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Aim To compare the degree of fibre shedding by six brands of endodontic paper point when used for the paper point technique ( PPT) of working length confirmation. Methodology An in vitro model simulating the clinical use of paper points in PPT was used to assess the degree of fibre shedding of six brands of size 20, .02 taper paper point. Whilst observing the artificial terminal foramen with polarized light microscopy, the number of fibres shed directly (point inserted 1 mm beyond the terminal foramen) and indirectly (point inserted to length then a gutta-percha point inserted) was assessed. The degree of direct fibre shedding as a function of brand was analysed with Fisher's exact test and multiple pairwise comparisons. Indirect fibre shedding was analysed with Kruskal-Wallis and Wilcoxon rank-sum tests. Results All brands shed fibres both directly and indirectly, with a significant influence of brand on the proportion of fibres shed directly ( P < 0.0306) and on the mean number of fibres shed indirectly ( P < 0.0001). Post hoc analysis demonstrated a similar hierarchy of point integrity for both tests with Classic (UnoDent, Witham, UK) shedding significantly more than other brands and SS White (Gloucester, UK) and Antæos® ( VDW, Munich, Germany) shedding the least. Conclusion All brands of paper point may shed cellulose fibres both directly and indirectly with a significant influence of brand on the degree of fibre shedding. Further work should be undertaken to develop biocompatible absorbent dental points. [ABSTRACT FROM AUTHOR]

Objectives: Transcerebellar diameter (TCD) has been utilized prenatally as a tool to estimate gestational age (GA) when fetal growth aberrations are suspected. Traditionally, first trimester ultrasound (1TUS) has been the gold standard of dating a pregnancy in spontaneous pregnancies. We sought to determine if neonatal TCD measurement was as accurate as 1TUS in the estimation of postconceptual gestational age (PCGA). Methods: A retrospective cohort from a registry of high‐quality transmastoid views of consecutive patients from July 2019 to November 2020, delivered from 24 to 34 weeks GA, and with a 1TUS were included. The reference PCGA was the sum of the GA at delivery by 1TUS and day of life. The PCGA by TCD was calculated from Chang et al for GA by TCD. Reference and experimental values were compared by correlation, agreement within 7 days, and Bland–Altman analysis. Results: Of the 154 individual patients in the registry of high‐quality transmastoid views during the study period, 62 met inclusion and exclusion criteria. PCGA by 1TUS and TCD were highly correlated (r = 0.86, P <.001; κ = 47% agreement within 7 days of PCGA). The bias of PCGA by TCD was 4.6 days earlier than the PCGA by 1TUS (95% confidence interval of agreement: −29.2, 20). Conclusions: PCGA estimation by neonatal transmastoid TCD was highly correlated with that of 1TUS. It generally underestimates GA by 4.6 days. This relationship warrants further investigation to determine if this method of estimating PCGA in undated gestations is generalizable. [ABSTRACT FROM AUTHOR]

This paper presents a novel technique to evaluate OSNR using asynchronous histograms. The technique is based on a comparison between a numerically estimated asynchronous histogram of the signal to be measured and the monitored signal. Experimental validation of proposed technique is presented. Measurement errors below 1 dB are achieved for OSNR values below 32 dB. The proposed technique is also validated for cases where the monitored signal presents significant dispersion-induced distortion, without presenting significant loss of accuracy. The principal limitations of the proposed technique are also investigated. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1369–1372, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21648 [ABSTRACT FROM AUTHOR]

Accurate fish size measurement in breeding areas is crucial for the fishing industry. Unlike acoustic methods with high equipment cost and low measurement accuracy, current image‐based methods offer a promising alternative. However, these image‐based methods still face challenges in selecting measurement points. To address this issue and achieve precise measurements of individual fish, this paper introduces an automatic fish size measurement method based on key point detection. We established a Fish‐Keypoints dataset and utilized deep learning techniques for the detection of fish and their key points. Using a binocular camera system, we reconstruct a three‐dimensional coordinate system to measure key points at the fish's head and tail, facilitating fish length calculation. The detection model achieves an accuracy of 85.1% in key point detection. The proposed method is tested in both land and underwater environments, demonstrating a relative measurement error of approximately 7% for fish in pools. This confirms the proposed method's ability to accurately detect measurement points, offering superior accuracy compared to other methods. [ABSTRACT FROM AUTHOR]

Slug flow processes draw much attention in chemical and pharmaceutical manufacturing thanks to their ability to eliminate downtime costs and batch‐to‐batch variation. Using in‐line video can monitor the current process status and improve the stability of the slug flow. However, there are no effective image processing methods aiming at such videos from chemical experiments due to limited training sample size and the variety of experimental settings. The paper proposes a training‐free method to automatically detect and measure the slugs from in‐line videos. Multiple image features are fused to identify the slug shapes under various lighting conditions, a six‐point model is fitted to achieve better volume estimation, and a consistency score is estimated to quantify the detection uncertainty. The proposed algorithm achieves similar results to manual labeling for various types of slug flow processes, improving the accuracy of slug column estimation by a large margin compared to the existing automatic methods. Finally, using it to monitor the slug flow process's stability and the change of the slug volume in an injection point are demonstrated. The method not only shows that handcrafted image features have the capability for detection and segmentation from chemical experiment images but also paves the road for a training‐based algorithm for the task. [ABSTRACT FROM AUTHOR]

This paper addresses the trajectory tracking control problem of a quadrotor under uncertain model parameters, external disturbances, and unmeasurable linear velocity. The main contribution of this paper is to present a geometric control strategy with a simple structure and easily adjustable parameters, which combines the differentiator and uncertainty and disturbance estimator techniques to achieve global trajectory tracking control. First, a cascade control framework is introduced to solve the strong coupling and under actuated problems of quadrotors. Furthermore, an anti disturbance outer-loop differentiator-based position controller is designed based on the uncertainty and disturbance estimators (UDE) to achieve accurate quadrotor tracking of the desired trajectory. The higher order control inputs of the translational dynamics are estimated using a differentiator to determine the desired angular velocity and its derivative. Then, a robust inner-loop geometric controller is derived in Lie algebraic space using the rotation matrix. After that, the stability analysis of the closed-loop system is executed using the Lyapunov stability theory. Finally, the numerical simulation verifies that the method enables the quadrotor to have strong robustness and excellent tracking capability in the presence of large initial angles, time-varying disturbances, and unmeasured linear velocity. [ABSTRACT FROM AUTHOR]

Phase retrieval gives the problem of recovering some signal from phaseless measurements. This paper mainly studies the stability estimation of phase recovery from the measurement of discrete linear canonical Gabor transformation (DLCGT). We first show that we can recover the signal x$$ x $$ on the connected components of G$$ G $$ in global phase sense. Then, we give the stability estimates results from the DLCGT measurements and the autocorrelation relation. [ABSTRACT FROM AUTHOR]

Provides guidelines on building a capillary action water clock. Comprehension of capillary action; Use of rulers to measure lengths; Utilization of estimation skills.

