scholarly journals How much information can be obtained from tracking the position of the leading edge in a scratch assay?

2014 ◽  
Vol 11 (97) ◽  
pp. 20140325 ◽  
Author(s):  
Stuart T. Johnston ◽  
Matthew J. Simpson ◽  
D. L. Sean McElwain
Keyword(s):  
Cell Motility ◽  
Leading Edge ◽  
Automated Image Analysis ◽  
Cell Counting ◽  
Cell Labelling ◽  
Scratch Assay ◽  
Short Period ◽  
Using Data ◽  
Short Time ◽  
Non Destructive

Moving cell fronts are an essential feature of wound healing, development and disease. The rate at which a cell front moves is driven, in part, by the cell motility, quantified in terms of the cell diffusivity D , and the cell proliferation rate λ . Scratch assays are a commonly reported procedure used to investigate the motion of cell fronts where an initial cell monolayer is scratched, and the motion of the front is monitored over a short period of time, often less than 24 h. The simplest way of quantifying a scratch assay is to monitor the progression of the leading edge. Use of leading edge data is very convenient because, unlike other methods, it is non-destructive and does not require labelling, tracking or counting individual cells among the population. In this work, we study short-time leading edge data in a scratch assay using a discrete mathematical model and automated image analysis with the aim of investigating whether such data allow us to reliably identify D and λ . Using a naive calibration approach where we simply scan the relevant region of the ( D , λ ) parameter space, we show that there are many choices of D and λ for which our model produces indistinguishable short-time leading edge data. Therefore, without due care, it is impossible to estimate D and λ from this kind of data. To address this, we present a modified approach accounting for the fact that cell motility occurs over a much shorter time scale than proliferation. Using this information, we divide the duration of the experiment into two periods, and we estimate D using data from the first period, whereas we estimate λ using data from the second period. We confirm the accuracy of our approach using in silico data and a new set of in vitro data, which shows that our method recovers estimates of D and λ that are consistent with previously reported values except that that our approach is fast, inexpensive, non-destructive and avoids the need for cell labelling and cell counting.

The Success of Cognitive Activity of Students of the Northern (Arctic) Federal University with Different Levels of Anxietyin Different Time Conditions

2021 ◽  
Vol 18 (1) ◽  
pp. 52-59
Author(s):  
A.I. Taleeva ◽  
◽  
I.T. Madumarova ◽  
N.V. Zvyagina ◽  
◽  
...  
Keyword(s):  
Emotional State ◽  
Cognitive Task ◽  
Cognitive Activity ◽  
Whole Body ◽  
Modern World ◽  
Short Period ◽  
Personal Anxiety ◽  
Psychophysiological Testing ◽  
Short Time ◽  
Different Levels

The dynamic development of the modern world requires the processing and development of a large enough amount of information in a short period of time, which leads to a violation of the psychophysiological and psycho-emotional balance of the person. Violation of the psycho-emotional state leads to the development of increased anxiety. Students need to learn a lot of information in a very short time. The time limit affects students as a stress factor, leads to increased stress and therefore negatively affects the quality of work and in general on the whole body. The aim of the study is to determine the success of cognitive tasks by students of the Northern (Arctic) Federal University with different levels of anxiety in different time conditions. The study used a psychophysiological testing device to determine the level of situational and personal anxiety, to assess the psycho-emotional state used the technique of simple visual-motor reaction, to determine the success of the cognitive task were presented words with one missing letter.

scholarly journals Study of Lamb Waves for Non-Destructive Testing Behind Screens

2018 ◽  
Vol 170 ◽  
pp. 03005 ◽  
Author(s):  
P. Kauffmann ◽  
M.-A. Ploix ◽  
J.-F. Chaix ◽  
C. Gueudré ◽  
G. Corneloup ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Lamb Waves ◽  
Nuclear Industry ◽  
Liquid Sodium ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Leaky Lamb Waves ◽  
Short Time ◽  
And Control ◽  
Non Destructive

