Coefficient Of Variation Values Research Articles

Comparative assessment of gravitational sedimentation methods for the evaluation of particle-size distribution in soils

The aim of the study was to carry out a comparative analysis of the results by determining of the particle-size distribution in different soil types by the 1) pipette method and 2) measurement device PARIO, using Integral Suspension Pressure plus method (ISP+). Location and time of the study. The study was performed in the Core Research Facility "Physico-chemical Methods of Soil and Ecosystem Research" and in the Department of Soil Cryology of the Institute of Physical-Chemical and Biological Problems of Soil Science the Russian Academy of Sciences. Methods. The determination of the particle-size distribution in soils was carried out by the pipette method and ISP+. Statistical processing of the analytical data was performed by Microsoft Excel and Statistica 12. Results. The determination of the degree of discrepancy between the results of repeated determinations of the particle-size distribution in soils obtained by the pipette method and ISP+ showed that the coefficients of variation (CV) were different for different fractions. High reproducibility of the results was obtained for the clay fraction. For fractions of the coarse and middle silt, the CV values did not exceed 10-20%. The largest variation in the between repeated measurements using both methods was obtained for the fine silt fraction. The assessment of the average difference and its significance for fine silt and clay fractions by the pipette method and ISP+ showed that there were no significant discrepancies. For the coarse and middle silt, such assessment showed significant differences. Most of the studied soils (14 out of 17) obtained the same classification according to the determinations of the soil particle-size distribution by the compared methods. Conclusions. The use of the PARIO measurement device for determining soil particle-size distribution allows to exclude disturbance of the suspension during the test run, to track the time and depth of sampling and to reduce measurement time significantly. This study showed the importance of taking into consideration the method of soil granulometry assessment, as results may be quite different, especially for the fractions of coarse and medium silt, thus affecting soil taxonomic attribution.

Grease the gears: how lubrication of syringe pumps impacts microfluidic flow precision.

Pumps are indispensable for analytical applications and ensure controlled fluid movement. Syringe pumps are among today's most prevalent liquid delivery systems, especially for high-pressure, stable, low-flow-rate microfluidic applications. Due to moving mechanical parts of the assembly, regular maintenance is essential to ensure reliable operation and flow rates. However, lubrication of the mechanics is easily overlooked because the research focuses on novel analytical applications rather than on the maintenance of pumps. Here, we investigate the lubrication of the syringe pump guide rods with its effect on the flow rate stability after regular pump cleaning from contaminations. The guide rods of syringe pumps were thoroughly cleaned from any lubricant, and the flow rate for specified flowrates between 5 and 100 μL min-1 was measured, revealing tremendous flow rate fluctuations with a coefficient of variation (CV) value up to 0.34. In contrast, flow rate measurements of syringe pumps with lubricated guide rods show a five-fold smoother flow rate fluctuation depending on the specified flow rate with CV values below 0.07. These differences in flow rate's CV were most significant for pressure drops below 500 mbar, relevant for many lab-on-a-chip applications. In summary, we emphasize the awareness of lubricating moving parts of syringe pumps to achieve constant flow rates, minimize wear, and ensure the reliable operation of, for instance, accurate lab-on-a-chip workflows.

Changes in mechanical properties at the muscle level could be detected by Nakagami imaging during in-vivo fixed-end contractions.

In this study, we investigated the capability of the Nakagami transformation to detect changes in vastus lateralis muscle-tendon stiffness (k) during dynamic (and intense) contractions. k was evaluated in eleven healthy males using the gold-standard method (a combination of ultrasound and dynamometric measurements) during maximal and sub-maximal voluntary fixed-end contractions of the knee extensors (20, 40, 60, 80, and 100% of maximum voluntary force), while Nakagami parameters were analysed using the Nakagami transformation during the same contractions. Muscle-belly behaviour was investigated by means of B-mode ultrasound analysis, while Nakagami parameters were obtained in post-processing using radiofrequency data. k was calculated as the slope of the force-muscle-belly elongation relationship. Three contractions at each intensity were performed to calculate the intra-trial reliability and the coefficient of variation (CV) of the Nakagami parameters. At all contraction intensities, high values of intra-trial reliability (range: 0.92-0.96) and low CV (<9%) were observed. k and Nakagami parameters increased as a function of contraction intensity, and significant positive correlations were observed between these variables. These data suggest that changes in mechanical properties (e.g., stiffness) at the muscle level could be investigated by means of Nakagami parameters.

