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There are relatively few experimental studies on the hydromechanical and critical state behaviours of unsaturated silty sand. In this paper, suction-controlled, consolidated, drained triaxial shear tests were conducted on silty sand under saturated (net confining pressures of 100, 200, 300 and 400 kPa) and unsaturated (suctions of 30, 100 and 200 kPa and net confining pressures of 100, 200 and 300 kPa) conditions. For unsaturated silty sand, the effects of dry density, matric suction and net confining pressure on the hydromechanical and critical state behaviour were investigated, and the critical state parameters were obtained. The main findings for unsaturated silty sand included shear shrinkage at low dry density (1·6 g/cm3) and dilatancy at higher density (1·96 g/cm3). The peak shear strength was positively correlated with dry density, matric suction and net confining pressure. The critical state volumetric strain and critical state degree of saturation were negatively correlated with dry density and matric suction but positively correlated with net confining pressure. A new dilatancy equation that includes the state parameter for unsaturated silty sand was established. A unique critical state line passes through the origin in the effective stress p ∗ –deviator q plane, and its slope is the saturated critical state stress ratio M s . In the lnp*–v plane ( v is the specific volume), the critical state lines corresponding to different matric suctions are parallel. [ABSTRACT FROM AUTHOR]

The volume change behaviour of an unsaturated compacted loess under thermo-hydro-mechanical loads is comprehensively investigated in this experimental research. A new temperature/suction-controlled triaxial apparatus with triple cells was developed. Temperature- and suction-controlled isotropic tests, heating–cooling tests with isotropic net stress and suction control and drying–wetting tests with isotropic net stress and temperature control were conducted on an unsaturated compacted loess from Shaanxi, China. Experimental results show that compressibility indices remain unchanged at various temperatures, but show different variation trends with changes in suction. Both suction hardening and thermal softening were observed. Irreversible volumetric contraction is induced in the compacted loess upon heating–cooling path and becomes more significant at higher isotropic net stresses and higher suctions. Lower over-consolidation ratio prior to heating results in greater irreversible contraction in loess samples. Water-holding capacity of loess samples decreases upon heating, but it is independent of the stress level. The hydraulic hysteresis of samples has no significant change with temperature changes. Slight shrinkage occurs during drying process in loess samples, and collapse can be observed in wetting process. Heating has limited effect on the drying shrinkage of loess samples but induces more distinctive wetting collapse. [ABSTRACT FROM AUTHOR]

Loess is usually compacted as building filler in geotechnical engineering construction and the wetting-induced deformation characteristics of compacted loess are closely related to engineering safety. The influence of hydromechanical paths on compacted loess wetting-induced deformation characteristics has been rarely addressed in the literature, especially for compacted sandy loess. In this study, the scanning electron microscopy (SEM) and soil–water retention curve (SWRC) tests are performed to investigate the microstructure and water retention characteristics of compacted sandy loess. Single-oedometer triaxial wetting tests with three complex hydromechanical paths (consolidation-wetting under isotropic stress state, consolidation-loading-wetting-loading and consolidation-unloading-wetting-unloading under deviator stress) are carried out on unsaturated compacted sandy loess. Results indicate that: (1) As the dry density increases, the large inter-aggregate pores inside the compacted sandy loess turned into medium inter-aggregate pores and small inter-aggregate pores; the air entry value increases and the water retention capacity is enhanced. (2) Within a certain range of confining pressure (no more than 400 kPa), the wetting volumetric strain increases with the increase in confining pressure and dry density under isotropic stress condition; the loading paths wetting-induced deformation is greater than unloading paths wetting-induced deformation under deviator stress condition. (3) At a lower stress ratio, compacted sandy loess undergoes significant wetting-induced dilatancy; the wetting-induced deformation under the unloading path appears significant, compared with that under the loading path. [ABSTRACT FROM AUTHOR]

Focusing mainly on the compressive-shear (C-S) stress, the existing soil strength theories fail to well describe the soil strength under tenso–shear (T-S) stress and are not suitable for analyzing the tensile strength and T-S coupling strength. Taking the T-S strength into account, a three-dimensional nonlinear strength model of soil is established. The failure function on the π plane is a Lade Lade-curved triangle in principal stress space, which reasonably reflects the effect of medium principal stress. The failure function on the triaxial compression meridian plane is divided into the T-S and C-S zones, in which the two failure functions are smoothly connected at the closed stress point. To easily combine it with the specific elastoplastic constitutive theory, the proposed strength model is transformed into the D-P criterion in transformed stress space using the transformation stress method, which provides a theoretical foundation for numerical calculations. Compared with the true triaxial test results and numerical slope examples, the proposed model gives a good description of the nonlinear soil strength under complex stresses and the instability failure mechanism of the slope. [ABSTRACT FROM AUTHOR]

Cell migration is a pivotal step in metastatic process, which requires cancer cells to navigate a complex spatially‐confined environment, including tracks within blood vessels and in the vasculature of target organs. Here it is shown that during spatially‐confined migration, the expression of insulin‐like growth factor‐binding protein 1 (IGFBP1) is upregulated in tumor cells. Secreted IGFBP1 inhibits AKT1‐mediated phosphorylation of mitochondrial superoxide dismutase (SOD2) serine (S) 27 and enhances SOD2 activity. Enhanced SOD2 attenuates mitochondrial reactive oxygen species (ROS) accumulation in confined cells, which supports tumor cell survival in blood vessels of lung tissues, thereby accelerating tumor metastasis in mice. The levels of blood IGFBP1 correlate with metastatic recurrence of lung cancer patients. This finding reveals a unique mechanism by which IGFBP1 sustains cell survival during confined migration by enhancing mitochondrial ROS detoxification, thereby promoting tumor metastasis. [ABSTRACT FROM AUTHOR]

The microstructure can have an important impact on the hydraulic and mechanical behaviors of unsaturated soil; therefore, it must be considered in constitutive models to enable accurate predictions of soil behavior. This paper focused on the constitutive modeling of soils that exhibited a dual porosity structure. Based on the assumption that macro and micropores contained in the double porosity structure had different influences on the mechanical and hydraulic behaviors, the effective degree of saturation (Se) was selected as a microstructural index. This microstructural index was implemented within Bishop's effective stress-based approach and the Glasgow coupled (GCM) and modified Cam-Clay models (MCC) were adopted as the basic framework for the development of a constitutive model. Typical samples of low expansive, nonexpansive, and collapsible soils with dual porosity were selected to validate the model's performance, and the model performed well when compared with experimental data for isotropic compression, triaxial shear, and wetting tests. [ABSTRACT FROM AUTHOR]

