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There is an increasing demand to develop predictive medicine through the creation of predictive models and digital twins of the different body organs. To obtain accurate predictions, real local microstructure, morphology changes and their accompanying physiological degenerative effects must be taken into account. In this article, we present a numerical model to estimate the long-term aging effect on the human intervertebral disc response by means of a microstructure-based mechanistic approach. It allows to monitor in-silico the variations in disc geometry and local mechanical fields induced by age-dependent long-term microstructure changes. Both lamellar and interlamellar zones of the disc annulus fibrosus are constitutively represented by considering the main underlying microstructure features in terms of proteoglycans network viscoelasticity, collagen network elasticity (along with content and orientation) and chemical-induced fluid transfer. With age, a noticeable increase in shear strain is especially observed in the posterior and lateral posterior regions of the annulus which is in correlation with the high vulnerability of elderly people to back problems and posterior disc hernia. Important insights about the relation between age-dependent microstructure features, disc mechanics and disc damage are revealed using the present approach. These numerical observations are hardly obtainable using current experimental technologies which makes our numerical tool useful for patient-specific long-term predictions. [ABSTRACT FROM AUTHOR]

Based on sea surface height anomaly (SSHA) from satellite altimeter and microwave radiometer datasets, this study investigates atmospheric responses to oceanic eddies in four subdomains of the North Pacific Ocean with strongest eddy activity: Kuroshio Extension (KE), Subtropical Front (SF), California Coastal Current (CC) and Aleutian Islands (AI). Analyses show that anticyclonic eddies cause sea surface temperature, surface wind speed and precipitation rate to increase in all four subdomains, and vice versa. Through a further examination of the regional dependence of atmospheric responses to oceanic eddies, it is found that the strongest and the weakest surface wind speed responses (in winter and summer) are observed in the KE and AI region, respectively. For precipitation rate, seasonal variation of the atmospheric responses to oceanic eddies is strongest in winter and weakest in summer in the KE, CC and AI regions, but stronger in summer in the SF area. The reasons for such regional dependence and seasonality are the differences in the strength of SST anomalies, the vertical kinetic energy flux and atmospheric instability in the four subdomains.

In the present article, a fully three-dimensional human annulus fibrosus model is developed by considering the regional variation of the complex structural organization of collagen network at different scales to predict the regional anisotropic multiaxial damage of the intervertebral disc. The model parameters are identified using experimental data considering as elementary structural unit, the single annulus lamellae stretched till failure along the micro-sized collagen fibers. The multi-layered lamellar/inter-lamellar annulus model is constructed by considering the effective interactions between adjacent layers and the chemical-induced volumetric strain. The regional dependent model predictions are analyzed under various loading modes and compared to experimental data when available. The stretching along the circumferential and radial directions till failure serves to check the predictive capacities of the annulus model. Model results under simple shear, biaxial stretching and plane-strain compression are further presented and discussed. Finally, a full disc model is constructed using the regional annulus model and simulations are presented to assess the most likely failed areas under disc axial compression. The damage in annulus soft tissues is a complex multiscale phenomenon due to a complex structural arrangement of collagen network at different scales of hierarchical organization. A fully three-dimensional constitutive representation that considers the regional variation of the structural complexity to estimate annulus multiaxial mechanics till failure has not yet been developed. Here, a model is developed to predict deformation-induced damage and failure of annulus under multiaxial loading histories considering as time-dependent physical process both chemical-induced volumetric effects and damage accumulation. After model identification using single lamellae extracted from different disc regions, the model predictability is verified for various multiaxial elementary loading modes representative of the spine movement. The heterogeneous mechanics of a full human disc model is finally presented. [Display omitted] [ABSTRACT FROM AUTHOR]

