Modeling of Blood Flow in the Human Brain

2010 ◽  
Author(s):  
Md. Shahadat Hossain ◽  
Bhavin Dalal ◽  
Ian S. Fischer ◽  
Pushpendra Singh ◽  
Nadine Aubry
Keyword(s):  
Blood Flow ◽  
Human Brain ◽  
Flow Rate ◽  
Regulatory Mechanisms ◽  
Dimensional Model ◽  
Normal Range ◽  
One Dimensional ◽  
Baseline Levels ◽  
The Individual ◽  
The Brain

The non-Newtonian properties of blood, i.e., shear thinning and viscoelasticity, can have a significant influence on the distribution of Cerebral Blood Flow (CBF) in the human brain. The aim of this work is to quantify the role played by the non-Newtonian nature of blood. Under normal conditions, CBF is autoregulated to maintain baseline levels of flow and oxygen to the brain. However, in patients suffering from heart failure (HF), Stroke, or Arteriovenous malformation (AVM), the pressure in afferent vessels varies from the normal range within which the regulatory mechanisms can ensure a constant cerebral flow rate, leading to impaired cerebration in patients. It has been reported that the change in the flow rate is more significant in certain regions of the brain than others, and that this might be relevant to the pathophysiological symptoms exhibited in these patients. We have developed mathematical models of CBF under normal and the above disease conditions that use direct numerical simulations (DNS) for the individual capillaries along with the experimental data in a one-dimensional model to determine the flow rate and the methods for regulating CBF. The model also allows us to determine which regions of the brain would be affected relatively more severely under these conditions.

Fit Vs Faint: Assessing Work Causation in “Idiopathic Fall” Cases

2014 ◽  
Vol 19 (5) ◽  
pp. 3-12
Author(s):  
Lorne Direnfeld ◽  
David B. Torrey ◽  
Jim Black ◽  
LuAnn Haley ◽  
Christopher R. Brigham
Keyword(s):  
Blood Flow ◽  
Electrical Activity ◽  
Loss Of Consciousness ◽  
Brain Electrical Activity ◽  
Medical Terminology ◽  
Scientific Analysis ◽  
Medical Causation ◽  
The Individual ◽  
The Brain ◽  
Current Science

Abstract When an individual falls due to a nonwork-related episode of dizziness, hits their head and sustains injury, do workers’ compensation laws consider such injuries to be compensable? Bearing in mind that each state makes its own laws, the answer depends on what caused the loss of consciousness, and the second asks specifically what happened in the fall that caused the injury? The first question speaks to medical causation, which applies scientific analysis to determine the cause of the problem. The second question addresses legal causation: Under what factual circumstances are injuries of this type potentially covered under the law? Much nuance attends this analysis. The authors discuss idiopathic falls, which in this context means “unique to the individual” as opposed to “of unknown cause,” which is the familiar medical terminology. The article presents three detailed case studies that describe falls that had their genesis in episodes of loss of consciousness, followed by analyses by lawyer or judge authors who address the issue of compensability, including three scenarios from Arizona, California, and Pennsylvania. A medical (scientific) analysis must be thorough and must determine the facts regarding the fall and what occurred: Was the fall due to a fit (eg, a seizure with loss of consciousness attributable to anormal brain electrical activity) or a faint (eg, loss of consciousness attributable to a decrease in blood flow to the brain? The evaluator should be able to fully explain the basis for the conclusions, including references to current science.

Anoxia and adenosine induce increased cerebral blood flow rate in crucian carp

1994 ◽  
Vol 267 (2) ◽  
pp. R590-R595 ◽  
Author(s):  
G. E. Nilsson ◽  
P. Hylland ◽  
C. O. Lofman
Keyword(s):  
Blood Flow ◽  
Flow Rate ◽  
Crucian Carp ◽  
Blood Flow Rate ◽  
Fold Increase ◽  
Liver Glycogen ◽  
Glycolytic Flux ◽  
Brain Blood Flow ◽  
Atp Production ◽  
The Brain

