Small Solutes Research Articles

Morphological and Molecular Investigations of Aquaporin-7 (AQP-7) in Male Camelus dromedarius Reproductive Organs

Aquaporins (AQP) are involved in bidirectional transfers of water and small solutes across cell membranes. They are present in all tissues. However, the expression of AQP-7 has not yet been demonstrated in the reproductive tract of the camelid Camelus dromedarius. The study presented here concerns the immunohistochemical evidence of aquaporin-7 (AQP-7) in different parts of the male genital tract of Camelus dromedarius. To check the immune reactivity levels of anti-AQP-7 antibody in the male genital tract of Camelus dromedarius, the testes (proximal part, distal part and rete testis), epididymis (head, body and tail), ductus deferens (initial, middle and ampullary part) and prostate gland (compact and disseminated part) were collected from 12 male camels during the rutting and non-rutting seasons and subjected to immunohistochemistry. The result showed that the highest level of AQP-7 mRNA expression was in the testis of rutting and non-rutting males compared to the ductus deferens, epididymis and prostate. In addition, the highest mRNA gene expression of AQP-7 was in rutting males compared to non-rutting males. AQP-7 mRNA expression was higher in the ret testis, the body of the epididymis, the ampullary part of the ductus deferens and the compact part of the prostate. The immune reactivity levels of AQP-7 in rutting males showed strong reactivity in the testis and prostate compared to the epididymis and ductus deferens. On the basis of the results, it can be concluded that the distribution of the AQP-7 transcript and protein varied among rutting and non-rutting seasons and that the physiological roles of AQP-7 in the transportation of lipids, energy and water should be considered the main challenge in the activity and establishment of male Camelus dromedarius fertility during the rutting and non-rutting seasons. Moreover, AQP-7 detection is critical in assessing regulation and screening for new modulators that can prompt the development of effective medication to enhance fertility during rutting and non-rutting seasons.

Low regularity solutions for the Vlasov–Poisson–Landau/Boltzmann system

In the paper, we are concerned with the nonlinear Cauchy problem on the Vlasov–Poisson–Landau/Boltzmann system around global Maxwellians in a torus or a finite channel. The main goal is to establish the global existence and large time behaviour of small amplitude solutions for a class of low regularity initial data. The molecular interaction type is restricted to the case of hard potentials for two classical collision operators because of the effect of the self-consistent forces. The result extends the one by Duan–Liu–Sakamoto-Strain (Duan et al 2021 Commun. Pure Appl. Math. 74 932–1020) for the pure Landau/Boltzmann equation to the case of the VPL and VPB systems.

A deep reinforcement learning algorithm for the rectangular strip packing problem.

As a branch of the two-dimensional (2D) optimal blanking problem, rectangular strip packing is a typical non-deterministic polynomial (NP-hard) problem. The classical packing solution method relies on heuristic and metaheuristic algorithms. Usually, it needs to be designed with manual decisions to guide the solution, resulting in a small solution scale, weak generalization, and low solution efficiency. Inspired by deep learning and reinforcement learning, combined with the characteristics of rectangular piece packing, a novel algorithm based on deep reinforcement learning is proposed in this work to solve the rectangular strip packing problem. The pointer network with an encoder and decoder structure is taken as the basic network for the deep reinforcement learning algorithm. A model-free reinforcement learning algorithm is designed to train network parameters to optimize the packing sequence. This design can not only avoid designing heuristic rules separately for different problems but also use the deep networks with self-learning characteristics to solve different instances more widely. At the same time, a piece positioning algorithm based on the maximum rectangles bottom-left (Maxrects-BL) is designed to determine the placement position of pieces on the plate and calculate model rewards and packing parameters. Finally, instances are used to analyze the optimization effect of the algorithm. The experimental results show that the proposed algorithm can produce three better and five comparable results compared with some classical heuristic algorithms. In addition, the calculation time of the proposed algorithm is less than 1 second in all test instances, which shows a good generalization, solution efficiency, and practical application potential.

