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.

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.

Non-linear photonic crystals as a source of entangled photons

Non-linear photonic crystals can be used to provide phase-matching for frequency conversion in optically isotropic materials. The phase-matching mechanism proposed here is a combination of form birefringence and phase velocity dispersion in a periodic structure. Since the phase-matching relies on the geometry of the photonic crystal, it becomes possible to use highly non-linear materials. This is illustrated considering a one-dimensional periodic Al$_{0.4}$Ga$_{0.6}$As / air structure for the generation of 1.5 $\mu$m light. We show that phase-matching conditions used in schemes to create entangled photon pairs can be achieved in photonic crystals.Comment: 4 pages, 3 figure

Contemplations and discussions on the quality of forensic assessment in sentencing:Puzzling pieces for decision makers

In essence, forensic assessment is labour of a diagnostic nature. This chapter discusses the origins of forensic assessment, types, and measures of quality and possible biases that come with the legal context. It focuses on the most common psycholegal concepts relevant for the quality of forensic assessment in sentencing will be described respectively: mental disorder, criminal responsibility, and dangerousness. Risk assessment is often informed by the Risk-Needs-Responsivity model. Structured guidelines for risk assessment exist in various forms. Roughly two main categories of tools can be divided: actuarial measures and those following a structured professional judgement (SPJ) approach. Both kinds of tools include a list of factors that have empirically been shown to be related to an increased likelihood of future offending. Generally, personalised interventions and risk-management as offered in a forensic treatment setting are much more effective in terms of recidivism reduction than harsh punishments and lengthy prison sentences

Arbeidsaanbodelasticiteit en beleid

De invloed van beleidshervormingen op de werkgelegenheid is in belangrijke mate afhankelijk van de loonelasticiteit van het arbeidsaanbod. Ondanks de enorme hoeveelheid empirische studies is de hoogte van deze elasticiteit nog altijd onderwerp van discussie

Photon statistics from coupled quantum dots

We present an optical study of closely-spaced self-assembled InAs/GaAs quantum dots. The energy spectrum and correlations between photons subsequently emitted from a single pair provide not only clear evidence of coupling between the quantum dots but also insight into the coupling mechanism. Our results are in agreement with recent theories predicting that tunneling is largely suppressed between nonidentical quantum dots and that the interaction is instead dominated by dipole-dipole coupling and phonon-assisted energy transfer processes.Comment: 4 pages, 4 figures, to appear in Phys. Re

Europees minimum voor vennootschapsbelasting is goede zaak

Het voorstel voor een Europees minimumtarief voor de vennootschapsbelasting is verstandig. Enerzijds voorkomt een minimumtarief een al te scherpe race naar de bodem. Anderzijds blijft de mogelijkheid voor belastingsconcurrentie bestaan

What explains the Variation in Estimates of Labour Supply Elasticities?

This paper performs a meta-analysis of empirical estimates of uncompensated labour supply elasticities. We find that much of the variation in elasticities can be explained by the variation in gender, participation rates, and country fixed effects. Country differences appear to be small though. There is no systematic impact of the model specification or marital status on reported elasticities. The decision to participate is more responsive than is the decision regarding hours worked. Even at the intensive margin, we find that the elasticity for women exceeds that for men. For men and women in the Netherlands, we predict an uncompensated labour supply elasticity of 0.1 (or 0.2 if an alternative specification is preferred) and 0.5, respectively. These values are robust for alternative samples and specifications of the meta regression

Big Changes in How Students are Tested

For the past decade, school accountability has relied on tests for which the essential format has remained unchanged. Educators are familiar with the yearly testing routine: schools are given curriculum frameworks, teachers use the frameworks to guide instruction, students take one big test at year’s end which relies heavily upon multiple-choice bubble items, and then school leaders wait anxiously to find out whether enough of their students scored at or above proficiency to meet state standards. All this will change with the adoption of Common Core standards. Testing and accountability aren’t going away. Instead, they are developing and expanding in ways that aim to address many of the present shortcomings of state testing routines. Most importantly, these new tests will be computer-based. As such, they will potentially shorten testing time, increase tests’ precision, and provide immediate feedback to students and teachers