Axis Length Research Articles

A novel method to study the fragmentation behavior of marine snow aggregates in controlled shear flow

AbstractThe sinking of marine aggregates impacts the global carbon cycle as it is one of the primary sources of carbon export from the surface ocean. Aggregation and fragmentation alter the size of aggregates, which governs their sinking speed. Although aggregation theory is well established, aggregate fragmentation strength and breakup characteristics are less well understood. This study developed a cylindrical tank that formed and then exposed diatom aggregates to calibrated laminar shear through a combined rotating and oscillating motion. The shear rate was predictable using a developed analytical solution for the fluid motion within the tank. Under proper operating conditions, this facility provided fluid shear with a similar magnitude to that in multiple ocean environments. We also developed a unique image processing method that enabled continuous tracking of particles' position, size, and morphology as well as determination of the individual aggregate breakup events. The method has great potential to capture breakup events of large marine snow particles, quantify the aggregate morphological changes leading up to and at breakup, and provide data sufficient for statistical analysis of laboratory aggregate populations. We tested the method using laboratory‐cultured Odontella aurita and captured 79 breakup events of the resulting aggregates. These fragmented aggregates ranged from 1 to 5 mm in major axis length and underwent substantial morphological evolutions prior to the fragmentation.

An Analysis of Trace Information of Different-shaped Fracture Networks Having a Same Fracture Intensity (P32)

Discrete fracture network (DFN) simulation is the basis of studying the properties of a rock mass. An important premise of constructing three-dimensional (3-D) DFNs is to ensure that the fracture intensity (P32) of the simulated rock mass equals to that of the real one. In fact, the natural fracture shapes are various, and we can only obtain one-dimensional (1-D) and two-dimensional (2-D) measurements of a rock mass and usually infer 3-D DFNs based on 1-D and 2-D measurements. The following question would be induced: whether the DFNs with the same P32 and different shapes have similar 2-D trace information. Hence, a series of hypothetical 3-D elliptical DFNs with different values of long-short axis length ratio ke are constructed, and disc models are used to represent them. The algorithms of obtaining traces on sampling windows concerning circular and elliptical fractures are developed. The results show that as the values of ke increase, the error rate of the trace numbers and lengths between the elliptical fractures and simulated disc models on the same sampling windows increases. Moreover, because of the significant impact of fracture shape, the Accuracy representation Index is proposed to better evaluate which model is more appropriate for constructing DFNs.

The Mass Scale of High-redshift Galaxies: Virial Mass Estimates Calibrated with Stellar Dynamical Models from LEGA-C

Dynamical models for 673 galaxies at z = 0.6–1.0 with spatially resolved (long-slit) stellar kinematic data from LEGA-C are used to calibrate virial mass estimates defined as , with K a scaling factor, the spatially integrated stellar velocity second moment from the LEGA-C survey, and R the effective radius measured from a Sérsic profile fit to Hubble Space Telescope imaging. The sample is representative for M ⋆ > 3 × 1010 M ⊙ and includes all types of galaxies, irrespective of morphology and color. We demonstrate that using R = R sma (the semimajor axis length of the ellipse that encloses 50% of the light) in combination with an inclination correction on produces an unbiased M vir. We confirm the importance of projection effects on by showing the existence of a similar residual trend between virial mass estimates and inclination for the nearby early-type galaxies in the ATLAS3D survey. Also, as previously shown, when using a Sérsic profile-based R estimate, a Sérsic index-dependent correction to account for nonhomology in the radial profiles is required. With respect to analogous dynamical models for low-redshift galaxies from the ATLAS3D survey we find a systematic offset of 0.1 dex in the calibrated virial constant for LEGA-C, which may be due to physical differences between the galaxy samples or an unknown systematic error. Either way, with our work we establish a common mass scale for galaxies across 8 Gyr of cosmic time with a systematic uncertainty of at most 0.1 dex.

Bone Density and Bone Geometry in University Athletes From Sports With Different Levels of Impact: Simultaneous Association With Multiple Factors.

