Dipole Oscillations in Fermionic Mixtures

We study dipole oscillations in a general fermionic mixture: starting from the Boltzmann equation, we classify the different solutions in the parameter space through the number of real eigenvalues of the small oscillations matrix. We discuss how this number can be computed using the Sturm algorithm and its relation with the properties of the Laplace transform of the experimental quantities. After considering two components in harmonic potentials having different trapping frequencies, we study dipole oscillations in three-component mixtures. Explicit computations are done for realistic experimental setups using the classical Boltzmann equation without intra-species interactions. A brief discussion of the application of this classification to general collective oscillations is also presented.Comment: Published versio

Role of fourth-order phase-space moments in collective modes of trapped Fermi gases

We study the transition from hydrodynamic to collisionless behavior in collective modes of ultracold trapped Fermi gases. To that end, we solve the Boltzmann equation for the trapped Fermi gas via the moments method. We showed previously that it is necessary to go beyond second-order moments if one wants to reproduce the results of a numerical solution of the Boltzmann equation. Here, we will give the detailed description of the method including fourth-order moments. We apply this method to the case of realistic parameters, and compare the results for the radial quadrupole and scissors modes at unitarity to experimental data obtained by the Innsbruck group. It turns out that the inclusion of fourth-order moments clearly improves the agreement with the experimental data. In particular, the fourth-order moments reduce the effect of collisions and therefore partially compensate the effect of the enhanced in-medium cross section at low temperatures.Comment: 10 pages, 2 figures; published versio

Collective modes of trapped Fermi gases with in-medium interaction

Due to Pauli blocking of intermediate states, the scattering matrix (or $T$ matrix) of two fermionic atoms in a Fermi gas becomes different from that of two atoms in free space. This effect becomes particularly important near a Feshbach resonance, where the interaction in free space is very strong but becomes effectively suppressed in the medium. We calculate the in-medium $T$ matrix in ladder approximation and study its effects on the properties of collective modes of a trapped gas in the normal-fluid phase. We introduce the in-medium interaction on both sides of the Boltzmann equation, namely in the calculation of the mean field and in the calculation of the collision rate. This allows us to explain the observed upward shift of the frequency of the quadrupole mode in the collisionless regime. By including the mean field, we also improve considerably the agreement with the measured temperature dependence of frequency and damping rate of the scissors mode, whereas the use of the in-medium cross section deteriorates the description, in agreement with previous work.Comment: 17 page

Shear Viscosity of Quark Matter

We consider the shear viscosity of a system of quarks and its ratio to the entropy density above the critical temperature for deconfinement. Both quantities are derived and computed for different modeling of the quark self-energy, also allowing for a temperature dependence of the effective mass and width. The behaviour of the viscosity and the entropy density is argued in terms of the strength of the coupling and of the main characteristics of the quark self-energy. A comparison with existing results is also discussed.Comment: 15 pages, 4 figure

Another Chance: Adaptive reuse of the built heritage strategies for circular creativity

The study delves into the realm of adaptive reuse, exploring its potential in sustainable urban development, particularly focusing on public buildings within the cultural and creative sectors. Through a multiple case study analysis, both qualitative and quantitative methods were employed to scrutinize design strategies and spatial transformations in recent adaptive reuse projects of existing structures. This research investigates the evolution of adaptive reuse, highlighting its historical and theoretical underpinnings, and subsequently examines contemporary approaches towards existing structures in cultural, creative, and public domains. The study findings reveal common characteristics and innovative design strategies employed in recent adaptive reuse projects, emphasizing the transformative potential of neglected or abandoned urban spaces. Utilizing a comprehensive methodology involving case study analyses and diverse data collection techniques, the research underscores the significance of adaptive reuse as an established practice in contemporary architectural and urban design. The article's contribution to the social and economic dimensions of urban development lies in understanding and promoting sustainable, resource-saving strategies. This work paves the way for future research, suggesting potential expansions in creating an 'atlas of adaptive reuse' and exploring comparative analyses between existing reuse and new construction, specifically focusing on public buildings with civic-cultural uses

Numerical solution of the Boltzmann equation for the collective modes of trapped Fermi gases

We numerically solve the Boltzmann equation for trapped fermions in the normal phase using the test-particle method. After discussing a couple of tests in order to estimate the reliability of the method, we apply it to the description of collective modes in a spherical harmonic trap. The numerical results are compared with those obtained previously by taking moments of the Boltzmann equation. We find that the general shape of the response function is very similar in both methods, but the relaxation time obtained from the simulation is significantly longer than that predicted by the method of moments. It is shown that the result of the method of moments can be corrected by including fourth-order moments in addition to the usual second-order ones and that this method agrees very well with our numerical simulations.Comment: 13 pages, 8 figures, accepted for publication in Phys. Rev.

