Double Differentiation Research Articles

Diagnosis of sensitive leaf types and spectral segments during maize heading stage under simulated copper stress environment in mining areas

ABSTRACT This paper designed CSSDM (Copper Stress Spectral Diagnosis Method) from the perspective of frequency domain, combined with time-frequency analysis, to obtain sensitive leaf types and spectral segments under heavy metal copper stress, providing technical support for heavy metal monitoring in crops. Firstly, the hyperspectral reflectance data of maize leaves under copper stress were subjected to DD (Double Differentiation) and EE (Envelope Elimination), and transformed into the frequency domain. The d6 (Daubechies wavelet 6-layer) decomposition was performed using time-frequency analysis methods. Then, based on the signal anomaly points, wavelet high value points and DDEE (Double Differentiation Envelope Elimination) curve high value points, the SRVP (Spectral Reflectance Variation Parameters) of maize leaves are defined. Finally, by examining the correlation between spectral reflectance variation parameters and heavy metal content in maize leaves, we aim to explore the leaf types and spectral segments that are sensitive to copper pollution. The results showed that CSSDM can efficiently enhance weak information in maize leaves and accurately locate the spectral anomaly caused by heavy metal copper stress, with the anomaly range concentrated within 350 nm−800 nm. Spectral reflectance variation parameters can quantitatively measure the spectral anomalies of maize leaves under heavy metal copper stress. Under different copper stress gradients, maize new leaves exhibit sensitive leaf types, with sensitive spectral segments including Blue Edges, Green Peaks, Yellow Edges and Red Valleys.

A novel high sensitive, specificity duplex enzyme-activated differentiating probes PCR method for the SNP detection and differentiation of MS-H vaccine strains from wild-type Mycoplasma synoviae strains

Mycoplasma synoviae (MS) is a contagious pathogen that poses a significant threat to the poultry industry. Detection plays an important role in the prevention and control of MS, particularly in differentiating between wild-type MS and live attenuated vaccine strains for vaccination selection and culling of animals with wild-type only. The live attenuated ts+ vaccine strain MS-H is recognized as the most effective and widely used vaccine. In this study, we have developed a method called double enzyme-activated differentiation probes PCR (DEA-probes PCR) for the differentiation of MS-H vaccine strain from wild-type strain by targeting the single nucleotide polymorphism (SNP) of the 367th nucleotide in the Obg gene sequence. We developed 2 modified probes with the ribonucleotide insert. When the probe perfectly complements with the target, the ribonuclease H2 (RNase H2) will cleave the ribonucleotide, resulting in the generation of fluorescent signal. With a detection limit of 5.8 copies/µL, the DEA-probes PCR method demonstrates 100% specificity in distinguishing wild-type MS from MS-H strains in 1 h. The method demonstrated great performance in real application of 100 superior palate cleft swab samples from chickens in poultry farms. Twenty-eight samples were detected as MS positive, consistent with the results of the Chinese industry standard method. Additionally, our method was able to distinguish 19 wild-type MS strains from 9 MS-H vaccine strains. The DEA-probes PCR method is rapid, specific and sensitive for SNP detection, overcoming the misidentification in MS detection and differentiation. It can be also applied to the differentiation of infected from vaccinated animals (DIVA) for other pathogens.

Global marine gravity gradient tensor inverted from altimetry-derived deflections of the vertical: CUGB2023GRAD

Abstract. Geodetic applications of altimetry have largely been inversions of gravity anomaly. Previous studies of Earth's gravity gradient tensor mostly presented only the vertical gravity gradient (VGG). However, there are six unique signals that constitute the gravity gradient tensor. Gravity gradients are signals suitable for detecting short-wavelength topographic and tectonic features. They are derived from double differentiation of the disturbing potential and hence are susceptible to noise amplification which was exacerbated by low across-track resolution of altimetry data in the past. However, current generation of altimetry observations have improved spatial resolutions, with some better than 5 km. Therefore, this study takes advantage of current high-resolution altimetry datasets to present CUGB2023GRAD, a global (latitudinal limits of ±80°) 1 arcmin model of Earth's gravity gradient tensor over the oceans using deflections of the vertical as inputs in the wavenumber domain. The results are first assessed via Laplace's equation, whereby the resultant residual gradient is virtually zero everywhere. Further analysis at local regions in the Arctic and south Indian oceans showed that Txy, Txz and Tyz are the most dominant gravity gradients for bathymetric studies. This proves that bathymetric signatures in the non-diagonal tensor components are worth exploiting. Bathymetric coherence analysis of Tzz over the Tonga Trench showed strong correlation with multibeam shipboard depths. This study proves that current generation of altimetry geodetic missions can effectively resolve Earth's gravity gradient tensor. The CUGB2023GRAD model data can be freely accessed at https://doi.org/10.5281/zenodo.10511125 (Annan et al., 2024).

