Kaplan, Alexis C. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87544 (United States); Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 500 S State St., Ann Arbor, MI 48109 (United States); Henzl, Vladimir; Menlove, Howard O.; Swinhoe, Martyn T.; Belian, Anthony P. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87544 (United States); Flaska, Marek; Pozzi, Sara A. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 500 S State St., Ann Arbor, MI 48109 (United States)
2014-11-11
As a part of the Next Generation Safeguards Initiative Spent Fuel project, we simulate the response of the Differential Die-away Self-Interrogation (DDSI) instrument to determine total elemental plutonium content in an assayed spent nuclear fuel assembly (SFA). We apply recently developed concepts that relate total plutonium mass with SFA multiplication and passive neutron count rate. In this work, the multiplication of the SFA is determined from the die-away time in the early time domain of the Rossi-Alpha distributions measured directly by the DDSI instrument. We utilize MCNP to test the method against 44 pressurized water reactor SFAs from a simulated spent fuel library with a wide dynamic range of characteristic parameters such as initial enrichment, burnup, and cooling time. Under ideal conditions, discounting possible errors of a real world measurement, a root mean square agreement between true and determined total Pu mass of 2.1% is achieved.
Kaplan, Alexis C. [Los Alamos National Laboratory, Los Alamos, NM 87544 (United States); Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Henzl, Vladimir; Menlove, Howard O.; Swinhoe, Martyn T.; Belian, Anthony P. [Los Alamos National Laboratory, Los Alamos, NM 87544 (United States); Flaska, Marek; Pozzi, Sara A. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States)
2014-09-01
We present a novel method for determining the multiplication of a spent nuclear fuel assembly with a Differential Die-Away Self-Interrogation (DDSI) instrument. The signal, which is primarily created by thermal neutrons, is measured with four {sup 3}He detector banks surrounding a spent fuel assembly. The Rossi-alpha distribution (RAD) at early times reflects coincident events from single fissions as well as fission chains. Because of this fact, the early time domain contains information about both the fissile material and spontaneous fission material in the assembly being measured. A single exponential function fit to the early time domain of the RAD has a die-away time proportional to the spent fuel assembly (SFA) multiplication. This correlation was tested by simulating assay of 44 different SFAs with the DDSI instrument. The SFA multiplication was determined with a variance of 0.7%.
Trahan, Alexis Chanel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2016-01-27
New nondestructive assay techniques are sought to better characterize spent nuclear fuel. One of the NDA instruments selected for possible deployment is differential die-away self-interrogation (DDSI). The proposed DDSI approach for spent fuel assembly assay utilizes primarily the spontaneous fission and (α, n) neutrons in the assemblies as an internal interrogating radiation source. The neutrons released in spontaneous fission or (α,n) reactions are thermalized in the surrounding water and induce fission in fissile isotopes, thereby creating a measurable signal from isotopes of interest that would be otherwise difficult to measure. The DDSI instrument employs neutron coincidence counting with 3He tubes and list-mode-based data acquisition to allow for production of Rossi-alpha distributions (RADs) in post-processing. The list-mode approach to data collection and subsequent construction of RADs has expanded the analytical possibilities, as will be demonstrated throughout this thesis. One of the primary advantages is that the measured signal in the form of a RAD can be analyzed in its entirety including determination of die-away times in different time domains. This capability led to the development of the early die-away method, a novel leakage multiplication determination method which is tested throughout the thesis on different sources in simulation space and fresh fuel experiments. The early die-away method is a robust, accurate, improved method of determining multiplication without the need for knowledge of the (α,n) source term. The DDSI technique and instrument are presented along with the many novel capabilities enabled by and discovered through RAD analysis. Among the new capabilities presented are the early die-away method, total plutonium content determination, and highly sensitive missing pin detection. Simulation of hundreds of different spent and fresh fuel assemblies were used to develop the analysis algorithms and the techniques were tested on a
Differential die-away instrument: Report on comparison of fuel assembly experiments and simulations
Goodsell, Alison Victoria [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Henzl, Vladimir [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Swinhoe, Martyn Thomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rael, Carlos D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Desimone, David J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2015-01-14
Experimental results of the assay of mock-up (fresh) fuel with the differential die-away (DDA) instrument were compared to the Monte Carlo N-Particle eXtended (MCNPX) simulation results. Most principal experimental observables, the die-away time and the in tegral of the DDA signal in several time domains, have been found in good agreement with the MCNPX simulation results. The remaining discrepancies between the simulation and experimental results are likely due to small differences between the actual experimental setup and the simulated geometry, including uncertainty in the DT neutron generator yield. Within this report we also present a sensitivity study of the DDA instrument which is a complex and sensitive system and demonstrate to what degree it can be impacted by geometry, material composition, and electronics performance.
Martinik, Tomas; Henzl, Vladimir; Grape, Sophie; Jansson, Peter; Swinhoe, Martyn T.; Goodsell, Alison V.; Tobin, Stephen J.
2016-06-01
As part of the United States (US) Department of Energy's Next Generation Safeguards Initiative Spent Fuel (NGSI-SF) project, the traditional Differential Die-Away (DDA) method that was originally developed for waste drum assay has been investigated and modified to provide a novel application to characterize or verify spent nuclear fuel (SNF). Following the promising, yet largely theoretical and simulation based, research of physics aspects of the DDA technique applied to SNF assay during the early stages of the NGSI-SF project, the most recent effort has been focused on the practical aspects of developing the first fully functional and deployable DDA prototype instrument for spent fuel. As a result of the collaboration among US research institutions and Sweden, the opportunity to test the newly proposed instrument's performance with commercial grade SNF at the Swedish Interim Storage Facility (Clab) emerged. Therefore the design of this instrument prototype has to accommodate the requirements of the Swedish regulator as well as specific engineering constrains given by the unique industrial environment. Within this paper, we identify key components of the DDA based instrument and we present methodology for evaluation and the results of a selection of the most relevant design parameters in order to optimize the performance for a given application, i.e. test-deployment, including assay of 50 preselected spent nuclear fuel assemblies of both pressurized (PWR) as well as boiling (BWR) water reactor type.
Differential Die-Away Instrument: Report on Initial Simulations of Spent Fuel Experiment
Goodsell, Alison V. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Henzl, Vladimir [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Swinhoe, Martyn T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2014-04-01
New Monte Carlo simulations of the differential die-away (DDA) instrument response to the assay of spent and fresh fuel helped to redefine the signal-to-Background ratio and the effects of source neutron tailoring on the system performance. Previously, burst neutrons from the neutron generator together with all neutrons from a fission chain started by a fast fission of ^{238}U were considered to contribute to active background counts. However, through additional simulations, the magnitude of the ^{238}U first fission contribution was found to not affect the DDA performance in reconstructing ^{239}Pu_{eff}. As a result, the newly adopted DDA active background definition considers now any neutrons within a branch of the fission chain that does not include at least one fission event induced by a thermal neutron, before being detected, to be the active background. The active background, consisting thus of neutrons from a fission chain or its individual branches composed entirely of sequence of fast fissions on any fissile or fissionable nuclei, is not expected to change significantly with different fuel assemblies. Additionally, while source tailoring materials surrounding the neutron generator were found to influence and possibly improve the instrument performance, the effect was not substantial.
Antoni, Rodolphe; Passard, Christian; Perot, Bertrand [CEA Cadarache DEN/Nuclear Measurement Laboratory, 13108 Saint-Paul lez Durance (France); Batifol, Marc; Vandamme, Jean-Christophe [Nuclear Measurement Team, AREVA NC, La Hague plant F-50444 Beaumont-Hague (France); Grassi, Gabriele [AREVA NC, 1 place Jean-Millier, 92084 Paris-La-Defense cedex (France)
2015-07-01
The fissile mass in radioactive waste drums filled with compacted metallic residues (spent fuel hulls and nozzles) produced at AREVA NC La Hague reprocessing plant is measured by neutron interrogation with the Differential Die-away measurement Technique (DDT). In the next years, old hulls and nozzles mixed with Ion-Exchange Resins will be measured. The ion-exchange resins increase neutron moderation in the matrix, compared to the waste measured in the current process. In this context, the Nuclear Measurement Laboratory (LMN) of CEA Cadarache has studied a matrix effect correction method, based on a drum monitor, namely a 3He proportional counter located inside the measurement cavity. After feasibility studies performed with LMN's PROMETHEE 6 laboratory measurement cell and with MCNPX simulations, this paper presents first experimental tests performed on the industrial ACC (hulls and nozzles compaction facility) measurement system. A calculation vs. experiment benchmark has been carried out by performing dedicated calibration measurements with a representative drum and {sup 235}U samples. The comparison between calculation and experiment shows a satisfactory agreement for the drum monitor. The final objective of this work is to confirm the reliability of the modeling approach and the industrial feasibility of the method, which will be implemented on the industrial station for the measurement of historical wastes. (authors)
Henzl, Vladimir [Los Alamos National Laboratory; Croft, Stephen [Los Alamos National Laboratory; Swinhoe, Martyn T. [Los Alamos National Laboratory; Tobin, Stephen J. [Los Alamos National Laboratory
2012-07-18
A key objective of the Next Generation Safeguards Initiative (NGSI) is to evaluate and develop non-destructive assay (NDA) techniques to determine the elemental plutonium content in a commercial-grade nuclear spent fuel assembly (SFA) [1]. Within this framework, we investigate by simulation a novel analytical approach based on combined information from passive measurement of the total neutron count rate of a SFA and its multiplication determined by the active interrogation using an instrument based on a Differential Die-Away technique (DDA). We use detailed MCNPX simulations across an extensive set of SFA characteristics to establish the approach and demonstrate its robustness. It is predicted that Pu content can be determined by the proposed method to a few %.
Blanc, Pauline [Los Alamos National Laboratory; Tobin, Stephen J [Los Alamos National Laboratory; Croft, Stephen [Los Alamos National Laboratory; Menlove, Howard O [Los Alamos National Laboratory; Swinhoe, M [Los Alamos National Laboratory; Lee, T [NON LANL
2010-12-02
The Next Generation Safeguards Initiative (NGSI) of the U.S. Department of Energy (DOE) has funded multiple laboratories and universities to develop a means to accurately quantify the Plutonium (Pu) mass in spent nuclear fuel assemblies and ways to also detect potential diversion of fuel pins. Delayed Neutron (DN) counting provides a signature somewhat more sensitive to {sup 235}U than Pu while Differential Die-Away (DDA) is complementary in that it has greater sensitivity to Pu. The two methods can, with care, be combined into a single instrument which also provides passive neutron information. Individually the techniques cannot robustly quantify the Pu content but coupled together the information content in the signatures enables Pu quantification separate to the total fissile content. The challenge of merging DN and DDA, prompt neutron (PN) signal, capabilities in the same design is the focus of this paper. Other possibilities also suggest themselves, such as a direct measurement of the reactivity (multiplication) by either the boost in signal obtained during the active interrogation itself or by the extension of the die-away profile. In an early study, conceptual designs have been modeled using a neutron detector comprising fission chambers or 3He proportional counters and a {approx}14 MeV neutron Deuterium-Tritium (DT) generator as the interrogation source. Modeling was performed using the radiation transport code Monte Carlo N-Particles eXtended (MCNPX). Building on this foundation, the present paper quantifies the capability of a new design using an array of {sup 3}He detectors together with fission chambers to optimize both DN and PN detections and active characterization, respectively. This new design was created in order to minimize fission in {sup 238}U (a nuisance DN emitter), to use a realistic neutron generator, to reduce the cost and to achieve near spatial interrogation and detection of the DN and PN, important for detection of diversion, all within
American Society for Testing and Materials. Philadelphia
2009-01-01
1.1 This test method covers a system that performs nondestructive assay (NDA) of uranium or plutonium, or both, using the active, differential die-away technique (DDT), and passive neutron coincidence counting. Results from the active and passive measurements are combined to determine the total amount of fissile and spontaneously-fissioning material in drums of scrap or waste. Corrections are made to the measurements for the effects of neutron moderation and absorption, assuming that the effects are averaged over the volume of the drum and that no significant lumps of nuclear material are present. These systems are most widely used to assay low-level and transuranic waste, but may also be used for the measurement of scrap materials. The examples given within this test method are specific to the second-generation Los Alamos National Laboratory (LANL) passive-active neutron assay system. 1.1.1 In the active mode, the system measures fissile isotopes such as 235U and 239Pu. The neutrons from a pulsed, 14-MeV ne...
Antoni, R.; Passard, C.; Perot, B.; Batifol, M.; Vandamme, J.C. [CEA, DEN, Cadarache, Nuclear Measurement Laboratory, F-13108 St Paul-lez-Durance, (France); Grassi, G. [AREVA NC, 1 place Jean-Millier, 92084 Paris-La-Defense cedex (France)
2015-07-01
The fissile mass in radioactive waste drums filled with compacted metallic residues (spent fuel hulls and nozzles) produced at AREVA La Hague reprocessing plant is measured by neutron interrogation with the Differential Die-away measurement Technique (DDT. In the next years, old hulls and nozzles mixed with Ion-Exchange Resins will be measured. The ion-exchange resins increase neutron moderation in the matrix, compared to the waste measured in the current process. In this context, the Nuclear Measurement Laboratory (NML) of CEA Cadarache has studied a matrix effect correction method, based on a drum monitor ({sup 3}He proportional counter inside the measurement cavity). A previous study performed with the NML R and D measurement cell PROMETHEE 6 has shown the feasibility of method, and the capability of MCNP simulations to correctly reproduce experimental data and to assess the performances of the proposed correction. A next step of the study has focused on the performance assessment of the method on the industrial station using numerical simulation. A correlation between the prompt calibration coefficient of the {sup 239}Pu signal and the drum monitor signal was established using the MCNPX computer code and a fractional factorial experimental design composed of matrix parameters representative of the variation range of historical waste. Calculations have showed that the method allows the assay of the fissile mass with an uncertainty within a factor of 2, while the matrix effect without correction ranges on 2 decades. In this paper, we present and discuss the first experimental tests on the industrial ACC measurement system. A calculation vs. experiment benchmark has been achieved by performing dedicated calibration measurement with a representative drum and {sup 235}U samples. The preliminary comparison between calculation and experiment shows a satisfactory agreement for the drum monitor. The final objective of this work is to confirm the reliability of the
Henzl, V.; Croft, S.; Richard, J.; Swinhoe, M. T.; Tobin, S. J.
2013-06-01
In this paper, we present a novel approach to estimating the total plutonium content in a spent fuel assembly (SFA) that is based on combining information from a passive measurement of the total neutron count rate (PN) of the assayed SFA and a measure of its multiplication. While PN can be measured essentially with any non-destructive assay (NDA) technique capable of neutron detection, the measure of multiplication is, in our approach, determined by means of active interrogation using an instrument based on the Differential Die-Away technique (DDA). The DDA is a NDA technique developed within the U.S. Department of Energy's Next Generation Safeguards Initiative (NGSI) project focused on the utilization of NDA techniques to determine the elemental plutonium content in commercial nuclear SFA's [1]. This approach was adopted since DDA also allows determination of other SFA characteristics, such as burnup, initial enrichment, and cooling time, and also allows for detection of certain types of diversion of nuclear material. The quantification of total plutonium is obtained using an analytical correlation function in terms of the observed PN and active multiplication. Although somewhat similar approaches relating Pu content with PN have been adopted in the past, we demonstrate by extensive simulation of the fuel irradiation and NDA process that our analytical method is independent of explicit knowledge of the initial enrichment, burnup, and an absolute value of the SFA's reactivity (i.e. multiplication factor). We show that when tested with MCNPX™ simulations comprising the 64 SFA NGSI Spent Fuel Library-1 we were able to determine elemental plutonium content, using just a few calibration parameters, with an average variation in the prediction of around 1-2% across the wide dynamic range of irradiation history parameters used, namely initial enrichment (IE=2-5%), burnup (BU=15-60 GWd/tU) and cooling time (CT=1-80 y). In this paper we describe the basic approach and the
Verification of plutonium content in spent fuel assemblies using neutron self-interrogation
Menlove, Howard O [Los Alamos National Laboratory; Menlove, Apencer H [Los Alamos National Laboratory; Tobin, Stephen J [Los Alamos National Laboratory
2009-01-01
The large amounts of plutonium in reactor spent fuel assemblies has led to increased research directed toward the measurement of the plutonium for safeguards verification. The high levels of fission product gamma-ray activity and curium neutron backgrounds have made the plutonium measurement difficult. We have developed a new technique that can directly measure both the {sup 235}U concentration and the plutonium fissile concentration using the intrinsic neutron emission fronl the curium in the fuel assembly. The passive neutron albedo reactivity (PNAR) method has been described previously where the curium neutrons are moderated in the surrounding water and reflect back into the fuel assembly to induce fissions in the fissile material in the assembly. The cadmium (Cd) ratio is used to separate the spontaneous fission source neutrons from the reflected thermal neutron fission reactions. This method can measure the sum of the {sup 235}U and the plutonium fissile mass, but not the separate components. Our new differential die-away self-interrogation method (DDSI) can be used to separate the {sup 235}U from the {sup 239}Pu. The method has been applied to both fuel rods and full assemblies. For fuel rods the epi-thermal neutron reflection method filters the reflected neutrons through thin Cd filters so that the reflected neutrons are from the epi-cadmium energy region. The neutron fission energy response in the epi-cadmium region is distinctly different for {sup 235}U and {sup 239}Pu. We are able to measure the difference between {sup 235}U and {sup 239}Pu by sampling the neutron induced fission rate as a function of time and multiplicity after the initial fission neutron is detected. We measure the neutron fission rate using list-mode data collection that stores the time correlations between all of the counts. The computer software can select from the data base the time correlations that include singles, doubles, and triples. The die-away time for the doubles
Die-Away Kinetics of Aerosolized Bacteria from Sprinkler Application of Wastewater
Teltsch, B; Shuval, H I; Tadmor, J
1980-01-01
A methodology for estimating, under field conditions, the microbial die-away constant (lambda) is presented. This constant may be used in predicting the aerosolized pathogenic microorganism concentrations downwind from a wastewater spray or aeration site by means of modified atmospheric diffusion equations. The mean lambda of Escherichia coli for very early morning runs was 8.8 X 10(-3)s-1, and that for afternoon runs was 6.6 X 10(-2)s-1.
Goodsell, Alison Victoria [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Swinhoe, Martyn Thomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Henzl, Vladimir [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ianakiev, Kiril Dimitrov [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Iliev, Metodi [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rael, Carlos D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Desimone, David J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2014-09-22
Four helium-3 (^{3}He) detector/preamplifier packages (¾”/KM200, DDSI/PDT-A111, DDA/PDT-A111, and DDA/PDT10A) were experimentally tested to determine the deadtime effects at different DT neutron generator output settings. At very high count rates, the ¾”/KM200 package performed best. At high count rates, the ¾”/KM200 and the DDSI/PDT-A111 packages performed very well, with the DDSI/PDT-A111 operating with slightly higher efficiency. All of the packages performed similarly at mid to low count rates. Proposed improvements include using a fast recovery LANL-made dual channel preamplifier, testing smaller diameter ^{3}He tubes, and further investigating quench gases.
Neutron die-away experiment for remote analysis of the surface of the moon and the planets, phase 3
Mills, W. R.; Allen, L. S.
1972-01-01
Continuing work on the two die-away measurements proposed to be made in the combined pulsed neutron experiment (CPNE) for analysis of lunar and planetary surfaces is described. This report documents research done during Phase 3. A general exposition of data analysis by the least-squares method and the related problem of the prediction of variance is given. A data analysis procedure for epithermal die-away data has been formulated. In order to facilitate the analysis, the number of independent material variables has been reduced to two: the hydrogen density and an effective oxygen density, the latter being determined uniquely from the nonhydrogeneous elemental composition. Justification for this reduction in the number of variables is based on a set of 27 new theoretical calculations. Work is described related to experimental calibration of the epithermal die-away measurement. An interim data analysis technique based solely on theoretical calculations seems to be adequate and will be used for future CPNE field tests.
Henzl, Vladimir [Los Alamos National Laboratory; Croft, Stephen [Los Alamos National Laboratory; Swinhoe, Martyn T. [Los Alamos National Laboratory; Tobin, Stephen J. [Los Alamos National Laboratory
2012-07-13
Inspired by approach of Bignan and Martin-Didier (ESARDA 1991) we introduce novel (instrument independent) approach based on multiplication and passive neutron. Based on simulations of SFL-1 the accuracy of determination of {sup tot}Pu content with new approach is {approx}1.3-1.5%. Method applicable for DDA instrument, since it can measure both multiplication and passive neutron count rate. Comparison of pro's & con's of measuring/determining of {sup 239}Pu{sub eff} and {sup tot}Pu suggests a potential for enhanced diversion detection sensitivity.
LaFleur, Adrienne M., E-mail: alafleur@lanl.gov [Nuclear Nonproliferation Division, Los Alamos National Laboratory, P.O. Box 1663 MS E540, Los Alamos, NM 87545 (United States); Charlton, William S., E-mail: wcharlton@tamu.edu [Nuclear Security Science and Policy Institute, Texas A and M University, 3473 TAMU, College Station, TX 77843 (United States); Menlove, Howard O., E-mail: hmenlove@lanl.gov [Nuclear Nonproliferation Division, Los Alamos National Laboratory, P.O. Box 1663 MS E540, Los Alamos, NM 87545 (United States); Swinhoe, Martyn T., E-mail: swinhoe@lanl.gov [Nuclear Nonproliferation Division, Los Alamos National Laboratory, P.O. Box 1663 MS E540, Los Alamos, NM 87545 (United States)
2012-07-11
A new non-destructive assay technique called Self-Interrogation Neutron Resonance Densitometry (SINRD) is currently being developed at Los Alamos National Laboratory (LANL) to improve existing nuclear safeguards measurements for Light Water Reactor (LWR) fuel assemblies. SINRD consists of four {sup 235}U fission chambers (FCs): bare FC, boron carbide shielded FC, Gd covered FC, and Cd covered FC. Ratios of different FCs are used to determine the amount of resonance absorption from {sup 235}U in the fuel assembly. The sensitivity of this technique is based on using the same fissile materials in the FCs as are present in the fuel because the effect of resonance absorption lines in the transmitted flux is amplified by the corresponding (n,f) reaction peaks in the fission chamber. In this work, experimental measurements were performed in air with SINRD using a reference Pressurized Water Reactor (PWR) 15 Multiplication-Sign 15 low enriched uranium (LEU) fresh fuel assembly at LANL. The purpose of this experiment was to assess the following capabilities of SINRD: (1) ability to measure the effective {sup 235}U enrichment of the PWR fresh LEU fuel assembly and (2) sensitivity and penetrability to the removal of fuel pins from an assembly. These measurements were compared to Monte Carlo N-Particle eXtended transport code (MCNPX) simulations to verify the accuracy of the MCNPX model of SINRD. The reproducibility of experimental measurements via MCNPX simulations is essential to validating the results and conclusions obtained from the simulations of SINRD for LWR spent fuel assemblies. - Highlights: Black-Right-Pointing-Pointer Development of new measurement technique called SINRD to improve LWR safeguards. Black-Right-Pointing-Pointer Performed SINRD experiment to measure {sup 235}U and pin diversions in PWR fresh assembly. Black-Right-Pointing-Pointer Excellent agreement of MCNPX and measured results confirmed accuracy of SINRD model. Black-Right-Pointing-Pointer SINRD
Hu, Jianwei, E-mail: huj1@ornl.gov [Reactor and Nuclear Systems Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, PO Box 2008, MS-6172, Oak Ridge, TN 37831-6172 (United States); Tobin, Stephen J.; LaFleur, Adrienne M.; Menlove, Howard O.; Swinhoe, Martyn T. [Nuclear Engineering and Nonproliferation Division, Los Alamos National Laboratory (United States)
2013-11-21
Self-Interrogation Neutron Resonance Densitometry (SINRD) is one of several nondestructive assay (NDA) techniques being integrated into systems to measure spent fuel as part of the Next Generation Safeguards Initiative (NGSI) Spent Fuel Project. The NGSI Spent Fuel Project is sponsored by the US Department of Energy's National Nuclear Security Administration to measure plutonium in, and detect diversion of fuel pins from, spent nuclear fuel assemblies. SINRD shows promising capability in determining the {sup 239}Pu and {sup 235}U content in spent fuel. SINRD is a relatively low-cost and lightweight instrument, and it is easy to implement in the field. The technique makes use of the passive neutron source existing in a spent fuel assembly, and it uses ratios between the count rates collected in fission chambers that are covered with different absorbing materials. These ratios are correlated to key attributes of the spent fuel assembly, such as the total mass of {sup 239}Pu and {sup 235}U. Using count rate ratios instead of absolute count rates makes SINRD less vulnerable to systematic uncertainties. Building upon the previous research, this work focuses on the underlying physics of the SINRD technique: quantifying the individual impacts on the count rate ratios of a few important nuclides using the perturbation method; examining new correlations between count rate ratio and mass quantities based on the results of the perturbation study; quantifying the impacts on the energy windows of the filtering materials that cover the fission chambers by tallying the neutron spectra before and after the neutrons go through the filters; and identifying the most important nuclides that cause cooling-time variations in the count rate ratios. The results of these studies show that {sup 235}U content has a major impact on the SINRD signal in addition to the {sup 239}Pu content. Plutonium-241 and {sup 241}Am are the two main nuclides responsible for the variation in the count
LaFleur, Adrienne M., E-mail: alafleur@lanl.gov; Menlove, Howard O., E-mail: hmenlove@lanl.gov
2015-05-01
Self-Interrogation Neutron Resonance Densitometry (SINRD) is a new NDA technique that was developed at Los Alamos National Laboratory (LANL) to improve existing nuclear safeguards measurements for LWR fuel assemblies. The SINRD detector consists of four fission chambers (FCs) wrapped with different absorber filters to isolate different parts of the neutron energy spectrum and one ion chamber (IC) to measure the gross gamma rate. As a result, two different techniques can be utilized using the same SINRD detector unit and hardware. These techniques are the Passive Neutron Multiplication Counter (PNMC) method and the SINRD method. The focus of the work described in this paper is the analysis of experimental measurements of fresh and spent PWR fuel assemblies that were performed at LANL and the Korea Atomic Energy Research Institute (KAERI), respectively, using the SINRD detector. The purpose of these experiments was to assess the following capabilities of the SINRD detector: 1) reproducibility of measurements to quantify systematic errors, 2) sensitivity to water gap between detector and fuel assembly, 3) sensitivity and penetrability to the removal of fuel rods from the assembly, and 4) use of PNMC/SINRD ratios to quantify neutron multiplication and/or fissile content. The results from these simulations and measurements provide valuable experimental data that directly supports safeguards research and development (R&D) efforts on the viability of passive neutron NDA techniques and detector designs for partial defect verification of spent fuel assemblies. - Highlights: • Experimental measurements of PWR fresh and spent FAs were performed with SINRD. • Good agreement of MCNPX and measured results confirmed accuracy of SINRD model. • For fresh fuel, SINRD and PNMC ratios were not sensitive to water gaps of ≤5-mm. • Practical use of SINRD would be in Fork detector to reduce systematic uncertainties.
Rossa, Riccardo, E-mail: rrossa@sckcen.be [SCK-CEN, Belgian Nuclear Research Centre, Boeretang, 200, B2400 Mol (Belgium); Université libre de Bruxelles, Ecole polytechnique de Bruxelles, Service de Métrologie Nucléaire (CP 165/84), Avenue F.D. Roosevelt, 50, B1050 Brussels (Belgium); Borella, Alessandro, E-mail: aborella@sckcen.be [SCK-CEN, Belgian Nuclear Research Centre, Boeretang, 200, B2400 Mol (Belgium); Labeau, Pierre-Etienne, E-mail: pelabeau@ulb.ac.be [Université libre de Bruxelles, Ecole polytechnique de Bruxelles, Service de Métrologie Nucléaire (CP 165/84), Avenue F.D. Roosevelt, 50, B1050 Brussels (Belgium); Pauly, Nicolas, E-mail: nipauly@ulb.ac.be [Université libre de Bruxelles, Ecole polytechnique de Bruxelles, Service de Métrologie Nucléaire (CP 165/84), Avenue F.D. Roosevelt, 50, B1050 Brussels (Belgium); Meer, Klaas van der, E-mail: kvdmeer@sckcen.be [SCK-CEN, Belgian Nuclear Research Centre, Boeretang, 200, B2400 Mol (Belgium)
2015-08-11
The Self-Interrogation Neutron Resonance Densitometry (SINRD) is a passive non-destructive assay (NDA) technique that is proposed for the direct measurement of {sup 239}Pu in a spent fuel assembly. The insertion of neutron detectors wrapped with different neutron absorbing materials, or neutron filters, in the central guide tube of a PWR fuel assembly is envisaged to measure the neutron flux in the energy region close to the 0.3 eV resonance of {sup 239}Pu. In addition, the measurement of the fast neutron flux is foreseen. This paper is focused on the determination of the Gd and Cd neutron filters thickness to maximize the detection of neutrons within the resonance region. Moreover, several detector types are compared to identify the optimal condition and to assess the expected total neutron counts that can be obtained with the SINRD measurements. Results from Monte Carlo simulations showed that ranges between 0.1–0.3 mm and 0.5–1.0 mm ensure the optimal conditions for the Gd and Cd filters, respectively. Moreover, a {sup 239}Pu fission chamber is better suited to measure neutrons close to the 0.3 eV resonance and it has the highest sensitivity to {sup 239}Pu, in comparison with a {sup 235}U fission chamber, with a {sup 3}He proportional counter, and with a {sup 10}B proportional counter. The use of a thin Gd filter and a thick Cd filter is suggested for the {sup 239}Pu and {sup 235}U fission chambers to increase the total counts achieved in a measurement, while a thick Gd filter and a thin Cd filter are envisaged for the {sup 3}He and {sup 10}B proportional counters to increase the sensitivity to {sup 239}Pu. We concluded that an optimization process that takes into account measurement time, filters thickness, and detector size is needed to develop a SINRD detector that can meet the requirement for an efficient verification of spent fuel assemblies.
Lafleur, Adrienne M [Los Alamos National Laboratory; Charlton, William S [Los Alamos National Laboratory; Menlove, Howard O [Los Alamos National Laboratory; Swinhoe, Martyn T [Los Alamos National Laboratory
2009-01-01
The use of Self-Interrogation Neutron Resonance Densitometry (SINRD) to measure the {sup 235}U and {sup 239}Pu content in a PWR spent fuel assembly was investigated via Monte Carlo N-Particle eXtended transport code (MCNPX) simulations. The sensitivity of SINRD is based on using the same fissile materials in the fission chambers as are present in the fuel because the effect of resonance absorption lines in the transmitted flux is amplified by the corresponding (n, f) reaction peaks in fission chamber. These simulations utilize the {sup 244}Cm spontaneous fission neutrons to self-interrogate the fuel pins. The amount of resonance absorption of these neutrons in the fuel can be measured using {sup 235}U and {sup 239}Pu fission chambers placed adjacent to the assembly. We used ratios of different fission chambers to reduce the sensitivity of the measurements to extraneous material present in fuel. The development of SINRD to measure the fissile content in spent fuel is of great importance to the improvement of nuclear safeguards and material accountability. Future work includes the use of this technique to measure the fissile content in FBR spent fuel and heavy metal product from reprocessing methods.
Chernikova, Dina; Trnjanin, Nermin; Axell, Kåre; Nordlund, Anders
2015-01-01
A new concept for thermal neutron based correlation and multiplicity measurements is proposed in this paper. The main idea of the concept consists of using 2.223 MeV gammas (or 1.201 MeV, DE) originating in the 1H(n,gamma)2D-reaction instead of using traditional thermal neutron counting. Results of investigations presented in this paper indicate that gammas from thermal neutron capture reaction preserve the information about the correlation characteristics of thermal (fast) neutrons in the same time scale. Therefore, instead of thermal neutron detectors (or as a complement) one may use traditional and inexpensive gamma detectors, such NaI, BGO, CdZnTe or any other gamma detectors. In this work we used D8x8 cm2 NaI scintillator to test the concept. Thus, the new approach helps to address the problem of replacement of 3He-counters and problems related to the specific measurements of spent nuclear fuel directly in the spent fuel pool. It has a particular importance for nuclear safeguards and security. Overall, t...
Ulrich, Timothy J. II [Los Alamos National Laboratory; Lafleur, Adrienne M. [Los Alamos National Laboratory; Menlove, Howard O. [Los Alamos National Laboratory; Swinhoe, Martyn T. [Los Alamos National Laboratory; Tobin, Stephen J. [Los Alamos National Laboratory; Seya, Michio [Los Alamos National Laboratory; Bolind, Alan M. [Los Alamos National Laboratory
2012-07-16
An integrated nondestructive assay instrument, which combined the Passive Neutron Albedo Reactivity (PNAR) and the Self-Interrogation Neutron Resonance Densitometry (SINRD) techniques, is the research focus for a collaborative effort between Los Alamos National Laboratory (LANL) and the Japanese Atomic Energy Agency as part of the Next Generation Safeguard Initiative. We will quantify the anticipated performance of this experimental system in two physical environments: (1) At LANL we will measure fresh Low Enriched Uranium (LEU) assemblies for which the average enrichment can be varied from 0.2% to 3.2% and for which Gd laced rods will be included. (2) At Fugen we will measure spent Mixed Oxide (MOX-B) and LEU spent fuel assemblies from the heavy water moderated Fugen reactor. The MOX-B assemblies will vary in burnup from {approx}3 GWd/tHM to {approx}20 GWd/tHM while the LEU assemblies ({approx}1.9% initial enrichment) will vary from {approx}2 GWd/tHM to {approx}7 GWd/tHM. The estimated count rates will be calculated using MCNPX. These preliminary results will help the finalization of the hardware design and also serve a guide for the experiment. The hardware of the detector is expected to be fabricated in 2012 with measurements expected to take place in 2012 and 2013. This work is supported by the Next Generation Safeguards Initiative, Office of Nuclear Safeguards and Security, National Nuclear Security Administration.
Chernikova, Dina; Pazsit, Imre; Pal, Lenard
2014-01-01
This paper presents a full derivation of the variance-to-mean or Feynman-alpha formula in a two energy group and two spatial region-treatment. The derivation is based on the Chapman - Kolmogorov equation with the inclusion of all possible neutron reactions and passage intensities between the two regions. In addition, the two-group one-region and the two-region one-group Feynman-alpha formulas, treated earlier in the literature for special cases, are extended for further types and positions of detectors.We focus on the possibility of using these theories for accelerator-driven systems and applications in the safeguards domain, such as the differential self-interrogation method and the differential die-away method. This is due to the fact that the predictions from the models which are currently used do not fully describe all the effects in the heavily reflected fast or thermal systems. Therefore, in conclusion a comparative study of the two-group two-region, the two-group one-region, the one-group two-region an...
Leake, J. W.; Lowe, T.; Mason, R. S.; White, G.
2010-01-01
Computer simulations of the response to very short pulses of neutron and gamma radiation of a spherical polyethylene moderator with a central thermal neutron counter and a new, fast, active restore amplifier system have been carried out. A large neutron burst produces count rates in the detector that are too high to measure initially but when the exponential decay of the count rate falls below about 50 k per sec then counting can start. If the counts are recorded in contiguous time intervals (of 60 μs in this case) and the time is measured at which the measured count in an interval falls to 1 or 2 then the size of the initial burst can be calculated. It is shown that it should be possible to measure pulsed neutron ambient dose equivalent H*(10) or dose equivalent rate from about 2 nSv up to about 100 μSv per burst, or 7.2 N μSv s h -1 to 360 N mSv s h -1, where N is the number of neutron bursts per second. The calculations show that a gamma burst of about 10 μGy can be tolerated without affecting the measurement of the largest neutron bursts. This extends our earlier estimate of the maximum dose that can be measured for pulsed neutrons by more than 10 k. This method could also be used to measure the neutron fluence or dose from a single unplanned event such as a beam dump on an accelerator or a criticality incident from fissile material. Although the method described is new it is based on a combination of proven techniques.
Bär, Christian
2014-01-01
Providing a systematic introduction to differential characters as introduced by Cheeger and Simons, this text describes important concepts such as fiber integration, higher dimensional holonomy, transgression, and the product structure in a geometric manner. Differential characters form a model of what is nowadays called differential cohomology, which is the mathematical structure behind the higher gauge theories in physics.
Kosinski, Antoni A
2007-01-01
The concepts of differential topology form the center of many mathematical disciplines such as differential geometry and Lie group theory. Differential Manifolds presents to advanced undergraduates and graduate students the systematic study of the topological structure of smooth manifolds. Author Antoni A. Kosinski, Professor Emeritus of Mathematics at Rutgers University, offers an accessible approach to both the h-cobordism theorem and the classification of differential structures on spheres.""How useful it is,"" noted the Bulletin of the American Mathematical Society, ""to have a single, sho
J.A. Bergstra; A. Ponse
2008-01-01
A meadow is a zero totalised field (0^{-1}=0), and a cancellation meadow is a meadow without proper zero divisors. In this paper we consider differential meadows, i.e., meadows equipped with differentiation operators. We give an equational axiomatization of these operators and thus obtain a finite b
Barbu, Viorel
2016-01-01
This textbook is a comprehensive treatment of ordinary differential equations, concisely presenting basic and essential results in a rigorous manner. Including various examples from physics, mechanics, natural sciences, engineering and automatic theory, Differential Equations is a bridge between the abstract theory of differential equations and applied systems theory. Particular attention is given to the existence and uniqueness of the Cauchy problem, linear differential systems, stability theory and applications to first-order partial differential equations. Upper undergraduate students and researchers in applied mathematics and systems theory with a background in advanced calculus will find this book particularly useful. Supplementary topics are covered in an appendix enabling the book to be completely self-contained.
Friedman, Avner
2006-01-01
This volume lays the mathematical foundations for the theory of differential games, developing a rigorous mathematical framework with existence theorems. It begins with a precise definition of a differential game and advances to considerations of games of fixed duration, games of pursuit and evasion, the computation of saddle points, games of survival, and games with restricted phase coordinates. Final chapters cover selected topics (including capturability and games with delayed information) and N-person games.Geared toward graduate students, Differential Games will be of particular interest
Mukherjee, Amiya
2015-01-01
This book presents a systematic and comprehensive account of the theory of differentiable manifolds and provides the necessary background for the use of fundamental differential topology tools. The text includes, in particular, the earlier works of Stephen Smale, for which he was awarded the Fields Medal. Explicitly, the topics covered are Thom transversality, Morse theory, theory of handle presentation, h-cobordism theorem, and the generalised Poincaré conjecture. The material is the outcome of lectures and seminars on various aspects of differentiable manifolds and differential topology given over the years at the Indian Statistical Institute in Calcutta, and at other universities throughout India. The book will appeal to graduate students and researchers interested in these topics. An elementary knowledge of linear algebra, general topology, multivariate calculus, analysis, and algebraic topology is recommended.
Stoker, J J
2011-01-01
This classic work is now available in an unabridged paperback edition. Stoker makes this fertile branch of mathematics accessible to the nonspecialist by the use of three different notations: vector algebra and calculus, tensor calculus, and the notation devised by Cartan, which employs invariant differential forms as elements in an algebra due to Grassman, combined with an operation called exterior differentiation. Assumed are a passing acquaintance with linear algebra and the basic elements of analysis.
Differential Krull dimension in differential polynomial extensions
Smirnov, Ilya
2011-01-01
We investigate the differential Krull dimension of differential polynomials over a differential ring. We prove a differential analogue of Jaffard's Special Chain Theorem and show that differential polynomial extensions of certain classes of differential rings have no anomaly of differential Krull dimension.
Mödersheim, Sebastian Alexander; Basin, David; Viganò, Luca
2010-01-01
, under the assumption that the original constraint-based approach has these properties. Practically, as a concrete case study, we have integrated this technique into OFMC, a state-of-the-art model-checker for security protocol analysis, and demonstrated its effectiveness by extensive experimentation. Our......We introduce constraint differentiation, a powerful technique for reducing search when model-checking security protocols using constraint-based methods. Constraint differentiation works by eliminating certain kinds of redundancies that arise in the search space when using constraints to represent...
Guggenheimer, Heinrich W
1977-01-01
This is a text of local differential geometry considered as an application of advanced calculus and linear algebra. The discussion is designed for advanced undergraduate or beginning graduate study, and presumes of readers only a fair knowledge of matrix algebra and of advanced calculus of functions of several real variables. The author, who is a Professor of Mathematics at the Polytechnic Institute of New York, begins with a discussion of plane geometry and then treats the local theory of Lie groups and transformation groups, solid differential geometry, and Riemannian geometry, leading to a
Graustein, William C
2006-01-01
This first course in differential geometry presents the fundamentals of the metric differential geometry of curves and surfaces in a Euclidean space of three dimensions. Written by an outstanding teacher and mathematician, it explains the material in the most effective way, using vector notation and technique. It also provides an introduction to the study of Riemannian geometry.Suitable for advanced undergraduates and graduate students, the text presupposes a knowledge of calculus. The first nine chapters focus on the theory, treating the basic properties of curves and surfaces, the mapping of
Margalef-Roig, J
1992-01-01
...there are reasons enough to warrant a coherent treatment of the main body of differential topology in the realm of Banach manifolds, which is at the same time correct and complete. This book fills the gap: whenever possible the manifolds treated are Banach manifolds with corners. Corners add to the complications and the authors have carefully fathomed the validity of all main results at corners. Even in finite dimensions some results at corners are more complete and better thought out here than elsewhere in the literature. The proofs are correct and with all details. I see this book as a reliable monograph of a well-defined subject; the possibility to fall back to it adds to the feeling of security when climbing in the more dangerous realms of infinite dimensional differential geometry. Peter W. Michor
Kreyszig, Erwin
1991-01-01
An introductory textbook on the differential geometry of curves and surfaces in three-dimensional Euclidean space, presented in its simplest, most essential form, but with many explanatory details, figures and examples, and in a manner that conveys the theoretical and practical importance of the different concepts, methods and results involved. With problems at the end of each section, and solutions listed at the end of the book. Includes 99 illustrations.
Ciarlet, Philippe G
2007-01-01
This book gives the basic notions of differential geometry, such as the metric tensor, the Riemann curvature tensor, the fundamental forms of a surface, covariant derivatives, and the fundamental theorem of surface theory in a selfcontained and accessible manner. Although the field is often considered a classical one, it has recently been rejuvenated, thanks to the manifold applications where it plays an essential role. The book presents some important applications to shells, such as the theory of linearly and nonlinearly elastic shells, the implementation of numerical methods for shells, and
Guillemin, Victor
2010-01-01
Differential Topology provides an elementary and intuitive introduction to the study of smooth manifolds. In the years since its first publication, Guillemin and Pollack's book has become a standard text on the subject. It is a jewel of mathematical exposition, judiciously picking exactly the right mixture of detail and generality to display the richness within. The text is mostly self-contained, requiring only undergraduate analysis and linear algebra. By relying on a unifying idea-transversality-the authors are able to avoid the use of big machinery or ad hoc techniques to establish the main
Tricomi, FG
2013-01-01
Based on his extensive experience as an educator, F. G. Tricomi wrote this practical and concise teaching text to offer a clear idea of the problems and methods of the theory of differential equations. The treatment is geared toward advanced undergraduates and graduate students and addresses only questions that can be resolved with rigor and simplicity.Starting with a consideration of the existence and uniqueness theorem, the text advances to the behavior of the characteristics of a first-order equation, boundary problems for second-order linear equations, asymptotic methods, and diff
On differential characteristic classes
Ho, Man-Ho
2013-01-01
In this paper we give explicit formulas of differential characteristic classes of principal $G$-bundles with connections and prove their expected properties. In particular, we obtain explicit formulas for differential Chern classes, differential Pontryagin classes and differential Euler class. Furthermore, we show that the differential Chern class is the unique natural transformation from (Simons-Sullivan) differential $K$-theory to (Cheeger-Simons) differential characters that is compatible ...
Concentrated Differential Privacy
Dwork, Cynthia; Rothblum, Guy N.
2016-01-01
We introduce Concentrated Differential Privacy, a relaxation of Differential Privacy enjoying better accuracy than both pure differential privacy and its popular "(epsilon,delta)" relaxation without compromising on cumulative privacy loss over multiple computations.
Osteoblastic cells: differentiation and trans-differentiation
Kassem, Moustapha; Abdallah, Basem; Saeed, Hamid
2008-01-01
The osteoblast is the bone forming cell and is derived from mesenchymal stem cells (MSC) present among the bone marrow stroma. MSC are capable of multi-lineage differentiation into mesoderm-type cells such as osteoblasts and adipocytes. Understanding the mechanisms underlying osteoblast...... differentiation from MSC is a central topic in bone biology that can provide insight into mechanisms of bone maintenance and also novel pharmacological targets to increase osteoblast differentiation and consequently bone formation....
The Differential Dimension Polynomial for Characterizable Differential Ideals
Lange-Hegermann, Markus
2014-01-01
We generalize the differential dimension polynomial from prime differential ideals to characterizable differential ideals. Its computation is algorithmic, its degree and leading coefficient remain differential birational invariants, and it decides equality of characterizable differential ideals contained in each other.
Symposium on Differential Geometry and Differential Equations
Berger, Marcel; Bryant, Robert
1987-01-01
The DD6 Symposium was, like its predecessors DD1 to DD5 both a research symposium and a summer seminar and concentrated on differential geometry. This volume contains a selection of the invited papers and some additional contributions. They cover recent advances and principal trends in current research in differential geometry.
