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The global public health concern of nitrate (NO 3 −) contamination in groundwater is particularly pronounced in irrigated agricultural regions. This paper aims to analyze the spatial distribution of groundwater NO 3 −, assess potential health risks for local residents, and quantitatively identify nitrate sources during different seasons and land use types in the Jinghuiqu Irrigation District, a region in northwestern China with a longstanding agricultural history. The investigation utilizes hydrochemical parameters, dual isotopic data, and the Bayesian stable isotope mixing model (MixSIAR). The findings underscore significant seasonal variations in the average concentrations of NO 3 −, with values of 87.72 mg/L and 101.87 mg/L during the wet and dry seasons, respectively. Furthermore, distinct fluctuations in nitrate concentration were observed across different land use types, whereby vegetable lands manifested the maximum concentration. Prolonged exposure to elevated nitrate concentrations may pose potential health risks to residents, especially in the dry season when the non-carcinogenic groundwater nitrate risk surges past its wet season counterpart. The MixSIAR analysis revealed that chemical fertilizers accounted for the majority of nitrate pollution in vegetable lands, both during the dry season (49.6%) and wet season (41.2%). In contrast, manure and sewage contributed significantly to NO 3 −concentrations in residential land during the wet (74.9%) and dry seasons (67.6%). For croplands, soil nitrogen emerged as a dominant source during the wet season (42.2%), while chemical fertilizers prevailed in the dry season (38.7%). In addition to source variations, the nitrate concentration of groundwater is further affected by hydrogeological conditions, with more permeable aquifers tending to display higher nitrate concentrations. Thus, targeted measures were proposed to modify or impede the nitrogen migration pathway, taking into consideration hydrogeological conditions and incorporating domestic sewage, organic fertilizer, and agricultural management practices. [Display omitted] • The permeability of aquifer affects the concentration of nitrate in groundwater. • Vegetable land is the area with the highest nitrate concentration in groundwater. • Nitrate concentration in the dry season was higher than that in the wet season. • Long-term agricultural activities lead to high nitrate concentration in groundwater. [ABSTRACT FROM AUTHOR]

Land use/land cover (LULC) is a crucial factor that directly influences the hydrology and water resources of a watershed. In order to assess the impacts of LULC changes on river runoff in the Danjiang River source area, we analyzed the characteristics of LULC data for three time periods (2000, 2010, and 2020). The LULC changes during these periods were quantified, and three Soil and Water Assessment Tool (SWAT) models were established and combined with eight LULC scenarios to quantitatively analyze the effects of LULC changes on river runoff. The results revealed a decrease in the cropland area and an increase in the forest, grassland, and urban land areas from 2000 to 2020. Grassland, forest, and cropland collectively accounted for over 94% of the total area, and conversions among these land types were frequent. The SWAT models constructed based on the LULC data demonstrated good calibration and validation results. Based on the LULC data in three periods, the area of each LULC type changed slightly, so the simulation results were not significantly different. In the subsequent LULC scenarios, we found that the expansion of cropland, grassland, and urban areas was associated with increased river runoff, while an increase in forest area led to a decrease in river runoff. Among the various LULC types, urban land exerted the greatest influence on changes in river runoff. This study establishes three SWAT models and combines multiple LULC scenarios, which is novel and innovative. It can provide scientific basis for the rational allocation of water resources and the optimization of LULC structure in the Danjiang River source area. • Land use changes from 2000 to 2020 in the study area were systematically analyzed. • Three SWAT models were set up to reveal river runoff responses to eight LULC scenarios. • Reduced river runoff from 2000 to 2010 was due to decreased cropland and increased forest. • Urban land expansion has the most apparent impacts on river runoff. [ABSTRACT FROM AUTHOR]

This paper is concerned with the stationary problem for a diffusive Lotka-Volterra predator-prey-mutualist model with a protection zone under homogeneous Neumann boundary conditions. Compared with the case where the mutualist is absent in [12] , this paper aims to reveal the effects of mutualism coefficients α and β on the existence, number and stability of steady states. It turns out that when α is large, the model has at most one steady state and it is stable (if it exists); however existence of multiple steady states is examined for large β , moreover asymptotic profiles of steady states are established as β tends to infinity. [ABSTRACT FROM AUTHOR]

