Absolute Value Of Difference Research Articles

Study on long-term morphological stability of three-dimensional-printed photosensitive resin dental models

Objective: To study the long-term morphological stability of three-dimensional (3D) printed photosensitive resin dental models under natural light and dark conditions. Methods: Eighty sets of resin dental models were made by the desktop 3D printer from one digital standard model set, and randomly divided into two groups, namely natural light group (40 sets) and dark group (40 sets). All resin models were stored in sealed bags, with 4 model sets from each group randomly collected after 1, 3, 5, 7, 14, 21, 28, 40, 60, or 90 days of storage and 3D scanned using an optical model scanner. The root-mean-square error (RMSE) was calculated to represent the mean deviation of the difference between the digital standard model and the scanned resin model. Meanwhile, three linear indexes (the width between the canines, the width between the first molars, and the arch length) of the resin dental model were measured and compared with the corresponding values of the standard model. RMSE and the linear measurements between the digital standard model and the scanned resin models were compared between the natural light group and the dark group and among models from different time points. Results: Compared with the digital standard model, the RMSE values of 96.9% (155/160) resin dental models were less than 0.1 mm within 90-day storage. Also, at the same time point, there was no significant difference in the RMSE between the natural light group and the dark group (P>0.05). 75.0% (360/480) of the absolute values of the linear differences (differences in inter-canine width, intra-molar width, and arch length between the digital standard model and the scanned resin model) were within 0.2 mm, and about 0.1% (3/480) of the linear differences were greater than 0.5 mm, and all of the linear differences were within 0.6 mm. Conclusions: 3D-printed resin dental models can be stored stably under natural light and dark conditions for a long time.

No-tillage with straw mulching boosts wheat grain yield by improving the eco-physiological characteristics in arid regions

Straw returning to the field is a technical measure of crop production widely adopted in arid areas. It is unknown whether crop yield can be further increased by improving the eco-physiological characteristics when straw returning is applied in the crop production system. So, a three-year field experiment was conducted with various straw returning treatments for wheat production: (i) no-tillage with straw mulching (NTSM), (ii) no-tillage with straw standing (NTSS), (iii) conventional tillage with straw incorporation (CTS), and (iv) conventional tillage with no straw returning (CT, control). The eco-physiological and yield formation indicators were investigated to provide the basis for selecting the appropriate straw returning method to increase wheat yield and clarifying its regulation mechanism on eco-physiology. The results showed that NTSM and NTSS treatments had better regulation of eco-physiological characteristics and had a higher yield increase than CTS and CT. Meanwhile, NTSM had a relatively higher yield than NTSS through better regulation of eco-physiological characteristics. Compared to CT, the leaf area index of NTSM was decreased by 6.1–7.6% before the Feekes 10.0 stage of wheat, but that of NTSM was increased by 38.9–45.1% after the Feekes 10.0 stage. NTSM effectively regulated the dynamics of the photosynthetic source of green leaves during the wheat growth period. NTSM improved net photosynthetic rate by 10.2–21.4% and 11.0–21.6%, raised transpiration rate by 4.4–10.0% and 5.3–6.1%, increased leaf water use efficiency by 5.6–10.4% and 5.4–14.6%, at Feekes 11.0 and 11.2 stages of wheat, compared to CT, respectively. NTSM had higher leaf water potential (LWP) by 7.5–12.0% and soil water potential (SWP) by 8.9–24.0% from Feekes 10.3 to 11.2 stages of wheat than CT. Meanwhile, the absolute value of difference on LWP and SWP with NTSM was less than that with CT, indicating that NTSM was conducive to holding the stability of water demand for wheat plants and water supply of soil at arid conditions. Thus, NTSM had a greater grain yield of wheat by 18.6–27.3% than CT, and the high yield was attributed to the synchronous increase and cooperative development of ear number, grain number per ear, and 1 000-grain weight. NTSM had a positive effect on regulating the eco-physiological characteristics and can be recommended to enhance wheat grain yield in arid conditions.

