227 research outputs found

    Phase transitions in social sciences: two-populations mean field theory

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    A new mean field statistical mechanics model of two interacting groups of spins is introduced and the phase transition studied in terms of their relative size. A jump of the average magnetization is found for large values of the mutual interaction when the relative percentage of the two populations crosses a critical threshold. It is shown how the critical percentage depends on internal interactions and on the initial magnetizations. The model is interpreted as a prototype of resident-immigrant cultural interaction and conclusions from the social sciences perspectives are drawn

    Dynamic thermal simulation on retrofitting scenarios for semi-extensive sheep farms

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    Sheep and goat have a high adaptability to different climatic conditions. Nevertheless, even in extensive farming, these species benefit from the presence of structures that can mitigate stress from heat, cold and humidity changes. These shelters are used at night or for limited periods during the year. These are characterised by a low engineering and make extensive use of recycled material. Interesting innovation in rural areas could be represented by the re-development of these buildings in order to improve their internal microclimate. This work develops a thermal dynamic simulation model aimed at identifying the best solution to retrofit the envelope of existing livestock buildings. In this paper, three different solutions have been tested: insulation of vertical surfaces, insulation of roof and window type. Eight different materials have been considered for roof and vertical surfaces and four for the different kind of window glazing, analysing the building microclimate responses. As a reference building to compare the different solutions adopted has been chosen an extensive sheep farm located in the Italian Apennines. The results suggest that the best solution is to insulate the roof. The other elements offer negligible results in term of improving the internal microclimate conditions. For coating the roof it can also be considered a good response of all the analysed insulating materials, in order to increase the period of maintaining the temperature of comfort and not exceeding its critical values within the building

    Unusual localization of pennella sp. In swordfish (xiphias gladius) hearts

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    The genus Pennella comprises hematophagous parasites of marine aquatic species, including cephalopods, marine mammals, and pelagic fish. Nine species have been officially included in the genus Pennella plus another six species inquirendae. They are most often found in the host’s musculature, without penetrating internal organs. For the present study, 83 hearts from swordfish (Xiphias gladius) caught in the Mediterranean Sea were sampled and immediately fixed in formalin for histopathological analysis. In total, 10 (12.05%) hearts were found to be parasitized by copepods of the genus Pennella. Macroscopically, there was mild-to-severe fibrinous pericarditis with atrial wall thickening and multiple parasitic nodules. Histologically, the parasitic nodules were surrounded by an inflammatory-necrotizing reaction. Parasitic infestation by Pennella spp. is common in pelagic fish and in swordfish, in particular. Here, however, we report atypical cardiac localization. A future area of focus is the evaluation of cardiac Pennella spp. infestation by histopathology and genetic identification of the parasites

    Assessment of Biological and Sanitary Condition of Alien Fish from a High-Mountain Lake (Cottian Alps)

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    This study aimed to assess the biological and sanitary conditions of alien fish in a high-mountain lake (Balma Lake) located in the Cottian Alps. A single fish sampling session (August 2018) using gillnets collected 90 specimens of brook trout (Salvelinus fontinalis). Sex and age were determined (59 females and 31 males, age class 0+ to 4+). Regression analysis showed no difference in total weight and total length between males and females (ANCOVA: F = 0.453; p = 0.954). The mean condition factor (Kmean) decreased with increasing age for males and females. Terrestrial insects were the main prey found in the fish stomachs. The parasitological exam was negative, and the bacteriological exam was positive for Carnobacterium maltaromaticum and C. divergens in 33% of specimens. The total mercury, cadmium, and lead concentration in muscle tissue was within the maximum limit established by the European Commission for human consumption. The brook trout population was found to be well structured; these findings may help local administrations in the implementation of eradication measures

    A proposal of a new methodology for best location of environmentally sustainable roads infrastructures. Validation along the Fabriano-Muccia road

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    El trabajo contempla la creación de un modelo para definir la mejor localización en el territorio de nuevos proyectos de infraestructuras viarias y su convalidación en una carretera que forma parte de un proyecto de gran envergadura denominado Cuadrilátero Marcas-Umbría, en vías de realización. El objetivo del trabajo consiste en la puesta a punto de una herramienta ágil y versátil, capaz de sopesar, interpretándolos de forma correlacionada, los distintos aspectos de carácter medioambiental, socioeconómico, técnico y operativo, ligados a la construcción de una obra viaria. Se ha prestado especial atención a las dinámicas de uso y consumo de los hábitats naturales y a las problemáticas vinculadas a los fenómenos de fragmentación ecológica provocados por la red viaria y los asentamientos. La metodología que se ha puesto a punto prevé la recogida y la implementación, dentro de un sistema de información territorial dedicado, de un amplio abanico de datos capaces de definir las características peculiares del ámbito que es objeto del estudio, posteriormente interpretados y reconducidos a síntesis mediante la aplicación de una serie de indicadores específicos. Los indicadores definidos se incorporan posteriormente mediante la aplicación de técnicas de análisis multicriterio para definir un índice de evaluación sintético capaz de estimar de forma correlacionada la sensibilidad del territorio ante la introducción de nuevas infraestructuras viarias. Para convalidar la metodología, los índices propuestos se han aplicado a un área de estudio donde se está construyendo una infraestructura viaria de importancia considerable para las conexiones transversales de Italia central

    Relationship between the prevalence of Dibothriocephalus latus(Cestoda: Diphyllobothriidea) and the load of Escherichia coli: New findings in a neglected fish-borne parasitic zoonosis