A temperature-dependent water retention curve (WRC) model is necessary in numerous geotechnical engineering cases such as the disposal and storage of nuclear waste, buried high-voltage cables, heat dissipation embankments and geothermal structures. A series of pioneering models attempting to consider the mechanisms of temperature effect have been proposed. Nevertheless, it should be noted that very limited research can be found in the literature to consider temperature effects on both capillarity and adsorption. Thus, a temperature-dependent WRC model for both adsorption and capillarity is developed in this study. An adsorption equation is first proposed by integrating Kelvin equation, Clausius–Clapeyron equation and the adsorption enthalpy equation. Then, the proposed adsorption equation and an existing capillary equation are incorporated into Peters–Durner–Iden (PDI) model to establish the temperature-dependent WRC model. Sixteen series of non-isothermal WRC data are employed to illustrate the application and performances of the proposed model. The proposed WRC model provides good agreement between the predicted and measured temperature-dependent WRCs. Moreover, the main differences between different types of soils are temperature effects on adsorption. The value of parameter α gradually increases from sandy soils to bentonite, representing an increasingly strong soil–water interaction and increasingly significant temperature effects on adsorption. By comparing with three existing models, the proposed model is found as the most suitable for describing the observed data. [ABSTRACT FROM AUTHOR]

Shear strength (τ) analysis has received considerable attention, because of its importance when designing various geotechnical structures, such as tunnels, retaining walls, shallow foundations, and slopes. Predicting the unsaturated τ from water retention curves (WRCs) is an existing method. The validity of this method for the prediction of unsaturated τ over a wide suction (ψ) range has been discussed by several researchers. However, the existing method ignores the influence of void ratio (e), which plays a strong part in the water holding capacity and the τ analysis of unsaturated soils. Therefore, according to an existing WRC equation that distinguishes capillary water and adsorbed water, a new WRC equation was proposed to consider the effect of e on the water holding capacity. In addition, using the e dependent WRC, a new method that predicted the τ of unsaturated silts or silty clays at various e over a wide ψ range (that included the residual zone) was proposed. The prediction of τ by the proposed method produced better predictions for experimental data than that of the existing method. [ABSTRACT FROM AUTHOR]

In the past, the capillary effect is rarely considered for microcontact models when two adjacent particles are separated by a certain distance. In this paper, a liquid-bridge contact model of unsaturated particles is presented, which is applied to the discrete-element software PFC. Based on this, simulations of uniaxial tensile for unsaturated soils under (2D) situation are carried out, and influence of a water retention angle on uniaxial tensile strength are studied. The simulation results show that the uniaxial tensile strength of unsaturated soil decreases gradually with the increase of the water retention angle, obvious cracks generate at both ends of the soil samples, and the soil sample possesses a residual strength. According to the particle displacement field, velocity field, and contact force chain, the failure forms of samples with different water retention angles are determined. Based on the rose diagram of normal contact force, the changes of its direction and value during failure process are observed directly, so as to analyze the evolution law of contact force for unsaturated soils. [ABSTRACT FROM AUTHOR]

The interparticle bonding effect due to water menisci plays an important role in the hydromechanical coupling properties of unsaturated soils. This paper presents an unsaturated hydromechanical coupling model that considers the influence of matric suction, degree of saturation, and microscopic pore structure on the interparticle bonding effect. The enhanced effective stress and bonding variable are selected as constitutive variables. The bonding variable is correlated with the ratio between unsaturated void ratio and saturated void ratio. The deformation characteristics of unsaturated soils are described based on the bounding surface plasticity theory. A soil–water characteristic model that considers deformation and hydraulic hysteresis is integrated into the constitutive model to achieve hydromechanical coupling. The proposed model can effectively describe the hydromechanical coupling characteristics and the meniscus bonding force of unsaturated bimodal structure soils; the model parameters can be easily obtained through routine experiments. The experimental results of unsaturated isotropic compression, the wetting/drying cycle, and unsaturated triaxial shear tests are used to validate the capability of the proposed model. [ABSTRACT FROM AUTHOR]

The delay effect caused by the switching device is not considered in traditional methods of induction motor flux observation. However, ignoring the delay effect causes the mathematical model of the induction motor flux observation to be inaccurate. In actual work, this disadvantage will affect the flux observation of the induction motor. It will also influence the anti-load performance of the motor and even lead to system instability. Especially at low switching frequencies, switch delay causes input delay. Input delay will result in configuration poles deviating from their expected position in the closed-loop control, affecting the induction motor performance. In this study, the induction motor time-delay model is established to modify the model and solve the above problem. Spectral decomposition theory is used to establish the induction motor flux observer, which configures the unstable poles of the system. The poles that deviate from their expected position are also reconfigured to the desired position, which improves the motor performance and the observing accuracy of the flux chain. Finally, the process of proving the stability of the spectral decomposition flux observer (SDFO) is provided. The reliability of the SDFO is proven through specific simulations and experiments. [ABSTRACT FROM AUTHOR]

This paper presents an experimental investigation of the soil water retention curve (SWRC) and volume change curve over a large suction range (0–286.7 MPa), and microstructure evolution of Guilin lateritic soil under drying and wetting processes. The scanning electron microscopy results show that the reconstituted and compacted samples have very different microstructures. The soil samples compacted at optimum water content features flocculation of the colloids showing a low degree of particle orientation, while the reconstituted samples prepared from slurry produce dispersed arrangement of particles showing a high degree of particle orientation. The pore size distribution curves of reconstituted and compacted samples show the unimodal and bimodal distributions, leading to S-shaped and double S-shaped SWRCs, respectively. At the same initial density, the soils with a low degree of particle orientation (like compacted samples) exhibit less shrinkage than those with a high degree of particle orientation (like reconstituted samples). The mercury intrusion porosimetry test results show that the drying and wetting processes and initial density clearly affect the macropores of the compacted samples, while the micropores remain almost unchanged. For the reconstituted samples, the drying and wetting processes and initial density primarily affect the micropores. [ABSTRACT FROM AUTHOR]