Nano Urea: A Small Solution with a Big Impact on Sustainable Agriculture

Nano urea is a promising alternative to conventional urea for improving nitrogen use efficiency in agriculture. However, the nitrogen holding capacity of nano urea is a critical factor in its effectiveness as a fertilizer. This paper explores various approaches for increasing the nitrogen holding capacity of nano urea, including the use of coatings, encapsulation, and functionalization with polymers or other additives. The results suggest that these strategies can improve the stability and release characteristics of nano urea, enhancing its nitrogen holding capacity and reducing the risk of nitrogen loss through leaching or volatilization. The paper also discusses the challenges and opportunities associated with the development and commercialization of these technologies, including considerations related to safety, scalability, and cost-effectiveness. The findings of this study have implications for the design and optimization of nano urea products, with potential benefits for sustainable agriculture and environmental conservation. Overall, the paper highlights the potential of increasing the nitrogen holding capacity of nano urea through innovative approaches in materials science and engineering. Keywords: Nano urea, encapsulation, additives, scalability, sustainable agriculture, material science.

Interplay between membrane imperfections and external concentration polarization

Reverse osmosis membranes provide a highly effective and efficient barrier against various kinds of pollutants. Their reliability depends on the integrity of the active layer: in case the active layer is damaged and contains imperfections, unfiltered feed solution can contaminate the permeate. Various types of integrity monitoring techniques have been developed to verify membrane performance, of which the rejection of fluorescent dyes is a well-established technique. Fluorescent dyes are however relatively small solutes for which the membranes can display non-zero diffusive permeability, such that not all dye passage can be attributed to membrane imperfections. Additionally, fluorescent dyes are subject to external concentration polarization (ECP) during filtration, causing a flux-dependent enrichment at the membrane surface, further complicating the analysis of dye rejection data. This study presents a model to discern between membrane permeability, enrichment by ECP and passage through imperfections. The consequences of imperfections on solute passage are explored, showing that imperfections only contribute significantly to the passage of solutes with a low membrane permeability. This leads to underestimates of the external mass transfer coefficient, with the error being increasingly large with decreasing membrane permeability coefficient, relative to the case of an imperfection-free membrane. This error is then related to the proportionality of the Sherwood number, used to calculate external mass transfer coefficients, with solute diffusivity, allowing the quantification of the contribution of imperfections to water flux. The model was experimentally verified using Pyranine rejection in two membrane types, both operated in a lab-scale flat sheet crossflow test system, finding proof of imperfections in one membrane type.

On the transition to dripping of an inverted liquid film

The transition to dripping in the gravity-driven flow of a liquid film under an inclined plate is investigated at zero Reynolds number. Computations are carried out on a periodic domain assuming either a fixed fluid volume or a fixed flow rate for a hierarchy of models: two lubrication models with either linearised curvature or full curvature (the LCM and FCM, respectively), and the full equations of Stokes flow. Of particular interest is the breakdown of travelling-wave solutions as the plate inclination angle is increased. For any fixed volume, the LCM reaches the horizontal state where it attains a cosine-shaped profile. For sufficiently small volume, the FCM and Stokes solutions attain a weak Young–Laplace equilibrium profile, the approach to which is described by an asymptotic analysis generalising that of Kalliadasis & Chang (J. Fluid Mech., vol. 261, 1994, pp. 135–168) for the LCM. For large volumes, the bifurcation curves for the FCM and Stokes model have a turning point so that the fully inverted state is never reached. For fixed flow rate, the LCM blows up at a critical angle that is well predicted by asymptotic analysis. The bifurcation curve for the FCM either has a turning point or else reaches a point at which the surface profile has an infinite slope singularity, indicating the onset of multi-valuedness. The latter is confirmed by the Stokes model, which can be continued to obtain overturning surface profiles. Overall, the thin-film models either provide an accurate prediction for dripping onset or else supply an upper bound on the critical inclination angle.

Fuzzy Neural Network with Ordered Fuzzy Numbers for Life Quality Technologies

The general goal of the research in this article is to devise an artificial neural network that requires less computational power than an ordinary one for assessing overall life satisfaction—a term often referred to as quality of life (QoL). The development of the mentioned ANN was possible due to the application of fuzzy logic, especially ordered fuzzy numbers (OFN). Research on the appliance of OFN aims at different issues such as the detection of an attack on a computer network, the anticipation of server load, management of multiplexing of data transmission paths, or transmission error rate forecasting that allows the improvement of the quality of life. It occurs due to, for instance, reduced energy demand, savings through better data transmission, and the distribution of computers’ power used in the cloud. Finally, the application of OFN on single neurons of a deep ANN allows achieving a network that is able to solve the same problem as a normal network, but with a lower number of neurons. Such networks in the future may be implemented easier in small solutions, such as solutions for the Internet of Things to improve the quality of human life. This approach is unique and has no equivalent in the literature. Due to the application of OFN in an ANN, fewer requirements for network architecture were needed to solve the same problems, and as a result, there is less demand for processor power and RAM.

