Kitaev chains with long-range pairing

We propose and analyze a generalization of the Kitaev chain for fermions with long-range $p$-wave pairing, which decays with distance as a power-law with exponent $\alpha$. Using the integrability of the model, we demonstrate the existence of two types of gapped regimes, where correlation functions decay exponentially at short range and algebraically at long range ($\alpha > 1$) or purely algebraically ($\alpha < 1$). Most interestingly, along the critical lines, long-range pairing is found to break conformal symmetry for sufficiently small $\alpha$. This is accompanied by a violation of the area law for the entanglement entropy in large parts of the phase diagram in the presence of a gap, and can be detected via the dynamics of entanglement following a quench. Some of these features may be relevant for current experiments with cold atomic ions.Comment: 5+3 pages, 4+2 figure

Collision of impurities with Bose-Einstein condensates

open5noQuantum dynamics of impurities in a bath of bosons is a long-standing problem of solid-state, plasma, and atomic physics. Recent experimental and theoretical investigations with ultracold atoms focused on this problem, studying atomic impurities immersed in a atomic Bose-Einstein condensate (BEC) and for various relative coupling strengths tuned by the Fano-Feshbach resonance technique. Here we report extensive numerical simulations on a closely related problem: the collision between a bosonic impurity made of few 41K atoms and a BEC made of 87Rb atoms in a quasi one-dimensional configuration and under a weak harmonic axial confinement. For small values of the interspecies interaction strength (no matter the sign of it), we find that the impurity, which starts from outside the BEC, simply oscillates back and forth the BEC cloud, but the frequency of oscillation depends on the interaction strength. For intermediate couplings, after a few cycles of oscillation the impurity is captured by the BEC and strongly changes its amplitude of oscillation. In the strong interaction regime, if the interspecies interaction is attractive, a local maximum (bright soliton) in the density of BEC occurs where the impurity is trapped; instead, if the interspecies interaction is repulsive, the impurity is not able to enter in the BEC cloud and the reflection coefficient is close to one. On the other hand, if the initial displacement of the impurity is increased, the impurity is able to penetrate in the cloud leading to the appearance of a moving hole (dark soliton) in the BEC.openLingua, F.; Lepori, L.; Minardi, F.; Penna, V.; Salasnich, L.Lingua, F.; Lepori, Luca; Minardi, F.; Penna, V.; Salasnich, L

Deficiency in Perlecan/HSPG2 During Bone Development Enhances Osteogenesis and Decreases Quality of Adult Bone in Mice

Perlecan/HSPG2 (Pln) is a large heparan sulfate proteoglycan abundant in the extracellular matrix of cartilage and the lacunocanalicular space of adult bones. Although Pln function during cartilage development is critical, evidenced by deficiency disorders including Schwartz–Jampel Syndrome and dyssegmental dysplasia Silverman-Handmaker type, little is known about its function in development of bone shape and quality. The purpose of this study was to understand the contribution of Pln to bone geometric and mechanical properties. We used hypomorph mutant mice that secrete negligible amount of Pln into skeletal tissues and analyzed their adult bone properties using micro-computed tomography and three-point-bending tests. Bone shortening and widening in Pln mutants was observed and could be attributed to loss of growth plate organization and accelerated osteogenesis that was reflected by elevated cortical thickness at older ages. This effect was more pronounced in Pln mutant females, indicating a sex-specific effect of Pln deficiency on bone geometry. Additionally, mutant females, and to a lesser extent mutant males, increased their elastic modulus and bone mineral densities to counteract changes in bone shape, but at the expense of increased brittleness. In summary, Pln deficiency alters cartilage matrix patterning and, as we now show, coordinately influences bone formation and calcification

Simulation of gauge transformations on systems of ultracold atoms

We show that gauge transformations can be simulated on systems of ultracold atoms. We discuss observables that are invariant under these gauge transformations and compute them using a tensor network ansatz that escapes the phase problem. We determine that the Mott-insulator-to-superfluid critical point is monotonically shifted as the induced magnetic flux increases. This result is stable against the inclusion of a small amount of entanglement in the variational ansatz.Comment: 14 pages, 6 figure

RNA analysis of consensus sequence splicing mutations: implications for thediagnosis of Wilson disease

