Optimal experiment design revisited: fair, precise and minimal tomography

Given an experimental set-up and a fixed number of measurements, how should one take data in order to optimally reconstruct the state of a quantum system? The problem of optimal experiment design (OED) for quantum state tomography was first broached by Kosut et al. [arXiv:quant-ph/0411093v1]. Here we provide efficient numerical algorithms for finding the optimal design, and analytic results for the case of 'minimal tomography'. We also introduce the average OED, which is independent of the state to be reconstructed, and the optimal design for tomography (ODT), which minimizes tomographic bias. We find that these two designs are generally similar. Monte-Carlo simulations confirm the utility of our results for qubits. Finally, we adapt our approach to deal with constrained techniques such as maximum likelihood estimation. We find that these are less amenable to optimization than cruder reconstruction methods, such as linear inversion.Comment: 16 pages, 7 figure

8 claves del desarrollo y el diseño para la sostenibilidad

La presentación de algunas ideas de diseño que pueden contribuir a la consecución de Los objetivos para el desarrollo sostenibleestán proyectados a materializarse en el 2030

Experimental intra-abdominal hypertension influences airway pressure limits for lung protective mechanical ventilation

BACKGROUND: Intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) may complicate monitoring of pulmonary mechanics owing to their impact on the respiratory system. However, recommendations for mechanical ventilation of patients with IAH/ACS and the interpretation of thoracoabdominal interactions remain unclear. Our study aimed to characterize the influence of elevated intra-abdominal pressure (IAP) and positive end-expiratory pressure (PEEP) on airway plateau pressure (PPLAT) and bladder pressure (PBLAD). METHODS: Nine deeply anesthetized swineweremechanically ventilated via tracheostomy: volume-controlled mode at tidal volume (VT) of 10mL/kg, frequency of 15, inspiratory-expiratory ratio of 1:2, and PEEP of 1 and 10 cm H2O (PEEP1 and PEEP10, respectively). A tracheostomy tube was placed in the peritoneal cavity, and IAP levels of 5, 10, 15, 20, and 25 mm Hg were applied, using a continuous positive airway pressure system. At each IAP level, PBLAD and airway pressure measurements were performed during both PEEP1 and PEEP10. RESULTS: PBLAD increased as experimental IAP rose (y = 0.83x + 0.5; R2 = 0.98; p G 0.001 at PEEP1). Minimal underestimation of IAP by PBLAD was observed (j2.5 T 0.8 mm Hg at an IAP of 10-25 mm Hg). Applying PEEP10 did not significantly affect the correlation between experimental IAP and PBLAD. Approximately 50% of the PBLAD (in cm H2O) was reflected by changes in P PLAT, regardless of the PEEP level applied. Increasing IAP did not influence hemodynamics at any level of IAP generated. CONCLUSION: With minimal underestimation, PBLAD measurements closely correlated with experimentally regulated IAP, independent of the PEEP level applied. For each PEEP level applied, a constant proportion (approximately 50%) of measured PBLAD (in cm H2O) was reflected in PPLAT. A higher safety threshold for PPLAT should be considered in the setting of IAH/ACS as the clinician considers changes in VT. A strategy of reducing V T to cap PPLAT at widely recommended values may not be warranted in the setting of increased IAP. Copyright © 2013 Lippincott Williams and amp; Wilkins

El empleo de etnoespecies locales en las comidas típicas de las familias bolivianas del cinturón hortícola platense (Buenos Aires, Argentina)

This contribution is part of the urban ethnobotany research line whose main objective is to study botanical knowledge in the urban and peri-urban environment. This work is oriented to know the ethnospecies (which include plant species and local botanical varieties) used by the Bolivian families of the La Plata horticultural belt for the elaboration of their typical/daily dishes. Six fairs and 22 vegetable and fruit sales stalls in the urban area were surveyed, three of which concentrate the largest number of registered ethnospecies: Solanaceae (13), Cucurbitaceae (8) and Brassicaceae (6); along with the part of the plant that is commercialized, being the fresh fruits in bulk the predominant form (59%). This contribution expands knowledge of the diet of migrants, the uses and adaptation of their gastronomy. In conclusion, the sellers reported that they use all the ethnospecies that they sell in their daily cooking, fulfilling an important role within their home, as well as their crops that increase the local agrobiodiversity.Esta contribución se enmarca dentro de la línea de investigación de la etnobotánica urbana que tiene como principal objetivo estudiar el conocimiento botánico en el ámbito urbano y periurbano. Este trabajo está orientado a conocer las etnoespecies (que incluyen especies vegetales y variedades botánicas locales) utilizadas por las familias bolivianas del cinturón hortícola de La Plata para la elaboración de sus platos típicos/cotidianos. El relevamiento se realizó en 6 ferias y 22 puestos de venta de hortalizas y frutas en el ámbito urbano, a partir de estos se realizaron 10 entrevistas abiertas y semiestructuradas a los vendedores/ productores bolivianos en sus sitios de venta. Como resultado se identificaron 61 etnoespecies pertenecientes a 16 familias botánicas, tres de las cuales concentran la mayor cantidad de etnoespecies registradas: Solanaceae (13), Cucurbitaceae (8) y Brassicaceae (6); junto a la parte de la planta que se comercializa, siendo los frutos frescos a granel la forma predominante (59%). Esta contribución amplía el conocimiento de la dieta de los migrantes, los usos y la adaptación de su gastronomía. En conclusión, los vendedores informaron que emplean todas las etnoespecies que comercializan en su cocina diaria cumpliendo un rol importante dentro de su hogar, como así también sus cultivos que aumentan la agrobiodiversidad local

