Self-Commitment-Institutions and Cooperation in Overlapping Generations Games

This paper focuses on a two-period OLG economy with public imperfect observability over the intergenerational cooperative dimension. Individual endowment is at free disposal and perfectly observable. In this environment we study how a new mechanism, we call Self-Commitment-Institution (SCI), outperforms personal and community enforcement in achieving higher ex-ante e¢ciency. Social norms with and without SCI are characterized. If social norms with SCI are implemented, agents might freely dispose of their endowment. As long as they reduce their marginal gain from deviation in terms of current utility, they also credibly self-commit on intergenerational cooperation. Under quite general conditions we find that, even if individual strategies are still characterized by behavioral uncertainty, the introduction of SCI relaxes the inclination toward opportunistic behavior and sustains higher e¢ciency compared to social norms without SCI. We quantify the value of SCI and investigate the role of memory with di§erent social norms. Finally, applications on intergenerational public good games and transfer games with productive SCI are provided

A Dynamic Politico-Economic Model of Intergenerational Contracts

This paper investigates the conditions for the emergence of implicit intergenerational contracts without assuming reputation mechanisms, commitment technology and altruism. We present a tractable dynamic politico-economic model in OLG environment where politicians play Markovian strategies in a probabilistic voting environment, setting multidimensional political agenda. Both backward and forward intergenerational transfers, respectively in the form of pension benefits and higher education investments, are simultaneously considered in an endogenous human capital setting with labor income taxation. On one hand, social security sustains investment in public education; on the other hand investment in education creates a dynamic linkage across periods through both human and physical capital driving the economy toward dierent Welfare State Regimes. Embedding a repeated-voting setup of electoral competition, we find that in a dynamic ecient economy both forward and backward intergenerational transfers simultaneously arise. The equilibrium allocation is education ecient, but, due to political overrepresentation of elderly agents, the electoral competition process induces overtaxation compared with a Benevolent Government solution with balanced welfare weights

Reactive mesogens for ultraviolet-transparent liquid crystal polymer networks

Transparency and stability to UV light are important and desirable properties for modern tunable optical elements and active soft robots. A library of novel reactive mesogens for liquid crystal polymer networks resilient and transparent to UV light has been synthetised and characterised. Phase behaviours of the reactive mesogens have been determined by polarised optical microscopy and differential scanning calorimetry. Liquid crystal polymer networks based on the combination of these novel reactive mesogens have been evaluated and compared to those based on common commercially available compounds. The results showed a twofold increase in transparency in a broad UV spectral region (200–400 nm) and importantly showed no degradation upon prolonged UV exposure contrary to the networks composed from commercial counterparts

Two Fatal Intoxications Due to Tramadol Alone: Autopsy Case Reports and Review of the Literature

Since tramadol was marketed, it has been widely prescribed as a pain killer because of its relatively safe profile among opioids. Nevertheless, intoxication can occur: overdose can lead to fatal outcomes mostly in association with other drugs, via the potential interaction with serotonergic antidepressant medications, as well as the potential for increased central nervous system (CNS) depression. Fatal outcomes only attributable to tramadol are a rare entity. In this case report, 2 fatal cases are described due to tramadol stand-alone intoxication with peculiar characteristics. In case 1, gas chromatography - mass spectrometry analysis detected tramadol in all specimens (32 \u3bcg/mL in the heart blood, 23.9 \u3bcg/mL in the femoral blood, 3.3 \u3bcg/mL in the bile, and 1.4 \u3bcg/mL in the urine). No other CNS depressants were detected by toxicological analysis. In case 2, gas chromatography - mass spectrometry analysis detected tramadol in all specimens (7.5 \u3bcg/mL in the heart blood, 5.8 \u3bcg/mL in the femoral blood, and 18 \u3bcg/mL in the urine). No other CNS depressants were detected by toxicological analysis. Review of the literature was performed to clarify the actual knowledge on this topic

Fatal Clostridium perfringens Septicemia After Colonoscopic Polypectomy, Without Bowel Perforation

