Choice of Measurement Sets in Qubit Tomography

Optimal generalized measurements for state estimation are well understood. However, practical quantum state tomography is typically performed using a fixed set of projective measurements and the question of how to choose these measurements has been largely unexplored in the literature. In this work we develop theoretical asymptotic bounds for the average fidelity of pure qubit tomography using measurement sets whose axes correspond to vertices of Platonic solids. We also present complete simulations of maximum likelihood tomography for mixed qubit states using the Platonic solid measurements. We show that overcomplete measurement sets can be used to improve the accuracy of tomographic reconstructions.Comment: 13 Pages, 6 figure

Adaptive homodyne measurement of optical phase

We present an experimental demonstration of the power of real-time feedback in quantum metrology, confirming a theoretical prediction by Wiseman regarding the superior performance of an adaptive homodyne technique for single-shot measurement of optical phase. For phase measurements performed on weak coherent states with no prior knowledge of the signal phase, we show that the variance of adaptive homodyne estimation approaches closer to the fundamental quantum uncertainty limit than any previously demonstrated technique. Our results underscore the importance of real-time feedback for reaching quantum performance limits in coherent telecommunication, precision measurement and information processing.Comment: RevTex4, color PDF figures (separate files), submitted to PR

Preterm infants have deficient monocyte and lymphocyte cytokine responses to Group B Streptococcus

Group B streptococcus GBS) is an important cause of early-and late-onset sepsis in the newborn. Preterm infants have markedly increased susceptibility and worse outcomes, but their immunological responses to GBS are poorly defined. We compared mononuclear cell and whole-blood cytokine responses to heat-killed GBS HKGBS) of preterm infants gestational age [GA], 26 to 33 weeks), term infants, and healthy adults. We investigated the kinetics and cell source of induced cytokines and quantified HKGBS phagocytosis. HKGBS-induced tumor necrosis factor TNF) and interleukin 6 (IL-6) secretion was significantly impaired in preterm infants compared to that in term infants and adults. These cytokines were predominantly monocytic in origin, and production was intrinsically linked to HKGBS phagocytosis. Very preterm infants GA, < 30 weeks) had fewer cytokine-producing monocytes, but nonopsonic phagocytosis ability was comparable to that for term infants and adults. Exogenous complement supplementation increased phagocytosis in all groups, as well as the proportion of preterm monocytes producing IL-6, but for very preterm infants, responses were still deficient. Similar defective preterm monocyte responses were observed in fresh whole cord blood stimulated with live GBS. Lymphocyte-associated cytokines were significantly deficient for both preterm and term infants compared to levels for adults. These findings indicate that a subset of preterm monocytes do not respond to GBS, a defect compounded by generalized weaker lymphocyte responses in newborns. Together these deficient responses may increase the susceptibility of preterm infants to GBS infection

Transfer of Training from Flight Training Devices to Flight for Ab-Initio Pilots

The application of flight simulation to meet pilot training needs continues to evolve. Flight simulations built with powerful and inexpensive computers are making high fidelity simulation available as a medium for training ab-initio pilots at Pilot Schools and Training Centers. The researchers conducted an 18-month study that applied an experimental flight-training curriculum comprised of 60% flight training device (FTD) flight and 40% airplane flight to certify Private Pilots under Federal Aviation Regulation (FAR) Part 142. The results from the research provided data to ascertain the effective transfer for each flight-training task. Ab-initio student pilots practiced each task to standard in an FTD prior to training in an actual airplane. The researchers measured a significant degree of effective transfer for the majority of flight tasks examined

Estimated dose exposure of the neonate to buprenorphine and its metabolite norbuprenorphine via breastmilk during maternal buprenorphine substitution treatment

