Primary Source Of Differences Research Articles

A radiative–convective model computing precipitation with the maximum entropy production hypothesis

Abstract. All climate models use parameterizations and tuning in order to be accurate. The different parameterizations and tuning processes are the primary source of difference between models. Because models are tuned with present observations of Earth, they may not accurately simulate climates of other planets or palaeoclimate. A model with no adjustable parameter that happens to fit today's observations is probably more universal and should be more appropriate to model palaeoclimate. However, to our knowledge, such a model does not exist or is yet to be developed. This paper aims to improve a parameter-free radiative–convective model that computes a realistic temperature vertical profile to compute the water cycle, giving a value on average tropical precipitation. Although it is known that the radiative transfer constrains the order of magnitude of precipitation, no parameter-free model has yet been able to compute precipitation. Our model finds a precipitation value closer to observations than similar radiative–convective models or some general circulation models (GCMs).

Nivolumab and ipilimumab population pharmacokinetics in support of pediatric dose recommendations-Going beyond the body-size effect.

Body size has historically been considered the primary source of difference in the pharmacokinetics (PKs) of monoclonal antibodies (mAbs) between children aged greater than or equal to 2 years and adults. The contribution of age-associated differences (e.g., ontogeny) beyond body-size differences in the pediatric PKs of mAbs has not been comprehensively evaluated. In this study, the population PK of two mAbs (nivolumab and ipilimumab) in pediatric oncology patients were characterized. The effects of age-related covariates on nivolumab or ipilimumab PKs were assessed using data from 13 and 10 clinical studies, respectively, across multiple tumor types, including melanoma, lymphoma, central nervous system tumors (CNSTs), and other solid tumors. Clearance was lower in pediatric patients (aged 1-17 years) with solid tumors or CNST than in adults after adjusting for other covariates, including the effect of body size. In contrast, clearance was similar in pediatric patients with lymphoma to that in adults with lymphoma. The pediatric effects characterized have increased the accuracy of the predictions of the model, facilitating its use in subsequent exposure comparisons between pediatric and adult patients, as well as for exposure-response analyses to inform pediatric dosing. This study approach may be applicable to the optimization of pediatric dosing of other mAbs and possibly other biologics.

Standardizing the estimation of ischemic regions can harmonize CT perfusion stroke imaging

ObjectivesWe aimed to evaluate the real-world variation in CT perfusion (CTP) imaging protocols among stroke centers and to explore the potential for standardizing vendor software to harmonize CTP images.MethodsStroke centers participating in a nationwide multicenter healthcare evaluation were requested to share their CTP scan and processing protocol. The impact of these protocols on CTP imaging was assessed by analyzing data from an anthropomorphic phantom with center-specific vendor software with default settings from one of three vendors (A–C): IntelliSpace Portal, syngoVIA, and Vitrea. Additionally, standardized infarct maps were obtained using a logistic model.ResultsEighteen scan protocols were studied, all varying in acquisition settings. Of these protocols, seven, eight, and three were analyzed with center-specific vendor software A, B, and C respectively. The perfusion maps were visually dissimilar between the vendor software but were relatively unaffected by the acquisition settings. The median error [interquartile range] of the infarct core volumes (mL) estimated by the vendor software was − 2.5 [6.5] (A)/ − 18.2 [1.2] (B)/ − 8.0 [1.4] (C) when compared to the ground truth of the phantom (where a positive error indicates overestimation). Taken together, the median error [interquartile range] of the infarct core volumes (mL) was − 8.2 [14.6] before standardization and − 3.1 [2.5] after standardization.ConclusionsCTP imaging protocols varied substantially across different stroke centers, with the perfusion software being the primary source of differences in CTP images. Standardizing the estimation of ischemic regions harmonized these CTP images to a degree.Clinical relevance statementThe center that a stroke patient is admitted to can influence the patient’s diagnosis extensively. Standardizing vendor software for CT perfusion imaging can improve the consistency and accuracy of results, enabling a more reliable diagnosis and treatment decision.Key Points• CT perfusion imaging is widely used for stroke evaluation, but variation in the acquisition and processing protocols between centers could cause varying patient diagnoses.• Variation in CT perfusion imaging mainly arises from differences in vendor software rather than acquisition settings, but these differences can be reconciled by standardizing the estimation of ischemic regions.• Standardizing the estimation of ischemic regions can improve CT perfusion imaging for stroke evaluation by facilitating reliable evaluations independent of the admission center.

