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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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

Sample size is a challenge for most field scientists determined not by the statistically ideal, but by the available. In vertebrate ichnology, track length is an important variable correlating well with the track‐maker's biology. It is also key to estimating the minimum number of individuals (MNI) present on a trampled horizon. Broad assumptions on biometrics of the track‐makers are often made based on a few prints without consideration for intra‐trackway variability. In this study we use a simple bootstrapping algorithm to explore variance within sample size for a range of trackways with fossil and experimental examples to determine the minimum sample size required to extract linear measurements. Predictably, experimentation shows that inter‐step variability changes with track‐maker and substrate, but the degree of variance is not as marked as previously anticipated. Change‐point modelling suggests that a maximum sample size of 22–25 captures most of the variance present in track length at least; another threshold at 7–10 has been identified, which represents the reasonable sample size minimum. Samples of fewer than seven tracks are subject to large amounts of potential variance and are unlikely to provide reliable and consistent measurements. These sampling thresholds hold across a wide range of depositional environments and track‐makers. We calculate generic standard errors for human track‐makers which may assist the practitioner with small samples to estimate the likely errors, especially when making MNI estimates. The challenge is placed to the wider vertebrate ichnology to explore this issue for other track‐makers and develop similar guidance. [ABSTRACT FROM AUTHOR]

Evaluates the teaching of length measurement in elementary schools in the United States. Limitations of traditional teaching methods; Recommended approaches to the teaching of length measurement that incorporate problems and encourages children to modify their ways of thinking.

A new method for the description of leaf shape is presented, based on an interactive computer program for describing rosette leaves of Chondrilla juncea. In addition to the usual measures of length, breadth and area an alternative description is provided based on a coding of the boundaries of the leaves. The efficiency of the machine-assisted description is assessed and a comparison of the alternative descriptions provided. [ABSTRACT FROM AUTHOR]

Aim: Across a variety of taxonomic scales, species diversity is unevenly distributed among its constituent units, and clades with few species are more common than expected assuming homogeneous rates of speciation and extinction among lineages. In order to explain the prevalence of species‐poor families among a global and species‐rich radiation of passerine birds, we test whether these groups share common eco‐morphological, geographical and phylogenetic attributes. Location: Global. Time period: Late Oligocene to the present day. Major taxa studied: The Corvides (c. 790 species). Methods: We obtained 10 linear measurements of external morphology for 782 species of corvoid passerines. Using these measurements as a proxy for species ecology, we assessed the positioning of corvoid families in eco‐morphological trait space and how these factors were associated with their species richness and rates of lineage diversification. Subsequently, we compared these same characteristics (species richness, morphological positioning and rates of lineage diversification) between families that are currently endemic to the Australasian ancestral area of the Corvides with those that have dispersed and diversified throughout other continental and insular landmasses. Results: Families with low species richness and rates of diversification tend to occupy the most peripheral positions in eco‐morphological trait space, with almost all of these groups being endemic to Australasia. The peripheral eco‐morphological positioning of the Australasian groupings is generally greater than expected upon accounting for differences in phylogenetic isolation and heterogeneity in rates of trait evolution, implying that species‐poor corvoid families repeatedly evolved towards marginal areas of morphospace. Main conclusions: The over‐representation of species‐poor clades across diverse sets of organismal groups is consistent with their evolution towards, and the maintenance in, marginal areas of ecological niche space. The evolution of peripheral eco‐morphological characters represents a potentially significant limit to rates of range expansion and lineage diversification. [ABSTRACT FROM AUTHOR]

