Low Coefficient Of Variation Research Articles

Predicting Carbonate Chemistry on the Northwest Atlantic Shelf Using Neural Networks

AbstractThe Northwest Atlantic Shelf (NAS) region has experienced accelerated warming, heatwaves, and is susceptible to ocean acidification, yet also suffers from a paucity of carbonate chemistry observations, particularly at depth. We address this critical data gap by developing three different neural network models to predict dissolved inorganic carbon (DIC) and total alkalinity (TA) in the NAS region from more readily available hydrographic and satellite data. The models predicted DIC withr2between 0.913–0.963 and root mean square errors (RMSE) between 15.4–23.7 (μmol kg−1) and TA withr2between 0.986–0.983 and RMSE between 9.0–10.4 (μmol kg−1) on an unseen test data set that was not used in training the models. Cross‐validation analysis revealed that all models were insensitive to the choice of training data and had good generalization performance on unseen data. Uncertainty in DIC and TA were low (coefficients of variation 0.1%–1%). Compared with other predictive models of carbonate system variables in this region, a larger and more diverse data set with full seasonal coverage and a more sophisticated model architecture resulted in a robust predictive model with higher accuracy and precision across all seasons. We used one of the models to generate a reconstructed seasonal distribution of carbonate chemistry fields based on DIC and TA predictions that shows a clear seasonal progression and large spatial gradients consistent with observations. The distinct models will allow for a range of applications based on the predictor variables available and will be useful to understand and address ocean sustainability challenges.

High-consistent optical fiber photoacoustic generator with carbon nanoparticles-PDMS composite

Optical fiber photoacoustic (PA) probe is considered to have great prospects in high resolution invasive imaging due to the advantages of flexible, miniaturized broadband ultrasonic excitation. Unfortunately, more attentions are currently focused on the fabrication of the PA probe with a high PA conversion efficiency, instead of the consistency of the developed probe that is of great importance for practical applications. In this paper, in consideration of the coating thickness and flatness closely concerned with the consistency, a number of PA probes with 15 wt.% carbon nanoparticles (CNPs) and polydimethylsiloxane (PDMS) composite were fabricated by a spin-transfer method with the help of transferring uniformly spin-coated film on the endface of an optical fiber. Underwater ultrasonic detection showed that the fabricated probes exhibited a good consistency with the corresponding lower coefficients of variation of 1.7%, 1.4% and 1.1% for the sound pressure, center frequency and bandwidth, sharply reduced by 89%, 72% and 81% in comparison with the commonly used dip-coating probes tested in this work. Also, due to the thinner film obtained through the presented fabrication method, the maximum PA pressure value of 1.04 MPa with a -6 dB bandwidth of 54.2 MHz was achieved, which further demonstrates a great potential in high-resolution ultrasound imaging utilizing multiple probes with high consistency.

Acute effect of short-term immobilization on lower leg muscle tissue hardness in healthy adults.

Previous studies have reported altered neural activity in the motor cortex after short-term cast immobilization, even in healthy participants. However, the effects of short-term movement restriction on tissue structure are not well understood. To investigate the effects of short-term lower limb immobilization on muscle tissue hardness. Seventeen healthy participants were enrolled in the study. Each participant's non-dominant lower limb was fixed with a soft bandage and medical splint for 10 h. Gastrocnemius muscle tissue hardness was measured using a tissue hardness meter before cast application and immediately after cast removal. Measurements were performed five times for each lower limb, and the three values with the lowest coefficient of variance were adopted as the value of muscle tissue hardness. Gastrocnemius muscle tissue hardness in the immobilized limb was lower after cast removal than that before cast application (from 53.6 to 51.8; p< 0.01), whereas the non-fixed limb showed an increase in muscle tissue hardness at the end of the experiment (from 52.9 to 54.3; p= 0.03). The findings indicate that 10 h movement restriction induced a reduction in muscle tissue hardness, suggesting acute adverse effects of cast immobilization for orthopedic treatment.