The inspection and control of sodium-cooled fast reactors (SFR) is a major issue for the nuclear industry. Ultrasonic solutions are under study because of the opacity of liquid sodium. In this paper, the use of leaky Lamb waves is considered for non-destructive testing (NDT) on parallel and immersed structures assimilated as plates. The first phase of our approach involved studying the propagation properties of leaky Lamb waves. Equations that model the propagation of Lamb waves in an immersed plate were solved numerically. The phase velocity can be experimentally measured using a two dimensional Fourier transform. The group velocity can be experimentally measured using a short-time Fourier transform technique. Attenuation of leaky Lamb waves is mostly due to the re-emission of energy into the surrounding fluid, and it can be measured by these two techniques.

scholarly journals The nature of crowdfunding in China: initial evidence

2018 ◽  
Vol 12 (3) ◽  
pp. 300-322 ◽  
Author(s):  
Zaiyu Huang ◽  
Candy Lim Chiu ◽  
Sha Mo ◽  
Rob Marjerison
Keyword(s):  
Risk Sharing ◽  
Small And Medium Enterprises ◽  
New Ventures ◽  
Public And Private ◽  
Content Type ◽  
Regulatory Frameworks ◽  
Short Period ◽  
Key Issues ◽  
Using Data ◽  
Medium Enterprises

Purpose The purpose of this paper is to develop initial evidence about the nature and features of crowdfunding in China, given it is largely unregulated regulatory frameworks. Design/methodology/approach The paper used extensive desk research using data collected from the public and private sectors, after which the data was analyzed parallel to existing academic literature, that is, institutional context by Bruton et al. (2014). This paper uncovered patterns of development, profiling crowdfunding platforms, examining the regulatory landscape and providing antecedents of successful crowdfunding projects in China. Findings When the traditional financial markets are hard to reach, micro, small and medium enterprises (MSMEs) were starved for capital. Crowdfunding can play a major role in funding and risk sharing. It is an innovative and dynamic vehicle for MSMEs as well as enthusiastic investors in China. Since its initial introduction to China in 2009, crowdfunding has gained substantial popularity in a relatively short period. Currently, there is still not an identifiable guideline on how to delineate the significance of the crowdfunding platform. The development of crowdfunding in China faces a few unresolved key issues. As researchers exploring this phenomenon in new ways, crowdfunding platforms can be enhanced in a manner that benefits the capital seeker, investors and society as a whole. Originality/value There is a dearth of information on start-up crowdfunding in Asia. With little data available to analyze, so this paper hopes to contribute to knowledge and provide valuable information to researchers and industry representations. Crowdfunding represents a potentially disruptive change in the way that new ventures are funded. This paper represents an initial analysis in the study of new ventures in China. Finally, the authors provide recommendations for entrepreneurs, investors and policymakers as well as researchers and practitioners with suggestions about yet unexplored avenues of research.

scholarly journals Economics analysis of Seed Yam production in Aeroponic system

2020 ◽  
Vol 56 (2) ◽  
Author(s):  
Patricia Pinamang Acheampong ◽  
Marian Dorcas Quain ◽  
David Appiah-Kubi ◽  
Jonas Osei-Adu ◽  
Stella Ama Ennin ◽  
...  
Keyword(s):  
Tissue Culture ◽  
Private Sector ◽  
Production Costs ◽  
Variable Cost ◽  
Fixed Cost ◽  
Cost Ratio ◽  
Total Cost ◽  
Benefit Cost Ratio ◽  
Short Period ◽  
Using Data

The supply of seed yams for intensive yam production is hindered by many constraints, including diseases and pest infestations as well as the unavailability of quality planting material. The combination of tissue culture and aeroponics system is perceived to be the way towards clean and adequate supply of seed yam for enhanced yam production. However, the system is considered as expensive for any individual to implement. In order to encourage private sector to participate in this venture, the economic analysis determining the feasibility and viability of using aeroponics in seed yam production was performed. Using data from established tissue culture and aeroponics system in Ghana, the fixed cost and variable cost parameters as well as production costs were obtained. Results revealed that total cost of building aeroponics structure amounted to GH₵ 94,178.00 (USD 17,938.70). Annual cost of aeroponics structure was GH₵ 9,417.82 (USD 1,793.87). Annual total cost of production totalled GH₵ 204,391.75 (USD 38,931.61). Annual net revenue was GH₵ 75,888.00 (USD 14,454.86). Payback period was 15 months and benefit cost ratio was 1.4. Aeroponics system for seed yam production is therefore profitable since short period would be needed to recoup investment. For food security and creation of workplaces, government could partner with the private sector in the establishment of aeroponics systems to increase yam production and export.