Wilson disease (WD) is an autosomal recessive disorder caused by a defective function of the copper-transporting ATP7B protein. This results in progressive copper overload and consequent liver, brain, and kidney damage. Approximately 300 WD-causing mutations have been described to date. Missense mutations are largely prevalent, while splice-site mutations are rarer. Of these, only a minority are detected in splicing consensus sequences. Further, few splicing mutations have been studied at the RNA level. In this study we report the RNA molecular characterization of three consensus splice-site mutations identified by DNA analysis in WD patients. One of them, c.51 + 4 A --> T, resides in the consensus sequence of the donor splice site of intron 1; the second, c. 2121 + 3 A --> G, occurred in position + 3 of intron 7; and the c.2447 + 5 G --> A is localized in the consensus sequence of the donor splice site of intron 9. Analysis revealed predominantly abnormal splicing in the samples carrying mutations compared to the normal controls. These results strongly suggest that consensus sequence splice-site mutations result in disease by interfering with the production of the normal WD protein. Our data contribute to understanding the mutational spectrum that affect splicing and improve our capability in WD diagnosis

Clinicopathologic predictors of renal outcomes in light chain cast nephropathy: a multicenter retrospective study

Light chain cast nephropathy (LCCN) in multiple myeloma often leads to severe and poorly reversible acute kidney injury. Severe renal impairment influences the allocation of chemotherapy and its tolerability; it also affects patient survival. Whether renal biopsy findings add to the clinical assessment in predicting renal and patient outcomes in LCCN is uncertain. We retrospectively reviewed clinical presentation, chemotherapy regimens, hematologic response, and renal and patient outcomes in 178 patients with biopsy-proven LCCN from 10 centers in Europe and North America. A detailed pathology review, including assessment of the extent of cast formation, was performed to study correlations with initial presentation and outcomes. Patients presented with a mean estimated glomerular filtration rate (eGFR) of 13 ± 11 mL/min/1.73 m2, and 82% had stage 3 acute kidney injury. The mean number of casts was 3.2/mm2 in the cortex. Tubulointerstitial lesions were frequent: acute tubular injury (94%), tubulitis (82%), tubular rupture (62%), giant cell reaction (60%), and cortical and medullary inflammation (95% and 75%, respectively). Medullary inflammation, giant cell reaction, and the extent of cast formation correlated with eGFR value at LCCN diagnosis. During a median follow-up of 22 months, mean eGFR increased to 43 ± 30 mL/min/1.73 m2. Age, β2-microglobulin, best hematologic response, number of cortical casts per square millimeter, and degree of interstitial fibrosis/tubular atrophy (IFTA) were independently associated with a higher eGFR during follow-up. This eGFR value correlated with overall survival, independently of the hematologic response. This study shows that extent of cast formation and IFTA in LCCN predicts the quality of renal response, which, in turn, is associated with overall survival.info:eu-repo/semantics/publishedVersio

Relativistic quantum effects of Dirac particles simulated by ultracold atoms

Quantum simulation is a powerful tool to study a variety of problems in physics, ranging from high-energy physics to condensed-matter physics. In this article, we review the recent theoretical and experimental progress in quantum simulation of Dirac equation with tunable parameters by using ultracold neutral atoms trapped in optical lattices or subject to light-induced synthetic gauge fields. The effective theories for the quasiparticles become relativistic under certain conditions in these systems, making them ideal platforms for studying the exotic relativistic effects. We focus on the realization of one, two, and three dimensional Dirac equations as well as the detection of some relativistic effects, including particularly the well-known Zitterbewegung effect and Klein tunneling. The realization of quantum anomalous Hall effects is also briefly discussed.Comment: 22 pages, review article in Frontiers of Physics: Proceedings on Quantum Dynamics of Ultracold Atom

Euclid Preparation. TBD. Impact of magnification on spectroscopic galaxy clustering

