416 research outputs found
Insights into the music patterns of St Basil liturgy according to the Coptic rite
The exact roots of Coptic music and its creation remain unknown, with speculations suggesting potential Pharaonic, Jewish and Greek roots. This thesis focuses on the musical features of both the priest’s chants and the congregational responses in the St Basil liturgy according to the Coptic rite, in an attempt to discern its patterns and roots since it seems impossible to identify its composers and origin. The practice-based empirical methods used were audio and video
recording of the liturgy, notating its music using the Arabic music rules, comparing melodies of Greek responses practised in the Byzantine and Coptic traditions and attempting to
reproduce the Coptic melodies using Pharaonic nay replicas.
The current literature shows no description of musical features and scales of St Basil liturgy, as stated decades ago by H Hickmann, being transmitted via the oral tradition. Audio analysis of some of the liturgical responses revealed significant scale discrepancies between three renowned contemporary musicians. Also, having compared four sets of notations by eminent Coptic musicians, there were significant differences in the style of notation and the dominating scales. These results raised doubt about the accuracy of the conventional Arabic music analyses in describing the Coptic music, since scale recognition is based only on the tetrachord. Despite that, my suggestion of the seven musical sections of the liturgy has been confirmed. Also, comparing the music of thirteen Greek responses shared between the Byzantine and Coptic traditions, showed similarities only between two; the rest of the responses were different. Furthermore, attempts to reproduce the St Basil melodies using Pharaonic nay (flute) replicas showed limited ability of the oldest long nays compared to the more recent short ones. Thus, despite being the first empirical study of the music features of St Basil liturgy according to the Coptic rite, this thesis successfully describes unique patterns and puts forward suggestions, with some speculations, regarding the roots of such ancient music, which requires further analysis
The S shape of a granular pile in a rotating drum
The shape of a granular pile in a rotating drum is investigated. Using
Discrete Elements Method (DEM) simulations we show that the "S shape" obtained
for high rotation speed can be accounted for by the friction on the end plates.
A theoretical model which accounts for the effect of the end plates is
presented and the equation of the shape of the free surface is derived. The
model reveals a dimensionless number which quantifies the influence of the end
plates on the shape of the pile. Finally, the scaling laws of the system are
discussed and numerical results support our conclusions
A Review of the Effect of Diet on Cardiovascular Calcification
Abstract: Cardiovascular (CV) calcification is known as sub-clinical atherosclerosis and is recognised as a predictor of CV events and mortality. As yet there is no treatment for CV calcification and conventional CV risk factors are not consistently correlated, leaving clinicians uncertain as to optimum management for these patients. For this reason, a review of studies investigating diet and serum levels of macro-and micronutrients was carried out. Although there were few human studies of macronutrients, nevertheless transfats and simple sugars should be avoided, while long chain ω-3 fats from oily fish may be protective. Among the micronutrients, an intake of 800 μg/day calcium was beneficial in those without renal disease or hyperparathyroidism, while inorganic phosphorus from food preservatives and colas may induce calcification. A high intake of magnesium (≥380 mg/day) and phylloquinone (500 μg/day) proved protective, as did a serum 25(OH)D concentration of ≥75 nmol/L. Although oxidative damage appears to be a cause of CV calcification, the antioxidant vitamins proved to be largely ineffective, while supplementation of α-tocopherol may induce calcification. Nevertheless other antioxidant compounds (epigallocatechin gallate from green tea and resveratrol from red wine) were protective. Finally, a homocysteine concentration >12 µmol/L was predictive of CV calcification, although a plasma folate concentration of >39.4 nmol/L could both lower homocysteine and protect against calcification. In terms of a dietary programme, these recommendations indicate avoiding sugar and the transfats and preservatives found in processed foods and drinks and adopting a diet high in oily fish and vegetables. The micronutrients magnesium and vitamin K may be worthy of further investigation as a treatment option for CV calcification
Gravity insensitive flexure pivots for watch oscillators
Classical pivots have frictional losses leading to the limited quality factor of oscillators used as time bases in mechanical watches. Flexure pivots address these issues by greatly reducing friction. However, they have drawbacks such as gravity sensitivity and limited angular stroke. This paper analyses these problems for the cross-spring flexure pivot and presents an improved version addressing these issues. We first show that the cross spring pivot cannot be both insensitive to gravity and have a long stroke. A 10 ppm sensitivity to gravity acceptable for watchmaking applications occurs only when the leaf springs cross at about 87.3 % of their length, but the stroke is only 30.88 % of the stroke of the symmetrical cross-spring pivot. For the symmetrical pivot, gravity sensitivity is of the order of 104 ppm. Our solution is to introduce the co-differential concept which we show to be gravity insensitive. We then use the co-differential to build a gravity insensitive flexure pivot with long stroke. The design consists of a main rigid body, two co-differentials and a torsional beam. We show that our pivot is gravity insensitive and achieves 100 % of the stroke of symmetrical pivots
Evaluation of Left Atrial Size and Function: Relevance for Clinical Practice
Left atrial (LA) structural and functional evaluation have recently emerged as powerful biomarkers for adverse events in a variety of cardiovascular conditions. Moreover, noninvasive evaluation of LA pressure has gained importance in the characterization of the hemodynamic profile of patients. This review describes the methodology, benefits and pitfalls of measuring LA size and function by echocardiography and provides a brief overview of the prognostic utility of newer echocardiographic metrics of LA geometry and function (i.e., three-dimensional volumes, longitudinal strain, and phasic function parameters)
Effects of communication and utility-based decision making in a simple model of evacuation
We present a simple cellular automaton based model of decision making during
evacuation. Evacuees have to choose between two different exit routes,
resulting in a strategic decision making problem. Agents take their decisions
based on utility functions, these can be revised as the evacuation proceeds,
leading to complex interaction between individuals and to jamming transitions.
