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Zemroch, Peter J. "The Computerized Generation of Fractional-replicate Designs Using Galois Fields and Hadamard Matrices." Quality and Reliability Engineering International 31, no. 7 (August 10, 2015): 1197–207. http://dx.doi.org/10.1002/qre.1846.
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Kahn, S. N., and L. P. Strony. "Imprecision of quantification of serum protein fractions by electrophoresis on cellulose acetate." Clinical Chemistry 32, no. 2 (February 1, 1986): 356–57. http://dx.doi.org/10.1093/clinchem/32.2.356.
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Abstract We studied the precision of densitometric quantification of the protein zones resolved by cellulose acetate electrophoresis. Replicate analyses of patients' samples by a single technologist showed mean CVs ranging from 2.9% for serum albumin to 9.5% for alpha 1-globulin. There were marked differences in measurements obtained by replicate analysis of the same samples by two experienced technologists. We calculated what changes in fractional concentrations would be analytically significant and concluded that densitometry of cellulose acetate electrophoretograms can only be semi-quantitative. We suggest that visual interpretation of high-resolution electrophoretic patterns by a trained observer can replace densitometry in most cases.
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Alharthi, Nadiyah Hussain, Abdon Atangana, and Badr S. Alkahtani. "Numerical analysis of some partial differential equations with fractal-fractional derivative." AIMS Mathematics 8, no. 1 (2022): 2240–56. http://dx.doi.org/10.3934/math.2023116.
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<abstract> <p>In this study, we expanded the partial differential equation framework to which fractal-fractional differentiation can be applied. For this, we employed the generalized Mittag-Leffler function, and the fractal-fractional derivatives based on the power-law kernel. A general partial differential equation with the fractal-fractional derivative, the power law kernel and the generalized Mittag-Leffler function was thoroughly examined. There is almost no numerical scheme for solving partial differential equations with fractal-fractional derivatives, as less investigation has been done in this direction in the last decades. In this work, therefore, we shall attempt to provide a numerical method that might be used to solve these equations in each circumstance. The heat equation was taken into consideration for the application and numerically solved using a few simulations for various values of fractional and fractal orders. It is observed that, when the fractal order is 1, one obtains fractional partial differential equations which have been known to replicate nonlocal behaviors. Meanwhile, if the fractional order is 1, one obtains fractal-partial differential equations. Thus, when the fractional order and fractal dimension are different from zero, nonlocal processes with similar features are developed.</p> </abstract>
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Doungmo Goufo, Emile Franc. "The Proto-Lorenz System in Its Chaotic Fractional and Fractal Structure." International Journal of Bifurcation and Chaos 30, no. 12 (September 30, 2020): 2050180. http://dx.doi.org/10.1142/s0218127420501801.
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It is not common in applied sciences to realize simulations which depict fractal representation in attractors’ dynamics, the reason being a combination of many factors including the nature of the phenomenon that is described and the type of differential operator used in the system. In this work, we use the fractal-fractional derivative with a fractional order to analyze the modified proto-Lorenz system that is usually characterized by chaotic attractors with many scrolls. The fractal-fractional operator used in this paper is a combination of fractal process and fractional differentiation, which is a relatively new concept with most of the properties and features still to be known. We start by summarizing the basic notions related to the fractal-fractional operator. After that, we enumerate the main points related to the establishment of proto-Lorenz system’s equations, leading to the [Formula: see text]th cover of the proto-Lorenz system that contains [Formula: see text] scrolls ([Formula: see text]). The triple and quadric cover of the resulting fractal and fractional proto-Lorenz system are solved using the Haar wavelet methods and numerical simulations are performed. Due to the impact of the fractal-fractional operator, the system is able to maintain its chaotic state of attractor with many scrolls. Additionally, such attractor can self-replicate in a fractal process as the derivative order changes. This result reveals another great feature of the fractal-fractional derivative with fractional order.
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Krehbiel, Timothy C., and Donald A. Anderson. "The use of a monetary loss function to determine the optimal fractional replicate of factorial experiments." Communications in Statistics - Theory and Methods 21, no. 8 (January 1992): 2383–98. http://dx.doi.org/10.1080/03610929208830919.
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Faridi, Waqas Ali, Muhammad Imran Asjad, Shabir Ahmad, Adrian Iftene, Magda Abd El-Rahman, and Mohammed Sallah. "Deterministic and Fractional-Order Co-Infection Model of Omicron and Delta Variants of Asymptomatic SARS-CoV-2 Carriers." Fractal and Fractional 7, no. 2 (February 14, 2023): 192. http://dx.doi.org/10.3390/fractalfract7020192.
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The Delta and Omicron variants’ system was used in this research study to replicate the complex process of the SARS-CoV-2 outbreak. The generalised fractional system was designed and rigorously analysed in order to gain a comprehensive understanding of the transmission dynamics of both variants. The proposed dynamical system has heredity and memory effects, which greatly improved our ability to perceive the disease propagation dynamics. The non-singular Atangana–Baleanu fractional operator was used to forecast the current pandemic in order to meet this challenge. The Picard recursions approach can be used to ensure that the designed fractional system has at least one solution occupying the growth condition and memory function regardless of the initial conditions. The Hyers–Ulam–Rassias stability criteria were used to carry out the stability analysis of the fractional governing system of equations, and the fixed-point theory ensured the uniqueness of the solution. Additionally, the model exhibited global asymptotically stable behaviour in some conditions. The approximate behaviour of the fatal virus was investigated using an efficient and reliable fractional numerical Adams–Bashforth approach. The outcome demonstrated that there will be a significant decline in the population of those infected with the Omicron and Delta SARS-CoV-2 variants if the vaccination rate is increased (in both the symptomatic and symptomatic stages).
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Escribano-García, Ruben, Pedro Álvarez, and David Marquez-Monje. "Calibration of Finite Element Model of Titanium Laser Welding by Fractional Factorial Design." Journal of Manufacturing and Materials Processing 6, no. 6 (October 26, 2022): 130. http://dx.doi.org/10.3390/jmmp6060130.
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This paper focuses on the calibration of heat source parameters to reproduce temperatures and distortions in welded joints. Specifically, the proposed methodology, which combines the Finite Element Method and Design of Experiments, is applied to calibrate a T-joint dissimilar titanium laser welding process. The thermal problem is addressed using a 3D transient model with a Conical Gaussian heat flux, and the mechanical problem is tackled using a 3D elastic-plastic model. A Fractional-Factorial Design is performed to define a set of thermo-mechanical uncoupled models. Finally, optimal parameter combinations that replicate experimental data are identified. This methodology allows automation that replaces the traditional trial and error process, which frequently does not provide good results, is an exhausting task and requires a dubious amount of time.
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Mandapati, Vinny Cris, Harsh Vardhan, Shashi Prabhakar, Sakshi, Ravi Kumar, Salla Gangi Reddy, Ravindra P. Singh, and Kehar Singh. "Multi-User Nonlinear Optical Cryptosystem Based on Polar Decomposition and Fractional Vortex Speckle Patterns." Photonics 10, no. 5 (May 11, 2023): 561. http://dx.doi.org/10.3390/photonics10050561.
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In this paper, we propose a new multiuser nonlinear optical cryptosystem using fractional-order vortex speckle (FOVS) patterns as security keys. In conventional optical cryptosystems, mostly random phase masks are used as the security keys which are prone to various attacks such as brute force attack. In the current study, the FOVSs are generated optically by the scattering of the fractional-order vortex beam, known for azimuthal phase and helical wavefronts, through a ground glass diffuser. FOVSs have a remarkable property that makes them almost impossible to replicate. In the input plane, the amplitude image is first phase encoded and then modulated with the FOVS phase mask to obtain the complex image. This complex image is further processed to obtain the encrypted image using the proposed method. Two private security keys are obtained through polar decomposition which enables the multi-user capability in the cryptosystem. The robustness of the proposed method is tested against existing attacks such as the contamination attack and known-plaintext attack. Numerical simulations confirm the validity and feasibility of the proposed method.
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Chacko, Shaji K., Agneta L. Sunehag, Susan Sharma, Pieter J. J. Sauer, and Morey W. Haymond. "Measurement of gluconeogenesis using glucose fragments and mass spectrometry after ingestion of deuterium oxide." Journal of Applied Physiology 104, no. 4 (April 2008): 944–51. http://dx.doi.org/10.1152/japplphysiol.00752.2007.
