900 research outputs found
Paths reunited: initiation of the classical and lectin pathways of complement activation
Understanding the structural organisation and mode of action of the initiating complex of the classical pathway of complement activation (C1) has been a central goal in complement biology since its isolation almost 50 years ago. Nevertheless, knowledge is still incomplete, especially with regard to the interactions between its subcomponents C1q, C1r and C1s that trigger activation upon binding to a microbial target. Recent studies have provided new insights into these interactions, and have revealed unexpected parallels with initiating complexes of the lectin pathway of complement: MBL–MASP and ficolin–MASP. Here, we develop and expand these concepts and delineate their implications towards the key aspects of complement activation via the classical and lectin pathways
BPACE: A Bayesian, Patient-Centered Procedure for Matrix Speech Tests in Noise.
Matrix sentence tests in noise can be challenging to the listener and time-consuming. A trade-off should be found between testing time, listener's comfort and the precision of the results. Here, a novel test procedure based on an updated maximum likelihood method was developed and implemented in a German matrix sentence test. It determines the parameters of the psychometric function (threshold, slope, and lapse-rate) without constantly challenging the listener at the intelligibility threshold. A so-called "credible interval" was used as a mid-run estimate of reliability and can be used as a termination criterion for the test. The procedure was evaluated and compared to a STAIRCASE procedure in a study with 20 cochlear implant patients and 20 normal hearing participants. The proposed procedure offers comparable accuracy and reliability to the reference method, but with a lower listening effort, as rated by the listeners ( points on a 10-point scale). Test duration can be reduced by 1.3 min on average when a credible interval of 2 dB is used as the termination criterion instead of testing 30 sentences. Particularly, normal hearing listeners and well performing, cochlear implant users can benefit from shorter test duration. Although the novel procedure was developed for a German test, it can easily be applied to tests in any other language
The art of ecological living
El problema ecológico no es nuevo; ha acompañado toda la historia reciente de la humanidad. Sin embargo, lo que es nuevo es el alcance que ha tenido desde la modernización tecnológica e industrial de los siglos XIX y XX y que, si los indicios y la información no son engañosos, amenaza con convertirse en un desastre para toda la humanidad en el siglo XXI. El informe de la ONU de la Conferencia sobre el Cambio Climático, del año 2007, y recientemente el desastre nuclear de Fukushima aportan evidencias en esta dirección. ¿Cómo se llegó a esa problemática, cómo evolucionó el saber al respecto y cómo se deja justificar convincentemente la actuación humana y social? ¿Qué puede hacer un individuo para proyectar una vida más sostenible? ¿Qué es el Antropoceno? ¿Es posible construir una sociedad ecológica y solidaria? Estas y otras preguntas se abordan desde la reflexión filosófica en el presente artículo.Ecological problem is not new; it has been with us the entire history of mankind. What is new, however, is the extent to which it has spread since the technological and industrial modernisation of the 19th and 20th centuries and, if the evidence and information are not misleading, it threatens to become a disaster for the whole of humanity in the 21st century. The UN Climate Change Conference report of 2007 and, recently, the Fukushima nuclear disaster provide evidence in this direction. How did this problem come about, how did knowledge about it evolve and how can human and social action be convincingly justified? What can individuals do in order to build a more sustainable life? What is the Anthropocene? Is it possible to build an ecological and caring society? These and other questions are addressed philosophically in this paper
Reflexões para uma Ética Segundo Foucault:: Estética da Existência
We live in the period of rediscovering the question of Ethics. But "Ethics" not only mean a normative form,well-known since Kant and predominant in the time of modernity. To step back to Ancient times gives the example of an Ethicswhich is based on the individual choice and prudence of the individual. The new foundation of an Ethics as "Aesthetics ofExistence" is inspired by Michel Foucault.Vivemos o período de redescoberta da questão da ética. Mas "ética" não significa apenas uma forma normativa, bem conhecida desde Kant e predominante no tempo da modernidade. O retorno aos tempos da Antigüidade fornece o exemplo de uma ética baseada na escolha individual e na prudência do indivíduo. A nova fundação de uma ética como "estética da existência" é inspirada em Michel Foucaul
Kondo Effect in Multiple-Dot Systems
We study the Kondo effect in multiple-dot systems for which the inter- as
well as intra-dot Coulomb repulsions are strong, and the inter-dot tunneling is
small. The application of the Ward-Takahashi identity to the inter-dot
dynamical susceptibility enables us to analytically calculate the conductance
for a double-dot system by using the Bethe-ansatz exact solution of the SU(4)
impurity Anderson model. It is clarified how the inter-dot Kondo effect
enhances or suppresses the conductance under the control of the gate voltage
and the magnetic field. We then extend our analysis to multiple-dot systems
including more than two dots, and discuss their characteristic transport
properties by taking a triple-dot system as an example.Comment: 8 pages, 9 figure
Training-related modulations of the autonomic nervous system in endurance athletes: is female gender cardioprotective?
The risk of sudden death is increased in athletes with a male predominance. Regular physical activity increases vagal tone, and may protect against exercise-induced ventricular arrhythmias. We investigated training-related modulations of the autonomic nervous system in female and male endurance athletes. Runners of a 10-mile race were invited. Of 873 applicants, 68 female and 70 male athletes were randomly selected and stratified according to their average weekly training hours in a low (≤4h) and high (>4h) volume training group. Analysis of heart rate variability was performed over 24h. Spectral components (high frequency [HF] and low frequency [LF] power in normalized units) were analyzed for hourly 5min segments and averaged for day- and nighttime. One hundred and fourteen athletes (50% female, mean age 42±7years) were included. No significant gender difference was observed for training volume and 10-mile race time. Over the 24-h period, female athletes exhibited a higher HF and lower LF power for each hourly time-point. Female gender and endurance training hours were independent predictors of a higher HF and lower LF power. In female athletes, higher training hours were associated with a higher HF and lower LF power during nighttime. In male athletes, the same was true during daytime. In conclusion, female and male athletes showed a different circadian pattern of the training-related increase in markers of vagal tone. For a comparable amount of training volume, female athletes maintained their higher markers of vagal tone, possibly indicating a superior protection against exercise-induced ventricular arrhythmia
Stellung und Quellen des Präventivgedankens bei Don Bosco im Zusammenhang mit der pädagogischen Lage seiner Zeit
Marinbiologische Untersuchungen des Instituts für Polarökologie auf der ARK VII/2 - Expedition der "Polarstern" 1990
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