399 research outputs found
Design and Characterization of a Novel Knee Articulation Mechanism
Abstract
The paper is focused on designing a novel controllable and adjustable mechanism for reproducing human knee joint's complex motion by taking into account the flexion/extension movement in the sagittal plane, in combination with roll and slide. Main requirements for a knee rehabilitation supporting device are specified by researching the knee's anatomy and already existing mechanisms. A three degree of freedom (3 DOF) system (four-bar like linkage with controlled variable lengths of rockers) is synthesised to perform the reference path of instantaneous centre of rotation (ICR). Finally, a preliminary design of the adaptive mechanism is elaborated and a numerical model is built in Adams. Numerical results are derived from simulations that are presented to evaluate the accuracy of the reproduced movement and the mechanism's capabilities
Dealing with digital: the economic organisation of streamed music
© The Author(s) 2020. The intervention of digital service providers (DSPs) or platforms, such as Spotify Apple Music and Tidal, that supply streamed music has fundamentally altered the operation of copyright management organisations (CMOs) and the way song-writers and recording artists are paid. Platform economics has emerged from the economic analysis of two- and multi-sided markets, offering new insights into the way business is conducted in the digital sphere and is applied here to music streaming services. The business model for music streaming differs from previous arrangements by which the royalty paid to song-writers and performers was a percentage of sales. In the case of streamed music, payment is based on revenues from both subscriptions and ad-based free services. The DSP agrees a rate per stream with the various rights holders that varies according to the deal made with each of the major record labels, with CMOs, with representatives of independent labels and with unsigned artists and song-writers with consequences for artists’ earnings. The article discusses these various strands with a view to understanding royalty payments for streamed music in terms of platform economics, offering some data and information from the Norwegian music industry to give empirical support to the analysis
The tree species matters: Belowground carbon input and utilization in the myco-rhizosphere
© 2017 Elsevier Masson SAS Rhizodeposits act as major carbon (C) source for microbial communities and rhizosphere-driven effects on forest C cycling receive increasing attention for maintaining soil biodiversity and ecosystem functions. By in situ 13 CO 2 pulse labeling we investigated C input and microbial utilization of rhizodeposits by analyzing 13 C incorporation into phospholipid fatty acids (PLFA) of beech- (Fagus sylvatica) and ash-associated (Fraxinus excelsior) rhizomicrobial communities. Plant compartments and soil samples were analyzed to quantify the allocation of assimilates. For 1 m high trees, ash assimilated more of the applied 13 CO 2 (31%) than beech (21%), and ash allocated twice as much 13 C belowground until day 20. Approximately 0.01% of the applied 13 C was incorporated into total PLFAs, but incorporation varied significantly between microbial groups. Saprotrophic and ectomycorrhizal fungi under beech and ash, but also arbuscular mycorrhizal fungi and Gram negative bacteria under ash, incorporated most 13 C. PLFA allowed differentiation of C fluxes from tree roots into mycorrhiza: twice as much 13 C was incorporated into the fungal biomarker 18:2ω6,9 under beech than under ash. Within 5 days, 30% of the fungal PLFA-C was replaced by rhizodeposit-derived 13 C under beech but only 10% under ash. None of the other microbial groups reached such high C replacement, suggesting direct C allocation via ectomycorrhizal symbioses dominates the C flux under beech. Based on 13 CO 2 labeling and 13 C tracing in PLFA we conclude that ash allocated more C belowground and has faster microbial biomass turnover in the rhizosphere compared to beech
Surgical management of life threatening events caused by intermittent aortic insufficiency in a native valve: case report
We describe a case of a patient admitted with apparent life threatening events characterized by hypotension and bradycardia. The patient was ultimately found to have intermittent severe aortic insufficiency. Upon surgical exploration, abnormalities were discovered in the aortic valve, which had a small left coronary cusp with absence of the nodulus of Arantius. Following surgical repair of the valve, aimed at preventing the small cusp from becoming stuck in the open position, the patient has remained episode free for over one year
The politics of the digital single market:Culture vs. competition vs. copyright
This paper examines the implications for European music culture of the European Union’s Digital Single Market strategy. It focuses on the regulatory framework being created for the management of copyright policy, and in particular the role played by Collective Management Organisations (or Collecting Societies). One of the many new opportunities created by digitalization has been the music streaming services. These depend on consumers being able to access music wherever they are, but such a system runs counter to the management of rights on a national basis and through collecting organisations who act as monopolies within their own territories. The result has been ‘geo-blocking’. The EU has attempted to resolve this problem in a variety of ways, most recently in a Directive designed to reform the CMOs. In this paper, we document these various efforts, showing them to be motivated by a deep-seated and persisting belief in the capacity of ‘competition’ to resolve problems that, we argue, actually lie elsewhere - in copyright policy itself. The result is that the EU’s intervention fails to address its core concern and threatens the diversity of European music culture by rewarding those who are already commercially successful
