Split Model Research Articles

Splitting model and rapid simulation for large-scale natural gas pipeline networks

Numerical discrete methods must typically solve high-dimensional nonlinear partial differential equations when simulating large-scale natural gas pipeline networks. This leads to a sharp increase in computational complexity, resulting in reduced simulation speed. In response to these issues, this study focused on the development of a splitting model and rapid simulation techniques for large-scale pipeline networks. A novel simulation method named linearized lumped parameter model (LLPM) was proposed; by using Lanczos integrate and Taylor expansion methods, the LLPM considers the inertial and gravity terms. Combining with the linearized finite difference method, a simulation technique was constructed, in which the pipeline network is split into an independent node model and pipeline models. Additionally, the boundary conditions of each pipeline are decoupled from the network. This method not only accelerates the simulation efficiency by breaking down the high-dimensional network model into low-dimensional node and pipeline models, but also provides detailed parameter profiles along the pipeline, thus overcoming the limitations of traditional lumped parameter methods. Finally, to validate the proposed method, an actual offshore pipeline network with a total length of 930.36 km was simulated. The results reveal that, compared with the measurement data, the simulation error of the proposed method is 0.92%, and the calculation speed is 132.16 times faster than that of the discrete method. The findings of this study provide a valuable reference for the fast and accurate simulation of large-scale natural gas pipeline networks.

Introduction and Consultation on the Indonesia's Oil and Gas Sharing Contract at CNG Co.

Indonesia's oil and gas sector has traditionally employed Production Sharing Contracts (PSCs) to regulate the sharing of revenues between the government and contractors. Two key PSC models are used: PSC Cost Recovery and PSC Gross Split. The PSC Cost Recovery model allows contractors to recover their exploration and production costs before profits are shared, providing financial protection but reducing long-term profitability. Conversely, the PSC Gross Split model, introduced in 2017, offers a simpler revenue-sharing mechanism, eliminating cost recovery and directly splitting gross revenue between the government and contractors. This study analyzes the financial implications of both models using economic simulations, focusing on key indicators like net cash flow, net present value (NPV), pay-out time, and discounted cash flow (DCF) rate of return. Results show that the Gross Split model generates significantly higher gross revenue ($420.908 million) than Cost Recovery ($46.362 million), but at the cost of greater financial risks for contractors due to higher upfront investments and operating costs. The Gross Split model also provides higher long-term returns, with a net cash flow of $67.138 million compared to $8.252 million in Cost Recovery. However, the pay-out time is longer, and the DCF rate of return is slightly lower (29.95% vs. 31.8%). Ultimately, PSC Gross Split is more suited for contractors with higher risk tolerance and capital resources, while PSC Cost Recovery may be preferable for smaller contractors seeking to minimize financial risks. Both models offer distinct advantages depending on the contractor’s financial capacity and risk appetite.

The rheological structure of East Asian continental lithosphere

The rheological structure of the East Asia continent is the key to understanding its broad, heterogeneous, and intense Cenozoic deformation. Based on a refined three-dimensional thermal structure of the lithosphere in this region and the latest strain rate data, we derived a model of the rheological structure of the East Asian continental lithosphere. The strength envelopes, defined by the yield strength of frictional, fractural, and plastic creep, are constrained by the lithological stratification based on previous studies and the depth distribution of earthquakes. The results show large vertical and lateral variations of lithospheric strength in the East Asian continent. A weak lower crust with low effective viscosity is ubiquitous. The rheological structure agrees with the jelly sandwich model in cratons, where the mantle lithosphere is relatively strong. The Tibetan Plateau has the weakest lower crust, with its effective viscosity ranging from 1019 to 1020 Pa∙s. Its mantle lithosphere is weakened by relatively high temperature; hence, its rheological structure can be described by the crème brûlée model. The lithospheric scale faults and suture zones in and around the Tibetan Plateau, with low strength or viscosity, correspond to the banana split model. The strength of the lithosphere in the Tibetan Plateau and other zones of active Cenozoic tectonics mainly derive from the crust, while the strength of the cratonic lithosphere is dominated by that of the mantle lithosphere. The rheological heterogeneity controls the lateral growth of the Tibetan Plateau and the widespread and differential deformation in the East Asian continent.