This study was carried out to evaluate and analyze the fluctuations in groundwater for certain trace metals (Fe, Mn, Cu, Zn, Al, Cd, Cr, Pb, As, and Se) in Taizhou City over three years (2020–2022), evaluate the potential human health risks due to the consumption of groundwater. To quantify the spatiotemporal changes in groundwater trace metals, the heavy metal pollution index (HPI) and heavy metal evaluation index (HEI) were utilized. Furthermore, multivariate statistical methods were utilized to distinguish the sources of trace elements. Deterministic health risk assessment and Monte Carlo health risk simulation methods were employed to evaluate human health risks associated with exposure to trace metals. The results indicate that areas with higher pollution are in the south-central region, with low HPI increasing from 50% to 75% and low HEI from 68.75% to 81.25%, reflecting improved water quality. Correlation matrix analysis and principal component analysis (PCA) pinpointed anthropogenic sources as major trace metal contributors. Cr and As concentrations were associated with farming activities, Cd and Pb concentrations showed links to local industries such as e-waste recycling and shipbuilding. Furthermore, Cu levels in groundwater was influenced by the combined effects of industry, agriculture, and urban sewage discharge. Based on the hazard quotient (HQ) and hazard index (HI) calculations, the majority of groundwater samples did not exceed the reference values, indicating acceptable noncarcinogenic risks for both adults and children. However, the analysis of carcinogenic risk (CR) and uncertainty revealed an overall decreasing trend in carcinogenic risk, with Cr and Cd possessing the highest potential for causing carcinogenic risks. The sensitivities were 46.3%, 53.3%, and 70.3% for Cr, and 18.8%, 27.6%, and 9.3% for Cd. • Trace metals in groundwater showed decreasing trend from 2020 to 2022. • Groundwater trace metal contents were primarily influenced by human activities. • Cr and Cd are key carcinogens responsible for the cancer risk. [ABSTRACT FROM AUTHOR]

We study an integro-difference equation that describes the spatial dynamics of a species in a shifting habitat. The growth function is nondecreasing in density and space for a given time, and shifts at a constant speed c. The spreading speeds for the model were previously studied. The contribution of the current paper is to provide sharp conditions for existence of forced traveling waves with speed c. We show the existence of traveling waves with zero value at ∞ or −∞ for c in different value ranges determined by the spreading speeds. We also show the existence of a traveling wave with any speed c for the case that the species can grow everywhere. Our results demonstrate the existence of different types of traveling waves with the same speed. [ABSTRACT FROM AUTHOR]

In this paper, we continue to study a spatially heterogeneous predator–prey system where the interaction is governed by a Holling type II functional response, which has been studied in Du and Shi (2007) [14] . We further study the asymptotic profile of positive solutions and give a complete understanding of coexistence region. Moreover, a good understanding of the number, stability and asymptotic behavior of positive solutions is gained for large m . Finally, we further compare the difference of steady-state solutions between m > 0 and m = 0 . It turns out that the spatial heterogeneity of the environment and the Holling type II functional response play a very important role in this model. [ABSTRACT FROM AUTHOR]

Regenerative chatter is a major hindrance for achieving high quality and high production rate in machining processes. Various active controllers have been proposed to mitigate chatter. However, most of existing controllers were developed on the basis of multi-states feedback of the system and state observers were usually needed. Moreover, model parameters of the machining process (mass, damping and stiffness) were required in existing active controllers. In this study, an active sliding mode controller, which employs a dynamic output feedback sliding surface for the unmatched condition and an adaptive law for disturbance estimation, is designed, analyzed, and validated for chatter suppression in turning process. Only displacement measurement is required by this approach. Other sensors and state observers are not needed. Moreover, it facilitates a rapid implementation since the designed controller is established without using model parameters of the turning process. Theoretical analysis, numerical simulations and experiments on a computer numerical control (CNC) lathe are presented. It shows that the chatter can be substantially attenuated and the chatter-free region can be significantly expanded with the presented method. [ABSTRACT FROM AUTHOR]

