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In this paper, a penalty-based cell vertex finite volume method (P-CV-FVM) is proposed for the computation of two-dimensional contact problems. The deformation of objects during contact is described using the Total Lagrangian momentum equation. The governing equations are discretized using the cell vertex finite volume method. The control volume is constructed around each grid node to facilitate the efficient and accurate calculation of contact stress using penalty functions. By analyzing a classic contact example, the appropriate range of scaling factors in the penalty function method is obtained. Multiple contact problems are calculated and the results are compared with those from the finite element method (FEM). The results indicate that a stable and accurate solution can only be obtained with a scaling factor range of 103–1012 under this method. In addition, the mesh convergence of this method is better than that of FEM, and it meets the computational accuracy of Hertz contact and frictional contact problems. [ABSTRACT FROM AUTHOR]

This manuscript introduces the concept of scaling factors for rotational constants. These factors are designed to bring computed equilibrium rotational constants closer to experimentally fitted ground-state-averaged rotational constants. The parameterization of the scaling factors was performed for several levels of theory, namely DF-Dn/def2-mVP ( DF = B 3 LYP , PBE 0 , n = 3 (BJ) , 4 , m = S , TZ ), PBEh-3c, and r ⁢ 2 SCAN-3c. The obtained scaling factors systematically improved the consistency between the theoretical and experimental rotational constants. [ABSTRACT FROM AUTHOR]

It is reported in the literature that the load-carrying capacity of the reinforced sand bed increases with increasing the footing settlement. However, the nature of settlement plays a critical role in shallow foundation designs due to the conditional allowable settlement of the footings. In this present study, laboratory model tests have been performed on a model jute geotextile reinforced sand bed under 1g condition. The associated scaling laws are adopted for the geometrical parameters of the model footing and reinforcements as proposed in the literature. On the other hand, a new approach has been developed for the model reinforcements for scaling down of geosynthetic materials under 1g condition to simulate the condition of geosynthetic reinforcement layers as in the field or Ng conditions. The test results revealed that based on the scaling factors the model footing can be allowed to settle according to the criteria of footing settlement and allowable reinforcement tensile strains. Finally, the suitable guidelines have also been developed as per the safety considerations in order to understand the effect of reinforcement layers on the improvement of soil bearing capacity ratio (BCR) up to a certain settlement ratio (s/D) of the footing. [ABSTRACT FROM AUTHOR]

Spectral unmixing (SU) is a significant preprocessing task for handling hyperspectral images (HSI), but its process is affected by nonlinearity and spectral variability (SV). Currently, SV is considered within the framework of linear mixing models (LMM), which ignores the nonlinear effects in the scene. To address that issue, we consider the effects of SV on SU while investigating the nonlinear effects of hyperspectral images. Furthermore, an augmented generalized bilinear model is proposed to address spectral variability (abbreviated AGBM-SV). First, AGBM-SV adopts a generalized bilinear model (GBM) as the basic framework to address the nonlinear effects caused by second-order scattering. Secondly, scaling factors and spectral variability dictionaries are introduced to model the variability issues caused by the illumination conditions, material intrinsic variability, and other environmental factors. Then, a data-driven learning strategy is employed to set sparse and orthogonal bases for the abundance and spectral variability dictionaries according to the distribution characteristics of real materials. Finally, the alternating direction method of multipliers (ADMM) optimization method is used to split and solve the objective function, enabling the AGBM-SV algorithm to estimate the abundance and learn the spectral variability dictionary more effectively. The experimental results demonstrate the comparative superiority of the AGBM-SV method in both qualitative and quantitative perspectives, which can effectively solve the problem of spectral variability in nonlinear mixing scenes and to improve unmixing accuracy. [ABSTRACT FROM AUTHOR]

[Display omitted] • Rapid development of membrane scaling for PW desalination technologies was revealed. • The pretreatment, operation conditions and membrane properties influenced scaling. • Occurrence and control of membrane scaling for desalination of PW were summarized. • FO showed more excellent scaling resistance in treating PW compared MD and RO. • Effect of organic fouling on scaling varied obviously with various membrane processes. As a byproduct of oil and gas (O&G) extraction, large volumes of produced water (PW) with complex compositions have a potential threat if they are not appropriately managed. Although membrane technologies are promising approaches for PW desalination, the widespread application of membrane desalination technologies is significantly hindered by fouling and inorganic scaling. The research interest in membrane scaling has been proven by the growing number of literature with an average annual growth rate of 17 %. Inorganic scaling was impacted by various factors, mainly including operation conditions, membrane properties and pretreatments. Thus, the review summarized the latest research on inorganic scaling during PW treatment using membrane distillation (MD), forward osmosis (FO) and nanofiltration/reverse osmosis (NF/RO), focusing on these influencing factors. Moreover, FO showed the best resistance performance of inorganic scaling in PW treatment by comparing MD, FO and RO/NF processes. Finally, the trade-off between scaling mitigation behaviors and permeate flux, exploring the effect of fouling on scaling, and studying the unknown risks of chemical agents on desalination could be regarded as future research directions. It is beneficial for the large market prospects of membrane processes in PW treatment by addressing membrane scaling. [ABSTRACT FROM AUTHOR]