The communicative management of large companies in Spain: structure, resources and main challenges of their managers

This article studies the communicative structures of the main companies in Spain. Based on the fact that these organisations have significant economic and human resources, the structure of their communication areas is analysed, as well as the specific training of their top managers. In addition, the article will outline the main concerns that these organisational structures have with regard to the day-to-day management of business communication (transparency, reputation, identity, etc.). To do this, the object of the study is made up of the main companies in the Spanish continuous market, some of them included in the Ibex 35 in 2018. This population has been selected because it has the greatest impact on the national economy and is susceptible to greater information transparency.El presente artículo reflexiona sobre las estructuras comunicativas de las principales empresas españolas. Partiendo de la base de que estas organizaciones tienen importantes recursos económicos y humanos, se analiza la organización de sus áreas de comunicación, las prácticas que llevan a cabo y la formación específica de sus máximos responsables. Además, se detallan las principales preocupaciones y retos de esos departamentos de comunicación en el presente y el futuro inmediato (transparencia, reputación, identidad, etc.). El objeto de estudio lo constituyen las empresas españolas con mayor volumen de facturación, incluyendo las del Ibex 35 en 2018, por ser las de mayor impacto en la economía nacional, además de susceptibles de una mayor transparencia informativa

Tailored photon-pair generation in optical fibers

We experimentally control the spectral structure of photon pairs created via spontaneous four-wave mixing in microstructured fibers. By fabricating fibers with designed dispersion, one can manipulate the photons' wavelengths, joint spectrum, and, thus, entanglement. As an example, we produce photon-pairs with no spectral correlations, allowing direct heralding of single photons in pure-state wave packets without filtering. We achieve an experimental purity of $85.9\pm1.6$, while theoretical analysis and preliminary tests suggest 94.5% purity is possible with a much longer fiber

Mapping coherence in measurement via full quantum tomography of a hybrid optical detector

Quantum states and measurements exhibit wave-like --- continuous, or particle-like --- discrete, character. Hybrid discrete-continuous photonic systems are key to investigating fundamental quantum phenomena, generating superpositions of macroscopic states, and form essential resources for quantum-enhanced applications, e.g. entanglement distillation and quantum computation, as well as highly efficient optical telecommunications. Realizing the full potential of these hybrid systems requires quantum-optical measurements sensitive to complementary observables such as field quadrature amplitude and photon number. However, a thorough understanding of the practical performance of an optical detector interpolating between these two regions is absent. Here, we report the implementation of full quantum detector tomography, enabling the characterization of the simultaneous wave and photon-number sensitivities of quantum-optical detectors. This yields the largest parametrization to-date in quantum tomography experiments, requiring the development of novel theoretical tools. Our results reveal the role of coherence in quantum measurements and demonstrate the tunability of hybrid quantum-optical detectors.Comment: 7 pages, 3 figure

Absolute efficiency estimation of photon-number-resolving detectors using twin beams

A nonclassical light source is used to demonstrate experimentally the absolute efficiency calibration of a photon-number-resolving detector. The photon-pair detector calibration method developed by Klyshko for single-photon detectors is generalized to take advantage of the higher dynamic range and additional information provided by photon-number-resolving detectors. This enables the use of brighter twin-beam sources including amplified pulse pumped sources, which increases the relevant signal and provides measurement redundancy, making the calibration more robust

Description of Sarcocystis scandentiborneensis sp. nov. from treeshrews (Tupaia minor, T. tana) in northern Borneo with annotations on the utility of COI and 18S rDNA sequences for species delineation

Sarcocystis scandentiborneensis sp. nov. was discovered in histological sections of striated musculature of treeshrews (Tupaia minor, T. tana) from Northern Borneo. Sarcocysts were cigar-shaped, 102 μm–545 μm long, and on average 53 μm in diameter. The striated cyst wall varied in thickness (2–10 μm), depending on whether the finger-like, villous protrusions (VP) were bent. Ultrastructurally, sarcocysts were similar to wall type 12 but basal microtubules extended into VPs that tapered off with a unique U-shaped, electron-dense apical structure. In phylogenetic trees of the nuclear 18S rRNA gene, S. scandentiborneensis formed a distinct branch within a monophyletic subclade of Sarcocystis spp. with (colubrid) snake-rodent life cycle. We mapped all intraspecific (two haplotypes) and interspecific nucleotide substitutions to the secondary structure of the 18S rRNA gene: in both cases, the highest variability occurred within helices V2 and V4 but intraspecific variability mostly related to transitions, while transition/transversion ratios between S. scandentiborneensis, S. zuoi, and S. clethrionomyelaphis were skewed towards transversions. Lack of relevant sequences restricted phylogenetic analysis of the mitochondrial Cytochrome C oxidase subunit I (COI) gene to include only one species of Sarcocystis recovered from a snake host (S. pantherophisi) with which the new species formed a sister relationship. We confirm the presence of the functionally important elements of the COI barcode amino acid sequence of S. scandentiborneensis, whereby the frequency of functionally important amino acids (Alanine, Serine) was markedly different to other taxa of the Sarcocystidae. We regard S. scandentiborneensis a new species, highlighting that structurally or functionally important aspects of the 18S rRNA and COI could expand their utility for delineation of species. We also address the question why treeshrews, believed to be close to primates, carry a parasite that is genetically close to a Sarcocystis lineage preferably developing in the Rodentia as intermediate hosts