Spatiotemporal variation of the ecosystem service value in China based on surface area

The assessment of ecological assets is of great significance for protecting and using ecological resources. Traditional methods of ecological assets assessment, which adopt the planar area as the standard, often ignore the impact of the surface area, resulting in a large difference between the evaluation and the actual result. To fill this gap, this paper conducted research on ecological assets assessment based on surface area. Taking mainland China into consideration, this paper constructed a triangulation network based on 30 m resolution DEM data to simulate the real land surface form and calculate its surface area. Then, land use/cover data from 1995, 2000, 2005, 2010, and 2015 were used to estimate the ecosystem service value (ESV) and analyze its spatial variation. This paper found that: (1) The surface area of mainland China is 1.04 × 107 km2, which is 8.2 × 105 km2 larger than the planar area; (2) A huge difference was found between the total ESV based on the surface and planar area, with an absolute difference of ∼$141.66-$144.14 billion and a relative difference of ∼ 10%. For different ecosystem types, the largest difference was found in the forest ecosystem, followed by the grassland ecosystem, while the wetland ecosystem showed the smallest difference; (3) The high value of absolute difference between the ESV based on the surface and planar area was concentrated in Tibet and Northeast China. The high value of relative difference was mainly distributed in Central and Southern China. On the provincial level, the absolute difference in Tibet ranked in the first place. There was a total of 14 provinces showing a relative difference above 10%; (4) The total ESV based on surface area was basically unchanged, while various ecosystems underwent significant changes. The ESV of wetland increased by nearly 50%, while the ESV of grassland decreased by more than 10%; and (5) Change in the ESV based on surface area showed obvious spatial heterogeneity. High-High cluster was located in Tibet and the Northeast China while the Low-Low cluster was distributed in the North China Plain and Xinjiang. This paper emphasized the importance of the surface area in resource survey and asset estimation and gave more effective suggestions for ecological protection.

Impact of intraoral scanner, scanning strategy, and scanned arch on the scan accuracy of edentulous arches: An in vitro study

Statement of problemThe scanning strategy used when making complete arch digital scans affects the accuracy of the scan, and the accuracy of the strategy may be influenced by the scanner used. However, these effects have not been investigated thoroughly with complete arch edentulous scanning. PurposeThe purpose of this in vitro study was to determine the effect of scanning strategies and the scanned arch on the accuracy of complete arch edentulous scans using 2 intraoral scanner (IOS) systems. Material and methodsTwo IOSs were used (TRIOS 4 and Emerald S) to scan maxillary and mandibular typodonts using 6 scanning strategies (test scans), and conventional impressions of both arches were also made. By using a metrology software program, test scans were superimposed onto a reference scan, and the root mean square (RMS) of the absolute deviation values was calculated to express trueness. The sample with the best trueness was used as reference onto which the remaining samples from the same group were superimposed, and the RMS of the absolute deviation values was calculated to express precision. Statistical modeling was applied using the fixed effects models (α=.05). ResultsThe main effects of scanner and strategy significantly impacted the trueness RMS values (P<.001), with significant interactions between them (P=.012). The main effects of scanner, strategy, and arch significantly impacted the precision of RMS values (P=.004), (P=.033), and (P=.023). Conventional impressions and the TRIOS 4 scanner had comparable accuracy, while the Emerald S scanner was inferior to both. P-O-B had the highest overall accuracy and strategy ZZ had the worst. Better precision was found with the maxillary arch. ConclusionsThe scanner type and scanning strategy significantly impacted the accuracy of the digital scans of completely edentulous arches, with a significant interaction between scanner and strategy. The arch being scanned had a significant effect on scan precision but not on scan trueness.

Development of Combined Methods Using Non-Destructive Test Methods to Determine the In-Place Strength of High-Strength Concretes

This study aims to develop combined methods with dual and triple use of different non-destructive test (NDT) methods and to examine the effectiveness of these methods. For this purpose, nine different high-strength concrete series were produced, and destructive and NDT methods were applied to these samples on the 3rd and 90th days. Surface hardness, ultrasonic pulse velocity, and penetration resistance were considered from NDT methods. Analyses were made on the response surface method using the NDT measurements and compressive strength values obtained, and four different mathematical models were developed. Models 1, 2, and 3 were designed with dual use of NDT methods, and model 4 was designed with triple use. The absolute relative deviation values for all the developed models’ early and final-age strengths were below 10%. It is of great importance to determine concrete quality with high accuracy and practicality, especially in places like Elazig, where there are thousands of newly constructed buildings since the Sivrice-Elazig earthquake, and rapid production is required. Therefore, it is thought that determining the strength values with high accuracy using the developed combined methods without damaging the building element will provide benefits in terms of time, labor, and cost.