The design of a camera-based fisheries-independent survey for untrawlable habitat in the Gulf of Alaska

Biomass and size composition estimates from the fishery independent biennial Alaska Fisheries Science Center Resource Assessment and Conservation Engineering Division’s Groundfish Assessment Program Gulf of Alaska bottom trawl survey are an integral component of stock assessments and management of fishes in the region. A substantial proportion of the seafloor in the Gulf of Alaska survey area consists of rocky, high-relief habitat that is not accessible to trawl survey gear and is important habitat for many harvested fish species, especially rockfishes (Sebastes spp.). Survey estimates of groundfish abundance from trawlable grounds are expanded across the entire region. Therefore, survey abundance estimates could potentially be biased as a result of sampling that does not spatially represent all of the available habitat circumscribed by the Gulf of Alaska study area. Mapping the extent of the untrawlable habitat is a critical step toward understanding the scale of these potential biases and would benefit the design of a future untrawlable habitat survey. Several previous efforts have provided trawlability maps for part or all of the Gulf of Alaska based on different data inputs. In the present work, we compile two previously published untrawlable habitat maps with three other relevant data sources to create a new untrawlable habitat map, and use this map in conjunction with density estimates from existing underwater camera studies to investigate the feasibility of an untrawlable habitat rockfish survey in the Gulf of Alaska. An analysis of 1 km2 grids sampled more than once with a lowered camera system suggested that a single-stage sampling design (one camera transect per grid) would be most effective. Post-stratification analysis showed that either a simple depth stratification or stratification based on species distribution models provided lower coefficient of variation (CV) values at a given sample size compared to random sampling. Furthermore, a target CV of 25 % could be reached for a camera survey of dusky rockfish, northern rockfish, or Pacific ocean perch with less than 200 lowered camera transects if a stratification scheme based on species distribution models was used.

Conventional or Shariah Compliant Investment: Performance Evaluation of Mutual Funds in Pakistan

The current study was initiated to compare the performance of conventional and Shariah-compliant mutual funds in Pakistan, keeping in view the contradictory opinions found in the literature in this regard. The data utilized to conduct the analysis covered the time span 2013-2021. Assessment of risk and return tradeoff was made with three ratios, namely Jenson’s alpha, Treynor ratio, and Sharpe ratio by evaluating the monthly returns of conventional and Shariah-compliant mutual funds. The findings revealed that Shariah-compliant mutual funds outperformed conventional funds in terms of absolute risk measure, higher Sharpe ratio, and low coefficient of variation. While, in terms of funds’ exposure to systematic risk, mixed results were obtained for both types of funds. The results produced sufficient information about the risks and returns associated with the two kinds of mutual funds which would enable fund managers and investors to make informed decisions while selecting the best mutual fund, thus generating maximum returns and with minimum risks.

663-P: Dynamic Real-Time Relationships among Glucose and Cognitive Performance in Diverse Adults with T1D

Introduction: Blood glucose (BG) regulation is linked to cognitive performance among people with diabetes. Most studies are cross-sectional and limited to adults with T2D. Pairing continuous glucose monitoring (CGM) with ambulatory cognitive tests, we examined real-time bidirectional associations between BG and cognition in everyday life among adults with T1D. Methods: Participants wore a blinded CGM for 10-14 days and completed ambulatory cognitive tests 5-6 times daily. Using dynamic structural equation modeling, we evaluated within-person bidirectional relationships between BG and cognition over sequential 3-hr periods. BG metrics included mean BG, time in range (TIR; 70-180 mg/dL), % time in low (50-69 mg/dL), high (181-250 mg/dL) and very high BG (&amp;gt;250 mg/dL), and coefficient of variation (CV). Cognitive variables included processing speed and sustained attention. Results: Among 182 adults with T1D (40±14 yrs, 46% male, 41% Latino, 29% White, 15% Black), greater mean BG (beta=0.03), lower TIR (beta=-0.03), and more time in high (beta=0.03) and very high BG (beta=0.03) predicted slower processing speed 3 hrs later (ps&amp;lt;.05); no BG metric predicted sustained attention ability. Surprisingly, slower processing speed predicted lower mean BG (beta=-0.05), more TIR (beta=0.04) and less time in high (beta=-0.01) and very high BG (beta=-0.04) over the next 3 hrs. Reduced sustained attention predicted more time in very high BG (beta=-0.01) and lower CV (beta=0.03) (ps&amp;lt;0.05). Conclusion: Our findings suggest that poorer BG regulation negatively influences processing speed over short time frames. Slower processing speed predicted subsequent improvements in CGM metrics, suggesting that individuals may take steps to correct BG when experiencing cognitive effects of poor BG regulation. These short-term relationships illuminate opportunities for in-the-moment interventions. Disclosure C.J.Hoogendoorn: None. D.Spruijt-metz: None. E.Pyatak: Research Support; Abbott Diabetes. J.S.Gonzalez: Consultant; Virta Health Corp. R.Hernandez: None. S.Schneider: None. A.L.Peters: Advisory Panel; Abbott Diabetes, Medscape, Novo Nordisk, Vertex Pharmaceuticals Incorporated, Zealand Pharma A/S, Research Support; Abbott Diabetes, Dexcom, Inc., Insulet Corporation, Stock/Shareholder; Omada Health, Inc., Livongo. J.P.Crandall: Research Support; Abbott. G.Crespo-ramos: None. H.Jin: None. L.T.Pham: None. S.Agarwal: Advisory Panel; Medtronic, Consultant; Beta Bionics, Inc., Research Support; Abbott Diabetes, Dexcom, Inc. Funding National Institutes of Health (R01DK121298, P30DK020541, P30DK111022)

