Genome-wide association identifies nine common variants associated with fasting proinsulin levels and provides new insights into the pathophysiology of type 2 diabetes.

OBJECTIVE: Proinsulin is a precursor of mature insulin and C-peptide. Higher circulating proinsulin levels are associated with impaired β-cell function, raised glucose levels, insulin resistance, and type 2 diabetes (T2D). Studies of the insulin processing pathway could provide new insights about T2D pathophysiology. RESEARCH DESIGN AND METHODS: We have conducted a meta-analysis of genome-wide association tests of ∼2.5 million genotyped or imputed single nucleotide polymorphisms (SNPs) and fasting proinsulin levels in 10,701 nondiabetic adults of European ancestry, with follow-up of 23 loci in up to 16,378 individuals, using additive genetic models adjusted for age, sex, fasting insulin, and study-specific covariates. RESULTS: Nine SNPs at eight loci were associated with proinsulin levels (P < 5 × 10(-8)). Two loci (LARP6 and SGSM2) have not been previously related to metabolic traits, one (MADD) has been associated with fasting glucose, one (PCSK1) has been implicated in obesity, and four (TCF7L2, SLC30A8, VPS13C/C2CD4A/B, and ARAP1, formerly CENTD2) increase T2D risk. The proinsulin-raising allele of ARAP1 was associated with a lower fasting glucose (P = 1.7 × 10(-4)), improved β-cell function (P = 1.1 × 10(-5)), and lower risk of T2D (odds ratio 0.88; P = 7.8 × 10(-6)). Notably, PCSK1 encodes the protein prohormone convertase 1/3, the first enzyme in the insulin processing pathway. A genotype score composed of the nine proinsulin-raising alleles was not associated with coronary disease in two large case-control datasets. CONCLUSIONS: We have identified nine genetic variants associated with fasting proinsulin. Our findings illuminate the biology underlying glucose homeostasis and T2D development in humans and argue against a direct role of proinsulin in coronary artery disease pathogenesis

Predicting sandy-clayey soil properties using electrical resistivity testing

Non-destructive tests are economical and easy-to-use techniques to determine different soil properties, which speed up the determination of sub-surface characteristics. They include ground-penetrating radar, seismographs, shear wave velocity and electrical resistivity testing. The latter is gaining worldwide popularity for determining sub-surface geology in geotechnical engineering as it does not require extensive testing. The aim of the study reported in this paper was to develop empirical correlations of electrical resistivity testing with different soil parameters by performing extensive conventional laboratory tests. These correlations would help in computing the required soil parameters by performing solely electrical resistivity testing, saving the time and effort required by conventional tests. The correlations developed included the relationship of resistivity values of soil with the drained angle of internal friction, effective cohesion, Atterberg's limits, maximum dry density, optimum moisture content and bearing capacity of a variety of shallow foundations. The regression coefficients obtained ensured the development of quite a good correlation, such that the result of electrical resistivity testing can be used for reasonably accurate determination of sandy-clayey soil propertie

Transient flow analysis for pumping system comprising pressure vessel using unsteady friction model

Recent myriad studies on the application of pressure vessels (PVs) to dampen the potentially hazardous transient pressure caused by pump failure are available in the literature. However, little research has been done on integrating these PVs into an instantaneous acceleration-based (IAB) model for transient flow analysis, while most of the reported investigations have been accomplished using the steady-state friction models. Also, scarce literature exists on optimizing the connection configuration of the PV. Nevertheless, unsteady friction (UF) is vital in accurately modeling a transient event, and therefore this study utilizes the IAB UF model to accurately predict the transient response of the pumping pipeline protected by a PV. Based on the proposed numerical model and computational algorithms, a novel approach is also explored to increase the working efficiency of the PV during transient events via a modified connection configuration with the main pipeline. A parametric study has been conducted to determine the impact of the PV's numerous parameters on transient pressure signals. The results reveal that the IAB UF model with two decay parameters can accurately replicate the amplitude and form of transient waves in a pumping system comprising a PV, with almost no deviations between numerical and experimental results. Furthermore, the numerical study shows that the initial air volume, polytropic exponent, installation location, PV size, and connection arrangement of PV with the pump-rising pipeline significantly affect the performance of water hammer protection. However, the flow resistance of connecting pipes containing perforated plates in a separate bypass line reduces the desired vessel volume from the standpoint of economy. The energy-based approach corroborates the use of this design for vessel-to-pipeline connections. The redesigned connection configuration reduces the required volume of PV by up to 70%, which leads to cost-effectiveness.This research was supported by the National Natural Science Foundation of China (Nos. 52079122, 51779216)

On the Recent Trends in Expansive Soil Stabilization Using Calcium-Based Stabilizer Materials (CSMs): A Comprehensive Review