In this paper, we consider a reaction–diffusion model with Degn–Harrison reaction scheme. Some fundamental analytic properties of nonconstant positive solutions are first investigated. We next study the stability of constant steady-state solution to both ODE and PDE models. Our result also indicates that if either the size of the reactor or the effective diffusion rate is large enough, then the system does not admit nonconstant positive solutions. Finally, we establish the global structure of steady-state bifurcations from simple eigenvalues by bifurcation theory and the local structure of the steady-state bifurcations from double eigenvalues by the techniques of space decomposition and implicit function theorem. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we consider an ecosystem of phytoplankton–nutrient which comes from pelagic zone of the ocean, by using remote sensing. We are concerned with the pattern formation of the model. We first give the asymptotic behavior of positive solutions of parabolic dynamical system. Then, we discuss the stability of constant positive solution and the boundedness of stationary solutions. Finally, the non-existence and existence results of the pattern are investigated by considering some parameters, the result shows that under certain range of these parameters, the pattern of the model occurs. [Copyright &y& Elsevier]

Abstract: We consider a diffusive predator–prey model with Beddington–DeAngelis functional response under homogeneous Dirichlet boundary conditions. The effect of large k which represents the extent of mutual interference between predators is extensively studied. By making use of the fixed point index theory, we obtain a complete understanding of the existence, uniqueness and stability of positive steady-states when k is sufficiently large. Moreover, we present some numerical simulations that supplement the analytic results in one dimension. [Copyright &y& Elsevier]

Abstract: Objective: Although overall survival is the ultimate goal of cancer therapy, many clinical and health economic decisions are taken when only progression free survival (PFS) data are available. This study evaluates the relationship between PFS and post progression survival (i.e. the time between disease progression and death) to estimate how many months a new drug for ovarian cancer might add to overall survival if the number of months the drug added to PFS (relative to a standard drug) was already known. Methods: A literature search was conducted over Medline for randomised controlled trials published between January 1990 and July 2010 that evaluated the effect of a drug treatment in comparison to alternative drug treatment in patients with either advanced stage primary or recurrent ovarian cancer. A systematic review of progression free and post progression survival (PPS) was performed. The relationship between PFS and PPS was evaluated by a graphical method and standard statistical tests. Results: Thirty-seven trials involving 15,850 patients met the inclusion criteria. The review found that increases in median PFS generally lead to little change in post-progression survival. Percentage gains in PFS are generally associated with no percentage gains or with very slight percentage gains or losses in post-progression survival Conclusion: If the effect of a new drug treatment for ovarian cancer is to extend median PFS by x months, then it is reasonable to estimate that the treatment will also extend median overall survival by x months. This information will be useful for individual and collective decision making. [Copyright &y& Elsevier]

Abstract: In this paper the existence and non-existence of traveling wave solutions are established for a bio-reactor model with stage-structure. The method to prove the existence of wave solutions is to construct an invariant cone of initial functions defined in a large but bounded domain, to apply a fixed point theorem on this cone and then extend to the unbounded spatial domain by a limiting argument. [Copyright &y& Elsevier]

Abstract: This paper is concerned with the existence and stability of periodic traveling curved fronts for reaction–diffusion equations with time-periodic bistable nonlinearity in two-dimensional space. By constructing supersolution and subsolution, we prove the existence of periodic traveling wave fronts. Furthermore, we show that the front is globally stable. [Copyright &y& Elsevier]

Abstract: This paper deals with a competition model between two species for two growth-limiting and perfectly complementary resources in the unstirred chemostat. The main purpose is to determine the exact range of the parameters of two species so that the system possesses positive solutions, and to investigate multiple positive steady states of the system. The main tools used here include the monotone methods and the topological fixed point theory developed by Amann. [Copyright &y& Elsevier]