An extensive overview is presented of Vickers indentation crack lengths in ceramics in air. Measurement of such crack lengths is one of the most common and powerful assessments of the fracture properties of ceramics and the overview provides a critical evaluation of observed behavior as functions of material type and indentation load, and an extensive basis for comparison of results from new materials and analyses. The overview considers single crystals, polycrystals, transforming materials, glasses, and multiphase materials, including cermets, glass‐ceramics, and tooth enamel. The coverage extends over structural and electronic ceramics, including oxides, carbides, nitrides, and titanates. The data are presented in a single format for ease of interpretation in terms of idealized indentation fracture and for inter‐material comparisons; most data are unique to this work, but the results of selected studies from the published literature are included. The overview considers the precision and accuracy of crack length measurements and demonstrates a simple quantitative evaluation and ranking scheme for ceramic fracture based on load‐adjusted crack length and cracking susceptibility. Indentation hardness and cracking threshold are also determined and related to the susceptibility. Material toughness is related to cracking susceptibility by fracture mechanics analyses: typical crack length measurements in air are shown to provide estimates of inert toughness with a relative uncertainty of ±50%. [ABSTRACT FROM AUTHOR]

This study proposes an analytical method for calibrating and orienting online photogrammetric systems using a scale bar. The primary idea is building control lengths in the measurement volume by moving and rotating the scale bar and then conducting a self-calibration bundle adjustment using images of the control lengths. In this study, the five-point relative orientation method is used to provide estimations of the exterior camera parameters. Additionally, this study elaborates the model of the lengths constrained self-calibration bundle adjustment, the block computation algorithm and the accuracy assessment. This method obtains both the interior and the exterior orientation parameters of the two cameras, and provides spatial bar length reconstruction precision as the performance evaluation. Simulations are conducted to analyze the calibration accuracy and the results show that the method achieves comparable accuracy and precision against the state-of-the-art method. However, the method does not need steady and well distributed 3D points and is easy to operate. Real data experimental results show that the maximum length measurement error of this method in a volume of 5 m × 4 m × 2 m is <0.4 mm. [ABSTRACT FROM AUTHOR]

Abstract: The Theory of Critical Distances (TCD) is the name that has been given to a group of design methodologies that all make use of a material length scale parameter to postprocess the local linear‐elastic stress fields in the vicinity of the crack initiation locations. The aim of the present investigation is to check whether the simple linear‐elastic TCD is successful in predicting static strength of notched components made of 3D‐printed polylactide (PLA). PLA is a thermoplastic aliphatic polyester that is produced from renewable biodegradable resources. The accuracy and reliability of the TCD in estimating the static strength of additively manufactured (AM) PLA were assessed against a large number of experimental results generated by testing, under tensile loading as well as under bending, AM notched specimens containing different geometrical features (open notches included). The TCD was seen to be highly accurate, its systematic use resulting in estimates falling mainly within an error interval of about 20%. This result is certainly very relevant since it demonstrates that the linear‐elastic TCD can be used successfully to design against static loading notched components of AM PLA by directly postprocessing the results from simple linear‐elastic Finite Element (FE) models. [ABSTRACT FROM AUTHOR]

Linked article: This Editorial comments on the article by Gadsbøll et al. Click here to view the article. [ABSTRACT FROM AUTHOR]

Aim We compared the accuracy and reproducibility of using ulnar and lower leg length measurements to predict length and height in infants and children aged 0 to 6 years. Method Length/height and ulnar and lower leg length were measured in 352 healthy preterm and term-born children (167 males, 185 females) (Mean age= 2.6±1.6 years). Ulna length was measured as the distance between the proximal olecranon process and the distal styloid process of the ulna. Tibia length was measured as the distance from the proximal aspect of the medial condyle and the most distal aspect of the medial malleolus of the tibia using a segmometer. Length measurements were taken using an infant length board in children less than 24 months of age, whereas a portable stadiometer was used to measure height in older children. Equations were developed using ulnar and lower leg length and age. Intra- and inter-examiner variability ( n=167) was calculated, and dual-energy X-ray absorptiometry scans ( n=126) were used to determine accuracy of limb lengths. Results Ulnar and lower leg length explained over 95% of the variability in length/height in term infants and children, but less in preterm infants ( R2=0.80-0.87). In preterm infants, the limits of agreement ( LOA) for males were −2.44 to 2.44cm and −2.88 to 2.88cm for the ulna and lower leg respectively, whereas the LOA for females were −1.90 to 1.90cm and −1.87 to 1.87cm respectively. In older children, the LOA for males were −5.53 to 4.48cm and −5.59 to 4.62cm for the ulna and lower leg respectively, whereas the LOA for females were −5.57 to 5.01cm and −6.02 to 5.02cm respectively. Intra- and inter-examiner variability was low for all measurements in both sexes and age groups. Interpretation Length and height measurements using infant length board or stadiometer are reproducible. Because of the wide limits of agreement, estimation of length and height in children using ulnar and lower leg length is not an acceptable alternative to traditional methods. [ABSTRACT FROM AUTHOR]