THE EFFECT OF AUDITOR SWITCHING AND PROFITABILITY ON AUDIT REPORT LAG WITH THE AUDIT COMMITTEE AS A MODERATING VARIABLE

This study aims to examine and analyze the effect of auditor switching, company size and profitability on audit report lag with audit committee as moderating variable. This study uses quantitative methods.The population of this study is companies in the consumer goods industry sector, hotels, restaurants and tourism sub-sector companies and transportation sub-sectors listed on the Indonesia Stock Exchange in 2016-2020, totaling 149 companies. Sampling was done by purposive sampling method so that a sample of 41 companies was obtained. Data analysis using multiple linear regression analysis and moderated regression analysis with absolute difference value approach.The results of the study indicate that auditor switching and company size do not affect audit report lag. Profitability has a negative effect on audit report lag. The audit committee is unable to strengthen or weaken the effect of auditor switching, company size and profitability on audit report lag.

Reference Standard for Digital Infrared Thermography of the Surface Temperature of the Lower Limbs

Digital infrared thermographic imaging (DITI) is a supplementary diagnostic technique to visualize the surface temperature of the human body. However, there is currently no reference standard for the lower limbs for accurate diagnosis. In this study, we performed DITI on the lower limbs of 905 healthy Korean volunteers (411 males and 494 females aged between 20 and 69 years) to obtain reference standard data. Thermography was conducted on the front, back, lateral sides, and sole area, and 188 regions of interest (ROIs) were analyzed. Additionally, subgroup analysis was conducted according to the proximity of ROIs, sex, and age groups. The mean temperatures of ROIs ranged from 24.60 ± 5.06 to 28.75 ± 5.76 °C and the absolute value of the temperature difference between both sides reached up to 1.06 ± 2.75 °C. According to subgroup analysis, the sole area had a significantly lower temperature than any other areas, men had higher temperatures than women, and the elderly had higher temperatures than the young adults except for the 20s age group (p < 0.001, respectively). This result could be used as a foundation for the establishment of a reference standard for DITI. Practical patient DITI can be accurately interpreted using these data, and it can serve as a basis for further scientific research.

Computational Modelling of Airflow and Heat Transfer during Cooling of Stacked Tomatoes: Optimal Crate Design

A 3D computational fluid dynamics (CFD) model was developed to predict the airflow and heat transfer in half of a pallet layer of tomatoes. The numerical and experimental results were compared, and a good agreement was obtained between both results using the root-mean-square error (RMSE) and absolute relative deviation (ARD) values as criteria. The validated CFD model was then used to minimise the product temperature heterogeneity by optimising the airflow rate and the crate design. A downward flow of the air along the central parts of the crates and an upward flow close to the lateral walls of the crates were observed. Three different total ventilated areas (TVAs) were tested to study their influence on the product temperature uniformity and cooling rate. The MTD and ATD decreased from 6.8 to 3.5 °C and from 1.5 to 0.7 °C, respectively, when the TVA was increased from 11 to 15%.

SERUM CYSTATIN C AS A PREDICTOR OF THE DEVELOPMENT OF ACUTE KIDNEY INJURY IN NEWBORNS WITH HYPOXIC- ISCHEMIC ENCEPHALOPATHY SUBMITTED TO THERAPEUTIC COOLING

