Systemdynamische Betrachtungen zur Sturzdynamik und -prophylaxe: Entwicklung eines deterministischen Modells

Zusammenfassung: Hintergrund: Stürze älterer Personen ist derzeit eine große Public-Health-Herausforderung. Da Instrumente zur Erkennung sturzgefährdeter Personen wenig genaue Vorhersagen machen, wurde ein deterministisches systemdynamisches Modell der Sturzdynamik entwickelt. Methoden: Unter Verwendung bekannter Sturzrisikofaktoren, quantitativer Forschungsergebnisse und Abschätzungen, Ursachen- und Wirkbeziehungen wurde ein deterministisches Modell simuliert. Ergebnisse: Grundvoraussetzungen für Stürze sind Bewegung oder Bewegungsabsichten ("Mobilität im Alltag"), ein Sturzrisiko und ein Ungleichgewicht zwischen Gehanforderungen und Gehfähigkeit. Kraft, Koordination und Gleichgewicht wurden als Speichergrößen definiert und Ursache-Wirkungs-Zusammenhänge ins Modell integriert. Zahlreiche andere bekannte Sturzrisikofaktoren wurden ins Modell aufgenommen und quantifiziert. Die Simulation einer Fixierung zeigte, dass die Sturzwahrscheinlichkeit unmittelbar nach der Fixierung erhöht ist. Das Modell zeigt in der Simulation systemdynamische Aspekte wie Verzögerung, Rückkoppelung und Nicht-Linearität. Schlussfolgerung: Mit Hilfe der Systemdynamik konnte ein deterministisches systemdynamisches Modell der Sturzdynamik und -prophylaxe für eine Pflegeheimpopulation unter Einbeziehung bekannter Sturzrisikofaktoren entwickelt werden, das von Praktikern als plausibel beurteilt wird und das "richtungssicher" reagier

CP Violation in \tau ->\nu\pi K_S and D->\pi K_S: The Importance of K_S-K_L Interference

The $B$-factories have measured CP asymmetries in the $\tau\to\pi K_S\nu$ and $D\to K_S\pi$ modes. The $K_S$ state is identified by its decay to two pions at a time that is close to the $K_S$ lifetime. Within the Standard Model and many of its extensions, the asymmetries in these modes come from CP violation in $K^0-\bar{K}^0$ mixing. We emphasize that the interference between the amplitudes of intermediate $K_S$ and $K_L$ is as important as the pure $K_S$ amplitude. Consequently, the measured asymmetries depend on the times over which the relevant decay rates are integrated and on features of the experiment.Comment: 4 pages, 4 figure

Systematic quantitative overviews of the literature to determine the value of diagnostic tests for predicting acute appendicitis: study protocol

BACKGROUND: Suspected acute appendicitis is the most frequent cause for emergency operations in visceral surgery worldwide. In approximately twenty percent of all cases however, the diagnosis is incorrect and patients undergo surgery without having acute appendicitis. Operations of bland appendices put patients at risk and entail a serious waste of resources. Several highly accurate tests have been introduced to diagnose acute appendicitis. The false positive rate however, has not changed over the last twenty years. Given the variation that exists in both practice and research, the uncertainty regarding the quality of the underlying evidence, there is a clear need for comprehensive, systematic and quantitative overviews of the diagnostic value of the various tests purported to be predictive of acute appendicitis. METHODS: Literature will be identified searching general bibliographic databases (MEDLINE and EMBASE), specialist computer databases (DARE, Cochrane Database of Systematic Reviews, conference proceedings, MEDION, SCISEARCH, BIOSIS) without language restrictions. We will contact experts and the manufacturers of tests. Hand-searching will complete our searches. Identified articles will be selected according to populations, tests, outcomes and study design. Papers meeting the selection criteria will be appraised to rate their methodological quality. Analysis will include exploration of heterogeneity in results. We will conduct meta-analyses to generate summary estimates of test accuracy measures and summary ROC curves where appropriate. If meta-analysis is considered to be inappropriate, we will describe the identified evidence in the context of appraised quality. DISCUSSION: These reviews should lead to formulation of recommendations for current practice and future research

Bacterial pore-forming toxins: the (w)hole story?