1450-P: Profiles of Glycemic Control in People with Type 1 Diabetes Using CGM—A Clustering Approach in the SFDT1 Study

CGM-derived data are usually analyzed in silos, metric by metric, for diabetes care or therapeutic strategy. Simultaneous analysis of the various dimensions of glycemic control would allow a more comprehensive overview. We analyzed data of people with type 1 diabetes (PWT1D) in the SFDT1 cohort study. A K-means clustering model was developed with HbA1c, coefficient of variation (CV), time in range (TIR), time below 70 mg/dl (TBR), Gold score and Glycemic Risk Index (GRI). We included 618 participants (53% men, age 41±14 years) from 20 centres in France. The optimal model had 3 clusters. The “Euglycemia” cluster (n=280, 45%) was characterized by a high TIR (mean 69.3%); low TBR ​​(4.2%), TAR (time above 180 mg/dl: 26.5%), CV (35.7%), HbA1c (7.0%) and GRI (36.4) values. The “Hyperglycaemia" cluster (n=197, 32%) was characterized by high TAR (56.5%), GRI (71.8) and HbA1c (8.5%) and low TIR (40.3%), TBR (3.2%) and Gold score (2.3). The “Hypoglycemia” cluster (n=141, 23%) was characterized by high TBR (15.8%), CV (46.1%), GRI (69.2) and Gold score (3.0). Participants in the “Hyperglycemia” cluster were younger, socially vulnerable, and had more frequent hypertension than those in the “Euglycemia” cluster. To conclude, we identified three distinct, clinically relevant glycemic control profiles, enabling better characterization of PWT1D and, thus, more personalised management. Disclosure E.Cosson: Board Member; Abbott, Medtronic. G.A.Aguayo: None. L.Sablone: None. M.Huet: None. J.Riveline: Board Member; Abbott Diabetes, Medtronic, Dexcom, Inc., Novo Nordisk, Eli Lilly and Company, Sanofi. G.Fagherazzi: Advisory Panel; Roche Diabetes Care, Consultant; AbbVie Inc., Lilly. Sfdt1 study team: n/a.

Reproducibility and repeatability of biventricular function/volume and strain parameters by 2D and 4D stress echocardiography in adult patients with repaired TOF

Abstract Funding Acknowledgements Type of funding sources: None. Background The use of 2D and 4D during stress echocardiography to undertake complex measures in complex patients like patients with repaired TOF is challenging and the validity of these measures is not known yet. Methods For test-retest variability, 20 patients with repaired TOF with no or mild pulmonary regurgitation were selected randomly and underwent a cardiopulmonary exercise test (CPET) with echocardiography. Intra-observer variability study was performed for all 20 patients by the same observer. Interobserver variability study was performed for 5 patients by different experienced observer. Intraclass correlation coefficient (ICC), and coefficients of variation (COV) were used to quantify reproducibility and variability. Results For 2D measures, better reproducibility was observed for semiautomated 2D strain measures than 2D functional measures for biventricular systolic function at baseline and during the stress (ICC&amp;gt;.90 vs &amp;gt;.70, p&amp;lt;0.001), with least COV was observed (COV&amp;lt;10%). 4D semiautomated volumetric measures demonstrated less reproducibility during stress with highest COV was observed for 4D RV volume parameters (COV, 35%), followed by 4D LV volume parameters (COV, 27%). CPET had an excellent agreement of all measures (ICC &amp;gt;.90). with very low COV (&amp;lt;10%). Conclusions Semiautomated echo measures outperformed manual measures during stress echocardiography and can be performed with acceptable reproducibility. Variability is at highest for 4D semiautomated measures despite good reproducibility, while lowest variability was observed for 2D semiautomated measures of myocardial deformation.