Based on sea surface height anomaly (SSHA) from satellite altimeter and microwave radiometer datasets, this study investigates atmospheric responses to oceanic eddies in four subdomains of the North Pacific Ocean with strongest eddy activity: Kuroshio Extension (KE), Subtropical Front (SF), California Coastal Current (CC) and Aleutian Islands (AI). Analyses show that anticyclonic eddies cause sea surface temperature, surface wind speed and precipitation rate to increase in all four subdomains, and vice versa. Through a further examination of the regional dependence of atmospheric responses to oceanic eddies, it is found that the strongest and the weakest surface wind speed responses (in winter and summer) are observed in the KE and AI region, respectively. For precipitation rate, seasonal variation of the atmospheric responses to oceanic eddies is strongest in winter and weakest in summer in the KE, CC and AI regions, but stronger in summer in the SF area. The reasons for such regional dependence and seasonality are the differences in the strength of SST anomalies, the vertical kinetic energy flux and atmospheric instability in the four subdomains.

Aim: To examine the burden of noncommunicable diseases (NCDs) in the Indian agro-climatic and political regions.Subjects and methods: Data from two rounds of National Sample Survey (NSS) 68th (2011-12) and 71st (2014) was used to estimate the subnational spatial heterogeneity of NCD burden across 87 agro-climatic and political regions in India. Quantile maps, local Moran’s I, LISA cluster and significance maps were generated.Results: Results show a high spatial heterogeneity in disease burden across the agro-climatic regions. Moran’s I scatterplot depict a significantly high level of regional dependence (Moran’s I = 0.558) of NCDs with larger concentration of disease in southern states like Kerala (northern and southern), Tamil Nadu (inland, coastal, and northern-coastal), Karnataka (inland, coastal and Ghats) and Pondicherry. The proportion of the elderly population, those belonging to urban areas, widowed/divorced/separated population, high  per capita alcohol and tobacco consumption were more likely to affect the prevalence of NCDs.Conclusion: Findings call for an immediate programmatic attention at the subnational level due to significantly high regional dependence of NCDs. Policies and programme should focus on strengthening the implementation of existing  policies with a special focus on geriatric population to combat the disease burden. [ABSTRACT FROM AUTHOR]

The effects of check dams for torrent control were analysed in the river Toplica drainage basin, upstream of the future water reservoir "Selova" in the central part of Serbia. The effects were analysed from the aspect of bedload retention, decrease in the natural bed slope, and the stabilisation of the torrent channel. Special analysis was focused on the conditions and criteria of forming the slope of siltation and the methods of its calculation in the function of the correct determination of the distance between check dams. It was shown that some formulas for the calculation of the slope of siltation produce results which differ very much from the real slopes of siltation. The best agreement with the real slopes of siltation was obtained by the calculations based on the regional analytical dependence obtained by the statistical analysis of the dependence of the slope of siltation on natural bed slope. The research shows that all check dams are stable and, regardless of the retained bedload, they contributed to the stabilisation of the torrent channel. [ABSTRACT FROM AUTHOR]

• We develop biomimetic designs of the human annulus fibrosus. • We propose lattice structure with specially designed octagonal cells patterns. • We introduce hydrogel as matrix reinforced by polylactide fibers. • We model hydrogel time-dependent response in relation to polylactide features. • We show a perfect replication of the natural annulus unusual transversal response. Intervertebral disc hernia and dysfunctions are the most common health problems that affect humans. For this reason, the need of disc prosthetics, and especially annulus fibrosus replacements, is becoming increasingly mandatory and urgent. In the present paper, we present a novel bio-inspired hydrogel-based replacement system with rational mechanically mimetic designs of human annulus fibrosus. The new system consists of hydrogel-based lattice structure with octagonal cells separated by polylactide fibers reinforced hydrogel-based sheets. The mechanics of the new designs may be rationally controlled by tailoring microstructure, in terms of polylactide fibers orientation and hydrogel intrinsic viscosity, and mesostructure in terms of cell walls/sheets thickness. The new designs are successfully compared to the natural annulus fibrosus mechanics in terms of nonlinear stiffness and transversal behavior while considering regional dependency. The impressive biomimetic capabilities of the proposed hydrogel-based lattice structure allow foreseeing the possibility of designing personalized disc prosthetics by advanced 3D printing technologies. [Display omitted] [ABSTRACT FROM AUTHOR]