Strength Of Linear Correlation Research Articles

Fructosamine and HbA1c: A Correlational Study in a Southeast Asian Population.

Fructosamine correlates well with glycated haemoglobin (HbA1c) in Caucasians. This study investigates this correlation and whether fructosamine can reliably estimate glycated haemoglobin in Southeast Asians. We recruited 193 participants based on 4 HbA1c bands (<6.0%; 6.0 - 7.9%; 8.0- 9.9%; ≥10%) from a secondary hospital in Singapore between August 2017 and December 2021. Blood samples for fructosamine, glycated haemoglobin, albumin, haemoglobin, thyroid stimulating hormone and creatinine were drawn in a single setting for all participants. Scatter plot was used to explore correlation between fructosamine and glycated haemoglobin. Strength of linear correlation was reported using Pearson's correlation coefficient. Simple linear regression was used to examine the relationship between fructosamine and glycated haemoglobin. We performed simple linear regression to study the relationship between fructosamine and HbA1c in the research participants (R2 = 0.756, p<0.01). Further analysis with natural logarithmic transformation of fructosamine demonstrated a stronger correlation between HbA1c and fructosamine (R2 = 0.792, p<0.01). Fructosamine is reliably correlated with HbA1c for the monitoring of glycaemic control in Southeast Asians.

INFLUENCE OF THE BASICITY INDEX ON WELDING ELECTRODE COATINGS ON THEIR WELDING AND TECHNOLOGICAL PROPERTIES

At this article presented the results of researches on studying of influence of basicity index BI of the electrode coating and the Melting Temperature Tm of the slag of electrode coatings consisting of a two-component CaO-SiO2 oxide system and ore-mineral raw materials of the Republic of Uzbekistan on the welding and technological properties of the welding electrodes. The relationship between these indicators was determined, the strength of linear correlation of which was estimated using the coefficient of determination R2. The influence of the BI value on such properties of the welding electrode as the breaking length of the arc, the formation of the deposited metal, and the formation of a visor or cover at the end of the electrode is established. Based on the research results, recommendations for the basicity index BI of the electrode coating were identified, which can be used in the development of electrode coating compositions for their effective impact on the welding and technological properties of welding electrodes.

Disagreement in cardiac output measurements between fourth-generation FloTrac and critical care ultrasonography in patients with circulatory shock: a prospective observational study

BackgroundCardiac output measurements may inform diagnosis and provide guidance of therapeutic interventions in patients with hemodynamic instability. The FloTrac™ algorithm uses uncalibrated arterial pressure waveform analysis to estimate cardiac output. Recently, a new version of the algorithm has been developed. The aim was to assess the agreement between FloTrac™ and routinely performed cardiac output measurements obtained by critical care ultrasonography in patients with circulatory shock.MethodsA prospective observational study was performed in a tertiary hospital from June 2016 to January 2017. Adult critically ill patients with circulatory shock were eligible for inclusion. Cardiac output was measured simultaneously using FloTrac™ with a fourth-generation algorithm (COAP) and critical care ultrasonography (COCCUS). The strength of linear correlation of both methods was determined by the Pearson coefficient. Bland-Altman plot and four-quadrant plot were used to track agreement and trending ability.ResultEighty-nine paired cardiac output measurements were performed in 17 patients during their first 24 h of admittance. COAP and COCCUS had strong positive linear correlation (r2 = 0.60, p < 0.001). Bias of COAP and COCCUS was 0.2 L min−1 (95% CI − 0.2 to 0.6) with limits of agreement of − 3.6 L min−1 (95% CI − 4.3 to − 2.9) to 4.0 L min−1 (95% CI 3.3 to 4.7). The percentage error was 65.6% (95% CI 53.2 to 77.3). Concordance rate was 64.4%.ConclusionsIn critically ill patients with circulatory shock, there was disagreement and clinically unacceptable trending ability between values of cardiac output obtained by uncalibrated arterial pressure waveform analysis and critical care ultrasonography.Trial registrationClinicaltrials.gov, NCT02912624, registered on September 23, 2016

General perspectives on model construction and evaluation for stochastic estimation, with application to a blunt trailing edge wake

