A Comparative Study of the L2 Pragmatic Competence of University Students in Hong Kong and the Chinese Mainland:The Contributions of Sociocultural Context and Linguistic Proficiency

This study investigates the differences in pragmatic competence between Hong Kong and Chinese mainland university students.Participants included 19 native speakers of English,115 Chinese mainland students,divided into those who had spent time abroad in an English-speaking country(CM A)and those who had not(CM NA),and 97 Hong Kong students,divided into those from an English-medium secondary school(Hong Kong EMI)and those from a Chinese-medium school(Hong Kong CMI).Linguistic proficiency was measured by a C-test,and pragmatic competence by a Metapragmatic Knowledge Test,an Irony Test and a Monologic Role Play.Group scores were compared using ANCOVAs to control for differences in proficiency.The results point to a continuum of pragmatic competence—EMI>CMI>CM A>CM NA—reflecting the groups’access to English in real-life contexts.The differences between the Hong Kong groups and the Chinese mainland groups were clearest in those tests measuring processing capacity(i.e.,Irony Response Time and the Monologic Role Play).CM A,but not CM NA,performed as well as the Hong Kong groups on measures of metapragmatic awareness.The results are discussed in terms of Bialystok’s(1993)distinction between analyzed representation and control of processing.

Ontology-based framework for personalized recommendation in digital libraries

To promote information service ability of digital libraries, a browsing and searching personalized recommendation framework based on the use of ontology is described, where the advantages of ontology are exploited in different parts of the retrieval cycle including query-based relevance measures, semantic user preference representation and automatic update, and personalized result ranking. Both the usage and information resources can be exploited to extract useful knowledge from the way users interact with a digital library. Through combination and mapping between the extracted knowledge and domain ontology, semantic content retrieval between queries and documents can be utilized. Furthermore, ontology-based conceptual vector of user preference can be applied in personalized recommendation feedback.

Reconstruction of HP Intein with Overlap-extension PCR

[Objective] This study aimed to reconstruct the HP intein by overlap-exten- sion PCR. [Method] Several primers were designed according to the principle of overlap-extension PCR that the repeat sequences were overlapped and served as the template to the other DNA strand in amplification. Then, several rounds of over- lap PCR reaction were conducted to mutate the four cysteines in the HP intein into serines, and introduce a linker sequence containing a tag for product detection and purification. [Result] DNA sequencing analysis proved that the four cysteines in the HP intein were successfully mutated into serines; the PCR precursor fragments were also rejoined into an intact HP gene fragment, without introducing any other unex- pected mutation; the DNA linker of 46 bp was successfully inserted into the de- signed HP gene sequences, without any mutation and base pair mismatch. [Conclu- sion] The HP intein was rapidly reconstructed by overlap-extension PCR in this study, which not only expands the application of overlap PCR in protein engineering, but also provides a simple, efficient and highly accurate tool for the reconstruction and modification of intein.

Curb parking pricing method based on parking choice behavior

In order to improve the use efficiency of curb parking, a reasonable curb parking pricing is evaluated by considering individual parking choice behavior. The parking choice behavior is analyzed from micro-aspects, and the choice behavior utility function is established combining trip time, search time, waiting time, access time and parking fee. By the utility function, a probit-based parking choice behavior model is constructed. On the basis of these, the curb parking pricing model is deduced by considering the constrained conditions, and an incremental assignment algorithm of the model is also designed. Finally, the model is applied to the parking planning of Tongling city. It is pointed out that the average parking time of curb parking decreases 34%, and the average turnover rate increases 67% under the computed parking price system. The results show that the model can optimize the utilization of static traffic facilities.

Seasonal Dynamics of Biomass under Different Land Use Patterns

[Objective] The aim was to study seasonal dynamics of biomass under different land use patterns. [Methed] Aboveground biomass and underground biomass of plants under 3 different surface cover conditions of Stipa krylovii, Leymus chinensis and farmland were determined in growing season （ from May to October） of 2008. [ Result ] The aboveground biomass of Stipa krylovii, Leymus chinensis and farmland in August all reached the highest value, which of Stipa krylovii, Leymus chinensis and farmland was 287.91,117.05 and 193.59 g/m2, respectively. The total biomass of plant roots of the 3 plots in July all reached the highest value, which of Stipa krylovii, Leymus chinensis and farmland was 1 683.9, 1 601.9 and 513.9 g/m2, respectively. Leymus chinensis had the biggest biomass ratio of upper plant roots （0 - 15 cm） to lower plant roots （15 -30 cm）, Stipa krylovii took second place, and farmland had the smallest one. ~ Conclusion The research provides theoretical basis for the ecological environment protection of ecological fragile area.