In this work, a new methodology for the dynamic analysis of non-linear systems is developed by applying the Mamdani fuzzy model. With this model, parameters such as settling time, peak time and overshoot will be obtained. The dynamic analysis of non-linear fuzzy systems with triangular membership functions is performed, and linguistic variables describing overly complex or ill-defined phenomena are used to fit the model. Scaling factors will simplify the modification of the variables, making them easier to find the system model. The specifications of second-order characteristics in the time domain, such as overshoot and peak time, will be represented graphically. As a case study, the proposed methods are implemented to analyse the dynamics of a tank and a simple pendulum for first-order and second-order systems, respectively, where it is observed that the proposed methodology offers highly positive results. [ABSTRACT FROM AUTHOR]

Here we use observations and simulations from 40 global climate models from phase 5 of the Coupled Model Intercomparison Project (CMIP5), under preindustrial, historical, and a high emission scenario (RCP8.5) to provide estimates of Victorian cool season (April–October) rainfall for the coming century. This includes a new method which exploits recent research that estimated the relative contribution of external forcing and natural variability to the observed multidecadal decline in cool season rainfall in Victoria from 1997. The new method is aimed at removing the influence of external forcing on Victoria's cool-season rainfall, effectively rendering a stationary time-series. The resulting historical record is then modified by scaling derived from the mean projected change evident in climate models out to 2100. The results suggest that the median value of the All-Victoria rainfall PDF will decrease monotonically over the remainder of the twenty-first century under RCP8.5. The likelihood that All-Victoria rainfall in any given year from 2025 onward will be below the observed 5th percentile of the observations (291 mm) increases monotonically, becoming three times larger by the end of the century. The new method is assessed using cross-validation and its ability to hindcast observed multidecadal rainfall change. The latter indicates that CMIP5 models poorly replicate recent interdecadal rainfall change. So, while we have more confidence in the new method because it accounts for the non-stationarity in the observed climate, limitations in the CMIP5 models results in us having low confidence in the reliability of the estimated future rainfall distributions. [ABSTRACT FROM AUTHOR]

How do species coexist? A framework known as modern coexistence theory can 'measure coexistence' by partitioning invasion growth rates into coexistence mechanisms, terms which correspond to classes of explanations for coexistence. There are several reasonable ways to define coexistence mechanisms, each depending on exactly how a species perturbed to low density (the invader) is compared to other species that remain at their typical densities (the residents). Using conceptual arguments and two case studies, we compare five methods for calculating coexistence mechanisms: 1) scaling factors, the traditional approach which attempts to eliminate the linear effects of regulating factors; 2) the simple comparison, which gives equal weight to all resident species; 3) generation time scaling, a novel method which corrects for intrinsic differences in population‐dynamical speed; 4) β scaling, where resident growth rates are scaled by a measure of relative sensitivity to competition; and 5) the invader–invader comparison, a previously obscure method in which a focal species is compared to itself at high versus low density. We find that the conventional scaling factors can lead to nonsensical results when species have strong and asymmetric niche differences; though scaling factors can be useful in certain theoretical studies, they are not recommended for explaining coexistence in real communities. Invader–invader comparisons are also problematic, as they do not effectively measure specialization or niche differentiation. The universally‐applicable simple comparison often works well, but can give counterintuitive results when species have disparate generation times. The β scaling method often works well in simple models, but faces implementation problems in complex models. We tentatively recommend generation time scaling as the all‐purpose method for calculating coexistence mechanisms. [ABSTRACT FROM AUTHOR]

Generally, most existing super-resolution (SR) methods do not consider noise, which treats SR reconstruction and denoising as two separate problems and performs separately. However, noise is inevitably introduced in the imaging process. Based on analysis of the degraded model, in this paper, the problems of interpolation and denoising are modeled to estimate the noiseless and missing images under the same framework. By applying local fractal dimension (LFD) into image local feature analysis, a noisy single-image SR method is proposed. For each noisy image, we first construct a rational fractal interpolation model containing scaling factors, which can effectively maintain the inherent properties of the data. Furthermore, the original image structure can be well preserved by applying the interpolation model. Considering the local characteristics of the image, scaling factors are calculated on the basis of the LFDs. Then, through further local feature analysis of the interpolated image, a denoising method based on LFD is proposed for recovering a noiseless image. Finally, a high-quality high-resolution image is obtained. Experimental results demonstrate that our method outperforms the state-of-the-art methods both quantitatively and qualitatively.

