The threshold values of visceral fat area (VFA) proposed by existing studies for predicting metabolic syndrome (MetS) are contentious, necessitating further empirical evidence. We conducted a cross-sectional study to assess VFA using bioelectrical impedance analysis (BIA) technology among middle-aged and elderly individuals in the Sichuan area of China. Firstly, we compared the predictive ability of VFA, waist circumference (WC), and body mass index (BMI) among participants with MetS (excluding WC). In males, the area under the receiver operating characteristic curve (AUC) was 0.680 for VFA, 0.670 for WC, and 0.665 for BMI, with corresponding optimal cut-off values of 77.45 cm2, 83.50 cm, and 24.19 kg/m2. In females, the AUC values and optimal cut-offs were 0.628 (103.55 cm2) for VFA, 0.671 (77.50 cm) for WC, and 0.643 (24.32 kg/m2) for BMI. Additionally, for MetS defined with WC included, the AUC of VFA for prediction was higher in males (0.785) than in females (0.717), with optimal cut-offs of 85.15 cm2 (males) and 109.55 cm2 (females). Further age-stratified analysis revealed gender-specific VFA cut-offs: in males, 80.95 cm2 (45-59 years), 85.15 cm2 (60-74 years), and 77.50 cm2 (≥75 years); in females, 109.65 cm2 (45-59 years), 112.15 cm2 (60-74 years), and 103.05 cm2 (≥75 years). In conclusion, VFA is an effective predictor of MetS, with its optimal cut-off value varying by age and being higher in females than in males.

Kisspeptin, encoded by Kiss1 gene, regulates reproduction via the hypothalamic-pituitary-gonadal axis. While kisspeptin treatment promotes follicular development in Tan sheep, its direct action on ovarian granulosa cells remains unclear. For this, we first detected the expression of Kiss1 and its receptor Kiss1r in primary ovarian granulosa cells of Tan sheep. Second, the effect of kisspeptin on steroid hormone secretion, proliferation and apoptosis of ovarian granulosa cells was investigated. Third, the signaling pathway of kisspeptin regulating steroid hormone secretion was revealed by western bolting in ovarian granulosa cells. The results showed that the Kiss1 and Kiss1r genes were present in ovarian granulosa cells of Tan-sheep, and 500 nM dose of kisspeptin significantly stimulated steroids hormone secretion (P < 0.05), and up-regulated StAR, HSD17B2, CPY19A1, FSHR, LHR, ERβ, PGR and p-ERK1/2 proteins expression (P < 0.05). Moreover, this treatment significantly promoted cell proliferation and increased the proportion of cells in S phase (P < 0.05), and significantly suppressed granulosa cell apoptosis (P < 0.05). Additionally, the stimulatory effects of kisspeptin on estradiol and progesterone secretion were blocked by inhibitors of the Mitogen-activated Protein Kinase (MAPK) signaling pathway (including PKA inhibitor, PLC inhibitor, PKC inhibitor, and Ca2+inhibitor). Western blot analysis confirmed that kisspeptin regulates steroid hormone secretion primarily through the MAPK-ERK signaling pathway. Our results demonstrate that kisspeptin can directly act on ovarian granulosa cells to promote steroidogenesis, proliferation, and inhibit apoptosis, providing a foundational basis for developing novel kisspeptin-mediated techniques to regulate reproduction in Tan sheep.

Alterations in hypothalamic–pituitary–adrenal axis function may underlie the relation between childhood maltreatment and nonsuicidal self-injury (NSSI) behaviors. This study examined how co-occurring patterns of maltreatment types influenced adolescent NSSI behaviors and the mediating role of diurnal cortisol, using a longitudinal design. The sample included 295 Chinese adolescents (Mage = 10.79 years, SD = 0.84 years; 67.1% boys). The study employed latent profile analysis to identify childhood maltreatment patterns and conducted path analysis to examine the mediating mechanism. Four maltreatment patterns were identified: Low Maltreatment (67.8%), High Neglect (15.6%), Moderate Maltreatment (10.2%), and High Abuse with Moderate Neglect (6.4%). Furthermore, compared to the Low Maltreatment profile, adolescents in the High Neglect profile were at increased risk for later NSSI behaviors through higher waking cortisol levels, while those in the High Abuse with Moderate Neglect profile were at increased risk through a steeper diurnal slope. Disturbances in diurnal cortisol rhythm serve as a pathway through which childhood maltreatment “gets under the skin” to lead to adolescent NSSI behaviors. These findings offer promise for identifying maltreated youth at risk for NSSI behaviors and informing targeted prevention strategies.