Assessment of renal function in newborns is extremely important and at the same time challenging due to the unique body structure, increased vulnerability and rapid growth of the latter. However, for the early detection of acute kidney injury (АКI), rational dosing of drugs and safe drug therapy, the identification of early markers of renal dysfunction is essential.The objective is to evaluate the prognostic value of serum biomarkers for the early diagnosis of АКI in newborns with hypoxic-ischemic encephalopathy against the background of therapeutic hypothermia and preventive use of methylxanthines.Materials and Methods. A single-center, prospective, randomized trial involving 44 neonates with АКI requiring therapeutic hypothermia and prophylactically receiving caffeine citrate or theophylline to prevent АКI progression was conducted in from 2019 to 2022 on the basis of the NICU of Zaporizhzhia Regional Clinical Children's Hospital.Laboratory analysis of blood serum samples was performed on day 1, day 3 and 5 from birth, creatinine (Cr) and cystatin C (CysC) levels and their associations with the development of АКI were determined according to the neonatal criteria of the 2012 KDIGO guideline.Statistical analysis was performed using Statistica 13.0 program, TIBCO Software Inc. (license number JPZ804I382130ARCN10-J) and Microsoft Excel 2013 (license number 00331-10000-00001-АА404). The probability of the difference in absolute values of mean values was determined using non-parametric methods of statistical analysis: the Mann-Whitney U-Test for unrelated groups and the Wilcoxon signed-rank t test for related groups. Statistical significance was defined as p &lt; 0.0500.The study was performed in accordance with the moral and ethical standards established by the IGH / GCP guidelines, the World Medical Association Helsinki Declaration, adopted in 1964 and amended in 1975, 1983, 1989, 1996 and 2000, The European Convention of Human Rights and Biomedicine and the legislation of Ukraine. The protocol was approved by the Medical Ethics Commission at Zaporizhzhia State Medical University. The study was performed as part of the research project "Optimization of diagnostics and intensive care of polyetiologic lesions of the brain, gastrointestinal tract, and kidneys in newborns and older children" (State registration number O118U007142) of the Pediatric Surgery and Anesthesiology Department of the State Institution "Zaporizhzhia State Medical University of the Ministry of Health of Ukraine."Results and their discussion. In general, AKI according to KDIGO developed in 5.00 (11.36 %) neonates out of 44.00 (100.00 %), stage 0 was found in 39.00 (88.64 %). 4.00 (9.09%) newborns had stage I, and 1 (2.27%) developed stage II; the data obtained were similar: p = 0.7872; U = 230.00. None of the patients progressed to stage III.In the newborns with preserved renal function during the study there was a decrease in Cr and a predictable, by this marker, increase in GFR. A statistically significant increase in Cr level and decrease in GFR was found in the newborns with renal dysfunction on days 3 and 5 of the study. Cr level progressed from baseline 1.07 (0.87; 1.10) mg/dl to 1.13 (0.86; 1.25) mg/dl on day 3 and to 1.40 (1.15; 1.82) mg/dl on day 5, while GFR decreased from 19.76 (19.07; 22.90) ml/min/1.73m2 to 17.97 (13.84; 24.42) ml/min/1.73m2 on day 3 and was 12.38 (11.12; 17.54) ml/min/1.73m2 on day 5, with p &lt; 0.0500.CysC progressively decreased in the neonates without AKI from 2.50 (2.20; 2.60) ng/ml to 2.25 (2.08; 2.49) ng/ml, p = 0.0095; while in the neonates with AKI the level of this marker did not change and was 2.56 (2.41; 2.70) ng/ml on day 1 and 2.42 (1.89; 2.45) ng/ml on day 5, p = 0.2963. As this marker changed, eGFR (CysC) increased progressively in the cohort of patients without kidney damage but did not change in the other group.The diuresis rates in the newborns of both groups did not differ, being ≥ 1.5 ml/kg/h, which is probably due to methylxanthine therapies, p ≥ 0.0500.Conclusions. CysC assessment did not provide additional information on the development of acute kidney injury in neonates (nAKI) in the first 5 days of life, which would have allowed a quick decision to change the intensive care program. Further studies involving newborns who did not receive prophylactic therapy are needed.

Multi-Objective Bus Timetable Coordination Considering Travel Time Uncertainty

This paper proposes a timetable coordination method for transfer problems in a bus transit system. With a given bus network, a stochastic mixed-integer linear programming (MILP) model has been formulated to obtain coordinated bus timetables with the objective of minimizing a weighted sum of the average value of total waiting time and its average absolute deviation value, allowing for random bus travel time. The vital decision variable is the terminal departure offset time of each target bus trip within a certain off-peak period. The robust MILP model can also be used to solve the first-bus transfer problem with the introduction of several new linear constraints. A solution method based on the Monte Carlo simulation has been developed to solve the MILP model. Numerical experiments have been conducted for different scenarios. The results indicate that bus timetables coordinated by the developed model are capable of substantially reducing waiting time for transfer and non-transfer passengers. In addition, the feasibility of simplifying a common sub-route into a single transfer stop in a timetable coordination problem has been explored based on numerical experiments.

Assessment of black rot development on apple surface using laser biospeckle technique

In our present study, the laser biospeckle technique has been applied to monitor the spread of black rot fungal disease and evaluate the infected area on apple surface for the first time to the best of our knowledge. Image processing algorithms such as inertia moment (IM), absolute value of differences (AVD) and spatial-temporal speckle correlation show the reduction of biospeckle activity of the black rot infected apples in comparison to that of the healthy apples with increase in time, once the visible symptom of the disease sets in. Spectral activity maps obtained using Fujii, inverse Fujii and parameterized Fujii show the spread of this infection with the progression of day. Under exposition test and histogram plot have been used to evaluate the increase of darkness of the infected apple with the progression of day and the results have come out as a replica of the change of colour of the region of interest. % biospeckle activity loss on the final day of the experiment has been found to be 17.83% and 11.91% for healthy apples & 92.42% and 78.63% for infected apples using IM and AVD respectively. An increase in the infected area and % increase in infected area of the region of interest on the image plane has been determined to be 0.33 mm2 and 58.57% respectively on the final day of the experiment.