Reactive flash sintering is a process where off‐the‐shelf powders of elemental oxides can be simultaneously sintered and reacted to form a multicomponent oxide in a matter of seconds at low furnace temperatures. The fact that several cation species, each residing within their own particles, can migrate over distances of several micrometers, and mix on the atomic scale to form multicomponent oxides, so quickly, is quite remarkable. The question arises as to the rate of this solid‐state diffusion phenomenon. In this paper, we present measurements of this diffusion coefficient from live flash experiments. The results are obtained from millimeter scale bilayers of yttria‐stabilized zirconia and lanthana where the flash initiates in the zirconia layer and then migrates into the lanthana layer, forming lanthanum zirconates. The velocities of migration of the flash‐front, coupled with measurements of the length scale of the profile of zirconium and lanthanum interdiffusion, across the bilayer interface, provide an estimate of the effective diffusion coefficient. These measurements give a value for the cation diffusion to lie in the range of 2.5 × 10−10 m2 s−1 at 1380°C, with an activation energy of 200–250 kJ mol−1. In comparison, the cation diffusion coefficient in yttria‐stabilized zirconia, at 1350°C, is stated to be 1.1 × 10−20 m2 s−1 with an activation energy of ∼550 kJ mol−1. A pause for reflection. [ABSTRACT FROM AUTHOR]

This paper presents the development of a metamaterial‐based microwave sensor for dielectric constant measurements. The sensor is constructed with a circular split‐ring resonator on one side and a coplanar waveguide transmission line on the other side. The proposed sensor has a size of 35 mm × 35 mm × 1.27 mm and resonates at 3.31 GHz. The sensor is fabricated on a RO3210 substrate with a dielectric constant of 10.2 and a loss tangent of 0.003. Both the simulation and experimental measurements show a linear relationship between the shift of the resonance frequency and the dielectric constants of the test samples, with a coefficient of determination R2 above 0.99. The dielectric constant of an unknown material can therefore be easily estimated using the inverse linear regression model. To validate the performance of the sensor, three known substrate materials, namely, Rogers RT6002, FR4, and Rogers TMM10, were used as test samples. The measured dielectric constants for these three materials were 2.8045, 4.3775, and 8.8719, respectively. The results agree closely with those indicated in the data sheets, with discrepancies of less than 5%. [ABSTRACT FROM AUTHOR]

In this investigation, three subjects are considered. First, the effect of the human factor is examined. In carrying out analyses of fatigue delamination propagation tests on laminate composites, the delamination length must be measured. The human effect on measurement of the delamination length a by different investigators is discussed. A limited influence of the human factor on the measurement of the delamination length a, as well as on delamination propagation rate da/dN, is observed in this study. Secondly, the paper proceeds to discuss the influence of the R‐ratio on the fatigue delamination growth rate. It is found that a higher rate of crack/delamination propagation is associated with lower R‐ratios which appears to contradict conventional wisdom. This behavior is confirmed in tests. Thirdly, a comparison between the fatigue propagation rates of two material systems is considered. It is concluded that the energy release rate used to assess these materials should not be normalized. Highlights: Impact of human factor on fatigue delamination tests in laminate composites.Limited influence of the human factor on delamination length and propagation rate.The lower the R‐ratio, the higher the delamination propagation rate.The crack driving force for laminates should be taken as GImax. [ABSTRACT FROM AUTHOR]

This paper studies the decentralized solution to the linear quadratic social‐optimal mean field control problem, when a finite number subsystems is considered. We use the term average field, to distinguish this case from the one with infinite subsystems. The goal of each subsystem is to design its input to optimize a common cost of social type. To this end, each subsystem use only real‐time information which can be either its local state, or a linear measurement noisy measurement of it. Our result generalizes previous ones in three senses. First, it permits designing controls when there are a finite number of subsystems. Second, it permits considering heterogeneous subsystems, that is, having different structural parameters. Third, it permits designing not only state feedback controls but also output feedback ones. In particular, we show that the separation principle holds in the latter case. [ABSTRACT FROM AUTHOR]

Determining which bilateral bones belong to the same person based on shape and size similarity is called pair‐matching and it is instrumental for sorting commingled skeletons. To date, pair‐matching has popularly been accomplished by visual inspection and/or linear caliper measurements; however, attention is turning increasingly to computational analysis. In this paper, we investigate a fast three‐dimensional (3D) computerized shape‐analysis method for whole‐bone pair‐matching using a test sample of 14 individuals (23 femora, 26 humeri, and 26 tibiae). Specifically, the method aims to find bilateral pairs using, as the shape signature criterion, a single 3D outline that snakes around each bone's perimeter as described by a 3D elliptical Fourier analysis function. This permits substantial 3D‐point‐cloud data reduction, that is, to 0.02% of the starting c.500,000 point cloud or just 100 points, while preserving key 3D shape information. The mean Hausdorff distance (Hd) was applied to measure the distance between each mirrored right‐side outline to every left‐side outline in pairwise fashion (132, 168 and 169 comparisons, respectively). Both thresholds and lowest Hd were investigated as pair‐match criteria, with the lowest Hd producing the best performance results for searches jointly utilizing right‐left and left‐right directions for comparison: true positive rates of 1.00 (10/10), 1.00 (12/12), and 0.92 (11/12) for the femora, humeri, and tibiae, respectively. The computational time to calculate 469 pairwise 3D comparisons on a single stock‐standard Intel® Core™ i7‐4650U CPU @ 1.70 GHz was 5 s. This short data processing time makes the method viable for real‐world application. [ABSTRACT FROM AUTHOR]

The article provides gudelines for authors who want to contribute in social and cultural phenomena through their articles for the publication in the journal "Journal of Social History (JHS)." A JHS article will say something substantial and new about its empirical subject matter and will be of interest to readers beyond a specialist geographical or disciplinary audience. These guidelines brief up on the format of paper submission, the length of articles, refereeing, the possibility of acceptance of the paper. The contributions should be accompanied by an abstract of no more than 100 words, and a brief biographical note including institutional affiliation. Articles should normally be no longer than 10,000 words or 35 double-spaced standard north American letter-size pages. The contributions that are wished to be considered further after being edited, will only be sent to the external referees, and once the papers have been finally accepted, the full final text has to be sent by the authors. There are few guidelines on production and the copyright also to be taken care of by contributors.

