36 research outputs found
Wave-current interaction in the Porto di Lido entrance of the Venice Lagoon
No full textThe wave propagation and flow modules of the TELEMAC system have been applied to the “Porto di Lido” entrance of the Venice Lagoon. Wave-current interactions were analysed by direct coupling of the phase-averaged model TOMAWAC and of the two-dimensional depth-averaged flow TELEMAC 2D model. ARTEMIS software was separately applied to estimate the effect of refraction.
The model includes the “Porto di Lido” entrance, one of the three channels connecting the Lagoon and the Adriatic Sea. The aim of the analysis is to evaluate the wave climate and the harbour tranquillity of a planned landing cruise, recently proposed in order to prevent the cruise ships from entering the Lagoon and mooring near San Marco. Several tests were performed and the results permit a comparison between the present condition and a future scenario including the planned terminal (landing cruise)
A SHORT SURVEY ON CHAOTIC DYNAMICS IN SOLOW-TYPE GROWTH MODELS
No full textIn 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); B�hm 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
Some special cases on Stolarsky’s means
No full textIn this paper we observe that one-parameter Stolarsky’s means (SM) are deduced from both the Mean Value Theorem for derivatives (MVTD) and the Mean Value Theorem for definite integrals (MVTI), and we study their elementary properties as the parameter varies. In the subfamily of SM having a natural number as parameter, we geometrically interpret one of them in particular as a real elliptic cone. We link SM having the integer power of a prime number as a parameter to classical means (i.e., harmonic mean, geometric mean, arithmetic mean, power mean). Finally, from an extension of Flett's Theorem (FT), we derive the expression of a new mean that is a upper bound of the arithmetic mean
Una rassegna su alcuni modelli di crescita economica tipo Solow con dinamica caotica
No full textIn 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
Una rassegna su alcuni modelli di crescita economica tipo Solow con dinamica caotica
No full textIn 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
Invasive neurostimulation
No full textChronic migraine afflicts 1-5% of the global population and poses a substantial burden on subjects’ quality of life and on health services utilization [1]. Although most patients benefit from abortive and preventive drugs, a subgroup of patients remains refractory to treatment. Refractory chronic migraine is one of the greatest chal- lenges in headache medicine and, in these patients, inva- sive techniques should be considered.
In the past 20 years neuromodulatory approaches, already proved effective in other chronic pain syndromes, have been increasingly used for refractory primary headaches.
Neuromodulation, a reversible and adjustable manipula- tion of pain pathways is an evidence-based invasive treat- ment for chronic pain conditions and it may be applied to any neural structure: spinal cord, deep brain, and periph- eral nerves.
Recently, three 12-week follow-up prospective, rando- mised trials have been conducted to validate occipital nerve stimulation in chronic migraine and intractable chronic migraine associated to occipital localization of pain. Considering the primary outcomes (50% reduction in pain intensity, 50% decrease of headache days) all the three trials have failed. In one of these studies [2], although the second follow-up at 52 weeks has shown important effects on pain severity, headache days, HIT-6 and MIDAS scores (60% of patients achieved 30% reduction in headache days and/or pain, 50% achieved 50% reduction in headache days and/or pain, 70% reported excellent or good headache relief and improved QoL, 70% would undergo the procedure again), it has also shown high incidence of adverse events related to the procedure (70% of patients experienced at least one
* Correspondence: [email protected]
1Department of Medical-Surgical Sciences and Traslational Medicine, Sapienza University of Rome, Sant’Andrea Hospital, Rome, Italy
Full list of author information is available at the end of the article
AE, 41% of AEs required supplemental surgery, 8.6% of AEs required hospitalization).
A more recent prospective, open-label, exploratory study [3] assessing the long-term (6-months) safety, tolerability and efficacy of cervical high frequency (10 kHz), paresthe- sia-free, spinal cord stimulation in a cohort of 14 refrac- tory chronic migraine patients (refractory also to Onabotulinumtoxin-A) has shown good results on reduc- tion of headache days, medication intake, HIT-6 and MIDAS scores. The patients were carefully selected, for refractory chronic migraine, not considering topographic criteria for localization of pain, and were assessed by two different psychologists before eligibility. A significant reduction in headache days was observed at 24 weeks (average 7.0 days). Seven (50%) subjects recorded a >30% decrease in headache days, while 5 (36%) subjects reported a reduction in headache days greater than 50%. Eight sub- jects (57%) reverted to an episodic pattern of headache (<15 days a month). Medication intake reduced signifi- cantly, and four subjects discontinued triptans. Few adverse events have been reported.
HF10-SCS deserves further clinical investigations to evaluate its possible role in the management of rCM
A Data Envelopment Analysis Approach to the Assessment of Natural Parks’ Economic Efficiency and Sustainability. The Case of Italian National Parks
No full textWilderness protection is a growing necessity for modern societies, and this is particularly true for areas where population density is extremely high, as for example Europe. Conservation, however, implies very high opportunity costs. It is thus crucial to create incentives to efficient management practices, to promote benchmarking and to improve conservation management. In the present paper we propose a methodology based on Data Envelopment Analysis, DEA, a non parametric benchmarking technique specifically developed to assess the relative efficiency of decision-making units. In particular, the objective of the discussed methodology is to assess the relative efficiency of the management units of the protected area and to indicate how it could be improved, by providing a set of guidelines. The main advantage of this methodology is that it allows to assess the efficiency of natural parks’ management not only internally (comparing the performance of the park to itself in time) but also by external benchmarking, thus providing new and different perspectives on potential improvements. Although the proposed methodology is fairly general, we have applied it to the context of Italian National Parks in order to produce a representative case study. Specifically, the choice of adequate cost and benefit indicators is a very important and delicate phase of any benchmark analysis. For this purpose, a questionnaire was used to investigate the opinions of Italian National Parks managers and stakeholders and to define the relevant indicators for the analysis. Finally, relevant policy implications for the case study are given.Data envelopment analysis, Natural park management
Key Environmental Innovations
No full textThis paper is based on empirical research on a taxonomy of technological environmental innovations. It draws on a databank with over 500 examples of new technologies (materials, products, processes and practices) which come with benign environmental effects. The approaches applied to interpreting the datasets are innovation life cycle analysis, and product chain analysis. Main results include the following: 1. Innovations merely aimed at eco-efficienc y do in most cases not represent significant contributions to improving the properties of the industrial metabolism. This can better be achieved by technologies that fulfill the criteria of eco-consistency (metabolic consistency), also called eco-effectiveness. 2. Ecological pressure of a technology is basically determined by its conceptual make-up and design. Most promising thus are technologies in earlier rather than later stages of their life cycle (i.e. during R&D and customisation in growing numbers), because it is during the stages before reaching the inflection point and maturity in a learning curve where technological environmental innovations can best contribute to improving ecological consistency of the industrial metabolism while at the same time delivering their maximum increase in efficiency as well.3. Moreover, environmental action needs to focus on early steps in the vertical manufacturing chain rather than on those in the end. Most of the ecological pressure of a technology is no rmally not caused end-of-chain in use or consumption, but in the more basic steps of the manufacturing chain (with the exception of products the use of which consumes energy, e.g. vehicles, appliances). There are conclusions to be drawn for refocusing attention from downstream to upstream in life cycles and product chains, and for a shift of emphasis in environmental policy from regulation to innovation. Ambitious environmental standards, though, continue to be an important regulative precondition of ecologically benign technological innovation.Technological innovation, Environmental innovation, Life cycle analysis, Sustainability strategies, Environmental policy
