Simple Systems Research Articles

A Geometric Interpretation of Kinetic Zone Diagrams in Electrochemistry.

Electrochemical systems with increasing complexity are gaining importance in catalytic energy conversion applications. Due to the interplay between transport phenomena and chemical kinetics, predicting optimization is a challenge, with numerous parameters controlling the overall performance. Zone diagrams provide a way to identify specific kinetic regimes and track how variations in the governing parameters translate the system between either adverse or optimal kinetic states. However, the current procedures for constructing zone diagrams are restricted to simplified systems with a minimal number of governing parameters. We present a computationally based method that maps the entire parameter space of multidimensional electrochemical systems and automatically identifies kinetic regimes. Once the current output over a discrete set of parameters is interpreted as a geometric surface, its geometry encodes all of the information needed to construct a zone diagram. Zone boundaries and limiting zones are defined by curved and flat regions, respectively. This geometric framework enables a systematic exploration of the parameter space, which is not readily accessible by analytical or direct numerical methods. This will become increasingly valuable for the rational design of electrochemical systems with intrinsically high complexity.

H Induced Metal-Insulation Transition Boosts the Stability of High Temperature Polymer Electrolyte Membrane Fuel Cells.

High temperature polymer electrolyte membrane fuel cells (HT-PEMFCs) have garnered significant attention due to their expanded range of hydrogen sources and simplified management systems. However, the frequent start-up and shut-down (SU/SD)caused fuel starvationoperation condition seriously deteriorates the performance and lifetime of the fuel cell.In this manuscript, VO2was incorporated in the anodeto restrain fuel starvationof the electrode. Under the operation condition, the insulative VO2would reversiblytransform into metallic HxVO2byintercalating hydrogen, and HxVO2can automatically release hydrogen,whichcouldact as the hydrogen bufferand suppress reverse-current degradation. After the hydrogen release, the generated insulating VO2would prevent theside reactions during fuel starvation.Comparedto the traditionalPt anode, the electrodewith VO2showed much higheroutput powerand greatly improved durability after fuel starvation. This work demonstrates the in-situreversible hydrogen storage/release-controlled metal-insulator phase transition strategy to enhance the durability of fuel cells.

H Induced Metal‐Insulation Transition Boosts the Stability of High Temperature Polymer Electrolyte Membrane Fuel Cells

High temperature polymer electrolyte membrane fuel cells (HT‐PEMFCs) have garnered significant attention due to their expanded range of hydrogen sources and simplified management systems. However, the frequent start‐up and shut‐down (SU/SD) caused fuel starvation operation condition seriously deteriorates the performance and lifetime of the fuel cell. In this manuscript, VO2 was incorporated in the anode to restrain fuel starvation of the electrode. Under the operation condition, the insulative VO2 would reversibly transform into metallic HxVO2 by intercalating hydrogen, and HxVO2 can automatically release hydrogen, which could act as the hydrogen buffer and suppress reverse‐current degradation. After the hydrogen release, the generated insulating VO2 would prevent the side reactions during fuel starvation. Compared to the traditional Pt anode, the electrode with VO2 showed much higher output power and greatly improved durability after fuel starvation. This work demonstrates the in‐situ reversible hydrogen storage/release‐controlled metal‐insulator phase transition strategy to enhance the durability of fuel cells.

Harnessing Simple Animal Models to Decode Sleep Mysteries.

Whether it involves human subjects or non-human animals, basic, translational, or clinical sleep research poses significant ethical challenges for researchers and ethical committees alike. Sleep research greatly benefits from using diverse animal models, each offering unique insights into sleep control mechanisms. The fruit fly (Drosophila melanogaster) is a superior genetic model due to its quick generation period, large progenies, and rich genetic tools. Its well-characterized genome and ability to respond to hypnotics and stimulants make it an effective tool for studying sleep genetics and physiological foundations. The nematode (Caenorhabditis elegans) has a simpler neural organization and transparent body, allowing researchers to explore molecular underpinnings of sleep control. Vertebrate models, like zebrafish (Danio rerio), provide insights into circadian rhythm regulation, memory consolidation, and drug effects on sleep. Invertebrate models, like California sea hare (Aplysia californica) and Upside-down jellyfish (Cassiopea xamachana), have simpler nervous systems and behave similarly to humans, allowing for the examination of sleep principles without logistical and ethical challenges. Combining vertebrate and invertebrate animal models offers a comprehensive approach to studying sleep, improving our understanding of sleep regulation and potentially leading to new drug discovery processes for sleep disorders and related illnesses.