The Impact of Vaccination on Disease Course and Outcome in Intensive Care Patients With COVID-19

BACKGROUND Our study provides a unique opportunity to compare the course of the disease with a new coronavirus infection in seriously ill patients in the groups of vaccinated and unvaccinated patients hospitalized in the infectious intensive care units of N.V. Sklifosovsky Research Institute for Emergency Medicine of the Moscow Health Department since the start of the vaccination campaign.AIM OF STUDY The study of the composition of hospitalized patients with COVID-19 in the N.V. Sklifosovsky Research Institute for Emergency Medicine of the Moscow Health Department in serious condition, requiring resuscitation, in groups of vaccinated and unvaccinated patients in terms of their age and gender characteristics, the severity of the condition and duration of treatment, the presence of concomitant (chronic) diseases, as well as the outcome of hospitalization.MATERIAL AND METHODS The initial analyzed material was data from the Unified Medical Information and Analytical System (EMIAS) of the Institute and statistical cards of patients who left the hospital. The formation of the main group of vaccinated patients was carried out in accordance with the instructions of the Moscow Department of Health and in pursuance of the letter of the Office of Rospotrebnadzor for the city of Moscow No. I-17-17/1 dated January 26, 2021 “On monitoring COVID-19 cases in those vaccinated against a new coronavirus infection “. The Institute has created a registry of hospitalized patients diagnosed with Coronavirus infection caused by the COVID-19 virus, who have a certificate of vaccination with registration in EMIAS. Also, to determine vaccinated patients, we used information from the Headquarters for measures to prevent the importation and spread of infection caused by the 2019-nCoV coronavirus in the city of Moscow. The comparison group included patients with coronavirus infection caused by the SARS-CoV-2 virus, hospitalized in the infectious diseases intensive care units of the Institute and not having information about the certificate in EMIAS. The analyzed period was counted from the moment the register was created and amounted to 6 months: from May 1 to October 31, 2021. Discrete numerical accounting characteristics of each unit of observation (hospitalized patient) were age, duration of stay in the hospital (including in intensive care). Categorical data were gender, diagnosis, source of admission, severity, presence of pneumonia upon admission, history of chronic diseases, outcomes of hospitalization. After the anonymization of the personal data of patients and the distribution of patients into comparison groups, the obtained information was processed by standard means of mathematical statistics using the R-free software computing environment. The calculation of additional absolute and relative values, average errors of indicators was made. Statistical significance of differences in numerical values was determined using the Student’s t-test, categorical values were calculated using the ӽ2 test. In both cases, the p-value was chosen to be less than 0.05.RESULTS When comparing the course of coronavirus infection, concomitant diseases, the duration and nature of inpatient treatment, the frequency of external and internal transfers between different departments, as well as disease outcomes in vaccinated and unvaccinated patients hospitalized at N.V. Sklifosovsky Research Institute for Emergency Medicine of the Moscow Health Department revealed:the average duration of stay both in clinical units and in intensive care units in vaccinated patients is significantly less than in unvaccinated patients;all patients were admitted to the hospital in a serious or extremely serious condition caused by severe clinical manifestations of coronavirus infection in unvaccinated patients and comorbid diseases in most of the vaccinated patients;the mortality among vaccinated patients is significantly lower, and the immediate cause of death was almost always complications of a severe course of competing (non-infectious)CONCLUSION The study showed that in vaccinated patients with intense post-vaccination immunity, the risk of developing a severe course of coronavirus infection (requiring resuscitation) is much lower. Along with this, the duration of treatment is also significantly reduced, especially in intensive care units, and the likelihood of an unfavorable outcome of the disease is reduced to a minimum.

High expression level of the FTH1 gene is associated with poor prognosis in children with non-M3 acute myeloid leukemia.

