Analysis Code Research Articles

Chemical Bonding in Large Systems Using Projected Population Analysis from Real-Space Density Functional Theory Calculations.

We present an efficient and scalable computational approach for conducting projected population analysis from real-space finite-element (FE)-based Kohn-Sham density functional theory calculations (DFT-FE). This work provides an important direction toward extracting chemical bonding information from large-scale DFT calculations on materials systems involving thousands of atoms while accommodating periodic, semiperiodic, or fully nonperiodic boundary conditions. Toward this, we derive the relevant mathematical expressions and develop efficient numerical implementation procedures that are scalable on multinode CPU architectures to compute the projected overlap and Hamilton populations. The population analysis is accomplished by projecting either the self-consistently converged FE discretized Kohn-Sham orbitals or the FE discretized Hamiltonian onto a subspace spanned by a localized atom-centered basis set. The proposed methods are implemented in a unified framework within the DFT-FE code where the ground-state DFT calculations and the population analysis are performed on the same FE grid. We further benchmark the accuracy and performance of this approach on representative material systems involving periodic and nonperiodic DFT calculations with LOBSTER, a widely used projected population analysis code. Finally, we discuss a case study demonstrating the advantages of our scalable approach to extract the quantitative chemical bonding information of hydrogen chemisorbed in large silicon nanoparticles alloyed with carbon, a candidate material for hydrogen storage.

Calculation of boron concentration dependent reactivity versus moderator density curve with application on ATWS analysis for Maanshan PWR plant

A method used for determining the moderator density coefficient (MDC) based on the effective multiplication factor (keff) calculated from the SIMULATE-3 code is developed in this study. The calculation is performed at various water density and boron conditions for Maanshan unit 1 cycle 27. The calculated MDC data are fitted as a second-order polynomial function of density, modified with a factor of linear function of boron concentration. The fitted equation is then integrated and normalized to zero at rated density to represent the reactivity as a function of moderator density and boron concentration. A reactivity vs. density table under different boron concentrations can then be generated based on this function. The table generated is used as an input for the ATWS analysis to be performed using the RETRAN-02 thermal–hydraulic analysis code. As an illustration, a table based on a boron concentration of 1500 ppm is generated and used as an input for the analysis of the potential limiting ATWS case, i.e., Loss of Normal Feedwater Flow Event. The ASME emergency level limit of reactor coolant system pressure less than 220.63 bar is used as the acceptance criterion for the current ATWS analysis. It is known that the critical boron concentration at hot full power for each operating fuel cycle varies with the burnup through the cycle. Hence, the calculated ATWS results at different boron concentrations are equivalent to that calculated at different cycle burnup conditions. The cycle burnup point after which the calculated ATWS maximum is within the ASME limit can be determined based on the sensitivity analyses considering different boron concentrations.

An approach for an extension of the deflagration model in containment code system COCOSYS to separate burned and unburned atmosphere via junctions

Abstract In case of a postulated severe accident in a water-cooled nuclear power plant significant amounts of hydrogen (H2) and carbon monoxide (CO) can be generated and released into the containment or reactor building where it might form a combustible mixture with air assuming passive autocatalytic recombiners are not available. In case of ignition, pressure peaks might occur, that are relevant for the integrity of safety relevant equipment and the containment or reactor building. It is therefore important for safety analysis to be able to correctly predict combustion phenomena that might occur. The accident analysis code AC2 2021.0 which is developed by Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) includes the Containment Code System (COCOSYS version 3.1) for the simulation of containment phenomena. COCOSYS contains the model FRONT for the simulation of premixed deflagration of H2 and CO. Recent code validation using H2 deflagration tests conducted in the multi-compartment THAI+ test facility shows that the flame propagation stops prematurely in simulations of some tests. This is partly attributed to the missing separation of burned and unburned atmosphere which leads to a reduction in fuel concentration in not yet burning zones connected to a burning zone. Model improvement potential was identified which is addressed in this paper. A model extension to separate burned and unburned atmosphere via a junction model is proposed and implemented into a development version of COCOSYS 3.1. First validation results using the THAI test HD-39 are discussed that show improved prediction capability by the extended model.

Development of a synchronous recording and photo-stimulating electrode in multiple brain neurons.