A Monte-Carlo based 3-D ballistics model for guiding bat carcass surveys using environmental and turbine operational data

Wind turbines cause direct mortality of bats through collision with turbine blades. However, accurate bat fatality estimates are unavailable for many facilities and regions due to lack of physically consistent guidance for surveying bat carcasses. We develop a Monte-Carlo based 3-D ballistics model to address this important gap to guide carcass surveys, help improve fatality estimates by combining it with statistical models and offer post-construction impact assessment guidelines. Monte-Carlo simulations account for variability of environmentally relevant parameters and subsequently the variability of the generated carcass fall zone distributions. The input parameters are bat characteristics, including mass, size, and drag coefficient, wind speed, turbine RPM, yaw, bat flight speed, bat strike angle, and bat strike locations on the rotor. Using turbine SCADA (Supervisory Control and Data Acquisition), bat biometrics data, and carcass drag coefficient range, probability density functions of the input parameters were computed. With the help of carcass survey and SCADA details, bat fatalities were selected, and Monte-Carlo based ballistics model simulations were performed using corresponding values of the input parameters of the ballistics model. The surveyed carcass location for a bat found on the same day was in good agreement with the modelled fall zone distribution, providing a measure of model validation. Next, simulations were conducted for a bat fatality for which the carcass was found four days after collision. It was found that the observed location was within the modeled fall zone distribution showing the model capacity for planning surveys. Further, Monte-Carlo based 3-D ballistics model simulations were performed for the full migration season and the resulting 1-D (radial) and 2-D (surface) histograms were compared with the survey 1-D and 2-D histograms, respectively. The modelled 2-D fall zone distribution hot spot overlaps with surveyed carcass positions indicating the model robustness over a wide range of meteorological conditions and time scales. However, by comparison, the modeled 1-D fall zone distribution was found to be different from the surveyed 1-D fall zone distribution. We hypothesize that uncertainty in bat radial strike location (distribution of bat collisions on turbine blades in radial direction) distribution is primary source of difference between the surveyed and modelled 1-D fall zone distribution. There are no measurements available for this key input parameter. As a next step, the sensitivity of carcass fall zone distributions with respect to bat radial strike location distributions were tested. It was found that the probability density function for bat radial strike location affects the modelled fall zone distributions significantly. There is a need to measure bat radial and angular strike locations which can be used as input in the ballistics modeling framework to improve prediction of carcass fall zone distributions. The proposed model is useful for carcass survey planning, improving survey estimates, designing turbine curtailment studies, and collision risk modeling.

Analysis on Regional Differences and Spatial Convergence of Digital Village Development Level: Theory and Evidence from China

In the context of the rapid development of the global Internet, evaluating the digital village development level (DVI) in different regions is important for policy formulation and scientific research in the field of rural digital development. Based on the measurement of DVI using panel data of provinces from 2005 to 2018, we also explored the causes of DVI development differences using the Dagum Gini coefficient decomposition and spatial convergence method. The study found that: (1) During the whole sample period, the DVI in China and the four major regions showed a significant upward trend as a whole, with the highest in the eastern region and the lowest in the western region, but the development of DVI among different provinces showed regional non-equilibrium characteristics. (2) DVI has a typical agglomeration effect in the spatial and geographical distribution, and regional differences are the primary source of differences in DVI development in China, but the overall regional differences show a decreasing trend. (3) Except for the northeast region, σ-convergence exists in the other three regions; in addition, all regions have significant conditional β-convergence, but the convergence speed is significantly different. (4) Rural population density, industrial structure, and economic development level significantly affect DVI. Therefore, we suggest strengthening the inter-regional connection and element flow and realizing the improvement of the overall DVI of the region through cooperation and mutual assistance.

Microstructural correlation with formability aspects of low carbon steels during deep drawing operations

Mechanical and fluid assisted (hydro-mechanical) deep drawing operations were performed on drawing quality (DQ) and interstitial free (IF) steels at various forming depths. The evolving microstructure in terms of textural developments, in-grain misorientations and residual stresses measurements were significantly different between the two grades and deep drawing processes. In all the deformed microstructures, however, clear formation of near boundary gradient zones (NBGZs) was observed, quantified from electron backscattered diffraction (EBSD) data. The effective presence and extent of the NBGZs appeared to be the primary source of differences in deformed microstructure developments leading to changes in strain distributions between two different forming processes. It was observed that the formation of NBGZ was lower in hydro mechanical deep drawing (HMDD) operations. Moreover, the estimated statistical parameter strain non-uniformity index (SNI) confirmed the development of uniform strain distributions during HMDD operations. The determined correlation coefficient R2 values showed best fit for HMDD operations.

