EPR-entangled Bose-Einstein condensates in state-dependent potentials: a dynamical study

We study generation of non-local correlations by atomic interactions in a pair of bi-modal Bose-Einstein Condensates in state-dependent potentials including spatial dynamics. The wave-functions of the four components are described by combining a Fock state expansion with a time-dependent Hartree-Fock Ansatz, so that both the spatial dynamics and the local and non-local quantum correlations are accounted for. We find that despite the spatial dynamics, our protocole generates enough non-local entanglement to perform an EPR steering experiment with two spatially separated con-densates of a few thousands of atoms

Limits of atomic entanglement by cavity-feedback : from weak to strong coupling

We theoretically investigate the entangled states of an atomic ensemble that can be obtained via cavity-feedback, varying the atom-light coupling from weak to strong, and including a systematic treatment of decoherence. In the strong coupling regime for small atomic ensembles, the system is driven by cavity losses into a long-lived, highly-entangled many-body state that we characterize analytically. In the weak coupling regime for large ensembles, we find analytically the maximum spin squeezing that can be achieved by optimizing both the coupling and the atom number. This squeezing is fundamentally limited by spontaneous emission to a constant value, independent of the atom number. Harnessing entanglement in many-body systems is of fundamental interest [1] and is the key requirement for quantum enhanced technologies, in particular quantum metrology [2]. In this respect, many efforts have been devoted to prepare entangled states in atomic ensembles because of their high degree of coherence and their potential for precision measurement. Spin squeezed states as well as number states have been produced following methods based either on coherent evolution in the presence of a non-linearity in the atomic field [3--5], or on quantum non-demolition measurement [6--8]. Among methods of the first kind, cavity feedback [5, 9] is one of the most promising: it has already allowed for the creation of highly squeezed states [5] and the effective non-linearity introduced by the atom-cavity coupling can be easily switched off, making it very attractive for metrol-ogy applications. In this Letter, we analyze the entangled states that can be produced by cavity feedback in different coupling regimes from weak to strong, and derive the ultimate limits of the metrology gain, extending the optimization of squeezing to unexplored domains of parameters values. After optimization of both the coupling strength and the atom number, we find a maximum squeezing limit that depends only on the atomic structure

Mesoscopic quantum superpositions in bimodal Bose-Einstein condensates: decoherence and strategies to counteract it

We study theoretically the interaction-induced generation of mesoscopic coherent spin state superpositions (small cat states) from an initial coherent spin state in bimodal Bose-Einstein condensates and the subsequent phase revival, including decoherence due to particle losses and fluctuations of the total particle number. In a full multimode description, we propose a preparation procedure of the initial coherent spin state and we study the effect of preexisting thermal fluctuations on the phase revival, and on the spin and orbito-spinorial cat fidelities.Comment: 26 pages, 12 figures; published versio

Crystallization and preliminary crystallographic analysis of the major capsid proteins VP16 and VP17 of bacteriophage P23-77

The major capsid proteins VP16 and VP17 of bacteriophage P23-77 have been crystallized using both recombinant and purified virus and preliminary diffraction analyses have been performed

Fiabilidad del Instrumento de Evaluación Neuropsicológica Breve Neupsilin

La investigación examinó la fiabilidad del Instrumento de Evaluación Neuropsicológica Breve Neupsilin, desarrollado en Brasil. Participaron 102 hombres y mujeres brasileños, de 18 a 40 años de edad. Se evaluó la fiabilidad del test-retest del Neupsilin y de la corrección, por distintos evaluadores, de la prueba para evaluación de apraxia constructiva. Se analizaron los datos con: el test de correlación de Spearman, el coeficiente de correlación intraclase y el coeficiente alpha de Cronbach. Las habilidades de lenguaje, memoria, praxias y funciones ejecutivas presentaron las más altas correlaciones para los resultados del test-retest. Se encontró una concordancia de moderada a alta entre los correctores de la tarea de praxia constructiva. Los resultados indicaron fiabilidad temporal para las tareas evaluadas por el Neupsilin y fiabilidad del corrector para la tarea praxia constructiva. Se presentan sugerencias para perfeccionar las tareas y mejorar la fiabilidad y la validez de la prueba