The investigation of brain networks and neural circuits involves the crucial aspects of observing and modulating neurophysiological activity. Recently, opto-electrodes have emerged as an efficient tool for electrophysiological recording and optogenetic stimulation, which has greatly facilitated the analysis of neural coding. However, implantation and electrode weight control have posed significant challenges in achieving long-term and multi-regional brain recording and stimulation. To address this issue, we have developed a mold and custom-printed circuit board-based opto-electrode. We report successful opto-electrode placement and high-quality electrophysiological recordings from the default mode network (DMN) of the mouse brain. This novel opto-electrode facilitates synchronous recording and stimulation in multiple brain regions and holds promise for advancing future research on neural circuits and networks.

Implementing a Digital Depression Prevention Program in Australian Secondary Schools: Cross-Sectional Qualitative Study

Background Depression is common during adolescence and is associated with adverse educational, employment, and health outcomes in later life. Digital programs are increasingly being implemented in schools to improve and protect adolescent mental health. Although digital depression prevention programs can be effective, there is limited knowledge about how contextual factors influence real-world delivery at scale in schools. Objective The purpose of this study was to examine the contextual factors that influence the implementation of the Future Proofing Program (FPP) from the perspectives of school staff. The FPP is a 2-arm hybrid type 1 effectiveness-implementation trial evaluating whether depression can be prevented at scale in schools, using an evidence-based smartphone app delivered universally to year 8 students (13-14 years of age). Methods Qualitative interviews were conducted with 23 staff from 20 schools in New South Wales, Australia, who assisted with the implementation of the FPP. The interviews were guided by our theory-driven logic model. Reflexive thematic analysis, using both deductive and inductive coding, was used to analyze responses. Results Staff perceived the FPP as a novel (“innovative approach”) and appropriate way to address an unmet need within schools (“right place at the right time”). Active leadership and counselor involvement were critical for planning and engaging; teamwork, communication, and staff capacity were critical for execution (“ways of working within schools”). Low student engagement and staffing availability were identified as barriers for future adoption and implementation by schools (“reflecting on past experiences”). Conclusions Four superordinate themes pertaining to the program, implementation processes, and implementation barriers were identified from qualitative responses by school staff. On the basis of our findings, we proposed a select set of recommendations for future implementation of digital prevention programs delivered at scale in schools. These recommendations were designed to facilitate an organizational change and help staff to implement digital mental health programs within their schools. International Registered Report Identifier (IRRID) RR2-10.1136/bmjopen-2020-042133

Digital transformation of post-pandemic learning and teaching: Utilising TPACK to support educator development in a flipped learning pilot

As higher education looks to continue on its path of digital transformation to support pedagogical approaches such as online and blended learning, lessons must be taken from the emergency distance learning response, during Covid-19, and steps implemented to move towards a more thoughtfully designed strategic approach to digital education.This case study examines an Australian university’s global campus in the United Arab Emirates, a traditionally teacher-led institution, that aims to address ‘what’ post-pandemic education will look like by articulating an approach to the digital transformation of learning and teaching, specifically related to educator professional development. The specific focus of this research considers the ‘how’ by proposing a Technological, Pedagogical and Content Knowledge (TPACK) framework to guide the learning design of a faculty training pilot that supports educators in the development and implementation of a specific pedagogical model, namely flipped learning. The TPACK framework was used to inform the design of the flipped learning faculty training pilot and was used in the analysis coding of participants’ feedback to determine what domains of knowledge were touched and what domains require further attention.The study found that the TPACK framework can be a useful learning design tool for the development of faculty training programs that look to digitally transform learning and teaching, however, while the framework prompts explicit consideration of pedagogical and technological knowledge development, it can be found lacking in the fostering of community elements for a more impactful approach. The author believes this study will provide valuable insight for researchers and policymakers concerned with the digital transformation of learning and teaching in the post-pandemic higher educational landscape, specifically those interested in the development of teaching practice for blended learning approaches.Keywords: digital transformation; higher education; professional development; educator competencies; blended learning; flipped learning; TPACK; learning designPart of the Special Issue Teaching practices in times of digital transformation <https://doi.org/10.21428/8c225f6e.ac86609b>

