Advocates for education reforms frequently call for policies to increase school efficiency performance. The Greek educational system has undergone several reforms while the recent financial crisis ...alters significantly. Using a unique dataset this study attempts to shed light on 643 Greek secondary education schools’ efficiency performance, over the period 2000–2017, and to perform an investigation of the efficiency determinants in a multilevel framework. Results reveal that there is substantial room for improvements especially for specific Greek NUTS2 regions while the adopted reforms seem to have a very low effect. Our findings also denote a favourable effect for physics, science laboratories, and class size and a significant negative effect for the variable of student per class. In addition, at a second level the gross domestic product per capita of the NUTS2 region that each school belongs positively affects its efficiency performance.
The polyglutamine diseases are caused in part by a gain-of-function mechanism of neuronal toxicity involving protein conformational changes that result in the formation and deposition of β-sheet rich ...aggregates. Recent evidence suggests that the misfolding mechanism is context-dependent, and that properties of the host protein, including the domain architecture and location of the repeat tract, can modulate aggregation. In order to allow the bioinformatic investigation of the context of polyglutamines, we have constructed a database, PolyQ (http://pxgrid.med.monash.edu.au/polyq). We have collected the sequences of all human proteins containing runs of seven or more glutamine residues and annotated their sequences with domain information. PolyQ can be interrogated such that the sequence context of polyglutamine repeats in disease and non-disease associated proteins can be investigated.
This article focuses on gradient-based backpropagation algorithms that use either a common adaptive learning rate for all weights or an individual adaptive learning rate for each weight and apply the ...Goldstein/Armijo line search. The learning-rate adaptation is based on descent techniques and estimates of the local Lipschitz constant that are obtained without additional error function and gradient evaluations. The proposed algorithms improve the backpropagation training in terms of both convergence rate and convergence characteristics, such as stable learning and robustness to oscillations. Simulations are conducted to compare and evaluate the convergence behavior of these gradient-based training algorithms with several popular training methods.
The crystallographic determination of protein structures can be computationally demanding and for difficult cases can benefit from user-friendly interfaces to high-performance computing resources. ...Molecular replacement (MR) is a popular protein crystallographic technique that exploits the structural similarity between proteins that share some sequence similarity. But the need to trial permutations of search models, space group symmetries and other parameters makes MR time- and labour-intensive. However, MR calculations are embarrassingly parallel and thus ideally suited to distributed computing. In order to address this problem we have developed MrGrid, web-based software that allows multiple MR calculations to be executed across a grid of networked computers, allowing high-throughput MR.
MrGrid is a portable web based application written in Java/JSP and Ruby, and taking advantage of Apple Xgrid technology. Designed to interface with a user defined Xgrid resource the package manages the distribution of multiple MR runs to the available nodes on the Xgrid. We evaluated MrGrid using 10 different protein test cases on a network of 13 computers, and achieved an average speed up factor of 5.69.
MrGrid enables the user to retrieve and manage the results of tens to hundreds of MR calculations quickly and via a single web interface, as well as broadening the range of strategies that can be attempted. This high-throughput approach allows parameter sweeps to be performed in parallel, improving the chances of MR success.
GRBNeT is a project aiming at the detection of ultra–high energy neutrinos, for example neutrinos originating from Gamma Ray Bursts. The goal is to design, construct and deploy a prototype unit of an ...autonomous (data/energy–wise) neutrino detector. Being autonomous is crucial since for the detection of ultra–high energy neutrinos a very large volume of water is required. Large scale facilities such as IceCube and KM3NeT are designed to be more sensitive to galactic and diffuse flux neutrinos rather than extragalactic ultra–high energy neutrinos. However, their sensitivity to such neutrinos could be increased by placing around and at larger distances detectors such as the one of the GRBNeT project. This extension would increase the instrumented volume of neutrino telescopes to several cubic kilometres. In addition to that, as no cable connection to the shore is required, GRBNeT detection units cost significantly less than regular detection units and can become a cost effective extension of large scale facilities. For the GRBNeT prototype unit ultra low power electronics have been developed. The response to high energy neutrinos from GRBs and to the atmospheric muon background has been simulated.
In this paper the development, convergence theory and numerical testing of a class of gradient unconstrained minimization algorithms with adaptive stepsize are presented. The proposed class comprises ...four algorithms: the first two incorporate techniques for the adaptation of a common stepsize for all coordinate directions and the other two allow an individual adaptive stepsize along each coordinate direction. All the algorithms are computationally efficient and possess interesting convergence properties utilizing estimates of the Lipschitz constant that are obtained without additional function or gradient evaluations. The algorithms have been implemented and tested on some well-known test cases as well as on real-life artificial neural network applications and the results have been very satisfactory.
