Extension Mechanism Research Articles

Research on SDP-BF Method with Low False Positive Face to Passive Detection System

With the rapid development of 5G, UAV, and military communications, the data volume obtained by the non-cooperative perception system has increased exponentially, and the distributed system has become the development trend of the non-cooperative perception system. The data distribution service (DDS) produces a significant effect on the performance of distributed non-cooperative perception systems. However, the traditional DDS discovery protocol has problems such as false positive misjudgment and high flow overhead, so it can hardly adapt to a large multi-node distributed system. Therefore, the design of a DDS discovery protocol for large distributed system is technically challenging. In this paper, we proposed SDP-DCBF-SFF, a discovery protocol based on the Dynamic Counter Bloom Filter (DCBF) and Second Feedback Filter (SFF). The proposed discovery protocol coarsely filters the interested endpoints through DCBF and then accurately screens the uninterested endpoints through SFF to eliminate the connection requests of false positive endpoints and avoid extra flow overhead. The experimental results indicate that the proposed discovery protocol could effectively reduce the network overhead, and eliminate the false positive probability of endpoints in small, medium, large, and super large systems. In addition, it adopts the self-adaptive extension mechanism of BF to reduce the reconfiguration delay of BF and achieve the smallest system transmission delay. Therefore, the proposed discovery protocol has optimal comprehensive performance and system adaptability.

Preparation of 2-Aminoimidazole-Activated Substrates for the Study of Nonenzymatic Genome Replication.

Nonenzymatic genome replication is thought to be an important process for primitive lifeforms, but this has yet to be demonstrated experimentally. Recent studies on the nonenzymatic primer extension mechanism mediated by nucleoside 5'-monophosphates (NMPs) activated with 2-aminoimidazole have revealed that imidazolium-bridged dinucleotide intermediates (N*N) account for the majority of the chemical copying process. As a result, an efficacious synthetic pathway for producing substrates activated with an imidazoyl moiety is desirable. This article provides a detailed protocol for the standard dehydrative redox reaction between NMPs and 2-aminoimidazole to produce nucleotide phosphoroimidazolides. In addition, we describe a similar synthetic pathway to produce N*N in high yields for homodimers. Finally, a simple reversed-phase cation exchange step is described to increase NMP solubility, which significantly increases yields for certain substrates. This approach allows for an efficient and cost-effective methodology to prepare high-quality substrates utilized in origins-of-life studies. © 2024 The Author(s). Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Synthesis of 2-aminoimidazolephosphoroimidazolide-activated cytidine Basic Protocol 2: Synthesis of 2-aminoimidazolium-bridged dicytidyl intermediate Basic Protocol 3: Cation exchange of guanosine 5'-monophosphate disodium salt Alternate Protocol: Synthesis of cytidine 5'-phosphoroimidazolide or 2-aminoimidazolium-bridged dicytidyl from cytidine 5'-monophosphate disodium salt.

Propagation of interfered hydraulic fractures by alternated radial-circumferential extensions and its impact on proppant distribution

The fracture extension mechanisms and proppant transport characteristics play key roles for optimizing hydraulic fracturing in unconventional reservoirs. In this work, the visual physical simulation method was used to analyze the 3D dynamic extension processes of multi-stage hydraulic fractures and the subsequent impact on proppant distribution. The interfered fracture in multi-stage hydraulic fracturing exhibit alternated radial-circumferential extension behavior. More specifically, these behavior changes from unilaterally radial initiation, circumferential extension to radial extension. Unilaterally radial initiation results in the formation of both mirror and conchoidal features, while circumferential extension leads to stepped feature, and radial extension gives rise to feather feature. The four features of hydraulic fractures result in four types of non-uniform proppant distribution: uniform, scattered, cluster, and regional distribution. The proppant transport shifted from linear to radial mode, promoting further fracture extension. The effects of segment spacing and proppant injection sequence were studied. The results showed that the influence on the interfered fracture decreases as the segment spacing increases. In addition, the propped fracture area is larger when the small-size proppant is injected first, followed by large-size one. The research can improve understanding and optimization of multi-stage hydraulic fracturing in unconventional oil and gas reservoirs.

Analysis of bacterial transcriptome and epitranscriptome using nanopore direct RNA sequencing.

