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Chrisoula Papazoglou Panagiotis G. Sarigiannidis Georgios I. Papadimitriou Andreas S. Pomportsis 《International Journal of Communication Systems》2010,23(2):187-203
In an optical burst switched network, variable‐sized data bursts are switched on the fly using bandwidth previously reserved by their control packets. A key problem in OBS networks is the assignment of wavelengths to incoming bursts, that is, the scheduling of bursts. This paper proposes a new class of burst scheduling algorithms based on a triangular estimator. The proposed tool reduces the complexity of the scheduling scheme (measured in channel checks) without compromising its performance (measured by the burst drop ratio). Simulation results demonstrate both the accuracy and the efficiency of the estimator in a variety of scenarios and under self‐similar network traffic. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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This research explores the design of practice toolkits as components, distinct from community management systems, allowing members of a virtual community to engage in the practice the community is about. Our analysis is informed by two case studies in different application domains each presenting alternative but complementary insights to the design of computer-mediated practice toolkits. The first case study describes how established practices in music performance are encapsulated in a suitably augmented music notation toolkit so as to support the learning objectives of virtual teams engaged in music master classes. The second case study presents experience with the development of a toolkit for engaging in the practice of vacation package assembly. This time the virtual team is a cross-organization virtual community of practice whose members streamline their efforts by internalizing and performing in accordance to a new (virtual) practice. Findings from the two studies reveal two distinct orientations in the design of practice toolkits. Specifically, in application domains where practices are well established (i.e., music performance), the toolkit serves as the medium for reconstructing an existing practice in virtual settings. In contrast, when cross-organization collaboration is involved (i.e., vacation package assembly), the toolkit should be designed so as to encapsulate a “meta”-practice, exhibiting both boundary and locality. 相似文献
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Chrisoula Tananaki Andreas Thrasyvoulou Emmanouel Karazafiris Anastasia Zotou 《Food Additives & Contaminants》2006,23(2):159-163
Greek honey was monitored during a three-year surveillance program for residues of chemicals used to protect honey-bee combs from wax-moth. A total of 115 samples purchased from stores (commercial samples) and 1060 samples collected from beekeepers (bulk samples) were analysed for 1,4-dichlorobenzene (p-DCB), 1,2-dibromoethane (DBE) and naphthalene. A purge & trap-gas chromatograph-mass spectrometer system was used for the analysis. During the first year of the study, 82.9% of the commercial samples had residues of p-DCB that exceeded the established limit of 10 microg kg(-1), whilst during the second year 53.6% and during the third 30% exceeded the limit. The percentage of beekeepers samples that had more than 10 microg kg(-1) decreased from 46.6 to 34.7% and 39.8% respectively during the three consecutive years of analysis. Only one commercial sample (0.8%) had residues of DBE that exceeded 10 microg kg(-1) during the three years study, while 9.9% of the beekeepers samples exceeded this limit in 2003. This percentage fell to 1.9 and 2.8% during the following years. Naphthalene was found in more commercial samples than in samples from beekeepers during the first year, but decreased to similar levels during the next two years. Honeys that are produced earlier in the season are more contaminated those produced later. 相似文献
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Pipili C Grapsa E Koutsobasili A Sorvinou P Poirazlar E Kiosses D Xatzigeorgiou G 《Hemodialysis international. International Symposium on Home Hemodialysis》2011,15(3):306-311
An increasing number of successful pregnancies have been reported among women on chronic hemodialysis. Even with reduced fertility and high risk of complications, women of childbearing age receiving hemodialysis, should not be discouraged from pregnancy. Practitioners should be familiar with the effects of renal disease on pregnancy, consult patients about the possibility of pregnancy and its hazards and provide, if necessary, prompt surveillance and treatment. This paper describes the case of an unplanned but successful pregnancy of a woman receiving hemodialysis, emphasizing pregnancy management, mother's response evaluation, and infant growth. 相似文献
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Voula Alexandraki Marina Georgalaki Konstantinos Papadimitriou Rania Anastasiou Georgia Zoumpopoulou Iordanis Chatzipavlidis Marina Papadelli Nikos Vallis Kostas Moschochoritis Effie Tsakalidou 《LWT》2014
Maslinic and oleanolic acids are among the most abundant triterpenic acids found in olive fruits. Both acids are considered to be important bioactive compounds which can confer multiple beneficial health effects to the consumer. In the present work, we have monitored and quantified maslinic and oleanolic acids throughout processing in alkaline-treated green olives (Spanish-style) and in natural green olives of the Conservolea variety that is particularly popular in Greece. Our findings clearly demonstrate that the fast de-bittering process with NaOH treatment in Spanish-style olives has a profound negative effect on the concentration of both acids. This decrease of concentration was more prominent regarding maslinic acid when compared to oleanolic acid. In contrast, the slow de-bittering during natural fermentation of green olives had no effect on the content of maslinic or oleanolic acid. To verify the broad applicability of our observation we have also looked into the natural processing of the Kalamon variety (Greek-style). Our findings were consistent, since once again, natural fermentation did not influence the concentration of both acids. 相似文献
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Georgakopoulos T Koutroubas G Vakonakis I Tzermia M Prokova V Voutsina A Alexandraki D 《Yeast (Chichester, England)》2001,18(12):1155-1171
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Purpose: To investigate the anti-cancer, chemosensitizing and/or immunomodulating effects of decitabine (DAC) to be used as a potential therapeutic agent for the treatment of cervical cancer (CC). Methods: Cervical cancer cell lines were treated with low doses of DAC treatment used as a single agent or in combination with chemotherapy. End-point in vitro assays were developed as indicators of the anti-cancer and/or immunomodulating effects of DAC treatment in CC cells. These assays include cell viability, cell cycle analysis, apoptosis, induction of a viral-mimicry response pathway, expression of MHC-class I and PD-L1 and chemosensitivity. Results: High and low doses of DAC treatment induced reduction in cell viability in HeLa (HPV18+), CaSki (HPV16+) and C33A (HPV−) cells. Specifically, a time-dependent reduction in cell viability of HeLa and CaSki cells was observed accompanied by robust cell cycle arrest at G2/M phase and alterations in the cell cycle distribution. Decrease in cell viability was also observed in a non-transformed immortal keratinocyte (HaCat) suggesting a non-cancer specific target effect. DAC treatment also triggered a viral mimicry response through long-term induction of cytoplasmic double-stranded RNA (dsRNA) and activation of downstream IFN-related genes in both HPV+ and HPV− cells. In addition, DAC treatment increased the number of CC cells expressing MHC-class I and PD-L1. Furthermore, DAC significantly increased the proportion of early and late apoptotic CC cells quantified using FACS. Our combination treatments showed that low dose DAC treatment sensitizes cells to chemotherapy. Conclusions: Low doses of DAC treatment promotes robust induction of a viral mimicry response, immunomodulating and chemosensitizing effects in CC, indicating its promising therapeutic role in CC in vitro. 相似文献
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We report the entire sequence of a 26·4 kb segment of chromosome XI of Saccharomyces cerevisiae. Identification of the known loci URA1, TRP3 and SAC1 revealed a translocation compared to the genetic map. Additionally, six unknown open reading frames have been identified. One of them is similar to catabolic threonine dehydratases. Another one contains characteristic features of membrane transporters. A third one is homologous in half of its length to the prokaryotic hydantoinase HyuA and in the other half to hydatoinase HyuB. A fourth one is homologous to the mammalian phospholipase A2-activating protein. A fifth one, finally, is homologous to the hypothetical open reading frame YCR007C of chromosome III. The sequence has been deposited in the EMBL data library under Accession Number X75951. 相似文献