The Grip on Health Intervention to Prevent Health Problems Among Workers With a Lower Socioeconomic Position: A Pilot Implementation Study.

Workers with a lower socioeconomic position (SEP) often face problems on multiple life domains. This study evaluated an intervention to identify and solve problems on multiple life domains, called "Grip on Health." A mixed-methods process evaluation was performed among occupational health professionals (OHPs) and lower SEP workers with problems on multiple life domains. Thirteen OHPs delivered the intervention to 27 workers. For seven workers, the supervisor was involved, and for two, stakeholders from outside the workplace were involved. Agreements between OHPs with employers often affected implementation. OHPs were essential to help workers identify and solve problems. The intervention increased workers' health awareness and self-control, and led to small and practical solutions. Grip on Health can support lower SEP workers with solving problems on multiple life domains. However, contextual factors make implementation difficult.

Infinitely Many Small Energy Solutions to the Double Phase Anisotropic Variational Problems Involving Variable Exponent

This paper is devoted to double phase anisotropic variational problems for the case of a combined effect of concave–convex nonlinearities when the convex term does not require the Ambrosetti–Rabinowitz condition. The aim of the present paper, on a class of superlinear term which is different from the previous related works, is to discuss the multiplicity result of non-trivial solutions by applying the dual fountain theorem as the main tool. In particular, our main result is obtained without assuming the conditions on the nonlinear term at infinity.

Big challenges, small solution: Microcourses at the University of Oklahoma

Die Unterrichtspraxis/Teaching GermanEarly View FORUM Big challenges, small solution: Microcourses at the University of Oklahoma Kaleigh Bangor, Kaleigh Bangor Modern Languages, Literatures, & Linguistics, University of Oklahoma, Norman, Oklahoma, USASearch for more papers by this authorRobert Lemon, Robert Lemon Modern Languages, Literatures, & Linguistics, University of Oklahoma, Norman, Oklahoma, USASearch for more papers by this authorKarin Schutjer, Corresponding Author Karin Schutjer [email protected] orcid.org/0000-0003-4919-5577 Modern Languages, Literatures, & Linguistics, University of Oklahoma, Norman, Oklahoma, USA Correspondence Karin Schutjer, Modern Languages, Literatures, & Linguistics, University of Oklahoma, Norman, OK, USA. Email: [email protected]Search for more papers by this author Kaleigh Bangor, Kaleigh Bangor Modern Languages, Literatures, & Linguistics, University of Oklahoma, Norman, Oklahoma, USASearch for more papers by this authorRobert Lemon, Robert Lemon Modern Languages, Literatures, & Linguistics, University of Oklahoma, Norman, Oklahoma, USASearch for more papers by this authorKarin Schutjer, Corresponding Author Karin Schutjer [email protected] orcid.org/0000-0003-4919-5577 Modern Languages, Literatures, & Linguistics, University of Oklahoma, Norman, Oklahoma, USA Correspondence Karin Schutjer, Modern Languages, Literatures, & Linguistics, University of Oklahoma, Norman, OK, USA. Email: [email protected]Search for more papers by this author First published: 20 April 2023 https://doi.org/10.1111/tger.12240Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Early ViewOnline Version of Record before inclusion in an issue RelatedInformation

(Re‐)Discoveries in a time of disruption

(Re‐)Discoveries in a time of disruption

Selecting relevant moderators with Bayesian regularized meta-regression.

