Статті в журналах з теми "Modular PKS engineering"

ABSTRACTFunctional cross talk between fatty acid biosynthesis and secondary metabolism has been discovered in several cases in microorganisms; none of them, however, involves a modular biosynthetic enzyme. Previously, we reported a hybrid modular nonribosomal peptide synthetase (NRPS)-polyketide synthase (PKS) pathway for the biosynthesis of FK228 anticancer depsipeptide inChromobacterium violaceumstrain 968. This pathway contains two PKS modules on the DepBC enzymes that lack a functional acyltransferase (AT) domain, and no apparent AT-encoding gene exists within the gene cluster or its vicinity. We report here that, through reconstitution of the FK228 biosynthetic pathway inEscherichia colicells, two essential genes,fabD1andfabD2, both encoding a putative malonyl coenzyme A (CoA) acyltransferase component of the fatty acid synthase complex, are positively identified to be involved in FK228 biosynthesis. Either gene product appears sufficient to complement the AT-less PKS modules on DepBC for polyketide chain elongation. Concurrently, a gene (sfp) encoding a putative Sfp-type phosphopantetheinyltransferase was identified to be necessary for FK228 biosynthesis as well. Most interestingly, engineeredE. colistrains carrying variable genetic components produced significant levels of FK228 under both aerobic and anaerobic cultivation conditions. Discovery of thetranscomplementation of modular PKSs by housekeeping ATs reveals natural product biosynthesis diversity. Moreover, demonstration of anaerobic production of FK228 by an engineered facultative bacterial strain validates our effort toward the engineering of novel tumor-targeting bioagents.

Polyketides belong to the most valuable natural products, including diverse bioactive compounds, such as antibiotics, anticancer drugs, antifungal agents, immunosuppressants and others. Their structures are assembled by polyketide synthases (PKSs). Modular PKSs are composed of modules, which involve sets of domains catalysing the stepwise polyketide biosynthesis. The acyltransferase (AT) domains and their “partners”, the acyl carrier proteins (ACPs), thereby play an essential role. The AT loads the building blocks onto the “substrate acceptor”, the ACP. Thus, the AT dictates which building blocks are incorporated into the polyketide structure. The precursor- and occasionally the ACP-specificity of the ATs differ across the polyketide pathways and therefore, the ATs contribute to the structural diversity within this group of complex natural products. Those features make the AT enzymes one of the most promising tools for manipulation of polyketide assembly lines and generation of new polyketide compounds. However, the AT-based PKS engineering is still not straightforward and thus, rational design of functional PKSs requires detailed understanding of the complex machineries. This review summarizes the attempts of PKS engineering by exploiting the AT attributes for the modification of polyketide structures. The article includes 253 references and covers the most relevant literature published until May 2018.

ABSTRACT Geldanamycin and the closely related herbimycins A, B, and C were the first benzoquinone ansamycins to be extensively studied for their antitumor properties as small-molecule inhibitors of the Hsp90 protein chaperone complex. These compounds are produced by two different Streptomyces hygroscopicus strains and have the same modular polyketide synthase (PKS)-derived carbon skeleton but different substitution patterns at C-11, C-15, and C-17. To set the stage for structural modification by genetic engineering, we previously identified the gene cluster responsible for geldanamycin biosynthesis. We have now cloned and sequenced a 115-kb segment of the herbimycin biosynthetic gene cluster from S. hygroscopicus AM 3672, including the genes for the PKS and most of the post-PKS tailoring enzymes. The similarities and differences between the gene clusters and biosynthetic pathways for these closely related ansamycins are interpreted with support from the results of gene inactivation experiments. In addition, the organization and functions of genes involved in the biosynthesis of the 3-amino-5-hydroxybenzoic acid (AHBA) starter unit and the post-PKS modifications of progeldanamycin were assessed by inactivating the subclusters of AHBA biosynthetic genes and two oxygenase genes (gdmM and gdmL) that were proposed to be involved in formation of the geldanamycin benzoquinoid system. A resulting novel geldanamycin analog, KOS-1806, was isolated and characterized.

ABSTRACT Five meilingmycins, A to E, with A as the major component, were isolated from Streptomyces nanchangensis NS3226. Through nuclear magnetic resonance (NMR) characterization, meilingmycins A to E proved to be identical to reported milbemycins α11, α13, α14, β1, and β9, respectively. Sequencing of a previously cloned 103-kb region identified three modular type I polyketide synthase genes putatively encoding the last 11 elongation steps, three modification proteins, and one transcriptional regulatory protein for meilingmycin biosynthesis. However, the expected loading module and the first two elongation modules were missing. In meilingmycin, the presence of a methyl group at C-24 and a hydroxyl group at C-25 suggests that the elongation module 1 contains a methylmalonyl-coenzyme A (CoA)-specific acyltransferase (ATp) domain and a ketoreductase (KR) domain. Based on the conserved motifs of the ATp and KR domains, a pair of primers was designed for PCR amplification, and a 1.40-kb expected fragment was amplified, whose sequence shows significant homology with the elongation module 1 of the aveA1-encoded enzyme AVES1. A polyketide synthase (PKS) gene encoding one loading and two elongation modules, with a downstream C-5-O-methyltransferase gene, meiD, was subsequently localized 55 kb apart from the previously sequenced region, and its deletion abolishes meilingmycin production. A series of deletions within the 55-kb intercluster region rules out its involvement in meilingmycin biosynthesis. Furthermore, gene deletion of meiD eliminates meilingmycins D and E, with methyls at C-5. Our work provides a more specific strategy for the cloning of modular type I PKS gene clusters. The cloning of the meilingmycin gene clusters paves the way for its pathway engineering.

The macrolide antibiotic concanamycin A has been identified as an exceptionally potent inhibitor of the vacuolar (V-type) ATPase. Such compounds have been mooted as the basis of a potential drug treatment for osteoporosis, since the V-ATPase is involved in the osteoclast-mediated bone resorption that underlies this common condition. To enable combinatorial engineering of altered concanamycins, the biosynthetic gene cluster governing the biosynthesis of concanamycin A has been cloned from Streptomyces neyagawaensis and shown to span a region of over 100 kbp of contiguous DNA. An efficient transformation system has been developed for S. neyagawaensis and used to demonstrate the role of the cloned locus in the formation of concanamycin A. Sequence analysis of the 28 ORFs in the region has revealed key features of the biosynthetic pathway, in particular the biosynthetic origin of portions of the backbone, which arise from the unusual polyketide building blocks ethylmalonyl-CoA and methoxymalonyl-ACP, and the origin of the pendant deoxysugar moiety 4′-O-carbamoyl-2′-deoxyrhamnose, as well as the presence of a modular polyketide synthase (PKS) encoded by six giant ORFs. Examination of the methoxymalonyl-specific acyltransferase (AT) domains has led to recognition of an amino acid sequence motif which can be used to distinguish methylmalonyl-CoA- from methoxymalonyl-ACP-specific AT domains in natural PKSs.

AbstractThe operation of large production assets requires many decisions from the acquisition and design of new assets to the choice of lubricant for a specific piece of equipment. The decisions made in maintenance have a direct effect on the management of the production process, making it important to ensure correct maintenance decision making. However, studies on maintenance decision making tend to focus on smaller areas of decisions being made in a process, but rarely the entire process. To introduce more studies that consider the entire maintenance process, this paper proposes using a modular Maintenance Decision Architecture. The paper introduces a framework for structuring information sources into standardized information modules and mapping them to maintenance decisions made across the entire organization. The application of approaches from product, system, and service engineering are used to support the management of the complexities of maintenance of large production facilities.

Purpose This paper aims to study a modular method for designing a paste filling station (PFS) for a coal mine (CM) to reduce the PFS’s input cost and achieve reutilization. Design/methodology/approach Modular design criteria for the PFS are proposed and a modular division (MDiv) model and an evaluation method are established. The correlation-strength matrix of the PFS parts expressed in the form of rough numbers is transformed into a fuzzy equivalent matrix. The theory of rough sets and the fuzzy clustering method are introduced for PFS MDiv. The evaluating method is established for the PFS MDiv scheme based on the principle of fuzzy comprehensive evaluation. Findings Taking a particular CM PFS as an example, the above method is used to modularize the PFS, and the optimal division of the PFS is finally determined via the above evaluation system. Applying this method solves the problem of high cost investment in the initial stage of PFS construction. Originality/value The theory of rough sets and the fuzzy clustering method are introduced for PFS MDiv. An evaluating method is established for the PFS MDiv scheme based on the principle of fuzzy comprehensive evaluation, thereby providing new ideas for PFS transformation and reutilization.