FEASIBILITY OF SOYBEAN FARMING IN INDONESIA: A SYSTEMATIC LITERATURE REVIEW

Soybeans are an essential commodity in the Indonesian economy; therefore, the government encourages soybean cultivation at the farmer level. This article aims to analyze variations in the feasibility level of soybean farming in Indonesia, the distribution of R/C values, and its forming parameters based on the results of a research literature review. This paper also attempts to look at the factors that influence R/C achievement and provide input for similar studies in the future. Literature was taken from the Google Scholar database, which published research on the feasibility of soybean farming in Indonesia, published in journals or proceedings, both in Indonesian and English, and published in 2013-2023. A total of 122 articles were screened, around 51 (113 case studies) for further explanation, consisting of 39 journal articles and 12 proceedings articles. The analysis technique uses CV (coefficient of variation) and simple tabulation. All articles concluded that soybean farming was worth cultivating (R/C &gt; 1), but three articles received an R/C value &lt; 1, or soybean farming was not worth cultivating. The highest R/C value is 3.96, and the lowest is 0.50. In contrast, the CV value of R/C shows the lowest value (of 0.33) compared to the CV values of TR, TC, productivity, and selling price of harvest, meaning the distribution The R/C value of soybean farming over the last ten years tends to be homogeneous (does not vary). High productivity does not indicate high R/C achievement, nor do certain superior varieties always show high R/C. Farming feasibility research needs to explain more fully the parameters that form R/C values, use standard writing standards in writing the units for each parameter, and explain varieties, cultivation techniques, and the conditions of farmers in soybean farming.

Determination of Effects the Different Holes Position in the Vacuum Discs of Pneumatic Precision Vegetable Planters on Emergence and Uniform Plant Distribution in Black Carrot Production

The objective of this study was to determine the seed releasing characteristics of seed metering discs used in the precision seeding of black carrot seeds. High precision vegetable seeder was tested in the field conditions using black carrot seeds in Kuzukuyu village of Ereğli-Konya in 2018. Three different seed metering discs that have holes in three different circle positions were used in the experiments. These applications referred to seeding techniques, ST1, ST2 and ST3. The seed metering discs with three trajectories, each diameter was 210, 185, and 155 mm respectively. Each trajectory on vacuum plate using in ST1 had equal number of holes (96 holes), while P1 and P2 hole positions had same number of holes in ST2 ve ST3, however, 25% and 50% decrease in the number of holes in the P3 (bottom hole position), respectively. The downforce on the press wheel was kept constant throughout all trials. In these three different seeding techniques, the planting performance of the machine under field conditions was evaluated and the coefficient of variation values expressing the seed distribution uniformity, mean of the emergence rates were determined. According to the results, the mean of emergence rates and coefficient variation values were determined as %59.86 ve %76.84, %68.91 ve %75.31, %66.26 ve %72.48for ST1, ST2 ve ST3, respectively. Given hole positions (planting rows), emergence rates and CV values were obtained %59.71 ve %81.94 for P1, %62.69 ve %74.49 for P2 and %72.60 ve %68.20 for P3.

