scholarly journals Hyperbolic Ricci Flow and Its Application in Studying Lateral Ventricle Morphometry

2012 ◽  
pp. 61-76 ◽  
Author(s):  
Jie Shi ◽  
Paul M. Thompson ◽  
Yalin Wang
Keyword(s):  
Ricci Flow ◽  
Lateral Ventricle

Vasopressin enhances the clearance of β-endorphin immunoreactivity from rat cerebrospinal fluid

1990 ◽  
Vol 122 (2) ◽  
pp. 191-200 ◽  
Author(s):  
C. G. J. Sweep ◽  
Margreet D. Boomkamp ◽  
István Barna ◽  
A. Willeke Logtenberg ◽  
Victor M. Wiegant
Keyword(s):  
Cerebrospinal Fluid ◽  
Receptor Antagonist ◽  
Short Duration ◽  
Lateral Ventricle ◽  
Underlying Mechanism ◽  
Terminal Phase ◽  
Intracerebroventricular Injection ◽  
Intracerebroventricular Administration ◽  
Biphasic Pattern ◽  
The Brain

Abstract The effect of intracerebroventricular (lateral ventricle) administration of arginine8-vasopressin (AVP) on the concentration of β-endorphin immunoreactivity in the cerebrospinal fluid obtained from the cisterna magna was studied in rats. A decrease was observed 5 min following injection of 0.9 fmol AVP. No statistically significant changes were found 5 min after intracerebroventricular treatment of rats with 0.09 or 9 fmol. The decrease induced by 0.9 fmol AVP was of short duration and was found 5 min after treatment but not 10 and 20 min. Desglycinamide9-AVP (0.97 fmol), [pGlu4, Cyt6]-AVP-(4–9) (1.44 fmol), Nα-acetyl-AVP (0.88 fmol), lysine8-vasopressin (0.94 fmol) and oxytocin (1 fmol) when intracerebroventricularly injected did not affect the levels of β-endorphin immunoreactivity in the cerebrospinal fluid 5 min later. This suggests that the intact AVP-(1–9) molecule is required for this effect. Intracerebroventricular pretreatment of rats with the vasopressin V1-receptor antagonist d(CH2)5Tyr(Me)AVP (8.63 fmol) completely blocked the effect of AVP (0.9 fmol). In order to investigate further the underlying mechanism, the effect of AVP on the disappearance from the cerebrospinal fluid of exogenously applied β-endorphin was determined. Following intracerebroventricular injection of 1.46 pmol camel β-endorphin-(1–31), the β-endorphin immunoreactivity levels in the cisternal cerebrospinal fluid increased rapidly, and reached peak values at 10 min. The disappearance of β-endorphin immunoreactivity from the cerebrospinal fluid then followed a biphasic pattern with calculated half-lifes of 28 and 131 min for the initial and the terminal phase, respectively. Treatment of rats with AVP (0.9 fmol; icv) during either phase (10, 30, 55 min following intracerebroventricular administration of 1.46 pmol β-endorphin-(1–31)) significantly enhanced the disappearance of β-endorphin immunoreactivity from the cerebrospinal fluid. The data suggest that vasopressin plays a role in the regulation of β-endorphin levels in the cerebrospinal fluid by modulating clearance mechanisms via V1-receptors in the brain.

Ricci Flow on Quasi Einstein Manifold

2010 ◽  
Vol 0 (-1) ◽  
pp. 447-454
Author(s):  
A. Bhattacharyya ◽  
T. De
Keyword(s):  
Ricci Flow ◽  
Einstein Manifold

1054 Effect of exogenous β-hydroxybutyrate in the lateral ventricle on circulating serum metabolites and luteinizing hormone in castrated lambs

2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 505-505
Author(s):  
E. R. Cope ◽  
B. H. Voy ◽  
B. K. Whitlock ◽  
J. D. Hobbs ◽  
Z. D. Mcfarlane ◽  
...  
Keyword(s):  
Luteinizing Hormone ◽  
Lateral Ventricle ◽  
Serum Metabolites

scholarly journals Deformation classes in generalized Kähler geometry

2020 ◽  
Vol 7 (1) ◽  
pp. 241-256
Author(s):  
Matthew Gibson ◽  
Jeffrey Streets
Keyword(s):  
Symmetry Group ◽  
Ricci Flow ◽  
Kahler Geometry ◽  
Poisson Tensor ◽  
Natural Extensions ◽  
Generalized Kähler Geometry ◽  
Kähler Structures