AbstractThe concept of volumetric spaces has evolved in the Architecture, Engineering, and Construction (AEC) sector, ranging from traditional onsite built spaces to modern modular houses and portable architecture. Despite this diversity, there lacks a comprehensive framework to analyze volumetric space products across dimensions. This paper presents a conceptual framework based on abductive reasoning and qualitative analysis, aiming to explore interdependencies among dimensions. It hypothesizes that volumetric space dimensions are perceived differently and demonstrate interdependencies.

AbstractClimate change and the growing consumption of natural resources has made it increasingly clear that engineering must focus on the development of more sustainable products. To do so, the methodologies for developing products need to address sustainability. However, many of the frequently used methodologies, such as Modular Function Deployment (MFD) or the Life Phases Modularisation (LPM), do not do that sufficiently. The product life phases, these methodologies are based, only address sustainability in the form of recycling. That is why a broader approach to sustainability, such as the R-imperatives, is not considered. Therefore, in this contribution, the model of product life phases is extended by integrating the R-imperatives. Furthermore, the module drivers resulting from the extended product life phases that are necessary to apply the MFD and the LPM are developed. Finally, the positive impact of the developed module drivers on the product architecture is shown by applying the resulting method onto an industrial example.

AbstractIntegrated Natural Resource Conservation and Development (INRCD) Projects are efforts at worldwide locations to promote economic development of local communities consistent with conservation of natural resources. This umbrella term includes Integration Conservation and Development Projects (ICDPs) introduced by the World Wide Fund to combine social development and conservation s through the use of socio-economic investments, and the Integrated Natural Resource Management (INRM) research and development efforts that have employed a systems approach for quantitative modeling and optimization. In the spirit of the INRCD framework, we describe the development of a system-level agriculture and energy model comprising engineering and economic models for crop, irrigation, and energy subsystem designs for a community in Central Uganda. The model architecture is modular allowing modifications for different system configurations and project locations. We include some initial results and discuss next steps for system optimization, refining model assumptions, and modeling community social benefits as drivers of such projects.

This paper presents an FPGA implementation of the most critical operations of Public Key Cryptography (PKC), namely the Modular Exponentiation (ME) and the Modular Multiplication (MM). Both operations are integrated as Programmable System on Chip (PSoC) where the processor Microblaze of Xilinx is used for flexibility. Our objective is to achieve a best trade-off between time execution, occupied area and flexibility. The implementation of these operations on such environment requires taking into account several criteria. Indeed, the Hardware (HW) architectures data bus should be smaller than the input data length. The design must be scalable to support different security levels. The implementation achieves optimums execution time and HW resources number. In order to satisfy these constraints, Montgomery Power Ladder (MPL) and Montgomery Modular Multiplication (MMM) algorithms are utilized for the ME and the MM implementations as HW accelerators, respectively. Our implementation approach is based on the digit-serial method for performing the basic arithmetic operations. Efficient parallel and pipeline strategies are developed at the digit level for the optimization of the execution times. The application for 1024-bits data length shows that the MMM run in 6.24[Formula: see text][Formula: see text]s and requires 647 slices. The ME is executed in 6.75[Formula: see text]ms using 2881 slices.

DC microgrid has been gaining popularity as solution as a more efficient and simpler power system especially for remote areas, where the main grid has yet to be built. This paper proposes a DC microgrid system based on renewable energy sources that employs decentralized control and without communication between one grid point and another. It can be deployed as an individual isolated unit or to form an expandable DC microgrid through DC bus for better reliability and efficiency. The key element of the proposed system is the power conditioner system (PCS) that works as an interface between energy sources, storage system, and load. PCS consists of modular power electronics devices and a power management unit, which controls power delivery to the AC load and the grid as well as the storage system charging and discharging sequence. Prototypes with 3 kWp solar PV and 13.8 kWh energy storage were developed and adopt a pole-mounted structure for ease of transportation and installation that are important in remote areas. This paper presents measurement results under several conditions of the developed prototypes. The evaluation shows promising results and a solid basis for electrification in remote areas.

Although widely applied in varied scenarios, unmanned aerial vehicles (UAVs) suffer severe flight time and flight range limitations due to constrained onboard battery capacity, causing frequent battery recharging when performing persistent missions. The wireless power transfer technology is a promising solution for UAV charging by utilizing unmanned ground vehicles (UGVs) equipped with wireless charging facilities, where charging time slots are auctioned and assigned to UAVs. However, UGVs themselves also have limited energy capacity, resulting in the need to revoke a UAV charging transaction after auction to satisfy their own demand if necessary. In addition, as UAVs and UGVs are mutually distrustful, inherent security and privacy concerns must be resolved during the revocation. In this paper, we resort to blockchain technology for secure and efficient revocable charging in vehicle-assisted wireless UAV networks. We present PAS, an efficient privacy-preserving attestation scheme for revocable UAV charging based on hybrid state channels, where UAVs and UGVs perform off-chain operations as blockchain users for privacy and efficiency, while security and fairness are guaranteed by the on-chain mechanism. PAS consists of a multi-party state channel and multiple two-party state channels responsible for charging scheduling and transaction revocation, respectively. PAS ensures fair and private revocation negotiation and compensation in a trust-free manner by developing a set of carefully designed modular protocols. We provide PAS’ constituent primitives in detail, prove its security properties following the universally composable (UC) framework, and present experimental results to demonstrate its feasibility and scalability.

With the growing popularity of microgrids for alternative energy management, there is demand for tools that allow us to study the effect of microgrids in distributed power systems. Popular methods involve software simulation and prototype validation with physical hardware. Simulations often do not capture the complex interactions, and combinations of software simulations with hardware testbeds promise to give a more accurate picture. These testbeds, however, usually aim at the validation of hardware for industrial-scale use, which makes them expensive and not readily accessible. To fill the gap between full-scale hardware and software simulation, we propose a modular lab-scale grid model at a 1:100 power scale over residential single-phase networks with 12 V AC and 60 Hz grid voltage. We present different modules—power sources, inverters, demanders, grid monitors, and grid-to-grid bridges—that can be assembled into distributed grids of almost arbitrary complexity. The model voltage poses no electrical hazards, and microgrids can readily be assembled with an open power line model. Unlike a prior DC-based grid testbed, the proposed AC model allows us to examine additional aspects, such as frequency, phase, active and apparent power, and reactive loads. Grid metrics, including the discretely sampled voltage and current waveforms, can be collected and sent to higher-tier grid management systems. We integrated the modules with Beagle Bone micro-PCs, which in turn connect any such microgrid with an emulation platform built on CORE (Common Open Research Emulator) and the Gridlab-D power simulator, thereby allowing hybrid software/hardware simulations. Our grid modules were shown to fully operate in this environment. Through the CORE system, multitiered control and even remote grid management is possible. However, we also found that the AC waveform poses design challenges that require us to balance accurate emulation (most notably with respect to harmonic distortion) with per-module costs.

By Data Grid to handle data sharing problems of distributed position in Group Purchasing. And so, evaluating and mining massive amounts of data is without fail required replication is important techniques to provide fast data access. Several replication modeling algorithms are studied in the paper. OptorSim provides a modular framework under different Grid environment. OptorSim is used to achieve the Grid simulator to research the stability and transient action. Modern group-companies are often made of many subsidiary companies. Stocking centralization can economize much fund for its large-scale purchasing action. Subordinate companies hope to choose the best provider according to reliable data in most possible area. Advanced data in variety units is massive amounts of data that must be post-processed and organized to support provider evaluation actions. Increasing data volumes from all of the companies challenge to state-of-the-art database system and data-loading techniques. Grid concept is adopted to solve the problem in the project which is named Price Comparison System (PCS). One of the key technologies in the system is to improve the data access.

A high-resolution microsatellite’s focal plane components have high heat flux and a long working time. In order to solve the heat-dissipation problem of a microsatellite’s focal plane components under the condition of narrow space, this paper uses a new type of ultralight and super-high thermal conductivity Pyrolytic Graphite Sheet to make a thin and flexible thermal conduction strip. Such a strip is used to design the thermal control scheme for a fully passive, modular, and fast integration of the focal plane components. Analysis and test results show that under the conditions of an installation space of ≤0.5 mm and the mass of the thermal conduction strip of ≤20 g, the focal plane components work continuously for 600 s; the maximum temperature of the CMOS (Complementary Metal-Oxide-Semiconductor) sensor is 31.8°C. Five groups of CMOS sensors had a temperature nonuniformity no higher than 1°C. The application of the new PGS (Pyrolytic Graphite Sheet) provides a new solution for the related space thermal design.

