Results 121 to 130 of about 15,933 (255)

A Boothby–Wang Construction in Generalized Contact Geometry

open access: yesMathematische Nachrichten, EarlyView.
ABSTRACT We establish a generalized analogue of the Boothby–Wang theorem in generalized contact geometry, along with related results. We present a general method for constructing examples of generalized contact structures that are not of Poon–Wade type, and even examples that fail to be generalized contact structures.
Debjit Pal
wiley   +1 more source

Nonconstant Positive Steady States for a Predator–Prey System With Signal‐Dependent Diffusion

open access: yesMathematische Nachrichten, EarlyView.
ABSTRACT This paper investigates a highly nonlinear predator–prey reaction–diffusion system featuring signal‐dependent prey diffusion, where the motility of the prey is modulated by a chemical signal released by predators. For unbounded functional responses, we establish the global‐in‐time existence and uniform‐in‐time boundedness of classical ...
Qigang Deng   +3 more
wiley   +1 more source

Graded Differential Polynomial Rings

open access: yesMathematische Nachrichten, EarlyView.
ABSTRACT We study differential polynomial rings R[t;δ]$R[t;\delta]$ over Γ$\Gamma$‐graded rings, where Γ$\Gamma$ is an arbitrary group. We show that R[t;δ]$R[t;\delta]$ admits a Γ$\Gamma$‐grading compatible with that of R$R$ if and only if δ$\delta$ is a γ$\gamma$‐derivation for some γ∈CΓ(ΓR)$\gamma \in C_\Gamma (\Gamma _R)$, and that this grading is ...
Yassine Ait Mohamed
wiley   +1 more source

Decoding the Gut‐Brain Axis: Multi‐Omics Reveals a Causal Chain Linking Human Genome, Gut Microbiota, Blood Metabolites, and Alertness in the Brain

open access: yesMed Research, EarlyView.
This multi‐omics study identified genetic loci, gut microbiota, blood metabolites, and gray matter volumes of orbitofrontal cortex and cerebellum that were potentially relevant to alerting in healthy Chinese adults. Subsequent two‐step one‐sample Mendelian randomization further revealed a serial mediation pathway: Bacteroides intestinalis influences ...
Hongru Li   +8 more
wiley   +1 more source

Extending the hyper‐logistic model to the random setting: New theoretical results with real‐world applications

open access: yesMathematical Methods in the Applied Sciences, EarlyView.
We develop a full randomization of the classical hyper‐logistic growth model by obtaining closed‐form expressions for relevant quantities of interest, such as the first probability density function of its solution, the time until a given fixed population is reached, and the population at the inflection point.
Juan Carlos Cortés   +2 more
wiley   +1 more source

A highly accurate numerical method for solving boundary value problem of generalized Bagley‐Torvik equation

open access: yesMathematical Methods in the Applied Sciences, EarlyView.
A highly accurate numerical method is given for the solution of boundary value problem of generalized Bagley‐Torvik (BgT) equation with Caputo derivative of order 0<β<2$$ 0<\beta <2 $$ by using the collocation‐shooting method (C‐SM). The collocation solution is constructed in the space Sm+1(1)$$ {S}_{m+1}^{(1)} $$ as piecewise polynomials of degree at ...
Suzan Cival Buranay   +2 more
wiley   +1 more source

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