Calcium-based stabilizer materials (CSMs) exhibit pozzolanic properties which improve the properties of clayey soils by hydration, cation exchange, flocculation, pozzolanic reaction, and carbonation. In this comprehensive review, comprising over past three decades from 1990 to 2019, a mechanistic literature of expansive soil stabilization by incorporating CSMs is presented by reviewing 183 published research articles. The advantages and disadvantages of CSMs as the ground stabilizing agent are succinctly presented, and the major outcomes of physicochemical effects on soil properties are discussed in detail. After blending with CSM, the main and interaction effects on soil properties with focus on chemical processes such as X-ray fluorescence, X-ray diffraction analyses, and microstructure interaction by using scanning electron microscopy and thermogravimetric analysis have been reviewed in light of findings of past researchers. This work will help geotechnical engineers to opt for suitable CSM in the field of geoenvironmental engineering in committing to sustainable construction of civil engineering structures over expansive soils

Sustainable use of soda lime glass powder (SLGP) in expansive soil stabilization

The focus of this experimental study is to ameliorate the engineering behavior of Palygorskite-rich medium Expansive soils (ES) by utilizing soda lime glass powder (SLGP). The hydrophilic ES are problematic and tend to damage the pavements, boundary walls, and slab-on-grade members Whereas, the accumulation of huge amounts of SLGP is responsible for multitude of environmental issues. Therefore, SLGP was added to the ES using various dosage levels (0 %, 6 %, 10 %, 14 %, 16 %, 18 %, and 22 % by dry weight of the ES to assess the compaction, consolidation and strength characteristics by performing geotechnical laboratory tests. Also, the effect of curing on th unconfined compressive strength of ES (UCS-ES) after 3, 7, 14, and 28 days was studied by considering the mineralogical changes. The microscopic mechanisms of the virgin ES and the SLGP-treated mixtures was evaluated by X-ray fluorescence (XRF), X-ray diffraction (XRD), and scanning electron microscopy (SEM) analyses. The results revealed that, plasticity dropped by almost 80 % (due to filler effect, cohesionless character, and higher silica amount of the SLGP), MDD increased from 18.25 to 19.16 kN/m3, and the OMC lowered down (due to the reduction in volume of clay minerals and interlayer spaces). With increasing SLGP dosage levels the coefficient of compression (Cc) decreased by 42.86 %, coefficient of volume (mv) by 60 %, coefficient of consolidation (cv) by 91.53 %, and the pre-consolidation pressures (Pc) witnessed an increase of 240 %. The UCS-ESunsoaked values exceed than the UCS-ES soaked values, particularly at early days of curing (1-7 days) such that UCS-ESsoaked = 13 x UCS-ESsoaked after one day, whereas UCS-ESsoaked = 5.25 x UCS-ESsoaked after 28 days. Similarly, a remarkable improvement (of six-fold) in strength was recorded based on California bearing ratio (CBR) values with 16 % replacement of the SLGP additive. Also, the compactability and strength characteristics were significantly improved and the plasticity plummeted due to formation of C-S-H and C-A-H compounds. Thus, the inclusion of 16 % SLGP in the medium ES was found as the optimum amount in reducing plasticity, improving consolidation characteristics and imparting strength

Strength, hydraulic, and microstructural characteristics of expansive soils incorporating marble dust and rice husk ash

Expansive/swell-shrink soils exhibit high plasticity and low strength, which lead to settlement and instability of lightly loaded structures. These problematic soils contain various swelling clay minerals that are unsuitable for engineering requirements. In an attempt to counter the treacherous damage of such soils in modern geotechnical engineering, efforts are underway to utilize environmentally friendly and sustainable waste materials as stabilizers. This study evaluates the strength and consolidation characteristics of expansive soils treated with marble dust (MD) and rice husk ash (RHA) through a multitude of laboratory tests, including consistency limits, compaction, uniaxial compression strength (UCS), and consolidation tests. By using X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses, the effect of curing on UCS after 3, 7, 14, 28, 56, and 112 days was studied from the standpoint of microstructural changes. Also, the long-term strength development of treated soils was analyzed in terms of the interactive response of impacting factors with the assistance of a series of ANN-based sensitivity analyses. It is found from the results that the addition of MD and RHA lowered down the water holding capacity, thereby causing a reduction in soil plasticity (by 21% for MD and 14.5% for RHA) and optimum water content (by 2% for MD and increased by 6% for RHA) along with an increase in the UCS (for 8% MD from 97 kPa to 471 kPa and for 10% RHA from 211 kPa to 665 kPa, after 3 days and 112 days of curing, respectively). Moreover, from the oedometer test results, mv initially increased up to 6% dosage and then dropped with further increase in the preconsolidation pressure. Furthermore, the compression index dropped with an increase in the preconsolidation pressure and addition of MD/RHA, while the coefficient of permeability (k) of RHA stabilized soil was higher than that of MD-treated samples for almost all dosage levels. The formation of the fibrous cementitious compounds (C-S-H; C-A-H) increased at optimum additive dosage after 7 days and at higher curing periods. Hence, the use of 10% RHA and 12% MD as replacement of the expansive soil is recommended for higher efficacy. This research would be helpful in reducing the impacts created by the disposal of both expansive soil and industrial and agricultural waste materials