This study addresses the passive target tracking problem using the range difference (RD) information measured by seaskimming anti-ship missiles. Apart from the conventional non-linear filtering approaches, the RD-based passive target tracking problem is newly formulated within the framework of the recently developed non-conservative robust Kalman filter (NCRKF). By applying NCRKF, the authors are able to cope with the performance degradation in the process of adopting linear measurement model as well as to determine the desirable missile formation in view of target tracking performance. Moreover, the proposed filter might be adequate for the real-time multiple-missile applications for its linear recursive structure. Through the simulations for a typical missile homing scenario, it is shown that the proposed scheme could provide faster convergence rate and better target tracking performance than the previous methods. [ABSTRACT FROM AUTHOR]

An abstract of the research paper "Assessment of crown-rump length measurement variability," by A. McLennan and colleagues is presented.

Fundamental mathematical relationships are widespread in biology yet there is little information on this topic with regard to human limb bone lengths and none related to human limb bone volumes. Forty-six sets of ipsilateral upper and lower limb long bones and third digit short bones were imaged by computed tomography. Maximum bone lengths were measured manually and individual bone volumes calculated from computed tomography images using a stereologic method. Length ratios of femur : tibia and humerus : ulna were remarkably similar (1.21 and 1.22, respectively) and varied little (<7%) between individuals. The volume ratio of femur : tibia was approximately half that of humerus : ulna (1.58 and 3.28, respectively; P < 0.0001). Lower limb bone volume ratios varied much more than upper limb ratios. The relationship between bone length and volume was found to be well described by power laws, with R2 values ranging from 0.983 to 0.995. The most striking finding was a logarithmic periodicity in bone length moving from distal to proximal up the limb (upper limb λ = 0.72, lower limb λ = 0.93). These novel data suggest that human limb bone lengths and volumes follow fundamental and highly conserved mathematical relationships, which may contribute to our understanding of normal and disordered growth, stature estimation, and biomechanics. [ABSTRACT FROM AUTHOR]

Er:In:LiNbO3 crystals were grown by Czochralski method from congruent melts containing 0.5/0.5, 0.5/1.0, and 0.5/1.5 mol%/ mol% Er2O3/In2O3. The Er and In concentrations in the crystals were determined by neutron activation analysis. The refractive indices at the 473, 633, and 1536 nm wavelengths were measured by prism coupling technique. The unpolarized Er3+ and OH- absorption spectra of the crystals were measured at room temperature. The Er3+ absorption cross-section spectra were determined, and the Er3+ spectroscopic properties were analyzed by Judd-Ofelt (J-O) theory. The In segregation coefficient is 1.20±0.06, 0.95±0.05, and 0.89±0.05, respectively, and the Er concentrations in all of the three crystals studied have a nearly same value of 1 mol%. The ordinary index decreases while the extraordinary index increases with the increased In doping level. The 0.5 and 1.0 mol% In2O3-doped two crystals are below while the 1.5 mol% In2O3-doped crystal is above the photorefractive threshold concentration. The Er3+ absorption cross sections of some transitions change definitely due to In codoping, but reveal a weak dependence on the In2O3 doping level. The J-O-predicted spectroscopic parameters show similar In codoping effects. The In codoping hardly affects the Er3+ 1.5 lm radiative lifetime. [ABSTRACT FROM AUTHOR]

The article investigates the reproducibility of fetal liver-length measurement in pregnant women with diabetes. Results reveal that measurement of fetal liver length in the diabetic pregnancy is reproducible. The intraobserver SD was 3.06 mm, the interobserver SD was 2.17 mm, the intraobserver correlation was 0.77, and the interobserver correlation was 0.84.

