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51.
Eirini Giannakidou Vassiliki Koutsonikola Athena Vakali Ioannis Kompatsiaris 《Journal of Intelligent Information Systems》2012,38(3):685-708
The common ground behind most approaches that analyze social tagging systems is addressing the information challenge that emerges from the massive activity of millions of users who interact and share resources and/or metadata online. However, lack of any time-related data in the analysis process implicitly denies much of the dynamic nature of social tagging activity. In this paper we claim that holding a temporal dimension, allows for tracking macroscopic and microscopic users’ interests, detecting emerging trends and recognizing events. To this end, we propose a time-aware co-clustering approach for acquiring semantic and temporal patterns out of the tagging activity. The resulted clusters contain both users and tags of similar patterns over time, and reveal non-obvious or “hidden” relations among users and topics of their common interest. Zoom in & out views serve as visualization methods on different aspects of the clusters’ structure, in order to evaluate the efficiency of the approach. 相似文献
52.
Eirini Kalliamvakou Georgios Gousios Kelly Blincoe Leif Singer Daniel M. German Daniela Damian 《Empirical Software Engineering》2016,21(5):2035-2071
With over 10 million git repositories, GitHub is becoming one of the most important sources of software artifacts on the Internet. Researchers mine the information stored in GitHub’s event logs to understand how its users employ the site to collaborate on software, but so far there have been no studies describing the quality and properties of the available GitHub data. We document the results of an empirical study aimed at understanding the characteristics of the repositories and users in GitHub; we see how users take advantage of GitHub’s main features and how their activity is tracked on GitHub and related datasets to point out misalignment between the real and mined data. Our results indicate that while GitHub is a rich source of data on software development, mining GitHub for research purposes should take various potential perils into consideration. For example, we show that the majority of the projects are personal and inactive, and that almost 40 % of all pull requests do not appear as merged even though they were. Also, approximately half of GitHub’s registered users do not have public activity, while the activity of GitHub users in repositories is not always easy to pinpoint. We use our identified perils to see if they can pose validity threats; we review selected papers from the MSR 2014 Mining Challenge and see if there are potential impacts to consider. We provide a set of recommendations for software engineering researchers on how to approach the data in GitHub. 相似文献
53.
A Thiolactone Strategy for Straightforward Synthesis of Disulfide‐Linked Side‐Chain‐to‐Tail Cyclic Peptides Featuring an N‐Terminal Modification Handle 下载免费PDF全文
Dorien Van Lysebetten Stefania Felissati Eirini Antonatou Dr. Lieselot L. G. Carrette Dr. Pieter Espeel Evelien Focquet Prof. Dr. Filip E. Du Prez Prof. Dr. Annemieke Madder 《Chembiochem : a European journal of chemical biology》2018,19(6):641-646
The development of straightforward and versatile peptide cyclisation methods is highly desired to meet the demand for more stable peptide‐based drugs. Herein, a new method for the synthesis of side‐chain‐to‐tail cyclic peptides with the simultaneous introduction of an N‐terminal handle, based on the introduction of an N‐terminal thiolactone building block, is described. A primary amine liberates a homocysteine analogue from the thiolactone building block, which further enables cyclisation of the peptide through disulfide‐bond formation with a C‐terminal cysteamine. Postcyclisation modification can be achieved by using small bifunctional amines. Alternatively, the synthesis of lipopeptides is demonstrated through direct thiolactone opening with long‐chain alkyl amines. 相似文献
54.
