Strain rate, temperature and deformation state effect on Ecoflex 00-50 silicone mechanical behaviour

Silicone elastomers are extremely attractive materials due to their wide range of possible applications, from biomedical engineering to soft robotics. In this work, an extensive thermo-mechanical characterization of Ecoflex Shore hardness 00–50, a commercially available silicone elastomer, has been carried out to compensate for the lack of relevant literature. The mechanical behaviour of the material has been characterized by performing monotonic and cyclic loading tests. These tests were performed in different deformation states, i.e. uniaxial tension, pure shear and biaxial tension, at different strain rates and temperatures. Experimental findings allowed to highlight the material time-dependent response and quantify the contribution of dissipative deformation phenomena to the overall strain energy. Uniaxial tensile tests performed at different temperatures (between −40 °C and 140 °C) showed that the material mechanical behaviour is sensitive to temperature in this range: a decrease of the ultimate stress and strain has been observed with increasing temperature. Finally, the data obtained from the latter tests have been used to define a failure envelope, applied for the first time to Ecoflex silicones, and valuable to describe the material ultimate stress and strain at any temperature and strain rate

Fine grained process modelling: An experiment at British Airways

We report on the experimental application of process technology at British Airways (BA). We used SLANG to model BA's C++ class library management process, and we constructed an experimental process centred software engineering environment (PSEE) based on SPADE. BA required processes to be automated at a finer degree of granularity than tool invocation. We have demonstrated that SLANG and SPADE offer the basic mechanisms for modelling these fine grained processes. We have also shown that it is feasible to generate tools for dedicated processes and integrate them with a SLANG model so as to facilitate fine grained process automation. However, our experience highlighted some open problems. For instance, SLANG process models are tuned to efficient enactment, thus containing very detailed process fragments. These are not the most appropriate representation for humans trying to understand the process model. A more comprehensible notation is needed for design and documentation purposes. Although the airline did not deploy the PSEE in its production environment, the experiment proved beneficial for BA. The modelling uncovered serious flaws in the existing process, and the BA engineers improved their knowledge of process technology

Field and experimental data indicate that the eastern cottontail (Sylvilagus floridanus) is susceptible to infection with European brown hare syndrome (EBHS) virus and not with rabbit haemorrhagic disease (RHD) virus

This is an Open Access article distributed under the terms of the Creative Commons Attribution License.-- et al.The eastern cottontail (Sylvilagus floridanus) is an American lagomorph. In 1966, it was introduced to Italy, where it is currently widespread. Its ecological niche is similar to those of native rabbits and hares and increasing overlap in distribution brings these species into ever closer contact. Therefore, cottontails are at risk of infection with the two lagoviruses endemically present in Italy: Rabbit Haemorrhagic Disease virus (RHDV) and European Brown Hare Syndrome Virus (EBHSV). To verify the susceptibility of Sylvilagus to these viruses, we analyzed 471 sera and 108 individuals from cottontail populations in 9 provinces of north-central Italy from 1999 to 2012. In total, 15-20% of the cottontails tested seropositive for EBHSV; most titres were low, but some were as high as 1/1280. All the cottontails virologically tested for RHDV and EBHSV were negative with the exception of one individual found dead with hares during a natural EBHS outbreak in December 2009. The cottontail and the hares showed typical EBHS lesions, and the EBHSV strain identified was the same in both species (99.9% identity). To experimentally confirm the diagnosis, we performed two trials in which we infected cottontails with both EBHSV and RHDV. One out of four cottontails infected with EBHSV died of an EBHS-like disease, and the three surviving animals developed high EBHSV antibody titres. In contrast, neither mortality nor seroconversion was detected after infection with RHDV. Taken together, these results suggest that Sylvilagus is susceptible to EBHSV infection, which occasionally evolves to EBHS-like disease; the eastern cottontail could therefore be considered a >spill over> or > dead end > host for EBHSV unless further evidence is found to confirm that it plays an active role in the epidemiology of EBHSV.Peer Reviewe

Quantitative risk assessment of hepatitis E virus: modelling the occurrence of viraemic pigs and the presence of the virus in organs of food safety interest

Hepatitis E virus (HEV) is a zoonotic pathogen with consumption of pork and derived products identified in different countries as a risk factor for human exposure to HEV. Great efforts have been made to understand the dynamics of virus transmission within domestic swine populations through modelling. However, from a food safety prospective, it is critical to integrate the parameters involved in the transmission dynamics with those governing the actual presence of HEV in the bloodstream, the liver, gallbladder or faeces. To date, several aspects related to the pathogenesis of the disease are still unknown or characterized by significant levels of uncertainty, making this conjunction challenging. We used published serological data obtained from pigs in a farrow-to-finish farm to implement an Immune-Susceptible-Infected-Recovered (MSIR) model reproducing the on-farm dynamics that lead to the occurrence of viraemic pigs at slaughter. Expert opinion on the length of time infectious HEV can be detected in liver, gallbladder/bile and faeces after recovery from viraemic status were used to inform a stochastic model aimed at estimating the expected proportion of viraemic pigs, pigs with infectious HEV in liver, gallbladder/bile and faeces entering the slaughterhouse. To simulate the potential effect of on-farm mitigation strategies, we estimated the changes in outcomes of interest as a function of variations in the baseline transmission parameters. The model predicted a proportion of viraemic pigs entering the slaughterhouse of 13.8% while the proportions of, and ranged from 13.8% to 94.4%, 13.8% to 94.7% and from 25.3% to 30.8% respectively, due to the uncertainty surrounding the experts’ opinions. Variations in MSIR model’s parameters alert of the need to carefully consider the application of mitigation strategies aimed at delaying the decay of maternal immunity or the peak of the within herd transmission. When the rate of decay of maternal immunity and the transmission rate were decreased between 80% and 5% and 40% and 5% from the baseline values respectively, adverse effects on were observed. The model highlights the relevance of specific aspects in the pathogenesis of the disease from a food safety prospective and it was developed to be easily reproducible and updatable as soon as accurate data becomes available. As presented, the model can be directly connected to existing or future pig-related models to estimate the significance of the identified parameters on the risk of human exposure to HEV through consumption of pork products

