4,354 research outputs found

    The move to quality assurance in Chinese higher education: Tensions between policy and practices

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    This paper investigates quality assurance in Chinese higher education by looking at the Evaluation of the University Baccalaureate Programmes Project (EUBPP) conducted in China. It analyses factors that bring about tensions between policy and practice in this area through a study of two contrasting tertiary institutions. The results show that the aims of the EUBPP have been partly achieved through the interaction of policy-making and implementation. In the process, contextual factors connected to institutional status and stages of development have led to varying degrees of tension between policy and practices.published_or_final_versio

    Membrane fouling in a submerged membrane bioreactor (SMBR): Characterisation of the sludge cake and its high filtration resistance

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    The attachment of sludge cake to the membrane surface is the main cause of the fouling problem in the submerged membrane bioreactors (SMBR) used in biological wastewater treatment. In this laboratory study, the sludge cake deposited on the membrane was found to have a specific filtration resistance of the order of 1014 m/kg, which is much greater than expected for sludge cake formed during the dewatering of activated sludge. The filterability tests showed that the cake sludge removed from the fouled membrane of the SMBR had an average specific filtration resistance of 4.9 × 1013 m/kg, whereas the sludge cake of the SMBR bulk sludge had an average filtration resistance of only 1.9 × 1011 m/kg. Detailed chemical analysis showed there was a pool of biopolymer clusters (BPC) that was trapped within the sludge cake on the membrane. These clusters could be readily separated from the cake sludge by stirring it into a suspension. The abundance of non-filterable BPC as measured by the total organic carbon (TOC) in the suspended solids (SS) was about 10.3 mg/g SS for the cake sludge, in comparison to 0.4 mg/g SS for the bulk sludge. When the BPC were removed from the cake sludge, the filtration resistance of the cake sludge could be reduced considerably from 4.9 × 1013 to 8.4 × 1012 m/kg. It is argued that the BPC are a special form of organic matter formed by affinity clustering of the free extracellular polymeric substances (EPS) and soluble microbial products (SMP) in the sludge cake deposited on the membrane surface. The accumulation of BPC within the pores of the sludge cake is mostly responsible for the unusually high filtration resistance of the cake sludge during the SMBR operation. © 2006 Elsevier B.V. All rights reserved.postprin

    Generation of repetitive sequence-depleted microdissected chromosome arm painting probe

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    Program no. 897postprin

    Game-Theoretic Approach to Tourism Supply Chain Coordination under Demand Uncertainty For Package Holidays

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    Demand uncertainty is one of the most significant characteristics of the tourism industry. In a typical tourism supply chain (TSC) for package holidays, multiple tour operators reserve rooms from a hotel chain in advance according to their demand predictions. Discrepancies between demand predictions and actual demand lead to shortages or unused room reservations, which inevitably leads to reduced profits for the tour operators concerned. This article examines different TSC coordination strategies to determine how they can be used to help alleviate such negative effects. A game-theoretic approach is used to analyze the different coordination relationships between TSC players. Two coordination programs are discussed. The first is a horizontal coordination program in which tour operators exchange shortages or unused reservations with each other. The second is a vertical coordination program in which tour operators trade shortages or unused reservations with hotel chains. Game models are established and analyzed for the two coordination strategies and uncoordinated conditions, respectively. The analytical results suggest that both coordination strategies can be used to reduce the negative impacts of the demand uncertainty. The results also show that the horizontal coordination is preferred to the vertical coordination when the competition among tour operators is fierce.published_or_final_versio

    Fast-FISH using repeat sequence-depleted painting probes from microdissected DNA

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    Highly reproducible SERS substrate based on polarization-free Ag nanoparticles decorated SiO2/Si core-shell nanowires array

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    SiO2/Si core-shell nanowires array coated with gap-rich silver nanoparticles were demonstrated as a highly reproducible surface-enhanced Raman scattering (SERS) substrate. SERS detection of a relative standard deviation of 8% for 10−4 M R6G with a spot size of ∼2 μm and 900 spots over an area of 150 × 150 μm2 was reported. The high reproducibility is ascribed to the polarization-independent electrical field distribution among three-dimensional nanowire structure with an optimized thickness of SiO2 shell layer.published_or_final_versio

    Perforation resistance of aluminum/polyethylene sandwich structure

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    © 2016 Elsevier Ltd. Ballistic tests were performed on two types of polyethylene core sandwich structures (AA6082/LDPE/AA6082 and AA6082/UHMWPE/AA6082) to investigate their perforation resistance. Bulging and dishing deformation of layered plates were compared under low-velocity impact by hemispherical-nosed projectiles. Different impact failure mechanisms leading to perforation were revealed for laminates composed of a pair of aluminum alloy face sheets separated by a polyethylene interlayer. Using the finite element code Abaqus/Explicit, the perforation behavior and distribution of energy dissipation of each layer during penetration were simulated and analysed. The deformation resistance and anti-penetration properties of polyethylene core sandwich structures were compared with those of monolithic AA6082-T6 plates that had the same areal density. Although the polyethylene interlayer enlarged the plastic deformation zone of the back face, the polyethylene core sandwich structure was a little less effective than the monolithic Al alloy target at resisting hemispherical-nosed projectile impact.The authors gratefully acknowledge the Foundation of State Key Laboratory of Explosion Science and Technology of China under Grant No. KFJJ13-1Z, and Natural Science Foundation of China under Grant No. 11102023, 11172071