Joao M. Duarte Eirini Kalogeiton Ridha Soua Gaetano Manzo Maria Rita Palattella Antonio Di Maio Torsten Braun Thomas Engel Leandro A. Villas Gianluca A. Rizzo 《Mobile Networks and Applications》2018,23(5):1247-1259
Content dissemination in Vehicular Ad-hoc Networks (VANETs) has the potential to enable a myriad of applications, ranging from advertising, traffic and emergency warnings to infotainment. This variety in applications and services calls for mechanisms able to optimize content storing, retrieval and forwarding among vehicles, without jeopardizing network resources. Content Centric Networking (CCN), takes advantage of inherent content redundancy in the network in order to decrease the utilization of network resources, improve response time and content availability, coping efficiently with some of the effects of mobility. Floating Content (FC), on the other hand, holds potential to implement efficiently a large amount of vehicular applications thanks to its property of geographic content replication, while Software Defined Networking (SDN), is an attractive solution for the lack of flexibility and dynamic programmability that characterizes current VANET architectures. By implementing a logical centralization of the network, SDN enables dynamic and efficient management of network resources. In this paper, for a few reference scenarios, we illustrate how approaches that combine CCN, FC and SDN enable an innovative adaptive VANET architecture able to efficiently accommodate to intermittent connectivity, fluctuating node density and mobility patterns on one side and application performance and network resources on the other side, aiming to achieve high QoS. For each scenario, we highlight the main open research challenges, and we describe possible solutions to improve content dissemination and reduce replication without affecting content availability. 相似文献
55.
Eirini Karapistoli Ioannis Gragopoulos Ioannis Tsetsinas Fotini-Niovi Pavlidou 《Computer Networks》2009,53(7):961-972
Ultra-wideband (UWB) is a key solution for wireless connectivity, characterized by ultralow power consumption and a good degree of robustness to interference and multipath fading. Evidence of its significance, is its recent use in the IEEE 802.15.4a standard. UWB technology with joint consideration of directional antennas can benefit when compared to classical omni-directional antennas from the energy conservation viewpoint, which is of fundamental concern when it comes to wireless sensor networks (WSNs). However, exploiting directionality requires new approach in the design of a medium access control (MAC) protocol to be applied. In this work, idle nodes continuously rotate their receiving beams over 360° until a predefined preamble trailer is detected. The resulting scheme is a directional ultra-wideband MAC protocol, named DU-MAC, which deals effectively with the problem of deafness and the problem of determination of neighbors’ location. Simulation-based studies will demonstrate the effectiveness of the proposed protocol in many critical parameters, such as throughput and network lifetime. 相似文献
56.
Eirini Filidou Leonidas Kandilogiannakis Gesthimani Tarapatzi Michail Spathakis Paschalis Steiropoulos Dimitrios Mikroulis Konstantinos Arvanitidis Vasilis Paspaliaris George Kolios 《International journal of molecular sciences》2022,23(9)
Idiopathic pulmonary fibrosis (IPF) is caused by progressive lung tissue impairment due to extended chronic fibrosis, and it has no known effective treatment. The use of conditioned media (CM) from an immortalized human adipose mesenchymal stem cell line could be a promising therapeutic strategy, as it can reduce both fibrotic and inflammatory responses. We aimed to investigate the anti-inflammatory and anti-fibrotic effect of CM on human pulmonary subepithelial myofibroblasts (hPSM) and on A549 pulmonary epithelial cells, treated with pro-inflammatory or pro-fibrotic mediators. CM inhibited the proinflammatory cytokine-induced mRNA and protein production of various chemokines in both hPSMs and A549 cells. It also downregulated the mRNA expression of IL-1α, but upregulated IL-1β and IL-6 mRNA production in both cell types. CM downregulated the pro-fibrotic-induced mRNA expression of collagen Type III and the migration rate of hPSMs, but upregulated fibronectin mRNA production and the total protein collagen secretion. CM’s direct effect on the chemotaxis and cell recruitment of immune-associated cells, and its indirect effect on fibrosis through the significant decrease in the migration capacity of hPSMs, makes it a plausible candidate for further development towards a therapeutic treatment for IPF. 相似文献
57.