Numerical Study of the Rate of Convergence of Chernoff Approximations to Solutions of the Heat Equation

The article is devoted to construction of examples illustrating (using computer calculation) the convergence rate of Chernoff approximations to the solution of the Cauchy problem for the heat equation. Two Chernoff functions (of the first and second order of Chernoff tangency to the double differentiation operator) and several initial conditions of different smoothness are considered. As an illustration for the initial condition equal to the absolute value of the sine function to the power of five over two, a graph of the exact solution of the Cauchy problem and graphs of the tenth Chernoff approximations given by two different Chernoff functions are plotted. It is visually determined that the approximations are close to the solution. For each of the two Chernoff functions, for several initial conditions of different smoothness and for the approximation numbers up to 11, the error corresponding to each approximation is numerically found. This error is understood as the supremum of the absolute value of the difference between the exact solution and its approximating function. As it turned out, in all the cases studied, the error dependence on the approximation number nearly power-law form. This follows from the fact that the dependence of the error logarithm on the logarithm of the approximation number is close to linear. By finding the equation of the approximating line using linear regression, we find the exponent in the power dependence of the error on the approximation number and call it the order of convergence. These orders for all studied initial conditions are compiled in a table. The empirical dependence of the convergence order on the smoothness class of the initial condition is found on the considered family of initial conditions.

Mathematical modeling of velocity and accelerations fields of image motion in the optical equipment of the Earth remote sensing satellite

Objectives. The paper considers a satellite with an optoelectronic payload designed to take pictures of the Earth’s surface. The work sets out to develop a mathematical model for determining the dependencies between the state vector of the satellite, the state vector of the point being imaged on the Earth’s surface, and the distribution fields of the velocity vectors and accelerations of the motion of the image along the focal plane of the optoelectronic payload.Methods. The method is based on double differentiation of the photogrammetry equation when applied to a survey of the Earth’s surface from space. For modeling the orbital and angular motion of the satellite, differential equations with numerical integration were used. The motion parameters of the Earth’s surface were calculated based on the Standards of Fundamental Astronomy software library.Results. Differential equations of motion of the image were obtained. Verification of the developed mathematical model was carried out. The motion of the considered satellite was simulated in orbital orientation mode using an image velocity compensation model. The distribution fields of velocity vectors and accelerations of motion of the image of the Earth’s surface were constructed. The residual motion of the field of image following compensation was investigated.Conclusions. The proposed mathematical model can be used both with an optoelectronic payload when modeling shooting modes and estimating image displacements at the design stage of a satellite, as well as at the satellite operation stage when incorporating the presented model in the onboard satellite software. The presented dependencies can also be used to construct an image transformation matrix, both when restoring an image and when obtaining a super-resolution.

Algorithm for Recognizing the Type of Modulation and Measuring Parameters of Radar Signals with Chirp

One of the most informative parameters of the signal of radar signals is its carrier frequency. Measuring and memorizing the carrier frequency of a reconnaissance radio-electronic device is one of the most important functions of a radio intelligence station, radio monitoring. Using the concept of an analytical signal, any signal can be represented through an envelope and phase, or quadrature components, which makes it possible to calculate the instantaneous frequency. The purpose of the work is to determine the effectiveness of the instantaneous frequency calculation method based on direct conversion in the time domain using several differentiators for measuring the time and frequency parameters of a chirp signal. The developed algorithm makes it possible to measure such parameters of the signal with chirp as steepness, pulse duration, repetition period, central frequency, spectrum width. This paper presents the implementation of an algorithm for measuring the instantaneous frequency with augmented double differentiation. The first differentiation allows you to measure the steepness of the signal as a sample average, the second differentiation – time points (pulse duration, repetition period). The signs of signal portraits are presented for a symmetrical, asymmetric signal with chirp, as well as in the absence of intra-pulse modulation. The simulation results showed that with the ratio of the sampling frequency to the signal band equal to 2.3, the error in measuring the steepness of the signal is 25 %, and at 11 – 8.8 %; the simulation results were carried out with a signal-to-noise ratio of 10 dB.

