Security-Oriented Trellis Code Design for Spatial Modulation

To achieve physical layer security (PLS) with a flexible implementation, a novel design named security-oriented trellis coded spatial-modulation (SO-TCSM) is proposed in this paper, where the transmitter does not know the channel state information (CSI) of wiretapping channels and relies on the legitimate CSI to vary the mapping patterns for the antenna information and the radiated information, aiming at the optimisation of free Euclidean distances between the resultant SO-TCSM symbols. Eavesdroppers cannot decode the confidential information delivered in the legitimate link, as they do not know the legitimate CSI and, hence, have no basis to acquire the transmitter's mapping pattern of the moment. Moreover, the SO-TCSM symbols are then compensated to maximise their Euclidean distances, which further improves the legitimate receiver's decoding performance while enhancing the PLS. However, the compensation results in high transmit power when the legitimate channels are in deep fades. To boost the energy efficiency, a constraint is set to limit the transmit power. Under this constraint, the SO-TCSM performance is investigated in terms of bit error rate and transmit power consumption. The outcome of these investigations substantiates that, compared to conventional TCSM designs, our SO-TCSM achieves better performance in the legitimate link with lower decoding complexity

Rodent models of postherpetic neuralgia: How far have we reached?

BackgroundInduced by varicella zoster virus (VZV), postherpetic neuralgia (PHN) is one of the common complications of herpes zoster (HZ) with refractory pain. Animal models play pivotal roles in disclosing the pain mechanisms and developing effective treatments. However, only a few rodent models focus on the VZV-associated pain and PHN.ObjectiveTo summarize the establishment and characteristics of popular PHN rodent models, thus offer bases for the selection and improvement of PHN models.DesignIn this review, we retrospect two promising PHN rodent models, VZV-induced PHN model and HSV1-induced PHN model in terms of pain-related evaluations, their contributions to PHN pathogenesis and pharmacology.ResultsSignificant difference of two PHN models is the probability of virus proliferation; 2) Most commonly used pain evaluation of PHN model is mechanical allodynia, but pain-induced anxiety and other behaviours are worth noting; 3) From current PHN models, pain mechanisms involve changes in virus gene and host gene expression, neuroimmune–glia interactions and ion channels; 4) antiviral drugs and classical analgesics serve more on the acute stage of herpetic pain.ConclusionsDifferent PHN models assessed by various pain evaluations combine to fulfil more comprehensive understanding of PHN

Impacts of a wildfire on soil organic carbon in Warrumbungle National Park, Australia

A wildfire in the Warrumbungle Range in January 2013 burnt 56,290 ha of forest land, 72% of it at high-extreme severity. We investigated the effects of fire on soil organic carbon (SOC), soil carbon fractions (Particulate Organic Carbon (POC), Humus Organic Carbon (HOC) and Resistant Organic Carbon (ROC)) at 64 sites stratified according to geology and fire severity across Warrumbungle National Park. Statistical models were used to identify the main factors controlling the soil chemical parameters and we spatially extrapolated results based on these main factors to estimate the overall impacts of the fire. Statistical models indicated that the key effects on SOC were fire severity and geology/soil type. SOC declined with increasing fire severity − topsoil SOC in low severity sites was 14% lower than unburnt sites, and severely burnt sites were 54% lower than unburnt. There were also significant differences in SOC fractions between the different geology/soil types. These results were also reflected in N and pH changes. The highest SOC values were from unburnt volcanic topsoils. Sandier and especially sandstone-derived soils had less SOC irrespective of the fire severity class. The lowest SOC values were from severely burnt sandstone ridges, where most of the remaining SOC occurs as ROC (including charcoal). Site data was classified according to a fire severity map and geological mapping, and class averages spatially extrapolated to obtain an estimate of the amounts of SOC lost due to the fire. An estimated 1.52 Mt (26.99 t/ha) of SOC was lost over the fire ground to 10 cm. SOC levels in unburnt control sites are much higher than averages in the generally cleared central west of NSW, thus underlining the importance of forested ecosystems in carbon sequestration in soils, and of Warrumbungle National Park with its high proportion of trachytic clayey soils in particular