Femtosecond laser-induced filamentation typically exhibits pronounced spectral broadening, featuring a bright central white core encircled by concentric colored rings that span from the ultraviolet to the visible range and extend into the infrared. While ionization, self-steepening and self-phase modulation are widely accepted as explanations for the white spot, the underlying physics of colored rings remain inadequately understood by current models, such as Cherenkov radiation and four-wave mixing. In this study, inspired by the observation of similar discrete colored rings produced by cascaded four-wave mixing (CFWM) of intersecting beams, we systematically investigated the relationship between the colored rings in the white-light supercontinuum and CFWM. The CFWM model accurately predicted the correlation between color and divergence angles, thereby enhancing our understanding of spectral broadening in filamentation and providing guidance for optimizing the conversion efficiency and configuration of multi-wavelength ultrashort optical pulses in both spatial and spectral domains.

We introduce the concept of dual Lyapunov exponents, leading to a multiplicative version of the classical Jensen’s formula for one-frequency analytic Schrödinger cocycles. This formula, in particular, gives a new proof and a quantitative version of the fundamentals of Avila’s global theory [3], fully explaining the behavior of complexified Lyapunov exponent through the dynamics of the dual cocycle. The key concepts of (sub/super) critical regimes and acceleration are all explained (in a quantitative way) through the duality approach. In particular, for trigonometric polynomial potentials, we establish partial hyperbolicity of the dual symplectic cocycle and show that the acceleration is equal to half the dimension of its center, this holding also in the appropriate sense for the general analytic case. These results lead to a number of powerful spectral and physics applications.

This study examines how internal CEO alliances, defined as social and structural ties between CEOs, subordinate executives, and board members, influence corporate carbon performance. Drawing on data from 36 countries over the period 2002–2023, we find that strong internal alliances are associated with weaker carbon performance, suggesting that concentrated internal power may hinder firms’ emission reduction efforts. However, this adverse effect is significantly moderated by various organizational and institutional factors. Specifically, it is attenuated in contexts characterized by stringent environmental regulation, robust media oversight, high regulatory quality, and greater board gender diversity. At the individual level, CEO characteristics such as hometown affiliation and older age also appear to reduce the negative influence of internal alliances. These findings advance our understanding of how CEO power dynamics interact with external and internal governance mechanisms to influence firms’ climate-related outcomes.

The diversity and stability of the gut microbiota, along with various microbial and host–microbe interactions, are crucial factors in maintaining a healthy state. In this study, a total of 12 healthy 1–2 years old cats of similar weight were recruited and divided into two groups according to the experimental design and breed: the British shorthair (BS) group and the nulla luctus felis (NLF) group. After 21 days of the same diet, we analyzed and compared the gut microbiota of BS and NLF. Our results showed that the values of the serum biochemical indicators of the BS and NLF selected for this experiment were within the normal range. The Venn diagram showed that the two groups had 310 common operational taxonomic units. Significant differences in beta diversity (P < 0.05), but not in alpha diversity (P > 0.05), distinguished the two groups. Comparative analysis revealed the NLF group was enriched in Lactobacillus and Bacillus, but depleted in Enterococcus at the genus level (P < 0.05). Furthermore, 59 taxa were established as biomarkers based on a linear discriminant analysis score greater than 3.5. According to PICRUSt2 function analyses, the BS group and NLF group had a ratio of 77.11% and 76.55% for metabolism at level 1, respectively. At level 3, the NLF group significantly increased 15 metabolism pathways, while decreasing 13 metabolism pathways (P < 0.05). Finally, NLF-P1, which was screened from the feces of NLF, exhibited a good antibacterial effect on three strains of pet-associated pathogens, and the evolutionary tree was constructed to show that it may be Lactobacillus paracasei or Lactobacillus casei. In conclusion, there were significant differences in intestinal microbiota composition between BS and NLF, and NLF-P1 has research and application potential.

Path planning, as a critical component of mobile robotic systems, significantly impacts operational efficiency and energy consumption ratios. State-of-the-art algorithms often suffer from inadequate real-time adjustment capability, insufficient dynamic environment adaptation, and suboptimal computational efficiency. To resolve these limitations, we propose a bidirectionally optimized path planning algorithm named Bidirectional Q-learning LPA* (BQ-LPA*), which incorporates three key innovations. Specifically, to enhance the global search capability of the LPA* framework, we replace fixed heuristic functions with a Q-learning-driven adaptive heuristic mechanism, which improves path quality through dynamic heuristic weighting and update strategies. Additionally, to improve the convergence rate and sample efficiency of Q-learning in complex environments, we propose integrating the LPA* framework to provide prior knowledge guidance, which can effectively minimize redundant exploration attempts by informed pathfinding initialization. Moreover, the Q-learning method inherently faces dimensionality challenges in high-dimensional continuous spaces, which manifest as action space congestion, storage bottlenecks, and computational inefficiency. To mitigate these risks, we devise an LPA*-based space discretization strategy that can reduce action space dimensionality and preserve the path feasibility. Experimental results show that, compared with mainstream path planning algorithms, BQ-LPA* achieves higher accuracy and faster convergence in mobile robot path planning.

