11,567 research outputs found

    On the strategy frequency problem in batch Minority Games

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    Ergodic stationary states of Minority Games with S strategies per agent can be characterised in terms of the asymptotic probabilities Ï•a\phi_a with which an agent uses aa of his strategies. We propose here a simple and general method to calculate these quantities in batch canonical and grand-canonical models. Known analytic theories are easily recovered as limiting cases and, as a further application, the strategy frequency problem for the batch grand-canonical Minority Game with S=2 is solved. The generalization of these ideas to multi-asset models is also presented. Though similarly based on response function techniques, our approach is alternative to the one recently employed by Shayeghi and Coolen for canonical batch Minority Games with arbitrary number of strategies.Comment: 17 page

    Whole blood transcriptome profiling reveals positive effects of olive leaves-supplemented diet on cholesterol in goats

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    Agro-industrial by-products represent an important source of compounds credited with high biotechnological potential. In the last decade, considerable interest has developed toward the use of these matrices as dietary supplements in the zootechnical field, paying particular attention to the qualitative aspects associated with animal products. However, less is known about the effect of these matrices on gene expression and thus on animal metabolism. Therefore, the aim of this study was to analyze the whole blood transcriptome of lactating goats fed a dietary supplementation with 10% olive leaves (OL), one of the main by-products deriving from the olive oil chain supply. By applying a false discovery rate (FDR) < 0.05 and a Log2 Fold change (Log2Fc) lower than −0.5 or higher than +0.5, it was possible to identify the differential regulation of gene coding for the apolipoprotein B (apoB) mRNA editing enzyme catalytic subunit 2 (APOBEC2), which showed downregulation in goats that received the dietary supplementation. An evaluation of both blood and milk cholesterol was performed, taking into account the strong association between plasma apoB and low-density lipoprotein (LDL). Results showed significantly lower concentrations of circulating cholesterol and cholesterol released into the milk through the mammary gland, demonstrating positive effects of OL feeding on animal welfare and potential health benefits for consumers

    Serosurvey of schmallenberg virus infection in sheep in Abruzzo, Italy : short report

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    Infection with Schmallenberg virus (SBV) causes congenital musculoskeletal and vertebral malformations as well as neurological failures in fetuses of several ruminant species. In this study 1038 sheep samples from 10 flocks in the provinces of Chieti, Teramo and Pescara in Italy have been tested for antibodies against SBV by ELISA test. The purpose of the study was to ascertain the extent of SBV infections in sheep in Italy. The results of the ELISA test identified at least one positive animal in 9 of the 10 sheep flocks tested, and a mean within-flock prevalence of 8.57%. Furthermore, large variability of positive animals between flocks was observed (0 and 42.5%). These results demonstrate that SBV was endemic in this region and there could be is a risk of novel SBV infections in the following lambing season, raising serious concerns about its so rapid and pervasive spread

    Evaluation of Commercial Meat Products of Red Chicken Reared under LED Lights

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    The objective of our study was to investigate the role of three different light-color tempera-tures of Light-Emitting Diodes (LEDs) [Neutral (K = 3300 − 3700); Warm (K = 3000 − 2500) and Cool (K = 5500 − 6000)] on the qualitative attributes of breast meat obtained from male AZ Extra Heavy Red chickens. The comparison was made with meat deriving from chickens reared in the presence of classic neon lighting (Control). The meat was analyzed for the determination of both physical and chemical properties (cooking loss, moisture, total lipids and fatty acid composition). Furthermore, meat samples subjected to cooking were also analyzed for the identification of volatile compounds produced during the process; such evaluation was performed both immediately after cooking (T0) and after 7 days (T7) of cooked-meat storage at 4◦ C. Cooking-loss values were higher for samples from chickens raised with Neutral LED (p < 0.05) compared to the other groups. For the fatty acid profiles of the meat, higher values were found for monounsaturated fatty acids (MUFAs) such as C18:1, C9 and C16:1 in Cool LED compared to the Control. Regarding the volatile profile of cooked meat, compounds belonging to the families of aldehydes, alcohols, ketones, and aromatic compounds were identified. Compounds belonging to the aldehyde family, such as hexanal, increased in Cool LED samples at T0 in comparison to the Control. On the other hand, the amounts of 1-Pentanol, 1-Octanol and 2-Octen-1-ol, which belong to the alcohol family, increased at T7 in Cool LED samples compared to the Warm LED. In conclusion, LED lighting showed to be effective in inducing significant variations on chicken breast meat ready to be introduced to the market, in particular regarding fatty acid profiles and the accumulation of volatile compounds. However more in-depth evaluation is needed for the identification of modifications regarding the sensorial sphere, which could have an impact on the consumer acceptability of the product

    Performance of the diamond active target prototype for the PADME experiment at the DAΦ\PhiNE BTF

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    The PADME experiment at the DAΦ\PhiNE Beam-Test Facility (BTF) is designed to search for the gauge boson of a new U(1)\rm U(1) interaction in the process e+^+e−→γ^-\rightarrow\gamma+A′\rm A', using the intense positron beam hitting a light target. The A′\rm A', usually referred as dark photon, is assumed to decay into invisible particles of a secluded sector and it can be observed by searching for an anomalous peak in the spectrum of the missing mass measured in events with a single photon in the final state. The measurement requires the determination of the 4-momentum of the recoil photon, performed by a homogeneous, highly segmented BGO crystals calorimeter. A significant improvement of the missing mass resolution is possible using an active target capable to determine the average position of the positron bunch with a resolution of less than 1 mm. This report presents the performance of a real size (2x2cm2)\rm (2x2 cm^2) PADME active target made of a thin (50 μ\mum) diamond sensor, with graphitic strips produced via laser irradiation on both sides. The measurements are based on data collected in a beam test at the BTF in November 2015.Comment: 7 pages, 10 figure