There is an urgent need to understand the characteristics of both precipitation and drought in arid regions of China. Different indexes may provide differing results in terms of the detection and estimation of the temporal and spatial extent of droughts. In this study, the temporal and spatial characteristics of rainfall and drought at 53 meteorological stations from 1960 to 2016 across the Xinjiang region of China were analyzed. Four precipitation-related indexes (precipitation concentration degree (PCD), precipitation concentration period (PCP), standardized precipitation index (SPI), and long-cycle drought–flood abrupt alternation index (LDFAI)) were used to investigate the spatial and temporal patterns of drought and flood. In addition, the Bayesian method and Pettitt test were used as detection tools to identify changing points in precipitation time series. The study indicated the following: (1) a wetting tendency was evident in recent years and was supported by the upward trend in SPI and inter-decadal variation in summer precipitation; (2) the spatial patterns and tendencies of PCD, PCP, and SPI were markedly different in southern and northern Xinjiang; (3) compared with the Pettitt test, use of the Bayesian method provided data closer to the real drought events; (4) it is suggested that multiple indices be used for detecting precipitation and drought characteristics as use of the SPI may lead to other indexes related to flood and drought risks being ignored. [ABSTRACT FROM AUTHOR]

This paper describes the development of a direct tension apparatus and its application to test the tensile strength of unsaturated fine sands. The apparatus consists of two halves of wedge-shaped specimen molds. A criterion is developed for designing the inclination angle of the inner sidewall of the specimen molds as a function of soil–wall interface frictional angle and soil dilatancy angle. Tensile strength of unsaturated fine sands is measured over a range of dry density and water content. Results show that tensile strength generally increases with the increase in dry density. For relatively dense sand, tensile strength follows a non-monotonic double-peak pattern with increasing water content. The first peak occurs in the pendular regime and is attributed to peak occurrence of interparticle stress contributed by pendular water bridges. The second peak occurs in the capillary regime and is attributed to the capillary component of interparticle stress arising from negative pore pressure. [ABSTRACT FROM AUTHOR]

This paper presents a study of the tensile strength of unsaturated soil by a DEM model in a novel uniaxial tensile test device. For validation and comparison, traditional triaxial shear test of unsaturated soil are also conducted. In the DEM model, the capillary effects and some other cementation effects are modelled by a bond, whose strength is a function of the moisture content and void ratio in uniaxial tensile tests and also the confining pressure in triaxial tests. To compare the DEM simulations with experiments, the bond strength function is calibrated through a quantity measurable in both laboratory and DEM simulations such as the shear strength in triaxial tests or the uniaxial tensile strength in uniaxial tensile tests. The comparison shows that the proposed model is able to capture the phenomena observed in experiments. Most importantly, through investigation of the grain-scale data such as the motion, force chains and development of fractures, it is possible to explain some macroscopic observations such as the form of shear bands in the sample, the influence of the moisture content on the shear and tensile strength, etc. [ABSTRACT FROM AUTHOR]

Frost heave and thaw settlement of subgrade is the most typical engineering disease in permafrost regions, which seriously threatens the safe construction and operation of transportation infrastructure. On the basis of the Modified Cam Clay model, a thermoelastoplastic constitutive model of unsaturated frozen soil is proposed. This model can effectively describe two key issues of the mechanical behavior of frozen soils, that is, soil hardening caused by temperature reduction and volume compression during thawing. The proposed constitutive model is realized in the established thermo-hydro-mechanical (THM) coupled mathematical model, and the reliability of the coupled model is verified by comparing with the experimental results. In addition, the proposed THM framework is applied to describe the long-term freezing and thawing behavior of typical railway subgrade sections in the permafrost region of western China. The results show that water-heat transfer and deformation frequently occur on the subgrade surface as the seasons change. Moreover, the variation of thaw settlement is greater than that of frost heave, which seriously threatens the operation safety of railways in permafrost regions. • A thermoelastoplastic constitutive model of unsaturated frozen soil is proposed. • A THM framework considering frost heave and thaw settlement is established. • Long-term deformation of a railway subgrade in a permafrost region is simulated. [ABSTRACT FROM AUTHOR]

This paper presents a novel elastic-viscoplastic constitutive model for reproducing the time-dependent behaviour of coarse-grained soil considering particle breakage, by integrating the Unified Hardening (UH) model, the elastic-viscoplastic (EVP) model and the overstress theory. The relationship between the degree of particle breakage and the loading rate is established, and the state variables associated with the critical state of coarse-grained soil are derived to jointly consider both time and particle breakage. A new three-dimensional elastic-viscoplastic constitutive model is then constructed through combining the one-dimensional viscoplastic hardening parameter with a secondary consolidation coefficient considering particle breakage. The proposed model requires 19 parameters and it can well describe the influence of time-dependency and particle breakage to the shear, dilatancy, and compression behaviours of coarse-grained soil with various confining pressures or initial void ratios. Comparisons between the model predictions and experimental data are employed to validate the capability of the proposed model to replicate the time-dependent behaviour of coarse-grained soil. [ABSTRACT FROM AUTHOR]

The long-term drying/wetting (D/W) and freezing/thawing (F/T) cycles damage the structure of the roadbed soil in loess areas, leading to a series of engineering geological disasters, such as roadbed collapse and cracking. In this study, a series of field monitoring was carried out on the Jihe Expressway, which was built on the Loess Plateau in China. It shows that drying/wetting (D/W) and freezing/thawing (F/T) cycles are important factors leading to periodic settlement and heave of loess roadbeds. A new temperature-controlled unsaturated soil triaxial apparatus was developed to explore the deformation mechanism of compacted loess under D/W and F/T cycles. The results of laboratory tests indicate that, in the isotropic stress state, both D/W and F/T cycles can reduce the void ratio and increase the volume deformation of compacted loess. In the D/W cycle, the soil samples show the collapse behavior, but the deformation of heavily over-consolidated samples is relatively less compared with lightly over-consolidated samples. On the other hand, repeated F/T cycles lead to fluctuating changes in the volume of compacted loess. Increasing the dry density can effectively reduce the deformation caused by F/T cycles. Moreover, the combination of the D/W and F/T cycles may further enhance the volume changes of the compacted loess. As the number of D/W and F/T cycles increases, the compressibility and irrecoverable deformation of the compacted loess increases, leading to a deterioration of its engineering properties. • The characteristics and causes of roadbed deformation in loess area were investigated by field monitoring. • A new temperature-controlled unsaturated soil triaxial apparatus was developed. • The mechanism of D/W and F/T cycles on the deformation of compacted loess was discussed. • The coupling of D/W and F/T intensifies the volume changes of the compacted loess. [ABSTRACT FROM AUTHOR]