The crucian carp (Carassius carassius) has the rare ability to survive prolonged anoxia, indicating an extraordinary capacity for glycolytic ATP production, especially in a highly energy-consuming organ like the brain. For the brain to be able to increase its glycolytic flux during anoxia and profit from the large liver glycogen store, an increased glucose delivery from the blood would be expected. Nevertheless, the effect of anoxia on brain blood flow in crucian carp has never been studied previously. We have used epireflection microscopy to directly observe and measure blood flow rate on the brain surface (optic lobes) during normoxia and anoxia in crucian carp. We have also examined the possibility that adenosine participates in the regulation of brain blood flow rate in crucian carp. The results showed a 2.16-fold increase in brain blood flow rate during anoxia. A similar increase was seen after topical application of adenosine during normoxia, while adenosine was without effect during anoxia. Moreover, superfusing the brain with the adenosine receptor blocker aminophylline inhibited the effect of anoxia on brain blood flow rate, clearly suggesting a mediatory role of adenosine in the anoxia-induced increase in brain blood flow rate.

scholarly journals The Localization of Activity Sources in a Three-Dimensional Model of the Human Brain Using the Joint Analysis of EEG / sMRI Data

2019 ◽  
Vol 17 (3) ◽  
pp. 18-28
Author(s):  
E. Bykova ◽  
A. Savostyanov
Keyword(s):  
Inverse Problem ◽  
Brain Activity ◽  
Three Dimensional ◽  
Human Head ◽  
Joint Analysis ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Use Of Data ◽  
The Individual ◽  
The Brain

Despite the large number of existing methods of the diagnosis of the brain, brain remains the least studied part of the human body. Electroencephalography (EEG) is one of the most popular methods of studying of brain activity due to its relative cheapness, harmless, and mobility of equipment. While analyzing the EEG data of the brain, the problem of solving of the inverse problem of electroencephalography, the localization of the sources of electrical activity of the brain, arises. This problem can be formulated as follows: according to the signals recorded on the surface of the head, it is necessary to determine the location of sources of these signals in the brain. The purpose of my research is to develop a software system for localization of brain activity sources based on the joint analysis of EEG and sMRI data. There are various approaches to solving of the inverse problem of EEG. To obtain the most exact results, some of them involve the use of data on the individual anatomy of the human head – structural magnetic resonance imaging (sMRI data). In this paper, one of these approaches is supposed to be used – Electromagnetic Spatiotemporal Independent Component Analysis (EMSICA) proposed by A. Tsai. The article describes the main stages of the system, such as preprocessing of the initial data; the calculation of the special matrix of the EMSICA approach, the values of which show the level of activity of a certain part of the brain; visualization of brain activity sources on its three-dimensional model.

Imaging and the Human Brain Project: A Review

2002 ◽  
Vol 41 (04) ◽  
pp. 245-260 ◽  
Author(s):  
C. Rosse ◽  
J. F. Brinkley
Keyword(s):  
Human Brain ◽  
Physical Structure ◽  
Imaging Informatics ◽  
The Body ◽  
Human Brain Project ◽  
The Us ◽  
Physical Organization ◽  
The Subject ◽  
The Individual ◽  
The Brain

Summary Objectives: Survey current work primarily funded by the US Human Brain Project (HBP) that involves substantial use of images. Organize this work around a framework based on the physical organization of the body. Methods: Pointers to individual research efforts were obtained through the HBP home page as well as personal contacts from HBP annual meetings. References from these sources were followed to find closely related work. The individual research efforts were then studied and characterized. Results: The subject of the review is the intersection of neuroinformatics (information about the brain), imaging informatics (information about images), and structural informatics (information about the physical structure of the body). Of the 30 funded projects currently listed on the HBP web site, at least 22 make heavy use of images. These projects are described in terms of broad categories of structural imaging, functional imaging, and image-based brain information systems. Conclusions: Understanding the most complex entity known (the brain) gives rise to many interesting and difficult problems in informatics and computer science. Although much progress has been made by HBP and other neuroinformatics researchers, a great many problems remain that will require substantial informatics research efforts. Thus, the HPB can and should be seen as an excellent driving application area for biomedical informatics research.