Investigation of thermophysical properties of milk thistle seeds and oils with the differential scanning calorimetry method

The purpose of work was to study the possibility of increasing the information content of differential scanning calorimetry (DSC) data when studying properties of various samples of milk thistle seeds and oils. The possibility of DSC method application for studying milk thistle oils thermophysical properties is shown, and the method for conducting temperature measurements is described in the work. The results of thermal analysis of milk thistle raw materials and oils obtained with cold pressing by the DSC method showed noticeable differences in oils melting profiles. When analyzing samples of milk thistle oils, differing from each other in the variety, place and growing conditions, it can be seen that the melting curves have differences with the general similarity of the profiles. The peaks of the DSC profile curves of oil stored at room temperature for six months are shifted towards higher temperatures compared to the DSC profile of freshly pressed oil, which is explained by oxidative deterioration and leads to an increase in the temperature of triacylglycerols phase transitions. This confirms the assumption that the DSC method can be used as an independent method for quality control of liquid vegetable oils. The selection of phase transitions temperatures of oils and raw materials was carried out with double differentiation. The use of the NETZSCH Peak Separation program according to the general algorithm for calculating the second melting curves derivatives and determining the endothermic peaks area made it possible to increase the information content of thermograms obtained by the DSC method. Thermal analysis showed an increased residual content of unsaturated fats in the meal obtained by cold pressing oil extracting.

COMPACT PICOSECOND DIODE LASERS

This article presents the electrical circuit, a description of the design, and results of measurements of the radiative watt–ampere and time characteristics of compact inexpensive emitters based on commercial laser diodes with wavelengths from 405 to 850 nm, which operate in the picosecond (70–180 ps) and nanosecond (0.69–1.2 ns) modes. The optical emitter includes a master crystal oscillator based on a microcontroller (frequencies of 76 Hz–20/80 MHz), a synchronization circuit, a low-voltage (9–12 V) subnanosecond electric pulse shaper that operates according to the method of double differentiation, a pump circuit with an adjustable direct current source, and a laser diode. The average light power at a frequency of 80 MHz varies in pico mode from 0.6 to 1.6 mW and in nano mode from 6 to 18 mW. The lasers are powered by a 220 V/12 V, 0.25 A serial power supply, with a power consumption of 3 W and a weight of 0.2 kg.

Double Differentiation in Baumgarten’s Theory of Substance

Double Differentiation in Baumgarten’s Theory of Substance

Coordinated Control of the Fuel Cell Air Supply System Based on Fuzzy Neural Network Decoupling.

In order to achieve the goal of carbon neutralization, hydrogen plays an important role in the new global energy pattern, and its development has also promoted the research of hydrogen fuel cell vehicles. The air supply system is an important subsystem of hydrogen fuel cell engine. The increase of air supply can improve the output characteristics of a fuel cell, but excessive gas supply will destroy the pressure balance of the anode and cathode. In the actual operation of a proton-exchange membrane fuel cell, considering the load change, it is necessary not only to ensure the stability of reactor pressure but also to meet the rapid response of inlet pressure and flow in the process of change. Therefore, the coordinated control of the two is the key to improving fuel cell output performance. In this paper, the dynamic model of the intake system is built based on the mechanism and experimental data. On this basis, the double closed-loop proportion integration differentiation (PID) control and feedforward compensation decoupling PID control are carried out for the air supply system, respectively. Then, the fuzzy neural network decoupling control strategy is proposed to make up for the shortcomings that the double closed-loop PID cannot achieve decoupling and the feedforward compensation decoupling does not have adaptability. The results show that the fuzzy neural network control can realize the decoupling between air intake flow and pressure and ensure that the air intake flow and pressure have a good follow-up, and the system’s response speed is fast.