Current sheath dynamics is an important parameter for good focusing or pinching in a dense plasma focus device. In this paper, we present pinching evidence and details of the filamentary structure of ...the current sheath in a miniature plasma focus device using a time-resolved laser shadowgraphic technique and time-integrated optical imaging.
In this paper, an alternative optimization strategy incorporating the ideas of lexicographic optimization and evolutionary algorithms is presented. The given optimization problem is approximated by ...others in which priorities are given. Under the sequential optimization method, they are optimized, not exhaustively, in order to produce an initial point for the given problem. An important role in the proposed approach plays the way of generating the involved problems and the given priorities on them. General principles to produce the objective functions of the involved problems are proposed. An algorithm named LexOpt Algorithm, which implements the suggested process, is given. Numerical results via LexOpt Algorithm, on a set of widely used test problems show noticeable promising convergence behaviour of the proposed strategy in comparison with the utilized optimization methods.
Abstract
Background
Few epidemiological data show a worst prognosis of hypertensive emergencies compared with hypertensive urgencies (HU). To the best of our knowledge, there is even fewer published ...evidence comparing prognosis of hypertensive patients (HP) with and without HU.
Purpose
The purpose of our prospective study was to record the prevalence and clinical characteristics of patients with HU assessed in the emergency department (ED) in a tertiary Hospital and to compare them with HP without urgencies for new events and hard-end points for a 12-month follow-up.
Methods
The study population consisted of 256 patients presenting at the ED with acute increase in blood pressure (BP) (systolic BP≥180mmHg and/or diastolic BP≥120mmHg) with absence of acute hypertension-mediated target organ damage in a period of one year. Each of these participants were matched one-to-one by age, gender and history of hypertension with HP with either controlled, grade 1 or grade 2 hypertension attending our Hypertension excellence center the same period. However, 78 of HU did not conclude the follow up and 5 could not be matched with HP for the above covariates and were therefore excluded. Both groups, 173 of HU and 173 of controls, concluded 12 months follow up for fatal and non fatal cardiovascular events, including acute coronary syndrome, stroke, newly diagnosed heart failure or deterioration of NYHA class, and composite end points such as stroke-myocardial infarction and overall cardiovascular disease outcome.
Results
The mean age of all patients was 64.9±12.5 years (64±12.2 for controls and 65.7±12.7 for HU), 48.8% were males (49.1% of controls and 48.6% of HU) and 26.6% had a history of smoking (22.5% of controls and 30.6% of HU). Overall, 15 (5.5%) patients had nonfatal clinical cardiovascular events and 4 (1.2%) had fatal cardiovascular events. Cox regression models were adjusted for age, gender, smoking, previous cardiovascular disease, diabetes mellitus and the population. The frequency of the composite stroke-myocardial infarction event was statistically significant higher in HU (5 vs 4, p<0.0001, Hazard Ratio for HU 181.7, 95% Confidence Intervals 19.7–1677.2) adjusted for the rest covariates. In addition, there was a higher trend for stroke in the group of HU (p=0.067) and in patients with a history of diabetes mellitus irrespective of group (p=0.055). Finally, the Cox regression analysis identified age (p=0.035) and history of cardiovascular disease (p=0.038) as independent predictors for death, and smoking (p=0.035) as independent predictor for overall cardiovascular events.
Conclusions
Our study emphasizes the higher trend for cardiovascular outcomes, especially stroke, in the group of HU compared with HP without urgencies, while it highlights the necessity for more intensive follow-up for the first group and the need for further research in this pathological entity.
Funding Acknowledgement
Type of funding sources: None.
The next generation of water Cherenkov neutrino telescopes in the Mediterranean Sea are under construction offshore France (KM3NeT/ORCA) and Sicily (KM3NeT/ARCA). The KM3NeT/ORCA detector features an ...energy detection threshold which allows to collect atmospheric neutrinos to study flavour oscillation. This paper reports the KM3NeT/ORCA sensitivity to this phenomenon. The event reconstruction, selection and classification are described. The sensitivity to determine the neutrino mass ordering was evaluated and found to be 4.4
σ
if the true ordering is normal and 2.3
σ
if inverted, after 3 years of data taking. The precision to measure
Δ
m
32
2
and
θ
23
were also estimated and found to be
85
.
10
-
6
eV
2
and
(
-
3.1
+
1.9
)
∘
for normal neutrino mass ordering and,
75
.
10
-
6
eV
2
and
(
-
7.0
+
2.0
)
∘
for inverted ordering. Finally, a unitarity test of the leptonic mixing matrix by measuring the rate of tau neutrinos is described. Three years of data taking were found to be sufficient to exclude
event rate variations larger than 20% at
3
σ
level.
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