A Critical Review of the Deviance Detection Theory of Mismatch Negativity

Mismatch negativity (MMN) is a component of the difference waveform derived from passive auditory oddball stimulation. Since its inception in 1978, this has become one of the most popular event-related potential techniques, with over two-thousand published studies using this method. This is a testament to the ingenuity and commitment of generations of researchers engaging in basic, clinical and animal research. Despite this intensive effort, high-level descriptions of the mechanisms theorized to underpin mismatch negativity have scarcely changed over the past four decades. The prevailing deviance detection theory posits that MMN reflects inattentive detection of difference between repetitive standard and infrequent deviant stimuli due to a mismatch between the unexpected deviant and a memory representation of the standard. Evidence for these mechanisms is inconclusive, and a plausible alternative sensory processing theory considers fundamental principles of sensory neurophysiology to be the primary source of differences between standard and deviant responses evoked during passive oddball stimulation. By frequently being restated without appropriate methods to exclude alternatives, the potentially flawed deviance detection theory has remained largely dominant, which could lead some researchers and clinicians to assume its veracity implicitly. It is important to have a more comprehensive understanding of the source(s) of MMN generation before its widespread application as a clinical biomarker. This review evaluates issues of validity concerning the prevailing theoretical account of mismatch negativity and the passive auditory oddball paradigm, highlighting several limitations regarding its interpretation and clinical application.

Ethanol or Bioelectricity? Life Cycle Assessment of Lignocellulosic Bioenergy Use in Light-Duty Vehicles

Our study evaluates life cycle energy use and GHG emissions of lignocellulosic ethanol and bioelectricity use in U.S. light-duty vehicles. The well-to-pump, pump-to-wheel, and vehicle cycle stages are modeled. All ethanol (E85) and bioelectricity pathways have similar life cycle fossil energy use (~ 100 MJ/100 vehicle kilometers traveled (VKT)) and net GHG emissions (~5 kg CO2eq./100 VKT), considerably lower (65-85%) than those of reference gasoline and U.S. grid-electricity pathways. E85 use in a hybrid vehicle and bioelectricity use in a fully electric vehicle also have similar life cycle biomass and total energy use (~ 350 and ~450 MJ/100 VKT, respectively); differences in well-to-pump and pump-to-wheel efficiencies can largely offset each other. Our energy use and net GHG emissions results contrast with findings in literature, which report better performance on these metrics for bioelectricity compared to ethanol. The primary source of differences in the studies is related to our development of pathways with comparable vehicle characteristics. Ethanol or vehicle electrification can reduce petroleum use, while bioelectricity may displace nonpetroleum energy sources. Regional characteristics may create conditions under which either ethanol or bioelectricity may be the superior option; however, neither has a clear advantage in terms of GHG emissions or energy use.

The natural history of class I primate alcohol dehydrogenases includes gene duplication, gene loss, and gene conversion.

BackgroundGene duplication is a source of molecular innovation throughout evolution. However, even with massive amounts of genome sequence data, correlating gene duplication with speciation and other events in natural history can be difficult. This is especially true in its most interesting cases, where rapid and multiple duplications are likely to reflect adaptation to rapidly changing environments and life styles. This may be so for Class I of alcohol dehydrogenases (ADH1s), where multiple duplications occurred in primate lineages in Old and New World monkeys (OWMs and NWMs) and hominoids.Methodology/Principal FindingsTo build a preferred model for the natural history of ADH1s, we determined the sequences of nine new ADH1 genes, finding for the first time multiple paralogs in various prosimians (lemurs, strepsirhines). Database mining then identified novel ADH1 paralogs in both macaque (an OWM) and marmoset (a NWM). These were used with the previously identified human paralogs to resolve controversies relating to dates of duplication and gene conversion in the ADH1 family. Central to these controversies are differences in the topologies of trees generated from exonic (coding) sequences and intronic sequences.Conclusions/SignificanceWe provide evidence that gene conversions are the primary source of difference, using molecular clock dating of duplications and analyses of microinsertions and deletions (micro-indels). The tree topology inferred from intron sequences appear to more correctly represent the natural history of ADH1s, with the ADH1 paralogs in platyrrhines (NWMs) and catarrhines (OWMs and hominoids) having arisen by duplications shortly predating the divergence of OWMs and NWMs. We also conclude that paralogs in lemurs arose independently. Finally, we identify errors in database interpretation as the source of controversies concerning gene conversion. These analyses provide a model for the natural history of ADH1s that posits four ADH1 paralogs in the ancestor of Catarrhine and Platyrrhine primates, followed by the loss of an ADH1 paralog in the human lineage.

The Limits of Radical Institutionalism: A Marxian Critique of Thorstein Veblen’s Political Economy

Some commentators pose Veblen’s political economy as a corrective to the “reductionist” character of Marxism. This article counters by highlighting the primary source of differences between Veblen and Marx: their methods. Veblen’s generalized conceptions of monopoly and technology, for example, misread the specificity of the systemic logic of capitalism. These dynamics are fully captured only in Marx’s movement from simple, abstract laws to complex, concrete reality, where “non-economic” factors are not reduced to the economic, but rather intervene at a later moment of the concretization process.JEL classification: B14, B15, P16

Influence of IFN-γ on gene expression in normal human bronchial epithelial cells: modulation of IFN-γ effects by dexamethasone

