4,716 research outputs found

    Making ways for 'better education': Placing the Shenzhen-Hong Kong mobility industry

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    Tens of thousands of children living on Mainland China cross the border between Shenzhen and Hong Kong for a ‘better education’ every day. A well-oiled industry is in place to manage, facilitate and control this education mobility field. It involves schools, diverse businesses and non-governmental organisations that, in articulation with the Chinese and Hong Kong states, stimulate and regulate the movement of people, materialities, ideas and practices. Drawing on our fieldwork and media analysis, this paper unpacks the transurban mobility industry to illustrate the role of the various players and how they work in conjunction to facilitate cross-border schooling, especially among the very young children. We map out and visualise with photos the workings of the schools, buses, escorts, tutoring centres, day care and boarding houses. We show how the mobility industry, intersecting with other business networks and mobility systems, links Shenzhen and Hong Kong, taking and making places in these cities, especially in the border region. Our paper illustrates the role of this mobility industry in the making of the political-economy and socio-culture of the border area, which constantly connects, divides and redefines the two cities and regions it bridges. We end with some reflections on the implications of the recent political challenges and COVID-19 pandemic on this cross-border education mobility system

    The influences of phytohormones on triacylglycerol accumulation in an oleaginous marine diatom Phaeodactylum tricornutum

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    Environmental stresses such as nitrate deprivation and high light are effective at increasing lipid content in microalgae, but they can also slow down and even stop growth. In this study, the phytohormones methyl jasmonate, salicylic acid, gibberellin, abscisic acid, and ethephon were introduced to cultures of the oleaginous marine diatom Phaeodactylum tricornutum in an attempt to increase growth and lipid production. Single-factor experiments showed that the influences of some of the phytohormones were closely related to their concentrations. Methyl jasmonate, abscisic acid, and salicylic acid promoted P. tricornutum growth and lipid accumulation at certain concentrations. The differing effects of the three phytohormones on P. tricornutum may be related to the respective phytohormone's responsive cis-regulatory elements in the upstream regions of the triacylglycerol (TAG) synthesis genes. Methyl jasmonate, abscisic acid, and salicylic acid were further studied in response surface experiments, through which a 141% increase in TAG production was attained for 10-L cultures of P. tricornutum grown under optimal conditions. This study suggests that some phytohormones can promote P. tricornutum lipid accumulation without hindering growth. It also provides another strategy for improving the production of microalgae for use as biodiesel

    Exploiting Chordality in Optimization Algorithms for Model Predictive Control

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    In this chapter we show that chordal structure can be used to devise efficient optimization methods for many common model predictive control problems. The chordal structure is used both for computing search directions efficiently as well as for distributing all the other computations in an interior-point method for solving the problem. The chordal structure can stem both from the sequential nature of the problem as well as from distributed formulations of the problem related to scenario trees or other formulations. The framework enables efficient parallel computations.Comment: arXiv admin note: text overlap with arXiv:1502.0638

    Loss of heterozygosity in multistage carcinogenesis of esophageal carcinoma at high-incidence area in Henan Province, China

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    Aim: Microsatellites are the repeated DNA sequences scattered widely within the genomes and closely linked with many important genes. This study was designed to characterize the changes of microsatellite DNA loss of heterozygosity (LOH) in esophageal carcinogenesis. Methods: Allelic deletions in 32 cases of matched precancerous, cancerous and normal tissues were examined by syringe microdissection under an anatomic microscope and microsatellite polymorphism analysis using 15 polymorphic markers on chromosomes 3p, 5q, 6p, 9p, 13q, 17p, 17q and 18q. Results: Microsatellite DNA LOH was observed in precancerous and cancerous tissues, except D9S1752. The rate of LOH increased remarkably with the lesions progressed from basal cell hyperplasia (BCH) to squamous cell carcinoma (SCC) (P60%). LOH loci were different in precancerous and cancerous tissues. LOH in D3S1234 and TP53 was the common event in different lesions from the same patients. Conclusion: Microsatellite DNA LOH occurs in early stage of human esophageal carcinogenesis, even in BCH. With the lesion progressed, gene instability increases, the accumulation of this change may be one of the important mechanisms driving precancerous lesions to cancer. © 2005 The WJG Press and Elsevier Inc. All rights reserved.published_or_final_versio

    Characteristics of Sediment Bacterial Community in Response to Environmental Impacts in a Sewage Polluted River

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    The Jiaolai River is the main source of industrial and irrigation water for its catchment of 3900 km(2). Anthropogenic activities have caused heavy pollution of this river, but their impacts on biota have never been evaluated. In this study, molecular techniques were applied to investigate the impacts of environmental pollution on the river. Quantitative PCR revealed that total bacterial abundance ranged from 2.90x10(7) to 2.12x10(8) copies/g, with no significant differences among sampling sites or seasons. Bacterial abundance and pore water ammonium concentration were negatively correlated. Cluster analysis revealed that bacterial communities were mainly distributed into groups corresponding to nitrate concentration. Two clone libraries were constructed to compare the bacterial composition of samples with high (J308) and moderate (J304) nitrate impact. Sample J308 was characterized by more members in Clostridia and disappearance of Betaproteobacteria members, which are the primary contributors to nitrogen biogeochemical cycling. Bacterial communities in the sediment were clearly differentiated by environmental nitrogen pollution, suggesting that nitrogen eutrophication was the main environmental problem influencing the Jiaolai River

