162 research outputs found
"Stile e composizione degli Encomi di Clemente di Ocrida". Saggio di traduzione e commento
La presente tesi di dottorato analizza lo stile individuale di Clemente di Ocrida e la composizione interna dei nove Encomi clementini sulla cui paternit\ue0 non paiono sussistere dubbi: gli encomi per il profeta Zaccaria e la nascita di Giovanni Battista, per Demetrio di Tessalonica, per gli arcangeli Michele e Gabriele, per Clemente papa, per Giovanni Battista, per Cirillo, per i Quaranta martiri di Sebaste, per il santo Lazzaro e per la Dormizione della Vergine Maria.Italian
Elimination of unoccupied state summations in it ab initio self-energy calculations for large supercells
We present a new method for the computation of self-energy corrections in large supercells. It eliminates the explicit summation over unoccupied states, and uses an iterative scheme based on an expansion of the Green's function around a set of reference energies. This improves the scaling of the computational time from the fourth to the third power of the number of atoms for both the inverse dielectric matrix and the self-energy, yielding improved efficiency for 8 or more silicon atoms per unit cell
Transition to Stochastic Synchronization in Spatially Extended Systems
Spatially extended dynamical systems, namely coupled map lattices, driven by
additive spatio-temporal noise are shown to exhibit stochastic synchronization.
In analogy with low-dymensional systems, synchronization can be achieved only
if the maximum Lyapunov exponent becomes negative for sufficiently large noise
amplitude. Moreover, noise can suppress also the non-linear mechanism of
information propagation, that may be present in the spatially extended system.
A first example of phase transition is observed when both the linear and the
non-linear mechanisms of information production disappear at the same critical
value of the noise amplitude. The corresponding critical properties can be
hardly identified numerically, but some general argument suggests that they
could be ascribed to the Kardar-Parisi-Zhang universality class. Conversely,
when the non-linear mechanism prevails on the linear one, another type of phase
transition to stochastic synchronization occurs. This one is shown to belong to
the universality class of directed percolation.Comment: 21 pages, Latex - 14 EPS Figs - To appear on Physical Review
Effects of metformin and exercise training, alone or in association, on cardio-pulmonary performance and quality of life in insulin resistance patients
BACKGROUND:
Metformin (MET) therapy exerts positive effects improving glucose tolerance and preventing the evolution toward diabetes in insulin resistant patients. It has been shown that adding MET to exercise training does not improve insulin sensitivity. The aim of this study was to determine the effect of MET and exercise training alone or in combination on maximal aerobic capacity and, as a secondary end-point on quality of life indexes in individuals with insulin resistance.
METHODS:
75 insulin resistant patients were enrolled and subsequently assigned to MET (M), MET with exercise training (MEx), and exercise training alone (Ex). 12-weeks of supervised exercise-training program was carried out in both Ex and MEx groups. Cardiopulmonary exercise test and SF-36 to evaluate Health-Related Quality of Life (HRQoL) was performed at basal and after 12-weeks of treatment.
RESULTS:
Cardiopulmonary exercise test showed a significant increase of peak VO2 in Ex and MEx whereas M showed no improvement of peak VO2 (∆ VO2 [CI 95%] Ex +0.26 [0.47 to 0.05] l/min; ∆ VO2 MEx +0.19 [0.33 to 0.05] l/min; ∆ VO2 M -0.09 [-0.03 to -0.15] l/min; M vs E p < 0.01; M vs MEx p < 0.01; MEx vs Ex p = ns). SF-36 highlighted a significant increase in general QoL index in the MEx (58.3 ± 19 vs 77.3 ± 16; p < 0.01) and Ex (62.1 ± 17 vs 73.7 ± 12; p < 0.005) groups.
CONCLUSIONS:
We evidenced that cardiopulmonary negative effects showed by MET therapy may be counterbalanced with the combination of exercise training. Given that exercise training associated with MET produced similar effects to exercise training alone in terms of maximal aerobic capacity and HRQoL, programmed exercise training remains the first choice therapy in insulin resistant patients
The CARSO (Computer Aided Response Surface Optimization) Procedure in Optimization Studies
The paper illustrates innovative ways of using the CARSO (Computer Aided Response Surface Optimization)
procedure for response surfaces analyses derived by DCM4 experimental designs in
multivariate spaces. Within this method, we show a new feature for optimization studies: the results
of comparing their quadratic and linear models for discussing the best way to compute the
most reliable predictions of future compound
Effects of metformin and exercise training, alone or in combination, on cardiac function in individuals with insulin resistance
Introduction: In patients affected by insulin resistance (IR), metformin (MET) therapy has been shown to exert its positive effects by improving glucose tolerance and preventing the evolution to diabetes. Recently, it was shown that the addition of metformin to physical training did not improve sensitivity to insulin or peak oxygen consumption (peak VO2). The purpose of this study was to establish the effect of metformin and exercise, separately or in combination, on systolic left ventricular (LV) function in individuals with IR.
Methods: Seventy-five patients with IR were enrolled and subsequently assigned to MET, combination MET and exercise, or exercise alone. The LV systolic and diastolic functions were evaluated with standard echocardiography tissue Doppler imaging (TDI) and speckle tracking echocardiography at baseline and after 12 weeks of treatment.
Results: MET, administered alone or in association with exercise, improved longitudinal LV function, as evidenced by an increase in systolic (S) wave on TDI, alongside increases in longitudinal global strain and strain rate in comparison to the group undergoing physical training alone. The traditional echocardiographic parameters showed no statistically significant differences among the three groups before or after the different cycles of therapy.
Conclusions: Treatment with MET, either with or without exercise, but not exercise alone, produced a significant increase in global longitudinal LV systolic function at rest. These findings validate the observation that the use of MET alone or in association with exercise has a crucial role to counteract the negative effects of IR on cardiovascular function
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