Euclid preparation

The Euclid mission, designed to map the geometry of the dark Universe, presents an unprecedented opportunity for advancing our understanding of the cosmos through its photometric galaxy cluster survey. Central to this endeavor is the accurate calibration of the mass- and redshift-dependent halo bias (HB), which is the focus of this paper. Our aim is to enhance the precision of HB predictions, which is crucial for deriving cosmological constraints from the clustering of galaxy clusters. Our study is based on the peak-background split (PBS) model linked to the halo mass function (HMF), and it extends it with a parametric correction to precisely align with results from an extended set of N-body simulations carried out with the OpenGADGET3 code. Employing simulations with fixed and paired initial conditions, we meticulously analyzed the matter-halo cross-spectrum and modeled its covariance using a large number of mock catalogs generated with Lagrangian perturbation theory simulations with the PINOCCHIO code. This ensures a comprehensive understanding of the uncertainties in our HB calibration. Our findings indicate that the calibrated HB model is remarkably resilient against changes in cosmological parameters, including those involving massive neutrinos. The robustness and adaptability of our calibrated HB model provide an important contribution to the cosmological exploitation of the cluster surveys to be provided by the Euclid mission. This study highlights the necessity of continuously refining the calibration of cosmological tools such as the HB to match the advancing quality of observational data. As we project the impact of our calibrated model on cosmological constraints, we find that given the sensitivity of the Euclid survey, a miscalibration of the HB could introduce biases in cluster cosmology analysis. Our work fills this critical gap, ensuring the HB calibration matches the expected precision of the Euclid survey.

Synthesis and crystal structure of poly[[μ-chlorido-μ-(2,3-di-methyl-pyrazine)-copper(I)] ethanol hemisolvate], which shows a new isomeric CuCl(2,3-di-methyl-pyrazine) network.

Reaction of copper(I)chloride with 2,3-di-methyl-pyrazine in ethanol leads to the formation of the title compound, poly[[μ-chlorido-μ-(2,3-di-methyl-pyrazine)-copper(I)] ethanol hemisolvate], {[CuCl(C6H8N2)]·0.5C2H5OH} n or CuCl(2,3-di-methyl-pyrazine) ethanol hemisolvate. Its asymmetric unit consists of two crystallographically independent copper cations, two chloride anions and two 2,3-di-methyl-pyrazine ligands as well as one ethanol solvate mol-ecule in general positions. The ethanol mol-ecule is disordered and was refined using a split model. The methyl H atoms of the 2,3-di-methyl-pyrazine ligands are also disordered and were refined in two orientations rotated by 60° relative to each other. In the crystal structure, each copper cation is tetra-hedrally coordinated by two N atoms of two bridging 2,3-di-methyl-pyrazine ligands and two μ-1,1-bridg-ing chloride anions. Each of the two copper cations are linked by pairs of bridging chloride anions into dinuclear units that are further linked into layers via bridging 2,3-di-methyl-pyrazine coligands. These layers are stacked in such a way that channels are formed in which the disordered solvent mol-ecules are located. The topology of this network is completely different from that observed in the two polymorphic modifications of CuCl(2,3-di-methyl-pyrazine) reported in the literature [Jess & Näther (2006). Inorg. Chem. 45, 7446-7454]. Powder X-ray diffraction measurements reveal that the title compound is unstable and transforms immediately into an unknown crystalline phase.

A High-Throughput Screening Platform for Engineering Poly(ethylene Terephthalate) Hydrolases.

