Symmetry breaking in small rotating cloud of trapped ultracold Bose atoms

We study the signatures of rotational and phase symmetry breaking in small rotating clouds of trapped ultracold Bose atoms by looking at rigorously defined condensate wave function. Rotational symmetry breaking occurs in narrow frequency windows, where the ground state of the system has degenerated with respect to the total angular momentum, and it leads to a complex wave function that exhibits vortices clearly seen as holes in the density, as well as characteristic vorticity. Phase symmetry (or gauge symmetry) breaking, on the other hand, is clearly manifested in the interference of two independent rotating clouds.Comment: 4 pages, 2 figure

Relationships between phenotypic plasticity and environmental variables.

To understand the relations between environment and phenotypic plasticity is important to forecast any possible adaptation of plants to climate change. We tested for any difference between central and marginal (Mediterranean and Alpine). Study was performed on 20 populations chosen on the basis of their distance from niche optimum.In Mediterranean marginal populations : \u2022 wide flowers display corolla, \u2022 short stamen, inducing more investment in attractiveness than in seed maturation \u2022 lower pollen production and seed set. Our results suggestthat: Largest floral display and lowest allocation of resources for seeds production in Mediterranean populations may be due to the highest competition for resources (pollinators, water and soil nutrient) together with the lowest resource availability. Future climate change will probably bring about: extinction of low altitudes populations the upward shift of other

Vortex nucleation in mesoscopic Bose superfluid and breaking of the parity symmetry

We analyze vortex nucleation in mezoscopic 2D Bose superfluid in a rotating trap. We explicitly include a weakly anisotropic stirring potential, breaking thus explicitly the axial symmetry. As the rotation frequency passes the critical value $\Omega_c$ the system undergoes an extra symmetry change/breaking. Well below $\Omega_c$ the ground state is properly described by the mean field theory with an even condensate wave function. Well above $\Omega_c$ the MF solution works also well, but the order parameter becomes odd. This phenomenon involves therefore a discrete parity symmetry breaking. In the critical region the MF solutions exhibit dynamical instability. The true many body state is a strongly correlated entangled state involving two macroscopically occupied modes (eigenstates of the single particle density operator). We characterize this state in various aspects: i) the eligibility for adiabatic evolution; ii) its analytical approximation given by the maximally entangled combination of two single modes; and finally iii) its appearance in particle detection measurements.Comment: 14 pages, 27 figure

Ordered structures in rotating ultracold Bose gases

The characterization of small samples of cold bosonic atoms in rotating microtraps has recently attracted increasing interest due to the possibility to deal with a few number of particles per site in optical lattices. We analyze the evolution of ground state structures as the rotational frequency $\Omega$ increases. Various kinds of ordered structures are observed. For $N<10$ atoms, the standard scenario, valid for large sytems, is absent, and only gradually recovered as $N$ increases. The vortex contribution to the total angular momentum $L$ as a function of $\Omega$ ceases to be an increasing function of $\Omega$, as observed in experiments of Chevy {\it et al.} (Phys. Rev. Lett. 85, 2223 (2000)). Instead, for small $N$, it exhibits a sequence of peaks showing wide minima at the values of $\Omega$, where no vortices appear.Comment: 35 pages, 17 figure

Análise sobre a Viabilidade de Revitalização da Indústria de Defesa Brasileira

Since 2003, the Brazilian government and certain sectors of Brazilian society have been debating the revitalization of the Brazilian defense industry (BDI). This article analyses some of the arguments in these debates (the rights of nations and duties of governments as regards defense, the possibility of coercive action by the great arms exporters, evidence that the defense industry has always run a deficit, and the export needs the country would have if it decided to revitalize its defense industry) and analyzes other questions that merit scrutiny (the causes of the crisis in the BDI that occurred in the 1980s, the causes of low internal demand, the economic and technological impact of the BDI). This is done by comparing these arguments and exploring these questions based on an analysis of documents. In this way, we aim to provide reliable information from Brazil and elsewhere to contribute to this debate.O governo brasileiro e setores da sociedade brasileira vêm promovendo, desde 2003, debates sobre a revitalização da indústria de defesa brasileira (IDB). O artigo analisa alguns argumentos presentes nestes debates (direito das nações e deveres dos governos em relação à defesa, possibilidade de uma ação coercitiva dos grandes exportadores de armamento, evidência de que a indústria de defesa sempre funciona de maneira deficitária e necessidade de exportar que teria o País como imposição da decisão da revitalizar a IBD) e analisa outras questões que também merecem aprofundamento (as causas da crise da IBD ocorrida na década de 1980, as causas da baixa demanda interna, o impacto econômico e tecnológico da IBD). O método adotado foi o de confrontar aqueles argumentos e explorar aquelas questões baseando-se em análise documental. Pretende-se, assim, proporcionar informação abalizada de origem nacional e estrangeira capaz de propiciar uma maior reflexão sobre o tema pela sociedade