Axiomatic differential geometry II-2 - differential forms
Nishimura, Hirokazu
2013-01-01
We refurbish our axiomatics of differential geometry introduced in [Mathematics for Applications,, 1 (2012), 171-182]. Then the notion of Euclideaness can naturally be formulated. The principal objective in this paper is to present an adaptation of our theory of differential forms developed in [International Journal of Pure and Applied Mathematics, 64 (2010), 85-102] to our present axiomatic framework.
Axiomatic Differential Geometry Ⅱ-2: Differential Forms
Nishimura, Hirokazu
2013-01-01
We refurbish our axiomatics of differential geometry introduced in [arXiv 1203.3911]. Then the notion of Euclideaness can naturally be formulated. The principal objective in this paper is to present an adaptation of our theory of differential forms developed in [International Journal of Pure and Applied Mathematics, 64 (2010), 85-102] to our present axiomatic framework.
Automatic differentiation bibliography
Corliss, G.F. (comp.)
1992-07-01
This is a bibliography of work related to automatic differentiation. Automatic differentiation is a technique for the fast, accurate propagation of derivative values using the chain rule. It is neither symbolic nor numeric. Automatic differentiation is a fundamental tool for scientific computation, with applications in optimization, nonlinear equations, nonlinear least squares approximation, stiff ordinary differential equation, partial differential equations, continuation methods, and sensitivity analysis. This report is an updated version of the bibliography which originally appeared in Automatic Differentiation of Algorithms: Theory, Implementation, and Application.
Arditti, Mort A.; Silva, Rosemary
1993-01-01
Differential adding circuit (or, equivalently, subtracting circuit) faster and consumes less power because it contains only one differential amplifier. Suitable for use in high-frequency-switching, high power-regulating circuit.
Partial Differential Equations
1988-01-01
The volume contains a selection of papers presented at the 7th Symposium on differential geometry and differential equations (DD7) held at the Nankai Institute of Mathematics, Tianjin, China, in 1986. Most of the contributions are original research papers on topics including elliptic equations, hyperbolic equations, evolution equations, non-linear equations from differential geometry and mechanics, micro-local analysis.
functional-differential inequalities
Ludwik Byszewski
1995-01-01
Full Text Available A theorem about a system of strong impulsive degenerate nonlinear parabolic functional-differential inequalities in an arbitrary parabolic set is proved. As a consequence of the theorem, some theorems about impulsive degenerate nonlinear parabolic differential inequalities and the uniqueness of a classical solution of an impulsive degenerate nonlinear parabolic differential problem are established.
Using Differentials to Differentiate Trigonometric and Exponential Functions
Dray, Tevian
2013-01-01
Starting from geometric definitions, we show how differentials can be used to differentiate trigonometric and exponential functions without limits, numerical estimates, solutions of differential equations, or integration.
Using Differentials to Differentiate Trigonometric and Exponential Functions
Dray, Tevian
2013-01-01
Starting from geometric definitions, we show how differentials can be used to differentiate trigonometric and exponential functions without limits, numerical estimates, solutions of differential equations, or integration.
Nuclear Resonance Fluorescence to Measure Plutonium Mass in Spent Nuclear Fuel
Ludewigt, Bernhard A; Quiter, Brian J.; Ambers, Scott D.
2011-01-14
The Next Generation Safeguard Initiative (NGSI) of the U.S Department of Energy is supporting a multi-lab/university collaboration to quantify the plutonium (Pu) mass in spent nuclear fuel (SNF) assemblies and to detect the diversion of pins with non-destructive assay (NDA) methods. The following 14 NDA techniques are being studied: Delayed Neutrons, Differential Die-Away, Differential Die-Away Self-Interrogation, Lead Slowing Down Spectrometer, Neutron Multiplicity, Passive Neutron Albedo Reactivity, Total Neutron (Gross Neutron), X-Ray Fluorescence, {sup 252}Cf Interrogation with Prompt Neutron Detection, Delayed Gamma, Nuclear Resonance Fluorescence, Passive Prompt Gamma, Self-integration Neutron Resonance Densitometry, and Neutron Resonance Transmission Analysis. Understanding and maturity of the techniques vary greatly, ranging from decades old, well-understood methods to new approaches. Nuclear Resonance Fluorescence (NRF) is a technique that had not previously been studied for SNF assay or similar applications. Since NRF generates isotope-specific signals, the promise and appeal of the technique lies in its potential to directly measure the amount of a specific isotope in an SNF assay target. The objectives of this study were to design and model suitable NRF measurement methods, to quantify capabilities and corresponding instrumentation requirements, and to evaluate prospects and the potential of NRF for SNF assay. The main challenge of the technique is to achieve the sensitivity and precision, i.e., to accumulate sufficient counting statistics, required for quantifying the mass of Pu isotopes in SNF assemblies. Systematic errors, considered a lesser problem for a direct measurement and only briefly discussed in this report, need to be evaluated for specific instrument designs in the future. Also, since the technical capability of using NRF to measure Pu in SNF has not been established, this report does not directly address issues such as cost, size
Fundamentals of differential beamforming
Benesty, Jacob; Pan, Chao
2016-01-01
This book provides a systematic study of the fundamental theory and methods of beamforming with differential microphone arrays (DMAs), or differential beamforming in short. It begins with a brief overview of differential beamforming and some popularly used DMA beampatterns such as the dipole, cardioid, hypercardioid, and supercardioid, before providing essential background knowledge on orthogonal functions and orthogonal polynomials, which form the basis of differential beamforming. From a physical perspective, a DMA of a given order is defined as an array that measures the differential acoustic pressure field of that order; such an array has a beampattern in the form of a polynomial whose degree is equal to the DMA order. Therefore, the fundamental and core problem of differential beamforming boils down to the design of beampatterns with orthogonal polynomials. But certain constraints also have to be considered so that the resulting beamformer does not seriously amplify the sensors’ self noise and the mism...
Developmental Partial Differential Equations
Duteil, Nastassia Pouradier; Rossi, Francesco; Boscain, Ugo; Piccoli, Benedetto
2015-01-01
In this paper, we introduce the concept of Developmental Partial Differential Equation (DPDE), which consists of a Partial Differential Equation (PDE) on a time-varying manifold with complete coupling between the PDE and the manifold's evolution. In other words, the manifold's evolution depends on the solution to the PDE, and vice versa the differential operator of the PDE depends on the manifold's geometry. DPDE is used to study a diffusion equation with source on a growing surface whose gro...
High resolution differential thermometer
Gotra Z. Yu.
2009-11-01
Full Text Available Main schematic solutions of differential thermometers with measurement resolution about 0.001°C are considered. Differential temperature primary transducer realized on a transistor differential circuit in microampere mode. Analytic calculation and schematic mathematic simulation of primary transducer are fulfilled. Signal transducer is realized on a high precision Zero-Drift Single-Supply Rail-to-Rail operation amplifier AD8552 and 24-Bit S-D microconverter ADuC834.
Mueller matrix differential decomposition.
Ortega-Quijano, Noé; Arce-Diego, José Luis
2011-05-15
We present a Mueller matrix decomposition based on the differential formulation of the Mueller calculus. The differential Mueller matrix is obtained from the macroscopic matrix through an eigenanalysis. It is subsequently resolved into the complete set of 16 differential matrices that correspond to the basic types of optical behavior for depolarizing anisotropic media. The method is successfully applied to the polarimetric analysis of several samples. The differential parameters enable one to perform an exhaustive characterization of anisotropy and depolarization. This decomposition is particularly appropriate for studying media in which several polarization effects take place simultaneously. © 2011 Optical Society of America
Singular stochastic differential equations
Cherny, Alexander S
2005-01-01
The authors introduce, in this research monograph on stochastic differential equations, a class of points termed isolated singular points. Stochastic differential equations possessing such points (called singular stochastic differential equations here) arise often in theory and in applications. However, known conditions for the existence and uniqueness of a solution typically fail for such equations. The book concentrates on the study of the existence, the uniqueness, and, what is most important, on the qualitative behaviour of solutions of singular stochastic differential equations. This is done by providing a qualitative classification of isolated singular points, into 48 possible types.
Calculus & ordinary differential equations
Pearson, David
1995-01-01
Professor Pearson's book starts with an introduction to the area and an explanation of the most commonly used functions. It then moves on through differentiation, special functions, derivatives, integrals and onto full differential equations. As with other books in the series the emphasis is on using worked examples and tutorial-based problem solving to gain the confidence of students.
Equivalence of Differential System
Zheng-xin Zhou
2004-01-01
Using refiecting function of Mironenko we construct some differential systems which are equivalent to the given differential system.This gives us an opportunity to find out the monodromic matrix of these periodi csystems which are not integrable in finite terms.
Lifting the Differentiation Embargo.
Latif, Anne-Louise; Holyoake, Tessa L
2016-09-22
Effective differentiation therapy for acute myeloid leukemia (AML) has been restricted to a small subset of patients with one defined genetic abnormality. Using an unbiased small molecule screen, Sykes et al. now identify a mechanism of de-repression of differentiation in several models of AML driven by distinct genetic drivers.
Differentiering - Hvorfor & hvordan?
Pedersen, Michael Svendsen
Rapporten indeholder en introduktion til differentiering i undervisningen i dansk som andetsprog, hvor der lægges vægt på at differentiering ikke kan reduceres til nogle "teknikker" eller "værktøjer", men er en generel tilgang til undervisning der har deltagernes ressourcer og ligeværd som udgang...
On Quadratic Differential Forms
Willems, J.C.; Trentelman, H.L.
1998-01-01
This paper develops a theory around the notion of quadratic differential forms in the context of linear differential systems. In many applications, we need to not only understand the behavior of the system variables but also the behavior of certain functionals of these variables. The obvious cases w
"Nowhere" differentiable horizons
Chrúsciel, P T
1996-01-01
It is folklore knowledge amongst general relativists that horizons are well behaved, continuously differentiable hypersurfaces except perhaps on a negligible subset one needs not to bother with. We show that this is not the case, by constructing a Cauchy horizon, as well as a black hole event horizon, which contain no open subset on which they are differentiable.
Automatic Differentiation Package
2007-03-01
Sacado is an automatic differentiation package for C++ codes using operator overloading and C++ templating. Sacado provide forward, reverse, and Taylor polynomial automatic differentiation classes and utilities for incorporating these classes into C++ codes. Users can compute derivatives of computations arising in engineering and scientific applications, including nonlinear equation solving, time integration, sensitivity analysis, stability analysis, optimization and uncertainity quantification.
Surveillance for Secure Differentiation
Hamilton, William B; Brickman, Joshua M
2017-01-01
The precise place and time where embryonic differentiation begins is regulated by regionalized signaling. In this issue of Cell Stem Cell, Wang et al. (2017) investigate how converging Wnt and Nodal signals promote mesendoderm through a p53, Wnt3 feed-forward loop, pointing to a mechanism by which...... cells gauge time and fitness during differentiation....
Differential equations for dummies
Holzner, Steven
2008-01-01
The fun and easy way to understand and solve complex equations Many of the fundamental laws of physics, chemistry, biology, and economics can be formulated as differential equations. This plain-English guide explores the many applications of this mathematical tool and shows how differential equations can help us understand the world around us. Differential Equations For Dummies is the perfect companion for a college differential equations course and is an ideal supplemental resource for other calculus classes as well as science and engineering courses. It offers step-by-step techniques, practical tips, numerous exercises, and clear, concise examples to help readers improve their differential equation-solving skills and boost their test scores.
Randomness and Differentiability
Brattka, Vasco; Nies, André
2011-01-01
We characterize some major algorithmic randomness notions via differentiability of effective functions. (1) We show that a real number z in [0,1] is computably random if and only if every nondecreasing computable function [0,1]->R is differentiable at z. (2) A real number z in [0,1] is weakly 2-random if and only if every almost everywhere differentiable computable function [0,1]->R is differentiable at z. (3) Recasting results of the constructivist Demuth (1975) in classical language, we show that a real z is ML random if and only if every computable function of bounded variation is differentiable at z, and similarly for absolutely continuous functions. We also use the analytic methods to show that computable randomness of a real is base invariant, and to derive preservation results for randomness notions.
Linking Diversity and Differentiation
Hans-Rolf Gregorius
2010-03-01
Full Text Available Generally speaking, the term differentiation refers to differences between collections for the distribution of specified traits of their members, while diversity deals with (effective numbers of trait states (types. Counting numbers of types implies discrete traits such as alleles and genotypes in population genetics or species and taxa in ecology. Comparisons between the concepts of differentiation and diversity therefore primarily refer to discrete traits. Diversity is related to differentiation through the idea that the total diversity of a subdivided collection should be composed of the diversity within the subcollections and a complement called “diversity between subcollections”. The idea goes back to the perception that the mixing of differentiated collections increases diversity. Several existing concepts of “diversity between subcollections” are based on this idea. Among them, β-diversity and fixation (inadvertently called differentiation are the most prominent in ecology and in population genetics, respectively. The pertaining measures are shown to quantify the effect of differentiation in terms of diversity components, though from a dual perspective: the classical perspective of differentiation between collections for their type compositions, and the reverse perspective of differentiation between types for their collection affiliations. A series of measures of diversity-oriented differentiation is presented that consider this dual perspective at two levels of diversity partitioning: the overall type or subcollection diversity and the joint type-subcollection diversity. It turns out that, in contrast with common notions, the measures of fixation (such as FST or GST refer to the perspective of type rather than subcollection differentiation. This unexpected observation strongly suggests that the popular interpretations of fixation measures must be reconsidered.
Differential equations problem solver
Arterburn, David R
2012-01-01
REA's Problem Solvers is a series of useful, practical, and informative study guides. Each title in the series is complete step-by-step solution guide. The Differential Equations Problem Solver enables students to solve difficult problems by showing them step-by-step solutions to Differential Equations problems. The Problem Solvers cover material ranging from the elementary to the advanced and make excellent review books and textbook companions. They're perfect for undergraduate and graduate studies.The Differential Equations Problem Solver is the perfect resource for any class, any exam, and
Ordinary differential equations
Miller, Richard K
1982-01-01
Ordinary Differential Equations is an outgrowth of courses taught for a number of years at Iowa State University in the mathematics and the electrical engineering departments. It is intended as a text for a first graduate course in differential equations for students in mathematics, engineering, and the sciences. Although differential equations is an old, traditional, and well-established subject, the diverse backgrounds and interests of the students in a typical modern-day course cause problems in the selection and method of presentation of material. In order to compensate for this diversity,
Ordinary differential equations
Pontryagin, Lev Semenovich
1962-01-01
Ordinary Differential Equations presents the study of the system of ordinary differential equations and its applications to engineering. The book is designed to serve as a first course in differential equations. Importance is given to the linear equation with constant coefficients; stability theory; use of matrices and linear algebra; and the introduction to the Lyapunov theory. Engineering problems such as the Watt regulator for a steam engine and the vacuum-tube circuit are also presented. Engineers, mathematicians, and engineering students will find the book invaluable.
Beginning partial differential equations
O'Neil, Peter V
2011-01-01
A rigorous, yet accessible, introduction to partial differential equations-updated in a valuable new edition Beginning Partial Differential Equations, Second Edition provides a comprehensive introduction to partial differential equations (PDEs) with a special focus on the significance of characteristics, solutions by Fourier series, integrals and transforms, properties and physical interpretations of solutions, and a transition to the modern function space approach to PDEs. With its breadth of coverage, this new edition continues to present a broad introduction to the field, while also addres
Hyperbolic partial differential equations
Witten, Matthew
1986-01-01
Hyperbolic Partial Differential Equations III is a refereed journal issue that explores the applications, theory, and/or applied methods related to hyperbolic partial differential equations, or problems arising out of hyperbolic partial differential equations, in any area of research. This journal issue is interested in all types of articles in terms of review, mini-monograph, standard study, or short communication. Some studies presented in this journal include discretization of ideal fluid dynamics in the Eulerian representation; a Riemann problem in gas dynamics with bifurcation; periodic M
Theory of differential equations
Gel'fand, I M
1967-01-01
Generalized Functions, Volume 3: Theory of Differential Equations focuses on the application of generalized functions to problems of the theory of partial differential equations.This book discusses the problems of determining uniqueness and correctness classes for solutions of the Cauchy problem for systems with constant coefficients and eigenfunction expansions for self-adjoint differential operators. The topics covered include the bounded operators in spaces of type W, Cauchy problem in a topological vector space, and theorem of the Phragmén-Lindelöf type. The correctness classes for the Cau
Differentiation transforming system
Qiang Cheng; Haibin Zhang; Bin Wang; Yonghua Zhao
2009-01-01
The differentiation transforming(DFT)system is developed to produce the tangent linear codes,which is used to calculate the Jacobian-and the Hessian-vector products with no truncation errors.This paper first gives the introduction of the functionality and features of the DFT system,and then discusses several techniques for the implementation of automatic differentiation tools,including data dependence analysis,singular differentiation and code optimization.Finally,the codes generated with DFT used in several applications have been demonstrated.
Differential Equations as Actions
Ronkko, Mauno; Ravn, Anders P.
1997-01-01
We extend a conventional action system with a primitive action consisting of a differential equation and an evolution invariant. The semantics is given by a predicate transformer. The weakest liberal precondition is chosen, because it is not always desirable that steps corresponding to differential...... actions shall terminate. It is shown that the proposed differential action has a semantics which corresponds to a discrete approximation when the discrete step size goes to zero. The extension gives action systems the power to model real-time clocks and continuous evolutions within hybrid systems....
Uncertain differential equations
Yao, Kai
2016-01-01
This book introduces readers to the basic concepts of and latest findings in the area of differential equations with uncertain factors. It covers the analytic method and numerical method for solving uncertain differential equations, as well as their applications in the field of finance. Furthermore, the book provides a number of new potential research directions for uncertain differential equation. It will be of interest to researchers, engineers and students in the fields of mathematics, information science, operations research, industrial engineering, computer science, artificial intelligence, automation, economics, and management science.
Elementary differential geometry
Pressley, Andrew
2001-01-01
Curves and surfaces are objects that everyone can see, and many of the questions that can be asked about them are natural and easily understood Differential geometry is concerned with the precise mathematical formulation of some of these questions, and with trying to answer them using calculus techniques It is a subject that contains some of the most beautiful and profound results in mathematics yet many of these are accessible to higher-level undergraduates Elementary Differential Geometry presents the main results in the differential geometry of curves and surfaces while keeping the prerequisites to an absolute minimum Nothing more than first courses in linear algebra and multivariate calculus are required, and the most direct and straightforward approach is used at all times Numerous diagrams illustrate both the ideas in the text and the examples of curves and surfaces discussed there The book will provide an invaluable resource to all those taking a first course in differential geometry, for their lecture...
Geometry of differential equations
Khovanskiĭ, A; Vassiliev, V
1998-01-01
This volume contains articles written by V. I. Arnold's colleagues on the occasion of his 60th birthday. The articles are mostly devoted to various aspects of geometry of differential equations and relations to global analysis and Hamiltonian mechanics.
Problems in differential equations
Brenner, J L
2013-01-01
More than 900 problems and answers explore applications of differential equations to vibrations, electrical engineering, mechanics, and physics. Problem types include both routine and nonroutine, and stars indicate advanced problems. 1963 edition.
Beginning partial differential equations
O'Neil, Peter V
2014-01-01
A broad introduction to PDEs with an emphasis on specialized topics and applications occurring in a variety of fields Featuring a thoroughly revised presentation of topics, Beginning Partial Differential Equations, Third Edition provides a challenging, yet accessible,combination of techniques, applications, and introductory theory on the subjectof partial differential equations. The new edition offers nonstandard coverageon material including Burger's equation, the telegraph equation, damped wavemotion, and the use of characteristics to solve nonhomogeneous problems. The Third Edition is or
Stochastic partial differential equations
Chow, Pao-Liu
2014-01-01
Preliminaries Introduction Some Examples Brownian Motions and Martingales Stochastic Integrals Stochastic Differential Equations of Itô Type Lévy Processes and Stochastic IntegralsStochastic Differential Equations of Lévy Type Comments Scalar Equations of First Order Introduction Generalized Itô's Formula Linear Stochastic Equations Quasilinear Equations General Remarks Stochastic Parabolic Equations Introduction Preliminaries Solution of Stochastic Heat EquationLinear Equations with Additive Noise Some Regularity Properties Stochastic Reaction-Diffusion Equations Parabolic Equations with Grad
Differential geometry and thermodynamics
Quevedo, H
2003-01-01
In this work we present the first steps of a new approach to the study of thermodynamics in the context of differential geometry. We introduce a fundamental differential 1-form and a metric on a pseudo-Euclidean manifold coordinatized by means of the extensive thermodynamic variables. The study of the connection and the curvature of these objects is initialized in this work by using Cartan structure equations. (Author)
Differential topology an introduction
Gauld, David B
2006-01-01
Offering classroom-proven results, Differential Topology presents an introduction to point set topology via a naive version of nearness space. Its treatment encompasses a general study of surgery, laying a solid foundation for further study and greatly simplifying the classification of surfaces.This self-contained treatment features 88 helpful illustrations. Its subjects include topological spaces and properties, some advanced calculus, differentiable manifolds, orientability, submanifolds and an embedding theorem, and tangent spaces. Additional topics comprise vector fields and integral curv
Ordinary differential equations
Greenberg, Michael D
2014-01-01
Features a balance between theory, proofs, and examples and provides applications across diverse fields of study Ordinary Differential Equations presents a thorough discussion of first-order differential equations and progresses to equations of higher order. The book transitions smoothly from first-order to higher-order equations, allowing readers to develop a complete understanding of the related theory. Featuring diverse and interesting applications from engineering, bioengineering, ecology, and biology, the book anticipates potential difficulties in understanding the various solution steps
A convenient differential category
Blute, Richard; Tasson, Christine
2010-01-01
In this paper, we show that the category of Mackey-complete, separated, topological convex bornological vector spaces and bornological linear maps is a differential category. Such spaces were introduced by Fr\\"olicher and Kriegl, where they were called convenient vector spaces. While much of the structure necessary to demonstrate this observation is already contained in Fr\\"olicher and Kriegl's book, we here give a new interpretation of the category of convenient vector spaces as a model of the differential linear logic of Ehrhard and Regnier. Rather than base our proof on the abstract categorical structure presented by Fr\\"olicher and Kriegl, we prefer to focus on the bornological structure of convenient vector spaces. We believe bornological structures will ultimately yield a wide variety of models of differential logics.
Differentiation of real functions
Bruckner, Andrew
1994-01-01
Topics related to the differentiation of real functions have received considerable attention during the last few decades. This book provides an efficient account of the present state of the subject. Bruckner addresses in detail the problems that arise when dealing with the class \\Delta ' of derivatives, a class that is difficult to handle for a number of reasons. Several generalized forms of differentiation have assumed importance in the solution of various problems. Some generalized derivatives are excellent substitutes for the ordinary derivative when the latter is not known to exist; others are not. Bruckner studies generalized derivatives and indicates "geometric" conditions that determine whether or not a generalized derivative will be a good substitute for the ordinary derivative. There are a number of classes of functions closely linked to differentiation theory, and these are examined in some detail. The book unifies many important results from the literature as well as some results not previously pub...
[Differential diagnosis of hoarseness].
Voigt-Zimmermann, S; Lampe, K; Arens, C
2014-04-01
Hoarseness can be the leading symptom of dysphonia. In combination with impaired vocal performance and subjective voice-related discomfort, it can represent an individually different handicap for patients and lead to limited participation in social and professional life. Since the reasons for dysphonia may be not only functional but also organic with a potentially poor prognosis, hoarseness must be clarified using differential diagnosis. In addition to the knowledge of possible diseases, pathogenesis, and treatment options for dysphonia, the differential diagnostic approach requires profound knowledge of the various diagnostic methods, and of the interpretation of the results in particular. The etiology of dysphonia is very diverse and rarely monocausal. Therefore, a team-based and interdisciplinary differential diagnostic approach is recommended.
Zheng, Fangyang
2002-01-01
The theory of complex manifolds overlaps with several branches of mathematics, including differential geometry, algebraic geometry, several complex variables, global analysis, topology, algebraic number theory, and mathematical physics. Complex manifolds provide a rich class of geometric objects, for example the (common) zero locus of any generic set of complex polynomials is always a complex manifold. Yet complex manifolds behave differently than generic smooth manifolds; they are more coherent and fragile. The rich yet restrictive character of complex manifolds makes them a special and interesting object of study. This book is a self-contained graduate textbook that discusses the differential geometric aspects of complex manifolds. The first part contains standard materials from general topology, differentiable manifolds, and basic Riemannian geometry. The second part discusses complex manifolds and analytic varieties, sheaves and holomorphic vector bundles, and gives a brief account of the surface classifi...
Partial differential equations
Evans, Lawrence C
2010-01-01
This text gives a comprehensive survey of modern techniques in the theoretical study of partial differential equations (PDEs) with particular emphasis on nonlinear equations. The exposition is divided into three parts: representation formulas for solutions; theory for linear partial differential equations; and theory for nonlinear partial differential equations. Included are complete treatments of the method of characteristics; energy methods within Sobolev spaces; regularity for second-order elliptic, parabolic, and hyperbolic equations; maximum principles; the multidimensional calculus of variations; viscosity solutions of Hamilton-Jacobi equations; shock waves and entropy criteria for conservation laws; and, much more.The author summarizes the relevant mathematics required to understand current research in PDEs, especially nonlinear PDEs. While he has reworked and simplified much of the classical theory (particularly the method of characteristics), he primarily emphasizes the modern interplay between funct...
Advanced differential quadrature methods
Zong, Zhi
2009-01-01
Modern Tools to Perform Numerical DifferentiationThe original direct differential quadrature (DQ) method has been known to fail for problems with strong nonlinearity and material discontinuity as well as for problems involving singularity, irregularity, and multiple scales. But now researchers in applied mathematics, computational mechanics, and engineering have developed a range of innovative DQ-based methods to overcome these shortcomings. Advanced Differential Quadrature Methods explores new DQ methods and uses these methods to solve problems beyond the capabilities of the direct DQ method.After a basic introduction to the direct DQ method, the book presents a number of DQ methods, including complex DQ, triangular DQ, multi-scale DQ, variable order DQ, multi-domain DQ, and localized DQ. It also provides a mathematical compendium that summarizes Gauss elimination, the Runge-Kutta method, complex analysis, and more. The final chapter contains three codes written in the FORTRAN language, enabling readers to q...
Differentially Private Spatial Decompositions
Cormode, Graham; Shen, Entong; Srivastava, Divesh; Yu, Ting
2011-01-01
Differential privacy has recently emerged as the de facto standard for private data release. This makes it possible to provide strong theoretical guarantees on the privacy and utility of released data. While it is well-known how to release data based on counts and simple functions under this guarantee, it remains to provide general purpose techniques to release different kinds of data. In this paper, we focus on spatial data such as locations and more generally any data that can be indexed by a tree structure. Directly applying existing differential privacy methods to this type of data simply generates noise. Instead, we introduce a new class of "private spatial decompositions": these adapt standard spatial indexing methods such as quadtrees and kd-trees to provide a private description of the data distribution. Equipping such structures with differential privacy requires several steps to ensure that they provide meaningful privacy guarantees. Various primitives, such as choosing splitting points and describi...
Overshooting by differential heating
Andrássy, R
2015-01-01
On the long nuclear time scale of stellar main-sequence evolution, even weak mixing processes can become relevant for redistributing chemical species in a star. We investigate a process of "differential heating," which occurs when a temperature fluctuation propagates by radiative diffusion from the boundary of a convection zone into the adjacent radiative zone. The resulting perturbation of the hydrostatic equilibrium causes a flow that extends some distance from the convection zone. We study a simplified differential-heating problem with a static temperature fluctuation imposed on a solid boundary. The astrophysically relevant limit of a high Reynolds number and a low P\\'eclet number (high thermal diffusivity) turns out to be interestingly non-intuitive. We derive a set of scaling relations for the stationary differential heating flow. A numerical method adapted to a high dynamic range in flow amplitude needed to detect weak flows is presented. Our two-dimensional simulations show that the flow reaches a sta...
Digital Differential Geometry Processing
Xin-Guo Liu; Hu-Jun Bao; Qun-Sheng Peng
2006-01-01
The theory and methods of digital geometry processing has been a hot research area in computer graphics, as geometric models serves as the core data for 3D graphics applications. The purpose of this paper is to introduce some recent advances in digital geometry processing, particularly mesh fairing, surface parameterization and mesh editing, that heavily use differential geometry quantities. Some related concepts from differential geometry, such as normal, curvature, gradient,Laplacian and their counterparts on digital geometry are also reviewed for understanding the strength and weakness of various digital geometry processing methods.
Introduction to differential equations
Taylor, Michael E
2011-01-01
The mathematical formulations of problems in physics, economics, biology, and other sciences are usually embodied in differential equations. The analysis of the resulting equations then provides new insight into the original problems. This book describes the tools for performing that analysis. The first chapter treats single differential equations, emphasizing linear and nonlinear first order equations, linear second order equations, and a class of nonlinear second order equations arising from Newton's laws. The first order linear theory starts with a self-contained presentation of the exponen
Correspondence Differential Ghost Imaging
Li, Ming-Fei; Luo, Kai-Hong; Wu, Ling-An; Fan, Heng
2013-01-01
Experimental data with digital masks and a theoretical analysis are presented for a nonlocal imaging scheme that we name correspondence differential ghost imaging (CDGI). It is shown that by conditional averaging of the information from the reference detector but with the negative signals inverted, the quality of the reconstructed images is, in general, superior to all other ghost imaging (GI) methods to date. The advantages of both differential GI and correspondence GI are combined, plus less data and shorter computation time are required to obtain equivalent quality images under the same conditions. This CDGI method offers a general approach applicable to all GI techniques, especially when objects with continuous gray tones are involved.
Numerical differential protection
Ziegler, Gerhard
2012-01-01
Differential protection is a fast and selective method of protection against short-circuits. It is applied in many variants for electrical machines, trans?formers, busbars, and electric lines.Initially this book covers the theory and fundamentals of analog and numerical differential protection. Current transformers are treated in detail including transient behaviour, impact on protection performance, and practical dimensioning. An extended chapter is dedicated to signal transmission for line protection, in particular, modern digital communication and GPS timing.The emphasis is then pla
Fractional Differential Equations
Jianping Zhao
2012-01-01
Full Text Available An extended fractional subequation method is proposed for solving fractional differential equations by introducing a new general ansätz and Bäcklund transformation of the fractional Riccati equation with known solutions. Being concise and straightforward, this method is applied to the space-time fractional coupled Burgers’ equations and coupled MKdV equations. As a result, many exact solutions are obtained. It is shown that the considered method provides a very effective, convenient, and powerful mathematical tool for solving fractional differential equations.
Hajimiri, Seyed-Ali (Inventor); Kee, Scott D. (Inventor); Aoki, Ichiro (Inventor)
2013-01-01
A cross-differential amplifier is provided. The cross-differential amplifier includes an inductor connected to a direct current power source at a first terminal. A first and second switch, such as transistors, are connected to the inductor at a second terminal. A first and second amplifier are connected at their supply terminals to the first and second switch. The first and second switches are operated to commutate the inductor between the amplifiers so as to provide an amplified signal while limiting the ripple voltage on the inductor and thus limiting the maximum voltage imposed across the amplifiers and switches.
Mathematical analysis differentiation and integration
Aramanovich, IG; Lyusternik, LA; Sneddon, I N
1965-01-01
Mathematical Analysis: Differentiation and Integration is devoted to two basic operations of mathematical analysis, differentiation and integration. The problems directly connected with the operations of differentiation and integration of functions of one or several variables are discussed, together with elementary generalizations of these operations. This volume is comprised of seven chapters and begins by considering the differentiation of functions of one variable and of n variables, paying particular attention to derivatives and differentials as well as their properties. The next chapter d
Differential Equations with Linear Algebra
Boelkins, Matthew R; Potter, Merle C
2009-01-01
Linearity plays a critical role in the study of elementary differential equations; linear differential equations, especially systems thereof, demonstrate a fundamental application of linear algebra. In Differential Equations with Linear Algebra, we explore this interplay between linear algebra and differential equations and examine introductory and important ideas in each, usually through the lens of important problems that involve differential equations. Written at a sophomore level, the text is accessible to students who have completed multivariable calculus. With a systems-first approach, t
Stochastic differential equations and applications
Friedman, Avner
2006-01-01
This text develops the theory of systems of stochastic differential equations, and it presents applications in probability, partial differential equations, and stochastic control problems. Originally published in two volumes, it combines a book of basic theory and selected topics with a book of applications.The first part explores Markov processes and Brownian motion; the stochastic integral and stochastic differential equations; elliptic and parabolic partial differential equations and their relations to stochastic differential equations; the Cameron-Martin-Girsanov theorem; and asymptotic es
Invariant differential operators
Dobrev, Vladimir K
2016-01-01
With applications in quantum field theory, elementary particle physics and general relativity, this two-volume work studies invariance of differential operators under Lie algebras, quantum groups, superalgebras including infinite-dimensional cases, Schrödinger algebras, applications to holography. This first volume covers the general aspects of Lie algebras and group theory.
Modified differential equations
Chartier, Philippe; Hairer, Ernst; Vilmart, Gilles
2007-01-01
Motivated by the theory of modified differential equations (backward error analysis) an approach for the construction of high order numerical integrators that preserve geometric properties of the exact flow is developed. This summarises a talk presented in honour of Michel Crouzeix.
[Cluster headache differential diagnosis].
Guégan-Massardier, Evelyne; Laubier, Cécile
2015-11-01
Cluster headache is characterized by disabling stereotyped headache. Early diagnosis allows appropriate treatment, unfortunately diagnostic errors are frequent. The main differential diagnoses are other primary or essential headaches. Migraine, more frequent and whose diagnosis is carried by excess, trigeminal neuralgia or other trigemino-autonomic cephalgia. Vascular or tumoral underlying condition can mimic cluster headache, neck and brain imaging is recommended, ideally MRI.
Bär, Christian; Schwarz, Matthias
2012-01-01
This volume contains a collection of well-written surveys provided by experts in Global Differential Geometry to give an overview over recent developments in Riemannian Geometry, Geometric Analysis and Symplectic Geometry. The papers are written for graduate students and researchers with a general interest in geometry, who want to get acquainted with the current trends in these central fields of modern mathematics.
Klasseledelse, inklusion og differentiering
Jørgensen, Christina; Mottelson, Martha
2014-01-01
Kapitlet behandler forholdet mellem de tre begreber klasseledelse, inklusion og differentiering og ser på, hvordan de folder sig ud i folkeskolens praksis. Der tages afsæt i en definition af klasseledelse som alle de redskaber, læreren tager i anvendelse med henblik på at få timen til tage form på...
Parametric Differentiation and Integration
Chen, Hongwei
2009-01-01
Parametric differentiation and integration under the integral sign constitutes a powerful technique for calculating integrals. However, this topic is generally not included in the undergraduate mathematics curriculum. In this note, we give a comprehensive review of this approach, and show how it can be systematically used to evaluate most of the…
Molecular Typing and Differentiation
In this chapter, general background and bench protocols are provided for a number of molecular typing techniques in common use today. Methods for the molecular typing and differentiation of microorganisms began to be widely adopted following the development of the polymerase chai...
Hepatocyte differentiation of mesenchymalstemcells
Xu-Bo Wu; Ran Tao
2012-01-01
BACKGROUND: Liver cell transplantation and bioartiifcial liver may provide metabolic support of liver function temporary and are prospective treatments for patients with liver failure. Mesenchymal stem cells (MSCs) are expected to be an ideal cell source for transplantation or liver tissue engineering, however the hepatic differentiation of MSCs is still insufifcient for clinical application. DATA SOURCES: A PubMed search on "mesenchymal stem cells","liver cell"and"hepatocyte differentiation"was performed on the topic, and the relevant articles published in the past ten years were reviewed. RESULTS:Hepatocyte-like cells differentiated from MSCs are a promising cell source for liver regeneration or tissue engineering. Although it is still a matter of debate as to whether MSC-derived hepatocytes may efifciently repopulate a host liver to provide adequate functional substitution, the majority of animal studies support that MSCs can become key players in liver-directed regenerative medicine. However the clinical application of human stem cells in the treatment of liver diseases is still in its infancy. CONCLUSIONS: Future studies are required to improve the efifcacy and consistency of hepatic differentiation from MSCs. It is necessary to better understand the mechanism to achieve transdifferentiation with high efifciency. More clinical trials are warranted to prove their efifcacy in the management of patients with liver failure.
Parametric Differentiation and Integration
Chen, Hongwei
2009-01-01
Parametric differentiation and integration under the integral sign constitutes a powerful technique for calculating integrals. However, this topic is generally not included in the undergraduate mathematics curriculum. In this note, we give a comprehensive review of this approach, and show how it can be systematically used to evaluate most of the…
Investigating typographic differentiation
Beier, Sofie; Dyson, Mary
2016-01-01
Text designers are likely to benefit from guidance on how to use typographic differentiation for emphasis. Three experiments use purposely-designed fonts to explore the size and nature of differences in the stylistic characteristics of fonts (weight, width, contrast, italic) which affect letter...
Differential Equation of Equilibrium
user
than the classical method in the solution of the aforementioned differential equation. Keywords: ... present a successful approximation of shell ... displacement function. .... only applicable to cylindrical shell subject to ..... (cos. 4. 4. 4. 3 β. + β. + β. -. = β. - β x x e ex. AL. xA w. Substituting equations (29); (30) and (31) into.
Ghrelin and cell differentiation
Geyang Xu; Yin Li; Wenjiao An; Weizhen Zhang
2008-01-01
Ghrelin, an endogenous ligand for the growth hormone secretagogue receptor, is a gastric hormone that has been found to have a wide variety of biological functions. This review summarizes our current understanding of the effects of ghrelin on cell differentiation and tissue development, with an emphasis on the lineage determination of mesenchymal stem cells.
Pseudo-differentiation syndrome
Dina Khalaf
2011-12-01
Full Text Available A patient with relapsed acute myeloid leukemia (AML (M2 FAB classification developed a differentiating syndrome upon receiving Decitabine therapy given with palliative intent. The patient presented with high grade fever, constitutional symptoms and severe chest symptoms with no underlying lung condition. Chest x-ray (CXR showed diffuse pulmonary infiltrates. Septic work up followed by intravenous broad spectrum antimicrobials did not improve his condition. Pan cultures’ results were repeatedly negative. Treatment with high dose Dexamethasone (DXM resulted in marked clinical and radiological improvement. Our patient initially presented with relapsed AML (M2 Fab classification with t (8; 21; negative FMS-like tyrosine kinase -internal tandem duplication (FLT3-ITD which are all good prognostic factors, yet the patient had an atypical clinical course with early frequent relapses, differentiation syndrome associated with Decitabine therapy and late in his disease, he developed a granulocytic sarcoma.
Supremum norm differentiability
I. E. Leonard
1983-01-01
Full Text Available The points of Gateaux and Fréchet differentiability of the norm in C(T,E are obtained, where T is a locally compact Hausdorff space and E is a real Banach space. Applications of these results are given to the space ℓ∞(E of all bounded sequences in E and to the space B(ℓ1,E of all bounded linear operators from ℓ1 into E
Differential equations with Mathematica
Abell, Martha L
2004-01-01
The Third Edition of the Differential Equations with Mathematica integrates new applications from a variety of fields,especially biology, physics, and engineering. The new handbook is also completely compatible with recent versions of Mathematica and is a perfect introduction for Mathematica beginners.* Focuses on the most often used features of Mathematica for the beginning Mathematica user* New applications from a variety of fields, including engineering, biology, and physics* All applications were completed using recent versions of Mathematica
Renormalizing Partial Differential Equations
Bricmont, J.; Kupiainen, A.
1994-01-01
In this review paper, we explain how to apply Renormalization Group ideas to the analysis of the long-time asymptotics of solutions of partial differential equations. We illustrate the method on several examples of nonlinear parabolic equations. We discuss many applications, including the stability of profiles and fronts in the Ginzburg-Landau equation, anomalous scaling laws in reaction-diffusion equations, and the shape of a solution near a blow-up point.
Arithmetic partial differential equations
Buium, Alexandru; Simanca, Santiago R.
2006-01-01
We develop an arithmetic analogue of linear partial differential equations in two independent ``space-time'' variables. The spatial derivative is a Fermat quotient operator, while the time derivative is the usual derivation. This allows us to ``flow'' integers or, more generally, points on algebraic groups with coordinates in rings with arithmetic flavor. In particular, we show that elliptic curves have certain canonical ``flows'' on them that are the arithmetic analogues of the heat and wave...
Differentiation in Classroom Practice
Mottelson, Martha
2015-01-01
Differentiation in School Practice is an ongoing research project currently being carried out in UCC’s research department by myself and my coworker Christina Jørgensen. The project includes a field study of everyday life in a Danish 5th grade classroom with the aim to observe, describe and analy...... those everyday practices in the classroom that ultimately result in offering students different positions, identities and opportunities for participation....
Differential equations I essentials
REA, Editors of
2012-01-01
REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Differential Equations I covers first- and second-order equations, series solutions, higher-order linear equations, and the Laplace transform.
Differentially Private Distributed Sensing
Fink, Glenn A.
2016-12-11
The growth of the Internet of Things (IoT) creates the possibility of decentralized systems of sensing and actuation, potentially on a global scale. IoT devices connected to cloud networks can offer Sensing and Actuation as a Service (SAaaS) enabling networks of sensors to grow to a global scale. But extremely large sensor networks can violate privacy, especially in the case where IoT devices are mobile and connected directly to the behaviors of people. The thesis of this paper is that by adapting differential privacy (adding statistically appropriate noise to query results) to groups of geographically distributed sensors privacy could be maintained without ever sending all values up to a central curator and without compromising the overall accuracy of the data collected. This paper outlines such a scheme and performs an analysis of differential privacy techniques adapted to edge computing in a simulated sensor network where ground truth is known. The positive and negative outcomes of employing differential privacy in distributed networks of devices are discussed and a brief research agenda is presented.
Is Titan Partially Differentiated?
Mitri, G.; Pappalardo, R. T.; Stevenson, D. J.
2009-12-01
The recent measurement of the gravity coefficients from the Radio Doppler data of the Cassini spacecraft has improved our knowledge of the interior structure of Titan (Rappaport et al. 2008 AGU, P21A-1343). The measured gravity field of Titan is dominated by near hydrostatic quadrupole components. We have used the measured gravitational coefficients, thermal models and the hydrostatic equilibrium theory to derive Titan's interior structure. The axial moment of inertia gives us an indication of the degree of the interior differentiation. The inferred axial moment of inertia, calculated using the quadrupole gravitational coefficients and the Radau-Darwin approximation, indicates that Titan is partially differentiated. If Titan is partially differentiated then the interior must avoid melting of the ice during its evolution. This suggests a relatively late formation of Titan to avoid the presence of short-lived radioisotopes (Al-26). This also suggests the onset of convection after accretion to efficiently remove the heat from the interior. The outer layer is likely composed mainly of water in solid phase. Thermal modeling indicates that water could be present also in liquid phase forming a subsurface ocean between an outer ice I shell and a high pressure ice layer. Acknowledgments: This work was conducted at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.
Nth-order Fuzzy Differential Equations Under Generalized Differentiability
Soheil Salahshour
2011-11-01
Full Text Available In this paper, the multiple solutions of Nth-order fuzzy differential equations by the equivalent integral forms are considered. Also, an Existence and uniqueness theorem of solution of Nth-order fuzzy differential equations is proved under Nth-order generalized differentiability in Banach space.
Conservation laws, differential identities, and constraints of partial differential equations
Zharinov, V. V.
2015-11-01
We consider specific cohomological properties such as low-dimensional conservation laws and differential identities of systems of partial differential equations (PDEs). We show that such properties are inherent to complex systems such as evolution systems with constraints. The mathematical tools used here are the algebraic analysis of PDEs and cohomologies over differential algebras and modules.
Differential transimpedance amplifier circuit for correlated differential amplification
Gresham, Christopher A.; Denton, M. Bonner; Sperline, Roger P.
2008-07-22
A differential transimpedance amplifier circuit for correlated differential amplification. The amplifier circuit increase electronic signal-to-noise ratios in charge detection circuits designed for the detection of very small quantities of electrical charge and/or very weak electromagnetic waves. A differential, integrating capacitive transimpedance amplifier integrated circuit comprising capacitor feedback loops performs time-correlated subtraction of noise.
Differential invariants of second-order ordinary differential equations
Rosado Maria, Maria Eugenia
2011-01-01
The notion of a differential invariant for systems of second-order differential equations on a manifold M with respect to the group of vertical automorphisms of the projection is de?ned and the Chern connection attached to a SODE allows one to determine a basis for second-order differential invariants of a SODE.
Putting Differentials Back into Calculus
Dray, Tevian; Manogue, Corrine A.
2010-01-01
We argue that the use of differentials in introductory calculus courses is useful and provides a unifying theme, leading to a coherent view of the calculus. Along the way, we meet several interpretations of differentials, some better than others.
Putting Differentials Back into Calculus
Dray, Tevian; Manogue, Corrine A.
2010-01-01
We argue that the use of differentials in introductory calculus courses is useful and provides a unifying theme, leading to a coherent view of the calculus. Along the way, we meet several interpretations of differentials, some better than others.
Group valued differential forms revisited
Kock, Anders
We study the relationship between combinatorial group valued differential forms, and classical differential forms with values in the corresponding Lie algebra. In particular, we compare simplicial coboundary and exterior derivative for 1-forms. The results represent strengthenings of results...
Group valued differential forms revisited
Kock, Anders
We study the relationship between combinatorial group valued differential forms, and classical differential forms with values in the corresponding Lie algebra. In particular, we compare simplicial coboundary and exterior derivative for 1-forms. The results represent strengthenings of results...