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We report a new method to measure the fraction of glucose derived from gluconeogenesis using gas chromatography-mass spectrometry and positive chemical ionization. After ingestion of deuterium oxide by subjects, glucose derived from gluconeogenesis is labeled with deuterium. Our calculations of gluconeogenesis are based on measurements of the average enrichment of deuterium on carbon 1, 3, 4, 5, and 6 of glucose and the deuterium enrichment in body water. In a sample from an adult volunteer after ingestion of deuterium oxide, fractional gluconeogenesis using the “average deuterium enrichment method” was 48.3 ± 0.5% (mean ± SD) and that with the C-5 hexamethylenetetramine (HMT) method by Landau et al. (Landau BR, Wahren J, Chandramouli V, Schumann WC, Ekberg K, Kalhan SC; J Clin Invest 98: 378–385, 1996) was 46.9 ± 5.4%. The coefficient of variation of 10 replicate analyses using the new method was 1.0% compared with 11.5% for the C-5 HMT method. In samples derived from an infant receiving total parenteral nutrition, fractional gluconeogenesis was 13.3 ± 0.3% using the new method and 13.7 ± 0.8% using the C-5 HMT method. Fractional gluconeogenesis measured in six adult volunteers after 66 h of continuous fasting was 83.7 ± 2.3% using the new method and 84.2 ± 5.0% using the C-5 HMT method. In conclusion, the average deuterium enrichment method is simple, highly reproducible, and cost effective. Furthermore, it requires only small blood sample volumes. With the use of an additional tracer, glucose rate of appearance can also be measured during the same analysis. Thus the new method makes measurements of gluconeogenesis available and affordable to large numbers of investigators under conditions of low and high fractional gluconeogenesis (∼10 to ∼90) in all subject populations.
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FUNAHASHI, HIDEHARU. "REPLICATION SCHEME FOR THE PRICING OF EUROPEAN OPTIONS." International Journal of Theoretical and Applied Finance 24, no. 03 (May 2021): 2150014. http://dx.doi.org/10.1142/s021902492150014x.
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This paper proposes an efficient method for calculating European option prices under local, stochastic, and fractional volatility models. Instead of directly calculating the density function of a target underlying asset, we replicate it from a simpler diffusion process with a known analytical solution for the European option. For this purpose, we derive six functions that characterize the density function of a diffusion process, for both the original and simpler processes and match these functions so that the latter mimics the former. Using the analytical formula, we then approximate the option price of the target asset. By comparison with previous works and numerical experiments, we show that the accuracy of our approximation is high, and the calculation is fast enough for practical purposes; hence, it is suitable for calibration purposes.
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Iftikhar, Nazish, Muhammad Bilal Riaz, Jan Awrejcewicz, and Ali Akgül. "Effect of Magnetic Field with Parabolic Motion on Fractional Second Grade Fluid." Fractal and Fractional 5, no. 4 (October 11, 2021): 163. http://dx.doi.org/10.3390/fractalfract5040163.
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This paper is an analysis of the flow of magnetohydrodynamics (MHD) second grade fluid (SGF) under the influence of chemical reaction, heat generation/absorption, ramped temperature and concentration and thermodiffusion. The fluid was made to flow through a porous medium. It has been proven in many already-published articles that heat and mass transfer do not always follow the classical mechanics process that is known as memoryless process. Therefore, the model using classical differentiation based on the rate of change cannot really replicate such a dynamical process very accurately; thus, a different concept of differentiation is needed to capture such a process. Very recently, new classes of differential operators were introduced and have been recognized to be efficient in capturing processes following the power law, the decay law and the crossover behaviors. For the study of heat and mass transfer, we applied the newly introduced differential operators to model such flow. The equations for heat, mass and momentum are established in the terms of Caputo (C), Caputo–Fabrizio (CF) and Atangana–Baleanu in Caputo sense (ABC) fractional derivatives. The Laplace transform, inversion algorithm and convolution theorem were used to derive the exact and semi-analytical solutions for all cases. The obtained analytical solutions were plotted for different values of existing parameters. It is concluded that the fluid velocity shows increasing behavior for κ, Gr and Gm, while velocity decreases for Pr and M. For Kr, both velocity and concentration curves show decreasing behavior. Fluid flow accelerates under the influence of Sr and R. Temperature and concentration profiles increase for Sr and R. Moreover, the ABC fractional operator presents a larger memory effect than C and CF fractional operators.
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RIAZ, MUHAMMAD BILAL, ABDON ATANGANA, and THABET ABDELJAWAD. "LOCAL AND NONLOCAL DIFFERENTIAL OPERATORS: A COMPARATIVE STUDY OF HEAT AND MASS TRANSFERS IN MHD OLDROYD-B FLUID WITH RAMPED WALL TEMPERATURE." Fractals 28, no. 08 (August 10, 2020): 2040033. http://dx.doi.org/10.1142/s0218348x20400332.
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Study of heat and mass transfers is carried out for MHD Oldroyd-B fluid (OBF) over an infinite vertical plate having time-dependent velocity and with ramped wall temperature and constant concentration. It is proven in many already published articles that the heat and mass transfers do not really or always follow the classical mechanics process that is known as memoryless process. Therefore, the model using classical differentiation based on the rate of change cannot really replicate such dynamical process very accurately, thus, a different concept of differentiation is needed to capture such process. Very recently, a new class of differential operators were introduced and have been recognized to be efficient in capturing processes following the power-law, the decay law and the crossover behaviors. For the study of heat and mass transfers, we applied the newly introduced differential operators to model such flow and compare the results with integer-order derivative. Laplace transform and inversion algorithms are used for all the cases to find analytical solutions and to predict the influences of different parameters. The obtained analytical solutions were plotted for different values of fractional orders [Formula: see text] and [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] on the velocity field. In comparison, Atangana–Baleanu (ABC) fractional derivatives are found to be the best to explain the memory effects than the classical, Caputo (C) and Caputo–Fabrizio (CF) fractional derivatives. Some calculated values for Nusselt number and Sherwood number are presented in tables. Moreover, from the present solutions, the already published results were found as limiting cases.
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McKinnon, M. M. "Exponential Fluctuations in the Modes of Orthogonal Polarization in Pulsar Radio Emission." Astrophysical Journal 937, no. 2 (October 1, 2022): 92. http://dx.doi.org/10.3847/1538-4357/ac8dfa.
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Abstract A statistical model for the polarization of pulsar radio emission is enhanced to account for the heavy modulation of the emission, the possible covariance of the Stokes parameters, and the observed asymmetries in the distributions of total intensity, polarization, and fractional polarization, by treating the intensities of the orthogonal polarization modes as exponential random variables. The model is used to derive theoretical distributions to compare with what is observed. The resulting distributions are unimodal and generally asymmetric. The unimodality arises from the model’s fundamental assumption that the orthogonal modes are superposed. The asymmetry originates primarily from different fluctuations in mode intensities. The distributions of fractional polarization are truncated at the degree of linear and circular polarization intrinsic to the modes. A number of observable parameters that quantify the statistical properties of the emission and its polarization are derived and are shown to be functions only of the ratio of the modes’ mean intensities, M, suggesting their spectra coevolve according to the frequency dependence of M. This particular implementation of the model requires the modes to fluctuate differently in order to replicate the observations. Given that a single underlying emission mechanism seems unlikely to selectively modulate the mode intensities, the different fluctuations are attributed either to different emission mechanisms for the modes or to mode-dependent propagation or scattering effects in the pulsar magnetosphere.
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Verseghy, Diana, Ross Brown, and Libo Wang. "Evaluation of CLASS Snow Simulation over Eastern Canada." Journal of Hydrometeorology 18, no. 5 (April 12, 2017): 1205–25. http://dx.doi.org/10.1175/jhm-d-16-0153.1.