Since Coppersmith proposed the use of the LLL algorithm to solve univariate modular polynomial equations at EUROCRYPT’96, it has sparked a fervent research interest in lattice analysis among cryptographers. Despite its polynomial-time nature, the LLL algorithm exhibits a high-order polynomial upper bound in terms of theoretical complexity, particularly with longer computation times when applied to high-dimensional lattices. In addressing this issue, we propose an improved algorithm based on block preprocessing, building on the original Coppersmith algorithm and thus providing proof of correctness for this algorithm. This approach effectively reduces the solution time of the algorithm, offering a maximum improvement of 8.1% compared to the original Coppersmith algorithm. Additionally, we demonstrate the compatibility of our algorithm with the rounding algorithm proposed at PKC 2014. The combined utilization of these approaches further enhances the efficiency of our algorithm. The experimental results show that the combined algorithm achieves a maximum improvement of 22.4% in solution time compared to the original Coppersmith algorithm. It also outperforms the standalone rounding algorithm with a maximum improvement of 12.1%. When compared to the improved Coppersmith algorithm based on row common factor extraction, our proposed algorithm demonstrates comparable or even superior performance in certain dimensions. The block preprocessing algorithm in our approach enables independent execution without data exchange, making it suitable for leveraging multi-processing advantages in scenarios involving higher degrees of modular polynomial equations. This offers a new perspective for achieving the parallel computation of the Coppersmith algorithm, facilitating parallel execution and providing valuable insights.

The increased uptake of variable renewable energy sources has increased electricity price volatility in many energy pool markets, providing an opportunity for storage systems to profit through energy arbitrage. Comparison between the cost or value of storage systems engaging in energy arbitrage should be performed on a levelised basis due to differences in system lifetime. Existing energy arbitrage models with bid/offer curves and imperfect forecasting are typically computationally expensive and are impractical for calculating lifetime levelised cost metrics. In this work, an open-source modular energy arbitrage model with bid and offer curve inputs was developed for a lithium-ion battery energy storage system (BESS) and pumped hydro system (PHS) to analyse lifetime levelised cost and revenue. The mixed integer linear program scheduling module included a new piece-wise linearised description of PHS charging behaviour for rapid optimisation. A one-at-a-time sensitivity analysis indicated that levelised cost and revenue were highly sensitive to discharging efficiency. In a case study based on Australia’s National Electricity Market, imperfect forecasting with no risk hedging was found to increase levelised costs by up to 24% and decrease levelised revenue by up to 50% relative to perfect price forecasting, despite 95% of prices being forecast to be within $35/MWh of the actual trading price. BESS levelised costs were more significantly correlated with consistent low risk bids (Kendall Tau-b of 0.75), since the undiscounted capital costs contribute to a larger proportion of the overall costs than in the PHS systems.

A strategy to operate a power conversion system (PCS) to minimize the electricity rate of an energy storage system (ESS) is formulated. The ESS operation method is determined considering the power management system (PMS). The primary functions include peak-cut, peak-shifting, and frequency regulation typically related to electricity rates. Thus, the battery is charged and discharged when the price is low and high, respectively, thereby monetizing the battery. However, the ESS incurs a high cost for the batteries and PCS. Therefore, ESSs that reuse electric vehicle (EV) batteries are being actively developed. Many researchers have attempted to maximize the profit of ESSs by developing algorithms to calculate the optimal ESS capacity by performing a power load analysis of electricity consumers. An ESS selected based on this calculation can be operated through the PMS. This ESS can use the battery state of charge (SoC), ranging from 10–90%, to conduct a feasibility analysis using the net present value, which reflects the current electricity rate. This feasibility analysis is performed considering the difference between the initial investment cost of the ESS and the profit obtained from the power generation of the ESS. In South Korea, many policies have been implemented to encourage the installation of ESSs. The ESS promotion policy was implemented until 2020 to reduce the electricity rate, including the contracted capacity of batteries. However, since 2021, this policy has been transformed to reduce the electricity rate based on the daily maximum power generation. Thus, the conventional method of increasing the battery capacity is not suitable, and the profitability should be increased using limited batteries. For ESSs, PCSs composed of single and parallel structures can be used. When installing a large capacity ESS, a PCS using silicon (Si) is adopted to reduce the unit cost of the PCS. The unit price of a silicon carbide (SiC) device has recently decreased significantly. Thus, in this study, a PCS using this SiC device was developed. Moreover, an algorithm was formulated to minimize the electricity rate of the ESS, and the operation of a modular type PCS based on this algorithm was demonstrated.

Purpose This paper aims to describe the idea behind and design of a miniaturized distributed measurement system based on a controller area network (CAN) data bus. Design/methodology/approach The intention of the designers was to build a light and modular measurement system which can be used in remotely piloted aircraft systems and ultra-light aircraft during flight tests, as well as normal operation. The structure of this distributed measurement system is based on a CAN data bus. The CAN aerospace standard has been applied to the software as well as the hardware comprising this system. PRP-W2 software designed for PCs is an additional component of the proposed measurement system. This software supports data acquisition from a recorder unit and allows for preliminary data analysis, as well as data conversion and presentation. Findings The system, complete with a high-speed data recorder, was successfully installed on board of an MP-02 Czajka aircraft. A research experiment using the system and oriented on airframe high frequency vibration analysis is presented in the final part of this paper. Research limitations/implications This measurement system allows analysis of high-frequency vibrations occurring at selected points of the aircraft. A data set is recorded by three-axis accelerometers and gyroscopes at frequencies up to 1 kHz. Practical implications The use of a miniature and lightweight modular measurement system will, in many cases, be faster and less expensive than full-scale measurement and data acquisition systems, which often require a lengthy assembly process. The implementation of this class of lightweight flight test systems has many advantages, in particular to the operation of small aircraft. Such solutions are likely to become increasingly common in unmanned aerial vehicles and in other light aircraft in the future. Originality/value The adaptation of a distributed measuring system with a high frequency of measurements for purposes of small and miniature aircraft.

<span lang="EN-US">This work highlights a modular power conditioning system (PCS) in photovoltaic (PV) applications which consists with a DC-DC converter. The converter is able to regulate and amplify the input DC voltage produced by the PV panal. The implementation of Mosfet as bidirectional switch on the converter yields greater conversion ratio and better voltage regulation than a conventional DC-DC step up converter and PWM resonant converter. It also reduces the switching losses on the output DC voltage of the converter, as the MOSFET switches on primary winding of converter switch on under ZVS conditions. The proposed resonant converter has been designed, with the modification of series resonant converter and PWM boost converter that utilizes the high frequency of AC bidirectional switch to eliminate the weaknesses of used converters. The topology of the proposed converter includes the mode of operations, designing procedure and components selection of the new converter elements. This topology provides a DC output voltage to the inverter at range of about 120Vac-208 Vac. </span>

The main goal of Ambient Assisted Living solutions is to provide assistive technologies and services in smart environments allowing elderly people to have high quality of life. Since 3D sensing technologies are increasingly investigated as monitoring solution able to outperform traditional approaches, in this work a noninvasive monitoring platform based on 3D sensors is presented providing a wide-range solution suitable in several assisted living scenarios. Detector nodes are managed by low-power embedded PCs in order to process 3D streams and extract postural features related to person’s activities. The feature level of details is tuned in accordance with the current context in order to save bandwidth and computational resources. The platform architecture is conceived as a modular system suitable to be integrated into third-party middleware to provide monitoring functionalities in several scenarios. The event detection capabilities were validated by using both synthetic and real datasets collected in controlled and real-home environments. Results show the soundness of the presented solution to adapt to different application requirements, by correctly detecting events related to four relevant AAL services.

We present a low-cost and simple method to fabricate a novel lock-and-key mixer microfluidics using an economic stereolithography (SLA) three-dimensional (3D) printer, which costs less than USD 400 for the investment. The proposed study is promising for a high throughput fabrication module, typically limited by conventional microfluidics fabrications, such as photolithography and polymer-casting methods. We demonstrate the novel modular lock-and-key mixer for the connector and its chamber modules with optimized parameters, such as exposure condition and printing orientation. In addition, the optimization of post-processing was performed to investigate the reliability of the fabricated hollow structures, which are fundamental to creating a fluidic channel or chamber. We found out that by using an inexpensive 3D printer, the fabricated resolution can be pushed down to 850 µm and 550 µm size for squared- and circled-shapes, respectively, by the gradual hollow structure, applying vertical printing orientation. These strategies opened up the possibility of developing straightforward microfluidics platforms that could replace conventional microfluidics mold fabrication methods, such as photolithography and milling, which are costly and time consuming. Considerably cheap commercial resin and its tiny volume employed for a single printing procedure significantly cut down the estimated fabrication cost to less than 50 cents USD/module. The simulation study unravels the prominent properties of the fabricated devices for biological fluid mixers, such as PBS, urine and plasma blood. This study is eminently prospective toward microfluidics application in clinical biosensing, where disposable, low-cost, high-throughput, and reproducible chips are highly required.