Polycystic ovary syndrome (PCOS) is a complex, heterogeneous endocrine and metabolic disorder affecting 5% to 10% of reproductive-age women. A high rate of granulosa cell (GC) proliferation contributes to the abnormal folliculogenesis in patients with PCOS. Evidence has proved that dysregulation of microRNAs is involved in the pathogenesis of PCOS. In this study, we investigated the effect of miR-145 on cell proliferation and the underlying mechanism of miR-145 in isolated human GCs from the aspirated follicular fluid in women with PCOS. Our findings showed that miR-145 is downregulated in human GCs from PCOS. The miR-145 mimics suppress cell proliferation and promoted cell apoptosis in human GCs from PCOS. However, miR-145 inhibitor promotes cell proliferation and inhibited cell apoptosis. Moreover, using a dual-luciferase reporter assay, we confirmed that the insulin receptor substrate 1 (IRS1) gene is a direct target of miR-145. The miR-145 mimics inhibited messenger RNA and protein IRS1 expression levels, and silencing of IRS1 by small interfering RNA inhibits human GC proliferation, but IRS1 overexpression abrogates the suppressive effect of miR-145 mimics. Furthermore, miR-145 mimics can inhibit the activation of p38 mitogen-activated protein kinase (p38 MAPK) and extracellular signal-regulated kinase (ERK). The IRS1 overexpression abrogates the suppressive effect of miR-145 mimics on MAPK/ERK signaling pathways. Together, miR-145 mimics suppress cell proliferation by targeting and inhibiting IRS1 expression to inhibit MAPK/ERK signaling pathways. Our study further found that high concentrations of insulin decreases the miR-145 expression, upregulates IRS1, and promotes cell proliferation. These observations showed that miR-145 is a novel and promising molecular target for improving the dysfunction of GCs in PCOS. [ABSTRACT FROM AUTHOR]

The strength of granular materials during triaxial compression is investigated via a grain scale analysis in this paper. A 3D Discrete Element Method (DEM) program provides the triaxial strength data and helps to validate the micromechanical analysis. Some standard methods in statistics are employed first to quantitatively examine the assumptions made when deriving the stress-force-fabric (SFF) equation. After careful validation, a more concise format for the SFF equation is proposed for triaxial compressions. With this SFF equation, the strength is found to be jointly contributed by the magnitudes of the contact force anisotropy and fabric anisotropy. The influence of the initial void ratio, confining pressure and loading direction on the development of contact force anisotropy and fabric anisotropy is examined and presented. With similar techniques, the “force” term in the SFF equation is further decoupled, and an equation is obtained such that it explicitly links the contact force term with the friction coefficient between grains, a tensor defined as a statistic of the normal contact forces and a tensor defined as a statistic of the mobilisation status of contacts. Based on this equation, another equation regarding the stress ratio of granular assembly is obtained, and it clearly indicates two sources that contribute to the phenomenological friction nature of granular assembly. These two sources are caused by the contact force at the grain scale. The first is the anisotropy of the average normal contact forces, and the second is the mobilisation of contacts. [ABSTRACT FROM AUTHOR]

Cocaine- and amphetamine-regulated transcript (CART) peptide(s) is generally viewed as neuropeptide(s) and can control food intake in vertebrates, however, our recent study revealed that CART1 peptide is predominantly expressed in chicken anterior pituitary, suggesting that cCART1 peptide is a novel pituitary hormone in chickens and its expression is likely controlled by hypothalamic factor(s). To test this hypothesis, in this study, we examined the spatial expression of CART1 in chicken anterior pituitary and investigated the effect of hypothalamic corticotropin-releasing hormone (CRH) on pituitary cCART1 expression. The results showed that: 1) CART1 is expressed in both caudal and cephalic lobes of chicken anterior pituitary, revealed by quantitative real-time PCR (qPCR), western blot and immuno-histochemical staining; 2) CRH potently stimulates cCART1 mRNA expression in cultured chick pituitary cells, as examined by qPCR, and this effect is blocked by CP154526 (and not K41498), an antagonist specific for chicken CRH type I receptor (cCRHR1), suggesting that cCRHR1 expressed on corticotrophs mediates this action; 3) the stimulatory effect of CRH on pituitary cCART1 expression is inhibited by pharmacological drugs targeting the intracellular AC/cAMP/PKA, PLC/IP3/Ca 2+ , and MEK/ERK signaling pathways. This finding, together with the functional coupling of these signaling pathways to cCRHR1 expressed in CHO cells demonstrated by luciferase reporter assay systems, indicates that these intracellular signaling pathways coupled to cCRHR1 can mediate CRH action. Collectively, our present study offers the first substantial evidence that hypothalamic CRH can stimulate pituitary CART1 expression via activation of CRHR1 in a vertebrate species. [ABSTRACT FROM AUTHOR]

This paper proposes a detailed parametric design method for a round-pin inner-outer compound meshing silent-chain plate structure. A meshing design method for parameter harmonization among a silent chain, a sprocket hob, and an involute sprocket is proposed. To analyze the influence of extended arc parameters on the meshing process and impact, the extended arc parameter extension δ and height HY are considered as variables to formulate the motion-analysis model of the chain-drive system. The results reveal that the extended arc parameters δ and HY have a significant effect on the meshing process and the meshing impact. When δ and HY are optimal, the inner-outer compound meshing process of the chain-drive system can be smoothly realized; furthermore, the meshing impact force is minimal as it is reduced by more than 25 % compared to when only the outer meshing process occurs. Thus, the chain-plate structure is optimized. [ABSTRACT FROM AUTHOR]

Soil is a multiphase material with irregularly shaped particles, the behaviour of which is highly nonlinear, anisotropic, and inelastic. Anisotropy and its evolution characteristics are crucial in soil's constitutive modelling, particularly for clayey soil. A new anisotropic constitutive model for remoulded clay is proposed based on improved yield surfaces and rotational hardening rules for initial and induced anisotropy. The logarithmic interpolation function is adopted to describe the volumetric deformation characteristics of clay in an arbitrary stress state, and a flexible yield surface shape is obtained by changing the newly introduced parameter n. This new parameter can be determined by fitting the undrained shear strength or stiffness of stress–strain curves. A key feature of the proposed evolutional rule for anisotropy is that the principal direction of the yield surfaces in the stress plane can be consistent with the isotropic stress axis when the critical state is reached. The proposed elastoplastic model shows good capacity for describing laboratory results from oedometer tests with constant stress ratios, reconsolidation tests with various stress ratios, triaxial compression tests, and triaxial extension tests under both undrained and drained conditions. [ABSTRACT FROM AUTHOR]