Vortex nucleation as a case study of symmetry breaking in quantum systems

Mean-field methods are a very powerful tool for investigating weakly interacting many-body systems in many branches of physics. In particular, they describe with excellent accuracy trapped Bose-Einstein condensates. A generic, but difficult question concerns the relation between the symmetry properties of the true many-body state and its mean-field approximation. Here, we address this question by considering, theoretically, vortex nucleation in a rotating Bose-Einstein condensate. A slow sweep of the rotation frequency changes the state of the system from being at rest to the one containing one vortex. Within the mean-field framework, the jump in symmetry occurs through a turbulent phase around a certain critical frequency. The exact many-body ground state at the critical frequency exhibits strong correlations and entanglement. We believe that this constitutes a paradigm example of symmetry breaking in - or change of the order parameter of - quantum many-body systems in the course of adiabatic evolution.Comment: Minor change

Total hip arthroplasty in an inveterate femoral neck fracture in a patient with congenital insensitivity to pain with anhidrosis

Congenital insensitivity to pain with anhidrosis (CIPA) is an extremely rare disorder characterized by autonomic and sensory nerves malfunction with insensitivity to both deep and superficial painful stimuli, inability to sweat and produce tears, and mild to moderate mental retardation with self-mutilating behavior. Related consequences of inveterate musculoskeletal injuries represent a major issue for these patients, since pain cannot act as a protectionmechanism. For the same reason, the patients are at risk during postoperative rehabilitation, which should be taken into account when selecting an orthopaedic implant. To our knowledge, only one case of total hip arthroplasty has been reported in the literature to date. A 21-year-old Caucasian male patient affected with CIPA arrived at our attention complaining about a functional limitation of the left hip. No history of trauma was reported. The X-rays showed an inveterate femoral neck fracture with a severe necrosis and resorption of the femoral head. We decided to performa total hip arthroplasty with a cemented stem and a cemented dual mobility cup. The postoperative course and rehabilitation were satisfactory, with excellent clinical results, measured with the Harris Hip Score at 1 year

Quantum simulation of conductivity plateaux and fractional quantum Hall effect using ultracold atoms

We analyze the role of impurities in the fractional quantum Hall effect using a highly controllable system of ultracold atoms. We investigate the mechanism responsible for the formation of plateaux in the resistivity/conductivity as a function of the applied magnetic field in the lowest Landau level regime. To this aim, we consider an impurity immersed in a small cloud of an ultracold quantum Bose gas subjected to an artificial magnetic field. We consider scenarios corresponding to experimentally realistic systems with gauge fields induced by rotation of the trapping parabolic potential. Systems of this kind are adequate to simulate quantum Hall effects in ultracold atom setups. We use exact diagonalization for few atoms and to emulate transport equations, we analyze the time evolution of the system under a periodic perturbation. We provide a theoretical proposal to detect the up-to-now elusive presence of strongly correlated states related to fractional filling factors in the context of ultracold atoms. We analyze the conditions under which these strongly correlated states are associated with the presence of the resistivity/conductivity plateaux. Our main result is the presence of a plateau in a region, where the transfer between localized and non-localized particles takes place, as a necessary condition to maintain a constant value of the resistivity/conductivity as the magnetic field increases

Co-opetition models for governing professional football

In recent years, models for co-creating value in a business-to-business context have often been examined with the aim of studying the strategies implemented by and among organisations for competitive and co-operative purposes. The traditional concepts of competition and co-operation between businesses have now evolved, both in terms of the sector in which the businesses operate and in terms of the type of goods they produce. Many researchers have, in recent times, investigated the determinants that can influence the way in which the model of co-opetition can be applied to the football world. Research interest lies in the particular features of what makes a good football. In this paper, the aim is to conduct an analysis of the rules governing the “football system”, while also looking at the determinants of the demand function within football entertainment. This entails applying to football match management the co-opetition model, a recognised model that combines competition and co-operation with the view of creating and distributing value. It can, therefore, be said that, for a spectator, watching sport is an experience of high suspense, and this suspense, in turn, depends upon the degree of uncertainty in the outcome. It follows that the rules ensuring that both these elements can be satisfied are a fertile ground for co-operation between clubs, as it is in the interest of all stakeholders to offer increasingly more attractive football, in comparison with other competing products. Our end purpose is to understand how co-opetition can be achieved within professional football

Clonal haematopoiesis is not prevalent in survivors of childhood cancer

This project was funded by the Wellcome Trust Sanger Institute (grant number WT098051). G.S.V. is funded by a Wellcome Trust Senior Fellowship in Clinical Science (WT095663MA). F.F. is funded by Compagnia di San Paolo Grant: “Le cellule staminali del sangue nei guariti di leucemia” Codice SIME 2013-0958 (codice ROL 4201). I.V is funded by the Spanish Ministerio de Economía y Competitividad, Programa Ramón y Cajal