Moraes, MS, Fernandes, RA, Moreno, YMF, Pelegrini, A, and Silva, DAS. Bone density and bone geometry in university athletes from sports with different levels of impact: simultaneous association with multiple factors. J Strength Cond Res 36(11): 3113-3121, 2022-The aim of this study was to use the bone loading unit (BLU) classification to compare bone density and bone geometry of sports with different levels of impact, simultaneously controlling the multiple factors that interfere with bone metabolism in athletes. Overall, 167 university athletes (92 men) participated in the study. Bone mineral density (BMD), strength index, cross-sectional area (CSA) at the moment of inertia, section modulus (Z), CSA, neck-shaft angle (NSA), and hip axis length (HAL) were measured. Sports were categorized by level of impact, high BLU (higher impact) and moderate/low BLU (lower impact). Covariates were fat mass, lean tissue mass, training volume, time of practice, dietary supplementation, use of oral contraceptives and menstrual status. Multiple linear regression with 5% significance level ( p < 0.05) was used. In men, HAL was higher in sports with high BLU compared with those with moderate/low BLU (β: -0.21; R2 : 0.30; p = 0.03). In women, NSA was higher in sports with moderate/low BLU compared with those with high BLU (β: 0.31; R2 : 0.11; p = 0.02). There was no difference between BLU groups for BMD. These results persisted when the simultaneous interference of covariates was controlled. Thus, this study recommends BLU to classify sports and reinforces the importance of monitoring HAL and NSA in athletes in addition to the control of multiple factors that interfere with bone metabolism, because they influence physical performance and bone health during and after athletic life.

Assessment of cardiac dimensions in children diagnosed with hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is an inherited autosomal dominant heart disease, characterized by increased left ventricular wall thickness and abnormal loading conditions. Imaging modalities are the first choice for diagnosis and risk stratification. Although heart dimensions have been characterized widely in HCM adults from cardiac imaging, there is limited information about children affected by HCM. The aim of this study is to evaluate left ventricular function and left heart dimensions in a small population of children diagnosed with HCM. A total of 16 (seven male, nine female) pediatric patients with an average age of 14.0±2.5 years diagnosed with HCM at Great Ormond Street Hospital for Children were included in this study. Cardiac magnetic resonance (CMR) images were used to measure left and right ventricular dimensions, and septal and left ventricular free wall thicknesses in Simpleware ScanIP. The gender groups were compared using student t-test or non-parametric Mann-Whitney U-test depending on the sample distribution. Differences in heart rate, left ventricular end-diastolic volume and end-diastolic volume index, left ventricular stroke volume and stroke volume index, left ventricular end-systolic long axis length, left ventricular end-systolic long axis length index, left ventricular end-diastolic mid-cavity diameter, left ventricular end-diastolic free wall thickness, left ventricular end-diastolic free wall thickness index, right ventricular end-diastolic long axis length were statistically significant in males and females. Left ventricular wall and intraventricular septal thickness increase affecting left ventricle cavity dimensions and there may be differences in anatomical and physiological parameters in males and females affected by HCM.

Age Related Trends in Structural Indices of Proximal Femur in Women Aged 20-70 in Southern Sri Lanka

Age related trends of the indices of hip structure help understanding how bone strength changes with age and the increased bone fragility in old age. Community-dwelling women aged 20-70years (n = 419) were selected by stratified random method and divided into age categories; 20-29years (n-69), 30-39years (n = 60), 40-49years (n = 69), 50-59years (n = 107) and 60-70years (n = 114). All subjects underwent dual energy x-ray absorptiometry (DXA) and hip structure analysis using Hologic Discovery scanner (Hologic Inc, Bedford, USA). Measured indices included hip axis length (HAL) and neck shaft angle (NSA) of the proximal femur. Cross sectional area (CSA), cross sectional moment of inertia (CSMI), section modulus (SM), cortical thickness (CT), buckling ration (BR) of three regions of interest; narrow neck, intertrochanteric region and femoral shaft, were also measured. Age related trends of all indices were studied with Locally Weighted Scatterplot Smoothing lines (LOESS) and ANOVA. Mean HAL and NSA values were not different between age categories. CSA, CSMI, SM and CT in three different regions showed curvilinear relationships with age. These indices gradually increased with age between 20-50 years and the maximum values were seen in the 40-49years age category and they declined afterwards. The decline of these indices was more rapid in the narrow neck and intertrochanter regions when compared with femoral shaft and the lowest mean CSA, CSMI, SM and CT in these two regions were seen in the 60-70 age category. BR showed a gradual decrease with age between 20-50 years and the lowest mean value was seen in the 40-49 age category. BR increased afterwards and the maximum mean value was seen in the 60-70 age category. This study demonstrates the dynamics of structural properties of proximal femur in the three selected cross sections of community-dwelling women aged 20-70 years and the increased bone fragility in old age.