The ability of enzymes to hydrolyze the ubiquitous polyester, poly(ethylene terephthalate) (PET), has enabled the potential for bioindustrial recycling of this waste plastic. To date, many of these PET hydrolases have been engineered for improved catalytic activity and stability, but current screening methods have limitations in screening large libraries, including under high-temperature conditions. Here, we developed a platform that can simultaneously interrogate PET hydrolase libraries of 104-105 variants (per round) for protein solubility, thermostability, and activity via paired, plate-based split green fluorescent protein and model substrate screens. We then applied this platform to improve the performance of a benchmark PET hydrolase, leaf-branch compost cutinase, by directed evolution. Our engineered enzyme exhibited higher catalytic activity relative to the benchmark, LCC-ICCG, on amorphous PET film coupon substrates (∼9.4% crystallinity) in pH-controlled bioreactors at both 65 °C (8.5% higher conversion at 48 h and 38% higher maximum rate, at 2.9% substrate loading) and 68 °C (11.2% higher conversion at 48 h and 43% higher maximum rate, at 16.5% substrate loading), up to 48 h, highlighting the potential of this screening platform to accelerate enzyme development for PET recycling.

Split ways: Using GAN watermarking for digital image protection with privacy-preserving split model training

In recent years, the significant importance of digital data in the Industrial Internet of Things (IIoT) is receiving more and more attention, followed by more copyright violation challenges to the transmission and storage of sensitive data. To address this issue, we propose a generative adversarial network (GAN)-based image watermarking in privacy-preserving split model training. In the first stage, we trained our model in split ways without the client sharing raw data to reduce privacy leakage, if any. In the second stage, we designed a GAN-based watermarking embedder and extraction network to imperceptibly embed sensitive information while enhancing robustness. Moreover, the sensitive mark is jointly encrypted and compressed before sending it to the server, thus protecting user confidentiality while reducing the bandwidth and storage demand. We tested our proposed scheme using multiple standard datasets such as div2k, CelebA, and Flickr. The results on the div2k datasets showed that the proposed method surpassed several state-of-the-art methods, with average PSNR and NC increasing by 47.75% and 26.72% respectively. Our joint encryption and compression method also achieved superior performance compared with other methods with an average NPCR and UACI increasing by 18.25% and 16.87% respectively. To the best of our knowledge, we are the first to explore a GAN-based watermarking in split learning ways for digital images.

Split Majoron model confronts the NANOGrav signal and cosmological tensions

In the light of the evidence of a gravitational wave background from the NANOGrav 15 yr dataset, we reconsider the split Majoron model as a new physics extension of the standard model able to generate a needed contribution to solve the current tension between the data and the standard interpretation in terms of inspiraling supermassive black hole massive binaries. In the split Majoron model the seesaw right-handed neutrinos acquire Majorana masses from spontaneous symmetry breaking of global U(1)B−L in a strong first order phase transition of a complex scalar field occurring above the electroweak scale. The final vacuum expectation value couples to a second complex scalar field undergoing a low scale phase transition occurring after neutrino decoupling. Such a coupling enhances the strength of this second low scale first order phase transition and can generate a sizeable primordial gravitational wave background contributing to the NANOGrav 15 yr signal. Some amount of extraradiation is generated after neutron-to-proton ration freeze-out but prior to nucleosynthesis. This can be either made compatible with the current upper bound from primordial deuterium measurements or even be used to solve a potential deuterium problem. Moreover, the free streaming length of light neutrinos can be suppressed by their interactions with the resulting Majoron background, and this mildly ameliorates existing cosmological tensions. Thus cosmological observations nicely provide independent motivations for the model. Published by the American Physical Society 2024

Capturing impacts of travel preference on connected autonomous vehicle adoption of risk-averse travellers in multi-modal transportation networks

ABSTRACT This paper proposes a reliability-based combined modal split and traffic assignment model for the multi-modal transportation network with uncertainties in which the travellers' travel preferences, vehicle ownership, and the characteristics of connected autonomous vehicles (CAVs) are considered. Travellers are classified into captive travellers and choice travellers according to their preference for travel modes and vehicle ownership. The choice travellers need to make a tradeoff among the out-of-pocket cost, comfort, and travel time reliability and make decisions between continuing to commute by subway or purchasing a human-driven vehicle (HV) or CAV. The dogit-nested-logit model is adopted to characterise the effect of travel preference on the adoption of CAVs of the choice travellers, and the multinomial logit model is adopted to capture the effect of the differences between HV and CAV on information quality and value of travel time reliability on the path choice behaviour of travellers. The problem is formulated as an equivalent variational inequality model based on the properties of the equilibrium state, and its equivalency and solution existence are discussed. A path-based algorithm is employed for solving the problem, which combines the Monte Carlo simulation-based method and the column generation method. Numerical experiments are presented to illustrate the properties of the proposed models and validate the algorithm.

