Minimum cycle cover and Chinese postman problems on mixed graphs with bounded tree-width

Let M = (V, E, A) be a mixed graph with vertex set V, edge set E and arc set A. A cycle cover of M is a family C = {C(1), ... , C(k)} of cycles of M such that each edge/arc of M belongs to at least one cycle in C. The weight of C is Sigma(k)(i=1) vertical bar C(i)vertical bar. The minimum cycle cover problem is the following: given a strongly connected mixed graph M without bridges, find a cycle cover of M with weight as small as possible. The Chinese postman problem is: given a strongly connected mixed graph M, find a minimum length closed walk using all edges and arcs of M. These problems are NP-hard. We show that they can be solved in polynomial time if M has bounded tree-width. (C) 2008 Elsevier B.V. All rights reserved.

Cytotoxic and genotoxic effects of tambjamine D, an alkaloid isolated from the nudibranch Tambja eliora, on Chinese hamster lung fibroblasts

Marine organisms have been shown to be potential sources of bioactive compounds with pharmaceutical applications. Previous chemical investigation of the nudibranch Tambja eliora led to the isolation of the alkaloid tambjamine D. Tambjamines have been isolated from marine sources and belong to the family of 4-methoxypyrrolic-derived natural products, which display promising immunosuppressive and cytotoxic properties. Their ability to intercalate DNA and their pro-oxidant activity may be related to some of the biological effects of the 4-methoxypyrrolic alkaloids. The aim of the present investigation was to determine the cytotoxic, pro-oxidant and genotoxic properties of tambjamine D in V79 Chinese hamster lung fibroblast cells. Tambjamine D displayed a potent cytotoxic effect in V79 cells (IC50 1.2 mu g/mL) evaluated by the MTT assay. Based on the MTT result, V79 cells were treated with different concentrations of tambjamine D (0.6. 1.2. 2.4 and 4.8 mu g/mL). After 24 h, tambjamine D reduced the number of viable cells in a concentration-dependent way at all concentrations tested. assessed by the trypan blue dye exclusion test. The hemolytic assay showed that the cytotoxic activity of tambjamine D was not related to membrane disruption (EC50 > 100 mu g/mL). Tambjamine D increased the number of apoptotic cells in a concentration-dependent manner at all concentrations tested according to acridine orange/ethidium bromide staining, showing that the alkaloid cytotoxic effect was related to the induction of apoptosis. MTT reduction was stimulated by tambjamine D, which may indicate the generation of reactive oxygen species. Accordingly, treatment of cells with tambjamine D increased nitrite/nitrate at all concentrations and TBARS production starting at the concentration corresponding to the IC50. Tambjamine D, also, induced DNA strand breaks and increased the micronucleus cell frequency as evaluated by comet and micronucleus tests, respectively, at all concentrations evaluated. showing a genotoxic risk induced by tambjamine D. (C) 2008 Elsevier Ireland Ltd. All rights reserved.

Chinese Basic Pension Substitution Rate: A Monte Carlo Demonstration of the Individual Account Model

At the end of 2005, the State Council of China passed ”The Decision on adjusting the Individual Account of Basic Pension System”, which adjusted the individual account in the 1997 basic pension system. In this essay, we will analyze the adjustment above, and use Life Annuity Actuarial Theory to establish the basic pension substitution rate model. Monte Carlo simulation is also used to prove the rationality of the model. Some suggestions are put forward associated with the substitution rate according to the current policy.

