Ultramafic vegetation and soils in the circumboreal region of the Northern Hemisphere

The paper summarizes literature on climate, soil chemistry, vegetation and metal accumulation by plants found on ultramafic substrata in the circumboreal zone (sensu Takhtajan, Floristic regions of the world, 1986) of the Northern Hemisphere. We present a list of 50 endemic species and 18 ecotypes obligate to ultramafic soils from the circumboreal region of Holarctic, as well as 30 and 2 species of Ni and Zn hyperaccumulators, respectively. The number of both endemics and hyperaccumulators are markedly lower compared to that of the Mediterranean and tropical regions. The diversity of plant communities on ultramafics soils of the circumboral region is also described. The underlying causes for the differences of ultramafic flora between arctic, cold, cool temperate and Mediterranean and tropical regions are also discussed. © 2018, The Ecological Society of Japan

Simulations of PVD improved reconstituted specimens with surcharge, vacuum and heat preloading using equivalent vertical flow conditions

This paper presents the simulations of prefabricated vertical drain (PVD) improved reconstituted specimens with surcharge preloading (PVD), vacuum and surcharge with PVD (Vacuum-PVD), heat and surcharge with PVD (Thermo-PVD), heat plus vacuum and surcharge with PVD (Thermo-Vacuum-PVD) from large scale consolidometer tests in the laboratory. The flow conditions included equivalent vertical permeability (Kev) using back-calculated coefficient of horizontal consolidation (Ch). The simulation results indicated that the settlements obtained from equivalent vertical flows were similar at the same ratio of horizontal permeability at undisturbed zone to horizontal permeability at smear zone (Kh/Ks). The back-calculated Ch values were 1.93, 2.23, 4.17 and 4.38 m2/year as well as the corresponding Kh/Ks values were 3, 2.7, 1.4, and 1.1, for PVD, Vacuum-PVD, Thermo-PVD and Thermo-Vacuum PVD, respectively. The Ch values increased while the Kh/Ks values decreased corresponding to PVD, Vacuum-PVD, Thermo-PVD, and Thermo-Vacuum PVD, respectively

Ecological erosion control by limited life geotextiles (LLGs) as well as with Vetiver and Ruzi grasses

This paper presents the result of laboratory model tests using water hyacinth limited life geotextiles (LLGs) as well as using Vetiver and Ruzi grasses for erosion control. The mass per unit area and tensile strength of water hyacinth LLGs were obtained. The tensile properties of Ruzi and Vetiver grass roots were obtained after growing periods of 2, 3, 4, 5 and 6 months. Moreover, the rainfall effects were conducted in the laboratory model tests for the erosion control tests. Lateritic soil and sandy soil were investigated separately with LLGs and vegetation covers. Water hyacinth LLGs with opening size 8 mm by 8 mm and 12 mm by 12 mm was used to cover the bare soil. Ruzi and Vetiver grasses were planted in the container and tested at the age of 4, 6, 8 weeks, respectively. The model slope angle of 1H:1V, 2H:1V and 3H:1V were used for the tests. The maximum rainfall intensity used in this study was 120 mm/h which normally occurs in Thailand. The runoff rate and soil loss were used to measure the soil erosion. The results shows that the soil loss and runoff rate of lateritic soil were higher than sandy soil. Furthermore, the steeper slopes of 1H:1V yielded highest runoff rate and soil loss than flatter slopes of 2H:1V and 3H:1V. Slope 3H:1V with vegetation cover had the highest resistance to erosion. Generally, bare soil with woven LLGs 12 mm by 12 mm opening size resulted in less amount of runoff rate than 8 mm by 8 mm opening size for both soil types. In contrast, bare soil with LLGs 12 mm by 12 mm indicated higher soil loss than 8 mm by 8 mm opening size for both soil types. Additionally, the bare soil with Ruzi grass reduced the amount of runoff rate and soil loss than Vetiver grass. The combination of Ruzi and Vetiver grasses with lateritic soil can produce the best runoff rate and soil loss yield with slope 3H:1V. As slopes become steeper the surface runoff increased. The increasing growing periods at 4, 6, 8 weeks of Vetiver and Ruzi grasses reduced the amount of soil loss and surface runoff because of increasing coverage of vegetation. The observed data indicated the important role of vegetation in soil erosion prevention at different slope inclinations. The combination of Vetiver and Ruzi grass was highly effective against soil erosion and reducing the runoff rate

Surface Derivatization Strategy for Combinatorial Analysis of Cell Response to Mixtures of Protein Domains

We report a robust strategy for conjugating mixtures of two or more protein domains to non-fouling polyurethane surfaces. In our strategy, the carbamate groups of polyurethane are reacted with zirconium alkoxide from the vapor phase to give a surface bound oxide that serves as a chemical layer that can be used to bond organics to the polymer substrate. An hydroxyalkylphosphonate monolayer was synthesized on this layer, which was then used to covalently bind primary amine groups in protein domains using chloroformate-derived cross-linking. The effectiveness of this synthesis strategy was gauged by using an ELISA to measure competitive, covalent bonding of cell-binding (III(9–10)) and fibronectin-binding (III(1–2)) domains of the cell adhesion protein fibronectin. Cell adhesion, spreading, and fibronectin matrix assembly were examined on surfaces conjugated with single domains, a 1:1 surface mixture of III(1–2) and III(9–10), and a recombinant protein “duplex” containing both domains in one fusion protein. The mixture performed as well or better than the other surfaces in these assays. Our surface activation strategy is amenable to a wide range of polymer substrates and free amino group-containing protein fragments. As such, this technique may be used to create biologically specific materials through the immobilization of specific protein groups or mixtures thereof on a substrate surface