The chemical and structural diversity of minerals containing sulfur as an essential mineral-forming element has been analyzed in terms of the concept of mineral systems and the information-based structural and chemical complexity parameters. The study employs data for 1118 sulfur mineral species approved by the International Mineralogical Association. All known sulfur minerals belong to nine mineral systems, with the number of essential components ranging from one to nine. The chemical and structural complexity of S minerals correlate with each other; that is, on average, chemical complexification results in structural complexification. The minerals with S–O bonds (sulfates and sulfites) are more complex than those without S–O bonds (sulfides and sulfosalts). However, the most complex sulfur mineral known so far is incomsartorite, Tl6Pb144As246S516, a sulfosalt. The complexity-generating mechanism in sulfides and sulfosalts is the complex combination of different modules excised from parent PbS or SnS archetypes with the subsequent formation of superstructures. The drivers for structural complexity in sulfates are more diverse and, in addition to modular construction and superstructures, also include a high hydration state, the presence of polyatomic clusters, and framework complexity. The most complex Martian minerals are most probably halotrichite-group minerals. The chemical and structural complexity increases with the passage of geological time with the formation of the most complex sulfosalts at Lengenbach (Swiss Alps) triggered by life (activity of sulfur-reducing bacteria).

The web and its recent advancements represent a great opportunity to build universal, rich, multi-user and immersive Web3D/WebXR applications targeting Cultural Heritage field—including 3D presenters, inspection tools, applied VR games, collaborative teaching tools and much more. Such opportunity although, introduces additional challenges besides common issues and limitations typically encountered in this context. The “ideal” Web3D application should be able to reach every device, automatically adapting its interface, rendering and interaction models—resulting in a single, liquid product that can be consumed on mobile devices, PCs, Museum kiosks and immersive AR/VR devices, without any installation required for final users. The open-source ATON framework is the result of research and development activities carried out during the last 5 years through national and international projects: it is designed around modern and robust web standards, open specifications and large open-source ecosystems. This paper describes the framework architecture and its components, assessed and validated through different case studies. ATON offers institutions, researchers, professionals a scalable, flexible and modular solution to craft and deploy liquid web-applications, providing novel and advanced features targeting Cultural Heritage field in terms of 3D presentation, annotation, immersive interaction and real-time collaboration.

The rapid evolution of Cloud-based services and the growing interest in deep learning (DL)-based applications is putting increasing pressure on hyperscalers and general purpose hardware designers to provide more efficient and scalable systems. Cloud-based infrastructures must consist of more energy efficient components. The evolution must take place from the core of the infrastructure (i.e., data centers (DCs)) to the edges (Edge computing) to adequately support new/future applications. Adaptability/elasticity is one of the features required to increase the performance-to-power ratios. Hardware-based mechanisms have been proposed to support system reconfiguration mostly at the processing elements level, while fewer studies have been carried out regarding scalable, modular interconnected sub-systems. In this paper, we propose a scalable Software Defined Network-on-Chip (SDNoC)-based architecture. Our solution can easily be adapted to support devices ranging from low-power computing nodes placed at the edge of the Cloud to high-performance many-core processors in the Cloud DCs, by leveraging on a modular design approach. The proposed design merges the benefits of hierarchical network-on-chip (NoC) topologies (via fusing the ring and the 2D-mesh topology), with those brought by dynamic reconfiguration (i.e., adaptation). Our proposed interconnect allows for creating different types of virtualised topologies aiming at serving different communication requirements and thus providing better resource partitioning (virtual tiles) for concurrent tasks. To further allow the software layer controlling and monitoring of the NoC subsystem, a few customised instructions supporting a data-driven program execution model (PXM) are added to the processing element’s instruction set architecture (ISA). In general, the data-driven programming and execution models are suitable for supporting the DL applications. We also introduce a mechanism to map a high-level programming language embedding concurrent execution models into the basic functionalities offered by our SDNoC for easing the programming of the proposed system. In the reported experiments, we compared our lightweight reconfigurable architecture to a conventional flattened 2D-mesh interconnection subsystem. Results show that our design provides an increment of the data traffic throughput of 9.5% and a reduction of 2.2× of the average packet latency, compared to the flattened 2D-mesh topology connecting the same number of processing elements (PEs) (up to 1024 cores). Similarly, power and resource (on FPGA devices) consumption is also low, confirming good scalability of the proposed architecture.

The most numerous and most complex group of diseases which result in impairment of human function of support and walking are neuro-muscular diseases and traumas of a spine and a spinal cord. Impairments which rise as a consequence of such diseases, require effective orthotic management which will allow the patient to compensate the lost functions necessary at stable walking. For the last 15 years in Ukraine, as well as in the world, a great many of various constructions of orthoses on different levels of the lower extremity, which cover all existing pathologies, has appeared. But as practical experience of global and domestic orthotic management indicates, a significant amount of adult patients who have serious impairments of function of the lower extremities, and first of all new patients, do not use orthoses manufactured for them. The principal causes are: – Absence of comprehension by the patient, whether orthoses are necessary for him, whether he and his family can create conditions at home for his training; – Complexity of choice of an orthosis with correct functionality, made by the doctor and the orthotist. Recently in medical practice for the decision of this problem therapeutical – training orthoses or test-orthoses start to play the increasing role. More often test-orthoses are used before manufacturing of expensive orthoses, for example, knee-ankle-foot orthoses with a knee joint with electronic control. Use of such test-orthoses considerably reduces the time of orthotic management, but, unfortunately, they are not used for persons with serious pathology of lower extremities and cannot be used for determination of functional abilities of patients, especially in new ones. Therefore development of a new construction and a technique of application of test-orthoses (modular orthopedic systems) becomes an important stage in rehabilitation process of persons with serious pathological condition of a locomotor system. Purpose – to present and analyze the experience of application of new constructions of knee-ankle-foot test-orthoses for persons with impairments of functions of support and walking at the final stage of accomplishment of rehabilitation measures, namely provision with individual orthoses in hospital environment. Materials and methods. During realization of the research in the clinic of Ukrainian Research Institute for Prosthetics and Rehabilitation 28 patients (8 women and 20 men) from 21 to 50 years of age were examined, passed a course of rehabilitation treatment and were provided with new constructions of test-orthoses. 25 patients had consequences of traumatic injury of a spine (10 persons with injury at cervical level of a spine, 15 persons – at thoracic and lumbar levels of a spine), 2 persons – with consequences of a cerebral stroke, 1 – with consequences of a spinal stroke. All of them could not stand and walk independently. Rehabilitation measures directed on increasing of general physical status, elimination or decreasing of neurotrophic disorders have been earlier carried out for a significant amount (85.0%) of the examined persons; 72.0% of patients had experience of verticalization in a knee support device. Depending on a seriousness of a lesion the patients were divided into two groups: I group – patients with a lesion of the upper and lower extremities (12 persons); ІІ group – patients with a lesion of the lower extremities (16 persons). For each group the individual technique of application of test-orthoses and modes of their mastering have been developed. Test-orthoses, on the average, were used for one hour per day, within 8–11 days, for mastering of independent walking according to the developed techniques under supervision of the instructor. Service properties of testorthoses and their reliability were evaluated. Clinical, biomechanical diagnostic study of patients and manual testing of affected lower extremities of patients on residual muscle power were carried out, namely: muscle power on was evaluated five-scored Janda scale. Results. In Ukrainian Research Institute for Prosthetics and Rehabilitation within the framework of research work a new construction of a knee-anklefoot test-orthosis and a technique of its application for 2 groups of persons with serious lesions of a locomotor system have been developed. The feature of new constructions of test-orthoses is the possibility of their quick assembly and adjustment (within 2–3 hours) in view of the individual sizes of the patient, due to a modular approach of selection and connection of components. All patients of the group I could stand independently in orthoses in high walkers. Seven patients could move independently in walkers on the distance up to 30 meters, five moved on distance of 10 meters with the help of the instructor. After a 10-day course of mastering of verticalization and walking with test-orthoses a decision was made concerning the design of individual orthoses. Six patients have refused orthotic management for the lack of conditions for training at home. In their case test-orthoses were used as a trainer for verticalization and exercises in a standing position on a designed technique. Patients of the group II moved in bars and in low walkers on a distance from 100 to 300 meters. After mastering walking within 8–10 days with test-orthoses a decision was made concerning the design of individual orthoses. Knee-ankle-foot orthoses with locking knee joints were manufactured to seven patients, inarticulated knee joints and pneumocylinders – to four patients, an inarticulated floor reaction ankle-foot orthosis – to one patient. One patient with consequences of a spinal stroke used test-orthoses at home within 3.5 months. As a result of regular training the muscle power of her left leg and in part of her right leg was restored. In her case test-orthoses helped to avoid expenses on manufacturing of two individual knee-ankle-foot orthoses. The orthosis on her right leg was manufactured which has allowed her to save function of muscles of the leg during walking due to installation of the pneumatic cylinder in the field of the knee joint, that compensated weakness of the quadriceps muscle of the hip in the stance phase. Conclusions. Application of standard test-orthoses allows to estimate physical abilities of patients, to learn them to use orthoses on the lower extremities, to determine for everyone an optimal construction of individual orthoses that enables to refuse long and expensive process of manufacturing of a non-effective and not comfortable individual orthosis beforehand. The further research is necessary for expansion of possibilities of use of testorthoses for children with serious lesions of functions of support and walking. The research was carried out in accordance with the principles of the Helsinki declaration. The study protocol was approved by the Local ethics committee of the participating institution. The informed consent of the patient was obtained for conducting the studies. No conflict of interest was declared by the authors. Key words: locomotor functions impairment; constructions of test-orthoses; efficiency of orthotic management; knee joint; ankle joint.

