Positional information and pattern regulation in hydra: the formation of boundary regions following axial grafts

Development ◽  
1973 ◽  
Vol 30 (3) ◽  
pp. 701-725
Author(s):  
J. Hicklin ◽  
A. Hornbruch ◽  
L. Wolpert ◽  
M. Clarke
Keyword(s):  
Computer Simulations ◽  
Positional Information ◽  
The Other ◽  
Simple Computer ◽  
Gradient Model ◽  
Set Up ◽  
Pattern Regulation ◽  
Positional Value ◽  
Threshold Amount

A two-gradient model is proposed for regulation and regeneration of the head end of hydra in terms of positional information. One gradient is set up by a diffusible substance made at the head end, which may be regarded as a positional signal, and the other is a more stable cellular parameter which is the positional value. The rule for head end formation is that the concentration of the diffusible substance falls a threshold amount below the positional value. A variety of instantaneous axial grafts have been carried out which are discussed in terms of this model. Some simple computer simulations of diffusion are provided. There is some evidence that the source of the positional signal is localized at the head end. Some experiments on changes in polarity are given. It also seems that the positional signal from the head end inhibits foot end formation.

Doctrine and Dialectic in Plato’s Dialogues

2018 ◽  
Author(s):  
Rachana Kamtekar
Keyword(s):  
Methodological Approach ◽  
The Other ◽  
Set Up

Chapter 1 lays out the methodological approach employed throughout the book, which is to pay attention to the dialectical dependence of what the main speaker in the dialogue says on the intellectual problem(s) set up in the dialogue both by himself and the other speakers. To illustrate, Chapter 1 describes Socrates’ use of the method of hypotheses from the Meno and Phaedo to answer questions that go beyond his claims to knowledge in the Republic.

scholarly journals Preparation of alcohol-based handrub in COVID-19 Alsatian cluster

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Elodie Di-Falco ◽  
Johan Bourbon ◽  
Isalyne Sbaffe ◽  
Jean-Daniel Kaiser
Keyword(s):  
Critical Period ◽  
Hospital Management ◽  
Management Team ◽  
The Other ◽  
Packaging Materials ◽  
Local Production ◽  
Technical Grade ◽  
Hand Sanitizer ◽  
Set Up ◽  
Real Challenge

AbstractAlsace, in particular Haut-Rhin, is one of the main clusters of COVID-19 in France. There has been a shortage of essential supplies in the area, especially alcohol-based hand sanitizer. In this context, and in accordance with the decree dated March 6, 2020, our hospital management team asked us to start local production of alcohol-based handrub. This was a real challenge: In one week, we had to implement the production of handrub to meet the needs of a 1,400-bed hospital. The production had to comply with the French preparation guidelines and take place on specific premises, with qualified and calibrated equipment, by qualified staff, under the supervision of a pharmacist. The other big challenge we faced was the supply of pharmaceutical raw and packaging materials. During this particular critical period, all suppliers were out of stock. Here, we describe the organizational set-up and the decisions made, e. g., to use technical-grade ethanol before the publication of the decrees dated March 13 and March 23, 2020.

scholarly journals Astronomy to understand a human environment

1998 ◽  
Vol 162 ◽  
pp. 211-213
Author(s):  
S. Isobe
Keyword(s):  
School System ◽  
Environmental Science ◽  
The Other ◽  
Human Environment ◽  
Science Courses ◽  
The Public ◽  
Global Environmental Problems ◽  
Global Environmental ◽  
Set Up ◽  
School Period

Astronomy is an important science in understanding a human environment. However, it is thought by most politicians, economists, and members of the public that astronomy is a pure science having no contribution to daily human activities except a few matters relating to time. The Japanese government is studying a reorganisation of our school system to have 5 school days per week, instead of 6 days per week, and this July its committee made a recommendation to reduce school hours for science and set up new courses for practical computers and environmental science. I currently made a proposal. It is very difficult for most of the school pupils, who will have non-scientific jobs, to understand science courses currently taught in school, because each science is taught independently from the other sciences. Therefore, their knowledge of sciences obtained during their school period does not greatly help their understanding of global environmental problems.

