Quantum field tomography

We introduce the concept of quantum field tomography, the efficient and reliable reconstruction of unknown quantum fields based on data of correlation functions. At the basis of the analysis is the concept of continuous matrix product states, a complete set of variational states grasping states in quantum field theory. We innovate a practical method, making use of and developing tools in estimation theory used in the context of compressed sensing such as Prony methods and matrix pencils, allowing us to faithfully reconstruct quantum field states based on low-order correlation functions. In the absence of a phase reference, we highlight how specific higher order correlation functions can still be predicted. We exemplify the functioning of the approach by reconstructing randomised continuous matrix product states from their correlation data and study the robustness of the reconstruction for different noise models. We also apply the method to data generated by simulations based on continuous matrix product states and using the time-dependent variational principle. The presented approach is expected to open up a new window into experimentally studying continuous quantum systems, such as encountered in experiments with ultra-cold atoms on top of atom chips. By virtue of the analogy with the input-output formalism in quantum optics, it also allows for studying open quantum systems.Comment: 31 pages, 5 figures, minor change

Improvement in soybean sprouts production with ultrasound power.

The present work aimed the application of different ultrasound powers (10, 50 and 90W) to evaluate the germination and characteristics of soybean sprouts fromsoybeans of cultivar BRS 216 and 3 lines (A, B and C). In the germination test,the line A showed the highest percentage of germination (96% for 90W).The cultivar BRS 216 and line A present lower values of weight and higher yield of sprouts. The viable sprouts that presented the highest weight (for each 50g of soybean) were: line A followed by BRS 216, line C and B, with statistical differences (p<0.05) between them. For each 50g of soybean of cultivar BRS 216 and Lines A, B and C the production of viable sprouts was 231.47; 237.87; 170.74 and 199.94g, respectively, for 90W. In relation to the length of the sprouts using the power of 10W the line C presented a longer length. The line A using 90W showed better color characteristics. The highest protein value was found in cultivar BRS 216, for all applied potencies. With this work it can be concluded that the line A would be the most suitable for sprout production regardless of the ultrasound power applie

Experimentally exploring compressed sensing quantum tomography

In the light of the progress in quantum technologies, the task of verifying the correct functioning of processes and obtaining accurate tomographic information about quantum states becomes increasingly important. Compressed sensing, a machinery derived from the theory of signal processing, has emerged as a feasible tool to perform robust and significantly more resource-economical quantum state tomography for intermediate-sized quantum systems. In this work, we provide a comprehensive analysis of compressed sensing tomography in the regime in which tomographically complete data is available with reliable statistics from experimental observations of a multi-mode photonic architecture. Due to the fact that the data is known with high statistical significance, we are in a position to systematically explore the quality of reconstruction depending on the number of employed measurement settings, randomly selected from the complete set of data, and on different model assumptions. We present and test a complete prescription to perform efficient compressed sensing and are able to reliably use notions of model selection and cross-validation to account for experimental imperfections and finite counting statistics. Thus, we establish compressed sensing as an effective tool for quantum state tomography, specifically suited for photonic systems.Comment: 12 pages, 5 figure

Multiple social identities enhance health post-retirement because they are a basis for giving social support

This is the final version of the article. Available from the publisher via the DOI in this record.We examine the extent to which multiple social identities are associated with enhanced health and well-being in retirement because they provide a basis for giving and receiving social support. Results from a cross-sectional study show that retirees (N = 171) who had multiple social identities following (but not prior to) retirement report being (a) more satisfied with retirement, (b) in better health, and (c) more satisfied with life in general. Furthermore, mediation analyses revealed an indirect path from multiple social identities to greater satisfaction with retirement and better health through greater provision, but not receipt, of social support to others. These findings are the first to point to the value of multiple group membership post-retirement as a basis for increased opportunities to give meaningful support to others. We discuss the theoretical and practical implications for the management of multiple identities in the process of significant life transitions such as retirement.This work was supported by three grants from the Australian Research Council awarded to JJ (FT110100238), CH (DP160102514), and AH (FL110100199

Social group memberships in retirement are associated with reduced risk of premature death: evidence from a longitudinal cohort study.

This is the final version of the article. Available from [publisher] via the DOI in this record.OBJECTIVES: Retirement constitutes a major life transition that poses significant challenges to health, with many retirees experiencing a precipitous decline in health status following retirement. We examine the extent to which membership in social groups following retirement determines quality of life and mortality. DESIGN: The longitudinal impact of the number of social group memberships before and after the transition to retirement was assessed on retirees' quality of life and risk of death 6 years later. SETTING: Nationally representative cohort study of older adults living in England. PARTICIPANTS: Adults who underwent the transition to retirement (N=424). A matched control group (N=424) of participants who had comparable demographic and health characteristics at baseline but did not undergo the transition to retirement were also examined. OUTCOME MEASURES: Analyses examined participants' quality of life and mortality during a period of 6 years. RESULTS: Retirees who had two group memberships prior to retirement had a 2% risk of death in the first 6 years of retirement if they maintained membership in two groups, a 5% risk if they lost one group and a 12% risk if they lost both groups. Furthermore, for every group membership that participants lost in the year following retirement, their experienced quality of life 6 years later was approximately 10% lower. These relationships are robust when controlling for key sociodemographic variables (age, gender, relationship status and socioeconomic status prior to retirement). A comparison with a matched control group confirmed that these effects were specific to those undergoing the transition to retirement. The effect of social group memberships on mortality was comparable to that of physical exercise. CONCLUSIONS: Theoretical implications for our understanding of the determinants of retiree quality of life and health, and practical implications for the support of people transitioning from a life of work to retirement are discussed.This research was supported by two grants from the Australian Research Council awarded to JJ (FT110100238) and SAH (FL110100199). The funding body did not play any role in the research design; in the collection, analysis, and interpretation of data; in the writing of the manuscript; or in the decision to submit the manuscript for publication

Scheme Independence of g1p(x,Q2)g_1^p (x, Q^2)

We work with two general factorization schemes in order to explore the consequences of imposing scheme independence on $g_1^p (x, Q^2)$. We see that although the light quark sector is indifferent to the choice of a particular scheme, the extension of the calculations to the heavy quark sector indicates that a scheme like the $\bar{MS}$ is preferable.Comment: 11 pages, 2 figures. To appear in the Brief Reports of Phys. Rev.

