70 research outputs found
Performance evaluation in the arts:From the margins of accounting to the core of accountability
Due to the policies introduced by many European governments since the rise of New Public Management in the 1990s, performance measurement has become the dominant means of government control of publicly funded organizations. As a result, publicly funded organizations have been increasingly asked to account to external stakeholders based on quantitative performance measures. Inspired by the economic logic of the business sector, such supposedly objective performance measures have been uncritically applied to all public sector organizations, including those whose value and quality are hardly quantifiable, such as arts organizations. Based on a thorough study of relevant literatures and an in-depth case study of a publicly funded opera company, ‘Performance Evaluation in The Arts’ shows that the rules and procedures of accountability imposed by governments are unable to grasp the core value that arts organizations produce for their stakeholders; i.e., their artistic value. Artistic value is co-determined by all those involved in the processes of artistic creation and distribution - staff, audience, press and peers – and is evaluated by the artistic, administrative and technical managers of arts organizations through information that is largely unwritten, mainly qualitative, and often tacit. Before implementing new accountability rules and procedures, governments should seek to understand the nature of the work processes and their evaluation within arts organizations. Only rules and procedures of accountability which mirror the reality of artistic work and, thereby, provide arts organizations with an artistic language to account for their contribution to society, are likely to be relevant to such organizations and their stakeholders
Performance evaluation in the arts:From the margins of accounting to the core of accountability
Self-similar transport processes in a two-dimensional realization of multiscale magnetic field turbulence
We present the results of a numerical investigation of charged-particle
transport across a synthesized magnetic configuration composed of a constant
homogeneous background field and a multiscale perturbation component simulating
an effect of turbulence on the microscopic particle dynamics. Our main goal is
to analyze the dispersion of ideal test particles faced to diverse conditions
in the turbulent domain. Depending on the amplitude of the background field and
the input test particle velocity, we observe distinct transport regimes ranging
from subdiffusion of guiding centers in the limit of Hamiltonian dynamics to
random walks on a percolating fractal array and further to nearly diffusive
behavior of the mean-square particle displacement versus time. In all cases, we
find complex microscopic structure of the particle motion revealing long-time
rests and trapping phenomena, sporadically interrupted by the phases of active
cross-field propagation reminiscent of Levy-walk statistics. These complex
features persist even when the particle dispersion is diffusive. An
interpretation of the results obtained is proposed in connection with the
fractional kinetics paradigm extending the microscopic properties of transport
far beyond the conventional picture of a Brownian random motion. A calculation
of the transport exponent for random walks on a fractal lattice is advocated
from topological arguments. An intriguing indication of the topological
approach is a gap in the transport exponent separating Hamiltonian-like and
fractal random walk-like dynamics, supported through the simulation.Comment: 10 pages (including cover page), 7 figures, improved content,
accepted for publication in Physica Script
Spontaneous Synchronization in Two Mutually Coupled Memristor-Based Chua’s Circuits: Numerical Investigations
Chaotic dynamics of numerous memristor-based circuits is widely reported in literature. Recently, some works have appeared which study the problem of synchronization control of these systems in a master-slave configuration. In the present paper, the spontaneous dynamic behavior of two chaotic memristor-based Chua’s circuits, mutually interacting through a coupling resistance, was studied via computer simulations in order to study possible self-organized synchronization phenomena. The used memristor is a flux controlled memristor with a cubic nonlinearity, and it can be regarded as a time-varying memductance. The memristor, in effect, retains memory of its past dynamic and any difference in the initial conditions of the two circuits results in different values of the corresponding memductances. In this sense, due to the memory effect of the memristor, even if coupled circuits have the same parameters they do not constitute two completely identical chaotic oscillators. As is known, for nonidentical chaotic systems, in addition to complete synchronizations (CS) other weaker forms of synchronization which provide correlations between the signals of the two systems can also occur. Depending on initial conditions and coupling strength, both chaotic and nonchaotic synchronization are observed for the system considered in this work
An algebraic derivative-based approach for the zero-crossings estimation
International audienceA new approach to the design of a zero-crossings estimation algorithm is proposed. The approach uses elementary differential algebraic operations in the frequency domain for accu- rate derivative estimation. Such estimates are composed of iterated integrals of noisy observed signal. A detector-signal, which is exactly equal to zero when there is no intersection between the observed signal and the real axis and is greater than zero when a zero-crossing occurs, is obtained. To justify the theoretical analysis and to investigate the performances of the developed method, simulated experiments are performed
Performance evaluation in the arts:From the margins of accounting to the core of accountability
Comparison between early-onset and late-onset alzheimer's disease patients with amnestic presentation: CSF and 18F-FDG PET study
BACKGROUND/AIMS
To investigate the differences in brain glucose consumption between patients with early onset of Alzheimer's disease (EOAD, aged ≤65 years) and patients with late onset of Alzheimer's disease (LOAD, aged >65 years).