The in‐motion alignment for the underwater strapdown inertial navigation system is still a challenging problem due to various disturbances in the underwater environment. In this paper, a novel in‐motion alignment method, based on the Lie group representation, is developed. In this method, the process model is rewritten using the Lie group of the constant attitude matrix between two inertial frames as the state. An exact linear measurement model is constructed by analyzing the effect of the sensor errors in calculating the velocity vector. Next, the state‐dependent Lie group filter is designed basing on accurate derivation expressions for the covariance matrices of state‐dependent noises. The simulation and experiment results demonstrate that the proposed method can achieve better alignment accuracy and time than the existing method. The accuracy improves by 70% with the quaternion Kalman filter. [ABSTRACT FROM AUTHOR]

Massive computation of the reconstruction algorithm for compressive sensing (CS) has been a major concern for its real‐time application. In this paper, we propose a novel high‐speed architecture for the orthogonal matching pursuit (OMP) algorithm, which is the most frequently used to reconstruct compressively sensed signals. The proposed design offers a very high throughput and includes an innovative pipeline architecture and scheduling algorithm. Least‐squares problem solving, which requires a huge amount of computations in the OMP, is implemented by using systolic arrays with four new processing elements. In addition, a distributed‐arithmetic‐based circuit for matrix multiplication is proposed to counterbalance the area overhead caused by the multi‐stage pipelining. The results of logic synthesis show that the proposed design reconstructs signals nearly 19 times faster while occupying an only 1.06 times larger area than the existing designs for N = 256, M = 64, and m = 16, where N is the number of the original samples, M is the length of the measurement vector, and m is the sparsity level of the signal. [ABSTRACT FROM AUTHOR]

Summary: This paper studies the problem of recursive state estimation of stochastic linear systems with nonlinear measurements. The main idea is to rewrite the measurement map in a linear form by considering, as system output, a vector of "virtual" measurements. The result is a linear system with a non‐Gaussian and nonstationary output noise. State estimation is therefore obtained using a Kalman filter or, alternatively, a quadratic filter, suitably designed for non‐Gaussian systems. This work provides two sufficient conditions for the application of the virtual measurement approach and shows its effectiveness in the case of the maneuvering target tracking problem. [ABSTRACT FROM AUTHOR]

This paper describes singular value decomposition (SVD) aided extended Kalman filter (EKF) for nanosatellite's attitude estimation. The development of the filter kinematic/dynamic model, the measurement models of the sun sensors, and the magnetometers used to generate vector measurements are presented. Vector measurements are used in SVD for satellite attitude determination purposes. In the proposed method, EKF inputs come from SVD as the linear measurements of attitude angles and their error covariance. In this step, UD factorizes the attitude angles error covariance, forming the measurements in order to obtain the appropriate inputs for the filtering stage. Results are presented and analyzed in addition to discussion of the sub‐step, which is the UD factorization on the measurement covariance. The accuracy of the estimation results of the SVD‐aided EKF with and without UD factorization is compared for estimation performance. [ABSTRACT FROM AUTHOR]

In this paper, we propose a new variable control chart under type II or failure‐censored reliability tests by assuming that the lifetime of a part follows the Weibull distribution with fixed and stable shape parameter. The purpose is to monitor the mean and the variance of a Weibull process. In fact, the mean and the variance are related to the scale parameter. The necessary measures are given to calculate the average run length (ARL) for in‐control and shifted processes. The tables of ARLs are presented for various shift constants and specified parameters. A simulation study is given to show the performance of the proposed control chart. The efficiency of the proposed control chart is compared with a control chart based on the conditional expected value under type II censoring. An example is also given for the illustration purpose. [ABSTRACT FROM AUTHOR]

P. Y. Wang's classic bottom-up two-dimensional cutting stock algorithm generates cutting patterns by building rectangles both horizontally and vertically. This algorithm uses a parameter β1 to tradeoff the number of rectangles generated by the algorithm and hence the quality of the cutting pattern solution obtained versus the amount of computer resources required. Several researchers have made relatively straightforward modifications to Wang's basic algorithm resulting in improved computational times. However, even with these modifications, Wang's approach tends to require large amounts of computer resources in order to optimally or near-optimally solve difficult two-dimensional guillotine cutting stock problems. In this paper, we present an iterative approach that judiciously uses Wang's basic algorithm (with some previously defined modifications) to obtain optimal cutting patterns to difficult two-dimensional cutting stock problems in reasonable computer run times. [ABSTRACT FROM AUTHOR]

In this paper, we develop a strategy that enables a consistent wave transfer when coupling mechanical models exhibiting various description scales under dynamic loading. Incompatibilities between concurrent models are addressed by a selective filtering based on the perfectly matched layer framework and involving a dedicated projection operator. This filtering, performed in the vicinity of the coupling interface, aims at avoiding spurious wave reflections by automatically killing part of the signal with wavelength range not compatible with the downstream (coarser scale) model while the relevant complementary part is transferred. Performances of the proposed approach are evaluated in details by conducting one-dimensional and two-dimensional numerical experiments. The definition of the projection operator, which is a key point of the method, is particularly tackled by analyzing and comparing several possible choices. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In Trotter and Gleser's (Am J Phys Anthropol 1952;10:463) classic study of stature estimation, a definition of the tibia length measurement is given that agrees with the standard condylar‐malleolar length. That Trotter did not in fact measure according to her definition, but rather omitted the malleolus, has been well documented by Jantz et al. (J Forensic Sci 1995;40:758). Both the Terry collection and the World War 2 (WW2) samples were affected, although questions remain about the latter that cannot be resolved directly because it is no longer available for examination. Trotter's data from hundreds of servicemen are especially important because the statures were measured by technicians, rather than based on cadaver lengths or forensic statures. The questions examined in this note are as follows: Was WW2 measured uniformly in the same way as Terry; are there differences between Terry and WW2 that could influence estimation of the adjustment; and is the 10 millimeter (mm) adjustment proposed by Jantz et al. (J Forensic Sci 1995;40:758) still appropriate. Our analysis relies on a measurement taken by Trotter that is clearly and uniquely defined, what she called "ordinary length". This measurement was used to create expectations about how Trotter measured what she called maximum length of the tibia. Results provide no evidence that WW2 was measured any differently than Terry, with the exception of one small series. They also show slight morphological differences on the distal and/or proximal end of the tibia between Terry and WW2. Despite the slight difference, the adjustment to account for the malleolus is still valid. [ABSTRACT FROM AUTHOR]