The technique of stochastic estimation is examined as a specific application of linear least squares modelling. Factors that are relevant to the objectives of estimation in fluids, such as the number of sensors, the use of multiple time lags, and the strength of linear correlations, are discussed in the context of a general regression formulation. We consolidate the established findings of several research fields in order to outline clearly the potential pitfalls and reasonable performance expectations of these empirical strategies. Experimental measurements of velocity and fluctuating pressure in the wake of a blunt trailing edge body are used for quantitative illustration of key considerations for model construction and performance evaluation. It is emphasized that estimator accuracy is influenced strongly by the physical relationships among the measured variables, in addition to their correlation with the estimated variable. The evaluation of several performance metrics on an independent test set provides valuable information for the selection of a suitably complex model. In particular, “variance inflation” is interpreted as an indicator of the potential amplification of noise by a stochastic estimator.

Abstract 334: Comparison of an in situ hybridization technique based on fluorescence (FISH) with dual color silver-enhanced ISH (SISH) for the validation of equivocal (borderline) status of HER2 (erbb2) in invasive breast carcinoma

Abstract Aims: Accurate determination of HER2 gene amplification is necessary for the selection of patients for trastuzumab therapy. FISH is regarded as the gold standard method for detecting HER2 gene amplification. In comparison to FISH, SISH has the advantages of being a method evaluated by bright-field microscopy and generating stable signals. Several studies have shown an excellent concordance between different ISH methods in detection of clearly HER2 amplified and non-amplified breast carcinomas. Aim of this study is to compare the performance of dual color SISH (dSISH) in breast carcinoma with equivocal HER2 status with conventional FISH analysis. Material&amp;Methods: From two different Institutes, biopsies from 62 female patients with invasive breast carcinoma were investigated independently for HER2 with FISH, single color SISH (sSISH) and the dSISH technique. FDA-approved FISH method was used. HER2 gene and CEN17 signals were counted separately. The strength of linear correlation of HER2/CEN17 measurements between FISH and sSISH and between sSISH and dSISH was evaluated and agreement assessed using Bland-Altman plots, which describe the average HER2/CEN17 of the two methods versus the difference between both methods. Concordance of HER2/CEN17 assessed by FISH and dSISH for ratios of 1.5-1.8, 1.8-2.0, 2.0-2.2 and 2.2-2.5 (called categories) were determined using the weighted kappa statistic. Results: For FISH and sSISH, the correlation of HER2/CEN17 between both methods was 0.61 and considerably improved when comparing sSISH versus dSISH (correlation coefficient: 0.79). Compared to FISH, dSISH tended to over-estimate HER2/CEN17 by 0.42 signals on average, whereas 95% of all differences between FISH and dSISH ranged within a ratio of 2.4. In tumors with equivocal FISH-HER2 status (ratio 1.8-2.0 and 2.0-2.2) dSISH was highly discrepant with concordance only of 11.1% and 42.9%, respectively. In 22.2% and 28.6% of these cases dSISH results in HER2 amplification. Concordance between FISH and dSISH was greatest for HER2/C17 ratios of 1.5-1.8 and 2.2-2.5, yet kappa values still demonstrated only fair agreement (κ=0.30 and κ=0.33). Conclusion: In comparison to FISH, ISH methods like SISH have the advantage of generating stable signals and can be evaluated by bright-field microscopy. Fair agreement was achieved with dSISH when HER2/CEN17 ratio was between 1.5-1.8 and 2.2-2.5 respectively by FISH. Breast carcinoma with equivocal status for HER2 in FISH analysis was poorly reproducible with dSISH with concordance of 54% of the cases. Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 334.