How and when to measure pH in IVF culture media: validation of a portable blood gas analyzer in two IVF culture dishes for time lapse and conventional incubators.

Maintaining a stable pH at optimal level in human embryo culture media is crucial for embryo development but poses a challenge for all IVF laboratories. We validate analytically reliable conditions for pH measurement that are as close as possible to the embryo microenvironment during IVF. This was a multicentric study. A Siemens EPOC portable blood gas analyzer was used. The analytical validation was carried out under the culture medium (Global Total HSA®) conditions of use (microdroplets, under oil overlay, in a IVF incubator with (EmbryoScope®) or without a time lapse system (K system G210+®) and using IVF dishes. The validation included repeatability ("within-run" precision), total precision (between-day precision), trueness based on inter-laboratory comparison, inaccuracy based on external quality assessment and comparison to the reference technique. We also assessed the pre-analytical medium incubation time required to obtain a target value. A measurement after an incubation period of 24 to 48 h is more representative of the pH to which the embryo will be exposed throughout the culture. The "within-run" and "between-day" precision show very low coefficients of variation (CV%): 0.17 to 0.22% and 0.13 to 0.34%, respectively, with IVF culture media. Trueness (% bias) range from - 0.07 to - 0.03%. We demonstrate good correlation between EPOC and reference pH electrode with an overestimation of 0.03 pH units of EPOC. Our method demonstrates good analytical performance for IVF laboratories wishing to implement a robust quality assurance system to monitor pH in embryo culture media. Compliance with stringent pre-analytical and analytical conditions is essential.

The soil organic carbon: Clay ratio in North Devon, UK: Implications for marketing soil carbon as an asset class

AbstractBuilding up stocks of agricultural soil organic carbon (SOC) can improve soil conditions as well as contribute to climate change mitigation. As a metric, the ratio of SOC to clay offers a better predictor of soil condition than SOC alone, potentially providing a benchmark for ecosystem service payments. We determined SOC:clay ratios for 50 fields in the North Devon UNESCO World Biosphere Reserve using 30 cm soil cores (divided into 0–10 cm and 10–30 cm depth samples), with soil bulk density, soil moisture and land‐use history recorded for each field. All the arable soils exceeded the minimum desirable SOC:clay ratio threshold, and the ley grassland soils generally exceeded it but were inconsistent at 10–30 cm. Land use was the primary factor driving SOC:clay ratios at 0–10 cm, with permanent pasture fields having the highest ratios followed by ley grass and then arable fields. Approximately half of the fields sampled had potential for building up SOC stock at 10–30 cm. However, at this depth, the effect of land use is significantly reduced. Within‐field variability in SOC and clay was low (coefficient of variation was ~10%) at both 0–10 cm and 10–30 cm, suggesting that SOC:clay ratios precisely characterized the fields. Due to the high SOC:clay ratios found, we conclude that there is limited opportunity to market additional carbon sequestration as an asset class in the North Devon Biosphere or similar areas. Instead, preserving existing SOC stocks would be a more suitable ecosystem service payment basis.

The effect of low-abundance OTU filtering methods on the reliability and variability of microbial composition assessed by 16S rRNA amplicon sequencing.