Cocaine- and amphetamine-regulated transcript (CART) peptide is implicated in the control of avian energy balance, however, the structure and expression of CART gene(s) remains largely unknown in birds. Here, we cloned and characterized two CART genes (named cCART1 and cCART2) in chickens. The cloned cCART1 is predicted to generate two bioactive peptides, cCART1(42-89) and cCART1(49-89), which share high amino acid sequence identity (94-98%) with their mammalian counterparts, while the novel cCART2 may produce a bioactive peptide cCART2(51-91) with 59% identity to cCART1. Interestingly, quantitative RT-PCR revealed that cCART1 is predominantly expressed in the anterior pituitary and less abundantly in the hypothalamus. In accordance with this finding, cCART1 peptide was easily detected in the anterior pituitary by Western blot, and its secretion from chick pituitaries incubated in vitro was enhanced by ionomycin and forskolin treatment, indicating that cCART1 is a novel peptide hormone produced by the anterior pituitary. Moreover, cCART1 mRNA expression in both the pituitary and hypothalamus is down-regulated by 48-h fasting, suggesting its expression is affected by energy status. Unlike cCART1, cCART2 is only weakly expressed in most tissues examined by RT-PCR, implying a less significant role of cCART2 in chickens. As in chickens, 2 or more CART genes, likely generated by gene and genome duplication event(s), were also identified in other non-mammalian vertebrate species including coelacanth. Collectively, the identification and characterization of CART genes in birds helps to uncover the roles of CART peptide(s) in vertebrates and provides clues to the evolutionary history of vertebrate CART genes. [ABSTRACT FROM AUTHOR]

Abstract: Intercellular adhesion molecule-1 (ICAM-1, encoded by ICAM-1) is implicated in tumorigenesis and tumor progression. ICAM-1 modulates the susceptibility to several types of cancer and the disease prognosis; however, its role in epithelial ovarian cancer (EOC) is unclear. Here, we evaluate single nucleotide polymorphisms (SNPs) in ICAM-1 as predictors of EOC risk and prognosis. Six ICAM-1 polymorphisms were genotyped in 408 patients with EOC and 520 controls using the MassARRAY system. The ICAM-1 mRNA levels in 89 EOC tissues and 35 normal ovarian tissues were examined using quantitative PCR. The ICAM-1 rs5498 G allele was associated with increased tumor grade (OR=2.650) and EOC risk (OR=1.405). This risk was more evident in females who had first-degree relatives (FDRs) with a tumor (OR=3.475) or who experienced early menarche (OR=2.774). The ICAM-1 expression in the cancerous tissue was elevated compared with that of normal ovarian tissues (p <0.0001), and it was associated with an rs5498 genotype (p =0.0002). ICAM-1 SNPs did not significantly predict the overall EOC survival (p >0.05). However, the rs5498 G allele correlated with EOC survival time in patients whose FDRs suffered from a tumor (p =0.001). ICAM-1 rs5498 likely confers a high risk for EOC in G allele carriers accompanied by up-regulation of ICAM-1 expression during carcinogenesis. The combination of ICAM-1 rs5498 and tumor history predicts the EOC prognosis. [Copyright &y& Elsevier]

With the development of modern geotechnical engineering practices such as the construction of high level radioactive waste repositories, exploitation and utilization of geothermal resources, energy-saving buildings and underground storage of CO, research into the influence of temperature on the basic mechanical properties of unsaturated soils has become an important issue internationally. By using the work expression and considering the influence of temperature on the basic properties of unsaturated soils, the average soil skeleton stress, modified suction and temperature were selected as state variables of generalized forces in thermodynamics and the soil skeleton strain, saturation and entropy were chosen as state variables of generalized flows conjugate to the variables of generalized forces. Based on the nonlinear multi-field coupled model and by using existing experimental results, an elastic-plastic constitutive model of unsaturated soils under non-isothermal conditions was developed to analyze the influence of temperature on the deformation properties of unsaturated soils. The model was used to predict and analyze the influence of suction and temperature on the deformation properties of unsaturated soils under isotropic conditions, and was successfully verified using experimental results. [ABSTRACT FROM AUTHOR]

Modelling of unsaturated soil stress–strain relationships under cyclic loading with constant matric suction is a topic that is poorly addressed by the current literature. Using the theoretical framework of the bounding surface plasticity and Barcelona basic model (BBM) combined with the concept of fractional accumulated strain rate, a bounding surface model for accurately describing the unsaturated soil stress–strain relationship with constant matric suction is established here. The fractional accumulated strain rate is introduced to consider the influence of cyclic loading history. The movable mapping centre rule is used to describe the hysteresis characteristics of the dynamic stress–strain curve during the unloading process. The shape of the dynamic stress–strain curve can be described reasonably by considering the cyclic loading process as the three processes of initial loading, unloading, and reloading. The cyclic loading test data of unsaturated silt, sand, and lean clay with constant matric suction is used for parameter calibration and model validations. Results show that the proposed model can accurately capture the dynamic stress–strain relationship of unsaturated soil with constant matric suction. [ABSTRACT FROM AUTHOR]

This work presents a fully coupled constitutive model for thermo-hydro-mechanical behaviour of unsaturated soils. This model, with 18 parameters, can consider the primary features of unsaturated soils, such as mechanical responses at various temperatures and matric suctions, drying/wetting behaviour (water retention curves and volumetric strain) at various temperatures and net stresses, and thermal volumetric behaviour at various matric suctions. A numerical example on a drained heating-drying-isotropic loading-wetting path is used to show the basic properties and performance of the proposed model. Finally, the proposed model is validated against experimental data for temperature/suction-controlled isotropic tests, temperature-controlled wetting-drying tests, suction-controlled heating-cooling tests and temperature/suction-controlled triaxial tests. [ABSTRACT FROM AUTHOR]