Objective: The aim of the present study was to estimate the dose of buprenorphine and its primary metabolite norbuprenorphine that a breastfed infant would receive during maternal maintenance treatment with buprenorphine. Study Design: Seven pregnant opioid-dependent women taking buprenorphine (median, 7mg/day; range, 2.4–24 mg) and who intended to breastfeed were recruited. After lactation was established, several milk samples were collected from each subject over a 24-hour dose interval, and buprenorphine and norbuprenorphine concentrations were measured by liquid chromatography–tandem mass spectrometry. The average concentration (Cavg) across the dose interval was estimated as for both buprenorphine and norbuprenorphine (as buprenorphine equivalents). Absolute infant dose (AID), defined as Cavg daily milk intake, and relative infant dose (RID), defined as 100 AID/weight-adjusted maternal daily dose, via milk were calculated, assuming a milk intake of 0.15 L/kg/day. The infant’s health and progress were assessed directly and by questionnaire on the study day. Results: Mean (95% confidence interval) norbuprenorphine concentration in milk and AID values (1.94 [0.79–3.08] μg/L and 0.29 [0.12–0.46] μg/kg/day, respectively) were approximately half those for buprenorphine (3.65[1.61–5.7] μg/L and 0.55 [0.24–0.85] μg/kg/day, respectively). Similarly, the mean RID values were 0.18% (0.11–0.25%) for norbuprenorphine and 0.38% (0.23–0.53%) for buprenorphine. The breastfed infants showed no adverse effects, were all in good health, and were progressing as expected. Conclusion: Thus the dose of buprenorphine and norbuprenorphine received via milk is unlikely to cause any acute adverse effects in the breastfed infant

Unified Framework for Correlations in Terms of Local Quantum Observables

We provide a unified framework for nonsignalling quantum and classical multipartite correlations, allowing all to be written as the trace of some local (quantum) measurements multiplied by an operator. The properties of this operator define the corresponding set of correlations.We then show that if the theory is such that all local quantum measurements are possible, one obtains the correlations corresponding to the extension of Gleason's Theorem to multipartite systems. Such correlations coincide with the quantum ones for one and two parties, but we prove the existence of a gap for three or more parties.Comment: 4 pages, final versio

Biomarker Discovery in Animal Health and Disease: The Application of Post-Genomic Technologies

The causes of many important diseases in animals are complex and multifactorial, which present unique challenges. Biomarkers indicate the presence or extent of a biological process, which is directly linked to the clinical manifestations and outcome of a particular disease. Identifying biomarkers or biomarker profiles will be an important step towards disease characterization and management of disease in animals. The emergence of post-genomic technologies has led to the development of strategies aimed at identifying specific and sensitive biomarkers from the thousands of molecules present in a tissue or biological fluid. This review will summarize the current developments in biomarker discovery and will focus on the role of transcriptomics, proteomics and metabolomics in biomarker discovery for animal health and disease

Final design proposal: Delta Group-Nood Rider 821(tm)

The Nood Rider 821 (trademark) twin-engine, prop passenger aircraft is described. It is argued that the aircraft is very economical to operate and maintain, offering competitive advantages in the air travel marketplace. The aircraft was designed to operate in 'Aeroworld', a fictional world where the passengers are ping pong balls and the distances between cites are on the order of thousands of feet

Fast spin exchange between two distant quantum dots

The Heisenberg exchange interaction between neighboring quantum dots allows precise voltage control over spin dynamics, due to the ability to precisely control the overlap of orbital wavefunctions by gate electrodes. This allows the study of fundamental electronic phenomena and finds applications in quantum information processing. Although spin-based quantum circuits based on short-range exchange interactions are possible, the development of scalable, longer-range coupling schemes constitutes a critical challenge within the spin-qubit community. Approaches based on capacitative coupling and cavity-mediated interactions effectively couple spin qubits to the charge degree of freedom, making them susceptible to electrically-induced decoherence. The alternative is to extend the range of the Heisenberg exchange interaction by means of a quantum mediator. Here, we show that a multielectron quantum dot with 50-100 electrons serves as an excellent mediator, preserving speed and coherence of the resulting spin-spin coupling while providing several functionalities that are of practical importance. These include speed (mediated two-qubit rates up to several gigahertz), distance (of order of a micrometer), voltage control, possibility of sweet spot operation (reducing susceptibility to charge noise), and reversal of the interaction sign (useful for dynamical decoupling from noise).Comment: 6 pages including 4 figures, plus 8 supplementary pages including 5 supplementary figure