Viraemic pigs entering the food chain are the most likely source of hepatitis E virus (HEV) in pork meat: Modelling the fate of HEV during slaughtering of pigs

Hepatitis E Virus (HEV) is an emerging foodborne pathogen and consumption of raw or undercooked pork products has been associated with increased risk of human infection. This work represents the first attempt to evaluate the risk of HEV being present on pig carcasses and in meat at the end of the slaughtering process considering the steps of bleeding, scalding, dehairing, singeing, polishing, evisceration and trimming. Based on available knowledge on the epidemiology and biology of HEV, the risk pathways leading to the presence of HEV on carcasses as a consequence of (i) faecal contamination of the skin from environment and contacts with contaminated faeces during transport and lairage, (ii) contact with viraemic blood at bleeding and (iii) faecal/bile cross-contamination during evisceration were assessed qualitatively. The pathway through which HEV could be present in meat of viraemic pigs, as conveyed by residual blood in muscular tissue after bleeding was instead modelled quantitatively. Of the three risk pathways evaluated qualitatively, only the occurrence of HEV on carcasses as a consequence of accidental rupture of the gut or gallbladder at evisceration was found to be non-negligible, but with a very low likelihood of occurrence. The quantitative output for the expected amount of HEV in meat of viraemic pigs shows minimum and maximum values of 0.10 and 1.1 × 104 genome copies (gc)/g respectively with 4.8 × 102 and 5.3 × 103 gc/g at 95th and 99th percentile of the cumulative distribution. These results are consistent with the existing evidence that levels of HEV RNA in meat samples are usually low even in the presence of high viral loads in livers of the same animals. Results of the sensitivity analysis confirm highly viraemic pigs entering the slaughter line as those posing the greater risk for consumers. Our study suggests that prevention of HEV infection through consumption of pork meat at pre-harvest/harvest stages should focus on reducing the flow of highly viraemic pigs into the food chain

The GOODSTEP project: General Object-Oriented Database for Software Engineering Processes

The goal of the GOODSTEP project is to enhance and improve the functionality of a fully object-oriented database management system to yield a platform suited for applications such as software development environments (SDEs). The baseline of the project is the O2 database management system (DBMS). The O2 DBMS already includes many of the features regulated by SDEs. The project has identified enhancements to O2 in order to make it a real software engineering DBMS. These enhancements are essentially upgrades of the existing O2 functionality, and hence require relatively easy extensions to the O2 system. They have been developed in the early stages of the project and are now exploited and validated by a number of software engineering tools built on top of the enhanced O2 DBMS. To ease tool construction, the GOODSTEP platform encompasses tool generation capabilities which allow for generation of integrated graphical and textual tools from high-level specifications. In addition, the GOODSTEP platform provides a software process toolset which enables modeling, analysis and enaction of software processes and is also built on top of the extended O2 database. The GOODSTEP platform is to be validated using two CASE studies carried out to develop an airline application and a business application

Melatonin oral supplementation against fibromyalgia-related skeletal muscle alterations

Fibromyalgia is a chronic idiopathic pain syndrome characterized by widespread musculoskeletal pain and a deep range of other symptoms including disordered sleep, paresthesia, depression and anxiety (1). To date, its aetiopathogenesis and pathophysiology are still not understood, but the musculoskeletal, neuroendocrine and central nervous systems appear to play major roles in the development and progression of fibromyalgia (2). Important factors involved in the pathogenic process of fibromyalgia are oxidative stress and inflammation suggesting that antioxidative supplementation might be important in the management and modulation of fibromyalgia. Recent evidences suggest that melatonin may be suitable for this purpose. Melatonin is a small, highly conserved pineal indoleamine and due to its important and well known antioxidant and antinflammatory properties, together with also its analgesic effects, our research group studied the beneficial effects of the melatonin oral supplementation against the pathogenetic process of fibromyalgia. In detail, Sprague Dawley rats were randomly treated with reserpine, to reproduce the pathogenic process of fibromyalgia (3), and/or with melatonin (MelapureTM by Flamma S.p.A.). At the end of the treatments, the animals treated with reserpine showed moderate alteration at hind limb skeletal muscle level with difficult in moving, together with a significant expression of several oxidative stress and inflammatory markers at the gastrocnemius muscle level. Interestingly, melatonin, dose and time dependently, reduced the difficulties in walking and the musculoskeletal oxidative stress and inflammatory processes. In summary, this pilot study suggested that melatonin could be an in vivo effective tool against muscoloskeletal morphofunctional damages and dysfunctions in the management of fibromyalgia-related complications.Sincere thanks to Flamma S.p.A.- Italy (www.flammagroup.com) for courteously providing the melatonin and for the precious economic support to this study

Harmonizing methods for wildlife abundance estimation and pathogen detection in Europe-a questionnaire survey on three selected host-pathogen combinations

__Background:__ The need for wildlife health surveillance as part of disease control in wildlife, domestic animals and humans on the global level is widely recognized. However, the objectives, methods and intensity of existing wildlife health surveillance programs vary greatly among European countries, resulting in a patchwork of data that are difficult to merge and compare. This survey aimed at evaluating the need and potential for data harmonization in wildlife health in Europe. The specific objective was to collect information on methods currently used to estimate host abundance and pathogen prevalence. Questionnaires were designed t