Eirini Chouliara Anastasia Badeka Ioannis Savvaidis Michael G. Kontominas 《European Food Research and Technology》2008,226(4):877-888
In the present study the combined effect of gamma irradiation (2 and 4 kGy) and modified atmosphere packaging (MAP) (30% CO2/70% N2 and 70% CO2/30% N2) on shelf life extension of fresh chicken meat stored under refrigeration was investigated. The study was based on microbiological
(TVC, Pseudomonas spp., Lactic Acid Bacteria, Yeasts, Brochothrix thermosphacta, Enterobacteriaceae), physicochemical (pH, TBA, color) and sensory (odor, taste) changes occurring in chicken samples. Microbial
populations were reduced by 1–5 log cfu/g for a given sampling day depending on the specific treatment. The effect was more
pronounced in the case of the combination of MAP (70% CO2/30% N2) and the higher irradiation dose of 4 kGy. Of the chemical indicators of spoilage, TBA values for all treatments remained
lower than 1 mg malondialdehyde (MDA)/kg meat throughout the 25 day storage period. pH values varied between 6.4 (day 0) and
5.9 (day 25). The values of the color parameters L*, a* and b* were not considerably affected by MAP. Irradiation resulted in a small increase of the parameter a*. Irradiation had a greater effect in extending the shelf life of chicken as compared to MAP. Sensory evaluation showed that
the combination of irradiation at 4 kGy and MAP (70% CO2/30% N2) resulted in the highest shelf-life extension by 12 days compared to the air packaged samples. 相似文献
58.
Christina Papachristou Anastasia Badeka Eirini Chouliara Efthymia Kondyli Antonios Athanasoulas Michael G. Kontominas 《European Food Research and Technology》2006,223(6):711-718
Chemical, microbiological, and sensorial changes in premium quality whole pasteurized milk stored at 4 °C under fluorescent light for one day followed by storage in the dark for an additional 12 days was studied. Milk containers tested included 1 l bottles made of (a) clear PET + UV blocker, 350–400μm in thickness bearing a transparent label, (b) clear PET + UV blocker, 350–400 μm in thickness bearing a white colored label, (c) clear PET 350–400 μm in thickness. Milk packaged in 1 l coated paperboard cartons and stored under the same experimental conditions served as the “commercial control” sample. Data were obtained for lipid oxidation, lipolysis, proteolysis, vitamin A, E, and riboflavin content, microbial growth including mesophilic and psychrotrophic counts and sensorial attributes (odor and taste) of whole pasteurized milk. Results showed satisfactory protection of milk packaged in all containers with regard to microbiological and chemical parameters assessed over the 13 day period. Based on sensory analysis, the shelf life of premium quality whole pasteurized milk tested in the present study was 10–11 days for samples packaged in clear PET+UV bottles and 9–10 days for clear PET bottles and paperboard cartons. Vitamin A losses recorded after 10 days of storage were respectively 15.9, 20.6, and 14.3% for samples packaged in clear PET+UV protected bottles, clear PET, and control samples. Respective losses for Vitamin E were 26.4, 36.6, and 35.0% and for riboflavin 32.9, 38.3, and 32.5%. Clear PET + UV provided equal or better protection to milk as compared to the paperboard carton. Clear PET was the least effective in retaining light-sensitive vitamins. Based on spectral transmission curves of packaging materials tested, it is suggested that the use of a UV blocking agent in combination with a dark color pigmentation (blue, green etc.) in fresh milk packaging will provide a better protection to light-sensitive vitamins in cases where the expected shelf life of milk exceeds 5–6 days. 相似文献
59.
Tsironi T Gogou E Velliou E Taoukis PS 《International journal of food microbiology》2008,128(1):108-115
The objective of the study was to establish a validated kinetic model for growth of spoilage bacteria on vacuum packed tuna slices in the temperature range of 0 to 15 degrees C and to evaluate the applicability of the TTI (Time Temperature Integrators) based SMAS (Safety Monitoring and Assurance System) system to improve tuna product quality at the time of consumption in comparison to the conventional First In First Out (FIFO) approach. The overall measurements of total flora and lactic acid bacteria (LAB) on the tuna samples used in a laboratory simulated field test were in close agreement with the predictions of the developed kinetic model. The spoilage profile of the TTI bearing products, handled with SMAS, was improved. Three out of the thirty products that were handled randomly, according to the FIFO approach, were already spoiled at the time of consumption (logN(LAB)>6.5) compared to no spoiled products when handled with the SMAS approach. 相似文献
60.