Introduction: This study aims to investigate non‐invasive electrocardiography as a method for the detection of congenital heart disease (CHD) with the help of artificial intelligence. Material and methods: An artificial neural network was trained for the identification of CHD using non‐invasively obtained fetal electrocardiograms. With the help of a Bayesian updating rule, multiple electrocardiographs were used to increase the algorithm's performance. Results: Using 122 measurements containing 65 healthy and 57 CHD cases, the accuracy, sensitivity, and specificity were found to be 71%, 63%, and 77%, respectively. The sensitivity was however 75% and 69% for CHD cases requiring an intervention in the neonatal period and first year of life, respectively. Furthermore, a positive effect of measurement length on the detection performance was observed, reaching optimal performance when using 14 electrocardiography segments (37.5 min) or more. A small negative trend between gestational age and accuracy was found. Conclusions: The proposed method combining recent advances in obtaining non‐invasive fetal electrocardiography with artificial intelligence for the automatic detection of CHD achieved a detection rate of 63% for all CHD and 75% for critical CHD. This feasibility study shows that detection rates of CHD might improve by using electrocardiography‐based screening complementary to the standard ultrasound‐based screening. More research is required to improve performance and determine the benefits to clinical practice. [ABSTRACT FROM AUTHOR]

We have developed a prototype full-resolution Super Hi-Vision (SHV) plasma display panel (PDP) that has 4,320 scanning lines and over 33-million pixels. Highly realistic SHV programs were the first successfully reproduced on a 145-inch diagonal PDPs with a 0.417-mm pixel pitch by applying a new panel driving method. [ABSTRACT FROM AUTHOR]

In this paper, we use the notion of strict Mittag–Leffler modules, in order to study the flat length of injective modules over a ring R. We show that the supremum of these flat lengths is closely related to the invariants silp R and spli R, which were defined by Gedrich and Gruenberg, as well as to the finitistic dimension of R and the injective length of the regular module. We also examine the special case where R=ℤG is the integral group ring of a group G. [ABSTRACT FROM PUBLISHER]

Maximum length measurement of the tibia has been found to be variable both in description and implementation. Historically, the literature often excludes the intercondylar eminences from the tibia in metric analysis. This paper explores the quantitative effects of inclusion or exclusion of the eminences on the maximum length measure across ancestral population, age and sex in five human adult populations of American Whites and Blacks, two Native American samples, and East Asians. A Tukey’s post hoc comparison was employed to determine the overall effect of inclusion the intercondylar eminences has on metric assessment of the tibia. Results show no significant effect on comparative analysis of the tibia by age or sex. However, the difference between sample means by ancestry is significant ( p < 0.0001). These results pose interesting questions concerning the morphological differences between ancestral groups. This investigation prompts further study of population variation of the human knee. [ABSTRACT FROM AUTHOR]

In this paper, I argue that context sensitivity is crucial for a proper exegesis of Wittgenstein's remark that one can say of the standard metre rod neither that it is one metre long nor that it is not one metre long. I discuss cases in which we can meaningfully assert that the rod in question is one metre long and explain why these cases do not conflict with Wittgenstein's insight. I analyse Pollock's recent defence of Wittgenstein's remark, as well as Kripke's objections to it, and show that, while their commentaries are helpful, blindness to context renders them unsatisfactory. [ABSTRACT FROM AUTHOR]

Summary Very efficient and unbiased principles exist for estimating the total three-dimensional (3D), two-dimensional and zero-dimensional amounts of arbitrary structure in 3D space. The total one-dimensional length of real structure, in the ordinary sense, is an abstraction from the point of view of integral geometry. All stereological estimators of ‘tubular length’ are thus approximations. In addition, they are riddled by biases due to several types of artificial edges and other practical problems. This paper discusses several of these and proposes practical solutions of minimal biases. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study is to evaluate whether fully automatic cephalometric analysis software with artificial intelligence algorithms is as accurate as non‐automated cephalometric analysis software for clinical diagnosis and research. Materials and Methods: This is a retrospective archive study using lateral cephalometric radiographs taken from individuals aged 12‐20 years. Cephalometric measurement data were obtained from these lateral cephalometric radiographs by manual landmark marking with non‐automated computer software (Dolphin 11.8). Again, the same radiographs were made using fully automatic digital cephalometric analysis software OrthoDx™ (AI‐Powered Orthodontic Imaging System, Phimentum) and WebCeph (Assemblecircle, Seoul, Korea) with artificial intelligence algorithm, without manual intervention of the researcher and fully automatic markings and measurements were made by the software. Results: According to the consistency test, a statistically significant good level of consistency was found between Dolphin and OrthoDx™ measurements and Dolphin and WebCeph measurements in angular measurements (ICC > 0.75, P <.01, ICC > 0.75, P < 0, respectively. 01). A weak level of consistency was found in linear measurement and soft tissue parameters in both software (ICC < 0.50, P <.05, ICC < 0.50, P <.05), and the difference between measurements was statistically found to be different from "0." Conclusion: The results obtained from fully automatic cephalometric analysis software with artificial intelligence algorithms are similar to the results of non‐automated cephalometric analysis software, although there are differences in some parameters. To minimize the margin of error in artificial intelligence‐based fully automatic cephalometric software, the manual intervention of the observer is needed. [ABSTRACT FROM AUTHOR]