In this paper, we numerically investigate the orbit dynamics of three-dimensional symmetric Janus drops in shear flow using an improved ternary-fluids phase field method, focusing on how drop deformation and initial orientation affect the orbit drift of two configurations of Janus drops: dumbbell-shaped and near-spherical. We find that the motion of dumbbell-shaped drops eventually evolves into tumbling, while near-spherical drops attain stable spinning. We attribute this bifurcation in orbit drift to contrasting deformation dynamics and shape-dependent hydrodynamics of the two configurations. Specifically, the drift bifurcation is closely related to the aspect ratio of Janus drops at equilibrium, giving rise to two distinct mechanisms: (1) coupling between outer interface deformation and the surrounding flow field; and (2) interplay between inner interface deformation and vortices enclosed within the drop. In addition, we observe that for the dumbbell-shaped Janus drops with different aspect ratios, their tumbling dynamics resembles ellipsoids in shear flow. Moreover, the trajectories of the dumbbell-shaped Janus drops during orbit drift collapse onto a universal curve, independent of their initial orientations, and significant deformation and inertia accelerate the orbit transition. To quantitatively evaluate the effect of drop deformation on the orbit drift of the dumbbell-shaped Janus drops, we propose an effective aspect ratio model based on the drop shapes at equilibrium and at the maximum elongation. By incorporating the effective aspect ratio into Jeffery’s theory for solid particles, we accurately predict the rotation period and angular velocity of Janus drops in the tumbling regime and during the orbit drift, especially for drops with linear deformation. Moreover, the orbit parameter $C$ is found to vary exponentially with time for drops with linear deformation, while the time variation of $C$ transits from one exponential function to another for drops with nonlinear deformation.

We develop and test a theoretical model to investigate the effects of faultlines within the top management team (TMT) on corporate financial fraud. We propose that TMT faultlines can generate mutual monitoring among factional subgroups in the executive suite, which reduces fraudulent behavior. We also examine the contingent roles of subgroup configuration and the TMT members’ tenure overlap in shaping the relationship between TMT faultlines and financial fraud. The mutual monitoring effect is likely to be stronger when the TMT has a balanced subgroup configuration and shorter TMT members’ tenure overlap. We test our argument in the context of publicly listed firms in China. This article extends the mutual monitoring perspective of corporate governance and has important research implications for the corporate financial fraud literature.

Intrinsic capacity, introduced by the WHO, represents a shift in focus from treating disease to maintaining physical and mental capacities individuals as they age. It encompasses five interrelated domains: vitality, sensory, cognition, psychology, and locomotion. Vitality refers to the body’s physiological reserve and is shaped by processes such as energy metabolism, immune function, and neuromuscular integrity. By definition, vitality is closely linked to nutritional status, which plays a central role in maintaining resilience and health in older adults. However, integrating nutritional status into the vitality domain presents several challenges due to inconsistent definitions and varied measurement approaches. This review examines these challenges and explores possibilities for integrating nutritional status in the vitality domain. The absence of standardised nutrition-related indicators limits comparability across studies and constrains the practical application of intrinsic capacity in both research and clinical contexts. To strengthen the role of intrinsic capacity in nutritional monitoring, it is essential to reach consensus on which nutritional indicators to include and how to score them consistently. Addressing these methodological challenges will support the use of intrinsic capacity in identifying early signs of nutritional decline and guiding timely interventions to promote healthy ageing.

What are the effects of campaigns of coercive social mobilization on political attitudes? We show that such policies can strengthen authoritarian regimes by altering citizens’ patterns of trust. From 1968 to 1978, 16–17 million Chinese teenagers were “sent-down” to labor in rural areas, where they lived without their families under difficult conditions. Using a regression discontinuity design to account for selection into being sent-down, we show that former sent-down students are more critical of local government performance compared to their counterparts, yet they are less critical of the national government and generally more supportive of the regime. We see no significant differences in political participation, though there is some suggestive evidence that the sent-down students are more likely to favor officially sanctioned political activities. These results appear to stem from the close social control and isolation from family associated with the sent-down experience.