Nominations, Ratings, and the Dimensions of Sociometric Status

1997 ◽  
Vol 21 (1) ◽  
pp. 179-199 ◽  
Author(s):  
Gerard H. Maassen ◽  
Jos L. van der Linden ◽  
Wies Akkermans
Keyword(s):  
Rating Scales ◽  
Rating Scale ◽  
Sociometric Status ◽  
Dimensional Model ◽  
One Dimensional ◽  
Individual Level ◽  
Research Designs ◽  
The One ◽  
The Individual ◽  
Group Member

In 1944, U. Bronfenbrenner remarked on the need for a two-dimensional model of sociometric status. The low value of the correlation between the variables liking and disliking-assumed basic dimensions of sociometric status-is often cited as evidence for the correctness of Bronfenbrenner’ssuggestion. Sociometric status is derived from a coalescence of judgements at the individual level. In this article we argue that score attribution at this level (where one group member assesses another) is one-dimensional along the liking-disliking continuum. Two-dimensionality of sociometric status arises at the group level. However, we also show that at this level liking and disliking are not two distinct dimensions, but the poles of just one, the other being visibility (or impact). If the one-dimensional model of liking score attribution on the individual level is accepted, the obvious thing to do is to instruct respondents accordingly. Rating scales are suitable for this. The rating-scale methods we suggested in previous publications (e.g. Maassen, Akkermans, & van der Linden, 1996) are in keeping with this argument. Moreover, these methods may be recommended for their reliability, validity and for the variety of research designs to which they can be applied.

scholarly journals THE EFFECT OF POLIOMYELITIS VIRUS ON HUMAN BRAIN CELLS IN TISSUE CULTURE

1955 ◽  
Vol 102 (1) ◽  
pp. 29-36 ◽  
Author(s):  
M. J. Hogue ◽  
R. McAllister ◽  
A. E. Greene ◽  
L. L. Coriell
Keyword(s):  
Tissue Culture ◽  
Human Brain ◽  
Cell Body ◽  
Good Condition ◽  
Fetal Brain ◽  
Adult Brain ◽  
Brain Cells ◽  
Poliomyelitis Virus ◽  
The Individual ◽  
The Brain

Poliomyelitis virus I, Mahoney strain, affected human brain cells grown in tissue cultures usually causing death of the cells in 3 days. The neurons reacted in different ways to the virus, some died with their neurites extended, others contracted one or more of their neurites. Terminal bulbs were frequently formed at the tips of the neurites when they were being drawn into the cell body. The final contraction of the cell body and the change into a mass of granules were often very sudden. Vacuoles often developed in the neuron. There was no recovery. Astrocytes, oligodendroglia, and macrophages were affected by the virus but not as quickly as the neurons. The age of the tissue culture was not a factor when the cells were in good condition. The age of the individual donor of the brain tissue was a factor; the fetal brain cells appeared to be more sensitive to the virus than the adult brain cells. The fetal neurons often reacted ½ hour after inoculation while the adult neurons reacted more slowly, 2 to 24 hours after inoculation. All these changes seemed to be caused by virus infection because they were prevented by specific antiserum or by preheating the virus.

scholarly journals Age-Dependent Honey Bee Appetite Regulation Is Mediated by Trehalose and Octopamine Baseline Levels

Insects ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 863
Author(s):  
İrem Akülkü ◽  
Saleh Ghanem ◽  
Elif Filiztekin ◽  
Guntima Suwannapong ◽  
Christopher Mayack
Keyword(s):  
Honey Bee ◽  
Honey Bees ◽  
Appetite Regulation ◽  
Feedback Mechanisms ◽  
Age Dependent ◽  
Energetic State ◽  
Baseline Levels ◽  
The Individual ◽  
The Brain ◽  
Higher Sensitivity

There are multiple feedback mechanisms involved in appetite regulation, which is an integral part of maintaining energetic homeostasis. Older forager honey bees, in comparison to newly emerged bees and nurse bees, are known to have highly fluctuating hemolymph trehalose levels, higher appetite changes due to starvation, and higher octopamine levels in the brain. What remains unknown is if the hemolymph trehalose and octopamine levels interact with one another and how this varies as the bee ages. We manipulated trehalose and octopamine levels across age using physiological injections and found that nurse and forager bees increase their appetite levels due to increased octopamine levels in the brain. This is further enhanced by lower trehalose levels in the hemolymph. Moreover, nurse bees with high octopamine levels in the brain and low trehalose levels had the same appetite levels as untreated forager bees. Our findings suggest that the naturally higher levels of octopamine as the bee ages may result in higher sensitivity to fluctuating trehalose levels in the hemolymph that results in a more direct way of assessing the energetic state of the individual. Consequently, forager bees have a mechanism for more precise regulation of appetite in comparison to newly emerged and nurse bees.