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Abstract The Canadian Land Surface Scheme (CLASS), version 3.6.1, was run offline for the period 1990–2011 over a domain centered on eastern Canada, driven by atmospheric forcing data dynamically downscaled from ERA-Interim using the Canadian Regional Climate Model. The precipitation inputs were adjusted to replicate the monthly average precipitation reported in the CRU observational database. The simulated fractional snow cover and the surface albedo were evaluated using NOAA Interactive Multisensor Snow and Ice Mapping System and MODIS data, and the snow water equivalent was evaluated using CMC, Global Snow Monitoring for Climate Research (GlobSnow), and Hydro-Québec products. The modeled fractional snow cover agreed well with the observational estimates. The albedo of snow-covered areas showed a bias of up to −0.15 in boreal forest regions, owing to neglect of subgrid-scale lakes in the simulation. In June, conversely, there was a positive albedo bias in the remaining snow-covered areas, likely caused by neglect of impurities in the snow. The validation of the snow water equivalent was complicated by the fact that the three observation-based datasets differed widely. Also, the downward adjustment of the forcing precipitation clearly resulted in a low snow bias in some regions. However, where the density of the observations was high, the CLASS snow model was deemed to have performed well. Sensitivity tests confirmed the satisfactory behavior of the current parameterizations of snow thermal conductivity, snow albedo refreshment threshold, and limiting snow depth and underlined the importance of snow interception by vegetation. Overall, the study demonstrated the necessity of using a wide variety of observation-based datasets for model validation.
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Wadkin, L. E., S. Orozco-Fuentes, I. Neganova, M. Lako, N. G. Parker, and A. Shukurov. "A mathematical modelling framework for the regulation of intra-cellular OCT4 in human pluripotent stem cells." PLOS ONE 16, no. 8 (August 4, 2021): e0254991. http://dx.doi.org/10.1371/journal.pone.0254991.
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Human pluripotent stem cells (hPSCs) have the potential to differentiate into all cell types, a property known as pluripotency. A deeper understanding of how pluripotency is regulated is required to assist in controlling pluripotency and differentiation trajectories experimentally. Mathematical modelling provides a non-invasive tool through which to explore, characterise and replicate the regulation of pluripotency and the consequences on cell fate. Here we use experimental data of the expression of the pluripotency transcription factor OCT4 in a growing hPSC colony to develop and evaluate mathematical models for temporal pluripotency regulation. We consider fractional Brownian motion and the stochastic logistic equation and explore the effects of both additive and multiplicative noise. We illustrate the use of time-dependent carrying capacities and the introduction of Allee effects to the stochastic logistic equation to describe cell differentiation. We conclude both methods adequately capture the decline in OCT4 upon differentiation, but the Allee effect model has the advantage of allowing differentiation to occur stochastically in a sub-set of cells. This mathematical framework for describing intra-cellular OCT4 regulation can be extended to other transcription factors and developed into predictive models.
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Meletiadis, Joseph, Spyros Pournaras, Emmanuel Roilides, and Thomas J. Walsh. "Defining Fractional Inhibitory Concentration Index Cutoffs for Additive Interactions Based on Self-Drug Additive Combinations, Monte Carlo Simulation Analysis, and In Vitro-In Vivo Correlation Data for Antifungal Drug Combinations against Aspergillus fumigatus." Antimicrobial Agents and Chemotherapy 54, no. 2 (December 7, 2009): 602–9. http://dx.doi.org/10.1128/aac.00999-09.
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ABSTRACT The fractional inhibitory concentration (FIC) index range of 0.5 to 4 that is commonly used to define additivity results in no interactions in most combination studies of antifungal agents. These results may differ from those of in vivo studies, where positive and negative interactions may be observed. We reassessed this in vitro FIC index range based on (i) the experimental variation of the checkerboard technique using multiple replicates, (ii) the ability to correctly determine purely additive self-drug and two-drug antagonistic combinations of amphotericin B (AMB) and voriconazole (VRC), (iii) Monte Carlo simulation analysis, and (iv) in vitro-in vivo correlation using experimental models of invasive pulmonary aspergillosis against the same Aspergillus fumigatus isolate based on visual, spectrophotometric, and colorimetric determinations of FICs after 24 and 48 h of incubation. FICs obtained after 24 h of incubation ranged from 0.5 to 1.25 for the self-drug additive combinations of AMB plus AMB and VRC plus VRC and from 2.25 to 4.25 for the antagonistic combination of AMB plus VRC. Monte Carlo simulation analysis showed that self-drug combinations were correctly classified as additive and that the combination of AMB plus VRC was correctly classified as antagonistic for >85% of the simulated FICs when deviation of the 95% confidence interval (CI) of replicate FICs from the additivity range of 1 to 1.25 was used to assess interactions after 24 h. In vitro-in vivo correlation analysis showed that the 95% CIs of the FICs of the in vivo synergistic combination anidulafungin plus VRC determined after 24 h were lower than 1 and the 95% CIs of the FICs of the in vivo antagonistic combination AMB plus ravuconazole were higher than 1.25. Adequate insight into weak pharmacodynamic interactions with in vivo relevance may be obtained by demonstrating that triplicate FICs at 24 h are outside an inclusive additivity range of 1 to 1.25.
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Dasgupta, Nairanjana, Mike Jacroux, and Rita SahaRay. "Partially replicated fractional factorial designs." Metrika 71, no. 3 (January 23, 2009): 295–311. http://dx.doi.org/10.1007/s00184-009-0231-x.
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Raieszadeh, Hamid, Vahid Noaman, and Mehrdad Yadegari. "Echocardiographic Assessment of Cardiac Structural and Functional Indices in Broiler Chickens Treated with Silver Nanoparticles." Scientific World Journal 2013 (2013): 1–5. http://dx.doi.org/10.1155/2013/931432.
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270 Ross broiler chickens of twenty days old were housed in 18-floor pens in a completely randomized design with six treatment groups and three replicate groups and fifteen chicks per each pen. The treatment groups (1–6) consisted of 0, 10, 20, 30, 50, and 70 ppm of nanocide in drinking water, respectively. At 26 days of age, 3 chickens were selected randomly for echocardiography using a 7.5 MHz linear probe, and the left ventricular internal diameter at the end of diastole (LVIDd), left ventricular internal diameter at the end of systole (LVIDs), left ventricular fractional shortening (LVFS), ejection fraction (EF), stroke volume (SV), interventricular septum thickness at the end of systole (IVSTs), and interventricular septum thickness at the end of diastole (IVSTd) were evaluated. LVIDd and LVIDs in group six were of higher rate than other groups and showed statistically significant differences with groups two, three, and four (P<0.05). LVFS, percentage of EF, and IVSTd were minimum in group six and had significant difference with other groups (P<0.05). The results of this study showed that prescription of high dosage of nanocide leads to cardiovascular problems with decrease in myocardial contractility and increase in the internal diameter of left ventricle.
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Hellstrøm, Torgeir, Nada Andelic, Ann-Marie G. de Lange, Eirik Helseth, Kristin Eiklid, and Lars T. Westlye. "Apolipoprotein ɛ4 Status and Brain Structure 12 Months after Mild Traumatic Injury: Brain Age Prediction Using Brain Morphometry and Diffusion Tensor Imaging." Journal of Clinical Medicine 10, no. 3 (January 22, 2021): 418. http://dx.doi.org/10.3390/jcm10030418.
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Background: Apolipoprotein E (APOE) ɛ4 is associated with poor outcome following moderate to severe traumatic brain injury (TBI). There is a lack of studies investigating the influence of APOE ɛ4 on intracranial pathology following mild traumatic brain injury (MTBI). This study explores the association between APOE ɛ4 and MRI measures of brain age prediction, brain morphometry, and diffusion tensor imaging (DTI). Methods: Patients aged 16 to 65 with acute MTBI admitted to the trauma center were included. Multimodal MRI was performed 12 months after injury and associated with APOE ɛ4 status. Corrections for multiple comparisons were done using false discovery rate (FDR). Results: Of included patients, 123 patients had available APOE, volumetric, and DTI data of sufficient quality. There were no differences between APOE ɛ4 carriers (39%) and non-carriers in demographic and clinical data. Age prediction revealed high accuracy both for the DTI-based and the brain morphometry based model. Group comparisons revealed no significant differences in brain-age gap between ɛ4 carriers and non-carriers, and no significant differences in conventional measures of brain morphometry and volumes. Compared to non-carriers, APOE ɛ4 carriers showed lower fractional anisotropy (FA) in the hippocampal part of the cingulum bundle, which did not remain significant after FDR adjustment. Conclusion: APOE ɛ4 carriers might be vulnerable to reduced neuronal integrity in the cingulum. Larger cohort studies are warranted to replicate this finding.
