Cooperazione e competizione nello sfruttamento di una risorsa rinnovabile

In this paper we propose a static model describing the commercial exploitation of a common property renewable resource by a population of agents. Players can cooperate or compete; cooperators maximize the utility of their group while defectors maximize their own profit. Agents aren't assumed to be divided into the two groups from the beginning; by solving the static game we obtained the best response function of i-th player without making other agents positions. Then, the Nash equilibria we calculated point out how different strategies - all the players cooperate, all the players compete or players can be divided into cooperators and defectors - can coexist.Resource Exploitation, Game theory

Determinazione di strategie nello sfruttamento di una risorsa rinnovabile

In this paper we propose a static model describing the commercial exploitation of a common property renewable resource by a population of agents. Players can cooperate or compete; cooperators maximize the utility of their group while defectors maximize their own profit. The model provide for one utility function which can be used for every kind of player. Agents aren't assumed to be divided into the two groups from the beginning; by solving the static game we obtained the best response function of i-th player without making other agents positions. Then, the Nash equilibria we calculated point out how different strategies - all the players cooperate, all the players compete or players can be divided into cooperators and defectors - can coexist. In any case we have analyzed, it's possible to observe how the total harvest depend on renewable resource stock, and how it influences agents' positions. Keywords Resource Exploitation, Game Theory

Use of the iliac-outlet and iliac-inlet combined views in percutaneous posterior column retrograde screw fixation

Posterior column fractures are common acetabular injuries. Although displaced fractures require open reduction and fixation, undisplaced patterns may benefit from percutaneous screw fixation. The combination of iliac oblique with inlet and outlet views offers an intuitive and panoramic rendering of the bony corridor into the posterior column; lateral cross table view completes the sequence of fluoroscopic projections. Herein we describe the use of outlet/inlet iliac views and a detailed procedure for percutaneous retrograde posterior column screw fixation

Endosteal plating for the treatment of malunions and nonunions of distal femur fractures

PurposeTo describe the surgical technique and the outcome of a case series of nonunion and malunion of distal femur fractures treated with an endosteal medial plate combined with a lateral locking plate and with autogenous bone grafting. MethodsWe retrospectively analyzed a series of patients with malunion or nonunion of the distal femur treated with a medial endosteal plate in combination with a lateral locking plate, in a period between January 2011 and December 2019, Database from chart review was obtained including all the clinical relevant available baseline data (demographics, type of fracture, mechanism of injury, time from injury to surgery, number of previous surgical procedures, type of bone graft, and type of lateral plate). Time to bone healing, limb alignment at follow-up and complications were documented. ResultsTen patients were included into the study: 7 male and 3 female with mean age of 48.3 years (range 21-67). The mechanism of trauma was in 8 cases a road traffic accident and in 2 cases a fall from height. According to AO/OTA classification 5 fractures were 33 A3, 3 were 33 C1, 1 was 33 C2 and 1 was 33 C3. The average follow up was 13.5 months. In all cases but one bony union was achieved. Bone healing was observed in average 3.3 months after surgery. No intraoperative or postoperative complications were reported. ConclusionA medial endosteal plate is a useful augmentation for lateral plate fixation in nonunion or malunion following distal femur fractures, particularly in cases of medial bone loss, severe comminution, or poor bone quality

Foscolo critico

Il volume, primo della collana open access dei "Quaderni di Gargnano", ospita i contributi presentati al XV Convegno internazionale di Letteratura italiana "Gennaro Barbarisi", tenutosi a Gargnano del Garda dal 24 al 26 settembre 2012. Il "Quaderno", dedicato al Foscolo critico, accoglie contributi di Giovanni Biancardi, Arnaldo Bruni, Andrea Campana, Massimo Castellozzi, Gustavo Costa, Alfredo Cottignoli, Christian Del Vento, Sandro Gentili, Franco Longoni, Ilaria Mangiavacchi, Donatella Martinelli, Giuseppe Natale, Enzo Neppi, Matteo Palumbo, Elena Parrini Cantini, Chiara Piola Caselli. \uc8 aperto da una Prefazione di Claudia Berra, Paolo Borsa e Giulia Ravera.This volume on "Foscolo critico" is the first volume of the "Quaderni di Gargnano", an open access book series which publishes the Proceedings of the "Gennaro Barbarisi" International Conferences on Italian Literature, held in Gargnano del Garda. It contains contributions by Giovanni Biancardi, Arnaldo Bruni, Andrea Campana, Massimo Castellozzi, Gustavo Costa, Alfredo Cottignoli, Christian Del Vento, Sandro Gentili, Franco Longoni, Ilaria Mangiavacchi, Donatella Martinelli, Giuseppe Natale, Enzo Neppi, Matteo Palumbo, Elena Parrini Cantini, Chiara Piola Caselli, preceded by a Preface by the Editor: Claudia Berra, Paolo Borsa, Giulia Ravera

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Competition and Cooperation in a dynamical model of natural resources.

In this paper, we propose a model describing the commercial exploitation of a common renewable resource by a population of strategically interacting agents. Players can cooperate or compete; cooperators maximize the payoff of their group while defectors maximize their own profit. The partition of the players into two groups, defectors and cooperators, results from the players’ choices, so it is not predetermined. This partition is decided as a Nash equilibrium of a static game. It is shown that different types of players can exist in an equilibrium; more precisely, depending on the parameter values such as resource stock, cost, and so on, there might be equilibria only with defectors, cooperators, or with a combination of cooperators and defectors. In any case the total harvest depends on the renewable resource stock, so it influences agents’ positions. It is assumed that at each time period the agents harvest according to Nash equilibrium, which can be combined with a dynamic model describing the evolution of fish population. A complete analysis of the equilibria is presented and their stability is analysed. The effect of the different Nash equilibria on the stability of the fish stock, showing that full cooperation is the most stable case, is examined. Key Words: Nash equilibria, resource exploitation, population dynamics

Fondamenti di Matematica

Il capitolo propone un'ampia rivisitazione dei diversi argomenti di analisi matematica ed elementi di costruzione di algoritmi e calcolo computazionale necessari nella formazione di colui che si occupa di big data

Sharing R&D Investments in International Environmental Agreements with Asymmetric Countries

This paper studies the coalition formation and the stability of the International Environmental Agreements (IEAs) in a pollution abatement dynamic model. We point out two meaningful aspects of this topic. Firstly, we consider asymmetry among countries, dividing them into two types: developed countries with a considerable environmental awareness and developing ones that pay less attention to environmental preservation. In addition, the former have a high-technology industry that allows for a unit abatement cost lower than the latter, and that are characterized by a labour-intensive industrial structure. Secondly, we introduce a positive externality in the cooperation by considering the R&amp;D investment as two costs, namely the research investment and the developing cost. We assume that countries can coordinate their R&amp;D activities by sharing their fixed research investments in order to avoid duplication of green activities. Moreover, by collaborating developing efforts, cooperators benefit from a reduction of a unit abatement cost higher than defectors. On the other hand, although non-cooperators completely support R&amp;D investments for clean technologies, they realize lower abatements and benefits of a spillover effect due to development investments realized by cooperators. These two aspects could encourage the formation of stable coalitions