7,457 research outputs found

    Optimal Monetary Policy and the Asset Market: A Non-cooperative Game

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    In this paper we construct a model of a policy game in order to analyse the optimal reaction function of the Central Bank to a shock in the asset market. In doing so, we consider three different noncooperative games: Nash equilibrium, Stackelberg equilibrium with “FED” as leader and “ECB” Stacklberg as leader. Three major conclusions can be drawn from our work in the presence of asset market shocks. First, in the Nash equilibrium the ECB will adopt a less restrictive monetary policy compared to the FED’s behaviour. Second, comparing the Nash and Stackelberg non-cooperative equilibria, the Stackelberg solution is certainly superior when the FED is the leader, but the Nash solution is superior for the follower. Finally, irrespective of where the shocks originate, if the FED would choose the Stackelberg leader equilibrium the ECB would minimize its social loss along with a lower level of interest rates

    Dark Matter and IMF normalization in Virgo dwarf early-type galaxies

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    In this work we analyze the dark matter (DM) fraction, fDMf_{DM}, and mass-to-light ratio mismatch parameter, ÎŽIMF\delta_{IMF} (computed with respect to a Milky-Way-like IMF), for a sample of 39 dwarf early-type galaxies (dEs) in the Virgo cluster. Both fDMf_{DM} and ÎŽIMF\delta_{IMF} are estimated within the central (one effective radius) galaxy regions, with a Jeans dynamical analysis that relies on galaxy velocity dispersions, structural parameters, and stellar M/L ratios from the SMAKCED survey. In this first attempt to constrain, simultaneously, the IMF normalization and the DM content, we explore the impact of different assumptions on the DM model profile. On average, for a NFW profile, the ÎŽIMF\delta_{IMF} is consistent with a Chabrier-like normalization (ÎŽIMF∌1\delta_{IMF} \sim 1), with fDM∌0.35f_{DM} \sim 0.35. One of the main results of the present work is that for at least a few systems the ÎŽIMF\delta_{IMF} is heavier than the MW-like value (i.e. either top- or bottom-heavy). When introducing tangential anisotropy, larger ÎŽIMF\delta_{IMF} and smaller fDMf_{DM} are derived. Adopting a steeper concentration-mass relation than that from simulations, we find lower ÎŽIMF\delta_{IMF} (<1< 1) and larger fDMf_{DM}. A constant M/L profile with null fDMf_{DM} gives the heaviest ÎŽIMF\delta_{IMF} (∌2\sim 2). In the MONDian framework, we find consistent results to those for our reference NFW model. If confirmed, the large scatter of ÎŽIMF\delta_{IMF} for dEs would provide (further) evidence for a non-universal IMF in early-type systems. On average, our reference fDMf_{DM} estimates are consistent with those found for low-σe\sigma_{e} (∌100 kms−1\rm \sim 100 \, \rm km s^{-1}) early-type galaxies (ETGs). Furthermore, we find fDMf_{DM} consistent with values from the SMAKCED survey, and find a double-value behavior of fDMf_{DM} with stellar mass, which mirrors the trend of dynamical M/L and global star formation efficiency with mass.Comment: 11 pages, 3 figures, 1 table, published on MNRAS. Figure 1 has been updated with respect to version 1, including the range of values found if the S\'ersic index, n, is varied from 0.5 to 2 (dark-green curves

    Influence of space allowance on the welfare of weaned buffalo (Bubalus Bubalis) calves

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    Twenty weaned female buffalo calves were used to evaluate the effect of space allowance in relation to their body surface area on a range of behavioural and physiological parameters. Body surface area in m2 was calculated as 0.12 body weight0.60. Ten calves received 50% of body surface as space allocation (Group 50), 10 others received 90% of body surface area (Group 90). Animals in Group 50 lay with a lower number of outstretched legs than calves in Group 90. Buffaloes from Group 50 were observed standing more frequently than animals from Group 90 ( P < 0.001). The proportions of idling ( P < 0.01) and lying idle observations ( P < 0.001) were higher for Group 90 than for Group 50. Group 90 performed a higher number of non-agonistic interactions than Group 50 ( P < 0.01), whereas the opposite was observed for the number of agonistic interactions ( P < 0.01). When exposed to open field testing, Group 50 animals displayed an increased duration of movement, number of galloping events and more vocalisation. Neither immune responses to phytohemagglutinin and ovalbumin nor the cortisol response to exogenous ACTH were affected by treatment. It was concluded that 50% of body surface area may be an inadequate space allowance for weaned calves