The projection method was first introduced by Chorin [Bull. AMS 73 (1967), pp. 928–931] and Temam [Arch. Rat. Mech. Anal. 33 (1969), pp. 377–385] as a computationally efficient numerical method to solve the incompressible Navier–Stokes equations. Despite its success in decoupling the computations of velocity and pressure, it suffers from inaccurate numerical boundary layers. As an effort to resolve this inaccuracy, E and Liu [Int. J. Numer. Meth. Fluids 34 (2000), pp. 701–710] proposed the gauge method, which is a reformulation of the Navier–Stokes equations in terms of an auxiliary vector field and a gauge variable. This method utilizes the freedom of choosing a boundary condition for the gauge variable to reduce the numerical coupling between the considered variables. Nevertheless, the computational implementation of the boundary conditions for the auxiliary vector field is difficult in the context of finite elements since they involve either the normal or tangential derivative of the gauge variable. In order to circumvent this issue, we propose a weak formulation of the boundary conditions based on the symmetric Nitsche method. Computational results are presented to illustrate the accuracy of the proposed method. References J. H. Bramble, J. E. Pasciak, and A. T. Vassilev. Analysis of the Iinexact Uzawa algorithm for saddle point problems. SIAM J. Numer. Anal. 34.3 (1997), pp. 1072–1092. doi: 10.1137/S0036142994273343 D. L. Brown, R. Cortez, and M. L. Minion. Accurate projection methods for the incompressible Navier–Stokes equations. J. Comput. Phys. 168.2 (2001), pp. 464–499. doi: 10.1006/jcph.2001.6715 A. J. Chorin. The numerical solution of the Navier–Stokes equations for an incompressible fluid. Bull. Amer. Math. Soc. 73 (1967), pp. 928–931. doi: 10.1090/s0002-9904-1967-11853-6 on p. C100). W. E and J.-G. Liu. Gauge finite element method for incompressible flows. Int. J. Numer. Meth. Fluids 34 (2000), pp. 701–710. doi: 10.1002/1097-0363(20001230)34:8<701::AID-FLD76>3.0.CO;2-B W. E and J.-G. Liu. Projection method I: Convergence and numerical boundary layers. SIAM J. Numer. Anal. 32 (1995), pp. 1017–1057. doi: 10.1137/0732047 W. Ef and J.-G. Liu. Gauge method for viscous incompressible flows. Commun. Math. Sci. 1.2 (2003), pp. 317–332. doi: 10.4310/CMS.2003.v1.n2.a6 A. Ern and J.-L. Guermond. Theory and practice of finite elements. Vol. 159. Applied mathematical sciences. Springer, 2004. doi: 10.1007/978-1-4757-4355-5 P. Hansbo. Nitsche’s method for interface problems in computational mechanics. GAMM-Mitteilungen 28.2 (2005), pp. 183–206. doi: 10.1002/gamm.201490018 W. Layton, N. Mays, M. Neda, and C. Trenchea. Numerical analysis of modular regularization methods for the BDF2 time discretization of the Navier–Stokes equations. Math. Model. Numer. Anal. 48.3 (2014), pp. 765–793. doi: 10.1051/m2an/2013120 A. Logg, K.-A. Mardal, and G. Wells. Automated solution of differential equations by the finite element method: The FEniCS book. Vol. 84. Lecture notes in computational science and engineering. Springer, 2012. doi: 10.1007/978-3-642-23099-8 R. Mekhlouf, A. Baggag, and L. Remaki. Assessment of Nitsche’s method for Dirichlet boundary conditions treatment. J. Fluid Flow, Heat Mass Trans. 4.1 (2017), pp. 54–63. doi: 10.11159/jffhmt.2017.007 J. Nitsche. Über ein Variationsprinzip zur Lösung von Dirichlet-Problemen bei Verwendung von Teilräumen, die keinen Randbedingungen unterworfen sind. Abh. Math. Semin. Univ. Hambg. Vol. 36. Springer. 1971, pp. 9–15. doi: 10.1007/BF02995904 R. H. Nochetto and J.-H. Pyo. The gauge-Uzawa finite element method. Part I: The Navier–Stokes equations. SIAM J. Numer. Anal. 43.3 (2005), pp. 1043–1068. doi: 10.1137/040609756 J.-H. Pyo. Error estimates for the second order semi-discrete stabilized gauge-Uzawa method for the Navier–Stokes equations. Int. J. Numer. Anal. Mod. 10.1 (2013). url: https://www.global-sci.org/intro/article_detail/ijnam/557.html L. Ridgway Scott. Introduction to automated modeling with FEniCS. Computational Modeling Initiative, 2018. url: https://www.cminit.company/publications R. Temam. Sur l’approximation de la solution des équations de Navier–Stokes par la méthode des pas fractionnaires (II). Arch. Rat. Mech. Anal. 33.5 (1969), pp. 377–385. doi: 10.1007/BF00247696 C. Wang and J.-G. Liu. Convergence of gauge method for incompressible flow. Math. Comput. 69 (2000), pp. 1385–1407. doi: 10.1090/S0025-5718-00-01248-5 K. Wiratama. A comparison of projection and gauge methods for numerical incompressible fluid dynamics. Masters thesis. Australian National University, Oct. 2019 H. Zhang. Application of projection methods to the numerical solution of the incompressible Navier Stokes equations. Honours thesis. Australian National University, Oct. 2014

AbstractModular polyketide synthase (PKS) is an ingenious core machine that catalyzes abundant polyketides in nature. Exploring interactions among modules in PKS is very important for understanding the overall biosynthetic process and for engineering PKS assembly-lines. Here, we show that intermodular recognition between the enoylreductase domain ER1/2 inside module 1/2 and the ketosynthase domain KS3 inside module 3 is required for the cross-module enoylreduction in azalomycin F (AZL) biosynthesis. We also show that KS4 of module 4 acts as a gatekeeper facilitating cross-module enoylreduction. Additionally, evidence is provided that module 3 and module 6 in the AZL PKS are evolutionarily homologous, which makes evolution-oriented PKS engineering possible. These results reveal intermodular recognition, furthering understanding of the mechanism of the PKS assembly-line, thus providing different insights into PKS engineering. This also reveals that gene duplication/conversion and subsequent combinations may be a neofunctionalization process in modular PKS assembly-lines, hence providing a different case for supporting the investigation of modular PKS evolution.

Abstract Megasynthase enzymes such as type I modular polyketide synthases (PKSs) and nonribosomal peptide synthetases (NRPSs) play a central role in microbial chemical warfare because they can evolve rapidly by shuffling parts (catalytic domains) to produce novel chemicals. If we can understand the design rules to reshuffle these parts, PKSs and NRPSs will provide a systematic and modular way to synthesize millions of molecules including pharmaceuticals, biomaterials, and biofuels. However, PKS and NRPS engineering remains difficult due to a limited understanding of the determinants of PKS and NRPS fold and function. We developed ClusterCAD to streamline and simplify the process of designing and testing engineered PKS variants. Here, we present the highly improved ClusterCAD 2.0 release, available at https://clustercad.jbei.org. ClusterCAD 2.0 boasts support for PKS-NRPS hybrid and NRPS clusters in addition to PKS clusters; a vastly enlarged database of curated PKS, PKS-NRPS hybrid, and NRPS clusters; a diverse set of chemical ‘starters’ and loading modules; the new Domain Architecture Cluster Search Tool; and an offline Jupyter Notebook workspace, among other improvements. Together these features massively expand the chemical space that can be accessed by enzymes engineered with ClusterCAD.