Cultural-led Adaptive Reuse for development of consolidated urban spaces

As recent case studies show, the concept of Adaptive Reuse and its strategies – mainly associated to creative-led regenerations of post-industrial complexes – have been transferred to buildings and urban complexes inside the consolidated city. The analysis of recent strategies of re-activation of historical buildings and their enlarged urban context in European and International case studies shows how these reuse strategies are crucial for sustainable development of contemporary historical city centres. The analysis of emblematic and renowned case studies aims at underline architectural design strategies that make adaptive reuse of the built heritage a resource capable of generating added value for society

Resíduos de aflatoxina B1 em fígado de codornas japonesas (Coturnix japonica) expostas a alimentos contaminados e à corticosterona exógena

The combined effect of aflatoxin B1 (AFB1 ) exposition and stress induced by corticosterone (CORT) upon the residual aflatoxin levels in livers of Japanese quail was examined. A total of 144 Japanese quail (Coturnix japonica) were divided into 6 treatments with 6 replicates per treatment, each containing 2 males and 2 females. The different treatments resulted from the combination of the presence or absence of CORT in drinking water (5 mg/L) with the presence or absence of AFB1 supplementation (100 or 500 ng/g). Dietary treatments were offered from 5 to 11 weeks of age. The different diets were: Treatment (T) 1: basal diet (B) AFB1 (15 ng/g); T2: B plus AFB1 (100 ng/g); T3: B plus AFB1 (500 ng/g); T4: B plus CORT (5 mg/L); T5: B plus AFB1 (100 ng/g) and CORT (5 mg/L); and T6: B plus AFB1 (500 ng/g) and CORT (5 mg/L). The residual levels of AFB1 were remarkably higher in livers of birds fed with AFB1 in comparison with those belonging to the group that received a combination of AFB1 and CORT (P< 0.05). A plausible explanation about the facts that could be responsible for observed reduction in the toxin carryover in liver was suggested. These results are very striking and may constitute the start point for a series of studies that aim to elucidate the precise influence of hypothalamic-pituitary-adrenal axis (HPA) response to stress in birds exposed to AFB.Estudou-se o efeito combinado da exposição à aflatoxina B1 (AFB1 ) e o estresse induzido por corticosterona (CORT) sobre os níveis de residuais de AFB1 em fígados de codornas japonesas. Um total de 144 codornas japonesas (Coturnix japonica) foram divididas em 6 tratamentos com 6 repetições por tratamento, cada uma contendo 2 machos e 2 fêmeas. As dietas dos tratamentos foram oferecidas da 5ª até a 11ª semana de idade. Os diferentes tratamentos resultaram da combinação da presença ou ausência de CORT na água de beber (5 mg / L), com a presença ou ausência de suplementação AFB1 (100 ou 500 ng /g) As dietas diferentes foram: Tratamento (T) 1: dieta basal (B) AFB1 (15 ng/g); T2: B mais AFB1 (100 ng / g); T3: B mais AFB1 (500 ng / g); T4: B mais CORT (5 mg / L); T5: B mais AFB1 (100 ng / g) e CORT (5 mg / L), e T6: B mais AFB1 (500 ng / g) e CORT (5 mg / L). Os níveis residuais de AFB1 foram significativamente mais elevados em fígados de aves alimentadas com AFB1 em comparação com os que pertencem ao grupo que recebeu uma combinação de AFB1 e CORT (P< 0,05). Sugere-se uma possível explicação para a redução dos níveis da toxina observada naqueles animais submetidos a dieta com CORT. Estes resultados constituem-se de um ponto de início para uma série de estudos que visam a elucidar a influência da resposta do eixo hipotalâmico-hipofisário-adrenais (HPA) ao stress em aves expostas a AFB.Fil: Magnoli, Alejandra Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Chiacchiera, Stella Maris. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rosa, Carlos Alberto da Rocha. Universidade Federal Rural de Rio de Janeiro; BrasilFil: Dalcero, Ana Maria. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Marin, Raul Hector. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Negligible effects of tryptophan on the aflatoxin adsorption of sodium bentonite

The main objective of this study was to determine if the competitive adsorption of tryptophan (Trp) and aflatoxin B1 (AFB1) could potentially affect the ability of a sodium bentonite (NaB) to prevent aflatoxicosis in monogastric animals. The adsorption of Trp and AFB1 on this adsorbent is fast and could be operating on the same time-scale making competition feasible. In vitro competitive adsorption experiments under simulated gastrointestinal conditions were performed. A high affinity of the clay for Trp and NaB was observed. The effect of an excess of KCl to mimic the ionic strength of the physiological conditions were also investigated. A six-times decrease in the Trp surface excess at saturation was observed. A similar behaviour was previously found for AFB1 adsorption. Taking into account the amount of Trp adsorbed by the clay and the usual adsorbent supplementation level in diets, a decrease in Trp bioavailability is not expected to occur. Tryptophan adsorption isotherms on NaB were ‘S’-shaped and were adjusted by the Frumkin–Fowler–Guggenheim model. The reversibility of the adsorption processes was investigated in order to check a potential decrease in the ability of NaB to protect birds against chronic aflatoxicoses. Adsorption processes were completely reversible for Trp, while almost irreversible for AFB1. In spite of the high affinity of the NaB for Trp, probably due to the reversible character of Trp adsorption, no changes in the AFB1 adsorption isotherm were observed when an excess of the amino acid was added to the adsorption medium. As a consequence of the preferential and irreversible AFB1 adsorption and the reversible weak binding of Trp to the NaB, no changes in the aflatoxin sorption ability of the clay are expected to occur in the gastrointestinal tract of birds.Fil: Magnoli, Alejandra Paola. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Copia, P.. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; ArgentinaFil: Monge, Maria del Pilar. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Magnoli, Carina Elizabeth. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Dalcero, Ana Maria. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Chiacchiera, Stella Maris. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin