Lies, Deep Fries, and Statistics!! The search for the truth between public attitudes and public behaviour towards genetically modified foods

Consumer/Household Economics, Food Consumption/Nutrition/Food Safety,

Decoherence induced by a dynamic spin environment (I): The universal regime

This article analyzes the decoherence induced on a single qubit by the interaction with a spin chain with nontrivial internal dynamics (XY-type interactions). The aim of the paper is to study the existence and properties of the so-called universal regime, in which the decoherence time scale becomes independent of the strength of the coupling with the environment. It is shown that although such regime does exist, as previously established by Cucchietti \textit{et al} in {\em Phys. Rev. A}, 75:032337 (2007), it is not a clear signature of a quantum phase transition in the environment. In fact, this kind of universality also exists in the absence of quantum phase transitions. A universal regime can be related to the existence of an energy scale separation between the Hamiltonian of the environment and the one characterizing the system-environment interaction. The results presented also indicate that in the strong coupling regime the quantum phase transition does not produce an enhancement of decoherence (as opposed to what happens in the weak coupling regime).Comment: 8 pages, 9 figure

Structural transitions of ion strings in quantum potentials

We analyse the stability and dynamics of an ion chain confined inside a high-finesse optical resonator. When the dipolar transition of the ions strongly couples to one cavity mode, the mechanical effects of light modify the chain properties close to a structural transition. We focus on the linear chain close to the zigzag instability and show that linear and zigzag arrays are bistable for certain strengths of the laser pumping the cavity. For these regimes the chain is cooled into one of the configurations by cavity-enhanced photon scattering. The excitations of these structures mix photonic and vibrational fluctuations, which can be entangled at steady state. These features are signalled by Fano-like resonances in the spectrum of light at the cavity output.Comment: 5 pages, 3 figs - version to appear in PR

Merleau-Ponty and Foucault On the Problem of Knowledge as Conditione

Dialogando con el intento de Philippe Sabot (2013) de mostrar la cercanía de –por un lado– la reconstrucción foucaultiana sobre el “hombre” como “duplicado empí-rico-trascendental” y –por otro lado– el problema de la dualidad de visiones sobre la cuestión antropológica tal como fue planteado por Merleau-Ponty en su curso sobre Las ciencias humanas y la fenomenología, intentaremos sacar a la luz de manera más ajustada cuá-les son las preocupaciones epistemológicas específicas que guían la problematización merleaupontyana. Según señalaremos, el “problema del hombre” tal como aparece en este curso no es, como en Foucault, el que surge a partir de un conocimiento empírico susceptible de ser elevado al rol de reflexión trascendental sobre las condiciones del conocimiento, sino que, a la inversa, se suscita en virtud de que las investigaciones empí-ricas sobre el hombre lo presentan, de modo paradójico, como una conciencia causal-mente condicionada incapaz de nada que pudiéramos llamar “conocimiento”.A continuación, buscaremos reconstruir las premisas en las que se basa esta argumenta-ción merleaupontyana, lo que nos llevará a poner de manifiesto que su rechazo del “psi-cologismo”, el “sociologismo” y el “historicismo” se conecta con la exigencia de que la conciencia pueda ejercer algún tipo de control epistémico sobre sus tomas de posición. Sobre la base de este resultado, señalaremos, por último, que el problema “historicista” tal como aparece en Merleau-Ponty no es reductible a la forma de “relativismo históri-co” que, según Revel (2015), Foucault logra evitar.In a dialogue with the attempt by Philippe Sabot (2013) to show the nearness between, on the one hand, Foucault’s analysis of “man” as an “empirico-transcendental doublet” and, on the other hand, the problem of the duality of visions on the anthropo-logical problem as it was presented by Merleau-Ponty in his course on Human sciences and phenomenology, we will attempt to bring to light, in a more accurate way, what specific epistemological concerns guide the phenomenologist’s questioning. As we will point out, the “problem of man” as it appears in his course is not, as in Foucault, one which emer-ges on the basis of an empirical knowledge susceptible of being elevated to the role of transcendental reflection on the conditions of knowledge, but, on the contrary, it is a pro-blem posed by the fact that empirical research on man present it, in a paradoxical way, as a causally conditioned consciousness incapable of anything that could be called “kno-wledge”.We will later try to reconstruct the premises on which this Merleau-Pontyan argument is based, which will lead us to make explicit that his rejection of “psychologism”, “sociolo-gism” and “historicism” is connected with the requirement that consciousness be able to exert some kind of epistemic control on its theoretical stances. On the basis of this re-sult, we will finally point out that the “historicist” problem as it appears in Merleau-Ponty is not reducible to the form of “historical relativism” that, according to Revel (2015), Foucault manages to avoid

La Organización Comunista Poder Obrero y su perspectiva en el movimiento obrero. Una apuesta al clasismo : Del Sitrac Sitram a Villa Constitución

La Organización Comunista Poder Obrero (OCPO) fue una organización político-militar argentina que extendió su presencia a varios puntos del país. Aunque esa denominación fue acuñada recién en septiembre de 1975 el grupo fundamental funcionó desde fines de 1973, al menos. Y fue el fruto, a su vez, de la confluencia de una serie de agrupamientos forjados al calor del Cordobazo y los primeros años 70. Como otras organizaciones hijas de la “nueva izquierda” de los años 60, Poder Obrero (como solía llamársele entonces) no estaba encuadrada en una única tradición. Por el contrario, consideraba que uno de sus baluartes consistía en la apropiación desprejuiciada de aportes de diversas corrientes revolucionarias, principalmente del marxismo. Así los militantes de OCPO leían y trataban de tomar elementos aportados por Lenin, Trotsky, Rosa Luxemburgo, Gramsci, los primeros congresos de la III Internacional Comunista, el Che Guevara, Mao Tse Tung, y Ho Chi Minh, entre otros. Al igual que otras organizaciones, OCPO definió que la lucha armada era un aspecto fundamental de la estrategia revolucionaria para la toma del poder por parte de los trabajadores, e inició un recorrido práctico y teórico para abonar ese camino. En ese marco, dio impulso a su brazo armado, las Brigadas Rojas, y a experiencias de autodefensa de masas, y se esforzó por establecer una práctica militar ligada al desarrollo del movimiento obrero.Mesa 11: De la Revolución Libertadora al menemismo. Lucha de clases y conflictos políticos en Argentina (1955-1989)Facultad de Humanidades y Ciencias de la Educació

Optomechanical many-body cooling using frustration

We show that the vibrations of an ion Coulomb crystal can be cooled to the zero-point motion through the optomechanical coupling with a high-finesse cavity. Cooling results from the interplay between coherent scattering of cavity photons by the ions, which dynamically modifies the vibrational spectrum, and cavity losses, that dissipate motional energy. The cooling mechanism we propose requires that the length scales of the crystal and the cavity are mismatched so that the system is intrinsically frustrated, leading to the formation of defects (kinks). When the pump is strong enough, the anti-Stokes sidebands of all vibrational modes can be simultaneously driven. These dynamics can be used to prepare ultracold chains of dozens of ions within tens of milliseconds in state-of-the-art experimental setups. In addition, we identify parameter regimes of the optomechanical interactions where individual localized modes can be selectively manipulated, and monitored through the light at the cavity output. These dynamics exemplify robust quantum reservoir engineering of strongly-correlated mesoscopic systems and could find applications in optical cooling of solids.Comment: 13 pages, 7 figure

Fan-duct development

Design and performance of acoustically lined fan discharge duct for noise level reduction during aircraft landin

Dissipative ground-state preparation of a spin chain by a structured environment

We propose a dissipative method to prepare the ground state of the isotropic XY spin Hamiltonian in a transverse field. Our model consists of a spin chain with nearest-neighbour interactions and an additional collective coupling of the spins to a damped harmonic oscillator. The latter provides an effective environment with a Lorentzian spectral density and can be used to drive the chain asymptotically towards its multipartite-entangled ground state at a rate that depends on the degree of non-Markovianity of the evolution. We also present a detailed proposal for the experimental implementation with a chain of trapped ions. The protocol does not require individual addressing, concatenated pulses, or multi-particle jump operators, and is capable of generating the desired target state in small ion chains with very high fidelities.Comment: 16 pages, 10 fig