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Uncovering the fragility of large-scale engineering project networks [article]

Marc Santolini, Christos Ellinas, Christos Nicolaides
2020 arXiv   pre-print
Christos Nicolaides has received funding from the European Union 's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 786247.  ...  Nodes & Links Ltd provided support in the form of salary for Christos Ellinas, but did not have any additional role in the conceptualisation of the study, analysis, decision to publish, or preparation  ... 
arXiv:2009.11752v1 fatcat:jx2jcdsjyrhslbluxylbrqqf4a

Uncovering the fragility of large-scale engineering projects

Marc Santolini, Christos Ellinas, Christos Nicolaides
2021 EPJ Data Science  
Christos Nicolaides has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 786247.  ...  Nodes & Links Ltd provided support in the form of salary for Christos Ellinas, but did not have any additional role in the conceptualisation of the study, analysis, decision to publish, or preparation  ... 
doi:10.1140/epjds/s13688-021-00291-w fatcat:x2eb7uumufaormkszbrdn3faa4

Modelling disease transmission from touchscreen user interfaces [article]

Andrew DiBattista, Christos Nicolaides, Orestis Georgiou
2020 bioRxiv   pre-print
Christos Nicolaides has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie project NISIHealth, grant agreement No. 786247.  ... 
doi:10.1101/2020.10.28.358820 fatcat:jeidy2r3pbhg7ouvwmqam5bjee

Exercise contagion in a global social network

Sinan Aral, Christos Nicolaides
2017 Nature Communications  
Christos Nicolaides gratefully acknowledges generous funding and support from the James S. McDonnell Postdoctoral Fellowship.  ... 
doi:10.1038/ncomms14753 pmid:28418379 pmcid:PMC5399289 fatcat:zpf42ujgevf23kroh4sqe7raoe

Anomalous physical transport in complex networks

Christos Nicolaides, Luis Cueto-Felgueroso, Ruben Juanes
2010 Physical Review E  
The emergence of scaling in transport through interconnected systems is a consequence of the topological structure of the network and the physical mechanisms underlying the transport dynamics. We study transport by advection and diffusion in scale-free and Erdős-Rényi networks. Velocity distributions derived from a flow potential exhibit power-law scaling with exponent Ϸ ␥ + 1, where ␥ is the exponent of network connectivity. Using stochastic particle simulations, we find anomalous ͑nonlinear͒
more » ... caling of the mean-square displacement with time. We show the connection with existing descriptions of anomalous transport in disordered systems, and explain the mean transport behavior from the coupled nature of particle jump lengths and transition times.
doi:10.1103/physreve.82.055101 pmid:21230532 fatcat:urggy3rnjvej7fbf6xjwqx3vm4

Is attending a higher achieving school always beneficial for student learning?

Ioulia Televantou, Herbert Marsh, Thresea Dicke, Christos Nicolaides
2021 Zenodo  
Nicolaides Christos Nicolaides is a Marie S.  ...  Herbert Marsh Herbert Marsh is Professor Emeritus at the Department of Education, University of Oxford Theresa Dicke Theresa Dicke is Senior Research Fellow at the Australian Catholic University Christos  ... 
doi:10.5281/zenodo.4717471 fatcat:fjfd73mngbfaxir6nmnvhzfaw4

Modeling of Covid-19 Pandemic in Cyprus [article]

Sergios Agapiou, Andreas Anastasiou, Anastassia Baxevani, Tasos Christofides, Elisavet Constantinou, Georgios Hadjigeorgiou, Christos Nicolaides, Georgios Nikolopoulos, Konstantinos Fokianos
2020 arXiv   pre-print
Susceptible-Infectious-Recovered (SIR) and Susceptible-Exposed-Infectious-Recovered (SEIR) models and their modifications, have been used to model infectious diseases since the early 1920's (see Keeling and Rohani (2008) , Nicolaides  ... 
arXiv:2010.01927v1 fatcat:me6q5bxnvbdlbnydpm3w5izzem