Optimised liquid chromatography tandem mass spectrometry method for the simultaneous quantification of serum vitamin D analogues while also accounting for epimers and isobars

The accurate quantification of multiple vitamin D analogues simultaneously is challenging. This study set out to use liquid chromatography-tandem mass spectrometry (LC-MS/MS) to develop a method capable of measuring a comprehensive vitamin D profile, encompassing twelve vitamin D analogues (vitamin D2, D3, 25(OH)D2, 25(OH)D3, 1,25(OH)2D2, 1,25(OH)2D3, 24,25(OH)2D2, 24,25(OH)2D3, 3-epi-25(OH)D2, 3-epi-25(OH)D3, 7αC4 and1α(OH)D3) in a single run. Serum samples were prepared using double liquid–liquid extraction and analysed on an Agilent 6460 QQQ LC-MS/MS equipped with a Pursuit 3 Pentafluorophenyl (4.6 x 100 mm, 3 μm) column. Recovery rates for all analytes were above 95 % with a coefficient of variation (CV) below 10 %. The method exhibited good linearity (r > 0.995) and had a range of detection limits between 0.01 and 0.35 ng/mL and quantification limits between 0.15 and 0.96 ng/mL. Repeatability and within-lab precision were acceptable, with CV values below 10 % and 15 %, respectively. Method accuracy was excellent, with a systematic error below 6.60 %. additionally, all analytes-maintained stability for 48 h following sample preparation, and no interferences were observed among co-eluting analytes. Lastly, this method achieved “world-class” status according to the Sigma metric scale specifications, requiring minimal quality control to ensure data quality. This successfully validated method has the potential not only for improving vitamin D profiling procedures but also for aiding in the diagnosis of other genetic disorders where measuring beyond 25(OH)D is crucial.

Validity and Reliability of the FlightScope Mevo+ Launch Monitor for Assessing Golf Performance.

Brennan, A, Murray, A, Coughlan, D, Mountjoy, M, Wells, J, Ehlert, A, Xu, J, Broadie, M, Turner, A, and Bishop, C. Validity and reliability of the FlightScope Mevo+ launch monitor for assessing golf performance. J Strength Cond Res 38(4): e174-e181, 2024-The purpose of this study was to (a) assess the validity of the FlightScope Mevo+ against the TrackMan 4 and (b) determine the within-session reliability of both launch monitor systems when using a driver and a 6-iron. Twenty-nine youth golfers, with a minimum of 3 years of playing experience, volunteered for this study. All golfers completed 10 shots with a 6-iron and a driver, with 8 metrics concurrently monitored from both launch monitor systems in an indoor biomechanics laboratory. For both clubs, Pearson's r values ranged from small to near perfect ( r range = 0.254-0.985), with the strongest relationships evident for clubhead speed (CHS) and ball speed ( r ≥ 0.92). Bland-Altman plots showed almost perfect levels of agreement between devices for smash factor (mean bias ≤-0.016; 95% CI: -0.112, 0.079), whereas the poorest levels of agreement was for spin rate (mean bias ≤1,238; 95% CI: -2,628, 5,103). From a reliability standpoint, the TrackMan showed intraclass correlation coefficients (ICCs) ranging from moderate to excellent (ICC = 0.60-0.99) and coefficient of variation (CV) values ranged from good to poor (CV = 1.31-230.22%). For the Mevo+ device, ICC data ranged from poor to excellent (ICC = -0.22 to 0.99) and CV values ranged from good to poor (CV = 1.46-72.70%). Importantly, both devices showed similar trends, with the strongest reliability consistently evident for CHS, ball speed, carry distance, and smash factor. Finally, statistically significant differences ( p < 0.05) were evident between devices for spin rate (driver: d = 1.27; 6-iron: d = 0.90), launch angle (driver: d = 0.54), and attack angle (driver: d = -0.51). Collectively, these findings suggest that the FlightScope Mevo+ launch monitor is both valid and reliable when monitoring CHS, ball speed, carry distance, and smash factor. However, additional variables such as spin rate, launch angle, attack angle, and spin axis exhibit substantially greater variation compared with the TrackMan 4, suggesting that practitioners may wish to be cautious when providing golfers with feedback relating to these metrics.

