Results 131 to 140 of about 1,470,963 (294)
Lorentzian Beltrami-Euler formula and generalized Lorentzian Lamarle formila in R_1^n
Le Matematiche, 2009 In this paper, the sectional curvature of non-degenerate tangent sections of time-like ruled surface with the central ruled surface in n-dimensional Minkowski space, R_1^n is studied. The relationship between normal sectional curvature and the principal
Soley Ersoy, Murat Tosun
doaj
Conharmonically flat and conharmonically symmetric warped product manifolds
AIP AdvancesThis article presents characterizations of warped product manifolds based on the flatness and symmetry of the conharmonic curvature tensor. It is proved that when a warped product manifold is conharmonically flat, both the base and fiber manifolds ...
Abdallah Abdelhameed Syied +2 more
doaj +1 more source
On totally umbilical CR-submanifolds of a Kaehler manifold
International Journal of Mathematics and Mathematical Sciences, 1993 Let M be a compact 3-dimensional totally umbilical CR-submanifold of a Kaehler manifold of positive holomorphic sectional curvature. We prove that if the length of the mean curvature vector of M does not vanish, then M is either diffeomorphic to S3 or ...
M. A. Bashir
doaj +1 more source
Aging and Cancer, EarlyView.This systematic review synthesizes prognostic models for survival and recurrence in resected non‐small cell lung cancer. While many models demonstrate moderate to good discrimination, few are externally validated and reporting quality is variable, limiting clinical applicability and highlighting the need for robust, transparent model development ...
Evangeline Samuel +4 more
wiley +1 more source
Algebraic Properties of Curvature Operators in Lorentzian Manifolds with Large Isometry Groups
Symmetry, Integrability and Geometry: Methods and Applications, 2010 Together with spaces of constant sectional curvature and products of a real line with a manifold of constant curvature, the socalled Egorov spaces and ε-spaces exhaust the class of n-dimensional Lorentzian manifolds admitting a group of isometries of ...
Giovanni Calvaruso, Eduardo García-Río
doaj +1 more source
Chronobiology of Cancer: How Aging Fuels Oncogenesis at the Molecular Level
Aging and Cancer, EarlyView.This graphical abstract illustrates the key biological pathways linking aging with cancer development and progression. In the upper left, cumulative exposure to ultraviolet radiation, toxins, and reactive oxygen species (ROS) causes DNA damage and genomic instability, whereas age‐related decline in repair mechanisms, such as ATM/ATR, BER, and NER ...
Anu Singh, Aroonima Misra, Sufian Zaheer
wiley +1 more source
CSF Monoamine Metabolites and Cognitive Trajectory in Early Parkinson's Disease
Annals of Clinical and Translational Neurology, EarlyView.ABSTRACT Background Imaging and postmortem studies indicate that abnormalities in monoaminergic neurotransmission contribute to cognitive impairment in Parkinson's disease (PD). However, it remains uncertain if cerebrospinal fluid (CSF) monoamine metabolites can serve as biomarkers of cognitive decline in early PD.
Jing‐Yu Shao +7 more
wiley +1 more source
Relationship Between Neurologic Symptoms and Signs and FMR1 Genotype in Premutation Carriers
Annals of Clinical and Translational Neurology, EarlyView.ABSTRACT Background and Objectives Fragile X‐associated Tremor/Ataxia Syndrome (FXTAS) is the most severe late‐onset condition caused by a premutation in the FMR1 gene, characterized by expanded CGG triplet repeats of 55–200. Clinical presentations of FXTAS, including gait ataxia, kinetic tremor, cognitive decline, and rare Parkinsonism, are linked to ...
Flora Tassone +8 more
wiley +1 more source
SECTIONAL CURVATURES OF GRASSMANN MANIFOLDS [PDF]
Proceedings of the National Academy of Sciences, 1968 openaire +2 more sources
Annals of Clinical and Translational Neurology, EarlyView.ABSTRACT Objective To assess the association and discriminative performance of serum biomarkers with clinical disease progression and survival in patients with amyotrophic lateral sclerosis (ALS). Methods This retrospective study, conducted at Houston Methodist Hospital, Houston, TX, used longitudinal serum samples collected between January 2018 and ...
David R. Beers +7 more
wiley +1 more source