Gait analysis does not correlate with clinical and MR imaging parameters in patients with symptomatic lumbar spinal stenosis

<p>Abstract</p> <p>Background</p> <p>Parameters of MR imaging play a pivotal role in diagnosing lumbar spinal stenosis (LSS), and serve as an important tool in clinical decision-making. Despite the importance of MR imaging, little is known about the correlation between MRI parameters, objective gait analysis, and clinical presentation of patients with lumbar spinal stenosis.</p> <p>Methods</p> <p>Sixty-three patients from our clinic with symptomatic lumbar spinal stenosis leading to neurogenic claudication were included in this study in accordance with clearly defined inclusion and exclusion criteria. Clinical parameters, the depression status (CES-D), the subjective functional back capacity (FFbH-R), and the absolute walking distance (treadmill gait analysis) were quantitatively evaluated in correlation with morphological data from radiographs and MRI scans, in order to determine the coherence of spinal canal narrowing and clinical affliction.</p> <p>Results</p> <p>Sixty-three consecutive paents with a median age of 68 years and a mean Body Mass Index (BMI) of 28 were included in the study. The mean FFbH-R score displayed a value of 44 percent. The depression status scored an average of 13.6. Objectively measured walking distances showed a mean value of 172 m until patients stopped due to leg pain. A significant difference was found between the objectively measured and the subjectively estimated walking distance. The mean cross-sectional area of the dural tube at L1/2 was 113 mm², at L2/3 94 mm², at L3/4 73 mm², at L4/5 65 mm², and at L5/S1 93 mm². The mean overall cross sectional area of the dural tube of all segments did not correlate with the objectively measured walking distance. However, bivariate analysis found that the BMI (tau b = -0.194), functional back capacity (tau b = -0.225), and the cross sectional area of the dural tube at L1/2 (tau b = -0.188) correlated significantly with the objectively measured walking distance.</p> <p>Conclusion</p> <p>According to the results of this study MRI findings failed to show a major clinical relevance when evaluating the walking distance in patients with lumbar spinal stenosis and, therefore, should be treated with some caution as a predictor of walking distance. In determining the disease pattern of spinal stenosis functional back capacity and BMI might play a more active role than previously thought.</p

Analyse TNT-basierter Netzwerke in permanenten und primären Zellkulturen mittels mikrostrukturierten Oberflächen

Biofunktionalisierte mikrostrukturierte Oberflächen wurden als ideales Plattformsystem zur Kultivierung permanenter, sowie primärer Zellkultursysteme und zur Analyse der zwischen ihnen ausgebildeten Tunneling Nanotubes (TNTs) etabliert, die eine neuartige Form interzellulärer Kommunikation darstellen. Um eine optimale Zellvereinzelung auf den Plattformen zu gewährleisten wurden unterschiedliche Zelltypen durch geeignete, kovalent an die Goldpunkte angebundene Liganden vereinzelt auf den Goldpunkten der mikrostrukturierten Oberflächen immobilisiert. Diese Vereinzelung stellt eine entscheidende Voraussetzung für die Detektion der TNTs dar. Die optimierten, mittels photolithographischer Verfahren hergestellten Plattformen wurden im Zuge der Arbeit zur präzisen Analyse einer sowohl chemischen, als auch mechanischen Beeinflussung der Bildung, bzw. Stabilität von TNTs herangezogen. Zudem wurden die Strukturen hinsichtlich ihrer strukturellen Eigenschaften durch kraftspektroskopische Messungen im Detail charakterisiert, wobei unter anderem erstmals die Kraft ermittelt werden konnte, die nötig ist, ein TNT zum Reißen zu bringen

SCIM: Simultaneous Clustering, Inference, and Mapping for Open-World Semantic Scene Understanding

In order to operate in human environments, a robot's semantic perception has to overcome open-world challenges such as novel objects and domain gaps. Autonomous deployment to such environments therefore requires robots to update their knowledge and learn without supervision. We investigate how a robot can autonomously discover novel semantic classes and improve accuracy on known classes when exploring an unknown environment. To this end, we develop a general framework for mapping and clustering that we then use to generate a self-supervised learning signal to update a semantic segmentation model. In particular, we show how clustering parameters can be optimized during deployment and that fusion of multiple observation modalities improves novel object discovery compared to prior work. Models, data, and implementations can be found at https://github.com/hermannsblum/scimComment: accepted at ISRR 202

Influência da densidade de potência e da porcentagem de N2 na atmosfera de deposição na dureza e no módulo de Young em filmes de aço inoxidável AISI 316 depositados por pulverização catódica

