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To better understand what kinds of sports and exercise could be beneficial for the intervertebral disc (IVD), we performed a review to synthesise the literature on IVD adaptation with loading and exercise. The state of the literature did not permit a systematic review; therefore, we performed a narrative review. The majority of the available data come from cell or whole-disc loading models and animal exercise models. However, some studies have examined the impact of specific sports on IVD degeneration in humans and acute exercise on disc size. Based on the data available in the literature, loading types that are likely beneficial to the IVD are dynamic, axial, at slow to moderate movement speeds, and of a magnitude experienced in walking and jogging. Static loading, torsional loading, flexion with compression, rapid loading, high-impact loading and explosive tasks are likely detrimental for the IVD. Reduced physical activity and disuse appear to be detrimental for the IVD. We also consider the impact of genetics and the likelihood of a ‘critical period’ for the effect of exercise in IVD development. The current review summarises the literature to increase awareness amongst exercise, rehabilitation and ergonomic professionals regarding IVD health and provides recommendations on future directions in research.
We present a new Min-Max theorem for an optimization problem closely connected to matchings and vertex covers in balanced hypergraphs. The result generalizes Kőnig’s Theorem (Berge and Las Vergnas in Ann N Y Acad Sci 175:32–40, 1970; Fulkerson et al. in Math Progr Study 1:120–132, 1974) and Hall’s Theorem (Conforti et al. in Combinatorica 16:325–329, 1996) for balanced hypergraphs.
Regardless of size or destination, synthetic biology starts with com-parably small information units, which need to be combined and properly arranged in order to achieve a certain goal. This may be the de novo synthesis of individual genes from oligonucleotides, a shuffling of protein domains in order to create novel biocatalysts, the assembly of multiple enzyme encoding genes in metabolic pathway design, or strain development at the production stage. The CoLibry concept has been designed in order to close the gap between recombinant production of individual genes and genome editing.
Hintergrund
Die Anwendung und das Verständnis von Statistik sind sehr wichtig für die biomedizinische Forschung und für die klinische Praxis. Dies gilt insbesondere auch zur Abschätzung der Möglichkeiten unterschiedlichster Diagnostik- und Therapieoptionen beim Glaukom. Die scheinbare Komplexität der Statistik, die zum Teil dem „gesunden Menschenverstand“ zu widersprechen scheint, zusammen mit der nur vorsichtigen Akzeptanz der Statistik bei vielen Medizinern können zu bewussten und unbewussten Manipulationen bei der Datendarstellung und -interpretation führen.
Ziel der Arbeit
Ziel ist die verständliche Darstellung einiger typischer Fehler in der medizinisch-statistischen Datenbehandlung.
Material und Methoden
Anhand hypothetischer Beispiele aus der Glaukomdiagnostik erfolgen die Darstellung der Wirkung eines hypotensiven Medikamentes sowie die Beurteilung der Ergebnisse eines diagnostischen Tests. Es werden die typischsten statistischen Einsatzbereiche und Irrtumsquellen ausführlich und verständlich analysiert
Ergebnisse
Mechanismen von Datenmanipulation und falscher Dateninterpretation werden aufgeklärt. Typische Irrtumsquellen bei der statistischen Auswertung und Datendarstellung werden dabei erläutert.
Schlussfolgerungen
Die erläuterten praktischen Beispiele zeigen die Notwendigkeit, die Grundlagen der Statistik zu verstehen und korrekt anwenden zu können. Fehlendes Grundlagenwissen und Halbwissen der medizinischen Statistik können zu folgenschweren Missverständnissen und falschen Entscheidungen in der medizinischen Forschung, aber auch in der klinischen Praxis führen.
Purpose
The most commonly used mobility assessments for screening risk of falls among older adults are rating scales such as the Tinetti performance oriented mobility assessment (POMA). However, its correlation with falls is not always predictable and disadvantages of the scale include difficulty to assess many of the items on a 3-point scale and poor specificity. The purpose of this study was to describe the ability of the new Aachen Mobility and Balance Index (AMBI) to discriminate between subjects with a fall history and subjects without such events in comparison to the Tinetti POMA Scale.
Methods
For this prospective cohort study, 24 participants in the study group and 10 in the control group were selected from a population of patients in our hospital who had met the stringent inclusion criteria. Both groups completed the Tinetti POMA Scale (gait and balance component) and the AMBI (tandem stance, tandem walk, ten-meter-walk-test, sit-to-stand with five repetitions, 360° turns, timed-up-and-go-test and measurement of the dominant hand grip strength). A history of falls and hospitalization in the past year were evaluated retrospectively. The relationships among the mobility tests were examined with Bland–Altmananalysis. Receiver-operated characteristics curves, sensitivity and specificity were calculated.
Results
The study showed a strong negative correlation between the AMBI (17 points max., highest fall risk) and Tinetti POMA Scale (28 points max., lowest fall risk; r = −0.78, p < 0.001) with an excellent discrimination between community-dwelling older people and a younger control group. However, there were no differences in any of the mobility and balance measurements between participants with and without a fall history with equal characteristics in test comparison (AMBI vs. Tinetti POMA Scale: AUC 0.570 vs. 0.598; p = 0.762). The Tinetti POMA Scale (cut-off <20 points) showed a sensitivity of 0.45 and a specificity of 0.69, the AMBI a sensitivity of 0.64 and a specificity of 0.46 (cut-off >5 points).