Structures built by animals are extended phenotypes, and animal behavior can be better understood by recording the temporal development of structure construction. For most subterranean and wood‐boring animals, these structures consist of gallery systems, such as burrows made by mice, tunnel foraging by termites, and nest excavation in ants. Measurement of the length development of such structures is often performed manually. However, it is time‐consuming and cognitively costly to track length development in nested branching structures, hindering the quantitative determination of temporal development. Here, I introduce TManual, which aids the manual measurement of structure length development using a number of images. TManual provides a user interface to draw gallery structures and take over all other processes handling input datasets (e.g., zero‐adjustment, scaling the units, measuring the length, assigning gallery identities, and extracting network structures). Thus, users can focus on the measuring process without interruptions. As examples, I provide the results of the analysis of a dataset of tunnel construction by three termite species after successfully processing 1125 images in ~3 h. The output datasets clearly visualized the interspecific variation in tunneling speed and branching structures. Furthermore, I applied TManual to a complex gallery system by another termite species and extracted network structures. Measuring the lengths of objects from images is an essential task in biological observation. TManual helps users handle many images in a realistic time scale, enabling a comparative analysis across a wide array of species. TManual does not require programming skills and outputs a tidy data frame in CSV format. Therefore, it is suitable for any user who wants to perform image analysis for length measurements. [ABSTRACT FROM AUTHOR]

This study investigated the accuracy of two electronic apex locators (DentaPort and Bingo) using heat‐treated nickel‐titanium files. The true root canal length of 30 single‐rooted teeth was determined using K files. Next, the electronically measured length was determined using two nickel‐titanium files (ProGlider and HyFlex EDM Glide Path File) with two electronic apex locators at the 'APEX' marks. The accuracy of the electronic apex locator was evaluated by comparing the true root canal length and electronically measured length for each measurement. There was no significant difference between the measurements with two nickel‐titanium files, and all differences between true root canal length and electronically measured length were within ±0.5 mm regardless of the type of nickel‐titanium files or electronic apex locators. Based on the results, the heat treatment of the nickel‐titanium files showed no adverse effects on the working length determination using electronic apex locators. [ABSTRACT FROM AUTHOR]

A layered metastructure (LM) formed by a quasi‐periodic arrangement of graphene and isotropic dielectric mediums, which can realize the functions of the tunable logic gate and refractive index (RI) sensing based on spin Hall effect (SHE), is theoretically studied. The asymmetric arrangement of the mediums and the increased angle of the incident electromagnetic waves (EWs) equip the LM with Janus feature. Through the modulation of the graphene chemical potential, the sharp absorption peak (AP) in the terahertz (THz) range can be obtained, and then the AP can be used to implement NOT logic and OR logic respectively corresponding to the forward and backward scales. By locating the incident angle of light corresponding to the SHE displacement peak, the linear measurement relationship between RI and SHE angle can be realized, and the widest RI measurement range is 1–1.4 with the angles changing from 21.88° to 61.84°. Additionally, a good linear range can be achieved, owning the optimum sensitivity (S) up to 153.5° RIU−1. The RI sensing still strictly follows the logic functions of the forward NOT and backward OR via adjusting the chemical potential of graphene and discriminating the peak value of SHE displacement. [ABSTRACT FROM AUTHOR]

Form‐function relationships in mammalian feeding systems are active topics of research in evolutionary biology. This is due principally to their fundamental importance for understanding dietary adaptations in extinct taxa and macro‐evolutionary patterns of morphological transformations through changing environments. We hypothesize that three‐dimensional dental topographic metrics represent stronger predictors for dietary and other ecological variables than do linear measurements. To test this hypothesis, we measured three dental topographic metrics: Relief Index (RFI), Dirichlet Normal Energy (DNE), and Orientation Patch Count Rotated (OPCR) in 57 extant carnivoran species. Premolar and molar dental topographic indices were regressed against activity, diet breadth, habitat breadth, terrestriality, and trophic level variables within a phylogenetic framework. The results of this study showed significant correlations between RFI and the ecological variables diet breadth and trophic level. Weaker correlations are documented between OPCR and activity and between DNE and trophic level. Our results suggest that cusp height is strongly reflective of dietary ecology in carnivorans as a whole, and represents a proxy mainly for different degrees of hypercarnivory observed within this group of predatory mammals. [ABSTRACT FROM AUTHOR]

The existing prefabricated wireline construction technology is difficult to accurately measure the real‐time length of the deployed wires, resulting in too large construction errors and cannot be popularized and applied. To this end, a length measuring device that can accurately measure the length of the wire during the construction of the prefabricated wire is developed. In terms of the hardware of the length measuring equipment, based on the construction characteristics of the prefabricated wiring and the characteristics of the wire, the photoelectric encoder and the STC8G series single‐chip microcomputer are used to complete the collection and processing of the wire length data, and the mature and stable LoRa technology is used to complete the wireless transmission of the data. In terms of software program of length measurement equipment, the measurement of wire length data, transmission, and interaction of control command signals are realized by optimizing length measurement scheme, interface development of terminal equipment, and information interaction program design. Finally, according to the actual working conditions of the prefabricated wiring construction, the mechanical structure of the length measuring equipment is designed, and the assembly is completed. The developed length measuring equipment has been successfully applied to practical projects. According to the wire length measuring equipment, the deviation between the observation sag and the design sag after the wire length is measured by the wire length measuring equipment is 2.0%, which meets the design requirement of ±2.5%. [ABSTRACT FROM AUTHOR]

Objectives: The objective of the study was to quantify the 3‐D location of impacted canines by measuring their linear and angular deviations in relation to adjacent structures and further evaluate impaction severity. Methods: CBCT images of 314 impacted canines were analysed in the sagittal, coronal and axial planes. Linear and angular measurements were recorded. Canine inclination was identified in coronal and sagittal planes. An evaluation system was constructed for analysis. Upright canine was considered as the appropriate position for fully erupted maxillary canine. Outcomes were compared between right and left sides and by gender. For categorical variables, chi‐square tests were used while Mann‐Whitney U test was used for continuous variables. Regression models were used to measure severity. Results: Impactions were greater in females (119/207; 57.5%). No significant differences between unilateral (100/207; 49.3%) and bilateral (107/207; 51.7%) (P > 0.05). Out of 314 impactions, 105 (33.4%) were mild, 118 (37.58%) moderate and 91 (28.98%) severe. Severe impactions were primarily buccal (44/ 91; 48.3%), in the occlusal ½ of the adjacent incisor root (38/ 91, 41.7%), mesial to the distal border of central incisor (47/91, 51.6%), with sagittal angle value + >45 ̊ (46/ 91, 50.5%) and mesial tip + >30 ̊ (86/ 91, 94.5%). Conclusions: Severely impacted canines had their crowns buccal, closer to occlusal plane and mesial to the distal border of the central incisor with greater than 45‐degree buccal inclination and greater than 30‐degree mesial tip. The sagittal angle can have a significant impact on the severity of impaction. A new classification system was proposed to quantify severity. [ABSTRACT FROM AUTHOR]

