuable measurement of engagement in safety practices that might influence patient outcomes. Initial evidence regarding the validity and reliability of the translated versions supports their use in German, French and Italian. Concurrent validity will require confirmation via further analysis using more reliable outcome measures (e.g. mortality rates). The translated versions' predictive validity needs to be established in prospective studie

    Validity and reliability on three European language versions of the Safety Organizing Scale

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    Background: The Safety Organizing Scale (SOS) offers a reliable snapshot of nurses' engagement in unit-level safety behaviors in hospitals. As no comparable questionnaire exists in German, French and Italian, we explored the psychometric properties of SOS translations into each of those languages. Design and Methods: The psychometric properties of the nine-item SOS were tested according to American Educational Research Association guidelines. Subjects and Setting: Between October 2009 and June 2010, 1633 registered medical and/or surgical nurses in 35 Swiss hospitals completed translated SOS questionnaires. Results: For each translation, psychometric evaluation revealed evidence based on content (scale-content validity index >0.89), response patterns (e.g. average of missing values across all items = 0.80%), internal structure (e.g. comparative fit indices >0.90, root mean square error of approximation 0.79). We differentiated the scale regarding one related concept (implicit rationing of nursing care). Higher SOS scores correlated with supportive leadership and lower nurse-reported medication errors, but not with nurse-reported patient falls. Conclusions: The SOS offers a valuable measurement of engagement in safety practices that might influence patient outcomes. Initial evidence regarding the validity and reliability of the translated versions supports their use in German, French and Italian. Concurrent validity will require confirmation via further analysis using more reliable outcome measures (e.g. mortality rates). The translated versions' predictive validity needs to be established in prospective studies

    Tunable plasmonic resonances in highly porous nano-bamboo Si-Au superlattice-type thin films

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    We report on fabrication of spatially-coherent columnar plasmonic nanostructure superlattice-type thin films with high porosity and strong optical anisotropy using glancing angle deposition. Subsequent and repeated depositions of silicon and gold lead to nanometer-dimension subcolumns with controlled lengths. The superlattice-type columns resemble bamboo structures where smaller column sections of gold form junctions sandwiched between larger silicon column sections (“nano-bamboo”). We perform generalized spectroscopic ellipsometry measurements and finite element method computations to elucidate the strongly anisotropic optical properties of the highly-porous nano-bamboo structures. The occurrence of a strongly localized plasmonic mode with displacement pattern reminiscent of a dark quadrupole mode is observed in the vicinity of the gold subcolumns. We demonstrate tuning of this quadrupole-like mode frequency within the near-infrared spectral range by varying the geometry of the nano-bamboo structure. In addition, coupled-plasmon-like and inter-band transition-like modes occur in the visible and ultra-violet spectral regions, respectively. We elucidate an example for the potential use of the nano-bamboo structures as a highly porous plasmonic sensor with optical read out sensitivity to few parts-per-million solvent levels in water

    Solution structure of the equine infectious anemia virus p9 protein: a rationalization of its different ALIX binding requirements compared to the analogous HIV-p6 protein

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    <p>Abstract</p> <p>Background</p> <p>The equine infection anemia virus (EIAV) p9 Gag protein contains the late (L-) domain required for efficient virus release of nascent virions from the cell membrane of infected cell.</p> <p>Results</p> <p>In the present study the p9 protein and N- and C-terminal fragments (residues 1-21 and 22-51, respectively) were chemically synthesized and used for structural analyses. Circular dichroism and <sup>1</sup>H-NMR spectroscopy provide the first molecular insight into the secondary structure and folding of this 51-amino acid protein under different solution conditions. Qualitative <sup>1</sup>H-chemical shift and NOE data indicate that in a pure aqueous environment p9 favors an unstructured state. In its most structured state under hydrophobic conditions, p9 adopts a stable helical structure within the C-terminus. Quantitative NOE data further revealed that this α-helix extends from Ser-27 to Ser-48, while the N-terminal residues remain unstructured. The structural elements identified for p9 differ substantially from that of the functional homologous HIV-1 p6 protein.</p> <p>Conclusions</p> <p>These structural differences are discussed in the context of the different types of L-domains regulating distinct cellular pathways in virus budding. EIAV p9 mediates virus release by recruiting the ALG2-interacting protein X (ALIX) via the YPDL-motif to the site of virus budding, the counterpart of the YPX<sub>n</sub>L-motif found in p6. However, p6 contains an additional PTAP L-domain that promotes HIV-1 release by binding to the tumor susceptibility gene 101 (Tsg101). The notion that structures found in p9 differ form that of p6 further support the idea that different mechanisms regulate binding of ALIX to primary versus secondary L-domains types.</p