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WONG, WING-KEUNG, HABIBULLAH KHAN, and JUN DU. "DO MONEY AND INTEREST RATES MATTER FOR STOCK PRICES? AN ECONOMETRIC STUDY OF SINGAPORE AND USA." Singapore Economic Review 51, no. 01 (April 2006): 31–51. http://dx.doi.org/10.1142/s0217590806002214.
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This paper examines the long-term as well as short-term equilibrium relationships between the major stock indices and selected macroeconomic variables (such as money supply and interest rate) of Singapore and the United States by employing the advanced time series analysis techniques that include cointegration, Johansen multivariate cointegrated system, fractional cointegration and Granger causality. The cointegration results based on data covering the period January 1982 to December 2002 suggest that Singapore's stock prices generally display a long-run equilibrium relationship with interest rate and money supply (M1) but a similar relationship does not hold for the United States. To capture the short-run dynamics of the relationship, we replicate the same experiments with different subsets of data representing shorter time periods. It is evident that stock markets in Singapore moved in tandem with interest rate and money supply before the Asian Crisis of 1997, but this pattern was not observed after the crisis. In the United States, stock prices were strongly cointegrated with macroeconomic variables before the 1987 equity crisis but the relationships gradually weakened and totally disappeared with the emergence of Asian Crisis that also indirectly affected the United States. The results of fractional cointegration and the Johansen multivariate system are consistent with the earlier cointegration results that both Singapore and US stock markets did possess equilibrium relationships with M1 and interest rate at the early days. However, the stability of the systems was disturbed by a series of well-known financial turbulence in the past two decades and eventually weakened for Singapore and completely disappeared for the US. This may imply that monetary authority may take action to respond to the asset price turbulence in order to maintain the stability of monetary economy and thus break the existing equilibrium between stock markets and macroeconomic variables like interest rate and M1. Another possible explanation is that the market became more efficient after 1997 Asian crisis. Finally, the results of Granger causality tests uncover some systematic causal relationships, implying that stock market performance might be a good gauge for Central Bank's monetary policy adjustment.
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Park, Yunji, and Percival G. Matthews. "Revisiting and refining relations between nonsymbolic ratio processing and symbolic math achievement." Journal of Numerical Cognition 7, no. 3 (November 30, 2021): 328–50. http://dx.doi.org/10.5964/jnc.6927.
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In their 2016 Psych Science article, Matthews, Lewis and Hubbard (2016, https://doi.org/10.1177/0956797615617799) leveled a challenge against the prevailing theory that fractions—as opposed to whole numbers—are incompatible with humans’ primitive nonsymbolic number sense. Their ratio processing system (RPS) account holds that humans possess a primitive system that confers the ability to process nonysmbolic ratio magnitudes. Perhaps the most striking finding from Matthews et al. was that ratio processing ability predicted symbolic fractions knowledge and algebraic competence. The purpose of the current study was to replicate Matthews et al.’s novel results and to extend the study by including a control measure of fluid intelligence and an additional nonsymbolic magnitude format as predictors of multiple symbolic math outcomes. Ninety-nine college students completed three comparison tasks deciding which of two nonsymbolic ratios was numerically larger along with three simple magnitude comparison tasks in corresponding formats that served as controls. The formats included were lines, circles, and dots. We found that RPS acuity predicted fractions knowledge for three university math placement exam subtests when controlling for simple magnitude acuities and inhibitory control. However, this predictive power of the RPS measure appeared to stem primarily from acuity of the line-ratio format, and that predictive power was attenuated with the inclusion of fluid intelligence. These findings may help refine theories positing the RPS as a domain-specific foundation for building fractional knowledge and related higher mathematics.
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Liao, Chen-Tuo, and Feng-Shun Chai. "Partially replicated two-level fractional factorial designs." Canadian Journal of Statistics 32, no. 4 (December 2004): 421–38. http://dx.doi.org/10.2307/3316025.
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Wang, Ernest W., Max L. Trojano, Mechelle M. Lewis, Guangwei Du, Hairong Chen, Gregory L. Brown, Leslie C. Jellen, et al. "HFE H63D Limits Nigral Vulnerability to Paraquat in Agricultural Workers." Toxicological Sciences 181, no. 1 (March 18, 2021): 47–57. http://dx.doi.org/10.1093/toxsci/kfab020.
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Abstract Paraquat is an herbicide whose use is associated with Parkinson’s disease (PD), a neurodegenerative disorder marked by neuron loss in the substantia nigra pars compacta (SNc). We recently observed that the murine homolog to the human H63D variant of the homeostatic iron regulator (HFE) may decrease paraquat-associated nigral neurotoxicity in mice. The present study examined the potential influence of H63D on paraquat-associated neurotoxicity in humans. Twenty-eight paraquat-exposed workers were identified from exposure histories and compared with 41 unexposed controls. HFE genotypes, and serum iron and transferrin were measured from blood samples. MRI was used to assess the SNc transverse relaxation rate (R2*), a marker for iron, and diffusion tensor imaging scalars of fractional anisotropy (FA) and mean diffusivity, markers of microstructural integrity. Twenty-seven subjects (9 exposed and 18 controls) were H63D heterozygous. After adjusting for age and use of other PD-associated pesticides and solvents, serum iron and transferrin were higher in exposed H63D carriers than in unexposed carriers and HFE wildtypes. SNc R2* was lower in exposed H63D carriers than in unexposed carriers, whereas SNc FA was lower in exposed HFE wildtypes than in either unexposed HFE wildtypes or exposed H63D carriers. Serum iron and SNc FA measures correlated positively among exposed, but not unexposed, subjects. These data suggest that H63D heterozygosity is associated with lower neurotoxicity presumptively linked to paraquat. Future studies with larger cohorts are warranted to replicate these findings and examine potential underlying mechanisms, especially given the high prevalence of the H63D allele in humans.
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Robertson, Franklin R., and Jason B. Roberts. "Intraseasonal Variability in MERRA Energy Fluxes over the Tropical Oceans." Journal of Climate 25, no. 17 (March 2, 2012): 5629–47. http://dx.doi.org/10.1175/jcli-d-11-00428.1.
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Abstract This paper investigates intraseasonal variability as represented by the recent NASA Global Modeling and Assimilation Office (GMAO) reanalysis, the Modern-Era Retrospective analysis for Research and Applications (MERRA). The authors examine the behavior of heat, moisture, and radiative fluxes emphasizing their contribution to intraseasonal variations in heat and moisture balance integrated over the tropical oceans. MERRA successfully captures intraseasonal signals in both state variables and fluxes, though it depends heavily on the analysis increment update terms that constrain the reanalysis to be near the observations. Precipitation anomaly patterns evolve in close agreement with those from the Tropical Rainfall Measuring Mission (TRMM) though locally MERRA may occasionally be smaller by up to 20%. As in the TRMM observations, tropical convection increases lead tropospheric warming by approximately 7 days. Radiative flux anomalies are dominated by cloud forcing and are found to replicate the top-of-the-atmosphere (TOA) energy loss associated with increased convection found by other observationally based studies. However, MERRA’s convectively produced clouds appear to deepen too soon as precipitation increases. Total fractional cloud cover variations appear somewhat weak compared to observations from the Moderate Resolution Imaging Spectroradiometer (MODIS). Evolution of the surface fluxes, convection, and TOA radiation is consistent with the “discharge–recharge” paradigm that posits the importance of lower-tropospheric moisture accumulation prior to the expansion of organized deep convection. The authors conclude that MERRA constitutes a very useful representation of intraseasonal variability that will support a variety of studies concerning radiative–convective–dynamical processes and will help identify pathways for improved moist physical parameterization in global models.
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Hengst, S., J. P. Marshall, J. Horner, and S. C. Marsden. "Multi-wavelength, spatially resolved modelling of HD 48682’s debris disc." Monthly Notices of the Royal Astronomical Society 497, no. 1 (July 8, 2020): 1098–109. http://dx.doi.org/10.1093/mnras/staa1972.