On Degenerate Partial Differential Equations
Chen, Gui-Qiang G.
2010-01-01
Some of recent developments, including recent results, ideas, techniques, and approaches, in the study of degenerate partial differential equations are surveyed and analyzed. Several examples of nonlinear degenerate, even mixed, partial differential equations, are presented, which arise naturally in some longstanding, fundamental problems in fluid mechanics and differential geometry. The solution to these fundamental problems greatly requires a deep understanding of nonlinear degenerate parti...
Auto-Zero Differential Amplifier
Quilligan, Gerard T. (Inventor); Aslam, Shahid (Inventor)
2017-01-01
An autozero amplifier may include a window comparator network to monitor an output offset of a differential amplifier. The autozero amplifier may also include an integrator to receive a signal from a latched window comparator network, and send an adjustment signal back to the differential amplifier to reduce an offset of the differential amplifier.
Solving systems of fractional differential equations using differential transform method
Erturk, Vedat Suat; Momani, Shaher
2008-05-01
This paper presents approximate analytical solutions for systems of fractional differential equations using the differential transform method. The fractional derivatives are described in the Caputo sense. The application of differential transform method, developed for differential equations of integer order, is extended to derive approximate analytical solutions of systems of fractional differential equations. The solutions of our model equations are calculated in the form of convergent series with easily computable components. Some examples are solved as illustrations, using symbolic computation. The numerical results show that the approach is easy to implement and accurate when applied to systems of fractional differential equations. The method introduces a promising tool for solving many linear and nonlinear fractional differential equations.
Differential operator multiplication method for fractional differential equations
Tang, Shaoqiang; Ying, Yuping; Lian, Yanping; Lin, Stephen; Yang, Yibo; Wagner, Gregory J.; Liu, Wing Kam
2016-08-01
Fractional derivatives play a very important role in modeling physical phenomena involving long-range correlation effects. However, they raise challenges of computational cost and memory storage requirements when solved using current well developed numerical methods. In this paper, the differential operator multiplication method is proposed to address the issues by considering a reaction-advection-diffusion equation with a fractional derivative in time. The linear fractional differential equation is transformed into an integer order differential equation by the proposed method, which can fundamentally fix the aforementioned issues for select fractional differential equations. In such a transform, special attention should be paid to the initial conditions for the resulting differential equation of higher integer order. Through numerical experiments, we verify the proposed method for both fractional ordinary differential equations and partial differential equations.
Investigating typographic differentiation
Beier, Sofie
2016-01-01
Text designers are likely to benefit from guidance on how to use typographic differentiation for emphasis. Three experiments use purposely-designed fonts to explore the size and nature of differences in the stylistic characteristics of fonts (weight, width, contrast, italic) which affect letter...... identification. Results indicate that words set in bold and expanded fonts, when alternated with words set in a Neutral test font, may impair performance, whereas changing to italic does not. Possible explanations are explored through measuring the physical and perceptual similarities of the test fonts...
Boolean differential equations
Steinbach, Bernd
2013-01-01
The Boolean Differential Calculus (BDC) is a very powerful theory that extends the structure of a Boolean Algebra significantly. Based on a small number of definitions, many theorems have been proven. The available operations have been efficiently implemented in several software packages. There is a very wide field of applications. While a Boolean Algebra is focused on values of logic functions, the BDC allows the evaluation of changes of function values. Such changes can be explored for pairs of function values as well as for whole subspaces. Due to the same basic data structures, the BDC can
Partial differential equations
Sloan, D; Süli, E
2001-01-01
/homepage/sac/cam/na2000/index.html7-Volume Set now available at special set price ! Over the second half of the 20th century the subject area loosely referred to as numerical analysis of partial differential equations (PDEs) has undergone unprecedented development. At its practical end, the vigorous growth and steady diversification of the field were stimulated by the demand for accurate and reliable tools for computational modelling in physical sciences and engineering, and by the rapid development of computer hardware and architecture. At the more theoretical end, the analytical insight in
Pulsed differential pumping system
Antipov, G.N.; Bagautdinov, F.A.; Rybalov, S.V.
1985-06-01
A pulsed differential pumping system is described for extracting an electron beam from a shaping region at a pressure of 10/sup -5/ torr into a volume with a pressure of 10-100 torr. A fast valve is used with appropriate geometrical parameters to reduce the length of the outlet channel considerable while increasing its diameter. Test results are given. The pumping system has two sections which communicate one with the other and with the volume at the elevated pressure which is produced by gasdynamic nozzles.
Differentiating among penal states.
Lacey, Nicola
2010-12-01
This review article assesses Loïc Wacquant's contribution to debates on penality, focusing on his most recent book, Punishing the Poor: The Neoliberal Government of Social Insecurity (Wacquant 2009), while setting its argument in the context of his earlier Prisons of Poverty (1999). In particular, it draws on both historical and comparative methods to question whether Wacquant's conception of 'the penal state' is adequately differentiated for the purposes of building the explanatory account he proposes; about whether 'neo-liberalism' has, materially, the global influence which he ascribes to it; and about whether, therefore, the process of penal Americanization which he asserts in his recent writings is credible.
Partial differential equations
Friedman, Avner
2008-01-01
This three-part treatment of partial differential equations focuses on elliptic and evolution equations. Largely self-contained, it concludes with a series of independent topics directly related to the methods and results of the preceding sections that helps introduce readers to advanced topics for further study. Geared toward graduate and postgraduate students of mathematics, this volume also constitutes a valuable reference for mathematicians and mathematical theorists.Starting with the theory of elliptic equations and the solution of the Dirichlet problem, the text develops the theory of we
Partial differential equations
Levine, Harold
1997-01-01
The subject matter, partial differential equations (PDEs), has a long history (dating from the 18th century) and an active contemporary phase. An early phase (with a separate focus on taut string vibrations and heat flow through solid bodies) stimulated developments of great importance for mathematical analysis, such as a wider concept of functions and integration and the existence of trigonometric or Fourier series representations. The direct relevance of PDEs to all manner of mathematical, physical and technical problems continues. This book presents a reasonably broad introductory account of the subject, with due regard for analytical detail, applications and historical matters.
Ordinary differential equations
Cox, William
1995-01-01
Building on introductory calculus courses, this text provides a sound foundation in the underlying principles of ordinary differential equations. Important concepts, including uniqueness and existence theorems, are worked through in detail and the student is encouraged to develop much of the routine material themselves, thus helping to ensure a solid understanding of the fundamentals required.The wide use of exercises, problems and self-assessment questions helps to promote a deeper understanding of the material and it is developed in such a way that it lays the groundwork for further
Free graded differential superalgebras
van Nieuwenhuizen, P.
Two theorems of D. Sullivan on the structure of differential algebras are extended to the algebras mentioned in the title and a few applications of nontrivial cohomology classes to the gauging of extended groups are given. The applications are due to R. D'Auria, L. Castellani, P. Fré, F. Giani, K. Pilch and the author, and are discussed in more detail in the author's talk at the 1982 Chicago Meeting of the American Mathematical Society on group-theoretical methods in physics.
Differential diagnosis of tonsillolith
Luisa Schertel Cassiano
2010-07-01
Full Text Available Introduction:Tonsillolith is a rare type of dystrophic calcification in the palatine tonsils or in the peritonsilar region, which can mimics several intraosseous radiopaque lesions when evaluated by two-dimensional or overlapping images.This may lead to an erroneous diagnosis and to invasive and unnecessary procedures.This study reports a case of tonsillolith that was wrongly diagnosed as an odontoma. Case report: A patient with primary diagnosis of odontoma in the mandibular ramus was referred to surgical treatment of this lesion. Conclusion: Computed tomography (CT scans are fundamentally important to establish differential diagnosis and appropriate treatment for the patient.
Differentiation in online retailing
Kellner, Julian; Wagner, Gerhard; Zielke, Stephan
Due to the highly competitive nature of the online retail environment, differentiation strategies are of importance for online retailers to gain competitive advantages and to achieve a unique positioning in the market. However, little is known about perceptual dimensions used by consumers to make...... a distinction between online retailers. The present study addresses this research gap by using a repertory grid approach to identify points of difference between online retailers from a consumer’s perspective. The results have important implications for positioning strategies of online retailers and research...
Differentiation in online retailing
Kellner, Julian; Wagner, Gerhard; Zielke, Stephan;
Due to the highly competitive nature of the online retail environment, differentiation strategies are of importance for online retailers to gain competitive advantages and to achieve a unique positioning in the market. However, little is known about perceptual dimensions used by consumers to make...... a distinction between online retailers. The present study addresses this research gap by using a repertory grid approach to identify points of difference between online retailers from a consumer’s perspective. The results have important implications for positioning strategies of online retailers and research...... on online store formats....
On the path to differentiation
Martinsen, Dorte Sindbjerg; Uygur, Ayca
2014-01-01
by examining the ‘path to differentiation’ within EU working time regulation as it has unfolded over time. It identifies the ‘opt-out’ as a means of differentiation adopted to overcome policy deadlocks within collective decision-making, albeit one with unforeseen consequences. In particular, the contribution...... investigates the causes and effects of differentiation by examining (1) its origin, (2) the ‘logic of variation’ or ‘opt-out spiral’ that spurs differentiation and (3) the implications of differentiation over time. We conclude that differentiation has dynamic and broad consequences that are likely to produce...
Differential diagnosis diphtheria adults
Yu. I. Liashenko
2010-01-01
Full Text Available A total of 1,824 human cases of diphtheria, treated at the Clinical Infectious Diseases Hospital SP Botkin (St. Petersburg during 1993, as well as 19 deaths in 1994. It is known that early diagnosis of infectious diseases, especially diphtheria, contributes to the favorable outcome of the disease. The diagnosis of diphtheria at the prehospital stage is always difficult. Presented in detail the differential diagnosis of the disease, clinically similar to diphtheria: Lacunal angina, angina Simanovsky, infectious mononucleosis, angina Ludwig’s angina Dugue, syphilis, non-infectious with clinical «masks» of diphtheria and other. Diphtheria epidemic of 1993–1994 in Russia and, in particular, in St. Petersburg, showed that the late admission of patients with diphtheria infection in hospitals, usually associated with irregular differential diagnosis of this dangerous disease.
Differential diagnosis of hyponatraemia.
Thompson, Chris
2012-03-01
The appropriate management of hyponatraemia is reliant on the accurate identification of the underlying cause of the hyponatraemia. In the light of evidence which has shown that the use of a clinical algorithm appears to improve accuracy in the differential diagnosis of hyponatraemia, the European Hyponatraemia Network considered the use of two algorithms. One was developed from a nephrologist\\'s view of hyponatraemia, while the other reflected the approach of an endocrinologist. Both of these algorithms concurred on the importance of assessing effective blood volume status and the measurement of urine sodium concentration in the diagnostic process. To demonstrate the importance of accurate diagnosis to the correct treatment of hyponatraemia, special consideration was given to hyponatraemia in neurosurgical patients. The differentiation between the syndrome of inappropriate antidiuretic hormone secretion (SIADH), acute adrenocorticotropic hormone (ACTH) deficiency, fluid overload and cerebral salt-wasting syndrome was discussed. In patients with SIADH, fluid restriction has been the mainstay of treatment despite the absence of an evidence base for its use. An approach to using fluid restriction to raise serum tonicity in patients with SIADH and to identify patients who are likely to be recalcitrant to fluid restriction was also suggested.
Abnormalities of gonadal differentiation.
Berkovitz, G D; Seeherunvong, T
1998-04-01
Gonadal differentiation involves a complex interplay of developmental pathways. The sex determining region Y (SRY) gene plays a key role in testis determination, but its interaction with other genes is less well understood. Abnormalities of gonadal differentiation result in a range of clinical problems. 46,XY complete gonadal dysgenesis is defined by an absence of testis determination. Subjects have female external genitalia and come to clinical attention because of delayed puberty. Individuals with 46,XY partial gonadal dysgenesis usually present in the newborn period for the valuation of ambiguous genitalia. Gonadal histology always shows an abnormality of seminiferous tubule formation. A diagnosis of 46,XY true hermaphroditism is made if the gonads contain well-formed testicular and ovarian elements. Despite the pivotal role of the SRY gene in testis development, mutations of SRY are unusual in subjects with a 46,XY karyotype and abnormal gonadal development. 46,XX maleness is defined by testis determination in an individual with a 46,XX karyotype. Most affected individuals have a phenotype similar to that of Klinefelter syndrome. In contrast, subjects with 46,XX true hermaphroditism usually present with ambiguous genitalia. The majority of subjects with 46,XX maleness have Y sequences including SRY in genomic DNA. However, only rare subjects with 46,XX true hermaphroditism have translocated sequences encoding SRY. Mosaicism and chimaerism involving the Y chromosome can also be associated with abnormal gonadal development. However, the vast majority of subjects with 45,X/46,XY mosaicism have normal testes and normal male external genitalia.
Applied partial differential equations
Logan, J David
2004-01-01
This primer on elementary partial differential equations presents the standard material usually covered in a one-semester, undergraduate course on boundary value problems and PDEs. What makes this book unique is that it is a brief treatment, yet it covers all the major ideas: the wave equation, the diffusion equation, the Laplace equation, and the advection equation on bounded and unbounded domains. Methods include eigenfunction expansions, integral transforms, and characteristics. Mathematical ideas are motivated from physical problems, and the exposition is presented in a concise style accessible to science and engineering students; emphasis is on motivation, concepts, methods, and interpretation, rather than formal theory. This second edition contains new and additional exercises, and it includes a new chapter on the applications of PDEs to biology: age structured models, pattern formation; epidemic wave fronts, and advection-diffusion processes. The student who reads through this book and solves many of t...
Scaling of differential equations
Langtangen, Hans Petter
2016-01-01
The book serves both as a reference for various scaled models with corresponding dimensionless numbers, and as a resource for learning the art of scaling. A special feature of the book is the emphasis on how to create software for scaled models, based on existing software for unscaled models. Scaling (or non-dimensionalization) is a mathematical technique that greatly simplifies the setting of input parameters in numerical simulations. Moreover, scaling enhances the understanding of how different physical processes interact in a differential equation model. Compared to the existing literature, where the topic of scaling is frequently encountered, but very often in only a brief and shallow setting, the present book gives much more thorough explanations of how to reason about finding the right scales. This process is highly problem dependent, and therefore the book features a lot of worked examples, from very simple ODEs to systems of PDEs, especially from fluid mechanics. The text is easily accessible and exam...
Kousholt, Kristine
This presentation will explore how educational standardized testing becomes meaningful/not meaningful for children and teachers and at the same time how testing becomes part of everyday differentiation and categorization processes. The presentation is based on a 3 year long post doc project...... concerning the practice of standardized testing in the Danish primary and lower secondary school (Folkeskole). The empirical material consists of qualitative interviews of pupils and teachers and participative observations both in and outside test situations in 5 school classes. The theoretical basis...... is the Danish-German Critical Psychology which emerged from cultural historical activity theory and from the work of Klaus Holzkamp. This theoretical framework offers a historical dialectical materialism outset and understanding of children’s participation and action reasoning in and across test situations...
Koszul differential graded modules
HE JiWei; WU QuanShui
2009-01-01
The concept of Koszulity for differential graded (DG, for short) modules is introduced. It is shown that any bounded below DG module with bounded Ext-group to the trivial module over a Koszul DG algebra has a Koszul DG submodule (up to a shift and truncation), moreover such a DG module can be approximated by Koszul DG modules (Theorem 3.6). Let A be a Koszul DG algebra, and Dc (A) be the full triangulated subcategory of the derived category of DG A-modules generated by the object AA. If the trivial DG module kA lies in Dc(A), then the heart of the standard t-structure on Dc(A) is anti-equivalent to the category of finitely generated modules over some finite dimensional algebra. As a corollary, Dc(A) is equivalent to the bounded derived category of its heart as triangulated categories.
Koszul differential graded modules
2009-01-01
The concept of Koszulity for differential graded (DG, for short) modules is introduced. It is shown that any bounded below DG module with bounded Ext-group to the trivial module over a Koszul DG algebra has a Koszul DG submodule (up to a shift and truncation), moreover such a DG module can be approximated by Koszul DG modules (Theorem 3.6). Let A be a Koszul DG algebra, and Dc(A) be the full triangulated subcategory of the derived category of DG A-modules generated by the object AA. If the trivial DG module kA lies in Dc(A), then the heart of the standard t-structure on Dc(A) is anti-equivalent to the category of finitely generated modules over some finite dimensional algebra. As a corollary, Dc(A) is equivalent to the bounded derived category of its heart as triangulated categories.
DNA microarray analysis of genes differentially expressed in adipocyte differentiation
Chunyan Yin; Yanfeng Xiao; Wei Zhang; Erdi Xu; Weihua Liu; Xiaoqing Yi; Ming Chang
2014-06-01
In the present study, the human liposarcoma cell line SW872 was used to identify global changes in gene expression profiles occurring during adipogenesis. We further explored some of the genes expressed during the late phase of adipocyte differentiation. These genes may play a major role in promoting excessive proliferation and accumulation of lipid droplets, which contribute to the development of obesity. By using microarray-based technology, we examined differential gene expression in early differentiated adipocytes and late differentiated adipocytes. Validated genes exhibited a ≥ 10-fold increase in the late phase of adipocyte differentiation by polymerase chain reaction (RT-PCR). Compared with undifferentiated preadipocytes, we found that 763 genes were increased in early differentiated adipocytes, and 667 genes were increased in later differentiated adipocytes. Furthermore, 21 genes were found being expressed 10-fold higher in the late phase of adipocyte differentiation. The results were in accordance with the RT-PCR test, which validated 11 genes, namely, CIDEC, PID1, LYRM1, ADD1, PPAR2, ANGPTL4, ADIPOQ, ACOX1, FIP1L1, MAP3K2 and PEX14. Most of these genes were found being expressed in the later phase of adipocyte differentiation involved in obesity-related diseases. The findings may help to better understand the mechanism of obesity and related diseases.
Differential and holomorphic differential operators on noncommutative algebras
Beggs, E.
2015-07-01
This paper deals with sheaves of differential operators on noncommutative algebras, in a manner related to the classical theory of D-modules. The sheaves are defined by quotienting the tensor algebra of vector fields (suitably deformed by a covariant derivative). As an example we can obtain enveloping algebra like relations for Hopf algebras with differential structures which are not bicovariant. Symbols of differential operators are defined, but not studied. These sheaves are shown to be in the center of a category of bimodules with flat bimodule covariant derivatives. Also holomorphic differential operators are considered.
DNA microarray analysis of genes differentially expressed in adipocyte differentiation.
Yin, Chunyan; Xiao, Yanfeng; Zhang, Wei; Xu, Erdi; Liu, Weihua; Yi, Xiaoqing; Chang, Ming
2014-06-01
In the present study, the human liposarcoma cell line SW872 was used to identify global changes in gene expression profiles occurring during adipogenesis. We further explored some of the genes expressed during the late phase of adipocyte differentiation. These genes may play a major role in promoting excessive proliferation and accumulation of lipid droplets, which contribute to the development of obesity. By using microarray-based technology, we examined differential gene expression in early differentiated adipocytes and late differentiated adipocytes. Validated genes exhibited a greater than or equal to 10-fold increase in the late phase of adipocyte differentiation by polymerase chain reaction (RT-PCR). Compared with undifferentiated preadipocytes, we found that 763 genes were increased in early differentiated adipocytes, and 667 genes were increased in later differentiated adipocytes. Furthermore, 21 genes were found being expressed 10-fold higher in the late phase of adipocyte differentiation. The results were in accordance with the RTPCR test, which validated 11 genes, namely, CIDEC, PID1, LYRM1, ADD1, PPAR?2, ANGPTL4, ADIPOQ, ACOX1, FIP1L1, MAP3K2 and PEX14. Most of these genes were found being expressed in the later phase of adipocyte differentiation involved in obesity-related diseases. The findings may help to better understand the mechanism of obesity and related diseases.
Pseudo-differentiation syndrome
Fathi Jehani
2011-01-01
Full Text Available
A patient with relapsed acute myeloid leukemia (AML (M2 FAB classification developed a differentiating syndrome upon receiving Decitabine therapy given with palliative intent. The patient presented with high grade fever, constitutional symptoms and severe chest symptoms with no underlying lung condition. Chest x-ray (CXR showed diffuse pulmonary infiltrates. Septic work up followed by intravenous broad spectrum antimicrobials did not improve his condition. Pan cultures’ results were repeatedly negative. Treatment with high dose Dexamethasone (DXM resulted in marked clinical and radiological improvement.
Our patient initially presented with relapsed AML (M2 Fab classification with t (8; 21; negative FMS-like tyrosine kinase -internal tandem duplication (FLT3-ITD which are all good prognostic factors, yet the patient had an atypical clinical course with early frequent relapses, differentiation syndrome associated with Decitabine therapy and late in his disease, he developed a granulocytic sarcoma.
[Communication disorders: differential diagnosis].
Campos-Castelló, J; Briceño-Cuadros, S
To evaluate components of clinical semiology in the differential diagnosis of communication disorders (TC) and their possible biological markers. We consider two groups, according to the communication disorders themselves and their effects on social interaction. In the first case both aspects are affected in parallel and in the second it is predominantly social interaction which is affected. In the first groups we studied dyslalias, dyrhrythmias, acquired aphasias, TC relation to epilepsy, types of seizures and EEG discharges. The dysphasia of development and epilepsy may be associated by chance, as a result of the same cause or the epilepsy be responsible for the TC, either because of seizures or continuously (acquired epileptic aphasia, SLK). Based on personal data and the literature we studied the semiology, possible biological markers and differential diagnosis. We consider disorders of neurone migration and metabolic alterations of initial neuropsychological semiology and cerebellar anomalies involved in cognitive functions. In the second group we assessed autism, generalized disorders of development and particular syndromes with semantic pragmatic TC. The development of language cannot be separated from other aspects of neurological maturation. One cannot affirm that there is a direct relationship between epilepsy and TC, although this does occur in some cases. We accept the hypothesis that SLK, POCSL and atypical EPB are clinical forms of the same syndrome of epilepsy. Recognition of the cognitive affective cerebellar syndrome by its involvement in social executive function, language and personality characterizes certain conditions (Williams, Asperger, fragile X, autism). A progressive rational battery of complementary studies on clinical data is essential to determine biological markers in syndromes which still lack them.
Trypsin potentiates human fibrocyte differentiation.
Michael J V White
Full Text Available Trypsin-containing topical treatments can be used to speed wound healing, although the mechanism of action is unknown. To help form granulation tissue and heal wounds, monocytes leave the circulation, enter the wound tissue, and differentiate into fibroblast-like cells called fibrocytes. We find that 20 to 200 ng/ml trypsin (concentrations similar to those used in wound dressings potentiates the differentiation of human monocytes to fibrocytes in cell culture. Adding trypsin inhibitors increases the amount of trypsin needed to potentiate fibrocyte differentiation, suggesting that the potentiating effect is dependent on trypsin proteolytic activity. Proteases with other site specificities such as pepsin, endoprotease GluC, and chymotrypsin do not potentiate fibrocyte differentiation. This potentiation requires the presence of albumin in the culture medium, and tryptic fragments of human or bovine albumin also potentiate fibrocyte differentiation. These results suggest that topical trypsin speeds wound healing by generating tryptic fragments of albumin, which in turn potentiate fibrocyte differentiation.
Trypsin potentiates human fibrocyte differentiation.
White, Michael J V; Glenn, Melissa; Gomer, Richard H
2013-01-01
Trypsin-containing topical treatments can be used to speed wound healing, although the mechanism of action is unknown. To help form granulation tissue and heal wounds, monocytes leave the circulation, enter the wound tissue, and differentiate into fibroblast-like cells called fibrocytes. We find that 20 to 200 ng/ml trypsin (concentrations similar to those used in wound dressings) potentiates the differentiation of human monocytes to fibrocytes in cell culture. Adding trypsin inhibitors increases the amount of trypsin needed to potentiate fibrocyte differentiation, suggesting that the potentiating effect is dependent on trypsin proteolytic activity. Proteases with other site specificities such as pepsin, endoprotease GluC, and chymotrypsin do not potentiate fibrocyte differentiation. This potentiation requires the presence of albumin in the culture medium, and tryptic fragments of human or bovine albumin also potentiate fibrocyte differentiation. These results suggest that topical trypsin speeds wound healing by generating tryptic fragments of albumin, which in turn potentiate fibrocyte differentiation.
An introduction to differential manifolds
Lafontaine, Jacques
2015-01-01
This book is an introduction to differential manifolds. It gives solid preliminaries for more advanced topics: Riemannian manifolds, differential topology, Lie theory. It presupposes little background: the reader is only expected to master basic differential calculus, and a little point-set topology. The book covers the main topics of differential geometry: manifolds, tangent space, vector fields, differential forms, Lie groups, and a few more sophisticated topics such as de Rham cohomology, degree theory and the Gauss-Bonnet theorem for surfaces. Its ambition is to give solid foundations. In particular, the introduction of “abstract” notions such as manifolds or differential forms is motivated via questions and examples from mathematics or theoretical physics. More than 150 exercises, some of them easy and classical, some others more sophisticated, will help the beginner as well as the more expert reader. Solutions are provided for most of them. The book should be of interest to various readers: undergra...
Introduction to partial differential equations
Greenspan, Donald
2000-01-01
Designed for use in a one-semester course by seniors and beginning graduate students, this rigorous presentation explores practical methods of solving differential equations, plus the unifying theory underlying the mathematical superstructure. Topics include basic concepts, Fourier series, second-order partial differential equations, wave equation, potential equation, heat equation, approximate solution of partial differential equations, and more. Exercises appear at the ends of most chapters. 1961 edition.
Differential OTF Wavefront Sensing
Codona, Johanan L
2013-01-01
An image-based technique for measuring the complex field in the pupil of an imaging system is presented. Two point source images, one with a small modification introduced in the pupil, are combined using a simple and non-iterative algorithm. The non-interferometric method is based on the change in the optical transfer function (OTF), giving a differential OTF (dOTF). The dOTF includes two images of the complex pupil field, conjugated and reflected about the position of the pupil modification, leaving an overlap that obscures some the the pupil. The overlap can be minimized by introducing the modification near the edge of the pupil. The overlap region can be eliminated altogether by using a second modification and a third point source image. The pupil field is convolved by the change in the pupil field, so smaller modification areas are preferred. The non-monochromatic light, but the result incurs a proportional radial blurring determined by the fractional bandwidth. We include some simple demonstration experi...
Differential scanning calorimetry.
Spink, Charles H
2008-01-01
Differential scanning calorimetry (DSC) has emerged as a powerful experimental technique for determining thermodynamic properties of biomacromolecules. The ability to monitor unfolding or phase transitions in proteins, polynucleotides, and lipid assemblies has not only provided data on thermodynamic stability for these important molecules, but also made it possible to examine the details of unfolding processes and to analyze the characteristics of intermediate states involved in the melting of biopolymers. The recent improvements in DSC instrumentation and software have generated new opportunities for the study of the effects of structure and changes in environment on the behavior of proteins, nucleic acids, and lipids. This review presents some of the details of application of DSC to the examination of the unfolding of biomolecules. After a brief introduction to DSC instrumentation used for the study of thermal transitions, the methods for obtaining basic thermodynamic information from the DSC curve are presented. Then, using DNA unfolding as an example, methods for the analysis of the melting transition are presented that allow deconvolution of the DSC curves to determine more subtle characteristics of the intermediate states involved in unfolding. Two types of transitions are presented for analysis, the first example being the unfolding of two large synthetic polynucleotides, which display high cooperativity in the melting process. The second example shows the application of DSC for the study of the unfolding of a simple hairpin oligonucleotide. Details of the data analysis are presented in a simple spreadsheet format.
Practical Differential Profiling
Schulz, M; De Supinski, B R
2007-02-04
Comparing performance profiles from two runs is an essential performance analysis step that users routinely perform. In this work we present eGprof, a tool that facilitates these comparisons through differential profiling inside gprof. We chose this approach, rather than designing a new tool, since gprof is one of the few performance analysis tools accepted and used by a large community of users. eGprof allows users to 'subtract' two performance profiles directly. It also includes callgraph visualization to highlight the differences in graphical form. Along with the design of this tool, we present several case studies that show how eGprof can be used to find and to study the differences of two application executions quickly and hence can aid the user in this most common step in performance analysis. We do this without requiring major changes on the side of the user, the most important factor in guaranteeing the adoption of our tool by code teams.
Does brand differentiate pharmaceuticals?
Bednarik, Josef
2005-12-01
Role of marketing in pharmaceutical industry is increasing and inspiration by successful brands known from consumer goods market influenced pharmaceutical companies enough to switch their attention to branding initiatives. Still there is little evidence that pharmaceutical brands represent anything more than product only. This study aims to explore the area of branding in pharmaceutical industry. Central hypothesis of the research has been that brand and its emotional content differentiate pharmaceuticals as well as rational data derived from clinical studies. It has been tested by extensive review of available literature as well as by primary research focused on drivers of physicians' attitudes towards products and their influence on prescribing behavior. The research has been conducted in the sample of psychiatrists in the Czech Republic. No evidence about pharmaceutical brand exceeding value of product has been found in reviewed literature. Nevertheless, the primary research conducted in the sample of Czech psychiatrists indicates that emotional brand in pharmaceutical industry exists and enables author to draw a model of Customer/product life cycle that describes likely impact of functional, emotional and self-expressive benefits throughout pharmaceutical product's market presence. Pharmaceutical brand is likely to develop differently than the same of consumer goods products--it seems to be built predominantly on long-term positive experience. Marketing role in this process should lie in finding relevant product position and building brand identity compliant with real product capabilities.
Cognitive Differentiation in Intergroup Perception
Stephan, Walter G.
1977-01-01
Black, Chicano, and Anglo students from segregated and integrated schools perceived their ethnic groups as being less differentiated than outgroups. Students in integrated schools perceived outgroups as somewhat less differentiated than students in segregated schools. Intergroup contact, except between highly dissimilar groups, was not an…
LUROTH'S THEOREM IN DIFFERENTIAL FIELDS
GAO Xiaoshan; XU Tao
2002-01-01
In this paper, we present a constructive proof of Liroth's theorem in differentialcase. We also give a method to find the inversion maps for general differential rationalparametric equations. As a consequence, we prove that a differential rational curve alwayshas a set of proper parametric equations.
Intelligence Differentiation in Adult Samples.
Abad, Francisco J.; Colom, Robert; Juan-Espinosa, Manuel; Garcia, Luis F.
2003-01-01
Results for 3,340 participants taking a battery of cognitive tests and an analysis of the Spanish standardization of the Wechsler Adult Intelligence Scale-III support the differentiation of intelligence across the range of ability, with WAIS-III results more supportive of the differentiation theory. (SLD)
Thyroid differentiated carcinomas survey
Speich, P.V.; Couturier, M.; Mollet, E.; Bidet, R. (C.H.U., Besancon (France))
1982-01-01
We have adopted for the follow up of the differentiated thyroid carcinomas in adult cases, a protocol of control which is at the same time strict and not very constraining for the patient and which is based on two types of investigations. Most of your patients have been, at first, submitted for a total thyroidectomy which is followed with one or many therapeutic doses of 3700 MBq (100 mCi) of 131-Iodine and that to destroy thewhole of the thyroid tissue. The patients are then reexamined every six months and are submitted for a T4 opotherapeutic treatment the balance of a general check-up which includes a delicate clinic control, radiologic exam and biological exam, a general control of thyroid hormones, of the T.S.H. and the thyroglobulin and the antithyroglobulin antibodies. In case of any doubt, the balance sheet must be stopped and the patient which is suspected of having Iodine desaturation is submitted for a new general clinic and biologic check-up, which is accompanied with a total scanning after oral administration of 185 mBq (5 mCi) 131-Iodine. If this general check-up shows any active nodul, another therapeutic decision is taken which is often based on an new carcinologic dose of 131-Iodine. This treatment is always followed with a post therapeutic scanning 2 and 5 days later and than another new general check-up three months later to judge the efficiency of the treatment, and during this time the patient is compensed with a LT3.
Prognostic Significance of Melanoma Differentiation and Trans-Differentiation
Maddodi, Nityanand; Setaluri, Vijayasaradhi, E-mail: setaluri@wisc.edu [Department of Dermatology, University of Wisconsin School of Medicine and Public Health, 1300 University Avenue, B25, Madison WI 53706 (United States)
2010-05-26
Cutaneous malignant melanomas share a number of molecular attributes such as limitless replicative potential that define capabilities acquired by most malignancies. Accordingly, much effort has been focused on evaluating and validating protein markers related to these capabilities to function as melanoma prognostic markers. However, a few studies have also highlighted the prognostic value of markers that define melanocytic differentiation and the plasticity of melanoma cells to trans-differentiate along several other cellular pathways. Here, we provide a comprehensive review and evaluation of the prognostic significance of melanocyte-lineage markers such as MITF and melanogenic proteins, as well as markers of vascular epithelial and neuronal differentiation.
Introduction to Piecewise Differentiable Equations
Scholtes, Stefan
2012-01-01
This brief provides an elementary introduction to the theory of piecewise differentiable functions with an emphasis on differentiable equations. In the first chapter, two sample problems are used to motivate the study of this theory. The presentation is then developed using two basic tools for the analysis of piecewise differentiable functions: the Bouligand derivative as the non smooth analogue of the classical derivative concept and the theory of piecewise affine functions as the combinatorial tool for the study of this approximation function. In the end, the results are combined to develop
Differential forms theory and practice
Weintraub, Steven H
2014-01-01
Differential forms are utilized as a mathematical technique to help students, researchers, and engineers analyze and interpret problems where abstract spaces and structures are concerned, and when questions of shape, size, and relative positions are involved. Differential Forms has gained high recognition in the mathematical and scientific community as a powerful computational tool in solving research problems and simplifying very abstract problems through mathematical analysis on a computer. Differential Forms, 2nd Edition, is a solid resource for students and professionals needing a solid g
Elements of partial differential equations
Sneddon, Ian N
2006-01-01
Geared toward students of applied rather than pure mathematics, this volume introduces elements of partial differential equations. Its focus is primarily upon finding solutions to particular equations rather than general theory.Topics include ordinary differential equations in more than two variables, partial differential equations of the first and second orders, Laplace's equation, the wave equation, and the diffusion equation. A helpful Appendix offers information on systems of surfaces, and solutions to the odd-numbered problems appear at the end of the book. Readers pursuing independent st
Differential forms on electromagnetic networks
Balasubramanian, N V; Sen Gupta, D P
2013-01-01
Differential Forms on Electromagnetic Networks deals with the use of combinatorial techniques in electrical circuit, machine analysis, and the relationship between circuit quantities and electromagnetic fields. The monograph is also an introduction to the organization of field equations by the methods of differential forms. The book covers topics such as algebraic structural relations in an electric circuit; mesh and node-pair analysis; exterior differential structures; generalized Stoke's theorem and tensor analysis; and Maxwell's electromagnetic equation. Also covered in the book are the app
On Generalized Fractional Differentiator Signals
Hamid A. Jalab
2013-01-01
Full Text Available By employing the generalized fractional differential operator, we introduce a system of fractional order derivative for a uniformly sampled polynomial signal. The calculation of the bring in signal depends on the additive combination of the weighted bring-in of N cascaded digital differentiators. The weights are imposed in a closed formula containing the Stirling numbers of the first kind. The approach taken in this work is to consider that signal function in terms of Newton series. The convergence of the system to a fractional time differentiator is discussed.
Early Planetary Differentiation: Comparative Planetology
Jones, John H.
2006-01-01
We currently have extensive data for four different terrestrial bodies of the inner solar system: Earth, the Moon, Mars, and the Eucrite Parent Body [EPB]. All formed early cores; but all(?) have mantles with elevated concentrations of highly sidero-phile elements, suggestive of the addition of a late "veneer". Two appear to have undergone extensive differentiation consistent with a global magma ocean. One appears to be inconsistent with a simple model of "low-pressure" chondritic differentiation. Thus, there seems to be no single, simple paradigm for understand-ing early differentiation.
Differential equations extended to superspace
Torres, J. [Instituto de Fisica, Universidad de Guanajuato, A.P. E-143, Leon, Guanajuato (Mexico); Rosu, H.C. [Instituto Potosino de Investigacion Cientifica y Tecnologica, A.P. 3-74, Tangamanga, San Luis Potosi (Mexico)
2003-07-01
We present a simple SUSY Ns = 2 superspace extension of the differential equations in which the sought solutions are considered to be real superfields but maintaining the common derivative operators and the coefficients of the differential equations unaltered. In this way, we get self consistent systems of coupled differential equations for the components of the superfield. This procedure is applied to the Riccati equation, for which we obtain in addition the system of coupled equations corresponding to the components of the general superfield solution. (Author)
Sexual differentiation in fission yeast
Egel, R; Nielsen, O; Weilguny, D
1990-01-01
The regulation of sexual reproduction in yeast constitutes the highest level of differentiation observed in these unicellular organisms. The various ramifications of this system involve DNA rearrangement, transcriptional control, post-translational modification (such as protein phosphorylation...
Chiral anomalies and differential geometry
Zumino, B.
1983-10-01
Some properties of chiral anomalies are described from a geometric point of view. Topics include chiral anomalies and differential forms, transformation properties of the anomalies, identification and use of the anomalies, and normalization of the anomalies. 22 references. (WHK)
Nash and Stackelberg Differential Games
Alain BENSOUSSAN; Jens FREHSE; Jens VOGELGESANG
2012-01-01
A large class of stochastic differential games for several players is considered in this paper.The class includes Nash differential games as well as Stackelberg differential games.A mix is possible.The existence of feedback strategies under general conditions is proved.The limitations concern the functionals in which the state and the controls appear separately.This is also true for the state equations.The controls appear in a quadratic form for the payoff and linearly in the state equation.The most serious restriction is the dimension of the state equation,which cannot exceed 2. The reason comes from PDE (partial differential equations) techniques used in studying the system of Bellman equations obtained by Dynamic Programming arguments.In the authors' previous work in 2002,there is not such a restriction,but there are serious restrictions on the structure of the Hamiltonians,which are violated in the applications dealt with in this article.
Introductory course on differential equations
Gorain, Ganesh C
2014-01-01
Introductory Course on DIFFERENTIAL EQUATIONS provides an excellent exposition of the fundamentals of ordinary and partial differential equations and is ideally suited for a first course of undergraduate students of mathematics, physics and engineering. The aim of this book is to present the elementary theories of differential equations in the forms suitable for use of those students whose main interest in the subject are based on simple mathematical ideas. KEY FEATURES: Discusses the subject in a systematic manner without sacrificing mathematical rigour. A variety of exercises drill the students in problem solving in view of the mathematical theories explained in the book. Worked out examples illustrated according to the theories developed in the book with possible alternatives. Exhaustive collection of problems and the simplicity of presentation differentiate this book from several others. Material contained will help teachers as well as aspiring students of different competitive examinations.
Differential calculus and its applications
Field, Michael J
2013-01-01
Based on undergraduate courses in advanced calculus, the treatment covers a wide range of topics, from soft functional analysis and finite-dimensional linear algebra to differential equations on submanifolds of Euclidean space. 1976 edition.
An introduction to differential geometry
Willmore, T J
2012-01-01
This text employs vector methods to explore the classical theory of curves and surfaces. Topics include basic theory of tensor algebra, tensor calculus, calculus of differential forms, and elements of Riemannian geometry. 1959 edition.
Differential calculi on finite groups
Castellani, L
1999-01-01
A brief review of bicovariant differential calculi on finite groups is given, with some new developments on diffeomorphisms and integration. We illustrate the general theory with the example of the nonabelian finite group S_3.
Advances in discrete differential geometry
2016-01-01
This is one of the first books on a newly emerging field of discrete differential geometry and an excellent way to access this exciting area. It surveys the fascinating connections between discrete models in differential geometry and complex analysis, integrable systems and applications in computer graphics. The authors take a closer look at discrete models in differential geometry and dynamical systems. Their curves are polygonal, surfaces are made from triangles and quadrilaterals, and time is discrete. Nevertheless, the difference between the corresponding smooth curves, surfaces and classical dynamical systems with continuous time can hardly be seen. This is the paradigm of structure-preserving discretizations. Current advances in this field are stimulated to a large extent by its relevance for computer graphics and mathematical physics. This book is written by specialists working together on a common research project. It is about differential geometry and dynamical systems, smooth and discrete theories, ...
Partial Differential Equations of Physics
Geroch, Robert
1996-01-01
Apparently, all partial differential equations that describe physical phenomena in space-time can be cast into a universal quasilinear, first-order form. In this paper, we do two things. First, we describe some broad features of systems of differential equations so formulated. Examples of such features include hyperbolicity of the equations, constraints and their roles (e.g., in connection with the initial-value formulation), how diffeomorphism freedom is manifest, and how interactions betwee...
Partial Differential Equations An Introduction
Choudary, A. D. R.; Parveen, Saima; Varsan, Constantin
2010-01-01
This book encompasses both traditional and modern methods treating partial differential equation (PDE) of first order and second order. There is a balance in making a selfcontained mathematical text and introducing new subjects. The Lie algebras of vector fields and their algebraic-geometric representations are involved in solving overdetermined of PDE and getting integral representation of stochastic differential equations (SDE). It is addressing to all scientists using PDE in treating mathe...
Symmetries of partial differential equations
Gaussier, Hervé; Merker, Joël
2004-01-01
We establish a link between the study of completely integrable systems of partial differential equations and the study of generic submanifolds in C^n. Using the recent developments of Cauchy-Riemann geometry we provide the set of symmetries of such a system with a Lie group structure. Finally we determine the precise upper bound of the dimension of this Lie group for some specific systems of partial differential equations.
Lecture Notes on Differential Forms
2016-01-01
This is a series of lecture notes, with embedded problems, aimed at students studying differential topology. Many revered texts, such as Spivak's "Calculus on Manifolds" and Guillemin and Pollack's "Differential Topology" introduce forms by first working through properties of alternating tensors. Unfortunately, many students get bogged down with the whole notion of tensors and never get to the punch lines: Stokes' Theorem, de Rham cohomology, Poincare duality, and the realization of various t...
Differential calculi on noncommutative bundles
Pflaum, Markus J.; Schauenburg, Peter
1996-01-01
We introduce a category of noncommutative bundles. To establish geometry in this category we construct suitable noncommutative differential calculi on these bundles and study their basic properties. Furthermore we define the notion of a connection with respect to a differential calculus and consider questions of existence and uniqueness. At the end these constructions are applied to basic examples of noncommutative bundles over a coquasitriangular Hopf algebra.
Partial Differential Equations An Introduction
Choudary, A D R; Varsan, Constantin
2010-01-01
This book encompasses both traditional and modern methods treating partial differential equation (PDE) of first order and second order. There is a balance in making a selfcontained mathematical text and introducing new subjects. The Lie algebras of vector fields and their algebraic-geometric representations are involved in solving overdetermined of PDE and getting integral representation of stochastic differential equations (SDE). It is addressing to all scientists using PDE in treating mathematical methods.
Multi-output differential technologies
Bidare, Srinivas R.
1997-01-01
A differential is a very old and proven mechanical device that allows a single input to be split into two outputs having equal torque irrespective of the output speeds. A standard differential is capable of providing only two outputs from a single input. A recently patented multi-output differential technology known as `Plural-Output Differential' allows a single input to be split into many outputs. This new technology is the outcome of a systematic study of complex gear trains (Bidare 1992). The unique feature of a differential (equal torque at different speeds) can be applied to simplify the construction and operation of many complex mechanical devices that require equal torque's or forces at multiple outputs. It is now possible to design a mechanical hand with three or more fingers with equal torque. Since these finger are powered via a differential they are `mechanically intelligent'. A prototype device is operational and has been used to demonstrate the utility and flexibility of the design. In this paper we shall review two devices that utilize the new technology resulting in increased performance, robustness with reduced complexity and cost.
Comparison of two methods for customer differentiation
A.F. Gabor (Adriana); Y. Guang (Yang); S. Axsäter (Sven)
2014-01-01
textabstractIn response to customer specific time guarantee requirements, service providers can offer differentiated ser- vices. However, conventional customer differentiation methods often lead to high holding costs and may have some practical drawbacks. We compare two customer differentiation poli
Fractional complex transform for fractional differential equations
Lİ, Zheng Biao; HE, Ji Huan
2010-01-01
Fractional complex transform is proposed to convert fractional differential equations into ordinary differential equations, so that all analytical methods devoted to advanced calculus can be easily...
MEK5 suppresses osteoblastic differentiation
Kaneshiro, Shoichi [Department of Orthopaedic Surgery, Japan Community Health Care Organization Osaka Hospital, 4-2-78 Fukushima, Fukushima Ward, Osaka City, Osaka 553-0003 (Japan); Department of Orthopaedic Surgery, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Otsuki, Dai; Yoshida, Kiyoshi; Yoshikawa, Hideki [Department of Orthopaedic Surgery, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Higuchi, Chikahisa, E-mail: c-higuchi@umin.ac.jp [Department of Orthopaedic Surgery, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan)
2015-07-31
Extracellular signal-regulated kinase 5 (ERK5) is a member of the mitogen-activated protein kinase (MAPK) family and is activated by its upstream kinase, MAPK kinase 5 (MEK5), which is a member of the MEK family. Although the role of MEK5 has been investigated in several fields, little is known about its role in osteoblastic differentiation. In this study, we have demonstrated the role of MEK5 in osteoblastic differentiation in mouse preosteoblastic MC3T3-E1 cells and bone marrow stromal ST2 cells. We found that treatment with BIX02189, an inhibitor of MEK5, increased alkaline phosphatase (ALP) activity and the gene expression of ALP, osteocalcin (OCN) and osterix, as well as it enhanced the calcification of the extracellular matrix. Moreover, osteoblastic cell proliferation decreased at a concentration of greater than 0.5 μM. In addition, knockdown of MEK5 using siRNA induced an increase in ALP activity and in the gene expression of ALP, OCN, and osterix. In contrast, overexpression of wild-type MEK5 decreased ALP activity and attenuated osteoblastic differentiation markers including ALP, OCN and osterix, but promoted cell proliferation. In summary, our results indicated that MEK5 suppressed the osteoblastic differentiation, but promoted osteoblastic cell proliferation. These results implied that MEK5 may play a pivotal role in cell signaling to modulate the differentiation and proliferation of osteoblasts. Thus, inhibition of MEK5 signaling in osteoblasts may be of potential use in the treatment of osteoporosis. - Highlights: • MEK5 inhibitor BIX02189 suppresses proliferation of osteoblasts. • MEK5 knockdown and MEK5 inhibitor promote differentiation of osteoblasts. • MEK5 overexpression inhibits differentiation of osteoblasts.