EFEKTIVITAS SENAM OTAK TERHADAP KONSENTRASI BELAJAR PADA SISWA KELAS V DI YAYASAN PENDIDIKAN ISLAM ISTIQOMAH MEDAN TAHUN 2020

2021 ◽  
Vol 16 (1) ◽  
pp. 36-43
Author(s):  
Nila Hayati
Keyword(s):  
Blood Flow ◽  
Human Brain ◽  
Total Population ◽  
Sampling Technique ◽  
Wilcoxon Test ◽  
Islamic Education ◽  
P Value ◽  
Test Population ◽  
Quasi Experimental ◽  
The Brain

Brain exercise is a series of simple movements that help optimize the function of all kinds of centers in the human brain. The brain exercise method focuses on the use of movemment activities to draw out all one’s potential so that it is expected to facilitate blood flow and stretch nerves due to fatigue and stress of learning. The purpose of this study was to determine the effectiveness of brain exercise on learning concentration in grade V students at the Istiqomah Medan Islamic Education Foundation. This study used a quasi experimental research design with one group pretest-posttest designs. Analysis of data using the wilcoxon test. Population of 42 students, the sampling technique used a total population of 42 students. The results of data processing using the wilcoxon test obtained a p value of 0,000 < 0,05 then Ho is rejected and Ha is accepted. The conclusion is that there is the effectiveness of brain exercise on learning concentration in grade V students at the Istiqomah Medan Islamic Education Foundation. The suggestion from the reseacher is to recommend the teacher to intruct students to do brain exercises to increase learning concentration.

Changes in local cerebral blood flow following profound systemic hypotension

1976 ◽  
Vol 44 (2) ◽  
pp. 215-225 ◽  
Author(s):  
Francis W. Gamache ◽  
Ronald E. Myers ◽  
Esteban Monell
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Flow Rate ◽  
Rank Order ◽  
Blood Flow Rate ◽  
Rapid Onset ◽  
Border Zone ◽  
Local Cerebral Blood Flow ◽  
Content Type ◽  
The Brain

✓ The authors studied local cerebral blood flow in monkeys rendered hypotensive by infusion of a ganglionic blocking agent. Application of the 14C-antipyrine method demonstrated that the blood flow: 1) normally varies reproducibly from one structure to another within the brain; 2) appears at its lowest level in all structures during the early minutes of a rapid-onset hypotension; 3) maintains the same general rank order of blood flow rate during hypotension as was present during normotension; and 4) returns to supranormal levels immediately following the rapid restoration of blood pressure. The values for local cerebral blood flow remain close-to-normal in some animals and diminish significantly in others during late recovery from hypotension. The close-to-normal values accompany uncomplicated recoveries while the diminished values appear in those animals which became neurologically depressed. Areas of the brain considered predisposed to hypotensive injury did not exhibit depressions in blood flow rate during hypotension more markedly than did other brain areas. The present results are interpreted as strong evidence against the “border zone” hypothesis.

Blood-brain barrier permeability of 11C-labeled alcohols and 15O-labeled water

1976 ◽  
Vol 230 (2) ◽  
pp. 543-552 ◽  
Author(s):  
ME Raichle ◽  
JO Eichling ◽  
MG Straatmann ◽  
MJ Welch ◽  
KB Larson ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Time Course ◽  
Brain Capillary ◽  
Permeability Characteristics ◽  
Permeability Surface ◽  
Brain Barrier Permeability ◽  
The Individual ◽  
The Brain

The extraction of 11C-labeled methanol, ethanol, and isopropanol, as well as 15O-labeled water by the brain during a single capillary transit, was studied in vivo in six adult rhesus monkeys by external detection of the time course of these tracers subsequent to their internal carotid artery injection. The data demonstrate the feasibility of accurately measuring brain permeability of highly diffusible substances by this technique and show that neither water nor the alcohols studied freely equilibrate with brain when the cerebral blood flow exceeds 30 ml/100 g min-1. At a cerebral blood flow of 50 ml/100 g min-1 only about 93% of an injected bolus of labeled water freely exchanges with brain, compared with methanol (93%), ethanol (97%), and isopropanol (99%). The brain capillary permeability-surface area (PS) products computed from these data were 0.023 cm3/s g-1 (water), 0.024 cm3/s g-1 (methanol), 0.030 cm3/s g-1 (ethanol), and 0.062 cm3/s g-1 (isopropanol). This sequence of PS products is consistent with the individual lipid solubilities of the alcohols studied and underscores the unique brain permeability characteristics of lipid-insoluble water.

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