Osmotic and phoretic competition explains chemotaxic assembly and sorting

Microscale objects responding to chemical gradients by migrating toward or away from a preferred species is a simple yet constitutive mechanism by which transport occurs in biological organisms. Synthetic chemotaxis provides key physical descriptions of simplified systems that can be used in biological models, or in the creation of advanced responsive material systems. In this article, we provide a quantitative framework for understanding synthetic chemotaxis of microparticles which involves a competition between phoresis and osmosis. We present separate quantitative measurements of phoresis and osmosis acting on individual taxing particles, finding that phoresis follows the long-predicted [Formula: see text] scaling while the osmotic contribution depends on the geometry and details of the system, and must be solved on a case-by-case basis. Through this, we are able to develop a more accurate picture of particle transport at the single particle level. Equipped with this approach, we go on to describe how high concentrations of particles in a symmetric chemical gradient grow close-packed hives that reach a steady-state size tunable through light intensity or particle size. Last, we demonstrate that mixed particles experiencing the same chemical gradient will selectively migrate toward or away depending on the nature of the particle surface, thereby locally sorting out a particular species. We anticipate these results will be important in describing both biological and synthetic chemotaxis in phoretic systems and should bring a wealth of studies that take advantage of competing osmotic flows to illicit unexpected dynamic active behavior.

Non-invasive detection of pesticide residues in freshly harvested olives using hyperspectral imaging technology

Pesticides play a crucial role in boosting the overall yield and productivity of agricultural produce by controlling pests, insects, and various plant diseases. However, excessive use of pesticides has led to contamination of food products and water bodies, as well as disruption of ecological and environmental systems. Global health authorities have set limits for pesticide residues in individual food items to ensure the availability of safe foods in the supply chain and to assist farmers in developing optimal agronomic practices for crop production. In Spain, specifically regarding olive cultivation, the Ministry of Agriculture, Fisheries, and Food establishes a safety period that farmers must observe from the application of the pesticide until the fruit is harvested. This period ensures that the batch of olives will comply with the maximum residue level allowed. This article proposes a methodology based on hyperspectral imaging to detect whether the olives have been sprayed with pesticide products and, if so, when the spraying occurred. The proposed methodology operates at the pixel level, where each pixel of the hyperspectral image is an instance. The pesticides evaluated were Diflufenican, Oxyfluorfen, Deltamethrin, λ-Cyhalothrin, and Tebuconazole. The results are promising and the success rates achieved over 80% accuracy for most pesticides in controlled laboratory conditions, with individual performance varying according to each pesticide's chemical properties and stability on the olive surface. While the results are promising, the scalability of this approach for larger and more diverse batches of olives requires validation under field conditions, where variations in environmental factors, olive variety, and ripeness may impact the detection accuracy. Furthermore, the study highlights key wavelengths around 750 nm and 550 nm as effective discriminators, suggesting potential for cost-effective, simplified imaging systems. Although hyperspectral imaging shows potential as an accessible, in-line monitoring solution for cooperative use, further analysis of implementation costs is recommended to confirm its feasibility on an industrial scale.

Overcoming nucleotide bias in the nonenzymatic copying of RNA templates.