Crouzon syndrome is characterized by premature fusion of sutures and synchondroses. Recently, the first mouse model of the syndrome was generated, having the mutation Cys342Tyr in Fgfr2c, equivalent to the most common human Crouzon/Pfeiffer syndrome mutation. In this study, a set of micro-computed tomography (CT) scannings of the skulls of wild-type mice and Crouzon mice were analysed with respect to the dysmorphology caused by Crouzon syndrome. A computational craniofacial atlas was built automatically from the set of wild-type mouse micro-CT volumes using (1) affine and (2) non-rigid image registration. Subsequently, the atlas was deformed to match each subject from the two groups of mice. The accuracy of these registrations was measured by a comparison of manually placed landmarks from two different observers and automatically assessed landmarks. Both of the automatic approaches were within the interobserver accuracy for normal specimens, and the non-rigid approach was within the interobserver accuracy for the Crouzon specimens. Four linear measurements, skull length, height and width and interorbital distance, were carried out automatically using the two different approaches. Both automatic approaches assessed the skull length, width and height accurately for both groups of mice. The non-rigid approach measured the interorbital distance accurately for both groups while the affine approach failed to assess this parameter for both groups. Using the full capability of the non-rigid approach, local displacements obtained when registering the non-rigid wild-type atlas to a non-rigid Crouzon mouse atlas were determined on the surface of the wild-type atlas. This revealed a 0.6-mm bending in the nasal region and a 0.8-mm shortening of the zygoma, which are similar to characteristics previously reported in humans. The most striking finding of this analysis was an angulation of approximately 0.6 mm of the cranial base, which has not been reported in humans. Comparing the two different methodologies, it is concluded that the non-rigid approach is the best way to assess linear skull parameters automatically. Furthermore, the non-rigid approach is essential when it comes to analysing local, non-linear shape differences. [ABSTRACT FROM AUTHOR]

Objective: Less than 10% of women presenting with preterm contractions progress to active labor and delivery. This study investigates whether cervical length measurements by ultrasound can discriminate between true and false labor in women presenting with threatened preterm labor. Methods: Cervical length was measured by transvaginal ultrasound in 253 women with singleton pregnancies presenting with painful uterine contractions at a median age of 31 (range, 24-35) weeks of gestation. Women presenting in active labor, defined by the presence of cervical dilatation of >or = 3 cm, those with ruptured membranes and those that underwent prior or subsequent cervical cerclage were excluded from the study. The clinical management was determined by the attending obstetrician without taking into account the cervical length. Primary outcome of the study was delivery within 7 days of presentation based on the results of randomized studies on the use of tocolytics in women with preterm labor that reported a prolongation of pregnancy by 7 days. Results: Delivery within 7 days of presentation occurred in 21/253 (8.3%) pregnancies and this was inversely related to cervical length. Receiver-operating characteristics (ROC) curves established a cervical length of 15 mm as the most relevant cut-off level for the prediction of preterm delivery within 7 days. In 217 cases the cervical length was > or = 15 mm and only four of these (1.8%) delivered within 7 days. In the 36 women with cervical length < 15 mm, delivery occurred in 17 (47.2%) within 7 days. Logistic regression analysis demonstrated that significant independent contribution in the prediction of delivery within 7 days was provided by cervical length, contraction frequency at presentation, previous history of preterm delivery and vaginal bleeding. There was no significant contribution from gestation at presentation, ethnic origin, maternal age, parity, cigarette smoking or the administration of tocolysis, antibiotics or steroids. Similar results were shown in a subanalysis of 162 patients presenting at a gestational age below 32 weeks: 9/19 patients (47.4%) with a cervical length below 15 mm delivered within 7 days compared to 3/143 (2.1%) with a cervical length > or = 15 mm. Univariate as well as multivariate analyses confirmed cervical length to be a significant independent predictor of delivery within 7 days in this population. Conclusions: Sonographic measurement of cervical length helps to avoid overdiagnosis of preterm labor in women with preterm contractions and intact membranes. [ABSTRACT FROM AUTHOR]

