778 research outputs found
Identification of NADPH:Protochlorophyllide Oxidoreductases A and B: A Branched Pathway for Light-Dependent Chlorophyll Biosynthesis in Arabidopsis thaliana
Multiple-scattering effects on incoherent neutron scattering in glasses and viscous liquids
Incoherent neutron scattering experiments are simulated for simple dynamic
models: a glass (with a smooth distribution of harmonic vibrations) and a
viscous liquid (described by schematic mode-coupling equations). In most
situations multiple scattering has little influence upon spectral
distributions, but it completely distorts the wavenumber-dependent amplitudes.
This explains an anomaly observed in recent experiments
WEXTOR: A Web-based tool for generating and visualizing experimental designs and procedures
WEXTOR is a Javascript-based experiment generator and teaching tool on the World-Wide Web that can be used to design laboratory and Web experiments in a guided step-by-step process. It dynamically creates the customized Web pages and Javascripts needed for the experimental procedure and provides experimenters with a print-ready visual display of their experimental design. WEXTOR flexibly supports complete and incomplete factorial designs with between-subjects, within-subjects, and quasiexperimental factors, as well as mixed designs. The software implements client-side response time measurement
and contains a content wizard for creating interactive materials, as well as dependent measures (graphical scales, multiple-choice items, etc.), on the experiment pages. However, it does not aim to replace a full-fledged HTML editor. Several methodological features specifically needed in Web experimental design have been implemented in the Web-based tool and are described in this paper. WEXTOR
is platform independent. The created Web pages can be uploaded to any type of Web server in which data may be recorded in logfiles or via a database. The current version of WEXTOR is freely available for educational and noncommercial purposes. Its Web address is http://www.genpsylab.unizh.ch/wextor/index.html
A Sparse Stress Model
Force-directed layout methods constitute the most common approach to draw
general graphs. Among them, stress minimization produces layouts of
comparatively high quality but also imposes comparatively high computational
demands. We propose a speed-up method based on the aggregation of terms in the
objective function. It is akin to aggregate repulsion from far-away nodes
during spring embedding but transfers the idea from the layout space into a
preprocessing phase. An initial experimental study informs a method to select
representatives, and subsequent more extensive experiments indicate that our
method yields better approximations of minimum-stress layouts in less time than
related methods.Comment: Appears in the Proceedings of the 24th International Symposium on
Graph Drawing and Network Visualization (GD 2016
Predictors of state-of-the-art management of early breast cancer in Switzerland
Background: The aim of this study was to investigate predictors of state-of-the-art management of early breast cancer in Switzerland. Patients and methods: The study included 3499 women aged 25-79 years diagnosed with invasive breast cancer stages I-IIIA in 2003-2005. Patients were identified through population-based cancer registries and treated in all kinds of settings. Concordance with national and international recommendations was assessed for 10 items covering surgery, radiotherapy, systemic adjuvant therapy and histopathology reporting. We used multivariate logistic regression to identify independent predictors of high (10 points) and low (â€7 points) concordance. Results: In one-third of the patients, management met guidelines in all items, whereas in about one-fifth, three or more items did not comply. Treatment by a surgeon with caseload in the upper tercile and team involved in clinical research were independent predictors of a high score, whereas treatment by a surgeon with a caseload in the lower tercile was associated with a low score. Socioeconomic characteristics such as income and education were not independent predictors, but patient's place of residence and age independently predicted management according to recommendations. Conclusion: Specialization and involvement in clinical research seem to be key elements for enhancing the quality of early breast cancer management at population leve
Der deutsche Sydney Swallow Questionnaire
Hintergrund
Der Sydney Swallow Questionnaire (SSQ) ist ein patientenbasierter Fragebogen zur Erhebung von subjektiven Beschwerden oropharyngealer Schluckstörungen unterschiedlicher Ursachen, mit starker inhalts-, konstrukt-, diskriminativer und prÀdiktiver ValiditÀt.
Ziel der Arbeit/Fragestellung
Ziel dieser Arbeit war die ĂberprĂŒfung der ReliabilitĂ€t und ValiditĂ€t der deutschen Fassung des Sydney Swallow Questionnaire (SSQ-G).
Material und Methode
In einer Kreuzvalidierungsstudie fĂŒllten 48 erwachsene deutschsprachige Patienten (12 Frauen/36 MĂ€nner) mit neurogen (nâŻ=â16), strukturell (nâŻ=â16) und funktionell (nâŻ=â16) bedingten Schluckstörungen den deutschen SSQâG und MD Anderson Dysphagia Inventory (MDADI) aus. Die ReliabilitĂ€t des SSQâG wurde anhand der internen Konsistenz mittels Cronbachâα berechnet. Die ĂberprĂŒfung der Kriterien- und der KonstruktvaliditĂ€t erfolgte durch eine Kreuzvalidierung mittels Spearman-Korrelationskoeffizient.