Sistema simplificado para produção de brotos de soja: uma atividade econômica para pequenos empreendimentos.

A soja é uma excelente fonte de nutrientes, com a proteína perfazen­do cerca de 40% da matéria seca, e com adequado perfil de aminoácidos, segundo os padrões da FAO. Outro componente importante é o óleo, que corresponde a cerca de 20% da matéria seca, com teor de ácidos graxos polinsaturados da ordem de 85%. Além disso, contém vários micronutrientes incluindo cálcio, ácido fólico e ferro. Entretanto, a soja se destaca por ser boa fonte de isoflavonas, as quais são benéficas para a saúde humana, e fazem da soja ingrediente para alimentos funcionais. Embora o uso de soja seja mais popular nos países do oriente, seu consumo vem crescendo nos países do ocidente, tanto em relação aos produtos tradicionais (farinha de soja, ?kinako?, tofu e ?leite?), como para os produtos processados que utilizam soja como ingrediente. O consumo de soja tem aumentado devido às técnicas adequadas de processamento que favorecem o sabor e a qualidade dos produtos alimentícios. Consumo direto de soja é tradicional em países asiáticos, os quais consomem extrato hidrossolúvel, tofu, grãos verdes ou imaturos (edamame) e brotos de soja, entre outros alimentos. (...)O objetivo do trabalho foi avaliar a viabilidade da tecnologia do processo automatizado de produção de brotos de soja da Embrapa, a partir da simplificação do equipamento desenvolvido por Oliveira e Carrão-Panizzi (2016a). A qualidade dos brotos obtidos com o sistema simplificado também foi verificada nas avaliações das características físico-químicas dos mesmos. A cultivar BRS 216, desenvolvida pela Embrapa para produção de brotos de soja, foi utilizada nesse estudo, pois apresenta sementes pequenas (10 g/peso de 100 sementes), característica essencial para produção de brotos. Palavras-chaves: soja, Glycine max (L.)Merrill, BRS 2016, produção de broto, alimentação humanabitstream/item/221446/1/ComTec-374-online.pd

Diffusion Monte Carlo study of circular quantum dots

We present ground and excited state energies obtained from Diffusion Monte Carlo (DMC) calculations, using accurate multiconfiguration wave functions, for $N$ electrons ($N\le13$) confined to a circular quantum dot. We analyze the electron-electron pair correlation functions and compare the density and correlation energies to the predictions of local spin density approximation theory (LSDA). The DMC estimated change in electrochemical potential as function of the number of electrons in the dot is compared to that from LSDA and Hartree-Fock (HF) calculations.Comment: 7 pages, 4 eps figures. To be published in Phys. Rev. B, September 15th 2000. See erratum cond-mat/030571

C\u3csub\u3e3\u3c/sub\u3e Perennial Grass Dominates Mixed C\u3csub\u3e3\u3c/sub\u3e/C\u3csub\u3e4\u3c/sub\u3e Grasslands After Invasion by a C\u3csub\u3e3\u3c/sub\u3e Woody Sprouter

Honey mesquite (Prosopis glandulosa) encroachment has resulted in decreased C4 mid-grass production and increased C3 mid-grass in the Southern Great Plains of the US. Woody legumes have had similar effects in Africa, Australia, and South America. Prosopis initially facilitates Texas wintergrass (Nassella leucotricha) growth under canopies, in part because N-fixation by this woody legume enriches subcanopy soils, favoring C3 species. As stand density increases, Nassella extends into interspaces between trees as well. Here we report Nassella responses in several studies that either reduced Prosopis to indirectly impact Nassella or treated Nassella directly. In a 9-year study following mechanical top-kill of Prosopis, Nassella increased production for the first 3 years before slowly declining to pre-treatment levels. C4 mid-grass production increased, but was limited to only a third of its potential by drought and Prosopis regrowth. Following a root-killing treatment of Prosopis, Nassella production and total herbaceous production were greater in treated than untreated intercanopy and subcanopy microsites 1-yr post-treatment. Nassella and perennial grass production declined in treated microsites 2-yrs post-treatment; however, total herbaceous production remained greater in treated than untreated microsites due to increased annual forb production. Targeted grazing reduced Nassella cover and reproduction, but increased bare ground. Multiple-stemmed Prosopis with low-hanging limbs protected Nassella, thus limiting targeted grazing success when trees were not removed. The Prosopis/Nassella state appears to be resistant to change and may permanently limit transition back to C4 grassland unless Prosopis is root-killed, though our results indicate that even root-killing Prosopis does not guarantee an immediate increase in C4 production. If so, managing Prosopis height and canopy cover, C:N ratios of the vegetative layer, and grazing Nassella during peak production and nutritional quality may allow profitable production until anthropogenic or natural processes result in large scale mortality of the Prosopis overstory