scholarly journals Fast uncertainty quantification of tracer distribution in the brain interstitial fluid with multilevel and quasi Monte Carlo

2020 ◽  
Author(s):  
Matteo Croci ◽  
Vegard Vinje ◽  
Marie E. Rognes
Keyword(s):  
Monte Carlo ◽  
Uncertainty Quantification ◽  
Interstitial Fluid ◽  
Brain Interstitial Fluid ◽  
Quasi Monte Carlo ◽  
Tracer Distribution ◽  
The Brain

Fisiopatología de la hidrocefália idiopática de presión normal (parte 3): sistemaa glinfático

2016 ◽  
Vol 21 (2) ◽  
pp. 28-37
Author(s):  
Oscar Solís-Salgado ◽  
José Luis López-Payares ◽  
Mauricio Ayala-González
Keyword(s):  
Amyloid Beta ◽  
Interstitial Fluid ◽  
Amyloid Β ◽  
Bulk Flow ◽  
Polyethylene Glycols ◽  
Brain Interstitial Fluid ◽  
El Sistema ◽  
Arterial Pulsation ◽  
The Brain

Las vías de drenaje solutos del sistema nervioso central (SNC) participan en el recambio de liquido intersticial con el líquido cefalorraquídeo (LIT-LCR), generando un estado de homeostasis. Las alteraciones dentro de este sistema homeostático afectará la eliminación de solutos del espacio intersticial (EIT) como el péptido βa y proteína tau, los cuales son sustancias neurotóxicas para el SNC. Se han utilizado técnicas experimentales para poder analizar el intercambio LIT-LCR, las cuales revelan que este intercambio tiene una estructura bien organizada. La eliminación de solutos del SNC no tiene una estructura anatómica propiamente, se han descubierto vías de eliminación de solutos a través de marcadores florecentes en el espacio subaracnoideo, cisternas de la base y sistema ventricular que nos permiten observar una serie de vías ampliamente distribuidas en el cerebro. El LCR muestra que tiene una función linfática debido a su recambio con el LIT a lo largo de rutas paravasculares. Estos espacios que rodean la superficie arterial así como los espacios de Virchow-Robin y el pie astrocitico junto con la AQP-4, facilitan la entrada de LCR para-arterial y el aclaramiento de LIT para-venoso dentro del cerebro. El flujo y dirección que toma el LCR por estas estructuras, es conducido por la pulsación arterial. Esta función será la que finalmente llevara a la eliminación de estas sustancias neurotóxicas. En base a la dependencia de este flujo para la eliminación de sustancias se propone que el sistema sea llamado “ la Vía Glinfática”. La bibliografía así como las limitaciones que se encuentran en esta revisión están dadas por la metodología de búsqueda que ha sido realizada principalmente en PubMed utilizando los siguientes términos Mesh: Cerebral Arterial Pulsation, the brain via paravascular, drainage of amyloid-beta, bulk flow of brain interstitial fluid, radiolabeled polyethylene glycols and albumin, amyloid-β, the perivascular astroglial sheath, Brain Glymphatic Transport.

Parametric uncertainty quantification in the Rothermel model with randomised quasi-Monte Carlo methods

2015 ◽  
Vol 24 (3) ◽  
pp. 307 ◽  
Author(s):  
Yaning Liu ◽  
Edwin Jimenez ◽  
M. Yousuff Hussaini ◽  
Giray Ökten ◽  
Scott Goodrick
Keyword(s):  
Monte Carlo ◽  
Uncertainty Quantification ◽  
Monte Carlo Methods ◽  
Wildland Fire ◽  
Parametric Uncertainty ◽  
Monte Carlo Sampling ◽  
Model Parameters ◽  
Quasi Monte Carlo ◽  
Control Variate ◽  
Fuel Model

