Determination of local brain glucose level with [14C]methylglucose: effects of glucose supply and demand

1997 ◽  
Vol 273 (5) ◽  
pp. E839-E849 ◽  
Author(s):  
Gerald A. Dienel ◽  
Nancy F. Cruz ◽  
Keiji Adachi ◽  
Louis Sokoloff ◽  
James E. Holden
Keyword(s):  
Supply And Demand ◽  
Utilization Rate ◽  
Brain Glucose ◽  
Conscious Rats ◽  
Glucose Levels ◽  
Plasma Distribution ◽  
Wide Range ◽  
Straight Lines ◽  
The Relationship ◽  
Glucose Supply

Methylglucose can be used to assay brain glucose levels because the equilibrium brain-to-plasma distribution ratio for methylglucose ([Formula: see text]/[Formula: see text]) is quantitatively related to brain (Ce) and plasma (Cp) glucose contents. The relationship between Ce and[Formula: see text]/[Formula: see text]predicted by Michaelis-Menten kinetics has been experimentally confirmed when glucose utilization rate (CMRGlc) is maintained at normal, resting levels and Cp is varied in conscious rats. Theoretically, however, Ce and[Formula: see text]/[Formula: see text]should change when CMRGlc is altered and Cp is held constant; their relationship in such conditions was, therefore, examined experimentally. Drugs were applied topically to brains of conscious rats with fixed levels of Cp to produce focal alterations in CMRGlc, and Ce and[Formula: see text]/[Formula: see text]were measured. Plots of Ce as a function of[Formula: see text]/[Formula: see text]for each Cp produced straight lines; their slopes decreased as Cp increased. The results confirm that a single theoretical framework describes the relationship between Ce and[Formula: see text]/[Formula: see text]as either glucose supply or demand is altered over a wide range; they also validate the use of methylglucose to estimate local Ce under abnormal conditions.

scholarly journals The Grain Market between the Reigns of Alexey Mikhailovich and Catherine the Great: Was there a ‘Price Revolution’?

2021 ◽  
Vol 9 (3) ◽  
Author(s):  
Arthur Mustafin
Keyword(s):  
Eighteenth Century ◽  
Supply And Demand ◽  
Wide Range ◽  
Grain Market ◽  
The Impact ◽  
First Time ◽  
The Relationship ◽  
Regions Of Russia ◽  
Grain Prices

The author of this article attempts to reveal and systematise archival data on grain prices in Russia between the 1650s and 1700s and analyse their dynamics by comparing them with data for the eighteenth century. The study is based on a wide range of archival sources from the funds of the RSAAA (RGADA), CSA of Moscow (TsGA of Moscow), DM NLR (OR RNB), and SFI CANNR (GKU TsANO). The data from these sources make it possible to construct time series describing rye and oat price dynamics in the northern and central non-black earth regions of Russia. The author substantiates the homogeneity and reliability of the data received and determines the real prices. The resulting numbers make the author doubt the “price revolution” in eighteenth-century Russia. Throughout the eighteenth century, the average real prices remained below the level of the 1660s and 1670s. Only in the 1790s did prices briefly exceed this level. Overall, the Russian grain market was characterised by long-term price fluctuations. The author aims to explain this dynamic by analysing supply and demand in the grain market. More particularly, for the first time in the historiography, the author examines the connection between Russian grain prices and yield in the second half of the seventeenth and eighteenth centuries. It is established that in most cases, the relationship between these indicators was direct: as grain yield increased, prices did too. The article explains this seeming paradox. The data published by the author help not only to estimate the impact of various factors on grain prices during the period in question, but also solve practical tasks regarding various price indicators in grain equivalents.

