196,187 research outputs found
Effect of environmental enrichment and group size on behaviour and live weight in growing rabbits
No full text[EN] The aim of this research was to study the effects of group size and environmental enrichment on behaviour and growth of 108 hybrid growing rabbits (Oryctolagus cuniculus). We compared the behaviour (time budget and reactions to specific behavioural tests: "tonic immobility" and "emergence test") and live weight of growing rabbits housed in cages with a different number of rabbits per cage (2, 3 and 4; same density:14 rabbits/m2). Half of the cages were enriched with a wooden stick (Robinia Pseudoacacia, length: 20 cm ¿ diameter: 6 cm, cylindrical) hanging from the ceiling of the cage. The stick and number of animals per cage had no effect on weight gain or on behavioural tests responses. Interaction with the stick was significantly higher at the beginning of the growing period. Principal component analysis performed on the data for the whole period showed significant differences according to the treatments: increasing the number of rabbits per cage and introducing a wooden stick seemed to affect locomotor activity frequency and social interactions. Rabbits housed 3 and 4 per cage showed less lying behaviour and higher locomotor activity and sitting. The larger functional space allowance enabled rabbits to perform more natural behaviours compared to smaller cages (2 rabbits/cage). Environmental enrichment seems to be related to higher allogrooming behaviour frequency, which could indicate a social behaviour related to pheromonal olfactory stimulation and mutual recognition.Zucca, D.; Marelli, S.; Redaelli, V.; Heinzl, E.; Cardile, H.; Ricci, C.; Verga, M.... (2012). Effect of environmental enrichment and group size on behaviour and live weight in growing rabbits. World Rabbit Science. 20(2):89-95. https://doi.org/10.4995/wrs.2012.1082SWORD899520
Orthogonal-Array based Design Methodology for Complex, Coupled Space Systems
No full textThe process of designing a complex system, formed by many elements and sub-elements interacting between each other, is usually completed at a system level and in the preliminary phases in two major steps: design-space exploration and optimization. In a classical approach, especially in a company environment, the two steps are usually performed together, by experts of the field inferring on major phenomena, making assumptions and doing some trial-and-error runs on the available mathematical models. To support designers and decision makers during the design phases of this kind of complex systems, and to enable early discovery of emergent behaviours arising from interactions between the various elements being designed, the authors implemented a parametric methodology for the design-space exploration and optimization. The parametric technique is based on the utilization of a particular type of matrix design of experiments, the orthogonal arrays. Through successive design iterations with orthogonal arrays, the optimal solution is reached with a reduced effort if compared to more computationally-intense techniques, providing sensitivity and robustness information. The paper describes the design methodology in detail providing an application example that is the design of a human mission to support a lunar base
Temperature monitoring of a geosynthetic-reinforced embankment in a seismic area
No full textField data on reinforced embankments are of upmost importance for improving knowledge on their long behaviour. In Valdina, Sicily,
Italy, following a landslide that involved a slope in clay soils, a reinforced embankment has been constructed. Valdina is a small
village in the Eastern Sicily that displays a high frequency of landslides since clay soils outcrop extensively. In 2006, the reinforced
embankment constructed on a clay slope was instrumented and the results of the following 2 years of reinforced embankment
monitoring are presented together with an analysis of the collected data of temperatures. The equipment installed allows the
measurement of the weather parameters (rainfall, wind, air humidity and air temperature), of the loads and deformations of the
reinforced embankment, and of the ground vibrations caused by earthquakes. To estimate the trend of deformations, temperature,
humidity and loads along the geogrids used to reinforce the structure, measurement instruments were installed within the structure at
different depths
Studio della mitocondriogenesi in diversi modelli animali di obesità : ruolo dell'ossido nitrico
No full textMitochondrial biogenesis study on different animal models of obesity : role of nitric oxide. Obesity is associated with chronic low-grade inflammation. Thus, at metabolically relevant sites, including adipose tissue and muscle, there is abnormal production of proinflammatory cytokines such as TNF-alpha. Here we demonstrate that eNOS expression was reduced, with a concomitant reduction of mitochondrial biogenesis and function, in white and brown adipose tissue and in the soleus muscle of 3 different animal models of obesity. The genetic deletion of TNF receptor 1 in obese mice restored eNOS expression and mitochondrial biogenesis in fat and muscle; this was associated with less body weight gain than in obese wild-type controls. Furthermore, TNF-alpha downregulated eNOS expression and mitochondrial biogenesis in cultured white and brown adipocytes and muscle satellite cells of mice. The NO donors DETA-NO and SNAP prevented the reduction of mitochondrial biogenesis observed with TNF-alpha. Our findings demonstrate that TNF-alpha impairs mitochondrial biogenesis and function in different tissues of obese rodents by downregulating eNOS expression and suggest a novel pathophysiological process that sustains obesity