Derivation of stainless steel material factors for European and U.S. design standards

Modern structural design standards are based on the Limit State Design (LSD) philosophy, also known as Load and Resistance Factor Design (LRFD), which involves the use of resistance functions with accompanying safety factors that are based on a statistical evaluation of relevant experimental data, carried out within the framework of a probabilistic reliability theory. This paper presents the derivation of material factors for the yield strength and ultimate tensile strength of austenitic, duplex and ferritic stainless steels, and their associated coefficients of variation (COV) for use in evaluating the safety factors for the European design code EN 1993-1-4 and the American design codes Specification for Structural Stainless Steel Buildings (ANSI/AISC 370–21) and Specification for the Design of Cold-Formed Stainless Steel Structural Members (ASCE/SEI 8–22). Separate material factors and associated COV values are required for the U.S. and European design codes due to the different minimum specified strength values that are given in the respective product standards. The material factors were derived by analysing a large amount of material data provided by different stainless steel producers, which encompassed a wide range of stainless steels and material thicknesses.

Diagnostic Efficacy of Photostimulated Chemiluminescence Assay for Detecting Anti-HIV Antibodies: A Retrospective Study.

The transmission of human immunodeficiency virus (HIV) through blood poses a slightly increased risk. As a result, patients requiring blood transfusions should be screened for HIV antibodies. This study examined the diagnostic effectiveness of the photostimulated chemiluminescence assay in detecting anti-HIV antibodies and determined the cut-off value for this method. The performance of the fully automated photostimulated chemiluminescence assay system was validated according to CNAS-GL038:2019 (2020) and CNAS-GL037:2019 (2019) guidelines. A retrospective study was conducted at the Department of Medical Laboratory, Nanjing Tongren Hospital, affiliated with Southeast University, from January 2020 to December 2022. A total of 77,386 cases were tested for anti-HIV antibodies using the photostimulated chemiluminescence assay, with 79 cases initially testing positive. The method's performance in detecting anti-HIV antibodies was evaluated using the Receiver Operating Characteristic (ROC) curve and the average Coefficient of Variation (CV) value of 3-year in-house quality control. The precision, detection limit, coincidence rate, and critical value of the performance verification results met the requirements. Using Western blotting (WB) as the reference method, positive cases were initially screened using the light-induced chemiluminescence method to determine the cut-off index (COI) value and draw the ROC curve. The maximum area under the ROC curve using the chemiluminescence method was 0.997, with a cutoff value of < 28.56, sensitivity of 98%, specificity of 100%, Jordan index of 0.98, and an average CV value of 3.55%. In conclusion, the photostimulated chemiluminescence assay has good diagnostic efficacy in detecting anti-HIV antibodies and is suitable for rapid screening before blood transfusion and surgery.

Near‐Nozzle Mixing for Additive Manufacturing of Cementitious Mortar: A Homogeneity Study

AbstractThis paper investigates the Near‐nozzle Mixing (NNM) technique for 3D printing cementitious mortar, focusing on achieving continuous and homogeneous material properties. The NNM's ability to print Natural Sand Mortar (NSM), Recycled Aggregate Mortar (RAM), and Lightweight Mortar (LWM) was assessed. Fresh and hardened properties of each mortar were examined, emphasizing standard deviation (STD) and coefficient of variation (CV) to measure material homogeneity. Fresh properties included slump flow, yield stress, air void volume, density, and water‐to‐cement ratio, while hardened properties covered compressive strength, flexural strength, hardened density, and thermal conductivity. Results showed low CV values for all mortar types, indicating high consistency and homogeneity. NNM showed is capability to print of various materials with customized properties. NSM showed the highest compressive strength, RAM balanced strength and sustainability, and LWM provided the best thermal insulation. The study highlights NNM's versatility and potential for construction applications requiring tailored properties, proving it a promising additive manufacturing solution. The research serves as a foundation for future studies on graded multi‐material printing.