Ergebnisse
Die interne Konsistenz des SSQâG war mit Cronbach-αâŻ=â0,94 exzellent. Die SSQ-G-Fragen 1 und 17 wiesen mit MDADI-Frage 1 einen moderat signifikanten bzw. hochsignifikanten Korrelationskoeffizienten von â0,43 und â0,45 auf (pâŻ<âŻ0,5; pâŻ<âŻ0,001). Zwischen Fragen 8, 11 und 12 des SSQâG und Fragen 7, 13 und 10 des MDADI lag mit Korrelationen von â0,48 bis â0,55 ein mittlerer bis starker hochsignifikanter Zusammenhang vor (pâŻ<âŻ0,001). Somit wurden die ReliabilitĂ€t, die Kriteriums- und KonstruktvaliditĂ€t statistisch bestĂ€tigt.
Schlussfolgerung
Mit der deutschen Version des SSQ (SSQ-G) können funktionsspezifische Schluckbeschwerden reliabel und valide erfasst werden. In Kombination mit Fragenbögen zur symptomspezifischen LebensqualitÀt wie dem MDADI ist somit eine differenziertere klinische Analyse von Schluckbeschwerden möglich
Dynamics of DNA replication loops reveal temporal control of lagging-strand synthesis
In all organisms, the protein machinery responsible for the replication of DNA, the replisome, is faced with a directionality problem. The antiparallel nature of duplex DNA permits the leading-strand polymerase to advance in a continuous fashion, but forces the lagging-strand polymerase to synthesize in the opposite direction. By extending RNA primers, the lagging-strand polymerase restarts at short intervals and produces Okazaki fragments. At least in prokaryotic systems, this directionality problem is solved by the formation of a loop in the lagging strand of the replication fork to reorient the lagging-strand DNA polymerase so that it advances in parallel with the leading-strand polymerase. The replication loop grows and shrinks during each cycle of Okazaki fragment synthesis. Here we use single-molecule techniques to visualize, in real time, the formation and release of replication loops by individual replisomes of bacteriophage T7 supporting coordinated DNA replication. Analysis of the distributions of loop sizes and lag times between loops reveals that initiation of primer synthesis and the completion of an Okazaki fragment each serve as a trigger for loop release. The presence of two triggers may represent a fail-safe mechanism ensuring the timely reset of the replisome after the synthesis of every Okazaki fragment.
Disentangling the respective contribution of task selection and task execution in self-directed cognitive control development
peer reviewedTask selection and task execution are key constructs in cognitive control development. Yet, little is known about how separable they are and how each contributes to task switching performance. Here, 60 4- to 5-year olds, 60 7- to 8-year olds, and 60 10- to 11-year olds children completed the double registration procedure, which dissociates these two processes. Task selection yielded both mixing and switch costs, especially in younger children, and task execution mostly yielded switch costs at all ages, suggesting that task selection is costlier than task execution. Moreover, both task selection and execution varied with task self-directedness (i.e., to what extent the task is driven by external aids) demands. Whereas task selection and task execution are dissociated regarding performance costs, they nevertheless both contribute to self-directed control
Energy landscape - a key concept for the dynamics of glasses and liquids
There is a growing belief that the mode coupling theory is the proper
microscopic theory for the dynamics of the undercooled liquid above a critical
temperature T_c. In addition, there is some evidence that the system leaves the
saddlepoints of the energy landscape to settle in the valleys at this critical
temperature. Finally, there is a microscopic theory for the entropy at the
calorimetric glass transition T_g by Mezard and Parisi, which allows to
calculate the Kauzmann temperature from the atomic pair potentials.
The dynamics of the frozen glass phase is at present limited to
phenomenological models. In the spirit of the energy landscape concept, one
considers an ensemble of independent asymmetric double-well potentials with a
wide distribution of barrier heights and asymmetries (ADWP or Gilroy-Phillips
model). The model gives an excellent description of the relaxation of glasses
up to about T_g/4. Above this temperature, the interaction between different
relaxation centers begins to play a role. One can show that the interaction
reduces the number of relaxation centers needed to bring the shear modulus down
to zero by a factor of three.Comment: Contribution to the III Workshop on Nonequilibrium Phenomena in
Supercooled Fluids, Glasses and Amorphous Materials, 22-27 September 2002,
Pisa; 14 pages, 3 figures; Version 3 takes criticque at Pisa into account;
final version 4 will be published in J.Phys.: Condens.Matte
High-dose chemotherapy with peripheral blood progenitor cell support in breast cancer: WSG AM01 and MM01
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