A quantum-inspired algorithm for estimating the permanent of positive semidefinite matrices

We construct a quantum-inspired classical algorithm for computing the permanent of Hermitian positive semidefinite matrices, by exploiting a connection between these mathematical structures and the boson sampling model. Specifically, the permanent of a Hermitian positive semidefinite matrix can be expressed in terms of the expected value of a random variable, which stands for a specific photon-counting probability when measuring a linear-optically evolved random multimode coherent state. Our algorithm then approximates the matrix permanent from the corresponding sample mean and is shown to run in polynomial time for various sets of Hermitian positive semidefinite matrices, achieving a precision that improves over known techniques. This work illustrates how quantum optics may benefit algorithms development.Comment: 9 pages, 1 figure. Updated version for publicatio

Proposal for a loophole-free Bell test using homodyne detection

We propose a feasible optical setup allowing for a loophole-free Bell test with efficient homodyne detection. A non-gaussian entangled state is generated from a two-mode squeezed vacuum by subtracting a single photon from each mode, using beamsplitters and standard low-efficiency single-photon detectors. A Bell violation exceeding 1% is achievable with 6-dB squeezed light and an homodyne efficiency around 95%. A detailed feasibility analysis, based upon the recent generation of single-mode non-gaussian states, confirms that this method opens a promising avenue towards a complete experimental Bell test.Comment: 4 pages RevTex, 2 figure

DNA assembly standards: Setting the low-level programming code for plant biotechnology

[EN] Synthetic Biology is defined as the application of engineering principles to biology. It aims to increase the speed, ease and predictability with which desirable changes and novel traits can be conferred to living cells. The initial steps in this process aim to simplify the encoding of new instructions in DNA by establishing low-level programming languages for biology. Together with advances in the laboratory that allow multiple DNA molecules to be efficiently assembled together into a desired order in a single step, this approach has simplified the design and assembly of multigene constructs and has even facilitated the automated construction of synthetic chromosomes. These advances and technologies are now being applied to plants, for which there are a growing number of software and wetware tools for the design, construction and delivery of DNA molecules and for the engineering of endogenous genes. Here we review the efforts of the past decade that have established synthetic biology workflows and tools for plants and discuss the constraints and bottlenecks of this emerging field.Marta Vazquez-Vilar is funded by Wageningen University & Research. Diego Orzaez is funded by the Spanish Ministry of Economy and Competitiveness [grant number BIO2016-78601-R]. Nicola Patron is funded by the UK Biotechnological and Biological Sciences Research Council (BBSRC) and Engineering and Physics Research Council (EPSRC)Synthetic Biology for Growth programme [OpenPlant Synthetic Biology Research Centre, grant number BB/L0I4130/1], and by the Earlham DNA Foundry [grant number BB/CCG1720/1].Vázquez-Vilar, M.; Orzáez Calatayud, DV.; Patron, N. (2018). DNA assembly standards: Setting the low-level programming code for plant biotechnology. Plant Science. 273:33-41. https://doi.org/10.1016/j.plantsci.2018.02.024S334127

FPGA Implementation of a Telecommunications Trainer System

Field programmable gate arrays (FPGAs) have been used in a wide range of applications including the field of telecommunications. This paper presents the use of FPGAs in the implementation of both analog and digital modulation that includes amplitude modulation, frequency modulation, phase modulation, pulse code modulation, pulse width modulation, pulse position modulation, pulse amplitude modulation, delta modulation, amplitude shift keying, frequency shift keying, phase shift keying, time division multiplexing and different encoding techniques like non-return-to-zero line code, non-return-to-zero mark line code, non-return to zero inversion line code, Unipolar return-to-zero line code, bipolar return-to-zero line code, alternate mark inversion line code, and Manchester line code. Moreover, an FPGA can be designed to emulate a particular device like an oscilloscope, a function generator, or the like. This paper describes the capability of an FPGA to internally generate a low frequency input signal and through the use of a VGA port, it is able to display the signals in an output device. However, the use of FPGAs is not limited to the aforementioned applications because of its reconfigurability and reprogrammability

Соотношение теории и реальности в базовых экономических курсах

The article presents the analysis of methodological issues and problems of the correlation between theory and reality in basic courses taught at the Faculty of Economics of Lomonosov Moscow State University. The paper provides the methodological approaches that can be used in conducting lectures and seminars, based on many years of experience; analyzes basic methods and forms that help convince students of the practical usefulness of the disciplines studied. The authors also offer methodological solutions that allow to explain to the students the ultimate goal of studying theoretical courses and encourage their involvement and interest in the learning process.Статья посвящена анализу методических вопросов и проблем соотношения теории и реальности в базовых учебных курсах, преподаваемых на экономическом факультете МГУ имени М. В. Ломоносова. В работе представлены методические подходы, которые могут быть использованы в процессе ведения лекций и семинаров, и на основе многолетнего опыта проанализированы базовые способы и формы, которые помогают убедить студентов в практической полезности изучаемых дисциплин. Авторами также предложены методологические решения, позволяющие объяснить студентам конечную цель изучения теоретических курсов и повысить степень их вовлеченности и заинтересованности в процессе обучения

Induction of targeted, heritable mutations in barley and Brassica oleracea using RNA-guided Cas9 nuclease

Background The RNA-guided Cas9 system represents a flexible approach for genome editing in plants. This method can create specific mutations that knock-out or alter target gene function. It provides a valuable tool for plant research and offers opportunities for crop improvement. Results We investigate the use and target specificity requirements of RNA-guided Cas9 genome editing in barley (Hordeum vulgare) and Brassica oleracea by targeting multicopy genes. In barley, we target two copies of HvPM19 and observe Cas9-induced mutations in the first generation of 23 % and 10 % of the lines, respectively. In B. oleracea, targeting of BolC.GA4.a leads to Cas9-induced mutations in 10 % of first generation plants screened. In addition, a phenotypic screen identifies T 0 plants with the expected dwarf phenotype associated with knock-out of the target gene. In both barley and B. oleracea stable Cas9-induced mutations are transmitted to T 2 plants independently of the T-DNA construct. We observe off-target activity in both species, despite the presence of at least one mismatch between the single guide RNA and the non-target gene sequences. In barley, a transgene-free plant has concurrent mutations in the target and non-target copies of HvPM19. Conclusions We demonstrate the use of RNA-guided Cas9 to generate mutations in target genes of both barley and B. oleracea and show stable transmission of these mutations thus establishing the potential for rapid characterisation of gene function in these species. In addition, the off-target effects reported offer both potential difficulties and specific opportunities to target members of multigene families in crops

Sympathy for the Details: Dense Trajectories and Hybrid Classification Architectures for Action Recognition

Action recognition in videos is a challenging task due to the complexity of the spatio-temporal patterns to model and the difficulty to acquire and learn on large quantities of video data. Deep learning, although a breakthrough for Image classification and showing promise for videos, has still not clearly superseded action recognition methods using hand-crafted features, even when training on massive datasets. In this paper, we introduce hybrid video classification architectures based on carefully designed unsupervised representations of hand-crafted spatio-temporal features classified by supervised deep networks. As we show in our experiments on five popular benchmarks for action recognition, our hybrid model combines the best of both worlds: it is data efficient (trained on 150 to 10000 short clips) and yet improves significantly on the state of the art, including recent deep models trained on millions of manually labelled images and videos