    Colour gradients of high-redshift Early-Type Galaxies from hydrodynamical monolithic models

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    We analyze the evolution of colour gradients predicted by the hydrodynamical models of early type galaxies (ETGs) in Pipino et al. (2008), which reproduce fairly well the chemical abundance pattern and the metallicity gradients of local ETGs. We convert the star formation (SF) and metal content into colours by means of stellar population synthetic model and investigate the role of different physical ingredients, as the initial gas distribution and content, and eps_SF, i.e. the normalization of SF rate. From the comparison with high redshift data, a full agreement with optical rest-frame observations at z < 1 is found, for models with low eps_SF, whereas some discrepancies emerge at 1 < z < 2, despite our models reproduce quite well the data scatter at these redshifts. To reconcile the prediction of these high eps_SF systems with the shallower colour gradients observed at lower z we suggest intervention of 1-2 dry mergers. We suggest that future studies should explore the impact of wet galaxy mergings, interactions with environment, dust content and a variation of the Initial Mass Function from the galactic centers to the peripheries.Comment: 13 pages, 7 figures, 1 table, accepted for publication on MNRA

    Sustainability and welfare of Podolian cattle

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    The aim of the present study was to evaluate the sustainability and welfare of extensively farmed Podolian cattle. A trained interviewer visited 50 farms and filled in a checklist which included four cards corresponding to the following animal categories: calves, replacements, feeders and adults. The analysis of the farming system showed that animals were able to express their main behavioural patterns. In addition, recorded animal-related variables indicated that Podolian cattle could benefit from high standards of welfare. Sustainability of the Podolian farming system in terms of human edible returns was evaluated for two production systems producing 10-month-old calves (10 month) and 18-month-old young bulls (18 month), respectively. Edible returns for humans were low when all animal intakes were considered for both production systems. However, if returns were computed using not only the amount of food used by the animals but also consumable by humans, yields were much higher for 18-month systems [103% crude protein (CP) and 37.1% gross energy (GE)] and so high that they could not be computed for 10-month systems. These results indicate either a low degree of competition (18-month system) or no competition (10-month system) between humans and Podolian cattle. Perceptions of sustainability and welfare of Podolian cattle may promote a favourable positioning of products in premium-price markets and help preserving this breed and the related traditional farming system

    Rumination in Borderline Personality Disorder: An examination of interpersonal contexts in experimental and daily life settings

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    This study examined whether Borderline Personality Disorder (BPD) features predict increased rumination in response to interpersonal contexts, leading to increased negative affect (NA) outcomes across self-report, experimental, and daily life settings. As BPD is characterized by sustained NA, emotion dysregulation, and pervasive difficulties in interpersonal relationships, interpersonal contexts may present a specific liability for individuals with BPD to ruminate, and subsequently, experience enduring NA. Undergraduate participants (N=119) completed measures of BPD features, dispositional rumination, emotion dysregulation, and both 1) a laboratory protocol that measured spontaneous rumination and affective reactivity to non-interpersonal (sad film clip) and interpersonal (Cyberball) stimuli and 2) a 7-day Ecological Momentary Assessment (EMA) that measured hourly peak NA, deployment of rumination at time of peak NA, interpersonal context at peak NA, and immediate NA relative to the EMA prompt. Multiple mediation models and general linear models were fit to examine study hypotheses. Results suggest differences in the relationships at trait level compared to state and momentary levels, wherein BPD predicts trait rumination and emotion dysregulation only. However, findings support that interpersonal contexts produce increased rumination that, in turn, may sustain negative affective states. Results suggest the need to include interpersonal considerations as a context for understanding ruminative cycles and affective outcomes

