A Birkhoff connection between quantum circuits and linear classical reversible circuits

Birkhoff's theorem tells how any doubly stochastic matrix can be decomposed as a weighted sum of permutation matrices. Similar theorems on unitary matrices reveal a connection between quantum circuits and linear classical reversible circuits. It triggers the question whether a quantum computer can be regarded as a superposition of classical reversible computers

Expression systems for industrial Gram-positive bacteria with low guanine and cytosine content

Recent years have seen an increase in the development of gene expression systems for industrial Gram-positive bacteria with low guanine and cytosine content that belong to the genera Bacillus, Clostridium, Lactococcus, Lactobacillus, Staphylococcus and Streptococcus. In particular, considerable advances have been made in the construction of inducible gene expression systems based on the capacity of these bacteria to utilize specific sugars or to secrete autoinducing peptides that are involved in quorum sensing. These controlled expression systems allow for present and future exploitation of these bacteria as cell factories in medical, agricultural, and food biotechnology.

Towards a definition of SUBJECT in binding domains and subject-oriented anaphora

The question of subjecthood has dogged linguistic science since ancient times. However, in current versions of Minimalism, subjects do not have primitive status and can only be defined in derived terms. However, subjects and the broader theoretical notion of SUBJECT remain important in linguistic description. This paper develops a definition of subjecthood in terms of set-theoretic notions of functional dependency: when a feature, say phi, determines the value of some other feature, say u-phi. This notion is used to describe various phenomena where subjecthood has been invoked: binding domains and subject-oriented anaphors

The phenomenology of electric dipole moments in models of scalar leptoquarks

We study the phenomenology of electric dipole moments (EDMs) induced in various scalar leptoquark models. We consider generic leptoquark couplings to quarks and leptons and match to Standard Model effective field theory. After evolving the resulting operators to low energies, we connect to EDM experiments by using up-to-date hadronic, nuclear, and atomic matrix elements. We show that current experimental limits set strong constraints on the possible CP-violating phases in leptoquark models. Depending on the quarks and leptons involved in the interaction, the existing searches for EDMs of leptons, nucleons, atoms, and molecules all play a role in constraining the CP-violating couplings. We discuss the impact of hadronic and nuclear uncertainties as well as the sensitivities that can be achieved with future EDM experiments. Finally, we study the impact of EDM constraints on a specific leptoquark model that can explain the recent $B$-physics anomalies.Comment: Published versio

Controlled overproduction of proteins by lactic acid bacteria

Lactic acid bacteria are widely used in industrial food fermentations, contributing to flavour, texture and preservation of the fermented products. Here we describe recent advances in the development of controlled gene expression systems, which allow the regulated overproduction of any desirable protein by lactic acid bacteria. Some systems benefit from the fact that the expression vectors, marker genes and inducing factors can be used directly in food applications since they are all derived from food-grade lactic acid bacteria. These systems have also been employed for the development of autolytic bacteria, suitable for various industrial applications.

On two subgroups of U(n), useful for quantum computing

As two basic building blocks for any quantum circuit, we consider the 1-qubit PHASOR circuit Phi(theta) and the 1-qubit NEGATOR circuit N(theta). Both are roots of the IDENTITY circuit. Indeed: both (NO) and N(0) equal the 2 x 2 unit matrix. Additionally, the NEGATOR is a root of the classical NOT gate. Quantum circuits (acting on w qubits) consisting of controlled PHASORs are represented by matrices from ZU(2(w)); quantum circuits consisting of controlled NEGATORs are represented by matrices from XU(2(w)). Here, ZU(n) and XU(n) are subgroups of the unitary group U(n): the group XU(n) consists of all n x n unitary matrices with all 2n line sums (i.e. all n row sums and all n column sums) equal to 1 and the group ZU(n) consists of all n x n unitary diagonal matrices with first entry equal to 1. Any U(n) matrix can be decomposed into four parts: U = exp(i alpha) Z(1)XZ(2), where both Z(1) and Z(2) are ZU(n) matrices and X is an XU(n) matrix. We give an algorithm to find the decomposition. For n = 2(w) it leads to a four-block synthesis of an arbitrary quantum computer