Fractional Differentiability of Nowhere Differentiable Functions and Dimensions
Kolwankar, K M; Kolwankar, Kiran M.; Gangal, Anil D.
1996-01-01
Weierstrass's everywhere continuous but nowhere differentiable function is shown to be locally continuously fractionally differentiable everywhere for all orders below the `critical order' 2-s and not so for orders between 2-s and 1, where s, 1differentiability and the box dimension/ local Hölder exponent. Lévy index for one dimensional Lévy flights is shown to be the critical order of its characteristic function. Local fractional derivatives of multifractal signals (non-random functions) are shown to provide the local Hölder exponent. It is argued that Local fractional derivatives provide a powerful tool to analyze pointwise behavior of irregular signals.
Stochastic differential equations, backward SDEs, partial differential equations
Pardoux, Etienne
2014-01-01
This research monograph presents results to researchers in stochastic calculus, forward and backward stochastic differential equations, connections between diffusion processes and second order partial differential equations (PDEs), and financial mathematics. It pays special attention to the relations between SDEs/BSDEs and second order PDEs under minimal regularity assumptions, and also extends those results to equations with multivalued coefficients. The authors present in particular the theory of reflected SDEs in the above mentioned framework and include exercises at the end of each chapter. Stochastic calculus and stochastic differential equations (SDEs) were first introduced by K. Itô in the 1940s, in order to construct the path of diffusion processes (which are continuous time Markov processes with continuous trajectories taking their values in a finite dimensional vector space or manifold), which had been studied from a more analytic point of view by Kolmogorov in the 1930s. Since then, this topic has...
Differentiation, ageing, and terminal differentiation: a semantic analysis.
Reiner, J M
1983-12-21
The largely unsolved problems in the theoretical analysis of differentiation and ageing involve a substantial component of linguistic (semantic) difficulties. Some of these are simple traps of ambiguity, resulting from metaphorical or analogical employment of established terms--for example, "terminal differentiation" (loss of division potential in vitro) as a borrowing from "differentiation" as used by developmental biologists, or "commitment" by analogy with "determination". Some difficulties represent a failure to adopt (at least provisionally) an operational (empirical) view--for example, failure to ask what is the nature of the evidence for the view that a fertilized ovum is totipotential, or to scrutinize the evidence for the view that cells "terminally differentiated" in vitro in a conventional medium are in fact moribund under all conditions, or to examine more closely the view that the differentiated state and the cycling state are mutually exclusive. With respect to the problem of ageing, we review some of the critical experiments on "terminal differentiation" or "clonal senescence". We then proceed to consider some of the models that have been proposed, including a molecular model proposed by the author which appears to overcome some of the objections to other models. Some of the models exemplify the results of what are ultimately semantic vices. The problems with which these remarks began should indeed yield to the immense and novel resources of molecular biology. But the development of complete analyses demands not only good luck and delicate technique but also critical semantic clarity and severity. Given the best tools, we shall solve major theoretical problems only if we understand quite fully what problem it is that we are trying to solve--and the history of science illustrates that this is not as elementary a matter as it sounds.(ABSTRACT TRUNCATED AT 250 WORDS)
Differential equations methods and applications
Said-Houari, Belkacem
2015-01-01
This book presents a variety of techniques for solving ordinary differential equations analytically and features a wealth of examples. Focusing on the modeling of real-world phenomena, it begins with a basic introduction to differential equations, followed by linear and nonlinear first order equations and a detailed treatment of the second order linear equations. After presenting solution methods for the Laplace transform and power series, it lastly presents systems of equations and offers an introduction to the stability theory. To help readers practice the theory covered, two types of exercises are provided: those that illustrate the general theory, and others designed to expand on the text material. Detailed solutions to all the exercises are included. The book is excellently suited for use as a textbook for an undergraduate class (of all disciplines) in ordinary differential equations. .
State space consistency and differentiability
Serakos, Demetrios
2014-01-01
By investigating the properties of the natural state, this book presents an analysis of input-output systems with regard to the mathematical concept of state. The state of a system condenses the effects of past inputs to the system in a useful manner. This monograph emphasizes two main properties of the natural state; the first has to do with the possibility of determining the input-output system from its natural state set and the second deals with differentiability properties involving the natural state inherited from the input-output system, including differentiability of the natural state and natural state trajectories. The results presented in this title aid in modeling physical systems since system identification from a state set holds in most models. Researchers and engineers working in electrical, aerospace, mechanical, and chemical fields along with applied mathematicians working in systems or differential equations will find this title useful due to its rigorous mathematics.
INTERNATIONAL SPECIALIZATION AND VERTICAL DIFFERENTIATION
Furia Donatella
2010-07-01
Full Text Available During the last decades, market segmentation and intra-industry trade have become increasingly relevant. The underlying hypothesis of our work is that distinct articles have heterogeneous potential for vertical differentiation, implying that different patterns of international specialization should be identifiable. We carry out an analysis on revealed comparative advantage (through the Lafay Index in specific sectors of interest. Then we highlight the emergence of diverse degrees of product quality differentiation among sectors (through the Relative Quality Index. Results confirm our hypothesis. Indeed it appears that only certain goods, for which the pace of either creative or technological innovation (or both is particularly fast, present a high degree of vertical differentiation and market segmentation. This allows countries to specialize in a particular product variety and gain market power position for that variety. These findings should be taken in due consideration when designing trade policies.
ON NONLINEAR DIFFERENTIAL GALOIS THEORY
无
2002-01-01
Let X denote a complex analytic manifold, and let Aut(X) denote the space of invertible maps of a germ (X, a) to a germ (X, b); this space is obviously a groupoid; roughly speaking, a "Lie groupoid" is a subgroupoid of Aut(X) defined by a system of partial differential equations.To a foliation with singularities on X one attaches such a groupoid, e.g. the smallest one whose Lie algebra contains the vector fields tangent to the foliation. It is called "the Galois groupoid of the foliation". Some examples are considered, for instance foliations of codimension one, and foliations defined by linear differential equations; in this last case one recuperates the usual differential Galois group.
Algebrization of Nonautonomous Differential Equations
María Aracelia Alcorta-García
2015-01-01
Full Text Available Given a planar system of nonautonomous ordinary differential equations, dw/dt=F(t,w, conditions are given for the existence of an associative commutative unital algebra A with unit e and a function H:Ω⊂R2×R2→R2 on an open set Ω such that F(t,w=H(te,w and the maps H1(τ=H(τ,ξ and H2(ξ=H(τ,ξ are Lorch differentiable with respect to A for all (τ,ξ∈Ω, where τ and ξ represent variables in A. Under these conditions the solutions ξ(τ of the differential equation dξ/dτ=H(τ,ξ over A define solutions (x(t,y(t=ξ(te of the planar system.
Differential geometry techniques for sets of nonlinear partial differential equations
Estabrook, Frank B.
1990-01-01
An attempt is made to show that the Cartan theory of partial differential equations can be a useful technique for applied mathematics. Techniques for finding consistent subfamilies of solutions that are generically rich and well-posed and for introducing potentials or other usefully consistent auxiliary fields are introduced. An extended sample calculation involving the Korteweg-de Vries equation is given.
Solving Partial Differential Equations Using a New Differential Evolution Algorithm
Natee Panagant
2014-01-01
Full Text Available This paper proposes an alternative meshless approach to solve partial differential equations (PDEs. With a global approximate function being defined, a partial differential equation problem is converted into an optimisation problem with equality constraints from PDE boundary conditions. An evolutionary algorithm (EA is employed to search for the optimum solution. For this approach, the most difficult task is the low convergence rate of EA which consequently results in poor PDE solution approximation. However, its attractiveness remains due to the nature of a soft computing technique in EA. The algorithm can be used to tackle almost any kind of optimisation problem with simple evolutionary operation, which means it is mathematically simpler to use. A new efficient differential evolution (DE is presented and used to solve a number of the partial differential equations. The results obtained are illustrated and compared with exact solutions. It is shown that the proposed method has a potential to be a future meshless tool provided that the search performance of EA is greatly enhanced.
Differential diagnosis of feline pruritus.
Foil, C S
1988-09-01
Pruritic skin diseases in the cat are best approached in a problem-oriented fashion. The presentations of pruritic skin disease in the cat include miliary dermatitis, pruritus of the head, scaling and crusting dermatoses, alopecia, erythroderma and exfoliation, eosinophilic granuloma complex, macular and pustular eruptions, and pruritic nodular dermatoses. There is a specific differential diagnosis for each presentation. A rational diagnostic plan, based on the likelihood of each disease in the differential diagnosis, may be formulated for each presentation of pruritus in the cat.
Spatial and Temporal Ray Differentials
Sporring, Jon; Schjøth, Lars; Erleben, Kenny
We consider ray bundles emanating from a source such as a camera or light source. We derive the full spatial and temporal structure to ¿rst order of the intersection of ray bundles with scene geometry, where scene geometry given as any implicit function. Further, we present the full details of 2...... often used geometrical representations. The ¿rst order structure may be used as the linear approximation of the change of photons as the camera, ob jects, and light source change as function of space and time. Our work generalises previous work on ray differentials [Igehy, 1999] and photon differentials...
Race and Gender Pay Differentials
Francine D. Blau; Lawrence M. Kahn
1992-01-01
In this paper we review research findings from the 1980s and early 1990s on race and gender pay gaps. In addition. we present some evidence from the Current Population Surveys (1972, 1982 and 1989) regarding the impact of shifts in the industrial composition of employment and in interindustry wage differentials on these gaps. The gender gap in pay was stable in the 1970s but fell steadily in the 1980s; the opposite patterns were observed for black-white wage differentials--a trend towards con...
Group analysis of differential equations
Ovsiannikov, L V
1982-01-01
Group Analysis of Differential Equations provides a systematic exposition of the theory of Lie groups and Lie algebras and its application to creating algorithms for solving the problems of the group analysis of differential equations.This text is organized into eight chapters. Chapters I to III describe the one-parameter group with its tangential field of vectors. The nonstandard treatment of the Banach Lie groups is reviewed in Chapter IV, including a discussion of the complete theory of Lie group transformations. Chapters V and VI cover the construction of partial solution classes for the g
Basic linear partial differential equations
Treves, Francois
2006-01-01
Focusing on the archetypes of linear partial differential equations, this text for upper-level undergraduates and graduate students features most of the basic classical results. The methods, however, are decidedly nontraditional: in practically every instance, they tend toward a high level of abstraction. This approach recalls classical material to contemporary analysts in a language they can understand, as well as exploiting the field's wealth of examples as an introduction to modern theories.The four-part treatment covers the basic examples of linear partial differential equations and their
Nielsen number and differential equations
Andres Jan
2005-01-01
Full Text Available In reply to a problem of Jean Leray (application of the Nielsen theory to differential equations, two main approaches are presented. The first is via Poincaré's translation operator, while the second one is based on the Hammerstein-type solution operator. The applicability of various Nielsen theories is discussed with respect to several sorts of differential equations and inclusions. Links with the Sharkovskii-like theorems (a finite number of periodic solutions imply infinitely many subharmonics are indicated, jointly with some further consequences like the nontrivial -structure of solutions of initial value problems. Some illustrating examples are supplied and open problems are formulated.
Differential equations and mathematical biology
Jones, DS; Sleeman, BD
2009-01-01
""… Much progress by these authors and others over the past quarter century in modeling biological and other scientific phenomena make this differential equations textbook more valuable and better motivated than ever. … The writing is clear, though the modeling is not oversimplified. Overall, this book should convince math majors how demanding math modeling needs to be and biologists that taking another course in differential equations will be worthwhile. The coauthors deserve congratulations as well as course adoptions.""-SIAM Review, Sept. 2010, Vol. 52, No. 3""… Where this text stands out i
Full averaging of fuzzy impulsive differential inclusions
Natalia V. Skripnik
2010-09-01
Full Text Available In this paper the substantiation of the method of full averaging for fuzzy impulsive differential inclusions is studied. We extend the similar results for impulsive differential inclusions with Hukuhara derivative (Skripnik, 2007, for fuzzy impulsive differential equations (Plotnikov and Skripnik, 2009, and for fuzzy differential inclusions (Skripnik, 2009.
Differential Calculus on N-Graded Manifolds
Sardanashvily, G.; W. Wachowski
2017-01-01
The differential calculus, including formalism of linear differential operators and the Chevalley–Eilenberg differential calculus, over N-graded commutative rings and on N-graded manifolds is developed. This is a straightforward generalization of the conventional differential calculus over commutative rings and also is the case of the differential calculus over Grassmann algebras and on Z2-graded manifolds. We follow the notion of an N-graded manifold as a local-ringed space whose body is a s...
POLYMYOSITIS/DERMATOMIOSITIS: DIFFERENTIAL DIAGNOSIS
O. A. Antelava
2016-01-01
Full Text Available The lecture considers the problem of rare systemic connective tissue diseases, such as idiopathic inflammatory myopathies (IIMs. It underlines the clinical and immunological heterogeneity of their subtypes, which defines therapeutic tactics and prognosis. The diagnostic criteria for IIMs are given. A differential diagnostic algorithm based on the exclusion of phenotypically similar forms of myopathies of different genesis is proposed.
Differential geometry meets the cell.
Marshall, Wallace F
2013-07-18
A new study by Terasaki et al. highlights the role of physical forces in biological form by showing that connections between stacked endoplasmic reticulum cisternae have a shape well known in classical differential geometry, the helicoid, and that this shape is a predictable consequence of membrane physics.
Multiple Intelligences for Differentiated Learning
Williams, R. Bruce
2007-01-01
There is an intricate literacy to Gardner's multiple intelligences theory that unlocks key entry points for differentiated learning. Using a well-articulated framework, rich with graphic representations, Williams provides a comprehensive discussion of multiple intelligences. He moves the teacher and students from curiosity, to confidence, to…
Stochastic nonlinear differential equations. I
Heilmann, O.J.; Kampen, N.G. van
1974-01-01
A solution method is developed for nonlinear differential equations having the following two properties. Their coefficients are stochastic through their dependence on a Markov process. The magnitude of the fluctuations, multiplied with their auto-correlation time, is a small quantity. Under these co
Cultural Differentiation of Negotiating Agents
Hofstede, G.J.; Jonker, C.M.; Verwaart, D.
2012-01-01
Negotiations proceed differently across cultures. For realistic modeling of agents in multicultural negotiations, the agents must display culturally differentiated behavior. This paper presents an agent-based simulation model that tackles these challenges, based on Hofstede’s model of national cultu
Cultural differentiation of negotiating agents
Hofstede, G.J.; Jonker, C.M.; Verwaart, T.
2010-01-01
Negotiations proceed differently across cultures. For realistic modeling of agents in multicultural negotiations, the agents must display culturally differentiated behavior. This paper presents an agent-based simulation model that tackles these challenges, based on Hofstede’s model of national cultu
Pendulum Motion and Differential Equations
Reid, Thomas F.; King, Stephen C.
2009-01-01
A common example of real-world motion that can be modeled by a differential equation, and one easily understood by the student, is the simple pendulum. Simplifying assumptions are necessary for closed-form solutions to exist, and frequently there is little discussion of the impact if those assumptions are not met. This article presents a…
Transcriptional profiling of epidermal differentiation.
Radoja, Nada; Gazel, Alix; Banno, Tomohiro; Yano, Shoichiro; Blumenberg, Miroslav
2006-10-03
In epidermal differentiation basal keratinocytes detach from the basement membrane, stop proliferating, and express a new set of structural proteins and enzymes, which results in an impermeable protein/lipid barrier that protects us. To define the transcriptional changes essential for this process, we purified large quantities of basal and suprabasal cells from human epidermis, using the expression of beta4 integrin as the discriminating factor. The expected expression differences in cytoskeletal, cell cycle, and adhesion genes confirmed the effective separation of the cell populations. Using DNA microarray chips, we comprehensively identify the differences in genes expressed in basal and differentiating layers of the epidermis, including the ECM components produced by the basal cells, the proteases in both the basal and suprabasal cells, and the lipid and steroid metabolism enzymes in suprabasal cells responsible for the permeability barrier. We identified the signaling pathways specific for the two populations and found two previously unknown paracrine and one juxtacrine signaling pathway operating between the basal and suprabasal cells. Furthermore, using specific expression signatures, we identified a new set of late differentiation markers and mapped their chromosomal loci, as well as a new set of melanocyte-specific markers. The data represent a quantum jump in understanding the mechanisms of epidermal differentiation.
On the path to differentiation
Martinsen, Dorte Sindbjerg; Uygur, Ayca
2014-01-01
by examining the ‘path to differentiation’ within EU working time regulation as it has unfolded over time. It identifies the ‘opt-out’ as a means of differentiation adopted to overcome policy deadlocks within collective decision-making, albeit one with unforeseen consequences. In particular, the contribution...
Transcriptional networks controlling adipocyte differentiation
Siersbæk, R; Mandrup, Susanne
2011-01-01
Adipocyte differentiation is regulated by a complex cascade of signals that drive the transcriptional reprogramming of the fibroblastic precursors. Genome-wide analyses of chromatin accessibility and binding of adipogenic transcription factors make it possible to generate "snapshots" of the trans...
Experiments with a Differential Transformer
Aguilar, Horacio Munguía
2016-01-01
An experiment with an electric transformer based on single coils shows how electromagnetic induction changes when the magnetic coupling between coils is adjusted. This transformer has two secondary outputs which are taken differentially. This is the basis for a widely used position transducer known as LVDT.
Rho GTPases in ameloblast differentiation
Keishi Otsu
2016-05-01
Full Text Available During tooth development, ameloblasts differentiate from inner enamel epithelial cells to enamel-forming cells by modulating the signal pathways mediating epithelial–mesenchymal interaction and a cell-autonomous gene network. The differentiation process of epithelial cells is characterized by marked changes in their morphology and polarity, accompanied by dynamic cytoskeletal reorganization and changes in cell–cell and cell–matrix adhesion over time. Functional ameloblasts are tall, columnar, polarized cells that synthesize and secrete enamel-specific proteins. After deposition of the full thickness of enamel matrix, ameloblasts become smaller and regulate enamel maturation. Recent significant advances in the fields of molecular biology and genetics have improved our understanding of the regulatory mechanism of the ameloblast cell life cycle, mediated by the Rho family of small GTPases. They act as intracellular molecular switch that transduce signals from extracellular stimuli to the actin cytoskeleton and the nucleus. In our review, we summarize studies that provide current evidence for Rho GTPases and their involvement in ameloblast differentiation. In addition to the Rho GTPases themselves, their downstream effectors and upstream regulators have also been implicated in ameloblast differentiation.
Cartilage differentiation in cephalopod molluscs.
Cole, Alison G; Hall, Brian K
2009-01-01
Amongst the various metazoan lineages that possess cartilage, tissues most closely resembling vertebrate hyaline cartilage in histological section are those of cephalopod molluscs. Although elements of the adult skeleton have been described, the development of these cartilages has not. Using serial histology of sequential developmental stages of the European cuttlefish, Sepia officinalis, we investigate these skeletal elements and offer the first description of the formation of any cellular invertebrate cartilage. Our data reveal that cuttlefish cartilage most often differentiates from uncondensed mesenchymal cells near the end of embryonic development, but that the earliest-forming cartilages differentiate from a cellular condensation which goes through a protocartilage stage in a manner typical of vertebrate primary cartilage formation. We further investigate the distribution and degree of differentiation of cartilages at the time of hatching in an additional four cephalopod species. We find that the timing of cartilage development varies between elements within a single species, as well as between species. We identify a tendency towards cartilage differentiation from uncondensed connective tissue in elements that form at the end of embryogenesis or after hatching. These data suggest a form of metaplasia from connective tissue is the ancestral mode of cartilage formation in this lineage.
Differential equations a concise course
Bear, H S
2011-01-01
Concise introduction for undergraduates includes, among other topics, a survey of first order equations, discussions of complex-valued solutions, linear differential operators, inverse operators and variation of parameters method, the Laplace transform, Picard's existence theorem, and an exploration of various interpretations of systems of equations. Numerous clearly stated theorems and proofs, examples, and problems followed by solutions.
Pendulum Motion and Differential Equations
Reid, Thomas F.; King, Stephen C.
2009-01-01
A common example of real-world motion that can be modeled by a differential equation, and one easily understood by the student, is the simple pendulum. Simplifying assumptions are necessary for closed-form solutions to exist, and frequently there is little discussion of the impact if those assumptions are not met. This article presents a…
Generalized fast automatic differentiation technique
Evtushenko, Yu. G.; Zubov, V. I.
2016-11-01
A new efficient technique intended for the numerical solution of a broad class of optimal control problems for complicated dynamical systems described by ordinary and/or partial differential equations is investigated. In this approach, canonical formulas are derived to precisely calculate the objective function gradient for a chosen finite-dimensional approximation of the objective functional.
Defining and Differentiating the Makerspace
Dousay, Tonia A.
2017-01-01
Many resources now punctuate the maker movement landscape. However, some schools and communities still struggle to understand this burgeoning movement. How do we define these spaces and differentiate them from previous labs and shops? Through a multidimensional framework, stakeholders should consider how the structure, access, staffing, and tools…
Differential operators and automorphism schemes
无
2010-01-01
The ring of global differential operators of a variety is in closed and deep relation with its automorphism scheme.This relation can be applied to the study of homogeneous schemes,giving some criteria of homogeneity,a generalization of Serre-Lang theorem,and some consequences about abelian varieties.
Experiments with a Differential Transformer
Aguilar, Horacio Munguía
2016-01-01
An experiment with an electric transformer based on single coils shows how electromagnetic induction changes when the magnetic coupling between coils is adjusted. This transformer has two secondary outputs which are taken differentially. This is the basis for a widely used position transducer known as LVDT.
Pulmonary edema: radiographic differential diagnosis
Yoo, Dong Soo; Choi, Young Hi; Kim, Seung Cheol; An, Ji Hyun; Lee, Jee Young; Park, Hee Hong [Dankook Univ. College of Medicine, Chonan (Korea, Republic of)
1997-04-01
To evaluate the feasibility of using chest radiography to differentiate between three different etiologies of pulmonary edema. Plain chest radiographs of 77 patients, who were clinically confirmed as having pulmonary edema, were retrospectively reviewed. The patients were classified into three groups : group 1 (cardiogenic edema : n = 35), group 2 (renal pulmonary edema : n = 16) and group 3 (permeability edema : n = 26). We analyzed the radiologic findings of air bronchogram, heart size, peribronchial cuffing, septal line, pleural effusion, vascular pedicle width, pulmonary blood flow distribution and distribution of pulmonary edema. In a search for radiologic findings which would help in the differentiation of these three etiologies, each finding was assessed. Cardiogenic and renal pulmonary edema showed overlapping radiologic findings, except for pulmonary blood flow distribution. In cardiogenic pulmonary edema (n=35), cardiomegaly (n=29), peribronchial cuffing (n=29), inverted pulmonary blood flow distribution (n=21) and basal distribution of edema (n=20) were common. In renal pulmonary edema (n=16), cardiomegaly (n=15), balanced blood flow distribution (n=12), and central (n=9) or basal distribution of edema (n=7) were common. Permeability edema (n=26) showed different findings. Air bronchogram (n=25), normal blood flow distribution (n=14) and peripheral distribution of edema (n=21) were frequent findings, while cardiomegaly (n=7), peribronchial cuffing (n=7) and septal line (n=5) were observed in only a few cases. On plain chest radiograph, permeability edema can be differentiated from cardiogenic or renal pulmonary edema. The radiographic findings which most reliably differentiated these two etiologies were air bronchogram, distribution of pulmonary edema, peribronchial cuffing and heart size. Only blood flow distribution was useful for radiographic differentiation of cardiogenic and renal edema.
Differentiation into Endoderm Lineage: Pancreatic differentiation from Embryonic Stem Cells
2011-01-01
The endoderm gives rise to digestive and respiratory tracts, thyroid, liver, and pancreas. Representative disease of endoderm lineages is type 1 diabetes resulting from destruction of the insulin-producing β cells. Generation of functional β cells from human embryonic stem (ES) cells in vitro can be practical, renewable cell source for replacement cell therapy for type 1 diabetes. It has been achieved by progressive instructive differentiation through each of the developmental stages. In this...
The Signaling Pathways Involved in Chondrocyte Differentiation and Hypertrophic Differentiation
Jianmei Li
2016-01-01
Full Text Available Chondrocytes communicate with each other mainly via diffusible signals rather than direct cell-to-cell contact. The chondrogenic differentiation of mesenchymal stem cells (MSCs is well regulated by the interactions of varieties of growth factors, cytokines, and signaling molecules. A number of critical signaling molecules have been identified to regulate the differentiation of chondrocyte from mesenchymal progenitor cells to their terminal maturation of hypertrophic chondrocytes, including bone morphogenetic proteins (BMPs, SRY-related high-mobility group-box gene 9 (Sox9, parathyroid hormone-related peptide (PTHrP, Indian hedgehog (Ihh, fibroblast growth factor receptor 3 (FGFR3, and β-catenin. Except for these molecules, other factors such as adenosine, O2 tension, and reactive oxygen species (ROS also have a vital role in cartilage formation and chondrocyte maturation. Here, we outlined the complex transcriptional network and the function of key factors in this network that determine and regulate the genetic program of chondrogenesis and chondrocyte differentiation.
Graded q-differential matrix algebra
Abramov, V.; Raknuzzaman, Md.
2013-10-01
We consider the algebra of square matrices of order N as graded q-differential algebra, where q is a primitive Nth root of unity. We study the differential calculus of this algebra determined by a differential d, which satisfies the graded q-Leibniz rule and dN = 0. A graded q-differential algebra can be viewed as a generalization of graded differential algebra, and we consider the higher degree elements of graded q-differential matrix algebra as analogs of differential forms. We use two matrices x,ξ, which generate the algebra of square matrices of order N in order to express these analogs of differential forms in terms of "coordinate" x and its differentials dx,d2x,...,dN-1x. We study an analog of connection and calculate its curvature.
Introduction to partial differential equations
Borthwick, David
2016-01-01
This modern take on partial differential equations does not require knowledge beyond vector calculus and linear algebra. The author focuses on the most important classical partial differential equations, including conservation equations and their characteristics, the wave equation, the heat equation, function spaces, and Fourier series, drawing on tools from analysis only as they arise.Within each section the author creates a narrative that answers the five questions: (1) What is the scientific problem we are trying to understand? (2) How do we model that with PDE? (3) What techniques can we use to analyze the PDE? (4) How do those techniques apply to this equation? (5) What information or insight did we obtain by developing and analyzing the PDE? The text stresses the interplay between modeling and mathematical analysis, providing a thorough source of problems and an inspiration for the development of methods.
Differential geometry and mathematical physics
Rudolph, Gerd
Starting from an undergraduate level, this book systematically develops the basics of • Calculus on manifolds, vector bundles, vector fields and differential forms, • Lie groups and Lie group actions, • Linear symplectic algebra and symplectic geometry, • Hamiltonian systems, symmetries and reduction, integrable systems and Hamilton-Jacobi theory. The topics listed under the first item are relevant for virtually all areas of mathematical physics. The second and third items constitute the link between abstract calculus and the theory of Hamiltonian systems. The last item provides an introduction to various aspects of this theory, including Morse families, the Maslov class and caustics. The book guides the reader from elementary differential geometry to advanced topics in the theory of Hamiltonian systems with the aim of making current research literature accessible. The style is that of a mathematical textbook,with full proofs given in the text or as exercises. The material is illustrated by numerous d...
Differential Equations for Morphological Amoebas
Welk, Martin; Breuß, Michael; Vogel, Oliver
This paper is concerned with amoeba median filtering, a structure-adaptive morphological image filter. It has been introduced by Lerallut et al. in a discrete formulation. Experimental evidence shows that iterated amoeba median filtering leads to segmentation-like results that are similar to those obtained by self-snakes, an image filter based on a partial differential equation. We investigate this correspondence by analysing a space-continuous formulation of iterated median filtering. We prove that in the limit of vanishing radius of the structuring elements, iterated amoeba median filtering indeed approximates a partial differential equation related to self-snakes and the well-known (mean) curvature motion equation. We present experiments with discrete iterated amoeba median filtering that confirm qualitative and quantitative predictions of our analysis.
Dynamics of partial differential equations
Wayne, C Eugene
2015-01-01
This book contains two review articles on the dynamics of partial differential equations that deal with closely related topics but can be read independently. Wayne reviews recent results on the global dynamics of the two-dimensional Navier-Stokes equations. This system exhibits stable vortex solutions: the topic of Wayne's contribution is how solutions that start from arbitrary initial conditions evolve towards stable vortices. Weinstein considers the dynamics of localized states in nonlinear Schrodinger and Gross-Pitaevskii equations that describe many optical and quantum systems. In this contribution, Weinstein reviews recent bifurcations results of solitary waves, their linear and nonlinear stability properties, and results about radiation damping where waves lose energy through radiation. The articles, written independently, are combined into one volume to showcase the tools of dynamical systems theory at work in explaining qualitative phenomena associated with two classes of partial differential equ...
Age-differentiated work systems
Frieling, Ekkehart; Wegge, Jürgen
2013-01-01
The disproportionate aging of the population of working age in many nations around the world is a unique occurrence in the history of humankind. In the light of demographic change, it is becoming increasingly important to develop and use the potential of older employees. This edited volume Age-differentiated Work Systems provides a final report on a six-year priority program funded by the German Research Foundation (DFG) and presents selected research findings of 17 interdisciplinary project teams. The idea is that it will serve both as a reference book and overview of the current state of research in ergonomics, occupational psychology and related disciplines. It provides new models, methods, and procedures for analyzing and designing age-differentiated work systems with the aim of supporting subject matter experts from different areas in their decisions on labor and employment policies. Therefore over 40 laboratory experiments involving 2,000 participants and 50 field studies involving over 25,000 employees...
On the origin of differentiation
J T Bonner
2003-06-01
Following the origin of multicellularity in many groups of primitive organisms there evolved more than one cell type. It has been assumed that this early differentiation is related to size – the larger the organism the more cell types. Here two very different kinds of organisms are considered: the volvocine algae that become multicellular by growth, and the cellular slime moulds that become multicellular by aggregation. In both cases there are species that have only one cell type and others that have two. It has been possible to show that there is a perfect correlation with size: the forms with two cell types are significantly larger than those with one. Also in both groups there are forms of intermediate size that will vary from one to two cell types depending on the size of the individuals, suggesting a form of quorum sensing. These observations reinforce the view that size plays a critical role in influencing the degree of differentiation.
Differentially Private Trajectory Data Publication
Chen, Rui; Desai, Bipin C
2011-01-01
With the increasing prevalence of location-aware devices, trajectory data has been generated and collected in various application domains. Trajectory data carries rich information that is useful for many data analysis tasks. Yet, improper publishing and use of trajectory data could jeopardize individual privacy. However, it has been shown that existing privacy-preserving trajectory data publishing methods derived from partition-based privacy models, for example k-anonymity, are unable to provide sufficient privacy protection. In this paper, motivated by the data publishing scenario at the Societe de transport de Montreal (STM), the public transit agency in Montreal area, we study the problem of publishing trajectory data under the rigorous differential privacy model. We propose an efficient data-dependent yet differentially private sanitization algorithm, which is applicable to different types of trajectory data. The efficiency of our approach comes from adaptively narrowing down the output domain by building...
Numerical models for differential problems
Quarteroni, Alfio
2014-01-01
In this text, we introduce the basic concepts for the numerical modelling of partial differential equations. We consider the classical elliptic, parabolic and hyperbolic linear equations, but also the diffusion, transport, and Navier-Stokes equations, as well as equations representing conservation laws, saddle-point problems and optimal control problems. Furthermore, we provide numerous physical examples which underline such equations. We then analyze numerical solution methods based on finite elements, finite differences, finite volumes, spectral methods and domain decomposition methods, and reduced basis methods. In particular, we discuss the algorithmic and computer implementation aspects and provide a number of easy-to-use programs. The text does not require any previous advanced mathematical knowledge of partial differential equations: the absolutely essential concepts are reported in a preliminary chapter. It is therefore suitable for students of bachelor and master courses in scientific disciplines, an...
Reticulated acanthoma with sebaceous differentiation.
Fukai, Kazuyoshi; Sowa, Junko; Ishii, Masamitsu
2006-04-01
Reticulated acanthoma with sebaceous differentiation (RASD) is characterized by the reticulated proliferation of spinous cells with aggregates of mature sebocytes in the bases of the strands of the keratinocytes, often linking rete ridges. Here, we report the first case reported as RASD. A 55-year-old woman presented with a 15-year history of a slightly pruritic patch on the upper back, and the histology was typical for RASD. She had been bothered by a yellow discharge from the tumor. Skin tumors with sebaceous differentiation are occasionally associated with Muir-Torre syndrome. However, immunohistochemical staining for mutS homolog 2 (MSH-2) and mutL homolog 1 (MLH-1) showed positive staining within the nuclei of sebaceous cells and cells in the dermis. Therefore, it is most likely that the present case is not associated with Muir-Torre syndrome.
Dynamic optimization and differential games
Friesz, Terry L
2010-01-01
Dynamic Optimization and Differential Games has been written to address the increasing number of Operations Research and Management Science problems that involve the explicit consideration of time and of gaming among multiple agents. With end-of-chapter exercises throughout, it is a book that can be used both as a reference and as a textbook. It will be useful as a guide to engineers, operations researchers, applied mathematicians and social scientists whose work involves both the theoretical and computational aspects of dynamic optimization and differential games. Included throughout the text are detailed explanations of several original dynamic and game-theoretic mathematical models which are of particular relevance in today's technologically-driven-global economy: revenue management, oligopoly pricing, production planning, supply chain management, dynamic traffic assignment and dynamic congestion pricing. The book emphasizes deterministic theory, computational tools and applications associated with the stu...
[Differential diagnosis "vertigo and dizziness"].
Plontke, S K; Walther, L E
2014-08-01
Vertigo and dizziness are symptoms of interdisciplinary dimension. However, the differentiation and classification of vertigo syndromes also require experience and multidisciplinary knowledge. Since the clinical syndrome is subjective, a detailed analysis of the complaints underlying is required. International disease definitions are an indispensable tool in the differential diagnosis of vertigo syndromes today. With simple diagnostic tools eye movement disorders and nystagmus can be examined and assigned to specific vestibular disorders today. Screening tests (e.g. head impulse test) are now an important instrument in the investigation of patients with vertigo syndromes in case of emergency. With objective diagnostic methods (caloric irrigation, video head impulse test, vestibular evoked myogenic potentials) the degree of functional impairment of the five vestibular receptors can be assessed quantitatively. Furthermore, in vestibulopathies, a receptor and side-specific diagnostic assessment can be performed even with regard to dynamic aspects.
Differential growth of wrinkled biofilms
Espeso, D R; Einarsson, B
2015-01-01
Biofilms are antibiotic-resistant bacterial aggregates that grow on moist surfaces and can trigger hospital-acquired infections. They provide a classical example in biology where the dynamics of cellular communities may be observed and studied. Gene expression regulates cell division and differentiation, which affect the biofilm architecture. Mechanical and chemical processes shape the resulting structure. We gain insight into the interplay between cellular and mechanical processes during biofilm development on air-agar interfaces by means of a hybrid model. Cellular behavior is governed by stochastic rules informed by a cascade of concentration fields for nutrients, waste and autoinducers. Cellular differentiation and death alter the structure and the mechanical properties of the biofilm, which is deformed according to Foppl-Von Karman equations informed by cellular processes and the interaction with the substratum. Stiffness gradients due to growth and swelling produce wrinkle branching. We are able to repr...
Nielsen number and differential equations
Jan Andres
2005-06-01
Full Text Available In reply to a problem of Jean Leray (application of the Nielsen theory to differential equations, two main approaches are presented. The first is via PoincarÃƒÂ©'s translation operator, while the second one is based on the Hammerstein-type solution operator. The applicability of various Nielsen theories is discussed with respect to several sorts of differential equations and inclusions. Links with the Sharkovskii-like theorems (a finite number of periodic solutions imply infinitely many subharmonics are indicated, jointly with some further consequences like the nontrivial RÃŽÂ´-structure of solutions of initial value problems. Some illustrating examples are supplied and open problems are formulated.
Differential scanning calorimetry of coal
Gold, P. I.
1978-01-01
Differential scanning calorimetry studies performed during the first year of this project demonstrated the occurrence of exothermic reactions associated with the production of volatile matter in or near the plastic region. The temperature and magnitude of the exothermic peak were observed to be strongly affected by the heating rate, sample mass and, to a lesser extent, by sample particle size. Thermal properties also were found to be influenced by oxidation of the coal sample due to weathering effects.
Ufnarovski, Victor; Ahlander, Bo
2003-09-01
We define the derivative of an integer to be the map sending every prime to 1 and satisfying the Leibnitz rule. The aim of the article is to consider the basic properties of this map and to show how to generalize the notion to the case of rational and arbitrary real numbers. We make some conjectures and find some connections with Goldbach's Conjecture and the Twin Prime Conjecture. Finally, we solve the easiest associated differential equations and calculate the generating function.
Differential renormalization of gauge theories
Aguila, F. del; Perez-Victoria, M. [Dept. de Fisica Teorica y del Cosmos, Universidad de Granada, Granada (Spain)
1998-10-01
The scope of constrained differential renormalization is to provide renormalized expressions for Feynman graphs, preserving at the same time the Ward identities of the theory. It has been shown recently that this can be done consistently at least to one loop for Abelian and non-Abelian gauge theories. We briefly review these results, evaluate as an example the gluon self energy in both coordinate and momentum space, and comment on anomalies. (author) 9 refs, 1 fig., 1 tab
Interpolation and partial differential equations
MALIGRANDA, Lech; Persson, Lars-Erik; Wyller, John
1994-01-01
One of the main motivations for developing the theory of interpolation was to apply it to the theory of partial differential equations (PDEs). Nowadays interpolation theory has been developed in an almost unbelievable way {see the bibliography of Maligranda [Interpolation of Operators and Applications (1926-1990), 2nd ed. (Luleå University, Luleå, 1993), p. 154]}. In this article some model examples are presented which display how powerful this theory is when dealing with PDEs. One main aim i...
Impulsive differential inclusions with constrains
Tzanko Donchev
2006-05-01
Full Text Available In the paper, we study weak invariance of differential inclusions with non-fixed time impulses under compactness type assumptions. When the right-hand side is one sided Lipschitz an extension of the well known relaxation theorem is proved. In this case also necessary and sufficient condition for strong invariance of upper semi continuous systems are obtained. Some properties of the solution set of impulsive system (without constrains in appropriate topology are investigated.
Optimal control of motorsport differentials
Tremlett, A. J.; Massaro, M.; Purdy, D. J.; Velenis, E.; Assadian, F.; Moore, A. P.; Halley, M.
2015-12-01
Modern motorsport limited slip differentials (LSD) have evolved to become highly adjustable, allowing the torque bias that they generate to be tuned in the corner entry, apex and corner exit phases of typical on-track manoeuvres. The task of finding the optimal torque bias profile under such varied vehicle conditions is complex. This paper presents a nonlinear optimal control method which is used to find the minimum time optimal torque bias profile through a lane change manoeuvre. The results are compared to traditional open and fully locked differential strategies, in addition to considering related vehicle stability and agility metrics. An investigation into how the optimal torque bias profile changes with reduced track-tyre friction is also included in the analysis. The optimal LSD profile was shown to give a performance gain over its locked differential counterpart in key areas of the manoeuvre where a quick direction change is required. The methodology proposed can be used to find both optimal passive LSD characteristics and as the basis of a semi-active LSD control algorithm.
Farmer Income Differential in Regions
LU Qian; MIAO Shanshan
2006-01-01
China's success in reform and opening up policy for twenty years is regarded as China's miracles in the world,whereas the income differential widening phenomenon has been the focus of the policymakers and researchers. This article researches 1994-2003 China's rural regions income differential and its decomposition. The method this paper used to measure the disparity is Gini Index. There are many ways to compute it, so the easiest way to decompose Gini Index-Matrix method is adopted. And based on it, farmer's income could be divided into wage income, farming income,transfer income and property income according to its composition. The conclusion is that all of the indexes are between 0.2 and 0.3, at the comparatively average level. From the fluctuation trend, it increased from 1994 to 1995, while reduced from 1995 to 1996, fluctuated in 1997, and then diminished again. In general, farmer's regions income differential stays at comparatively average level, but it has the widening trend with time. Through decomposing Gini Index, wage income is the most important increasing factor, while farming income is the reducing factor.
Etiopathogenesis of Differentiated Thyroid Carcinomas
Tanja Makazlieva
2016-08-01
Full Text Available INTRODUCTION: Thyroid malignomas are a heterogeneous group of neoplasm consisting of most frequent differentiated encountered carcinomas, papillary and follicular thyroid carcinoma, then medullary thyroid carcinoma originating from neuroendocrine calcitonin-producing C-cells and rare forms of thyroid lymphomas arising from intrathyroidal lymphatic tissue, thyroid sarcomas and poorly differentiated anaplastic thyroid carcinoma. There are increasing numbers of epidemiological studies and publications that have suggested increased incidence rate of thyroid carcinomas. We have read, analysed and compare available reviews and original articles investigating different etiological factors in the development of thyroid carcinomas through Google Scholar and PubMed Database. DISCUSSION: Aetiology involved in the development of thyroid carcinomas is multifactorial and includes external influences, as well as constitutional predispositions and genetic etiological factors. The actual effect of environmental and constitutional factors is on promoting genetic and epigenetic alterations which result in cell proliferation and oncogenesis. Until now are identified numerous genetic alterations, assumed to have an important role in oncogenesis, with MAPK and PI3K-AKT as crucial signalling networks regulating growth, proliferation, differentiation and cell survival/apoptosis. CONCLUSION: This new molecular insight could have a crucial impact on diagnosis and also on improving and selecting an appropriate treatment to the patients with thyroid malignancies.
Differential morphology and image processing.
Maragos, P
1996-01-01
Image processing via mathematical morphology has traditionally used geometry to intuitively understand morphological signal operators and set or lattice algebra to analyze them in the space domain. We provide a unified view and analytic tools for morphological image processing that is based on ideas from differential calculus and dynamical systems. This includes ideas on using partial differential or difference equations (PDEs) to model distance propagation or nonlinear multiscale processes in images. We briefly review some nonlinear difference equations that implement discrete distance transforms and relate them to numerical solutions of the eikonal equation of optics. We also review some nonlinear PDEs that model the evolution of multiscale morphological operators and use morphological derivatives. Among the new ideas presented, we develop some general 2-D max/min-sum difference equations that model the space dynamics of 2-D morphological systems (including the distance computations) and some nonlinear signal transforms, called slope transforms, that can analyze these systems in a transform domain in ways conceptually similar to the application of Fourier transforms to linear systems. Thus, distance transforms are shown to be bandpass slope filters. We view the analysis of the multiscale morphological PDEs and of the eikonal PDE solved via weighted distance transforms as a unified area in nonlinear image processing, which we call differential morphology, and briefly discuss its potential applications to image processing and computer vision.
Differential correlation for sequencing data.
Siska, Charlotte; Kechris, Katerina
2017-01-19
Several methods have been developed to identify differential correlation (DC) between pairs of molecular features from -omics studies. Most DC methods have only been tested with microarrays and other platforms producing continuous and Gaussian-like data. Sequencing data is in the form of counts, often modeled with a negative binomial distribution making it difficult to apply standard correlation metrics. We have developed an R package for identifying DC called Discordant which uses mixture models for correlations between features and the Expectation Maximization (EM) algorithm for fitting parameters of the mixture model. Several correlation metrics for sequencing data are provided and tested using simulations. Other extensions in the Discordant package include additional modeling for different types of differential correlation, and faster implementation, using a subsampling routine to reduce run-time and address the assumption of independence between molecular feature pairs. With simulations and breast cancer miRNA-Seq and RNA-Seq data, we find that Spearman's correlation has the best performance among the tested correlation methods for identifying differential correlation. Application of Spearman's correlation in the Discordant method demonstrated the most power in ROC curves and sensitivity/specificity plots, and improved ability to identify experimentally validated breast cancer miRNA. We also considered including additional types of differential correlation, which showed a slight reduction in power due to the additional parameters that need to be estimated, but more versatility in applications. Finally, subsampling within the EM algorithm considerably decreased run-time with negligible effect on performance. A new method and R package called Discordant is presented for identifying differential correlation with sequencing data. Based on comparisons with different correlation metrics, this study suggests Spearman's correlation is appropriate for sequencing data
Abstract methods in partial differential equations
Carroll, Robert W
2012-01-01
Detailed, self-contained treatment examines modern abstract methods in partial differential equations, especially abstract evolution equations. Suitable for graduate students with some previous exposure to classical partial differential equations. 1969 edition.