The model also includes the possibility to communicate and exchange information
with distant agents, information received may affect the decision of agents. We
show that under a wider range of evacuation scenarios performance of the model
system as a whole is optimal at an intermediate fraction of evacuees with
access to communication.Comment: 9 pages, 9 figure
Materials Research in Microgravity 2012
Reducing gravitational effects such as thermal and solutal buoyancy enables investigation of a large range of different phenomena in materials science. The Symposium on Materials Research in Microgravity involved 6 sessions composed of 39 presentations and 14 posters with contributions from more than 14 countries. The sessions concentrated on four different categories of topics related to ongoing reduced-gravity research. Highlights from this symposium will be featured in the September 2012 issue of JOM. The TMS Materials Processing and Manufacturing Division, Process Technology and Modeling Committee and Solidification Committee sponsored the symposium
Efficacy and safety of colchicine in patients with coronary artery disease: a systematic review and meta-analysis of randomized controlled trials
Background: Inflammation plays a central role in the pathogenesis and clinical manifestations of atherosclerosis. Randomized controlled trials (RCTs) have investigated the potential benefit of colchicine in reducing cardiovascular events (CE) in patients with coronary artery disease (CAD) but produced conflicting results. The aim of this meta-analysis was to evaluate the efficacy and safety of colchicine in patients with CAD.
Methods: We systematically searched selected electronic databases from inception until 10th December 2020. Primary clinical endpoints were: major adverse cardiac events (MACE), allcause mortality, cardio-vascular (CV) mortality, recurrent myocardial infarction (MI), stroke, hospitalization and adverse medication effects. Secondary endpoints were short-term effect of colchicine on inflammatory markers.
Results: Twelve RCTs with a total of 13,073 patients with CAD (colchicine n=6351 and placebo n=6722) were included in the meta-analysis. At mean follow-up of 22.5 months, the colchicine group had lower risk of MACE (6.20% vs. 8.87%; p<0.001), recurrent MI (3.41% vs. 4.41%; p=0.005), stroke (0.40% vs. 0.90%; p=0.002) and hospitalization due to CE (0.90% vs. 2.87%; p=0.02) compared to the control group. The two patient groups had similar risk for all-cause mortality (2.08% vs. 1.88%; p=0.82) and CV mortality (0.71% vs. 1.01%; p=0.38). Colchicine significantly reduced hs-CRP (-4.25, p=0.001) compared to controls but did not significantly affect IL-β1 and IL-18 levels.
Conclusions: Colchicine reduced cardiovascular events and inflammatory markers, hs-CRP and IL-6, in patients with coronary disease compared to controls. Its impact on cardiovascular and all-cause mortality requires further investigation
Effect of Dobutamine Stress on Left Ventricular Filling in Ischemic Dilated Cardiomyopathy Pathophysiology and Prognostic Implications
ObjectivesThe purpose of this research was to study the effect of dobutamine on left ventricular (LV) filling in ischemic cardiomyopathy (ICM) and to determine whether restrictive filling pattern (RFP) at peak stress has prognostic value.BackgroundThe prognostic value of RFP at peak stress in ICM is unknown.MethodsA total of 69 patients with ICM were studied by Doppler echocardiography at rest and stress; RFP was defined as transmitral E:A ratio ≥1.0, isovolumic relaxation time (IVRT) <80 ms, and E-wave deceleration time (EDT) <120 ms.ResultsA total of 42 of 69 had RFP at rest, which reverted to non-RFP at stress in 24 (EA), but persisted in 18 (EE); 27 of 69 had non-RFP at rest and peak stress (AA). In EA, IVRT and EDT lengthened (by 43 ms and 46 ms), and tricuspid regurgitation (TR) decreased (by 26 mm Hg, p < 0.01), suggesting a fall in left atrial (LA) pressure. The stress response in AA was similar to EA. In EE, IVRT and EDT shortened (by 21 ms) and TR increased (by 13 mm Hg, p < 0.01), suggesting a rise in LA pressure. Peak aortic acceleration (LV inotropy) increased by 0.8 g in EA but only by 0.2 g in EE (difference p < 0.001). Median follow-up (interquartile range) was 34 (20 to 57) months. Three-year survival for EE, EA, and AA was 49%, 79%, and 89%, respectively (p < 0.001). Compared with AA, the hazard ratio for EE was 9.5 (p < 0.001) and for EA was 1.9 (p = 0.30).ConclusionsIn ischemic cardiomyopathy, persistence of restrictive filling during stress implies a striking rise in LA pressure, greatly attenuated LV inotropic response, and markedly reduced survival. Stress echocardiography uniquely identifies these high-risk patients
Heart transplantation and biomarkers: a review about their usefulness in clinical practice
Advanced heart failure (AdvHF) can only be treated definitively by heart transplantation (HTx), yet problems such right ventricle dysfunction (RVD), rejection, cardiac allograft vasculopathy (CAV), and primary graft dysfunction (PGD) are linked to a poor prognosis. As a result, numerous biomarkers have been investigated in an effort to identify and prevent certain diseases sooner. We looked at both established biomarkers, such as NT-proBNP, hs-troponins, and pro-inflammatory cytokines, and newer ones, such as extracellular vesicles (EVs), donor specific antibodies (DSA), gene expression profile (GEP), donor-derived cell free DNA (dd-cfDNA), microRNA (miRNA), and soluble suppression of tumorigenicity 2 (sST2). These biomarkers are typically linked to complications from HTX. We also highlight the relationships between each biomarker and one or more problems, as well as their applicability in routine clinical practice
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