Migration, urban population growth and regional disparity in China

The main objective of this paper is to study the determinants of city population growth in China during the 1990s’, as well as the determinants of migrations towards cities, which constitutes the main source of urban population growth in this period. A second objective is to identify regional differences in the urban growth and migrations, that is, whether urban growth and migration patterns are different between coastal and inland provinces. Additionally, we are interested in the differences between temporary and permanent migrations towards urban areas.

Migration, urban population growth and regional disparity in China

The main objective of this paper is to study the determinants of city population growth in China during the 1990s', as well as the determinants of migrations towards cities, which constitutes the main source of urban population growth in this period. A second objective is to identify regional differences in the urban growth and migrations, that is, whether urban growth and migration patterns are different between coastal and inland provinces. Additionally, we are interested in the differences between temporary and permanent migrations towards urban areas.cerdi

Experimental investigation with digital particle image velocimetry for turbulent flow of slender particles in a stirred tank

Stirred vessels are one of the oldest and most commonly encountered industrial devices. It is frequently used in chemical process industry where gas dispersion in liquids, liquid-liquid blending and solid suspensions in liquids are involved. The design of stirred tanks requires the knowledge of flow field and understanding of the effects of various system parameters on mixing efficiency. However the experimental data acquisitions for design purposes with solid-liquid two-phase flows in a stirred tank are difficult. Solid-liquid two-phase flow is very common and of considerable interest for multiphase flow in stirred tanks. Intrusive probe techniques introduce an undesirable physical disturbance to the flow and can result in either inaccuracies in the measurements or even permanent impairment of the probes. A number of non-intrusive methods for the measurement of particle velocities have been developed in the last decade. Among these new methods, Digital Particle Image Velocimetry (DPIV) is a very appropriate choice. DPIV is a technique that combines the accuracy of Laser Dynamic Velocimetry (LDV) with the qualitative information from flow visualization. Please click Additional Files below to see the full abstract

The effects of virtual mass force and particle aspect ratio on orientation of slender particles in a stirred tank

Fundamental knowledge on particle orientation is important for processing and utilizing irregular shape particles. The orientation of slender particles influences the application of slender particles in many fluidization processes, such as pulp and paper, catalytic reaction, air pollution control. In this paper, the effects of virtual mass force and aspect ratio on the orientation of a slender particle in a particle cloud are studied. Virtual mass force, also called added mass force, apparent mass force, is a force due to the relative acceleration of the phases. The definition of virtual mass force is defined by Kuo and Wallis (1): Please click Additional Files below to see the full abstract

Study on single and multi-phase laminar flow containing spherical or slender particles in a stirred tank using DPIV

Stirred tanks are ubiquitous in the chemical, polymer, and pharmaceutical industries and used extensively for conducting a variety of single liquid phase and multiphase operations. Turbulent flow is most often encountered in stirred tanks. While efficient mixing is often achieved under turbulent conditions, there are many applications in which turbulence is precluded because fluids are too viscous or shear sensitive materials may be damaged by vigorous agitation. In such cases, stirred tanks must be operated under laminar flow conditions. The low Reynolds number regime arises in many practical applications, such as culture of shear-sensitive cells, manufacture of creams and detergent. Therefore it is necessary and important to study the laminar flow in stirred tanks. Both single phase and solid-liquid two-phase systems are frequently encountered in stirred tanks, and the presence of solid particles makes the flow in stirred tanks more complicated. Little literature on laminar solid-liquid flow in stirred tanks is available. To the authors’ best knowledge, only Jones and Weinberger (1) studied the laminar solid-liquid flow in a baffled tank stirred by a Rushton turbine. Dyster et al. (2) experimented on the radial discharge laminar flow in a baffled stirred tank. Bakker et al. (3) using laser Doppler velocimetry (LDV) and digital particle image velocimetry (DPIV) investigated the flow field generated by a pitched-blade turbine in laminar operations. Their stirrer is either paddle impeller or Rushton turbine. Therefore, it would be a very interesting experiment if we can combine the measurement of the laminar flow field in a baffled stirred tank with the DPIV technology. Please click Additional Files below to see the full abstract