O processo de recobrimento por pulverização catódica é uma técnica amplamente utilizada para produção derevestimentos metálicos e cerâmicos, devido a versatilidade no controle das propriedades com pequenas mudançasnos parâmetros de processo, como densidade de potência aplica ao cátodo magnetron e atmosfera detrabalho. Sendo assim, as propriedades mecânicas dos filmes que estão altamente relacionadas à estruturacristalina e composição química podem ser controladas, tornando o processo viável para aplicações nas maisdiversas áreas. Utilizando-se um alvo de aço inoxidável AISI 316 foram depositados filmes com quatro valoresdiferentes de densidade de potência aplicada ao cátodo e com três porcentagens diferentes de N2 na atmosferade deposição. O objetivo é determinar a influência destes parâmetros na estabilização das fases alfa egama com estrutura cristalina cúbica de corpo centrado (CCC) e cúbica de face centrada (CFC), respectivamente.Os filmes obtidos foram caracterizados por difração de raios X, medida da espessura por microscopiaconfocal, dureza e módulo de Young por indentação instrumentada. Os resultados mostram que as variaçõesda densidade de potência aplicada ao cátodo resultam em filmes com estrutura CCC com dureza e módulo deYoung de 10,0 GPa e 210 GPa, respectivamente. Alterando-se a porcentagem de N2 na atmosfera de deposiçãoobteve-se filmes formados pela mistura das fases alfa e gama, com dureza e módulo de Young de 7,5GPa e 166 GPa, respectivamente.Palavras-chave: filmes finos, magnetron sputtering, aço inoxidável AISI 316, plasm

Meta-Stable Supersymmetry Breaking in a Cooling Universe

We look at the recently proposed idea that susy breaking can be accomplished in a meta-stable vacuum. In the context of one of the simplest models (the Seiberg-dual of super-QCD), we address the following question: if we look at this theory as it cools from high temperature, is it at all possible that we can end up in a susy-breaking meta-stable vacuum? To get an idea about the answer, we look at the free energy of the system at high temperature. We conclude that the phase-structure of the free-energy as the temperature drops, is indeed such that there is a second order phase transition in the direction of the non-susy vacuum at a finite $T=T_c^Q$. On the other hand, the potential barrier in the direction of the susy vacuum is there all the way till $T \sim 0$.Comment: writing full author name

A kinetic and theoretical study of the borate catalysed reactions of hydrogen peroxide: the role of dioxaborirane as the catalytic intermediate for a wide range of substrates

Our recent work has provided new insights into the equilibria and species that exist in aqueous solution at different pHs for the boric acid – hydrogen peroxide system, and the role of these species in oxidation reactions. Most recently, (M. C. Durrant, D. M. Davies and M. E. Deary, Org. Biomol. Chem., 2011, 9,7249–7254), we have produced strong theoretical and experimental evidence for the existence of a previously unreported monocyclic three membered peroxide species, dioxaborirane, that is the likely catalytic species in borate mediated electrophilic reactions of hydrogen peroxide in alkaline solution. In the present paper, we extend our study of the borate–peroxide system to look at a wide range of substrates that include substituted dimethyl anilines, methyl-p-tolyl sulfoxide, halides, hydrogen sulfide anion, thiosulfate ,thiocyanate, and hydrazine. The unusual selectivity–reactivity pattern of borate catalysed reactions compared with hydrogen peroxide and inorganic or organic peracids previously observed for theorganic sulfides (D. M. Davies, M. E. Deary, K. Quill and R. A. Smith, Chem.–Eur. J., 2005, 11, 3552–3558) is also seen with substituted dimethyl aniline nucleophiles. This provides evidence that the pattern is not due to any latent electrophilic tendency of the organic sulfides and further supports dioxaborirane being the likely reactive intermediate, thus broadening the applicability of this catalytic system. Moreover, density functional theory calculations on our proposed mechanism involving dioxaborirane are consistent with the experimental results for these substrates. Results obtained at high concentrations of both borate and hydrogen peroxide require the inclusion the diperoxodiborate dianion in the kinetic analysis .A scheme detailing our current understanding of the borate–peroxide system is presented

Superpotential de-sequestering in string models

Non-perturbative superpotential cross-couplings between visible sector matter and K\"ahler moduli can lead to significant flavour-changing neutral currents in compactifications of type IIB string theory. Here, we compute corrections to Yukawa couplings in orbifold models with chiral matter localised on D3-branes and non-perturbative effects on distant D7-branes. By evaluating a threshold correction to the D7-brane gauge coupling, we determine conditions under which the non-perturbative corrections to the Yukawa couplings appear. The flavour structure of the induced Yukawa coupling generically fails to be aligned with the tree-flavour structure. We check our results by also evaluating a correlation function of two D7-brane gauginos and a D3-brane Yukawa coupling. Finally, by calculating a string amplitude between n hidden scalars and visible matter we show how non-vanishing vacuum expectation values of distant D7-brane scalars, if present, may correct visible Yukawa couplings with a flavour structure that differs from the tree-level flavour structure.Comment: 37 pages + appendices, 8 figure

Using DBpedia as a knowledge source for culture-related user modelling questionnaires

In the culture domain, questionnaires are often used to obtain profiles of users for adaptation. Creating questionnaires requires subject matter experts and diverse content, and often does not scale to a variety of cultures and situations. This paper presents a novel approach that is inspired by crowdwisdom and takes advantage of freely available structured linked data. It presents a mechanism for extracting culturally-related facts from DBpedia, utilised as a knowledge source in an interactive user modelling system. A user study, which examines the system usability and the accuracy of the resulting user model, demonstrates the potential of using DBpedia for generating culture-related user modelling questionnaires and points at issues for further investigation