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    The sub-Alpine lakes of Switzerland, Italy and France have long been reported as an endemic area of diphyllobothriosis, a parasitic zoonosis aused by Dibothriocephalus latus. With this study, we explored the hypothesis for a relationship between the prevalence of D. latus in Perca fluviatilis and the Escherichia coli load in lake water. To do this, we identified eleven sampling sites in three areas (north, centre and south) of Lake Iseo (north Italy) to determine E. coli load and the prevalence of D. latus in P. fluviatilis. Prevalence and 95% confidence interval (CI) of D. latus infestation ranged from 0% (95% CI: 0.71–0.0) in Sarnico (southern area) to 20% (95% CI: 33.0–11.2) in Pisogne (northern area). There were significant differences in prevalence be-tween the sites (χ2= 31.12; p- value= .0006) and in E. coli load (Kruskal–Wallis test; p- value= .0005). There was decreasing gradient of E. coli load and prevalence of D. latus infestation from north to south. A significant positive correlation (r= .881; p- value= .003) was found between E. coli load and prevalence of D. latus. Also, linear regression showed a significant relationship between E. coli load and prevalence of infestation (R2= .775). Our findings offer an explanation for the link between E. coliload in water and D. latus prevalence. The potential factors in this link are the ef-ficiency of the local wastewater treatment plant, the bathymetric profile of the lake and the life cycle of D. latus, which is mainly affected by light and water temperature.KEYWORDSItaly, Lake Iseo, Perca fluviatilis, prevalence of infestation, wastewater treatment plant, the bathymetric profile of the lake and the life cycle of D. latus, which is mainly affected by light and water temperature

    The unusual isolation of carnobacteria in eyes of healthy salmonids in high‑mountain lakes

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    Carnobacteria are common bacteria in cold and temperate environments; they are also reported during fsh mortality events. In a previous study, carnobacteria were isolated from the eyes of healthy wild salmonids from a high-mountain lake. To better understand these fndings, salmonids were captured from three high-mountain lakes (Lower and Upper Balma Lake, Rouen Lake; northwest Italy) during August 2019 and subjected to bacteriological and histological examination. Although all were healthy, 8.7% (Lower Balma Lake), 24% (Upper Balma Lake), and 32.6% (Rouen Lake) were positive for carnobacteria colonization of the eyes. A Trojan-horse efect was hypothesized to explain carnobacteria isolation in the eye. This immune-escaping macrophage-mediated mechanism has been identifed in other Gram-positive bacteria. Biochemical, molecular, and phylogenetic analysis were carried out on isolated bacteria (Carnobacterium maltaromaticum and C. divergens). Based on previous references for carnobacteria isolated from fsh, C. maltaromaticum strains were tested for the pisA precursor gene of the bacteriocin piscicolin 126. Carnobacterium maltaromaticum strains were found to display genotypic heterogeneity and a low percentage of pisA positive amplifcation. Features of geomorphology, geographic isolation, and microbiota common to the three lakes are thought to be possibly related to our fndings. Moreover, terrestrial insects collected from the lake shoreline and the stomach contents were screened for the presence of carnobacteria. The salmonids in these high-mountain environments feed mainly on terrestrial insects, which are considered possible vectors for carnobacteria that might catabolize the exoskeleton chitin. All insects tested negative for carnobacteria, but as a small number of samples were analyzed, their role as possible vectors of infection cannot be excluded. Further studies are needed to corroborate our research hypothesis

    Deep Energy Retrofit of Residential Buildings in the Mediterranean Area: The MedZEB Approach

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    Publicado en : Green Energy and TechnologyMediterranean deep retrofit markets are characterized by common barriers and bottlenecks, which barely have been identified as shared challenges, and this has led to a lack of dedicated solutions and to a substantial delay in achieving the 2020 EU policy targets. This situation is addressed by the H2020 HAPPEN project by proposing a new MedZEB approach characterized by the following features: Holistic, i.e., aimed at integrating the most relevant aspects of the retrofitting supply chain;Transparent, i.e., aimed at putting on the market novel tools for enhancing investors’ trust;Adaptive, i.e., aimed at enhancing “added values” of the retrofitting such as flexibility, well-being, etc. Having arrived at its midpoint, HAPPEN has produced an advanced version of its main outputs, among which are: the HAPPEN cost-optimal technical solutions, developed according to a step-by-step logic;the HAPPEN financial solution, fully integrated with the step-by-step logic, and aimed at funding the retrofitting process by relying on the energy savings achieved;the MedZEB protocol conceived as a guarantee scheme for the achievement of retrofit targets;the HAPPEN platform, an assisted digital marketplace aimed at matching demand and offer according to a one-stop-shop logic, at defragmenting the retrofit value chain, and at supporting actors with dedicated tools. These outputs have been developed also thanks to an extensive living laboratory and pilot-building program, carried out within ten pilot sites across seven EU Med countries; this has made it possible for a large engagement of potential users, which resulted in the ideation of the HAPPEN program, an overall framework aimed at integrating project outputs into an exploitable renovation procedure powered by the HAPPEN platform. This paper describes the first simulation of such a procedure in its entirety based on a real case study. After characterizing the building according to the HAPPEN reference buildings and climates lists, a step-by-step cost-optimal package of solutions was calculated, followed by the application of the HAPPEN financial solution, and by the draft issue of the MedZEB protocol. Results provide the first evidence of the effectiveness of the MedZEB approach in potentially unlocking the deep retrofit market in the Med area, with special attention to the possibility of funding the interventions by relying on the economies generated by the energy savings achieved. Further, the project activities will be aimed at co-creating, together with relevant stakeholders, a go-to-market strategy for the HAPPEN program.Horizonte 2020 (Unión Europea) 78507
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