Does Practice Match Protocol? A Comparison of Triage-to-Provider Time Among More vs. Less Acute Emergency Department Patients.

Introduction The Emergency Severity Index (ESI) stratifies emergency department (ED) patients for triage, from "most acute" (level 1) to "least acute" (level 5). Many EDs have a split flow model where less acute (ESI 4 and 5) are seen in a fast track, while more acute (ESI 1, 2, and 3) are seen in the acute care area. A core principle of emergency medicine (EM) is to attend to more acute patients first. Deliberately designating an area for less acute patients to be initially assessed quickly by a first provider might result in them being seen before more acute patients. This study aims to determine the percentage of less acute patients seen by a provider sooner after triage than more acute patients who arrived within 10 minutes of one another. Additionally, this study compares the fast track and acute care areas to see if location affects triage-to-provider time. Methods A random convenience sample of 252 ED patients aged ≥18 was taken. Patients were included if their ESI was available for the provider during sign-up. Patients were excluded if they were directly sent to the ED psychiatric area or attended to by the author. We collected data on the ESI level, time stamps for triage and first provider sign-up, and the location to which the patient was triaged (fast track vs. acute care). Paired patients' ESI levels, locations, and triage and first provider sign-up times were compared. Results The study included 126 pairs of patients. There was a statistically significant difference in triage-to-provider times for paired ESI 2 vs. 3 patients (60.5 vs. 35.5 minutes, p = 0.0007) and overall paired high- vs. low-acuity patients (55 vs. 39.5 minutes, p = 0.004). However, in 34.8% of paired ESI 2 vs. 3 patients, the ESI 3 patient was seen prior to the paired ESI 2 patient, and in 39.4% of overall paired high vs. low acuity patients, the less acute patient was seen before the more acute patient. Additionally, patients in the acute care area had significantly shorter median triage-to-provider times (~40 minutes) compared to those in the fast track area for ESI 2 (acute care) vs. ESI 3 (fast track) and overall high acuity (acute care) vs. low acuity (fast track). Nonetheless, approximately one-third of ESI 3 patients triaged to fast track were seen before ESI 2 patients triaged to the acute care area. Conclusion The split flow model reduces overall ED length of stay, improving flow volume, revenue, and patient satisfaction. However, it comes at the expense of the fundamental ethos of EM and potentially subverts the intended triage process. Although most more acute patients are seen by a provider sooner after triage than less acute patients, a substantial number are seen later, which could delay urgent medical needs and negatively impact patients' outcomes. Furthermore, patients triaged to acute care are, in general, seen sooner post-triage than identical-ESI-level fast track patients, suggesting fast track might not function as intended (for low-acuity patients to be quickly assessed and initiate diagnostic and treatment plans). We intend to follow this exploratory study with a more comprehensive, multivariate analysis that will consider confounding variables such as initial vital signs, how busy a provider was that day, etc. The future study will also examine patient outcomes to determine the impact on more acute patients of the split flow model and, in particular, on less acute patients being seen sooner by a first provider.