Bacterial gene expression is a complex process involving extensive regulatory mechanisms. Along with growing interests in this field, Nanopore Direct RNA Sequencing (DRS) provides a promising platform for rapid and comprehensive characterization of bacterial RNA biology. However, the DRS of bacterial RNA is currently deficient in the yield of mRNA-mapping reads and has yet to be exploited for transcriptome-wide RNA modification mapping. Here, we showed that pre-processing of bacterial total RNA (size selection followed by ribosomal RNA depletion and polyadenylation) guaranteed high throughputs of sequencing data and considerably increased the amount of mRNA reads. This way, complex transcriptome architectures were reconstructed for Escherichia coliand Staphylococcus aureusand extended the boundaries of 225 known E. coli operons and 89 defined S. aureus operons. Utilizing unmodified in vitro-transcribed (IVT) RNA libraries as a negative control, several Nanopore-based computational tools globally detected putative modification sites in the E. coli and S. aureus transcriptomes. Combined with Next-Generation Sequencing-based N6-methyladenosine (m6A) detection methods, 75 high-confidence m6A candidates were identified in the E. coli protein-coding transcripts, while none were detected in S. aureus. Altogether, we demonstrated the potential of Nanopore DRS in systematic and convenient transcriptome and epitranscriptome analysis.

Soft tissue hemangioma of the right upper extremity with intraosseous extension and secondary intravascular papillary endothelial hyperplasia.

Intravascular papillary endothelial hyperplasia (IPEH), also known as Masson's tumor, is an uncommon exuberant form of organizing thrombus that may occur within a vessel, vascular tumor, or hematoma and may change the imaging appearance to mimic an aggressive process. It must be distinguished pathologically from angiosarcoma. They have been most commonly reported within superficial soft tissue tumors, and rapid growth and effect on bone are rarely described. We present a case of a patient with a soft tissue hemangioma with IPEH with intraosseous extension that presented with a pathologic fracture of her right humerus with an aggressive appearing osseous lesion. CT and MRI demonstrated a multifocal ill-defined soft tissue mass throughout the right upper extremity with underlying cortical tunneling and scalloping of the proximal humerus. Similar imaging findings were also present in the distal humerus and ipsilateral scapula and evolved during her hospitalization. Following percutaneous biopsy revealing hemangioma with features of papillary endothelial hyperplasia with intraosseous extension, the patient died in the ICU secondary to unrelated septic shock. Diagnosis was confirmed at autopsy. Primary and secondary IPEH have been generally characterized as well-defined solitary masses, most often in the superficial soft tissues. This case of a deep soft tissue hemangioma with type II IPEH, intraosseous extension, and imaging findings of regional multicompartmental involvement is very unusual. Reporting of this case in the literature should be beneficial for pathologic correlation with similar confounding masses as well as propose a possible mechanism for intraosseous extension of soft tissue hemangiomas.

An investigation into crack initiation and extension mechanism of laminar plasma quenched-tempered rail material with different quenched zones

Laminar Plasma Quenching Tempering (LPQT) is an innovative surface treatment technique for rails, which effectively enhances both their fatigue resistance and wear resistance. This study examines the crack initiation and propagation mechanisms in LPQT-treated rail materials with distinct quenched zones using double-disc testing and metallographic analysis. The findings indicate that the crack initiation and propagation process in LPQT rails with different quenched zones is characterized by four stages. Moreover, the grain size within the spot-quenched zone of LPQT rails is notably smaller, which results in a reduced resistance to RCF crack propagation. Consequently, the crack propagation in point-quenched LPQT rail material is more intricate, with a more severe damage scenario.

Extension Mechanism of Water-Conducting Cracks in the Thick and Hard Overlying Strata of Coal Mining Face

It is of great significance for coal safety production and water resource protection in the Yuheng mining area to master the evolution law of water-conducting fractures under the condition of thick and hard overburden. This research focuses on the 2102 fully mechanized mining face in the Balasu Coal Mine as the research background. The fracture evolution and strata movement characteristics in thick and hard overlying strata are simulated and analyzed by combining numerical simulation with physical simulation, and the formation mechanism of a water-conducting fracture in the overlying strata is revealed and verified by field measurements of the development height of “two zones”. The results show that the anisotropy of fracture propagation in low-position overlying strata is high, and the fracture propagation in high-position overlying strata is mainly vertical, which indicates characteristics of leapfrog development. The number and development height of fractures undergo the change–growth process of “slow–rapid–uniform”. Multiple rock strata together form a complex force chain network with multiple strong chain arches. The local stress concentration leads to the initiation of micro-cracks in contact fractures, and the cracks gradually penetrate from bottom to top and then the strong chain arches are broken. The water-conducting cracks in overlying strata show a dynamic expansion process of “local micro-cracks–jumping cracks–through cracks–water-conducting cracks”. The fracture between the caving zone and fracture zone presents obvious layered characteristics, the overall shape of the water-conducting fracture zone is “saddle-shaped”, and the maximum development height lags behind the coal mining face by about 180 m. Through the observation of water injection leakage and borehole TV observation of three boreholes under underground construction, combined with the results of water pressure tests, it is comprehensively determined that the height of the water-conducting fracture zone is 103.68~107.58, and the fracture–production ratio is 31.42~32.60, which is basically consistent with the results of numerical simulation and physical simulation. This research provides theoretical guidance and a scientific basis for coal mine water disaster prevention under similar geological conditions.