Equivalence of crossed product of linear categories and generalized Maschke theorem

Some sufficient and necessary conditions are given for the equivalence between two crossed product actions of Hopf algebra H on the same linear category, and the Maschke theorem is generalized. Based on the result of the crossed product in the classic Hopf algebra theory, first, let A be a k-linear category and H be a Hopf algebra, and the two crossed products A#_σH and A#＇_σH are isomorphic under some conditions. Then, let A#_σH be a crossed product category for a finite dimensional and semisimple Hopf algebra H. If V is a left A#σH-module and WC V is a submodule such that W has a complement as a left A-module, then W has a complement as a A#_σH-module.

Construction of the Plasmid Reference Molecule for Detection of Transgenic Soybean MON89788

[Objective] The aim was to construct a plasmid reference molecule (PRM) for detection of transgenic soybean MON89788. [Method] the lectin gene sequence,3'-junction and 5'-junction sequence between host plant DNA integrated DNA of MON89788 soybean were amplified independently,and the three fragments were cloned into the cloning vector pMD18-T in order through molecular manipulation method to construct pMD-LM3M5,the applicability of the constructed novel PRM was tested. [Result] Sequencing confirmation result showed that the PRM was 3 700 bp in length,containing 1 029 bp of recombined DNA fragment. The limits of qualitative detection of the PRM were 10 copies. [Conclusion] The PRM constructed in this study was suitable for the identification of MON89788 event.

A GPCR/secretase complex regulates β- and γ-secretase specificity for Aβ production and contributes to AD pathogenesis

Dysregulation of β-site APP-cleaving enzyme （BACE） and/or γ-secretase leads to anomalous production of amyloid-β peptide （Aβ） and contributes to the etiology of Alzheimer＇s disease （AD）. Since these secretases mediate proteolytic processing of numerous proteins, little success has been achieved to treat AD by secretase inhibitors because of inevitable undesired side effects. Thus, it is of importance to unravel the regulatory mechanisms of these secretases. Here, we show that δ-opioid receptor （DOR） promotes the processing of Aβ precursor protein （APP） by BACE1 and γ-secretase, but not that of Notch, N-cadherin or APLP. Further investigation reveals that DOR forms a complex with BACE1 and γ-seeretase, and activation of DOR mediates the co-endocytic sorting of the secretases/ receptor complex for APP endoproteolysis. Dysfunction of the receptor retards the endocytosis of BACE1 and γ-secretase and thus the production of Aβ Consistently, knockdown or antagonization of DOR reduces secretase activities and ameliorates Aβ pathology and Aβ-dependent behavioral deficits, but does not affect the processing of Notch, N-cadherin or APLP in AD model mice. Our study not only uncovers a molecular mechanism for the formation of a DOR/secretase complex that regulates the specificity of secretase for Aβ production but also suggests that intervention of either formation or trafficking of the GPCR/secretase complex could lead to a new strategy against AD, potentially with fewer side effects.

Clinical application of dip-assisted endoscopic method for nasoenteric feeding in patients with gastroparesis and gastroesophageal wounds

AIM: To report the clinical experiences in the application of clip-assisted endoscopic method for nasoenteric feeding in patients with gastroparesis and patients with gastroesophageal wounds, and to compare the efficacy of nasoenteric feeding in these two indications. METHODS: From April 2002 to January 2004,21 consecutive patients with gastroparesis or gastroesophageal wounds were enrolled and received nasoenteric feeding for nutritional support. A clip-assisted method was used to place the nasoenteric tubes. Outcomes in the two groups were compared with respect to the successful rate of enteral feeding, percentage of recommended energy intake (REI), and complication rates. RESULTS: The gastroparesis group included 13 patients with major burns (n = 7), trauma (n = 2), congestive heart failure (n = 2) and post-surgery gastric stasis syndrome (n = 2). The esophageogastric wound group included eight patients with tracheoesophageal fistula (n = 2) and wound leakage following gastric surgery (n = 6). Two study groups were similar in feeding successful rates (84.6% vs 75.0%). There were also no differences in the percentage of REI between groups (79.4% vs 78.6%). Additionally, no complications occurred in any of the study groups. CONCLUSION: Nasoenteric feeding is a useful method to provide nutritional support to most of the patients with gastroparesis who cannot tolerate nasogastric tube feeding and to the cases who need bypass feeding for esophageogastric wounds.