Rothermel's wildland surface fire model is a popular model used in wildland fire management. The original model has a large number of parameters, making uncertainty quantification challenging. In this paper, we use variance-based global sensitivity analysis to reduce the number of model parameters, and apply randomised quasi-Monte Carlo methods to quantify parametric uncertainties for the reduced model. The Monte Carlo estimator used in these calculations is based on a control variate approach applied to the sensitivity derivative enhanced sampling. The chaparral fuel model, selected from Rothermel's 11 original fuel models, is studied as an example. We obtain numerical results that improve the crude Monte Carlo sampling by factors as high as three orders of magnitude.

scholarly journals In vivo measurement of apolipoprotein E from the brain interstitial fluid using microdialysis

2013 ◽  
Vol 8 (1) ◽  
pp. 13 ◽  
Author(s):  
Jason D Ulrich ◽  
Jack M Burchett ◽  
Jessica L Restivo ◽  
Dorothy R Schuler ◽  
Philip B Verghese ◽  
...  
Keyword(s):  
Apolipoprotein E ◽  
Interstitial Fluid ◽  
Brain Interstitial Fluid ◽  
In Vivo Measurement ◽  
The Brain

scholarly journals Tau in the brain interstitial fluid is fragmented and seeding-competent

2021 ◽  
Author(s):  
Erica Barini ◽  
Gudrun Plotzky ◽  
Yulia Mordashova ◽  
Jonas Hoppe ◽  
Esther Rodriguez-Correa ◽  
...  
Keyword(s):  
Interstitial Fluid ◽  
Brain Interstitial Fluid ◽  
The Brain

scholarly journals Glymphatic pathways in the gyrencephalic brain

2021 ◽  
pp. 0271678X2199617
Author(s):  
Nicholas Burdon Bèchet ◽  
Nagesh C Shanbhag ◽  
Iben Lundgaard
Keyword(s):  
Interstitial Fluid ◽  
Three Dimensional ◽  
Light Sheet ◽  
Subcortical Structures ◽  
Large Mammal ◽  
Glymphatic System ◽  
Light Sheet Microscopy ◽  
Tracer Distribution ◽  
The Brain ◽  
Solute Clearance

Identification of the perivascular compartment as the point of exchange between cerebrospinal fluid (CSF) and interstitial fluid mediating solute clearance in the brain, named the glymphatic system, has emerged as an important clearance pathway for neurotoxic peptides such as amyloid-beta. However, the foundational science of the glymphatic system is based on rodent studies. Here we investigated whether the glymphatic system exists in a large mammal with a highly gyrified brain. CSF penetration into the brain via perivascular pathways, a hallmark of glymphatic function, was seen throughout the gyrencephalic cortex and subcortical structures, validating the conservation of the glymphatic system in a large mammal. Macroscopic CSF tracer distribution followed the sulci and fissures showing that these folds enhance CSF dispersion. Three-dimensional renditions from light sheet microscopy showed a PVS influx density 4-fold larger in the pig brain than in mice. This demonstrates the existence of an advanced solute transport system in the gyrencephalic brain that could be utilised therapeutically for enhancing waste clearance.

scholarly journals Fast approximation by periodic kernel-based lattice-point interpolation with application in uncertainty quantification

2021 ◽  
Author(s):  
Vesa Kaarnioja ◽  
Yoshihito Kazashi ◽  
Frances Y. Kuo ◽  
Fabio Nobile ◽  
Ian H. Sloan
Keyword(s):  
New York ◽  
Monte Carlo ◽  
Uncertainty Quantification ◽  
Approximation Problem ◽  
Elliptic Partial Differential Equations ◽  
Fast Evaluation ◽  
Quasi Monte Carlo ◽  
Optimal Rate Of Convergence ◽  
Point Interpolation ◽  
Numer Anal