Functional differential equations of third order
Tuncay Candan
2005-04-01
Full Text Available In this paper, we consider the third-order neutral functional differential equation with distributed deviating arguments. We give sufficient conditions for the oscillatory behavior of this functional differential equation.
Introduction to partial differential equations with applications
Zachmanoglou, E C
1988-01-01
This text explores the essentials of partial differential equations as applied to engineering and the physical sciences. Discusses ordinary differential equations, integral curves and surfaces of vector fields, the Cauchy-Kovalevsky theory, more. Problems and answers.
Applications of Differential Topology to Grid Generation.
1985-11-25
Differential Topology, Annals of Mathematics Studies Number 54, Princeton University Press, Princeton, New Jersey, 1966. * 4. Rudin, W., Principles of...Springer-Verlag, 1976. 8. Munkres, J. R., Elementary Differential Topology, Annals of Mathematics Studies Number 54, Princeton University Press
Handbook of differential equations stationary partial differential equations
Chipot, Michel
2006-01-01
This handbook is volume III in a series devoted to stationary partial differential quations. Similarly as volumes I and II, it is a collection of self contained state-of-the-art surveys written by well known experts in the field. The topics covered by this handbook include singular and higher order equations, problems near critically, problems with anisotropic nonlinearities, dam problem, T-convergence and Schauder-type estimates. These surveys will be useful for both beginners and experts and speed up the progress of corresponding (rapidly developing and fascinating) areas of mathematics. Ke
Partial differential equations possessing Frobenius integrable decompositions
Ma, Wen-Xiu [Department of Mathematics, University of South Florida, Tampa, FL 33620-5700 (United States)]. E-mail: mawx@cas.usf.edu; Wu, Hongyou [Department of Mathematical Sciences, Northern Illinois University, DeKalb, IL 60115-2888 (United States)]. E-mail: wu@math.niu.edu; He, Jingsong [Department of Mathematics, University of Science and Technology of China, Hefei, Anhui 230026 (China)]. E-mail: jshe@ustc.edu.cn
2007-04-16
Frobenius integrable decompositions are introduced for partial differential equations. A procedure is provided for determining a class of partial differential equations of polynomial type, which possess specified Frobenius integrable decompositions. Two concrete examples with logarithmic derivative Baecklund transformations are given, and the presented partial differential equations are transformed into Frobenius integrable ordinary differential equations with cubic nonlinearity. The resulting solutions are illustrated to describe the solution phenomena shared with the KdV and potential KdV equations.
Cubical version of combinatorial differential forms
Kock, Anders
2010-01-01
The theory of combinatorial differential forms is usually presented in simplicial terms. We present here a cubical version; it depends on the possibility of forming affine combinations of mutual neighbour points in a manifold, in the context of synthetic differential geometry.......The theory of combinatorial differential forms is usually presented in simplicial terms. We present here a cubical version; it depends on the possibility of forming affine combinations of mutual neighbour points in a manifold, in the context of synthetic differential geometry....
A reformulation of an ordinary differential equation
Barraza, Oscar A.
2013-01-01
The purpose of this note is to present a formulation of a given nonlinear ordinary differential equation into an equivalent system of linear ordinary differential equations. It is evident that the easiness of a such procedure would be able to open a new way in order to calculate or approximate the solution of an ordinary differential equation. Some examples are presented.
Differential Fee: From Conceptualisation to Implementation.
Ng, Todd C. Y.; Wong, Andrew L. S.
A differential fee policy was adopted at the Open Learning Institute (OLI) of Hong Kong after a process of conceptualization, planning, proposal, approval and implementation. Under the differential fee policy different tuition rates were charged for different courses. The differential fee policy was conceptualized at OLI based on economics,…
Formal theory for differential-difference operators
Faber, B.F.; Put, M. van der
2001-01-01
Differential-difference operators are linear operators involving both d/dz and the shift z ↦ z + 1 (or z(d/dz) and z ↦ qz). The aim is to give a formal classification and to provide solutions for these equations. Differential-difference operators can be considered as formal differential operators of
On Theories of Superalgebras of Differentiable Functions
Carchedi, D.J.; Roytenberg, D.
2013-01-01
This is the first in a series of papers laying the foundations for a differential graded approach to derived differential geometry (and other geometries in characteristic zero). In this paper, we study theories of supercommutative algebras for which infinitely differentiable functions can be
A cellular modelsystem of differentiated human myotubes
Gaster, M; Kristensen, S R; Beck-Nielsen, H
2001-01-01
The aim of this study was to select an effective and stable protocol for the differentiation of human satellite cells (Sc) and to identify the optimal time period for the experimental use of differentiated human Sc-cultures. In order to identify the differentiation conditions which give a good su...
Differentiation: A Strategic Response to Student Needs
Hedrick, Kelly A.
2012-01-01
Virginia Beach City Public Schools had decided to embrace differentiation as its philosophy of instruction. Differentiation was added to the teacher evaluation rubric, and by 2003 Virginia Beach launched full force into a division-wide focus on Carol Ann Tomlinson's model for differentiation. (Tomlinson is the author of several books on the…
On Theories of Superalgebras of Differentiable Functions
Carchedi, D.J.; Roytenberg, D.
2013-01-01
This is the first in a series of papers laying the foundations for a differential graded approach to derived differential geometry (and other geometries in characteristic zero). In this paper, we study theories of supercommutative algebras for which infinitely differentiable functions can be evaluat
Two Notes on Numerical Differentiation Formulae
ZHENG Hua-sheng
2012-01-01
Some new conclusions on asymptotic properties and inverse problems of numerical differentiation formulae have been drawn in this paper.In the first place,several asymptotic properties of intermediate points of numerical differentiation formulae are presented by using Taylor's formula.And then,based on the ideas of algebraic accuracy,several inverse problems of numerical differentiation formulae are given.
Teaching Differentials in Thermodynamics Using Spatial Visualization
Wang, Chih-Yueh; Hou, Ching-Han
2012-01-01
The greatest difficulty that is encountered by students in thermodynamics classes is to find relationships between variables and to solve a total differential equation that relates one thermodynamic state variable to two mutually independent state variables. Rules of differentiation, including the total differential and the cyclic rule, are…
Teaching Differentials in Thermodynamics Using Spatial Visualization
Wang, Chih-Yueh; Hou, Ching-Han
2012-01-01
The greatest difficulty that is encountered by students in thermodynamics classes is to find relationships between variables and to solve a total differential equation that relates one thermodynamic state variable to two mutually independent state variables. Rules of differentiation, including the total differential and the cyclic rule, are…
Differential rotation of geomagnetic field
WEI Zigang; XU Wenyao
2003-01-01
The latitudinal dependence of the westward drift in the main geomagnetic field is examined by using the correlation analysis of moving random pattern. The study reveals the characteristics in the differential rotation of the main field. The results show that the global geomagnetic field drifts westward with an average speed of 0.18°/a during 1900-2000. The westward drift rate is not symmetrical with respect to the equator. The maximum westward drift rate, 0.31°/a, occurs at the latitude --= -15°, forming a Rapid Westward Drift Belt (RDB) around this latitude. Going northward and southward from this belt, the drift rate decreases and reaches the minimum (0.12°/a) at --= 50° and the minimum (0.14°/a) at --= -56°, forming a Northern Hemisphere Slow Westward Drift Belt (N-SDB) and a Southern Hemisphere Slow Westward Drift Belt (S-SDB). Three phases can be detected in the evolution of the westward drift. In the first phase (1900-1940), the RDB dominates the global drift pattern. The westward drifts in this belt are much faster than those in other areas. In the second phase (1940-1960), the drift rates in the RDB are less than those in the first phase, while the drifts in the N-SDB and S-SDB are relatively large. In this phase, the differential rotation becomes less obvious. In the third phase (1960-2000), the westward drift in the RDB increases again and the differential rotation gradually becomes apparent.
Pulsed feedback defers cellular differentiation.
Joe H Levine
2012-01-01
Full Text Available Environmental signals induce diverse cellular differentiation programs. In certain systems, cells defer differentiation for extended time periods after the signal appears, proliferating through multiple rounds of cell division before committing to a new fate. How can cells set a deferral time much longer than the cell cycle? Here we study Bacillus subtilis cells that respond to sudden nutrient limitation with multiple rounds of growth and division before differentiating into spores. A well-characterized genetic circuit controls the concentration and phosphorylation of the master regulator Spo0A, which rises to a critical concentration to initiate sporulation. However, it remains unclear how this circuit enables cells to defer sporulation for multiple cell cycles. Using quantitative time-lapse fluorescence microscopy of Spo0A dynamics in individual cells, we observed pulses of Spo0A phosphorylation at a characteristic cell cycle phase. Pulse amplitudes grew systematically and cell-autonomously over multiple cell cycles leading up to sporulation. This pulse growth required a key positive feedback loop involving the sporulation kinases, without which the deferral of sporulation became ultrasensitive to kinase expression. Thus, deferral is controlled by a pulsed positive feedback loop in which kinase expression is activated by pulses of Spo0A phosphorylation. This pulsed positive feedback architecture provides a more robust mechanism for setting deferral times than constitutive kinase expression. Finally, using mathematical modeling, we show how pulsing and time delays together enable "polyphasic" positive feedback, in which different parts of a feedback loop are active at different times. Polyphasic feedback can enable more accurate tuning of long deferral times. Together, these results suggest that Bacillus subtilis uses a pulsed positive feedback loop to implement a "timer" that operates over timescales much longer than a cell cycle.
Strebel differentials and Hamilton sequences
LI; Zhong(
2001-01-01
［1］Strebel, K., Point shift differentials and extremal quasiconformal mappings, Annale Acad. Scle. Fenn. Math., 1998, 23: 475 -494.［2］Gardiner, F. P., Approximation of infinite dimensional Teichmutller space, Trans. Amer. Soc., 1999, 282: 367-383.［3］Lakic, N. , The Strebel points, Comptemp. Math. , 1997, 211: 417-431.［4］Wu Sheng jian, Hamilton sequences for extremal quasiconformal mappings of the unit disc, Science in China, Ser. A, 1999,42(10): 1033-1042.［5］Li Zhong, Qi Yi, A note on point shift differentials, Science in China, Ser. A, 1999, 42(5): 449-455.［6］Hamilton, R. S., Extremal quasiconformal mappings with prescribed boundary values, Trans. Amer. Math. Soc. , 1969,138: 399-406.［7］Krushkal, S. , Extremal quasiconformal mappings, Sirbirsk. Mat. Zh., 1969, 10: 573-583.［8］Reich, E., Strebel, K., Extremal quasiconformal mappings with given boundary values, Contributions to Analysis, New York: Academic Press, 1974, 375-391.［9］Strebel, K. , On quasiconformal mappings of open Riemann surfaces, Commemt. Math. Helr., 1978, 53: 301-321.［10］Earle, C., Li Zhong, Extremal quasiconformal mappings in plane domains, Quasiconformal Mappings and Analysis A Col-lection of Papers Honoring F. W. Gehring, New York: Springer-Verlag, 1998, 141-158.［11］Strebel, K., On quadratic differentials and extremal quasiconforrnal mappings, in Proc. of the Intern. Congress of Math.,Vancouver, 1974.［12］Li Zhong, Some new results on the geometry of infinite dimensional Teichmuller space, in Proceedings of the 3rd International Colloquium on Finite or Infinite Dimensional Complex Analysis, 1995, 369-378.
Lectures on ordinary differential equations
Hurewicz, Witold
2014-01-01
Hailed by The American Mathematical Monthly as ""a rigorous and lively introduction,"" this text explores a topic of perennial interest in mathematics. The author, a distinguished mathematician and formulator of the Hurewicz theorem, presents a clear and lucid treatment that emphasizes geometric methods. Topics include first-order scalar and vector equations, basic properties of linear vector equations, and two-dimensional nonlinear autonomous systems. Suitable for senior mathematics students, the text begins with an examination of differential equations of the first order in one unknown funct
Pursuit-evasion differential games
Yavin, Y
1987-01-01
Twenty papers are devoted to the treatment of a wide spectrum of problems in the theory and applications of dynamic games with the emphasis on pursuit-evasion differential games. The problem of capturability is thoroughly investigated, also the problem of noise-corrupted (state) measurements. Attention is given to aerial combat problems and their attendant modelling issues, such as variable speed of the combatants, the three-dimensionality of physical space, and the combat problem, i.e. problems related to 'role determination'.
Approximation of continuously differentiable functions
Llavona, JG
1986-01-01
This self-contained book brings together the important results of a rapidly growing area.As a starting point it presents the classic results of the theory. The book covers such results as: the extension of Wells'' theorem and Aron''s theorem for the fine topology of order m; extension of Bernstein''s and Weierstrass'' theorems for infinite dimensional Banach spaces; extension of Nachbin''s and Whitney''s theorem for infinite dimensional Banach spaces; automatic continuity of homomorphisms in algebras of continuously differentiable functions, etc.
Matlab differential and integral calculus
Lopez, Cesar
2014-01-01
MATLAB is a high-level language and environment for numerical computation, visualization, and programming. Using MATLAB, you can analyze data, develop algorithms, and create models and applications. The language, tools, and built-in math functions enable you to explore multiple approaches and reach a solution faster than with spreadsheets or traditional programming languages, such as C/C++ or Java. MATLAB Differential and Integral Calculus introduces you to the MATLAB language with practical hands-on instructions and results, allowing you to quickly achieve your goals. In addition to givi
Multidimensional real analysis I differentiation
Duistermaat, J J; van Braam Houckgeest, J P
2004-01-01
Part one of the authors' comprehensive and innovative work on multidimensional real analysis. This book is based on extensive teaching experience at Utrecht University and gives a thorough account of differential analysis in multidimensional Euclidean space. It is an ideal preparation for students who wish to go on to more advanced study. The notation is carefully organized and all proofs are clean, complete and rigorous. The authors have taken care to pay proper attention to all aspects of the theory. In many respects this book presents an original treatment of the subject and it contains man
Partial differential equations an introduction
Colton, David
2004-01-01
Intended for a college senior or first-year graduate-level course in partial differential equations, this text offers students in mathematics, engineering, and the applied sciences a solid foundation for advanced studies in mathematics. Classical topics presented in a modern context include coverage of integral equations and basic scattering theory. This complete and accessible treatment includes a variety of examples of inverse problems arising from improperly posed applications. Exercises at the ends of chapters, many with answers, offer a clear progression in developing an understanding of
Loop equations from differential systems
Eynard, Bertrand; Marchal, Olivier
2016-01-01
To any differential system $d\\Psi=\\Phi\\Psi$ where $\\Psi$ belongs to a Lie group (a fiber of a principal bundle) and $\\Phi$ is a Lie algebra $\\mathfrak g$ valued 1-form on a Riemann surface $\\Sigma$, is associated an infinite sequence of "correlators" $W_n$ that are symmetric $n$-forms on $\\Sigma^n$. The goal of this article is to prove that these correlators always satisfy "loop equations", the same equations satisfied by correlation functions in random matrix models, or the same equations as Virasoro or W-algebra constraints in CFT.
Marussi Hypothesis in Differential Geodesy
1994-06-13
writings. IHow- vver , since the b~road cotit ext of t heir I heor ’% is wel l-4ined, i.e. it is t he physical differential geoinet r.. of thle gravi...and knowing that his audience would not be familiar with his motivation and viewpoint, they were unusually detailed and included material assumed...understand his procedure, one must carefully delete the unnecessary material , or to borrow a famous comment of Dirac ’eliminate the dead- wood’ from the
Lectures on classical differential geometry
Struik, Dirk J
1988-01-01
Elementary, yet authoritative and scholarly, this book offers an excellent brief introduction to the classical theory of differential geometry. It is aimed at advanced undergraduate and graduate students who will find it not only highly readable but replete with illustrations carefully selected to help stimulate the student's visual understanding of geometry. The text features an abundance of problems, most of which are simple enough for class use, and often convey an interesting geometrical fact. A selection of more difficult problems has been included to challenge the ambitious student.Writ
Adipocyte differentiation and leptin expression
Hwang, C S; Loftus, T M; Mandrup, S
1997-01-01
, most notably those of the C/EBP and PPAR families, which combine to regulate each other and to control the expression of adipocyte-specific genes. One such gene, i.e. the obese gene, was recently identified and found to encode a hormone, referred to as leptin, that plays a major role in the regulation...... of energy intake and expenditure. The hormonal and transcriptional control of adipocyte differentiation is discussed, as is the role of leptin and other factors secreted by the adipocyte that participate in the regulation of adipose homeostasis....
Non-differentiable variational principles
Cresson, Jacky
2005-07-01
We develop a calculus of variations for functionals which are defined on a set of non-differentiable curves. We first extend the classical differential calculus in a quantum calculus, which allows us to define a complex operator, called the scale derivative, which is the non-differentiable analogue of the classical derivative. We then define the notion of extremals for our functionals and obtain a characterization in term of a generalized Euler-Lagrange equation. We finally prove that solutions of the Schrödinger equation can be obtained as extremals of a non-differentiable variational principle, leading to an extended Hamilton's principle of least action for quantum mechanics. We compare this approach with the scale relativity theory of Nottale, which assumes a fractal structure of space-time.Résumé (Principes variationnels non différentiable). Nous développons un calcul des variations pour des fonctionnelles définies sur un ensemble de courbes non différentiables. Pour cela, nous étendons le calcul différentiel classique, en calcul appelé calcul quantique, qui nous permet de définir un opérateur à valeur complexes, appelé dérivée d'échelle, qui est l'analogue non différentiable de la dérivée usuelle. On définit alors la notion d'extremale pour ces fonctionnelles pour lesquelles nous obtenons une caractérisation via une équation d'Euler-Lagrange généralisée. On prouve enfin que les solutions de l'équation de Schrödinger peuvent s'obtenir comme solution d'un problème variationnel non différentiable, étendant ainsi le principe de moindre action de Hamilton au cadre de la mécanique quantique. On discute enfin la connexion entre ce travail et la théorie de la relativité d'échelle développée par Nottale, et qui suppose une structure fractale de l'espace-temps.
Stability theory of differential equations
Bellman, Richard
2008-01-01
Suitable for advanced undergraduates and graduate students, this was the first English-language text to offer detailed coverage of boundedness, stability, and asymptotic behavior of linear and nonlinear differential equations. It remains a classic guide, featuring material from original research papers, including the author's own studies.The linear equation with constant and almost-constant coefficients receives in-depth attention that includes aspects of matrix theory. No previous acquaintance with the theory is necessary, since author Richard Bellman derives the results in matrix theory from
Early planetary differentiation: Geophysical consequences
Schubert, G.
1992-01-01
Differentiation of a planet can have profound consequences for its structure and thermal evolution, including core formation and crystal growth. Recent theories for the origin and evolution of the terrestrial planets and the Moon have all these bodies forming hot and cooling thereafter. Early core formation, and in the cases of Earth and Moon, a deep magma ocean possibly encompassing the entire mantle are characteristic features of these models. Secular cooling of Mars from a hot origin and cooling of Moon from a hot initial state with a deep magma ocean have been criticized on the basis of their tectonic implications. The cases of Mars and the Moon are discussed.
Applied analysis and differential equations
Cârj, Ovidiu
2007-01-01
This volume contains refereed research articles written by experts in the field of applied analysis, differential equations and related topics. Well-known leading mathematicians worldwide and prominent young scientists cover a diverse range of topics, including the most exciting recent developments. A broad range of topics of recent interest are treated: existence, uniqueness, viability, asymptotic stability, viscosity solutions, controllability and numerical analysis for ODE, PDE and stochastic equations. The scope of the book is wide, ranging from pure mathematics to various applied fields such as classical mechanics, biomedicine, and population dynamics.
Nonferromagnetic linear variable differential transformer
Ellis, James F.; Walstrom, Peter L.
1977-06-14
A nonferromagnetic linear variable differential transformer for accurately measuring mechanical displacements in the presence of high magnetic fields is provided. The device utilizes a movable primary coil inside a fixed secondary coil that consists of two series-opposed windings. Operation is such that the secondary output voltage is maintained in phase (depending on polarity) with the primary voltage. The transducer is well-suited to long cable runs and is useful for measuring small displacements in the presence of high or alternating magnetic fields.
Linearized asymptotic stability for fractional differential equations
Nguyen Cong
2016-06-01
Full Text Available We prove the theorem of linearized asymptotic stability for fractional differential equations. More precisely, we show that an equilibrium of a nonlinear Caputo fractional differential equation is asymptotically stable if its linearization at the equilibrium is asymptotically stable. As a consequence we extend Lyapunov's first method to fractional differential equations by proving that if the spectrum of the linearization is contained in the sector $\\{\\lambda \\in \\mathbb{C} : |\\arg \\lambda| > \\frac{\\alpha \\pi}{2}\\}$ where $\\alpha > 0$ denotes the order of the fractional differential equation, then the equilibrium of the nonlinear fractional differential equation is asymptotically stable.
Hossein Jafari
2016-04-01
Full Text Available The non-differentiable solution of the linear and non-linear partial differential equations on Cantor sets is implemented in this article. The reduced differential transform method is considered in the local fractional operator sense. The four illustrative examples are given to show the efficiency and accuracy features of the presented technique to solve local fractional partial differential equations.
Sobolev gradients and differential equations
Neuberger, J W
2010-01-01
A Sobolev gradient of a real-valued functional on a Hilbert space is a gradient of that functional taken relative to an underlying Sobolev norm. This book shows how descent methods using such gradients allow a unified treatment of a wide variety of problems in differential equations. For discrete versions of partial differential equations, corresponding Sobolev gradients are seen to be vastly more efficient than ordinary gradients. In fact, descent methods with these gradients generally scale linearly with the number of grid points, in sharp contrast with the use of ordinary gradients. Aside from the first edition of this work, this is the only known account of Sobolev gradients in book form. Most of the applications in this book have emerged since the first edition was published some twelve years ago. What remains of the first edition has been extensively revised. There are a number of plots of results from calculations and a sample MatLab code is included for a simple problem. Those working through a fair p...
Origin and differentiation of microglia
Florent eGinhoux
2013-04-01
Full Text Available Microglia are the resident macrophage population of the central nervous system (CNS. Adequate microglial function is crucial for a healthy CNS. Microglia are not only the first immune sentinels of infection, contributing to both innate and adaptive immune responses locally, but are also involved in the maintenance of brain homeostasis. Emerging data are showing new and fundamental roles for microglia in the control of neuronal proliferation and differentiation, as well as in the formation of synaptic connections. While microglia have been studied for decades, a long history of experimental misinterpretation meant that their true origins remained debated. However, recent studies on microglial origin indicate that these cells in fact arise early during development from progenitors in the embryonic yolk sac that seed the brain rudiment and, remarkably, appear to persist there into adulthood. Here, we review the history of microglial cells and discuss the latest advances in our understanding of their origin, differentiation and homeostasis, which provides new insights into their roles in health and disease.
Differentiation of Phytopathogenic Agrobacterium spp.
Nemanja Kuzmanović
2011-01-01
Full Text Available Due to the difficulties in differentiation of phytopathogenic Agrobacterium spp. and lack of a standardized protocol, we carried out selection and evaluation of suitable methods based on the bacterial physiological, genetic and pathogenic properties. Strains of Agrobacterium tumefaciens, A. rhizogenes and A. vitis were differentiated using standard bacteriological and molecular methods. The biochemical and physiological tests confirmed authenticity of the strains. Two duplex PCR methods were conducted with four different primer pairs. In all strains, presence of plasmid virD2 and virC pathogenicity genes was detected. Chromosomal pehA gene was determined in A. vitis strain. Pathogenicity was confirmed on carrot slices and young plants of tomato and sunflower. Strains of A. tumefaciens and A. vitis were pathogenic on all test plants, while strain of A. rhizogenes induced characteristic symptoms only on carrot slices. The tests used in this study provided reliable discrimination between the three species and confirmed their identity as tumorigenic (TiAgrobacterium tumefaciens and A. vitis, and rhizogenic (Ri A. rhizogenes.
Differential Performance on National Exams
Syed Latifi
2016-06-01
Full Text Available The purpose of this study is to evaluate two methodological perspectives of test fairness using a national Secondary School Certificate (SSC examinations. SSC is a suit of multi-subject national qualification tests at Grade 10 level in South Asian countries, such as Bangladesh, India, and Pakistan. Because it is a high-stakes test, the fairness of SSC tests is a major concern among public and educational policy planners. This study is a first attempt to investigate test fairness of the national SSC examination of Pakistan using two independent differential item functioning (DIF and differential bundle functioning (DBF procedures. The SSC was evaluated for possible gender bias using multiple-choice tests in three core subjects, namely, English, Mathematics, and Physics. The study was conducted in two phases using explanatory item response model (EIRM and Simultaneous Item Bias Test (SIBTEST. In Phase 1, test items were studied for DIF, and items with severe DIF were flagged in each subject. In Phase 2, the item bundles were analyzed for DBF. Three items were detected with large DIF, one for each subject, and one item bundle was detected with a negligible DBF. Taken together, the results demonstrate that there is no major threat to the validity of the interpretation of examinees’ test scores on the SSC examination. The outcome from this study provided evidence for test fairness, which will enhance test development practices at the national examination authorities.
CPG OLIGONUCLEOTIDES REGULATE OSTEOCLAST DIFFERENTIATION
Zhao Weigong; Han Xuezhe; Li Xinyou; Guo Xong; Liu Miao
2005-01-01
Objective Bacterial DNA is a pathogen-derived molecule which can regulate the innate immune system by stimulating NF-κB activation. The activity of bacterial DNA relies on its content of unmethylated CpG dinucleotides in particular base contexts("CpG motif"). In light of the pivotal role played by NF-κB in osteoclast differentiation, the ability of CpG oligodeoxynucleotides (CpG ODN) coming from bacterial DNA to modulate osteoclastogenesis was studied. Methods Bone marrow mononuclear cells (BMM) were purified from Balb/c mice, cultured in α-MEM media containing 10% FCS in the presence of mouse M-CSF, with either RANKL or ODNs for 5 days. Osteoclast formation was evaluated on day 5 according to TRAP and May-Grunwald-Giemsa staining. Results CpG ODN alone could induce osteoclast formation in the low degree in BMM culture. The relationship between CpG ODN and RANKL was that CpG ODN could inhibit RANKL-induced osteoclastogenesis when present from the beginning of BMM culture, but strongly increased RANKL-induced osteoclastogenesis in RANKL-pretreated BMMs. Conclusion The mechanism of CpG ODN regulating osteoclast differentiation was bidirectional, which might be a potential therapy for treating metabolic bone disease.
DIFFERENTIATING PERIMORTEM AND POSTMORTEM BURNING
Brahmaji Master
2015-01-01
Full Text Available One of the most challenging cases in forensic medicine is ascertaining the cause of death of burnt bodies under suspicious circumstances. The key questions that arise at the time of investigation include: 1 Was the person alive or dead prior to fire accident? Did the victim die because of burn? If death was not related to burns, could burns play a role in causing death? Were the burns sustained accidentally, did the person commit suicide or was the person murdered? Are the circumstances suggesting an attempt to conceal crime? How was the fire started? How was the victim identified? In case of mass fatalities, who died first? Postmortem burning of corpses is supposed to be one of the ways to hide a crime. Differentiating the actual cause of death in burn patients is therefore important. Medical examiners usually focus on the defining the changes that occur in tissues while forensic anthropologists deal with the changes related to the bone with or without any the influence of other tissues. Under the circumstances of fire, differentiating the perimortem trauma from that of postmortem cause of bone fractures is vital in determining the cause and motive of death
Relativistic differential-difference momentum operators and noncommutative differential calculus
Mir-Kasimov, R. M.
2013-09-01
The relativistic kinetic momentum operators are introduced in the framework of the Quantum Mechanics (QM) in the Relativistic Configuration Space (RCS). These operators correspond to the half of the non-Euclidean distance in the Lobachevsky momentum space. In terms of kinetic momentum operators the relativistic kinetic energy is separated as the independent term of the total Hamiltonian. This relativistic kinetic energy term is not distinguishing in form from its nonrelativistic counterpart. The role of the plane wave (wave function of the motion with definite value of momentum and energy) plays the generating function for the matrix elements of the unitary irreps of Lorentz group (generalized Jacobi polynomials). The kinetic momentum operators are the interior derivatives in the framework of the noncommutative differential calculus over the commutative algebra generated by the coordinate functions over the RCS.
Differential geometry based multiscale models.
Wei, Guo-Wei
2010-08-01
Large chemical and biological systems such as fuel cells, ion channels, molecular motors, and viruses are of great importance to the scientific community and public health. Typically, these complex systems in conjunction with their aquatic environment pose a fabulous challenge to theoretical description, simulation, and prediction. In this work, we propose a differential geometry based multiscale paradigm to model complex macromolecular systems, and to put macroscopic and microscopic descriptions on an equal footing. In our approach, the differential geometry theory of surfaces and geometric measure theory are employed as a natural means to couple the macroscopic continuum mechanical description of the aquatic environment with the microscopic discrete atomistic description of the macromolecule. Multiscale free energy functionals, or multiscale action functionals are constructed as a unified framework to derive the governing equations for the dynamics of different scales and different descriptions. Two types of aqueous macromolecular complexes, ones that are near equilibrium and others that are far from equilibrium, are considered in our formulations. We show that generalized Navier-Stokes equations for the fluid dynamics, generalized Poisson equations or generalized Poisson-Boltzmann equations for electrostatic interactions, and Newton's equation for the molecular dynamics can be derived by the least action principle. These equations are coupled through the continuum-discrete interface whose dynamics is governed by potential driven geometric flows. Comparison is given to classical descriptions of the fluid and electrostatic interactions without geometric flow based micro-macro interfaces. The detailed balance of forces is emphasized in the present work. We further extend the proposed multiscale paradigm to micro-macro analysis of electrohydrodynamics, electrophoresis, fuel cells, and ion channels. We derive generalized Poisson-Nernst-Planck equations that are
Stochastic integration and differential equations
Protter, Philip E
2003-01-01
It has been 15 years since the first edition of Stochastic Integration and Differential Equations, A New Approach appeared, and in those years many other texts on the same subject have been published, often with connections to applications, especially mathematical finance. Yet in spite of the apparent simplicity of approach, none of these books has used the functional analytic method of presenting semimartingales and stochastic integration. Thus a 2nd edition seems worthwhile and timely, though it is no longer appropriate to call it "a new approach". The new edition has several significant changes, most prominently the addition of exercises for solution. These are intended to supplement the text, but lemmas needed in a proof are never relegated to the exercises. Many of the exercises have been tested by graduate students at Purdue and Cornell Universities. Chapter 3 has been completely redone, with a new, more intuitive and simultaneously elementary proof of the fundamental Doob-Meyer decomposition theorem, t...
Functional methods in differential equations
Hokkanen, Veli-Matti
2002-01-01
In recent years, functional methods have become central to the study of theoretical and applied mathematical problems. As demonstrated in this Research Note, functional methods can not only provide more generality, but they can also unify results and techniques and lead to better results than those obtained by classical methods. Presenting entirely original results, the authors use functional methods to explore a broad range of elliptic, parabolic, and hyperbolic boundary value problems and various classes of abstract differential and integral equations. They show that while it is crucial to choose an appropriate functional framework, this approach can lead to mathematical models that better describe concrete physical phenomena. In particular, they reach a concordance between the physical sense and the mathematical sense for the solutions of some special models. Beyond its importance as a survey of the primary techniques used in the area, the results illuminated in this volume will prove valuable in a wealth ...
BLIND DIFFERENTIAL ADAPTIVE MULTIUSER DETECTION
无
2000-01-01
In this paper, a new blind equalization cost function, termed differential mean output energy (DMOE), was presented, and a new multiuser detection algorithm with variable step size was designed. It is shown through simulation results for a co-channel system involving severe MAI that the DMOE algorithm gives significantly enhanced signal to interference ratio (SIR) performance and converges rapidly to the optimum MMSE detector, together with a low computational complexity requirement relative to the recursive least squares (RLS) algorithm. Thus, it is not necessary to switch to the decision-directed mode. Moreover, it also exhibits global convergence, and can be used in different interference environment without the requirement of estimating and restricting the surplus energy.
Sobolev gradients and differential equations
Neuberger, John William
1997-01-01
A Sobolev gradient of a real-valued functional is a gradient of that functional taken relative to the underlying Sobolev norm. This book shows how descent methods using such gradients allow a unified treatment of a wide variety of problems in differential equations. Equal emphasis is placed on numerical and theoretical matters. Several concrete applications are made to illustrate the method. These applications include (1) Ginzburg-Landau functionals of superconductivity, (2) problems of transonic flow in which type depends locally on nonlinearities, and (3) minimal surface problems. Sobolev gradient constructions rely on a study of orthogonal projections onto graphs of closed densely defined linear transformations from one Hilbert space to another. These developments use work of Weyl, von Neumann and Beurling.
Transcriptional Regulation and Macrophage Differentiation.
Hume, David A; Summers, Kim M; Rehli, Michael
2016-06-01
Monocytes and macrophages are professional phagocytes that occupy specific niches in every tissue of the body. Their survival, proliferation, and differentiation are controlled by signals from the macrophage colony-stimulating factor receptor (CSF-1R) and its two ligands, CSF-1 and interleukin-34. In this review, we address the developmental and transcriptional relationships between hematopoietic progenitor cells, blood monocytes, and tissue macrophages as well as the distinctions from dendritic cells. A huge repertoire of receptors allows monocytes, tissue-resident macrophages, or pathology-associated macrophages to adapt to specific microenvironments. These processes create a broad spectrum of macrophages with different functions and individual effector capacities. The production of large transcriptomic data sets in mouse, human, and other species provides new insights into the mechanisms that underlie macrophage functional plasticity.
Wage differentials due to gender.
Smith, N; Westergard-nielsen, N
1988-10-01
"In this paper, a longitudinal data set covering 5% of all Danish wage earners over a 9-year period is used to shed light on the observed wage differentials due to gender. A human capital model is used to isolate the effects of changes in experience, schooling and unemployment, together with other factors.... Despite the observation from macro statistics that women have had the highest observed increases in wage rates, the models show that this increase is mainly due to an improvement in their background characteristics and that men still receive a higher return to their characteristics. The main difference between genders appears to be that female workers do not, in general, get any return to their experience. The estimates also show negative effects on the wage rate of previous spells of unemployment." excerpt
An introduction to differential equations
Ladde, Anil G
2012-01-01
This is a twenty-first century book designed to meet the challenges of understanding and solving interdisciplinary problems. The book creatively incorporates "cutting-edge" research ideas and techniques at the undergraduate level. The book also is a unique research resource for undergraduate/graduate students and interdisciplinary researchers. It emphasizes and exhibits the importance of conceptual understandings and its symbiotic relationship in the problem solving process. The book is proactive in preparing for the modeling of dynamic processes in various disciplines. It introduces a "break-down-the problem" type of approach in a way that creates "fun" and "excitement". The book presents many learning tools like "step-by-step procedures (critical thinking)", the concept of "math" being a language, applied examples from diverse fields, frequent recaps, flowcharts and exercises. Uniquely, this book introduces an innovative and unified method of solving nonlinear scalar differential equations. This is called ...
[Differential diagnosis in potency disorders].
Kockott, G; Dittmar, F
1976-12-02
Disorders of sexual libido are seldom organic, in general they are of psychological origin. It is, however, difficult to obtain a differential diagnosis. One of the first diagnostic considerations must be the establishment of primary or secondary libidinal dificit, or indeed, whether there is no libido at all. In cases of libido disorders with primary libido dificit, depression, organic disease, or side effects of pharmaca may be the cause. Libido disorders in the presence of functional libido, however, must be regarded as primarily psychologically caused. An exception are libido problems in the presence of diabetes mellitus and peripheral vasculatory defeciencies. In these cases libido is either totally absent or appears only secondarily. The symptomatology of libido disorders in the presence of depression, diabetes melitus, and peripheral vasculatory disturbancies, as well as psychologically caused erectile and ejaculatory difficulties are discussed in detail. These groups are compared with respect to libido and behavior involving erection, ejaculation, anxiety and avoidance.
Fat Triangulations and Differential Geometry
Saucan, Emil
2011-01-01
We study the differential geometric consequences of our previous result on the existence of fat triangulations, in conjunction with a result of Cheeger, M\\"{u}ller and Schrader, regarding the convergence of Lipschitz-Killing curvatures of piecewise-flat approximations of smooth Riemannian manifolds. A further application to the existence of quasiconformal mappings between manifolds, as well as an extension of the triangulation result to the case of almost Riemannian manifolds, are also given. In addition, the notion of fatness of triangulations and its relation to metric curvature and to excess is explored. Moreover, applications of the main results, and in particular a purely metric approach to Regge calculus, are also investigated.
Thyroglobulin in differentiated thyroid cancer.
Evans, Carol; Tennant, Sarah; Perros, Petros
2015-04-15
Identification of differentiated thyroid cancer (DTC) is becoming increasingly common. Patients usually have an excellent prognosis. Most undergo total thyroidectomy, radioiodine ablation and treatment with suppressive doses of levothyroxine. Patients require long term follow-up which includes measurement of serum thyroglobulin (Tg). Interpretation of serum Tg requires knowledge of the concurrent thyroid stimulating hormone (TSH) concentration, as secretion is TSH dependant, and an awareness of the limitations of the methods used to measure it. These limitations include the heterogeneity of Tg in serum, the ability of assays to recognise forms of Tg secreted by a tumour, assay biases and not least the potential for interference in immunoassays for Tg from endogenous thyroglobulin antibodies (TgAbs) in patient serum. This review considers what the clinician wants to know and how Tg results can be interpreted in light of an awareness of assay limitations.
Differentially Private Support Vector Machines
Sarwate, Anand; Monteleoni, Claire
2009-01-01
This paper addresses the problem of practical privacy-preserving machine learning: how to detect patterns in massive, real-world databases of sensitive personal information, while maintaining the privacy of individuals. Chaudhuri and Monteleoni (2008) recently provided privacy-preserving techniques for learning linear separators via regularized logistic regression. With the goal of handling large databases that may not be linearly separable, we provide privacy-preserving support vector machine algorithms. We address general challenges left open by past work, such as how to release a kernel classifier without releasing any of the training data, and how to tune algorithm parameters in a privacy-preserving manner. We provide general, efficient algorithms for linear and nonlinear kernel SVMs, which guarantee $\\epsilon$-differential privacy, a very strong privacy definition due to Dwork et al. (2006). We also provide learning generalization guarantees. Empirical evaluations reveal promising performance on real and...
Differential magnetometry with multiparticle singlets
Urizar-Lanz, Inigo; Egusquiza, Inigo; Mitchell, Morgan W; Toth, Geza
2012-01-01
We present a method for measuring the magnetic field gradient with singlets realized with spin-1/2 particles. While the singlet state does not change under the influence of homogenous magnetic fields, the variance of the collective spin components start to grow under a field gradient. We compute the dynamics of this variance analytically for a chain of spins and also for an ensemble of particles with a given density distribution. We calculate an upper bound on how exactly the field gradient can be estimated from the measured data. The proposal is relevant for cold atomic ensembles where multiparticle singlet states can be prepared by spin squeezing and the differential magnetometry can be carried out.
Differentiated teaching and teacher development
Hedegaard-Sørensen, Lotte
). From this emphasis inclusive education has been embraced in the theoretical debate as an alternative as it suggests that local schools should provide for all leaners – regardless of differences, disabilities or other social, emotional, cultural and linguistic differences. The current debate on special...... needs education and inclusive education has a focus on teaching to diversity. The discussion is about teachers’ ability to make sense of individual differences in their teaching without relying on specific disability categories. It’s acknowledged in the research discussion that responding to differences...... between pupils involves good teaching for all (inclusive education) and at the same time, that what works for most does not work for all (Norwich & Jones, 2012; Black-Hawkins, Florian & Rouse, 2007). Differentiated instruction is defined as responsive instruction and to teachers’ proficiency...
Transcriptomic response to differentiation induction
Dimitrov DS
2006-02-01
Full Text Available Abstract Background Microarrays used for gene expression studies yield large amounts of data. The processing of such data typically leads to lists of differentially-regulated genes. A common terminal data analysis step is to map pathways of potentially interrelated genes. Methods We applied a transcriptomics analysis tool to elucidate the underlying pathways of leukocyte maturation at the genomic level in an established cellular model of leukemia by examining time-course data in two subclones of U-937 cells. Leukemias such as Acute Promyelocytic Leukemia (APL are characterized by a block in the hematopoietic stem cell maturation program at a point when expansion of clones which should be destined to mature into terminally-differentiated effector cells get locked into endless proliferation with few cells reaching maturation. Treatment with retinoic acid, depending on the precise genomic abnormality, often releases the responsible promyelocytes from this blockade but clinically can yield adverse sequellae in terms of potentially lethal side effects, referred to as retinoic acid syndrome. Results Briefly, the list of genes for temporal patterns of expression was pasted into the ABCC GRID Promoter TFSite Comparison Page website tool and the outputs for each pattern were examined for possible coordinated regulation by shared regelems (regulatory elements. We found it informative to use this novel web tool for identifying, on a genomic scale, genes regulated by drug treatment. Conclusion Improvement is needed in understanding the nature of the mutations responsible for controlling the maturation process and how these genes regulate downstream effects if there is to be better targeting of chemical interventions. Expanded implementation of the techniques and results reported here may better direct future efforts to improve treatment for diseases not restricted to APL.
Regulators of Tfh cell differentiation
Gajendra Motiram Jogdand
2016-11-01
Full Text Available The follicular helper T (Tfh cells help is critical for activation of B cells, antibody class switching and germinal center formation. The Tfh cells are characterized by the expression of CXCR5, ICOS, PD-1, Bcl-6, and IL-21. They are involved in clearing infections and are adversely linked with autoimmune diseases and also have a role in viral replication as well as clearance. Tfh cells are generated from naïve CD4 T cells with sequential steps involving cytokine signaling (IL-21, IL-6, IL-12, activin A, migration and positioning in the germinal center by CXCR5, surface receptors (ICOS/ICOSL, SAP/SLAM as well as transcription factor (Bcl-6, c-Maf, STAT3 signaling and repressor miR155. On the other hand Tfh generation is negatively regulated at specific steps of Tfh generation by specific cytokine (IL-2, IL-7, surface receptor (PD-1, CTLA-4, transcription factors Blimp-1, STAT5, T-bet, KLF-2 signaling and repressor miR 146a. Interestingly, miR 17-92 and FOXO1 acts as a positive as well as a negative regulator of Tfh differentiation depending on the time of expression and disease specificity. Tfh cells are also generated from the conversion of other effector T cells as exemplified by Th1 cells converting into Tfh during viral infection. The mechanistic details of effector T cells conversion into Tfh are yet to be clear. To manipulate Tfh cells for therapeutic implication and or for effective vaccination strategies, it is important to know positive and negative regulators of Tfh generation. Hence, in this review we have highlighted and interlinked molecular signaling from cytokines, surface receptors, transcription factors, ubiquitin Ligase and miRNA as positive and negative regulators for Tfh differentiation.
Kim, Seong Ho; Kim, Se Hyung; Shin, Cheong-il; Han, Joon Koo; Choi, Byung Ihn [Seoul National University Hospital, Department of Radiology, Jongno-gu, Seoul (Korea, Republic of); Seoul National University Hospital, Institute of Radiation Medicine, Jongno-gu, Seoul (Korea, Republic of); Kim, Min-A [Seoul National University Hospital, Department of Pathology, Jongno-gu, Seoul (Korea, Republic of)
2015-07-15
To evaluate the differential CT features of gastric poorly-differentiated neuroendocrine tumours (PD-NETs) from well-differentiated NETs (WD-NETs) and gastric adenocarcinomas (ADCs) and to suggest differential features of hepatic metastases from gastric NETs and ADCs. Our study population was comprised of 36 patients with gastric NETs (18 WD-NETs, 18 PD-NETs) and 38 patients with gastric ADCs who served as our control group. Multiple CT features were assessed to identify significant differential CT findings of PD-NETs from WD-NETs and ADCs. In addition, CT features of hepatic metastases including the metastasis-to-liver ratio were analyzed to differentiate metastatic NETs from ADCs. The presence of metastatic lymph nodes was the sole differentiator of PD-NETs from WD-NETs (P =.001, odds ratio = 56.67), while the presence of intact overlying mucosa with mucosal tenting was the sole significant CT feature differentiating PD-NETs from ADCs (P =.047, odds ratio = 15.3) For hepatic metastases, metastases from NETs were more hyper-attenuated than those from ADCs. The presence of metastatic LNs and intact overlying mucosa with mucosal tenting are useful CT discriminators of PD-NETs from WD-NETs and ADCs, respectively. In addition, a higher metastasis-to-liver ratio may help differentiate hepatic metastases of gastric NETs from those of gastric ADCs with high accuracy. (orig.)
Differential induction of HNF-3 transcription factors during neuronal differentiation.