An unrolled neural network for accelerated dynamic MRI based on second-order half-quadratic splitting model

The reconstruction of dynamic magnetic resonance images from incomplete k-space data has sparked significant research interest due to its potential to reduce scan time. However, traditional iterative optimization algorithms fail to faithfully reconstruct images at higher acceleration factors and incur long reconstruction time. Furthermore, end-to-end deep learning-based reconstruction algorithms suffer from large model parameters and lack robustness in the reconstruction results. Recently, unrolled deep learning models, have shown immense potential in algorithm stability and applicability flexibility. In this paper, we propose an unrolled deep learning network based on a second-order Half-Quadratic Splitting(HQS) algorithm, where the forward propagation process of this framework strictly follows the computational flow of the HQS algorithm. In particular, we propose a degradation-sense module by associating random sampling patterns with intermediate variables to guide the iterative process. We introduce the Information Fusion Transformer(IFT) to extract both local and non-local prior information from image sequences, thereby removing aliasing artifacts resulting from random undersampling. Finally, we impose low-rank constraints within the HQS algorithm to further enhance the reconstruction results. The experiments demonstrate that each component module of our proposed model contributes to the improvement of the reconstruction task. Our proposed method achieves comparably satisfying performance to the state-of-the-art methods and it exhibits excellent generalization capabilities across different sampling masks. At the low acceleration factor, there is a 0.7% enhancement in the PSNR. Furthermore, when the acceleration factor reached 8 and 12, the PSNR achieves an improvement of 3.4% and 5.8% respectively.

Cellular mechanisms of monozygotic twinning: clues from assisted reproduction.

Monozygotic (MZ) twins are believed to arise from the fission of a single fertilized embryo at different stages. Monochorionic MZ twins, who share one chorion, originate from the splitting of the inner cell mass (ICM) within a single blastocyst. In the classic model for dichorionic MZ twins, the embryo splits before compaction, developing into two blastocysts. However, there are a growing number of ART cases where a single blastocyst transfer results in dichorionic MZ twins, indicating that embryo splitting may occur even after blastocyst formation. For monochorionic MZ twins, we conducted a comprehensive analysis of the cellular mechanisms involved in ICM splitting, drawing from both ART cases and animal experiments. In addition, we critically re-examine the classic early splitting model for dichorionic MZ twins. We explore cellular mechanisms leading to two separated blastocysts in ART, potentially causing dichorionic MZ twins. Relevant studies including research articles, reviews, and conference papers were searched in the PubMed database. Cases of MZ twins from IVF clinics were found by using combinations of terms including 'monozygotic twins' with 'IVF case report', 'ART', 'single embryo transfer', or 'dichorionic'. The papers retrieved were categorized based on the implicated mechanisms or as those with unexplained mechanisms. Animal experiments relating to MZ twins were found using 'mouse embryo monozygotic twins', 'mouse 8-shaped hatching', 'zebrafish janus mutant', and 'nine-banded armadillo embryo', along with literature collected through day-to-day reading. The search was limited to articles in English, with no restrictions on publication date or species. For monochorionic MZ twins, ART cases and mouse experiments demonstrate evidence that a looser ICM in blastocysts has an increased chance of ICM separation. Physical forces facilitated by blastocoel formation or 8-shaped hatching are exerted on the ICM, resulting in monochorionic MZ twins. For dichorionic MZ twins, the classic model resembles artificial cloning of mouse embryos in vitro, requiring strictly controlled splitting forces, re-joining prevention, and proper aggregation, which allows the formation of two separate human blastocysts under physiological circumstances. In contrast, ART procedures involving the transfer of a single blastocysts after atypical hatching or vitrified-warmed cycles might lead to blastocyst separation. Differences in morphology, molecular mechanisms, and timing across various animal model systems for MZ twinning can impede this research field. As discussed in future directions, recent developments of innovative in vitro models of human embryos may offer promising avenues for providing fundamental novel insights into the cellular mechanisms of MZ twinning during human embryogenesis. Twin pregnancies pose high risks to both the fetuses and the mother. While single embryo transfer is commonly employed to prevent dizygotic twin pregnancies in ART, it cannot prevent the occurrence of MZ twins. Drawing from our understanding of the cellular mechanisms underlying monochorionic and dichorionic MZ twinning, along with insights into the genetic mechanisms, could enable improved prediction, prevention, and even intervention strategies during ART procedures. N/A.