Vibrational frequency calculations performed under the harmonic approximation are widespread across chemistry. However, it is well‐known that the calculated harmonic frequencies tend to systematically overestimate experimental fundamental frequencies; a limitation commonly overcome with multiplicative scaling factors. In practice, multiplicative scaling factors are derived for each individual model chemistry choice (i.e., a level of theory and basis set pair), where performance is judged by, for example, the root‐mean square error (RMSE) between the predicted scaled and experimental frequencies. However, despite the overwhelming number of scaling factors reported in the literature and model chemistry approximations available, there is little guidance for users on appropriate model chemistry choices for harmonic frequency calculations. Here, we compile and analyze the data for 1495 scaling factors calculated using 141 levels of theory and 109 basis sets. Our meta‐analysis of this data shows that scaling factors and RMSE approach convergence with only hybrid functionals and double‐zeta basis sets, with anharmonicity error already dominating model chemistry errors. Noting inconsistent data and the lack of independent testing, we can nevertheless conclude that a minimum error of 25 cm−1—arising from insufficiently accurate treatment of anharmonicity—is persistent regardless of the model chemistry choice. Based on the data we compiled and cautioning the need for a future systematic benchmarking study, we recommend ωB97X‐D/def2‐TZVP for most applications and B2PLYP/def2‐TZVPD for superior intensity predictions. With a smaller benchmark set, direct comparison prefers ωB97X‐D/6‐31G* to B3LYP/6‐31G*. This article is categorized under:Electronic Structure Theory > Density Functional TheoryTheoretical and Physical Chemistry > Spectroscopy [ABSTRACT FROM AUTHOR]

Abstract Background With the explosion in the number of methods designed to analyze bulk and single-cell RNA-seq data, there is a growing need for approaches that assess and compare these methods. The usual technique is to compare methods on data simulated according to some theoretical model. However, as real data often exhibit violations from theoretical models, this can result in unsubstantiated claims of a method’s performance. Results Rather than generate data from a theoretical model, in this paper we develop methods to add signal to real RNA-seq datasets. Since the resulting simulated data are not generated from an unrealistic theoretical model, they exhibit realistic (annoying) attributes of real data. This lets RNA-seq methods developers assess their procedures in non-ideal (model-violating) scenarios. Our procedures may be applied to both single-cell and bulk RNA-seq. We show that our simulation method results in more realistic datasets and can alter the conclusions of a differential expression analysis study. We also demonstrate our approach by comparing various factor analysis techniques on RNA-seq datasets. Conclusions Using data simulated from a theoretical model can substantially impact the results of a study. We developed more realistic simulation techniques for RNA-seq data. Our tools are available in the seqgendiff R package on the Comprehensive R Archive Network: https://cran.r-project.org/package=seqgendiff .

Introduction: Water is the reference medium for electron beam calibration and quality assurance purposes. Nevertheless, chamber - positioning uncertainties in near surface regions, employing non - waterproof dosimeters, etc. may impose some limitations on employing water phantoms in certain conditions. Here, it is allowed to use water - equivalent plastic phantoms instead of water, provided that specific scaling factors (depth scaling (cpl) and fluence scaling (hpl)) be carefully measured for intended solid phantom. cpl and hpl for a new solid phantom, know as RW3, have been measured for different clinical electron energies in the current study. Methods: RW3 solid phantom was irradiated by nominal electron energies of 4, 6, 9, 12, and 16 MeV produced by a Varian Trilogy clinic. The same irradiations were also repeated in water to determine cpl and hpl values at corresponding electron energies following the recommendations of TRS - 398 dosimetry protocol. The validity of measured scaling factors were evaluated through comparing the in - water and in - plastic measured PDD curves. Advanced Markus ionization chamber was used for ionometric measurements. Results: Cpl values at 4, 6, 9, 12, and 16 MeV electron energies were respectively found as 0.915, 0.927, 0.934, 0.937, and 0.937. hpl values were dependent on electron energy and measurement depth. Measured PDD curves inside the water were in accordance with those indirectly acquired inside the plastic phantom, so that the observed deviations among corresponding PDD curves at different electron energies was less than 1.2%. Conclusions: cpl and hpl scaling factors were practically determined for a new solid phantom at different clinical electron energies. The validity of reported scaling factors was confirmed regarding the favorable accordance of in - water and in - plastic measured PDD curves. Therefore, these scaling factors can be reliably applied to mimic the water dosimetry results through indirect electron measurement inside the RW3 plastic phantom. [ABSTRACT FROM AUTHOR]

Previously unknown IR spectra of 2-nitrosopyridines 1-3 were recorded in the solid phase after cryogenic photolysis of their dimers, and identified by the comparison with the corresponding theoretical spectra. Optimal results were obtained with double-hybrid (DH) density functionals and def2-TZVP basis set, the best being DSD-PBEP86-D3(BJ), B2GP-PLYP-D3(BJ) and mPW2-PLYP-D2. Experimental frequencies were obtained by scaling harmonic frequencies with appropriate scaling factors, either taken from the literature or calculated using modified HFREQ2014 dataset. In the case of DH functionals, anharmonic frequencies do not offer any advantage in comparison with the scaled harmonic ones. Unexpectedly, all non-DH density functionals, including highly praised ωB97X-V and ωB97M-V, have serious problems with normal modes containing N=O bond stretching vibration. It was concluded that the origin of the problem is in the nitroso group itself, most likely caused by its multireference character. The best results among non-DH functionals were achieved at TPSSh-D3(BJ)/def2-TZVP level of theory. [ABSTRACT FROM AUTHOR]