Conclusion
The AMBI comprises mobility and balance tasks with increasing difficulty as well as a measurement of the dominant hand-grip strength. Its ability to identify fallers was comparable to the Tinetti POMA Scale. However, both measurement sets showed shortcomings in discrimination between fallers and non-fallers based on a self-reported retrospective falls-status.
While plate fixation of proximal ulna fractures might lead to superior clinical results compared to tension band wiring, regular plates represent an established risk factor for wound complications. The olecranon double plates (Medartis, Basel, CH) might decrease complications related to the osteosynthesis because of their low profile and better anatomical fit. This study aimed to evaluate the biomechanical performance and clinical results of the olecranon double plates.
Surgical reconstruction of the interosseous membrane (IOM) could restore longitudinal forearm stability to avoid persisting disability due to capituloradial and ulnocarpal impingement in Essex Lopresti lesions. This biomechanical study aimed to assess longitudinal forearm stability of intact specimens, after sectioning of the IOM and after reconstruction with a TightRope construct using either a single or double bundle technique.
Treatment of posttraumatic osteoarthritis of the radial column of the elbow joint remains a challenging yet common issue.
While partial joint replacement leads to high revision rates, radial head excision has shown to severely increase joint instability. Shortening osteotomy of the radius could be an option to decrease the contact pressure of the radiohumeral joint and thereby pain levels without causing valgus instability. Hence, the aim of this biomechanical study was to evaluate the effects of radial shortening on axial load distribution and valgus stability of the elbow joint.
Plate osteosynthesis of displaced proximal phalangeal neck fractures of the hand allows early mobilization due to a stable internal fixation. Nevertheless, joint stiffness—because of soft tissue irritation—represents a common complication leading to high complication rates. Del Pinal et al. recently reported promising clinical results for a new, minimally invasive fixation technique with a cannulated headless intramedullary compression screw. Hence, the aim of this study was to compare plate fixation of proximal phalangeal neck fractures to less two less invasive techniques: Crossed k-wire fixation and intramedullary screw fixation. We hypothesized that these fixation techniques provide inferior stability when compared to plate osteosynthesis.
Various models have been proposed for the prediction of the necessary support pressure at the face of a shallow tunnel. To assess their quality, the collapse of a tunnel face was modelled with small-scale model tests at single gravity. The development of the failure mechanism and the support force at the face in dry sand were investigated. The observed displacement patterns show a negligible influence of overburden on the extent and evolution of the failure zone. The latter is significantly influenced, though, by the initial density of the sand: in dense sand a chimney-wedge-type collapse mechanism developed, which propagated towards the soil surface. Initially, loose sand did not show any discrete collapse mechanism. The necessary support force was neither influenced by the overburden nor the initial density. A comparison with quantitative predictions by several theoretical models showed that the measured necessary support pressure is overestimated by most of the models. Those by Vermeer/Ruse and Léca/Dormieux showed the best agreement to the measurements.
In diesem Artikel werden zunächst einleitend der Gasmarkt Deutschland und der sich daraus ergebende Speicherbedarf skizziert. Folgend wird auf verschiedene Speichernutzen aus betriebswirtschaftlicher Perspektive eingegangen und die in diesem Artikel vorgestellten Bewertungsverfahren einleitend beschrieben. In diesem Artikel werden stochastische Optimierungsmethoden aufgegriffen, die sowohl eine Bewertung der Speicher gegenüber einem Spotpreis, als auch gegenüber einer gesamten Forwardcurve ermöglichen. Hierzu werden zunächst Modelle zur Beschreibung der Marktpreise vorgestellt und anhand empirischer Daten kalibriert. Dann wird eine beispielhafte Speicherscheibe zunächst auf Basis der LeastSquareMonteCarloTechnik gegenüber dem stochastischen mehrfaktoriellen Spotpreismodell bewertet. Hieran schließt sich die Vorstellung der Bewertung sowie des Hedgings gegenüber der Forwardcurve an. Abschließend erfolgt eine vergleichende Gegenüberstellung beider Verfahren.
Expeditious building of ring-porous earlywood vessel chronologies without loosing signal information
(2009)
• Most of the edible forest mushrooms are mycorrhizal and depend on carbohydrates produced by the associated trees. Fruiting patterns of these fungi are not yet fully understood since climatic factors alone do not completely explain mushroom occurrence.
• The objective of this study was to retrospectively find out if changing tree growth following an increment thinning has influenced the diversity patterns and productivity of associated forest mushrooms in the fungus reserve La Chanéaz, Switzerland.
• The results reveal a clear temporal relationship between the thinning, the growth reaction of trees and the reaction of the fungal community, especially for the ectomycorrhizal species. The tree-ring width of the formerly suppressed beech trees and the fruit body number increased after thinning, leading to a significantly positive correlation between fruit body numbers and tree-ring width.
• Fruit body production was influenced by previous annual tree growth, the best accordance was found between fruit body production and the tree-ring width two years previously.
• The results support the hypothesis that ectomycorrhizal fruit body production must be linked with the growth of the associated host trees. Moreover, the findings indicate the importance of including mycorrhizal fungi as important players when discussing a tree as a carbon source or sink.
The possibility of using the atomic-force microscopy as a method for detection of the analytical signal from plasticized polymeric sensor membranes was analyzed. The surfaces of cadmium-selective membranes based on two polymeric matrices were examined. The digital images were processed with multivariate image analysis techniques. A correlation was found between the surface profile of an ion-selective membrane and the concentration of the ion in solution.