Kombinasi Model Trip Generation-Modal Split (G-MS) Dalam Perencanaan Bus Bandara Terintegrasi

The modal split model can be varied to other model in the concept of four step models transportation. This approach model can be varied depending on the purpose of transport planning, such as the modal split planning process which is carried out at the trip generation calculation stage, and in this process the movement of public transport can be directly separated from private transport with the assumption that someone who will travel can choose the model that is influenced by socioeconomic valiable. The model combined experiment (G-MS) was carried out on the route to and from Jambi’s Sultan Thaha Airport, which is one of the transportation nodes that plays an important role in regional development in Jambi City. The aim of this research is to analyze potential demand using a combination of the Trip Generation-Modal Split (G-MS) model. Based on the results of the analysis using the binomial ratio logit model with the value Y = Proportion of passengers/days. The passenger distribution area is devided base on zones where the zones that have the potential to be passenger gathering point are zone 9, zone 10 and zone 11. Calculation of the chi-square test (goodness of fit test) shows that the calculation X2 value is 11.583 and the table X2 is 14.067 because X2 count <X2 table, then H0 is accepted which means the observation results are the same as the average model results so that model validation is declared successful, so this research can be used to calculate passenger demand to plan airport buses.

Discrete Boltzmann model with split collision for nonequilibrium reactive flows* *This work is supported by the National Natural Science Foundation of China (under Grant Nos. U2242214, 51806116 and 91441120), the Guangdong Basic and Applied Basic Research Foundation (under Grant Nos. 2022A1515012116 and 2024A1515010927), the Natural Science Foundation of Fujian Province (under Grant Nos. 2021J01652, 2021J01655), and the China Scholarship Council

A multi-relaxation-time discrete Boltzmann model (DBM) with split collision is proposed for both subsonic and supersonic compressible reacting flows, where chemical reactions take place among various components. The physical model is based on a unified set of discrete Boltzmann equations that describes the evolution of each chemical species with adjustable acceleration, specific heat ratio, and Prandtl number. On the right-hand side of discrete Boltzmann equations, the collision, force, and reaction terms denote the change rates of distribution functions due to self- and cross-collisions, external forces, and chemical reactions, respectively. The source terms can be calculated in three ways, among which the matrix inversion method possesses the highest physical accuracy and computational efficiency. Through Chapman–Enskog analysis, it is proved that the DBM is consistent with the reactive Navier–Stokes equations, Fick's law and the Stefan–Maxwell diffusion equation in the hydrodynamic limit. Compared with the one-step-relaxation model, the split collision model offers a detailed and precise description of hydrodynamic, thermodynamic, and chemical nonequilibrium effects. Finally, the model is validated by six benchmarks, including multicomponent diffusion, mixture in the force field, Kelvin–Helmholtz instability, flame at constant pressure, opposing chemical reaction, and steady detonation.

Methods of diagnostic meta-analysis: comparing the generalized linear mixed model and the split component synthesis model

Purpose of review Diagnostic meta-analyses combine data from several diagnostic test accuracy (DTA) studies to provide an in-depth assessment of a specific diagnostic test's performance across diverse populations and settings. Additionally, knowledge on common methods of diagnostic meta-analyses is crucial for researchers to make informed decisions on best practice for reporting analyses and results. This article provides an overview of commonly used methods of diagnostic meta-analyses using real-life and simulation data. Recent findings Advances in methods of diagnostic meta-analyses in recent years have increased uncertainty among researchers in relation to the most suitable method to be used. Currently, the most popular approaches for diagnostic evidence synthesis include hierarchical summary operating characteristic (HSROC) and bivariate random effects models though other methods such as the split component synthesis method have been proposed. In addition, different software modules exist for DTA meta-analyses. Summary This article presents a thorough evaluation of current frequentist DTA meta-analysis methods implementing both simulated and real-world data. By understanding the recent methods of diagnostic meta-analyses and their limitations, clinicians may better be equipped in selecting the optimum approach to improve clinical judgement and consequently better patient outcomes.