When meta-analyzing heterogeneous bodies of literature, meta-regression can be used to account for potentially relevant between-studies differences. A key challenge is that the number of candidate moderators is often high relative to the number of studies. This introduces risks of overfitting, spurious results, and model non-convergence. To overcome these challenges, we introduce Bayesian Regularized Meta-Analysis (BRMA), which selects relevant moderators from a larger set of candidates by shrinking small regression coefficients towards zero with regularizing (LASSO or horseshoe) priors. This method is suitable when there are many potential moderators, but it is not known beforehand which of them are relevant. A simulation study compared BRMA against state-of-the-art random effects meta-regression using restricted maximum likelihood (RMA). Results indicated that BRMA outperformed RMA on three metrics: BRMA had superior predictive performance, which means that the results generalized better; BRMA was better at rejecting irrelevant moderators, and worse at detecting true effects of relevant moderators, while the overall proportion of Type I and Type II errors was equivalent to RMA. BRMA regression coefficients were slightly biased towards zero (by design), but its residual heterogeneity estimates were less biased than those of RMA. BRMA performed well with as few as 20 studies, suggesting its suitability as a small sample solution. We present free open source software implementations in the R-package pema (for penalized meta-analysis) and in the stand-alone statistical program JASP. An applied example demonstrates the use of the R-package.

Simulated Tempering-Enhanced Umbrella Sampling Improves Convergence of Free Energy Calculations of Drug Membrane Permeation.

Molecular dynamics simulations have been widely used to study solute permeation across biological membranes. The potential of mean force (PMF) for solute permeation is typically computed using enhanced sampling techniques such as umbrella sampling (US). For bulky drug-like permeants, however, obtaining converged PMFs remains challenging and often requires long simulation times, resulting in an unacceptable computational cost. Here, we augmented US with simulated tempering (ST), an extended-ensemble technique that consists in varying the temperature of the system along a pre-defined temperature ladder. Simulated tempering-enhanced US (STeUS) was employed to improve the convergence of PMF calculations for the permeation of methanol and three common drug molecules. To obtain sufficient sampling of the umbrella histograms, which were computed only from the ground temperature, we modified the simulation time fraction spent at the ground temperature between 1/K and 50%, where K is the number of ST temperature states. We found that STeUS accelerates convergence, when compared to standard US, and that the benefit of STeUS is system-dependent. For bulky molecules, for which standard US poorly converged, the application of ST was highly successful, leading to a more than fivefold accelerated convergence of the PMFs. For the small methanol solute, for which conventional US converges moderately, the application of ST is only beneficial if 50% of the STeUS simulation time is spent at the ground temperature. This study establishes STeUS as an efficient and simple method for PMF calculations, thereby strongly reducing the computational cost of routine high-throughput studies of drug permeability.

Blow-up and lifespan estimates for solutions to the weakly coupled system of nonlinear damped wave equations outside a ball

In this paper, we consider the initial-boundary value problems with several fundamental boundary conditions (the Dirichlet/Neumann/Robin boundary condition) for the multi-component system of semi-linear classical damped wave equations outside a ball. By applying a test function approach with a judicious choice of test functions, which approximates the harmonic functions being subject to these boundary conditions on $$\partial \varOmega $$ , simultaneously we have succeeded in proving the blow-up result in a finite time as well as in catching the upper bound of lifespan estimates for small solutions in all spatial dimensions. Moreover, such kind of these results, which become sharp in the subcritical cases for one-dimensional case, will be discussed at the end of this paper.

Intradiscal treatment of the cartilage endplate for improving solute transport and disc nutrition.

Poor nutrient transport through the cartilage endplate (CEP) is a key factor in the etiology of intervertebral disc degeneration and may hinder the efficacy of biologic strategies for disc regeneration. Yet, there are currently no treatments for improving nutrient transport through the CEP. In this study we tested whether intradiscal delivery of a matrix-modifying enzyme to the CEP improves solute transport into whole human and bovine discs. Ten human lumbar motion segments harvested from five fresh cadaveric spines (38-66 years old) and nine bovine coccygeal motion segments harvested from three adult steers were treated intradiscally either with collagenase enzyme or control buffer that was loaded in alginate carrier. Motion segments were then incubated for 18h at 37 °C, the bony endplates removed, and the isolated discs were compressed under static (0.2MPa) and cyclic (0.4-0.8 MPa, 0.2Hz) loads while submerged in fluorescein tracer solution (376Da; 0.1mg/ml). Fluorescein concentrations from site-matched nucleus pulposus (NP) samples were compared between discs. CEP samples from each disc were digested and assayed for sulfated glycosaminoglycan (sGAG) and collagen contents. Results showed that enzymatic treatment of the CEP dramatically enhanced small solute transport into the disc. Discs with enzyme-treated CEPs had up to 10.8-fold (human) and 14.0-fold (bovine) higher fluorescein concentration in the NP compared to site-matched locations in discs with buffer-treated CEPs (p < 0.0001). Increases in solute transport were consistent with the effects of enzymatic treatment on CEP composition, which included reductions in sGAG content of 33.5% (human) and 40% (bovine). Whole disc biomechanical behavior-namely, creep strain and disc modulus-was similar between discs with enzyme- and buffer-treated CEPs. Taken together, these findings demonstrate the potential for matrix modification of the CEP to improve the transport of small solutes into whole intact discs.

