Description of the structure of Fomenko invariants on the boundary and inside 𝑄-domains, estimates of their number on the lower boundary for the manifolds 𝑆³, ℝℙ³, 𝕊¹×𝕊², and 𝕋³

1991 â—˝  
pp. 297-304
Author(s):  
V. Kalashnikov
Keyword(s):  
Lower Boundary

Morphometric characteristics of competent proximal valves of the great saphenous vein and superficial femoral vein in vivo according to ultrasound angioscanning data

2019 â—˝  
Vol 18 (3) â—˝  
pp. 16-22
Author(s):  
E. K. Gavrilov â—˝  
H. L. Bolotokov â—˝  
E. A. Babinets
Keyword(s):  
Saphenous Vein â—˝  
Great Saphenous Vein â—˝  
Femoral Vein â—˝  
Lower Boundary â—˝  
Average Diameter â—˝  
Lower Limbs â—˝  
Functional Test â—˝  
Natural Form â—˝  
Superficial Femoral Vein â—˝  
Venous Diameter

Introduction. It seems relevant to study the ultrasound anatomy and physiology of the proximal valve segments of the superficial femoral vein (SFV) and the great saphenous vein (GSV) to develop effective reconstructive surgical interventions on venous valves in chronic vein diseases.The aim of the survey was to study the ultrasound anatomy of the venous wall, the size and shape of the proximal SFV and GSV valves are normal at rest and during the functional test Valsalva.Material and methods. Proximal valve SFV studies were performed in 144 lower limbs in 115 people (mean age 51.1 ± 14.4 years, 60 women and 55 men), proximal GSV valves studies - in 82 lower limbs in 67 persons (average age 45, 1 ± 13.3 years, 33 women, 34 men). A longitudinal and transverse ultrasound scanning of the femoral vein bifurcation and safenofemoral junction areas were performed, the structures of the proximal SFV and GSV valves were visualized, the valve shape was measured and the diameter of the veins was measured at the level valves at the base of the valves (inlet diameter), at the point of maximum ectasia (diameter of ectasia), at the upper border of the valve (diameter of the outlet), as well as measuring the length of the valve a (length to ectasia, the total length of the valve). The degree of ectasia over the valve was judged by calculating the relative venous diameter change (RVDC).Results. the average diameter of the SFV at the level of the lower boundary of its first valve was 10.01 ± 1.44 mm. The average diameter of the SFV at the level of the maximum ectasia of its first valve was 13,1±2 mm. The average value of the index of RVDC for SFV was 31%±10,4%. An increase in the diameter of the vein in the zone of supravalvular ectasia up to 20% corresponded to the spindle-shaped valve, more than 20% - to the clavate form, which was noted in the majority of the examined. The change in the relative venous diameter of the SFV on the Valsalva test was 38,2%±12,4%. The average diameter of the GSV at the base of the first valves was 6,07±1,25 mm. The average diameter of the GSV at the level of the maximum ectasia of the osteal valve was 9,44±1,69 mm. The average RVDC for GSV was 58%±24%.Conclusion. the natural form of proximal SFV and GSV valves is clavate with presence of the significant supravalvular ectasia, which was noted in the majority of the subjects alone and in all during the performance of the Valsalva functional test.

Assessment of nutritional status of students of medical institute according to the blood biochemical parameters

2020 â—˝  
pp. 55-63
Author(s):  
Rofail Rakhmanov â—˝  
Elena Bogomolova â—˝  
Mariya Shaposhnikova â—˝  
Mariya Sapozhnikova
Keyword(s):  
Nutritional Status â—˝  
Lower Boundary â—˝  
Density Lipoprotein â—˝  
Blood Parameters â—˝  
Medical Institute â—˝  
Specific Situation â—˝  
Mathematical Methods â—˝  
Normal Range â—˝  
Mean Values â—˝  
The Mean