Abstract: This paper deals with a chemostat model with an internal inhibitor. First, the elementary stability and asymptotic behavior of solutions of the system are determined. Second, the effects of the inhibitor are considered. It turns out that the parameter μ, which measures the effect of the inhibitor, plays a very important role in deciding the stability and longtime behavior of solutions of the system. The results show that if μ is sufficiently large, this model has no coexistence solution and one of the semitrivial equilibria is a global attractor when the maximal growth rate a of the species u lies in certain range; but when a belongs to another range, all positive solutions of this model are governed by a limit problem, and two semitrivial equilibria are bistable. The main tools used here include monotone system theory, degree theory, bifurcation theory and perturbation technique. [Copyright &y& Elsevier]

Abstract: For leaky prediction based FGS (Fine Granularity Scalability), constant quality constrained rate adaptation, i.e., how to optimally truncate/allocate bits given the current channel bandwidth, is still an open problem. The difficulty lies in obtaining accurate R–D (rate–distortion) curves for leaky prediction based FGS (L-FGS) due to the dependency among video frames. In this paper, we propose an accurate R–D model, which considers not only the distortion introduced in the current frame and the propagated distortion from the reference frame due to rate adaptation, but also the correlation between them. An excellent property of our proposed R–D model is that even when applying the model for a long video sequence without any update of the actual distortion values, the estimation error is still negligible and the error is not accumulated. Based on our proposed R–D model, a sliding window technique is further developed to solve the problem of constant quality constrained bit allocation. Experimental results show that the proposed R–D model is very accurate and the corresponding bit allocation algorithm can achieve much more smooth video quality than the traditional uniform bit allocation under both CBR (constant bit rate) and VBR (variable bit rate) channels. [Copyright &y& Elsevier]

Abstract: In this paper, we study joint source channel coding for bitplane based video coding over wireless channels. We consider using frame-level intra-mode to stop error propagation and using unequal error protection (UEP) to combat channel errors. Our focus is on how to optimally select coding modes and find UEP solutions for bitplane based video coding. In particular, we propose an overall end-to-end rate–distortion (R–D) function, which considers not only the source distortion and the channel distortion introduced in the current frame but also the propagated channel distortion from the previous frames. Based on this end-to-end R–D function, we are able to find the optimal solutions for both mode selection and UEP so that an optimal tradeoff between efficiency and robustness can be achieved. Experimental results demonstrate the significant performance gain. [Copyright &y& Elsevier]

Under the assumption of the product τ:=l+l of the regular differential expression l and its adjoint l+, being well-formed, a complete characterization of all the positive self-adjoint extensions of the minimal operator generated by τ in terms of boundary conditions is given. [Copyright &y& Elsevier]

The traveling wave solutions of a reaction–diffusion model with general functional responses are considered in this paper. A necessary and sufficient condition is established for the existence of traveling wave solutions. Moreover, the minimum speed, asymptotic behavior and uniqueness of traveling wave solutions are also obtained in relation to the interaction parameters. [ABSTRACT FROM AUTHOR]

In this paper, a predator-prey model with predator-stage structured and diffusion is concerned. We deal with the system by endowing it with the homogeneous Neumann boundary conditions. We first give the a priori estimates of positive solutions for the reduced reaction diffusion system. Secondly, we discuss the effects of predator cannibalism and prey growth on the stability of nonnegative constant steady states of the model in detail. Thirdly, we investigate the nonexistence and existence of nonconstant positive solutions. Finally, we discuss the Hopf bifurcation created by diffusion. [ABSTRACT FROM AUTHOR]