Jacob, A; Budhiraja, S; Reichel, R R
1997-08-01
We have investigated the regulation of transcription factors HNF-3alpha and HNF-3beta during the retinoic acid-mediated differentiation of mouse P19 cells. Retinoic acid treatment converts P19 stem cells into neurons and astrocytes and we have clearly shown that gene expression of both HNF-3alpha and HNF-3beta is activated during this process. HNF-3alpha transcription was detected 2 h after addition of retinoic acid and took place in the absence of de novo protein synthesis. This suggests that HNF-3alpha is a primary target for retinoic acid action. HNF-3alpha induction displays a biphasic profile and HNF-3alpha mRNA reaches maximal levels at 2 and 6 days postdifferentiation. Additional experiments strongly suggest that the second peak is due to HNF-3alpha induction in postmitotic neurons. P19 stem cells, on the other hand, do not contain any detectable HNF-3alpha mRNA. According to our studies, the retinoic acid-mediated induction of HNF-3alpha occurs at the level of transcriptional initiation and is conferred by distal promoter sequences. In comparison to HNF-3alpha, HNF-3beta induction is a subsequent event and detectable levels of HNF-3beta mRNA materialize approximately 1 day after addition of retinoic acid to P19 stem cells. Time course studies firmly demonstrate that HNF-3beta mRNA peaks at about 2 days postdifferentiation and then declines to virtually unreadable levels. This temporal pattern is consistent with HNF-3beta being a secondary target for retinoic acid. In analogy to HNF-3alpha, HNF-3beta activation also takes place at the level of transcriptional initiation. Recent studies implicate HNF-3alpha and HNF-3beta in early mammalian neurogenesis. The detection of HNF-3alpha/beta activation during P19 cell differentiation provides us with a convenient cell culture system to elucidate the induction mechanism and the precise role of both transcriptional regulators in the formation of neuronal cells.
A theory of differentiation with dynamic clustering
Kaneko, K; Kaneko, Kunihiko; Yomo, Tetsuya
1995-01-01
A novel theory for cell differentiation is proposed, based on simulations with interacting artificial cells which have metabolic networks within, and divide into two when the final product is accumulated. Results of simulations with coupled chemical networks and division process lead to the following scenario of the differentiation: Up to some numbers of cells, divisions bring about almost identical cells with synchronized metabolic oscillations. As the number is increased the oscillations lose the synchrony, leading to groups of cells with different phases of oscillations. At later stage this differentiation is fixed in time, and cells spilt into groups with different chemical constituents spontaneously, which are transmitted to daughter cells by cell divisions. Hierarchical differentiation, origin of stem cells, and anomalous differentiation by transplantations are also discussed with relevance to real biological experimental results. (Keywords: differentiation, metabolic network, cell division, clustering,...
Introduction to complex theory of differential equations
Savin, Anton
2017-01-01
This book discusses the complex theory of differential equations or more precisely, the theory of differential equations on complex-analytic manifolds. Although the theory of differential equations on real manifolds is well known – it is described in thousands of papers and its usefulness requires no comments or explanations – to date specialists on differential equations have not focused on the complex theory of partial differential equations. However, as well as being remarkably beautiful, this theory can be used to solve a number of problems in real theory, for instance, the Poincaré balayage problem and the mother body problem in geophysics. The monograph does not require readers to be familiar with advanced notions in complex analysis, differential equations, or topology. With its numerous examples and exercises, it appeals to advanced undergraduate and graduate students, and also to researchers wanting to familiarize themselves with the subject.
PARTIAL DIFFERENTIAL EQUATIONS FOR DENSITIES OF RANDOM PROCESSES,
PARTIAL DIFFERENTIAL EQUATIONS , STOCHASTIC PROCESSES), (*STOCHASTIC PROCESSES, PARTIAL DIFFERENTIAL EQUATIONS ), EQUATIONS, STATISTICAL FUNCTIONS, STATISTICAL PROCESSES, PROBABILITY, NUMERICAL METHODS AND PROCEDURES
Phase jitter in a differential phase experiment.
Tanenbaum, B. S.; Connolly, D. J.; Austin, G. L.
1973-01-01
Austin (1971) had concluded that, because of the 'phase jitter,' the differential phase experiment is useful over a more limited height range than the differential absorption experiment. Several observations are presented to show that this conclusion is premature. It is pointed out that the logical basis of the differential absorption experiment also requires that the O- and X-mode echoes, at a given time, come from the same irregularities. Austin's calculations are believed to contain a systematic error above 80 km.
Functional differential equations—a reciprocity principle
Lloyd K. Williams
1986-01-01
Full Text Available The functional differential equations proposed for solution here are mainly ordinary differential equations with fairly general argument deviations. Included among them are equations with involutions and some with reflections of the argument. Solutions will be obtained by quadratures in terms of implicitly defined functions. They have a wide range of applicability from the stability theory of differential-difference equations to electrodynamics and biological models.
The absolute differential calculus (calculus of tensors)
Levi-Civita, Tullio
2013-01-01
Written by a towering figure of twentieth-century mathematics, this classic examines the mathematical background necessary for a grasp of relativity theory. Tullio Levi-Civita provides a thorough treatment of the introductory theories that form the basis for discussions of fundamental quadratic forms and absolute differential calculus, and he further explores physical applications.Part one opens with considerations of functional determinants and matrices, advancing to systems of total differential equations, linear partial differential equations, algebraic foundations, and a geometrical intro
DIFFERENTIAL DIAGNOSTICS OF INFECTIOUS EXANTHEMAS IN CHILDREN
D. Yu. Ovsyannikov
2015-01-01
The lecture is devoted to the problem of differential diagnosis of infectious exanthemas in children. Information about differential-diagnostic sings of infectious and non-infectious exanthemas is present. Differential diagnosis is proposed on the basis of morphological elements identified in objective research. Presents possible infectious and non-infectious causes of rashes which are characterized by different primary (spot, papula, blister, knob, knot, bubble, abscess, bladder) and seconda...
Introduction to differential equations with dynamical systems
Campbell, Stephen L
2011-01-01
Many textbooks on differential equations are written to be interesting to the teacher rather than the student. Introduction to Differential Equations with Dynamical Systems is directed toward students. This concise and up-to-date textbook addresses the challenges that undergraduate mathematics, engineering, and science students experience during a first course on differential equations. And, while covering all the standard parts of the subject, the book emphasizes linear constant coefficient equations and applications, including the topics essential to engineering students. Stephen Cam
Impulsive differential inclusions a fixed point approach
Ouahab, Abdelghani; Henderson, Johnny
2013-01-01
Impulsive differential equations have been developed in modeling impulsive problems in physics, population dynamics, ecology, biotechnology, industrial robotics, pharmacokinetics, optimal control, etc. The questions of existence and stability of solutions for different classes of initial values problems for impulsive differential equations and inclusions with fixed and variable moments are considered in detail. Attention is also given to boundary value problems and relative questions concerning differential equations. This monograph addresses a variety of side issues that arise from its simple
On new solutions of fuzzy differential equations
Chalco-Cano, Y. [Departamento de Matematica, Universidad de Tarapaca, Casilla 7D, Arica (Chile)], E-mail: ychalco@uta.cl; Roman-Flores, H. [Instituto de Investigacion, Universidad de Tarapaca, Casilla 7D, Arica (Chile)
2008-10-15
We study fuzzy differential equations (FDE) using the concept of generalized H-differentiability. This concept is based in the enlargement of the class of differentiable fuzzy mappings and, for this, we consider the lateral Hukuhara derivatives. We will see that both derivatives are different and they lead us to different solutions from a FDE. Also, some illustrative examples are given and some comparisons with other methods for solving FDE are made.
Partial differential equations of mathematical physics
Sobolev, S L
1964-01-01
Partial Differential Equations of Mathematical Physics emphasizes the study of second-order partial differential equations of mathematical physics, which is deemed as the foundation of investigations into waves, heat conduction, hydrodynamics, and other physical problems. The book discusses in detail a wide spectrum of topics related to partial differential equations, such as the theories of sets and of Lebesgue integration, integral equations, Green's function, and the proof of the Fourier method. Theoretical physicists, experimental physicists, mathematicians engaged in pure and applied math
DIFFERENTIAL DIAGNOSTICS OF INFECTIOUS EXANTHEMAS IN CHILDREN
D. Yu. Ovsyannikov
2015-01-01
Full Text Available The lecture is devoted to the problem of differential diagnosis of infectious exanthemas in children. Information about differential-diagnostic sings of infectious and non-infectious exanthemas is present. Differential diagnosis is proposed on the basis of morphological elements identified in objective research. Presents possible infectious and non-infectious causes of rashes which are characterized by different primary (spot, papula, blister, knob, knot, bubble, abscess, bladder and secondary (scale, erosion, ulcer morphological elements.
Marketing strategy to differentiate the offer
Miceski, Trajko; Pasovska, Silvana
2013-01-01
The marketing strategy for differentiation of the offers is important and accepted strategy especially by the bigger legal entities. The differentiation of the offers leads to bigger profit and bigger profitability in operation, through targeting of the demand towards the product of the enterprise. The vertical differentiation of the offers is directed towards the quality of the product itself which is observed as a something superior despite the competitive product which is observed as somet...
Hyperbolic differential operators and related problems
Ancona, Vincenzo
2003-01-01
Presenting research from more than 30 international authorities, this reference provides a complete arsenal of tools and theorems to analyze systems of hyperbolic partial differential equations. The authors investigate a wide variety of problems in areas such as thermodynamics, electromagnetics, fluid dynamics, differential geometry, and topology. Renewing thought in the field of mathematical physics, Hyperbolic Differential Operators defines the notion of pseudosymmetry for matrix symbols of order zero as well as the notion of time function. Surpassing previously published material on the top
GENERIC COMMODITY PROMOTION AND PRODUCT DIFFERENTIATION
1999-01-01
This paper considers whether generic promotion lowers the differentiation among competing brands as claimed in the 1997 Supreme Court case (Wileman et al. v. Glickman). Commodity promotion is modeled as a multi-stage game where products are vertically differentiated. Analytical results show that if the benefits of generic advertising from increased demand are outweighed by the costs from lower product differentiation then high-quality producers will not benefit from generic promotion but prod...
Embryonic stem cell differentiation: A chromatin perspective
Rasmussen Theodore P
2003-01-01
Abstract Embryonic stem (ES) cells hold immense promise for the treatment of human degenerative disease. Because ES cells are pluripotent, they can be directed to differentiate into a number of alternative cell-types with potential therapeutic value. Such attempts at "rationally-directed ES cell differentiation" constitute attempts to recapitulate aspects of normal development in vitro. All differentiated cells retain identical DNA content, yet gene expression varies widely from cell-type to ...
Comparison of two methods for customer differentiation
Gabor, Adriana; Guang, Yang; Axsäter, Sven
2014-01-01
textabstractIn response to customer specific time guarantee requirements, service providers can offer differentiated ser- vices. However, conventional customer differentiation methods often lead to high holding costs and may have some practical drawbacks. We compare two customer differentiation policies: stock reservation and pipeline stock priority for high priority customers. We derive exact analytical expressions of the waiting time distri- bution of both types of customers for a stock res...
Differential effects of lenalidomide during plasma cell differentiation
Jourdan, Michel; Cren, Maïlys; Schafer, Peter; Robert, Nicolas; Duperray, Christophe; Vincent, Laure; Ceballos, Patrice; Cartron, Guillaume; Rossi, Jean-François; Moreaux, Jérôme; Chopra, Rajesh; Klein, Bernard
2016-01-01
Thalidomide, lenalidomide and pomalidomide have greatly improved the outcome of patients with multiple myeloma. However, their effects on plasma cells, the healthy counterpart of myeloma cells, are unknown. Here, we investigated lenalidomide effects on normal human plasma cell generation using an in vitro model. Lenalidomide inhibited the generation of pre-plasmablasts and early plasma cells, while it moderately affected plasmablast production. It also reduced the expression level of Ikaros, Aiolos, and IRF4 transcription factors, in plasmablasts and early plasma cells. This suggests that their differential sensitivity to lenalidomide is not due to a difference in Ikaros or Aiolos degradation. Lenalidomide also inhibited long-lived plasma cell generation, but did not impair their long-term survival once generated. This last observation is in agreement with the finding that lenalidomide treatment for 3-18 months did not affect the bone marrow healthy plasma cell count in allografted patients with multiple myeloma. Our findings should prompt to investigate whether lenalidomide resistance in patients with multiple myeloma could be associated with the emergence of malignant plasmablasts or long-lived plasma cells that are less sensitive to lenalidomide. PMID:27057635
Differential effects of lenalidomide during plasma cell differentiation.
Jourdan, Michel; Cren, Maïlys; Schafer, Peter; Robert, Nicolas; Duperray, Christophe; Vincent, Laure; Ceballos, Patrice; Cartron, Guillaume; Rossi, Jean-François; Moreaux, Jérôme; Chopra, Rajesh; Klein, Bernard
2016-05-10
Thalidomide, lenalidomide and pomalidomide have greatly improved the outcome of patients with multiple myeloma. However, their effects on plasma cells, the healthy counterpart of myeloma cells, are unknown. Here, we investigated lenalidomide effects on normal human plasma cell generation using an in vitro model. Lenalidomide inhibited the generation of pre-plasmablasts and early plasma cells, while it moderately affected plasmablast production. It also reduced the expression level of Ikaros, Aiolos, and IRF4 transcription factors, in plasmablasts and early plasma cells. This suggests that their differential sensitivity to lenalidomide is not due to a difference in Ikaros or Aiolos degradation. Lenalidomide also inhibited long-lived plasma cell generation, but did not impair their long-term survival once generated. This last observation is in agreement with the finding that lenalidomide treatment for 3-18 months did not affect the bone marrow healthy plasma cell count in allografted patients with multiple myeloma. Our findings should prompt to investigate whether lenalidomide resistance in patients with multiple myeloma could be associated with the emergence of malignant plasmablasts or long-lived plasma cells that are less sensitive to lenalidomide.
Differentiation Therapy of Acute Myeloid Leukemia
Elzbieta Gocek
2011-05-01
Full Text Available Acute Myeloid Leukemia (AML is a predominant acute leukemia among adults, characterized by accumulation of malignantly transformed immature myeloid precursors. A very attractive way to treat myeloid leukemia, which is now called ‘differentiation therapy’, was proposed as in vitro studies have shown that a variety of agents stimulate differentiation of the cell lines isolated from leukemic patients. One of the differentiation-inducing agents, all-trans retinoic acid (ATRA, which can induce granulocytic differentiation in myeloid leukemic cell lines, has been introduced into clinics to treat patients with acute promyelocytic leukemia (APL in which a PML-RARA fusion protein is generated by a t(15;17(q22;q12 chromosomal translocation. Because differentiation therapy using ATRA has significantly improved prognosis for patients with APL, many efforts have been made to find alternative differentiating agents. Since 1,25-dihydroxyvitamin D3 (1,25D is capable of inducing in vitro monocyte/macrophage differentiation of myeloid leukemic cells, clinical trials have been performed to estimate its potential to treat patients with AML or myelodysplastic syndrome (MDS. Unfortunately therapeutic concentrations of 1,25D can induce potentially fatal systemic hypercalcemia, thus limiting clinical utility of that compound. Attempts to overcome this problem have focused on the synthesis of 1,25D analogs (VDAs which retain differentiation inducing potential, but lack its hypercalcemic effects. This review aims to discuss current problems and potential solutions in differentiation therapy of AML.
Differentiation Therapy of Acute Myeloid Leukemia
Gocek, Elzbieta; Marcinkowska, Ewa, E-mail: ema@cs.uni.wroc.pl [Department of Biotechnology, University of Wroclaw, ul Tamka 2, Wroclaw 50-137 (Poland)
2011-05-16
Acute Myeloid Leukemia (AML) is a predominant acute leukemia among adults, characterized by accumulation of malignantly transformed immature myeloid precursors. A very attractive way to treat myeloid leukemia, which is now called ‘differentiation therapy’, was proposed as in vitro studies have shown that a variety of agents stimulate differentiation of the cell lines isolated from leukemic patients. One of the differentiation-inducing agents, all-trans retinoic acid (ATRA), which can induce granulocytic differentiation in myeloid leukemic cell lines, has been introduced into clinics to treat patients with acute promyelocytic leukemia (APL) in which a PML-RARA fusion protein is generated by a t(15;17)(q22;q12) chromosomal translocation. Because differentiation therapy using ATRA has significantly improved prognosis for patients with APL, many efforts have been made to find alternative differentiating agents. Since 1,25-dihydroxyvitamin D{sub 3} (1,25D) is capable of inducing in vitro monocyte/macrophage differentiation of myeloid leukemic cells, clinical trials have been performed to estimate its potential to treat patients with AML or myelodysplastic syndrome (MDS). Unfortunately therapeutic concentrations of 1,25D can induce potentially fatal systemic hypercalcemia, thus limiting clinical utility of that compound. Attempts to overcome this problem have focused on the synthesis of 1,25D analogs (VDAs) which retain differentiation inducing potential, but lack its hypercalcemic effects. This review aims to discuss current problems and potential solutions in differentiation therapy of AML.
Partial differential equations for scientists and engineers
Farlow, Stanley J
1993-01-01
Most physical phenomena, whether in the domain of fluid dynamics, electricity, magnetism, mechanics, optics, or heat flow, can be described in general by partial differential equations. Indeed, such equations are crucial to mathematical physics. Although simplifications can be made that reduce these equations to ordinary differential equations, nevertheless the complete description of physical systems resides in the general area of partial differential equations.This highly useful text shows the reader how to formulate a partial differential equation from the physical problem (constructing th
Differential Calculus on N-Graded Manifolds
G. Sardanashvily
2017-01-01
Full Text Available The differential calculus, including formalism of linear differential operators and the Chevalley–Eilenberg differential calculus, over N-graded commutative rings and on N-graded manifolds is developed. This is a straightforward generalization of the conventional differential calculus over commutative rings and also is the case of the differential calculus over Grassmann algebras and on Z2-graded manifolds. We follow the notion of an N-graded manifold as a local-ringed space whose body is a smooth manifold Z. A key point is that the graded derivation module of the structure ring of graded functions on an N-graded manifold is the structure ring of global sections of a certain smooth vector bundle over its body Z. Accordingly, the Chevalley–Eilenberg differential calculus on an N-graded manifold provides it with the de Rham complex of graded differential forms. This fact enables us to extend the differential calculus on N-graded manifolds to formalism of nonlinear differential operators, by analogy with that on smooth manifolds, in terms of graded jet manifolds of N-graded bundles.
Topology Optimization of Structure Using Differential Evolution
Chun-Yin Wu
2008-02-01
Full Text Available The population-based evolutionary algorithms have emerged as powerful mechanism for finding optimum solutions of complex optimization problems. A promising new evolutionary algorithm, differential evolution, has garnered significant attention in the engineering optimization research. Differential evolution has the advantage of incorporating a relatively simple and efficient form of mutation and crossover. This paper aims at introducing differential evolution as an alternative approach for topology optimization of truss and continuous structure with stress and displacement constraints. In comparison the results with other studies, it shows that differential evolution algorithms are very effective and efficient in solving topology optimization problem of structure.
Differential Photoacoustic Particle Absorption Monitor Project
National Aeronautics and Space Administration — We developed a highly sensitive and compact instrument to directly measure particulate matter (PM) optical absorption. This device is based on differential...
Molecular differentiation of bovine sarcocysts.
Akhlaghi, Majedeh; Razavi, Mostafa; Hosseini, Arsalan
2016-07-01
Cattle are common intermediate hosts of Sarcocystis, and the prevalence in adult bovine muscle is close to 100 % in most regions of the world. Three Sarcocystis spp. are known to infect cattle as intermediate hosts, namely, S. cruzi, S. hirsuta, and S. hominis. The aim of the present study was the molecular identification and differentiation of these three species, Neospora caninum and Besnoitia by PCR and RFLP methods. Tissue samples were obtained from diaphragmatic muscle of 101 cattle slaughtered in Shiraz, Fars Province, Iran, for both smear preparation and DNA extraction. The samples were digested by Pepsin, washed three times with PBS solution before taking smears, fixed in absolute methanol and stained with 10 % Giemsa. The slides were examined microscopically for Sarcocystis bradyzoites and DNA was extracted from 100 mg of Sarcocystis-infected meat samples. Since the primers also bind to 18S rRNA gene of some tissue cyst-forming coccidian protozoa, DNA was also extracted from 100 μl of tachyzoite-containing suspension of N. caninum and Besnoitia isolated from goat to compare RFLP pattern. Polymerase chain reaction (PCR) was performed on DNA of samples which were microscopically positive for Sarcocystis. Five restriction enzymes Dra1, EcoRV, RsaI, AvaI, and SspI were used for RFLP and DNA of one sample from protozoa was sequenced. Based on the RFLP results, 87 (98.9 %) DNA samples were cut with DraI, indicating infection by S. cruzi. One sample (1.1 %) of PCR products of infected samples was cut only with EcoRV which showed S. hominis infection. Forty-eight samples (53.3 %) of PCR products were cut with both DraI, EcoRV, or with DraI, EcoRV, and RsaI while none of them was cut with SspI, which shows the mixed infection of both S. cruzi and S. hominis and no infection with S. hirsuta. It seems by utilizing these restriction enzymes, RLFP could be a suitable method not only for identification of Sarcocystis species but also for differentiating them
Differential diagnosis of leg ulcers.
Pannier, F; Rabe, E
2013-03-01
Leg and foot ulcers are symptoms of very different diseases. The aim of this paper is to demonstrate the differential diagnosis of leg ulcers. The majority of leg ulcers occur in the lower leg or foot. In non-venous ulcers the localization in the foot area is more frequent. The most frequent underlying disease is chronic venous disease. In 354 leg ulcers, Koerber found 75.25% venous leg ulcers, 3.66% arterial leg ulcers, 14.66% ulcers of mixed venous and arterial origin and 13.5% vasculitic ulcers. In the Swedish population of Skaraborg, Nelzen found a venous origin in 54% of the ulcer patients. Each leg ulcer needs a clinical and anamnestic evaluation. Duplex ultrasound is the basic diagnostic tool to exclude vascular anomalies especially chronic venous and arterial occlusive disease. Skin biopsies help to find a correct diagnosis in unclear or non-healing cases. In conclusion, chronic venous disease is the most frequent cause of leg ulcerations. Because 25% of the population have varicose veins or other chronic venous disease the coincidence of pathological venous findings and ulceration is very frequent even in non-venous ulcerations. Leg ulcers without the symptoms of chronic venous disease should be considered as non-venous.
Charging for differentiated Internet services
Stiller, Burkhard; Gerke, Jan; Hasan, Hasan; Reichl, Peter; Flury, Placi
2001-07-01
Internet communications today play a major role in data transport within the local as well as the wide area. On one hand, since emerging networked applications require a variety of different communication services, the number of service classes offered by service providers has to be targeted at this demand. On the other hand, assuming that a set of different traffic classes are offered by service providers, the 'right' incentives have to be provided, ensuring that applications or their users select the most appropriate traffic class. Even though users are considered to be selective, they intend to chose that class which offers the best available Quality-of-Service (QoS), as long as the price to be paid does not exceed their willingness-to-pay. Therefore, charging for differentiated Internet services is important in a commercialized Internet. The current Internet does not cater for charging at all, since the technology required, the pricing models going beyond a flat-fee approach, and the appropriate efficiency in technical as well as economic terms are still missing on a global basis. This paper outlines the major problems for charging Internet services and describes briefly an important new solution for a pricing approach, which solves the Internet pricing feasibility problem. Based on these preconditions an Internet Charging System (ICS) is introduced, focusing mainly on its leading characteristics and its generic approach to instantiate for a given scenario.
Chiral differential operators and topology
Cheung, Pokman
2010-01-01
The first part of this paper provides a new formulation of chiral differential operators (CDOs) in terms of global geometric quantities. The main result is a recipe to define essentially all sheaves of smooth CDOs on a cs-manifold; its ingredients consist of an affine connection and an even 3-form that trivializes the first Pontrjagin form. With the connection fixed, two suitable 3-forms define isomorphic sheaves of CDOs if and only if their difference is exact. Moreover, conformal structures are in one-to-one correspondence with even 1-forms that trivialize the first Chern form. The second part of this paper concerns the construction of what may be called "chiral Dolbeault complexes". The classical Dolbeault complex of a complex manifold M may be viewed as the functions on an associated cs-manifold with the action of an odd vector field Q that satisfies Q^2=0. Motivated by this, we study the condition under which a conformal sheaf of CDOs on that cs-manifold admits an odd derivation Q' that extends Q and sat...
Cytokine receptors and hematopoietic differentiation.
Robb, L
2007-10-15
Colony-stimulating factors and other cytokines signal via their cognate receptors to regulate hematopoiesis. In many developmental systems, inductive signalling determines cell fate and, by analogy with this, it has been postulated that cytokines, signalling via their cognate receptors, may play an instructive role in lineage specification in hematopoiesis. An alternative to this instructive hypothesis is the stochastic or permissive hypothesis. The latter proposes that commitment to a particular hematopoietic lineage is an event that occurs independently of extrinsic signals. It predicts that the role of cytokines is to provide nonspecific survival and proliferation signals. In this review, we look at the role of cytokine receptor signalling in hematopoiesis and consider the evidence for both hypotheses. Data from experiments that genetically manipulate receptor gene expression in vitro or in vivo are reviewed. Experiments in which cytokine receptors were installed in multipotential cells showed that, in some cases, stimulation with the cognate ligand could lead to alterations in lineage output. The creation of genetically manipulated mouse strains demonstrated that cytokine receptors are required for expansion and survival of single lineages but did not reveal a role in lineage commitment. We conclude that hematopoietic differentiation involves mainly stochastic events, but that cytokine receptors also have some instructive role.
Foundations of arithmetic differential geometry
Buium, Alexandru
2017-01-01
The aim of this book is to introduce and develop an arithmetic analogue of classical differential geometry. In this new geometry the ring of integers plays the role of a ring of functions on an infinite dimensional manifold. The role of coordinate functions on this manifold is played by the prime numbers. The role of partial derivatives of functions with respect to the coordinates is played by the Fermat quotients of integers with respect to the primes. The role of metrics is played by symmetric matrices with integer coefficients. The role of connections (respectively curvature) attached to metrics is played by certain adelic (respectively global) objects attached to the corresponding matrices. One of the main conclusions of the theory is that the spectrum of the integers is "intrinsically curved"; the study of this curvature is then the main task of the theory. The book follows, and builds upon, a series of recent research papers. A significant part of the material has never been published before.
Jacobian's Thermodynamic Transforms Replacing Differentiation
邝钜炽; 张军
2001-01-01
The noteworthy work in this article consists in combiningcharacters of thermodynamic variables with Jacobian determinants to develop the three significant J transforms of thermodynamics,which seem not to have been reported except Eq.(12) until now.The significance of them is not only to offer us a new convenient tool for proofing puzzle but also to reveal the inner interrelations of thermodynamic variables,or to foretell the rules of variation of any thermodynamic variable following others.By all appearances,this can hardly be done by way of differentiation.%结合雅可比行列式和热力学变量的特性，率先导出了三个极为重要的雅可比热力学变换式，除（12）式外，其余尚未见报道.雅可比热力学变换的重要意义不仅体现在它为我们提供了一种证明难题的便利工具，而且还体现在其揭示了热力学变量间的内在联系，或预告某热力学量随其它热力学量变化的情况，显然此用微分法往往难以实现.
Immunohistochemical differentiation of inflammatory myopathies
Jayalakshmi B Panicker
2011-01-01
Full Text Available Background: Idiopathic inflammatory myopathies are a heterogeneous group of acquired muscle disorders with considerable overlap in the histological features, making histological diagnosis difficult at times. Aims: To determine the immunohistochemical profile of clinically suspected cases of inflammatory myopathies, using monoclonal antibodies to HLA-1 and membrane attack complex (MAC, and to correlate the clinical, serological, and electromyographic profile and the histopathological picture, with the immunohistochemical profile. Settings and Design: This was a retrospective study analyzing the clinical and histopathological features in muscle of clinically suspected cases of inflammatory myopathy and correlating it to their HLA-1 and MAC immunostaining profiles. Material and Methods: The study subjects included 33 cases with suspected inflammatory myopathy and 59 with non-inflammatory muscle disease, as controls. Clinical data, electromyographic findings, serological profile, and details of therapy were obtained from patient records. Statistical Analysis: Student ′T′ test, Pearson′s Chi square test, and Kappa statistics were used appropriately. Results: Although HLA-1 and MAC immunostaining did not help to differentiate the individual subtypes of inflammatory myopathy, when either HLA-1 or MAC was positive, inflammatory myopathy could be ruled in with 86.5% certainty and when both HLA-1 and MAC were negative, it could be ruled out with 95% certainty. Conclusions: A combination of clinical presentation, serological profile, electromyographic and histopathological features, together with the immunoprofile for HLA-1 and MAC, contribute toward making a diagnosis of inflammatory myopathy.
The myth about nonlinear differential equations
Radhakrishnan, C.
2002-01-01
Taking the example of Koretweg--de Vries equation, it is shown that soliton solutions need not always be the consequence of the trade-off between the nonlinear terms and the dispersive term in the nonlinear differential equation. Even the ordinary one dimensional linear partial differential equation can produce a soliton.
Photon Differentials in Space and Time
Schjøth, Lars; Frisvad, Jeppe Revall; Erleben, Kenny;
2011-01-01
We present a novel photon mapping algorithm for animations. We extend our previous work on photon differentials [12] with time differentials. The result is a first order model of photon cones in space an time that effectively reduces the number of required photons per frame as well as efficiently...... reduces temporal aliasing without any need for in-between-frame photon maps....
Differential privacy in intelligent transportation systems
Kargl, Frank; Friedman, Arik; Boreli, Roksana
2013-01-01
In this paper, we investigate how the concept of differential privacy can be applied to Intelligent Transportation Systems (ITS), focusing on protection of Floating Car Data (FCD) stored and processed in central Traffic Data Centers (TDC). We illustrate an integration of differential privacy with
Vector Fields and Flows on Differentiable Stacks
A. Hepworth, Richard
2009-01-01
This paper introduces the notions of vector field and flow on a general differentiable stack. Our main theorem states that the flow of a vector field on a compact proper differentiable stack exists and is unique up to a uniquely determined 2-cell. This extends the usual result on the existence...... of vector fields....
Uniqueness of meromorphic functions concerning differential polynomials
QIAO Lei
2007-01-01
Based on a unicity theorem for entire funcitions concerning differential polynomials proposed by M. L. Fang and W. Hong, we studied the uniqueness problem of two meromorphic functions whose differential polynomials share the same 1-point by proving two theorems and their related lemmas. The results extend and improve given by Fang and Hong's theorem.
A Unified Introduction to Ordinary Differential Equations
Lutzer, Carl V.
2006-01-01
This article describes how a presentation from the point of view of differential operators can be used to (partially) unify the myriad techniques in an introductory course in ordinary differential equations by providing students with a powerful, flexible paradigm that extends into (or from) linear algebra. (Contains 1 footnote.)
A DIFFERENTIABLE CANTOR-LIKE FUNCTION
DingChuansong
1994-01-01
the Cantor function is one of the most important and useful exaraples in real function theory. Recently there are a lot of research on differentiable Cantor-like functions, but the methods involved are not elementary. In this note a differentiable Cantor-like function was given by an elementary method.
Lesson Plan Design for Facilitating Differentiated Instruction
Baker, Pamela Hudson; Fleming, Louise Conn
2005-01-01
This study examines the role of lesson plan design in helping teacher candidates to meet diverse learning needs. The authors studied student teachers who had been taught to use a differential lesson plan to see if they were differentiating in their planning, assessment, and instruction. They concluded that, indeed, lesson plan design does…
Strict Stability of Impulsive Differential Equations
Yu ZHANG; Ji Tao SUN
2006-01-01
In this paper, we will extend the strict stability to impulsive differential equations. By using Lyapunov functions, we will get some criteria for the strict stability of impulsive differential equations, and we can see that impulses do contribute to the system's strict stability behavior. An example is also given in this paper to illustrate the efficiency of the obtained results.
Differentiated thyroid carcinoma : A polygenic disease
Links, TP; van Tol, KM; te Meerman, GJ; de Vries, EGE
2001-01-01
Differentiated thyroid cancer is a rare disease and until recently was considered to be sporadic. However, increasing evidence has been found for a genetic basis of this disease. In approximately 5% of patients the differentiated thyroid cancer is dominantly inherited. Several families with
Inter-Industry Wage Differentials in Denmark?
Lausten, Mette
1995-01-01
This paper analyses empirically the inter-industry wage differentials in Denmark using cross-sectional human capital wage relations. The sample period is 1981-1990, a period with several changes in the wage bargaining set-up. Significant and highly persistent inter-industrial wage differentials...
PPARgamma in adipocyte differentiation and metabolism
Siersbaek, Rasmus; Nielsen, Ronni; Mandrup, Susanne
2010-01-01
Adipocyte differentiation is controlled by a tightly regulated transcriptional cascade in which PPARgamma and members of the C/EBP family are key players. Here we review the roles of PPARgamma and C/EBPs in adipocyte differentiation with emphasis on the recently published genome-wide binding prof...
Product and Quotient Rules from Logarithmic Differentiation
Chen, Zhibo
2012-01-01
A new application of logarithmic differentiation is presented, which provides an alternative elegant proof of two basic rules of differentiation: the product rule and the quotient rule. The proof can intrigue students, help promote their critical thinking and rigorous reasoning and deepen their understanding of previously encountered concepts. The…
Development of a new differential extensometer
Lu Chongwu
2011-02-01
Full Text Available This paper describes a new differential extensometer, which has a baseline rod in suspension with both ends free, and some preliminary test results. compared with a traditional differential extensometer, which has one end of the baseline rod fixed to the ground, this instrument is less affected by commonly encountered interferences, including environment vibration, momentary power failure, and power noise.
Differential privacy in intelligent transportation systems
Kargl, Frank; Friedman, Arik; Boreli, Roksana
2013-01-01
In this paper, we investigate how the concept of differential privacy can be applied to Intelligent Transportation Systems (ITS), focusing on protection of Floating Car Data (FCD) stored and processed in central Traffic Data Centers (TDC). We illustrate an integration of differential privacy with pr
Differentiated thyroid carcinoma : A polygenic disease
Links, TP; van Tol, KM; te Meerman, GJ; de Vries, EGE
2001-01-01
Differentiated thyroid cancer is a rare disease and until recently was considered to be sporadic. However, increasing evidence has been found for a genetic basis of this disease. In approximately 5% of patients the differentiated thyroid cancer is dominantly inherited. Several families with differen
Selected papers on analysis and differential equations
Society, American Mathematical
2010-01-01
This volume contains translations of papers that originally appeared in the Japanese journal Sūgaku. These papers range over a variety of topics in ordinary and partial differential equations, and in analysis. Many of them are survey papers presenting new results obtained in the last few years. This volume is suitable for graduate students and research mathematicians interested in analysis and differential equations.
New Electronic Technologies for Facilitating Differentiated Instruction
Scalise, Kathleen
2009-01-01
With electronic technologies, differentiated instruction has the same meaning as in traditional instruction, but different tools are available for teachers to help students learn. Electronic technologies for differentiated instruction can add powerful new types of media inclusion, levels of interactivity, and response actions. This rapidly…
Symbolic computations in applied differential geometry
Gragert, P.K.H.; Kersten, P.H.M.; Martini, R.
1983-01-01
The main aim of this paper is to contribute to the automatic calculations in differential geometry and its applications, with emphasis on the prolongation theory of Estabrook and Wahlquist, and the calculation of invariance groups of exterior differential systems. A large number of worked examples h
Topologies for neutral functional differential equations.
Melvin, W. R.
1973-01-01
Bounded topologies are considered for functional differential equations of the neutral type in which present dynamics of the system are influenced by its past behavior. A special bounded topology is generated on a collection of absolutely continuous functions with essentially bounded derivatives, and an application to a class of nonlinear neutral functional differential equations due to Driver (1965) is presented.
Solution techniques for elementary partial differential equations
Constanda, Christian
2012-01-01
Incorporating a number of enhancements, Solution Techniques for Elementary Partial Differential Equations, Second Edition presents some of the most important and widely used methods for solving partial differential equations (PDEs). The techniques covered include separation of variables, method of characteristics, eigenfunction expansion, Fourier and Laplace transformations, Green’s functions, perturbation methods, and asymptotic analysis.
Lie algebras and linear differential equations.
Brockett, R. W.; Rahimi, A.
1972-01-01
Certain symmetry properties possessed by the solutions of linear differential equations are examined. For this purpose, some basic ideas from the theory of finite dimensional linear systems are used together with the work of Wei and Norman on the use of Lie algebraic methods in differential equation theory.
Differential analysis of matrix convex functions II
Hansen, Frank; Tomiyama, Jun
2009-01-01
We continue the analysis in [F. Hansen, and J. Tomiyama, Differential analysis of matrix convex functions. Linear Algebra Appl., 420:102--116, 2007] of matrix convex functions of a fixed order defined in a real interval by differential methods as opposed to the characterization in terms of divide...
Solving Differential Equations Using Modified Picard Iteration
Robin, W. A.
2010-01-01
Many classes of differential equations are shown to be open to solution through a method involving a combination of a direct integration approach with suitably modified Picard iterative procedures. The classes of differential equations considered include typical initial value, boundary value and eigenvalue problems arising in physics and…
ON ALGEBRICO-DIFFERENTIAL EQUATIONS-SOLVING
WU Wenjun(Wu Wen-tsun)
2004-01-01
The char-set method of polynomial equations-solving is naturally extended to the differential case which gives rise to an algorithmic method of solving arbitrary systems of algebrico-differential equations. As an illustration of the method, the Devil's Problem of Pommaret is solved in details.
Simplicial approach to derived differential manifolds
Borisov, Dennis
2011-01-01
Derived differential manifolds are constructed using the usual homotopy theory of simplicial rings of smooth functions. They are proved to be equivalent to derived differential manifolds of finite type, constructed using homotopy sheaves of homotopy rings (D.Spivak), thus preserving the classical cobordism ring. This reduction to the usual algebraic homotopy can potentially lead to virtual fundamental classes beyond obstruction theory.
Lectures on differential equations for Feynman integrals
Henn, Johannes M
2014-01-01
Over the last year significant progress was made in the understanding of the computation of Feynman integrals using differential equations. These lectures give a review of these developments, while not assuming any prior knowledge of the subject. After an introduction to differential equations for Feynman integrals, we point out how they can be simplified using algorithms available in the mathematical literature. We discuss how this is related to a recent conjecture for a canonical form of the equations. We also discuss a complementary approach that allows based on properties of the space-time loop integrands, and explain how the ideas of leading singularities and d-log representations can be used to find an optimal basis for the differential equations. Finally, as an application of the differential equations method we show how single-scale integrals can be bootstrapped using the Drinfeld associator of a differential equation.
The differential induction machine: Theory and performance
Sumita Sinha; Nirmal K Deb; Nikhil Mondal; Sujit K Biswas
2008-10-01
This paper presents the theory and performance of a differential induction machine, which is a special type of induction machine having two shafts projected from the two ends of a single stator. Application of a differential load on the two shafts cause them to run at different speed as a motor, which permits true differential movement and thus can meet the requirements of a differential drive in an electric vehicle. The machine is also capable of regeneration in the differential mode. This paper presents the construction of the above machine and performance of the same based on experimental results from a laboratory prototype. The equivalent circuit of the motor has been presented and veriﬁed experimentally.
Fuzzy differential equations in various approaches
Gomes, Luciana Takata; Bede, Barnabas
2015-01-01
This book may be used as reference for graduate students interested in fuzzy differential equations and researchers working in fuzzy sets and systems, dynamical systems, uncertainty analysis, and applications of uncertain dynamical systems. Beginning with a historical overview and introduction to fundamental notions of fuzzy sets, including different possibilities of fuzzy differentiation and metric spaces, this book moves on to an overview of fuzzy calculus thorough exposition and comparison of different approaches. Innovative theories of fuzzy calculus and fuzzy differential equations using fuzzy bunches of functions are introduced and explored. Launching with a brief review of essential theories, this book investigates both well-known and novel approaches in this field; such as the Hukuhara differentiability and its generalizations as well as differential inclusions and Zadeh’s extension. Through a unique analysis, results of all these theories are examined and compared.
Regulating cell differentiation at different layers
Jiarui Wu
2011-01-01
Cell differentiation is a basic behavior in the developmental process of multi-cellular organisms,through which various cell types are generated from one embryonic cell for further building different tissues and organs of animals or plants.It is estimated that there are more than two hundred cell types in a human body.To understand the molecular mechanisms of cell differentiation,researchers usually focus on a question how particular genes are selectively expressed during the differentiation process.However,more and more evidence indicates that the regulation of cell differentiation is far beyond simply controlling the expression of genetic program,which is supported by the collection of four research articles in this issue that the regulation of cell differentiation involves various factors at different layers,including epigenetics,metabolism and cell-cell interaction.
Nuclear Mechanics and Stem Cell Differentiation.
Mao, Xinjian; Gavara, Nuria; Song, Guanbin
2015-12-01
Stem cells are characterized by their self-renewal and multi-lineage differentiation potential. Stem cell differentiation is a prerequisite for the application of stem cells in regenerative medicine and clinical therapy. In addition to chemical stimulation, mechanical cues play a significant role in regulating stem cell differentiation. The integrity of mechanical sensors is necessary for the ability of cells to respond to mechanical signals. The nucleus, the largest and stiffest cellular organelle, interacts with the cytoskeleton as a key mediator of cell mechanics. Nuclear mechanics are involved in the complicated interactions of lamins, chromatin and nucleoskeleton-related proteins. Thus, stem cell differentiation is intimately associated with nuclear mechanics due to its indispensable role in mechanotransduction and mechanical response. This paper reviews several main contributions of nuclear mechanics, highlights the hallmarks of the nuclear mechanics of stem cells, and provides insight into the relationship between nuclear mechanics and stem cell differentiation, which may guide clinical applications in the future.
Numerical methods for ordinary differential equations
Butcher, John C
2008-01-01
In recent years the study of numerical methods for solving ordinary differential equations has seen many new developments. This second edition of the author''s pioneering text is fully revised and updated to acknowledge many of these developments. It includes a complete treatment of linear multistep methods whilst maintaining its unique and comprehensive emphasis on Runge-Kutta methods and general linear methods. Although the specialist topics are taken to an advanced level, the entry point to the volume as a whole is not especially demanding. Early chapters provide a wide-ranging introduction to differential equations and difference equations together with a survey of numerical differential equation methods, based on the fundamental Euler method with more sophisticated methods presented as generalizations of Euler. Features of the book includeIntroductory work on differential and difference equations.A comprehensive introduction to the theory and practice of solving ordinary differential equations numeri...
DNA microsatellite analysis for tomato genetic differentiation
Miskoska-Milevska Elizabeta
2015-01-01
Full Text Available Commonly used method for determination of the genetic diversity among the populations is the test for genetic differentiation. DNA microsatellite markers are usually used to investigate the genetic structure of natural populations. The aim of this study was to evaluate the applicability of eight DNA microsatellite loci (LECH13, LE21085, LEMDDNa, LEEF1Aa, LELEUZIP, LE20592, TMS9 and LE2A11 in genetic differentiation of six morphologically different tomato varieties (var. grandifolium from subsp. cultum; var. cerasiforme - red and yellow, var. pruniforme and var. pyriforme from subsp. subspontaneum; and var. racemigerum from subsp. spontaneum. The fragment analyses was performed using Applied Biosystems DNA analyzer (ABI 3130 and GeneMapper® Software program. The data were analysed using the specific program Power Marker Software. The average number of detected alleles was 3,625. Also, the average PIC value for all 8 DNA microsatellites loci was 0,3571. The genetic differentiation test in the researched tomato subspecies showed minor differentiation for locus LELEUZIP (- 0,0009, modest differentiation for locus LECH13 (0,0896, locus LEMDDNa (0,0896 and locus LE21085 (0,0551 and major differentiation for locus LE2A11 (0,7633, locus LEEF1Aa (0,6167, locus TMS9 (0.4967 and locus LE20592 (0,4263. On the other hand, in the estimated tomato varieties, locus LE21085 (0,0297, locus LECH13 (0,0256 and locus LELEUZIP (0,0005 showed minor differentiation, locus LEMDDNa (0,1333 showed modest differentiation, while locus TMS9 (0,5929, locus LEEF1Aa (0,5006, locus LE2A11 (0,4013 and locus LE20592 (0,2606 showed major differentiation. The eight DNA microsatellite loci can be applicable solution for tomato genetic differentiation. The overall results suggest that these microsatellite loci could be used in further population genetic studies of tomatoes.
Superparasitism as a differential game.
Hamelin, Frédéric; Bernhard, Pierre; Wajnberg, Eric
2007-11-01
Superparasitism refers to a female parasitoid laying an egg in a host already parasitized by a conspecific. In solitary species, only one offspring per host is expected to complete development, hence the game. Hosts are often clumped in patches and several females exploiting such an aggregate of resource make its state change over time, hence the dynamical character of the game. Two coupled questions arise: (i) Is it worth accepting a parasitized host? (ii) When to leave the host patch? Through these decisions (i) the competition for healthy hosts and (ii) the trade-off between leaving in quest of a better patch and staying to make the patch less profitable for other parasitoids (this is a way to lower superparasitism likely to occur after having left the patch) are addressed. The aim of this work is to characterize a strategy that would be evolutionarily relevant in such a situation, as it directly concerns females' reproductive success. Investigating a (synchronous) nonzero-sum two-player differential game allows us to characterize candidate dynamic evolutionarily stable policies in terms of both oviposition and patch-leaving decisions. For that matter, the game is (in the most part of the parameter space) completely solved if the probability that superparasitism succeeds is assumed to be close to one-half, a fair value under direct competition. The strategic equilibrium consists, for each females, in (i) superparasitizing consistently upon arrival on the patch, and (ii) leaving when the loss of fitness due to superparasitism likely to occur after its departure is reduced to zero. The competing females are thus expected to leave the patch as they arrived: synchronously. Superparasitism does not necessarily lead to a war of attrition.
Differential dopamine function in fibromyalgia.