    DSP-Based Stepping Motor Drivers for the LHC Collimators

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    The control electronics of the LHC collimators stepping motors will be located in radiation safe zones up to 800 meters far from the motors. With such cable lengths the standard chopping drivers do not work properly because of the voltage losses on the cable and even more because of the high cable capacitance. The capacitance in fact produces a ringing phenomenon on the driver feedback current that limits the control chopping frequency to the point of being incompatible with the tight EM emissions requirements of the LHC tunnel. In some cases the feedback loop may even become unstable and the driver would fail. The problem was solved by accurately modeling the overall motor-cable system taking into account non-linearities due to hysteresis and eddy currents and by designing an adaptive digital controller, self-tuning to the real cable length. The controller will aim at increasing the chopping frequency to reduce the spectral density of the emissions and at damping the oscillations of the feedback current to avoid instability. In this paper the model of the motor-cable system as well as the digital controller are described. Particular attention is devoted to the hardware implementation based on a TI Cx2000 DSP

    Reconstructing Late Quaternary Paleovalley Systems of Italy Through mHVSR: A Tool for Seismic Hazard Assessment in Modern Coastal Lowlands

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    Effective site characterization in highly urbanized coastal lowlands requires accurate stratigraphic and geophysical investigations. In these regions, which typically host shallowly buried paleovalley systems formed in response to Quaternary glacio-eustatic fluctuations, the marked lithologic contrast between soft sediment paleovalley fills and the adjacent, stiff substrate has the potential to modify earthquake motions, and assessment of critical parameters, such as shear wave velocities (VS) and resonance frequencies (f), should be coupled with detailed stratigraphic architecture. To evaluate the potential of the microtremor horizontal-to-vertical spectral ratio (mHVSR) for paleovalley recognition and mapping, we performed mHVSR measurements along the Adriatic coastal plain of Italy, where two paleovalley systems (Pescara and Manfredonia) have been recently identified. In both areas, we detected rapid lateral variations in resonance frequencies and highlighted laterally continuous impedance contrasts. Relying on a robust stratigraphic framework, we carefully evaluated the relation between geological and geophysical data and identified the stratigraphic surfaces responsible for the observed resonances. We derived VS models for the sediment fill, reconstructing the geometry of the two buried paleovalleys. We address the importance of evaluating the geological context when designing microzonation studies, for a reliable interpretation of changes in resonance frequencies.When earthquakes occur, buildings shake differently based on several factors, including seismic wave velocity, natural resonance frequencies, and local geological characteristics. Beneath modern coastal lowlands, the presence of paleovalley systems can significantly modify the ground motion. Identification of these buried bodies is therefore essential to assess and reduce seismic hazard. Paleovalleys are shallow incisions formed under periods of fluvial erosion in response to Quaternary climate fluctuations, and subsequently filled with very soft clay. These bodies are found worldwide, and do not have any geomorphological evidence, making their recognition challenging. Geologists typically use expensive sediment core analysis to identify paleovalleys, but this method can only provide spotty information. Geophysical exploration techniques that rely on microtremors (small vibrations on the Earth) can complement mapping of these buried bodies. In this work, we tested this technique in Pescara and Mafredonia (Adriatic coastal plain, Italy), providing dense information about paleovalley geometries and geophysical parameters crucial for predicting how the ground will shake during an earthquake. This study also highlights the importance of integrating disciplines to improve our understanding of subsoil and to design future studies to mitigate seismic hazards.Paleovalley fills are key sediment bodies made up of soft clay, tens of m thick and few km wide, buried beneath coastal lowlands worldwideMicrotremor-based paleovalley profiles and stratigraphic cross-sections exhibit strong similarityMicrotremor can provide shear wave velocities and resonance frequencies of paleovalleys, key parameters for seismic hazard mitigatio

    Mechanical Systems: Symmetry and Reduction

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    Reduction theory is concerned with mechanical systems with symmetries. It constructs a lower dimensional reduced space in which associated conservation laws are taken out and symmetries are \factored out" and studies the relation between the dynamics of the given system with the dynamics on the reduced space. This subject is important in many areas, such as stability of relative equilibria, geometric phases and integrable systems

    Evolutive pattern of Calomys hummelincki (Husson, 1960; Rodentia, Sigmodontinae) inferred from cytogenetic and allozymic data.

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    The main purpose of this research was to understand the evolutive history of the sigmodontine rodent Calomys hummelincki (Husson 1960), tribe Phyllotini from chromosomal and allozymic data, and evaluate the hypotheses that explains the colonization and evolution of sigmodontine rodents in South America. C. hummelincki is restricted to the Northern South American region, which comprises Venezuela, Aruba and Curaçao islands where specimen sampling was done. The cytogenetic analysis showed that all populations studied have the same diploid number (2n=60) and fundamental number (FN=64). Constitutive heterochromatin was observed on pericentromeric positions in almost all chromosomes. NOR regions were observed on four pairs of acrocentric chromosomes. G-banding allowed us to identify almost all pair positions in the C. hummelincki chromosome complement. The G-banding also permitted a comparison of the C. hummelincki pattern with those published for C. callidus, C. venustus and C. laucha species. G-banded information indicates that hummelincki is not directly derived from laucha. The results are constrained with published allozymic and molecular data obtained in previous studies. The overall analysis seems to support Reig´s hypothesis of a south to north colonization of genus Calomys in South America
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