Broadening and Shift of the D1 and D2 Lines of Rb Atoms by Neon: Resolving Hyperfine Components in a Half-Wave Cell Using Double Differentiation with Respect to Frequency

Broadening and Shift of the D1 and D2 Lines of Rb Atoms by Neon: Resolving Hyperfine Components in a Half-Wave Cell Using Double Differentiation with Respect to Frequency

Application of the method of differential scanning calorimetry in the study of the properties of oilseeds

The method of differential scanning calorimetry (DSC) is used to characterize the thermophysical properties during melting of samples of milk thistle oil of various geographic origins, seeds and meal. The world experience in applying the DSC method on the study of milk thistle oils is generalized. The temperature measurement program is described. It is shown that, despite the general similarity of the curve profiles of the melting DSC, there are differences in the profiles due to genotypic and phenotypic factors - variety and growing location. The DSC curves of freshly squeezed oil distinguish from the DSC curves after 6 months storage of the oil due to oxidative deterioration and the formation of more refractory partially oxidized triacylglycerols. This fact is relevant to determining the capabilities of the DSC method in controlling the freshness of vegetable oils. The peaks amplitudes in the DSC curves of fresh oil are higher than those of oils that has been stored at room temperature for six months. Double differentiation of the melting curves makes it possible to reveal the temperatures of phase transitions in the case of overlapping endothermic peaks, the establishment of which is difficult without double differentiation. Using the «Netzsch Peak Separation» software to divide the peaks in the melting curves allows at once to estimate the areas of overlapping peaks and increase the informativeness of the DSC data. Thermal analysis of milk thistle seeds and meal reveals that the meal contains a residual amount of oil, in which the proportion of triunsaturated fats is overestimated in comparison to seeds, indicating that triunsaturated fats are more difficult to extract from oil by cold pressing.

Технология определения параметров гравитационного поля Земли по градиентометрическим измерениям 6. Вычисление компонент тензора гравитационного потенциала в земной пространственной прямоугольной системе координат

This is the sixth one in a series of articles describing the technology of determining the Earth’s gravitational field parameters through gradiometric measurements performed with an onboard satellite electrostatic gradiometer. It provides formulas for calculating the components of the gravitational potential tensor in a geocentric spatial rectangular earth coordinate system in order to convert them into a gradiometric one and obtain a free term for the equations of correcting gradiometric measurements when determining the parameters of the Earth’s gravitational field. The components of the gravitational gradient tensor are functions of test masses accelerations measured by accelerometers and relate to the gradiometer coordinate system, while the desired parameters of the Earth’s gravitational field model relate to the Earth’s coordinate one. The components of the gravitational gradient tensor are the second derivatives of the gravitational potential in rectangular coordinates. The calculated values of the gravitational potential tensor components in the earth’s spatial rectangular coordinate system are obtained through double differentiation of the gravitational potential formula. Basing on the obtained formulas, an algorithm and a program in the Fortran algorithmic language were developed. Using this program, experimental calculations were performed, the results of which were compared with the data of the EGG_TRF_2 product.

Magnetic and Plasmonic Composite Nanostructures for Creating Optical Filters at Substance and Material Diagnostics Systems

Introduction. Porous silicon (PS) and materials on its basis are of interest for application in nanoelectronics, targeted drug delivery and advanced gas sensors. In addition, PS-based nanostructures are promising as filters in fibre-optic communication systems, since conventional thin-film deposition filters possess sidebands in their operating range thus requiring high vacuum for nanometer-thick coatings.Aim. To develop optical band-stop filter prototypes based on composite magnetic nanoparticles and the effect of localized surface plasmon resonance (LSPR) in an array of silver nanoparticles located on the PS surface. Materials and methods. The development and synthesis of nanostructures for the creation of filter prototypes. The double differentiation method in conjunction with Mie absorption theory was used for processing and analyzing the prototypes attenuation characteristics.Results. Two prototypes were developed. An analysis of the attenuation characteristics of a prototype based on SiO2 matrix functionalized by FemOn indicated that the parameters of the detected absorption bands depend on the size of FemOn nanoparticles. The attenuation characteristics of the LSPR-based prototype contain two absorption bands. The center wavelength value in the band caused by LSPR in the array of silver nanoparticles, close to spherical, is 367.5 nm. Excitation of LSPR in silver quantum clusters, manifested by the appearance of the corresponding band, occurs at a wavelength of 265.5 nm. The suppression in each of the bands can be controlled by changing the parameters of the PS matrix synthesis.Conclusion. Despite the disadvantages, e.g. a relatively low accuracy in setting the center wavelength, as well as certain difficulties concerned with reducing the unevenness in the absorption band, the obtained prototypes surpass existing analogues and are prospective for the development of compact analysis and diagnostics systems in a wide energy range.