Acute myelogenous leukemia (AML) is a disease that severely affects the physical health of children. Thus, we aimed to identify biomarkers associated with AML prognosis in children. Using transcriptomics on an mRNA dataset from 27 children with non-M3 AML, we selected genes from among those with the top 5000 median absolute deviation (MAD) values for subsequent analysis which showed that two modules were associated with AML risk groups. Thus, enrichment analysis was performed using genes from these modules. A one-way Cox analysis was performed on a dataset of 149 non-M3 AML patients downloaded from the TCGA. This identified four genes as significant: FTH1, RCC2, ABHD17B, and IRAK1. Through survival analysis, FTH1 was identified as a key gene associated with AML prognosis. We verified the proliferative and regulatory effects of ferroptosis on MOLM-13 and THP-1 cells using Liproxstatin-1 and Erastin respectively by CCK-8 and flow cytometry assays. Furthermore, we assayed expression levels of FTH1 in MOLM-13 and THP-1 cells after induction and inhibition of ferroptosis by real-time quantitative PCR, which showed that upregulated FTH1 expression promoted proliferation and inhibited apoptosis in leukemia cells. In conclusion, high expression of FTH1 promoted proliferation and inhibited apoptosis of leukemic cells through the ferroptosis pathway and is thus a potential risk factor that affects the prognosis of non-M3 AML in children.

A Novel Point-Based Indexing Strategy for Biospeckle Sensors

In this letter, a novel point-based algorithm is presented for biospeckle sensors by combining random temporal history, robust normalization, and absolute value difference technique. Performance of the proposed strategy was evaluated and compared with existing strategies in simulation domain in terms of different analysis parameters (viz. frame invariance, correlation linearity, characterization of heterogeneity, and efficient computation). For experimental verification, biospeckle frames corresponding to coffee seeds ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">coffea arabica</i> ) and maize seeds ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">zea maize</i> ) were utilized. From obtained results it can be inferred that, the proposed strategy possesses high accuracy in terms of all the analysis parameters. In future, the strategy can be widely utilized for industrial automation and quality inspection.

Prediction of the Thermal Conductivity for Liquid Hydrocarbons and Halogenated Hydrocarbons

The thermal conductivity of compressed liquids has received less attention in prediction models compared with saturated liquids. This work proposes a new thermal conductivity prediction model for alkanes, alkenes, and halogenated hydrocarbons for saturated and compressed liquids. The model based on dimensional analysis was developed for n-alkanes. The critical temperature, critical density, molecular weight, reduced temperature, reduced density, and acentric factor of each fluid are required. Introducing the reduced density effectively implements the thermal conductivity calculation of the compressed liquid. Then, the particle density was found to affect the thermal conductivity of halogenated and isomeric hydrocarbons compared with normal hydrocarbons. Hence, a model with a correction term related to the particle density was developed for halogenated and isomeric hydrocarbons. Good agreements between the calculated results and experimental data for n-alkanes and halogenated (or isomeric) hydrocarbons were obtained with average absolute relative deviation values of 1.74% and 3.03%, respectively.

Relationship of Plant Species Diversity and Sampling Area Under Different Grazing Intensities in the Steppe of Northern China

The relationship between sampling area of plant community and number of species contained in it has an importance in vegetation ecology. Using a nested quadrat survey, the relationship between plant species and sampling area was discussed under different grazing pressure in the steppe and the determination of minimum sampling area was calculated herein. Ten curve models were selected to fit the species-area relation of plant community in a typical steppe of northern China. The residual standard deviation, correlation index, average value of absolute deviation, and average value of absolute relative deviation were used as the evaluation indexes for model fitting. The results show that the curve equations S = B + CAZ and S = C(1-e−BA)Z have the best simulation effect. According to the simulation results, the minimum sampling areas are determined as 1.16 m2 (T0), 1.23 m2 (T7), 1.28 m2 (T10), and 1.10 m2 (T14), presenting the minimum sampling area is feasible when the second derivative is zero. Generally, sheep grazing reduced the species richness of steppe, though some of the plans flourished while some others disappeared or dismissed, but increased spatial heterogeneity, especially on a smaller scale. However, there are also variances in different area scales and grazing intensities. When the sampling area was small (< 2 m2), heavy grazing T14 increased the number of plant species per unit area, yet light grazing T8 reduced the number of plant species per unit area of steppe. When the sampling area was large (> 16 m2), grazing reduced the number of plant species per unit area in the natural steppe. Anyhow, the effect of grazing intensity on plant species fluctuated greatly when the sampling area was medium (2 m2 ∼ 16 m2). In general, the similarity of plant communities had an increasing trend with accumulated sampling area, though it varied at different grazing intensities.