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ABSTRACT Asteroids and comets (planetesimals) are created in gas- and dust-rich protoplanetary discs. The presence of these planetesimals around main-sequence stars is usually inferred from the detection of excess continuum emission at infrared wavelengths from dust grains produced by destructive processes within these discs. Modelling of the disc structure and dust grain properties for those discs is often hindered by the absence of any meaningful constraint on the location and spatial extent of the disc. Multi-wavelength, spatially resolved imaging is thus invaluable in refining the interpretation of these systems. Observations of HD 48682 at far-infrared (Spitzer, Herschel) and sub-millimetre (JCMT, SMA) wavelengths indicated the presence of an extended, cold debris disc with a blackbody temperature of 57.9 ± 0.7 K. Here, we combined these data to perform a comprehensive study of the disc architecture and its implications for the dust grain properties. The deconvolved images revealed a cold debris belt, verified by combining a 3D radiative transfer dust continuum model with image analysis to replicate the structure using a single, axisymmetric annulus. A Markov chain Monte Carlo analysis calculated the maximum likelihood of HD48682’s disc radius ($R_{\rm disc} = 89^{+17}_{-20}~$ au), fractional width ($\Delta R_{\rm disc} = 0.41^{+0.27}_{-0.20}$), position angle ($\theta = 66{_{.}^{\circ}} 3^{+4.5}_{-4.9}$), and inclination ($\phi = 112{_{.}^{\circ}} 5^{+4.2}_{-4.2}$). HD 48682 has been revealed to host a collisionally active, broad disc whose emission is dominated by small dust grains, smin ∼ 0.6 μm, and a size distribution exponent of 3.60 ± 0.02.
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van Tol, M. J., M. Li, C. D. Metzger, N. Hailla, D. I. Horn, W. Li, H. J. Heinze, et al. "Local cortical thinning links to resting-state disconnectivity in major depressive disorder." Psychological Medicine 44, no. 10 (November 1, 2013): 2053–65. http://dx.doi.org/10.1017/s0033291713002742.
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BackgroundLocal structural and metabolic as well as inter-regional connectivity abnormalities have been implicated in the neuropathology of major depressive disorder (MDD). How local tissue properties affect intrinsic functional connectivity is, however, unclear. Using a cross-sectional, multi-modal imaging approach, we investigated the relationship between local cortical tissue abnormalities and intrinsic resting-state functional connectivity (RSFC) in MDD.MethodA total of 20 MDD in-patients and 20 healthy controls underwent magnetic resonance imaging at 3 T for structural and functional imaging. Whole-brain cortical thickness was calculated and compared between groups. Regions with reduced cortical thickness defined seeds for subsequent whole-brain RSFC analyses. Contributions of structural tissue abnormalities on inter-regional RSFC were explicitly investigated.ResultsLower cortical thickness was observed in MDD in the right dorsomedial prefrontal cortex (PFC), superior temporal gyrus/temporal pole, middle-posterior cingulate cortex, and dorsolateral PFC. No differences in local fractional amplitude of low-frequency fluctuations were observed. Lower thickness in patients' dorsomedial PFC further directly and selectively affected its RSFC with the precuneus, which was unaffected by symptom severity. No effects of cortical thickness in other regions showing abnormal thickness were observed to influence functional connectivity.ConclusionsAbnormal cortical thickness in the dorsomedial PFC in MDD patients was observed to selectively and directly affect its intrinsic connectivity with the precuneus in MDD patients independent of depression severity, thereby marking a potential vulnerability for maladaptive mood regulation. Future studies should include an unmedicated sample and replicate findings using independent component analysis to test for morphometric effects on network integrity.
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Robitaille, J. F., A. Abdeldayem, I. Joncour, E. Moraux, F. Motte, P. Lesaffre, and A. Khalil. "Statistical model for filamentary structures of molecular clouds." Astronomy & Astrophysics 641 (September 2020): A138. http://dx.doi.org/10.1051/0004-6361/201937085.
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We propose a new statistical model that can reproduce the hierarchical nature of the ubiquitous filamentary structures of molecular clouds. This model is based on the multiplicative random cascade, which is designed to replicate the multifractal nature of intermittency in developed turbulence. We present a modified version of the multiplicative process where the spatial fluctuations as a function of scales are produced with the wavelet transforms of a fractional Brownian motion realisation. This simple approach produces naturally a log-normal distribution function and hierarchical coherent structures. Despite the highly contrasted aspect of these coherent structures against a smoother background, their Fourier power spectrum can be fitted by a single power law. As reported in previous works using the multiscale non-Gaussian segmentation (MnGSeg) technique, it is proven that the fit of a single power law reflects the inability of the Fourier power spectrum to detect the progressive non-Gaussian contributions that are at the origin of these structures across the inertial range of the power spectrum. The mutifractal nature of these coherent structures is discussed, and an extension of the MnGSeg technique is proposed to calculate the multifractal spectrum that is associated with them. Using directional wavelets, we show that filamentary structures can easily be produced without changing the general shape of the power spectrum. The cumulative effect of random multiplicative sequences succeeds in producing the general aspect of filamentary structures similar to those associated with star-forming regions. The filamentary structures are formed through the product of a large number of random-phase linear waves at different spatial wavelengths. Dynamically, this effect might be associated with the collection of compressive processes that occur in the interstellar medium.
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Zhao, Yuna. "Split-Plot Designs with Few Whole Plot Factors Containing Clear Effects." Fractal and Fractional 6, no. 8 (August 20, 2022): 453. http://dx.doi.org/10.3390/fractalfract6080453.
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Fractional factorial split-plot designs are widely used when it is impractical to perform fractional factorial experiments in a completely random order. When there are too many subplots per whole plot, or too few whole plots, fractional factorial split-plot designs with replicated settings of the whole plot factors are preferred. However, such an important study is undeveloped in the literature. This paper considers fractional factorial split-plot designs with replicated settings of the WP factors from the viewpoint of clear effects. We investigate the sufficient and necessary conditions for this class of designs to have clear effects. An algorithm is proposed to generate the desirable designs which have the most clear effects of interest. The fractional factorial split-plot design with replicated settings of the WP factors is analysed and the results are discussed.
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AHMED, E., A. M. A. EL-SAYED, A. E. M. EL-MESIRY, and H. A. A. EL-SAKA. "NUMERICAL SOLUTION FOR THE FRACTIONAL REPLICATOR EQUATION." International Journal of Modern Physics C 16, no. 07 (July 2005): 1017–25. http://dx.doi.org/10.1142/s0129183105007698.
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Ou, Zujun, Hong Qin, and Xu Cai. "Partially replicated two-level fractional factorial designs via semifoldover." Journal of Statistical Planning and Inference 143, no. 4 (April 2013): 809–17. http://dx.doi.org/10.1016/j.jspi.2012.10.010.
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Doungmo Goufo, Emile Franc, and Stella Mugisha. "Mathematical Solvability of a Caputo Fractional Polymer Degradation Model Using Further Generalized Functions." Mathematical Problems in Engineering 2014 (2014): 1–5. http://dx.doi.org/10.1155/2014/392792.
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The continuous fission equation with derivative of fractional orderα, describing the polymer chain degradation, is solved explicitly. We prove that, whether the breakup rate depends on the size of the chain breaking up or not, the evolution of the polymer sizes distribution is governed by a combination of higher transcendental functions, namely, Mittag-Leffler function, the further generalizedG-function, and the Pochhammer polynomial. In particular, this shows the existence of an eigenproperty; that is, the system describing fractional polymer chain degradation contains replicated and partially replicated fractional poles, whose effects are given by these functions.
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Lupinacci, Paul J., and Joseph G. Pigeon. "A Class of Partially Replicated Two Level Fractional Factorial Designs." Journal of Quality Technology 40, no. 2 (April 2008): 184–93. http://dx.doi.org/10.1080/00224065.2008.11917724.
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Bengochea, Gabriel, and Manuel Ortigueira. "Fractional Line Integral." Mathematics 9, no. 10 (May 20, 2021): 1150. http://dx.doi.org/10.3390/math9101150.
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This paper proposed a definition of the fractional line integral, generalising the concept of the fractional definite integral. The proposal replicated the properties of the classic definite integral, namely the fundamental theorem of integral calculus. It was based on the concept of the fractional anti-derivative used to generalise the Barrow formula. To define the fractional line integral, the Grünwald–Letnikov and Liouville directional derivatives were introduced and their properties described. The integral was defined for a piecewise linear path first and, from it, for any regular curve.