We consider the upscaled linear elasticity problem in the context of periodic homogenization. Based on measurements of the deformation of the (macroscopic) boundary of a body for a given forcing, it is the aim to deduce information on the geometry of the microstructure. For a parametrized microstructure, we are able to prove that there exists at least one solution of the associated minimization problem based on the L2$$ {L}&amp;#x0005E;2 $$‐difference of the measured deformation and the resulting deformation for a given parameter. To facilitate the use of gradient‐based algorithms, we derive the Gâteaux derivatives using the Lagrangian method of Céa, and we present numerical experiments showcasing the functioning of the method. [ABSTRACT FROM AUTHOR]

Human remains from forensic and bioarcheological contexts are often fragmentary, requiring methods for estimating a forensic profile that are based upon limited skeletal features. In 2017, Berg and Keryhercz created an online application, (hu)MANid, that provides sex and ancestry estimation from mandibular morphoscopic traits and linear measurements. In this study, we examine the utility of the (hu)MANid application in a diverse, urban US adult sample (aged 20–45; n = 143) derived from computed tomography (CT) scans. We secondarily conduct a preliminary analysis of the program's utility in a sample of adolescents (aged 15–17; n = 40). Six morphoscopic, and eleven morphometric traits were recorded as directed by the literature associated with the (hu)MANid program. Percent correct classification and posterior predictive values were calculated for the sex and ancestry estimations output by the program; chi‐squared tests were employed to compare self‐reported and predicted ancestry. In the adult sample, sex was accurately predicted for 75.52% of the sample. Ancestry prediction, however, was less favorable ranging from 19.3% to 50% correct. For the adolescent sample, correct sex estimation (45%) did not surpass what could occur by chance alone, though ancestry prediction fared better than in the larger adult sample (percent correct prediction overall average: 47.5%, range 35.71%–71.43%). The (hu)MANid application shows utility for use with CT scan‐derived adult samples for sex estimation, but caution is warranted for ancestry estimation and use with samples that may not have reached full adult maturity. [ABSTRACT FROM AUTHOR]

Background: Detecting and measuring intraluminal thrombus has prognostic and therapeutic implications for stroke patients. Purpose: To investigate the feasibility of 3D isotropic high‐resolution T1w‐CUBE imaging to detect and measure intraluminal thrombus in stroke patients. Study Type: Retrospective. Subjects: A total of 93 patients with acute (N = 39) and subacute (N = 54) stroke. Field Strength/Sequence: A 3.0 T/spin‐echo echo‐planar diffusion‐weighted imaging (DWI), high‐resolution T1w‐CUBE imaging and 3D flow compensated gradient‐echo susceptibility‐weighted imaging (SWI). Assessment: Data assessment was performed by three neuroradiologists with 11, 13, and 20 years of clinical experience. The accuracy of T1W‐CUBE and SWI in diagnosing thrombosis was compared by using digital subtraction angiography (DSA) as the reference. For thrombus length measurement, the image quality of proximal and distal thrombus of T1w‐CUBE images was first evaluated with a 4‐point rating system. Then, the proximal and distal positions to lesions were determined on T1w‐CUBE images and compared with those from DSA acquired during endovascular reperfusion therapy. If comparable both locations were found between CUBE and DSA, CUBE imaging can thus be considered for accurate measurement of thrombus length. Statistical Tests: Fleiss' Kappa; the area under the receiver operating characteristic (ROC) curve (AUC); Pearson's chi‐squared test with Yates' continuity correction. Results: Moderate‐to‐good interobserver agreements were validated with all Kappa coefficients higher than 0.40 in thrombus diagnosis and measurement. CUBE imaging showed higher clinical efficacy than SWI (AUC: 0.966 vs. 0.850) in thrombus diagnosis. Additionally, high quality of CUBE imaging was confirmed with 3 or 4 points rated by all three observers. Compared to intraoperative DSA, T1w CUBE showed consistent proximal and distal positions of thrombi in 16 of the 18 patients, validating the accuracy of T1w‐CUBE in measuring thrombus length. Data Conclusion: T1w‐CUBE imaging has potential to facilitate diagnosis and measurement of intraluminal thrombus. Evidence Level: 4 Technical Efficacy: Stage 2 [ABSTRACT FROM AUTHOR]

In many species that fight over resources, individuals use specialized structures to gain a mechanical advantage over their rivals during contests (i.e. weapons). Although weapons are widespread across animals, how they affect the probability of winning contests is still debated. According to theory, understanding weapon function during contests is essential to: (i) understanding its importance in determining the winner, and (ii) identifying what weapon traits (e.g. weapon length versus shape versus performance) are most relevant for contest success. However, quantitative evaluations of how weapon function affects the extent to which weapon traits influence contest success are still lacking. Here, we first develop an individual‐based model to evaluate how increasing the influence of the weapon in determining the winner translates to differences between winners and losers. Then, we use a meta‐analysis to identify: (i) whether different weapon measures influence contest outcome differently; (ii) how animals use their weapons during fights – i.e. weapon function; and (iii) if weapon function correlates to how weapons influence contest outcome. Our model showed that, as weapons increased the chance of determining the winner, the mean difference between winners and losers also increased. Therefore, in our meta‐analysis we used the mean trait difference between winners and losers as a proxy for the extent to which weapons influence contest success. The literature search identified 49 suitable studies, containing information for 52 species, totalling 107 effect sizes. Four main patterns emerged. First, most of the literature focuses on linear measures of weapons, while performance measures are concentrated on Crustacea and Squamata; other types of measures were rare. Second, differences between winners and losers in linear measurements were greater than differences in performance measurements when all species were combined (and when we used only a subset). Third, species that bear weapons almost always perform visual/tactile displays before engaging in physical contact. And fourth, while the way individuals display their weapons did not influence the importance of weapon size on contest outcomes, fighting style predicted when differences between winners and losers would be higher. Species that used their weapons to push or lift (even when combined with other functions) showed greater differences between winners and losers when compared to species that used their weapons to impact, pierce, pull or squeeze. Overall, our results show that we have an incomplete understanding of animal weapons built mostly on weapon size and a few select taxa. Thus, we should start focusing on measuring weapons according to how they are used during contests and in a wider diversity of species. One way forward is to conduct studies that integrate weapon morphology to weapon function to ensure we are measuring the most ecologically relevant variables. [ABSTRACT FROM AUTHOR]