PCR amplicon sequencing may lead to detection of spurious operational taxonomic units (OTUs), inflating estimates of gut microbial diversity. There is no consensus in the analytical approach as to what filtering methods should be applied to remove low-abundance OTUs; moreover, few studies have investigated the reliability of OTU detection within replicates. Here, we investigated the reliability of OTU detection (% agreement in detecting OTU in triplicates) and accuracy of their quantification (assessed by coefficient of variation (CV)) in human stool specimens. Stool samples were collected from 12 participants 22-55 years old. We applied several methods for filtering low-abundance OTUs and determined their impact on alpha-diversity and beta-diversity metrics. The reliability of OTU detection without any filtering was only 44.1% (SE=0.9) but increased after filtering low-abundance OTUs. After filtering OTUs with <0.1% abundance in the dataset, the reliability increased to 87.7% (SE=0.6) but at the expense of removing 6.97% reads from the dataset. When filtering was based on individual sample, the reliability increased to 73.1% after filtering OTUs with <10 copies while removing only 1.12% of reads. High abundance OTUs (>10 copies in sample) had lower CV, indicating better accuracy of quantification than low-abundance OTUs. Excluding very low-abundance OTUs had a significant impact on alpha-diversity metrics sensitive to the presence of rare species (observed OTUs, Chao1) but had little impact on relative abundance of major phyla and families and alpha-diversity metrics accounting for both richness and evenness (Shannon, Inverse Simpson). To increase the reliability of microbial composition, we advise removing OTUs with <10 copies in individual samples, particularly in studies where only one subsample per specimen is available for analysis.

Optimizing reduction of western blotting analytical variations: Use of replicate test samples, multiple normalization methods, and sample loading positions

Western blot (WB) analysis is widely used, but obtaining consistent results can be problematic, especially when using multiple gels. This study examines WB performance by explicitly applying a method commonly used to test analytical instrumentation. Test samples were lysates from RAW 264.7 murine macrophages treated with LPS to activate MAPK and NF-kB signaling targets.Samples from the pooled cell lysates placed in every lane on multiple gels were analyzed by WBs for levels of p-ERK, ERK, IkBβ and non-target protein. Different normalization methods and sample groupings were applied to the density values and the resulting coefficients of variation (CV) and ratios of maximal to minimal values (Max/Min) were compared. Ideally with identical sample replicates the CVs would be 0 and the Max/Min 1; deviation indicating introduction of variability by the WB process. Common normalizations to reduce analytical variance, total lane protein, % Control, and p-ERK/ERK ratios, did not have the lowest CVs or Max/Min values. Normalization using the sum of target protein values combined with analytical replication most effectively reduced variability, resulting CV and Max/Min values as low as 5–10% and 1.1. These methods should allow reliable interpretation of complex experiments that require samples to be placed on multiple gels.

Assessment of the tensile behavior of twisted steel connectors for masonry retrofitting

The paper presents an experimental investigation on the tensile behavior of twisted stainless-steel bars considering different parameters that could affect their performance, namely the bar diameter (8, 10, 12 mm), the embedment depth, the position within the wall (installed into brick or in a T-mortar joint), the strength of the masonry and the type of loading (monotonic or cyclic load). Experimental results showed very good performance with reliable results associated to low coefficient of variation of the loads and very limited damage of the base material. The load–displacement curves showed a good ductility, an excellent superposition between monotonic and cyclic tests and an extended plateau at ultimate load. Among the different investigated parameters, the position within the wall was the most influential one, with higher loads associated to mid-brick location of the bar. Finally, based on the experimental results a user-friendly equation is proposed to predict the ultimate tensile load.

Progressively refined deep joint registration segmentation (ProRSeg) of gastrointestinal organs at risk: Application to MRI and cone-beam CT.