Statics Analysis of the Mechanical Model of Nucleosome

2011 ◽  
Vol 343-344 ◽  
pp. 661-667 ◽  
Author(s):  
Yun Xue ◽  
De Wei Weng ◽  
Gang Ming Gong
Keyword(s):  
Mechanical Model ◽  
The Other ◽  
Elastic Rod ◽  
Equilibrium Equations ◽  
Constraint Force ◽  
Precession Angle ◽  
Nutation Angle ◽  
Analytic Expression ◽  
Set Up ◽  
Calculated Analysis

Mechanical model of nucleoside and its equilibrium equations are set up, and the mechanical properties on the equilibrium position are analyzed. In the case constraint force and electrostatic attraction between cylinder OH and elastic rod are balanced, the analytic expression of nutation angle of the section and its conditions of existence are given. It is show that the cylinder OH can maintain equilibrium at any range of the precession angle. In the other case when unbanced, there is phenomenon of separation of elastic rod from cylinder OH in the spiral wound 2 circles, and numerical solution of the precession angle at separation points are calculated. Analysis of equilibrium of cylinder H1 illustrates that the generatrix of cylinder H1 and OH are not parallel, and the angle between them is obtained

Federal Aviation Administration’s Probability of Detection Testing Results for Structural Health Monitoring (SHM)

2021 ◽  
Author(s):  
Paul Swindell ◽  
Danielle Stephens
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Federal Aviation Administration ◽  
Steering Committee ◽  
Probability Of Detection ◽  
The Other ◽  
Atlantic City ◽  
Commercial Aviation ◽  
Structural Health ◽  
Set Up

Abstract The Federal Aviation Administration (FAA) has been participating with the Society of Automotive Engineers (SAE) Aerospace Industry Steering Committee (AISC) to develop a methodology for calculating the Probability of Detection (POD) for Structural Health Monitoring (SHM) for damage detection on commercial aviation. Two POD methodologies were developed: one by Dr. William Meeker, Iowa State University, and the other by Dennis Roach, Sandia National Laboratories (SNL). With Dr. Seth Kessler, Metis Design Corp, a test program of 24 samples of aluminum strips to be fatigued on MTS machines was developed. The samples were designed to meet the ASTM E647. Twelve samples had two SHM modalities on the front and back from Metis (PZT and carbon nanotubes), and the other twelve had SHM sensors from Structural Monitoring Systems (SMS) (comparative vacuum monitoring – CVM) and Acellent Technologies (PZT). The tests were performed at the FAA William J Hughes Technical Center in Atlantic City, NJ. The samples were cycled every 1500 cycles and then stopped for SHM data collection. Once the crack exceeded 0.125 inches and provided for a minimum of 15 inspections, a new sample was tested until all 12 samples were completed. The data was provided to each company to be set up in the format needed to run through the POD methodologies. Then the data was provided to Dr. Meeker and Dr. Roach for analysis. This paper will provide the results of those tests.

Vibration of Rectangular Plates by the Ritz Method

1950 ◽  
Vol 17 (4) ◽  
pp. 448-453 ◽  
Author(s):  
Dana Young
Keyword(s):  
Ritz Method ◽  
Normal Modes ◽  
Approximate Solutions ◽  
The Other ◽  
Rectangular Plates ◽  
Elastic Plates ◽  
Modes Of Vibration ◽  
Ritz’S Method ◽  
Square Plate ◽  
Set Up

Abstract Ritz’s method is one of several possible procedures for obtaining approximate solutions for the frequencies and modes of vibration of thin elastic plates. The accuracy of the results and the practicability of the computations depend to a great extent upon the set of functions that is chosen to represent the plate deflection. In this investigation, use is made of the functions which define the normal modes of vibration of a uniform beam. Tables of values of these functions have been computed as well as values of different integrals of the functions and their derivatives. With the aid of these data, the necessary equations can be set up and solved with reasonable effort. Solutions are obtained for three specific plate problems, namely, (a) square plate clamped at all four edges, (b) square plate clamped along two adjacent edges and free along the other two edges, and (c) square plate clamped along one edge and free along the other three edges.

Oscillating Contractions in Protoplasmic Strands of Physarum: Mechanical and Thermal Methods of Phase Shifting for Studying the Nature of the Synchronizing Factor and its Transmission

1980 ◽  
Vol 85 (1) ◽  
pp. 21-31
Author(s):  
U. ACHENBACH ◽  
K. E. WOHLFARTH-BOTTERMANN
Keyword(s):  
Contractile Activity ◽  
Signal Transmission ◽  
Rapid Change ◽  
Isometric Tension ◽  
The Other ◽  
Rapid Phase ◽  
Thermal Methods ◽  
Original Length ◽  
Set Up ◽  
Rhythmic Contractile Activity

