1,734,185 research outputs found
A review of methodology for sample size calculations in cluster randomised trials.
No full textPMCID: PMC3287737This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.PMCID: PMC3287737PMCID: PMC3287737PMCID: PMC3287737PMCID: PMC3287737PMCID: PMC3287737PMCID: PMC328773
Ingenio azucarero de Tamasopo, "6215. Sugar mill Tamasopo"
No full textI.O. Anverso: "6215. Sugar mill Tamasopo". Reverso: "3533". V.F. 455951
Hypertension Improvement Project (HIP): study protocol and implementation challenges
No full text10.1186/1745-6215-10-13Trials101
Neutral hydrogen gas in interacting galaxies: the NGC 6221/6215 galaxy group
No full textNeutral hydrogen observations of the spiral galaxies NGC 6221 and 6215 with the Australia Telescope Compact Array (ATCA) reveal a wide, two-stranded bridge of at least 3 × 108 M⊙ which can be traced between the two galaxies over a projected distance of 100 kpc. The velocity gradient of the H I bridge provides a rough estimate for the time since the encounter of 500 Myr. For NGC 6221, the brightest and most massive galaxy of the group, we derive a dynamical mass of Mtot = 8 × 1010 M⊙, while its companion NGC 6215 has a mass of only Mtot ∼ 2 × 109 M⊙. Further, we find three low-surface-brightness dwarf galaxies (Dwarfs 1, 2 and 3) in the neighbourhood of NGC 6221/15 with Hi masses of 3.3, 0.6 and 0.3 × 10 8 M⊙, respectively. The smallest, previously uncatalogued galaxy, Dwarf 3, lies between NGC 6221 and 6215, and may have formed out of bridge material. The brightest part of the Hi bridge lies roughly halfway between the interacting galaxies, indicating that bridge gas close to NGC 6221 and 6215 may have fallen back to the galaxies. The asymmetric extensions to the Hi envelope of NGC 6221 are likely to be reaccreted gas, still settling in. Also, the peculiar velocity field of NGC 6215 may be explained by accreted bridge material settling into a plane offset from the old disc
Software tools for implementing simulation studies in adaptive seamless designs : introducing R package ASD
Get PDFAdaptive designs for clinical trials have the potential to
improve the efficiency of clinical research by, for instance,
seamlessly combining different stages of a clinical development programme
Managing clinical trials.
Get PDFManaging clinical trials, of whatever size and complexity, requires efficient trial management. Trials fail because tried and tested systems handed down through apprenticeships have not been documented, evaluated or published to guide new trialists starting out in this important field. For the past three decades, trialists have invented and reinvented the trial management wheel. We suggest that to improve the successful, timely delivery of important clinical trials for patient benefit, it is time to produce standard trial management guidelines and develop robust methods of evaluation
DAU 6215, a novel 5-HT3-receptor antagonist, selectively antagonizes scopolamine-induced deficit in a passive-avoidance task, but not scopolamine-induced hypermotility in rats
No full textAbstract
This study examined the effects of DAU 6215, a selective 5-HT3-receptor antagonist, on either impairment of a passive-avoidance task or hypermotility, both caused by scopolamine in rats. In the first experiment, scopolamine (0·75 mg kg−1, i.p.) disrupted acquisition of a one-trial ‘step through’ passive-avoidance response. Pretreatment with DAU 6215 (1, 10, 30 and 100 μg kg−1, i.p.) antagonized this deficit induced by scopolamine, with a bell-shaped dose-response curve. Scopolamine (0·75 mg kg−1, i.p.) produced a significant increase in locomotor activity which was unaffected by pretreatment with DAU 6215 (10 and 30 μg kg−1, i.p.). The present results further support the suggestion that 5-HT3-receptor antagonists may prevent the memory disturbance caused by a reduction in central cholinergic function in the rat. The inefficacy shown by DAU 6215 on hyperactivity induced by scopolamine appears to rule out the possibility of a pharmacokinetic interference between DAU 6215 and scopolamine.</jats:p
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