Going means trouble and staying makes it double: the value of licensing recorded music online
This paper discusses whether a copyright compensation system (CCS) for recorded music—endowing private Internet subscribers with the right to download and use works in return for a fee—would be welfare increasing. It reports on the results of a discrete choice experiment conducted with a representative sample of the Dutch population consisting of 4986 participants. Under some conservative assumptions, we find that applied only to recorded music, a mandatory CCS could increase the welfare of rights holders and users in the Netherlands by over €600 million per year (over €35 per capita). This far exceeds current rights holder revenues from the market of recorded music of ca. €144 million per year. A monthly CCS fee of ca. €1.74 as a surcharge on Dutch Internet subscriptions would raise the same amount of revenues to rights holders as the current market for recorded music. With a voluntary CCS, the estimated welfare gains to users and rights holders are even greater for CCS fees below €20 on the user side. A voluntary CCS would also perform better in the long run, as it could retain a greater extent of market coordination. The results of our choice experiment indicate that a well-designed CCS for recorded music would simultaneously make users and rights holders better off. This result holds even if we correct for frequently observed rates of overestimation in contingent valuation studies
Decrease in shunt volume in patients with cryptogenic stroke and patent foramen ovale
<p>Abstract</p> <p>Background</p> <p>In patients with patent foramen ovale (PFO) there is evidence supporting the hypothesis of a change in right-to-left shunt (RLS) over time. Proven, this could have implications for the care of patients with PFO and a history of stroke. The following study addressed this hypothesis in a cohort of patients with stroke and PFO.</p> <p>Methods</p> <p>The RLS volume assessed during hospitalisation for stroke (index event/T0) was compared with the RLS volume on follow-up (T1) (median time between T0 and T1 was 10 months). In 102 patients with a history of stroke and PFO the RLS volume was re-assessed on follow-up using contrast-enhanced transcranial Doppler/duplex (ce-TCD) ultrasound. A change in RLS volume was defined as a difference of ≥20 microembolic signals (MES) or no evidence of RLS during ce-TCD ultrasound on follow-up.</p> <p>Results</p> <p>There was evidence of a marked reduction in RLS volume in 31/102 patients; in 14/31 patients a PFO was no longer detectable. An index event classified as cryptogenic stroke (P < 0.001; OD = 39.2, 95% confidence interval 6.0 to 258.2) and the time interval to the follow-up visit (P = 0.03) were independently associated with a change in RLS volume over time.</p> <p>Conclusions</p> <p>RLS volume across a PFO decreases over time, especially in patients with cryptogenic stroke. These may determine the development of new strategies for the management in the secondary stroke prevention.</p
Feasibility of TEE-guided stroke risk assessment in atrial fibrillation—background, aims, design and baseline data of the TIARA pilot study
Contains fulltext :
97916.pdf (publisher's version ) (Open Access)BACKGROUND: Antithrombotic management in atrial fibrillation (AF) is currently based on clinical characteristics, despite evidence of potential fine-tuning with transoesophageal echocardiography (TEE). This open, randomised, multicentre study addresses the hypothesis that a comprehensive strategy of TEE-based aspirin treatment in AF patients is feasible and safe. METHODS: Between 2005 and 2009, ten large hospitals in the Netherlands enrolled AF patients with a moderate risk of stroke. Patients without thrombogenic TEE characteristics were randomised to aspirin or vitamin K antagonists (VKA). The primary objective is to show that TEE-based aspirin treatment is safe compared with VKA therapy. The secondary objective tests feasibility of TEE as a tool to detect echocardiographic features of high stroke risk. This report compares randomised to non-randomised patients and describes the feasibility of a TEE-based approach. RESULTS: In total, 310 patients were included. Sixty-nine patients were not randomised because of non-visualisation (n = 6) or TEE risk factors (n = 63). Compared with non-randomised patients, randomised patients (n = 241) were younger (65 +/- 11 vs. 69 +/- 9 years, p = 0.004), had less coronary artery disease (9 vs. 20%, p = 0.018), previous TIA (1.7 vs. 7.2%, p = 0.029), AF during TEE (25 vs. 54%, p < 0.001), mitral incompetence (55 vs. 70%, p = 0.038), VKA use (69 vs. 82%, p = 0.032), had a lower mean CHADS(2) score (1.2 +/- 0.6 vs. 1.6 +/- 1.0, p = 0.004), and left ventricular ejection fraction (59 +/- 8 vs. 56 +/- 8%, p = 0.016). CONCLUSIONS: This study shows that a TEE-based approach for fine-tuning stroke risk in AF patients with a moderate risk for stroke is feasible. Follow-up data will address the safety of this TEE-based approach
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