AbstractThis paper deals with the kernel-based approximation of a multivariate periodic function by interpolation at the points of an integration lattice—a setting that, as pointed out by Zeng et al. (Monte Carlo and Quasi-Monte Carlo Methods 2004, Springer, New York, 2006) and Zeng et al. (Constr. Approx. 30: 529–555, 2009), allows fast evaluation by fast Fourier transform, so avoiding the need for a linear solver. The main contribution of the paper is the application to the approximation problem for uncertainty quantification of elliptic partial differential equations, with the diffusion coefficient given by a random field that is periodic in the stochastic variables, in the model proposed recently by Kaarnioja et al. (SIAM J Numer Anal 58(2): 1068–1091, 2020). The paper gives a full error analysis, and full details of the construction of lattices needed to ensure a good (but inevitably not optimal) rate of convergence and an error bound independent of dimension. Numerical experiments support the theory.

scholarly journals Tau in the brain interstitial fluid is fragmented and seeding-competent

2020 ◽  
Author(s):  
Erica Barini ◽  
Gudrun Plotzky ◽  
Yulia Mordashova ◽  
Jonas Hoppe ◽  
Esther Rodriguez-Correa ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Interstitial Fluid ◽  
List Type ◽  
Fragmentation Pattern ◽  
Tau Pathology ◽  
Brain Areas ◽  
Brain Interstitial Fluid ◽  
Tau Aggregation ◽  
The Brain

SUMMARYIn Alzheimer disease, Tau pathology is thought to propagate from cell to cell throughout interconnected brain areas. However, the forms of Tau released into the brain interstitial fluid (ISF) in vivo during the development of Tauopathy and their pathological relevance remain unclear. Combining in vivo microdialysis and biochemical analysis, we find that human Tau (hTau) present in brain ISF is truncated and comprises at least 10 distinct fragments spanning the entire Tau protein. The fragmentation pattern is similar across different Tau transgenic models, pathological stages and brain areas. ISF hTau concentration decreases during Tauopathy progression, while its phosphorylation increases. ISF from mice with established Tauopathy induces Tau aggregation in HEK293-Tau biosensor cells and notably, only a small fraction of Tau, separated by ultracentrifugation, is seeding competent. These results indicate that only a subset of Tau accounts for ISF seeding competence and have the potential to contribute to the propagation of Tau pathology.Graphical abstractHighlights✓In transgenic mice, interstitial fluid comprises several Tau fragments spanning the entire Tau sequence.✓Interstitial fluid Tau concentration decreases with Tauopathy progression, while phosphorylation increases.✓Only interstitial fluid from mice with established Tauopathy is seeding competent in vitro.✓Interstitial fluid seeding competence is driven by less soluble, aggregated and phosphorylated Tau species.In BriefBarini et al. show that in the brain interstitial fluid of Tau transgenic mice, truncated Tau decreases, while its phosphorylation increases during the progression of pathology. A subset of less soluble, aggregated and phosphorylated ISF Tau induces Tau aggregation in cells.

Determination of in vivo steady-state unbound drug concentration in the brain interstitial fluid by microdialysis

1992 ◽  
Vol 81 (2-3) ◽  
pp. 143-152 ◽  
Author(s):  
Terasaki Tetsuya ◽  
Deguchi Yoshiharu ◽  
Kasama Yuko ◽  
William M. Pardridge ◽  
Tsuji Akira
Keyword(s):  
Steady State ◽  
Drug Concentration ◽  
Interstitial Fluid ◽  
Brain Interstitial Fluid ◽  
The Brain

O4-02-03: Soluble Aβ clearance from the brain interstitial fluid of PDAPP mice is human apoE isoform-dependent

2010 ◽  
Vol 6 ◽  
pp. S153-S153
Author(s):  
Joseph M. Castellano ◽  
Floy R. Stewart ◽  
Patrick C. May ◽  
Ronald B. DeMattos ◽  
Steven M. Paul ◽  
...  
Keyword(s):  
Interstitial Fluid ◽  
Brain Interstitial Fluid ◽  
Human Apoe ◽  
Aβ Clearance ◽  
The Brain
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