Verification and validation (V&V) for fast reactor system analysis code FASYS

The fast reactor system analysis code FASYS is developed by CIAE for transient accident analysis in CEFR. By referring to the application scope of FASYS, the basic requirements of FASYS and PIRT in CEFR are established. A comprehensive verification and validation for the accuracy of FASYS is performed, which consist of bottom-up assessment, top-down assessment and uncertainty assessment. The bottom-up assessment applies the static analysis and dynamic analysis to verify the basic function of FASYS. The separate effect tests and integral effect tests are employed in the top-down assessment to validate the availability to simulate model and system. The calculated results confirms that the basic function and model in FASYS are reasonable and credible. The uncertainty assessment results show that FASYS can still calculate IET under the reasonable uncertainty of input parameters, indicating that the FASYS can simulate and analyze the transient accident processes of sodium-cooled fast reactor.

A novel method for calculating annular fuel cell resonance effective temperature

Annular fuels can increase the power density of reactors because of their double-sided cooling design, which is of great significance to the miniaturization and long-life operation of pressurized water reactors. In this study, a thermal–hydraulic analysis code named Thermal-Hydraulic Code of Annular Fuel with Single channel (THCAFS) was developed for annular fuels, and a calculation model for the resonance effective temperature of annular fuel cells was established. An annular fuel cell of a four-loop pressurized water reactor (PWR) designed by Westinghouse company was used as the calculation object, and the numerical results of THCAFS were compared with those of existing sub-channel codes such as VIPRE-01, TAFAX, and NACAF. Meanwhile, the Monte Carlo code RMC was used to simulate the radial power distribution and burnup process of the annular fuel, and its thermodynamic behavior was simulated using the self-developed code THCAFS. The radial power distribution, nuclide density variation, and cell temperature field under different burnup levels were also obtained, and the reaction rate equivalence was used instead of the effective resonance integral to investigate the calculation method used for resonance effective temperature of the annular fuel cell. The results show that THCAFS can be preliminarily applied to annular fuel designs and thermal–hydraulic analysis, while the effective temperature calculation method can provide important reference values for studying the resonance effective temperature of annular fuels.

Design feasibility and failure mode analysis for a HALEU-based Kilopower-class space power reactor

A space fission reactor that will be used on the lunar base in the future, must meet the requirements for a 10 years prolonged power supply depending upon only its inherent response characteristics. Therefore an analysis tool to optimize the design conditions as well as to predict the reactor behavior for self-regulating performance during the mission period is needed. For this purpose, the Lumped Network Analysis and Simulation (LuNAS) code has been developed for a kW-class space fission power reactor. We performed failure mode analyses for a 5 kW HALEU-fueled reactor combined with Stirling converters, heat pipes and a radiator panel, which demonstrated that more than half-power can be guaranteed up to 50% failure of each component.

Application of SCALE code for reactor physics analysis of the as-built Nigeria miniature neutron source reactor operating with low enriched uranium fuel

This study presents a broad reactor physics analysis including, neutronic, burnup, and decay heat of the ‘as-built’ NIRR-1 LEU core performed using SCALE 6.2.3 code package. First, verification of neutronic parameters of the NIRR-1 was performed by modeling the reactor ‘as-built’ LEU core. Thereafter validation of the model was done by comparing calculated result with measured data during the commissioning of the reactor. The results showed that the estimated neutronic parameters using KENO-VI code of SCALE 6.2.3 code package are in close agreement with the measured data. Hence, KENO-VI can be used for detailed neutronic assessment of MNSRs. The total decay heat at the end of core life after operation for 216 EFPD was estimated to be 1620.15 W and was majorly due to the contribution from fission products which was estimated to be 1608.10 W. This value explains why MNSRs are cooled through natural convection of the coolant during operation and at shutdown conditions. Additionally, the burnup of the core was determined to be 0.53 wt% which is within the expected burnup for a typical MNSRs (less than1 wt%) with a core lifetime of about 200 EFPD (∼10 years). Furthermore, the mass of 239Pu buildup after 216 EFPD was far less than the IAEA category III nuclear material and indicates a huge advantage of research reactor conversion in reducing proliferation risk.