CPSign: conformal prediction for cheminformatics modeling

Conformal prediction has seen many applications in pharmaceutical science, being able to calibrate outputs of machine learning models and producing valid prediction intervals. We here present the open source software CPSign that is a complete implementation of conformal prediction for cheminformatics modeling. CPSign implements inductive and transductive conformal prediction for classification and regression, and probabilistic prediction with the Venn-ABERS methodology. The main chemical representation is signatures but other types of descriptors are also supported. The main modeling methodology is support vector machines (SVMs), but additional modeling methods are supported via an extension mechanism, e.g. DeepLearning4J models. We also describe features for visualizing results from conformal models including calibration and efficiency plots, as well as features to publish predictive models as REST services. We compare CPSign against other common cheminformatics modeling approaches including random forest, and a directed message-passing neural network. The results show that CPSign produces robust predictive performance with comparative predictive efficiency, with superior runtime and lower hardware requirements compared to neural network based models. CPSign has been used in several studies and is in production-use in multiple organizations. The ability to work directly with chemical input files, perform descriptor calculation and modeling with SVM in the conformal prediction framework, with a single software package having a low footprint and fast execution time makes CPSign a convenient and yet flexible package for training, deploying, and predicting on chemical data. CPSign can be downloaded from GitHub at https://github.com/arosbio/cpsign.Scientific contribution CPSign provides a single software that allows users to perform data preprocessing, modeling and make predictions directly on chemical structures, using conformal and probabilistic prediction. Building and evaluating new models can be achieved at a high abstraction level, without sacrificing flexibility and predictive performance—showcased with a method evaluation against contemporary modeling approaches, where CPSign performs on par with a state-of-the-art deep learning based model.

Extension mechanism and failure mode investigation on a fissured loess slope induced by loading

Extension mechanism and failure mode investigation on a fissured loess slope induced by loading

Towards a dependable data set of structures for L-asparaginase research.

The Protein Data Bank (PDB) includes a carefully curated treasury of experimentally derived structural data on biological macromolecules and their various complexes. Such information is fundamental for a multitude of projects that involve large-scale data mining and/or detailed evaluation of individual structures of importance to chemistry, biology and, most of all, to medicine, where it provides the foundation for structure-based drug discovery. However, despite extensive validation mechanisms, it is almost inevitable that among the ∼215 000 entries there will occasionally be suboptimal or incorrect structure models. It is thus vital to apply careful verification procedures to those segments of the PDB that are of direct medicinal interest. Here, such an analysis was carried out for crystallographic models of L-asparaginases, enzymes that include approved drugs for the treatment of certain types of leukemia. The focus was on the adherence of the atomic coordinates to the rules of stereochemistry and their agreement with the experimental electron-density maps. Whereas the current clinical application of L-asparaginases is limited to two bacterial proteins and their chemical modifications, the field of investigations of such enzymes has expanded tremendously in recent years with the discovery of three entirely different structural classes and with numerous reports, not always quite reliable, of the anticancer properties of L-asparaginases of different origins.

Reflexive Event-B: Semantics and Correctness the EB4EB Framework

The Event-B method enables correct by construction modeling of systems. It relies on set theory and first-order logic, to describe a series of refined system models expressed as a set of events modifying state variables. Invariants and theorems are introduced to express system properties submitted to the proof system associated with Event-B. While Event-B has proven its efficiency for the proof of this type of property, it does not offer powerful means allowing the explicit description of properties other than safety and specific forms of reachability. Checking other properties such as deadlock-freeness, liveness, or event scheduling requires ad hoc modeling techniques and external tools such as model checkers or other proof systems. This article presents <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">EB4EB</i> , a new modeling framework offering the capability to introduce formally defined Event-B extensions, in particular new proof obligations corresponding to new properties. It is based on metamodeling techniques. It includes a theory (a metatheory) modeling Event-B and offers means for explicit manipulation of Event-B features and an extension mechanism to explicitly formalize and prove other properties. This reflexive framework relies on a trace-based semantics of Event-B and introduces a set of Event-B theories defining data types, operators, well-defined conditions, theorems, and proof rules to define Event-B constructs and their semantics. Deep and shallow instantiation mechanisms are set up to instantiate the obtained metatheory. The EB4EB framework and its instantiation mechanisms are developed in Event-B using the Rodin platform ensuring correctness and internal consistency of the defined theories. Lamport's clock example, instantiating EB4EB in both shallow and deep mechanisms, is used to evaluate the proposed approach.