The RNA World hypothesis posits that RNA was the molecule of both heredity and function during the emergence of life. This hypothesis implies that RNA templates can be copied, and ultimately replicated, without the catalytic aid of evolved enzymes. A major problem with nonenzymatic template-directed polymerization has been the very poor copying of sequences containing rA and rU. Here, we overcome that problem by using a prebiotically plausible mixture of RNA mononucleotides and random-sequence oligonucleotides, all activated by methyl isocyanide chemistry, that direct the uniform copying of arbitrary-sequence templates, including those harboring rA and rU. We further show that the use of this mixture in copying reactions suppresses copying errors while also generating a more uniform distribution of mismatches than observed for simpler systems. We find that oligonucleotide competition for template binding sites, oligonucleotide ligation and the template binding properties of reactant intermediates work together to reduce product sequence bias and errors. Finally, we show that iterative cycling of templated polymerization and activation chemistry improves the yields of random-sequence products. These results for random-sequence template copying are a significant advance in the pursuit of nonenzymatic RNA replication.

Characterization of Human Melanoma Skin Cancer Models: A step towards Model-Based Melanoma Research

Advancing 3D in vitro human tissue models is crucial for biomedical research and drug development to address the ethical and biological limitations of animal testing. Recently, 3D skin models have proven to be effective for studying serious skin conditions, such as melanoma. For these advanced models to be applicable in preclinical studies, thorough characterization is essential to understand their applicability and limitations.In this study, we used bioimaging and RNA sequencing to assess the architecture and transcriptomic profiles of skin models, including models with melanoma. Our results indicated that these models closely mimicked skin morphology and gene expression patterns. The full-thickness (FT) model shows a superior resemblance to the human skin, particularly in basement membrane formation and cellular interactions.The integrity of the skin-like properties and gene expression signatures of both skin and melanoma cells were preserved upon the integration of melanoma cells, establishing these models as robust platforms for cancer research. The responsiveness of the FT melanoma models to vemurafenib treatment was successfully monitored, demonstrating their validity as a reliable, reproducible, and humane tool for pharmacological testing and drug development. Furthermore, the transcriptomic data showed that skin models with cancer spheroids had upregulated genes linked to aggressive and resilient cancer behavior compared to spheroids alone. This emphasizes the importance of the microenvironment in cancer progression and suggests that 3D skin models can serve to uncover mechanisms and therapeutic targets that are not detectable in simpler systems. Statement of SignificanceThis study introduces advanced, ethically sound skin and melanoma models as alternatives to animal testing in drug discovery. By thoroughly characterizing these models using bioimaging and RNA sequencing, we demonstrate their close resemblance to human skin, particularly in full-thickness models. These models not only replicate the complex cellular interactions and gene expression patterns of human tissue but also maintain robustness after melanoma integration. Our findings highlight the potential of these models in revealing cancer mechanisms and therapeutic targets, offering a significant impact on melanoma research and preclinical testing.

Immunophenotyping myelodysplastic neoplasms: the role of flow cytometry in the molecular classification era.

The unique heterogenous landscape of myelodysplastic syndromes/neoplasms (MDS) has resulted in continuous redefinition of disease sub-entities, in view of the novel translational research data that have clarified several areas of the pathogenesis and the progression of the disease. The new international classifications (WHO 2022, ICC 2022) have incorporated genomic data defining phenotypical alterations, that guide clinical management of specific patient subgroups. On the other hand, for over a decade, multiparameter flow cytometry (MFC) has proven its value as a complementary diagnostic tool for these diseases and although it has never been established as a mandatory test for the baseline evaluation of MDS patients in international guidelines, it is almost universally adopted in everyday clinical practice for the assessment of suspected cytopenias through simplified scoring systems or elaborate analytical strategies for the detection of immunophenotypical dysplastic features in every hematopoietic cell lineage in the bone marrow (BM). In this review, we explore the clinically meaningful interplay of MFC data and genetic profiles of MDS patients, to reveal the currently existing and the potential future role of each methodology for routine clinical practice, and the benefit of the patients. We reviewed the existing knowledge and recent advances in the field and discuss how an integrated approach could lead to patient re-stratification and guide personalized management.

