Influence of water temperature and salinity on pH during dry season in lower Dong Nai river system, Vietnam

This paper uses the gvSIG 2.2.0 software, IDW interpolation method, river and stream network data, and 36 sampling sites to build the maps of three monitored parameters such as pH, water temperature, and salinity in the Lower Dong Nai River system (2009–2010) in dry season. Based on an analysis of these maps and statistical assessment by using the R software, the correlations between pH, temperature, and salinity are clarified. The results show that the pH and temperature values have a tendency to decrease, whereas the salinity tends to increase annually. The pH value has good and significant correlations with the water temperature and salinity in both simple and multiple linear regression models. The results aim to provide a scientific reference for further research on the water environment in this area

A Robust Transformation-Based Learning Approach Using Ripple Down Rules for Part-of-Speech Tagging

In this paper, we propose a new approach to construct a system of transformation rules for the Part-of-Speech (POS) tagging task. Our approach is based on an incremental knowledge acquisition method where rules are stored in an exception structure and new rules are only added to correct the errors of existing rules; thus allowing systematic control of the interaction between the rules. Experimental results on 13 languages show that our approach is fast in terms of training time and tagging speed. Furthermore, our approach obtains very competitive accuracy in comparison to state-of-the-art POS and morphological taggers.Comment: Version 1: 13 pages. Version 2: Submitted to AI Communications - the European Journal on Artificial Intelligence. Version 3: Resubmitted after major revisions. Version 4: Resubmitted after minor revisions. Version 5: to appear in AI Communications (accepted for publication on 3/12/2015

A new stability results for the backward heat equation

In this paper, we regularize the nonlinear inverse time heat problem in the unbounded region by Fourier method. Some new convergence rates are obtained. Meanwhile, some quite sharp error estimates between the approximate solution and exact solution are provided. Especially, the optimal convergence of the approximate solution at t = 0 is also proved. This work extends to many earlier results in (f2,f3, hao1,Quan,tau1, tau2, Trong3,x1).Comment: 13 page

CHANGING ROAD TRAFFIC NOISE IN HANOI OF PREVIOUS 10 YEARS

Joint Research on Environmental Science and Technology for the Eart

Determining the Intracellular Concentrations of Flavonoids in MDA-MB-231 Cells Using HPLC-Coupled Mass Spectrometry

Flavonoids are polyphenolic compounds found in a wide variety of plants. In recent years, flavonoids have been found to be beneficial to human health. Our lab has investigated the ability of flavonoids to induce cytotoxicity in human breast cancer cell lines. We have discovered that some compounds can induce cytotoxicity very readily, whereas others cannot. We hypothesized that this difference is attributable to a compound\u27s ability to transverse the cell membrane. Therefore, we used LC-MS to measure the amount of each flavonoid that is able to enter into MDA-MB-231 cells, human breast cancer cells. We tested 14 flavonoids. MDA-MB-231 cells were plated and treated with 100 μM flavonoids for 24 and 48 hr. After treatment, cells were extracted using methanol. Flavonoids from extracts were characterized and quantitated by LC-MS. We found that intracellular flavonoid concentration increased over time for some of the flavonoids. We could not detect quercetin, myricetin, and catechin in cell extracts. However, quercetin was found to be a moderate inducer of cytotoxicity, whereas myricetin and catechin were not. We found that quercetin dimerized over time in the cell medium only in the presence of serum. The quercetin dimer could not be detected in cellular extracts, which suggested that it was unable to cross the membrane. Additionally, synthetic quercetin dimer did not induce cell death. Our results suggest that only fresh quercetin killed cells; once quercetin dimerized, it could not induce cell death