Separable Multipartite Mixed States - Operational Asymptotically Necessary and Sufficient Conditions

We introduce an operational procedure to determine, with arbitrary probability and accuracy, optimal entanglement witness for every multipartite entangled state. This method provides an operational criterion for separability which is asymptotically necessary and sufficient. Our results are also generalized to detect all different types of multipartite entanglement.Comment: 4 pages, 2 figures, submitted to Physical Review Letters. Revised version with new calculation

From Uncertainty Data to Robust Policies for Temporal Logic Planning

We consider the problem of synthesizing robust disturbance feedback policies for systems performing complex tasks. We formulate the tasks as linear temporal logic specifications and encode them into an optimization framework via mixed-integer constraints. Both the system dynamics and the specifications are known but affected by uncertainty. The distribution of the uncertainty is unknown, however realizations can be obtained. We introduce a data-driven approach where the constraints are fulfilled for a set of realizations and provide probabilistic generalization guarantees as a function of the number of considered realizations. We use separate chance constraints for the satisfaction of the specification and operational constraints. This allows us to quantify their violation probabilities independently. We compute disturbance feedback policies as solutions of mixed-integer linear or quadratic optimization problems. By using feedback we can exploit information of past realizations and provide feasibility for a wider range of situations compared to static input sequences. We demonstrate the proposed method on two robust motion-planning case studies for autonomous driving

Sparse identification of posynomial models

Posynomials are nonnegative combinations of monomials with possibly fractional and both positive and negative exponents. Posynomial models are widely used in various engineering design endeavors, such as circuits, aerospace and structural design, mainly due to the fact that design problems cast in terms of posynomial objectives and constraints can be solved efficiently by means of a convex optimization technique known as geometric programming (GP). However, while quite a vast literature exists on GP-based design, very few contributions can yet be found on the problem of identifying posynomial models from experimental data. Posynomial identification amounts to determining not only the coefficients of the combination, but also the exponents in the monomials, which renders the identification problem hard. In this paper, we propose an approach to the identification of multivariate posynomial models based on the expansion on a given large-scale basis of monomials. The model is then identified by seeking coefficients of the combination that minimize a mixed objective, composed by a term representing the fitting error and a term inducing sparsity in the representation, which results in a problem formulation of the “square-root LASSO” type, with nonnegativity constraints on the variables. We propose to solve the problem via a sequential coordinate-minimization scheme, which is suitable for large-scale implementations. A numerical example is finally presented, dealing with the identification of a posynomial model for a NACA 4412 airfoil

Phenotypic and Molecular Selection of a Superior Solanum pennellii Introgression Sub-Line Suitable for Improving Quality Traits of Cultivated Tomatoes

The Solanum pennellii Introgression Line (IL) population can be exploited to identify favorable alleles that can improve yield and fruit quality traits in commercial tomato varieties. Over the past few years, we have selected ILs that exhibit increased content of antioxidant compounds in the fruit compared to the cultivar M82, which represents the genetic background in which the different wild regions of the S. pennellii ILs were included. Recently, we have identified seven sub-lines of the IL7-3 accumulating different amounts of antioxidants in the ripe fruit. Since the wild region carried on chromosome 7 induces a low fruit production in IL7-3, the first aim of the present work was to evaluate yield performances of the selected sub-lines in three experimental fields located in the South of Italy. Another aim was to confirm in the same lines the high levels of antioxidants and evaluate other fruit quality traits. On red ripe fruit, the levels of soluble solids content, firmness, and ascorbic acid (AsA) were highly variable among the sub-lines grown in three environmental conditions, evidencing a significant genotype by environment interaction for soluble solids and AsA content. Only one sub-line (coded R182) exhibited a significantly higher firmness, even though no differences were observed for this trait between the parental lines M82 and IL7-3. The same sub-line showed significantly higher AsA content compared to M82, thus resembling IL7-3. Even though IL7-3 always exhibited a significantly lower yield, all the sub-lines showed yield variability over the three trials. Interestingly, the sub-line R182, selected for its better performances in terms of fruit quality, in all the trials showed a production comparable to that of the control line M82. A group of species-specific molecular markers was tested on R182 and on the parental genotypes in order to better define the wild genomic regions carried by the elite line R182. In these regions three candidate genes that could increase the level of AsA in the fruit were identified. In the future, the line R182 could be used as pre-breeding material in order to obtain new varieties improved for nutritional traits

