What is the Computational Value of Finite Range Tunneling?

Quantum annealing (QA) has been proposed as a quantum enhanced optimization heuristic exploiting tunneling. Here, we demonstrate how finite range tunneling can provide considerable computational advantage. For a crafted problem designed to have tall and narrow energy barriers separating local minima, the D-Wave 2X quantum annealer achieves significant runtime advantages relative to Simulated Annealing (SA). For instances with 945 variables, this results in a time-to-99%-success-probability that is $\sim 10^8$ times faster than SA running on a single processor core. We also compared physical QA with Quantum Monte Carlo (QMC), an algorithm that emulates quantum tunneling on classical processors. We observe a substantial constant overhead against physical QA: D-Wave 2X again runs up to $\sim 10^8$ times faster than an optimized implementation of QMC on a single core. We note that there exist heuristic classical algorithms that can solve most instances of Chimera structured problems in a timescale comparable to the D-Wave 2X. However, we believe that such solvers will become ineffective for the next generation of annealers currently being designed. To investigate whether finite range tunneling will also confer an advantage for problems of practical interest, we conduct numerical studies on binary optimization problems that cannot yet be represented on quantum hardware. For random instances of the number partitioning problem, we find numerically that QMC, as well as other algorithms designed to simulate QA, scale better than SA. We discuss the implications of these findings for the design of next generation quantum annealers.Comment: 17 pages, 13 figures. Edited for clarity, in part in response to comments. Added link to benchmark instance

Stress echocardiography for left ventricular diastolic dysfunction detection in patients with non-severe chronic obstructive pulmonary disease: a cross-sectional study

Aim To assess whether the simultaneous performance of exercise stress echocardiography and cardio-pulmonary testing (ESE-CPET) may facilitate the timely diagnosis of subclinical left ventricular diastolic dysfunction (LVDD) in patients with non-severe chronic obstructive pulmonary disease (COPD), preserved left ventricular systolic function, and exertional dyspnea or exercise intolerance. Methods This cross-sectional study, conducted between May 2017 and April 2018, involved 104 non-severe COPD patients with exertional dyspnea and preserved ejection fraction who underwent echocardiography before CPET and 1-2 minutes after peak exercise. Based on the peak E/e’ ratio, patients were divided into the group with stressinduced LVDD – E/e’>15 and the group without stress-induced LVDD. We assessed the association between LVDD and the following CPET variables: minute ventilation, peak oxygen uptake (VO2), ventilatory efficiency, heart rate reserve, and blood pressure.Results During ESE-CPET, stress-induced LVDD occurred in 67/104 patients (64%). These patients had lower work load, peak VO2, O2 pulse, and minute ventilation (VE), and higher VE/VCO2 slope than patients without stress-induced LVDD (35.18 ± 10.4 vs 37.01 ± 11.11, P < 0.05). None of the CPET variables correlated with E/e’. Conclusion Combined ESE-CPET may distinguish masked LVDD in patients with non-severe COPD with exertional dyspnea and preserved left ventricular systolic function. None of the CPET variables was a predictor for subclinical LVDD

Mechano-morphological studies of polyamide 6 based single polymer laminate composites prepared by different reactive processing techniques

Single polymer laminate composites based on polyamide 6 (PA6) were prepared by two methods: (i) reactive injection molding and (ii) powder coating/compression molding, both carried out in the presence of PA6 woven textile plies. The effect of the textile volume fraction Vf on the tensile properties of all composites was investigated. The laminates obtained by powder coating/compression molding displayed best mechanical performance, whereby in the composites with Vf = 15%, the improvement of the elastic modulus reached 98% in respect to commercial hydrolytic PA6 reference, or 50–86% as compared to neat anionic PA6 samples. Polarizing light microscopy with image processing was used for morphological characterization. A transcrystalline layer at the fiber-matrix interface was detected in all laminates with thicknesses between 0.5 and 3.0 μm, depending on the preparation technique applied. The thermal stability was studied in the temperature range of 30°C-550 °C. The laminates obtained by reactive injection molding displayed the lowest initial decomposition temperature due to the presence of oligomers. Selected laminate composites were reprocessed by grinding and injection molding. The recycled composites obtained by powder coating displayed a 38% increase of the elastic modulus in respect to commercial hydrolytic PA6 thus confirming the sustainability and recyclability of PA6-based single polymer composites.This work was partially financed by FEDER funds through the COMPETE program and by national funds through FCT – Foundation for Science and Technology within the project .POCI-01-0145-FEDER 007136 SDT thanks FCT for his PhD Grant SFRH/BD/94759/2013. ZZD and NVD thank the National Funds through FCT-Portuguese Foundation for Science and Technology, project reference UID/CTM/50025/2019. All authors gratefully acknowledge the support of the project TSSiPRO NORTE-01-0145-FEDER-000015 funded by the regional operational program NORTE 2020, under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund

Bovine serum albumin-imprinted magnetic poly(2-pyrrolidone) microparticles for protein recognition

