343 research outputs found
CARMENES input catalogue of M dwarfs IV. New rotation periods from photometric time series
Aims. The main goal of this work is to measure rotation periods of the M-type
dwarf stars being observed by the CARMENES exoplanet survey to help distinguish
radial-velocity signals produced by magnetic activity from those produced by
exoplanets. Rotation periods are also fundamental for a detailed study of the
relation between activity and rotation in late-type stars. Methods. We look for
significant periodic signals in 622 photometric time series of 337 bright,
nearby M dwarfs obtained by long-time baseline, automated surveys (MEarth,
ASAS, SuperWASP, NSVS, Catalina, ASAS-SN, K2, and HATNet) and for 20 stars
which we obtained with four 0.2-0.8 m telescopes at high geographical
latitudes. Results. We present 142 rotation periods (73 new) from 0.12 d to 133
d and ten long-term activity cycles (six new) from 3.0 a to 11.5 a. We compare
our determinations with those in the existing literature; we investigate the
distribution of P rot in the CARMENES input catalogue,the amplitude of
photometric variability, and their relation to vsin i and pEW(Halfa); and we
identify three very active stars with new rotation periods between 0.34 d and
23.6 d.Comment: 34 pages, 43 figures, 2 appendix table
An On-the-Road Comparison of In-Vehicle Navigation Assistance Systems
We compared system performance and driver opinion of 3 in-vehicle navigation aids - two advanced traveler information systems (ATISs; Ali-Scout and TetraStar) and written instructions - when used on the road concurrently under identical conditions. Few drivers in the study had difficulty finding initial routes or became lost. Users of Ali-Scout, an ATIS that utilizes traffic information in routing, drove longer-distance routes, got lost more frequently, and gave their system less positive ratings than did TetraStar users. Users of the 2 ATISs traversed routes that were significantly shorter in duration than those driven by users of written instructions. The time savings benefit of the advanced technology systems over written instructions was greatest during peak traffic conditions. Drivers who were familiar with the road network, overall, had less difficulty finding destinations and drove shorter-duration routes than drivers who were unfamiliar with the road network. Actual or potential applications of this research include improving the design of technologies that provide navigation assistance to travelers.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67382/2/10.1518_001872099779591222.pd
The GENESIS (Randomized, Multicenter Study of the Pimecrolimus-Eluting and Pimecrolimus/Paclitaxel-Eluting Coronary Stent System in Patients with De Novo Lesions of the Native Coronary Arteries) Trial
ObjectivesThe aim of this study was to compare, in a randomized multicenter trial, paclitaxel-eluting stents (CoStar, Conor Medsystems, Menlo Park, California) versus pimecrolimus-eluting stents (Corio, Conor Medsystems) versus stents with dual elution of both drugs (SymBio, Conor Medsystems) in native coronary arteries.BackgroundThe CoStar cobalt-chromium reservoir-based stent platform, eluting paclitaxel in a controlled way via a bioresorbable polymer, reduces restenosis versus its respective bare-metal stent. The reservoir system allows the use of other drugs targeted to different mechanisms involved in the process of vascular restenosis and simultaneous loading of multiple, synergistic drugs.MethodsPatients with single de novo lesions were asymmetrically randomized to 1 of the 3 types of stent (1:2:2). Six-month coronary angiography was planned in all. The primary analysis was a noninferiority test for the primary end point of 6-month angiographic in-stent late lumen loss of Corio versus CoStar and SymBio versus CoStar. Secondary end points included binary angiographic restenosis and major adverse clinical events (cardiac death, myocardial infarction, target vessel revascularization).ResultsThe trial was prematurely suspended after 246 patients were enrolled (planned enrollment: 375 patients): 49 patients received CoStar, 97 received SymBio, and 100 received Corio. In-stent late loss was significantly reduced with CoStar versus either SymBio or Corio (0.58 ± 0.58 mm vs. 0.96 ± 0.73 mm and 0.58 ± 0.58 mm vs. 1.40 ± 0.67 mm, p < 0.001 for both comparisons). Binary in-stent restenosis rates were, 7.1%, 20%, and 40.9%, respectively (p < 0.001 for both comparisons); 6-month major adverse cardiac event rates were, 2.0%, 14.4%, and 39.0%, respectively (p < 0.001 for both comparisons).ConclusionsStents eluting pimecrolimus or the dual combination of pimecrolimus and paclitaxel failed to show angiographic noninferiority when compared with paclitaxel-eluting stents. (A Randomized, Multi-Center Study of the Pimecrolimus-Eluting and Pimecrolimus/Paclitaxel-Eluting Coronary Stent Systems; NCT00322569
Is equal access to higher education in South Asia and sub-Saharan Africa achievable by 2030?