Survival and Neural Models for Private Equity Exit Prediction

Within the Private Equity (PE) market, the event of a private company undertaking an Initial Public Offering (IPO) is usually a very high-return one for the investors in the company. For this reason, an effective predictive model for the IPO event is considered as a valuable tool in the PE market, an endeavor in which publicly available quantitative information is generally scarce. In this paper, we describe a data-analytic procedure for predicting the probability with which a company will go public in a given forward period of time. The proposed method is based on the interplay of a neural network (NN) model for estimating the overall event probability, and Survival Analysis (SA) for further modeling the probability of the IPO event in any given interval of time. The proposed neuro-survival model is tuned and tested across nine industrial sectors using real data from the Thomson Reuters Eikon PE database

High-throughput genotyping of resilient tomato landraces to detect candidate genes involved in the response to high temperatures

The selection of tolerant varieties is a powerful strategy to ensure highly stable yield under elevated temperatures. In this paper, we report the phenotypic and genotypic characterization of 10 tomato landraces to identify the best performing under high temperatures. The phenotyping of five yield-related traits allowed us to select one genotype that exhibits highly stable yield performances in different environmental conditions. Moreover, a Genotyping-by-Sequencing approach allowed us to explore the genetic variability of the tested genotypes. The high and stable yielding landrace E42 was the most polymorphic one, with ~49% and ~47% private SNPs and InDels, respectively. The effect of 26,113 mutations on proteins’ structure was investigated and it was discovered that 37 had a high impact on the structure of 34 proteins of which some are putatively involved in responses to high temperatures. Additionally, 129 polymorphic sequences aligned against tomato wild species genomes revealed the presence in the genotype E42 of several introgressed regions deriving from S. pimpinellifolium. The position on the tomato map of genes affected by moderate and high impact mutations was also compared with that of known markers/QTLs (Quantitative Trait Loci) associated with reproductive and yield-related traits. The candidate genes/QTLs regulating heat tolerance in the selected landrace E42 could be further investigated to better understand the genetic mechanisms controlling traits for high and stable yield trait under high temperatures

Certification of Bounds of Non-linear Functions: the Templates Method

The aim of this work is to certify lower bounds for real-valued multivariate functions, defined by semialgebraic or transcendental expressions. The certificate must be, eventually, formally provable in a proof system such as Coq. The application range for such a tool is widespread; for instance Hales' proof of Kepler's conjecture yields thousands of inequalities. We introduce an approximation algorithm, which combines ideas of the max-plus basis method (in optimal control) and of the linear templates method developed by Manna et al. (in static analysis). This algorithm consists in bounding some of the constituents of the function by suprema of quadratic forms with a well chosen curvature. This leads to semialgebraic optimization problems, solved by sum-of-squares relaxations. Templates limit the blow up of these relaxations at the price of coarsening the approximation. We illustrate the efficiency of our framework with various examples from the literature and discuss the interfacing with Coq.Comment: 16 pages, 3 figures, 2 table

Exploiting genomics resources to identify candidate genes underlying antioxidants content in tomato fruit