Archean Pb isotope variability tracks crust-mantle fractionation, granite production, and ore deposit formation

Various geological processes that affect Earth's crust may be encoded into isotopic tracers preserved in rocks and minerals. The enhanced sensitivity of U, Th, and Pb to crustal fractionation processes allows Pb isotopes to complement information from the Nd and Hf isotope systems. However, melt fractionation, crustal contamination and recycling, hydrothermal fluid flow and fluid-rock interaction, and other processes in the continental crust can lead to mixing of Pb isotopic signatures. Here, we report new Pb isotopic data from granite-K-feldspar and integrate these data with published Pb isotope ratios from granite K-feldspar and Pb-rich ores across the Yilgarn Craton in Western Australia. The aim of this study is to explore how the variability of Pb isotope ratios and derivative parameters can be used to gain information on specific geological processes occurring throughout the crustal column. We develop a model that subdivides different sampling media into chemical process groups and links their initial Pb signatures to Pb source regions and fractionation processes at various locations within the crust and upper mantle. Equilibration of Pb signatures with a primary mantle source reservoir (in part represented by volcanic-hosted massive sulfides) is contrasted with granite formation in the mid to lower crust (granite K-feldspar), and mineralization of ore deposits in the mid to upper crust (Pb-rich ores). Spatial trends similar to those in Nd and Hf isotopic data are recorded by Pb isotopic derivative parameters (μ = source 238U/204Pb, ω = 232Th/204Pb, and Δt - the difference between true sample age and Pb model age) calculated for komatiite-hosted Ni sulfide ores, granite K-feldspar, and volcanic-hosted massive sulfide (VHMS) ores. The significance of subtle differences in absolute values of derivative parameters is supported by the diversity of Pb isotope ratios, Pb model ages, and ∆t as tracked by a statistical metric, quantifying the variability of Pb sources involved in the formation of different chemical process groups. Generally greater variety in an older terrane (Youanmi) documents more ancient and recycled continental crust as compared with more homogeneous Pb isotopic signatures in a younger terrane (Eastern Goldfields Superterrane). The Pb signatures are interpreted, in part, to relate to the timing of source fractionation in the upper mantle with a legacy of this source signal preserved through various depths in the lithospheric section. The least radiogenic VHMS ore samples appear to provide a good approximation of mantle Pb signatures, indicated for example by a deficit in 206Pb and 208Pb relative to the other process groups. A significant heterogeneity recorded in Pb isotopic data from Pb-rich gold ores is explained by the interplay of hydrothermal fluids with diverse sources leading to the mineralization of gold deposits (e.g., leaching of Pb from surrounding rocks or fluid mixing). Such gold ore Pb signatures are distinct from other process groups, which together track sources less heterogeneous in age and/or U and Th.

Absorption-based algorithm for satellite estimating the particulate organic carbon concentration in the global surface ocean

Particulate organic carbon (POC) in the surface ocean contributes to understanding the global ocean carbon cycle system. The surface POC concentration can be effectively detected using satellites. In open oceans, the blue-to-green band ratio (BG) algorithm is often used to obtain global surface ocean POC concentrations. However, POC concentrations are underestimated in waters with complex optical environments. To generate a more accurate global POC mapping in the surface ocean, we developed a new ocean color algorithm using a mixed global-scale in situ POC dataset with the concentration ranging from 11.10 to 4389.28 mg/m3. The new algorithm (a-POC) was established to retrieve the POC concentration using the strong relationship between the absorption coefficient at 490 nm (a(490)) and POC, in which a(490) was from the Ocean Color Climate Change Initiative (OC-CCI) v5.0 suite. Afterward, the a-POC algorithm was applied to OC-CCI v5.0 data for special regions and the global ocean. The performances of the a-POC algorithm and the BG algorithm were compared by combining the match-ups of satellite data and in situ dataset. The results showed that the statistical parameters of the a-POC algorithm were similar to those of the BG algorithm in the Atlantic oligotrophic gyre regions, with a median absolute percentage deviation (MAPD) value of 22.04%. In the eastern coastal waters of the United States and the Chesapeake Bay, the POC concentration retrieved by the a-POC algorithm was highly consistent with the match-ups, and MAPD values were 33.06% and 26.11%. The a-POC algorithm was also applied to the Ocean and Land Color Instrument (OLCI) data pre-processed with different atmospheric correction algorithms to evaluate the universality. The result showed that the a-POC algorithm was robust and less sensitive to atmospheric correction than the BG algorithm.