USCID fourth international conference

Presented at the Role of irrigation and drainage in a sustainable future: USCID fourth international conference on irrigation and drainage on October 3-6, 2007 in Sacramento, California.Includes bibliographical references.Studying the impact of microtopography on irrigation performance is important for improving the management of basin irrigation systems. However, the limitation of field experiments will restrict the studies on the impact of microtopography spatial variability on basin irrigation performance. Thus, firstly this paper analyzed the spatial variability characteristics of field-measured Surface Relative Elevations (SRE). The correlations between the field geometry parameters and the spatial variability characteristics of SRE were evaluated, and the estimation methods for parameters of the semi-variogram of SRE were determined. Secondly, a microtopography stochastic generating model was built up based on the Monte-Carlo and the Kriging interpolation techniques. Lastly, the effect of spatial variability of microtopography on the performance of basin irrigation was evaluated by using of the numerical simulation model. Results showed that the microtopography undulation degree and the spatial distribution difference of undulation location had obvious effect on the basin irrigation performance. The average irrigation depth (Z'avg), corresponding to the water just cover the whole basin surface is increased while the irrigation application efficiency (Ea) and the irrigation uniformity (CU) is decreased when the field elevation non-uniformity, measured by the standard deviation of SRE (Sd) is increased. The effect of spatial distribution of undulation location on the irrigation performance was dependent upon the microtopography undulation degree, when Sd is less than 2cm the impacts can be neglected, while Sd is greater than 2cm, the influence should be considered

Evaluation of chidamide and PFI-1 as a combination therapy for triple-negative breast cancer

Purpose: To evaluate the in vitro and in vivo effects of the combination therapy of histone deacetylases (HDAsC) inhibitor, chidamide, and bromodomain-containing proteins (BETs) inhibitor, PFI-1, on triplenegative breast cancer (TNBC). Methods: Four distinct breast cancer cell lines and one TNBC mouse model were treated with vehicle, chidamide, PFI-1 alone, or chidamide and PFI-1. The inhibitory effect of chidamide or PFI-1 on HDACs and BETs was assessed by HDAC enzyme inhibition and AlphaScreen assays. Cell viability was determined by MTT assay while protein expression of p-STAT3 was evaluated by western blotting and immunohistochemistry (IHC) staining assay. Results: Chidamide exerted inhibitory effect on HDACs while PFI-1 inhibited BET proteins. The threedimensional model demonstrated the interactions between chidamide and HDAC2, and between PFI-1 and BRD4. Chidamide or PFI-1 exerted inhibitory effects on breast cancer cell proliferation in vitro. However, the combination of PFI-1 and chidamide significantly inhibit MDA-MB-231 cell viability, and decrease the expression of p-STAT3, when compared to that treated with chidamide or PFI-1 alone. Moreover, the combined inhibitory effect of PFI-1 and chidamide on tumor growth was also found in the in vivo mice experiments. Conclusion: The combination of chidamide and PFI-1 is a potential is a potential therapeutic strategy for the management of TNBC. Keywords: Triple-negative breast cancer, Histone deacetylases, Bromodomai

Response of Three Kinds of Detoxifying Enzymes from Odontotermes formosanus (Shiraki) to the Stress Caused by Serratia marcescens Bizio (SM1)

Subterranean termite Odontotermes formosanus (Shiraki) (Blattodea: Isoptera: Termitidae), is a pest species found in forests and dams. Serratia marcescens Bizio (SM1) has a potential pathogenic effect on O. formosanus. However, the response of detoxifying enzymes to exposure by S. marcescens in O. formosanus has not been studied. In the present work, 20 detoxifying enzyme genes, including 6 glutathione S-transferases (GSTs), 5 UDP glycosyltransferases (UGTs) and 9 Cytochrome P450s (CYPs), were identified from the O. formosanus transcriptome dataset by bioinformatics analysis. Furthermore, the effects of SM1 infection on the transcription levels of detoxifying enzyme genes (GSTs, UGTs and CYPs) in O. formosanus were determined. The results showed that the expression of all detoxifying enzyme gene, except one GST, in O. formosanus were altered in response to the infection by SM1. The response of GSTs, UGTs and CYPs to SM1 in O. formosanus suggested that they may play an important role in the defense against bacterial infection such as SM1, and implies that termites have evolved a complex immune response to potential pathogens