Results 41 to 50 of about 10,270 (229)

Q-system Cluster Algebras, Paths and Total Positivity

Symmetry, Integrability and Geometry: Methods and Applications, 2010
In the first part of this paper, we provide a concise review of our method of solution of the A_r Q-systems in terms of the partition function of paths on a weighted graph. In the second part, we show that it is possible to modify the graphs and transfer
Philippe Di Francesco, Rinat Kedem
doaj   +1 more source

Total positivity of recursive matrices

Linear Algebra and its Applications, 2015
Let $A=[a_{n,k}]_{n,k\ge 0}$ be an infinite lower triangular matrix defined by the recurrence $$a_{0,0}=1,\quad a_{n+1,k}=r_{k}a_{n,k-1}+s_{k}a_{n,k}+t_{k+1}a_{n,k+1},$$ where $a_{n,k}=0$ unless $n\ge k\ge 0$ and $r_k,s_k,t_k$ are all nonnegative. Many well-known combinatorial triangles are such matrices, including the Pascal triangle, the Stirling ...
Chen, Xi, Liang, Huyile, Wang, Yi
openaire   +3 more sources

Engineered extracellular vesicles enriched with the miR‐214/199a cluster enhance the efficacy of chemotherapy in ovarian cancer

Molecular Oncology, EarlyView.
Loss of the miR‐214/199a cluster is associated with recurrence in ovarian cancer. Engineered small extracellular vesicles (m214‐sEVs) elevate miR‐214‐3p/miR‐199a‐5p in tumor cells, suppress β‐catenin, TLR4, and YKT6 signaling, reprogram tumor‐derived sEV cargo, reduce chemoresistance and migration, and enhance carboplatin efficacy and survival in ...
Weida Wang, Ayesha Alvero, Yi Qin, Mingjin Wang, Alexandra Fox, Yanfeng Li, Michael Millman, Amy Kemper, Gil Mor, Xian Shuang Liu, Michael Chopp, Zheng Gang Zhang, Yi Zhang   +12 more
wiley   +1 more source

Intervals of almost totally positive matrices

Linear Algebra and its Applications, 2003
The author shows that a stronger form of the total nonnegativity is preserved on matrix intervals with respect to the chequerboard partial ordering on the real nonsingular matrices. The analogous question for totally nonnegative matrices seems to remain open since 1996.
openaire   +2 more sources

Generalized totally positive matrices

Linear Algebra and its Applications, 2000
A matrix over a ring with identity and a positive part is called generalized totally positive (GTP) if the Schur complements are positive in all nested sequences of so-called relevant submatrices, i.e. ones having either the first \(k\) rows and \(k\) consecutive columns, or \(k\) consecutive rows and the first \(k\) columns.
Fiedler, Miroslav, Markham, Thomas L.
openaire   +2 more sources

Scaffoldings of totally positive matrices and line insertion

Linear and Multilinear Algebra, 2022
Given a totally positive matrix, can one insert a line (row or column) between two given lines while maintaining total positivity? This question was first posed and solved by Johnson and Smith who gave an algorithm that results in one possible line insertion. In this work we revisit this problem.
openaire   +2 more sources

IMPDH inhibition enhances cytarabine efficacy in SAMHD1‐expressing leukaemia cells via guanine nucleotide depletion

Molecular Oncology, EarlyView.
Cytarabine is a key therapy for acute myeloid leukaemia (AML), but its efficacy is limited by the dNTPase SAMHD1, which hydrolyses its active metabolite. Screening nucleotide biosynthesis inhibitors revealed that IMPDH inhibitors selectively sensitise SAMHD1‐proficient AML cells to cytarabine.
Miriam Yagüe‐Capilla, Christopher Dirks, Caroline Eiden, Sonja K. Fesenmayer, Femke M. Hormann, Yolande Klootsema, Ingrid Lilienthal, Si Min Zhang, Nikolas Herold, Sean G. Rudd   +9 more
wiley   +1 more source

On Totally Geodesic Submanifolds

Axioms
We give a proof of Cartan’s Theorem on totally geodesic submanifolds for real analytic manifolds endowed with a real analytic, torsion-free, affine connection. We apply the theorem to real analytic Hadamard manifolds and, more generally, to real analytic
Antonella Nannicini, Donato Pertici
doaj   +1 more source

Keratin 19 as a prognostic marker and contributing factor of metastasis and chemoresistance in high‐grade serous ovarian cancer

Molecular Oncology, EarlyView.
Keratin 19 (KRT19) is overexpressed in high‐grade serous ovarian cancer with high levels of Kallikrein‐related peptidases (KLK) 4–7 and is associated with poor survival. In vivo analyses demonstrate that elevated KRT19 increases peritoneal tumour burden.
Sophia Bielesch, Isabel Vogel, Sina Nokodian, Johanna Moeller, Antonia Blechschmidt, Vicky Hecht, Vanessa Kuentzel, Katharina Thiedig, Melissa Schwab, Oliver Schilling, Holger Bronger, Marion Kiechle, Viktor Magdolen, Tobias Dreyer   +13 more
wiley   +1 more source

Coherence Matrix Estimation With Total Positivity Regularization for Interferometric Phase Linking

IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Interferometric phase linking has become a critical step in distributed scatterer interferometry, yet its performance is significantly affected by inaccuracies in the coherence matrix and its inverse, such as the precision matrix.
Changjun Zhao, Yan Yan, Hanwen Yu
doaj   +1 more source