Quantifying GFAP immunohistochemistry in the brain – Introduction of the Reactivity score (R-score) and how it compares to other methodologies

BackgroundImmunohistochemical upregulation of glial fibrillary acidic protein (GFAP) is commonly used to detect astrogliosis in tissue sections and includes measurement of intensity and/or distribution of staining. There remains a lack of standard objective measures when diagnosing astrogliosis and its severity. New methodAim was to test a novel semi-quantitative assessment of GFAP which we term reactivity (R)-score, on its reproducibility and sensitivity to measure astrogliosis. The R-score, which is based on the proportion of astrocytes seen at each level of reactivity, was compared to 3 other commonly employed quantification methods in research: (1) thresholding, (2) point-counting, and (3) qualitative grading. Sub-regions of the hippocampus, medulla, and cerebellum were studied in piglet, and 4 human cases with clinically reported astrogliosis. Intra-assay coefficient of variation (CV) and percentage agreement cut-offs of ≤ 20% and ≥ 75% were used respectively to compare amongst the methods, with outcome measures being reproducibility across serial and non-serial sections, resilience to changes in experimental conditions, and inter- and intra-rater concordance. ResultsAveraged across 3 brain regions, the intra-assay coefficient of variation (CV) was 5% for R-score, with inter and intra-rater kappa scores being 0.99 and 0.95 respectively. Comparison with existing methods and conclusionsBased on CV values, the R-score was superior to thresholding (CV of 51%) and point-counting (CV of 16%), with the qualitative grade being found to be on par (percentage agreement 95%). Given the ease, reproducibility and selectivity of the R-score, we propose its validity in future research purposes and clinical application.

Global ozone variability

In this work total column ozone (TCO) analysis and variability over globe has been studied during the period 1959–2022 using monthly mean data from ERA5 reanalysis database. The lower values of TCO occurs in equatorial latitudes, while the higher values of TCO appears over the mid-latitude and subpolar latitudes in both hemispheres (slightly farther poleward in the NH). The higher values of the coefficient of variation (CV) of TCO in NH and SH occur over the mid-latitude and subpolar latitudes, it increases gradually latitudinally poleward of 40°N. The lower values of CV appears over tropical and subtropical regions (between 40°S and 40°N). The trend study for the seasonal and annual spatial distribution of TCO divided the globe into three belts the trend values in the first belt (40°N- 90°N) are negative the trend values of TCO in the second belt (40°S- 40°N) are positive (increasing TCO). The third belt (40°S to 90°S) is characterized by the existence of negative trend values of TCO. The study of the Manne Whitney test for abrupt change of the time series of TCO for the three-time series of NHB confirms that there is abrupt change in TCO around the year 1971, 1979, 1992 (increasing) and 2013 (decreasing).

Fixed Spraying Systems Application in Citrus Orchards: Nozzle Type and Nozzle Position Effects on Droplet Deposition and Pest Control

Pesticide application is an essential means of controlling plant diseases and pests in citrus orchards. In recent years, fixed spraying systems have gradually been used as alternatives to traditional sprayers and manual sprayers in some hilly citrus orchards. In this paper, influences of fixed system spraying parameters, such as droplet size and spraying height, on spraying quality were elucidated and analyzed. The performances of two nozzle types, pressure-swirl nozzles and fixed spray plate sprinklers, were assessed and compared by effective droplet coverage ratio (DCR), droplet distribution uniformity coefficient of variation (CV), and droplet penetration ratio (DPR). The results showed that appropriately increasing droplet size and spraying height could improve the DCR and distribution uniformity of pressure-swirl nozzles. The DCR and distribution uniformity of fixed spray plate sprinklers had a positive correlation with droplet size, while spraying height had no significant effect on these variables. Additionally, with the increase in droplet size, DPR initially increased and then gradually decreased. The optimized results showed that the optimal parameters for pressure-swirl nozzles were a droplet size of 240 μm and spraying height of 100 cm, while for fixed spray plate sprinklers, the results were a droplet size of 240 μm and spraying height of 50 cm. Comparison results showed that the spraying quality of fixed spray plate sprinklers was better overall, with values of DCR, CV, and DPR being 37.15%, 24.20%, and 71.67%, respectively, while the corresponding values for pressure-swirl nozzles were 39.65%, 35.41%, and 56.02%. Based on the above results and the occurrence rule of citrus pests and disease, the optimal spraying parameters of fixed spraying systems were selected to control the Asian citrus psyllid Diaphorina citri. Furthermore, the effect of fixed spraying systems on controlling Diaphorina citri reached the maximum at 3 days after spraying, which was 97.83%, and the effect declined at 14 days after spraying, which was 85.47%. This study provides valuable scientific references for guiding the application of fixed spraying systems in hilly citrus orchards.