A new experimental investigation chamber was used to analyse the control of rhythmic contractile activity in Physarum. A strand was mounted in such a way that isometric tension measurements of contraction forces could be made on two regions independently, the two regions remaining connected. It was possible to disturb one region experimentally and to compare its behaviour with the other. A short time after being set up in the apparatus, the isometric contraction cycles in the two regions became synchronous. Stretching one region by 50% of its original length induced a phase delay relative to the other. A brief unilateral cold shock (Δt = 5舑15 °C) had a similar phase-retarding effect. Synchrony was subsequently reattained, unless the connecting region was cut or, for example, treated with 30 mM benzamide. In approximately 25% of the investigated strands, a rapid change to a higher temperature (Δt = 2舑5 °C) caused the warmed side to be phase-advanced. However, 75% of the strands did not show a phase shift, suggesting that a rapid phase regulation is supported by increased temperature. The described experimental assay is suitable for analysing the pathway and the nature of signal transmission in plasmodial strands. Note: Partly presented at the International Titisee-Conference on Cellular Oscillators, 22舑24 March 1979 (see J. exp. Biol. (1979)).

Theory Design Research and the Application Prospect of the Future for the Ever Moving Car

2013 ◽  
Vol 456 ◽  
pp. 142-145
Author(s):  
Guo Qiang Cao ◽  
Yuan Ji Li ◽  
Jiang Ning Liu
Keyword(s):  
Wind Power ◽  
Power Loss ◽  
Electromagnetic Induction ◽  
Energy Recovery ◽  
Design Research ◽  
Automobile Driving ◽  
The Other ◽  
Induction Principle ◽  
Energy Maximum ◽  
Set Up

Using faraday electromagnetic induction principle will car each wheel as a generator. For car generates its own energy recovery; In the front of car set up a blade, It can recovery the wind power what automobile driving produced, For wind power generation, So that it can recover the energy maximum for the car itself. Because of the two kinds of energy all are car generates its own energy, so it can not recovery completely, in addition to there is power loss in the other part of the car, So it needs to the energy loss and power loss for supplement, I choose the solar energy used as supplementary energy that finally achieve the purpose of "ever moving".

scholarly journals The recertification of the professional accounting qualification in Estonia: the requirements and quality of CPD

2017 ◽  
pp. 113-0
Author(s):  
Kaidi Kallaste ◽  
Jaan Alver
Keyword(s):  
Labour Market ◽  
Professional Training ◽  
The Other ◽  
Professional Qualification ◽  
Other Hand ◽  
Set Up ◽  
Alternative Solutions

The recertification of the professional accounting qualification in Estonia: the requirements and quality of CPD As the purpose of a professional qualification should be to ensure quality to employers/customers, appro-priate requirements for professional training should not be too low. On the other hand, too high require-ments for the amount of training would lead to the situation where maintaining the level is expensive and if the labour market does not consider having a professional certificate necessary, recertification will be discarded. The purpose of the research was to identify the factors that influence an accountant’s decision whether to recertify his/her professional qualification or not. The conditions of recertification were ana-lysed and compared to other countries as were the requirements set up for auditors. The results of the survey revealed that in Estonia the decision not to recertify one’s professional qualification was mainly due to not having fulfilled the required number of qualification hours or not having certificates proving one’s participation in qualification training sessions. At the same time, compared to other countries, the requirements in Estonia are very low. So that the increase in the amount of training would not hinder recertification, alternative solutions for Estonia are proposed in the article.

scholarly journals A Double Sky-Hook Algorithm for Improving Road-Holding Property in Semi-Active Suspension Systems for Application to In-Wheel Motor

2021 ◽  
Vol 11 (19) ◽  
pp. 8912
Author(s):  
Seunghoon Woo ◽  
Donghoon Shin
Keyword(s):  
Computer Simulations ◽  
Dynamic Models ◽  
Active Suspension ◽  
The Other ◽  
Driving Mode ◽  
The Road ◽  
Suspension Systems ◽  
Active Suspension Systems ◽  
Main Disadvantage ◽  
Advanced Development

This paper presents a double sky-hook algorithm for controlling semi-active suspension systems in order to improve road-holding property for application in an in-wheel motor. The main disadvantage of the in-wheel motor is the increase in unsprung masses, which increases after shaking of the wheel, so it has poor road-holding that the conventional theoretical sky-hook algorithm cannot achieve. The double sky-hook algorithm uses a combination of damper coefficients, one from the chassis motion and the other from the wheel motion. Computer simulations using a quarter and full car dynamic models with the road conditions specified by ISO2631 showed the effectiveness of the algorithm. It was observed that the algorithm was the most effective in the vicinity of the wheel hop frequency. This paper also proposed the parameter set of the double sky-hook algorithm to differentiate the driving mode of vehicles under advanced development.

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