Solution of the problem with a small parameter in suspension filtration in a porous medium

Relevance. The necessity to calculate the changes in filtration properties during injection of suspensions for subsequent forecasting of technological parameters of wells. This calculation is complicated by the presence of different-scale effects, since the penetration depth of dispersed particles is orders of magnitude smaller than the characteristic dimensions of the formation. These effects have not been studied in detail before. Aim. To analyze the effect of a small parameter on the behavior of flow characteristics using a mathematical model of suspension filtration in a porous medium. Objects. Colmatation coefficient, filtration coefficient, distribution of concentration of dispersed particles in the formation, porosity, mathematical model of deep-bed suspension migration into a porous medium. Methods. Numerical modeling, explicit finite-difference scheme, solution of a problem with a small parameter, introduction of dimensionless parameters, method of characteristics. Results and conclusions. It is shown that the processes of conformance control and colmatation of a porous medium are described within the framework of a unified system of equations of deep-bed suspension migration into a porous medium. It is identified that the concentration of retained particles is a small parameter that allows reducing the complete system of equations of deep-bed suspension migration into a porous medium to a simplified form, in which the solution can be obtained analytically using the method of characteristics. The authors compared the solutions of the complete and simplified systems of equations of deep-bed suspension migration into a porous medium, indicating their compliance with an error of less than 4 %. They obtained the distributions of the concentration of dispersed particles and porosity in the reservoir during colmatation, showing that over time the colmatation front propagates at a constant rate. It is shown that the colmatation coefficient is a small parameter that significantly determines the nature of oil displacement by water, and a decrease in the colmatation coefficient leads to a decrease in the rate of colmatation and the appearance and growth of the size of the stabilized zone near the displacement front.

Performance Evaluation of Inerter and Negative Stiffness-Based Dampers for Seismic-Induced Vibration Response Control of a Cable-Stayed Bridge: A Comparative Study

The excessive main girder displacement responses of the large-span cable-stayed bridges during seismic events may precipitate collisions between the main girder and the approach bridge. The viscous dampers (VDs) have been extensively employed in the seismic response control of long-span bridges, yet their effectiveness is limited. To augment the seismic-induced vibration control performance of the VD, inerter element, negative stiffness (NS) element, and spring element have been incorporated into the VD to achieve energy dissipation capacity enhancement. The equations of motion for the simplified cable-stayed bridge-damper systems are established under stochastic seismic excitation, and the design parameters of inerter and NS-based damper are optimized by using the genetic algorithm. The seismic control performance of the VD and five types of dampers are systematically compared, demonstrating that these dampers can substantially enhance the main girder displacement mitigation performance in cable-stayed bridges. Owing to the NS characteristics attributes of the inerter element and NS element and the tuning effect of the spring element, the tuned viscous mass damper (TVMD) with NS achieves a 24.56% higher efficiency in control performance compared to the VD.

Characteristics of the legal status of an individual entrepreneur

The article examines the peculiarities of the legal status of an individual entrepreneur in the course of entrepreneurial activity. The relevance of the study lies in the fact that an individual entrepreneur is the most popular form of doing business in Ukraine due to a fairly simple registration procedure, low administration costs, and the possibility to use the simplified taxation system The purpose of the article is to determine the main characteristics of the legal status of an individual entrepreneur. The author examines the interpretation of the concept of an individual entrepreneur in the legal literature. The author establishes that the legal status of an individual entrepreneur is the legal status which certifies the right of a citizen to engage in entrepreneurial activity, in particular, independent, systematic, initiative, at his/her own risk economic activity carried out by an entrepreneur with a view to achieving certain economic and social results and making a profit. The author considers the main legal acts regulating the activities of individual entrepreneurs in Ukraine, in particular, the Constitution of Ukraine, the Civil Code of Ukraine, the Commercial Code of Ukraine, the Tax Code of Ukraine, the Law of Ukraine «On State Registration of Legal Entities, Individual Entrepreneurs and Public Organisations», decrees of the President of Ukraine, resolutions of the Verkhovna Rada of Ukraine, and resolutions of the Cabinet of Ministers of Ukraine. The author analyses the peculiarities of registration of individual entrepreneurs, their basic rights and obligations. The author identifies the peculiarities of taxation of activities of an individual entrepreneur, in particular, the peculiarities of the general and simplified taxation systems. The general taxation system provides for the payment of personal income tax on a progressive scale, as well as military duty and a single social contribution. The simplified taxation system is divided into several groups, each of which has its own restrictions on the amount of income and the number of employees. The most popular is the second group, which allows you to run a business without employees and with a limit on income up to a certain amount. The article briefly describes how the beginning of the full-scale invasion and martial law affected the activities of individual entrepreneurs.