Fidedignidade do Instrumento de Avaliação Neuropsicológica Breve Neupsilin

This study aimed to evaluate the reliability of Neupsilin Brief Neuropsychological Assessment Instrument, a brief battery developed in Brazil. Hundred two Brazilian man and women participated, from 18 to 40 years of age. It was evaluated the test-retest reliability of the Neupsilin tasks and the reliability of the correction of the constructional praxis task by different evaluators. The data were analyzed by Spearman’s correlation, intraclass correlation and Cronbach’s alpha. Language, memory, praxis and executive functions presented the highest correlations in the test-retest analyses. The agreement in the correction of the constructional praxis task was moderate to high. The results indicate temporal reliability of Neupsilin tasks and inter-rater agreement in the correction of the constructional praxis task. Suggestions to improve the tasks, the validity and reliability of Neupsilin were presented.La investigación examinó la fiabilidad del Instrumento de Evaluación Neuropsicológica Breve Neupsilin, desarrollado en Brasil. Participaron 102 hombres y mujeres brasileños, de 18 a 40 años de edad. Se evaluó la fiabilidad del test-retest del Neupsilin y de la corrección, por distintos evaluadores, de la prueba para evaluación de apraxia constructiva. Se analizaron los datos con: el test de correlación de Spearman, el coeficiente de correlación intraclase y el coeficiente alpha de Cronbach. Las habilidades de lenguaje, memoria, praxias y funciones ejecutivas presentaron las más altas correlaciones para los resultados del test-retest. Se encontró una concordancia de moderada a alta entre los correctores de la tarea de praxia constructiva. Los resultados indicaron fiabilidad temporal para las tareas evaluadas por el Neupsilin y fiabilidad del corrector para la tarea praxia constructiva. Se presentan sugerencias para perfeccionar las tareas y mejorar la fiabilidad y la validez de la prueba.Este estudo teve como objetivo investigar a fidedignidade do Instrumento de Avaliação Neuropsicológica Breve Neupsilin, desenvolvido no Brasil. Participaram 102 homens e mulheres brasileiros de 18 a 40 anos. Examinou- se a fidedignidade do teste-reteste das tarefas do Neupsilin e a fidedignidade da correção, por diferentes avaliadores, das tarefas de praxia construtiva. Os dados foram analisados utilizando correlação de Spearman, coeficiente de correlação intraclasse e coeficiente alfa de Cronbach. As habilidades de linguagem, memória, praxia e funções executivas apresentaram as maiores correlações nas análises de teste e reteste. Foi encontrada uma concordância de moderada a alta entre os corretores da tarefa praxia construtiva. Os resultados indicaram a fidedignidade temporal para as tarefas do Neupsilin e a concordância entre avaliadores das tarefas de praxia construtiva. Sugestões para melhorar as tarefas, a validade e a fidedignidade do Neupsilin foram apresentadas

Comment on "Evidence for dark matter in the inner Milky Way"

This is a brief rebuttal to arXiv:1502.03821, which claims to provide the first observational proof of dark matter interior to the solar circle. We point out that this result is not new, and can be traced back at least a quarter century.Comment: 3 pages, 2 figures. In this version we add a figure from a 1998 paper that shows the same result that arXiv:1502.03821 claims to be novel. We also add a short note rebutting arXiv:1503.08784 which was written in response to the first versio

Estudo comparativo de funções neuropsicológicas entre grupos etários de 21 a 90 anos