Combining genome size and pollen morphology data to study species relationships in the genus Daucus (Apiaceae)

BackgroundThe genus Daucus (Apiaceae) comprises about 40 wild species and the cultivated carrot, a crop of great economic and nutritional importance. The rich genetic diversity of wild Daucus species makes them a valuable gene pool for carrot improvement breeding programs. Therefore, it is essential to have good knowledge of the genome structure and relationships among wild Daucus species. To broaden such knowledge, in this research, the nuclear DNA content for 14 Daucus accessions and four closely related species was estimated by flow cytometry and their pollen morphology was analyzed by light and scanning electron microscopy (SEM).ResultsThe flow cytometric analysis showed a 3.2-fold variation in the mean 2C values among Daucus taxa, ranging from 0.999 (D. carota subsp. sativus) to 3.228 pg (D. littoralis). Among the outgroup species, the mean 2C values were 1.775–2.882 pg. The pollen grains of Daucus were tricolporate, mainly prolate or perprolate (rarely) in shape, and mainly medium or small (rarely) in size (21.19–40.38 µm), whereas the outgroup species had tricolporate, perprolate-shaped, and medium-sized (26.01–49.86 µm) pollen grains. In the studied taxa, SEM analysis revealed that exine ornamentation was striate, rugulate, perforate, or the ornamentation pattern was mixed. At the time of shedding, all pollen grains were three-celled, as evidenced by DAPI staining. We also found high positive correlations between the length of the polar axis (P) and the length of the equatorial diameter (E) of pollen grains, as well as between P and P/E. However, when comparing cytogenetic information with palynological data, no significant correlations were observed.ConclusionsThis study complements the information on the nuclear DNA content in Daucus and provides comprehensive knowledge of the pollen morphology of its taxa. These findings may be important in elucidating the taxonomic relationships among Daucus species and can help in the correct identification of gene bank accessions. In a broader view, they could also be meaningful for the interpretation of evolutionary trends in the genus.

Analytical and numerical investigation of Poiseuille flow through semi-elliptic annulus

A fully developed laminar flow through semi-elliptic annulus formed between two confocal elliptical ducts, driven by a constant pressure-gradient, has been analyzed. The elliptic cylindrical coordinate system has been used to determine the exact solutions for “wide” and “narrow” semi-elliptic annuli with cross sections being symmetric about the minor and major axes of the confocal elliptic boundaries, respectively. For both configurations, exact analytical expressions have been obtained for velocity distribution, volume flow rate, shear stress, and Poiseuille number. The results are expressed in terms of two non-dimensional physical parameters: the ratio of the length of the semi-minor axis to the semi-major axis of the outer boundary, ro, 0 ≤ro&amp;lt;1, and the ratio of the length of semi-major axes of inner and outer elliptic boundaries, rma, c ≤rma&amp;lt;1, with c being the non-dimensional focal distance of the elliptic boundaries. Based on the analytical expressions, the graphical and tabulated results of the flow fields are presented for representative values of ro and rma to illustrate the characteristic features of the flow. Numerical evaluation of the analytical expressions shows that the flow field and the corresponding distributions of velocity and shear stresses are characteristically different for wide and narrow semi-elliptic annuli. In addition to the analytical results, a bivariate Chebyshev pseudospectral method is formulated in the elliptic-cylindrical coordinate system for obtaining the numerical solution of the problem. The numerical results show that the proposed method yields “exponential convergence” or “infinite order of accuracy,” as expected from a spectral method; exact agreement has been observed between the analytical and numerical results.