In this paper, a compact vectored thruster based on a composite gear train is proposed. First, the space transformation between different coordinate systems is carried out, and the mathematical model of the vectored thruster is established, according to classical navigation mechanics theory. Then, the swing and roll motion analysis of the composite gear train is implemented, and the motion relationship of the whole thruster structure is analyzed systematically. Moreover, SolidWorks and MATLAB software are used for simulation to verify the accuracy of the mathematical model. In addition, the trajectories of the propeller shaft under different motion modes are analyzed and compared. Finally, the dynamic analysis of the vectored thruster is carried out, and the change trend of the scaling factors of the vector thrust components with the swing angle δ and the roll angle χ is studied, and comparison with the scaling factors of the vectored water jet propeller presented in other literature is taken into account. To endow the thruster with superior maneuverability, the fairwater structure of the vectored thruster is optimized, and the lateral vector component of the optimized vectored thruster is greatly increased. [ABSTRACT FROM AUTHOR]

Purpose: The inclusion of insect protein into the food system has been proposed as a promising solution to ensure future food security and mitigate negative environmental impacts related to food production. However, the market volume for edible insects in Europe is still small; consequently, producers need a decision-support system to ensure the sustainable upscaling of the sector. The study analyzed environmental and economic impacts of insect production to identify the most eco-efficient production scenarios. Methods: A novel modular eco-efficiency assessment approach was developed to analyze the production of dried Hermetia illucens larvae. An exemplary, industrial-scale insect production system was disaggregated into a total of 29 module variants that can be combined into 4608 distinct production scenarios, which are characterized by different feeds, energy efficiencies, and processing technologies. Environmental life cycle and cost assessments were carried out for each module variant, and eco-efficiency assessment was used to jointly assess these two sustainability dimensions. Additionally, the influence of the insect feed on the production system performance and impact was investigated by employing feed-specific scaling factors. These were used to aggregate module results into production scenario results. Results and discussion: The most eco-efficient production scenarios include energy-efficient rearing facilities that rely on blanching and microwave drying for processing. The insect feed is the largest contributor to the environmental impacts and costs, but from an eco-efficiency standpoint, the choice of feed might not be crucial. Waste-type feeds (e.g., manure, fruit, and vegetable waste) have low environmental impacts and costs, but the production scenarios based on these feeds are less efficient. The low impacts of the feed are offset by higher impacts during the rearing and processing stages. Conversely, scenarios based on higher quality feeds (e.g., by-products like wheat middlings or distiller's grains) require less resources, but the initial feed impacts and costs are higher. Moreover, of the feed types studied, only highly processed ones, such as compound chicken feed, should be avoided for insect rearing. Conclusions: The developed modular assessment approach is efficient in assessing multiple potential insect production scenarios. It can be adapted to incorporate additional variations of the production system via additional modules. Limitations include the potential for redundant module combinations and the up-front time investment needed. Finally, the results are sensitive to methodological choices: thus, these should be carefully considered and communicated during the design of the modular assessment system. [ABSTRACT FROM AUTHOR]

This review is a summary of factors affecting the drug pharmacokinetics (PK) of dogs versus humans. Identifying these interspecies differences can facilitate canine-human PK extrapolations while providing mechanistic insights into species-specific drug in vivo behavior. Such a cross-cutting perspective can be particularly useful when developing therapeutics targeting diseases shared between the two species such as cancer, diabetes, cognitive dysfunction, and inflammatory bowel disease. Furthermore, recognizing these differences also supports a reverse PK extrapolations from humans to dogs. To appreciate the canine-human differences that can affect drug absorption, distribution, metabolism, and elimination, this review provides a comparison of the physiology, drug transporter/enzyme location, abundance, activity, and specificity between dogs and humans. Supplemental material provides an in-depth discussion of certain topics, offering additional critical points to consider. Based upon an assessment of available state-of-the-art information, data gaps were identified. The hope is that this manuscript will encourage the research needed to support an understanding of similarities and differences in human versus canine drug PK. [ABSTRACT FROM AUTHOR]