Responsible research practices could be more strongly endorsed by Australian university codes of research conduct

BackgroundThis study aimed to investigate how strongly Australian university codes of research conduct endorse responsible research practices.MethodsCodes of research conduct from 25 Australian universities active in health and medical research were obtained from public websites, and audited against 19 questions to assess how strongly they (1) defined research integrity, research quality, and research misconduct, (2) required research to be approved by an appropriate ethics committee, (3) endorsed 9 responsible research practices, and (4) discouraged 5 questionable research practices.ResultsOverall, a median of 10 (IQR 9 to 12) of 19 practices covered in the questions were mentioned, weakly endorsed, or strongly endorsed. Five to 8 of 9 responsible research practices were mentioned, weakly, or strongly endorsed, and 3 questionable research practices were discouraged. Results are stratified by Group of Eight (n = 8) and other (n = 17) universities. Specifically, (1) 6 (75%) Group of Eight and 11 (65%) other codes of research conduct defined research integrity, 4 (50%) and 8 (47%) defined research quality, and 7 (88%) and 16 (94%) defined research misconduct. (2) All codes required ethics approval for human and animal research. (3) All codes required conflicts of interest to be declared, but there was variability in how strongly other research practices were endorsed. The most commonly endorsed practices were ensuring researcher training in research integrity [8 (100%) and 16 (94%)] and making study data publicly available [6 (75%) and 12 (71%)]. The least commonly endorsed practices were making analysis code publicly available [0 (0%) and 0 (0%)] and registering analysis protocols [0 (0%) and 1 (6%)]. (4) Most codes discouraged fabricating data [5 (63%) and 15 (88%)], selectively deleting or modifying data [5 (63%) and 15 (88%)], and selective reporting of results [3 (38%) and 15 (88%)]. No codes discouraged p-hacking or hypothesising after results are known.ConclusionsResponsible research practices could be more strongly endorsed by Australian university codes of research conduct. Our findings may not be generalisable to smaller universities, or those not active in health and medical research.

Multiphysics analysis of heat pipe cooled microreactor core with adjusted heat sink temperature for thermal stress reduction using OpenFOAM coupled with neutronics and heat pipe code

Heat-pipe-cooled microreactors (HPRs) have advantages such as a compact design, easy transportation, and improved system reliability and stability. The core of an HPR consists of fuel rods and heat pipes in a monolith, which is a solid block structure containing many holes for the fuel rods and heat pipes. When designing the core of an HPR, high thermal stress and reactivity feedback owing to thermal expansion are important considerations. Therefore, a high-fidelity multiphysics analysis tool is required for accurately analyzing an HPR core. When performing a multiphysics analysis, it is necessary to couple the heat pipe thermal analysis code, thermal-structural analysis code, and neutronics code. To develop a multiphysics analysis tool, OpenFOAM, an open source Computational Fluid Dynamics (CFD) tool, and ANLHTP, a heat pipe thermal analysis code, were coupled. In this process, the structural analysis solver of OpenFOAM was verified, and its limitations were improved. To confirm the proper working of the code, the mini-core problem was analyzed using the OpenFOAM-ANLHTP coupled code. Next, to consider the reactivity feedback, coupling with PRAGMA, a GPU-based continuous-energy-Monte Carlo neutronics code was performed, and the multiphysics analysis capability of the OpenFOAM-ANLHTP-PRAGMA coupled code was confirmed through an analysis of the MegaPower reactor core. To reduce the temperature distribution within the monolith, the temperature distribution of the heat pipe sink was adjusted, and the reduced thermal stress of an HPR core was observed.

MATTE: a pipeline of transcriptome module alignment for anti-noise phenotype-gene-related analysis.

A phenotype may be associated with multiple genes that interact with each other in the form of a gene module or network. How to identify these relationships is one important aspect of comparative transcriptomics. However, it is still a challenge to align gene modules associated with different phenotypes. Although several studies attempted to address this issue in different aspects, a general framework is still needed. In this study, we introduce Module Alignment of TranscripTomE (MATTE), a novel approach to analyze transcriptomics data and identify differences in a modular manner. MATTE assumes that gene interactions modulate a phenotype and models phenotype differences as gene location changes. Specifically, we first represented genes by a relative differential expression to reduce the influence of noise in omics data. Meanwhile, clustering and aligning are combined to depict gene differences in a modular way robustly. The results show that MATTE outperformed state-of-the-art methods in identifying differentially expressed genes under noise in gene expression. In particular, MATTE could also deal with single-cell ribonucleic acid-seq data to extract the best cell-type marker genes compared to other methods. Additionally, we demonstrate how MATTE supports the discovery of biologically significant genes and modules, and facilitates downstream analyses to gain insight into breast cancer. The source code of MATTE and case analysis are available at https://github.com/zjupgx/MATTE.

