Experimental study of optimal measurements for quantum state tomography

Quantum tomography is a critically important tool to evaluate quantum hardware, making it essential to develop optimized measurement strategies that are both accurate and efficient. We compare a variety of strategies using nearly pure test states. Those that are informationally complete for all states are found to be accurate and reliable even in the presence of errors in the measurements themselves, while those designed to be complete only for pure states are far more efficient but highly sensitive to such errors. Our results highlight the unavoidable tradeoffs inherent to quantum tomography.Comment: 5 pages, 3 figure

Quantum state tomography by continuous measurement and compressed sensing

The need to perform quantum state tomography on ever larger systems has spurred a search for methods that yield good estimates from incomplete data. We study the performance of compressed sensing (CS) and least squares (LS) estimators in a fast protocol based on continuous measurement on an ensemble of cesium atomic spins. Both efficiently reconstruct nearly pure states in the 16-dimensional ground manifold, reaching average fidelities FCS = 0.92 and FLS = 0.88 using similar amounts of incomplete data. Surprisingly, the main advantage of CS in our protocol is an increased robustness to experimental imperfections

Perfil de resistencia de Staphylococcus spp aislados de hemocultivos en el Hospital Central del Instituto de Previsión Social

Las infecciones nosocomiales por Staphylococcus spp constituyen uno de los problemas de mayor preocupación en salud pública en todo el mundo. Debido a que existen diferencias según centro hospitalario, paciente, área y tiempo de internación es esencial conocer el perfil de resistencia a los antibióticos más utilizados de las cepas de Staphylococcus involucradas en estas infecciones. El objetivo del presente estudio fue determinar el perfil de resistencia de los aislados de Staphylococcus aureus (Sau) y Estafilococo coagulasa negativo (ECN) de muestras de hemocultivos de pacientes adultos, pediátricos y recién nacidos internados entre el 1 de junio de 2005 al 30 de junio de2006, en varios servicios del Hospital Central del Instituto de Previsión Social (IPS.).Se realizó un análisis retrospectivo de los resultados de antibiograma realizados en el Servicio de Microbiología del IPS. Los antibióticos evaluados fueron oxacilina (OXA),penicilina (PEN), eritromicina (ERY), clindamicina (CLI), ciprofloxacina (CIP), gentamicina (GEN), trimetoprim-sulfametoxazol (TMS), tetraciclina (TET) y vancomicina (VAN). De 5698 hemocultivos realizados en este periodo, 1706 (30%) fueron positivos. De estos, en755 (44%) se aisló Staphylococcus spp; correspondiendo 327 (43,3%) a Sau y 428 (56,7%) a ECN. El perfil de resistencia para Sau y ECN fue respectivamente como sigue: OXA 64% y 87%, PEN 96% y 95%, ERY 48% y 52%, CIP 42% y 40%, GEN 48% y 48% yno presentaron R a VAN. El 58% de los Sau y el 56% de los ECN fueron resistentes a más de 4 antibióticos. La alta frecuencia de resistencia a la meticilina y la poliresistencia hallada en este trabajo deben ser tenidos en cuenta a la hora de indicar esquemas deantibióticos empíricos y para realizar ajustes oportunos de los ya iniciados. No se encontró ninguna cepa resistente a la vancomicina, que es considerada el mejor antimicrobiano disponible para el tratamiento de infecciones por estafilococos resistentesa las penicilinas que no son inhibidas por las penicilinasas

Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum

World-Wide FINGERS Network: A global approach to risk reduction and prevention of dementia

© 2020 The Authors. Alzheimer\u27s & Dementia published by Wiley Periodicals, Inc. on behalf of Alzheimer\u27s Association Reducing the risk of dementia can halt the worldwide increase of affected people. The multifactorial and heterogeneous nature of late-onset dementia, including Alzheimer\u27s disease (AD), indicates a potential impact of multidomain lifestyle interventions on risk reduction. The positive results of the landmark multidomain Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) support such an approach. The World-Wide FINGERS (WW-FINGERS), launched in 2017 and including over 25 countries, is the first global network of multidomain lifestyle intervention trials for dementia risk reduction and prevention. WW-FINGERS aims to adapt, test, and optimize the FINGER model to reduce risk across the spectrum of cognitive decline—from at-risk asymptomatic states to early symptomatic stages—in different geographical, cultural, and economic settings. WW-FINGERS aims to harmonize and adapt multidomain interventions across various countries and settings, to facilitate data sharing and analysis across studies, and to promote international joint initiatives to identify globally implementable and effective preventive strategies

Specific Roles of Akt iso Forms in Apoptosis and Axon Growth Regulation in Neurons

Akt is a member of the AGC kinase family and consists of three isoforms. As one of the major regulators of the class I PI3 kinase pathway, it has a key role in the control of cell metabolism, growth, and survival. Although it has been extensively studied in the nervous system, we have only a faint knowledge of the specific role of each isoform in differentiated neurons. Here, we have used both cortical and hippocampal neuronal cultures to analyse their function. We characterized the expression and function of Akt isoforms, and some of their substrates along different stages of neuronal development using a specific shRNA approach to elucidate the involvement of each isoform in neuron viability, axon development, and cell signalling. Our results suggest that three Akt isoforms show substantial compensation in many processes. However, the disruption of Akt2 and Akt3 significantly reduced neuron viability and axon length. These changes correlated with a tendency to increase in active caspase 3 and a decrease in the phosphorylation of some elements of the mTORC1 pathway. Indeed, the decrease of Akt2 and more evident the inhibition of Akt3 reduced the expression and phosphorylation of S6. All these data indicate that Akt2 and Akt3 specifically regulate some aspects of apoptosis and cell growth in cultured neurons and may contribute to the understanding of mechanisms of neuron death and pathologies that show deregulated growth

Mab21l2 Is Essential for Embryonic Heart and Liver Development

During mouse embryogenesis, proper formation of the heart and liver is especially important and is crucial for embryonic viability. In this study, we showed that Mab21l2 was expressed in the trabecular and compact myocardium, and that deletion of Mab21l2 resulted in a reduction of the trabecular myocardium and thinning of the compact myocardium. Mab21l2-deficient embryonic hearts had decreased expression of genes that regulate cell proliferation and apoptosis of cardiomyocytes. These results show that Mab21l2 functions during heart development by regulating the expression of such genes. Mab21l2 was also expressed in the septum transversum mesenchyme (STM). Epicardial progenitor cells are localized to the anterior surface of the STM (proepicardium), and proepicardial cells migrate onto the surface of the heart and form the epicardium, which plays an important role in heart development. The rest of the STM is essential for the growth and survival of hepatoblasts, which are bipotential progenitors for hepatocytes and cholangiocytes. Proepicardial cells in Mab21l2-deficient embryos had defects in cell proliferation, which led to a small proepicardium, in which α4 integrin expression, which is essential for the migration of proepicardial cells, was down-regulated, suggesting that defects occurred in its migration. In Mab21l2-deficient embryos, epicardial formation was defective, suggesting that Mab21l2 plays important roles in epicardial formation through the regulation of the cell proliferation of proepicardial cells and the migratory process of proepicardial cells. Mab21l2-deficient embryos also exhibited hypoplasia of the STM surrounding hepatoblasts and decreased hepatoblast proliferation with a resultant loss of defective morphogenesis of the liver. These findings demonstrate that Mab21l2 plays a crucial role in both heart and liver development through STM formation