Peripheral nerve sheath myxoma. Clinicopathological and immunohistochemical study of a morphologically distinctive myxoid peripheral nerve sheath tumor in the forelimb of a cat

Peripheral nerve sheath tumors (PNST) are a class of nervous system tumors which arise in both schwann cells and perineural fibroblasts. Benign and malignant PNSTs are reported to occur in all domestic animals. In cats they represent 3% of all cutaneous and subcutaneous neoplasms. Only in dogs mixoid PNST has been observed generally localized in the fingers. In humans, PNSTs are rare neoplasms, and nerve sheath myxomas are a distinct neoplasia most commonly found in limb extremities

Liposarcoma pleomorfo a localizzazione mammaria in un cane = Canine pleomorphic liposarcoma of mammary gland

Liposarcoma is the most common malignant soft tissue tumors in humans, whereas in dog is an uncommon neoplasm of all skin and subcutaneous tumors. Lipocytic tumors have been categorized as atypical lipoma, well differentiated liposarcoma, myxoid liposarcoma and pleomorphic liposarcoma

Runs of homozygosity in the Italian goat breeds: impact of management practices in low‑input systems

Background Climate and farming systems, several of which are considered as low-input agricultural systems, vary between goat populations from Northern and Southern Italy and have led to different management practices. These processes have impacted genome shaping in terms of inbreeding and regions under selection and resulted in differences between the northern and southern populations. Both inbreeding and signatures of selection can be pinpointed by the analysis of runs of homozygosity (ROH), which provides useful information to assist the management of this species in different rural areas. Results We analyzed the ROH distribution and inbreeding (FROH) in 902 goats from the Italian Goat Consortium2 dataset. We evaluated the differences in individual ROH number and length between goat breeds from Northern (NRD) and Central-southern (CSD) Italy. Then, we identified the signatures of selection that differentiate these two groups using three methods: ROH, ΔROH, and averaged FST. ROH analyses showed that some Italian goat breeds have a lower inbreeding coefficient, which is attributable to their management and history. ROH are longer in breeds that are undergoing non-optimal management or with small population size. In several small breeds, the ROH length classes are balanced, reflecting more accurate mating planning. The differences in climate and management between the NRD and CSD groups have resulted in different ROH lengths and numbers: the NRD populations bred in isolated valleys present more and shorter ROH segments, while the CSD populations have fewer and longer ROH, which is likely due to the fact that they have undergone more admixture events during the horizontal transhumance practice followed by a more recent standardization. We identified four genes within signatures of selection on chromosome 11 related to fertility in the NRD group, and 23 genes on chromosomes 5 and 6 related to growth in the CSD group. Finally, we identified 17 genes on chromosome 12 related to environmental adaptation and body size with high homozygosity in both groups. Conclusions These results show how different management practices have impacted the level of genomic inbreeding in two Italian goat groups and could be useful to assist management in a low-input system while safeguarding the diversity of small populations

Condition monitoring of suspension components in railway bogies

This paper describes approaches to the condition monitoring of suspension components in railway bogies developed at Politecnico di Milano, Dipartimento di Meccanica and their application to a high-speed rail vehicle. Two classes of FDI techniques are proposed and compared: model-free and model-based FDI. The two proposed FDI approaches were applied to the case of an ETR500 class high speed trailed car, and numerical experiments were carried out to assess their effectiveness. The next step of the research consists in the verification of the applicability of the methods to a real case and to this aim an experimental campaign was set-up on the high speed test train ETR 500-Y1 running on the Italian high speed railway network. The paper presents the results of the numerical analyses performed and provides information about the implementation of the CBM system on-board the experimental train

Condition monitoring of suspension components in railway bogies

This paper describes approaches to the condition monitoring of suspension components in railway bogies developed at Politecnico di Milano, Dipartimento di Meccanica and their application to a high-speed rail vehicle. Two classes of FDI techniques are proposed and compared: model-free and model-based FDI. The two proposed FDI approaches were applied to the case of an ETR500 class high speed trailed car, and numerical experiments were carried out to assess their effectiveness. The next step of the research consists in the verification of the applicability of the methods to a real case and to this aim an experimental campaign was set-up on the high speed test train ETR 500-Y1 running on the Italian high speed railway network. The paper presents the results of the numerical analyses performed and provides information about the implementation of the CBM system on-board the experimental train

Testing and Modelling of Elastomeric Element for an Embedded Rail System

Modelling of elastomeric elements of railway components, able to represent stiffness and damping characteristics in a wide frequency range, is fundamental for simulating the train–track dynamic interaction, covering issues such as rail deflection as well as transmitted forces and higher frequency phenomena such as short pitch corrugation. In this paper, a modified non-linear Zener model is adopted to represent the dependences of stiffness and damping of the rail fastening, made of elastomeric material, of a reference Embedded Rail System (ERS) on the static preload and frequency of its deformation. In order to obtain a reliable model, a proper laboratory test set-up is built, considering sensitivity and frequency response issues. The equivalent stiffness and damping of the elastomeric element are experimentally characterised with force-controlled mono-harmonic tests at different frequencies and under various static preloads. The parameters of the non-linear Zener model are identified by the experimental equivalent stiffness and damping. The identified model correctly reproduces the frequency- and preload-dependent dynamic properties of the elastomeric material. The model is verified to be able to predict the dynamic behaviour of the elastomeric element through the comparison between the numerically simulated and the experimentally measured reaction force to a given deformation time history. Time domain simulations with the model of the reference ERS demonstrate that the modelled frequency- and preload-dependent stiffness and damping of the elastomeric material make a clear difference in the transient and steady-state response of the system when distant frequency contributions are involved

The homologation of low-flatcar wagons: instrumentation and on-track tests

Low-flatcar wagons are designed to load entire articulated lorries instead of loading only the containers in order to make the loading and unloading stages easier and faster. This design implies a particular layout of the bogie and suspension system, aiming at minimizing the height of the flatcar with respect to the rail level. This solution influences the dynamic behavior of the wagons, reducing the steering capability and causing high lateral forces on the driving wheels when low-radius curves or turnouts are negotiated. Aim of the work is the homologation of low-flatcar wagons on the Italian railways. Besides the classical homologation procedure prescribed by the EN14363 rule, a particular focus will be devoted to the running safety when negotiating turnouts. Indeed, it will be demonstrated that, under certain conditions, this is a very critical running condition for these vehicles. First, a numerical analysis is performed to identify the most critical condition. Then, this condition is reproduced experimentally, measuring the wheel-rail contact forces in order to assess the running safety of these wagons