2,882 research outputs found
Technical Note: Year, season, and parity effect on weaning performance of the Carmagnola Grey Rabbit breed
No full textTo evaluate the main environmental factors in the productivity of Carmagnola Grey rabbits, an endangered breed indigenous to northern Italy, data collected over 8 years were analysed. Production data on the pure closed nucleus herd of the University of Turin were used. Effects of parity, season and age of weaning on the number of rabbits born alive and weaned, litter weight and individual average weight at weaning were studied. The following average performance rates over the 8 years period were determined: 8.1 live born and 7.2 weaned kits per litter and a litter weight at weaning of 7287 g or 1024 g individual weaning weight. Year and season both had a significant effect (P < 0.001) on all the traits studied as well as weaning age (P < 0.001).Lazzaroni, C.; Biagini, D.; Redaelli, V.; Luzi, F. (2012). Technical Note: Year, season, and parity effect on weaning performance of the Carmagnola Grey Rabbit breed. World Rabbit Science. 20(1):57-60. https://doi.org/10.4995/wrs.2012.1031SWORD576020
A priori estimates and large population limits for some nonsymmetric Nash systems with semimonotonicity
No full textWe address the problem of regularity of solutions (Formula presented.) to a family of semilinear parabolic systems of (Formula presented.) equations, which describe closed-loop equilibria of some (Formula presented.) -player differential games with Lagrangian having quadratic behaviour in the velocity variable, running costs (Formula presented.) and final costs (Formula presented.). By global (semi)monotonicity assumptions on the data (Formula presented.) and (Formula presented.), and assuming that derivatives of (Formula presented.) in directions (Formula presented.) are of order (Formula presented.) for (Formula presented.), we prove that derivatives of (Formula presented.) enjoy the same property. The estimates are uniform in the number of players (Formula presented.). Such a behaviour of the derivatives of (Formula presented.) arise in the theory of Mean Field Games, though here we do not make any symmetry assumption on the data. Then, by the estimates obtained we address the convergence problem (Formula presented.) in a ‘heterogeneous’ Mean Field framework, where players all observe the empirical measure of the whole population, but may react differently from one another. We also discuss some results on the joint (Formula presented.) and vanishing viscosity limit
Effect of handling in pre-weaning rabbits
No full text[EN] The aim of this study was to investigate the effects of regular daily handling on weight gain and on the fear reaction towards a new environment and human beings in domestic kits (Tonic Immobility test: TI, Emergence test: ET). Two groups in the same environment and fed the same diet were analysed: handled group and control (17 litters, 9 kits/litter per group). No differences in weight gain were recorded. During ET at 33 days of age, handled kits took less time to enter the arena than control group kits. TI duration was shorter in handled kits, which required more inductions than the control group. It was found that minimal human contact imposed before nursing reduced the fear of humans in rabbit kits. Our handling method requires minimal contact and can be used to reduce fear and improve welfare in rabbits. Moreover, the short length of the handling procedure allows stockpersons to produce tamer rabbits, reducing stress levels.This research was funded by PRIN 2005 (MUR - Roma). We would like to thank the farm “Erminia Vezzoli” located in Covo (Bergamo, Italy).Zucca, D.; Redaelli, V.; Marelli, S.; Bonazza, V.; Heinzl, E.; Verga, M.; Luzi, F. (2012). Effect of handling in pre-weaning rabbits. World Rabbit Science. 20(2):97-101. https://doi.org/10.4995/wrs.2012.1083SWORD9710120
Effect of environmental exposure conditions on the corrosion rate of carbon steel bars in carbonated concrete
No full textIn urban environments the propagation phase of corrosion can represent a significant part of the entire service life of a reinforced concrete structure. To properly evaluate its duration, the knowledge of the corrosion rate is essential. This paper reports the corrosion rate and corrosion potential of carbon steel bars embedded at different depths (i.e. 10, 25 and 40 mm) in concretes with different binders and water/binder ratio of 0.61, exposed both outdoor in Milan in unshel-tered conditions and in laboratory conditions characterized by different temperatures and relative humidity levels. Concrete resistivity at different depths is also reported. Relative humidity strong-ly influenced the corrosion potential, corrosion rate and resistivity, whilst temperature played an important role only at a high relative humidity level. Correlations between these parameters were analysed and discussed
Data set and 3d model from Emendi M, Sturla F, Ghosh RP, Bianchi M, Piatti F, Pluchinotta FR, Giese D, Lombardi M, Redaelli A, Bluestein D. Patient-Specific Bicuspid Aortic Valve Biomechanics: A Magnetic Resonance Imaging Integrated Fluid-Structure Interaction Approach. Ann Biomed Eng. 2020 Aug 17. doi: 10.1007/s10439-020-02571-4. Epub ahead of print. PMID: 32804291.
No full textData set and 3d model from Emendi M, Sturla F, Ghosh RP, Bianchi M, Piatti F, Pluchinotta FR, Giese D, Lombardi M, Redaelli A, Bluestein D. Patient-Specific Bicuspid Aortic Valve Biomechanics: A Magnetic Resonance Imaging Integrated Fluid-Structure Interaction Approach. Ann Biomed Eng. 2020 Aug 17. doi: 10.1007/s10439-020-02571-4. Epub ahead of print. PMID: 32804291.
