Uniaxial strain-modulated conductivity in manganite superlattice (LaMnO₃/SrMnO₃)

Author name used in this publication: Hai-Tao Huang2010-2011 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

A New Euler's Formula for DNA Polyhedra

DNA polyhedra are cage-like architectures based on interlocked and interlinked DNA strands. We propose a formula which unites the basic features of these entangled structures. It is based on the transformation of the DNA polyhedral links into Seifert surfaces, which removes all knots. The numbers of components , of crossings , and of Seifert circles are related by a simple and elegant formula: . This formula connects the topological aspects of the DNA cage to the Euler characteristic of the underlying polyhedron. It implies that Seifert circles can be used as effective topological indices to describe polyhedral links. Our study demonstrates that, the new Euler's formula provides a theoretical framework for the stereo-chemistry of DNA polyhedra, which can characterize enzymatic transformations of DNA and be used to characterize and design novel cages with higher genus

Récupération d'images GIF dans un environnement de cloud computing

International audienceGIF images have been used in the last years, especially on social media. Here it is explored a content-based image retrieval system to work specifically with GIF file format. Its implementation is extended to a cloud computing environment. Given the Tumblr GIF dataset, it is created a "search by example" image retrieval system. To describe the images, low-level features are used: (1) color, (2) texture and (3) shape. The system performs the search using just GIF images as query images. To obtain faster results on the retrieval process, a hashing indexing approach is used. The system showed a complexity of O(n 2) for indexing and O(log(n)) for retrieval. Additionally, better results were obtained (in relation to precision and recall) for simple images, instead of images with a lot of movements.Les images GIF ont été utilisées au cours des dernières années, en particulier sur les médias sociaux. Ici, nous explorons un système de récupération d’images basé sur le contenu pour travailler spécifiquement avec le format de fichier GIF. Son implémentation est étendue à un environnement informatique en nuage. Étant donné le jeu de données Tumblr GIF, il est créé un système de récupération d'image "recherche par exemple". Pour décrire les images, les caractéristiques de bas niveau sont utilisées: (1) couleur, (2) texture et (3) forme. Le système effectue la recherche en utilisant uniquement des images GIF en tant qu'images de requête. Pour obtenir des résultats plus rapides sur le processus de récupération, une approche d'indexation de hachage est utilisée. Le système a montré une complexité de O (n 2) pour l'indexation et de O (log (n)) pour la récupération. De plus, de meilleurs résultats ont été obtenus (en ce qui concerne la précision et le rappel) pour des images simples, au lieu d’images avec beaucoup de mouvements

Improving corporate governance in state-owned corporations in China: which way forward?

This article discusses corporate governance in China. It outlines the basic agency problem in Chinese listed companies and questions the effectiveness of the current mechanisms employed to improve their standards of governance. Importantly, it considers alternative means through which corporate practice in China can be brought into line with international expectations and stresses the urgency with which this task must be tackled. It concludes that regulators in China must construct a corporate governance model which is compatible with its domestic setting and not rush to adopt governance initiatives modelled on those in cultures which are fundamentally different in the hope of also reproducing their success

Magnetoelectric interaction and transport behaviours in magnetic nanocomposite thermoelectric materials

How to suppress the performance deterioration of thermoelectric materials in the intrinsic excitation region remains a key challenge. The magnetic transition of permanent magnet nanoparticles from ferromagnetism to paramagnetism provides an effective approach to finding the solution to this challenge. Here, we have designed and prepared magnetic nanocomposite thermoelectric materials consisting of BaFe12O19 nanoparticles and Ba0.3In0.3Co4Sb12 matrix. It was found that the electrical transport behaviours of the nanocomposites are controlled by the magnetic transition of BaFe12O19 nanoparticles from ferromagnetism to paramagnetism. BaFe12O19 nanoparticles trap electrons below the Curie temperature (TC) and release the trapped electrons above the TC, playing an ‘electron repository’ role in maintaining high figure of merit ZT. BaFe12O19 nanoparticles produce two types of magnetoelectric effect—electron spiral motion and magnon-drag thermopower—as well as enhancing phonon scattering. Our work demonstrates that the performance deterioration of thermoelectric materials in the intrinsic excitation region can be suppressed through the magnetic transition of permanent magnet nanoparticles