Abstract: We report on the synthesis and self-assembly behavior of a well-defined double hydrophilic brush–coil copolymer with poly(N-isopropylacrylamide)-b-poly(glycidly methacrylate) (PNIPAM-b-PGMA) as backbone and poly( l -glutamic acid) (PLGA) as brush. The PNIPAM-b-PGMA was firstly prepared by the sequential reversible addition–fragmentation chain transfer polymerization of N-isopropylacrylamide and glycidly methacrylate. The obtained diblock copolymer was reacted with ethylenediamine (EDA) yielding the aminated macroinitiator (PNIPAM-b-PGMA-EDA), which was then used to initiate ring-opening polymerization of γ-benzyl- l -glutamate-N-carboxyanhydride (BLG-NCA) to give PNIPAM-b-(PGMA-g-PBLG) copolymer. After the deprotection of benzyl groups on PBLG, double hydrophilic brush–coil copolymer, PNIPAM-b-(PGMA-g-PLGA), was obtained. The thermo- and pH-responsive micellization behaviors of PNIPAM-b-(PGMA-g-PLGA) in aqueous solution were investigated by fluorescence spectroscopy, 1H NMR, dynamic light scattering, scanning electron microscopy, and circular dichroism. It can self-assemble into PNIPAM-core micelles at pH 10 and elevated temperature and PLGA-core micelles at pH 4 and room temperature. Such brush–coil copolymers have the potential applications as biomedical and intelligent materials. [Copyright &y& Elsevier]

• Seven permutation polynomials of the form x + (Tr m n (x) k + δ) s are presented. • Three permutation polynomials of the form x + (Tr m n (x) k 1 + δ) s 1 + (Tr m n (x) k 2 + δ) s 2 are presented. • Accordingly, corresponding proofs are given in detail. In this paper, we propose several classes of permutation polynomials over F 2 2 m of the form x + (Tr m n (x) k + δ) s and x + (Tr m n (x) k 1 + δ 1) s 1 + (Tr m n (x) k 2 + δ 2) s 2 based on the AGW criterion. [ABSTRACT FROM AUTHOR]

In recent years, nanotechnology has been developing continuously. Due to their advantageous huge specific surface areas, microinterface characteristics, remediation ability and potential environmental risks, nanomaterials have become a hot topic in the field of environmental research. With the mass production and use of nanomaterials, they will inevitably be discharged or leaked into the water environment. In this paper, we will describe some typical nanomaterials, such as nanoscale zero valent iron (nZVI), graphene nanomaterials (GNMs), TiO 2 nanoparticles (NPs), ZnO NPs, Fe 3 O 4 NPs, carbon nanotubes (CNTs), Ag NPs, and other nanomaterials in water environments, focusing on the positive and negative effects of some nanomaterials in water environments. The remediation function and the impact of nanomaterials in water environments, including behavior of nanomaterials and their toxicity to aquatic organisms will be discussed. This will be of great significance for our subsequent research on nanomaterials. • The behavior of nanomaterials in the water environment (lakes, rivers, oceans and wetlands) was summarized. • The remediation effects and mechanisms of nanomaterials for the water environmental problems were reviewed. • Some nanomaterials can produce toxic effects on planktons and mocrobes in the water environment. [ABSTRACT FROM AUTHOR]

Abstract Diabetic nephropathy (DN) is one of the most common microvascular complications of diabetes mellitus and often results in chronic renal failure. Here, we found that Interleukin 1 receptor associated kinases (IRAK1) was up-regulated in kidney in both DN patients and high-fat diet (HFD)/streptozotocin (STZ)-induced diabetic mice. In vivo, down regulation of IRAK1 ameliorated renal injury and function, with lower podocyte apoptosis, increased expression of Nephrin, attenuated thickness of the glomerular basement membrane and podocyte footprocess effacement. Furthermore, in vitro , down regulation of IRAK1 in podocytes treated with high glucose (HG), podocyte apoptosis and inflammatory cytokines were significantly decreased, but Nephrin increased. Meanwhile, apoptosis-related genes caspase-3/-9 were inhibited and phosphorylation levels of PI3K/Akt were dramatically down regulated. Thus, IRAK1 is one of the critical components involved in podocyte apoptosis in DN. [ABSTRACT FROM AUTHOR]