Albrecht, Daniel S; MacKie, Palmer J; Kareken, David A; Hutchins, Gary D; Chumin, Evgeny J; Christian, Bradley T; Yoder, Karmen K
2016-09-01
Approximately 30 % of Americans suffer from chronic pain disorders, such as fibromyalgia (FM), which can cause debilitating pain. Many pain-killing drugs prescribed for chronic pain disorders are highly addictive, have limited clinical efficacy, and do not treat the cognitive symptoms reported by many patients. The neurobiological substrates of chronic pain are largely unknown, but evidence points to altered dopaminergic transmission in aberrant pain perception. We sought to characterize the dopamine (DA) system in individuals with FM. Positron emission tomography (PET) with [(18)F]fallypride (FAL) was used to assess changes in DA during a working memory challenge relative to a baseline task, and to test for associations between baseline D2/D3 availability and experimental pain measures. Twelve female subjects with FM and 11 female controls completed study procedures. Subjects received one FAL PET scan while performing a "2-back" task, and one while performing a "0-back" (attentional control, "baseline") task. FM subjects had lower baseline FAL binding potential (BP) in several cortical regions relative to controls, including anterior cingulate cortex. In FM subjects, self-reported spontaneous pain negatively correlated with FAL BP in the left orbitofrontal cortex and parahippocampal gyrus. Baseline BP was significantly negatively correlated with experimental pain sensitivity and tolerance in both FM and CON subjects, although spatial patterns of these associations differed between groups. The data suggest that abnormal DA function may be associated with differential processing of pain perception in FM. Further studies are needed to explore the functional significance of DA in nociception and cognitive processing in chronic pain.
Grbner bases in difference-differential modules and difference-differential dimension polynomials
Franz; WINKLER
2008-01-01
In this paper we extend the theory of Grbner bases to difference-differential modules and present a new algorithmic approach for computing the Hilbert function of a finitely generated difference-differential module equipped with the natural filtration. We present and verify algorithms for construct-ing these Grbner bases counterparts. To this aim we introduce the concept of "generalized term order" on Nm ×Zn and on difference-differential modules. Using Grbner bases on difference-differential mod-ules we present a direct and algorithmic approach to computing the difference-differential dimension polynomials of a difference-differential module and of a system of linear partial difference-differential equations.
Function of caspase-14 in trophoblast differentiation
Charles Adrian K
2009-09-01
Full Text Available Abstract Background Within the human placenta, the cytotrophoblast consists of a proliferative pool of progenitor cells which differentiate to replenish the overlying continuous, multi-nucleated syncytiotrophoblast, which forms the barrier between the maternal and fetal tissues. Disruption to trophoblast differentiation and function may result in impaired fetal development and preeclampsia. Caspase-14 expression is limited to barrier forming tissues. It promotes keratinocyte differentiation by cleaving profilaggrin to stabilise keratin intermediate filaments, and indirectly providing hydration and UV protection. However its role in the trophoblast remains unexplored. Methods Using RNA Interference the reaction of control and differentiating trophoblastic BeWo cells to suppressed caspase-14 was examined for genes pertaining to hormonal, cell cycle and cytoskeletal pathways. Results Transcription of hCG, KLF4 and cytokeratin-18 were increased following caspase-14 suppression suggesting a role for caspase-14 in inhibiting their pathways. Furthermore, hCG, KLF4 and cytokeratin-18 protein levels were disrupted. Conclusion Since expression of these molecules is normally increased with trophoblast differentiation, our results imply that caspase-14 inhibits trophoblast differentiation. This is the first functional study of this unusual member of the caspase family in the trophoblast, where it has a different function than in the epidermis. This knowledge of the molecular underpinnings of trophoblast differentiation may instruct future therapies of trophoblast disease.
Selective phosphorylation during early macrophage differentiation
Zhang, Huoming
2015-08-26
The differentiation of macrophages from monocytes is a tightly controlled and complex biological process. Although numerous studies have been conducted using biochemical approaches or global gene/gene profiling, the mechanisms of the early stages of differentiation remain unclear. Here we used SILAC-based quantitative proteomics approach to perform temporal phosphoproteome profiling of early macrophage differentiation. We identified a large set of phosphoproteins and grouped them as PMA-regulated and non-regulated phosphoproteins in the early stages of differentiation. Further analysis of the PMA-regulated phosphoproteins revealed that transcriptional suppression, cytoskeletal reorganization and cell adhesion were among the most significantly activated pathways. Some key involved regulators of these pathways are mTOR, MYB, STAT1 and CTNNB. Moreover, we were able to classify the roles and activities of several transcriptional factors during different differentiation stages and found that E2F is likely to be an important regulator during the relatively late stages of differentiation. This study provides the first comprehensive picture of the dynamic phosphoproteome during myeloid cells differentiation, and identifies potential molecular targets in leukemic cells.
Neural differentiation and synaptogenesis in retinal development.
Fan, Wen-Juan; Li, Xue; Yao, Huan-Ling; Deng, Jie-Xin; Liu, Hong-Liang; Cui, Zhan-Jun; Wang, Qiang; Wu, Ping; Deng, Jin-Bo
2016-02-01
To investigate the pattern of neural differentiation and synaptogenesis in the mouse retina, immunolabeling, BrdU assay and transmission electron microscopy were used. We show that the neuroblastic cell layer is the germinal zone for neural differentiation and retinal lamination. Ganglion cells differentiated initially at embryonic day 13 (E13), and at E18 horizontal cells appeared in the neuroblastic cell layer. Neural stem cells in the outer neuroblastic cell layer differentiated into photoreceptor cells as early as postnatal day 0 (P0), and neural stem cells in the inner neuroblastic cell layer differentiated into bipolar cells at P7. Synapses in the retina were mainly located in the outer and inner plexiform layers. At P7, synaptophysin immunostaining appeared in presynaptic terminals in the outer and inner plexiform layers with button-like structures. After P14, presynaptic buttons were concentrated in outer and inner plexiform layers with strong staining. These data indicate that neural differentiation and synaptogenesis in the retina play important roles in the formation of retinal neural circuitry. Our study showed that the period before P14, especially between P0 and P14, represents a critical period during retinal development. Mouse eye opening occurs during that period, suggesting that cell differentiation and synaptic formation lead to the attainment of visual function.
Compositional differentiation of Enceladus' plume
Khawaja, N.; Postberg, F.; Schmidt, J.
2014-04-01
The Cosmic Dust Analyser (CDA) on board the Cassini spacecraft sampled Enceladus' plume ice particles emanated directly from Enceladus' fractured south polar terrain (SPT), the so-called "Tiger Stripes", during two consecutive flybys (E17 and E18) in 2012. The spacecraft passed through the dense plume with a moderate velocity of ~7.5km/s, horizontally to the SPT with a closest approach (CA) at an altitude of ~75km almost directly over the south pole. In both flybys, spectra were recorded during a time interval of ~ ±3 minutes with respect to the closest approach achieving an average sampling rate of about 0.6 sec-1. We assume that the spacecraft passed through the plume during an interval of about ±60(sec) from the CA. Particles encountered before and after this period are predominately from the E-ring background in which Enceladus is embedded. Most CDA TOF-mass spectra are identified as one of three compositional types: (i) almost pure water (ii) organic rich and (iii) salt rich [2]. A Boxcar Analysis (BCA) is performed from a count database for compositional mapping of the plume along the space-craft trajectory. In BCA, counts of each spectrum type are integrated for a certain interval of time (box size). The integral of counts represents frequencies of compositional types in absolute abundances, which are converted later into proportions. This technique has been proven to be a suitable for inferring the compositional profiles from an earlier flyby (E5) [1]. The inferred compositional profiles show similar trends on E17 and E18. The abundances of different compositional types in the plume clearly differ from the Ering background and imply a compositional differentiation inside the plume. Following up the work of Schmidt et al, 2008 and Postberg et al, 2011 we can link different compositional types to different origins. The E17/E18 results are compared with the E5 flyby in 2008, which yielded the currently best compositional profile [2] but was executed at much
DIFFERENTIAL SOIL IMPEDANCE OBSTACLE DETECTION
Maximillian J. Kieba; Christopher J. Ziolkowski
2004-06-30
This project develops a new and unique obstacle detection sensor for horizontal directional drilling (HDD) equipment. The development of this new technology will greatly improve the reliability and safety of natural gas HDD construction practices. This sensor utilizes a differential soil impedance measurement technique that will be sensitive to the presence of plastic and ceramic, as well as metallic obstacles. The use of HDD equipment has risen significantly in the gas industry because HDD provides a much more cost-effective and less disruptive method for gas pipe installation than older, trenching methods. However, there have been isolated strikes of underground utilities by HDD equipment, which may have been avoided if methods were available to detect other underground obstacles when using HDD systems. GTI advisors from the gas industry have ranked the value of solving the obstacle detection problem as the most important research and development project for GTI to pursue using Federal Energy Regulatory Commission (FERC) funds available through its industry partner, GRI. GTI proposes to develop a prototype down-hole sensor system that is simple and compact. The sensor utilizes an impedance measurement technique that is sensitive to the presence of metallic or nonmetallic objects in the proximity of the HDD head. The system will use a simple sensor incorporated into the drill head. The impedance of the soil will be measured with a low frequency signal injected through the drill head itself. A pair of bridge type impedance sensors, mounted orthogonal to one another, is coupled to the soil. Inclusions in the soil will cause changes to the sensor balance distinguishable from homogeneous soil. The sensor will provide range and direction data for obstacles near the HDD head. The goal is to provide a simple, robust system that provides the information required to avoid obstacles. This must be done within the size and ruggedness constraints of the HDD equipment. Imaging
DIFFERENTIAL SOIL IMPEDANCE OBSTACLE DETECTION
Maximillian J. Kieba
2003-10-01
This project develops a new and unique obstacle detection sensor for horizontal directional drilling (HDD) equipment. The development of this new technology will greatly improve the reliability and safety of natural gas HDD construction practices. This sensor utilizes a differential soil impedance measurement technique that will be sensitive to the presence of plastic and ceramic, as well as metallic obstacles. The use of HDD equipment has risen significantly in the gas industry because HDD provides a much more cost-effective and less disruptive method for gas pipe installation than older, trenching methods. However, there have been isolated strikes of underground utilities by HDD equipment, which may have been avoided if methods were available to detect other underground obstacles when using HDD systems. GTI advisors from the gas industry have ranked the value of solving the obstacle detection problem as the most important research and development project for GTI to pursue using Federal Energy Regulatory Commission (FERC) funds available through its industry partner, GRI. GTI proposes to develop a prototype down-hole sensor system that is simple and compact. The sensor utilizes an impedance measurement technique that is sensitive to the presence of metallic or nonmetallic objects in the proximity of the HDD head. The system will use a simple sensor incorporated into the drill head. The impedance of the soil will be measured with a low frequency signal injected through the drill head itself. A pair of bridge type impedance sensors, mounted orthogonal to one another, is coupled to the soil. Inclusions in the soil will cause changes to the sensor balance distinguishable from homogeneous soil. The sensor will provide range and direction data for obstacles near the HDD head. The goal is to provide a simple, robust system that provides the information required to avoid obstacles. This must be done within the size and ruggedness constraints of the HDD equipment. Imaging
DIFFERENTIAL SOIL IMPEDANCE OBSTACLE DETECTION
Maximillian J. Kieba
2003-04-01
This project develops a new and unique obstacle detection sensor for horizontal directional drilling (HDD) equipment. The development of this new technology will greatly improve the reliability and safety of natural gas HDD construction practices. This sensor utilizes a differential soil impedance measurement technique that will be sensitive to the presence of plastic and ceramic, as well as metallic obstacles. The use of HDD equipment has risen significantly in the gas industry because HDD provides a much more cost-effective and less disruptive method for gas pipe installation than older, trenching methods. However, there have been isolated strikes of underground utilities by HDD equipment, which may have been avoided if methods were available to detect other underground obstacles when using HDD systems. GTI advisors from the gas industry have ranked the value of solving the obstacle detection problem as the most important research and development project for GTI to pursue using Federal Energy Regulatory Commission (FERC) funds available through its industry partner, GRI. GTI proposes to develop a prototype down-hole sensor system that is simple and compact. The sensor utilizes an impedance measurement technique that is sensitive to the presence of metallic or nonmetallic objects in the proximity of the HDD head. The system will use a thin film sensor conformal with the drill head. The impedance of the soil will be measured with a low frequency signal injected through the drill head itself. A pair of bridge type impedance sensors, mounted orthogonal to one another, is capacitively coupled to the soil. Inclusions in the soil will cause changes to the sensor balance distinguishable from homogeneous soil. The sensor will provide range and direction data for obstacles near the HDD head. The goal is to provide a simple, robust system that provides the information required to avoid obstacles. This must be done within the size and ruggedness constraints of the HDD
DIFFERENTIAL SOIL IMPEDANCE OBSTACLE DETECTION
Maximillian J. Kieba; Christopher J. Ziolkowski
2005-01-17
This project aimed at developing a new and unique obstacle detection sensor for horizontal directional drilling (HDD) equipment. The development of this new technology will greatly improve the reliability and safety of natural gas HDD construction practices. This sensor utilizes a differential soil impedance measurement technique that will be sensitive to the presence of plastic and ceramic, as well as metallic obstacles. The use of HDD equipment has risen significantly in the gas industry because HDD provides a much more cost-effective and less disruptive method for gas pipe installation than older, trenching methods. However, there have been isolated strikes of underground utilities by HDD equipment, which may have been avoided if methods were available to detect other underground obstacles when using HDD systems. GTI advisors from the gas industry ranked the value of solving the obstacle detection problem as the most important research and development project for GTI to pursue using Federal Energy Regulatory Commission (FERC) funds available through its industry partner, GTI. GTI proposed to develop a prototype down-hole sensor system that is simple and compact. The sensor utilizes an impedance measurement technique that is sensitive to the presence of metallic or non-metallic objects in the proximity of the HDD head. The system will use a simple sensor incorporated into the drill head. The impedance of the soil will be measured with a low frequency signal injected through the drill head itself. A pair of bridge type impedance sensors, mounted orthogonal to one another, is coupled to the soil. Inclusions in the soil will cause changes to the sensor balance distinguishable from homogeneous soil. The sensor will provide range and direction data for obstacles near the HDD head. The goal is to provide a simple, robust system that provides the information required to avoid obstacles. This must be done within the size and ruggedness constraints of the HDD equipment
DIFFERENTIAL SOIL IMPEDANCE OBSTACLE DETECTION
Maximillian J. Kieba
2003-01-30
This project develops a new and unique obstacle detection sensor for horizontal directional drilling (HDD) equipment. The development of this new technology will greatly improve the reliability and safety of natural gas HDD construction practices. This sensor utilizes a differential soil impedance measurement technique that will be sensitive to the presence of plastic and ceramic, as well as metallic obstacles. The use of HDD equipment has risen significantly in the gas industry because HDD provides a much more cost-effective and less disruptive method for gas pipe installation than older, trenching methods. However, there have been isolated strikes of underground utilities by HDD equipment, which may have been avoided if methods were available to detect other underground obstacles when using HDD systems. GTI advisors from the gas industry have ranked the value of solving the obstacle detection problem as the most important research and development project for GTI to pursue using Federal Energy Regulatory Commission (FERC) funds available through its industry partner, GRI. GTI proposes to develop a prototype down-hole sensor system that is simple and compact. The sensor utilizes an impedance measurement technique that is sensitive to the presence of metallic or nonmetallic objects in the proximity of the HDD head. The system will use a thin film sensor conformal with the drill head. The impedance of the soil will be measured with a low frequency signal injected through the drill head itself. A pair of bridge type impedance sensors, mounted orthogonal to one another, is capacitively coupled to the soil. Inclusions in the soil will cause changes to the sensor balance distinguishable from homogeneous soil. The sensor will provide range and direction data for obstacles near the HDD head. The goal is to provide a simple, robust system that provides the information required to avoid obstacles. This must be done within the size and ruggedness constraints of the HDD
DIFFERENTIAL SOIL IMPEDANCE OBSTACLE DETECTION
Maximillian J. Kieba; Christopher J. Ziolkowski
2004-10-29
This project develops a new and unique obstacle detection sensor for horizontal directional drilling (HDD) equipment. The development of this new technology will greatly improve the reliability and safety of natural gas HDD construction practices. This sensor utilizes a differential soil impedance measurement technique that will be sensitive to the presence of plastic and ceramic, as well as metallic obstacles. The use of HDD equipment has risen significantly in the gas industry because HDD provides a much more cost-effective and less disruptive method for gas pipe installation than older, trenching methods. However, there have been isolated strikes of underground utilities by HDD equipment, which may have been avoided if methods were available to detect other underground obstacles when using HDD systems. GTI advisors from the gas industry have ranked the value of solving the obstacle detection problem as the most important research and development project for GTI to pursue using Federal Energy Regulatory Commission (FERC) funds available through its industry partner, GRI. GTI proposes to develop a prototype down-hole sensor system that is simple and compact. The sensor utilizes an impedance measurement technique that is sensitive to the presence of metallic or non-metallic objects in the proximity of the HDD head. The system will use a simple sensor incorporated into the drill head. The impedance of the soil will be measured with a low frequency signal injected through the drill head itself. A pair of bridge type impedance sensors, mounted orthogonal to one another, is coupled to the soil. Inclusions in the soil will cause changes to the sensor balance distinguishable from homogeneous soil. The sensor will provide range and direction data for obstacles near the HDD head. The goal is to provide a simple, robust system that provides the information required to avoid obstacles. This must be done within the size and ruggedness constraints of the HDD equipment. Imaging
DIFFERENTIAL SOIL IMPEDANCE OBSTACLE DETECTION
Maximillian J. Kieba
2002-08-30
This project develops a new and unique obstacle detection sensor for horizontal directional drilling (HDD) equipment. The development of this new technology will greatly improve the reliability and safety of natural gas HDD construction practices. This sensor utilizes a differential soil impedance measurement technique that will be sensitive to the presence of plastic and ceramic, as well as metallic obstacles. The use of HDD equipment has risen significantly in the gas industry because HDD provides a much more cost-effective and less disruptive method for gas pipe installation than older, trenching methods. However, there have been isolated strikes of underground utilities by HDD equipment, which may have been avoided if methods were available to detect other underground obstacles when using HDD systems. GTI advisors from the gas industry have ranked the value of solving the obstacle detection problem as the most important research and development project for GTI to pursue using Federal Energy Regulatory Commission (FERC) funds available through its industry partner, GRI. GTI proposes to develop a prototype down-hole sensor system that is simple and compact. The sensor utilizes an impedance measurement technique that is sensitive to the presence of metallic or nonmetallic objects in the proximity of the HDD head. The system will use a thin film sensor conformal with the drill head. The impedance of the soil will be measured with a low frequency signal injected through the drill head itself. A pair of bridge type impedance sensors, mounted orthogonal to one another, is capacitively coupled to the soil. Inclusions in the soil will cause changes to the sensor balance distinguishable from homogeneous soil. The sensor will provide range and direction data for obstacles near the HDD head. The goal is to provide a simple, robust system that provides the information required to avoid obstacles. This must be done within the size and ruggedness constraints of the HDD
DIFFERENTIAL SOIL IMPEDANCE OBSTACLE DETECTION
Maximillian J. Kieba
2004-02-01
This project develops a new and unique obstacle detection sensor for horizontal directional drilling (HDD) equipment. The development of this new technology will greatly improve the reliability and safety of natural gas HDD construction practices. This sensor utilizes a differential soil impedance measurement technique that will be sensitive to the presence of plastic and ceramic, as well as metallic obstacles. The use of HDD equipment has risen significantly in the gas industry because HDD provides a much more cost-effective and less disruptive method for gas pipe installation than older, trenching methods. However, there have been isolated strikes of underground utilities by HDD equipment, which may have been avoided if methods were available to detect other underground obstacles when using HDD systems. GTI advisors from the gas industry have ranked the value of solving the obstacle detection problem as the most important research and development project for GTI to pursue using Federal Energy Regulatory Commission (FERC) funds available through its industry partner, GRI. GTI proposes to develop a prototype down-hole sensor system that is simple and compact. The sensor utilizes an impedance measurement technique that is sensitive to the presence of metallic or nonmetallic objects in the proximity of the HDD head. The system will use a simple sensor incorporated into the drill head. The impedance of the soil will be measured with a low frequency signal injected through the drill head itself. A pair of bridge type impedance sensors, mounted orthogonal to one another, is coupled to the soil. Inclusions in the soil will cause changes to the sensor balance distinguishable from homogeneous soil. The sensor will provide range and direction data for obstacles near the HDD head. The goal is to provide a simple, robust system that provides the information required to avoid obstacles. This must be done within the size and ruggedness constraints of the HDD equipment. Imaging
DIFFERENTIAL SOIL IMPEDANCE OBSTACLE DETECTION
Maximillian J. Kieba
2002-11-27
This project develops a new and unique obstacle detection sensor for horizontal directional drilling (HDD) equipment. The development of this new technology will greatly improve the reliability and safety of natural gas HDD construction practices. This sensor utilizes a differential soil impedance measurement technique that will be sensitive to the presence of plastic and ceramic, as well as metallic obstacles. The use of HDD equipment has risen significantly in the gas industry because HDD provides a much more cost-effective and less disruptive method for gas pipe installation than older, trenching methods. However, there have been isolated strikes of underground utilities by HDD equipment, which may have been avoided if methods were available to detect other underground obstacles when using HDD systems. GTI advisors from the gas industry have ranked the value of solving the obstacle detection problem as the most important research and development project for GTI to pursue using Federal Energy Regulatory Commission (FERC) funds available through its industry partner, GRI. GTI proposes to develop a prototype down-hole sensor system that is simple and compact. The sensor utilizes an impedance measurement technique that is sensitive to the presence of metallic or nonmetallic objects in the proximity of the HDD head. The system will use a thin film sensor conformal with the drill head. The impedance of the soil will be measured with a low frequency signal injected through the drill head itself. A pair of bridge type impedance sensors, mounted orthogonal to one another, is capacitively coupled to the soil. Inclusions in the soil will cause changes to the sensor balance distinguishable from homogeneous soil. The sensor will provide range and direction data for obstacles near the HDD head. The goal is to provide a simple, robust system that provides the information required to avoid obstacles. This must be done within the size and ruggedness constraints of the HDD
DIFFERENTIAL SOIL IMPEDANCE OBSTACLE DETECTION
Maximillian J. Kieba
2004-05-03
This project develops a new and unique obstacle detection sensor for horizontal directional drilling (HDD) equipment. The development of this new technology will greatly improve the reliability and safety of natural gas HDD construction practices. This sensor utilizes a differential soil impedance measurement technique that will be sensitive to the presence of plastic and ceramic, as well as metallic obstacles. The use of HDD equipment has risen significantly in the gas industry because HDD provides a much more cost-effective and less disruptive method for gas pipe installation than older, trenching methods. However, there have been isolated strikes of underground utilities by HDD equipment, which may have been avoided if methods were available to detect other underground obstacles when using HDD systems. GTI advisors from the gas industry have ranked the value of solving the obstacle detection problem as the most important research and development project for GTI to pursue using Federal Energy Regulatory Commission (FERC) funds available through its industry partner, GRI. GTI proposes to develop a prototype down-hole sensor system that is simple and compact. The sensor utilizes an impedance measurement technique that is sensitive to the presence of metallic or nonmetallic objects in the proximity of the HDD head. The system will use a simple sensor incorporated into the drill head. The impedance of the soil will be measured with a low frequency signal injected through the drill head itself. A pair of bridge type impedance sensors, mounted orthogonal to one another, is coupled to the soil. Inclusions in the soil will cause changes to the sensor balance distinguishable from homogeneous soil. The sensor will provide range and direction data for obstacles near the HDD head. The goal is to provide a simple, robust system that provides the information required to avoid obstacles. This must be done within the size and ruggedness constraints of the HDD equipment. Imaging
Vector Fields and Flows on Differentiable Stacks
A. Hepworth, Richard
2009-01-01
This paper introduces the notions of vector field and flow on a general differentiable stack. Our main theorem states that the flow of a vector field on a compact proper differentiable stack exists and is unique up to a uniquely determined 2-cell. This extends the usual result on the existence...... and uniqueness of flows on a manifold as well as the author's existing results for orbifolds. It sets the scene for a discussion of Morse Theory on a general proper stack and also paves the way for the categorification of other key aspects of differential geometry such as the tangent bundle and the Lie algebra...
Numerical Analysis of Partial Differential Equations
Lui, S H
2011-01-01
A balanced guide to the essential techniques for solving elliptic partial differential equations Numerical Analysis of Partial Differential Equations provides a comprehensive, self-contained treatment of the quantitative methods used to solve elliptic partial differential equations (PDEs), with a focus on the efficiency as well as the error of the presented methods. The author utilizes coverage of theoretical PDEs, along with the nu merical solution of linear systems and various examples and exercises, to supply readers with an introduction to the essential concepts in the numerical analysis
Stability analysis of impulsive functional differential equations
Stamova, Ivanka
2009-01-01
This book is devoted to impulsive functional differential equations which are a natural generalization of impulsive ordinary differential equations (without delay) and of functional differential equations (without impulses). At the present time the qualitative theory of such equationsis under rapid development. After a presentation of the fundamental theory of existence, uniqueness and continuability of solutions, a systematic development of stability theory for that class of problems is given which makes the book unique. It addresses to a wide audience such as mathematicians, applied research
Quantum algorithms for solving linear differential equations
Berry, Dominic W
2010-01-01
Linear differential equations are ubiquitous in science and engineering. Quantum computers can simulate quantum systems, which are described by homogeneous linear differential equations that produce only oscillating terms. Here we extend quantum simulation algorithms to general inhomogeneous linear differential equations, which can include exponential terms as well as oscillating terms in their solution. As with other algorithms of this type, the solution is encoded in amplitudes of the quantum state. The algorithm does not give the explicit solution, but it is possible to extract global features of the solution.
Psychological differentiation and the phenomenon of pain.
Feldman, H R
1984-01-01
This article deals with a theory of psychological differentiation, research supporting this theory and identified indicators of differentiation, and studies that connect several of these indicators with the phenomenon of pain. Problems for investigation are posed concerning the relationships between differentiation indicators and pain threshold, pain tolerance, relief measures, attention to pain, control, and counterirritation An understanding of the kinds of variables affecting the pain experience can lead to a clearer perception and more astute evaluation of that experience and a more organized approach to the implementation of nursing care.
Mortality level, trends and differentials in Malawi.
Palamuleni, M E
1994-01-01
"This article examines the levels, and trends and differentials in mortality in Malawi.... The study has shown that (i) the level of mortality is very high in Malawi; (ii) mortality has declined during the period under review; (iii) there was reduction in the rate of mortality decline in the seventies; and (iv) [there are] interesting differences in mortality in terms of rural-urban localities, regions and age-sex differentials. The observed levels, trends and differentials in mortality are however consistent with the level of social and economic development in the country."
Principle and Application of Differential Spectroradiometry
Metzdorf, J.; Möller, W.; Wittchen, T.; Hünerhoff, D.
1991-01-01
Differential spectroradiometry is based on the determination and analysis of the differential spectral response of photoelectric devices in the presence of bias irradiance that can be varied with wavelength and over many orders of magnitude. The principle is described. Differential spectroradiometry is particularly suitable for the following applications that are reviewed or illustrated by some examples: determination of spectral and weighted responsivities allowing the transfer of the spectral responsivity scale to high levels of irradiance; determination of nonlinearities in the photocurrent-irradiance characteristic; non-destructive characterization of photoinduced effects.
Exponentially Convergent Algorithms for Abstract Differential Equations
Gavrilyuk, Ivan; Vasylyk, Vitalii
2011-01-01
This book presents new accurate and efficient exponentially convergent methods for abstract differential equations with unbounded operator coefficients in Banach space. These methods are highly relevant for the practical scientific computing since the equations under consideration can be seen as the meta-models of systems of ordinary differential equations (ODE) as well as the partial differential equations (PDEs) describing various applied problems. The framework of functional analysis allows one to obtain very general but at the same time transparent algorithms and mathematical results which
Differential ghost imaging in time domain
O-oka, Yoshiki; Fukatsu, Susumu
2017-08-01
Differential ghost imaging is attempted in time domain, i.e., temporal differential ghost imaging (TDGI), using pseudo-randomized light pulses and a temporal object consisting of no-return-to-zero bit patterns of varying duty. Evaluation of the signal-to-noise characteristics by taking into account errors due to false cross-correlation between the reference and the bucket detector readings indicates that the TDGI outperforms its non-differential counterpart, i.e., time-domain GI, in terms of consistently high and even duty-independent signal-to-noise ratios that are achieved.
Statistical Methods for Stochastic Differential Equations
Kessler, Mathieu; Sorensen, Michael
2012-01-01
The seventh volume in the SemStat series, Statistical Methods for Stochastic Differential Equations presents current research trends and recent developments in statistical methods for stochastic differential equations. Written to be accessible to both new students and seasoned researchers, each self-contained chapter starts with introductions to the topic at hand and builds gradually towards discussing recent research. The book covers Wiener-driven equations as well as stochastic differential equations with jumps, including continuous-time ARMA processes and COGARCH processes. It presents a sp
On implicit abstract neutral nonlinear differential equations
Hernández, Eduardo, E-mail: lalohm@ffclrp.usp.br [Universidade de São Paulo, Departamento de Computação e Matemática, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto (Brazil); O’Regan, Donal, E-mail: donal.oregan@nuigalway.ie [National University of Ireland, School of Mathematics, Statistics and Applied Mathematics (Ireland)
2016-04-15
In this paper we continue our developments in Hernández and O’Regan (J Funct Anal 261:3457–3481, 2011) on the existence of solutions for abstract neutral differential equations. In particular we extend the results in Hernández and O’Regan (J Funct Anal 261:3457–3481, 2011) for the case of implicit nonlinear neutral equations and we focus on applications to partial “nonlinear” neutral differential equations. Some applications involving partial neutral differential equations are presented.
Anu S Maharjan
Full Text Available BACKGROUND: Following tissue injury, monocytes can enter the tissue and differentiate into fibroblast-like cells called fibrocytes, but little is known about what regulates this differentiation. Extracellular matrix contains high molecular weight hyaluronic acid (HMWHA; ∼2×10(6 Da. During injury, HMWHA breaks down to low molecular weight hyaluronic acid (LMWHA; ∼0.8-8×10(5 Da. METHODS AND FINDINGS: In this report, we show that HMWHA potentiates the differentiation of human monocytes into fibrocytes, while LMWHA inhibits fibrocyte differentiation. Digestion of HMWHA with hyaluronidase produces small hyaluronic acid fragments, and these fragments inhibit fibrocyte differentiation. Monocytes internalize HMWHA and LMWHA equally well, suggesting that the opposing effects on fibrocyte differentiation are not due to differential internalization of HMWHA or LMWHA. Adding HMWHA to PBMC does not appear to affect the levels of the hyaluronic acid receptor CD44, whereas adding LMWHA decreases CD44 levels. The addition of anti-CD44 antibodies potentiates fibrocyte differentiation, suggesting that CD44 mediates at least some of the effect of hyaluronic acid on fibrocyte differentiation. The fibrocyte differentiation-inhibiting factor serum amyloid P (SAP inhibits HMWHA-induced fibrocyte differentiation and potentiates LMWHA-induced inhibition. Conversely, LMWHA inhibits the ability of HMWHA, interleukin-4 (IL-4, or interleukin-13 (IL-13 to promote fibrocyte differentiation. CONCLUSIONS: We hypothesize that hyaluronic acid signals at least in part through CD44 to regulate fibrocyte differentiation, with a dominance hierarchy of SAP>LMWHA≥HMWHA>IL-4 or IL-13.
Genetic differentiation of watermelon landraces in Mozambique ...
Ezedom Theresa
2013-09-04
Sep 4, 2013 ... 2 Department of Plant and Environmental Sciences, Faculty of Science, University ... country, were analysed to assess their genetic differentiation. ...... Plant. Cell Physiol. 41: 864-873. Levi A, Thomas CE, Trebitsh T, Salman A, ...
Photon Differential Splatting for Rendering Caustics
Frisvad, Jeppe Revall; Schjøth, Lars; Erleben, Kenny;
2014-01-01
We present a photon splatting technique which reduces noise and blur in the rendering of caustics. Blurring of illumination edges is an inherent problem in photon splatting, as each photon is unaware of its neighbours when being splatted. This means that the splat size is usually based...... on heuristics rather than knowledge of the local flux density. We use photon differentials to determine the size and shape of the splats such that we achieve adaptive anisotropic flux density estimation in photon splatting. As compared to previous work that uses photon differentials, we present the first method...... where no photons or beams or differentials need to be stored in a map. We also present improvements in the theory of photon differentials, which give more accurate results and a faster implementation. Our technique has good potential for GPU acceleration, and we limit the number of parameters requiring...
Asymptotic integration of differential and difference equations
Bodine, Sigrun
2015-01-01
This book presents the theory of asymptotic integration for both linear differential and difference equations. This type of asymptotic analysis is based on some fundamental principles by Norman Levinson. While he applied them to a special class of differential equations, subsequent work has shown that the same principles lead to asymptotic results for much wider classes of differential and also difference equations. After discussing asymptotic integration in a unified approach, this book studies how the application of these methods provides several new insights and frequent improvements to results found in earlier literature. It then continues with a brief introduction to the relatively new field of asymptotic integration for dynamic equations on time scales. Asymptotic Integration of Differential and Difference Equations is a self-contained and clearly structured presentation of some of the most important results in asymptotic integration and the techniques used in this field. It will appeal to researchers i...
A Structured Population Model of Cell Differentiation
Doumic, Marie; Perthame, Benoit; Zubelli, Jorge P
2010-01-01
We introduce and analyze several aspects of a new model for cell differentiation. It assumes that differentiation of progenitor cells is a continuous process. From the mathematical point of view, it is based on partial differential equations of transport type. Specifically, it consists of a structured population equation with a nonlinear feedback loop. This models the signaling process due to cytokines, which regulate the differentiation and proliferation process. We compare the continuous model to its discrete counterpart, a multi-compartmental model of a discrete collection of cell subpopulations recently proposed by Marciniak-Czochra et al. in 2009 to investigate the dynamics of the hematopoietic system. We obtain uniform bounds for the solutions, characterize steady state solutions, and analyze their linearized stability. We show how persistence or extinction might occur according to values of parameters that characterize the stem cells self-renewal. We also perform numerical simulations and discuss the q...
Isologous diversification a theory of cell differentiation
Kaneko, K; Kaneko, Kunihiko; Yomo, Tetsuya
1996-01-01
Isologous diversification theory for cell differentiation is proposed, based on simulations of interacting cells with biochemical networks and cell division process following consumption of some chemicals. According to the simulations of the interaction-based dynamical systems model, the following scenario of the cell differentiation is proposed. (1) Up to some threshold number, divisions bring about almost identical cells with synchronized biochemical oscillations. (2)As the number is increased the oscillations lose the synchrony, leading to groups of cells with different phases of oscillations. (3)Amplitudes of oscillation and averaged chemical compositions start to differ by groups of cells. The differentiated behavior of states is transmitted to daughter cells. (4)Recursivity is formed so that the daughter cells keep the identical chemical character. This ``memory" is made possible through the transfer of initial conditions. (5) Successive differentiation proceeds. Mechanism of tumor cell formation, origi...
Discretizing a backward stochastic differential equation
Yinnan Zhang; Weian Zheng
2002-01-01
We show a simple method to discretize Pardoux-Peng's nonlinear backward stochastic differential equation. This discretization scheme also gives a numerical method to solve a class of semi-linear PDEs.
How Can Digital Learning Materials support Differentiation?
Graf, Stefan Ting
2013-01-01
Digital Learning Materials have again raised the question of how teaching can be differentiated so every child is challenged in an appropriate way without falling back to the individualization of learning in the 1970. Today diversity in ability, interest and background in learning groups has...... to be seen as a condition. On the other hand the question is raised because digitalization of learning materials seems to have an unfulfilled potential in that matter. In order to find connections between the use of digital learning materials and the differentiation of teaching there has been launched a two...... of a state of the art review, the key concept differentiation in the perspective of inclusion and the preliminary analysis of selected digital materials in the light of differentiation. Furthermore the paper discuss’ the methodological difficulties in designing suitable interventions on the background...
Trends in differential equations and applications
Neble, María; Galván, José
2016-01-01
This work collects the most important results presented at the Congress on Differential Equations and Applications/Congress on Applied Mathematics (CEDYA/CMA) in Cádiz (Spain) in 2015. It supports further research in differential equations, numerical analysis, mechanics, control and optimization. In particular, it helps readers gain an overview of specific problems of interest in the current mathematical research related to different branches of applied mathematics. This includes the analysis of nonlinear partial differential equations, exact solutions techniques for ordinary differential equations, numerical analysis and numerical simulation of some models arising in experimental sciences and engineering, control and optimization, and also trending topics on numerical linear Algebra, dynamical systems, and applied mathematics for Industry. This volume is mainly addressed to any researcher interested in the applications of mathematics, especially in any subject mentioned above. It may be also useful to PhD s...
An introduction to differential equations using MATLAB
Butt, Rizwan
2016-01-01
An Introduction to Differential Equations using MATLAB exploits the symbolic, numerical, and graphical capabilitiesof MATLAB to develop a thorough understanding of differential equations algorithms. This book provides the readerwith numerous applications, m-files, and practical examples to problems. Balancing theoretical concepts withcomputational speed and accuracy, the book includes numerous short programs in MATLAB that can be used to solveproblems involving first-and higher-order differential equations, Laplace transforms, linear systems of differentialequations, numerical solutions of differential equations, computer graphics, and more. The author emphasizes thebasic ideas of analytical and numerical techniques and the uses of modern mathematical software (MATLAB) ratherthan relying only on complex mathematical derivations to engineers, mathematician, computer scientists, andphysicists or for use as a textbook in applied or computational courses.A CD-ROM with all the figures, codes, solutions, appendices...
Habitat fragmentation causes rapid genetic differentiation and ...
STORAGESEVER
2009-08-04
Aug 4, 2009 ... differentiation and homogenization in natural plant populations – A ... The effects of habitat fragmentations on the forage grass Leymus thinness (Trin.) Tzvel, which ... selection etc, combined together with ecological factors.
Introduction to linear algebra and differential equations
Dettman, John W
1986-01-01
Excellent introductory text focuses on complex numbers, determinants, orthonormal bases, symmetric and hermitian matrices, first order non-linear equations, linear differential equations, Laplace transforms, Bessel functions, more. Includes 48 black-and-white illustrations. Exercises with solutions. Index.
Differential geometry basic notions and physical examples
Epstein, Marcelo
2014-01-01
Differential Geometry offers a concise introduction to some basic notions of modern differential geometry and their applications to solid mechanics and physics. Concepts such as manifolds, groups, fibre bundles and groupoids are first introduced within a purely topological framework. They are shown to be relevant to the description of space-time, configuration spaces of mechanical systems, symmetries in general, microstructure and local and distant symmetries of the constitutive response of continuous media. Once these ideas have been grasped at the topological level, the differential structure needed for the description of physical fields is introduced in terms of differentiable manifolds and principal frame bundles. These mathematical concepts are then illustrated with examples from continuum kinematics, Lagrangian and Hamiltonian mechanics, Cauchy fluxes and dislocation theory. This book will be useful for researchers and graduate students in science and engineering.
EVENTUAL STABILITY OF IMPULSIVE DIFFERENTIAL SYSTEMS
无
2007-01-01
In this article, criteria of eventual stability are established for impulsive differential systems using piecewise continuous Lyapunov functions. The sufficient conditions that are obtained significantly depend on the moments of impulses. An example is discussed to illustrate the theorem.
Partial Differential Equations Modeling and Numerical Simulation
Glowinski, Roland
2008-01-01
This book is dedicated to Olivier Pironneau. For more than 250 years partial differential equations have been clearly the most important tool available to mankind in order to understand a large variety of phenomena, natural at first and then those originating from human activity and technological development. Mechanics, physics and their engineering applications were the first to benefit from the impact of partial differential equations on modeling and design, but a little less than a century ago the Schrödinger equation was the key opening the door to the application of partial differential equations to quantum chemistry, for small atomic and molecular systems at first, but then for systems of fast growing complexity. Mathematical modeling methods based on partial differential equations form an important part of contemporary science and are widely used in engineering and scientific applications. In this book several experts in this field present their latest results and discuss trends in the numerical analy...
Cell Division, Differentiation and Dynamic Clustering
Kaneko, K; Kaneko, Kunihiko; Yomo, Tetsuya
1993-01-01
A novel mechanism for cell differentiation is proposed, based on the dynamic clustering in a globally coupled chaotic system. A simple model with metabolic reaction, active transport of chemicals from media, and cell division is found to show three successive stages with the growth of the number of cells; coherent growth, dynamic clustering, and fixed cell differentiation. At the last stage, disparity in activities, germ line segregation, somatic cell differentiation, and homeochaotic stability against external perturbation are found. Our results, in consistency with the experiments of the preceding paper, imply that cell differentiation can occur without a spatial pattern. From dynamical systems viewpoint, the new concept of ``open chaos" is proposed, as a novel and general scenario for systems with growing numbers of elements, also seen in economics and sociology.A
Impossible differential cryptanalysis of advanced encryption standard
CHEN Jie; HU YuPu; ZHANG YueYu
2007-01-01
Impossible differential cryptanalysis is a method recovering secret key, which gets rid of the keys that satisfy impossible differential relations. This paper concentrates on the impossible differential cryptanalysis of Advanced Encryption Standard (AES)and presents two methods for impossible differential cryptanalysis of 7-round AES-192 and 8-round AES-256 combined with time-memory trade-off by exploiting weaknesses in their key schedule. This attack on the reduced to 7-round AES-192 requires about 294.5 chosen plaintexts, demands 2129 words of memory, and performs 2157 7-round AES-192 encryptions. Furthermore, this attack on the reduced to 8-round AES-256 requires about 2101 chosen plaintexts, demands 2201 words of memory, and performs 2228 8-round AES-256 encryptions.
Stochastic differential equation model to Prendiville processes
Granita, E-mail: granitafc@gmail.com [Dept. of Mathematical Science, Universiti Teknologi Malaysia, 81310, Johor Malaysia (Malaysia); Bahar, Arifah [Dept. of Mathematical Science, Universiti Teknologi Malaysia, 81310, Johor Malaysia (Malaysia); UTM Center for Industrial & Applied Mathematics (UTM-CIAM) (Malaysia)
2015-10-22
The Prendiville process is another variation of the logistic model which assumes linearly decreasing population growth rate. It is a continuous time Markov chain (CTMC) taking integer values in the finite interval. The continuous time Markov chain can be approximated by stochastic differential equation (SDE). This paper discusses the stochastic differential equation of Prendiville process. The work started with the forward Kolmogorov equation in continuous time Markov chain of Prendiville process. Then it was formulated in the form of a central-difference approximation. The approximation was then used in Fokker-Planck equation in relation to the stochastic differential equation of the Prendiville process. The explicit solution of the Prendiville process was obtained from the stochastic differential equation. Therefore, the mean and variance function of the Prendiville process could be easily found from the explicit solution.
Differentiated thyroid carcinoma : diagnostic and therapeutic studies
Liu, Ying-ying
2006-01-01
Differentiated thyroid carcinoma (DTC) has favorable prognosis with high cure rate under treatment of thyroidectomy followed by radiotherapy. However, therapeutic efficiency decreases when dedifferentiation occurs. One of the purposes in this study is to use pharmaceuticals intervention to promote t
Fractional complex transforms for fractional differential equations
Ibrahim, Rabha W
2012-01-01
The fractional complex transform is employed to convert fractional differential equations analytically in the sense of the Srivastava-Owa fractional operator and its generalization in the unit disk...
Selected papers on analysis and differential equations
Nomizu, Katsumi
2003-01-01
This volume contains translations of papers that originally appeared in the Japanese journal, Sugaku. The papers range over a variety of topics, including nonlinear partial differential equations, C^*-algebras, and Schrödinger operators.
Stochastic differential equation model to Prendiville processes
Granita, Bahar, Arifah
2015-10-01
The Prendiville process is another variation of the logistic model which assumes linearly decreasing population growth rate. It is a continuous time Markov chain (CTMC) taking integer values in the finite interval. The continuous time Markov chain can be approximated by stochastic differential equation (SDE). This paper discusses the stochastic differential equation of Prendiville process. The work started with the forward Kolmogorov equation in continuous time Markov chain of Prendiville process. Then it was formulated in the form of a central-difference approximation. The approximation was then used in Fokker-Planck equation in relation to the stochastic differential equation of the Prendiville process. The explicit solution of the Prendiville process was obtained from the stochastic differential equation. Therefore, the mean and variance function of the Prendiville process could be easily found from the explicit solution.
International Financial Reporting Standards and differential reporting
Jarvis, Robin; Collis, Jill
2003-01-01
This paper examines the international development of financial reporting standards for smaller entities from a UK perspective. It examines the three elements of differential reporting: abbreviated accounts, the Financial Reporting Standard for Smaller Entities and exemption from the statutory audit.
Differential phase extraction in an atom gradiometer
Santos, Franck Pereira dos
2015-01-01
We present here a method for the extraction of the differential phase of an atom gradiometer that exploits the correlation of the vibration signal measured by an auxiliary classical sensor, such as a seismometer or an accelerometer. We show that sensitivities close to the quantum projection noise limit can be reached, even when the vibration noise induces phase fluctuations larger than 2$\\pi$. This method doesn't require the correlation between the atomic and classical signals to be perfect and allows for an exact determination of the differential phase, with no bias. It can also be applied to other configurations of differential interferometers, such as for instance gyrometers, conjugate interferometers for the measurement of the fine structure constant, or differential accelerometers for tests of the equivalence principle or detection of gravitational waves.
Specific Mindfulness Skills Differentially Predict Creative Performance.