Smoking, cessation and expenditure in low income Chinese: cross sectional survey

BACKGROUND: This study was carried-out to explore smoking behaviour and smoking expenditure among low income workers in Eastern China to inform tobacco control policy. METHODS: A self-completion questionnaire was administered to 1958 urban workers, 1909 rural workers and 3248 migrant workers in Zhejiang Province, Eastern China in 2004. RESULTS: Overall 54% of the men and 1.8% of all women were current smokers (at least 1 cigarette per day). Smoking was least common in migrant men (51%), compared with 58% of urban workers and 64% rural inhabitants (P < 0.0001). Forty-nine percent of rural males smoke more than 10 cigarettes/day, and 22% over 20/day. The prevalence of smoking increased with age. Overall 9% of the males had successfully quit smoking. Reasons for quitting were to prevent future illness (58%), current illness (31%), family pressures (20%) and financial considerations (20%). Thirteen percent of current smokers had ever tried to quit (cessation for at least one week) while 22% intended to quit, with migrants most likely to intend to quit. Almost all (96%) were aware that smoking was harmful to health, though only 25% were aware of the dangers of passive smoking. A mean of 11% of personal monthly income is spent on smoking rising to a mean of 15.4% in rural smokers. This expenditure was found to have major opportunity costs, including in terms of healthcare access. CONCLUSION: The prevalence of smoking and successful quitting suggest that smoking prevalence in low income groups in Eastern China may have peaked. Tobacco control should focus on support for quitters, on workplace/public place smoking restrictions and should develop specific programmes in rural areas. Health education messages should emphasise the opportunity costs of smoking and the dangers of passive smoking

Nel positively regulates the genesis of retinal ganglion cells by promoting their differentiation and survival during development

Peer reviewedPublisher PD

Mapping Dynamic Histone Acetylation Patterns to Gene Expression in Nanog-depleted Murine Embryonic Stem Cells

Embryonic stem cells (ESC) have the potential to self-renew indefinitely and to differentiate into any of the three germ layers. The molecular mechanisms for self-renewal, maintenance of pluripotency and lineage specification are poorly understood, but recent results point to a key role for epigenetic mechanisms. In this study, we focus on quantifying the impact of histone 3 acetylation (H3K9,14ac) on gene expression in murine embryonic stem cells. We analyze genome-wide histone acetylation patterns and gene expression profiles measured over the first five days of cell differentiation triggered by silencing Nanog, a key transcription factor in ESC regulation. We explore the temporal and spatial dynamics of histone acetylation data and its correlation with gene expression using supervised and unsupervised statistical models. On a genome-wide scale, changes in acetylation are significantly correlated to changes in mRNA expression and, surprisingly, this coherence increases over time. We quantify the predictive power of histone acetylation for gene expression changes in a balanced cross-validation procedure. In an in-depth study we focus on genes central to the regulatory network of Mouse ESC, including those identified in a recent genome-wide RNAi screen and in the PluriNet, a computationally derived stem cell signature. We find that compared to the rest of the genome, ESC-specific genes show significantly more acetylation signal and a much stronger decrease in acetylation over time, which is often not reflected in an concordant expression change. These results shed light on the complexity of the relationship between histone acetylation and gene expression and are a step forward to dissect the multilayer regulatory mechanisms that determine stem cell fate.Comment: accepted at PLoS Computational Biolog

CRPV Genomes with Synonymous Codon Optimizations in the CRPV E7 Gene Show Phenotypic Differences in Growth and Altered Immunity upon E7 Vaccination

Papillomaviruses use rare codons relative to their hosts. Recent studies have demonstrated that synonymous codon changes in viral genes can lead to increased protein production when the codons are matched to those of cells in which the protein is being expressed. We theorized that the immunogenicity of the virus would be enhanced by matching codons of selected viral genes to those of the host. We report here that synonymous codon changes in the E7 oncogene are tolerated in the context of the cottontail rabbit papillomavirus (CRPV) genome. Papilloma growth rates differ depending upon the changes made indicating that synonymous codons are not necessarily neutral. Immunization with wild type E7 DNA yielded significant protection from subsequent challenge by both wild type and codon-modified genomes. The reduction in growth was most dramatic with the genome containing the greatest number of synonymous codon changes

Factors related with the university degree selection in Spanish public university system. An structural equation model analysis

The final publication is available at Springer via http://dx.doi.org/10.1007/s11135-014-0008-9Students take into account different factors in their choice of university studies and college. Some are global, as the quality of the degree (ratio available places/firstchoice places in, cut-off grade, etc.), and others are subjective factors (e.g.: my friends are also taking this degree). In this work we present a partial multivariate model that takes into account the weight of the different variables shown by different works linked to this decision. We have studied three samples (n = 372 from the Universidad Pablo de Olavide; n = 2,244 from the Universitat Politécnica de Valencia, and n = 543 from the Universitat de Barcelona) from several degrees in the 2010 2011 and 2011 2012 academic years, all of them new students, coming from high school, and who had choosen these universities as first choice. The global effect shows that the structural model fits reasonably well in the three universities studied. Similarly, university and specialty models show different intensity effects, and we found that, in the case of Universitat Politécnica de Valencia (UPV) and Universitat de Barcelona (UB), they show higher intensity than in Universidad Pablo de Olavide (UPO). This makes us think that in most urban universities with a clear and regular offer of degrees (engineering in the case of UPV, and Health and Social Sciences in the case of UB), personal and social factors are more important than in the case of universities, as is the case of UPO, with an offer and dimension not yet completely defined.Guàrdia Olmos, J.; Peró Cebollero, M.; Hervás Jorge, A.; Capilla Lladró, R.; Soriano Jiménez, PP.; Porras Yañez, M. (2014). Factors related with the university degree selection in Spanish public university system. An structural equation model analysis. Quality and Quantity. 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