The angiotensin Ⅱ type 1 receptor and receptor-associated proteins

The mechanisms of regulation, activation and signal transduction of the angiotensin II (Ang II) type 1 (AT1) receptor have been studied extensively in the decade after its cloning. The AT1 receptor is a major component of the renin-angiotensin system (RAS). It mediates the classical biological actions of Ang II. Among the structures required for regulation and activation of the receptor, its carboxyl- terminal region plays crucial roles in receptor internalization, desensitization and phosphorylation. The mechanisms involved in heterotrimeric G-protein coupling to the receptor, activation of the downstream signaling pathway by G proteins and the Ang II signal transduction pathways leading to specific cellular responses are discussed. In addition, recent work on the identification and characterization of novel proteins associated with carboxy1-terminus of the AT1 receptor is presented. These novel proteins will advance our understanding of how the receptor is internalized and recycled as they provide molecular mechanisms for the activation and regulation of G-protein-coupled receptors.

Application of endoscopic hemoclips for nonvariceal bleeding in the upper gastrointestinal tract

AIM： To investigate acute nonvariceal bleeding in the upper gastrointestinal （GI） tract and evaluate the effects of endoscopic hemoclipping. METHODS： Sixty-eight cases of acute nonvariceal bleeding in the upper GI tract were given endoscopic treatment with hemoclip application. Clinical data, endoscopic findings, and the effects of the therapy were evaluated. RESULTS： The 68 cases （male：female = 42：26, age from 9 to 70 years, average 54.4） presented with hernatemesis in 26 cases （38.2%）, melena in nine cases （13.3%）, and both in 33 cases （48.5%）. The causes of the bleeding included gastric ulcer （29 cases）, duodenal ulcer （11 cases）, Dieulafoy＇s lesion （11 cases）, Mallory-Weiss syndrome （six cases）, post-operative （three cases）, post-polypectomy bleeding （five cases）, and post-sphincterotomy bleeding （three cases）; 42 cases had active bleeding. The mean number of hemoclips applied was four. Permanent hemostasis was obtained by hemoclip application in 59 cases; 6 cases required emergent surgery （three cases had peptic ulcers, one had Dieulafoy＇s lesion, and two were caused by sphincterotomy）; three patients died （two had Dieulafoy＇s lesion and one was caused by sphincterotomy）; and one had recurrent bleeding with Dieulafoy＇s lesion 10 mo later, but in a different location. CONCLUSION： Endoscopic hemoclip application was an effective and safe method for acute nonvariceal bleeding in the upper GI tract with satisfactory outcomes.

Endocytosis unplugged： multiple ways to enter the cell

Endocytosis occurs at the cell surface and involves internalization of the plasma membrane （PM） along with its constituent membrane proteins and lipids. Endocytosis is involved in sampling of the extracellular milieu and also serves to regulate various processes initiated at the cell surface. These include nutrient uptake, signaling from cell- surface receptors, and many other processes essential for cell and tissue functioning in metazoans. It is also central to the maintenance of PM lipid and protein homeostasis. There are multiple means of internalization that operate concurrently, at the cell surface. With advancement in high-resolution visualization techniques, it is now possible to track multiple endocytic cargo at the same time, revealing a remarkable diversity of endocytic processes in a single cell. A combination of live cell imaging and efficient genetic manipulations has also aided in understanding the functional hierarchy of molecular players in these mechanisms of internalization. Here we provide an account of various endocytic routes, their mechanisms of operation and occurrence across phyla.

Effects of Magnetic Needle Acupuncture on Blood Pressure and Plasma ET-1 Level in the Patient of Hypertension

Endothelin-1 (ET-1) is ever known as a bio-peptidewith the strongest vasoconstrictive action and withwide biological effects.

Peroral cholangioscopy in the new millennium

Peroral cholangioscopy was first described in 1970s and has recently gained popularity.Peroral cholangioscopy is appealing to therapeutic endoscopists because a direct intraluminal view of the biliary duct system offers possibilities for diagnosis and interventions beyond that which other imaging or endoscopic modalities can provide.As the image quality of cholangioscopies improves,so too does their diagnostic capability,and as their durability and maneuverability increases,so too does their potential use for therapeutic applications.This editorial is intended to provide a brief review of recent developments in peroral cholangioscopy and current indications for its use.

