Weak Dimension-Free Concentration of Measure

AbstractProbability measures satisfying a Poincaré inequality are known to enjoy a dimension-free concentration inequality with exponential rate. A celebrated result of Bobkov and Ledoux shows that a Poincaré inequality automatically implies a modified logarithmic Sobolev inequality. As a consequence the Poincaré inequality ensures a stronger dimension-free concentration property, known as two-level concentration. We show that a similar phenomenon occurs for the Latała–Oleszkiewicz inequalities, which were devised to uncover dimension-free concentration with rate between exponential and Gaussian. Motivated by the search for counterexamples to related questions, we also develop analytic techniques to study functional inequalities for probability measures on the line with wild potentials.

Download Full-text

The determination of binding parameters when the total and free substrate concentrations are not approximately equal

Biochemical Journal ◽

10.1042/bj1790697 ◽

1979 ◽

Vol 179 (3) ◽

pp. 697-700 ◽

Cited By ~ 3

Author(s):

N Gains

Keyword(s):

Substrate Concentration ◽

Graphical Method ◽

Enzyme Concentration ◽

Binding Parameters ◽

Free Concentration ◽

Equilibrium Binding ◽

Substrate Concentrations

By using a standard graphical method values of Km and V may be found that are independent of the conditions and assumptions that the total substrate concentration approximates to its free concentration and that Km is much larger than the enzyme concentration. The procedure is also applicable to the determination of equilibrium binding parameters of a ligand to a macromolecule.

Download Full-text

Free concentrations of intracellular fluorescent anions determined by cytoplasmic dialysis of isolated hepatocytes

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1994.267.5.g922 ◽

1994 ◽

Vol 267 (5) ◽

pp. G922-G931 ◽

Cited By ~ 1

Author(s):

S. A. Weinman ◽

L. M. Maglova

Keyword(s):

Isolated Hepatocytes ◽

Null Point ◽

Free Concentration ◽

Intracellular Location ◽

Organic Ions ◽

Cytoplasmic Proteins ◽

Solution Bound ◽

Intracellular Vesicles ◽

Fluorescent Molecules ◽

Intracellular Fluorescence

Intracellular organic ions exist in free solution bound to cytoplasmic proteins, partitioned within intracellular membranes, and enclosed in intracellular vesicles and organelles. The aim of this study was to develop a method for measurement of the free cytosolic concentration of organic ions. This was accomplished by measuring initial rates of diffusion between patch-clamp pipettes and cell cytoplasm and determining the null-point concentration of this process. Carboxydimethylfluorescein (CF) was used as a model compound. It readily diffused between cytoplasm and pipette, and there was a linear relationship between concentration in the pipette and equilibrium cell fluorescence. When cells previously loaded with CF were patched, intracellular fluorescence rapidly changed in a positive or a negative direction, depending on the concentration of CF in the pipette. The null point, defined as the concentration at which cells neither gained nor lost fluorescence, described the same relationship between free concentration and total cell fluorescence as that determined by direct loading of the cells to equilibrium. In hepatocytes preloaded with a fluorescent bile acid derivative, cholylglycylamidofluorescein (CGamF), by exposure (0.05 microM) for 30 min, the null point occurred at a CGamF concentration in the pipette of 0.6 microM. This value is 12 times greater than that in the bath. In conclusion, a new method is described that can measure free cytosolic concentrations of fluorescent molecules. It should prove useful in determining the intracellular location and state of transported organic ions.

Download Full-text

Total and Free Plasma Concentrations of Progesterone, Cortisol and Oestradiol-I7ß during Pregnancy, Parturition and Early Lactation in Sows

Australian Journal of Biological Sciences ◽

10.1071/bi9840267 ◽

1984 ◽

Vol 37 (4) ◽

pp. 267 ◽

Cited By ~ 11

Author(s):

JL Whitely ◽

DL Willcox ◽

JA Newton ◽

GD Bryant-Greenwood ◽

PE Hartmann

Keyword(s):