A Meta-Analysis of Sampled Maximal Aerobic Capacity Data for Boys Aged 11 Years Old or Less Obtained by Cycle Ergometry.

The aim of this study was to develop distributions of VO2max based on measured values that exist in the literature in prepubertal boys using cycle ergometry. PRISMA guidelines were followed in conducting this research. One database was searched for peak and maximal VO2 values in healthy boys with mean age under 11 years old. Data were split into articles reporting absolute and relative VO2max values and analyzed accordingly. Multilevel models grounded in Bayesian principles were used. We investigated associations between VO2max and body mass, year of the study, and country of origin. Differences in "peak" and "maximal" VO2 were assessed. Absolute VO2max (Lmin-1) increases with age (P ~100%) but mean relative VO2max does not change (P ~100%). Absolute VO2max is higher in more recent studies (P = 95.7 ± 0.3%) and mean relative VO2max is lower (P = 99.6 ± 0.1%). Relative VO2max in the USA is lower compared with boys from other countries (P = 98.8 ± 0.2%), but there are no differences in absolute values. Mean aerobic capacity estimates presented as "peak" values are higher than "maximal" values on an absolute basis (P = 97.5 ± 0.3%) but not on a relative basis (P = 99.6 ± 0.1%). Heavier boys have lower cardiorespiratory fitness (P ≈ 100%), and body mass seems to be increasing faster with age in the USA compared with other countries (P = 92.3 ± 0.3%). New reference values for cardiorespiratory fitness are presented for prepubertal boys obtained with cycle ergometry. This is new, as no reference values have been determined so far based on actual measured values in prepubertal boys. Aerobic capacity normalized to body weight does not change with age. Cardiorespiratory fitness in prepubertal boys is declining, which is associated with increasing body mass over the last few decades. Lastly, this study did not find any statistically significant difference in the sample's mean aerobic capacity estimates using the "peak" and "maximum" distinctions identified in the literature.

Accuracy of four recent intraoral scanners with respect to two different ceramic surfaces

ObjectivesTo investigate the complete arch accuracy of intraoral scanners (IOS) on two different ceramic surfaces. MethodsTwo maxillary master cast samples were prepared. The bases of both the master casts were made from zirconium oxide. The difference between the two casts was that the teeth of the [ZR] cast were produced from zirconium oxide and that of the [LD] cast were made of lithium disilicate glass-ceramic. Unlike the zirconia teeth of the [ZR] cast, the lithium disilicate teeth of the [LD] cast were glazed. The two master casts were digitized using a high-resolution scanner (Atos Compact Scan 5 M, GOM GmbH, Braunschweig, Germany) to obtain digital reference casts. Subsequently, each master cast was scanned 15 times using four IOSs. The IOSs were the Cerec Omnicam [OM], Primescan [PR], Trios 4 [TR4], and VivaScan [VS]. On surface comparison, the absolute mean deviation values were obtained for trueness and precision. For multiple comparisons, statistically significant differences were analyzed using one-way ANOVA and the Kruskal-Wallis H test. The p-value was adjusted to control for the increased risk of type I error (p < 0.0083). To compare the two means, the t-test and Mann-Whitney U test were used (p < 0.05). ResultsTrueness values for [ZR] ranged from 24.6 (±6.3) µm for [PR] and 77.1 (±8.3) µm for [OM]. Trueness values for [LD] were between 28.3 (±6.3) µm for [PR] and 72.8 (±15.6) µm for [OM]. Precision values for [ZR] ranged from 17.6 (±3.7) µm for [PR] to 37.3 (±9.9) µm for [OM]. Precision values for [LD] ranged from 17.5 (±3.6) µm for [PR] to 41.8 (±8.7) µm for [OM]. Statistically significant differences were found among all the IOSs (p < 0.0083). The trueness values of the four IOSs did not differ significantly (p < 0.05) with respect to either the [ZR] or [LD] cast. The precision values of [OM] and [VS] differed significantly with respect to the scanned surface. ConclusionsComplete arch scans achieved with the four IOSs showed significantly different trueness and precision results. [VS] and [OM] were more sensitive in terms of the scanned material. Clinical significanceThe latest IOSs showed the required accuracy for complete arch digital impressions in-vitro investigations. These findings should be implemented under conditions relevant to complete arch deviations, such as the construction of occlusal splints, analysis of occlusal relationships, and long-span restorations. Clinicians should be aware that the clinically acceptable threshold varies depending on the purpose of the IOS.