In this paper we investigate the impact of lensing magnification on the analysis of Euclid's spectroscopic survey, using the multipoles of the 2-point correlation function for galaxy clustering. We determine the impact of lensing magnification on cosmological constraints, and the expected shift in the best-fit parameters if magnification is ignored. We consider two cosmological analyses: i) a full-shape analysis based on the $\Lambda$CDM model and its extension $w_0w_a$CDM and ii) a model-independent analysis that measures the growth rate of structure in each redshift bin. We adopt two complementary approaches in our forecast: the Fisher matrix formalism and the Markov chain Monte Carlo method. The fiducial values of the local count slope (or magnification bias), which regulates the amplitude of the lensing magnification, have been estimated from the Euclid Flagship simulations. We use linear perturbation theory and model the 2-point correlation function with the public code coffe. For a $\Lambda$CDM model, we find that the estimation of cosmological parameters is biased at the level of 0.4-0.7 standard deviations, while for a $w_0w_a$CDM dynamical dark energy model, lensing magnification has a somewhat smaller impact, with shifts below 0.5 standard deviations. In a model-independent analysis aiming to measure the growth rate of structure, we find that the estimation of the growth rate is biased by up to $1.2$ standard deviations in the highest redshift bin. As a result, lensing magnification cannot be neglected in the spectroscopic survey, especially if we want to determine the growth factor, one of the most promising ways to test general relativity with Euclid. We also find that, by including lensing magnification with a simple template, this shift can be almost entirely eliminated with minimal computational overhead

Anthropocene and "development" : intertwined trajectories since the beginning of the Great Acceleration = Antropoceno e "desenvolvimento" : trajetórias entrelaçadas desde o começo da Grande Aceleração

Objectives: We aim to propose the thesis that the trajectories of the Anthropocene and the current mainstream understandings of development are intertwined from the beginning. It means that the Anthropocene and the “development” are coetaneous: the implementation of development policies for the so-considered underdeveloped regions started to happen at the same time of what is known as The Great Acceleration of production, consumption and environmental degradation in a global level. Method: In this conceptual paper, we adopt a decolonial critique as an analytical lens and argue that different geopolitical positions may be necessary for approaching the issue of the Anthropocene from epistemological reflections that can include the cultural and political context of the production and reproduction of local knowledge. Results: Our theoretical argumentation sheds light on the role of Global North and South relations in shaping the environmental crisis. Latin America (LA) exemplifies the modus operandi of the intertwinement of the practical effects of development policies and the environmental consequences underlying the Anthropocene, in which natural resources are over-explored to satisfy export-oriented trade, from the South toward the North. LA is not only a propitious context to show the validity of our thesis, but also the source of alternatives to such developmental model. Conclusion: The emphasis on development as a cause of the Anthropocene supports The Great Acceleration thesis. The proposition of the name Developmentocene comes from the thesis that development and Anthropocene are coetaneous, the intertwinement of both resulting in the very definition of the new epoch.Objetivo: Buscamos propor a tese de que as trajetórias do Antropoceno e o entendimento atualmente dominante sobre desenvolvimento estão entrelaçadas desde o começo. Isso implica que o Antropoceno e o “desenvolvimento” são coetâneos: a implementação de políticas de desenvolvimento em regiões tidas como subdesenvolvidas começou a acontecer ao mesmo tempo em que teve início A Grande Aceleração da produção, do consumo e da degradação ambiental em nível global. Método: Neste artigo conceitual, nós adotamos a crítica decolonial como lente analítica e argumentamos a necessidade de diferentes posições geopolíticas para abordar a questão do Antropoceno a partir de reflexões epistemológicas que possam incluir o contexto cultural e político de produção e reprodução do conhecimento. Resultados: Nossa argumentação teórica enaltece as relações entre o Norte e o Sul Global no delineamento da crise ambiental. A América Latina (AL) exemplifica o modus operandi do entrelaçamento entre os efeitos práticos das políticas de desenvolvimento e as consequências ambientais subjacentes ao Antropoceno, em que os recursos naturais são explorados além dos limites para satisfazer o comércio para exportações, desde o Sul para o Norte. Nesse quadro, a AL não é apenas um contexto propício para mostrar a validade da nossa tese, mas também a fonte de alternativas a esse modelo de desenvolvimento. Conclusão: A ênfase no desenvolvimento como causa do Antropoceno apoia a tese da Grande Aceleração. A proposição do nome Desenvolvimentoceno advém da tese de que o desenvolvimento e o Antropoceno são coetâneos e que o entrelaçamento de ambos resulta na própria definição da nova época