Search results for "Modelli"

A mathematical model of cardiovascular dynamics for the diagnosis and prognosis of hemorrhagic shock

2020

Abstract A variety of mathematical models of the cardiovascular system have been suggested over several years in order to describe the time-course of a series of physiological variables (i.e. heart rate, cardiac output, arterial pressure) relevant for the compensation mechanisms to perturbations, such as severe haemorrhage. The current study provides a simple but realistic mathematical description of cardiovascular dynamics that may be useful in the assessment and prognosis of hemorrhagic shock. The present work proposes a first version of a differential-algebraic equations model, the model dynamical ODE model for haemorrhage (dODEg). The model consists of 10 differential and 14 algebraic e…

Enhanced prediction of hemoglobin concentration in a very large cohort of hemodialysis patients by means of deep recurrent neural networks.

2019

Erythropoiesis Stimulating Agents (ESAs) have become a standard anemia management tool for End Stage Renal Disease (ESRD) patients. However, dose optimization constitutes an extremely challenging task due to huge inter and intra-patient variability in the responses to ESA administration. Current data-based approaches to anemia control focus on learning accurate hemoglobin prediction models, which can be later utilized for testing competing treatment choices and choosing the optimal one. These methods, despite being proven effective in practice, present several shortcomings which this paper intends to tackle. Namely, they are limited to a small cohort of patients and, even then, they fail to…

A Multivariate Age-Structured Stochastic Model with Immunization Strategies to Describe Bronchiolitis Dynamics

2021

Bronchiolitis has a high morbidity in children under 2 years old. Respiratory syncytial virus (RSV) is the most common pathogen causing the disease. At present, there is only a costly humanized monoclonal RSV-specific antibody to prevent RSV. However, different immunization strategies are being developed. Hence, evaluation and comparison of their impact is important for policymakers. The analysis of the disease with a Bayesian stochastic compartmental model provided an improved and more natural description of its dynamics. However, the consideration of different age groups is still needed, since disease transmission greatly varies with age. In this work, we propose a multivariate age-struct…

Transcatheter indirect mitral annuloplasty induces annular and left atrial remodelling in secondary mitral regurgitation

2020

Abstract Aims Mitral annuloplasty using the Carillon Mitral Contour System (CMCS) reduces secondary mitral regurgitation (SMR) and leads to reverse left ventricular remodelling. The aim of this study was to evaluate the effect of the CMCS on the mitral valve annulus (MA) and left atrial volume (LAV). Methods and results We retrospectively evaluated the data of all patients treated with the CMCS at our centre. Using transthoracic echocardiography, MA diameters were assessed by measuring the anterolateral to posteromedial extend (ALPM) and the anterior to posterior (AP) dimensions, respectively. Also, LAV and left ventricular end‐diastolic volume (LVEDV) were assessed. Patients were examined …

Characterisation of the Degree of Musical Non-Markovianity

2022

As an aid for musical analysis, in computational musicology mathematical andinformatics tools have been developed to characterise quantitatively some aspectsof musical compositions. A musical composition can be attributed by ear a certainamount of memory. These results are associated with repetitions and similarities ofthe patterns in musical scores. To higher variations, a lower amount of memory isperceived. However, the musical memory of a score has never been quantitativelydefined. Here we aim to give such a measure following an approach similar tothat used in physics to quantify the memory (non-Markovianity) of open quantumsystems. We apply this measure to some existing musical composit…

Modelling of mercury emissions from large solid fuel combustion and biomonitoring in Cz-Pl border region

2016

Tightening of norms for air protection leads to a development of new and significantly more effective techniques for removing particulate matter, SOx and NOx from flue gas which originates from large solid fuel combustion. Recently, it has been found that combinations of these environmental technologies can also lead to the reduction of mercury emissions from coal power plants. Now the greatest attention is paid especially to the coal power plant in Opatovice nad Labem, close to Hradec Kralove. Its system for flue gas dedusting was replaced by a modern type of cloth fabric filter with the highest particle separation efficiency which belongs to the category of BAT. Using this technology, tog…

NONEQUILIBRIUM PHENOMENA AND METASTABILITY IN MESOSCOPIC AND QUANTUM SYSTEMS

2020

Here we summarize some relevant results related to nonequilibrium phenomena in mesoscopic and quantum systems. A common phenomenon in the dynamics of out-of-equilibrium systems is the metastability, and the problem of the lifetime of metastable states involves fundamental aspects of nonequilibrium statistical mechanics. Metastability (see Fig. 1) is a signature of a first order phase transition, often characterized by a long-living metastable state. In particular, the stability of a metastable state can be enhanced by Gaussian and non-Gaussian noise sources. This counterintuitive effect has been found in different physical areas, ranging from spintronics, aggregation kinetics of Brownian pa…

Metodi adattativi e modelli multi agente per la valutazione del comfort indoor

2008

Predicting stiffness and strength of birch pulp:Polylactic acid composites

2016

This paper studies failure of birch pulp–polylactic acid composites. Stiffness and strength are calculated using the theory of short fibre composites and the results are compared to experimental data. The results differed from the experimental values by 0–6%. With less aligned fibres the short fibre theory is not feasible. The performance of the 40 wt% birch pulp – polylactic acid composite is predicted with X-ray microtomography based finite element modelling, and the results are compared with experiments. Stiffness results differed from experiments by 1–17% . By adding into the models a third material phase representing the interface between the fibres and the matrix, the stress–strain c…

Quel statut pour les espaces de montagne durant l'âge du Bronze ? Regards croisés sur les approches société-environnement dans les Pyrénées occidenta…

2005

After having been neglected for some time, mountain environments have now become an important research area for the study of anthropogenic impact on the environment and the interactions of societies with their environments. The recent development of several interdisciplinary programs in the Alps and in the Pyrenees reveals the interest and the scientific questions associated with these domains. In the Pyrenees, the work undertaken in the Basque Country illustrates the utility of the development of multidisciplinary research on a large scale, which is both diachronic and has a high resolution chronology. Combining environmental and archaeological data, allows us to present an image of popula…