RECOGNITION OF TEXT PHRASES DISTORTED BY INTERFERENCE BY BACK PROPAGATION NEURAL NETWORK

The paper takes into consideration risk systems that can use not only in nuclear reactions but other plants with frequent risks for people's life, such as mining, and other. Such facilities apply information systems in which take place exchange text messages through free space. The main problem of information radio reception is an increasing number of emitting means that equal the increase of noise level receiving set. As an additional means of processing distorted textual information, it is proposed to use a neural network, which must be pre-configured. For analysis, the back propagation neural network was selected. The adjustment is carried out by an algorithm assuming a double differentiation of the error function, which ensures a high network convergence rate. Learning is stopped according to the total criterion for the deviation of the output signal from the reference. The paper formulates the conditions of quadratic convergence of the back propagation network with one new tuning procedure, and also offers examples of the construction of a neural network for recognizing a text message in various reception conditions. The fed to the neural network is sequence of the letters of English alphabet. A feature of the structure of the neural network that provides correct recognition is the use of completely nonlinear neurons. Comparison of options for the structure of the neural network when recognizing text phrases is carried out according to indicators of the probability of recognition, error, and training time. The established properties of the neural network are useful in the design of efficient information system.

N. Luhmann's theory of double differentiation: concepts, interpretation, version

Luhmann's theory of double distinction is a cross-cutting theme that runs through the entire sociological heritage of the outstanding German sociologist. Since this theory is not a subject of sociology and goes far beyond its scope, it is natural that its essential consideration does not have to be sociological. In this regard, in the process of studying Luhmann's texts, one way or another, a contradiction arises between the collaboration representing the problem and the problem itself. What is its essence in short? We distinguish between something as such in itself — singular and indivisible, without experiencing any existential difficulties. But as soon as we intend to discern the very distinction, we immediately find ourselves in a turbulence of forms and identifications, measures and dimensions, along the way losing our own, once unshakable, observer position. A situation of uncertainty arises, pushing towards this or that choice, to this or that commitment as to something definite. Luhmann seeks to overcome the intention of commitment. The result is a dynamic panorama of continuously related distinctive acts. This is perhaps the most difficult passage not only in Luhmann, but also in the theory of distinction in his double dynamic perspective. The difficulty is to describe how it is possible to relate to what is itself as a result of the relationship. According to Luhmannany definite differentiated — is act in act, movement within movement, time within time, subject within subject, life in life, relationship within relationship, etc. No matter what we are talking about, we are always talking about a double perspective of differentiation. Luhmann seeks to clarify the essence of the relation in relation as the possibility of explication of what itself makes explicit. This opportunity Luhmann calls autopoiesis, in which the unity of distinctive acts finds its higher dynamic expression. The «stumbling block» that the theory of autopoiesis constantly «stumbles over» is not so much the fact that they want to find autopoiesis in applied empirical research, but rather the fact that at the moment of its discrimination, the very correlation of discrimination itself changes dramatically. Here there is no longer a return to the previous arguments, the development of a new context is constantly required, the grounds change many times. A few words about the method of presenting subject. In the process of writing the article, I had to make abstraction from specifically Luhmann's theoretical statements and «translate» the language of interpretation into the language of the version. We wanted not only to cover the scope of penetration into the problem of Luhmann's double distinctions, but also to approach it in my own way, as much as possible, at an extremely close distance. The task turned out to be twofold, in connection with which the so-called proposed by us was applied the formula for the relevance of the study, which would most likely be supported by a German sociologist: «author's interpretation» + «interpreter's version» = «lively response of understanding». Otherwise, we would have found ourselves in captivity exclusively to the author's system, unforgivably losing sight of the restless pulsation of the essence under study. Throughout his entire scientific path, Luhmann not only struggles with all sorts of signs of a strictly determined system — it is more a consequence than a goal — he with enviable constancy tries to free the dynamic unity of distinctive acts from rigid conceptual and theoretical structures in order to reveal in him his relict permanent self-movement at the risk of being misunderstood by their professional community. Inspiring those who are sensitive to the grasp of thought, regardless of the rubrics that claim it.

