University of Tübingen

About: University of Tübingen is a education organization based out in Tübingen, Germany. It is known for research contribution in the topics: Population & Transplantation. The organization has 40555 authors who have published 84108 publications receiving 3015320 citations. The organization is also known as: Eberhard Karls University & Eberhard-Karls-Universität Tübingen.

A Systematic Review of Propensity Score Methods in the Social Sciences.

Abstract: The use of propensity scores in psychological and educational research has been steadily increasing in the last 2 to 3 years. However, there are some common misconceptions about the use of different estimation techniques and conditioning choices in the context of propensity score analysis. In addition, reporting practices for propensity score analyses often lack important details that allow other researchers to confidently judge the appropriateness of reported analyses and potentially to replicate published findings. In this article we conduct a systematic literature review of a large number of published articles in major areas of social science that used propensity scores up until the fall of 2009. We identify common errors in estimation, conditioning, and reporting of propensity score analyses and suggest possible solutions.

Five-Year Survival Rates for Treatment-Naive Patients With Advanced Melanoma Who Received Ipilimumab Plus Dacarbazine in a Phase III Trial

Abstract: Purpose There is evidence from nonrandomized studies that a proportion of ipilimumab-treated patients with advanced melanoma experience long-term survival. To demonstrate a long-term survival benefit with ipilimumab, we evaluated the 5-year survival rates of patients treated in a randomized, controlled phase III trial. Patients and Methods A milestone survival analysis was conducted to capture the 5-year survival rate of treatment-naive patients with advanced melanoma who received ipilimumab in a phase III trial. Patients were randomly assigned 1:1 to receive ipilimumab at 10 mg/kg plus dacarbazine (n = 250) or placebo plus dacarbazine (n = 252) at weeks 1, 4, 7, and 10 followed by dacarbazine alone every 3 weeks through week 22. Eligible patients could receive maintenance ipilimumab or placebo every 12 weeks beginning at week 24. A safety analysis was conducted on patients who survived at least 5 years and continued to receive ipilimumab as maintenance therapy. Results The 5-year survival rate was 18.2% ...

Gravitational waves from hot young rapidly rotating neutron stars

Abstract: Gravitational radiation drives an instability in the r-modes of young rapidly rotating neutron stars. This instability is expected to carry away most of the angular momentum of the star by gravitational radiation emission, leaving a star rotating at about 100 Hz. In this paper we model in a simple way the development of the instability and evolution of the neutron star during the year-long spindown phase. This allows us to predict the general features of the resulting gravitational waveform. We show that a neutron star formed in the Virgo cluster could be detected by the LIGO and VIRGO gravitational wave detectors when they reach their “enhanced” level of sensitivity, with an amplitude signal-to-noise ratio that could be as large as about 8 if near-optimal data analysis techniques are developed. We also analyze the stochastic background of gravitational waves produced by the r-mode radiation from neutron-star formation throughout the universe. Assuming a substantial fraction of neutron stars are born with spin frequencies near their maximum values, this stochastic background is shown to have an energy density of about 10^(−9) of the cosmological closure density, in the range 20 Hz to 1 kHz. This radiation should be detectable by “advanced” LIGO as well.

Cerebellar ataxia and Purkinje cell dysfunction caused by Ca2+-activated K+ channel deficiency

Abstract: Malfunctions of potassium channels are increasingly implicated as causes of neurological disorders. However, the functional roles of the large-conductance voltage- and Ca(2+)-activated K(+) channel (BK channel), a unique calcium, and voltage-activated potassium channel type have remained elusive. Here we report that mice lacking BK channels (BK(-/-)) show cerebellar dysfunction in the form of abnormal conditioned eye-blink reflex, abnormal locomotion and pronounced deficiency in motor coordination, which are likely consequences of cerebellar learning deficiency. At the cellular level, the BK(-/-) mice showed a dramatic reduction in spontaneous activity of the BK(-/-) cerebellar Purkinje neurons, which generate the sole output of the cerebellar cortex and, in addition, enhanced short-term depression at the only output synapses of the cerebellar cortex, in the deep cerebellar nuclei. The impairing cellular effects caused by the lack of postsynaptic BK channels were found to be due to depolarization-induced inactivation of the action potential mechanism. These results identify previously unknown roles of potassium channels in mammalian cerebellar function and motor control. In addition, they provide a previously undescribed animal model of cerebellar ataxia.