High gain interleaved boost-derived DC-DC converters – A review on structural variations, gain extension mechanisms and applications

Boost and boost-derived converters play an important role in interfacing the low voltage input from renewable energy sources like photovoltaic (PV) panels with the high voltage DC bus or DC load. Interleaved boost converters (IBC) are a separate class of converters which have been in practical use for more than a decade. In this paper, high gain interleaved boost DC-DC converters are reviewed. Some gain extension mechanisms which are usually embedded along with the IBC structure are discussed. Such high gain converters are categorized based on their adopted gain extension mechanism. Further, the performance of the converters which employ hybrid combinations of few gain extension cells are also reviewed. The voltage gain capability, advantages, disadvantages, number of components employed and other salient features of all such interleaved high gain DC-DC converters are reviewed in detail. The review outcomes are portrayed using tables and images. Based on the voltage gain requirements, power level and efficiency of the target applications, the user may choose to adopt more than one gain extension technique.

Graphical Specification of Sensitive Business Processes

This paper aims at developing a new BPMN extension, called “BPMN4SBP”, supporting the multi-dimensional modeling of Sensitive Business Processes (SBPs) (i.e., the knowledge, functional, organizational, behavioral, informational and intentional dimensions). It aims to explicitly integrate all the relevant issues and aspects relevant at the coupling of the business process modeling (BPM) domain and the knowledge management (KM) domain for improving the identification and management of crucial knowledge which are mobilized and created by these processes. This paper provides the analysis of requirements and relevant concepts for modeling SBP. Based on a core domain ontology, need for extension is identified and the valid BPMN4SBP extension is designed (according to the BPMN extension mechanism) by the construction of a conceptional domain model and the corresponding BPMN extension model. This extended BPMN4SBP meta-model is derived by applying model transformation rules and by adapting, also, the UML profile mechanism to BPMN. The applicability of the proposed BPMN extension is demonstrated by modeling an SBP in a real case study in the healthcare domain.

Molecular Mechanisms of Genotype-Dependent Lifespan Variation Mediated by Caloric Restriction: Insight from Wild Yeast Isolates.

Caloric restriction (CR) is known to extend lifespan across different species and holds great promise for preventing human age-onset pathologies. However, two major challenges exist. First, despite extensive research, the mechanisms of lifespan extension in response to CR remain elusive. Second, genetic differences causing variations in response to CR and genetic factors contributing to variability of CR response on lifespan are largely unknown. Here, we took advantage of natural genetic variation across 46 diploid wild yeast isolates of Saccharomyces species and the lifespan variation under CR conditions to uncover the molecular factors associated with CR response types. We identified genes and metabolic pathways differentially regulated in CR-responsive versus non-responsive strains. Our analysis revealed that altered mitochondrial function and activation of GCN4-mediated environmental stress response are inevitably linked to lifespan variation in response to CR and a unique mitochondrial metabolite might be utilized as a predictive marker for CR response rate. In sum, our data suggests that the effects of CR on longevity may not be universal, even among the closely related species or strains of a single species. Since mitochondrial-mediated signaling pathways are evolutionarily conserved, the dissection of related genetic pathways will be relevant to understanding the mechanism by which CR elicits its longevity effect.

Semi-TSGAN: Semi-Supervised Learning for Highlight Removal Based on Teacher-Student Generative Adversarial Network.

Despite recent notable advancements in highlight image restoration techniques, the dearth of annotated data and the lightweight deployment of highlight removal networks pose significant impediments to further advancements in the field. In this paper, to the best of our knowledge, we first propose a semi-supervised learning paradigm for highlight removal, merging the fusion version of a teacher-student model and a generative adversarial network, featuring a lightweight network architecture. Initially, we establish a dependable repository to house optimal predictions as pseudo ground truth through empirical analyses guided by the most reliable No-Reference Image Quality Assessment (NR-IQA) method. This method serves to assess rigorously the quality of model predictions. Subsequently, addressing concerns regarding confirmation bias, we integrate contrastive regularization into the framework to curtail the risk of overfitting on inaccurate labels. Finally, we introduce a comprehensive feature aggregation module and an extensive attention mechanism within the generative network, considering a balance between network performance and computational efficiency. Our experimental evaluations encompass comprehensive assessments on both full-reference and non-reference highlight benchmarks. The results demonstrate conclusively the substantive quantitative and qualitative enhancements achieved by our proposed algorithm in comparison to state-of-the-art methodologies.