Higher education is back in the spotlight, with post-2015 sustainable development goals emphasising equality of access. In this paper, we highlight the long distance still to travel to achieve the goal of equal access to higher education for all, with a focus on poorer countries which tend to have lower levels of enrolment in higher education. Analysing Demographic and Health Survey data from 35 low- and middle-income countries in sub-Saharan Africa and South Asia, we show wide wealth inequalities in particular, with few if any of the poorest gaining access to higher education in some countries. We further identify that wealth and gender inequalities interact and tend to be wider in countries where levels of higher education are higher. This implies that expansion in access to higher education may predominantly benefit the rich, unless measures are taken to tackle inequalities. We find that that the rates of increase necessary for the attainment of the equal access goal by 2030 are particularly high. They pose a particularly difficult challenge given the access inequalities present from primary and secondary education in a wide majority of countries in our analysis. We therefore suggest that any measures aimed at attaining the goal need to tackle inequalities in access within a system-wide approach, focusing on the level of education at which inequalities initially manifest, alongside higher education.This is the final version of the article. It first appeared from Springer via http://dx.doi.org/10.1007/s10734-016-0039-
An ex vivo continuous passive motion model in a porcine knee for assessing primary stability of cell-free collagen gel plugs
<p>Abstract</p> <p>Background</p> <p>Primary stability of cartilage repair constructs is of the utmost importance in the clinical setting but few continuous passive motion (CPM) models are available. Our study aimed to establish a novel ex vivo CPM animal model and to evaluate the required motion cycles for testing the mechanical properties of a new cell-free collagen type I gel plug (CaReS<sup>®</sup>-1S).</p> <p>Methods</p> <p>A novel ex vivo CPM device was developed. Full-thickness cartilage defects (11 mm diameter by 6 mm deep) were created on the medial femoral condyle of porcine knee specimens. CaReS<sup>®</sup>-1S was implanted in 16 animals and each knee underwent continuous passive motion. After 0, 2000, 4000, 6000, and 8000 motions, standardized digital pictures of the grafts were taken, focusing on the worn surfaces. The percentage of worn surface on the total CaReS<sup>®</sup>-1S surface was evaluated with image processing software.</p> <p>Results</p> <p>Significant differences in the worn surface were recorded between 0 and 2000 motion cycles (p < 0.0001). After 2000 motion cycles, there was no significant difference. No total delamination of CaReS<sup>®</sup>-1S with an empty defect site was recorded.</p> <p>Conclusion</p> <p>The ex vivo CPM animal model is appropriate in investigating CaReS<sup>®</sup>-1S durability under continuous passive motion. 2000 motion cycles appear adequate to assess the primary stability of type I collagen gels used to repair focal chondral defects.</p
Therapeutic decision-making for patients with fluctuating mitral regurgitation
Mitral regurgitation (MR) is a common, progressive, and difficult-to-manage disease. MR is dynamic in nature, with physiological fluctuations occurring in response to various stimuli such as exercise and ischaemia, which can precipitate the development of symptoms and subsequent cardiac events. In both chronic primary and secondary MR, the dynamic behaviour of MR can be reliably examined during stress echocardiography. Dynamic fluctuation of MR can also have prognostic value; patients with a marked increase in regurgitant volume or who exhibit increased systolic pulmonary artery pressure during exercise have lower symptom-free survival than those who do not experience significant changes in MR and systolic pulmonary artery pressure during exercise. Identifying patients who have dynamic MR, and understanding the mechanisms underlying the condition, can potentially influence revascularization strategies (such as the surgical restoration of coronary blood flow) and interventional treatment (including cardiac resynchronization therapy and new approaches targeted to the mitral valve)
Inequalities in higher education in low‐ and middle‐income countries:A scoping review of the literature
Motivation: Higher education is regarded as a key instrument to enhance socioeconomic mobility andreduce inequalities. Recent literature reviews have examined inequalities in the higher education systemsof high-income countries, but less is known about the situation in low- and middle-income countries,where higher education is expanding fast.Purpose: The article reviews the academic literature on higher education in low- and middle-incomecountries using a research framework inspired by social justice and capability approaches. It considers the financial, socio-cultural, human, and political resource domains on which people draw, and how they relate to access, participation, and outcomes in higher education.Methods: A literature search for studies explicitly discussing in-country inequalities in higher education revealed 22 publications. Substantial knowledge gaps remain, especially regarding the political (and decision-making) side of inequalities; the ideologies and philosophies underpinning higher education systems; and the linkages between resource domains, both micro and macro.Findings: The review highlights key elements for policy-makers and researchers: (1) the financial lens alone is insufficient to understand and tackle inequalities, since these are also shaped by human and other non-financial factors; (2) socio-cultural constructs are central in explaining unequal outcomes; and (3) inequalities develop throughout one’s life and need to be considered during, but also before and afterhigher education. The scope of inequalities is wide, and the literature offers a few ideas for short-term fixes such as part-time and online education.Policy implications: Inclusive policy frameworks for higher education should include explicit goals related to (in)equality, which are best measured in terms of the extent to which certain actions or choices are feasible for all. Policies in these frameworks, we argue, should go beyond providing financial support, and also address socio-cultural and human resource constraints and challenges in retention, performance, and labour market outcomes. Finally, they should consider relevant contextual determinants of inequalities.</p
Role of computed tomography imaging for transcatheter valvular repair/insertion
During the last decade, the development of transcatheter based therapies has provided feasible therapeutic options for patients with symptomatic severe valvular heart disease who are deemed inoperable. The promising results of many nonrandomized series and recent landmark trials have increased the number of percutaneous transcatheter valve procedures in high operative risk patients. Pre-procedural imaging of the anatomy of the aortic or mitral valve and their spatial relationships is crucial to select the most appropriate device or prosthesis and to plan the percutaneous procedure. Multidetector row computed tomography provides 3-dimensional volumetric data sets allowing unlimited plane reconstructions and plays an important role in pre-procedural screening and procedural planning. This review will describe the evolving role of multidetector row computed tomography in patient selection and strategy planning of transcatheter aortic and mitral valve procedures
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