Identification of Resistor Types Using Extreme Learning Machine Algorithms and Morphological Operation

Electronic components are the basic elements to form a series of electronic devices that are usually used in everyday life. For someone who studies the field of electricity, knowledge of electrical components is an important thing. One of the components whose use is most often found in electronic circuits is a resistor. However, some people do not know about these types of resistors. Especially for someone or a student who will learn about electronic components. This study aims to develop an image processing system that can identify transistor type images using the Extreme Learning Machine (ELM) algorithm. This algorithm performs integrated learning through a special form of feedforward perceptron which has one hidden layer. In order for the ELM algorithm to work properly, information about the features contained in the object to be identified is needed. So, in this study the ELM algorithm is combined with morphological characteristics through parameters such as area, perimeter, eccentricity, major axis length, and minor axis length. Based on these parameters, features will be obtained which will be input in the identification process. At the evaluation stage, the precision value was 87%, recall was 84.47% and accuracy was 85.5%.

Design and optimization of a novel ellipsoidal baffle mixer with high mixing efficiency and low pressure drop

AbstractBACKGROUNDThroughput, mixing efficiency and pressure drop are three key performance indicators of a mixer or reactor. However, it is difficult to simultaneously achieve high throughput, high mixing efficiency and low pressure drop in a traditional mixer.RESULTSA novel mixer was designed and constructed by adding an ellipsoidal baffle to a large‐scale Y‐shaped mixer (YEBM) through computational fluid dynamics. The effects of ellipsoid period length, short and long axes, rotation direction, rotation angle and entrance angle of the mixer on mixing and flow characteristics were investigated and optimized. Compared with a 1 mm mixer, the throughput of the optimized YEBM is increased 100 times, the mixing efficiency is comparable and the pressure drop is reduced by 7.4%. Additionally, the application range of the YEBM with high mixing efficiency is extended to 499.1 &lt; Re &lt; 999.8.CONCLUSIONSThe results showed that the novel ellipsoidal baffle mixer could effectively enhance performance and reduce the pressure drop on the premise of ensuring high throughput. All the findings reported provide useful references for enhancement of mixing efficiency and reduction of pressure drop in a large‐scale mixer. © 2022 Society of Chemical Industry (SCI).

Wear characteristics of multi-tooth milling cutter in milling CFRP and its impact on machining performance

Multi-tooth milling cutters with segmented right-hand helical cutting edge (SRHCE) and segmented left-hand helical cutting edge (SLHCE) could effectively reduce milling damages for carbon fiber reinforced polymer (CFRP) composites. However, rapid tool wear is still challenging for long-distance milling, and especially wear characteristics of multi-tooth milling cutter and their impacts have not been fully understood. This paper investigated the wear characteristics of the uncoated multi-tooth milling cutter with SLHCE and SRHCE under various feeds per tooth (0.01–0.15 mm/tooth) and a constant spindle speed of 3000 rpm and the effects of tool wear on machining performance by theoretical and experimental analyses. SLHCE and SRHCE experienced abrasive wear, while the wear of SLHCE is slighter than SRHCE because a clearance was formed between SLHCE and nominal tool periphery. Consequently, the profiles of worn SRHCE and SLHCE were different, and they were in ellipse arc and circular arc shape, respectively. The half axis length of ellipse arc worn profile of SRHCE decreased significantly with increasing feed per tooth, while the cutting edge radius of SLHCE changed irregularly. As tool wear aggravated with longer cutting distance, the machining qualities generally worsened, including increased burr damages and surface roughness, and cutting force also increased. Fewer burr damages were found on the top ply, as SLHCE dominated the cutting of the top ply with slighter tool wear because of the clearance, compared to the bottom ply, where SRHCE dominated cutting. In addition, the lowest feed per tooth (0.01 mm/tooth) induced severe tool wear and produced worse machining qualities, especially under longer cutting distances, while the milling force was relatively low. Therefore, more attention should be paid to the SRHCE for multi-tooth milling cutters, and a higher feed rate is preferred under similar conditions.