Constraints on the emergence of RNA through non-templated primer extension with mixtures of potentially prebiotic nucleotides.

The emergence of RNA on the early Earth is likely to have been influenced by chemical and physical processes that acted to filter out various alternative nucleic acids. For example, UV photostability is thought to have favored the survival of the canonical nucleotides. In a recent proposal for the prebiotic synthesis of the building blocks of RNA, ribonucleotides share a common pathway with arabino- and threo-nucleotides. We have therefore investigated non-templated primer extension with 2-aminoimidazole-activated forms of these alternative nucleotides to see if the synthesis of the first oligonucleotides might have been biased in favor of RNA. We show that non-templated primer extension occurs predominantly through 5'-5' imidazolium-bridged dinucleotides, echoing the mechanism of template-directed primer extension. Ribo- and arabino-nucleotides exhibited comparable rates and yields of non-templated primer extension, whereas threo-nucleotides showed lower reactivity. Competition experiments confirmed the bias against the incorporation of threo-nucleotides. The incorporation of an arabino-nucleotide at the end of the primer acts as a chain terminator and blocks subsequent extension. These biases, coupled with potentially selective prebiotic synthesis, and the templated copying that is known to favour the incorporation of ribonucleotides, provide a plausible model for the effective exclusion of arabino- and threo-nucleotides from primordial oligonucleotides.

Crack detection and damage evaluation of asymmetrical steel-reinforced concrete frame nodes using acoustic emission technology

ABSTRACT Detecting cracks in steel-reinforced concrete (SRC) frame nodes is crucial for ensuring structural safety. This study employs acoustic emission (AE) technology to monitor the growth of concrete structural defects in real time. The aim is to establish a sensitive assessment method based on AE parameters to accurately assess the damage stages of SRC frame nodes by considering the complex crack extension mechanism in SRC structures. An experimental study of the AE characteristics of SRC frame nodes under low-cycle loading was performed. The crack evolution process of SRC frame nodes was monitored and analysed using the AE parameters. The results showed that ringing count is the AE parameter more sensitive to the damage of the SRC frame node. The damage evaluation method was established based on the variation coefficient analysis of the AE parameters. Considering the sudden change in the growth rate of the damage index, the damage evolution process of the SRC frame nodes can be accurately divided into three stages: initial crack compaction, rapid crack expansion, and crack penetration. These stages are consistent with the mechanical properties of SRC frame nodes.

Analysis of thermal damage formation and extension mechanism in CFRP short pulse laser cutting based on an inhomogeneous mesoscopic ablation model

Analysis of thermal damage formation and extension mechanism in CFRP short pulse laser cutting based on an inhomogeneous mesoscopic ablation model

A Unified SoS and System Architecture Modeling Approach Based on Language Transformation and Extension Mechanisms

UAFML or UPDM is the language for modeling System of System(SoS) architecture. While SysML is used to model system architecture with solid connections with requirements, multidisciplinary analysis, software development, verification, etc. Many companies export the SoS architecture model into an XMI file or even a Word document to the system-architecture-level design team to perform further development. It will cost more time and may cause information inconsistency in practice. To bridge the gap, studying a more economical way to perform the modeling information exchange is necessary. This paper studied architecture modeling language building and transformation mechanisms and proposed a unified SoSE and SE modeling approach, which will make the most of the architecture model, guarantee the different architecture level model consistency and save cost.

Polarised cell intercalation during Drosophila axis extension is robust to an orthogonal pull by the invaginating mesoderm.

As tissues grow and change shape during animal development, they physically pull and push on each other, and these mechanical interactions can be important for morphogenesis. During Drosophila gastrulation, mesoderm invagination temporally overlaps with the convergence and extension of the ectodermal germband; the latter is caused primarily by Myosin II-driven polarised cell intercalation. Here, we investigate the impact of mesoderm invagination on ectoderm extension, examining possible mechanical and mechanotransductive effects on Myosin II recruitment and polarised cell intercalation. We find that the germband ectoderm is deformed by the mesoderm pulling in the orthogonal direction to germband extension (GBE), showing mechanical coupling between these tissues. However, we do not find a significant change in Myosin II planar polarisation in response to mesoderm invagination, nor in the rate of junction shrinkage leading to neighbour exchange events. We conclude that the main cellular mechanism of axis extension, polarised cell intercalation, is robust to the mesoderm invagination pull. We find, however, that mesoderm invagination slows down the rate of anterior-posterior cell elongation that contributes to axis extension, counteracting the tension from the endoderm invagination, which pulls along the direction of GBE.