A thermodynamics-based mathematical model is presented for unsaturated freezing soils. The proposed model describes the contributions of the film water, capillary water and vapor in unsaturated freezing soils, based on hybrid mixture theory and phase field theory. A new parameter, namely φ B , is introduced to describe the freezing state of the capillary water in the pore space. The proposed model can describe the primary and secondary frost heave in a consistent manner. To illustrate the proposed model, expressions for the free energy function and the dissipative potential are formulated. The surface energy potential and the strain energy that is associated with the phase transition of pore fluid are considered. The stress tensors and constitutive relationships are then derived. Finally, the undercooling of the pore fluid and its moisture migration in freezing unsaturated soils are discussed. • The film, capillary and vapor water in soil play different roles on the frost heave. • This model can be applied to the soils with and without frozen fringe. • A theoretical framework for unsaturated freezing soils is proposed. • The constitutive equations can be obtained from the proposed model. • The undercooling of soil water in freezing soils is discussed. [ABSTRACT FROM AUTHOR]

To construct urban metro stations, the concrete diaphragm walls are widely used as the support of deep foundation. During the installation of concrete diaphragm wall, the global instability of slurry trench may occur due to the insufficient internal support. The instability originates at a shallow depth blow ground surface and propagates to the ground surface. This paper develops a three-dimensional mechanism for analysing the trench global instability. In the mechanism, the instability is initiated by the movement of a rigid block with conical discontinuity surfaces. The trench stability is analysed using the kinematic approach of limit analysis and the upper bound solution of the safety factor is obtained. The optimal mechanism is achieved through minimising the safety factor. The critical depth of instability and the influence zone on the ground surface are identified. With the higher frictional angle, the critical failure depth becomes smaller and the volume of the failure zone decreases. The drop of slurry level significantly increases the risk of trench instability especially for cohesionless soils. The mechanism is validated through analysing the slurry trench instability during the construction of a subway station in Suzhou, China. The analysis result shows a close agreement with the field measurements. [ABSTRACT FROM AUTHOR]

To study the phenomenon of convection diffusion and solute migration in porous media, the smoothed particle hydrodynamics method is used to solve the N–S equation describing pore water flow and the linear homogeneous second-order differential equation describing the solute diffusion process. The accuracy of the simulation method is verified by solving the one-dimensional definite solution of the convection diffusion equation at a low Peclet (Pe) number. Under the condition of a high Pe number, the simulation experiment of solute breakthrough porous media at the pore scale is simulated. Through the analysis of the velocity distribution of fluid particles in pore channels of porous media and the mechanical dispersion process of solutes in porous media, it is found that the flow velocity presents a parabolic distribution in the pore channel, and the particles with high velocity are mainly concentrated in the middle of the pore channel between the solid particles. The solute dispersion is obvious in porous media, and some fluid particles containing solutes penetrate porous media earlier along fast-flowing pore channels. Finally, the solute breakthrough curve and the motion path length of the particle are obtained through the simulation experiment. The calculation methods of the dispersion degree and tortuosity of porous media are further given, and the dispersion degree of porous media in this paper is 0.000 95 m. [ABSTRACT FROM AUTHOR]

The extraction process of methane hydrate involves interactions of multiple fields, phases, and loading stages. By extrapolating deductions from the thermodynamic equation in granular thermodynamic framework and amalgamating with coupled flow theory and linear non-equilibrium theory, a comprehensive Thermo-Hydro-Mechanic-Chemical (THMC) coupling model for hydrate-bearing sediment is established in this study. The mechanical field is established by energy dissipation conservation, the hydraulic field considers the increase in gas and liquid permeability due to temperature gradients, while the thermal field incorporates the rates of seepage, hydrate dissociation, and volumetric strain. Meanwhile, Darcy's law is explained as general deductions from the thermodynamic equation without the need for assumption. The proposed model is applied from the perspective of unit scale and coupling field, and verified with the test data. The modelling results show that the deduced model can capture the strain-softening, dilatancy, and stress paths behavior under various drainage conditions, and the volumetric strain, methane gas production and variations in heat exchange caused by the hydrate dissociation can also be predicted. Furthermore, the mechanical response and dissociation properties of sediment samples with various parameter values are discussed. [ABSTRACT FROM AUTHOR]

In this paper, the law of ice-rich permafrost embankment thaw consolidation is studied based on three-dimensional nonlinear large strain thaw consolidation theory. To avoid problems associated with numerical simulation efficiency and stability when a nonlinear stress-strain relationship is employed, a segment interpolation function is used to implement the nonlinear relationship between the compression modulus and the void ratio, and the corresponding simulation strategy is proposed. Through a comparison of the monitoring and calculated results, it is indicated that the calculation accuracy on ice-rich embankment thaw settlement can be notably improved after nonlinear theory is implemented with the proposed numerical simulation method. A further analysis of the calculated results indicates that the interactive effects between the thermal and mechanical fields can be more reasonably described by nonlinear theory than by linear theory. It is also determined that the postthaw pore water in the shallow embankment dissipates in the early operation period, while in the following long operation period, the development of the permafrost embankment thaw settlement is mainly due to the dissipation of newly postthaw pore water at the thaw depth or the permafrost table. This is one of the main differences in the law of permafrost embankment thaw settlement compared with that of unfrozen embankments. [ABSTRACT FROM AUTHOR]

Nowadays, more and more applications are dependent on storage and management of semi-structured information. For scientific research and knowledge-based decision-making, such data often needs to be published, e.g., medical data is released to implement a computer-assisted clinical decision support system. Since this data contains individuals’ privacy, they must be appropriately anonymized before to be released. However, the existing anonymization method based on l-diversity for hierarchical data may cause serious similarity attacks, and cannot protect data privacy very well. In this paper, we utilize fuzzy sets to divide levels for sensitive numerical and categorical attribute values uniformly (a categorical attribute value can be converted into a numerical attribute value according to its frequency of occurrences), and then transform the value levels to sensitivity levels. The privacy model ( α l e v h , k)-anonymity for hierarchical data with multi-level sensitivity is proposed. Furthermore, we design a privacy-preserving approach to achieve this privacy model. Experiment results demonstrate that our approach is obviously superior to existing anonymous approach in hierarchical data in terms of utility and security. [ABSTRACT FROM AUTHOR]