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Dingus, Cheryl, Bruce Ankenman, Angela Dean, and Fangfang Sun. "Identification of Dispersion Effects in Replicated Two-Level Fractional Factorial Experiments." Journal of Statistical Theory and Practice 7, no. 4 (October 2, 2013): 687–702. http://dx.doi.org/10.1080/15598608.2013.781851.
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Godolphin, J. D. "Two-level factorial and fractional factorial replicates in blocks of size two." Computational Statistics & Data Analysis 133 (May 2019): 120–37. http://dx.doi.org/10.1016/j.csda.2018.09.006.
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Khan, Zareen A., and Kamal Shah. "Discrete Fractional Inequalities Pertaining a Fractional Sum Operator with Some Applications on Time Scales." Journal of Function Spaces 2021 (June 18, 2021): 1–8. http://dx.doi.org/10.1155/2021/8734535.
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This content replicates some discrete nonlinear fractional inequalities by virtue of the fractional sum operator Ψ ¯ on time scales. Through the recognition of the principle of discrete fractional calculus, we are able to recover the precise estimates for unknown functions of inequalities of the Gronwall type. The resultant inequalities are of unique structure comparative with the latest reviewing disclosures and can be described as a complementary tool for numerically testing the solutions of discrete partial differential equations. The foremost consequences are probably confirmed via handling of assessment procedure and technique of mean value speculation. We display few examples of the proposed inequalities to represent the incentives of our effort.
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de Jesus, Vera, Mexia Tiago João, and Paulo Canas Rodrigues. "Binary Operations on Orthogonal Models, Application to Prime Basis Factorials and Fractional Replicates." Journal of Statistical Theory and Practice 3, no. 2 (June 2009): 505–21. http://dx.doi.org/10.1080/15598608.2009.10411941.
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Klaus, Christine R., Scott R. Daigle, Dorothy Iwanowics, L. Danielle Johnston, Carly A. Therkelsen, Jesse J. Smith, Mikel P. Moyer, et al. "DOT1L Inhibitor EPZ-5676 Displays Synergistic Antiproliferative Activity in Combination with Standard of Care Drugs or DNA Hypomethylating Agents in MLL-Rearranged Leukemia Cells." Blood 122, no. 21 (November 15, 2013): 3930. http://dx.doi.org/10.1182/blood.v122.21.3930.3930.
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Abstract EPZ-5676 is a small molecule inhibitor of the histone methyltransferase DOT1L that is currently under clinical investigation as a potential therapy for acute leukemias bearing MLL-rearrangements. Gene knockout and small molecule inhibitor studies have demonstrated that DOT1L is required for MLL-fusion protein–mediated leukemogenesis in model systems. In preclinical studies EPZ-5676 promoted cell killing of acute leukemia lines bearing MLL translocations in vitro while sparing those without MLL gene translocations and also caused sustained tumor regressions in a rat xenograft model of MLL-rearranged leukemia [Daigle et al. Blood 2013]. To support potential future clinical scenarios, we evaluated the activity of EPZ-5676 in combination with current standard of care agents for acute leukemias as well as other chromatin modifying drugs in cell proliferation assays with three human acute leukemia cell lines; Molm-13 (MLL-AF9 expressing acute myeloid leukemia (AML)), MV4-11 (MLL-AF4 expressing acute biphenotypic leukemia cell line) and SKM-1 (non-MLL-rearranged AML). We established a high density combination platform suitable for testing the anti-proliferative activity of a complete titration matrix of two agents with multiple replicate points to enable generation of statistically meaningful results. This platform was used to evaluate the anti-proliferative effects of EPZ-5676 combinations tested in a co-treatment model in which the second agent was added along with EPZ-5676 at the beginning of the assay, or in a pre-treatment model in which cells were incubated for several days in the presence of EPZ-5676 prior to the addition of the second agent. The drug combination analysis was performed using the Chou-Talalay method [Chou TC Pharmacological Reviews 2006]. Graphs representing values of combination index (CI) versus Fractional effect (Fa) known as Fa-CI plots were generated and synergy was evaluated. Drug synergy was statistically defined by CI values less than 1, antagonism by CI >1 and additive effect by CI equal to 1. We found that EPZ-5676 acts synergistically with the AML standard of care agents cytarabine or daunorubicin in Molm-13 and MV4-11 MLL-rearranged cell lines. However, in the non-rearranged SKM-1 cell line EPZ-5676 had no effect alone and did not act synergistically with cytarabine or daunorubicin. Moreover, a persistent combination benefit was observed even when EPZ-5676 was washed out prior to the addition of the standard of care agents (Figure 1), suggesting that EPZ-5676 sets up a durable altered chromatin state that enhances the effect of chemotherapeutic agents in MLL-rearranged cells. We are currently exploring the mechanism of action of this synergy in more detail.Figure 1. Fa-CI plots show that EPZ-5676 and cytarabine act synergistically to induce an antiproliferative effect in the Molm-13 cell line in a pre-treatment model. (A) Ten-day continuous dosing of EPZ-5676 with addition of cytarabine at day 7 showed a range of fractional effects with CI values <1 denoting synergy. (B) EPZ-5676 was removed at day 7 prior to the addition of cytarabine showing durable combination benefit.Figure 1. Fa-CI plots show that EPZ-5676 and cytarabine act synergistically to induce an antiproliferative effect in the Molm-13 cell line in a pre-treatment model. (A) Ten-day continuous dosing of EPZ-5676 with addition of cytarabine at day 7 showed a range of fractional effects with CI values <1 denoting synergy. (B) EPZ-5676 was removed at day 7 prior to the addition of cytarabine showing durable combination benefit. Our evaluation of EPZ-5676 in conjunction with other chromatin modifying drugs also revealed a consistent combination benefit including synergy with DNA hypomethylating agents. In summary, our results indicate that EPZ-5676 is highly efficacious as a single agent and is synergistic with other anticancer agents including AML standard of care drugs and DNA hypomethylating agents in MLL-rearranged cells. Disclosures: Klaus: Epizyme, Inc.: Employment, Equity Ownership, Patents & Royalties, Stock Options Other. Daigle:Epizyme, Inc.: Employment, Equity Ownership, Patents & Royalties, Stock Options Other. Iwanowics:Epizyme, Inc.: Employment, Equity Ownership, Stock Options Other. Johnston:Epizyme, Inc: Employment, Equity Ownership, Stock Options Other. Therkelsen:Epizyme, Inc.: Employment, Equity Ownership, Stock Options Other. Smith:Epizyme, Inc.: Employment, Equity Ownership, Stock Options Other. Moyer:Epizyme, Inc.: Employment, Equity Ownership, Stock Options Other. Copeland:Epizyme Inc. : Employment, Equity Ownership, Membership on an entity’s Board of Directors or advisory committees, Patents & Royalties; Mersana: Membership on an entity’s Board of Directors or advisory committees. Olhava:Epizyme, Inc: Employment, Equity Ownership, Patents & Royalties, Stock Options Other. Porter Scott:Epizyme, Inc: Employment, Equity Ownership, Patents & Royalties, Stock Options Other. Pollock:Epizyme Inc.: Employment, Equity Ownership, Patents & Royalties, Stock Options Other. Raimondi:Epizyme, Inc: Employment, Equity Ownership, Patents & Royalties, Stock Options Other.
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Iwundu, M. P., and D. E. Nwoshopo. "Efficiency of modified central composite designs with fractional factorial replicates for five-variable nonstandard models." Scientia Africana 21, no. 1 (June 1, 2022): 195–206. http://dx.doi.org/10.4314/sa.v21i1.17.
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The efficiencies of standard central composite designs are compared with modified central composite designs on non-standard models using D- and G-efficiency criteria. Diagonal elements of the Hat matrix are utilized in the construction of the modified central composite designs. Fractional factorial replicates are used to maintain manageable design sizes. Results show that D-efficiencies of the designs decline for standard CCDs as the number of missing quadratic terms increases but increase with modified CCDs for increased number of missing quadratic terms. Similarly, G-efficiencies of the designs decline for standard CCDs as the number of missing quadratic terms increases but increase with modified CCDs for increased number of missing quadratic terms.
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Hamlin, Robert, and Benjamin Hamlin. "An Experimental Comparison of the Impact of ‘Warning’ and ‘Health Star Rating’ FoP Labels on Adolescents’ Choice of Breakfast Cereals in New Zealand." Nutrients 12, no. 6 (May 26, 2020): 1545. http://dx.doi.org/10.3390/nu12061545.