Membrane steroid-binding protein 1 （MSBP1） negatively regulates brassinosteroid signaling by enhancing the endocytosis of BAK1

Brassinosteroids （BRs） are perceived by transmembrane receptors and play vital roles in plant growth and development, as well as cell in responses to environmental stimuli. The transmemhrane receptor BRI1 can directly bind to brassinolide （BL）, and BAK1 interacts with BRI1 to enhance the BRI1-mediated BR signaling. Our previous studies indicated that a membrane steroid-binding protein 1 （MSBP1） could bind to BL in vitro and is negatively involved in BR signaling. To further elucidate the underlying mechanism, we here show that MSBPI specifically interacts with the extraeellular domain of BAK1 in vivo in a BL-independent manner. Suppressed cell expansion and BR responses by increased expression of MSBP1 can be recovered by overexpressing BAK1 or its intracellnlar kinase domain, sug- gesting that MSBP1 may suppress BR signaling through interacting with BAK1. Subcellular localization studies re- vealed that both MSBPI and BAK1 are localized to plasma membrane and endocytic vesicles and MSBP1 accelerates BAK1 endocytosis, which results in suppressed BR signaling by shifting the equilibrium of BAKI toward endosomes. Indeed, enhanced MSBP1 expression reduces the interaction between BRI1 and BAK1 in vivo, demonstrating that MSBP1 acts as a negative factor at an early step of the BR signaling pathway.

Abnormal endogenous pain modulation and somatic and visceral hypersensitivity in female patients with irritable bowel syndrome

AIM： To investigate the role of endogenous pain modulatory mechanisms in the central sensitization implicated by the visceral hypersensitivity demonstrated in patients with irritable bowel syndrome （IBS）. Dysfunction of modulatory mechanisms would be expected to also result in changes of somatic sensory function. METHODS： Endogenous pain modulatory mechanisms were assessed using heterotopic stimulation and somatic and visceral sensory testing in IBS. Pain intensities （visual analogue scale, VAS 0-100） during suprathreshold rectal distension with a barostat, cold pressor stimulation of the foot and during both stimuli simultaneously （heterotopic stimulation） were recorded in 40 female patients with IBS and 20 female healthy controls. RESULTS： Rectal hypersensitivity （defined by 95% Cl of controls） was seen in 21 （53%）, somatic hypersensitivity in 22 （55%） and both rectal and somatic hypersensitivity in 14 of these IBS patients. Heterotopic stimulation decreased rectal pain intensity by 6 （-11 to -1） in controls, but increased rectal pain by 2 （-3 to ＋6） in all IBS patients （P 〈 0.05） and by 8 （-2 to ＋19） in IBS patients with somatic and visceral hypersensitivity （P 〈 0.02）. CONCLUSION： A majority of IBS patients had abnormal endogenous pain modulation and somatic hypersensitivity as evidence of central sensitization.

Endocytosis of adiponectin receptor I through a clathrin- and Rab5-dependent pathway

In eukaryotic cells, receptor endocytosis is a key event regulating signaling transduction. Adiponectin receptors belong to a new receptor family that is distinct from G-protein-coupled receptors and has critical roles in the pathogenesis of diabetes and metabolic syndrome. Here, we analyzed the endocytosis of adiponectin and adiponectin receptor 1 （AdipoR1） and found that they are both internalized into transferrin-positive compartments that follow similar traffic routes. Blocking clathrin-mediated endocytosis by expressing Eps15 mutants or depleting K^＋ trapped AdipoR1 at the plasma membrane, and K^＋ depletion abolished adiponectin internalization, indicating that the endocytosis of AdipoR1 and adiponectin is clathrin-dependent. Depletion of K^＋ and overexpression of Eps15 mutants enhance adiponectin- stimulated AMP-activated protein kinase phosphorylation, suggesting that the endocytosis of AdipoR1 might down-regulate adiponectin signaling. In addition, AdipoR1 colocalizes with the small GTPase Rab5, and a dominant negative Rab5 abrogates AdipoR1 endocytosis. These data indicate that AdipoR1 is internalized through a clathrin- and Rab5- dependent pathway and that endocytosis may play a role in the regulation of adiponectin signaling.