AbstractThe modular organization of the type I polyketide synthases (PKSs) would seem propitious for rational engineering of desirable analogous. However, despite decades of efforts, such experiments remain largely inefficient. Here, we combine multiple, state-of-the-art approaches to reprogram the stambomycin PKS by deleting seven internal modules. One system produces the target 37-membered mini-stambomycin metabolites − a reduction in chain length of 14 carbons relative to the 51-membered parental compounds − but also substantial quantities of shunt metabolites. Our data also support an unprecedented off-loading mechanism of such stalled intermediates involving the C-terminal thioesterase domain of the PKS. The mini-stambomycin yields are reduced relative to wild type, likely reflecting the poor tolerance of the modules downstream of the modified interfaces to the non-native substrates. Overall, we identify factors contributing to the productivity of engineered whole assembly lines, but our findings also highlight the need for further research to increase production titers.

AbstractTo harness the synthetic power of modular polyketide synthases (PKSs), many aspects of their biochemistry must be elucidated. A robust platform to study these megadalton assembly lines has not yet been described. Here, we in vitro reconstitute the venemycin PKS, a short assembly line that generates an aromatic product. Incubating its polypeptides, VemG and VemH, with 3,5-dihydroxybenzoic acid, ATP, malonate, coenzyme A, and the malonyl-CoA ligase MatB, venemycin production can be monitored by HPLC and NMR. Multi-milligram quantities of venemycin are isolable from dialysis-based reactors without chromatography, and the enzymes can be recycled. Assembly line engineering is performed using pikromycin modules, with synthases designed using the updated module boundaries outperforming those using the traditional module boundaries by over an order of magnitude. Using combinations of VemG, VemH, and their engineered derivatives, as well as the alternate starter unit 3-hydroxybenzoic acid, a combinatorial library of six polyketide products is readily accessed.

AbstractEngineered metabolic pathways in microbial cell factories often have no natural organization and have challenging flux imbalances, leading to low biocatalytic efficiency. Modular polyketide synthases (PKSs) are multienzyme complexes that synthesize polyketide products via an assembly line thiotemplate mechanism. Here, we develop a strategy named mimic PKS enzyme assembly line (mPKSeal) that assembles key cascade enzymes to enhance biocatalytic efficiency and increase target production by recruiting cascade enzymes tagged with docking domains from type I cis-AT PKS. We apply this strategy to the astaxanthin biosynthetic pathway in engineered Escherichia coli for multienzyme assembly to increase astaxanthin production by 2.4-fold. The docking pairs, from the same PKSs or those from different cis-AT PKSs evidently belonging to distinct classes, are effective enzyme assembly tools for increasing astaxanthin production. This study addresses the challenge of cascade catalytic efficiency and highlights the potential for engineering enzyme assembly.

AbstractType I modular polyketide synthases (PKSs) are multi-domain enzymes functioning like assembly lines. Many engineering attempts have been made for the last three decades to replace, delete and insert new functional domains into PKSs to produce novel molecules. However, inserting heterologous domains often destabilize PKSs, causing loss of activity and protein misfolding. To address this challenge, here we develop a fluorescence-based solubility biosensor that can quickly identify engineered PKSs variants with minimal structural disruptions. Using this biosensor, we screen a library of acyltransferase (AT)-exchanged PKS hybrids with randomly assigned domain boundaries, and we identify variants that maintain wild type production levels. We then probe each position in the AT linker region to determine how domain boundaries influence structural integrity and identify a set of optimized domain boundaries. Overall, we have successfully developed an experimentally validated, high-throughput method for making hybrid PKSs that produce novel molecules.

AbstractPolyketides, one of the largest classes of natural products, are often clinically relevant. The ability to engineer polyketide biosynthesis to produce analogs is critically important. Acyltransferases (ATs) of modular polyketide synthases (PKSs) catalyze the installation of malonyl-CoA extenders into polyketide scaffolds. ATs have been targeted extensively to site-selectively introduce various extenders into polyketides. Yet, a complete inventory of AT residues responsible for substrate selection has not been established, limiting the scope of AT engineering. Here, molecular dynamics simulations are used to prioritize ~50 mutations within the active site of EryAT6 from erythromycin biosynthesis, leading to identification of two previously unexplored structural motifs. Exchanging both motifs with those from ATs with alternative extender specificities provides chimeric PKS modules with expanded and inverted substrate specificity. Our enhanced understanding of AT substrate selectivity and application of this motif-swapping strategy are expected to advance our ability to engineer PKSs towards designer polyketides.

In this paper we invention all the principle indecomposablespin(projective) characters of the symmetric group when and the characteristic of the field is 19. The principle indecomposable spincharacters of the symmetric group ,also can get it by determine all irreducible spin characters for , and all irreducible modular spin characters for , the sum of multiplication of these characters it represents the principle indecomposable spin(projective) characters of the symmetric group .For their more can get on the irreducible spin characters for by fixing all bar partitions for , also we can get on all the irreducible modular spin characters for by -inducing method, finally induce the principal indecomposable characters(P.i.s)from (see creek*) give usprincipal indecomposable characters (P.i.s) or principal characters (P.s) of .

Modular multiplication (MM) is an important arithmetic operation in public key cryptography (PKC). In this paper, we present the FPGA implementation of the MM using Montgomery MM (MMM) algorithm. The execution performances of this operation depend on the radix-[Formula: see text] and the operands length. In fact, when increasing the radix-[Formula: see text], the MMM algorithm requires multiplications of digit by operand. On the other hand, when a long modulus is used, the hardware implementation of the MMM needs a large area. Our objective in this work is to realize a scalable architecture able to support any operands length. In order to achieve a best trade-off between computation throughput and hardware resources, our implementation approach is based on the execution of the basic arithmetic operations in serial way. In addition, efficient parallel and pipelined strategies are realized at low-level abstraction for the optimization of the execution time. The implementations results on Virtex-7 circuit show that a 1024-bit MMM runs in 2.09[Formula: see text][Formula: see text]s and consumes 581 slices.

Penapis Kuasa Aktif (PKA) terkenal dengan kebolehannya memampas harmonik arus dalam talian kuasa. Pelbagai jenis konfigurasi PKA telah dicadangkan dalam tempoh beberapa dekad yang lalu, tetapi jarang terdapat artikel yang mempertimbangkan kebolehan PKA meningkatkan tahap struktur pembinaannya. Artikel ini akan membandingkan operasi penyongsang biasa yang berbentuk H dengan Penyongsang Pelbagai Aras Struktur Bermodul (PPASB) yang dikawal oleh kaedah kawalan Pengamilan Disatukan Berfrekuensi Tetap (PDBT). Kelebihan struktur penyongsang baru tersebut dapat dipertambahkan peringkatnya untuk kegunaan kuasa yang lebih tinggi. Ciri–ciri setiap penyongsang tersebut akan dibincangkan dan keputusan simulasi berdasarkan MATLAB/SIMULINK juga dicatatkan. Kata kunci: Penapis kuasa aktif, penyongsang–H, penyongsang pelbagai aras struktur bermodul, pengamilan disatukan berfrekuensi tetap, pemampasan harmonik Active Power Filter (APF) is well known for its capability of compensating current harmonics in power lines. Vast varieties of APF configurations were proposed for the past few decades, but not many papers consider the expansion capability of APFs. This article presents the comparison of performance for the conventional single level H–bridge inverter and Modular Structured Multilevel Inverter where both are controlled by Unified Constant-Frequency Integration (UCI) control scheme. The latter inverter structure is more flexible to be expanded to suit higher power application. Characteristics of each topology are discussed and the simulation results based on MATLAB/SIMULINK are presented. Key words: Active power filter, H–bridge inverter, multilevel inverter, unified constant–frequency integration control, harmonic compensation

The safety of risky roadside zones such as kids’ playgrounds, schools, bus stops, petrol stations, critical roadside facilities, and pavements are becoming a significant worldwide problem. This study focused on the roadside safety of critical above-ground assets of natural gas grids due to its consequences such as fire, blast, traffic interruptions, service downtime, and consumer displeasure during the repair process. In this regard, a novel modular shallow mounted bollard system was designed considering the disadvantages of conventional bollard systems in the literature and the demands/needs of related institutions. Numerical simulations were carried out to analyze the structural and safety performance capabilities of the originally designed bollard system following PAS 68:2013 standard. In addition, FE models were created and incorporated with the verified vehicle models to simulate dynamic behaviors. LS-DYNA software analyzed the FE models. As a result of the simulations, the newly developed fixed bollard design can safely stop vehicles that weigh 18,000 kg max., except for the 30,000 kg N3 class vehicle, up to 50 km/h. The results revealed that proposed bollard designs successfully met the standard requirements for the vehicle types and speed that represent general urban traffic characteristics. Thus, the new fixed bollard design will contribute to roadside safety in metropolitan areas by protecting critical hazardous roadside facilities. In the next stage, the newly designed barrier system should be optimized to lighten the system and reduce the costs.