Purpose: The Western Australian Preterm Birth Prevention Initiative recommends a transabdominal cervical length (TACL) measurement at the mid‐pregnancy ultrasound to screen low‐risk women for preterm birth risk. In view of this recommendation, we assessed the inter‐observer consistency of TACL screening in mid‐pregnancy. Methods: Routinely collected mid‐pregnancy TACL ultrasound images were graded from 0 to 4 according to the anatomical landmarks identified by a single expert. A random selection of 10 images of each grade were disseminated in an electronic survey to determine inter‐ and intra‐observer variations in the classification of the cervical image. Results: A total of 244 participants graded 50 TACL images. Six participants repeated the grading. Overall agreement to the exact initial grade for all images was 49.6%, highest for images at both ends of the spectrum (83% Grade 0 and 70.4% for Grade 4). Overall agreement to the initial diagnostic Grades 3 and 4 was 75.3% (95% CI 74.5–76.0%) and was higher when the maternal bladder was empty. There was moderate inter‐rater agreement (κ = 0.42) for Grades 3 and 4 (diagnostic) or Grades 1 and 2 (non‐diagnostic). The intra‐rater agreement was fair to good (κ = 0.59, 95% CI 0.49–0.70) for those who repeated the assessment (including the expert grader). Conclusions: Sonographic CL screening is considered an important tool for the identification of women at high risk of preterm birth. Image classification of TACL performed poorly compared with previous studies assessing transvaginal cervical length. Improved reliability and measurement consistency may be achieved through high levels of quality assurance, ongoing training and image audit. [ABSTRACT FROM AUTHOR]

The Late Cretaceous (Maastrichtian) Ruth Mason Dinosaur Quarry (RMDQ) represents a monodominant Edmontosaurus annectens bonebed from the Hell Creek Formation of South Dakota and has been determined as a catastrophic death assemblage likely belonging to a single population, providing an ideal sample to investigate hadrosaurid growth and population dynamics. For this study, size‐frequency distributions were constructed from linear measurements of long bones (humeri, femora, tibiae) from RMDQ that revealed five relatively distinct size classes along a generally right‐skewed distribution, which is consistent with a catastrophic assemblage. To test the relationship between morphological size ranges and ontogenetic age classes, subsets from each size‐frequency peak were transversely thin‐sectioned at mid‐diaphysis to conduct an ontogenetic age assessment based on growth marks and observations of the bone microstructure. When combining these independent datasets, growth marks aligned with size‐frequency peaks, with the exclusion of the overlapping subadult‐adult size range, indicating a strong size‐age relationship in early ontogeny. A growth curve analysis of tibiae indicated that E. annectens exhibited a similar growth trajectory to the Campanian hadrosaurid Maiasaura, although attaining a much larger asymptotic body size by about 9 years of age, further suggesting that the clade as a whole may have inherited a similar growth strategy. This rich new dataset for E. annectens provides new perspectives on other hypotheses of hadrosaurid life history. When the RMDQ population was compared with size distributions from other hadrosaurid bonebed assemblages, juveniles (categorized as ages one and two) were either completely absent from or heavily underrepresented in the samples, providing support for the hypothesized segregation between juvenile and adult hadrosaurids. Osteohistological comparison with material from polar and temperate populations of Edmontosaurus revealed that previous conclusions correlating osteohistological growth patterns with the strength of environmental stressors were a result of sampling non‐overlapping ontogenetic growth stages. [ABSTRACT FROM AUTHOR]

Oceanographic lidar measurements of the linear depolarization ratio, δ, contain information on the bulk characteristics of marine particles that could improve our ability to study ocean biogeochemistry. However, a scarcity of information on the polarized light‐scattering properties of marine particles and the lack of a framework for separating single and multiple scattering effects on δ have hindered the development of polarization‐based retrievals of bulk particle properties. To address these knowledge gaps, we made single scattering measurements of δ for several compositionally and morphologically distinct marine particle assemblages. We then used a bio‐optical model to explore the influence of multiple scattering and particle characteristics on lidar measurements of δ made during an expedition to sample a mesoscale coccolithophore bloom. Laboratory measurements of linear depolarization revealed a complex dependency on particle shape, size, and composition that were consistent with scattering simulations for idealized nonspherical particles. Model results suggested that the variability in δ measured during the field expedition was driven predominantly by shifts in particle concentration rather than their bulk characteristics. However, model estimates of δ improved when calcite particles were represented by a distinct particle class, highlighting the influence of bulk particle properties on δ. To advance polarized lidar retrievals of bulk particle properties and to constrain the uncertainty in satellite lidar retrievals of particulate backscattering, these results point to the need for future efforts to characterize the variability of particulate depolarization in the ocean and to quantify the sensitivity of operational ocean lidar systems to multiple scattering. [ABSTRACT FROM AUTHOR]

In this work, a study of the mechanism by which free-stream acoustic and vorticity disturbances interact with a boundary layer flow developing over a flat plate featuring a step excrescence located at a certain distance from a blunt leading edge is included. The numerical tool is a high-fidelity implicit numerical algorithm solving for the unsteady, compressible form of the Navier-Stokes equations in a body-fitted curvilinear coordinates and employing high-accurate compact differencing schemes with Pade-type filters. Acoustic and vorticity waves are generated using a source term in the momentum and energy equations, as opposed to using inflow boundary conditions, to avoid spurious waves that may propagate from boundaries. The results show that the receptivity to surface step excrescences is largely the result of an overall adverse pressure gradient posed by the step, and that the free-stream disturbances accelerate the generation of instabilities in the downstream. As expected, it is found that the acoustic disturbance interacting with the surface imperfection is more efficient in exciting the Tollmien-Schlichting waves than the vorticity disturbance. The latter generates Tollmien-Schlichting waves that are grouped in wave packets consistent with the wavelength of the free-stream disturbance. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The article provides guidelines for authors who want to contribute to social and cultural phenomena through their articles for the publication in the journal "Journal of Social History (JHS)." Articles that contribute to the historically-grounded understanding of human societies, whatever their disciplinary provenance or theoretical standpoint, will be welcomed for this journal. These guidelines brief up on the format of paper submission, presentation on the terms of the length and style of the article, references, the possibility of acceptance of the paper. The contributions should be accompanied by an abstract of no more than 100 words, and a brief biographical note including institutional affiliation. Articles should normally be no longer than 10,000 words or 35 double-spaced standard north American letter-size pages. The contributions that are wished to be considered further after being edited, will only be sent to the external referees, and once the papers have been finally accepted, the full final text has to be sent by the authors. There are few guidelines on production and the copyright also to be taken care of by contributors.

