Development and status of protection functions for the normal conducting LINAC at ESS

The European Spallation Source faces a great challenge in succeeding with its ambitious availability goals. The aim is to construct a machine that allows for 95% availability for neutron beam production. This goal requires a robust protection system that allows for high availability by continuously monitoring and acting on the machine states, in order to avoid long facility downtimes and optimize the operation at any stage. The normal conducting section consists of the first 48 meters of the machine, and performs the initial acceleration, bunching, steering, and focusing of the beam, which sets it up for optimal transition into the superconducting section. Through a fit-for-purpose risk management process, a set of protection functions has been identified. The risk identification, analysis, and treatment were done in compliance with modern safety and ISO standards. This ensures that the risks, in this case downtime and equipment damage, are properly prevented and mitigated. This paper describes this process of defining the protection functions for the normal conducting LINAC at ESS

Evaluation of the Test Temperature Effect on Failure Mechanisms and Notched Impact Strength Characteristics of Ultra-Hard Low Alloy Steels

На основании данных фрактографического анализа оценено изменение механизмов разрушения высокопрочных малолегированных сталей ARMOX 500T и ARMOX 600T в зависимости оттемпературы испытаний. В экспериментально исследованномтемпературном диапазоне -80...100°C была установлена высокая вероятность достижения предельного состояния этих материалов.На основі даних фрактографічного аналізу оцінено зміну механізмів руйнування високоміцних малолегованих сталейARMOX 500T та ARMOX 600T у залежності від температури випробувань. В експериментально дослідженому температурному інтервалі-80...100°C установлено високу імовірність досягнення граничного стану цих матеріалів

Chemical and enzymatic synthesis of the alginate sugar nucleotide building block: GDP-d-mannuronic acid

Highlights Sugarnucleotide synthesis. Chemical and enzymatic access to GDP-d-ManA. Evaluation of protected and free uronate 1-phosphates for pyrophosphorylation

Applying the functional system interaction process at ESS

The European Spallation Source ERIC is being built in Lund, Sweden to complement the existing neutron sources in Europe and worldwide. ESS will be the brightest neutron source ever built upon completion and aims to have an availability of 95% during steady state operations. The purpose of Machine Protection at ESS is to protect the equipment in order to support the high availability. Due to the distributed nature of Machine Protection numerous design teams are involved to implement Protection Functions. The Machine Protection development at ESS follows the Functional Protection lifecycle for System-of-Systems developed at the facility. This paper focuses on the application of the Functional System Interaction Process part of the Functional Protection method. To obtain the system interaction model, behavioural requirements and allocate Protection Functions, System Interaction Use Case workshops are held. The feasibility of different system architectures and protection function implementations are discussed and simulated by going through foreseen operational sequences, use cases. The different architectures and use cases are documented using Enterprise Architect

Analysis of Two New Arabinosyltransferases Belonging to the Carbohydrate-Active Enzyme (CAZY) Glycosyl Transferase Family1 Provides Insights into Disease Resistance and Sugar Donor Specificity

Glycosylation of small molecules is critical for numerous biological processes in plants, including hormone homeostasis, neutralization of xenobiotics, and synthesis and storage of specialized metabolites. Glycosylation of plant natural products is usually carried out by uridine diphosphate-dependent glycosyltransferases (UGTs). Triterpene glycosides (saponins) are a large family of plant natural products that determine important agronomic traits such as disease resistance and flavor and have numerous pharmaceutical applications. Most characterised plant natural product UGTs are glucosyltransferases, and little is known about enzymes that add other sugars. Here we report the discovery and characterization of AsAAT1 (UGT99D1), which is required for biosynthesis of the antifungal saponin avenacin A-1 in oat. This enzyme adds L-arabinose to the triterpene scaffold at the C-3 position, a modification critical for disease resistance. The only previously reported plant natural product arabinosyltransferase is a flavonoid arabinosyltransferase from Arabidopsis. We show that AsAAT1 has high specificity for UDP-β-L-arabinopyranose, identify two amino acids required for sugar donor specificity, and through targeted mutagenesis convert AsAAT1 into a glucosyltransferase. We further identify a second arabinosyltransferase potentially implicated in the biosynthesis of saponins that determine bitterness in soybean. Our investigations suggest independent evolution of UDP-arabinose sugar donor specificity in arabinosyltransferases in monocots and eudicots

Iminosugar inhibitors of carbohydrate-active enzymes that underpin cereal grain germination and endosperm metabolism

Starch is a major energy store in plants. It provides most of the calories in the human diet and, as a bulk commodity, it is used across broad industry sectors. Starch synthesis and degradation are not fully understood, owing to challenging biochemistry at the liquid/solid interface and relatively limited knowledge about the nature and control of starch degradation in plants. Increased societal and commercial demand for enhanced yield and quality in starch crops requires a better understanding of starch metabolism as a whole. Here we review recent advances in understanding the roles of carbohydrate-active enzymes in starch degradation in cereal grains through complementary chemical and molecular genetics. These approaches have allowed us to start dissecting aspects of starch degradation and the interplay with cell-wall polysaccharide hydrolysis during germination. With a view to improving and diversifying the properties and uses of cereal grains, it is possible that starch degradation may be amenable to manipulation through genetic or chemical intervention at the level of cell wall metabolism, rather than simply in the starch degradation pathway per se

