26,551 research outputs found
Resonant response of forced complex networks: the role of topological disorder
We investigate the effect of topological disorder on a system of forced
threshold elements, where each element is arranged on top of complex
heterogeneous networks. Numerical results indicate that the response of the
system to a weak signal can be amplified at an intermediate level of
topological disorder, thus indicating the occurrence of
topological-disorder-induced resonance. Using mean field method, we obtain an
analytical understanding of the resonant phenomenon by deriving the effective
potential of the system. Our findings might provide further insight into the
role of network topology in signal amplification in biological networks.Comment: 12 pages, 4 figure
The Lax pair for C_2-type Ruijsenaars-Schneider model
We study the C_2 Ruijsenaars-Schneider(RS) model with interaction potential
of trigonometric type. The Lax pairs for the model with and without spectral
parameter are constructed. Also given are the involutive Hamiltonians for the
system. Taking nonrelativistic limit, we obtain the Lax pair of C_2
Calogero-Moser model.Comment: LaTeX2e, 10 pages, some misprints corrected and sections rearrange
Quantum Impurity in Luttinger Liquid: Universal Conductance with Entanglement Renormalization
We study numerically the universal conductance of Luttinger liquids wire with
a single impurity via the Muti-scale Entanglement Renormalization Ansatz
(MERA). The scale invariant MERA provides an efficient way to extract scaling
operators and scaling dimensions for both the bulk and the boundary conformal
field theories. By utilizing the key relationship between the conductance
tensor and ground-state correlation function, the universal conductance can be
evaluated within the framework of the boundary MERA. We construct the boundary
MERA to compute the correlation functions and scaling dimensions for the
Kane-Fisher fixed points by modeling the single impurity as a junction (weak
link) of two interacting wires. We show that the universal behavior of the
junction can be easily identified within the MERA and argue that the boundary
MERA framework has tremendous potential to classify the fixed points in general
multi-wire junctions.Comment: 14 pages, 18 figure
Does Exposure to Shared Solutions Lead to Better Outcomes? An Empirical Investigation in Online Crowdsourcing Contests
Crowdsourcing contests provide an effective way to elicit novel ideas and creative solutions from collective intelligence. A key design feature of crowdsourcing contests is the competition between contest participants to complete a specific task with financial awards to the winner(s). In recent years, some crowdsourcing contest platforms provide options to contest participants for solution sharing during the competition. This study intends to evaluate the influence of exposure to shared solutions on different stakeholders, including the team, and the requester. Our study employs a multiple-level panel data from a large online crowdsourcing platform, Kaggle.com, to examine these effects. For teams, exposure to shared solutions helps new entrant teams to jump-start and help teams to achieve better performance in the subsequent submissions, and the teams’ skill level negatively moderates these positive effects. For requesters, allowing solution sharing has both benefits and costs in terms of improving the best performance of the crowd. We highlight the theoretical implications of the study and provide practical suggestions for crowdsourcing contest platforms to help them decide whether to allow solution sharing during the competition
Microglia at sites of atrophy restrict the progression of retinal degeneration via galectin-3 and Trem2
Outer retinal degenerations, including age-related macular degeneration (AMD), are characterized by photoreceptor and retinal pigment epithelium (RPE) atrophy. In these blinding diseases, macrophages accumulate at atrophic sites, but their ontogeny and niche specialization remain poorly understood, especially in humans. We uncovered a unique profile of microglia, marked by galectin-3 upregulation, at atrophic sites in mouse models of retinal degeneration and human AMD. In disease models, conditional deletion of galectin-3 in microglia led to phagocytosis defects and consequent augmented photoreceptor death, RPE damage, and vision loss, indicating protective roles. Mechanistically, Trem2 signaling orchestrated microglial migration to atrophic sites and induced galectin-3 expression. Moreover, pharmacologic Trem2 agonization led to heightened protection but in a galectin-3-dependent manner. In elderly human subjects, we identified this highly conserved microglial population that expressed galectin-3 and Trem2. This population was significantly enriched in the macular RPE-choroid of AMD subjects. Collectively, our findings reveal a neuroprotective population of microglia and a potential therapeutic target for mitigating retinal degeneration
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