Aesthetic outcome of running subcuticular suture versus running horizontal mattress suture in closure of linear wounds of the trunk and extremities: A randomized evaluator-blinded split-wound comparative effectiveness trial

Both running horizontal mattress (HM) and running subcuticular (SQ) suturing techniques have been suggested to be superior to other running cuticular suturing techniques. These 2 techniques have not been directly compared. To compare cosmetic outcomes between a running HM and a running SQ technique in a split scar model following linear closure of trunk and extremity defects. Fifty patients were enrolled in a randomized, evaluator-blinded, split-scar study. One side of the surgical wound was randomized to receive one intervention (HM vs SQ) with the other side receiving the alternate intervention. The primary outcome was the Patient and Observer Scar Assessment Scale (POSAS) score at a minimum of 3months postoperatively. Observer POSAS sum of components was 19.49 and 17.76 for HM and SQ, respectively (P=.14). The mean score for patient overall opinion was 4.71 for HM and 3.50 for the SQ technique (P=.02). Overall opinion scores of evaluators were 3.87 and 3.29 for HM and SQ, respectively (P=.03). Single-center study of a relatively homogenous population. Although there was no significant difference in the sum of POSAS components between HM and SQ (P=.14), both patients and evaluators had a superior overall opinion of the SQ-treated side (patient P=.02, evaluator P=.03).

Computational analysis of the failure mechanisms of a laminated composite in double-edge notch compression configuration

This manuscript presents a combined experimental–computational investigation of the compression failure response of laminated composites in double-edge notch compression (DENC) configuration. Analysis of in-situ and post-test DENC experiment results indicates the presence of multiple failure mechanisms, including ply splitting, delamination, and compression kink bands. In order to characterize the onset, growth, and interplay of the critical and subcritical damage mechanisms, a multiscale progressive damage analysis approach is implemented. A nonlocal multiscale damage model explicitly tracks the intraply failure mechanisms that lead to the formation and propagation of kink bands in the specimen. A cohesive zone model is used to track initiation and progression of ply splitting in the specimen. The splitting model was implemented using implicit finite element simulations and deployed with a pre-crack insertion technique to reduce simulation time while preserving prediction accuracy. Model parameters are calibrated based on available calibration data and measurements. The effects of split location and growth characteristics on model predictions are studied. The computational model along with a suite of experiments were employed to study the formation, growth and interactions of damage mechanisms in the composite specimens subjected to compression loading. The onset of matrix damage is not clear from the experimental images but the model predicts early onset around the onset time of splits which greatly reduce the stress concentration at the notches. Analysis of acoustic emission energy experimental data indicate that observable compression failure mechanisms are not causing nonlinearity consistently exhibited in the experiment responses. Simulation results demonstrate the capability of the multiscale modeling approach to predict critical kink bands and sub-critical matrix cracking and splitting in the DENC specimens while reducing computational cost compared to a direct numerical simulation of fibers and matrix.

Exploring Preservation Modalities in a Split Human Pancreas Model to Investigate the Effect on the Islet Isolation Outcomes.

In islet transplantation, the use of dynamic hypothermic preservation techniques is a current challenge. This study compares the efficacy of 3 pancreas preservation methods: static cold storage, hypothermic machine perfusion (HMP), and oxygenated HMP. A standardized human pancreas split model was employed using discarded organs from both donation after brain death (n = 15) and donation after circulatory death (DCD) (n = 9) donors. The pancreas head was preserved using static cold storage (control group), whereas the tail was preserved using the 3 different methods (study group). Data on donor characteristics, pancreas histology, isolation outcomes, and functional tests of isolated islets were collected. Insulin secretory function evaluated by calculating stimulation indices and total amount of secreted insulin during high glucose stimulation (area under the curve) through dynamic perifusion experiments was similar across all paired groups from both DCD and donation after brain death donors. In our hands, islet yield (IEQ/g) from the pancreas tails used as study groups was higher than that of the pancreas heads as expected although this difference did not always reach statistical significance because of great variability probably due to suboptimal quality of organs released for research purposes. Moreover, islets from DCD organs had greater purity than controls (P ≤ 0.01) in the HMP study group. Furthermore, our investigation revealed no significant differences in pancreas histology, oxidative stress markers, and apoptosis indicators. For the first time, a comparative analysis was conducted, using a split model, to assess the effects of various preservation methods on islets derived from pancreas donors. Nevertheless, no discernible variances were observed in terms of islet functionality, histological attributes, or isolation efficacy. Further investigations are needed to validate these findings for clinical application.