This study presents a rate-independent constitutive model for granular materials which is based on the analysis of discrete element modelling (DEM) results. We examine the elastic and plastic strain rate at any state of shear, and explore how the plastic strain rate and the stress rate are related to some state variables (e.g. stress, void ratio, etc.). The elastic and plastic strain rate are evaluated by assuming that the rate of conservative energy defined in term of elastic strain rate equals the energy rate from work–energy analysis of granular assemblies. The verification of the theoretical work–energy analysis and the acquire of data regarding the mechanical rates at contacts between grains are done through DEM. It is shown that for a representative element volume of granular materials, the external work rate equals the sum of an elastic energy rate and a dissipation rate at contacts. The work rate is either the product of stress and strain rate or the sum of discrete work rate of external forces. Equations regarding the dilatancy, plastic deviatoric strain rate and stress rate are proposed. In the model, a yield surface is not explicitly defined and the deviatoric stress rate is related to not only the elastic deviatoric strain rate, but also a rate of dilatancy. Simulations show that the predictions match both virtual and Toyoura sand satisfactorily in various shear tests within a board range of densities. Additionally, the calibration of parameters is extremely simple. The treatment of cyclic loading condition is also presented. [ABSTRACT FROM AUTHOR]

In this study, a three-dimensional numerical model was used to analyze the transient pressure on a segment structure and the CFD caused to it under pneumatic loading action. The results of two trains meeting in the tunnel show that the tunnel cross-sectional area, train speed, and tunnel location significantly influence the peak pressure wave generated on the segment structure. After the trains completely exit the shield tunnel, the peak values of the aerodynamic load may still be higher than that of the aerodynamic pressure wave caused by the trains running in the tunnel, and may last for approximately 10 cycles. Based on the characteristics of the pressure peak values, the mathematical relationship between the attenuation rate of the peak-to-peak pressure values and the number of periods was fitted; the CFD equation was modified, and the rationality was verified. The CFD of the segment structure was approximately proportional to the square of the number of aerodynamic load periods. Thus, the maximum CFD calculated for 100 years is 0.107 × 10−2. This indicates that fatigue damage does not occur in the segment structure under an aerodynamic load. • A detailed analysis of the pressure wave peak variations on the segment structure under different working conditions. • A nonlinear correction to the linear cumulative damage equation when considering the interaction of the aerodynamic load. • Validation of the expression between the decay rate of pressure and the number of cycles based on a modified CFD equation. • The maximum cumulative fatigue damage of the 100-year segment structure was revealed to be 0.107 × 10−2. [ABSTRACT FROM AUTHOR]

Pore ice content is crucial in evaluating the mechanical properties of frozen soils. Existing strength criterion models are usually empirical and ignore the influence of pore ice content. By assuming that the critical state shear stress ratio of soil is a function of the stress level, a critical state line of frozen soil is proposed to consider pore ice content. By combining the Mohr–Coulomb (M–C) and Drucker–Prager strength criteria to describe the failure shape characteristics on the deviatoric plane, a new strength criterion is established for complex stress conditions. The proposed model is validated against existing models and measured data in the literature. In addition, the proposed model can uniformly describe the CSL of different types of geotechnical materials and has a clear physical meaning, which may provide a theoretical basis for constitutive models. [ABSTRACT FROM AUTHOR]

North China Plain is the largest agricultural production center in China and wheat-maize rotation is a widespread cultivation practice in this area. As gross primary production (GPP) is a proxy of land productivity, research on its spatial-temporal dynamics helps understand the variation of grain production in wheat-maize rotation. Here, Moderate Resolution Imaging Spectroradiometer (MODIS) data and ground observation data were combined to drive Vegetation Photosynthesis Model (VPM) in GPP estimation over wheat-maize rotation area during 2000–2015. Annual GPP has increased by 540.95 g C m−2 year−1 from 2000 to 2015, while total annual GPP has grown ∼150% than that of 2000. Moreover, annual GPP showed an increasing trend in the consecutively wheat-maize rotation area between 2000 and 2015. A strong linear relationship between GPP estimates and grain production demonstrated the potential of using VPM model to evaluate grain production in wheat-maize rotation area of Henan province, China. [ABSTRACT FROM AUTHOR]

Solid-fluid interactions in unsaturated expansive clays can be divided into capillarity and adsorption effects based on their physical mechanisms. Most constitutive models for unsaturated soils are proposed on the basis of the capillarity mechanism, ignoring the contributions of the adsorption effect to mechanical and hydraulic behaviors. For expansive clays, however, the adsorption effect which leads to more complex behavioral characteristics than that in low plasticity clays cannot be ignored. In the light of this, a new binary-medium model for unsaturated expansive clays is proposed, involving a consideration of the solid-fluid interactions stemming from the capillary and the adsorption mechanisms at the same time. Firstly, we assume that expansive clay is a mixture of two ideal parts, i.e. the ideal capillarity part and the ideal adsorption part, and then an ideal capillarity model and an ideal adsorption model, each of which is available for the corresponding ideal part, are established. Furthermore, a participation function is used to reflect the degrees of capillarity effect and adsorption effect. Finally, predictions are performed on the results of the consolidation tests and the cyclical controlled-suction tests published in literature. After comparing predicted results with test results, it is illustrated that the established model can quantitatively predict mechanical and hydraulic behaviors in expansive clays. [ABSTRACT FROM AUTHOR]

In this paper, based on the porous media theory, the specific expressions of the total stress and the input work of unsaturated expansive soils with double porosity are proposed, and then the energy-conjugate variables are further derived. We make distinctions between the effects of capillary water and adsorbed water on the soil behaviour, as well as between the deformations of micro- and macrostructure. According to the derived input work expression and the work-energy-dissipation relations for an open multiphase thermodynamic system, we establish a thermodynamics-based modelling framework for unsaturated expansive soils with double porosity. [ABSTRACT FROM AUTHOR]

Highlights: [•] The unique gene structure of chicken PRLR (cPRLR) was revealed. [•] Two types of cPRLR transcripts with distinct tissue expression patterns were found. [•] cPRLR gene transcription is controlled by multiple promoters. [•] cPRL-L is a novel functional ligand of cPRLR. [•] Membrane-proximal ligand-binding domain of cPRLR can interact with cPRL and cPRL-L. [Copyright &y& Elsevier]

The influence of gases on unsaturated soils is discussed in the paper. First, the selection of stress state variables is discussed. It is shown that gas pressure as well as generalized effective stress and modified suction are required to construct a constitutive model of an unsaturated soil. The deformation mechanisms of solid, liquid and gas phases in soils are then investigated. It is realized that the deformation of gas phase interacts with the deformations of the other two phases in soils. Gas laws are used to describe the gas behavior. Similar to the other two phases in soil, the change of gas volume can be divided into an elastic part and a plastic part, and the latter part is then introduced to the soil hardening equation to reflect the impact of the gas on the soil. Then, a simple elasto-plastic model considering the gas effect for isotropic states is developed. Finally, the model predictions are given and compared with existing experimental data. A good agreement between them is found. Comparisons of the predictions between our model and Wheeler's model are also performed. [ABSTRACT FROM AUTHOR]