Numerical study of heat transfer and fluid flow of supercritical water in twisted spiral tubes

ABSTRACT Supercritical water (SCW) as fluid with enough potential abilities such as high thermal efficiency can be replaced in water cooling systems. However, helical pipes are the most common type of swirl generators used for heat transfer enhancement, and their geometrical parameters contribute significantly to the compactness and efficiency of heat exchangers. In this study, for the Reynolds ranges of 8000–20000, a numerical study is performed to investigate SCW flow within circular tube, twisted oval tube and twisted multi-lobe tubes. Effects of such parameters as cross-section shapes and lobed numbers on heat transfer performance and flow physics of different spiral tubes were investigated. Results indicated SCW has a contradictory behavior with ordinary water. The results showed that twisted tri-lobed tubes had higher average Nusselt number than circular tube and twisted oval tube, which was 53% and 41%, respectively. Also in these tubes the larger radius of connecting arc and the smaller length of major axis conclude the higher amount like 4%-6% of heat flux due to the enhancement of swirling fluid flow in the pipe and the heat flux. By increasing the number of lobes, the swirling flow rate that is bounded by the lobes will increase.

Defocusing μPTV With Increased Measurement Depth Using Shadowgraphy

In this study we can show that shadowgraphy is a feasible alternative to fluorescence for microscopic particle imaging. Furthermore, using the particle shadow image geometry (diameter for defocusing methods or axis lengths for astigmatism methods), the particle location along the optical axis can be determined, enabling a three-dimensional flow measurement with a single camera. However, the rate of change of the particle shadow image geometry as a function of the distance to the focal plane is one order of magnitude smaller as compared to fluorescence/scattering imaging approaches, such that the measurement depths is effectively increased. This increase is due to the fact that the signal to noise ratio of the relatively small particle shadow images is large, even if the particle is located far away from the focal plane, as the intensity is distributed over a small sensor area. In addition, due to their smaller dimensions, more particle shadow images can be captured on the camera sensor, yielding a larger information density for microscopic particle imaging. A measurement of a micro-channel (channel height: 650 µm) flow showed a good agreement with the ideal parabolic flow profile, proving the viability of this microscopic particle shadow imaging approach as a suitable addition to the existing fluorescence-based methods.

Segmentation with Residual Attention U-Net and an Edge-Enhancement Approach Preserves Cell Shape Features.

The ability to extrapolate gene expression dynamics in living single cells requires robust cell segmentation, and one of the challenges is the amorphous or irregularly shaped cell boundaries. To address this issue, we modified the U-Net architecture to segment cells in fluorescence widefield microscopy images and quantitatively evaluated its performance. We also proposed a novel loss function approach that emphasizes the segmentation accuracy on cell boundaries and encourages shape feature preservation. With a 97% sensitivity, 93% specificity, 91% Jaccard similarity, and 95% Dice coefficient, our proposed method called Residual Attention U-Net with edge-enhancement surpassed the state-of-the-art U-Net in segmentation performance as evaluated by the traditional metrics. More remarkably, the same proposed candidate also performed the best in terms of the preservation of valuable shape features, namely area, eccentricity, major axis length, solidity and orientation. These improvements on shape feature preservation can serve as useful assets for downstream cell tracking and quantification of changes in cell statistics or features over time.

Long-runout pyroclastic density currents: Analysis and implications

Abstract Pyroclastic density currents are hazardous, ground-hugging, hot mixtures of gas and solid particles produced by volcanoes. Currents generated by the largest explosive eruptions have traveled distances on the order of 100 km, and their devastating impact has repeatedly marked Earth's geologic history. We show that pyroclastic density currents from super-eruptions during the Oligocene in the Great Basin of the United States had exceptional runout distances that may have exceeded 300 km. We present a quantitative analysis of the data from these currents and consider, in particular, the areal extent of their deposits (ignimbrites) as well as the relationship between their runout and the eruption mass discharge rate. The ignimbrites have elliptical distributions characterized by axis length ratios of ~2–6, in contrast to common subcircular ignimbrites, while the maximum runouts versus the discharge rates are clearly outside of the prediction intervals defined by other eruption data. We argue that the long runouts resulted from the channeling of concentrated currents in regional paleovalleys whose gentle slope worked to lengthen the travel distance. Our study demonstrates that these additional factors should be considered in assessing hazards posed by future super-eruptions.