La evaluación neuropsicológica permite la investigación de las habilidades cognitivas, comunicativas y/o emocionales, generando indicadores para el diagnóstico y rehabilitación de las funciones neuropsicológicas. Los estudios con individuos neurológicamente sanos, y de diferentes grupos etarios, son importantes para la interpretación de los datos de pacientes neurológicos y/o psiquiátricos. El objetivo de este estudio fue el de verificar posibles diferencias en relación al procesamiento de las funciones neuropsicológicas entre cuatro grupos etarios, analizándose más específicamente los diferentes sistemas de memoria, así como el lenguaje oral y escrito. Participaron del estudio 207 adultos neurológicamente sanos y de alta escolaridad: 53 jóvenes (21- 39 años), 63 de edad intermedia (40-59 años), 48 adultos mayores (60-75 años) y 43 adultos mayores longevos (76-90 años). Las siguientes funciones fueron evaluadas en los participantes: orientación témporo-espacial, atención, percepción, memoria, aritmética, lenguaje, praxias y funciones ejecutivas (resolución de problemas y fluencia verbal) a través del Instrumento de Evaluación Neuropsicológica Breve NEUPSILIN. Se comparó el desempeño entre los grupos con un ANCOVA de un factor con escolaridad y frecuencia de hábitos de lectura y escritura como covariables. Los resultados indican un desempeño inferior para el grupo etario de 76 a 90 años en las tareas de percepción, resolución de problemas, fluencia verbal y en los componentes de memoria de trabajo, episódica verbal y prospectiva. En lenguaje escrito, los resultados arrojaron diferencias significativas entre los grupos de jóvenes y longevos. El desempeño en las funciones neuropsicológicas parece cambiar a medida que se avanza en el proceso de envejecimiento, especialmente a partir de los 76 años. No obstante, el factor edad tiene un papel distinto según el componente cognitivo del que se trate.L’évaluation neuropsychologique permet l’étude des capacités cognitives, communicationelles et émotionnelles, produisant des indices au diagnostic et à la réadaptation des déficiences neuropsychologiques. Des études avec les individus sains de différents âges sont appropriées pour l'interprétation des données d'évaluation de patients neurologiques et/ou psychiatriques. Cette recherche a visé à vérifier s'il y a des différences entre quatre tranches d'âge quant à leur traitement des fonctions neuropsychologiques, analysant plus spécifiquement des systèmes mnémoniques différents, ainsi que le langage oral et écrit. L'échantillon a été composé de 207 adultes neurologiquement sains et fortement instruits : 53 plus jeunes (21-39 ans), 63 d'âge moyen (40-59 ans), 48 personnes âgées (60-75 ans) et 43 plus vieux (76-90 ans). Les fonctions cognitives des participants ont été évaluées avec la “Brazilian Brief Neuropsychological Assessment Battery NEUPSILIN”. L'évaluation a inclus les capacités suivantes : temps et orientation spatiale, attention, mémoire, arithmétique, langage, fonctions motrices et fonctions exécutives (résolution de problème et fluence verbale). La comparaison des performances entre les groupes a été analysée avec l’ANCOVA à un critère de classification, et l'éducation et la fréquence d'écriture et les habitudes de lecture comme covariables. Les résultats ont suggéré qu'il y avait une basse performance dans quelques composants cognitifs principalement dans le groupe des 76 ans, tels la perception, la résolution de problème, la fluence verbale, le travail, les composants mnémoniques épisodiques et prospectifs. De plus, il y avait des différences entre les groupes les plus âgés et plus jeunes dans le langage écrit. La performance neuropsychologique semblait changer au cours du processus du vieillissement, particulièrement à partir de l'âge de 76 ans, bien que cette variable avait un rôle différent pour chaque composant cognitif.A avaliação neuropsicológica possibilita investigar habilidades cognitivas, comunicativas e/ou emocionais, gerando indicadores para diagnóstico e reabilitação de disfunções neuropsicológicas. Estudos com indivíduos neurologicamente preservados, de diferentes faixas etárias, são importantes para a interpretação dos dados de pacientes neurológicos e/ou psiquiátricos. O objetivo deste estudo foi verificar se há diferenças entre quatro grupos etários quanto ao seu processamento de funções neuropsicológicas, analisando-se mais especificamente diferentes sistemas mnemônicos, assim como linguagem oral e escrita. Participaram do estudo 207 adultos neurologicamente preservados e de alta escolaridade: 53 jovens (21-39 anos), 63 de idade intermediária (40-59 anos), 48 idosos (60-75 anos) e 43 idosos longevos (76-90 anos). Os participantes foram avaliados quanto às funções de orientação têmporo-espacial, atenção, percepção, memória, habilidades aritméticas, linguagem, praxias, e funções executivas (resolução de problemas e fluência verbal) pelo Instrumento de Avaliação Neuropsicológica Breve NEUPSILIN. A comparação do desempenho entre grupos foi analisada com o teste ANCOVA de um fator, com as covariantes escolaridade e freqüência de hábitos de leitura e escrita. Os resultados indicaram desempenho inferior para o grupo etário de 76 a 90 anos nas tarefas de percepção, resolução de problemas, fluência verbal e nos componentes de memória de trabalho, episódica verbal e prospectiva. Para linguagem escrita, os resultados mostraram-se significativamente diferentes entre os grupos de jovens e longevos. O desempenho das funções neuropsicológicas parece apresentar mudanças com o processo de envelhecimento, especialmente a partir dos 76 anos, embora o fator idade tenha um papel diferente para cada componente cognitivo.Neuropsychological assessment allows the investigation of cognitive, communicative and emotional abilities, generating indices to diagnosis and rehabilitation of neuropsychological impairments. Studies with healthy individuals of different ages are relevant to the interpretation of the assessment data of neurologic and/or psychiatric patients. This research aimed at verifying if there are differences between four age groups regarding their neuropsychological functions processing, analyzing more specifically different mnemonic systems, as well as the oral and written language. The sample was composed of 207 neurologically healthy and highly-educated adults: 53 younger (21-39 years old), 63 middle-aged (40-59 years old), 48 elderly (60-75 years old) and 43 oldest old (76-90 years old). Participants’ cognitive functions were assessed with the Brazilian Brief Neuropsychological Assessment Battery NEUPSILIN. The assessment included the following abilities: time and space orientation, attention, memory, arithmetic, language, motor functions, and executive functions (problem solving and verbal fluency). Between groups performance comparison was analyzed with one-way ANCOVA, and education and frequency of writing and reading habits as covariates. Results suggested that there was a low performance in some cognitive components mainly regarding the 76 year-old group, such as perception, problem solving, verbal fluency, working, episodic and prospective mnemonic components. In addition, there were differences between the oldest and the youngest groups when it comes to written language. Neuropsychological performance seems change throughout the aging process, especially from the age of 76, although this variable had a different role for each cognitive component