Pore-forming toxins (PFTs) are the most common class of bacterial protein toxins and constitute important bacterial virulence factors. The mode of action of PFT is starting to be better understood. In contrast, little is known about the cellular response to this threat. Recent studies reveal that cells do not just swell and lyse, but are able to sense and react to pore formation, mount a defense, even repair the damaged membrane and thus survive. These responses involve a variety of signal-transduction pathways and sophisticated cellular mechanisms such as the pathway regulating lipid metabolism. In this review we discuss the different classes of bacterial PFTs and their modes of action, and provide examples of how the different bacteria use PFTs. Finally, we address the more recent field dealing with the eukaryotic cell response to PFT-induced damag

The Physics of Heavy Flavours at SuperB

This is a review of the SuperB project, covering the accelerator, detector, and highlights of the broad physics programme. SuperB is a flavour factory capable of performing precision measurements and searches for rare and forbidden decays of $B_{u,d,s}$, $D$, $\tau$ and $\Upsilon({\mathrm{nS}})$ particles. These results can be used to test fundamental symmetries and expectations of the Standard Model, and to constrain many different hypothesised types of new physics. In some cases these measurements can be used to place constraints on the existence of light dark matter and light Higgs particles with masses below $10GeV/c^2$. The potential impact of the measurements that will be made by SuperB on the field of high energy physics is also discussed in the context of data taken at both high energy in the region around the \Upsilon({\mathrm{4S}})$, and near charm threshold.Comment: 49 pages, topical review submitted to J. Phys

Measurement of the muon decay spectrum with the ICARUS liquid Argon TPC

Examples are given which prove the ICARUS detector quality through relevant physics measurements. We study the muon decay energy spectrum from a sample of stopping muon events acquired during the test run of the ICARUS T600 detector. This detector allows the spatial reconstruction of the events with fine granularity, hence, the precise measurement of the range and dE/dx of the muon with high sampling rate. This information is used to compute the calibration factors needed for the full calorimetric reconstruction of the events. The Michel rho parameter is then measured by comparison of the experimental and Monte Carlo simulated muon decay spectra, obtaining rho = 0.72 +/- 0.06(stat.) +/- 0.08(syst.). The energy resolution for electrons below ~50 MeV is finally extracted from the simulated sample, obtaining (Emeas-Emc)/Emc = 11%/sqrt(E[MeV]) + 2%.Comment: 16 pages, 8 figures, LaTex, A4. Some text and 1 figure added. Final version as accepted for publication in The European Physical Journal

Observation of B+ -> Dbar*0 tau+ nu_tau and Evidence for B+ -> Dbar^0 tau+ nu_tau at Belle

We present measurements of B+ -> Dbar*0 tau+ nu_tau and B+ -> Dbar^0 tau+ nu_tau decays in a data sample of 657 x 10^6 BBbar pairs collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. We find 446^{+58}_{-56} events of the decay B+ -> Dbar*0 tau+ nu_tau with a significance of 8.1 standard deviations, and 146^{+42}_{-41} events of the decay B+ -> Dbar0 tau+ nu_tau with a significance of 3.5 standard deviations. The latter signal provides the first evidence for this decay mode. The measured branching fractions are B(B+ -> Dbar*0 tau+ nu_tau)=(2.12^{+0.28}_{-0.27} (stat) +- 0.29 (syst)) % and B(B+ -> Dbar0 tau+ nu_tau)=(0.77 +- 0.22 (stat) +- 0.12 (syst)) %.Comment: 6 pages, 4 figures, submitted to Phys. Rev. Let

Search for CP violation in tau -> K^0_S pi nu_tau decays at Belle

We report on a search for CP violation in tau -> K^0_S pi nu_tau decays using a data sample of 699 fb^{-1} collected in the Belle experiment at the KEKB electron-positron asymmetric-energy collider. The CP asymmetry is measured in four bins of the invariant mass of the K^0_S pi system and found to be compatible with zero with a precision of O(10^{-3}) in each mass bin. Limits for the CP violation parameter Im(eta_S) are given at a 90 % confidence level. These limits are |Im(eta_S)|<0.026 or better, depending on the parameterization used to describe the hadronic form factors and improve upon previous limits by one order of magnitude

First study of \eta_c, \eta(1760) and X(1835) production via \eta'\pi^+\pi^- final states in two-photon collisions

The invariant mass spectrum of the \eta' \pi^+ \pi^- final state produced in two-photon collisions is obtained using a 673 fb^{-1} data sample collected in the vicinity of the \Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^+e^- collider. We observe a clear signal of the \eta_c and measure its mass and width to be M(\eta_c)=(2982.7 +- 1.8(stat) +- 2.2(syst) +- 0.3(model)) MeV/c^2 and \Gamma(\eta_c) = (37.8^{+5.8}_{-5.3}(stat) +- 2.8(syst) +- 1.4(model)) MeV/c^2. The third error is an uncertainty due to possible interference between the \eta_c and a non-resonant component. We also report the first evidence for \eta(1760) decay to \eta' \pi^+ \pi^-; we find two solutions for its parameters, depending on the inclusion or not of the X(1835), whose existence is of marginal significance in our data. From a fit to the mass spectrum using coherent X(1835) and \eta(1760) resonant amplitudes, we set a 90% confidence level upper limit on the product \Gamma_{\gamma\gamma} \BR (\eta' \pi^+ \pi^-) for the X(1835).Comment: 13 pages, 7 figures, submitted to PR