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This research investigated the performance of the red, octagonal Vienna Convention traffic ‘STOP’ sign as a front of pack (FoP) warning nutritional label. While the Vienna Convention traffic light system is an established FoP label, the potential of the ‘STOP’ sign in the role has not been investigated. The performance of the ‘STOP’ label was compared with that of a single star (low nutritional value) Australasian Health Star Rating (HSR) label using a fractionally replicated Latin square design. The labels were presented on choice diads of cold breakfast cereal packets. The sample of 240 adolescents aged 16–18 was drawn from a secondary school in the South Island of New Zealand. A large and significant main effect was observed at the p < 0.01 level for the difference between the ’STOP’ sign and the control condition (no nutritional FoP label), and at p < 0.05 for the difference between the HSR and the ‘STOP’ label. There was no significant difference between the HSR FoP and the control condition. A significant non-additivity (interaction) (p < 0.01) was also observed via the fractional replication. The results indicate that the Vienna Convention ‘STOP’ sign is worthy of further research with regard to its potential as an FoP nutritional label.
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Dormidontova, Tatiana, and Anastasiya Filatova. "Analyzing building materials and their properties in connection with the theory of experiment planning." MATEC Web of Conferences 196 (2018): 04009. http://dx.doi.org/10.1051/matecconf/201819604009.
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The task of planning an experiment can be divided into two stages: screening experiments conducting, step-by-step experiments performed on complete factorial design or on fractional replicates. As the number of publications on the practical use of plans-experiments in construction is insufficient, the paper presents appropriate recommendations in common form. Screening experiments are usually conducted with the aim of approximate orientation among many factors and for more precise future planning. These experiments can be carried out on the minimum fractional replicates making it possible to obtain the first order model. After obtaining the model, the factors that are included in it are appropriately ranked. Using the results of ranking, researchers take into account economic considerations, leave away unimportant factors and conduct experiments with remaining factors to obtain a mathematical model of the process. In order to find out the nomenclature of these factors, screening experiments are carried out. These experiments are performed to obtain an approximate dependence between the outcome of the process and the factors. This dependence is used to determine the influence that each of the factors has on the experience result. When the crucial factors are considered, it is possible to plan the basic experiment.
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Daoud, M., and M. Kibler. "Fractional supersymmetric quantum mechanics as a set of replicas of ordinary supersymmetric quantum mechanics." Physics Letters A 321, no. 3 (February 2004): 147–51. http://dx.doi.org/10.1016/j.physleta.2003.12.027.
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Zheng, Haixia, Maurizio Bergamino, Bart N. Ford, Rayus Kuplicki, Fang-Cheng Yeh, Jerzy Bodurka, Kaiping Burrows, et al. "Replicable association between human cytomegalovirus infection and reduced white matter fractional anisotropy in major depressive disorder." Neuropsychopharmacology 46, no. 5 (January 26, 2021): 928–38. http://dx.doi.org/10.1038/s41386-021-00971-1.
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AbstractMajor depressive disorder (MDD) is associated with reductions in white matter microstructural integrity as measured by fractional anisotropy (FA), an index derived from diffusion tensor imaging (DTI). The neurotropic herpesvirus, human cytomegalovirus (HCMV), is a major cause of white matter pathology in immunosuppressed populations but its relationship with FA has never been tested in MDD despite the presence of inflammation and weakened antiviral immunity in a subset of depressed patients. We tested the relationship between FA and HCMV infection in two independent samples consisting of 176 individuals with MDD and 44 healthy controls (HC) (Discovery sample) and 88 participants with MDD and 48 HCs (Replication sample). Equal numbers of HCMV positive (HCMV+) and HCMV negative (HCMV−) groups within each sample were balanced on ten different clinical/demographic variables using propensity score matching. Anti-HCMV IgG antibodies were measured using a solid-phase ELISA. In the Discovery sample, significantly lower FA was observed in the right inferior fronto-occipital fasciculus (IFOF) in HCMV+ participants with MDD compared to HCMV− participants with MDD (cluster size 1316 mm3; pFWE < 0.05, d = −0.58). This association was confirmed in the replication sample by extracting the mean FA from this exact cluster and applying the identical statistical model (p < 0.05, d = −0.45). There was no significant effect of diagnosis or interaction between diagnosis and HCMV in either sample. The effect of chronic HCMV infection on white matter integrity may—in at-risk individuals—contribute to the psychopathology of depression. These findings may provide a novel target of intervention for a subgroup of patients with MDD.
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Shah, Adil, Olivier Laurent, Luc Lienhardt, Grégoire Broquet, Rodrigo Rivera Martinez, Elisa Allegrini, and Philippe Ciais. "Characterising the methane gas and environmental response of the Figaro Taguchi Gas Sensor (TGS) 2611-E00." Atmospheric Measurement Techniques 16, no. 13 (July 5, 2023): 3391–419. http://dx.doi.org/10.5194/amt-16-3391-2023.
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Abstract. In efforts to improve methane source characterisation, networks of cheap high-frequency in situ sensors are required, with parts-per-million-level methane mole fraction ([CH4]) precision. Low-cost semiconductor-based metal oxide sensors, such as the Figaro Taguchi Gas Sensor (TGS) 2611-E00, may satisfy this requirement. The resistance of these sensors decreases in response to the exposure of reducing gases, such as methane. In this study, we set out to characterise the Figaro TGS 2611-E00 in an effort to eventually yield [CH4] when deployed in the field. We found that different gas sources containing the same ambient 2 ppm [CH4] level yielded different resistance responses. For example, synthetically generated air containing 2 ppm [CH4] produced a lower sensor resistance than 2 ppm [CH4] found in natural ambient air due to possible interference from supplementary reducing gas species in ambient air, though the specific cause of this phenomenon is not clear. TGS 2611-E00 carbon monoxide response is small and incapable of causing this effect. For this reason, ambient laboratory air was selected as a testing gas standard to naturally incorporate such background effects into a reference resistance. Figaro TGS 2611-E00 resistance is sensitive to temperature and water vapour mole fraction ([H2O]). Therefore, a reference resistance using this ambient air gas standard was characterised for five sensors (each inside its own field logging enclosure) using a large environmental chamber, where logger enclosure temperature ranged between 8 and 38 ∘C and [H2O] ranged between 0.4 % and 1.9 %. [H2O] dominated resistance variability in the standard gas. A linear [H2O] and temperature model fit was derived, resulting in a root mean squared error (RMSE) between measured and modelled resistance in standard gas of between ±0.4 and ±1.0 kΩ for the five sensors, corresponding to a fractional resistance uncertainty of less than ±3 % at 25 ∘C and 1 % [H2O]. The TGS 2611-E00 loggers were deployed at a landfill site for 242 d before and 96 d after sensor testing. Yet the standard (i.e. ambient air) reference resistance model fit based on temperature and [H2O] could not replicate resistance measurements made in the field, where [CH4] was mostly expected to be close to the ambient background, with minor enhancements. This field disparity may have been due to variability in sensor cooling dynamics, a difference in ambient air composition during environmental chamber testing compared to the field or variability in natural sensor response, either spontaneously or environmentally driven. Despite difficulties in replicating a standard reference resistance in the field, we devised an excellent methane characterisation model up to 1000 ppm [CH4] by using the ratio between measured resistance with [CH4] enhancement and its corresponding reference resistance in standard gas. A bespoke power-type fit between resistance ratio and [CH4] resulted in an RMSE between the modelled and measured resistance ratio of no more than ±1 % Ω Ω−1 for the five sensors. This fit and its corresponding fit parameters were then inverted and the original resistance ratio values were used to derive [CH4], yielding an inverted model [CH4] RMSE of less than ±1 ppm, where [CH4] was limited to 28 ppm. Our methane response model allows other reducing gases to be included if necessary by characterising additional model coefficients. Our model shows that a 1 ppm [CH4] enhancement above the ambient background results in a resistance drop of between 1.4 % and 2.0 % for the five tested sensors. With future improvements in deriving a standard reference resistance, the TGS 2611-E00 offers great potential in measuring [CH4] with parts-per-million-level precision.