This paper established a coupled thermo-hydro-mechanical mechanism in view of the soil particle rearrangement for saturated/unsaturated soils under the framework of granular thermodynamics. This model avoids concepts such as the flow rule, yield function, dissipation potential function, and hardening criterion. The effects of the loading path and the soil structure are reflected by constructing a density function of elastic potential energy considering the structural strength of a solid skeleton with a degradation factor. That is, the changes in the stress states are closely related to soil particle rearrangement and the transitions between different matter phases. A generalized effective stress principle is derived and is suitable for the coupled thermo-hydro- mechanical process. The deduced generalized phase stresses differ from the classical effective principle based on linear elastic porous media and can automatically consider the impact of the stress path, temperature path and soil structure. The established model spans the complete process from unsaturated to saturated soils and is verified by the typical test results. [ABSTRACT FROM AUTHOR]

With the development of power electronics technology, power modules delivery considerably greater power density, which makes junction temperature an important parameter for reliable operation. Existing thermal models often ignore the influence of the thermal boundary conditions on the thermal parameter and cannot accurately predict junction temperature in various operating conditions. This article proposes a three-dimensional compact thermal network model that considers the thermal boundary conditions and can be obtained by the finite-element method (FEM). A novel two-step method for thermal parameter extraction is presented and the effects of boundary conditions on thermal network parameters are discussed in detail. The experimental results and FEM simulation show that the proposed thermal network model can accurately estimate the junction temperature in different thermal boundary conditions. [ABSTRACT FROM AUTHOR]

The stability of slurry trench is of importance in diaphragm wall construction. The local stability of slurry trench under seepage application is investigated in this research. In the current research, the local instability of slurry trench is identified as the soil collapse in an instable sublayer and a three-dimensional translational failure mechanism is developed. In this mechanism, the local stability is initialed by the movement of a single rigid block and the seepage application is accounted by introducing the analytical model of semi-confined seepage. The stability is analyzed through kinematic approach and the upper bound solution of safety factor is deduced as a result. The stability is evaluated by optimizing the mechanism for the local failure. Using the current solution, the seepage effect on the stability is analyzed. Regardless of seepage, the stability is mainly dependent on the shear strength of the sublayer. Under seepage application, the failure zone is enlarged and the safety factor decreases as a result. The effect of seepage on the stability is significantly influenced by piezometric head difference Δ p and leakage ratio λ of the sublayer. The validity of the current solution is examined by investigating the case of diaphragm wall installation in Suzhou, China. [ABSTRACT FROM AUTHOR]

Summary: This study uses an incompressible smoothed‐particle hydrodynamics model to investigate the interaction between dry granular material flows and rigid barriers. The primary aim is to summarise some practical guidelines for the design of debris‐resisting barriers. The granular materials are modelled as a rigid‐perfectly plastic material where the plastic flow corresponds to the critical state. The coupled continuity equation and momentum equation are solved by a semi‐implicit algorithm. Compared with flows in controlled flume experiments, the model adequately reproduces both the kinetic of the flows and the impact force under various conditions. Then the numerical simulations are used to study the detailed interaction process. It is illustrated quantitatively that the interaction force consists of two parts, ie, the earth pressure force caused by the weight of the soil and a dynamic force caused by the internal deformation (flowing mass on top of a dead zone). For the estimation of impact load, this study suggests that an increased earth pressure coefficient depending on the Froude number should be incorporated into the hydrostatic model. [ABSTRACT FROM AUTHOR]

Understanding how chemotherapeutic agents mediate testicular toxicity is crucial in light of compelling evidence that male infertility, one of the severe late side effects of intensive cancer treatment, occurs more often than they are expected to. Previous study demonstrated that bortezomib (BTZ), a 26S proteasome inhibitor used to treat refractory multiple myeloma (MM), exerts deleterious impacts on spermatogenesis in pubertal mice via unknown mechanisms. Here, we showed that intermittent treatment with BTZ resulted in fertility impairment in adult mice, evidenced by testicular atrophy, desquamation of immature germ cells and reduced caudal sperm storage. These deleterious effects may originate from the elevated apoptosis in distinct germ cells during the acute phase and the subsequent disruption of Sertoli–germ cell anchoring junctions (AJs) during the late recovery. Mechanistically, balance between AMP-activated protein kinase (AMPK) activation and Akt/ERK pathway appeared to be indispensable for AJ integrity during the late testicular recovery. Of particular interest, the upregulated testicular apoptosis and the following disturbance of Sertoli–germ cell interaction may both stem from the excessive oxidative stress elicited by BTZ exposure. We also provided the in vitro evidence that AMPK-dependent mechanisms counteract follicle-stimulating hormone (FSH) proliferative effects in BTZ-exposed Sertoli cells. Collectively, BTZ appeared to efficiently prevent germ cells from normal development via multiple mechanisms in adult mice. Employment of antioxidants and/or AMPK inhibitor may represent an attractive strategy of fertility preservation in male MM patients exposed to conventional BTZ therapy and warrants further investigation. [ABSTRACT FROM AUTHOR]

This paper investigates the passive instability of the working face of large-diameter shield tunneling in frictional soils by developing a new mechanism. The proposed composite mechanism comprises rotational and translational blocks, and failure is involved within the movement of the blocks. The upper bound solution of support pressure for passive instability is derived using a kinematic approach. The stability analysis explores the critical support pressure and associated failure mode by optimizing the mechanism. The proposed mechanism indicates that the failure in the cover layer is fully involved in the translational movement, while in the crossed layer, the failure is partially involved in rotational movement. The mechanism is influenced more significantly by the frictional angle than by cohesion and surcharge on the ground surface. The proportion of rotational blocks to translational blocks decreases with increasing φ ′. In the presence of a rotational block, the proposed composite mechanism outperforms the previous translational mechanisms in predicting the critical support pressure and associated failure mode. Finally, the current solution is validated by comparing with previous centrifuge tests, where agreement on the critical support pressure and the associated failure mode is found. [ABSTRACT FROM AUTHOR]