DEVELOPMENT OF MEASUREMENT METHODOLOGIES IN METROLOGY FOR CELL BIOLOGY AND REGENERATIVE MEDICINE
No full textAim of this thesis is the development of measurement methodologies in metrology for cell biology and regenerative medicine. Regenerative medicine is a novel branch of medicine based on the use of autologous stem cells and biocompatible medical devices to regenerate and repair damaged tissues of patients, i.e. by using three-dimensional scaffolds to implant stem cells into the tissue to be regenerated. Stakeholders of metrology for regenerative medicine are: health care providers who require safe, reliable and cost effective treatments, supported by evidence and approved by regulators; regulators who require standard materials and traceable data demonstrating the safety and efficacy of new products and treatments; medical products companies who require advanced and traceable techniques to develop new products and need methods to measure processes, such as cell growth on scaffolds, to ensure quality and efficiency of the medical products implanted into the patients. Consequently, regenerative medicine has the important requisite of a real time monitoring and not invasiveness neither destructiveness processes to measure the cell-scaffold interactions, in order to preserve the samples from any contamination or modification. Thus non-invasive measurement methodologies need to be developed for analysing the 3D cell culture on scaffolds and, in order to evaluate the uncertainty, highly reproducible measurement procedures are strongly required to minimize the type A uncertainties and to define the type B uncertainties. The non-invasive and non-destructive measurement of cell-scaffold interactions (i.e. stem cell proliferation and differentiation on scaffolds) is one of the most effective methodology to answer the need of testing the efficacy of the design, production/manufacturing, development and performances of stem cell-scaffold products. To satisfy the requirements and the needs for metrology in regenerative medicine, for this thesis it has been chosen to develop a measurement methodology for cellular activity (proliferation and differentiation) on 3D Biocoral® scaffolds and to conduce a metrological study to evaluate the uncertainty of the methodology. This thesis has been developed in the Bioscience group of the Italian National Metrological Institute (Istituto Nazionale di Ricerca Metrologica - INRIM). The main important contributes of this thesis to the metrology in biosciences have been: • to lay the foundations for a metrological approach to cell biology and particularly to regenerative medicine research and applications; • to address the filling of the lack of traceability in the metrology for cell biology metabolic methodologies used to evaluate cellular activities in living sample with non-invasive procedures. The main results and originalities achieved during this PhD work are: • a metabolic assay, the resazurin/resorufin assay, for the first time, has been metrologically characterized and the uncertainty of the measurement has been evaluated; • the resazurin/resorufin assay has been for the first time tailored for a 3D cell culture on Biocoral® scaffolds and the uncertainty of the measurement has been evaluated; • it was demonstrated that Biocoral® induces osteodifferentiation of stem cells and for the first time it was demonstrated on human mesenchymal stem cells; • it was demonstrated, for the first time, that the resazurin/resorufin metabolic assay can be a methodology to detect not only the proliferation but also the differentiation of stem cells on Biocoral® scaffolds; A description of the METREGEN regional project, which this thesis is part of, will follow in the introduction. The chapter 1 will give an overview on regenerative medicine field and its application with scaffolds, particularly referring to the Biocoral® scaffold. The resazurin/resorufin methodology will be deeply described in chapter 2 with a uncertainty budget evaluation and discussion. Chapter 3 will present in details a series of experiments made to establish and characterize a hMSCs in vitro 2D culture, establish a hMSCs in vitro 3D culture on Biocoral, tailor the resazurin/resorufin assay for 3D cell culture on Biocoral and evaluate the hMSCs osteodifferentiation induced by Biocoral scaffolds. All the results have been analysed with a metrological approach to evaluate the uncertainty. Finally, the conclusion will give a recapitulation and some interesting perspective of employment for the resazurin/resorufin methodology to final users, such as the cell factorie
Use of the CFD for the analysis of the exhausts trajectory
No full textThe problem of the evaluation of the trajectory of the gas exhaust is important in a car project, because its particular impact on the comfort level. For the high performance cars the problem could be critical, because the high level of deceleration of the car during the braking phase.