Investigating the role of imaging factors in the variability of CT-based texture analysis metrics.

This study assesses the robustness of first-order radiomic texture features namely interquartile range (IQR), coefficient of variation (CV) and standard deviation (SD) derived from computed tomography (CT) images by varying dose, reconstruction algorithms and slice thickness using scans of a uniform water phantom, a commercial anthropomorphic liver phantom, and a human liver in-vivo. Scans were acquired on a 16cm detector GE Revolution Apex Edition CT scanner with variations across three different nominal slice thicknesses: 0.625, 1.25, and 2.5mm, three different dose levels: CTDIvol of 13.86 mGy for the standard dose, 40% reduced dose and 60% reduced dose and two different reconstruction algorithms: a deep learning image reconstruction (DLIR-high) algorithm and a hybrid iterative reconstruction (IR) algorithm ASiR-V50% (AV50) were explored, varying one at a time. To assess the effect of non-linear modifications of images by AV50 and DLIR-high, images of the water phantom were also reconstructed using filtered back projection (FBP). Quantitative measures of IQR, CV and SD were extracted from twelve pre-selected, circular (1cm diameter) regions of interest (ROIs) capturing different texture patterns across all scans. Across all scans, imaging, and reconstruction settings, CV, IQR and SD were observed to increase with reduction in dose and slice thickness. An exception to this observation was found when using FBP reconstruction. Lower values of CV, IQR and SD were observed in DLIR-high reconstructions compared to AV50 and FBP. The Poisson statistics were more stringently noted in FBP than DLIR-high and AV50, due to the non-linear nature of the latter two algorithms. Variation in image noise due to dose reduction algorithms, tube current, and slice thickness show a consistent trend across phantom and patient scans. Prospective evaluation across multiple centers, scanners and imaging protocols is needed for establishing quality assurance standards of radiomics.

Determination of Soil Fertility Characteristics and Heavy Metal Health Risks Using the Camellia oleifera Planting Base in Guizhou Province, China

To clarify the soil nutrient status and identify the safety risks of heavy metals in Camellia oleifera planting regions, the integrated soil fertility status was assessed using the improved Nemero composite index method, weighted average method, and coefficient of variation (CV) method, and the impact of heavy metals in the soil on human health was evaluated with a health risk assessment model using the Qianyu C. oleifera planting base in Yuping County, Guizhou Province, as the study object. The results showed the following: (1) The soil pH levels were 4.12–6.17, with CV values of 0.04–0.66, and no significant differences were observed among the plots. The soil was rich in organic matter, alkali-hydrolyzed nitrogen, and available phosphorus, with a high total potassium content, total phosphorus content, and rapidly available potassium, indicating a high level of comprehensive soil fertility. (2) The total carcinogenic risk (CR) index of the arsenic (As), cadmium (Cd), and chromium (Cr) in the soil was 1.92 × 10−7, and among these elements, the CR index of the As was the highest (1.3–8.0 × 10−7), but all were below the highest acceptable level (10−6) recommended by the United States Environmental Protection Agency (USEPA). (3) The redundancy analysis (RDA) between the soil fertility and trace elements revealed that the soil organic matter content was positively correlated with the contents of lead (Pb), manganese (Mn), and Cr and negatively correlated with the contents of zinc (Zn), iron (Fe), Cd, mercury (Hg), As, and copper (Cu). The soil pH was positively correlated with the contents of Cr, Fe, and Cu and negatively correlated with the contents of Mn, Pb, Zn, Cd, Hg, and As. In the study area, the soil was slightly acidic with overall high fertility without any CR. The quality of the C. oleifera was degraded by soil acidification, but the slightly acidic soil facilitated the absorption of trace elements by C. oleifera. Soil acidification could be relieved by taking appropriate measures, such as the addition of biochar or CaCO3. This study determined the soil fertility of the Qianyu C. oleifera planting base and assessed the health risk of heavy metals in the soil, providing a theoretical reference for enhancing C. oleifera quality, preventing the excessive accumulation of soil heavy metals, and improving the soil in this planting base.

