scholarly journals Community detection with node attributes in multilayer networks

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Martina Contisciani ◽  
Eleanor A. Power ◽  
Caterina De Bacco

Abstract Community detection in networks is commonly performed using information about interactions between nodes. Recent advances have been made to incorporate multiple types of interactions, thus generalizing standard methods to multilayer networks. Often, though, one can access additional information regarding individual nodes, attributes, or covariates. A relevant question is thus how to properly incorporate this extra information in such frameworks. Here we develop a method that incorporates both the topology of interactions and node attributes to extract communities in multilayer networks. We propose a principled probabilistic method that does not assume any a priori correlation structure between attributes and communities but rather infers this from data. This leads to an efficient algorithmic implementation that exploits the sparsity of the dataset and can be used to perform several inference tasks; we provide an open-source implementation of the code online. We demonstrate our method on both synthetic and real-world data and compare performance with methods that do not use any attribute information. We find that including node information helps in predicting missing links or attributes. It also leads to more interpretable community structures and allows the quantification of the impact of the node attributes given in input.

GIS Business ◽  
2019 ◽  
Vol 14 (4) ◽  
pp. 85-98
Author(s):  
Idoko Peter

This research the impact of competitive quasi market on service delivery in Benue State University, Makurdi Nigeria. Both primary and secondary source of data and information were used for the study and questionnaire was used to extract information from the purposively selected respondents. The population for this study is one hundred and seventy three (173) administrative staff of Benue State University selected at random. The statistical tools employed was the classical ordinary least square (OLS) and the probability value of the estimates was used to tests hypotheses of the study. The result of the study indicates that a positive relationship exist between Competitive quasi marketing in Benue State University, Makurdi Nigeria (CQM) and Transparency in the service delivery (TRSP) and the relationship is statistically significant (p<0.05). Competitive quasi marketing (CQM) has a negative effect on Observe Competence in Benue State University, Makurdi Nigeria (OBCP) and the relationship is not statistically significant (p>0.05). Competitive quasi marketing (CQM) has a positive effect on Innovation in Benue State University, Makurdi Nigeria (INVO) and the relationship is statistically significant (p<0.05) and in line with a priori expectation. This means that a unit increases in Competitive quasi marketing (CQM) will result to a corresponding increase in innovation in Benue State University, Makurdi Nigeria (INVO) by a margin of 22.5%. It was concluded that government monopoly in the provision of certain types of services has greatly affected the quality of service experience in the institution. It was recommended among others that the stakeholders in the market has to be transparent so that the system will be productive to serve the society effectively


The review article discusses the possibilities of using fractal mathematical analysis to solve scientific and applied problems of modern biology and medicine. The authors show that only such an approach, related to the section of nonlinear mechanics, allows quantifying the chaotic component of the structure and function of living systems, that is a priori important additional information and expands, in particular, the possibilities of diagnostics, differential diagnosis and prediction of the course of physiological and pathological processes. A number of examples demonstrate the specific advantages of using fractal analysis for these purposes. The conclusion can be made that the expanded use of fractal analysis methods in the research work of medical and biological specialists is promising.


Author(s):  
Stefan Thurner ◽  
Rudolf Hanel ◽  
Peter Klimekl

Understanding the interactions between the components of a system is key to understanding it. In complex systems, interactions are usually not uniform, not isotropic and not homogeneous: each interaction can be specific between elements.Networks are a tool for keeping track of who is interacting with whom, at what strength, when, and in what way. Networks are essential for understanding of the co-evolution and phase diagrams of complex systems. Here we provide a self-contained introduction to the field of network science. We introduce ways of representing and handle networks mathematically and introduce the basic vocabulary and definitions. The notions of random- and complex networks are reviewed as well as the notions of small world networks, simple preferentially grown networks, community detection, and generalized multilayer networks.


2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S439-S439
Author(s):  
Eric Ellorin ◽  
Jill Blumenthal ◽  
Sonia Jain ◽  
Xiaoying Sun ◽  
Katya Corado ◽  
...  