From the computational point of view the problem appears really challenging. In fact, it is necessary to made an unsteady evaluation, following the car in its velocity history. Furthermore, the geometry representation must be very refined, because the problem is highly related to the small details, and a corrected representation of all the geometrical elements is necessary to avoid an uncorrected analysis of the resulting flow. This imply really high requirements in computational capabilities, and HPC appears essential.
In order to make an assessment of this problem, a numerical procedure, be presented in the present paper, was settled. The numerical procedure is based on the CFD code Ansys-Fluent 14.5, by using a RANS approach with a realizable k-ε model and non-equilibrium wall function.
The reference car is the Ferrari production one. The geometry representation is very refined, and the volume grid is represented by about 60 millions of cells.
Both the time history of the car velocity and the gas mass flow rate are given, defined by means of user-defined functions, and the evaluation was made following them.
The total time of the simulation was 20 s, with a time step of 0.01 s and 10 internal iterations.
In order to analyse the trajectory of the exhaust gas a particle tracking technique was used, by activating the discrete phase model. The injection zone was coincident with the exhausts. As an example, the particle traces at a given time step is shown in fig. 1.
The evaluation was made on a 512 cores cluster in about 4 days.
The results of the numerical evaluation has been confirmed by the analysis of the real behaviour, and the presented results given an important support to define a geometrical set-up suitable to avoid the problem of the interference between the car and the gas exhaust, with a consequent improvement in the comfort level
Chamazulene-rich artemisia arborescens essential oils affect the cell growth of human melanoma cells
No full textArtemisia arborescens is an aromatic shrub whose essential oils are considered a potential source of molecules with industrial and pharmaceutical interest. The chemical profile of A. arborescens essential oils (EOs) was shown to be quite variable and various chemotypes have been identified. In this study, we compared the EOs composition of A. arborescens leaves and flowers collected from four different locations in Sicily. The EOs were assayed for their antiproliferative activity against A375 human malignant melanoma cells, also testing cell viability and cell membrane integrity. The evaluation of DNA fragmentation and caspase-3 activity assay was employed for the detection of apoptosis. The expression of Bcl-2, Bax, cleaved caspase-9, PTEN (Phosphatase and tensin homolog), Hsp70 (Heat Shock Protein 70 kilodaltons) and SOD (superoxide dismutase) proteins was evaluated by Western blot analysis. The levels of ROS and GSH were also analyzed. Results show that EOs presented significant differences in their composition, yield, and cytotoxic activity depending on the collection site. The chamazulene/camphor-rich EOs from plants collected in Acqua Calda (Lipari) resulted particularly active on melanoma cancer cells (IC50 values of 6.7 and 4.5 μg/mL), being able to trigger apoptotic death probably interfering with endogenous defense mechanisms. These oils may be considered as a natural resource of chamazulene, containing this compound up to 63%
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