AbstractWe describe natural deformation classes of generalized Kähler structures using the Courant symmetry group, which determine natural extensions of the notions of Kähler class and Kähler cone to generalized Kähler geometry. We show that the generalized Kähler-Ricci flow preserves this generalized Kähler cone, and the underlying real Poisson tensor.

scholarly journals A Case Report of Adult-Onset Alexander Disease with a Tumor-Like Lesion in the Lateral Ventricle

2021 ◽  
pp. 355-360
Author(s):  
Tongjia Cai ◽  
Sisi Jing ◽  
Ying Li ◽  
Jianjun Wu
Keyword(s):  
White Matter ◽  
Contrast Enhancement ◽  
Medulla Oblongata ◽  
Lateral Ventricle ◽  
Brain Lesion ◽  
Alexander Disease ◽  
Adult Onset ◽  
White Matter Abnormality ◽  
Frontal White Matter ◽  
Upper Cervical

Adult-onset Alexander disease (AOAD) is an autosomal dominant progressive astrogliopathy caused by pathogenic variants in glial fibrillary acidic protein (<i>GFAP</i>). Individuals with this disorder often present with a typical neuroradiologic pattern, including frontal white matter abnormality with contrast enhancement, atrophy and signal intensity changes of the medulla oblongata and upper cervical cord on MRI. Focal lesions are rarely seen in AOAD, which causes concern for primary malignancies. This study aimed to present the case of a 37-year-old male patient initially diagnosed with an astrocytoma in the lateral ventricle that was later identified as GFAP mutation-confirmed AOAD. <i>GFAP</i> sequencing revealed a heterogeneous missense mutation point c.236G&#x3e;A. Hence, AOAD should be considered in patients with tumor-like lesion brain lesion in association with atrophy of medulla oblongata and upper cervical spinal cord, and frontal white matter abnormality with contrast enhancement.

scholarly journals Sliding Mode Control and Geometrization Conjecture in Seismic Response

Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 353
Author(s):  
Ligia Munteanu ◽  
Dan Dumitriu ◽  
Cornel Brisan ◽  
Mircea Bara ◽  
Veturia Chiroiu ◽  
...  
Keyword(s):  
Sliding Mode Control ◽  
Ricci Flow ◽  
Lyapunov Functions ◽  
Seismic Waves ◽  
Sliding Mode ◽  
Flow Process ◽  
Mode Control ◽  
Finite Period ◽  
The Stability ◽  
Story Building

The purpose of this paper is to study the sliding mode control as a Ricci flow process in the context of a three-story building structure subjected to seismic waves. The stability conditions result from two Lyapunov functions, the first associated with slipping in a finite period of time and the second with convergence of trajectories to the desired state. Simulation results show that the Ricci flow control leads to minimization of the displacements of the floors.

scholarly journals Ancient solutions for Andrews’ hypersurface flow

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Peng Lu ◽  
Jiuru Zhou
Keyword(s):  
Ricci Flow ◽  
Mean Curvature ◽  
Mean Curvature Flow ◽  
Curvature Flow ◽  
Euclidean Spaces ◽  
Round Cylinder ◽  
Ancient Solutions ◽  
Singular Time

AbstractWe construct the ancient solutions of the hypersurface flows in Euclidean spaces studied by B. Andrews in 1994.As time {t\rightarrow 0^{-}} the solutions collapse to a round point where 0 is the singular time. But as {t\rightarrow-\infty} the solutions become more and more oval. Near the center the appropriately-rescaled pointed Cheeger–Gromov limits are round cylinder solutions {S^{J}\times\mathbb{R}^{n-J}}, {1\leq J\leq n-1}. These results are the analog of the corresponding results in Ricci flow ({J=n-1}) and mean curvature flow.

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