scholarly journals Chirplet Transform in Ultrasonic Non-Destructive Testing and Structural Health Monitoring: A Review

2019 ◽  
Vol 9 (1) ◽  
pp. 3778-3781
Author(s):  
M. S. Mohammed ◽  
K. Ki-Seong
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Ultrasonic Signal ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Structural Health ◽  
Chirplet Transform ◽  
Testing Signal ◽  
Short Time ◽  
Non Destructive

Ultrasonic non-destructive testing signal can be decomposed into a set of chirplet signals, which makes the chirplet transform a fitting ultrasonic signal analysis and processing method. Moreover, compared to wavelet transform, short-time Fourier transform and Gabor transform, chirplet transform is a comprehensive signal approximation method, nevertheless, the former methods gained more popularity in the ultrasonic signal processing research. In this paper, the principles of the chirplet transform are explained with a simplified presentation and the studies that used the transform in ultrasonic non-destructive testing and in structural health monitoring are reviewed to expose the existing applications and motivate the research in the potential ones.

scholarly journals A simple, high-resolution, non-destructive method for determining the spatial gradient of the elastic modulus of insect cuticle

2018 ◽  
Vol 15 (145) ◽  
pp. 20180312 ◽  
Author(s):  
S h. Eshghi ◽  
M. Jafarpour ◽  
A. Darvizeh ◽  
S. N. Gorb ◽  
H. Rajabi
Keyword(s):  
Elastic Modulus ◽  
High Resolution ◽  
Three Dimensional ◽  
Insect Cuticle ◽  
Spatial Gradient ◽  
Engineering Systems ◽  
Small Complex ◽  
Load Carrying ◽  
Using Data ◽  
Non Destructive

Nature has evolved structures with high load-carrying capacity and long-term durability. The principles underlying the functionality of such structures, if studied systematically, can inspire the design of more efficient engineering systems. An important step in this process is to characterize the material properties of the structure under investigation. However, direct mechanical measurements on small complex-shaped biological samples involve numerous technical challenges. To overcome these challenges, we developed a method for estimation of the elastic modulus of insect cuticle, the second most abundant biological composite in nature, through simple light microscopy. In brief, we established a quantitative link between the autofluorescence of different constituent materials of insect cuticle, and the resulting mechanical properties. This approach was verified using data on cuticular structures of three different insect species. The method presented in this study allows three-dimensional visualisation of the elastic modulus, which is impossible with any other available technique. This is especially important for precise finite-element modelling of cuticle, which is known to have spatially graded properties. Considering the simplicity, ease of implementation and high-resolution of the results, our method is a crucial step towards a better understanding of material–function relationships in insect cuticle, and can potentially be adapted for other graded biological materials.

scholarly journals The Polar Fields and Time Fluctuations of the General Magnetic Field of the Sun

1971 ◽  
Vol 43 ◽  
pp. 675-695 ◽  
Author(s):  
A. B. Severny
Keyword(s):  
Magnetic Field ◽  
Close Agreement ◽  
Present Knowledge ◽  
Short Time Scale ◽  
The Sun ◽  
Statistical Nature ◽  
General Magnetic Field ◽  
Short Period ◽  
The Mean ◽  
Short Time

In an attempt to summarize the present knowledge on the general magnetic field (gmf) of the Sun we pointed out the fine structure and the statistical nature of the gmf as one of its most important properties. The dipole-like behaviour of the mean polar field strengths is combined sometimes (since 1964) with a bias of the S-polarity flux for both poles. Highly uneven distribution of gmf with latitude and longitude, the disappearance of gmf at the South pole for months, and short period, almost synchronous at both poles, variations in the sign of gmf are pointed out. The fluctuations with time of the mean magnetic field of the Sun seen as a star (as well as mf at different latitudes) shows periodicity connected with the rotation of the Sun and very close agreement with the fluctuations of the interplanetary field (sector structure). The effect of faster rotation of N-polarities as compared with S-polarities as well as the bias of mean solar as well as interplanetary S-polarity fields are also pointed out. The possibility of short time-scale (hours) intrinsic changes in the local pattern of gmf is demonstrated.

