Effect of Slope Aspect on Arbuscular Mycorrhizal Colonization of Centipedegrass in a Hill Pasture

Arbuscular mycorrhizal fungi (AMF) form a symbiotic association with more than 80% of terrestrial plants and benefit their hosts principally by increasing uptake of nutrients. This is particularly important for phosphorus uptakes as fungal extraradical mycelium can access relatively immobile phosphate ions through an ability to grow beyond the phosphate depletion zone that rapidly develops around the root (Gosling et al. 2006). This symbiotic association is known to promote growth and improve drought and disease resistance of the host plants (Gosling et al. 2006). Centipedegrass (Eremochloa ophiuroides (Munro) Hack.) is a warm-season perennial that is native to central and southern China and is widely distributed in south-east Asia, southern USA, South America, West Indies, and parts of Africa and tropical north and east Australia (Islam and Hirata 2005). Centipedgegrass (CG) has been considered to be of potential value for use in low-input grassland systems in central to southern parts of Japan. An experiment conducted in a hill pasture in the mid-altitude region of Kyushu has shown that CG is well adapted to all slope aspects (north, east, south and west) despite the aspect differences in environmental conditions (Hirata et al. 2007). In this study, we monitored AM colonization of CG growing on the 4 slopes of the pasture to examine aspect differences in the grass–AMF association

Explicit treatment of tensor force with a method of Antisymmetrized Molecular Dynamics

In order to treat tensor force explicitly, we propose a microscopic model for nuclear structure based on antisymmetrized molecular dynamics (AMD). As a result of the present study, it is found that some extentions of the AMD method are effective to incorporate the tensor correlation into wave functions. Calculating the deuteron, triton and $^4$He with the extended version of AMD, we obtained solutions that have large contribution of the tensor force. By analyzing the wave funtion of $^4$He, it is found that its single-particle orbits are composed of normal-size $0s$ orbits and shrunk $p$ orbits so as to gain the tensor force.Comment: 20 pages, 4 figure

Distribution and stoichiometry of Al, Mn, Fe, Co, Ni, Cu, Zn, Cd, and Pb in the East China Sea

The dissolved (d) and total dissolvable (td) trace metals were determined in seawater samples collected from the East China Sea (ECS). Labile particulate (lp) species was calculated as td minus d, and the sectional and vertical distributions of d and lp trace metals were evaluated. The surface concentrations of dAl, dCo, dNi, dCu, and dPb were higher in the continental shelf region than in the Kuroshio region. lpAl and lpFe were the dominant species below a depth of 400 m, and a strong positive correlation was observed between them in the Kuroshio region. The enrichment factor (EF) against crustal abundance was calculated for the purpose of estimating the origin of dMs in the ECS. The EF(dFe) was close to unity. These results suggest that both lpFe and dFe are dominated by crustal sources. The other elements had high EF, indicating significant contributions from other sources. EF(dPb) was close to the enrichment factor in aerosol, suggesting atmospheric input from anthropogenic sources. The dM/P ratios were calculated to investigate the validity of the extended Redfield ratio in the ECS. The Mn/P, Co/P, Cu/P, Zn/P, and Cd/P ratios in shallow water (< 200 m) were within the same order of magnitude as those in phytoplankton. In contrast, the Al/P and Fe/P ratios were, respectively, 27 and 213 times higher in phytoplankton compared to those in shallow water. These results suggest that dFe is a potential limiting factor for biological production, although it is not exhausted in surface water

formation of a laminar electron flow for 300GHz high-power pulsed gyrotron

This paper describes the design of a triode magnetron injection gun for use in a 200 kW, 300 GHz gyrotron. As power and frequency increase, the performance of the gyrotron becomes quite sensitive to the quality of the electron beam. Formation of a laminar electron flow is essential for the realization of a high quality beam with a small velocity spread. In this study, a new method is developed for a quantitative evaluation of the laminarity and is applied to optimize the electrode design. The laminarity depends not only on conventional design parameters such as the cathode slant angle but also on the spatial distribution of the electric field along the beam trajectory. In the optimized design, the velocity pitch factors, a, larger than 1.2 are obtained at 65 kV, 10A with spreads, Da, less than 5%

Endothelial Progenitor Cells Promote Directional Three-Dimensional Endothelial Network Formation by Secreting Vascular Endothelial Growth Factor

Endothelial progenitor cell (EPC) transplantation induces the formation of new blood-vessel networks to supply nutrients and oxygen, and is feasible for the treatment of ischemia and cardiovascular diseases. However, the role of EPCs as a source of proangiogenic cytokines and consequent generators of an extracellular growth factor microenvironment in three-dimensional (3D) microvessel formation is not fully understood. We focused on the contribution of EPCs as a source of proangiogenic cytokines on 3D microvessel formation using an in vitro 3D network model. To create a 3D network model, EPCs isolated from rat bone marrow were sandwiched with double layers of collagen gel. Endothelial cells (ECs) were then cultured on top of the upper collagen gel layer. Quantitative analyses of EC network formation revealed that the length, number, and depth of the EC networks were significantly enhanced in a 3D model with ECs and EPCs compared to an EC monoculture. In addition, conditioned medium (CM) from the 3D model with ECs and EPCs promoted network formation compared to CM from an EC monoculture. We also confirmed that EPCs secreted vascular endothelial growth factor (VEGF). However, networks cultured with the CM were shallow and did not penetrate the collagen gel in great depth. Therefore, we conclude that EPCs contribute to 3D network formation at least through indirect incorporation by generating a local VEGF gradient. These results suggest that the location of EPCs is important for controlling directional 3D network formation in the field of tissue engineering

Engineering Bone Formation from Human Dental Pulp- and Periodontal Ligament-Derived Cells.