Privacy preserving data visualizations

Demetris Avraam, Rebecca Wilson, Oliver Butters, Thomas Burton, Christos Nicolaides, Elinor Jones, Andy Boyd, Paul Burton
2021 EPJ Data Science  
AbstractData visualizations are a valuable tool used during both statistical analysis and the interpretation of results as they graphically reveal useful information about the structure, properties and relationships between variables, which may otherwise be concealed in tabulated data. In disciplines like medicine and the social sciences, where collected data include sensitive information about study participants, the sharing and publication of individual-level records is controlled by data
more » ... ection laws and ethico-legal norms. Thus, as data visualizations – such as graphs and plots – may be linked to other released information and used to identify study participants and their personal attributes, their creation is often prohibited by the terms of data use. These restrictions are enforced to reduce the risk of breaching data subject confidentiality, however they limit analysts from displaying useful descriptive plots for their research features and findings.Here we propose the use of anonymization techniques to generate privacy-preserving visualizations that retain the statistical properties of the underlying data while still adhering to strict data disclosure rules. We demonstrate the use of (i) the well-known k-anonymization process which preserves privacy by reducing the granularity of the data using suppression and generalization, (ii) a novel deterministic approach that replaces individual-level observations with the centroids of each k nearest neighbours, and (iii) a probabilistic procedure that perturbs individual attributes with the addition of random stochastic noise. We apply the proposed methods to generate privacy-preserving data visualizations for exploratory data analysis and inferential regression plot diagnostics, and we discuss their strengths and limitations.
doi:10.1140/epjds/s13688-020-00257-4 pmid:33442528 pmcid:PMC7790778 fatcat:lmbanwnvyvcgxe3me2t2ays4ty

HIV-1 Integrase: From Biology to Chemotherapeutics

Eriketi Zeinalipour-Loizidou, Christos Nicolaou, Athanasios Nicolaides, Leondios G. Kostrikis
2007 Current HIV Research  
AIDS has claimed the lives of 25 million people worldwide, an additional 40 million people are HIV-infected and new cases are being diagnosed every year. Despite the fact that HAART has moved AIDS from the category of terminal diseases to that of treatable chronic illnesses, its long-term therapeutic success may be compromised by the development of resistance to the currently used drugs. Despite the availability of RT, PR and fusion inhibitors, the development of further drugs such as
more » ... that target the third enzyme IN is essential for the clinical management of HIV-infected patients. The absence of cellular homolgues to IN and the unique nature of the reactions catalyzed by IN, make it an ideal target for drug design. Considerable progress towards designing HIV-1 IN inhibitors has been made over the last years and several lead compounds have been identified, synthesized and clinically studied. This review focuses on the existing knowledge of the biology of HIV-1 IN with emphasis on the mechanism of integration, structure and function and the technologies for measuring IN activity. This is followed by the current trends on designing HIV-1 IN inhibitors with the aid of molecular informatics and a review on the main classes of HIV-1 IN inhibitors reported this far with special emphasis on the clinical candidates.
doi:10.2174/157016207781023965 pmid:17627500 fatcat:enzqc5botrbxfo55wvm7sth5gi

Hand-hygiene mitigation strategies against global disease spreading through the air transportation network [article]

Christos Nicolaides, Demetris Avraam, Luis Cueto-Felgueroso, Marta C Gonzalez, Ruben Juanes
2019 bioRxiv   pre-print
Hand hygiene is considered as an efficient and cost-effective way to limit the spread of diseases and, as such, it is recommended by both the World Health Organization (WHO) and the Centres for Disease Control and Prevention (CDC). While the effect of hand washing on individual transmissibility of a disease has been studied through medical and public-health research, its potential as a mitigation strategy against a global pandemic has not been fully explored yet. In this study, we investigate
more » ... ntagion dynamics through the world air transportation network and analyze the impact of hand-hygiene behavioural changes of airport population against the spread of infectious diseases worldwide. Using a granular dataset of the world air transportation traffic, we build a detailed individual mobility model that controls for the correlated and recurrent nature of human travel and the waiting-time distributions of individuals at different locations. We perform a Monte-Carlo simulation study to assess the impact of different hand-washing mitigation strategies at the early stages of a global epidemic. From the simulation results we find that increasing the hand cleanliness homogeneously at all airports in the world can inhibit the impact of a potential pandemic by 24 to 69%. By quantifying and ranking the contribution of the different airports to the mitigation of an epidemic outbreak, we identify ten key airports at the core of a cost-optimal deployment of the hand-washing strategy: increasing the engagement rate at those locations alone could potentially reduce a world pandemic by 8 to 37%. This research provides evidence of the effectiveness of hand hygiene in airports on the global spread of infectious diseases, and has important implications for the way public-health policymakers may design new effective strategies to enhance hand hygiene in airports through behavioral changes.
doi:10.1101/530618 fatcat:pp2drgxn45g6rlnlevddzqjije