High-throughput approaches to uncover synergistic drug combinations in leukemia.

We report a comprehensive drug synergy study in acute myeloid leukemia (AML). In this work, we investigate a panel of cell lines spanning both MLL-rearranged and non-rearranged subtypes. The work comprises a resource for the community, with many synergistic drug combinations that could not have been predicted a priori, and open source code for automation and analyses. We base our definitions of drug synergy on the Chou-Talalay method, which is useful for visualizations of synergy experiments in isobolograms, and median-effects plots, among other representations. Our key findings include drug synergies affecting the chromatin state, specifically in the context of regulation of the modification state of histone H3 lysine-27. We report open source high throughput methodology such that multidimensional drug screening can be accomplished with equipment that is accessible to most laboratories. This study will enable preclinical investigation of new drug combinations in a lethal blood cancer, with data analysis and automation workflows freely available to the community.

TRNA-derived fragments (tRFs) as regulators of oncogenes and tumor suppressor genes in head and neck squamous cell carcinoma.

e18082 Background: Roughly 50,000 individuals are diagnosed with head and neck cancers in the United States yearly. Though risk factors and common therapeutic strategies are well-established, early detection of head and neck cancers remains challenging. One strategy for early detection is high-throughput analysis of both coding and noncoding RNA transcripts, which has become increasing implicated in cancer pathogenesis. One such noncoding transcript is tRNA-derived fragments (tRFs), which are the products of enzymatic cleavage of precursor tRNAs. Though tRFs have been suggested to play important roles in the regulation of mRNA translation (similar to other noncoding RNAs), their utility as cancer biomarkers is not well-known. Methods: In this study, we investigate tRFs for correlation to cancer prevalence with specific consideration of translational regulation of oncogenes (OG) and tumor suppressor genes (TSG). tRF read counts were obtained for 499 head and neck squamous cell carcinoma tumor tissue samples and 44 adjacent normal samples. Results: The read counts between both groups were compared to identify tRFs dysregulated in tumor samples, which may be pertinent biomarkers for diagnosis. Ten tRFs were found to be significantly dysregulated in cancer samples. These tRFs were further assessed for correlation to expression of OGs and TSGs using the COSMIC database. Due to the mRNA-degrading nature of tRFs, we analyzed tRF abundance for inverse correlation to gene expression. Four tRFs upregulated in tumor samples showed significant anticorrelation to select TSG expression (ATP2B3, CSMD3, LZTR1, NTHL1, PTPRC), and three tRFs downregulated in tumor samples showed anticorrelation to OG expression (A1CF, MPL, SALL4, TNC). Notably, LeuCAG 5’ tRF was associate with high binding affinity for the TSGs CSMD3 and LZTR1, supporting the likelihood of tRF-mediated degradation. Interestingly, this tRF was inversely correlated with patient survival length. LeuCAG 5’ was also of significantly lesser abundance in patients who experienced complete or partial remission following chemotherapy treatment, further indicating this tRFs’ clinical relevance in HNSCC, potentially as an oncogenic-related agent. Conclusions: Investigation into these tRFs may reveal their potential for use in early diagnosis. High abundance of this tRF may be indicative of oncogenesis. In exploring tRFs’ for their potential as biomarkers of cancer, they may prove useful in allowing earlier diagnosis. Moreover, studying tRFs may provide additional considerations for patient care and treatment.

Experimental and Analytical Codes Comparative Study for Enhanced BFRP R.C. Columns Under Different Types of Loading

Experimental and Analytical Codes Comparative Study for Enhanced BFRP R.C. Columns Under Different Types of Loading

Analisis Perbandingan Sistem Persinyalan Konvensional Dengan CBTC Terhadap Headway Kereta Api

KRL Commuter Line and MRT Jakarta, serving urban population mobility with high transport capacity. The development of urban rail signaling, making the choice of signaling system application to headway be competitive. However, it is necessary to choose the right one, so this research is carried out, with the aim of knowing the effect of the signaling system on headway urban railways, by comparing conventional and CBTC signaling systems. This research method is quantitative and qualitative, using primary data from observation at MRT Jakarta, Gapeka KRLCommuter Line and Time Table MRT Jakarta, interviews with experts and passenger through techniques purposive sampling and based analysis coding. The results of research that CBTC uses moving block, make headway more stable. Headway Jakarta MRT 3 minutes, with 99.98% time liness and better than KRL Commuter Line. Factor affecting headway urban trains, namely crossing gates, number of facilities, length of traffic, number of stopping stations, dwelling time, signaling systems, and personnel.