Repeatability and Agreement of Chord Mu Between Scheimpflug Tomography and Swept-source Optical Coherence Tomography.

To evaluate repeatability and agreemeny of chord mu between Scheimpflug tomography (Pentacam HR, Oculus Optikgeräte GmbH, Wetzlar, Germany) and swept-source optical coherence tomography-based optical biometer (IOLMaster 700, Carl Zeiss Meditec AG, Jena, Germany). In this retrospective study, 63 eyes of 33 patients were included. Chord mu, X, and Y Cartesian distances between the corneal vertex and the pupil center (Px and Py), and the pupil diameter were compared using two instruments. Repeatability was evaluated using intraclass correlation coefficient (ICC), coefficient of variation (CoV), and within-subject standard deviation (Sw). Inter-device agreement was evaluated using paired t-tests and Bland-Altman plots. Although Sw values for all parameters were similar between the two devices, CoV values of chord mu and pupil diameter were lower, and ICC values of those parameters were higher, in the IOLMaster 700 than in the Pentacam HR. Chord mu and pupil diameter values were higher in IOLMaster 700 than Pentacam HR (p < 0.01). The width of the 95% limit of agreement was wide for all parameters. IOLMaster 700 showed better repeatability than Pentacam HR in chord mu, Px, Py, and pupil diameter values. Because there were statistically significant differences and a low level of agreement in chord mu and pupil diameter values between the two devices, they cannot be used interchangeably.

Reliability of phase-specific outcome measurements in change-of-direction tests using a motorized resistance device.

This study aims to determine test-retest reliability of phase-specific information during initial acceleration, deceleration, and re-acceleration phases of different change-of-direction (CoD) tests using a motorized resistance device (MRD). A total of 21 participants (16 males and five females, with mean age of 22.3 ± 3.9 years, body mass of 75.2 ± 6.9 kg, height of 177.9 ± 6.8 cm) completed the modified 505 (m505), 10-0-5, and 15-0-5 CoD tests on four different test sessions while exposed to an external load (3 kg) provided by the MRD. Outcome variables included overall and phase-specific kinetic (force, power, and impulse) and kinematic (time, distance, velocity, and acceleration/deceleration) data during the initial acceleration, deceleration, and re-acceleration phases. The deceleration and re-acceleration phases were further divided into two subphases, namely, early and late subphases, using 50% of maximum velocity. Reliability was assessed using an intraclass correlation coefficient (ICC), coefficient of variation (CV), typical error (TE), and minimal detectable change (MDC). Good to excellent ICC values (>0.75) and acceptable (<10%) to good (<5%) CV values were observed for most outcome measurements. Specifically, 80.1% (822 out of 1,026) of all variables showed good or better relative reliability (i.e., ICC ≥ 0.75), while 97.0% (995 out of 1,026) of all variables showed acceptable or better absolute reliability (i.e., CV < 10%). In conclusion, the present study demonstrates that the MRD can obtain reliable phase-specific outcome measurements across different CoD tests, providing coaches and researchers with new opportunities to advance our understanding of CoD ability and inform more advanced CoD training prescriptions.

Serum Cytokines and Growth Factors in Subjects with Type 1 Diabetes: Associations with Time in Ranges and Glucose Variability.

