102 research outputs found
The “beauty in the beast”—the multiple uses of Priestia megaterium in biotechnology
Over 30 years, the Gram-positive bacterium Priestia megaterium (previously known as Bacillus megaterium) was systematically developed for biotechnological applications ranging from the production of small molecules like vitamin B12, over polymers like polyhydroxybutyrate (PHB) up to the in vivo and in vitro synthesis of multiple proteins and finally whole-cell applications. Here we describe the use of the natural vitamin B12 (cobalamin) producer P. megaterium for the elucidation of the biosynthetic pathway and the subsequent systematic knowledge-based development for production purposes. The formation of PHB, a natural product of P. megaterium and potential petro-plastic substitute, is covered and discussed. Further important biotechnological characteristics of P. megaterium for recombinant protein production including high protein secretion capacity and simple cultivation on value-added carbon sources are outlined. This includes the advanced system with almost 30 commercially available expression vectors for the intracellular and extracellular production of recombinant proteins at the g/L scale. We also revealed a novel P. megaterium transcription-translation system as a complementary and versatile biotechnological tool kit. As an impressive biotechnology application, the formation of various cytochrome P450 is also critically highlighted. Finally, whole cellular applications in plant protection are completing the overall picture of P. megaterium as a versatile giant cell factory
Representations of stream processors using nested fixed points
We define representations of continuous functions on infinite streams of discrete values, both in the case of discrete-valued functions, and in the case of stream-valued functions. We define also an operation on the representations of two continuous functions between streams that yields a representation of their composite. In the case of discrete-valued functions, the representatives are well-founded (finite-path) trees of a certain kind. The underlying idea can be traced back to Brouwer's justification of bar-induction, or to Kreisel and Troelstra's elimination of choice-sequences. In the case of stream-valued functions, the representatives are non-wellfounded trees pieced together in a coinductive fashion from well-founded trees. The definition requires an alternating fixpoint construction of some ubiquity
Stylistic pastiche and intertextuality in musical theatre: Practice and theory
This paper was presented at the international Crosstown Traffic Conference, University of Huddersfield, 3-5 September 2018 (meeting of the IASPM and Art of Record Production). The paper presents a theory of intertextuality uses in musical theatre with reference to the connections between analysis of existing shows and creative outputs. The slides are attached
Tracing monadic computations and representing effects
In functional programming, monads are supposed to encapsulate computations,
effectfully producing the final result, but keeping to themselves the means of
acquiring it. For various reasons, we sometimes want to reveal the internals of
a computation. To make that possible, in this paper we introduce monad
transformers that add the ability to automatically accumulate observations
about the course of execution as an effect. We discover that if we treat the
resulting trace as the actual result of the computation, we can find new
functionality in existing monads, notably when working with non-terminating
computations.Comment: In Proceedings MSFP 2012, arXiv:1202.240
A Framework for Generating Diverse Haskell-IO Exercise Tasks
We present the design of a framework to automatically generate a large range
of different exercise tasks on Haskell-I/O programming. Automatic task
generation is useful in many different ways. Manual task creating is a time
consuming process, so automating it saves valuable time for the educator.
Together with an automated assessment system automatic task generation allows
students to practice with as many exercise tasks as needed. Additionally, each
student can be given a slightly different version of a task, reducing issues
regarding plagiarism that arise naturally in an e-learning environment. Our
task generation is centered around a specification language for I/O behavior
that we developed in an earlier work. The task generation framework, an EDSL in
Haskell, provides powerful primitives for the creation of various artifacts,
including program code, from specifications. We will not go into detail on the
technical realization of these primitives. This article instead showcases how
such artifacts and the framework as a whole can be used to build exercise tasks
templates that can then be (randomly) instantiated.Comment: Part of WFLP 2020 pre-proceeding
Wedding Singer
Program for the July 31, August 1, 6, 7, 2010 performances of The Wedding Singer by Southland Area Theatre Ensemble (SLATE).https://opus.govst.edu/cpa_memorabilia/1267/thumbnail.jp
Characterization of arsenic-resistant endophytic Priestia megaterium R2.5.2 isolated from ferns in an arsenic-contaminated multi-metal mine in Vietnam
Bioremediation is a biological process to remove or neutralize environmental pollutants. This study was carried out to investing at the efficacy of arsenic resistant endophytic bacteria isolated from Pteris vittata, Pityrogramma calomelanos, Blenchum orientale, and Nephrolepis exaltata, which grow in a highly arsenic (As) contamination mining site in Vietnam. Their segmented roots, stems, and leaves were homogenized separately and inoculated on LB agar plates containing 5mM As(III) and As(V). A total of 31 arsenic resistant endophytic strains were selected, in which strain R2.5.2 isolated from the root of P. calomelanos had the highest arsenic resistant capability. Strain R2.5.2 tolerated up to 320 mM and 160 mM of arsenate and arsenite, respectively. The strain developed well on a media of 0.1 5% NaCl, at 20-40ºC and pH 5 9, and actively utilized most of the sugar sources. It had a high IAA biosynthesis capacity with an average concentration of 19.14 mg/L, tolerated to 0.5-16 mM concentration of Ag+, Hg2+, Co2+, Ni2+, Cu2+, Cr4+, and reduced As(V). Based on 16s rDNA, R2.5.2 was identified as Priestia megaterium. The ars C gene coding for arsenate reductase catalyzing reduction of As(V) was successfully amplified in P. megaterium R2.5.2. The selected strain may have potential use for bioremediation practice
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