Hip Geometry and Proximal Femoral Fractures among Elderly Filipino Women: A Single Centre Cross-Sectional Study.

Introduction:Few controlled studies explore proximal femoral geometry and association with femoral neck (FN) or intertrochanteric (IT) fractures, especially among the elderly Filipino population. Previous reports, however, still reveal multiple inconsistencies. The objective of the study is to establish a possible association between radiographic hip geometry and proximal femoral fractures based on measurements taken from elderly Filipino women.Materials and methods:This is a cross-sectional study of 182 Filipino women ≥ 60 years old at a single institution last 2019-2020. Patients were divided into groups with femoral neck fractures (n=84), intertrochanteric fractures (n=64), and those without diagnosed hip fractures (n=34). Standard pelvic radiographs with control of hip internal rotation was done and the following radiographic parameters were compared: hip axis length (HAL), femoral neck length (FNL), neck shaft angle (NSA), horizontal offset (HO), femoral head diameter (FHD), and femoral neck diameter (FND).Results:Data suggests that an increased FND increased the risk for acquiring both femoral neck (OR = 1.31, 95% CI 1.06 - 1.62; p=.011) and intertrochanteric fractures (OR: 1.22, 95% CI 1.07-2.16; p=0.018). For intertrochanteric fractures alone, a wider NSA (OR 1.27, 95% CI 1.02 - 1.58, p=0.033) and larger HO (OR 1.29, 95% CI 1.02 - 1.64, p=0.036) also increased the risk for this fracture type while a longer HAL was protective (OR 0.85, 95% CI 0.73 - 0.98, p=0.30). Other radiographic parameters and ratios revealed no association.Conclusion:Results show that there are certain hip geometric parameters that play a role in the risk and incidence of developing femoral neck or intertrochanteric fractures. These measurements may aid in identification of patients at risk. This study may act as a guide for future implant design and increase accuracy of hip reconstruction among elderly Filipino women.

Study on the Method of Matched Splice Grafting for Melon Seedlings Based on Visual Image

Due to the cutting mechanism of the existing grafting machine, it cannot adjust the cutting angle in real time, resulting in low fitting precision on the cutting surfaces between the rootstocks and scion seedlings and, thus, seriously affecting the survival rate and quality of the grafting seedlings. In this paper, a kind of splice grafting method based on visual image is proposed, aiming at maximizing the joint rate between cutting surfaces of rootstocks and scion seedlings and realizing precise cutting and grafting of grafting machine. After analysis, we determined that melon rootstock seedlings have a structure of pith cavity inside, and the solid structure from the top of the pith cavity to the left and right base points of a growing point forms the important area of a cutting surface. In order to obtain the geometric model of the cutting surfaces of the seedlings, a visual image analysis system was established to identify, analyze, and model the pith cavity structure inside the rootstock seedling, as well as the external morphological characteristics, and the ultimate cutting angle of the rootstock seedling and cutting surface parameters were determined. By measuring the length of minor axis of scion seedlings in order to achieve the maximum joint rate, the optimal cutting angle of the rootstocks and scion seedlings was determined. Then grafting and seedling cultivation tests were carried out. The test results showed that the range of ultimate cutting angle on rootstock seedlings (Cucurbita moschata) was 18.21 ± 1.92°; the cutting angles of the rootstock (Cucurbita moschata) and scion seedlings (watermelon) were 22° and 19.68°, respectively; the cutting surface length of the two was 4.96 mm; and the cutting surface thickness of the rootstock was 0.13 mm, all of which could satisfy the technological requirements of the matched splice grafting of melons. The research results can serve as a reference for the design in vision-guided precision cutting and real-time grafting operation on grafting robots.