Analytical expressions for the mean wall-normal velocity and wall shear stress in compressible boundary layers are derived by integrating the mean continuity and momentum equations. In the constant-density limit, the momentum integral formulation recovers the classical Kármán–Pohlhausen equation for incompressible boundary-layer flows. In compressible regimes, particularly under strong pressure gradients, streamwise density gradients are shown to play a crucial role in shaping boundary-layer dynamics. The derived analytical equations are validated against high-fidelity direct numerical simulation data, demonstrating both accuracy and robustness. Furthermore, the analytical equations offer insights into the physical mechanisms of compressible boundary layers, particularly the influence of density gradients. The effect of compressibility on the wall-normal velocity is explicitly demonstrated, highlighting the distinct behaviour of compressible boundary layers compared with incompressible flows. Finally, an analytical expression for the skin-friction coefficient is developed, revealing its close connection to the mean wall-normal velocity at the boundary-layer edge.

Robotic manufacturing systems offer significant advantages, including increased flexibility and reduced costs. However, challenges in trajectory planning, error compensation, and system integration hinder their broader application in additive manufacturing. To address these issues, this paper proposes a generalized non-parametric trajectory planning method tailored for robotic additive manufacturing. The proposed trajectory planner incorporates chord error and speed continuity constraints and integrates the look-ahead planning with real-time interpolation in a parallel structure to ensure smooth transitions in the robot’s trajectory. Additionally, a real-time path tracking control method is introduced, combining RBF neural network-based dynamic feedforward control with visual servoing-based feedback control. This control strategy significantly improves the robot’s tracking accuracy, particularly for complex additive manufacturing paths that involve multiple short connected line segments and frequent speed variations. The effectiveness of the proposed methods is validated through experiments on a robotic additive manufacturing platform. The experimental results (line segment, circular arc segment, and continuous path tracking) show that the robot’s tracking error remains within $\pm$0.15 mm and $\pm 0.05^{\circ }$.

The digital transformation of Chinese companies offers a new frontier for organizational research. Widespread use of workplace platforms creates rich archives of unobtrusive data, providing continuous, real-time insights into organizational life that traditional surveys cannot capture. The central challenge for scholars is turning this data abundance into meaningful theory. This special issue highlights three studies that meet this challenge by using innovative methods to convert granular data into valuable knowledge. The papers employ digital-context experiments, real-time behavioral tracking, and machine-learning-assisted theory building to study phenomena from interpersonal dynamics to crisis productivity. Looking ahead, we explore the potential of unstructured multimodal data and new AI tools to make complex analysis more accessible. We conclude with a research agenda calling for methodological rigor, interdisciplinary collaboration, and a firm balance between technological innovation and theoretical depth.

This paper is concerned with the following problem involving almost critical growth

\begin{equation*}\begin{cases}(-\Delta) ^su=|u|^{2_{s}^{*}-2-\varepsilon}u,& \text{in } \varOmega ,\\u=0,& \text{on } \Sigma ,\\\end{cases}\end{equation*}

where $2_{s}^{*}=\frac{2N}{N-2s}$, $s\in(\frac{1}{2},1)$, $N \gt 2s$, Ω is a bounded domain in $\mathbb{R}^N$, ɛ is a small parameter, and the boundary Σ is given in different ways according to the different definitions of the fractional Laplacian operator $(-\Delta)^{s}$. The operator $(-\Delta)^{s}$ is defined in two types: the spectral fractional Laplacian and the restricted fractional Laplacian. For the spectral case, Σ stands for $\partial \Omega$; for the restricted case, Σ is $\mathbb{R}^{N}\setminus \Omega$. Firstly, we provide a positive confirmation of the fractional Brezis–Peletier conjecture, that is, the above almost critical problem has a single bubbling solution concentrating around the non-degenerate critical point of the Robin function. Furthermore, the non-degeneracy andlocal uniqueness of this bubbling solution are established.

This study applies the scaling patch approach to investigate the influence of pressure gradients on the mean-momentum balance in turbulent boundary layers (TBLs). Under strong pressure gradients, the force balance in the outer region is dominated by advective and pressure forces, with gradients of Reynolds stresses playing a minimal role. To retain the relevance of Reynolds stress gradients within the scaling patch framework, we propose a redistribution of the component $U_e \textrm {d}U_e/\textrm {d}x$ from the advective term to the pressure-gradient term. Here, $U_e$ is the mean streamwise velocity at the boundary layer edge. This reformulation enhances the outer-scaling framework of Wei & Knopp (2023 J. Fluid Mech. 958, 1–21), ensuring consistency across a wide range of pressure gradients, including those involving flow separation. Remarkably, the new outer-scaled gradient of Reynolds shear stress in TBLs under a pressure gradient closely resembles that observed in zero-pressure-gradient TBLs. In the inner region, the impact of pressure gradient is well captured by the Stratford–Mellor parameter $\beta _{\textit{in}}$. For weak pressure gradients ($|\beta _{\textit{in}}| \ll 0.07$), traditional inner scaling remains valid. However, for stronger pressure gradients $|\beta _{\textit{in}}| \gtrsim 0.07$, the near-wall dynamics is governed by a balance between pressure gradient and viscous force, as described by Stratford (1959 J. Fluid Mech. 5, 1–16) and Mellor (1966 J. Fluid Mech. 24, 255–274). In this sub-layer, viscosity and the imposed wall pressure gradient dictate the relevant velocity and length scales. Moreover, when $|\beta _{\textit{in}}| \gtrsim 0.7$ and the wall pressure $P_{w\textit{all}}$ gradient $\textrm { d}P_{w\textit{all}}/\textrm {d}x \gt 0$, a distinct sub-layer emerges outside the pressure–viscous balance region, characterised by a dominant balance between the imposed pressure gradient and the gradient of the Reynolds shear stress. In this region, the Reynolds shear stress increases linearly with distance from the wall. These findings provide new insights into the structure of TBLs under pressure gradients and establish a refined framework for modelling their dynamics.