The detrimental effect of hyperglycemia and glucose variability (GV) on target organs in diabetes can be implemented through a wide network of regulatory peptides. In this study, we assessed a broad panel of serum cytokines and growth factors in subjects with type 1 diabetes (T1D) and estimated associations between concentrations of these molecules with time in ranges (TIRs) and GV. One hundred and thirty subjects with T1D and twenty-seven individuals with normal glucose tolerance (control) were included. Serum levels of 44 cytokines and growth factors were measured using a multiplex bead array assay. TIRs and GV parameters were derived from continuous glucose monitoring. Subjects with T1D compared to control demonstrated an increase in concentrations of IL-1β, IL-1Ra, IL-2Rα, IL-3, IL-6, IL-7, IL-12 p40, IL-16, IL-17A, LIF, M-CSF, IFN-α2, IFN-γ, MCP-1, MCP-3, and TNF-α. Patients with TIR ≤ 70% had higher levels of IL-1α, IL-1β, IL-6, IL-12 p70, IL-16, LIF, M-CSF, MCP-1, MCP-3, RANTES, TNF-α, TNF-β, and b-NGF, and lower levels of IL-1α, IL-4, IL-10, GM-CSF, and MIF than those with TIR > 70%. Serum IL-1β, IL-10, IL-12 p70, MCP-1, MCP-3, RANTES, SCF, and TNF-α correlated with TIR and time above range. IL-1β, IL-8, IL-10, IL-12 p70, MCP-1, RANTES, MIF, and SDF-1α were related to at least one amplitude-dependent GV metric. In logistic regression models, IL-1β, IL-4, IL-10, IL-12 p70, GM-CSF, HGF, MCP-3, and TNF-α were associated with TIR ≤ 70%, and MIF and PDGF-BB demonstrated associations with coefficient of variation values ≥ 36%. These results provide further insight into the pathophysiological effects of hyperglycemia and GV in people with diabetes.

Variability in Capillary Perfusion Is Increased in Regions of Retinal Ischemia Due to Branch Retinal Vein Occlusion.

To investigate alterations in macular perfusion variability due to branch retinal vein occlusion (BRVO) using a novel approach based on optical coherence tomography angiography (OCTA) coefficient of variation (CoV) analysis. Thirteen eyes of 13 patients with macular ischemia due to BRVO were studied. Multiple consecutive en face OCTA images were acquired. Bias field correction, spatial alignment, and normalization of intensities across the images were performed followed by pixelwise computation of standard deviation divided by the mean to generate a CoV map. Region of interest-based CoV values, derived from this map, for arterioles, venules, and the microvasculature were compared between regions with macular ischemia and control areas of the same eye. Control areas were regions of the same macula that were not affected by the BRVO and had normal retinal vascular structure as seen on multimodal imaging and normal retinal vascular density measurements as quantified using OCTA. CoV increased by a mean value of 17.6% within the microvasculature of ischemic regions compared to the control microvasculature (P < 0.0001). CoV measurements of microvasculature were consistently greater in the ischemic area of all 13 eyes compared to control. There were no differences in CoV measurements between ischemic and control areas for arterioles (P = 0.13) and venules (P = 1.0). Greater variability in microvasculature perfusion occurs at sites of macular ischemia due to BRVO. We report a novel way for quantifying macular perfusion variability using OCTA. This technique may have applicability for studying the pathophysiology of other retinal vascular diseases.

Comparative study of homogenization techniques for evaluating the bearing capacity of bimsoils under shallow foundations

Bimsoils, characterized by discrete blocks within a finer-grained matrix, pose challenges in evaluating the bearing capacity of shallow foundations due to their spatial variability. To address this, a binary random field coupled with a Finite-Element model is used to simulate the variability of bimsoils. This study focuses on investigating the effect of the blocks spatial fraction (γ), the isotropic and anisotropic spatial correlations, and the undrained shear strength (cu) ratio between the matrix and the blocks. The results reveal that the coefficients of variation (CV) for the bearing capacity (qu), at a given γ, reach nearly 20% due to the diverse spatial configurations. This dispersion is attributed to the development of distinct failure mechanisms. However, optimizing the local average area used to evaluate γ can help reduce these CV values. The average qu for a given γ can be accurately determined using the Bruggeman symmetric effective medium (BEM) equation, ensuring safe design compared to traditional homogenization techniques. The BEM equation considers γ and the cu ratio, providing an accurate estimation of bearing capacity for an equivalent homogeneous model suitable for probabilistic analyses.