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Mebel, Alexander M., Marcelino Agúndez, José Cernicharo, and Ralf I. Kaiser. "Elucidating the Formation of Ethynylbutatrienylidene (HCCCHCCC; X1A′) in the Taurus Molecular Cloud (TMC-1) via the Gas-phase Reaction of Tricarbon (C3) with the Propargyl Radical (C3H3)." Astrophysical Journal Letters 945, no. 2 (March 1, 2023): L40. http://dx.doi.org/10.3847/2041-8213/acbf41.
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Abstract The recent astronomical detection of ethynylbutatrienylidene (HCCCHCCC)—a high-energy isomer of triacetylene (HCCCCCCH) and hexapentaenylidene (H2CCCCCC)—in TMC-1 puzzled the laboratory astrophysics community since proposed reaction pathways could not synthesize the ethynylbutatrienylidene (HCCCHCCC) under cold molecular cloud conditions. Exploiting a retrosynthesis coupled with electronic structure calculations and astrochemical modeling, we reveal that observed fractional abundance of ethynylbutatrienylidene (HCCCHCCC) of 1.3 ± 0.2 × 10−11 can be quantitatively replicated though the barrierless and exoergic reaction of tricarbon (C3) with the resonantly stabilized propargyl radical (C3H3) after a few 105 yr—typical ages of cold molecular clouds. Our study provides persuasive evidence that previously assumed “dead” reactants such as tricarbon (C3) and the propargyl radical (C3H3) provide fundamental molecular building blocks in molecular mass growth processes leading to exotic, high-energy isomers of hydrocarbons: ethynylbutatrienylidene (HCCCHCCC).
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Rodríguez-Fernández, Daniel Ernesto, José Angel Rodríguez-León, Júlio Cesar de Carvalho, Vanete Thomaz-Soccol, José Luis Parada, and Carlos Ricardo Soccol. "Recovery of phytase produced by solid-state fermentation on citrus peel." Brazilian Archives of Biology and Technology 53, no. 6 (December 2010): 1487–96. http://dx.doi.org/10.1590/s1516-89132010000600026.
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The extraction of phytase produced by solid-state fermentation of citrus peel was studied employing a multistage leaching process. It was observed that the extracts containing EDTA retained over 90% of phytase activity at room temperature after 24 h after the leaching. A fractional design 2² (with 4 replicates at the central point) was carried out for testing the pH and agitation as process independent factors. Only the interaction between the pH and agitation showed a significant influence. These factors were optimized with a central composite design. Agitation at 300 rpm and pH at 5.0 were the best conditions to extract the enzyme from solid matrix. The modeling of the process indicated that diffusivity of the enzyme in the solvent was the controlling mechanism. The corresponding kinetic constant and saturation concentration in this process were 0.89 min-1 and 4.0 IU/mL, respectively. The multistage process indicated that after two steps, it was possible to recover 85% of total enzyme produced.
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Besseris, George. "Multi-factorial Lean Six Sigma product optimization for quality, leanness and safety." International Journal of Lean Six Sigma 5, no. 3 (July 29, 2014): 253–78. http://dx.doi.org/10.1108/ijlss-06-2013-0033.
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Purpose – The purpose of this study is to provide a method for Lean Six Sigma (LSS) improvement projects that may aid LSS practitioners to plan and conduct robust and lean product/process optimization studies for complex and constrained products, such as those encountered in food industry operations. Design/methodology/approach – The technique is to be used for replicated LSS product experimentation on multiple effects elicited on several product traits. The authors compress replicated information reducing each response to simpler lean and robust median and range response components. Then, the desirability method is utilized to optimize concurrently location and dispersion contributions. Findings – The suggested method is demonstrated with a case study drawn from the area of food development where cocoa-cream filling for a large-scale croissant production operation undergoes a robust screening on two crucial characteristics – viscosity and water activity – that influence product and process performance as well as product safety. Originality/value – The proposed method amalgamates concepts of fractional factorial designs for expedient experimentation along with robust multi-factorial inference methods easily integrated to the desirability function for determining significant process and product effects in a synchronous multi-characteristic improvement effort. The authors show that the technique is not hampered by ordinary limitations expected with mainstream solvers, such as MANOVA. The case study is unique because it brings in jointly lean, quality and safety aspects of an edible product. The showcased responses are unique because they influence both process and product behavior. Lean response optimization is demonstrated through the paradigm.
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Talukdar, Isita Nandana, Virginia Anne Kowal, Binbin Huang, and Charlotte Weil. "Vegetation Drastically Reduces Wind Erosion: An Implementation of the RWEQ in the Mongolian Gobi Steppe." Land 11, no. 8 (July 30, 2022): 1204. http://dx.doi.org/10.3390/land11081204.
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Soil loss prevention is an important ecosystem service for protecting human and environmental health. Using spatiotemporal climate and environmental data of the Eastern Gobi Steppe, a region missing from previous studies of Mongolian wind-based soil erosion, we implemented the Revised Wind Erosion Equation (RWEQ) model to estimate soil loss. A replicable pipeline was developed to perform these computations, and made available openly. Soil loss was estimated on a monthly basis to analyze seasonal variations. The results show that the annual total soil loss was 61 × 1010 kg over an area of 69.3 × 103 km2, which is about 90 tonnes per hectare. Increasing fractional vegetation coverage to a uniform 50% coverage (doubling current vegetation coverage in every 1 km2) could reduce soil loss by 60%, highlighting the importance of protecting and increasing vegetation coverage in ecosystem service preservation.
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Vågen and Winowiecki. "Predicting the Spatial Distribution and Severity of Soil Erosion in the Global Tropics using Satellite Remote Sensing." Remote Sensing 11, no. 15 (July 31, 2019): 1800. http://dx.doi.org/10.3390/rs11151800.
Full textAbstract:
Soil erosion has long been recognized as a major process of land degradation globally, affecting millions of hectares of land in the tropics and resulting in losses in productivity and biodiversity, decreased resilience of both marine and terrestrial ecosystems, and increased vulnerability to climate change. This paper presents an assessment of the extent of soil erosion in the global tropics at a moderate spatial resolution (500 m) based on a combination of systematic field surveys using the Land Degradation Surveillance Framework (LDSF) methodology and Earth observation data from the Moderate Resolution Imaging Spectroradiometer (MODIS) platform. The highest erosion prevalence was observed in wooded grassland, bushland, and shrubland systems in semi-arid areas, while the lowest occurrence was observed in forests. Observed erosion decreased with increasing fractional vegetation cover, but with high rates of erosion even at 50–60% fractional cover. These findings indicate that methods to assess soil erosion need to be able to detect erosion under relatively dense vegetation cover. Model performance was good for prediction of erosion based on MODIS, with high accuracy (~89% for detection) and high overall precision (AUC = 0.97). The spatial predictions from this study will allow for better targeting of interventions to restore degraded land and are also important for assessing the dynamics of land health indicators such as soil organic carbon. Given the importance of soil erosion for land degradation and that the methodology gives robust results that can be rapidly replicated at scale, we would argue that soil erosion should be included as a key indicator in international conventions such as the United Nations Convention to Combat Desertification.
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Nunes, João A. S., Edna M. Bonfim-Silva, and Tonny J. A. da Silva. "Bulk density and water tensions in the soil on corn root production." Revista Brasileira de Engenharia Agrícola e Ambiental 20, no. 4 (April 2016): 357–63. http://dx.doi.org/10.1590/1807-1929/agriambi.v20n4p357-363.
Full textAbstract:
ABSTRACT Inadequate management of soil and water can cause changes in soil physical characteristics, resulting in lower root development. Thus the objective of the present study was to evaluate the dry matter production of corn roots under combinations of levels of bulk density and water tension in the soil. The experiment was conducted in a greenhouse in a randomized block design, based on a modified central composite design of a 52 fractional factorial scheme, of combinations of bulk densities (1.0, 1.2, 1.4, 1.6 and 1.8 Mg m-3) and water tensions in the soil (10, 20, 30 40 and 50 kPa), resulting in 13 treatments with four replicates. An Oxisol collected in the layer of 0-0.2 m was used. The pots were made of PVC (polyvinyl chloride) tube with compacted soil in the middle layer. The tensiometers were installed at a depth of 0.15 m, remaining in the central region of the compacted layer. The experiment was collected 104 days after sowing. Root dry matter production of corn was limited by increased water stress and bulk density.