A robust method for inducing bone formation from cultured dental mesenchymal cells has not been established. In this study, a method for generating bone tissue in vivo from cultured human dental pulp- and periodontal ligament-derived cells (DPCs and PDLCs, respectively) was designed using exogenous bone morphogenetic protein 2 (BMP2). DPCs and PDLCs showed enhanced alkaline phosphatase (ALP) activity and calcified nodule formation in medium containing dexamethasone, beta-glycerophosphate, and ascorbic acid (osteogenic medium). However, the addition of recombinant human bone morphogenetic protein 2 (rhBMP2) to osteogenic medium remarkably increased ALP activity and in vitro calcification above the increases observed with osteogenic medium alone. rhBMP2 also significantly upregulated the expression of osteocalcin, osteopontin, and dentin matrix protein 1 mRNA in both cell types cultured in osteogenic medium. Finally, we detected prominent bone-like tissue formation in vivo when cells had been exposed to rhBMP2 in osteogenic medium. In contrast, treatments with osteogenic medium or rhBMP2 alone could not induce abundant mineralized tissue formation. We propose here that treatment with rhBMP2 in osteogenic medium can make dental mesenchymal tissues a highly useful source of cells for bone tissue engineering. In addition, both DPCs and PDLCs showed similar and remarkable osteo-inducibility.The original publication is available at www.springerlink.co

Improved sensitivity of magnetic measurements under high pressure in miniature ceramic anvil cell for a commercial SQUID magnetometer

Two modifications have been made to a miniature ceramic anvil high pressure cell (mCAC) designed for magnetic measurements at pressures up to 12.6 GPa in a commercial superconducting quantum interference (SQUID) magnetometer [N. Tateiwa et al., Rev. Sci. Instrum. 82, 053906 (2011)., ibid. 83, 053906 (2012)]. Replacing the Cu-Be piston in the former mCAC with a composite piston composed of the Cu-Be and ceramic cylinders reduces the background magnetization significantly smaller at low temperatures, enabling more precise magnetic measurements at low temperatures. A second modification to the mCAC is the utilization of a ceramic anvil with a hollow in the center of the culet surface. High pressures up to 5 GPa were generated with the "cupped ceramic anvil" with the culet size of 1.0 mm.Comment: Rev. Sci. Instrum. 84, 046105 (2013

Observation of Dynamic Interactions between Fundamental and Second-Harmonic Modes in a High-Power Sub-Terahertz Gyrotron Operating in Regimes of Soft and Hard Self-Excitation

Dynamic mode interaction between fundamental and second-harmonic modes has been observed in high-power sub-terahertz gyrotrons [T. Notake et al., Phys. Rev. Lett. 103, 225002 (2009); T. Saito et al. Phys. Plasmas 19, 063106 (2012)]. Interaction takes place between a parasitic fundamental or firstharmonic (FH) mode and an operating second-harmonic (SH) mode, as well as among SH modes. In particular, nonlinear excitation of the parasitic FH mode in the hard self-excitation regime with assistance of a SH mode in the soft self-excitation regime was clearly observed. Moreover, both cases of stable twomode oscillation and oscillation of the FH mode only were observed. These observations and theoretical analyses of the dynamic behavior of the mode interaction verify the nonlinear hard self-excitation of the FH mode

Usefulness of brain natriuretic peptide for predicting left atrial appendage thrombus in patients with unanticoagulated nonvalvular persistent atrial fibrillation

AbstractBackgroundThe CHADS2 scoring system is simple and widely accepted for predicting thromboembolism in patients with nonvalvular atrial fibrillation (NVAF). Although congestive heart failure (CHF) is a component of the CHADS2 score, the definition of CHF remains unclear. We previously reported that the presence of CHF was a strong predictor of left atrial appendage (LAA) thrombus. Therefore, the present study aimed to elucidate the relationship between LAA thrombus and the brain natriuretic peptide (BNP) level in patients with unanticoagulated NVAF.MethodsThe study included 524 consecutive patients with NVAF who had undergone transesophageal echocardiography to detect intracardiac thrombus before cardioversion between January 2006 and December 2008, at Hiroshima City Asa Hospital. The exclusion criteria were as follows: paroxysmal atrial fibrillation, unknown BNP levels, prothrombin time international normalized ratio ≥2.0, and hospitalization for systemic thromboembolism.ResultsReceiver operating characteristic analysis yielded optimal plasma BNP cut-off levels of 157.1pg/mL (area under the curve, 0.91; p<0.01) and 251.2pg/mL (area under the curve, 0.70; p<0.01) for identifying CHF and detecting LAA thrombus, respectively. Multivariate analyses demonstrated that a BNP level >251.2pg/mL was an independent predictor of LAA thrombus (odds ratio, 3.51; 95% confidence interval, 1.08–10.7; p=0.046).ConclusionsIn patients with unanticoagulated NVAF, a BNP level >251.2pg/mL may be helpful for predicting the incidence of LAA thrombus and may be used as a surrogate marker of CHF. The BNP level is clinically useful for the risk stratification of systemic thromboembolism in patients with unanticoagulated NVAF