A Method of Analyzing Creep Data

1936 ◽  
Vol 3 (2) ◽  
pp. A62-A66
Author(s):  
R. G. Sturm ◽  
C. Dumont ◽  
F. M. Howell
Keyword(s):  
Cold Working ◽  
Relative Effect ◽  
Creep Data ◽  
The Past ◽  
Elapsed Time ◽  
Wide Range ◽  
Creep Time ◽  
Straight Lines ◽  
Constant Slope ◽  
The Relationship

Abstract The authors present a method for studying creep data which has been in use for the past four years at the Aluminum Research Laboratories. It is shown by graphs that a linear relationship exists between the logarithm of the creep and the logarithm of the elapsed time for a given material at ordinary room temperatures and constant stress. This is established by the fact that the logarithmic curves for a given material at a constant temperature have a constant slope for a relatively wide range of stresses. It is pointed out that the relative effect of cold working upon the strength of different metals seems to explain the behavior of the metals when failure is impending, this being indicated by the tendency of the logarithmic creep-time curves to depart from straight lines. The authors conclude that when homologous stresses based on the tensile strength of the material are considered, different materials exhibit very similar characteristics in the relationship between the homologous stress and the logarithm of the time necessary for a given amount of creep to occur.

PS1 - 3. The relationship between plasma and brain glucose levels under hypoglycemic conditions in humans

2011 ◽  
Vol 9 (3) ◽  
pp. 92-92
Author(s):  
Kim C.C. van de Ven ◽  
Marinette van der Graaf ◽  
Cees J.J. Tack ◽  
Arend Heerschap ◽  
Bastiaan E. de Galan
Keyword(s):  
Brain Glucose ◽  
Glucose Levels ◽  
The Relationship

Unlocking the underlying information of golden ratio in the Hogarth curves

2018 ◽  
Vol 30 (6) ◽  
pp. 738-746 ◽  
Author(s):  
Xuyun Zhu ◽  
Yun Luo ◽  
Yanlin Huang ◽  
Xuming Wen
Keyword(s):  
Golden Ratio ◽  
Research Work ◽  
Fibonacci Sequence ◽  
Fundamental Study ◽  
Content Type ◽  
Wide Range ◽  
Underlying Mechanisms ◽  
Experimental Findings ◽  
Straight Lines ◽  
The Relationship

Purpose Curves with various profiles have been demonstrated to be more attractive and decorative than the straight lines by William Hogarth. Among all kinds of curves, Hogarth proposed seven serpentine lines as the most beautiful curves, i.e., Hogarth curves. Those seven Hogarth curves are subsequently applied in a wide range of fields, e.g., sculpture, painting, architecture and fashion design, indicating their significance to the development of the formal beauty. Recently, the beauty of Hogarth curves has been suspected to be induced by their special-designed curvature, which could have the potential relationship with the Golden Ratio. The purpose of this paper is to explore the relationship between the Hogarth curves and golden ratio by comparing the curvature of curves with the Fibonacci sequence. Design/methodology/approach Each of the Hogarth curves was fully restored and divided into two parts according to the turning point of the curvature; the ratios of span, curvature and angles between these two parts were compared with the Fibonacci sequence. Findings The experimental results disclosed that the ratio of the fourth Hogarth curve, which was considered as the most beautiful line by Hogarth, was infinitely approaching the golden ratio. Based on the relationship between the fourth Hogarth curve and the golden ratio, the ratios of each curve were employed to define and normalize these curves, providing a quantitative way to redraw the Hogarth curves. Originality/value This research work unlocked the information of the relationship between the Hogarth curves and golden ratio, and proposed an effective and convenient mathematic way to quantify the Hogarth curves. The experimental findings disclosed the underlying mechanisms of the beauty of the forth Hogarth curves. Such a fundamental study will promote the establishment of the normalized methods for evaluating the beauty of arts and provide novel ideas for researchers and industrial technologists to use the Hogarth curves.

The Problem of Identifying and Modeling the Relationship between Monetary Factor and Inflation in the Russian Economy

2008 ◽  
pp. 61-76
Author(s):  
A. Porshakov ◽  
A. Ponomarenko
Keyword(s):  
Money Supply ◽  
Money Demand ◽  
Russian Economy ◽  
Long Run ◽  
Complex Approach ◽  
Wide Range ◽  
Long Time ◽  
The Relationship ◽  
Supply Side Factors

The role of monetary factor in generating inflationary processes in Russia has stimulated various debates in social and scientific circles for a relatively long time. The authors show that identification of the specificity of relationship between money and inflation requires a complex approach based on statistical modeling and involving a wide range of indicators relevant for the price changes in the economy. As a result a model of inflation for Russia implying the decomposition of inflation dynamics into demand-side and supply-side factors is suggested. The main conclusion drawn is that during the recent years the volume of inflationary pressures in the Russian economy has been determined by the deviation of money supply from money demand, rather than by money supply alone. At the same time, monetary factor has a long-run spread over time impact on inflation.

