Comparative Study on Characteristics of P Fixation by Mn, Fe and Al

An experiment was conducted to examine the role of Mn in P fixation through comparing with Al and Fe. Hydroxides and oxides of Al, Fe and Mn were prepared in lab under opened and closed conditions to react with phosphate. The newly formed Mn hydroxide showed the strongest P-fixing abilityl even several times higher than Fe hydroxide, but became the lowest rapidly due to ageing when exposed to air. Mn oxide showed the lowest p-fixing ability. Therefore, a sound consideration on P fixation should be based on both quantities and p-fixing abilities of the compounds of Fe, Al and Mn. The importance of Mn on P availability should receive more attention especially under oxidation-reduction dynamic conditions.

Vesicular Arbuscular Mycorrhizae-Mediated Uptake and Thanslocation of P and Zn by Wheat in Calcareous Soil

Vesicular-arbuscular mycorrhizal (VAM) fungi have been credited with improving the groWth and mineral nutrition of many host plants but these effects are moderated by soil factors and nutrient balance. The combined effects of VAM, Zn and P application on the growth and translocation of nutrients in wheat were investigated using a calcareous soil marginal in P and Zn concentrations. Wheat was grown in a growth chamber under various combinations of VAM, P and Zn with measurements done at heading stage and maturity.Vegetative dry matter accumulation was increased by P application and reduced by VAM treatments. Both P and VAM increased grain yield. Zinc concentration and uptake were generally reduced by P addition and VAM infection. There were no antagonistic effects of Zn on P acquisition in the plant. The role of VAM in enhancing the translocation of Zn and P from root to grain would be beneficial to seed setting and yield.

Study on Soil and Pine-Seedling Zn and Mn and Predicting-Model Design

Soils were collected from 2-year (2-y) and 3-year (3-y) old red-pine seedling plots in two tree nurseries, Hayward in the north and Wilson in the southwestern part of Wisconsin State respectively, and equilibrated with 0.01 M Ca(NO3)2 for soil solution Zn and Mn (solu-Zn and Mn), and with 0.01 M Ca(NO3)2+0.005 M EDTA for soil adsorbed Zn and Mn (ad-Zn and Mn). Buffering capacity of soil Zn and Mn (b-Zn and Mn) was obtained from the ratio of ad-Zn and Mn to the solu-Zn and Mn. The concerned traces in pine seedling needles (ndls), stems(sts) and roots (rts) were simultaneously measured. The results obtained show that:About 60% of solu- and ad- Zn ranged from 0.2 to 0.4 and from 1 to 2μ/g soil respectively. About 70% of b-Zn was within) 3-10.The highest content of solu-Zn compared with the lowest showed a discrepancy of more than 10-fold. The two forms of soil Zn were commonly higher in Wilson than in Hayward Nursery.About 80% of solu-, ad- and b-Mn were within 3-10, 5-5.8 μg/ g soil and 1-2 respectively. Influence of low buffering capacity on solu-Zn and Mn was about 20 times stronger than that of the high.The E-value, a ratio of accumulated Zn and Mn in needles to those in the soil solution, is proved to be: E-Zn > E-Mn;E-sts> E-ndls or E-rts; and E-2y > E-3y.Curvilinear and/ or linear correlations between soil solu-, ad- and b-Zn and Mn and ndls-, sts-, rts-Zn and Mn were at very significant or significant levels.For predicting ndls-Zn and Mn, two realizable and simple models from two regression equations were established through the selection of related parameters and dependent variables. Binary regression analysis basically eliminated the influence of soil pH on the prediction of Zn and Mn in needles. Soil pH was thus thought to be excluded from the model.

Country presentation——Republic of the Philippines（2004 TCDC Training Workshop on SHP Equipment Hangzhou, China）

REPUBLIC ACT NO. 7638 （RA 7638) - an act creating the Department of Energy, rationalizing the organization and functions of government agencies related to energy, and for other purposes. This act is also known as the “department of energyact of 1992”.

TESTS OF COVARIANCE MATRIX BY USING PROJECTION PURSUIT AND BOOTSTRAP METHOD

Testing equality of covariance matrix has long been an interesting issue in statistics inference, To overcome the sparseness of data points in high-dimensional space and deal with the general cases, the author suggests several projection pursuit type statistics. Some results on the limiting distidbutions of the statistics are obtained. Some properties of bootstrap approximation are investigated. Furthermore, for computational reasons an approximation for the statistics based on number-theoretic roethod is applied. Several simulation experiments are performed.

Magnetic Bingham fluid-assisted deterministic polishing for super-smooth surfaces

The characteristics of magnetorheological fin- ishing (MRF) technique such as the behavior of magnetic particles and the magnetic field distribution have been inves- tigated. Based on the established theoretical model, material removal function and removal rate experiments involving a K9 glass mirror are designed and carried out. Further experiments are carried out to improve the surface roughness of the workpiece. The final surface roughness with an initial value of 17.58 nm reached 0.4351 nm rms after 35 min of deterministic MRF, and the AFM measurements on microstructures of the polished surface are also improved by 0.445 nm rms without obvious defects.

Biomimetic gold nanocomplexes for gene knockdown： Will gold deliver dividends for small interfering RNA nanomedicines？

RNA interference （RNAi） effectors such as small interfering RNA （siRNA） and micro RNA （miRNA） can selectively downregulate any gene implicated in the pathology of a disease. Therefore, RNAi-based therapies have immense potential for the treatment of a wide range of diseases. However, pharmacokinetic and pharmacodynamic studies have revealed that these therapeutic agents have poor bioactivity due to a number of factors, including insufficient plasma drug levels, short plasma half-lives, renal clearance, and hepatic metabolism. Non-viral delivery may facilitate the clinical application of siRNA-based therapeutics by helping to overcome these barriers. Recently, the potential of gold nanoparticles （AuNPs） as multifunctional carriers for transporting drugs, proteins, and genetic materials has been demonstrated. In this review, some of the key properties of AuNPs relevant to siRNA delivery, such as physical properties and surface chemistry have been described. In addition, the ability of AuNP-based formulation strategies to successfully overcome delivery barriers associated with siRNA, and the potential for this material to translate into safe and effective nanomedicines are critically discussed.