Cloud computing - Moving to the cloud

Cloud computing innebär användning av datorresurser som är tillgängliga via ett nätverk, oftast Internet och är ett område som har vuxit fram i snabb takt under de senaste åren. Allt fler företag migrerar hela eller delar av sin verksamhet till molnet. Sogeti i Borlänge har behov av att migrera sina utvecklingsmiljöer till en molntjänst då drift och underhåll av dessa är kostsamma och tidsödande. Som Microsoftpartners vill Sogeti använda Microsoft tjänst för cloud computing, Windows Azure, för detta syfte. Migration till molnet är ett nytt område för Sogeti och de har inga beskrivningar för hur en sådan process går till. Vårt uppdrag var att utveckla ett tillvägagångssätt för migration av en IT-lösning till molnet. En del av uppdraget blev då att kartlägga cloud computing, dess beståndsdelar samt vilka för- och nackdelar som finns, vilket har gjort att vi har fått grundläggande kunskap i ämnet. För att utveckla ett tillvägagångssätt för migration har vi utfört flera migrationer av virtuella maskiner till Windows Azure och utifrån dessa migrationer, litteraturstudier och intervjuer dragit slutsatser som mynnat ut i ett generellt tillvägagångssätt för migration till molnet. Resultatet har visat att det är svårt att göra en generell men samtidigt detaljerad beskrivning över ett tillvägagångssätt för migration, då scenariot ser olika ut beroende på vad som ska migreras och vilken typ av molntjänst som används. Vi har dock utifrån våra erfarenheter från våra migrationer, tillsammans med litteraturstudier, dokumentstudier och intervjuer lyft vår kunskap till en generell nivå. Från denna kunskap har vi sammanställt ett generellt tillvägagångssätt med större fokus på de förberedande aktiviteter som en organisation bör genomföra innan migration. Våra studier har även resulterat i en fördjupad beskrivning av cloud computing. I vår studie har vi inte sett att någon tidigare har beskrivit kritiska framgångsfaktorer i samband med cloud computing. I vårt empiriska arbete har vi dock identifierat tre kritiska framgångsfaktorer för cloud computing och i och med detta täckt upp en del av kunskapsgapet där emellan.

A Linguistic Analysis of the Written Production of Second Language Learners : The Variation of Article Usage by Adult Chinese Learners of English

This study aims to test Robertson’s lexical transfer principle, which posits that Chinese learners use demonstratives (particularly this) and the numeral one as markers of definiteness and indefiniteness. This is tested by analysing Chinese learners’ written production collected from the Spoken and Written English Corpus of Chinese Learners 2.0 (SWECCL 2.0). The purpose is to understand the variation of article usage by adult Chinese learners of English. More specifically, the study examines to what extent articles, possessive and demonstrative pronouns are used in Chinese learners’ English and how definite and indefinite articles are used by the Chinese learners. Findings suggest that Robertson’s lexical transfer principle was corroborated by the present study. In addition, Chinese learners prefer to use demonstrative determiners, the possessive determiner our, and the numeral one to perform the function of marking definiteness and indefiniteness. In particular, the learners try to use the demonstrative determiners that and this in the anaphoric function instead of the definite article, and the demonstrative determiner those is frequently used in the cataphoric function. What is more, the learners use the numeral one as a marker of indefiniteness, and it is also used as a marker of definiteness in the anaphoric function. Further, the possessive determiner our is used as a marker of definiteness in larger situation uses referring to something unique. To this end, the study is able to show that the definite article is used to perform the function of marking indefiniteness, and in some particular contexts the definite article functions as a Chinese specifier in Chinese learners’ English. Also, the indefinite article is frequently used in quantifier phrases but is rarely used in other functions. There are three main reasons that may explain why Chinese learners use determiners variously. Firstly, the choice of determiners by Chinese learners is influenced by linguistic contexts. Secondly, because of learning strategies, Chinese learners try to ignore the anaphoric function and cataphoric function that they are not yet ready to process in article usage. Thirdly, interlanguage grammar influences the optionality in the use of articles. 

Enhancing Intercultural Communication in Teaching Chinese as a Foreign Language : An Action Research Study

Enhancing Intercultural Communication in Teaching Chinese as a Foreign Language – An Action Research Study Over the past few decades, the rapid development of information communication technology, internationalization and globalization worldwide have required a shift in the focus of Chinese as a foreign language (CFL) towards competence in intercultural communication in which the role of culture in the acquisition of CFL and in the pragmatic use of the language is emphasized and promoted. However, most of the current research in this academic area remains only on a theoretical level. Practical examples, particularly with regard to distance learning/teaching of the Chinese language, are very limited. This motivated the implementation of an action research study which aimed at exploring the possibilities and limitations of integrating Chinese culture and applying intercultural communication theory into a contemporary distance CFL course for beginners. By observing and comparing the performance of subjects in the control and experimental groups, this action research study focuses on exploring three basic areas. Firstly, it discloses the cultural elements which underlie effective daily communication. Secondly, it investigates how students acquire cultural knowledge and develop their ability to competently communicate in the target course. And thirdly, it evaluates how the modified course syllabus could enhance students’ intercultural communicative competence. The findings of the research aim to serve as both a resource and reference for educators and researchers who are interested in carrying out reforms and research in this academic domain.