Adaptive radiation treatment (ART) for locally advanced pancreatic cancer (LAPC) requires consistently accurate segmentation of the extremely mobile gastrointestinal (GI) organs at risk (OAR) including the stomach, duodenum, large and small bowel. Also, due to lack of sufficiently accurate and fast deformable image registration (DIR), accumulated dose to the GI OARs is currently only approximated, further limiting the ability to more precisely adapt treatments. Develop a 3-D Progressively refined joint Registration-Segmentation (ProRSeg) deep network to deformably align and segment treatment fraction magnetic resonance images (MRI)s, then evaluate segmentation accuracy, registration consistency, and feasibility for OAR doseaccumulation. ProRSeg was trained using five-fold cross-validation with 110 T2-weighted MRI acquired at five treatment fractions from 10 different patients, taking care that same patient scans were not placed in training and testing folds. Segmentation accuracy was measured using Dice similarity coefficient (DSC) and Hausdorff distance at 95th percentile (HD95). Registration consistency was measured using coefficient of variation (CV) in displacement of OARs. Statistical comparison to other deep learning and iterative registration methods were done using the Kruskal-Wallis test, followed by pair-wise comparisons with Bonferroni correction applied for multiple testing. Ablation tests and accuracy comparisons against multiple methods were done. Finally, applicability of ProRSeg to segment cone-beam CT (CBCT) scans was evaluated on a publicly available dataset of 80 scans using five-foldcross-validation. ProRSeg processed 3D volumes (128 × 192 × 128) in 3 s on a NVIDIA Tesla V100 GPU. It's segmentations were significantly more accurate ( ) than compared methods, achieving a DSC of 0.94 ±0.02 for liver, 0.88±0.04 for large bowel, 0.78±0.03 for small bowel and 0.82±0.04 for stomach-duodenum from MRI. ProRSeg achieved a DSC of 0.72±0.01 for small bowel and 0.76±0.03 for stomach-duodenum from public CBCT dataset. ProRSeg registrations resulted in the lowest CV in displacement (stomach-duodenum : 0.75%, : 0.73%, and : 0.81%; small bowel : 0.80%, : 0.80%, and : 0.68%; large bowel : 0.71%, : 0.81%, and : 0.75%). ProRSeg based dose accumulation accounting for intra-fraction (pre-treatment to post-treatment MRI scan) and inter-fraction motion showed that the organ dose constraints were violated in four patients for stomach-duodenum and for three patients for small bowel. Study limitations include lack of independent testing and ground truth phantom datasets to measure dose accumulationaccuracy. ProRSeg produced more accurate and consistent GI OARs segmentation and DIR of MRI and CBCTs compared to multiple methods. Preliminary results indicates feasibility for OAR dose accumulation usingProRSeg.

Validity and Reliability of the V-Cut Dribbling Test in Young Basketball Players.

Change of direction while dribbling appears to be of interest for on-court performance in basketball. The study aim was to assess the validity and reliability of the V-cut dribbling test (VcutBk) in young basketball players. Ninety-two young basketball players from 8 to 21years old (74% male) were classified in relation to peak height velocity (PHV) offset. To examine validity and test-retest reliability, VcutBk was performed in 2 identical sessions separated by 1week. Participants also performed the V-cut test and linear sprint test with and without dribbling to analyze correlations between tests in different somatic maturity stages. The relationships of the VcutBk with the other tests and skill-time-related deficits were interpreted from large (r > .51) to very large (r > .71). The comparisons between pre-PHV and post-PHV groups of basketball players showed significant and large effect in the VcutBk (d = 2.04;mean difference = 2.59;95% CI, 1.86 to 3.32). Also, significant main effects when comparing PHV groups were reported in all skill-time-related deficits (P < .001, ηp2=.13-.28, moderate to large effect size). Test-retest reliability and signal-to-noise ratio analysis did not show substantial between-trials differences in VcutBk. Reliability scores showed high intraclass correlation coefficient (.95) and low coefficient of variation (0.23%). The VcutBk seems to be a valid and reliable test to assess change of direction while dribbling. VcutBk performance and skill-time-related deficits seem to be sensitive to somatic maturity. Basketball coaches should consider the VcutBk to assess young basketball players.

COMPARISON OF EFFECTS OF BLOOD PRESSURE, BLOOD GLUCOSE AND LIPID VARIABILITY ON CARDIOVASCULAR PROGNOSIS IN DIABETIC PATIENTS