Study on the deposition migration and heat transfer characteristics in the reactor core based on OpenFOAM

Corrosion deposition in heat exchangers may lead to a reduction in heat transfer efficiency, and even can affect equipment operational safety. Traditional CFD deposition heat transfer analysis methods are limited by model size, making it difficult to obtain global, long-term deposition heat transfer characteristics for complex heat exchange equipment. In this paper, a corrosion product deposition prediction and heat transfer model based on sub-channel analysis is proposed. By integrating it into the nuclear reactor core thermal–hydraulic characteristics analysis code CorTAF, which is developed on the OpenFOAM platform, the corrosion deposition and heat transfer calculation for the entire reactor is achieved. A numerical simulation of the deposition and heat transfer of the AP1000 reactor core during a 300-day operation is conducted. The calculation results clearly show the distribution of corrosion products in the reactor core and the temperature changes of the fuel cladding with the deposition days: the maximum deposition thickness on the core cladding surface is 38.3 μm, and the highest temperature increase is 11.0 K. The deposition and cladding temperature rise distribution is not linear with operation time but is closely related to the core power distribution. The modeling method successfully obtains the corrosion deposition and heat transfer characteristics of the entire reactor core, and has potential implications for the prediction of corrosion deposition distribution and thermal effect calculations in other large-scale heat exchange equipment.

A comparison between two kinetic models for the pyrolysis and gasification of woody wastes under a carbon dioxide atmosphere

A pine forest residue, a pine wood industrial waste and their mixture were pyrolyzed and subsequently gasified under a carbon dioxide atmosphere up to 1000 °C in a thermal analysis system. Thermal decomposition parameters, such as reactivity, reaction rate and syngas yield, were determined and the influence of CaO catalyst was examined. Two kinetic models, independent parallel reactions model (IPR) and distributed activation energy model (DAEM), were developed in Matlab® code for the kinetic analysis of the processes. Three first order reactions were found to accurately describe the pyrolysis process by both models, with deviation values between 1.3 % and 2.9 %. Activation energy values varied between 26 kJ/mol and 201 kJ/mol. One pseudo-component was necessary to describe successfully the gasification process by application of both models, with deviation values 2.4–6.5 %. Activation energy values ranged between 192 kJ/mol and 345 kJ.mol. The IPR model was found to be more practical to employ.

Gender and Sexual Health-Related Knowledge Gaps and Educational Needs of Parents of Transgender and Non-Binary Youth

Parents can have a substantial impact on adolescent sexual decision-making, but few studies have explored the role of parents in providing sexual health information to transgender and non-binary (TNB) youth, a population that experiences significant sexual and mental health disparities and lower levels of perceived family support compared with other youth. This study aimed to elucidate existing knowledge gaps and content deemed important for a sexual health curriculum and educational materials for parents of TNB youth. We conducted 21 qualitative interviews with five parents of TNB youth, 11 TNB youth aged 18+, and five healthcare affiliates to identify parents’ educational needs. We analyzed the data using theoretical thematic analysis and consensus coding. Parents self-reported multiple knowledge deficits regarding gender/sexual health for TNB individuals and were primarily concerned with long-term impacts of medical interventions. Youth goals for parents included greater understanding of gender/sexuality and sufficient knowledge to support youth through social transition to their affirmed gender identity. Content areas suggested for a future curriculum for parents of TNB youth included: basics of gender/sexuality, diverse narratives of TNB experiences/identities, gender dysphoria, non-medical gender-affirming interventions, medical gender-affirming interventions, and resources for peer support. Parents desired access to accurate information and wanted to feel equipped to facilitate affirming conversations with their child, something that could combat health disparities among TNB youth. An educational curriculum for parents has the potential to provide a trusted information source, expose parents to positive representations of TNB individuals, and help parents support their TNB child through decisions about potential gender-affirming interventions.