Inhibition kinetics for propionate degradation using propionate-enriched mixed cultures

1998 ◽  
Vol 38 (8-9) ◽  
pp. 443-451 ◽  
Author(s):  
S. H. Hyun ◽  
J. C. Young ◽  
I. S. Kim
Keyword(s):  
Phase I ◽  
Competitive Inhibition ◽  
Gas Production ◽  
Phase Iii ◽  
Utilization Rate ◽  
Inhibition Kinetics ◽  
Wide Range ◽  
Propionate Degradation ◽  
Acetate Utilization ◽  
Velocity Coefficient

To study propionate inhibition kinetics, seed cultures for the experiment were obtained from a propionate-enriched steady-state anaerobic Master Culture Reactor (MCR) operated under a semi-continuous mode for over six months. The MCR received a loading of 1.0 g propionate COD/l-day and was maintained at a temperature of 35±1°C. Tests using serum bottle reactors consisted of four phases. Phase I tests were conducted for measurement of anaerobic gas production as a screening step for a wide range of propionate concentrations. Phase II was a repeat of phase I but with more frequent sampling and detailed analysis of components in the liquid sample using gas chromatography. In phase III, different concentrations of acetate were added along with 1.0 g propionate COD/l to observe acetate inhibition of propionate degradation. Finally in phase IV, different concentrations of propionate were added along with 100 and 200 mg acetate/l to confirm the effect of mutual inhibition. Biokinetic and inhibition coefficients were obtained using models of Monod, Haldane, and Han and Levenspiel through the use of non-linear curve fitting technique. Results showed that the values of kp, maximum propionate utilization rate, and Ksp, half-velocity coefficient for propionate conversion, were 0.257 mg HPr/mg VSS-hr and 200 mg HPr/l, respectively. The values of kA, maximum acetate utilization rate, and KsA, half-velocity coefficient for acetate conversion, were 0.216 mg HAc/mg VSS-hr and 58 mg HAc/l, respectively. The results of phase III and IV tests indicated there was non-competitive inhibition when the acetate concentration in the reactor exceeded 200 mg/l.

scholarly journals Polymorphic Iterable Sequential Effect Systems

2021 ◽  
Vol 43 (1) ◽  
pp. 1-79
Author(s):  
Colin S. Gordon
Keyword(s):  
Algebraic Structure ◽  
Position Effect ◽  
Type Systems ◽  
Sequential Effect ◽  
Prior Work ◽  
Sequential Effects ◽  
Wide Range ◽  
The Relationship ◽  
Categorical Semantics

Effect systems are lightweight extensions to type systems that can verify a wide range of important properties with modest developer burden. But our general understanding of effect systems is limited primarily to systems where the order of effects is irrelevant. Understanding such systems in terms of a semilattice of effects grounds understanding of the essential issues and provides guidance when designing new effect systems. By contrast, sequential effect systems—where the order of effects is important—lack an established algebraic structure on effects. We present an abstract polymorphic effect system parameterized by an effect quantale—an algebraic structure with well-defined properties that can model the effects of a range of existing sequential effect systems. We define effect quantales, derive useful properties, and show how they cleanly model a variety of known sequential effect systems. We show that for most effect quantales, there is an induced notion of iterating a sequential effect; that for systems we consider the derived iteration agrees with the manually designed iteration operators in prior work; and that this induced notion of iteration is as precise as possible when defined. We also position effect quantales with respect to work on categorical semantics for sequential effect systems, clarifying the distinctions between these systems and our own in the course of giving a thorough survey of these frameworks. Our derived iteration construct should generalize to these semantic structures, addressing limitations of that work. Finally, we consider the relationship between sequential effects and Kleene Algebras, where the latter may be used as instances of the former.

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