The biochemical blood parameters characterizing the students ’nutritional status were evaluated: protein, lipid, carbohydrate metabolism, a number of minerals. The mean values, errors of the mean, median (Me), boundary (Q) and the range of 25–75 percentiles were determined. In 9.1 % of students and 28.6 % of students, the total protein was increased. Creatinine in men was in the upper normal range, in women — at the upper limit of normal, of which 46.2 % was higher than normal. The interval Q25–75 of uric acid in students is determined in the lower normal zone. In 40.0 % of men, decreased high-density lipoprotein cholesterol (Q25–75 corresponded to 1.15–1.79), in women — below normal, Q25–75 5 was 1.3–1.5, decreased in 73.3 %. Me and Q25–75 iron were in the lower normal range; 14.1 % of men and 13.2 % of women are below normal. Me sodium and potassium at the level of the lower boundary of the norm, Q25–75 in the lower zone of the norm: in 16.0 % and 15.4 % of students the levels are reduced. Calcium is slightly above the lower limit of the norm, Q25–75–2.1–2.24, indicating an insufficient intake in the whole group; 25.0 % are below normal. The border of the 25th percentile of magnesium is at the level of the lower border of the norm, in 19.2 % it is reduced. 7.2 % lack of chlorine. Phosphorus is normal, but Q25–75 is in the upper zone; 17.9 % increased. Biochemical markers can identify individuals with metabolic disorders of nutrients. Statistical indicators — the median, the boundaries of 25–75 quartiles and their scope characterize the metabolism of macronutrients and minerals in the group and subgroups of students. Laboratory and mathematical methods can provide a basis for identifying the specific causes of these changes. For this, you can use the questionnaire method of studying the nutrition of students, possibly using the developed questionnaires for a specific situation.

scholarly journals Frictional properties of anorthite (feldspar): implications for the lower boundary of the seismogenic zone

2020 â—˝  
Vol 72 (1) â—˝  
Author(s):  
Koji Masuda
Keyword(s):  
Dominant Role â—˝  
Lower Boundary â—˝  
Earthquake Magnitude â—˝  
Seismogenic Zone â—˝  
Effective Pressure â—˝  
Velocity Dependence â—˝  
Brittle Deformation â—˝  
Frictional Properties â—˝  
Depth Extent â—˝  
Mineral Constituents

Abstract Earthquake magnitude is closely related to the depth extent of the seismogenic zone, and higher magnitude earthquakes occur where the seismogenic zone is thicker. The frictional properties of the dominant mineral constituents of the crust, such as feldspar-group minerals, control the depth extent of the seismogenic zone. Here, the velocity dependence of the steady-state friction of anorthite, the calcic endmember of the feldspar mineral series, was measured at temperatures from 20 to 600 °C, pore pressures of 0 (“dry”) and 50 MPa (“wet”), and an effective pressure of 150 MPa. The results support previous findings that the frictional properties of feldspar play a dominant role in limiting the depth extent of the seismogenic zone. This evidence suggests that brittle deformation of anorthite may be responsible for brittle fault movements in the brittle–plastic transition zone.

Measurements of Loudness Growth in 1/2-Octave Bands for Children and Adults With Normal Hearing

1999 â—˝  
Vol 8 (1) â—˝  
pp. 40-46 â—˝  
Author(s):  
Melisa R. Ellis â—˝  
Michael K. Wynne
Keyword(s):  
Hearing Loss â—˝  
Hearing Aids â—˝  
Hearing Aid â—˝  
Age Groups â—˝  
Lower Boundary â—˝  
Normal Hearing â—˝  
Boundary Values â—˝  
Simple Modification â—˝  
Point Data â—˝  
Loudness Growth

The loudness growth in 1/2-octave bands (LGOB) procedure has been shown previously to provide valid estimates of loudness growth for adults with normal hearing and those with hearing loss (Allen, Hall, & Jeng, 1990), and it has been widely incorporated into fitting strategies for adult hearing aid users by a hearing aid manufacturer. Here, we applied a simple modification of LGOB to children and adults with normal hearing and then compared the loudness growth functions (as obtained from end-point data) between the two age groups. In addition, reliability data obtained within a single session and between test sessions were compared between the two groups. Large differences were observed in the means between the two groups for the lower boundary values, the upper boundary values, and the range between boundaries both within and across all frequencies. The data obtained from children also had greater variance than the adult data. In addition, there was more variability in the data across test sessions for children. Many test-retest differences for children exceeded 10 dB. Adult test-retest differences were generally less than 10 dB. Although the LGOB with the modifications used in this study may be used to measure loudness growth in children, its poor reliability with this age group may limit its clinical use for children with hearing loss. Additional work is needed to explore whether loudness growth measures can be adapted successfully to children and whether these measures contribute worthwhile information for fitting hearing aids to children.