Objective: Metabolic abnormalities such as dyslipidemia, glucose and high blood pressure are common in diabetic patients. Variabilities in these measures have been reported as a potential residual cardiovascular risk factors. This study aimed to analyze the relationship between variabilities of blood pressure, blood glucose, total cholesterol and triglyceride levels (metabolic variability parameters) and their effects on cardiovascular prognosis in diabetic patients. Design and method: A total of 22,310 diabetic patients aged 40 years or older who had their blood pressure, blood glucose, total cholesterol, and triglyceride levels measured three or more times for three years after January 1, 2017 at three tertiary general hospitals were selected. They were divided into high/low groups based on their systolic blood pressure (SBP), blood glucose, total cholesterol (TC) and triglyceride coefficient of variation (CV) over a 3-year period. The incidence of major adverse cardiovascular events (MACE), a composite of cardiovascular death, myocardial infarction, and stroke, was compared between groups, and significant risk factors for MACE were estimated by multivariable Cox regression analysis. Results: The number of measurements for 3 years was 15.1 times for SBP, 7.8 times for TC, 6.9 times for triglyceride, and 8.6 times for glucose. The correlation between the CV of SBP and the CV of glucose was highest, and the correlation between the CV of SBP and the CV of triglycerides was the lowest. All groups with high CV had a higher incidence of MACE than those with low CV (2.5% vs 6.0% for SBP CV groups, 3.0% vs 5.5% for TC CV groups, 3.8% vs 4.7% for triglyceride CV groups, 2.7% vs 5.8% for glucose CV groups). Multivariable Cox regression analysis suggested male, creatinine, prior myocardial infarction, SCORE2, SBP CV, TC CV, mean TC, and mean triglyceride as independent risk predictors for MACE in diabetic patients (HR 1.087 (95% CI 1.068 – 1.107) for SBP CV, 1.023 (1.016 – 1.031) for TC CV). Conclusions: Metabolic variability parameters, especially SBP CV and TC CV are important residual risk factors for cardiovascular events in diabetic patients.

Utilizing a Functional Lumen Imaging Probe for Evaluation of the Pediatric Airway, A Pilot Study.

Accurate and reproducible measurements of the pediatric airway are critical for diagnostic evaluation and management of subglottic and tracheal stenosis. The endoluminal functional lumen imaging probe (EndoFLIP) is a catheter-based imaging probe which utilizes impedance planimetry to calculate luminal parameters, including cross-sectional area and compliance. Herein, we demonstrate the feasibility of this system for multidimensional evaluation of the pediatric airway. 3D-printed pediatric laryngotracheal models were created based on computed tomography scans, then artificially deformed to simulate both circumferential and posterior subglottic stenosis. Two observers made six measurements of the minimum cross-sectional area (MCSA) and length of stenosis of each model with EndoFLIP. Agreement between observer measurements and model dimensions was evaluated using Lin's concordance correlation coefficient; inter-observer reliability was assessed using intraclass correlation. Four models were created: two without pathology (MCSA: 132.4, 44.3 mm2 ) and two with subglottic stenosis (MCSA: 28.7, 59.7 mm2 , stenotic length 27.8, 24.4 mm). Observer measurements of MCSA and length of stenosis demonstrated high concordance with the models (r = 0.99, 0.95, p < 0.001) with a mean error of 4.5% and 18.2% respectively. There was a low coefficient of variation (0.6%-2.8%) for measurements, indicating high precision. Interrater reliability was high for both MCSA and stenotic length (ICC: 0.99, 0.98). The EndoFLIP system allows for accurate and reproducible measurements of cross-sectional area and stenotic length in pediatric airway models. This method may provide further advantages in the evaluation of airway distensibility, as well as measurements of asymmetric airway pathology. NA Laryngoscope, 134:108-112, 2024.

Effects of metabolic parameters’ variability on cardiovascular outcomes in diabetic patients

BackgroundMetabolic abnormalities such as dyslipidemia, glucose and high blood pressure are common in diabetic patients. Visit-to-visit variabilities in these measures have been reported as potential residual cardiovascular risk factors. However, the relationship between these variabilities and their effects on cardiovascular prognosis have not been studied.MethodsA total of 22,310 diabetic patients with ≥ 3 measurements of systolic blood pressure (SBP), blood glucose, total cholesterol (TC), and triglyceride (TG) levels during a minimum of three years at three tertiary general hospitals were selected. They were divided into high/low variability groups for each variable based on the coefficient of variation (CV) values. The primary outcome was the incidence of major adverse cardiovascular events (MACE), a composite of cardiovascular death, myocardial infarction, and stroke.ResultsAll high CV groups had a higher incidence of MACE than those with low CV (6.0% vs. 2.5% for SBP-CV groups, 5.5% vs. 3.0% for TC-CV groups, 4.7% vs. 3.8% for TG-CV groups, 5.8% vs. 2.7% for glucose-CV groups). In multivariable Cox regression analysis,, high SBP-CV (HR 1.79 [95% CI 1.54–2.07], p < 0.01), high TC-CV (HR 1.54 [95% CI 1.34–1.77], p < 0.01), high TG-CV (HR 1.15 [95% CI 1.01–1.31], p = 0.040) and high glucose-CV (HR 1.61 [95% CI 1.40–1.86], p < 0.01) were independent predictors of MACE.ConclusionVariability of SBP, TC, TG and glucose are important residual risk factors for cardiovascular events in diabetic patients.