    Testing Verlinde's emergent gravity in early-type galaxies

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    Verlinde derived gravity as an emergent force from the information flow, through two-dimensional surfaces and recently, by a priori postulating the entanglement of information in 3D space, he derived the effect of the gravitational potential from dark matter (DM) as the entropy displacement of dark energy by baryonic matter. In Emergent Gravity (EG) this apparent DM depends only on the baryonic mass distribution and the present-day value of the Hubble parameter. In this paper we test the EG proposition, formalized by Verlinde for a spherical and isolated mass distribution, using the central velocity dispersion, σ\sigma and the light distribution in a sample of 4260 massive and local early-type galaxies (ETGs) from the SPIDER sample. Our results remain unaltered if we consider the sample of 807 roundest field galaxies. We derive the predictions by EG for the stellar mass-to-light ratio (M/L) and the Initial Mass Function (IMF), and compare them with the same inferences derived from a) DM-based models, b) MOND and c) stellar population models. We demonstrate that, consistently with a classical Newtonian framework with a DM halo component, or alternative theories of gravity as MOND, the central dynamics can be fitted if the IMF is assumed non-universal. The results can be interpreted with a IMF lighter than a standard Chabrier at low-σ\sigma, and bottom-heavier IMFs at larger σ\sigma. We find lower, but still acceptable, stellar M/L in EG theory, if compared with the DM-based NFW model and with MOND. The results from EG are comparable to what is found if the DM haloes are adiabatically contracted and with expectations from spectral gravity-sensitive features. If the strain caused by the entropy displacement would be not maximal, as adopted in the current formulation, then the dynamics of ETGs could be reproduced with larger M/L. (abridged)Comment: 12 pages, 2 figures, submitted to MNRAS. The updated manuscript presents significantly altered conclusions, after discovering an internal bug in an older version of the Mathematica package, leading to incorrect numerical results when calculating the derivatives of Gamma function

    Housing system and welfare of buffalo (Bubalus bubalis) cows

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    Twenty-eight buffalo cows were used to evaluate the effect of housing system on a range of behavioural and physiological variables. Fourteen cows were group-housed in a loose open-sided barn with a concrete floor and 10 m2 per head as space allowance (group IS). Fourteen others were group-housed in a similar barn but they could also benefit from an outdoor yard with 500 m2 per head as space allowance, free access to potholes for wallowing and spontaneous vegetation (group TS). Animals were subjected to six sessions of instantaneous scan sampling at 10-day intervals. Behavioural variables were expressed as proportions of subjects observed in each category of posture and activity. Phytohaemagglutinin (PHA) was used to perform a skin test based on non-specific delayed type hypersensitivity, whereas 20 mg of ovalbumin were injected subcutaneously to evaluate humoral immune response. Blood samples for evaluation of cortisol concentration were collected immediately prior to exogenous porcine ACTH injection and 1, 2 and 4 h after. The metabolic status of the animals and milk production were also monitored. The proportion of idling animals was higher in group IS than in group TS (P< 0·001). More IS buffalo cows were observed eating at the manger than TS animals (P< 0·001). A higher proportion of TS animals were observed in the sun (P< 0·001). Grazing and bathing activities were recorded only for TS animals. Our findings suggest that buffalo cows kept in intensive conditions and having no access to ample yards and potholes may extend their periods of idling with negative effects on the state of welfare. Immune responses, metabolite concentrations and milk production were not affected by treatment, whereas cortisol levels were higher in IS animals (P< 0·05). The provision of a housing system similar to natural conditions was able to improve the welfare of buffalo cows as indicated by the expression of some species-specific natural behaviours. Such conditions were also associated with lower adrenal cortex response to ACTH injection, possibly as a consequence of the higher degree of initiative allowed to TS cows

    MOND and IMF variations in early-type galaxies from ATLAS3D

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    MOdified Newtonian dynamics (MOND) represents a phenomenological alternative to dark matter (DM) for the missing mass problem in galaxies and clusters of galaxies. We analyze the central regions of a local sample of ∌220\sim 220 early-type galaxies from the ATLAS3D\rm ATLAS^{3D} survey, to see if the data can be reproduced without recourse to DM. We estimate dynamical masses in the MOND context through Jeans analysis, and compare to ATLAS3D\rm ATLAS^{3D} stellar masses from stellar population synthesis. We find that the observed stellar mass--velocity dispersion relation is steeper than expected assuming MOND with a fixed stellar initial mass function (IMF) and a standard value for the acceleration parameter a0a_{\rm 0}. Turning from the space of observables to model space, a) fixing the IMF, a universal value for a0a_{\rm 0} cannot be fitted, while, b) fixing a0a_{\rm 0} and leaving the IMF free to vary, we find that it is "lighter" (Chabrier-like) for low-dispersion galaxies, and "heavier" (Salpeter-like) for high dispersions. This MOND-based trend matches inferences from Newtonian dynamics with DM, and from detailed analysis of spectral absorption lines, adding to the converging lines of evidence for a systematically-varying IMF.Comment: 6 pages, 3 figures, accepted for publication on MNRAS Letters, typos corrected and further references adde
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