Spinning sugars in antigen biosynthesis: characterization of the Coxiella burnetii and Streptomyces griseus TDP-sugar epimerases (article)

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordThe dataset associated with this article is available in ORE at https://doi.org/10.24378/exe.3724The sugars streptose and dihydrohydroxystreptose (DHHS) are unique to the bacteria Streptomyces griseus and Coxiella burnetii, respectively. Streptose forms the central moiety of the antibiotic streptomycin, whilst DHHS is found in the O-antigen of the zoonotic pathogen C. burnetii. Biosynthesis of these sugars has been proposed to follow a similar path to that of TDP-rhamnose, catalyzed by the enzymes RmlA, RmlB, RmlC, and RmlD, but the exact mechanism is unclear. Streptose and DHHS biosynthesis unusually requires a ring contraction step that could be performed by orthologues of RmlC or RmlD. Genome sequencing of S. griseus and C. burnetii has identified StrM and CBU1838 proteins as RmlC orthologues in these respective species. Here, we demonstrate that both enzymes can perform the RmlC 3'',5'' double epimerization activity necessary to support TDP-rhamnose biosynthesis in vivo. This is consistent with the ring contraction step being performed on a double epimerized substrate. We further demonstrate that proton exchange is faster at the 3''-position than the 5''-position, in contrast to a previously studied orthologue. We additionally solved the crystal structures of CBU1838 and StrM in complex with TDP, and show that they form an active site highly similar to those of the previously characterized enzymes RmlC, EvaD, and ChmJ. These results support the hypothesis that streptose and DHHS are biosynthesized using the TDP pathway and that an RmlD paralogue most likely performs ring contraction following double epimerization. This work will support the elucidation of the full pathways for biosynthesis of these unique sugars.Biotechnology and Biological Sciences Research Council (BBSRC)DstlJohn Innes FoundationInnovate U

Insights into toxic prymnesium parvum blooms:The role of sugars and algal viruses

Prymnesium parvum is a toxin-producing microalga that causes harmful algal blooms globally, which often result in large-scale fish kills that have severe ecological and economic implications. Although many toxins have previously been isolated from P. parvum, ambiguity still surrounds the responsible ichthyotoxins in P. parvum blooms and the biotic and abiotic factors that promote bloom toxicity. A major fish kill attributed to P. parvum occurred in Spring 2015 on the Norfolk Broads, a low-lying set of channels and lakes (Broads) found on the East of England. Here, we discuss how water samples taken during this bloom have led to diverse scientific advances ranging from toxin analysis to discovery of a new lytic virus of P. parvum, P. parvum DNA virus (PpDNAV-BW1). Taking recent literature into account, we propose key roles for sialic acids in this type of viral infection. Finally, we discuss recent practical detection and management strategies for controlling these devastating blooms

Genomics and biochemical analyses reveal a metabolon key to β-L-ODAP biosynthesis in Lathyrus sativus

Grass pea (Lathyrus sativus L.) is a rich source of protein cultivated as an insurance crop in Ethiopia, Eritrea, India, Bangladesh, and Nepal. Its resilience to both drought and flooding makes it a promising crop for ensuring food security in a changing climate. The lack of genetic resources and the crop’s association with the disease neurolathyrism have limited the cultivation of grass pea. Here, we present an annotated, long read-based assembly of the 6.5 Gbp L. sativus genome. Using this genome sequence, we have elucidated the biosynthetic pathway leading to the formation of the neurotoxin, β-L-oxalyl-2,3-diaminopropionic acid (β-L-ODAP). The final reaction of the pathway depends on an interaction between L. sativus acyl-activating enzyme 3 (LsAAE3) and a BAHD-acyltransferase (LsBOS) that form a metabolon activated by CoA to produce β-L-ODAP. This provides valuable insight into the best approaches for developing varieties which produce substantially less toxi

Identification and evolution of a plant cell wall specific glycoprotein glycosyl transferase, ExAD

Extensins are plant cell wall glycoproteins that act as scaffolds for the deposition of the main wall carbohydrate polymers, which are interlocked into the supramolecular wall structure through intra- and inter-molecular iso-di-tyrosine crosslinks within the extensin backbone. In the conserved canonical extensin repeat, Ser-Hyp(4), serine and the consecutive C4-hydroxyprolines (Hyps) are substituted with an α-galactose and 1–5 β- or α-linked arabinofuranoses (Arafs), respectively. These modifications are required for correct extended structure and function of the extensin network. Here, we identified a single Arabidopsis thaliana gene, At3g57630, in clade E of the inverting Glycosyltransferase family GT47 as a candidate for the transfer of Araf to Hyp-arabinofuranotriose (Hyp-β1,4Araf-β1,2Araf-β1,2Araf) side chains in an α-linkage, to yield Hyp-Araf(4) which is exclusively found in extensins. T-DNA knock-out mutants of At3g57630 showed a truncated root hair phenotype, as seen for mutants of all hitherto characterized extensin glycosylation enzymes; both root hair and glycan phenotypes were restored upon reintroduction of At3g57630. At3g57630 was named Extensin Arabinose Deficient transferase, ExAD, accordingly. The occurrence of ExAD orthologs within the Viridiplantae along with its’ product, Hyp-Araf(4), point to ExAD being an evolutionary hallmark of terrestrial plants and charophyte green algae