On 1d Quadratic Klein–Gordon Equations with a Potential and Symmetries

This paper is a continuation of a previous work Germain-Pusateri (2020) by the first two authors. We focus on $1$ dimensional quadratic Klein-Gordon equations with a potential, under some assumptions that are less general than Germain-Pusateri (2020), but allow us to present some simplifications in the proof of global existence with decay for small solutions. In particular, we can propagate a stronger control on a basic $L^2$-weighted type norm while providing some shorter and less technical proofs for some of the arguments.

Infinitely Many Small Energy Solutions to Schrödinger-Kirchhoff Type Problems Involving the Fractional r(·)-Laplacian in RN

This paper is concerned with the existence result of a sequence of infinitely many small energy solutions to the fractional r(·)-Laplacian equations of Kirchhoff–Schrödinger type with concave–convex nonlinearities when the convex term does not require the Ambrosetti–Rabinowitz condition. The aim of the present paper, under suitable assumptions on a nonlinear term, is to discuss the multiplicity result of non-trivial solutions by using the dual fountain theorem as the main tool.

Liver Transplantation and dd-cfDNA: A Small Solution for a Big Problem

Dd-cfDNA is a novel biomarker with many diagnostic applications in various areas of medicine. In this review of the literature, we investigate its role in the diagnosis of many complications that occur in liver transplantations. In our review, we retrieved data from the medical databases PubMed and Scopus. In our bibliography, many areas concerning the contributions of dd-cfDNA to the field of liver transplantation, such as in the diagnosis of complications that include signsof rejection or graft injury, are mentioned. Dd-cfDNA, which are correlated with other biomarkers such as liver enzymes, can have a high diagnostic value. Measurements of Dd-cfDNA also depend on the graft’s size and origin; therefore, these data should be taken into account for the estimation and explanation of dd-cfDNA values. Despite the utility of this novel diagnostic technique, it comes with some limitations and applicational exclusions, such as cases where there is a blood relation between the donor and recipient.

An optimal control approach to the computation of g-g diagrams

The so-called g-g diagram is widely employed to assess the performance of road vehicles since it provides the maximum longitudinal and lateral accelerations that can be extracted from the selected vehicle. The different points of the g-g diagram are usually computed independently from one another, e.g. the maximum longitudinal accelerations corresponding to given lateral accelerations are computed sequentially. In this work, the problem of computing the points of the g-g diagram is transformed into an optimal control problem, which allows to avoid one of the most annoying practical problems often encountered when deriving such diagrams, namely the ‘jumps’ between different solutions (i.e. large slip vs. small slip solutions at similar lateral acceleration) in adjacent points along the g-g envelope. In the proposed method, the objective is to maximise the area enclosed within the g-g diagram, which has a polar representation. The rate of change of the radial coordinate is the control input. Additional constraints are included to enforce the continuity between the states of the vehicle model in adjacent points along the envelope. These conditions can hardly be enforced using standard methods based on sequential and independent computation of the g-g points. An example of the application of the method is demonstrated on the classic double-track car model with nonlinear tyres.

Critical exponent for global existence of solutions to the Schrödinger equation with a nonlinear boundary condition

We consider the nonlinear initial boundary value problem of one dimensional Schrödinger equation with the power nonlinearity of order q in boundary conditions. Our purpose in this paper is to prove that if q>2 and the initial data are small in suitable norms, then we have a global in time of solutions in a scale invariant space. Furthermore, we present a blow up result of small amplitude solutions when 1<q≤2 and derive an upper-bound of existence time Our results indicate that the quadratic nonlinearity is a critical exponent.