This is the abstract:
Congenital bicuspid aortic valve (BAV) consists of two fused cusps and represents a major risk factor for calcific valvular stenosis. Herein, a fully coupled fluid-structure interaction (FSI) BAV model was developed from patient-specific magnetic resonance imaging (MRI) and compared against in vivo 4-dimensional flow MRI (4D Flow). FSI simulation compared well with 4D Flow, confirming direction and magnitude of the flow jet impinging onto the aortic wall as well as location and extension of secondary flows and vortices developing at systole: the systolic flow jet originating from an elliptical 1.6 cm2 orifice reached a peak velocity of 252.2 cm/s, 0.6% lower than 4D Flow, progressively impinging on the ascending aorta convexity. The FSI model predicted a peak flow rate of 22.4 L/min, 6.7% higher than 4D Flow, and provided BAV leaflets mechanical and flow-induced shear stresses, not directly attainable from MRI. At systole, the ventricular side of the non-fused leaflet revealed the highest wall shear stress (WSS) average magnitude, up to 14.6 Pa along the free margin, with WSS progressively decreasing towards the belly. During diastole, the aortic side of the fused leaflet exhibited the highest diastolic maximum principal stress, up to 322 kPa within the attachment region. Systematic comparison with ground-truth non-invasive MRI can improve the computational model ability to reproduce native BAV hemodynamics and biomechanical response more realistically, and shed light on their role in BAV patients' risk for developing complications; this approach may further contribute to the validation of advanced FSI simulations designed to assess BAV biomechanics
Polar effects in free-radical reactions. New catalytic processes in the substitution of heteroaromatic bases bynucleophilic free radicals
No full textPartitioning and Scheduling of Task Graphs on Partially Dynamically Reconfigurable FPGAs
No full textThis paper proposes a new model for the partitioning and scheduling of a specification on partially dynamically reconfigurable hardware. Although this problem can be solved optimally only by tackling its subproblems jointly, the exceeding complexity of such a task leads to a decomposition into two phases. The partitioning phase is based on a new graph-theoretic approach, which aims to obtain near optimality even if performed independently from the subsequent phase. For the scheduling phase, a new integer linear programming formulation and a heuristic approach are developed. Both take into account configuration prefetching and module reuse. The experimental results show that the proposed method compares favorably with existing solutions
Effect of rearing system on carcass traits and meat quality of rabbits
No full textWe have developed a working protocol in order to evaluate the air contamination in different kinds of rabbitries for breeding rabbit used for experimental procedures using an easy instrument for sampling, the SAS® System (PBI International, Italy) and plates filled with different types of cultural media. [1‐2]
The two trials have been performed in a rabbit farm located in the NW of Italy. White New Zealand rabbits (NZR) were housed in two different rooms of the same building, with forced ventilation, one for does and one for fatteners. For air sampling we have used the SAS® System that is an impaction method that allows to enumerate the number of microorganisms directly in elevated convex plates filled with cultural media. A known volume of air is thrown onto a Surfair plate; then the sample is incubated depending on the microorganisms we want to isolate. The results are expressed as CFU (Colony Forming Unit)/m3.
During the first trial developed in the rabbit farm, the bacterial charge we have observed was always above 50 CFU/m3 of aspired air; Micrococcus luteus and Staphylococcus spp. were the most isolated microorganisms in both kind of samples. For fungi, 100% of plates were positive for environmental fungi and yeasts such as Aspergillus spp., Penicillium spp., Alternaria spp. and Rhodotorula rubra but their number remained under 50 CFU/m3. The percentage of dermatophytes isolated was between 50 and 70 and the only species identified was
Trichophyton mentagrophytes as in opened plates. [3] During the second trial, the microbiological results showed a total bacterial charge between 50 and 100 CFU/m3 air flow, using the SAS® System. On the contrary, the total fungal charge (environmental fungi and dermathophytes), keeps below 50 CFU/m3. These values could be considered low (50‐100 CFU/m3) and very low (<50 CFU/m3) with regards to the environmental risk according to the parameters supplied by the SAS System’s producer. The isolated microorganisms were Bacillus (100%), Alternaria (11,09%), Aspergillus
niger (36,12%) and Microsporum gypseum (41,67%). None of the bacteria/fungi that we have isolated was strictly pathogens.
So, the method we have applied for the evaluation of the microbial air quality allows us to obtain good and reproducible qualitative and quantitative results while opened plates allow only a qualitative results. Moreover, the SAS® System is portable and noiseless and it is optimal for sampling air in the nests and in cages or in a facility room.
1. Martino PA, Jacchia G, Cocilovo A. Prevalenza delle dermatofitosi in conigli con lesioni cutanee, utilizzati
per fini scientifici. Atti LII Conv. Naz. SISVet 1998;159‐160
2. Martino PA, Luzi F, Verga M. Microbiological control of the environment in an intensive rabbit rearing.
Proc. of the 8. World Rabbit Congr., WRSA, 576‐581 (2005).
3. Mehta SK, Mishra SK, Pierson DL. Evaluation of three portable sampler for monitoring airborne fungi.
Appl. And Environm. Micr. 1835‐1838 (1996)
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
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