Results 51 to 60 of about 735,632 (298)
Signed degree sets in signed graphs [PDF]
Czechoslovak Mathematical Journal, 2007 The set D of distinct signed degrees of the vertices in a signed graph G is called its signed degree set. In this paper, we prove that every non-empty set of positive (negative) integers is the signed degree set of some connected signed graph and determine the smallest possible order for such a signed graph.
Pirzada, S., Naikoo, T. A., Dar, F. A.
openaire +2 more sources
From mice to humans—divergent strategies for intestinal homeostasis and regeneration
FEBS Letters, EarlyView.Recent advances such as organoid genome editing, xenotransplantation, imaging, and whole‐genome sequencing have enabled direct studies of human intestinal stem cells (ISCs). These studies reveal species‐specific features, including slower ISC proliferation, distinct injury responses, slower somatic mutation accumulation in humans, and an inverse ...
Keiko Ishikawa +2 more
wiley +1 more source
Discrete Applied MathematicsLet $G$ be a graph and $A$ be its adjacency matrix. A graph $G$ is invertible if its adjacency matrix $A$ is invertible and the inverse of $G$ is a weighted graph with adjacency matrix $A^{-1}$. A signed graph $(G,σ)$ is a weighted graph with a special weight function $σ: E(G)\to \{-1,1\}$. A graph is sign-invertible (or sign-invertible) if its inverse
Isaiah Osborne, Dong Ye 0002
openaire +2 more sources
Signed degree sequences of signed graphs [PDF]
Journal of Graph Theory, 1997 \textit{G. Chartrand}, \textit{H. Gavlas}, \textit{F. Harary} and \textit{M. Schultz} [Czech. Math. J. 44, No. 4, 677-690 (1994; Zbl 0837.05110)] asked whether \textit{S. L. Hakimi's} procedure [SIAM J. Appl. Math. 10, 496-506 (1962; Zbl 0109.16501)] for degree sequences in graphs also works for signed degree sequences.
Jing-Ho Yan +3 more
openaire +3 more sources
Design and analysis strategies for robust microbiome ageing research
FEBS Letters, EarlyView.The gut microbiome changes with age and associates with age‐related morbidity and mortality, establishing it as a potential biomarker and intervention target for ageing. Realising this potential requires methodological rigour, yet distinguishing biological signals from methodological artefacts remains challenging across cohorts. This review provides an
Mark Olenik +5 more
wiley +1 more source
Further Results on the Nullity of Signed Graphs
Journal of Applied Mathematics, 2014 The nullity of a graph is the multiplicity of the eigenvalue zero in its spectrum. A signed graph is a graph with a sign attached to each of its edges. In this paper, we apply the coefficient theorem on the characteristic polynomial of a signed graph and
Yu Liu, Lihua You
doaj +1 more source
On composition of signed graphs
Discussiones Mathematicae Graph Theory, 2012 A graph whose edges are labeled either as positive or negative is called a signed graph. In this article, we extend the notion of composition of (unsigned) graphs (also called lexicographic product) to signed graphs. We employ Kronecker product of matrices to express the adjacency matrix of this product of two signed graphs and hence find its ...
K. Augustine Germina +1 more
openaire +1 more source
Microbiome‐blood–brain barrier interactions in aging — mechanisms and therapeutic potential
FEBS Letters, EarlyView.Aging reshapes the gut microbiome (↓SCFA‐producing commensals; ↑pro‐inflammatory outputs), shifting circulating metabolites (↓SCFAs; ↑LPS, ↑TMAO, ↑PAA) that act at the BBB to increase nonspecific transcytosis, alter transport, and promote astrocyte reactivity, heightening brain vulnerability.
Daniel Cuervo‐Zanatta +3 more
wiley +1 more source
European Journal of Combinatorics, 1991 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
openaire +2 more sources
A Graph Convolution for Signed Directed Graphs
CoRR, 2022 Preprint ...
Ko, Taewook, Kim, Chong-Kwon
openaire +2 more sources