Incidence and correlates of breast-feeding practices in the non-European Community migrant women

The purpose of this case-control study was to compare post-migration attitudes of non-European Community migrant women towards infant feeding, in comparison with industrialized area native Italian women of North-eastern Italy (Noventa Vicentina Maternity Hospital, Vicenza). A questionnaire was used for maternal and infant characteristic data collection at hospital discharge following delivery and at 3 and 6 months postpartum, to identify patterns and correlates in the quantitative breast-feeding practices. From March, 1999 to September 2000 50 consecutive migrant women (55% African, 35% Balcanic, 7% Latin-American and 3% Indo-Chinese) and 100 consecutive native control mothers, matched for gestational age, were invited to participate in this study. Twelve weeks was chosen as a reasonable cut-off time for “Early or Later Weaning”, after breast-feeding initiation upon hospital discharge. The strength of linear correlation between educational level (years) of native and migrant lactating women versus age, parity, pre- and post-gestational body weight, duration of breast-feeding (3 and 6 months), and number of fetal ultrasound screenings during gestation was assessed. At maternity hospital discharge the migrant women had high breast-feeding rates, similar to native women (99% and 96%, respectively). In both migrant and native mother samples a sharp fall in breast-feeding practice followed discharge. Migrant women presented the highest occurrence of Early Weaning (3rd month, breast-feeding rates 42% and 61%, respectively; p < 0.05). No significant differences were found across the 2 groups in Later Weaning (6th month, breast-feeding rates 38% vs 40%, respectively).Thus, the breast-feeding trend toward smaller values with time within each of the 2 groups on initiation, on the 3rd month, and on the 6th month was statistically significant (p per trend <0.01). In addition, the schooling years of migrant women were significantly correlated with the duration of breast-feeding (r = 0,11; p < 0.03) and a greater number of ultrasound screenings during gestation (r = 0.29; p < 0.03). Findings revealed that more cultured women are prone following migration to industrialized settings to adopt the sociosanitary facilities and cultural characteristics on plane mode of feeding of the host country.

Correlation analysis of visual field thresholds and scanning laser ophthalmoscopic optic nerve head measurements in glaucoma.

In a cross-sectional study of 50 consecutive primary open-angle glaucoma cases, full threshold 30-2 visual fields on Humphrey Visual Field Analyser were correlated to stereometric parameters obtained using a scanning laser ophthalmoscope (HRT II). The strength of linear correlation between the stereometric parameters and visual thresholds was used to generate a correspondence map between the optic disc and the visual field. Rim/disc area ratio and cup/disc area ratio correlated with the visual thresholds at the highest number of points in the visual fields. Thresholds at superior hemifield locations correlated best with the rim/disc area ratio and cup/disc area ratio in the inferonasal sector and the ones in the inferior hemifield correlated best with the rim/disc area ratio and cup/disc area ratio in the superotemporal sector. Optic disc parameters correlated better with inferior field locations and non-edge points than superior field locations and edge points. The data indicate that rim/disc area ratio and cup/disc area ratio measurements on HRT II have a good correlation with visual field damage seen on automated visual fields.

Medullary lateral tegmental field: an important synaptic relay in the baroreceptor reflex pathway of the cat.

This study was designed to test the hypothesis that the medullary lateral tegmental field (LTF) is an important synaptic relay in the baroreceptor reflex pathway controlling sympathetic nerve discharge (SND) of urethan-anesthetized cats. We determined the effects of blockade of excitatory amino acid-mediated neurotransmission in the LTF on three indexes of baroreceptor reflex function: cardiac-related power in SND, strength of linear correlation (coherence value) of SND to the arterial pulse (AP), and inhibition of SND during increased arterial pressure produced by abrupt obstruction of the abdominal aorta. Bilateral microinjection of D-(-)-2-amino-5-phosphonopentanoic acid, an N-methyl-D-aspartate (NMDA) receptor antagonist, abolished cardiac-related power and coherence of SND to the AP, and it prevented inhibition of SND during aortic obstruction. These data support the view that NMDA receptor-mediated neurotransmission in the LTF is critical for baroreceptor reflex control of SND. Bilateral microinjection of 1,2, 3,4-tetrahydro-6-nitro-2,3-dioxobenzo-[f]-quinoxaline-7-sulfonamid e, a non-NMDA receptor antagonist, decreased cardiac-related power and total power in the 0- to 6-Hz band of SND; however, the AP-SND coherence value remained high, and inhibition of SND during aortic obstruction was preserved. These data imply that non-NMDA receptor-mediated neurotransmission in the LTF is involved in setting the level of excitatory drive to sympathetic nerves.