scholarly journals Strategic Analysis of the Pricing Mechanisms in an Online Book Supply Chain in the Presence of Reference Price Effects

2021 â—˝  
Vol 16 (5) â—˝  
pp. 1492-1516
Author(s):  
Wenhua Hou â—˝  
Yuwen Zeng
Keyword(s):  
Supply Chain â—˝  
Discount Rate â—˝  
Reference Price â—˝  
Stackelberg Game â—˝  
Lower Boundary â—˝  
Retail Price â—˝  
Reference Points â—˝  
Price Effects â—˝  
Retail Prices â—˝  
Online Book

(1) Background: A binding recommended retail price has been used in several markets in a variety of forms, and the book market is a typical example. Publishers sell books to online retailers at a unit wholesale discount computed on the cover price. Retailers are then allowed to set the retail price. Therefore, if consumers regard the cover prices as reference points, then they may be more likely to purchase books if retail prices are lower than the cover prices. (2) Methods: We develop a Stackelberg game model for a book supply chain to investigates how reference price effects affect retailers and publisher’s pricing strategies. (3) Results: The results show that retailers will sell printed books at a discount only when the publisher’s wholesale discount rate is not high. Further, as the intensity of the reference price effects increases, (a) the lower boundary of the wholesale discount rate rises, (b) publishers’ profits increase and (c) retailers’ profits increase relative to the level of consumers’ e-books acceptance. (4) Conclusions: This result is related to the fact that the online retailer, such as Amazon and JD.com, like to invoke reference price effects in consumers’ minds by highlighting the printed book’s discount rate.

scholarly journals Analysis of Soil Water Response to Grass Transpiration

10.17221/6510-swr â—˝  
2013 â—˝  
Vol 1 (No. 3) â—˝  
pp. 85-98
Author(s):  
Dohnal Michal â—˝  
Dušek Jaromír â—˝  
Vogel Tomáš â—˝  
Herza Jiří
Keyword(s):  
Soil Water â—˝  
Water Uptake â—˝  
Preferential Flow â—˝  
Water Movement â—˝  
Control Volume â—˝  
Water Pressure â—˝  
Lower Boundary â—˝  
Root Water Uptake â—˝  
Water Dynamics â—˝  
Soil Water Dynamics

This paper focuses on numerical modelling of soil water movement in response to the root water uptake that is driven by transpiration. The flow of water in a lysimeter, installed at a grass covered hillslope site in a small headwater catchment, is analysed by means of numerical simulation. The lysimeter system provides a well defined control volume with boundary fluxes measured and soil water pressure continuously monitored. The evapotranspiration intensity is estimated by the Penman-Monteith method and compared with the measured lysimeter soil water loss and the simulated root water uptake. Variably saturated flow of water in the lysimeter is simulated using one-dimensional dual-permeability model based on the numerical solution of the Richards’ equation. The availability of water for the root water uptake is determined by the evaluation of the plant water stress function, integrated in the soil water flow model. Different lower boundary conditions are tested to compare the soil water dynamics inside and outside the lysimeter. Special attention is paid to the possible influence of the preferential flow effects on the lysimeter soil water balance. The adopted modelling approach provides a useful and flexible framework for numerical analysis of soil water dynamics in response to the plant transpiration.