Post Partum ◽

Plasma Concentrations ◽

Free Fraction ◽

Maternal Plasma ◽

Free Concentration ◽

Free Cortisol ◽

Dialysis Method ◽

Three Stages ◽

Free Plasma ◽

Total Concentrations

The total (bound plus free) concentrations of progesterone, 20a-<iihydroprogesterone, oestradiol-17{:1 and cortisol were determined in the plasma of sows at three stages during pregnancy and more intensively from 5 days pre-partum to 5 days post-partum. The free fractions of progesterone, oestradiol-17{3 and cortisol were measured in the same samples by a rate dialysis method. Up to day 110 of gestation, the amounts of free hormone in plasma did not fluctuate independently of their total concentrations. During farrowing, the total and free concentrations of progesterone and cortisol varied independently of each other, whereas total and free oestradiol-17{3 declined simultaneously. The initiation of parturition was associated with a decrease in circulating total progesterone, and was accentuated by a decrease in the free fraction (P<O� 005) so that its active free concentration was only 20% of its day 1 pre-partum value. Total and free cortisol concentrations rose rapidly during labour so that at 12-18 h after birth of the first piglet 30% of that cortisol in maternal plasma was free hormone.

Download Full-text

Pengaruh Pemberian Kedelai terhadap Sistem Reproduksi

Jurnal Penelitian Perawat Profesional ◽

10.37287/jppp.v1i1.18 ◽

2019 ◽

Vol 1 (1) ◽

pp. 53-60

Author(s):

Rizky Aprilia Wikayanti ◽

Andre Parmonangan Panjaitan

Keyword(s):

Menstrual Cycle ◽

Reproductive System ◽

Experimental Studies ◽

Review Literature ◽

Follicular Phase ◽

Free Concentration ◽

Human Reproductive ◽

17Β Estradiol ◽

Lh Secretion

Kedelai merupakan tanaman Leguminoceae, yang mengandung senyawa isoflavon. Struktur kimianya menyerupai 17β-estradiol yang memiliki kemampuan untuk berikatan dengan reseptor estrogen yang dapat berpengaruh terhadap sistem reproduksi manusia. Tujuan literatur review ini untuk mengetahui efek kedelai terhadap sistem reproduksi manusia. Metode yang digunakan adalah metode literatur review dari 50 artikel PubMed NCBI, Elsevier dan BMJ Journal yang diperoleh hanya 38 artikel yang digumakan dari tahun 2000 sampai dengan tahun 2018. Berbagai penelitian eksperimental yang dilakukan menunjukkan bahwa kedelai memiliki efek terhadap sistem reproduksi manusia. Kedelai dapat menyebabkan sekresi FSH, sekresi LH menurun dan meningkatkan konsentrasi estradiol bebas. Penurunan FSH dan LH dapat menyebabkan gangguan dalam siklus menstruasi terutama pada fase folikular dan ovulasi, jika fase folikular terganggu maka siklus menstruasi akan menjadi tidak teratur. Selain itu fitoestrogen yang terkandung dalam kedelai diketahui dapat menghambat 17-β hidroksisteroidoksidoreduktase sehingga mengakibatkan penurunan kadar testosteron. Kata kunci: kedelai, manusia, reproduksi THE ROLE OF SOYBEAN FOR REPRODUCTIVE SYSTEM ABSTRACT Soybean is a Leguminoceae plant, which contains isoflavone compounds. Its chemical structure resembles 17β-estradiol which has ability to bind to estrogen receptors which can affect the human reproductive system. The purpose of this review literature is to determine the effect of soy on the human reproductive system. Using research articles and books related to the effect of soy on the reproductive system from 2000 to 2018. Various experimental studies conducted showed that soy has an effect on the human reproductive system. Soy can cause FSH secretion, decreased LH secretion and increasing the free concentration of estradiol. Decreased FSH and LH can cause disruption in the menstrual cycle, especially in the follicular phase and ovulation, if the follicular phase is disrupted then the menstrual cycle will become irregular. In addition, phytoestrogens contained in soy are known to inhibit 17-β hydroxysteroidoxidoreductase, resulting in a decrease in testosterone levels. Keywords : human, reproductive, soybean

Download Full-text