Modes of action of Trichoderma virens Gl006 and Bacillus velezensis Bs006: decoding the arsenal of the microbial consortium

The consortium based on Trichoderma virens Gl006 and Bacillus velezensis Bs006 was selected in a previous study because the high effectiveness against Fusarium wilt of cape gooseberry (Fusarium oxysporum f. sp. physali—Foph). The compatibility among the strains was determined previously, but the modes of action exerted by the consortium remained unknown. In this study, the modes of action displayed by the Gl006 and Bs006 consortium against the Foph strain Map5 were determined and compared with the modes of action of the single microorganisms. Production of cell wall degrading enzymes (CWDE), cyclic lipopeptides (CLPs) by Bs006 and gliotoxin by Gl006, and fusaric acid (FA) production by Foph were evaluated in the co-culture of the strains in several culture media. Furthermore, the survival of the strains in the soil, the colonization of plant tissues and the induction of systemic responses through a split root model bioassay were evaluated. While Bs006 showed protease, β-1,3-glucanase, and chitobiosidase enzymatic activities, and production of CLPs, Gl006 showed β-N-acetylglucosaminidase, chitobiosidase, total chitinase, β-1,3-glucanase, and protease activities. All the metabolites produced by the single strains were also found in the consortium, but in a culture medium dependent manner. The FA was found in the experiment on the interaction of the consortium with Foph Map5 in the minimal basal medium and in potato dextrose broth. The population of Foph was reduced by the consortium in vitro, under the synthetic media that favored the production of all the CWDE tested. In soil conditions, the consortium reduced the population of Foph by 63% in a synergistic way. Bs006 was recovered from the inner tissues of the plant, where Gl006 prevented the entry of Foph to the roots and reduced the incidence of the disease under the split root model. These results suggest that the consortium of Gl006 and Bs006 displays modes of action through CWDE and CLP´s and indirectly through induction of systemic resistance, which could act complementary since neither of them were enhanced in consortium. Here we characterized a consortium capable of reducing the population of Foph in soil and control the disease in a synergistic way.

Adrenergic relaxations in an in situ urinary bladder model evoked by stimulation of sensory pelvic and pudendal nerves in the rat

Urinary bladder dysfunction might be related to disturbances at different levels of the micturition reflex arc. The current study aimed to further develop and evaluate a split bladder model for detecting and analysing relaxatory signalling in the rat urinary bladder. The model allows for discrimination between effects at the efferent and the afferent side of the innervation. In in vivo experiments, the stimulation at a low frequency (1 Hz) of the ipsilateral pelvic nerve tended to evoke relaxation of the split bladder half (contralateral side; −1.0 ± 0.4 mN; n = 5), in contrast to high frequency-evoked contractions. In preparations in which the contralateral pelvic nerve was cut the relaxation occurred at a wider range of frequencies (0.5–2 Hz). In separate experiments, responses to 1 and 2 Hz were studied before and after intravenous injections of propranolol (1 mg/kg IV). The presence of propranolol significantly shifted the relaxations into contractions. Also, electrical stimulation of the ipsilateral pudendal nerve evoked relaxations of similar magnitude as for the pelvic stimulations, which were also affected by propranolol. In control in vitro experiments, substances with β-adrenoceptor agonism, in contrast to a selective α-agonist, evoked relaxations. The current study shows that the split bladder model can be used for in vivo studies of relaxations. In the model, reflex-evoked sympathetic responses caused relaxations at low intensity stimulation. The involvement of β-adrenoceptors is supported by the sensitivity to propranolol and by the in vitro observations.