Interferon gamma (IFN-gamma) plays a role in a variety of lung inflammatory responses, and corticosteroids are frequently employed as a treatment in these conditions. Therefore, the effect of IFN-gamma, of the corticosteroid dexamethasone (Dex), or of both on gene expression was studied in normal human bronchial epithelial (NHBE) cells. NHBE cells were exposed to medium alone, IFN-gamma (300 U/ml), Dex (10(-7) M), or both IFN-gamma and Dex for 8 or 24 h. Gene expression was examined using oligonucleotide microarrays. A principal components analysis demonstrated that the IFN-gamma treatment effect was the primary source of differences in the data. With a 5% false discovery rate, of the 66 genes upregulated by IFN-gamma by twofold or greater at 8 h and 287 genes upregulated at 24 h, coincubation with Dex inhibited the expression of 2 genes at 8 h and 45 genes at 24 h. Prominent among these were cytokines and secreted proteins. Dex cotreatment increased expression of 65 of the 376 genes that were inhibited by IFN-gamma by 50% at 24 h. The majority of these genes encode cell cycle or nuclear proteins. Dex alone increased the expression of only 22 genes and inhibited the expression of 7 genes compared with controls at 24 h. The effect of Dex on IFN-gamma-induced changes suggests a specific, targeted effect on IFN-gamma responses that is substantially greater than the effect of Dex alone. Dex had little effect on the immediate early response to IFN-gamma but a significant effect on the late responses.

Introduction to special issue on studying

Twelve years ago, William Rohwer (1984) extended an invitation to educational researchers to forge an educational psychology of studying on par with the field's interest in and investigations of instruction. Rohwer argued that students are increasingly expected to learn independently as they proceed from elementary to secondary to post-secondary schools. Col lege students, Rohwer pointed out, are expected to spend at least twice as much time studying as they spend attending class. Rohwer contended that there was considerable work to be done but that the work was worthwhile and necessary. The phenomena of study, then, invite a commitment to an arduous, complex and protracted effort, an affair more like a house-raising than a house-warming. Yet, if differences in the effectiveness of study are a primary source of differences in educational success, the invitation to build an educational psychology of studying is surely worth accepting. By all indications, Rohwer's invitation was widely accepted. A special interest group on studying was formed in the American Educational Re search Association. Investigators examined social, motivational, and strate gic aspects of studying under the rubric of self-regulated learning (e.g., Pintrich and DeGroot, 1990; Zimmerman, 1989, 1990). And, texts detailing how to study flourished (e.g., Gardner and Jewler, 1989; Longman and At

Dynamic initialization by repeated insertion of data

In this study we isolate and assess the impact of dynamic initialization by repeated insertion of data (RI), also known as ‘nudging’. A novel control experiment compares this iterative technique with an alternative intermittent analysis-forecast cycle (AF) framework within the same assimilation system. Both schemes are versions of the operational global data assimilation system for numerical weather prediction at the Meteorological Office. A secondary issue is the impact of divergence damping as an extra initialization measure. The effectiveness of RI for control of high-frequency gravity waves is demonstrated, together with its beneficial impact on the short-period forecast of surface pressure. Changes to analysed fields due to RI are only a small fraction of the changes due to model evolution in six hours. RI is found to enhance upper-level divergence in the equatorial west Pacific and the problem of spin-up of the global mean precipitation is virtually absent, except when divergence damping is imposed during assimilation and removed during the forecast. The main benefit from divergence damping is a more accurate tropical wind field. RI is found to degrade the short-period forecast of the wind field in the basic system studied, and the extra errors are largest in strong upper winds at mid latitudes. This fact is discussed in the context of an earlier idealized study of RI. Analysis constraints are a primary source of difference between various ‘nudging’ schemes used in numerical weather prediction. The sensitivity of the impact from RI to these is evaluated by relaxing constraints in the basic system. The result emerges that as the analysis step of a nudging scheme becomes better balanced, the scope for improvement by using RI for initialization becomes smaller. Also, if the better-balanced analysis step entails stronger enforcement of non-divergence on the wind increments, then the damaging effect of RI on the wind field through advection becomes larger and can outweigh the benefit through initialization. A scheme combining RI for mass data with an iterative AF method for wind data retains much of the benefit and avoids most of the problems in the scheme with RI of all data. This suggests a method of improving the contribution of an RI structure to the overall performance of an assimilation scheme based on the nudging approach.

Examination of Operational Aspects of Fruit Pressure Tests

The Ballauf fruit pressure tester and a compact Italian instrument were compared in testing apples. It was found that the primary source of differences between the instrument readings was systematic calibration errors. The different size, shape and spring rate of the two instruments did not affect the rate of increase of force applied by the average operator. Females, however, used nearly twice the rate of males. It appeared advantageous to calibrate the instruments dynamically since this simulated the operating conditions of the instruments.