Abstract Background “PrEP whore” has been used both as a pejorative by PrEP opponents in the gay community and, reactively, by PrEP advocates as a method to reclaim the label from stigmatization and “slut-shaming.” The actual prevalence and impact of such PrEP-directed stigma on adherence have been insufficiently studied. Methods CCTG 595 was a randomized controlled PrEP demonstration project in 398 HIV-uninfected MSM and transwomen. Intracellular tenofovir-diphosphate (TFV-DP) levels at weeks 12 and 48 were used as a continuous measure of adherence. At study visits, participants were asked to describe how they perceived others’ reactions to them being on PrEP. These perceptions were categorized a priori as either “positively framed,” “negatively framed,” or both. We used Wilcoxon rank-sum to determine the association between positive and negative framing and TFV-DP levels at weeks 12 and 48. Results By week 4, 29% of participants reported perceiving positive reactions from members of their social groups, 5% negative, and 6% both. Reporting decreased over 48 weeks, but positive reactions were consistently reported more than negative. At week 12, no differences in mean TFV-DP levels were observed in participants with positively-framed reactions compared with those reporting no outcome or only negatively-framed (1338 [IQR, 1036-1609] vs. 1281 [946-1489] fmol/punch, P = 0.17). Additionally, no differences were observed in those with negative reactions vs. those without (1209 [977–1427] vs. 1303 [964–1545], P = 0.58). At week 48, mean TFV-DP levels trended toward being higher among those that report any reaction, regardless if positive (1335 [909–1665] vs. 1179 [841–1455], P = 0.09) or negative (1377 [1054–1603] vs. 1192 [838–1486], P = 0.10) than those reporting no reaction. At week 48, 46% of participants reported experiencing some form of PrEP-directed judgment, 23% reported being called “PrEP whore,” and 21% avoiding disclosing PrEP use. Conclusion Over 48 weeks, nearly half of participants reported some form of judgment or stigmatization as a consequence of PrEP use. However, individuals more frequently perceived positively framed reactions to being on PrEP than negative. Importantly, long-term PrEP adherence does not appear to suffer as a result of negative PrEP framing. Disclosures All authors: No reported disclosures.


Biology ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 463
Author(s):  
Narjiss Sallahi ◽  
Heesoo Park ◽  
Fedwa El Mellouhi ◽  
Mustapha Rachdi ◽  
Idir Ouassou ◽  
...  

Epidemiological Modeling supports the evaluation of various disease management activities. The value of epidemiological models lies in their ability to study various scenarios and to provide governments with a priori knowledge of the consequence of disease incursions and the impact of preventive strategies. A prevalent method of modeling the spread of pandemics is to categorize individuals in the population as belonging to one of several distinct compartments, which represents their health status with regard to the pandemic. In this work, a modified SIR epidemic model is proposed and analyzed with respect to the identification of its parameters and initial values based on stated or recorded case data from public health sources to estimate the unreported cases and the effectiveness of public health policies such as social distancing in slowing the spread of the epidemic. The analysis aims to highlight the importance of unreported cases for correcting the underestimated basic reproduction number. In many epidemic outbreaks, the number of reported infections is likely much lower than the actual number of infections which can be calculated from the model’s parameters derived from reported case data. The analysis is applied to the COVID-19 pandemic for several countries in the Gulf region and Europe.


Author(s):  
Robert F Engle ◽  
Martin Klint Hansen ◽  
Ahmet K Karagozoglu ◽  
Asger Lunde

Abstract Motivated by the recent availability of extensive electronic news databases and advent of new empirical methods, there has been renewed interest in investigating the impact of financial news on market outcomes for individual stocks. We develop the information processing hypothesis of return volatility to investigate the relation between firm-specific news and volatility. We propose a novel dynamic econometric specification and test it using time series regressions employing a machine learning model selection procedure. Our empirical results are based on a comprehensive dataset comprised of more than 3 million news items for a sample of 28 large U.S. companies. Our proposed econometric specification for firm-specific return volatility is a simple mixture model with two components: public information and private processing of public information. The public information processing component is defined by the contemporaneous relation with public information and volatility, while the private processing of public information component is specified as a general autoregressive process corresponding to the sequential price discovery mechanism of investors as additional information, previously not publicly available, is generated and incorporated into prices. Our results show that changes in return volatility are related to public information arrival and that including indicators of public information arrival explains on average 26% (9–65%) of changes in firm-specific return volatility.