Imperceptible, robust, and embedding capacity are three main requirements for the steganography of digital audio signal. To enhance them, this study presents a novel steganography for digital audio signal in the wavelet domain. Since the performance of imperceptible and robust are usually in term of signal-to-noise ratio (SNR) and bit-error-rate (BER), we propose a quantization-based optimization model to maximize SNR and reduce BER in embedding secret message. In the proposed model, quantization technique with unknow coefficients of discrete wavelet transform (DWT) is rewritten as the first constraint. The adjustment of scaling DWT coefficients is considered as the second constraint. At the same time, signal-to-noise ratio (SNR) is converted into a performance index. In solving this model, we use matrix operations and Lagrange multiplier to obtain optimal DWT coefficients and scaling factors. Moreover, the invariant feature of the scaling factors against amplitude scaling attack is proved. In extraction, secret message can be detected without original audio signal. Experimental results show that the proposed steganography has high SNR and strong robustness against many malicious attacks when comparing to some exiting methods. [ABSTRACT FROM AUTHOR]

AC vector magnetometers have recently become increasingly widespread. The calibration of ac vector magnetometers before use is critical. Based on traditional ellipsoid fitting, which is suitable for calibrating dc vector magnetometers, a method suitable for calibrating ac vector magnetometers is presented. Simulation analysis and experimental verification demonstrate that this method is effective in calibrating ac vector magnetometers, including scaling factors, angular misalignments, and offset errors. [ABSTRACT FROM AUTHOR]

In this article, we consider the problem of finding zeros of monotone inclusions of three operators in real Hilbert spaces, where the first operator's inverse is strongly monotone and the third is linearly composed, and we suggest an extended splitting method. This method allows relative errors and is capable of decoupling the third operator from linear composition operator well. At each iteration, the first operator can be processed with just a single forward step, and the other two need individual computations of the resolvents. If the first operator vanishes and linear composition operator is the identity one, then it coincides with a known method. Under the weakest possible conditions, we prove its weak convergence of the generated primal sequence of the iterates by developing a more self-contained and less convoluted techniques. Our suggested method contains one parameter. When it is taken to be either zero or two, our suggested method has interesting relations to existing methods. Furthermore, we did numerical experiments to confirm its efficiency and robustness, compared with other state-of-the-art methods. [ABSTRACT FROM AUTHOR]

Purpose: The microstructure of a given soil is neither unique nor fixed as it evolves during deformation of the soil. Quantitative characterization of the microstructural evolution is crucial for interpretation of the soil mechanical behavior and development of the mechanical model taking account of the structural effect. This study aims to investigate the pore-size distribution (PSD) evolution of a compacted loess during deformation associated with consolidation and shearing. Materials and method: The studied loess was a low-plasticity clay and collected from Xi'an, China. Compacted loess specimens having the same initial condition were loaded in triaxial cells to different final stress–strain states. Investigations of the initial and final microstructures were carried out using the mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM) techniques. The PSD evolution during consolidation was examined by comparing the PSDs of the specimens consolidated to different confining stresses, and the PSD evolution during shearing was examined by comparing the PSDs of the specimens sheared at the same confining stress to a series of increasing axial strains. Results and discussion: Inter-aggregate pores (those greater than 1 μm in particular) were compressed from the larger to the smaller as the soil specimen contracts, intra-aggregate pores were almost unaffected, irrespective of the stress path. According to these findings, the inter-aggregate pore-size density function (PSDF) evolution is suggested to be depicted using two scaling factors (α and β). The inter-aggregate PSDF is assumed as a normal distribution function for simplicity and the empirical relationship between the cumulative intrusion void ratio, ein, and the dominant macro pore diameter, dmacro, is used, α and β can be related to ein. Thus, the PSD of compacted loess in any deformed state can be predicted from the reference PSD provided that ein in the deformed state is estimated by a mechanical model. Conclusions: Aggregates would not be destroyed due to loading, and the mechanical responses of compacted loess are the interactions among aggregates. The proposed model assumes the inter-aggregate PSDF scales along the horizontal axis, which is consistent with the experimental findings; and it provides a simple way to predict the PSD variation using two scaling factors. [ABSTRACT FROM AUTHOR]

Background: With the explosion in the number of methods designed to analyze bulk and single-cell RNA-seq data, there is a growing need for approaches that assess and compare these methods. The usual technique is to compare methods on data simulated according to some theoretical model. However, as real data often exhibit violations from theoretical models, this can result in unsubstantiated claims of a method's performance. Results: Rather than generate data from a theoretical model, in this paper we develop methods to add signal to real RNA-seq datasets. Since the resulting simulated data are not generated from an unrealistic theoretical model, they exhibit realistic (annoying) attributes of real data. This lets RNA-seq methods developers assess their procedures in non-ideal (model-violating) scenarios. Our procedures may be applied to both single-cell and bulk RNA-seq. We show that our simulation method results in more realistic datasets and can alter the conclusions of a differential expression analysis study. We also demonstrate our approach by comparing various factor analysis techniques on RNA-seq datasets. Conclusions: Using data simulated from a theoretical model can substantially impact the results of a study. We developed more realistic simulation techniques for RNA-seq data. Our tools are available in the seqgendiff R package on the Comprehensive R Archive Network: https://cran.r-project.org/package=seqgendiff. [ABSTRACT FROM AUTHOR]