    Cerebellar defects in Pdss2 conditional knockout mice during embryonic development and in adulthood

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    PDSS2 is a gene that encodes one of the two subunits of trans-prenyl diphosphate synthase that is essential for ubiquinone biosynthesis. It is known that mutations in PDSS2 can cause primary ubiquinone deficiency in humans and a similar disease in mice. Cerebellum is the most often affected organ in ubiquinone deficiency, and cerebellar atrophy has been diagnosed in many infants with this disease. In this study, two Pdss2 conditional knockout mouse lines directed by Pax2-cre and Pcp2-cre were generated to investigate the effect of ubiquinone deficiency on cerebellum during embryonic development and in adulthood, respectively. The Pdss2 f/-; Pax2-cre mouse recapitulates some symptoms of ubiquinone deficiency in infants, including severe cerebellum hypoplasia and lipid accumulation in skeletal muscles at birth. During early cerebellum development (E12.5-14.5), Pdss2 knockout initially causes the delay of radial glial cell growth and neuron progenitor migration, so the growth of mutant cerebellum is retarded. During later development (E15.5-P0), increased ectopic apoptosis of neuroblasts and impaired cell proliferation result in the progression of cerebellum hypoplasia in the mutant. Thus, the mutant cerebellum contains fewer neurons at birth, and the cells are disorganized. The developmental defect of mutant cerebellum does not result from reduced Fgf8 expression before E12.5. Electron microscopy reveals mitochondrial defects and increased autophagic-like vacuolization that may arise in response to abnormal mitochondria in the mutant cerebellum. Nevertheless, the mutant mice die soon after birth probably due to cleft palate and micrognathia, which may result from Pdss2 knockout caused by ectopic Pax2-cre expression in the first branchial arch. On the other hand, the Pdss2 f/-; Pcp2-cre mouse is healthy at birth but gradually loses cerebellar Purkinje cells and develops ataxia-like symptoms at 9.5months; thus this conditional knockout mouse may serve as a model for ubiquinone deficiency in adult patients. In conclusion, this study provides two mouse models of Pdss2 based ubiquinone deficiency. During cerebellum development, Pdss2 knockout results in severe cerebellum hypoplasia by impairing cell migration and eliciting ectopic apoptosis, whereas Pdss2 knockout in Purkinje cells at postnatal stages leads to the development of cerebellar ataxia. © 2011 Elsevier Inc.postprin

    Clinical significance of CHD1L in hepatocellular carcinoma and therapeutic potentials of virus-mediated CHD1L depletion

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    Background: Hepatocellular carcinoma (HCC) is among the most lethal of human malignancies. It is difficult to detect early, has a high recurrence rate and is refractory to chemotherapies. Amplification of 1q21 is one of the most frequent genetic alterations in HCC. CHD1L is a newly identified oncogene responsible for 1q21 amplification. This study aims to investigate the role of CHD1L in predicting prognosis and chemotherapy response of patients with HCC, its chemoresistant mechanism and whether virus-mediated CHD1L silencing has therapeutic potentials for HCC treatment. Methods: The clinical significance of CHD1L in a cohort of 109 HCC cases including 50 cases who received transarterial chemoembolisation treatment was assessed by clinical correlation and Kaplan-Meier analyses. A CHD1L-overexpressing cell model was generated and the mechanism of chemoresistance involving CHD1L was investigated. An adenovirus-mediated silencing method was used to knockdown CHD1L, and its effects on tumorigenicity and chemoresistance were investigated in vivo and in vitro. Results: Overexpression of CHD1L was significantly associated with tumour microsatellite formation (p=0.045), advanced tumour stage (p=0.018), overall survival time (p=0.002), overall survival time of patients who received transarterial chemoembolisation treatment (p=0.028) and chemoresistance (p=0.020) in HCC. Interestingly, CHD1L could inhibit apoptosis induced by 5-fluorourail (5-FU) but not doxorubicin. The mechanistic study revealed that the involvement of the Nur77-mediated pathway in chemotherapeutic agent-induced apoptosis can dictate if CHD1L could confer resistance to chemotherapy. Furthermore, an adenoviral vector containing short hairpin RNAs against CHD1L (CHD1L-shRNAs) could suppress cell growth, clonogenicity and chemoresistance to 5-FU. An in vivo study found that CHD1L-shRNAs could inhibit xenograft tumour growth and increase the sensitivity of tumour cells to 5-FU in nude mice. Conclusions: This study highlighted for the first time the prognostic value of CHD1L in HCC and the potential application of virus-mediated CHD1L silencing in HCC treatment.published_or_final_versio
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