Butachlor is a herbicide extensively employed in rice (Oryza sativa L.) cultivation but historically under-investigated for its toxicological impacts on terrestrial vegetation. This study examines the dose-dependent effects of butachlor on the germination and antioxidant defense mechanisms in the seeds of Asian tape grass [Vallisneria natans (Lour.) H. Hara], an important submerged plant species widely distributed in the agricultural ponds. In a hydroponic setup, seeds were exposed to four concentrations of butachlor (0, 20, 200, and 2,000 μg ai L−1), and cultivated under controlled light conditions to quantify germination rates and assess oxidative stress responses. Our findings showed that butachlor concentrations up to 20 μg L−1 had no effect on the germination rate of V. natans seeds, while germination rates decreased by 6.0% and 8.7% at 200 and 2,000 μg L−1, respectively. At 2,000 μg L−1, malondialdehyde (MDA) content increased by 5.7 nmol g−1 FW, and catalase (CAT) activity declined by 21%, indicating oxidative damage. Additionally, the antioxidants proline (Pro) and glutathione (GSH) were upregulated under 20 μg L−1 butachlor treatment after 12 h, contributing to reactive oxygen species (ROS) scavenging and cellular stability. This study highlights the nuanced interactions between butachlor exposure and the antioxidant defenses in V. natans, providing valuable insights into the ecological impacts of herbicide pollution. Understanding these interactions is crucial for development of sustainable agricultural practices and management of herbicide resistance in aquatic systems.

This paper studies a distributed fixed-time dynamic event-triggered formation control framework for a group of hypersonic gliding vehicles (GHGVs) suffering from internal uncertainties and non-affine properties. The main challenge is strong coupling of non-affine nonlinear dynamic with hypervelocity characteristics and multi-source uncertainties make it difficult to design the control protocol. Firstly, by integrating the distributed consensus control strategy, fractional order control theory and dynamic event-triggered mechanism, a framework of fixed-time formation control for GHGVs system is constructed. Secondly, to mitigate the issue of ‘explosion of complexity’ (EI), a fixed-time command filter (FCF) is proposed and a compensative strategy is formulated to tackle the impact of filtering errors. Thirdly, an additional auxiliary differential equation (ADE) is developed to decouple the control input from the status variable. Several radial base function neural networks (RBFNN) are utilised to handle the unknown internal uncertainties. Furthermore, a unique dynamic event-triggered mechanism (DTEM) is introduced for each follower, facilitating seamless transitions between two distinct dynamic threshold strategies. Analysis based on Lyapunov function illustrates that the output tracking error of followers exponentially converges to a small range within a fixed time, and Zeno behaviour is prevented. Finally, several numerical simulations are presented to demonstrate the practicability and meliority of the suggested approach.

This article proposes a dielectric waveguide bandpass filter (BPF) with good stopband suppression based on different kinds of dielectric waveguide resonators (DWRs). Three distinct types of DWRs are modified from the traditional rectangular DWR, i.e., one with a metallized blind hole, one with a metallized U-shaped slot and another one with a pair of parallel ridges. These resonators are designed that their fundamental mode frequencies are basically the same and their higher-order modes are staggered. As a result, the higher-order modes can be suppressed to a certain extent when conducting BPF designs. For verification, a sixth-order BPF with an operating frequency band ranging from 3.4 to 3.5 GHz is designed, fabricated and measured. It is composed of the above three distinct types of DWRs, with a deliberate arrangement that prevents the DWRs of the same type from being adjacent to each other, guaranteeing that the harmonics are well suppressed. In measurement, the in-band return loss is better than 12 dB, the minimum in-band insertion loss is about 1.0 dB. Besides, the 20 dB out-of-band suppression reaches 6.9 GHz, which is almost twice the center frequency.

The $L^p$ boundedness of the commutator $[b, T]$ has been intensively studied in recent decades in part because it has important connections and applications to partial differential equations. Inspired by these works, we study the boundedness and compactness of the Riesz transform commutator in a general setting, namely, in the scale of Lorentz spaces and on stratified Lie groups. In this article, we provide a complete characterization between the space of the symbol b and the Lorentz estimates of $[b, R_j]$.