Objective: To determine whether sonographic measurement of cervical length in pregnancies complicated by preterm prelabor amniorrhexis helps distinguish between those women who deliver within 7 days and those who do not. Methods: In 101 women with singleton pregnancies presenting with preterm prelabor amniorrhexis at 24-36 (median, 32) weeks of gestation cervical length was measured by transvaginal ultrasound. Exclusion criteria were active labor defined by the presence of cervical dilatation of > or = 3 cm and iatrogenic delivery for fetal or maternal indication when not in active labor. The clinical management was determined by the attending obstetrician. The primary outcome of the study was delivery within 7 days of presentation. Results: Delivery within 7 days of presentation occurred in 58/101 (57%) pregnancies. Logistic regression analysis demonstrated that significant independent contribution in the prediction of delivery within 7 days was provided by cervical length (odds ratio (OR) = 0.91, 95% CI 0.86-0.96, P = 0.001), gestation at presentation (OR = 1.35, 95% CI 1.14-1.59, P = 0.001) and presence of contractions at presentation (OR = 3.07, 95% CI 1.05-8.92, P = 0.039) with no significant independent contribution from ethnic origin, maternal age, body mass index, parity, previous history of preterm delivery, cigarette smoking, vaginal bleeding or the administration of tocolytics, antibiotics or steroids. Conclusion: In women with preterm prelabor amniorrhexis prediction of delivery within 7 days is provided by cervical length, gestation and presence of contractions at presentation. [ABSTRACT FROM AUTHOR]

The article presents a study which assesses the spectral composition and effects of light intensity on woodland plants in Heidelberg, Germany. It suggests that wavelength must be measured first in order to determine which woodland is lighter or darker. It reveals that the composition falls on a horizontal surface about 25 centimeters from the ground where the sky is clear and discrete. The study also claims that the regression of plant growth on light and form of apparent relation influence the color of the light measured.

A simple method for the determination of the lengths and distribution of conduits in plant stems and petioles is described using graphical and algebraic methods. The method proposed by Skene and Balodis (1968) is shown to give improper probability distributions. The data presented by these workers for Eucalyptus 'vessels' is reinterpreted, giving different results, so far as the accuracy of the data will show. The need for great accuracy in determination of conduit lengths from injection profiles is emphasized. [ABSTRACT FROM AUTHOR]

Children 3-6 years of age, when given an identification task where number was redundant to length or density, Solved the task on the basis of number. Surreptitious subtraction or addition elicited strong surprise as well as search behavior whereas displacements did not. Children who noticed the change in number or length and density gave unambiguous explanations of the nature of the intervening operations and were able to indicate how to reverse the effect. These findings are taken to show young children can treat small numbers as invariant. The results are discussed in terms of why children of the same age fail to conserve numbers in the standard conservation task and how complex number concepts might develop. [ABSTRACT FROM AUTHOR]

The article reports on the development of a three-dimensional materials that can bend visible light the wrong way, effectively reversing its direction of travel. The study justifies the idea that all materials found in nature have a positive refractive index, which explains why a rod dipped in water appears disjointed. It is noted that the three-dimensional metamaterials with a negative refractive index are only reported at longer wavelengths.

Lists the names, symbols and equivalence of common quantities allowed in the SI metric system. Length; Time; Mass; Electric current; Force; Pressure.