    Spherical montmorillonite-supported nano-silver as a self-sedimentary catalyst for methylene blue removal

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    Supported metal nanoparticles using various substrates have been proven as a highly efficient approach for solving the problems of aggregation and recyclability of metal nanoparticles. However, the reusability procedure often involved the abundant devices, which obviously increased the cost and heavily limited the large-scale application of metal nanoparticles. In this work, spherical montmorillonite was used firstly as the substrate for supporting silver nanoparticles on its surface through polydopamine chemistry method. The loading of silver nanoparticles with 40 nm in diameter was 15.2 wt% and the specific surface area of this prepared spherical montmorillonite supported silver nanoparticles catalyst was 45.3 m(2)/g, giving the catalyst an optimized apparent reduction rate constant k of 1.22 min(-1) for the reduction of methylene blue. Furthermore, the prepared catalyst with quickly self-sedimentary property in aqueous solution were conveniently recovered and reused without any devices involves. The spherical morphology and catalytic performance of prepared catalyst were almost unaltered after 5 cycles. Our research aims at opening a new avenue to easily realize the reusability of silver nanoparticles through using the substrate with the self-sedimentary property

    The microaerophilic microbiota of de-novo paediatric inflammatory bowel disease: the BISCUIT study

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    <p>Introduction: Children presenting for the first time with inflammatory bowel disease (IBD) offer a unique opportunity to study aetiological agents before the confounders of treatment. Microaerophilic bacteria can exploit the ecological niche of the intestinal epithelium; Helicobacter and Campylobacter are previously implicated in IBD pathogenesis. We set out to study these and other microaerophilic bacteria in de-novo paediatric IBD.</p> <p>Patients and Methods: 100 children undergoing colonoscopy were recruited including 44 treatment naïve de-novo IBD patients and 42 with normal colons. Colonic biopsies were subjected to microaerophilic culture with Gram-negative isolates then identified by sequencing. Biopsies were also PCR screened for the specific microaerophilic bacterial groups: Helicobacteraceae, Campylobacteraceae and Sutterella wadsworthensis.</p> <p>Results: 129 Gram-negative microaerophilic bacterial isolates were identified from 10 genera. The most frequently cultured was S. wadsworthensis (32 distinct isolates). Unusual Campylobacter were isolated from 8 subjects (including 3 C. concisus, 1 C. curvus, 1 C. lari, 1 C. rectus, 3 C. showae). No Helicobacter were cultured. When comparing IBD vs. normal colon control by PCR the prevalence figures were not significantly different (Helicobacter 11% vs. 12%, p = 1.00; Campylobacter 75% vs. 76%, p = 1.00; S. wadsworthensis 82% vs. 71%, p = 0.312).</p> <p>Conclusions: This study offers a comprehensive overview of the microaerophilic microbiota of the paediatric colon including at IBD onset. Campylobacter appear to be surprisingly common, are not more strongly associated with IBD and can be isolated from around 8% of paediatric colonic biopsies. S. wadsworthensis appears to be a common commensal. Helicobacter species are relatively rare in the paediatric colon.</p&gt

    Intraflagellar Transport (IFT) Protein IFT25 Is a Phosphoprotein Component of IFT Complex B and Physically Interacts with IFT27 in Chlamydomonas

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    BACKGROUND: Intraflagellar transport (IFT) is the bidirectional movement of IFT particles between the cell body and the distal tip of a flagellum. Organized into complexes A and B, IFT particles are composed of at least 18 proteins. The function of IFT proteins in flagellar assembly has been extensively investigated. However, much less is known about the molecular mechanism of how IFT is regulated. METHODOLOGY/PRINCIPAL FINDINGS: We herein report the identification of a novel IFT particle protein, IFT25, in Chlamydomonas. Dephosphorylation assay revealed that IFT25 is a phosphoprotein. Biochemical analysis of temperature sensitive IFT mutants indicated that IFT25 is an IFT complex B subunit. In vitro binding assay confirmed that IFT25 binds to IFT27, a Rab-like small GTPase component of the IFT complex B. Immunofluorescence staining showed that IFT25 has a punctuate flagellar distribution as expected for an IFT protein, but displays a unique distribution pattern at the flagellar base. IFT25 co-localizes with IFT27 at the distal-most portion of basal bodies, probably the transition zones, and concentrates in the basal body region by partially overlapping with other IFT complex B subunits, such as IFT46. Sucrose density gradient centrifugation analysis demonstrated that, in flagella, the majority of IFT27 and IFT25 including both phosphorylated and non-phosphorylated forms are cosedimented with other complex B subunits in the 16S fractions. In contrast, in cell body, only a fraction of IFT25 and IFT27 is integrated into the preassembled complex B, and IFT25 detected in complex B is preferentially phosphorylated. CONCLUSION/SIGNIFICANCE: IFT25 is a phosphoprotein component of IFT particle complex B. IFT25 directly interacts with IFT27, and these two proteins likely form a subcomplex in vivo. We postulate that the association and disassociation between the subcomplex of IFT25 and IFT27 and complex B might be involved in the regulation of IFT
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