METHODS
Differences in brain glucose consumption between the groups have been evaluated by means of Statistical Parametric Mapping version 8, with the use of age, sex, Mini-Mental State Examination and cerebrospinal fluid values of AÎ’1-42, phosphorylated Tau and total Tau as covariates in the comparison between EOAD and LOAD.
RESULTS
As compared to LOAD, EOAD patients showed a significant decrease in glucose consumption in a wide portion of the left parietal lobe (BA7, BA31 and BA40). No significant differences were obtained when subtracting the EOAD from the LOAD group.
CONCLUSIONS
The results of our study show that patients with EOAD show a different metabolic pattern as compared to those with LOAD that mainly involves the left parietal lobe
A Large Family with p.Arg554His Mutation in ABCD1: Clinical Features and Genotype/Phenotype Correlation in Female Carriers
X-linked adrenoleukodystrophy (X-ALD, OMIM #300100) is the most common peroxisomal disorder clinically characterized by two main phenotypes: adrenomyeloneuropathy (AMN) and the cerebral demyelinating form of X-ALD (cerebral ALD). The disease is caused by defects in the gene for the adenosine triphosphate (ATP)-binding cassette protein, subfamily D (ABCD1) that encodes the peroxisomal transporter of very-long-chain fatty acids (VLCFAs). The defective function of ABCD1 protein prevents β-oxidation of VLCFAs, which thus accumulate in tissues and plasma, to represent the hallmark of the disease. As in many X-linked diseases, it has been routinely expected that female carriers are asymptomatic. Nonetheless, recent findings indicate that most ABCD1 female carriers become symptomatic, with a motor disability that typically appears between the fourth and fifth decade. In this paper, we report a large family in which affected males died during the first decade, while affected females develop, during the fourth decade, progressive lower limb weakness with spastic or ataxic-spastic gait, tetra-hyperreflexia with sensory alterations. Clinical and genetic evaluations were performed in nine subjects, eight females (five affected and three healthy) and one healthy male. All affected females were carriers of the c.1661G>A (p.Arg554His, rs201568579) mutation. This study strengthens the relevance of clinical symptoms in female carriers of ABCD1 mutations, which leads to a better understanding of the role of the genetic background and the genotype-phenotype correlation. This indicates the relevance to include ABCD1 genes in genetic panels for gait disturbance in women
Decipher non-canonical SPAST splicing mutations with the help of functional assays in patients affected by spastic paraplegia 4 (SPG4)
Flowchart showing the molecular approach used to decipher the non-canonical splicing mutations
Validation of the REM behaviour disorder phenoconversion-related pattern in an independent cohort
Background: A brain glucose metabolism pattern related to phenoconversion in patients with idiopathic/isolated REM sleep behaviour disorder (iRBDconvRP) was recently identified. However, the validation of the iRBDconvRP in an external, independent group of iRBD patients is needed to verify the reproducibility of such pattern, so to increase its importance in clinical and research settings. The aim of this work was to validate the iRBDconvRP in an independent group of iRBD patients. Methods: Forty iRBD patients (70 ± 5.59 years, 19 females) underwent brain [18F]FDG-PET in Seoul National University. Thirteen patients phenoconverted at follow-up (7 Parkinson disease, 5 Dementia with Lewy bodies, 1 Multiple system atrophy; follow-up time 35 ± 20.56 months) and 27 patients were still free from parkinsonism/dementia after 62 ± 29.49 months from baseline. We applied the previously identified iRBDconvRP to validate its phenoconversion prediction power. Results: The iRBDconvRP significantly discriminated converters from non-converters iRBD patients (p = 0.016; Area under the Curve 0.74, Sensitivity 0.69, Specificity 0.78), and it significantly predicted phenoconversion (Hazard ratio 4.26, C.I.95%: 1.18–15.39). Conclusions: The iRBDconvRP confirmed its robustness in predicting phenoconversion in an independent group of iRBD patients, suggesting its potential role as a stratification biomarker for disease-modifying trials.</p
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