Analyzing the role of extracellular matrix during nervous system development to advance new regenerative strategies

Regeneration in the central nervous system （CNS） is limited, and CNS damage often leads to cognitive impairment or permanent functional motor and sensory loss. Impaired regenerative capacity is multifactorial and includes inflammation, loss of the blood-brain barrier, and alteration in the extracellular matrix （ECM）. One of the main problems is the formation of a glial scar and the production of inhibitory ECM, such as proteoglycans, that generates a physical and mechanical barrier, impeding axonal regrowth （Figure 1A）.

Regenerative Braking Strategy for Motor Hoist by Ultracapacitor

Rising concern in environmental issues on global scale has made energy saving in powered equipment a very important subject.In order to improve the energy efficiency and driving range of a motor hoist,a regenerative braking system is designed and discussed.The system takes a unique ultracapacitor-only approach to energy storage system.The bi-directional bride DC？DC converter which regulates current flow to and from the ultracapacitor operates in two modes：boost and buck,depending on the direction of the flow.In order to provide constant input and output current at the ultracapacitor,this system uses a double proportional-integral（PI） control strategy in regulating the duty cycle of PWM to the DC？DC converter.The permanent magnet synchronous motor（PWSM） drive system is also studied.The space vector pulse width modulation（SVPWM） technique,along with a two-closed-loop vector control model,is adopted after detailed analysis of PMSM characteristics.The overall model and control strategy for this regenerative braking system is ultimately built and simulated under the MATLAB and Simulink environment.A test platform is built to obtain experimental results.Analysis of the results reveals that more than half of the gravitational potential energy can be recovered by this system.Simulation and experimentation results testify the validity of the double PI control strategy for interface circuit of ultracapacitor and SVPWM strategy for PMSM.

Regenerative Strategy for Sum-rate Enhancement in Bi-directional Three-node Cooperation

In bi-directional three-node cooperation, one regenerative strategy with network coding and power optimization is proposed for system sum-rate under a total energy constraint. In this paper, the network coding and power optimization are applied to improve system sum-rate. But max-rain optimization problem in power allocation is a NP-hard problem. In high Signal-to-Noise Ratio regime, this NP-hard problem is transformed into constrained polynomial optimization problem, which can be computed in polynomial time. Although it is a suboptimal solution, numerical simulations show that this strategy enhances the system sum-rate up to 45% as compared to a traditional four-phase strategy, and up to 13% as compared to the three-phase strategy without power optimization.

Soil-vegetation relationships in Mediterranean forests after fire

Background:Wildfires are one of the major environmental concerns in Mediterranean ecosystems.Thus,many studies have addressed wildfire impacts on soil and vegetation in Mediterranean forests,but the linkages between these ecosystem compartments after fire are not well understood.The aim of this work is to analyze soil-vegetation relationships in Mediterranean burned forests as well as the consistency of these relationships among forests with different environmental conditions,at different times after fire,and among vegetation with different functional traits.Results:Our results indicate that study site conditions play an important role in mediating soil-vegetation relationships.Likewise,we found that the nature of soil-vegetation relationships may vary over time as fire effects are less dominant in both ecosystem compartments.Despite this,we detected several common soil-vegetation relationships among study sites and times after fire.For instance,our results revealed that available P content and stoichiometry(C:P and N:P)were closely linked to vegetation growth,and particularly to the growth of trees.We found that enzymatic activities and microbial biomass were inversely related to vegetation growth rates,whereas the specific activities of soil enzymes were higher in the areas with more vegetation height and cover.Likewise,our results suggest that resprouters may influence soil properties more than seeders,the growth of seeders being more dependent on soil status.Conclusions:We provide pioneer insights into how vegetation is influenced by soil,and vice-versa,in Mediterranean burned areas.Our results reflect variability in soil-vegetation relationships among study sites and time after fire,but consistent patterns between soil properties and vegetation were also detected.Our research is highly relevant to advance in forest science and could be useful to achieve efficient post-fire management.

A Comparative Study of Morphological Responses of Seedling Roots to Drying Soil in 20 Species from Different Habitats

Rooting depth and root and shoot biomass were measured for seedlings of 20 species in both watered and unwatered sand columns. The species were from habitats of widely varying moisture status, ranging from marsh to desert. Moisture status of the species' habitats was quantified as Ellenberg moisture number. Seedlings were allowed to grow in moist sand for 21 days and were then exposed to the treatments (watered and unwatered) for a further 21 days. Rooting depth of control plants was not correlated with Ellenberg number. Root depth of plants from dry habitats tended to increase in drying sand, while roots of plants from wet habitats decreased in depth. Plasticity of rooting depth (depth in unwatered / depth in watered sand) was significantly correlated with Ellenberg number ( r 2 = 0.56). Plasticity of shoot/root ratio was also correlated with Ellenberg number, but the relationship was weaker than for rooting depth plasticity. Species that showed the greatest plasticity in rooting depth also showed the greatest ability to sustain shoot growth in unwatered sand. There was some evidence that growth of plants from very dry habitats was reduced in the watered treatment. Results of this study suggest that a major, although not the only, adaptation of plants of dry habitats is the ability of their seedlings to exploit deeply buried water resources.