Endocytosis of FcαR is clathrin and dynamin dependent, but its cytoplasmic domain is not required

FcαR, the Fc receptor for IgA, is essential for IgA-mediated immune responses. Previous studies have shown that IgA and IgA immune complexes can be rapidly endocytosed by FcαR. However, the underlying mechanism remains unclear. Here, we investigated the endocytic pathway of FcαR in monocytic cell line, U937, that naturally express FcuR and in transfected Chinese hamster ovary （CHO）, COS-7 and Hela cells. By using selective chemical inhibitors of different endocytic pathways, overexpression of dominant-negative mutants of Eps15 and knockdown of clathrin heavy chain （CHC） via RNA interference, we demonstrated that endocytosis of FcaR was through a clathrin-mediated pathway. The endocytosed FcαR went into Rab5- and Rabll-positive endosomes. However, endocytosis of FcaR could not be blocked by a dominant-negative mutant of Rab5. We also demonstrated that endocytosis of FcαR was dynamin-dependent by overexpressing a dominant-negative mutant of dynamin. The potential endocytic motif for FcαR was also examined. Unexpectedly, we found that the entire cytoplasmic domain of FcaR was not required for the endocytic process of FcαR. We conclude that endocytosis of FcaR is clathrin- and dynamin-dependent, but is not regulated by RabS, and the endocytic motif is not located in the cytoplasmic domain of FcαR.

Inhibitory effect of antisense vascular endothelial growth factor RNA on the profile of hepatocellular carcinoma cell line in vitro and in vivo

AIM： To evaluate the effect of antisense vascular endothelial growth factor （VEGF） RNA （PCMV-FGEV） transfection on the profile of hepatocellular carcinoma （HCC） SMMC-7721 cells in vitro and in vivo.METHODS： SMMC-7721 cells were transfected with PCMV-FGEV antisense, PCMV-VEGF sense and empty vector plasmid encapsulated by lipofectamine as antisense group, sense group and control group respectively. The positive cell clones were selected with G418. The stable transfection and expression of VEGF in the cells were determined by RT-PCR and immunohistochemistry. Cell proliferation was observed by Mnassay. FACS analysis was used to determine the effect of PCMV-FGEV transfection on cell apoptosis. The growth of transfected cells in vivo was also observed in nude mice.RESULTS： VEGF expression was reduced in SMMC-7721 transfected with PCMV-FGEV, which was confirmed by RT-PCR and immunohistochemistry. No effect of PCMV- FGEV transfection was found on cell proliferation and cell apoptosis of SMMC-7721 in vitro. The growth of cells transfected with PCMV-FGEV was slow in nude mice and accompanied with obvious apoptosis. The latent time of tumors in the antisense group was 25.0 ：l： 1.8 d, which was longer than that in sense and control groups （F= 19.455, P〈 0.01）. The average tumor weight in antisense group （0.96 g±0.28 g） was the smallest among the three groups （F= 21.501, P〈 0.01）.CONCLUSION： The expression of VEGF can be inhibited by antisense PCMV-FGEV. Antisense PCMV-FGEV has no effect on cell proliferation and apoptosis of SMMC-7721 in vitro but can inhibit tumor growth and induce cell apoptosis in vivo.

Endocytic regulation of TGF-β signaling

Transforming growth factor-β （TGF-β） signaling is tightly regulated to ensure its proper physiological functions in different cells and tissues. Like other cell surface receptors, TGF-β receptors are internalized into the cell, and this process plays an important regulatory role in TGF-β signaling. It is well documented that TGF-β receptors are endocytosed via clathrin-coated vesicles as TGF-β endocytosis can be blocked by potassium depletion and the GTPasedeficient dynamin K44A mutant. TGF-β receptors may also enter cells via cholesterol-rich membrane microdomain lipid rafts/caveolae and are found in caveolin-l-positive vesicles. Although receptor endocytosis is not essential for TGF-β signaling, clathrin-mediated endocytosis has been shown to promote TGF-β-induced Smad activation and transcriptional responses. Lipid rafts/caveolae are widely regarded as signaling centers for G protein-coupled recep- tors and tyrosine kinase receptors, but they are indicated to facilitate the degradation of TGF-β receptors and there- fore turnoff of TGF-β signaling. This review summarizes current understanding of TGF-β receptor endocytosis, the possible mechanisms underlying this process, and the role of endocytosis in modulation of TGF-β signaling.