281 research outputs found
A SHORT SURVEY ON CHAOTIC DYNAMICS IN SOLOW-TYPE GROWTH MODELS
In this paper we review some Solow-type growth models, framed is discrete time, which are able to generate complex dynamic behaviour. For these models ĂŻÂżÂœ put forward by Day (1982, 1983); BĂŻÂżÂœhm and Kaas (2000); and Commendatore (2005) ĂŻÂżÂœ we show that crucial features which could determine the emergence of regular or irregular growth cycles are (i) if the average saving ratio is constant or not; and (ii) the curvature of production function, representing the degree of substitutability between labour and capital. The lower the degree of substitutability, the higher the likelihood of complex behaviour.Logistic Map, Li-York Chaos, Growth Models, Local Stability, Triangle Stability
Una rassegna su alcuni modelli di crescita economica tipo Solow con dinamica caotica
In this paper we review some Solow-type growth models, framed is discrete time, which are able to generate complex dynamic behaviour. For these models put forward by Day (1982, 1983); Böhm and Kaas (2000); and Commendatore (2005) we show that crucial features which could determine the emergence of regular or irregular growth cycles are (i) if the average saving ratio is constant or not; and (ii) the curvature of production function, representing the degree of substitutability between labour and capital. The lower the degree of substitutability, the higher the likelihood of complex behaviour.Logistic Map, Li-York Chaos, Growth Models, Local Stability, Triangle Stability
Integrated Environmental Study for Beach Management: A Methodological Approach
This paper aims to present a project convened by the University of Genoa and Fondazione Eni Enrico Mattei (FEEM), in collaboration with Local Authorities, concerning the development of tools for beach management in the Riviera del Beigua (Liguria Region, Italy). The aim of the first step of the project is to assess the environmental state of resort beaches examining them interdisciplinary, through a data analysis based on a sound understanding of the components of the physical and the human system. The following step will be the treatment of the data, through the use of various instruments, which use a synthesis analysis, such as the traditional SWOT (Strengths, Weaknesses, Opportunities and Threats) analysis, and the use of a set of environmental and socio-economic indicators. Finally, our ultimate target is to propose guidelines, which will supply an instrument to back up policies concerning beach planning and management.Costal management, Sustainable tourist, Integrated assessment, Indicators
Una rassegna su alcuni modelli di crescita economica tipo Solow con dinamica caotica
In this paper we review some Solow-type growth models, framed is
discrete time, which are able to generate complex dynamic behaviour.
For these models put forward by Day (1982, 1983); Böhm and Kaas
(2000); and Commendatore (2005) we show that crucial features which
could determine the emergence of regular or irregular growth cycles
are (i) if the average saving ratio is constant or not; and (ii) the
curvature of production function, representing the degree of
substitutability between labour and capital. The lower the degree of
substitutability, the higher the likelihood of complex behaviour
Effetti della pandemia da covid-19 e della Didattica a Distanza (DAD) sulle abilitĂ di lettura in bambini normo-lettori
Due to covid-19 pandemic, in February 2020 Italian government decided to take action in order to reduce physical contact and contain the spread of the virus; among the other measures, face-to-face teaching was suspended. All along 2020 and for the major part of 2021 online teaching replaced face-to-face teaching. Teachers and parents were unprepared for this kind of didactic activities and online modality varied during the lockdown months and among different schools. Different studies analyzed the outcome of these online modalities, mostly on pathological samples (Baschenis et al., 2021). We conducted a longitudinal study in order to investigate whether online teaching had a negative effect on reading skills development in Italian children typical readers. We recruited forty-nine children from a primary school in Alessandria (Piedmont, Italy) and assessed their reading skills before (T1) and after (T2) covid-19 pandemic. All children with learning disabilities, cognitive and sensory impairments were excluded from our sample. Children attended third grade at T1 and fifth grade at T2. We evaluated reading speed, accuracy and comprehension; data from existing literature has been used to confront our sample with the population of children typical readers. We compared the results obtained at T1 and T2; our findings show that our sample reached the expected improvement in reading fluency. The subjects obtained a significant improvement in reading comprehension as well, but existing data are insufficient to determine if the improvement reached by our sample is the same as expected. Therefore, we can state that online teaching has not worsened reading skills development in typical readers
A six year retrospective review of occipital nerve stimulation practice--controversies and challenges of an emerging technique for treating refractory headache syndromes
BACKGROUND: A retrospective review of patients treated with Occipital Nerve Stimulation (ONS) at two large tertiary referral centres has been audited in order to optimise future treatment pathways.
METHODS: Patient's medical records were retrospectively reviewed, and each patient was contacted by a trained headache expert to confirm clinical diagnosis and system efficacy. Results were compared to reported outcomes in current literature on ONS for primary headaches.
RESULTS: Twenty-five patients underwent a trial of ONS between January 2007 and December 2012, and 23 patients went on to have permanent implantation of ONS. All 23 patients reached one-year follow/up, and 14 of them (61%) exceeded two years of follow-up. Seventeen of the 23 had refractory chronic migraine (rCM), and 3 refractory occipital neuralgia (ON). 11 of the 19 rCM patients had been referred with an incorrect headache diagnosis. Nine of the rCM patients (53%) reported 50% or more reduction in headache pain intensity and or frequency at long term follow-up (11-77 months). All 3 ON patients reported more than 50% reduction in pain intensity and/or frequency at 28-31 months. Ten (43%) subjects underwent surgical revision after an average of 11 ± 7 months from permanent implantation - in 90% of cases due to lead problems. Seven patients attended a specifically designed, multi-disciplinary, two-week pre-implant programme and showed improved scores across all measured psychological and functional parameters independent of response to subsequent ONS.
CONCLUSIONS: Our retrospective review: 1) confirms the long-term ONS success rate in refractory chronic headaches, consistent with previously published studies; 2) suggests that some headaches types may respond better to ONS than others (ON vs CM); 3) calls into question the role of trial stimulation in ONS; 4) confirms the high rate of complications related to the equipment not originally designed for ONS; 5) emphasises the need for specialist multidisciplinary care in these patients
An Innovative Methodological Approach for Monitoring and Chemical Characterization of Odors around Industrial Sites
This study aims to highlight the potentialities of an innovative methodological approach for monitoring and chemical characterization of odors, especially in high concern and complex industrial areas. The proposed approach was developed in order to monitor and identify odor-active compounds responsible for odor annoyance coming from different industrial activities such as landfills, wastewater treatment plants, and petroleum plants. The methodology's strengths are as follows: (1) the tailored approach for each typology of industrial areas/sites; (2) integration of technologies able to provide real-time information about the emissive sources; (3) mapping of air pollutants on the territory aimed to identify and discriminate among different fugitive emissions responsible for odor annoyance; (4) collection of more representative air samples only during the nuisance events, thanks to the implementation of innovative sampling systems and citizens' involvement; and (5) increased analytical sensitivity in odor-active VOCs detection. This methodology reveals to be a useful tool to collect real-time information about the emission sources and their impacts on the surrounding area giving credit to citizens' complaints. Moreover, it allows to overcome the limitations of the conventional approaches related to the lack of instrumental sensitivity and to identify the chemical compounds contributing to the odor annoyance
A meta-analysis to estimate the ârealâ placebo effect in juvenile idiopathic arthritis (JIA) trials
- âŠ