Transcriptomics in Interferon-α-Treated Patients Identifies Inflammation-, Neuroplasticity- and Oxidative Stress-Related Signatures as Predictors and Correlates of Depression

Owing to the unique opportunity to assess individuals before and after they develop depression within a short timeframe, interferon-α (IFN-α) treatment for chronic hepatitis C virus (HCV) infection is an ideal model to identify molecular mechanisms relevant to major depression, especially in the context of enhanced inflammation. Fifty-eight patients were assessed prospectively, at baseline and monthly over 24 weeks of IFN-α treatment. New-onset cases of depression were determined using the Mini International Neuropsychiatric Interview (MINI). Whole-blood transcriptomic analyses were conducted to investigate the following: (1) baseline gene expression differences associated with future development of IFN-α-induced depression, before IFN-α, and (2) longitudinal gene expression changes from baseline to weeks 4 or 24 of IFN-α treatment, separately in those who did and did not develop depression. Transcriptomics data were analyzed using Partek Genomics Suite (1.4-fold, FDR adjusted pless than or equal to0.05) and Ingenuity Pathway Analysis Software. Twenty patients (34%) developed IFN-α-induced depression. At baseline, 73 genes were differentially expressed in patients who later developed depression compared with those who did not. After 4 weeks of IFN-α treatment, 592 genes were modulated in the whole sample, representing primarily IFN-α-responsive genes. Substantially more genes were modulated only in patients who developed depression (n=506, compared with n=70 in patients who did not), with enrichment in inflammation-, neuroplasticity- and oxidative stress-related pathways. A similar picture was observed at week 24. Our data indicate that patients who develop IFN-α-induced depression have an increased biological sensitivity to IFN-α, as shown by larger gene expression changes, and specific signatures both as predictors and as correlates