Chemical evolution in a model for the joint formation of quasars and spheroids

Direct and indirect pieces of observational evidence point to a strong connection between high-redshift quasars and their host galaxies. In the framework of a model where the shining of the quasar is the episode that stops the formation of the galactic spheroid inside a virialized halo, it has been proven possible to explain the submillimetre source counts together with their related statistics and the local luminosity function of spheroidal galaxies. The time delay between the virialization and the quasar manifestation required to fit the counts is short and incresing with decresing the host galaxy mass. In this paper we compute the detailed chemical evolution of gas and stars inside virialized haloes in the framework of the same model, taking into account the combined effects of cooling and stellar feedback. Under the assumption of negligible angular momentum, we are able to reproduce the main observed chemical properties of local ellipticals. In particular, by using the same duration of the bursts which are required in order to fit the submillimetre source counts, we recover the observed increase of the Mg/Fe ratio with galactic mass. Since for the most massive objects the assumed duration of the burst is Tburst < 0.6 Gyr, we end up with a picture for elliptical galaxy formation in which massive spheroids complete their assembly at early times, thus resembling a monolithic collapse, whereas smaller galaxies are allowed for a more prolonged star formation, thus allowing for a more complicated evolutionary history.Comment: 17 pages, 11 figures, accepted for publication in MNRA

Environmental sustainability and service quality beyond economic and financial indicators: A performance evaluation of Italian water utilities

As water utilities operate as natural monopolists and they provide essential services for human life, their activities are regulated by public authorities. The sustainable use of water resources and a specific attention on social needs should be essential goals for this kind of firms, so that the evaluation of their business should go beyond their profitability and their financial solvency. Keeping pace with the new Circular Economy paradigm and the evolution of the water regulatory framework, in this paper we suggest a global composite indicator apt to evaluate in a novel way the water utilities performance, encompassing financial and economic indexes together with environmental sustainability and service quality measures. To show its empirical implementation we evaluate the performance of Italian water utilities. The operating context is also under scrutiny focusing on specific water utility features such as size, geographical location, degree of diversification and ownership. In this light, operating in the Center and being large are considered favourable background conditions, while the South and the medium size display a significant unfavourable influence on the water utility performance. Multi-utilities are more advantaged with respect to the mono-utilities and no significant distinction can be made among the different ownership models. ispartof: Socio-Economic Planning Sciences status: Published onlin

Meeting the challenges of the waste hierarchy: A performance evaluation of EU countries

The focus of this paper is to evaluate how well European countries are advancing towards a Circular Economy transition and to which extent they are fulfilling the European Union (EU) requirements in terms of municipal waste management. With this aim, an innovative composite indicator is devised by integrating the Goal Programming Synthetic Indicator (GPSI) methodology with the Analytic Hierarchy Process (AHP). The suggested methodology allows to encompass not only the guidelines provided by the EU directives and the EU Waste Hierarchy, but also the deviations from the EU thresholds. As a first step of the analysis, a dashboard of indicators is identified together with a set of targets that European countries are supposed to meet. Indicators, targets and their relative importance in the dashboard have been discussed and validated by a team of experts. Then, two Goal Programming Synthetic Indicators are computed taking into account two different perspectives. The first one rewards the countries with good performance in the higher level of the Waste Hierarchy, while the second one penalizes countries whose infringements are in the lower part of the Waste Hierarchy. Hence two different systems of aggregating weights are identified by means of the Analytic Hierarchy Process and accordingly two scenarios are explored. The analysis is performed using Eurostat data on 28 European countries from 2013 to 2018. For each year, countries are assessed in terms of their ability to keep the right waste management track delineated by the Waste Hierarchy principles. Countries’ ranking over time is first obtained and then interpreted in light of countries policies and achievements, deriving policy suggestions to improve waste management strategy able to reach the expected results

Importance of perforating vessels in nipple-sparing mastectomy. an anatomical description

BACKGROUND: Nipple-sparing mastectomy (NSM), understood as an oncologically valid procedure, is relatively new, and is an evolution of traditional mastectomy, particularly in relation to breast-conserving surgery. The anterior perforating branches are responsible for the cutaneous vascularization of the breast skin, and their preservation is a fundamental step to avoid possible postoperative necrosis. Therefore, evaluating the potential complications of cancer-related reconstructive surgical procedures such as NSM, both the distance of the tumoral lesion from the skin and the surgical incision site should be carefully considered. The preferred site of incision corresponds to the inframammary fold or possibly the periareolar area. METHODS: We retrospectively reviewed 113 patients who underwent NSM from January 2005 to October 2012 to evaluate skin complications. The anatomical study was performed by magnetic resonance imaging of the breast. RESULTS: Only one of the 113 women who had undergone a NSM procedure had total necrosis (0.9%) and six patients had partial necrosis (5.8%) of the nipple-areola complex

Acceptability of the transitional wearable companion “+me” in typical children: a pilot study

This work presents the results of the first experimentation of +me-the first prototype of Transitional Wearable Companion–run on 15 typically developed (TD) children with ages between 8 and 34 months. +me is an interactive device that looks like a teddy bear that can be worn around the neck, has touch sensors, can emit appealing lights and sounds, and has input-output contingencies that can be regulated with a tablet via Bluetooth. The participants were engaged in social play activities involving both the device and an adult experimenter. +me was designed with the objective of exploiting its intrinsic allure as an attractive toy to stimulate social interactions (e.g., eye contact, turn taking, imitation, social smiles), an aspect potentially helpful in the therapy of Autism Spectrum Disorders (ASD) and other Pervasive Developmental Disorders (PDD). The main purpose of this preliminary study is to evaluate the general acceptability of the toy by TD children, observing the elicited behaviors in preparation for future experiments involving children with ASD and other PDD. First observations, based on video recording and scoring, show that +me stimulates good social engagement in TD children, especially when their age is higher than 24 months

Water pollution in wastewater treatment plants: An efficiency analysis with undesirable output

The environmental efficiency of 96 Tuscan (Italian) wastewater treatment plants (WWTPs) is investigated taking into account the quality of the outgoing water in terms of pollutant. In this regard, the presence of the residual nitrogen in the outgoing treated water is considered as undesirable output. The efficiency analysis is performed by applying a novel integrated Analytic Hierarchy Process/Non-radial Directional Distance Function (AHP/NDDF) approach, combining the benefits of the two techniques. Similarly to the standard NDDF approach, the suggested model allows to include simultaneously inputs, desirable and undesirable outputs and not to overestimate the efficiency scores. At the same time, the AHP inclusion gives the possibility to directly take into account the decision maker preferences in the weighting system and to encompass some existing directional distance function models as special cases.The obtained results are then used to identify the efficiency explanatory variables: among them, the facilities' capacity, the percentage of wastewater discharged by the industrial and agricultural activities and the level of compliance with the pollutant concentration threshold set by the legislator have a significant impact on the WWTP performance. The integrated performance assessment allows the water authorities to combine the WWTP efficiency together with the environmental sustainability issue and it has the potential for further promising environmental inspections