Since its introduction, colonoscopy has played an important role as a diagnostic, therapeutic, and screening tool. In general, colonoscopy is regarded as a safe procedure, but complications may occur. The most dreaded of these complications is colonic perforation. Bacteremia postprocedure may occur, and although it is not uncommon, it rarely results in clinically significant complications. Patients with IBD (inflammatory bowel disease) are a high-risk population for bacteremia, which may leads to bowel wall overstepping by the bacteria. With regard to that, we report a fatal case of gas gangrene complicating colonoscopy polypectomy without bowel perforation in a healthy adult. To the best of our knowledge, only two other cases of retroperitoneal gas gangrene associated with colonoscopy polypectomy without bowel perforation have been described in international literature, but none of which was completed by a molecular biology analysis

A case of bilateral extracranial internal carotid artery dissection due to the helmet strap after motorcycle crash

The authors report a case of a man who developed stroke symptoms a few days after a road accident on his motorcycle. Radio-graphic examinations revealed the presence of bilateral dissection of the extracranial internal carotid arteries with signs of involvement of the brain parenchyma. The location, timing, and presentation lead to the conclusion that the carotid lesions were secondary to the motorcycle collision; in particular, we suppose that it is due to the pressure exerted by the helmet strap worn. Although helmets have undoubtedly prevented serious injuries, this report highlights that the helmets themselves may cause injuries, especially to cervical soft tissues and vessels

Selective gold and palladium adsorption from standard aqueous solutions

The intensive exploitation of resources on a global level has led to a progressive depletion of mineral reserves, which were proved to be insufficient to meet the high demand for high-technological devices. On the other hand, the continuous production of Waste from Electrical and Electronic Equipment (WEEE) is causing serious environmental problems, due to the complex composition of WEEE, which makes the recycling and reuse particularly challenging. The average metal content of WEEE is estimated to be around 30% and varies depending on the manufacturing period and brand of production. It contains base metals and precious metals, such as gold and palladium. The remaining 70% of WEEEs is composed of plastics, resins, and glassy materials. The recovery of metals from WEEEs is characterized by two main processes well represented by the literature: Pyrometallurgy and hydrometallurgy. Both of them require the pre-treatment of WEEEs, such as dismantling and magnetic separation of plastics. In this work, the selective adsorption of precious metals has been attempted, using copper, gold, and palladium aqueous solutions and mixtures of them. A screening on different adsorbent materials such as granular activated carbons and polymers, either as pellets or foams, has been performed. Among these, PolyEther Block Amide (PEBA) was elected as the most performing adsorbent in terms of gold selectivity over copper. Spent PEBA has been then characterized using scanning electron microscope, coupled with energy dispersive spectroscopy, demonstrating the predominant presence of gold in most analyzed sites, either in the pellet or foam form

Selective leaching of precious metals from electrical and electronic equipment through hydrometallurgical methods

The rapid human evolution has improved the quality of our lives through the use of technology. This not only resulted in increased raw materials extraction but also in the production of a worrying amount of electronic wastes. Indeed, in 2019 worldwide production of Electronic and Electric Equipment Waste (WEEE) was worth 50 million tons, causing several disadvantages such as the reduced space in landfills and massive shipping to countries with less restrictive regulations. On the other side, the billionaire electrical devices market is causing a significant increase in Precious Metals (PM) demand. Nowadays, the economic importance of PMs is as high as their supply risk. The answer to this problem consists of finding selective methods to extract and raffinate precious metals from disposed WEEE. On average, WEEEs contain around 30 % of plastics, 30 % ceramics, and 40 % metals; among these only around 0.1 % is characterized by PMs, such as gold, silver, rhodium, platinum, and palladium. The separation of PMs from other non-precious components is generally obtained using pyrometallurgy, which consists of fusing the wastes at temperatures up to 1500 ÷ 1700 °C. However, this method produces toxic gaseous byproducts and implies high energy costs. A possible alternative is given by hydrometallurgical processes, consisting of leaching the WEEE with solutions containing acids and oxidants at temperatures lower than 100°C. One of the main issues of the hydrometallurgical process is to leach copper and other non-precious base-metals selectively while keeping PMs in the solid-state. In this work, we report preliminary results of equilibrium and kinetic leaching tests in a well-stirred batch reactor, aimed at the optimization of the main operating parameters of a hydrometallurgical process for selective leaching of copper and other base-metals from Wasted Printed Circuit Boards (WPCBs). In particular, experiments have been carried out at different HCl and NaCl concentrations of the leaching solutions, exploring also the effect of temperature variation (20, 50, and 70 °C)