Complex-valued gradient descent algorithm is a popular tool to optimize functions of complex variables, especially for the training of complex-valued neural networks. However, the choice of suitable learning stepsize is a challenging task during the training process. In this paper, an adaptive complex-valued stepsize design method is proposed for complex-valued neural networks by generalizing the adaptable learning rate tree technique to the complex domain. The scaling and rotation factors are introduced to simultaneously adjust the amplitude and phase of complex-valued stepsize. The search range is thus expanded from half line to half plane such that better search direction is obtained at each iteration. We analyze the dynamics of the algorithm near a saddle point and find that it is very easy to escape from the saddle point to guarantee fast convergence and high accuracy. Some experimental results on function approximation and pattern classification tasks are presented to illustrate the advantages of the proposed algorithm over some previous ones. [ABSTRACT FROM AUTHOR]

The model of Regularized Quantum Mechanical Force Field (RQMFF) was applied to the joint treatment of ab initio and experimental vibrational data of the four primary nucleobases using a new algorithm based on the scaling procedure in Cartesian coordinates. The matrix of scaling factors in Cartesian coordinates for the considered molecules includes diagonal elements for all atoms of the molecule and off-diagonal elements for bonded atoms and for some non-bonded atoms (1–3 and some 1–4 interactions). The choice of the model is based on the results of the second-order perturbation analysis of the Fock matrix for uncoupled interactions using the Natural Bond Orbital (NBO) analysis. The scaling factors obtained within this model as a result of solving the inverse problem (regularized Cartesian scale factors) of adenine, cytosine, guanine, and thymine molecules were used to correct the Hessians of the canonical base pairs: adenine–thymine and cytosine–guanine. The proposed procedure is based on the block structure of the scaling matrix for molecular entities with non-covalent interactions, as in the case of DNA base pairs. It allows avoiding introducing internal coordinates (or coordinates of symmetry, local symmetry, etc.) when scaling the force field of a compound of a complex structure with non-covalent H-bonds.

The calculation of denudation rates from the measured cosmogenic nuclide concentrations in river sediments requires assumptions and approximations. Several different approaches and numerical tools are available in the literature. A widely used analytical approach represents the muogenic production with one or two exponentials, assumes the attenuation length of muons to be constant and also neglects temporal variations in the Earth's magnetic field. The denudation rates are then calculated directly and analytically from the measured concentrations. A second numerical and iterative approach was more recently proposed and considers a more rigorous muogenic production law based on pre‐calculated variable attenuation length of muons and accounts for temporal changes of the magnetic field. It also assumes a specific distribution of denudation rates throughout the basin and uses an iterative approach to calculate the basin average denudation rates. We tested the two approaches across several natural basins and found that both approaches provide similar denudation results. Hence, assuming exponential muogenic production and constant attenuation length of muons in the rock has little impact on the derived denudation rates. Therefore, unless a priori known distributions of denudation rates are to be tested, there does not appear to be any particular gain from using the second iterative method which is computationally less effective. Based on these findings, we developed and describe here Basinga, a new ArcGIS® and QGIS toolbox which computes the basin average scaling factors, cosmogenic production rates and denudation rates for several tens of drainage basins together. Basinga follows either the Lal/Stone or the Lifton/Sato/Dunai scaling schemes and includes several optional tools for correcting for topographic shielding, ice cover and lithology. We have also developed an original method for correcting the cosmogenic production rates for past variations in the Earth's magnetic field. © 2019 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

We present the new computational procedure for the fitting ab initio molecular force fields represented in Cartesian coordinates to the experimental frequencies with inclusion data for isotopic species and symmetry constraints. This procedure is based on the original numerical algorithms developed within theory of regularization of ill-posed problems and included in the software package SPECTRUM. New procedure allows organize the synthesis of molecular force field of the target molecule from the matrices in Cartesian coordinates of corresponding patterns and to avoid difficulties with introducing internal coordinates for a case of complicated molecules, so appears beneficial for fitting vibrational spectra of the large molecular systems, when only moderately accurate quantum chemistry methods may be applied. In this work, an earlier suggested algorithm for scaling force matrices in Cartesian coordinates has been extended to allow direct reduction by symmetry and simultaneous use of the experimental data on several isotopic species of a molecule. The molecules of pyrrole and indole (typical fragments of biological molecules) were chosen to demonstrate the efficiency of scaling procedure in Cartesian coordinates with symmetry constraints. [ABSTRACT FROM AUTHOR]