Multiple Organ Dysfunction Syndrome in Malawian Children with Cerebral Malaria.

More than 1,000 children under 5 years of age die every day from malaria. Cerebral malaria (CM) is the most severe and deadly manifestation of the disease. The occurrence of multiple organ dysfunction syndrome (MODS) has been associated with increased mortality in adult patients with CM. However, little is known about the frequency and severity of MODS in children with CM. This was a retrospective study of 199 pediatric patients with CM admitted to a referral hospital in Blantyre, Malawi, between January 2019 and May 2023. Data were abstracted from charts to calculate scores using four established scoring systems: Pediatric Logistic Organ Dysfunction-2 (PELOD-2), Pediatric Sequential Organ Failure Assessment (pSOFA), Signs of Inflammation in Children that Can Kill (SICK), and Lambaréné Organ Dysfunction Score (LODS). Mortality was 16% (n = 32). All four scoring systems were predictive of mortality, but the PELOD-2 and pSOFA scores outperformed the others with area under the curve values of 0.75 and 0.67, respectively. Multiple organ dysfunction syndrome was diagnosed in 182 patients (91%) using the PELOD-2 score, 172 patients (86%) using the pSOFA score, 99 patients (50%) using the SICK score, and 30 patients (15%) using the LODS. The PELOD-2 and pSOFA identify MODS in children with CM but require laboratory-based testing that is often unavailable in malaria-endemic areas. Furthermore, these scoring systems may identify primary malarial disease pathology rather than true organ dysfunction. Simplified scoring systems designed to recognize and quantify MODS in this patient population may provide opportunities for improved resource allocation and timely, organ-specific treatment.

Improvement of the gait deviation index for spinal cord injury to broaden its applicability: the reduced gait deviation index for spinal cord injury (rSCI-GDI).

The SCI-GDI is an accurate and effective metric to summarize gait kinematics in adults with SCI. It is usually computed with the information registered with a photogrammetry system because it requires accurate information of pelvic and hip movement in the three anatomic planes, which is hard to record with simpler systems. Additionally, due to being developed from the GDI, the SCI-GDI is built upon nine joint movements selected for a pediatric population with cerebral palsy, for which the GDI was originally developed, but those nine movements are not necessarily as meaningful for adults with SCI. Nevertheless, pelvic movement and hip rotation have been proven to have low reliability even when acquired with gold-standard photogrammetry systems. Additionally, the use of photogrammetry is limited in real-life scenarios and when used with rehabilitation technologies, which limits the use of the SCI-GDI to evaluate gait in alternative scenarios to gait laboratories and to evaluate technologies for gait assistance. This research aimed to improve the SCI-GDI to broaden its applicability beyond the use of photogrammetry. An exploration of the mathematical relevance of each joint movement included in the original GDI for the performance of the metric is performed. Considering the results obtained and the clinical relevance of each of the 9 joints used to compute the SCI-GDI in the gait pattern of the SCI population, a more adaptable SCI-GDI is proposed using four joint movements that can be precisely captured with simpler systems than photogrammetry: sagittal planes of hip, knee and ankle and hip abduction/adduction. The reduced SCI-GDI (rSCI-GDI) effectively represents gait variability of adults with SCI as does the SCI-GDI, while providing more generalizable results and equivalent or stronger correlations with clinical tests validated in the population. During the derivation of the improved index, it was demonstrated that pelvic movements, hip rotation, and foot progression angle introduce high variability to the dataset of gait patterns of the adult population with SCI, but they have low relevance to characterize gait kinematics of this population. The rSCI-GDI can be calculated using the 14-feature vectorial basis included in the electronic addendum provided.