F-box only protein 8 (FBX8), a novel component of F-box proteins, has recently been observed in several malignancies. However, its clinical implication in the progression of gastric cancer still remains unclear. The aim of this study was to explore the role of FBX8 in gastric cancer (GC) and analyze its correlation with tumor progression and prognosis. The expression of FBX8 in GC cell lines and matched pairs of fresh gastric cancer tissues were detected by real-time RT-PCR and Western blotting. Immunohistochemistry was used to analyze clinicopathological patterns of FBX8 in 136 cases of clinical paraffin-embedded GC tissues. A series of functional assays were conducted to evaluate the effect of FBX8 on proliferation and invasion in vitro and metastasis in vivo. FBX8 was markedly down-regulated in GC tissues compared to adjacent normal tissues. Patients with low FBX8 had shorter overall survival time and poor prognosis. Knocking down FBX8 obviously promoted proliferation and invasion in BGC823 cells, while over-expression of FBX8 in SGC7901 and AGS cells had the opposite effects. Moreover, FBX8 was sufficient to suppress metastasis in nude mice. Down-regulation of FBX8 significantly correlates with invasion, metastasis and poor survival time in GC patients. FBX8 may serve as a promising therapeutic target for inhibition of GC metastasis. [ABSTRACT FROM AUTHOR]

Abstract: CARMA3 was recently reported to be overexpressed in cancers and associated with the malignant behavior of cancer cells. However, the expression of CARMA3 and its biological roles in colon cancer have not been reported. In the present study, we analyzed the expression pattern of CARMA3 in colon cancer tissues and found that CARMA3 was overexpressed in 30.8% of colon cancer specimens. There was a significant association between CARMA3 overexpression and TNM stage (p =0.0383), lymph node metastasis (p =0.0091) and Ki67 proliferation index (p =0.0035). Furthermore, knockdown of CARMA3 expression in HT29 and HCT116 cells with high endogenous expression decreased cell proliferation and cell cycle progression while overexpression of CARMA3 in LoVo cell line promoted cell proliferation and facilitated cell cycle transition. Further analysis showed that CARMA3 knockdown downregulated and its overexpression upregulated cyclin D1 expression and phospho-Rb levels. In addition, we found that CARMA3 depletion inhibited p-IκB levels and NF-κB activity and its overexpression increased p-IκB expression and NF-κB activity. NF-κB inhibitor BAY 11-7082 reversed the role of CARMA3 on cyclin D1 upregulation. In conclusion, our study found that CARMA3 is overexpressed in colon cancers and contributes to malignant cell growth by facilitating cell cycle progression through NF-κB mediated upregulation of cyclin D1. [Copyright &y& Elsevier]

Abstract: E-selectin-mediated rolling on vascular surface of circulating leukocyte on vascular surface is a key initial event during inflammatory response and lymphocyte homing. This event depends not only on the specific interactions of adhesive molecules but also on the hemodynamics of blood flow. Little is still understood about whether wall shear stress or shear rate regulates the rolling. With flow chamber techniques, we here measured the effects of transport, shear stress and cell deformation on rolling of both unfixed and fixed HL-60 cells on E-selectin either in the absence or in the presence of 3% Ficoll in medium at various wall shear stresses from 0.05 to 0.7dyn/cm2. The results demonstrated a triphasic force-dependent rolling, that is, as increasing of force, the rolling would be accelerated firstly, then followed a decelerating phase occurred at the initial shear threshold of about 0.1dyn/cm2, and lastly returned to an accelerating process starting at the optimal shear threshold of 0.35dyn/cm2 approximately. The catch bond regime was completely reflected to rolling behaviors, such as tether lifetime, cell stop time and rolling velocity, meaning that the dominant factor to govern rolling is force. The initial shear threshold might be the minimum level of wall shear stress to sustain a stationary rolling, and the optimal shear threshold would make rolling to the most stable and regular. These findings strongly elucidate the catch bond mechanism for flow-enhanced rolling through E-selectin since longer bond lifetimes led to slower and stabler rolling. [Copyright &y& Elsevier]

Abstract: This paper is concerned with an autocatalysis model subject to no-flux boundary conditions. The existence of Hopf bifurcation are firstly obtained. Then by the center manifold theory and the normal form method, the direction of Hopf bifurcation and the stability of spatially homogeneous and inhomogeneous periodic solutions are established. On the other hand, the steady-state bifurcations from simple and double eigenvalues are intensively studied. The techniques of space decomposition and implicit function theorem are adopted to deal with the case of double eigenvalues. Finally, some numerical simulations are shown to verify the analytical results. [Copyright &y& Elsevier]