The irregular strip-packing problem (ISP) requires a given set of non-convex polygons to be placed without overlap within a rectangular container having a fixed width and a variable length, which is to be minimized. As a core sub-problem to solve ISP, we consider an overlap minimization problem (OMP) whose objective is to place all polygons into a container with given width and length so that the total amount of overlap between polygons is made as small as possible. We propose to use directional penetration depths to measure the amount of overlap between a pair of polygons, and present an efficient algorithm to find a position with the minimum overlap for each polygon when it is translated in a specified direction. Based on this, we develop a local search algorithm for OMP that translates a polygon in horizontal and vertical directions alternately. Then we incorporate it in our algorithm for OMP, which is a variant of the guided local search algorithm. Computational results show that our algorithm improves the best-known values of some well-known benchmark instances. [ABSTRACT FROM AUTHOR]

Monte Carlo simulations and analytical results are used to demonstrate that the hexagonal close-packed (h.c.p.) pair correlation functions for different values of randomly distributed growth and deformation faults can be collapsed into master curves when plotted against a spatial variable, scaled with respect to a characteristic length ( L). The functional dependences of L on different types of faults are found to be non-universal. A simple method for the determination of L from the measured intensity distributions is also outlined. [ABSTRACT FROM AUTHOR]

The method of generalized displacements (GDC) is a path-following algorithm for non-linear mechanics, capable to overcome both limit and snap-back points. It was proposed as a consistent alternative to most existing techniques, such as the arc-length family of algorithms. Although it is a reliable algorithm, it has not been as widely used as the arc-length methods, possibly because it has been seen as belonging to a different category. This paper shows that the GDC method can be seen as an orthogonal arc-length method, with an interesting constraint equation which leads to its appealing features. Copyright © 2006 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Previously, the direct use of prior phase information from a single-wavelength anomalous diffraction (SAD) experiment with a multivariate likelihood function applied to automated model building with iterative refinement has been proposed [Skubák et al. (2004), Acta Cryst. D 60, 2196–2201]. In this approach, the anomalous information from the experimental data is used in refinement to derive phase information in a maximum-likelihood formalism and provided a more theor­etically valid way of incorporating prior phase information compared with current approaches. In the present work, the SAD multivariate likelihood function that directly uses prior phase information is tested against currently used functions on many different SAD data sets which exhibit a wide range of resolution limits and anomalous signal. The results clearly show the importance of the more theoretically valid utilization of prior phase information: the SAD function extends the resolution and phase-quality limits needed for successful automated model building with iterative refinement. Indeed, the multivariate likelihood function reduces the overfitting in the refinement procedure and performs consistently better than the current refinement targets in terms of the quality of the models obtained and the number of residues built. [ABSTRACT FROM AUTHOR]

Background: Spermatogenesis is an elaborately organized and tightly regulated differentiation process. The spermatogenesis duration is stable within a certain species but highly variable between species of the same family. Objectives: In this study, the spermatogenesis duration of the Roborovski hamster was measured for the first time, and the spermatogenesis duration of the Chinese hamster was re‐assessed. Materials and methods: Stage classification and cycle length measurement were carried out by labeling the dividing cells with bromodeoxyuridine and an antibody‐based chromogen as well as with the periodic acid‐Schiff/hematoxylin stain. Analysis was conducted using reference calculation and linear regression. Morphological measurements completed our set of methods. Results: The mean duration of one seminiferous epithelium cycle was 8.58 ± 0.34 days (mean ± SEM; Phodopus roborovskii) and 16.59 ± 0.47 days (Cricetulus griseus) based on the reference calculation. Slightly higher results were obtained using linear regression analysis: 9.72 ± 0.41 days for P. roborovskii and 17.64 ± 0.61 days for C. griseus. Additionally, a newly developed exemplary flowchart was proposed for the Roborovski hamster to facilitate spermatogenesis stage classification also in other species. The Chinese hamster presented an unexpectedly high paired epididymides weight of 1.701 ± 0.046 g (mean ± SEM) although having a body weight of only 40.5 ± 0.7 g. However, no significant correlation between the relative epididymis weight and spermatogenesis duration in mammals (Spearman rank correlation: r = −0.119, p = 0.607, n = 21) or rodents could be found (r = 0.045, p = 0.903, n = 11). Conclusion: Our data emphasize the stability of the spermatogenesis duration within species and its remarkable variability between species. Further research is needed to identify the principal mechanisms and selection drivers that are responsible for such stability within species and the variability between species. [ABSTRACT FROM AUTHOR]

Objective: To examine the impact of first-trimester crown-rump length (CRL) measurement error on the interpretation of estimated fetal weight (EFW) and classification of fetuses as small-, large- or appropriate-for-gestational age on subsequent growth scans.Methods: We examined the effects of errors of ± 2, ± 3 and ± 4 mm in the measurement of fetal CRL on percentiles of EFW at 20, 32 and 36 weeks' gestation and classification as small-, large- or appropriate-for-gestational age. Published data on CRL measurement error were used to determine variation present in practice.Results: A measurement error of -2 mm in first-trimester CRL shifts an EFW on the 10th percentile at the 20-week scan to around the 20th percentile, and the effect of a CRL measurement error of + 2 mm would shift an EFW on the 10th percentile to around the 5th percentile. At 32 weeks, a first-trimester CRL measurement error would shift an EFW on the 10th percentile to the 7th (+ 2 mm) or 14th (-2 mm) percentile; at 36 weeks, the EFW would shift from the 10th percentile to the 8th (+ 2 mm) or 12th (-2 mm) percentile. Published data suggest that measurement errors of 2 mm or more are common in practice.Conclusion: Because of the widespread and potentially severe consequences of CRL measurement errors as small as 2 mm on clinical assessment, patient management and research results, there is a need to increase awareness of the impact of CRL measurement error and to reduce measurement error variation through standardization and quality control. © 2021 International Society of Ultrasound in Obstetrics and Gynecology. [ABSTRACT FROM AUTHOR]