The Efficiency of U.S. Public Space Utilization During the COVID‐19 Pandemic

Seth G. Benzell, Avinash Collis, Christos Nicolaides
2021 Risk Analysis  
., masks and better usage of outdoor spaces like courtyards and takeout windows), and improving hospital treatments (Benzell, Collis, Nicolaides, & Bardhan, 2020) are unincorporated factors that also  ... 
doi:10.1111/risa.13800 pmid:34549813 pmcid:PMC8661668 fatcat:ukgkukand5h6vmn63ltyvq2npe

The Efficiency of US Public Space Utilization During the COVID-19 Pandemic

Seth Benzell, Avinash Collis, Christos Nicolaides
2021 Social Science Research Network  
. * Address correspondence to Christos Nicolaides, School of Economics and Management, University of Cyprus, Nicosia, Cyprus; † Authors listed in alphabetical order [WHO]  ...  nonpharmaceutical interventions (NPIs) other than social distancing measures (e.g., masks and better usage of outdoor spaces like courtyards and takeout windows), and improving hospital treatments (Benzell, Collis, Nicolaides  ... 
doi:10.2139/ssrn.3774478 fatcat:w6ctjcogwfejngt52reoxmrogm

The price of anarchy in mobility-driven contagion dynamics

Christos Nicolaides, Luis Cueto-Felgueroso, Ruben Juanes
2013 Journal of the Royal Society Interface  
Public policy and individual incentives determine the patterns of human mobility through transportation networks. In the event of a health emergency, the pursuit of maximum social or individual utility may lead to conflicting objectives in the routing strategies of network users. Individuals tend to avoid exposure so as to minimize the risk of contagion, whereas policymakers aim at coordinated behaviour that maximizes the social welfare. Here, we study agent-driven contagion dynamics through
more » ... nsportation networks, coupled to the adoption of either selfish-or policy-driven rerouting strategies. In analogy with the concept of price of anarchy in transportation networks subject to congestion, we show that maximizing individual utility leads to a loss of welfare for the social group, measured here by the total population infected after an epidemic outbreak.
doi:10.1098/rsif.2013.0495 pmid:23904588 pmcid:PMC3758010 fatcat:uywxstfz3rhzlowxdgp2tm3zri

Impact of viscous fingering and permeability heterogeneity on fluid mixing in porous media

Christos Nicolaides, Birendra Jha, Luis Cueto-Felgueroso, Ruben Juanes
2015 Water Resources Research  
doi:10.1002/2014wr015811 fatcat:7wqj7asicjdcvcskcdhvkpobye

A Metric of Influential Spreading during Contagion Dynamics through the Air Transportation Network

Christos Nicolaides, Luis Cueto-Felgueroso, Marta C. González, Ruben Juanes, Alessandro Vespignani
2012 PLoS ONE  
The spread of infectious diseases at the global scale is mediated by long-range human travel. Our ability to predict the impact of an outbreak on human health requires understanding the spatiotemporal signature of early-time spreading from a specific location. Here, we show that network topology, geography, traffic structure and individual mobility patterns are all essential for accurate predictions of disease spreading. Specifically, we study contagion dynamics through the air transportation
more » ... twork by means of a stochastic agent-tracking model that accounts for the spatial distribution of airports, detailed air traffic and the correlated nature of mobility patterns and waiting-time distributions of individual agents. From the simulation results and the empirical air-travel data, we formulate a metric of influential spreading--the geographic spreading centrality--which accounts for spatial organization and the hierarchical structure of the network traffic, and provides an accurate measure of the early-time spreading power of individual nodes.
doi:10.1371/journal.pone.0040961 pmid:22829902 pmcid:PMC3400590 fatcat:sda6j7unerbaheno7ultvrzw44
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