This study reports on the synthesis and adsorption properties of molecularly imprinted porous magnetic microparticles (MIP) based on the biodegradable and sustainable poly(2-pyrrolidone) (PPD or PA4). These new PPD MIP materials were obtained via activated anionic ring-opening polymerization of 2-pyrroldone carried out at 40 °C, in the presence of iron fillers and bovine serum albumin (BSA) as a template. Neither solvent, nor additional crosslinking or porogen agents were used in the PPD MIP synthesis. Analogously, PPD particles without BSA imprinting (NIP) were also produced. Depending on the microparticles composition, their yields were in the 55–70 wt% range, the average size varying between 8 and 25 μm. After characterization of the surface topography of all samples, their adsorption capacity toward the BSA target was assessed as a function of the adsorption time, protein concentration and pH of the medium. All three PPD MIP samples displayed adsorption capacity toward BSA being up to one order of magnitude higher as compared to other BSA-imprinted polymer systems. It was found that the rebinding of BSA on MIP is best described by the Langmuir isotherm, whereas for rebinding on NIP the Freundlich isotherm was the more adequate model. On this basis, the nature of the adsorption on MIP and NIP was discussed. The adsorption toward two other proteins, namely Ovalbumin and Cytochrome C was also tested. The newly synthesized BSA-imprinted PPD MIP displayed selective adsorption for the BSA target being dependent on the pH values of the medium. The easy recovery of the Fe-containing MIP and the capacity of all MIP samples for multiple sorption/desorption cycles was demonstrated.The authors gratefully acknowledge the financial support of the project TSSiPRO NORTE-01-0145-FEDER-000015, supported by the regional operation program NORTE2020, under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund, as well as the support by National Funds through Fundação para a Ciência e Tecnologia (FCT), project UID/CTM/50025/2019. N. Dencheva is also grateful for the financial support of FCT in the frames of the strategic project UID/CTM/50025/2013 and the personal pro gram-contract CTTI-51/18-IP

Distribution of the anther-smut pathogen Microbotryum on species of the Caryophyllaceae

Artículo de publicación ISIUnderstanding disease distributions is of fundamental and applied importance, yet few studies benefit from integrating broad sampling with ecological and phylogenetic data. Here, anther-smut disease, caused by the fungus Microbotryum, was assessed using herbarium specimens of Silene and allied genera of the Caryophyllaceae. • A total of 42 000 herbarium specimens were examined, and plant geographical distributions and morphological and life history characteristics were tested as correlates of disease occurrence. Phylogenetic comparative methods were used to determine the association between disease and plant life-span. • Disease was found on 391 herbarium specimens from 114 species and all continents with native Silene. Anther smut occurred exclusively on perennial plants, consistent with the pathogen requiring living hosts to overwinter. The disease was estimated to occur in 80% of perennial species of Silene and allied genera. The correlation between plant life-span and disease was highly significant while controlling for the plant phylogeny, but the disease was not correlated with differences in floral morphology. • Using resources available in natural history collections, this study illustrates how disease distribution can be determined, not by restriction to a clade of susceptible hosts or to a limited geographical region, but by association with host life-span, a trait that has undergone frequent evolutionary transitions.We acknowledge grant support from the John Simon Guggenheim Memorial Foundation and the National Science Foundation (DEB-0747222) to MEH, the National Science Foundation Minority Postdoctoral Fellowship (DBI-0706721) to JIMA, University of Chile awards PFB-23 and ICM P05-002 to MTKA, and The Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (FORMAS) support to BO, and Royal Society Incoming Fellowship and Center for Infection, Immunity, and Evolution Advanced Fellowship to ABP

Glacial Refugia in Pathogens: European Genetic Structure of Anther Smut Pathogens on Silene latifolia and Silene dioica

Climate warming is predicted to increase the frequency of invasions by pathogens and to cause the large-scale redistribution of native host species, with dramatic consequences on the health of domesticated and wild populations of plants and animals. The study of historic range shifts in response to climate change, such as during interglacial cycles, can help in the prediction of the routes and dynamics of infectious diseases during the impending ecosystem changes. Here we studied the population structure in Europe of two Microbotryum species causing anther smut disease on the plants Silene latifolia and Silene dioica. Clustering analyses revealed the existence of genetically distinct groups for the pathogen on S. latifolia, providing a clear-cut example of European phylogeography reflecting recolonization from southern refugia after glaciation. The pathogen genetic structure was congruent with the genetic structure of its host species S. latifolia, suggesting dependence of the migration pathway of the anther smut fungus on its host. The fungus, however, appeared to have persisted in more numerous and smaller refugia than its host and to have experienced fewer events of large-scale dispersal. The anther smut pathogen on S. dioica also showed a strong phylogeographic structure that might be related to more northern glacial refugia. Differences in host ecology probably played a role in these differences in the pathogen population structure. Very high selfing rates were inferred in both fungal species, explaining the low levels of admixture between the genetic clusters. The systems studied here indicate that migration patterns caused by climate change can be expected to include pathogen invasions that follow the redistribution of their host species at continental scales, but also that the recolonization by pathogens is not simply a mirror of their hosts, even for obligate biotrophs, and that the ecology of hosts and pathogen mating systems likely affects recolonization patterns