Cardiovascular autonomic neuropathy is associated with increased glycemic variability driven by hyperglycemia rather than hypoglycemia in patients with diabetes

AimCardiac autonomic neuropathy (CAN) has been suggested to be associated with hypoglycemia and impaired hypoglycemia unawareness. We have assessed the relationship between CAN and extensive measures of glucose variability (GV) in patients with type 1 and type 2 diabetes. MethodsParticipants with diabetes underwent continuous glucose monitoring (CGM) to obtain measures of GV and the extent of hyperglycemia and hypoglycemia and cardiovascular autonomic reflex testing. ResultsOf the 40 participants (20 T1DM and 20 T2DM) (aged 40.70 ± 13.73 years, diabetes duration 14.43 ± 7.35 years, HbA1c 8.85 ± 1.70%), 23 (57.5%) had CAN. Despite a lower coefficient of variation (CV) (31.26 ± 11.87 vs. 40.33 ± 11.03, P = 0.018), they had a higher CONGA (8.42 ± 2.58 vs. 6.68 ± 1.88, P = 0.024) with a lower median LBGI (1.60 (range: 0.20–3.50) vs. 4.90 (range: 3.20–7.40), P = 0.010) and percentage median time spent in hypoglycemia (4 (range:4–13) vs. 1 (range:0–5), P = 0.008), compared to those without CAN. The percentage GRADEEuglycemia (3.30 ± 2.78 vs. 5.69 ± 3.09, P = 0.017) and GRADEHypoglycemia (0.3 (range: 0 – 3.80) vs. 1.8 (range: 0.9–6.5), P = 0.036) were significantly lower, while the percentage median GRADEHyperglycemia (95.45 (range:93–98) vs. 91.6 (82.8–95.1), P = 0.013) was significantly higher in participants with CAN compared to those without CAN. ConclusionCAN was associated with increased glycemic variability with less time in euglycemia attributed to a greater time in hyperglycemia but not hypoglycemia.

Increasing the Reliability of Formation Factor-Based Transport Property Prediction for High Performance Concrete Mixtures Through Innovative Matching Pore Solution Curing

Recent specifications for concrete bulk resistivity tests (ASTM C 1876 and AASHTO TP 119) recommend a submerged standard (simulated) pore solution (SPS, solution conductivity = 78.74 mS/cm) for curing concrete specimens. The rationale for the bucket test is that immersing concrete specimens in a soak solution similar to their pore solution would eliminate the need to determine pore solution resistivity for calculating the formation factor (FF) of concrete mixtures. However, the thermodynamic modeling predictions of 91-day pore solution concentration (PSC) for eight high performance concrete (HPC) mixtures evaluated in the current study showed SPS to be a close representation only for reference ordinary Portland cement (OPC) and binary silica fume mixtures. In contrast, the average PSC of Class F and Class C fly ash mixtures was approximately 12% to 20% lower and 20% to 40% higher, respectively, than the SPS. Accordingly, an innovative matching pore solution (MPS) curing approach was developed in which mixtures are grouped based on the influence of supplementary cementitious materials (SCMs), that is, their type and replacement levels of the long-term PSC of concrete mixtures and, thereby, cured in a simulated solution matching the average PSC of a particular group. Based on experimental work in the current study, HPC mixtures under MPS demonstrated a lower coefficient of variation (COV) and more comparable (&lt;10% difference) bulk resistivity (BR) and surface resistivity (SR) measurements compared with SPS. Moreover, the MPS improved the reliability in FF determination and FF-based transport property prediction for HPC mixtures, as verified by lower mean absolute error and improved R2 between FF-predicted diffusion coefficients and experimental measurements.