Flamanville EPR RPV’s Heads Carbon Segregation: Characterization of the Segregation in the Heads

2018 ◽  
Author(s):  
Philippe Fichot ◽  
Olivier Calonne ◽  
Mathieu Segond ◽  
Stéphane Marie ◽  
Yvon Desnoyers ◽  
...  
Keyword(s):  
Carbon Content ◽  
Residual Carbon ◽  
Testing Program ◽  
Specific Strategy ◽  
Carbon Segregation ◽  
Geostatistical Approach ◽  
Short Time ◽  
Non Destructive

To characterize the mechanical properties of the residual carbon segregation of the Flamanville EPR RPV heads, a testing program has been defined by Framatome using three sacrificial representative heads. The first step of this program was a 3D characterization of the carbon content inside each piece. A specific strategy has been defined using two methods for the carbon measuring: - In situ measurements using a mobile arc spark spectrometer. This device allows a higher number of non-destructive measurements in a particularly constrained environment and in a short time, - Conventional spectrometry performed on chips sampled from the pieces. This technique is more accurate but is destructive and more time consuming. Also, to consolidate the representativeness of the sacrificial vessels heads, the results were analysed using a geostatistical approach. This paper presents how these two techniques have been used to characterize the carbon content in the segregated part of the pieces and the conclusion of the geostatistical analyses.

Total body water and the exchangeable hydrogen. I. Theoretical calculation of nonaqueous exchangeable hydrogen in man

1977 ◽  
Vol 232 (1) ◽  
pp. R54-R59 ◽  
Author(s):  
J. M. Culebras ◽  
F. D. Moore
Keyword(s):  
Theoretical Calculation ◽  
Total Body Water ◽  
Body Water ◽  
The Body ◽  
Protein Conformations ◽  
Molecular Conformations ◽  
Exchangeable Hydrogen ◽  
Short Period ◽  
Total Body ◽  
Short Time

A theoretical calculation of the total nonaqueous exchangeable hydrogen in protein, carbohydrates, and fat in man has been made. It shows that of the total exchangeable hydrogen in the body 5.22% is located in biochemical components, soluble in body water, containing hydrogen that is exchangeable with the isotope. This value represents a maximum upward distortion of total body water measurements by isotope dilution, due to the maximum possible exchangeability in these molecular conformations. From comparative measurements reported in the literature it is clear that this maximum is not achieved during the short period of time during which tritium-dilution studies are performed. It is the authors' belief that the hard-to-exchange amide hydrogens described by Blout in the protein conformations account for this failure of the isotope to achieve complete exchange in the short time allowed.

Fluid Impact Under Various Tapping Conditions for Biomedical Application (Shirodhara)

2018 ◽  
Author(s):  
Swathika Meenraj ◽  
Chebolu Lakshmana Rao ◽  
Balasubramanian Venkatesh
Keyword(s):  
Integrated Circuit ◽  
Biomedical Application ◽  
Force Sensor ◽  
Intermittent Flow ◽  
Time Duration ◽  
Impact Experiment ◽  
Controlled Flow ◽  
Using Data ◽  
Short Time ◽  
The Impact

Shirodhara is an ayurveda therapy treating subjects for stress (depression/anxiety/hypertension) insomnia, headache and several kinds of psychosis. When there is a fluid impact on a solid surface, a transient impact will be developed at the interface in short time duration as vibration on forehead. The fluid impact of the liquid falling from the beaker at controlled flow rate is measured using an integrated circuit piezoelectric (ICP) force sensor for various tapping condition. The time-dependent response of the sensor is acquired using data acquisition system which is connected to the computer. The force is determined by measuring the voltage output from the piezoelectric force sensor. The impact experiment is done for single droplet, intermittent flow of drops and continuous flow of liquid falling from a fixed height of 7.5 cm. From the results, we observe the impact force for each fluid have a subtle variation depending on the falling condition and impact velocity of the fluid falling from a height.

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