The tomato is a model species for fleshy fruit development and ripening, as well as for genomics studies of others Solanaceae. Many genetic and genomics resources, including databases for sequencing, transcriptomics and metabolomics data, have been developed and are today available. The purpose of the present work was to uncover new genes and/or alleles that determine ascorbic acid and carotenoids accumulation, by exploiting one Solanum pennellii introgression lines (IL7-3) harboring quantitative trait loci (QTL) that increase the content of these metabolites in the fruit. The higher ascorbic acid and carotenoids content in IL7-3 was confirmed at three fruit developmental stages. The tomato genome reference sequence and the recently released S. pennellii genome sequence were investigated to identify candidate genes (CGs) that might control ascorbic acid and carotenoids accumulation. First of all, a refinement of the wild region borders in the IL7-3 was achieved by analyzing CAPS markers designed in our laboratory. Afterward, six CGs associated to ascorbic acid and one with carotenoids metabolism were identified exploring the annotation and the Gene Ontology terms of genes included in the region. Variants between the sequence of the wild and the cultivated alleles of these genes were investigated for their functional relevance and their potential effects on the protein sequences were predicted. Transcriptional levels of CGs in the introgression region were extracted from RNA-Seq data available for the entire S. pennellii introgression lines collection and verified by Real-Time qPCR. Finally, seven IL7-3 sub-lines were genotyped using 28 species-specific markers and then were evaluated for metabolites content. These analyses evidenced a significant decrease in transcript abundance for one 9-cis-epoxycarotenoid dioxygenase and one L-ascorbate oxidase homolog, whose role in the accumulation of carotenoids and ascorbic acid is discussed. Comprehensively, the reported results demonstrated that combining genetic and genomic resources in tomato, including bioinformatics tools, was a successful strategy to dissect one QTL for the increase of ascorbic acid and carotenoids in tomato fruit

Xenotransplantation of microencapsulated pancreatic islets contained in a vascular prosthesis: preliminary results

Porcine and human pancreatic islets were microencapsulated in an alginate-polylysine biomembrane and put in a chamber of a new vascular prosthesis composed of an inner tubing of Dacron mesh and an outer tubing of expanded polytetrafluorethylene material. The vascular prosthesis was anastomized between the iliac artery and the contralateral vein of diabetic dogs. The recipients did not receive any immunosuppressive therapy. Function of porcine and human islets was monitored by measuring serum glucose levels and human C-peptide concentrations. After transplantation, serum glucose levels were maintained at values lower than 200 mg/dl, and C-peptide concentrations were between 0.8 and 3.2 ng/ml. Injected insulin requirements decreased by 50%-60%. Four to 8 weeks after transplantation, histologic examination showed well-preserved and functioning islets in the majority of intact microcapsules. Fibrin and inflammatory cells were not observed in the chamber. These data suggest long-term survival and function of microencapsulated pancreatic islets in the vascular prosthesis. © 1991 Springer-Verlag

Defective One- or Two-electron Reduction of the Anticancer Anthracycline Epirubicin in Human Heart RELATIVE IMPORTANCE OF VESICULAR SEQUESTRATION AND IMPAIRED EFFICIENCY OF ELECTRON ADDITION

One-electron quinone reduction and two-electron carbonyl reduction convert the anticancer anthracycline doxorubicin to reactive oxygen species (ROS) or a secondary alcohol metabolite that contributes to inducing a severe form of cardiotoxicity. The closely related analogue epirubicin induces less cardiotoxicity, but the determinants of its different behavior have not been elucidated. We developed a translational model of the human heart and characterized whether epirubicin exhibited a defective conversion to ROS and secondary alcohol metabolites. Small myocardial samples from cardiac surgery patients were reconstituted in plasma that contained clinically relevant concentrations of doxorubicin or epirubicin. In this model only doxorubicin formed ROS, as detected by fluorescent probes or aconitase inactivation. Experiments with cell-free systems and confocal laser scanning microscopy studies of H9c2 cardiomyocytes suggested that epirubicin could not form ROS because of its protonation-dependent sequestration in cytoplasmic acidic organelles and the consequent limited localization to mitochondrial one-electron quinone reductases. Accordingly, blocking the protonation-sequestration mechanism with the vacuolar H+-ATPase inhibitor bafilomycin A1 relocalized epirubicin to mitochondria and increased its conversion to ROS in human myocardial samples. Epirubicin also formed ∼60% less alcohol metabolites than doxorubicin, but this was caused primarily by its higher Km and lower Vmax values for two-electron carbonyl reduction by aldo/keto-reductases of human cardiac cytosol. Thus, vesicular sequestration and impaired efficiency of electron addition have separate roles in determining a defective bioactivation of epirubicin to ROS or secondary alcohol metabolites in the human heart. These results uncover the molecular determinants of the reduced cardiotoxicity of epirubicin and serve mechanism-based guidelines to improving antitumor therapies