    Instability-Driven Benthic Storms Below the Separated Gulf Stream and the North Atlantic Current in a High-Resolution Ocean Model

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    Benthic storms are important for both the energy budget of the ocean and for sediment resuspension and transport. Using 30 years of output from a high-resolution model of the North Atlantic, it is found that most of the benthic storms in the model occur near the western boundary in association with the Gulf Stream and the North Atlantic Current, in regions that are generally co-located with the peak near-bottom eddy kinetic energy. A common feature are meander troughs in the near-surface jets that are accompanied by deep low pressure anomalies spinning up deep cyclones with near-bottom velocities of up to more than 0.5 m/s. A case study of one of these events shows the importance of both baroclinic and barotropic instability of the jet, with energy being extracted from the jet in the upstream part of the meander trough and partly returned to the jet in the downstream part of the meander trough. This motivates examining the 30-year time mean of the energy transfer from the (annual mean) background flow into the eddy kinetic energy. This quantity is shown to be co-located well with the region in which benthic storms and large increases in deep cyclonic relative vorticity occur most frequently, suggesting an important role for mixed barotropic-baroclinic instability driven cyclogenesis in generating benthic storms throughout the model simulation. Regions of largest energy transfer and most frequent benthic storms are found to be the Gulf Stream west of the New England Seamounts and the North Atlantic Current near Flemish Cap

    Modeling eelgrass spatial response to nutrient abatement measures in a changing climate

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    For many coastal areas including the Baltic Sea, ambitious nutrient abatement goals have been set to curb eutrophication, but benefits of such measures were normally not studied in light of anticipated climate change. To project the likely responses of nutrient abatement on eelgrass (Zostera marina), we coupled a species distribution model with a biogeochemical model, obtaining future water turbidity, and a wave model for predicting the future hydrodynamics in the coastal area. Using this, eelgrass distribution was modeled for different combinations of nutrient scenarios and future wind fields. We are the first to demonstrate that while under a business as usual scenario overall eelgrass area will not recover, nutrient reductions that fulfill the Helsinki Commission’s Baltic Sea Action Plan (BSAP) are likely to lead to a substantial areal expansion of eelgrass coverage, primarily at the current distribution’s lower depth limits, thereby overcompensating losses in shallow areas caused by a stormier climate

    Emulsion polymerizations for a sustainable preparation of efficient TEMPO‐based electrodes

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    Organic polymer‐based batteries represent a promising alternative to present‐day metal‐based systems and a valuable step toward printable and customizable energy storage devices. However, most scientific work is focussed on the development of new redox‐active organic materials, while straightforward manufacturing and sustainable materials and production will be a necessary key for the transformation to mass market applications. Here, a new synthetic approach for 2,2,6,6‐tetramethyl‐4‐piperinidyl‐ N ‐oxyl (TEMPO)‐based polymer particles by emulsion polymerization and their electrochemical investigation are reported. The developed emulsion polymerization protocol based on an aqueous reaction medium allowed the sustainable synthesis of a redox‐active electrode material, combined with simple variation of the polymer particle size, which enabled the preparation of nanoparticles from 35 to 138 nm. Their application in cell experiments revealed a significant effect of the size of the active‐polymer particles on the performance of poly(2,2,6,6‐tetramethyl‐4‐piperinidyl‐ N ‐oxyl methacrylate) (PTMA)‐based electrodes. In particular rate capabilities were found to be reduced with larger diameters. Nevertheless, all cells based on the different particles revealed the ability to recover from temporary capacity loss due to application of very high charge/discharge rates.Sustainable and efficient organic electrode : A new synthetic approach for polymers for organic batteries includes an emulsion polymerization with adjustable particle sizes in aqueous dispersions and allows the sustainable manufacturing of active materials and composite electrodes. The electrochemical investigation shows that the influence of particle sizes and the resulting morphologies of composite films on the cell performance is as important as the active material itself
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