Baas, Matthijs; Nevicka, Barbara; Ten Velden, Femke S
2014-05-23
Past work has linked mindfulness to improved emotion regulation, interpersonal skills, and basic cognitive abilities, but is unclear about the relation between mindfulness and creativity. Studies examining effects of mindfulness on factors pertinent to creativity suggest a uniform and positive relation, whereas work on specific mindfulness skills suggests that mindfulness skills may differentially predict creativity. To test whether the relation between mindfulness and creativity is positive and uniform (the uniform hypothesis) or differentially depends on particular components of mindfulness (the differential hypothesis), we conducted four studies in which mindfulness skills were measured, extensively trained, or manipulated with a short, incidental meditation session. Results supported a differential relation between mindfulness and creativity: Only the ability to observe and attend to various stimuli consistently and positively predicted creativity. Results regarding other mindfulness skills were less consistent. Implications for theory and practice are discussed.
Positive Solutions of Advanced Differential Systems
Josef Diblík
2013-01-01
graph coordinates of two (lower and upper auxiliary vector functions. This result is applied to scalar advanced linear differential equations. Criteria of existence of positive solutions are given and their asymptotic behavior is discussed.
Impact-induced differentiation in icy bodies
Tonks, W Brian; Melosh, H Jay
2016-01-01
By the time icy objects grow to about the mass of Europa and silicate bodies grow to approximately lunar mass, a large high-speed impact can generate an intact melt region that allows the dense material to gravitationally segregate, forming a large density anomaly. If this anomaly generates sufficient differential stress, it rapidly segregates to the object's center, triggering whole body differentiation. We used an impact melting model based on the Hugoniot equations, the linear shock-particle velocity relationship, and the empirical relationship between shock pressure and distance coupled with a Monte Carlo simulation of the late accretion process to determine conditions under which large impacts trigger differentiation in icy bodies. In a gas-free environment, impacts of projectiles in the satellite's accretion zone have a small probability of triggering differentiation in surviving proto-satellites as small as Triton. The probability increases to 100% by the time surviving proto-satellites grow to the mas...
Linearized gravity in terms of differential forms
Baykal, Ahmet; Dereli, Tekin
2017-01-01
A technique to linearize gravitational field equations is developed in which the perturbation metric coefficients are treated as second rank, symmetric, 1-form fields belonging to the Minkowski background spacetime by using the exterior algebra of differential forms.
Teaching Differentials in Thermodynamics using Spatial Visualization
Wang, Chih-Yueh
2011-01-01
The greatest difficulty that is encountered by students in Thermodynamics classes is to find relationships between variables and solve a total differential equation that relates one thermodynamic state variable to two mutually-independent state variables. Rules of differentiation, including the total differential and the cyclic rule, are fundamental to solving thermodynamics problems. However, many students do not well understand such basic mathematics principles, because the underlying geometric meaning is unclear to them. Studies have shown that proficient symbolic techniques may become an obstacle to learning in a qualitative approach. Spatial visualization allows an emergence of new reasoning for students. In this investigation, the total differential rule and the cyclic rule are interpreted geometrically.
Traces of differential forms and Hochschild homology
Hübl, Reinhold
1989-01-01
This monograph provides an introduction to, as well as a unification and extension of the published work and some unpublished ideas of J. Lipman and E. Kunz about traces of differential forms and their relations to duality theory for projective morphisms. The approach uses Hochschild-homology, the definition of which is extended to the category of topological algebras. Many results for Hochschild-homology of commutative algebras also hold for Hochschild-homology of topological algebras. In particular, after introducing an appropriate notion of completion of differential algebras, one gets a natural transformation between differential forms and Hochschild-homology of topological algebras. Traces of differential forms are of interest to everyone working with duality theory and residue symbols. Hochschild-homology is a useful tool in many areas of k-theory. The treatment is fairly elementary and requires only little knowledge in commutative algebra and algebraic geometry.
Transcriptome changes during intestinal cell differentiation
Tadjali, Mehrdad; Seidelin, Jakob B; Olsen, Jørgen Lillelund
2002-01-01
The expression of 18149 genes have been analysed during the differentiation of the human intestinal cell line Caco-2. cDNA probes from undifferentiated and differentiated Caco-2 cells were separately hybridised to EST DNAs spotted in an array on a nylon membrane. A remarkable change...... in the transcriptome was observed during the differentiation of the Caco-2 cells. 8762 of the 18149 genes analysed were expressed above background level in the undifferentiated Caco-2 cells, whereas only 5767 genes were expressed above background in differentiated Caco-2 cells. This pattern of expression was caused...... by a general down-regulation of genes in the low abundance class. Similar results were found using mouse small intestinal crypt and villus cells, suggesting that the phenomenon also occurs in the intestine in vivo. The expression data were subsequently used in a search for markers for subsets of epithelial...
Differential equations and applications recent advances
2014-01-01
Differential Equations and Applications : Recent Advances focus on the latest developments in Nonlinear Dynamical Systems, Neural Networks, Fluid Dynamics, Fractional Differential Systems, Mathematical Modelling and Qualitative Theory. Different aspects such as Existence, Stability, Controllability, Viscosity and Numerical Analysis for different systems have been discussed in this book. This book will be of great interest and use to researchers in Applied Mathematics, Engineering and Mathematical Physics.
Weighted Decomposition Estimates for Differential Forms
Yong Wang
2010-01-01
Full Text Available After introducing the definition of Ar,λβ-weights, we establish the Ar(Ω-weighted decomposition estimates and Ar,λβ(Ω-weighted Caccioppoli-type estimates for A-harmonic tensors. Furthermore, by Whitney covering lemma, we obtain the global results in domain Ω⊂Rn. These results can be used to study the integrability of differential forms and to estimate the integrals for differential forms.
On a complex differential Riccati equation
Khmelnytskaya, Kira V; Kravchenko, Vladislav V [Department of Mathematics, CINVESTAV del IPN, Unidad Queretaro, Libramiento Norponiente No. 2000, Fracc. Real de Juriquilla, Queretaro, Qro. C.P. 76230 Mexico (Mexico)], E-mail: vkravchenko@qro.cinvestav.mx
2008-02-29
We consider a nonlinear partial differential equation for complex-valued functions which is related to the two-dimensional stationary Schroedinger equation and enjoys many properties similar to those of the ordinary differential Riccati equation such as the famous Euler theorems, the Picard theorem and others. Besides these generalizations of the classical 'one-dimensional' results, we discuss new features of the considered equation including an analogue of the Cauchy integral theorem.
Thomas Decomposition of Algebraic and Differential Systems
Bächler, Thomas; Lange-Hegermann, Markus; Robertz, Daniel
2010-01-01
In this paper we consider disjoint decomposition of algebraic and non-linear partial differential systems of equations and inequations into so-called simple subsystems. We exploit Thomas decomposition ideas and develop them into a new algorithm. For algebraic systems simplicity means triangularity, squarefreeness and non-vanishing initials. For differential systems the algorithm provides not only algebraic simplicity but also involutivity. The algorithm has been implemented in Maple.
Discrete Surface Modelling Using Partial Differential Equations.
Xu, Guoliang; Pan, Qing; Bajaj, Chandrajit L
2006-02-01
We use various nonlinear partial differential equations to efficiently solve several surface modelling problems, including surface blending, N-sided hole filling and free-form surface fitting. The nonlinear equations used include two second order flows, two fourth order flows and two sixth order flows. These nonlinear equations are discretized based on discrete differential geometry operators. The proposed approach is simple, efficient and gives very desirable results, for a range of surface models, possibly having sharp creases and corners.
Symbolic computations in applied differential geometry
Gragert, P.K.H.; Kersten, P. H. M.; Martini, R.
1983-01-01
The main aim of this paper is to contribute to the automatic calculations in differential geometry and its applications, with emphasis on the prolongation theory of Estabrook and Wahlquist, and the calculation of invariance groups of exterior differential systems. A large number of worked examples have been included in the text to demonstrate the concrete manipulations in practice. In the appendix, a list of programs discussed in the paper is added.
Nanomechanics controls neuronal precursors adhesion and differentiation.
Migliorini, Elisa; Ban, Jelena; Grenci, Gianluca; Andolfi, Laura; Pozzato, Alessandro; Tormen, Massimo; Torre, Vincent; Lazzarino, Marco
2013-08-01
The ability to control the differentiation of stem cells into specific neuronal types has a tremendous potential for the treatment of neurodegenerative diseases. In vitro neuronal differentiation can be guided by the interplay of biochemical and biophysical cues. Different strategies to increase the differentiation yield have been proposed, focusing everything on substrate topography, or, alternatively on substrate stiffness. Both strategies demonstrated an improvement of the cellular response. However it was often impossible to separate the topographical and the mechanical contributions. Here we investigate the role of the mechanical properties of nanostructured substrates, aiming at understanding the ultimate parameters which govern the stem cell differentiation. To this purpose a set of different substrates with controlled stiffness and with or without nanopatterning are used for stem cell differentiation. Our results show that the neuronal differentiation yield depends mainly on the substrate mechanical properties while the geometry plays a minor role. In particular nanostructured and flat polydimethylsiloxane (PDMS) substrates with comparable stiffness show the same neuronal yield. The improvement in the differentiation yield obtained through surface nanopatterning in the submicrometer scale could be explained as a consequence of a substrate softening effect. Finally we investigate by single cell force spectroscopy the neuronal precursor adhesion on the substrate immediately after seeding, as a possible critical step governing the neuronal differentiation efficiency. We observed that neuronal precursor adhesion depends on substrate stiffness but not on surface structure, and in particular it is higher on softer substrates. Our results suggest that cell-substrate adhesion forces and mechanical response are the key parameters to be considered for substrate design in neuronal regenerative medicine.
Differential equations inverse and direct problems
Favini, Angelo
2006-01-01
DEGENERATE FIRST ORDER IDENTIFICATION PROBLEMS IN BANACH SPACES A NONISOTHERMAL DYNAMICAL GINZBURG-LANDAU MODEL OF SUPERCONDUCTIVITY. EXISTENCE AND UNIQUENESS THEOREMSSOME GLOBAL IN TIME RESULTS FOR INTEGRODIFFERENTIAL PARABOLIC INVERSE PROBLEMSFOURTH ORDER ORDINARY DIFFERENTIAL OPERATORS WITH GENERAL WENTZELL BOUNDARY CONDITIONSTUDY OF ELLIPTIC DIFFERENTIAL EQUATIONS IN UMD SPACESDEGENERATE INTEGRODIFFERENTIAL EQUATIONS OF PARABOLIC TYPE EXPONENTIAL ATTRACTORS FOR SEMICONDUCTOR EQUATIONSCONVERGENCE TO STATIONARY STATES OF SOLUTIONS TO THE SEMILINEAR EQUATION OF VISCOELASTICITY ASYMPTOTIC BEHA
On weakly D-differentiable operators
Christensen, Erik
2016-01-01
Let DD be a self-adjoint operator on a Hilbert space HH and aa a bounded operator on HH. We say that aa is weakly DD-differentiable, if for any pair of vectors ξ,ηξ,η from HH the function 〈eitDae−itDξ,η〉〈eitDae−itDξ,η〉 is differentiable. We give an elementary example of a bounded operator aa, suc...
Solutions manual to accompany Ordinary differential equations
Greenberg, Michael D
2014-01-01
Features a balance between theory, proofs, and examples and provides applications across diverse fields of study Ordinary Differential Equations presents a thorough discussion of first-order differential equations and progresses to equations of higher order. The book transitions smoothly from first-order to higher-order equations, allowing readers to develop a complete understanding of the related theory. Featuring diverse and interesting applications from engineering, bioengineering, ecology, and biology, the book anticipates potential difficulties in understanding the various solution steps
Monotone Semiflows Generated by Functional Differential Equations,
1986-02-01
These results have been applied to ordinary differential equations in Rn (see e.g. [10,23]) where the well-known Kamke theorem applies and to nonlinear...sufficient condition (H) Whenever 0 - 0 and ,i(0) = i( 0) it follows that fi(0) ( fi(O). For those familiar with the Kamke (quasimonotone) condition for...ordinary differential equations, (H) will seem quite natural, it reduces to the Kamke condition. The order preserving property of a semiflow is not
Differential diagnosis of myelitis; Differenzialdiagnostik der Myelitis
Langner, Soenke [Universitaetsmedizin Greifswald (Germany). Inst. fuer Diagnostische Radiologie und Neuroradiologie
2016-09-15
Acute transverse Myelitis is an inflammatory myelopathy characterized by rapid onset of bilateral neurological symptoms. There is a vast array of differential diagnoses and the underlying pathology often cannot be identified on clinical examination alone. Therefore neuroimaging has a central role in narrowing the differential diagnosis. This review aims to provide a summary of common causes of non-traumatic myelopathies, many of which may have similar radiological appearance.
NaCl potentiates human fibrocyte differentiation.
Cox, Nehemiah; Pilling, Darrell; Gomer, Richard H
2012-01-01
Excessive NaCl intake is associated with a variety of fibrosing diseases such as renal and cardiac fibrosis. This association has been attributed to increased blood pressure as the result of high NaCl intake. However, studies in patients with high NaCl intake and fibrosis reveal a connection between NaCl intake and fibrosis that is independent of blood pressure. We find that increasing the extracellular concentration of NaCl to levels that may occur in human blood after high-salt intake can potentiate, in serum-free culture conditions, the differentiation of freshly-isolated human monocytes into fibroblast-like cells called fibrocytes. NaCl affects the monocytes directly during their adhesion. Potassium chloride and sodium nitrate also potentiate fibrocyte differentiation. The plasma protein Serum Amyloid P (SAP) inhibits fibrocyte differentiation. High levels of extracellular NaCl change the SAP Hill coefficient from 1.7 to 0.8, and cause a four-fold increase in the concentration of SAP needed to inhibit fibrocyte differentiation by 95%. Together, our data suggest that NaCl potentiates fibrocyte differentiation. NaCl-increased fibrocyte differentiation may thus contribute to NaCl-increased renal and cardiac fibrosis.
NaCl potentiates human fibrocyte differentiation.
Nehemiah Cox
Full Text Available Excessive NaCl intake is associated with a variety of fibrosing diseases such as renal and cardiac fibrosis. This association has been attributed to increased blood pressure as the result of high NaCl intake. However, studies in patients with high NaCl intake and fibrosis reveal a connection between NaCl intake and fibrosis that is independent of blood pressure. We find that increasing the extracellular concentration of NaCl to levels that may occur in human blood after high-salt intake can potentiate, in serum-free culture conditions, the differentiation of freshly-isolated human monocytes into fibroblast-like cells called fibrocytes. NaCl affects the monocytes directly during their adhesion. Potassium chloride and sodium nitrate also potentiate fibrocyte differentiation. The plasma protein Serum Amyloid P (SAP inhibits fibrocyte differentiation. High levels of extracellular NaCl change the SAP Hill coefficient from 1.7 to 0.8, and cause a four-fold increase in the concentration of SAP needed to inhibit fibrocyte differentiation by 95%. Together, our data suggest that NaCl potentiates fibrocyte differentiation. NaCl-increased fibrocyte differentiation may thus contribute to NaCl-increased renal and cardiac fibrosis.
Embryonic stem cell differentiation: a chromatin perspective.
Rasmussen, Theodore P
2003-11-13
Embryonic stem (ES) cells hold immense promise for the treatment of human degenerative disease. Because ES cells are pluripotent, they can be directed to differentiate into a number of alternative cell-types with potential therapeutic value. Such attempts at "rationally-directed ES cell differentiation" constitute attempts to recapitulate aspects of normal development in vitro. All differentiated cells retain identical DNA content, yet gene expression varies widely from cell-type to cell-type. Therefore, a potent epigenetic system has evolved to coordinate and maintain tissue-specific patterns of gene expression. Recent advances show that mechanisms that govern epigenetic regulation of gene expression are rooted in the details of chromatin dynamics. As embryonic cells differentiate, certain genes are activated while others are silenced. These activation and silencing events are exquisitely coordinated with the allocation of cell lineages. Remodeling of the chromatin of developmentally-regulated genes occurs in conjunction with lineage commitment. Oocytes, early embryos, and ES cells contain potent chromatin-remodeling activities, an observation that suggests that chromatin dynamics may be especially important for early lineage decisions. Chromatin dynamics are also involved in the differentiation of adult stem cells, where the assembly of specialized chromatin upon tissue-specific genes has been studied in fine detail. The next few years will likely yield striking advances in the understanding of stem cell differentiation and developmental biology from the perspective of chromatin dynamics.
Embryonic stem cell differentiation: A chromatin perspective
Rasmussen Theodore P
2003-11-01
Full Text Available Abstract Embryonic stem (ES cells hold immense promise for the treatment of human degenerative disease. Because ES cells are pluripotent, they can be directed to differentiate into a number of alternative cell-types with potential therapeutic value. Such attempts at "rationally-directed ES cell differentiation" constitute attempts to recapitulate aspects of normal development in vitro. All differentiated cells retain identical DNA content, yet gene expression varies widely from cell-type to cell-type. Therefore, a potent epigenetic system has evolved to coordinate and maintain tissue-specific patterns of gene expression. Recent advances show that mechanisms that govern epigenetic regulation of gene expression are rooted in the details of chromatin dynamics. As embryonic cells differentiate, certain genes are activated while others are silenced. These activation and silencing events are exquisitely coordinated with the allocation of cell lineages. Remodeling of the chromatin of developmentally-regulated genes occurs in conjunction with lineage commitment. Oocytes, early embryos, and ES cells contain potent chromatin-remodeling activities, an observation that suggests that chromatin dynamics may be especially important for early lineage decisions. Chromatin dynamics are also involved in the differentiation of adult stem cells, where the assembly of specialized chromatin upon tissue-specific genes has been studied in fine detail. The next few years will likely yield striking advances in the understanding of stem cell differentiation and developmental biology from the perspective of chromatin dynamics.
Counting Coloured Planar Maps: Differential Equations
Bernardi, Olivier; Bousquet-Mélou, Mireille
2017-08-01
We address the enumeration of q-coloured planar maps counted by the number of edges and the number of monochromatic edges. We prove that the associated generating function is differentially algebraic, that is, satisfies a non-trivial polynomial differential equation with respect to the edge variable. We give explicitly a differential system that characterizes this series. We then prove a similar result for planar triangulations, thus generalizing a result of Tutte dealing with their proper q-colourings. In statistical physics terms, we solve the q-state Potts model on random planar lattices. This work follows a first paper by the same authors, where the generating function was proved to be algebraic for certain values of q, including {q=1, 2} and 3. It is known to be transcendental in general. In contrast, our differential system holds for an indeterminate q. For certain special cases of combinatorial interest (four colours; proper q-colourings; maps equipped with a spanning forest), we derive from this system, in the case of triangulations, an explicit differential equation of order 2 defining the generating function. For general planar maps, we also obtain a differential equation of order 3 for the four-colour case and for the self-dual Potts model.
Building Measures of Instructional Differentiation from Teacher Checklists
Williams, Ryan; Swanlund, Andrew; Miller, Shazia; Konstantopoulos, Spyros; van der Ploeg, Arie
2012-01-01
Differentiated instruction is commonly believed to be critical to improving the quality and efficiency of teachers' instructional repertoires (Fischer & Rose, 2001; Tomlinson, 2004). Tomlinson (2000) describes differentiation in four domains: content, process, product, and learning environment. Content differentiation involves varying…
Analytical solution of linear ordinary differential equations by differential transfer matrix method
Sina Khorasani
2003-08-01
Full Text Available We report a new analytical method for finding the exact solution of homogeneous linear ordinary differential equations with arbitrary order and variable coefficients. The method is based on the definition of jump transfer matrices and their extension into limiting differential form. The approach reduces the $n$th-order differential equation to a system of $n$ linear differential equations with unity order. The full analytical solution is then found by the perturbation technique. The important feature of the presented method is that it deals with the evolution of independent solutions, rather than its derivatives. We prove the validity of method by direct substitution of the solution in the original differential equation. We discuss the general properties of differential transfer matrices and present several analytical examples, showing the applicability of the method.
Rene Cortese
Full Text Available Cellular differentiation involves widespread epigenetic reprogramming, including modulation of DNA methylation patterns. Using Differential Methylation Hybridization (DMH in combination with a custom DMH array containing 51,243 features covering more than 16,000 murine genes, we carried out a genome-wide screen for cell- and tissue-specific differentially methylated regions (tDMRs in undifferentiated embryonic stem cells (ESCs, in in-vitro induced neural stem cells (NSCs and 8 differentiated embryonic and adult tissues. Unsupervised clustering of the generated data showed distinct cell- and tissue-specific DNA methylation profiles, revealing 202 significant tDMRs (p1.96 enrichment for genes involved in neural differentiation, including, for example, Jag1 and Tcf4. Our results provide robust evidence for the relevance of DNA methylation in early neural development and identify novel marker candidates for neural cell differentiation.
Maharjan, Anu S; Darrell Pilling; Gomer, Richard H.
2011-01-01
BACKGROUND: Following tissue injury, monocytes can enter the tissue and differentiate into fibroblast-like cells called fibrocytes, but little is known about what regulates this differentiation. Extracellular matrix contains high molecular weight hyaluronic acid (HMWHA; ∼2×10(6) Da). During injury, HMWHA breaks down to low molecular weight hyaluronic acid (LMWHA; ∼0.8-8×10(5) Da). METHODS AND FINDINGS: In this report, we show that HMWHA potentiates the differentiation of human monocytes into ...
Chaolu Temuer; Yu-shan BAI
2009-01-01
In this paper,we present a differential polynomial characteristic set algorithm for the complete symmetry classification of partial differential equations (PDEs)with some parameters. It can make the solution to the complete symmetry classification problem for PDEs become direct and systematic. As an illustrative example,the complete potential symmetry classifications of nonlinear and linear wave equations with an arbitrary function parameter are presented. This is a new application of the differential form characteristic set algorithm,i.e.,Wu's method,in differential equations.
van IJzendoorn, Marinus H; Bakermans-Kranenburg, Marian J
2012-05-01
Reviewing the studies on differential susceptibility presented in this section, we argue that the time is ripe to go beyond correlational designs to differential susceptibility experiments. In such experiments, randomization prevents hidden moderator effects on the environment and guarantees the independence of moderator and outcome, while the environment is manipulated and assessed in standard ways. Correlational studies generate a priori expectations about crucial moderators (e.g., temperament, biological sensitivity, and genetics). We discuss the differential susceptibility experiments available up until now and conclude that these experiments are feasible and contribute in unique ways to our conceptions of differential susceptibility.
Differential Gene Expression in Retina of Myopic Chicken Eyes Using mRNA Differential Display
ShenHX; ZhangQJ
1999-01-01
Purpose:To study differentially expressed genes in retina of experimental myopic chicken.Methods:Experimental myopia in chicken was induced by form-deprivatin.The mRNA in chicen retina was analyzed by using differential display.Results:Experimental myopia was successfully induced in chicken through form-deprivation.Differentially expressed gene fragments were detected in retina of chicken with myopic evelopment and recovery as compared with normal controld.Conclusion:The differential display of mRNA may be a useful way in cloning myopic-related genes.
Zhao HE; Jing-jing LI; Chang-hong ZHEN; Lin-ying FENG; Xiao-yan DING
2006-01-01
Aim: Leukemia inhibitory factor (LIF), a pleiotropic cytokine, has been used extensively in the maintenance of mouse embryonic stem cell pluripotency. In this current work, we examined the effect of the LIF signaling pathway in embryonic stem (ES) cell differentiation to a neural fate. Methods: In the presence of LIF (1000 U/mL), the production of neuronal cells derived from embryoid bodies (EB)was tested under various culture conditions. Inhibition of the LIF pathway was examined with specific inhibitors. The effects of cell apoptosis and proliferation on neural differentiation were examined. ES cell differentiation into three-gem layers was compared. Results: Under various culture conditions, neuronal differentiation was increased in the presence of LIF. Blocking the LIF-activated STAT3signaling pathway with specific inhibitors abolished the neuronal differentiation of ES cells, whereas inhibition of the LIF-activated MEK signaling pathway impaired the differentiation of ES cells toward a glial fate. LIF suppressed cell apoptosis and promoted cell proliferation during ES cell differentiation. LIF inhibited the differentiation of ES cells to both mesoderm and extraembryonic endoderm fates, but enhanced the determination of neural progenitors. Conclusion:These results suggest that LIF plays a positive role during the differentiation of ES cells into neuronal cells.
Murat Osmanoglu
2013-01-01
Full Text Available We have considered linear partial differential algebraic equations (LPDAEs of the form , which has at least one singular matrix of . We have first introduced a uniform differential time index and a differential space index. The initial conditions and boundary conditions of the given system cannot be prescribed for all components of the solution vector here. To overcome this, we introduced these indexes. Furthermore, differential transform method has been given to solve LPDAEs. We have applied this method to a test problem, and numerical solution of the problem has been compared with analytical solution.
Differentiation of Keratinocytes Modulates Skin HPA Analog.
Wierzbicka, Justyna M; Żmijewski, Michał A; Antoniewicz, Jakub; Sobjanek, Michal; Slominski, Andrzej T
2017-01-01
It is well established, that epidermal keratinocytes express functional equivalent of hypothalamus-pituitary-adrenal axis (HPA) in order to respond to changing environment and maintain internal homeostasis. We are presenting data indicating that differentiation of primary neonatal human keratinocytes (HPEKp), induced by prolonged incubation or calcium is accompanied by significant changes in the expression of the elements of skin analog of HPA (sHPA). Expression of CRF, UCN1-3, POMC, ACTH, CRFR1, CRFR2, MC1R, MC2R, and GR (coded by NR3C1 gene) were observed on gene/protein levels along differentiation of keratinocytes in culture with similar pattern seen by immunohistochemistry on full thickness skin biopsies. Expression of CRF was more pronounced in less differentiated keratinocytes, which corresponded to the detection of CRF immunoreactivity preferentially in the stratum basale. POMC expression was enhanced in more differentiated keratinocytes, which corresponded to detection of ACTH immunoreactivity, predominantly in the stratum spinosum and stratum granulosum. Expression of urocortins was also affected by induction of HPEKp differentiation. Immunohistochemical studies showed high prevalence of CRFR1 in well differentiated keratinocytes, while smaller keratinocytes showed predominantly CRFR2 immunoreactivity. MC2R mRNA levels were elevated from days 4 to 8 of in vitro incubation, while MC2R immunoreactivity was the highest in the upper layers of epidermis. Similar changes in mRNA/protein levels of sHPA elements were observed in HPEKp keratinocytes treated with calcium. Summarizing, preferential expression of CRF and POMC (ACTH) by populations of keratinocytes on different stage of differentiation resembles organization of central HPA axis suggesting their distinct role in physiology and pathology of the epidermis. J. Cell. Physiol. 232: 154-166, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.
Nucleotide excision repair in differentiated cells
Wees, Caroline van der [Department of Toxicogenetics, Leiden University Medical Center, Leiden (Netherlands); Department of Cardiology, Leiden University Medical Center, Leiden (Netherlands); Jansen, Jacob [Department of Toxicogenetics, Leiden University Medical Center, Leiden (Netherlands); Vrieling, Harry [Department of Toxicogenetics, Leiden University Medical Center, Leiden (Netherlands); Laarse, Arnoud van der [Department of Cardiology, Leiden University Medical Center, Leiden (Netherlands); Zeeland, Albert van [Department of Toxicogenetics, Leiden University Medical Center, Leiden (Netherlands); Mullenders, Leon [Department of Toxicogenetics, Leiden University Medical Center, Leiden (Netherlands)]. E-mail: l.mullenders@lumc.nl
2007-01-03
Nucleotide excision repair (NER) is the principal pathway for the removal of a wide range of DNA helix-distorting lesions and operates via two NER subpathways, i.e. global genome repair (GGR) and transcription-coupled repair (TCR). Although detailed information is available on expression and efficiency of NER in established mammalian cell lines, little is known about the expression of NER pathways in (terminally) differentiated cells. The majority of studies in differentiated cells have focused on repair of UV-induced cyclobutane pyrimidine dimers (CPD) and 6-4-photoproducts (6-4PP) because of the high frequency of photolesions at low level of toxicity and availability of sensitive technologies to determine photolesions in defined regions of the genome. The picture that emerges from these studies is blurred and rather complex. Fibroblasts and terminally differentiated myocytes of the rat heart display equally efficient GGR of 6-4PP but poor repair of CPD due to the absence of p48 expression. This repair phenotype is clearly different from human terminal differentiated neurons. Furthermore, both cell types were found to carry out TCR of CPD, thus mimicking the repair phenotype of established rodent cell lines. In contrast, in intact rat spermatogenic cells repair was very inefficient at the genome overall level and in transcriptionally active genes indicating that GGR and TCR are non-functional. Also, non-differentiated mouse embryonic stem (ES) cells exhibit low levels of NER after UV irradiation. However, the mechanisms that lead to low NER activity are clearly different: in differentiated spermatogenic cells differences in chromatin compaction and sequestering of NER proteins may underlie the lack of NER activity in pre-meiotic cells, whereas in non-differentiated ES cells NER is impaired by a strong apoptotic response.
Differentiation in cutaneous adnexal tumors: Immunohistochemical study
Figen BARUT
2006-09-01
Full Text Available Cutaneous adnexal neoplasms are rare tumors that display differentiation in different ways. The aim of this study is, to present embryonic developmental properties and to determine the way of differentiation of adnexal neoplasms by evaluating the immunohistochemical expression of various markers.Forty-seven cases with adnexal tumors enrolled in this study. Histopathologic groups of these 47 cases were: 15 (32% hair follicle tumors, 11 (23.4% sebaceous tumors, 8 (17% apocrine tumors, and 13 (27.6% eccrine tumors. CK5-6, CK6, CK7, CK8, CK10, CK19, GCDFP-15, carcinoembryonic antigen, epithelial membrane antigen and S100 protein expressions were examined by immunohistochemical methods.As a result of this immunohistochemical study it was concluded that the expression of CK5-6 and CK8 carries more importance than other markers in determining certain types of differentiation of hair follicle tumors. It was also determined that, epithelial membrane antigen expression is important for the diagnosis of sebaceous tumors and the markers like CK8, CK10 and carcinoembryonic antigen may aid for the same purpose as well. It was found that, GCDFP-15 as well as CK5-6 expressions are significant for apocrine tumors, and carcinoembryonic antigen reaction as well as CK8 positivity will aid in determining differentiation of eccrine tumors. The presence of similar CK6 expression in all kinds of adnexal tumors has demonstrated that this marker is useless in differential diagnosis.
Neurogenic differentiation of amniotic fluid stem cells.
Rosner, M; Mikula, M; Preitschopf, A; Feichtinger, M; Schipany, K; Hengstschläger, M
2012-05-01
In 2003, human amniotic fluid has been shown to contain stem cells expressing Oct-4, a marker for pluripotency. This finding initiated a rapidly growing and very promising new stem cell research field. Since then, amniotic fluid stem (AFS) cells have been demonstrated to harbour the potential to differentiate into any of the three germ layers and to form three-dimensional aggregates, so-called embryoid bodies, known as the principal step in the differentiation of pluripotent stem cells. Marker selection and minimal dilution approaches allow the establishment of monoclonal AFS cell lineages with high proliferation potential. AFS cells have a lower risk for tumour development and do not raise the ethical issues of embryonic stem cells. Compared to induced pluripotent stem cells, AFS cells do not need exogenic treatment to induce pluripotency, are chromosomal stable and do not harbour the epigenetic memory and accumulated somatic mutations of specific differentiated source cells. Compared to adult stem cells, AFS can be grown in larger quantities and show higher differentiation potential. Accordingly, in the recent past, AFS became increasingly accepted as an optimal tool for basic research and probably also for specific cell-based therapies. Here, we review the current knowledge on the neurogenic differentiation potential of AFS cells.
Search for a Differentiated Asteroid Family
Thomas, Cristina A.; Lim, Lucy F.; Trilling, David E.; Moskovitz, Nicholas
2014-08-01
Dynamical asteroid families resulting from catastrophic disruptions represent the interiors of their former parent bodies. Differentiation of a large initially chondritic parent body is expected to produce an ``onion shell" object with a metal core, a thick olivine-rich mantle, and a thin basaltic crust. However, instead of the mineralogical diversity expected from the disruption of a differentiated parent body, most asteroid families tend to show similar spectra among the members. Moreover, spectra of metal-like materials and olivine-dominated assemblages have not been detected in asteroid families in the Main Belt and the expected mantle material is missing from the meteorite record. The deficit of olivine-rich mantle material in the meteorite record and in asteroid observations is known as the ``Missing Mantle" problem. For years the best explanation for the lack of mantle material has been the ``battered to bits" hypothesis that states that all differentiated parent bodies (aside from Vesta) were disrupted very early in the solar system and the resulting olivine-rich material was collisionally broken down until the object diameters fell below our observational limits. However, in a new, competing, hypothesis, Elkins-Tanton et al. (2013) has suggested that previous work has overestimated the amount of olivine produced by the differentiation of a chondritic parent body. We propose to obtain visible spectra of asteroids within the Massalia, Merxia, and Agnia S-type families to search for compositional variations that are indicators of differentiation and to quantitatively constrain the two competing ``Missing Mantle" hypotheses.
Differentiation and compaction in the Skaergaard intrusion
Tegner, C.; Thy, P.; Holness, M.; Jakobsen, J. K.; Salmonsen, L.; Humphreys, M.; Lesher, C. E.
2009-12-01
Although it is largely agreed that crystallization occurs inwardly in crystal mushes along the margins of magma chambers, the efficiency and mechanisms of differentiation are contended. The fractionation paradigm hinges on mass exchange between a crystal mush and the main magma reservoir resulting in coarse-grained, refractory (cumulate) rocks of primary crystals, and complementary enrichment of incompatible elements in the main magma. Diffusion, convection, liquid immiscibility and compaction have been proposed as mechanisms driving this mass exchange. We examine the efficiency of differentiation in basaltic crystal mushes of the Skaergaard magma chamber. The contents of incompatible elements such as phosphorus and calculated final porosities are smallest in cumulate rocks at the floor (~5% final porosity above the level of magnetite-in), intermediate at the walls (~20%) and highest at the roof (~55%). Mass exchange and differentiation are thus highly efficient at the floor but inefficient at the roof. This is best explained by compaction squeezing interstitial liquid out of the crystal mush preferentially at the floor. At the walls only mush with porosity less than ~20% was able to stick rather than collapsing into the chamber, resulting in moderately efficient differentiation. We conclude that compaction moderates the final crystal mush porosity and the efficiency of magma differentiation depending on chamber dynamics.
Osteogenic Differentiation of Dental Follicle Stem Cells
Giorgio Mori, Andrea Ballini, Claudia Carbone, Angela Oranger, Giacomina Brunetti, Adriana Di Benedetto, Biagio Rapone, Stefania Cantore, Mariasevera Di Comite, Silvia Colucci, Maria Grano, Felice R. Grassi
2012-01-01
Full Text Available Background: Stem cells are defined as clonogenic cells capable of self-renewal and multi-lineage differentiation. A population of these cells has been identified in human Dental Follicle (DF.Dental Follicle Stem Cells (DFSCs were found in pediatric unerupted wisdom teeth and have been shown to differentiate, under particular conditions, into various cell types of the mesenchymal tissues.Aim: The aim of this study was to investigate if cells isolated from DF show stem features, differentiate toward osteoblastic phenotype and express osteoblastic markers.Methods: We studied the immunophenotype of DFSCs by flow cytometric analysis, the osteoblastic markers of differentiated DFSCs were assayed by histochemical methods and real-time PCR.Results: We demonstrated that DFSCs expressed a heterogeneous assortment of makers associated with stemness. Moreover DFSCs differentiated into osteoblast-like cells, producing mineralized matrix nodules and expressed the typical osteoblastic markers, Alkaline Phosphatase (ALP and Collagen I (Coll I.Conclusion: This study suggests that DFSCs may provide a cell source for tissue engineering of bone.
Differential gene expression during Trypanosoma cruzi metacyclogenesis
Marco Aurelio Krieger
1999-09-01
Full Text Available The transformation of epimastigotes into metacyclic trypomastigotes involves changes in the pattern of expressed genes, resulting in important morphological and functional differences between these developmental forms of Trypanosoma cruzi. In order to identify and characterize genes involved in triggering the metacyclogenesis process and in conferring to metacyclic trypomastigotes their stage specific biological properties, we have developed a method allowing the isolation of genes specifically expressed when comparing two close related cell populations (representation of differential expression or RDE. The method is based on the PCR amplification of gene sequences selected by hybridizing and subtracting the populations in such a way that after some cycles of hybridization-amplification genes specific to a given population are highly enriched. The use of this method in the analysis of differential gene expression during T. cruzi metacyclogenesis (6 hr and 24 hr of differentiation and metacyclic trypomastigotes resulted in the isolation of several clones from each time point. Northern blot analysis showed that some genes are transiently expressed (6 hr and 24 hr differentiating cells, while others are present in differentiating cells and in metacyclic trypomastigotes. Nucleotide sequencing of six clones characterized so far showed that they do not display any homology to gene sequences available in the GeneBank.
van IJzendoorn, Marinus H.; Bakermans-Kranenburg, Marian J.
2012-01-01
Reviewing the studies on differential susceptibility presented in this section, we argue that the time is ripe to go beyond correlational designs to differential susceptibility experiments. In such experiments, randomization prevents hidden moderator effects on the environment and guarantees the independence of moderator and outcome, while the…
A genome-wide methylation study on obesity Differential variability and differential methylation
Xu, Xiaojing; Su, Shaoyong; Barnes, Vernon A.; De Miguel, Carmen; Pollock, Jennifer; Ownby, Dennis; Shi, Huidong; Zhu, Haidong; Snieder, Harold; Wang, Xiaoling
2013-01-01
Besides differential methylation, DNA methylation variation has recently been proposed and demonstrated to be a potential contributing factor to cancer risk. Here we aim to examine whether differential variability in methylation is also an important feature of obesity, a typical non-malignant common
A genome-wide methylation study on obesity Differential variability and differential methylation
Xu, Xiaojing; Su, Shaoyong; Barnes, Vernon A.; De Miguel, Carmen; Pollock, Jennifer; Ownby, Dennis; Shi, Huidong; Zhu, Haidong; Snieder, Harold; Wang, Xiaoling
2013-01-01
Besides differential methylation, DNA methylation variation has recently been proposed and demonstrated to be a potential contributing factor to cancer risk. Here we aim to examine whether differential variability in methylation is also an important feature of obesity, a typical non-malignant common
Sensitivity Analysis of Differential-Algebraic Equations and Partial Differential Equations
Petzold, L; Cao, Y; Li, S; Serban, R
2005-08-09
Sensitivity analysis generates essential information for model development, design optimization, parameter estimation, optimal control, model reduction and experimental design. In this paper we describe the forward and adjoint methods for sensitivity analysis, and outline some of our recent work on theory, algorithms and software for sensitivity analysis of differential-algebraic equation (DAE) and time-dependent partial differential equation (PDE) systems.
Idan Cohen
Full Text Available Disrupted skin barrier due to altered keratinocyte differentiation is common in pathologic conditions such as atopic dermatitis, ichthyosis and psoriasis. However, the molecular cascades governing keratinocyte terminal differentiation are poorly understood. We have previously demonstrated that a dominant mutation in ZNF750 leads to a clinical phenotype reminiscent of psoriasis and seborrheic dermatitis. Here we show that ZNF750 is a nuclear protein bearing a functional C-terminal nuclear localization signal. ZNF750 was specifically expressed in the epidermal suprabasal layers and its expression was augmented during differentiation, both in human skin and in-vitro, peaking in the granular layer. Silencing of ZNF750 in Ca2+-induced HaCaT keratinocytes led to morphologically apparent arrest in the progression of late differentiation, as well as diminished apoptosis and sustained proliferation. ZNF750 knockdown cells presented with markedly reduced expression of epidermal late differentiation markers, including gene subsets of epidermal differentiation complex and skin barrier formation such as FLG, LOR, SPINK5, ALOX12B and DSG1, known to be mutated in various human skin diseases. Furthermore, overexpression of ZNF750 in undifferentiated cells induced terminal differentiation genes. Thus, ZNF750 is a regulator of keratinocyte terminal differentiation and with its downstream targets can serve in future elucidation of therapeutics for common diseases of skin barrier.
PC12 differentiation on biopolymer nanostructures
Cecchini, Marco [Scuola Normale Superiore and NEST-CNR-INFM, Pisa (Italy); Bumma, Giorgia [Scuola Normale Superiore and Italian Institute of Technology, Pisa (Italy); Serresi, Michela [Scuola Normale Superiore and Italian Institute of Technology, Pisa (Italy); Beltram, Fabio [Scuola Normale Superiore and NEST-CNR-INFM, Pisa (Italy)
2007-12-19
The study of nervous system regeneration and axonal outgrowth control are relevant in several research areas, like neurophysiology or biomedical engineering. Among the elements that control neuron dynamics, the host substrate topography is a key parameter in determining cell differentiation. We present time-lapse experiments to analyze the differentiation dynamics of PC12 cells on nanopatterned biocompatible substrates. 200 nm depth gratings were fabricated on tissue-culture polystyrene substrates by nanoimprint lithography; different linewidths and pitches were compared down to 500 nm and 1000 nm, respectively. PC12 cells were cultured on these substrates and, following NGF administration to the medium, body morphology, cell movement and neuritogenesis were monitored at different time periods. In addition to demonstrating guided differentiation, our studies show complex time variations in body morphology and axon length, and guided cell movement. We show unstable synaptic connections and cell-body polarization, and the competition between topographical guidance and cell-cell interactions.
PC12 differentiation on biopolymer nanostructures
Cecchini, Marco; Bumma, Giorgia; Serresi, Michela; Beltram, Fabio
2007-12-01
The study of nervous system regeneration and axonal outgrowth control are relevant in several research areas, like neurophysiology or biomedical engineering. Among the elements that control neuron dynamics, the host substrate topography is a key parameter in determining cell differentiation. We present time-lapse experiments to analyze the differentiation dynamics of PC12 cells on nanopatterned biocompatible substrates. 200 nm depth gratings were fabricated on tissue-culture polystyrene substrates by nanoimprint lithography; different linewidths and pitches were compared down to 500 nm and 1000 nm, respectively. PC12 cells were cultured on these substrates and, following NGF administration to the medium, body morphology, cell movement and neuritogenesis were monitored at different time periods. In addition to demonstrating guided differentiation, our studies show complex time variations in body morphology and axon length, and guided cell movement. We show unstable synaptic connections and cell-body polarization, and the competition between topographical guidance and cell-cell interactions.
From ordinary to partial differential equations
Esposito, Giampiero
2017-01-01
This book is addressed to mathematics and physics students who want to develop an interdisciplinary view of mathematics, from the age of Riemann, Poincaré and Darboux to basic tools of modern mathematics. It enables them to acquire the sensibility necessary for the formulation and solution of difficult problems, with an emphasis on concepts, rigour and creativity. It consists of eight self-contained parts: ordinary differential equations; linear elliptic equations; calculus of variations; linear and non-linear hyperbolic equations; parabolic equations; Fuchsian functions and non-linear equations; the functional equations of number theory; pseudo-differential operators and pseudo-differential equations. The author leads readers through the original papers and introduces new concepts, with a selection of topics and examples that are of high pedagogical value.
Differential geometry connections, curvature, and characteristic classes
Tu, Loring W
2017-01-01
This text presents a graduate-level introduction to differential geometry for mathematics and physics students. The exposition follows the historical development of the concepts of connection and curvature with the goal of explaining the Chern–Weil theory of characteristic classes on a principal bundle. Along the way we encounter some of the high points in the history of differential geometry, for example, Gauss' Theorema Egregium and the Gauss–Bonnet theorem. Exercises throughout the book test the reader’s understanding of the material and sometimes illustrate extensions of the theory. Initially, the prerequisites for the reader include a passing familiarity with manifolds. After the first chapter, it becomes necessary to understand and manipulate differential forms. A knowledge of de Rham cohomology is required for the last third of the text. Prerequisite material is contained in author's text An Introduction to Manifolds, and can be learned in one semester. For the benefit of the reader and to establ...
A short course in ordinary differential equations
Kong, Qingkai
2014-01-01
This text is a rigorous treatment of the basic qualitative theory of ordinary differential equations, at the beginning graduate level. Designed as a flexible one-semester course but offering enough material for two semesters, A Short Course covers core topics such as initial value problems, linear differential equations, Lyapunov stability, dynamical systems and the Poincaré—Bendixson theorem, and bifurcation theory, and second-order topics including oscillation theory, boundary value problems, and Sturm—Liouville problems. The presentation is clear and easy-to-understand, with figures and copious examples illustrating the meaning of and motivation behind definitions, hypotheses, and general theorems. A thoughtfully conceived selection of exercises together with answers and hints reinforce the reader's understanding of the material. Prerequisites are limited to advanced calculus and the elementary theory of differential equations and linear algebra, making the text suitable for senior undergraduates as w...
Particle Systems and Partial Differential Equations I
Gonçalves, Patricia
2014-01-01
This book presents the proceedings of the international conference Particle Systems and Partial Differential Equations I, which took place at the Centre of Mathematics of the University of Minho, Braga, Portugal, from the 5th to the 7th of December, 2012. The purpose of the conference was to bring together world leaders to discuss their topics of expertise and to present some of their latest research developments in those fields. Among the participants were researchers in probability, partial differential equations and kinetics theory. The aim of the meeting was to present to a varied public the subject of interacting particle systems, its motivation from the viewpoint of physics and its relation with partial differential equations or kinetics theory, and to stimulate discussions and possibly new collaborations among researchers with different backgrounds. The book contains lecture notes written by François Golse on the derivation of hydrodynamic equations (compressible and incompressible Euler and Navie...