Correlation of electrical resistivity test with the geotechnical parameters of Sandy soil

There are different techniques to stabilize and improve the properties of soils with low shear strength, bearing capacity and other swelling parameters. This study includes the chemical analysis of expansive soils using X-ray diffraction (XRD) and scanning electron microscopy (SEM) before and after the stabilization using tire rubber powder (TRP) and cement kiln dust (CKD) in order to evaluate the geotechnical properties. Test results indicate that the inclusion of CKD-TRP mixture, not only reduces the plasticity of soil but also increases its unconfined compression strength, maximum dry density, and other strength characteristics. Finally, 5% TRP and 10% CKD addition is recommended as an optimum amount from the viewpoint of plasticity and strength characteristics

Isolated effect and sensitivity of agricultural and industrial waste Ca-based stabilizer materials (CSMs) in evaluating swell shrink nature of palygorskite-rich clays

This paper evaluates the suitability of sugarcane bagasse ash (SCBA) and waste marble dust (WMD) on the geotechnical properties of Palygorskite-rich expansive clays located in northwest Pakistan. These problematic soils exhibit undesirable characteristics which greatly affect the pavements, boundary walls, slab-on-grade members, and other civil engineering infrastructures. A series of geotechnical tests were performed on soil specimens using prescribed percentages of the aforementioned Ca-based stabilizer materials (CSMs). The investigation includes X-Ray Diffraction (XRD) Analysis, Scanning Electron Microscopy (SEM), X-Ray Fluorescence (XRF) tests, and physicomechanical properties such as moisture-density relationship, Atterberg's limits, swell pressure, and an ANN-based sensitivity analyses of overall swell pressure development. The outcomes of these experimental investigations showed that the addition of CSMs into the expansive soils increased to 4% SCBA and 10% WMD, the plasticity index reduced by 30% and 49%, the volumetric swell decreased from approximately 49% to 86% and 63%, and the swelling pressure reduction was from 189kPa to 120kPa and 160kPa (about 15% and 36%), respectively. It is interesting to note that replacement with specified CSM accelerated the strength of soil at extended curing periods and the optimum improvement in the strength behavior of the soil was also recorded. Moreover, with addition of the respective CSMs, the compactability and strength characteristics were ameliorated, while plasticity was significantly lowered. Given the amount of SCBA and WMD produced annually, their utilization for the stabilization of problematic soils, even in relatively low concentrations, could potentially have a substantial impact on the sustainable reuse of these waste materials

Application of Gene Expression Programming to Evaluate Strength Characteristics of Hydrated-Lime-Activated Rice Husk Ash-Treated Expansive Soil

Gene expression programming has been applied in this work to predict the California bearing ratio (CBR), unconfined compressive strength (UCS), and resistance value (R value or Rvalue) of expansive soil treated with an improved composites of rice husk ash. Pavement foundations suffer failures due to poor design and construction, poor materials handling and utilization, and management lapses. The evolution of sustainable green materials and optimization and soft computing techniques have been deployed to improve on the deficiencies being suffered in the abovementioned areas of design and construction engineering. In this work, expansive soil classified as A-7-6 group soil was treated with hydrated-lime activated rice husk ash (HARHA) in an incremental proportion to produce 121 datasets, which were used to predict the behavior of the soil’s strength parameters utilizing the mutative and evolutionary algorithms of GEP. The input parameters were HARHA, liquid limit (wL), (plastic limit wP, plasticity index IP, optimum moisture content (wOMC), clay activity (AC), and (maximum dry density (δmax) while CBR, UCS, and R value were the output parameters. A multiple linear regression (MLR) was also conducted on the datasets in addition to GEP to serve as a check mechanism. At the end of the computing and iterations, MLR and GEP optimization methods proposed three equations corresponding to the output parameters of the work. The responses validation on the predicted models shows a good correlation above 0.9 and a great performance index. The predicted models’ performance has shown that GEP soft computing has predicted models that can be used in the design of CBR, UCS, and R value for soils being used as foundation materials and being treated with admixtures as a binding component