Biotransformation rates extrapolated from in vitro data are used increasingly in human physiologically based pharmacokinetic (PBPK) models. This practice requires use of scaling factors, including microsomal content (mg of microsomal protein/g liver, MPPGL), enzyme specific content, and liver mass as a fraction of body weight (FVL). Previous analyses indicated that scaling factor variability impacts pharmacokinetic (PK) outcomes used in adult population dose-response studies. This analysis was extended to pediatric populations because large inter-individual differences in enzyme ontogeny likely would further contribute to scaling factor variability. An adult bromodichloromethane (BDCM) model (Kenyon, E. M. Eklund, C. Leavens, T. L. and Pegram, R. A. (2016a). Development and application of a human PBPK model for bromodichloromethane (BDCM) to investigate impacts of multi-route exposure. J. Appl. Toxicol. 36, 1095–1111) was re-parameterized for neonates, infants, and toddlers. Monte Carlo analysis was used to assess the impact of pediatric scaling factor variation on model-derived PK outcomes compared with adult findings. BDCM dose metrics were estimated following a single 0.05-liter drink of water or a 20-min bath, under typical (5 µg/l) and plausible higher (20 µg/l) BDCM concentrations. MPPGL, CYP2E1, and FVL values reflected the distribution of reported pediatric population values. The impact of scaling factor variability on PK outcome variation was different for each exposure scenario, but similar for each BDCM water concentration. The higher CYP2E1 expression variability during early childhood was reflected in greater variability in predicted PK outcomes in younger age groups, particularly for the oral exposure route. Sensitivity analysis confirmed the most influential parameter for this variability was CYP2E1, particularly in neonates. These findings demonstrate the importance of age-dependent scaling factor variation used for in vitro to in vivo extrapolation of biotransformation rates. [ABSTRACT FROM AUTHOR]

Abstract The article presents the results of modeling of the contamination of primary circuit of WWER-440 type reactor. The modeling has been performed using the OSCAR computer code (Nuclear research Centre in Cadarache, CEA, France), version V1.3 for decommissioning of nuclear power plants, taking into account the peculiarities of the WWER-440 reactor primary circuit, such as geometry, volumes, operational regime, materials. The results have been analyzed in the light of the scaling factor approach with the aim to demonstrate the modeling capabilities to identify the possibility of scaling factor application and to reproduce the activity correlation between difficult to measure and key nuclides. Calculated scaling factors for corrosion products are comparable with the ones of other nuclear power plants. Calculation results of surface activity contamination confirmed the applicability of 60Co as a key radionuclide. Highlights • Contamination modeling by OSCAR code (CEA France) of reactor primary circuit. • Nuclide surface activities analyzed by scaling factor approach for decommissioning. • The good correlation of key and difficult to measure nuclides predicted and analyzed. • The modeling can be used for identification of places for surface activity sampling. [ABSTRACT FROM AUTHOR]

1. Scaling factor values for the in vitro-in vivo extrapolation of hepatic metabolic clearance for xenobiotics have not yet been determined in horses. Scaling factors were determined by comparing the total protein and or cytochrome (CYP) P450 content in microsomes and cryopreserved hepatocytes against the content in the liver. 2. Microsomal protein per gram of liver (MPPGL) and hepatocellularity number per gram of liver (HPGL) using CYP P450 content method ranged 41-73 mg/gram of liver (mean = 57 mg/gram of liver, n = 39) and 146-320 x 106 cells/g of liver (mean = 227 x 106 cells/g of liver, n = 18), respectively and 156-352 x 106 cells/g of liver (mean = 232 x 106 cells/g of liver) using total protein method. 3. A non-monotonic and inverse relationship between age and MPPGL and HPGL, respectively, was observed. Between one and 20 y of age, the liver cell size decreases as age increases. Subsequently, the cell size increases until the hepatocytes of the oldest horses approached the size found in the youngest horses. Hepatocyte density was inversely related to the size of the hepatocytes. 4. This study provides the first extensive and comprehensive data demonstrating the relationship between the size of hepatocytes and HPGL in any species. [ABSTRACT FROM AUTHOR]

Infiltration plays an important role in the hydrologic cycle, runoff generation, soil erosion, as well as irrigation. In the current study, we evaluated a variety of infiltration models, in order to determine the model that is best suited to predict infiltration on agricultural lands in arid areas of the Semnan province in Iran. Additionally, we analyzed spatial variability of the infiltration process using scaling parameters. A number of 60 points were determined for the measurement of water infiltration using the conditioned Latin hypercube sampling (cLHS) method. Each infiltration measurement was carried out with a tension infiltrometer apparatus. Several infiltration models, including Philip, Horton, Kostiakov (KO), Modified Kostiakov (MKO) and Revised Modified Kostiakov (RMKO) models, were fitted to the measured infiltration data. Among the mean coefficient of determination (R 2 ) values, the highest R 2 values were associated with the RMKO, MKO and Horton models, respectively. While base on the Akaike criterion (ACI), the MKO model was slightly better than the RMKO model for prediction of cumulative infiltration. Cumulative infiltration was scaled using Sorptivity (α S ) and transmissivity (α A ) scaling factors. By minimizing the differences of the sum of squares between the scaled and the average infiltration, the optimum scaling factors (α opt ) were estimated. Arithmetic, geometric and harmonic means (i.e. α m, α G, α H ; respectively) of α S and α A scaling factors were calculated and the infiltration data were scaled utilizing the mentioned scaling factors. Our findings indicated that the best result was yielded by α H . Strong correlations were found for α G ( r  = 0.86) and α H (r = 0.86) with α opt. For defining the relationship between α opt and α A , α S , α m , α G and α H data, a regression analysis was performed. According to our results, curves reflecting the relationship between α opt and α A , α S , α m , α G and α H were sigmoid. Based on the results of this study, infiltration in agricultural lands in the arid area displays a great spatial variability. [ABSTRACT FROM AUTHOR]