The lower boundary of the Cambrian System in Taymyr

1979 â—˝  
Vol 21 (7) â—˝  
pp. 765-768
Author(s):  
I. I. Kopfev â—˝  
V. V. Bezzubtsev â—˝  
V. A. Shipitsyn
Keyword(s):  
Lower Boundary â—˝  
Cambrian System

scholarly journals An experimental investigation of convection in a fluid that exhibits phase change

1981 â—˝  
Vol 102 â—˝  
pp. 85-100 â—˝  
Author(s):  
D. E. Fitzjarrald
Keyword(s):  
Thin Layer â—˝  
Phase Change â—˝  
Latent Heat â—˝  
Thermal Gradient â—˝  
Lower Boundary â—˝  
Working Fluid â—˝  
Heavy Fluid â—˝  
Convective Motions â—˝  
Rayleigh Benard Convection â—˝  
Rayleigh Benard

Convection flows have been systematically observed in a layer of fluid between two isothermal horizontal boundaries. The working fluid was a nematic liquid crystal, which exhibits a liquid–liquid phase change at which latent heat is released and the density changed. In addition to ordinary Rayleigh–Bénard convection when either phase is present alone, there exist two distinct types of convective motions initiated by the unstable density difference. When a thin layer of heavy fluid is present near the top boundary, hexagons with downgoing centres exist with no imposed thermal gradient. When a thin layer of light fluid is brought on near the lower boundary, the hexagons have upshooting centres. In both cases, the motions are kept going once they are initiated by the instability due to release of latent heat. Relation of the results to applicable theories is discussed.

scholarly journals Safe sex: male–female coalitions and pre-copulatory mate-guarding in a fiddler crab

Biology Letters â—˝  
2009 â—˝  
Vol 6 (2) â—˝  
pp. 180-182 â—˝  
Author(s):  
Richard N. C. Milner â—˝  
Michael D. Jennions â—˝  
Patricia R. Y. Backwell
Keyword(s):  
Sexual Dimorphism â—˝  
Reproductive Success â—˝  
Observational Data â—˝  
Fiddler Crab â—˝  
Lower Boundary â—˝  
Mate Guarding â—˝  
Maintenance Costs â—˝  
Boundary Maintenance â—˝  
Uca Annulipes â—˝  
Males And Females

In fiddler crabs both males and females defend territories that are essential for survival. Given pronounced sexual dimorphism in weaponry, how do weaponless females defend their territory from well-armed males? Using observational data and two simple experiments, we test whether male Uca annulipes protect their female neighbours from conspecific intruders. We show that males defend their female neighbours against male but not female intruders. We also show that females sometimes mate with their immediate neighbours. Male defence of female neighbours appears to represent both pre-copulatory mate-guarding and a territorial coalition. Males who ensure that their neighbour remains female could benefit through increased opportunity for future reproductive success and lower boundary maintenance costs.

The Lid-Driven Cavity Flow: A Synthesis of Qualitative and Quantitative Observations

10.1115/1.3243136 â—˝  
1984 â—˝  
Vol 106 (4) â—˝  
pp. 390-398 â—˝  
Author(s):  
J. R. Koseff â—˝  
R. L. Street
Keyword(s):  
Heat Flux â—˝  
Flow Visualization â—˝  
Three Dimensional â—˝  
Symmetry Plane â—˝  
Lower Boundary â—˝  
Thymol Blue â—˝  
Width Ratio â—˝  
Cavity Depth â—˝  
Driven Cavity â—˝  
Turbulent Characteristics

A synthesis of observations of flow in a three-dimensional lid-driven cavity is presented through the use of flow visualization pictures and velocity and heat flux measurements. The ratio of the cavity depth to width used was 1:1 and the span to width ratio was 3:1. Flow visualization was accomplished using the thymol blue technique and by rheoscopic liquid illuminated by laser-light sheets. Velocity measurements were made using a two-component laser-Doppler-anemometer and the heat flux on the lower boundary of the cavity was measured using flush mounted sensors. The flow is three-dimensional and is weaker at the symmetry plane than that predicted by accurate two-dimensional numerical simulations. Local three-dimensional features, such as corner vortices in the end-wall regions and longitudinal Taylor-Go¨rtler-like vortices, are significant influences on the flow. The flow is unsteady in the region of the downstream secondary eddy at higher Reynolds numbers (Re) and exhibits turbulent characteristics in this region at Re = 10,000.

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