Abstract Background Prime editing enables precise base substitutions, insertions, and deletions at targeted sites without the involvement of double-strand DNA breaks or exogenous donor DNA templates. However, the large size of prime editors (PEs) hampers their delivery in vivo via adeno-associated virus (AAV) due to the viral packaging limit. Previously reported split PE versions provide a size reduction, but they require intricate engineering and potentially compromise editing efficiency. Results Herein, we present a simplified split PE named as CC-PE, created through non-covalent recruitment of reverse transcriptase to the Cas9 nickase via coiled-coil heterodimers, which are widely used in protein design due to their modularity and well-understood sequence-structure relationship. We demonstrate that the CC-PE maintains or even surpasses the efficiency of unsplit PE in installing intended edits, with no increase in the levels of undesired byproducts within tested loci amongst a variety of cell types (HEK293T, A549, HCT116, and U2OS). Furthermore, coiled-coil heterodimers are used to engineer SpCas9-NG-PE and SpRY-PE, two Cas9 variants with more flexible editing scope. Similarly, the resulting NG-CC-PE and SpRY-CC-PE also achieve equivalent or enhanced efficiency of precise editing compared to the intact PE. When the dual AAV vectors carrying CC-PE are delivered into mice to target the Pcsk9 gene in the liver, CC-PE enables highly efficient precise editing, resulting in a significant reduction of plasma low-density lipoprotein cholesterol and total cholesterol. Conclusions Our innovative, modular system enhances flexibility, thus potentially facilitating the in vivo applicability of prime editing.