Sufficient Statistics for Nonlinear Tax Systems with General Across-Income Heterogeneity

This paper provides empirically implementable sufficient statistics formulas for optimal nonlinear tax systems in the presence of across-income heterogeneity in preferences, inheritances, income-shifting capabilities, and other sources. We characterize optimal smooth tax systems on income and savings (or other commodities), as well as simpler tax systems. We use familiar elasticity concepts and a novel sufficient statistic for heterogeneity correlated with earnings ability: the difference between across-income variation in savings and the causal effect of income on savings. We apply these formulas to the United States and find that the optimal savings tax is mostly positive and progressive. (JEL E21, G51, H21, H24)

Ultrafast 550-W average-power thin-disk laser oscillator

SESAM modelocked oscillators are interesting for applications in strong-field physics such as high-harmonic generation and attosecond science at high repetition rates or frequency combs in the ultraviolet. Here we present a SESAM modelocked ultrafast thin-disk laser oscillator providing 550W of average output power with 852fs pulses at 5.5MHz repetition rate. To reach this significant power scaling, a replicating cavity design for modelocked oscillators is utilized. The oscillator delivers 103 MW of peak power with a pulse energy of 100 µJ at a beam quality of M2<1.2, with a high optical-to-optical efficiency of 35%. The advances in SESAM design and manufacturing that enabled this result are discussed, as well as practical challenges when scaling oscillators to the kW-class. When combined with established pulse compression technologies, this oscillator can enable simpler systems by avoiding the complexity of chirped pulse amplifier chains. Additionally, high power oscillators support a much lower noise floor due to the reduced influence of shot noise, which may provide a route to more sensitive pump-probe measurements.

A DFT Mechanistic Study on the Aza-Aldol Reaction of Boron Aza-Enolates: Relative Stability of Six-Membered Transition State and Its Relevance to the Coordination Mode of the Leaving Group.

The mechanism of the aza-aldol reaction between boron aza-enolate and benzaldehyde is investigated by using density functional theory calculations. The result shows that the syn-E isomer is preferentially formed, consistent with experimental observations. The six-membered ring transition state (TS) with the boat form leads to the E isomer, while the more unstable chair TS does to the Z isomer. The preference of the syn isomer is determined by the interactions between the substituents of aza-enolate and benzaldehyde. Structural distortion and intrinsic reaction coordinate analyses of simplified model systems provide insights into the origin of the relative stability of the rate-determining TS with boat and chair forms. The boat TS is an early TS; thus, minimal structural distortions of the reactant are required to reach this TS. The Lewis pair interactions between the boron and imine groups during B-N elimination also influenced the relative stability of the TSs. This interaction involves the nitrogen lone pair in the boat TS, while the π(N═C) orbital is involved in the chair TS. The Lewis pair with the lone pair stabilizes the TS more than that with the π orbital. The boron aza-enolate with 9-BBN generates an ate complex and forms C-C bonds sequentially, whereas that with Bpin does not generate an ate complex and exhibits the concerted formation of B-O and C-C bonds. Thus, the higher electrophilicity of boron such as 9-BBN enhances the reactivity by facilitating the formation of the ate complex. A reaction design is proposed to reverse the syn/anti selectivity. Proof-of-concept DFT calculations suggested that the modification of the imine group would change the relative stability of the boat/chair TSs and give the anti-product.

TRNA lysidinylation is essential for the minimal translation system found in the apicoplast of Plasmodium falciparum.

