118 research outputs found
Global and regional brain metabolic scaling and its functional consequences
Background: Information processing in the brain requires large amounts of
metabolic energy, the spatial distribution of which is highly heterogeneous
reflecting complex activity patterns in the mammalian brain.
Results: Here, it is found based on empirical data that, despite this
heterogeneity, the volume-specific cerebral glucose metabolic rate of many
different brain structures scales with brain volume with almost the same
exponent around -0.15. The exception is white matter, the metabolism of which
seems to scale with a standard specific exponent -1/4. The scaling exponents
for the total oxygen and glucose consumptions in the brain in relation to its
volume are identical and equal to , which is significantly larger
than the exponents 3/4 and 2/3 suggested for whole body basal metabolism on
body mass.
Conclusions: These findings show explicitly that in mammals (i)
volume-specific scaling exponents of the cerebral energy expenditure in
different brain parts are approximately constant (except brain stem
structures), and (ii) the total cerebral metabolic exponent against brain
volume is greater than the much-cited Kleiber's 3/4 exponent. The
neurophysiological factors that might account for the regional uniformity of
the exponents and for the excessive scaling of the total brain metabolism are
discussed, along with the relationship between brain metabolic scaling and
computation.Comment: Brain metabolism scales with its mass well above 3/4 exponen
The PARAChute project: remote monitoring of posture and gait for fall prevention
Falls in the elderly are a major public health problem due to both their frequency and their medical and social consequences. In France alone, more than two million people aged over 65 years old fall each year, leading to more than 9 000 deaths, in particular in those over 75 years old (more than 8 000 deaths). This paper describes the PARAChute project, which aims to develop a methodology that will enable the detection of an increased risk of falling in community-dwelling elderly. The methods used for a remote noninvasive assessment for static and dynamic balance assessments and gait analysis are described. The final result of the project has been the development of an algorithm for movement detection during gait and a balance signature extracted from a force plate. A multicentre longitudinal evaluation of balance has commenced in order to validate the methodologies and technologies developed in the project
A qualitative study on the ethics of transforming care: examining the development and implementation of Canada’s first mental health strategy
Adaptation of an Instrument for Measuring the Cognitive Complexity of Organic Chemistry Exam Items
Respiratory symptoms and lung function 8–10 months after community exposure to chlorine gas: a public health intervention and cross-sectional analysis
NO synthase inhibition modulates NMDA-induced changes in cerebral blood flow and EEG activity
Brain glucose utilization and transport and cortical function in chronic vs. acute hypoglycemia
Model of Kinetic Behavior of Deoxyglucose in Heterogeneous Tissues in Brain: A Reinterpretation of the Significance of Parameters Fitted to Homogeneous Tissue Models
Nascent EDHF-mediated cerebral vasodilation in ovariectomized rats is not induced by eNOS dysfunction
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