Introduction Almost all industries in Australia today have adopted digital media in some way. However, uses in large scale activities such as mining may seem to be different from others. This article looks at mining practices with a media studies approach, and concludes that, just as many other industries, mining and media have converged. Many Australian mine sites are adopting new media for communication and control to manage communication, explore for ore bodies, simulate forces, automate drilling, keep records, and make transport and command robotic. Beyond sharing similar digital devices for communication and computation, new media in mining employ characteristic digital media operations, such as numerical operation, automation and managed variability. This article examines the implications of finding that some of the most material practices have become mediated by new media. Mining has become increasingly mediated through new media technologies similar to GPS, visualisation, game remote operation, similar to those adopted in consumer home and mobile digital media. The growing and diversified adoption of digital media championed by companies like Rio Tinto aims not only ‘improve’ mining, but to change it. Through remediating practices of digital mining, new media have become integral powerful tools in prospective, real time and analytical environments. This paper draws on two well-known case studies of mines in the Pilbara and Western NSW. These have been documented in press releases and media reports as representing changes in media and mining. First, the West Angelas mines in the Pilbara is an open cut iron ore mine introducing automation and remote operation. This mine is located in the remote Pilbara, and is notable for being operated remotely from a control centre 2000km away, near Perth Airport, WA. A growing fleet of Komatsu 930E haul trucks, which can drive autonomously, traverses the site. Fitted with radars, lasers and GPS, these enormous vehicles navigate through the open pit mine with no direct human control. Introducing these innovations to mine sites become more viable after iron ore mining became increasingly profitable in the mid-2000s. A boom in steel building in China drove unprecedented demand. This growing income coincided with a change in public rhetoric from companies like Rio Tinto. They pointed towards substantial investments in research, infrastructure, and accelerated introduction of new media technologies into mining practices. Rio Tinto trademarked the term ‘Mine of the future’ (US Federal News Service 1), and publicised their ambitious project for renewal of mining practice, including digital media. More recently, prices have been more volatile. The second case study site is a copper and gold underground mine at Northparkes in Western NSW. Northparkes uses substantial sensing and control, as well as hybrid autonomous and remote operated vehicles. The use of digital media begins with prospecting, and through to logistics of transportation. Engineers place explosives in optimal positions using computer modelling of the underground rock formations. They make heavy use of software to coordinate layer-by-layer use of explosives in this advanced ‘box cut’ mine. After explosives disrupt the rock layer a kilometre underground, another specialised vehicle collects and carries the ore to the surface. The Sandvik loader-hauler-dumper (LHD) can be driven conventionally by a driver, but it can also travel autonomously in and out of the mine without a direct operator. Once it reaches a collection point, where the broken up ore has accumulated, a user of the surface can change the media mode to telepresence. The human operator then takes control using something like a games controller and multiple screens. The remote operator controls the LHD to fill the scoop with ore. The fully-loaded LHD backs up, and returns autonomously using laser senses to follow a trail to the next drop off point. The LHD has become a powerful mediator, reconfiguring technical, material and social practices throughout the mine. The Meanings of Mining and Media Are Converging Until recently, mining and media typically operated ontologically separately. The media, such as newspapers and television, often tell stories about mining, following regular narrative scripts. There are controversies and conflicts, narratives of ecological crises, and the economics of national benefit. There are heroic and tragic stories such as the Beaconsfield mine collapse (Clark). There are new industry policies (Middelbeek), which are politically fraught because of the lobbying power of miners. Almost completely separately, workers in mines were consumers of media, from news to entertainment. These media practices, while important in their own right, tell nothing of the approaching changes in many other sectors of work and everyday life. It is somewhat unusual for a media studies scholar to study mine sites. Mine sites are most commonly studied by Engineering (Bellamy & Pravica), Business and labour and cultural histories (McDonald, Mayes & Pini). Until recently, media scholarship on mining has related to media institutions, such as newspapers, broadcasters and websites, and their audiences. As digital media have proliferated, the phenomena that can be considered as media phenomena has changed. This article, pointing to the growing roles of media technologies, observes the growing importance that media, in these terms, have in the rapidly changing domain of mining. Another meaning for ‘media’ studies, from cybernetics, is that a medium is any technology that translates perception, makes interpretations, and performs expressions. This meaning is more abstract, operating with a broader definition of media — not only those institutionalised as newspapers or radio stations. It is well known that computer-based media have become ubiquitous in culture. This is true in particular within the mining company’s higher ranks. Rio Tinto’s ambitious 2010 ‘Mine of the Future’ (Fisher & Schnittger, 2) program was premised on an awareness that engineers, middle managers and senior staff were already highly computer literate. It is worth remembering that such competency was relatively uncommon until the late 1980s. The meanings of digital media have been shifting for many years, as computers become experienced more as everyday personal artefacts, and less as remote information systems. Their value has always been held with some ambivalence. Zuboff’s (387-414) picture of loss, intimidation and resistance to new information technologies in the 1980s seems to have dissipated by 2011. More than simply being accepted begrudgingly, the PC platform (and variants) has become a ubiquitous platform, a lingua franca for information workers. It became an intimate companion for many professions, and in many homes. It was an inexpensive, versatile and generalised convergent medium for communication and control. And yet, writers such as Gregg observe, the flexibility of networked digital work imposes upon many workers ‘unlimited work’. The office boundaries of the office wall break down, for better or worse. Emails, utility and other work-related behaviours increasingly encroach onto domestic and public space and time. Its very attractiveness to users has tied them to these artefacts. The trail that leads the media studies discipline down the digital mine shaft has been cleared by recent work in media archaeology (Parikka), platform studies (Middelbeek; Montfort & Bogost; Maher) and new media (Manovich). Each of these redefined Media Studies practices addresses the need to diversify the field’s attention and methods. It must look at more specific, less conventional and more complex media formations. Mobile media and games (both computer-based) have turned out to be quite different from traditional media (Hjorth; Goggin). Kirschenbaum’s literary study of hard drives and digital fiction moves from materiality to aesthetics. In my study of digital mining, I present a reconfigured media studies, after the authors, that reveals heterogeneous media configurations, deserving new attention to materiality. This article also draws from the actor network theory approach and terminology (Latour). The uses of media / control / communications in the mining industry are very complex, and remain under constant development. Media such as robotics, computer modelling, remote operation and so on are bound together into complex practices. Each mine site is different — geologically, politically, and economically. Mines are subject to local and remote disasters. Mine tunnels and global prices can collapse, rendering active sites uneconomical overnight. Many technologies are still under development — including Northparkes and West Angelas. Both these sites are notable for their significant use of autonomous vehicles and remote operated vehicles. There is no doubt that the digital technologies modulate all manner of the mining processes: from rocks and mechanical devices to human actors. Each of these actors present different forms of collusion and opposition. Within a mining operation, the budgets for computerised and even robotic systems are relatively modest for their expected return. Deep in a mine, we can still see media convergence at work. Convergence refers to processes whereby previously diverse practices in media have taken on similar devices and techniques. While high-end PCs in mining, running simulators; control data systems; visualisation; telepresence, and so on may be high performance, ruggedised devices, they still share a common platform to the desktop PC. Conceptual resources developed in Media Ecology, New Media Studies, and the Digital Humanities can now inform readings of mining practices, even if their applications differ dramatically in size, reliability and cost. It is not entirely surprising that some observations by new media theorists about entertainment and media applications can also relate to features of mining technologies. Manovich argues that numerical representation is a distinctive feature of new media. Numbers have always already been key to mining engineering. However, computers visualise numerical fields in simulations that extend out of the minds of the calculators, and into visual and even haptic spaces. Specialists in geology, explosives, mechanical apparatuses, and so on, can use plaftorms that are common to everyday media. As the significance of numbers is extended by computers in the field, more and more diverse sources of data provide apparently consistent and seamless images of multiple fields of knowledge. Another feature that Manovich identifies in new media is the capacity for automation of media operations. Automation of many processes in mechanical domains clearly occurred long before industrial technologies were ported into new media. The difference with new media in mine sites is that robotic systems must vary their performance according to feedback from their extra-system environments. For our purposes, the haul trucks in WA are software-controlled devices that already qualify as robots. They sense, interpret and act in the world based on their surroundings. They evaluate multiple factors, including the sensors, GPS signals, operator instructions and so on. They can repeat the path, by sensing the differences, day after day, even if the weather changes, the track wears away or the instructions from base change. Automation compensates for differences within complex and changing environments. Automation of an open-pit mine haulage system… provides more consistent and efficient operation of mining equipment, it removes workers from potential danger, it reduces fuel consumption significantly reducing greenhouse gas (GHG) emissions, and it can help optimize vehicle repairs and equipment replacement because of more-predictable and better-controlled maintenance. (Parreire and Meech 1-13) Material components in physical mines tend to become modular and variable, as their physical shape lines up with the logic of another of Manovich’s new media themes, variability. Automatic systems also make obsolete human drivers, who previously handled those environmental variations, for better or for worse, through the dangerous, dull and dirty spaces of the mine. Drivers’ capacity to control repeat trips is no longer needed. The Komatsu driverless truck, introduced to the WA iron ore mines from 2008, proved itself to be almost as quick as human drivers at many tasks. But the driverless trucks have deeper advantages: they can run 23 hours each day with no shift breaks; they drive more cautiously and wear the equipment less than human drivers. There is no need to put up workers and their families up in town. The benefit most often mentioned is safety: even the worst accident won’t produce injuries to drivers. The other advantage less mentioned is that autonomous trucks don’t strike. Meanwhile, managers of human labour also need to adopt certain strategies of modulation to support the needs and expectations of their workers. Mobile phones, televisions and radio are popular modes of connecting workers to their loved ones, particularly in the remote and harsh West Angelas site. One solution — regular fly-in-fly out shifts — tends also to be alienating for workers and locals (Cheshire; Storey; Tonts). As with any operations, the cost of maintaining a safe and comfortable environment for workers requires trade-offs. Companies face risks from mobile phones, leaking computer networks, and espionage that expose the site to security risks. Because of such risks, miners tend be subject to disciplinary regimes. It is common to test alcohol and drug levels. There was some resistance from workers, who refused to change to saliva testing from urine testing (Latimer). Contesting these machines places the medium, in a different sense, at the centre of regulation of the workers’ bodies. In Northparkes, the solution of hybrid autonomous and remote operation is also a solution for modulating labour. It is safer and more comfortable, while also being more efficient, as one experienced driver can control three trucks at a time. This more complex mode of mediation is necessary because underground mines are more complex in geology, and working environments to suit full autonomy. These variations provide different relationships between operators and machines. The operator uses a games controller, and watches four video views from the cabin to make the vehicle fill the bucket with ore (Northparkes Mines, 9). Again, media have become a pivotal element in the mining assemblage. This combines the safety and comfort of autonomous operation (helping to retain staff) with the required use of human sensorimotor dexterity. Mine systems deserve attention from media studies because sites are combining large scale physical complexity with increasingly sophisticated computing. The conventional pictures of mining and media rarely address the specificity of subjective and artefactual encounters in and around mine sites. Any research on mining communication is typically within the instrumental frames of engineering (Duff et al.). Some of the developments in mechanical systems have contributed to efficiency and safety of many mines: larger trucks, more rock crushers, and so on. However, the single most powerful influence on mining has been adopting digital media to control, integrate and mining systems. Rio Tinto’s transformative agenda document is outlined in its high profile ‘Mine of the Future’ agenda (US Federal News Service). The media to which I refer are not only those in popular culture, but also those with digital control and communications systems used internally within mines and supply chains. The global mining industry began adopting digital communication automation (somewhat) systematically only in the 1980s. Mining companies hesitated to adopt digital media because the fundamentals of mining are so risky and bound to standard procedures. Large scale material operations, extracting and processing minerals from under the ground: hardly to be an appropriate space for delicate digital electronics. Mining is also exposed to volatile economic conditions, so investing in anything major can be unattractive. High technology perhaps contradicts an industry ethos of risk-taking and masculinity. Digital media became domesticated, and familiar to a new generation of formally educated engineers for whom databases and algorithms (Manovich) were second nature. Digital systems become simultaneously controllers of objects, and mediators of meanings and relationships. They control movements, and express communications. Computers slide from using meanings to invoking direct actions over objects in the world. Even on an everyday scale, computer operations often control physical processes. Anti-lock Braking Systems regulate a vehicle’s braking pressure to avoid the danger when wheels lock-up. Or another example, is the ATM, which involves both symbolic interactions, and also exchange of physical objects. These operations are examples of the ‘asignifying semiotic’ (Guattari), in which meanings and non-meanings interact. There is no operation essential distinction between media- and non-media digital operations. Which are symbolic, attached or non-consequential is not clear. This trend towards using computation for both meanings and actions has accelerated since 2000. Mines of the Future Beyond a relatively standard set of office and communications software, many fields, including mining, have adopted specialised packages for their domains. In 3D design, it is AutoCAD. In hard sciences, it is custom modelling. In audiovisual production, it may be Apple and Adobe products. Some platforms define their subjectivity, professional identity and practices around these platforms. This platform orientation is apparent in areas of mining, so that applications such as the Gemcom, Rockware, Geological Database and Resource Estimation Modelling from Micromine; geology/mine design software from Runge, Minemap; and mine production data management software from Corvus. However, software is only a small proportion of overall costs in the industry. Agents in mining demand solutions to peculiar problems and requirements. They are bound by their enormous scale; physical risks of environments, explosive and moving elements; need to negotiate constant change, as mining literally takes the ground from under itself; the need to incorporate geological patterns; and the importance of logistics. When digital media are the solution, there can be what is perceived as rapid gains, including greater capacities for surveillance and control. Digital media do not provide more force. Instead, they modulate the direction, speed and timing of activities. It is not a complete solution, because too many uncontrolled elements are at play. Instead, there are moment and situations when the degree of control refigures the work that can be done. Conclusions In this article I have proposed a new conception of media change, by reading digital innovations in mining practices themselves as media changes. This involved developing an initial reading of the operations of mining as digital media. With this approach, the array of media components extends far beyond the conventional ‘mass media’ of newspapers and television. It offers a more molecular media environment which is increasingly heterogeneous. It sometimes involves materiality on a huge scale, and is sometimes apparently virtual. The mining media event can be a semiotic, a signal, a material entity and so on. It can be a command to a human. It can be a measurement of location, a rock formation, a pressure or an explosion. The mining media event, as discussed above, is subject to Manovich’s principles of media, being numerical, variable and automated. In the mining media event, these principles move from the aesthetic to the instrumental and physical domains of the mine site. The role of new media operates at many levels — from the bottom of the mine site to the cruising altitude of the fly-in-fly out aeroplanes — has motivated significant changes in the Australian industry. When digital media and robotics come into play, they do not so much introduce change, but reintroduce similarity. This inversion of media is less about meaning, and more about local mastery. Media modulation extends the kinds of influence that can be exerted by the actors in control. In these situations, the degrees of control, and of resistance, are yet to be seen. Acknowledgments Thanks to Mining IQ for a researcher's pass at Mining Automation and Communication Conference, Perth in August 2012. References Bellamy, D., and L. 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