Inducible transgene expression provides a useful tool to analyze gene function. The moss Physcomitrellapatens is a model basal land plant with well-developed research tools, including a high efficiency of gene targeting and substantial genomics resources. However, current systems for controlled transgene expression remain limited. Here we report the development of an estrogen receptor mediated inducible gene expression system, based on the system used in flowering plants. After identifying the appropriate promoters to drive the chimeric transducer, we succeeded in inducing transcription over 1,000-fold after 24 h incubation with β-estradiol. The P. patens system was also effective for high-level long-term induction of gene expression; transcript levels of the activated gene were maintained for at least seven days on medium containing β-estradiol. We also established two potentially neutral targeting sites and a set of vectors for reproducible expression of two transgenes. This β-estradiol-dependent system will be useful to test genes individually or in combination, allowing stable, inducible transgenic expression in P. patens.

/pdf/system-for-stable-b-estradiol-inducible-gene-expression-in-2kmnrxytuz.pdf

System for Stable β-Estradiol-Inducible Gene Expression in the Moss Physcomitrella patens

(2002). What Is a Random Sequence? The American Mathematical Monthly: Vol. 109, No. 1, pp. 46-63.

/pdf/what-is-a-random-sequence-21oo8hiqii.pdf

What Is a Random Sequence

We present an experiment for education which demonstrates random transmission or reflection of heralded single photons on beam splitters. With our set-up, we can realize different quantum random experiments by appropriate settings of polarization rotators. The concept of entanglement is motivated by correlated randomness. The experiments are suitable for undergraduate education and are available as interactive screen experiments.

https://iopscience.iop.org/article/10.1088/0143-0807/30/5/026/pdf

Demonstrating quantum random with single photons

/pdf/physical-random-numbers-generated-by-radioactivity-5ggrkorgwd.pdf

Physical random numbers generated by radioactivity

A specific class of partially entangled states known as Knill–Laflamme–Milburn states (or KLM states) has been proved to be useful in relation to quantum information processing (Knill et al 2001 Nature 409 46). Although the usage of such states is widely investigated, considerably less effort has been invested into experimentally accessible preparation schemes. This paper discusses the possibility of employing a tunable controlled phase gate to generate an arbitrary KLM state. In the first part, the idea of using the controlled phase gate is explained on the case of two-qubit KLM states. Optimization of the proposed scheme is then discussed for the framework of linear optics. Subsequent generalization of the scheme to the arbitrary n-qubit KLM state is derived in the second part of this paper.

Preparation of Knill–Laflamme–Milburn states using a tunable controlled phase gate

A new method of generating random digits using radiations from radioactive nuclide is described. The digits are stored on magnetic tape which allows repeated use if required. One hundred million such digits have been subjected to stringent tests for randomness. These tests, some of which are described, show that the random digits avoid the well‐documented defects of digits generated by arithmetic means. They perform well for applications where sequences of independent random digits are required.

H. Kumahora

Papers

Random Numbers Generated by a Physical Device