For decades, researchers have sought to define minimal genomes to elucidate the fundamental principles of life and advance biotechnology. tRNAs, essential components of this machinery, decode mRNA codons into amino acids. The apicoplast of malaria parasites encodes 25 tRNA isotypes in its organellar genome - the lowest number found in known translation systems. Efficient translation in such minimal systems depends heavily on post-transcriptional tRNA modifications, especially at the wobble anticodon position. Lysidine modification at the wobble position (C34) of tRNACAU distinguishes between methionine (AUG) and isoleucine (AUA) codons, altering the amino acid delivered by this tRNA and ensuring accurate protein synthesis. Lysidine is formed by the enzyme tRNA isoleucine lysidine synthetase (TilS) and is nearly ubiquitous in bacteria and essential for cellular viability. We identified a TilS ortholog (PfTilS) located in the apicoplast of Plasmodium falciparum parasites. By complementing PfTilS with a bacterial ortholog, we demonstrated that the lysidinylation activity of PfTilS is critical for parasite survival and apicoplast maintenance, likely due to its impact on apicoplast protein translation. Our findings represent the first characterization of TilS in an endosymbiotic organelle, advancing eukaryotic organelle research and our understanding of minimal translational machinery. Due to the absence of lysidine modifications in humans, this research also exposes a potential vulnerability in malaria parasites that could be targeted by antimalarial strategies.

The Effect of Tillage Systems and Weed Control Methods on Grain Yield and Gluten Protein Compositional and Content-Related Changes in Hybrid Bread Wheat

The use of simplified tillage systems and weed control methods using reduced herbicide doses in wheat production technology is one of the basic requirements of sustainable agriculture in terms of obtaining high-quality grain of this species. The aim of three-year field studies was to determine the yield and quality characteristics of hybrid wheat grain depending on two tillage systems (CT and RT) and four weed control methods: mechanical (M) and mechanical–chemical, using recommended herbicide doses (MH100) and doses reduced by 25 and 50% (MH75, MH50). A comparable grain yield, number of grains per spike, weight of one thousand wheat grains, and amount of gluten and ω gliadin subunits (GLI) were obtained in the RT and CT systems. The CT system increased protein content (by 15.2 g kg−1) and the increase in the sum of gluten protein fractions was higher for glutenins (GLU) and their LMW and HMW subunits (from 20.9 to 29.8%). The application of the method with the recommended herbicide dose (MH100), compared to M and MH50, resulted in an increase in grain yield by 0.89 and 1.04 t ha−1, respectively, as well as in the sum of GLI (by 8.4 and 12.3%) and GLU (by 13.7 and 25.3%). The application of the herbicide dose reduced by 25% (MH75) compared to the recommended dose (MH100), especially in the RT system, did not cause a significant decrease in protein content and the amount of GLI and GLU, while reducing grain yield (by 0.26 t ha−1) and the amount of gluten (by 3.1%).

Optimal Sparsity in Nonlinear Nonparametric Reduced Order Models for Transonic Aeroelastic Systems

Machine learning and artificial intelligence algorithms typically require a large amount of data for training. This means that for nonlinear aeroelastic applications, where small training budgets are driven by the high computational burden associated with generating data, the usability of such methods has been limited to highly simplified aeroelastic systems. This paper presents a novel approach for the identification of optimized sparse higher-order polynomial-based aeroelastic reduced order models (ROMs) to significantly reduce the amount of training data needed without sacrificing fidelity. Several sparsity promoting algorithms are considered, including rigid sparsity, least absolute shrinkage and selection operator (LASSO) regression, and orthogonal matching pursuit (OMP). The study demonstrates that through OMP, it is possible to efficiently identify optimized s-sparse nonlinear aerodynamic ROMs using only aerodynamic response information. This approach is exemplified in a three-dimensional aeroelastic stabilator model experiencing high-amplitude freeplay-induced limit cycles. The comparison shows excellent agreement between the ROM and the full-order aeroelastic response, including the ability to generalize to new freeplay and velocity index values, with online computational savings of several orders of magnitude. The development of an optimally sparse ROM extends previous higher-order polynomial-based ROM approaches for feasible application to complex three-dimensional nonlinear aeroelastic problems, without incurring significant computational burdens or loss of accuracy.