A large-strain radial consolidation theory for soft clays improved by vertical drains

A system of vertical drains with combined vacuum and surcharge preloading is an effective solution for promoting radial flow, accelerating consolidation. However, when a mixture of soil and water is deposited at a low initial density, a significant amount of deformation or surface settlement occurs. Therefore, it is necessary to introduce large-strain theory, which has been widely used to manage dredged disposal sites in one-dimensional theory, into radial consolidation theory. A governing equation based on Gibson's large-strain theory and Barron's free-strain theory incorporating the radial and vertical flows, the weight of the soil, variable hydraulic conductivity and compressibility during the consolidation process is therefore presented

Human Stiff-Person Syndrome IgG Induces Anxious Behavior in Rats

Background: Anxiety is a heterogeneous behavioral domain playing a role in a variety of neuropsychiatric diseases. While anxiety is the cardinal symptom in disorders such as panic disorder, co-morbid anxious behavior can occur in a variety of diseases. Stiff person syndrome (SPS) is a CNS disorder characterized by increased muscle tone and prominent agoraphobia and anxiety. Most patients have high-titer antibodies against glutamate decarboxylase (GAD) 65. The pathogenic role of these autoantibodies is unclear. Methodology/Principal Findings: We re-investigated a 53 year old woman with SPS and profound anxiety for GABA-A receptor binding in the amygdala with (11)C-flumazenil PET scan and studied the potential pathogenic role of purified IgG from her plasma filtrates containing high-titer antibodies against GAD 65. We passively transferred the IgG fraction intrathecally into rats and analyzed the effects using behavioral and in vivo electrophysiological methods. In cell culture, we measured the effect of patient IgG on GABA release from hippocampal neurons. Repetitive intrathecal application of purified patient IgG in rats resulted in an anxious phenotype resembling the core symptoms of the patient. Patient IgG selectively bound to rat amygdala, hippocampus, and frontal cortical areas. In cultured rat hippocampal neurons, patient IgG inhibited GABA release. In line with these experimental results, the GABA-A receptor binding potential was reduced in the patient’s amygdala/hippocampus complex. No motor abnormalities were found in recipient rats. Conclusion/Significance: The observations in rats after passive transfer lead us to propose that anxiety-like behavior can be induced in rats by passive transfer of IgG from a SPS patient positive for anti-GAD 65 antibodies. Anxiety, in this case, thus may be an antibody-mediated phenomenon with consecutive disturbance of GABAergic signaling in the amygdala region

A dopaminergic switch for fear to safety transitions

Overcoming aversive emotional memories requires neural systems that detect when fear responses are no longer appropriate. The midbrain ventral tegmental area (VTA) dopamine system has been implicated in reward and more broadly in signalling when a better than expected outcome has occurred. This suggests that it may be important in guiding fear to safety transitions. We report that when an expected aversive outcome does not occur, activity in midbrain dopamine neurons is necessary to extinguish behavioral fear responses and engage molecular signalling events in extinction learning circuits. Furthermore, a specific dopamine projection to the nucleus accumbens medial shell is partially responsible for this effect. By contrast, a separate dopamine projection to the medial prefrontal cortex opposes extinction learning. This demonstrates a novel function for the canonical VTA-dopamine reward system and reveals opposing behavioural roles for different dopamine neuron projections in fear extinction learning

The practice of an MSE wall/embarkment on a hard foundation: a case study from Phitsanulok, Thailand

The Department of Highways (DOHs), Thailand, designed and constructed a 6m high reinforced earth embankment near Highway No.11 Phitsanulok-Uttaradit in Thailand. Two types of reinforced earth embank-ment were constructed; on one side, bags of soil were used to construct a Reinforced Steep Slope (RSS) with a 70 degree sloping face and on the other side, a Mechanically Stabilized Earth Wall (MSEW) was constructed with a vertical concrete panel as a facing. The test embankment was 18m long and 15m wide at the top. Three types of polymeric geogrid reinforcements were installed in the reinforced steep slope (RSS) facing and two types of metal-lic reinforcement were installed in the mechanically stabilised earth wall (MSEW) facing. The polymeric geogrid reinforcement consisted of polyester (PET), high density polyethylene (HDPE) and polypropylene (PP), while the metallic reinforcement consisted of steel wire grid (SWG) and metallic strip (MS). Monitoring instruments such as inclinometers, settlement plates, total pressure cells, standpipe piezometers, vibrating wire strain gauges and fibre optic strain gauges were installed to check the displacement, stresses, excess pore water pressures, groundwater ta-ble, and strains in the reinforcing material. PLAXIS 3D (Version 2011) was utilised for the FEM numerical simula-tions of the embankment. The behaviour of a reinforced soil slope (RSS) and mechanically stabilised earth wall (MSEW) on a hard foundation were observed and compared with the predictions from PLAXIS 3D software, in terms of any lateral and vertical deformation