Uniform stability of the inverse spectral problem for a convolution integro-differential operator

The operator of double differentiation perturbed by the composition of the differentiation operator and a convolution one on a finite interval with Dirichlet boundary conditions is considered. We obtain uniform stability of recovering the convolution kernel from the spectrum both in a weighted L2-norm and in a weighted uniform norm. For this purpose, we successively prove uniform stability of each step of the algorithm for solving this inverse problem in both norms. The obtained results reveal some essential difference from the classical inverse Sturm–Liouville problem.

Microstructure Evolution, Mechanical Properties and Deformation Behavior of an Additively Manufactured Maraging Steel.

In this work, the microstructure and mechanical properties of an additively manufactured X3NiCoMoTi18-9-5 maraging steel were determined. Optical and electron microscopies revealed the formation of melt pool boundaries and epitaxial grain growth with cellular dendritic structures after the laser powder bed fusion (LPBF) process. The cooling rate is estimated to be around 106 °C/s during solidification, which eliminates the nucleation of any precipitates. However, it allows the formation of austenite with a volume fraction of about 5% and dendritic structures with primary arm spacing of 0.41 ± 0.23 µm. The electron backscatter diffraction analysis showed the formation of elongated grains with significant low-angle grain boundaries (LAGBs). Then, a solutionizing treatment was applied to the as-printed samples to dissolve all the secondary phases, followed by aging treatment. The reverted austenite was evident after heat treatment, which transformed into martensite after tensile testing. The critical plastic stresses for this transformation were determined using the double differentiation method. The tensile strength of the alloy increased from 1214 MPa to 2106 MPa after the aging process due to the formation of eta phase. The experimental data were complemented with thermodynamic and mechanical properties simulations, which showed a discrepancy of less than 3%.

Analytical design of control system mathematical models for mobile robots based on the methods of inverse problems of dynamics and modal PID controllers

Mathematical models of a three-wheeled mobile robot based on the variable state apparatus and in the operator’s form are presented. Based on these mathematical models, the synthesis of its adaptive control system is carried out according to the method of constructing Ziegler-Nichols PID controllers, as well as modal PID controllers. The design method of proportional controllers with double differentiation (PDD) of the autonomous robot is justified. The rules of wheel pair control are synthesized on the basis of reference models using a simple gradient scheme of the inverse problems method of dynamics in the formulation of P. D. Krutko for the problem of stabilizing (blanking) the angular velocities for a three-wheeled mobile robot. Simulink-models of robot movement are developed for cases with the use of PID-controllers which are adjusted by the Ziegler-Nichols method at synchronous deviation of wheels. Simulink-models of robot motion have been developed for cases using PID controllers set up according to the Ziegler-Nichols method for synchronous wheel deflection, modal and real PID controllers for differential wheel deflection, as well as double differentiation controllers. The analysis of modeling results is considered.

Establishment of mouse androgenetic embryonic stem cells by double sperm injection and differentiation into beating embryoid body.

Androgenetic embryonic stem (AgES) cells offer a possible tool for patient-specific pluripotent stem cells that will benefit genomic imprinting studies and clinic applications. However, the difficulty in producing androgenetic embryos and the unbalanced expression of imprinted genes make the therapeutic applicability of AgES cells uncertain. In this study, we produced androgenetic embryos by injecting two sperm into an enucleated metaphase II (MII) oocyte. By this method, 88.48% of oocytes survived after injection, and 20.24% of these developed to the blastocyst stage. We successfully generated AgES cell lines from the androgenetic embryos and assayed the expression of imprinted genes in the cell lines. We found that the morphological characteristics of AgES cells were similar to that of fertilized embryonic stem cells (fES), such as expression of key pluripotent markers, and generation of cell derivatives representing all three germ layers following in vivo and in vitro differentiation. Furthermore, activation of paternal imprinted genes was detected, H19, ASC12 and Tss3 in AgES cell activation levels were lower while other examined genes showed no significant difference to that of fES cells. Interestingly, among examined maternal imprinted genes, only Mest and Igf2 were significantly increased, while levels of other detected genes were no different to that of fES cells. These results demonstrated that activation of some paternal imprinted genes, as well as recovery of maternal imprinted genes, was present in AgES cells. We differentiated AgES cells into a beating embryoid body in vitro, and discovered that the AgES cells did not show significant higher efficiency in myocardial differentiation potential.