Design and Experiment of Full-Tray Grafting Device for Grafted Melon Seedling Production

At present, the existing vegetable grafting machines are cutting and grafting operations for a single plant or row. They need to manually or automatically grab the seedlings, and their grafting efficiency is not significantly higher than that of manual grafting techniques. In this paper, grafted melon seedlings were the subject of the research. Based on the splice-grafting method, we designed a clamping and positioning device for full-tray seedlings and a mechanical device to realize full-tray grafting by locating the vegetable seedlings and completing the full-tray grafting process without damaging the seedlings. The results show that the cutting success rate for pumpkin rootstock and for melon scion reached 100% and 92%, respectively. The lengths of the long axis of the section of the rootstock and the scion were 6.2–7.7 mm, and the cutting angle was maintained at 30 degrees, thereby able to meet the requirements of the grafting method. The average grafting efficiency for the rootstock and scion were 2134 plants/h, and the average grafting success rate was 67%.

Relationship Between Ovary Size and Anti-Müllerian Hormone Levels in Holstein-Friesian Cows.

The aim of this study was to verify the association between ovarian size and blood AMH levels in HF cows. Sixty multiparous HF cows from three herds were included in this study. The data required for calculating the ovarian volume included the “major axis (length),” “minor axis (width),” and “thickness” of the ovary. All ultrasonography (US) images were acquired at the outermost ends/poles of both the ovaries and of the follicles (>8 mm) and corpus luteum (CL); concomitantly, the blood was sampled from the jugular or coccygeal vein. Based on the ovarian images of each cow, the following ovarian size patterns were calculated using an image analysis software: (1) total area of both the left and right ovaries, (2) individual size of the large ovary, and (3) individual size of the small ovary. For each ovary area pattern, two properties were assessed: (A) presence of follicles (>8 mm) and CL, which may not secret AMH, in the ovaries and (B) absence of follicles (>8 mm) and CL in the ovaries. Serum AMH levels were measured using enzyme-linked immunosorbent assay. The correlation between ovary size and serum AMH levels was measured in terms of the aforementioned patterns and was evaluated statistically. The results of our preliminary study with ovaries from slaughter-house cows (n = 22) revealed that the “thickness” of the ovary was not necessary for estimating ovarian volume and that length and width were sufficient. A strong correlation was observed among ovarian length, width, and thickness (r > 0.96). No significant difference was observed (p > 0.05) in the mean ages or parities among the three herds. Among the ovary sizes measured in this study, the highest correlation was found between the total size of an individual large ovary (including follicular and luteal size) and AMH levels (r = 0.387, p = 0.002). This is the first study to demonstrate the correlation between total size of individual large ovaries and serum AMH levels in HF cows. US observations of the ovaries will allow for estimation of differences in AMH levels and help predict ovarian activity and superovulation performance of cows.

Experimental investigation of inertial fibres and disks in a turbulent boundary layer

We study experimentally the behaviour of negatively buoyant disks and fibres in a turbulent boundary layer. The regime is relevant to the transport of natural sediment or plastic particles in water, with density ratio $\rho _p/\rho _f \sim O(1)$ , major axis lengths $D_p^+ \sim 50$ , friction Stokes numbers $\mbox { {St}}^+ \sim O(10)$ and friction Reynolds number $\mbox { {Re}}_\tau = 620$ . The translational and rotational motion, as well as concentration and dispersion, are compared with those of spheres of similar inertia. Disks and fibres both oversample high-speed fluid near the wall, in agreement with particle-resolved numerical simulations. Fibres tend to orient mostly in the streamwise direction while disks maintain their symmetry axis quasi-normal to the wall. This alignment is more stable for disks than for fibres: the latter undergo strong tumbling near the wall in response to the mean shear and turbulent fluid velocity fluctuations, whereas the former wobble about their preferential wall-normal orientation. The translational and rotational accelerations indicate that, despite the nominal relaxation times being similar, the disks are slower than the fibres in responding to wall turbulence. For both, wall contact causes strong and intermittent tumbling. The concentration profiles follow Rouse–Prandtl theory over a limited portion of the boundary layer, deviating near the wall and in the outer region. This is largely due to the non-uniform settling velocity, which decreases steeply approaching the wall for all particle types. This is, in turn, a consequence of the reduced particle diffusivity, which closely matches the profile of the eddy viscosity.