Design rainfall estimates are primarily used in single-event deterministic design flood estimation methods where estimates of the peak discharge are based on the critical storm duration or time of concentration (TC) of a catchment. Therefore, daily design rainfall depths used in flood estimations must either be decreased or increased from durations less than or longer than 24 hours to the design rainfall depths for a rainfall duration of TC. This paper presents the comparison of two South African methods used to convert or scale 1-day fixed time interval observed rainfall (08:00 to 08:00) to continuous measures of n-hour rainfall for selected TC durations at a quaternary catchment level, in the C5 secondary drainage region in South Africa as pilot case study. In each quaternary catchment, the annual maximum series (AMS) of the 1-day fixed time interval point rainfall were extracted, infilled, converted and scaled to appropriate continuous measures of TC-hour point rainfall using conversion factors (Adamson, 1981) and scaling factors (Smithers and Schulze, 2003), respectively. Thereafter, all the TC-hour observed point rainfall values were averaged to observed catchment rainfall at a quaternary catchment level using the Thiessen polygon method. In using the two methods to estimate continuous short-duration n-hour (TC ⩽ 24 hours) and long-duration n-hour (TC > 24 hours) catchment rainfall from 1-day fixed time interval point rainfall, an acceptable (0.71 < r2 ⩽ 0.86) and high (r2 ⩾ 0.93) degree of association were achieved, respectively, despite the different approaches used in each method. Overall, the results confirmed that fixed time interval rainfall should be scaled to continuous measures of rainfall using the Smithers- Schulze scale invariance approach for various TC durations in the case study area. In comparison to the Adamson conversion methodology, the Smithers-Schulze scaling methodology is also based on a more extensive and recent rainfall database as incorporated in software for design rainfall estimation in modern flood hydrology practice in South Africa. [ABSTRACT FROM AUTHOR]

The EMRP project MetroDECOM was concerned with research addressing all aspects of nuclear decommissioning in order to deliver integrity and cost-effectiveness in support of clearance and disposal processes as well as improving safety and accuracy. One of the work packages was focused on the characterisation of materials present on decommissioning. Within this work package, work on scaling factors was aimed at applying the principles set out in ISO 21238:2007 to the measurement of contaminated areas in decommissioning sites. In this paper, we report the progress made under MetroDECOM in identifying decommissioning matrices of specific relevance to nuclear decommissioning within the EU and selecting priority hard-to-measure radionuclides for further study. [ABSTRACT FROM AUTHOR]

Abstract: A quantitative approach to species coexistence based on the invasibility criterion has led to an appreciation of coexistence mechanisms in terms of stabilizing and equalizing components, but major challenges are the need to consider general multispecies settings, interactions beyond competition, and multiple scales of space and time. Moreover, two essential concepts, species‐level average fitness and scaling factors, have not had clear definitions. A general approach to defining average fitnesses and scaling factors is given, along with the origin of stabilizing mechanisms as deviations from a reference model where no coexistence is possible. Illustrations are general Lotka–Volterra models, models accounting specifically for resource use and natural enemies, and models with temporal fluctuations. Community averages of stabilizing mechanisms reveal overall opportunities for coexistence, and define mechanisms more precisely through their formulae. Average fitnesses adjusted for the presence of coexistence mechanisms provide a better definition of equalizing mechanisms. While these ideas apply to the components of invasion rates, permanence theory and stochastic persistence theory show how invasion rates can be used to demonstrate species coexistence in complex settings. Although species coexistence has often focused on competition, detailed models of the roles of natural enemies provide a new perspective on the opportunities for coexistence in nature. The concept of apparent competition recognizes the essential symmetry between density‐dependence from resource depletion and from supporting natural enemies. Natural enemy partitioning is the natural analogue of resource partitioning and has an equivalent role in promoting coexistence. Rather than reinforcing each other, however, the strength of coexistence is often intermediate between that implied by resource partitioning alone and that implied by natural enemy partitioning alone, as elucidated by recent Lotka–Volterra theory. Synthesis. Although there are alternative approaches for understanding coexistence in multispecies settings, ideas based on stabilizing and equalizing mechanisms continue to provide new insights. Multiple species and multiple trophic levels are naturally challenging, but the new theories of permanence and stochastic persistence support the critical role of invasion rates in species coexistence, and thus support the understanding to be derived by partitioning invasion rates into average fitness differences and stabilizing components. [ABSTRACT FROM AUTHOR]