Mathematics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 692
Author(s):  
Clara Calvo ◽  
Carlos Ivorra ◽  
Vicente Liern ◽  
Blanca Pérez-Gladish

Modern portfolio theory deals with the problem of selecting a portfolio of financial assets such that the expected return is maximized for a given level of risk. The forecast of the expected individual assets’ returns and risk is usually based on their historical returns. In this work, we consider a situation in which the investor has non-historical additional information that is used for the forecast of the expected returns. This implies that there is no obvious statistical risk measure any more, and it poses the problem of selecting an adequate set of diversification constraints to mitigate the risk of the selected portfolio without losing the value of the non-statistical information owned by the investor. To address this problem, we introduce an indicator, the historical reduction index, measuring the expected reduction of the expected return due to a given set of diversification constraints. We show that it can be used to grade the impact of each possible set of diversification constraints. Hence, the investor can choose from this gradation, the set better fitting his subjective risk-aversion level.


2021 ◽  
pp. 000276422110216
Author(s):  
Kazimierz M. Slomczynski ◽  
Irina Tomescu-Dubrow ◽  
Ilona Wysmulek

This article proposes a new approach to analyze protest participation measured in surveys of uneven quality. Because single international survey projects cover only a fraction of the world’s nations in specific periods, researchers increasingly turn to ex-post harmonization of different survey data sets not a priori designed as comparable. However, very few scholars systematically examine the impact of the survey data quality on substantive results. We argue that the variation in source data, especially deviations from standards of survey documentation, data processing, and computer files—proposed by methodologists of Total Survey Error, Survey Quality Monitoring, and Fitness for Intended Use—is important for analyzing protest behavior. In particular, we apply the Survey Data Recycling framework to investigate the extent to which indicators of attending demonstrations and signing petitions in 1,184 national survey projects are associated with measures of data quality, controlling for variability in the questionnaire items. We demonstrate that the null hypothesis of no impact of measures of survey quality on indicators of protest participation must be rejected. Measures of survey documentation, data processing, and computer records, taken together, explain over 5% of the intersurvey variance in the proportions of the populations attending demonstrations or signing petitions.


Author(s):  
Evan D Robinson ◽  
Allison M Stilwell ◽  
April E Attai ◽  
Lindsay E Donohue ◽  
Megan D Shah ◽  
...  

Abstract Background Implementation of the Accelerate PhenoTM Gram-negative platform (RDT) paired with antimicrobial stewardship program (ASP) intervention projects to improve time to institutional-preferred antimicrobial therapy (IPT) for Gram-negative bacilli (GNB) bloodstream infections (BSIs). However, few data describe the impact of discrepant RDT results from standard of care (SOC) methods on antimicrobial prescribing. Methods A single-center, pre-/post-intervention study of consecutive, nonduplicate blood cultures for adult inpatients with GNB BSI following combined RDT + ASP intervention was performed. The primary outcome was time to IPT. An a priori definition of IPT was utilized to limit bias and to allow for an assessment of the impact of discrepant RDT results with the SOC reference standard. Results Five hundred fourteen patients (PRE 264; POST 250) were included. Median time to antimicrobial susceptibility testing (AST) results decreased 29.4 hours (P &lt; .001) post-intervention, and median time to IPT was reduced by 21.2 hours (P &lt; .001). Utilization (days of therapy [DOTs]/1000 days present) of broad-spectrum agents decreased (PRE 655.2 vs POST 585.8; P = .043) and narrow-spectrum beta-lactams increased (69.1 vs 141.7; P &lt; .001). Discrepant results occurred in 69/250 (28%) post-intervention episodes, resulting in incorrect ASP recommendations in 10/69 (14%). No differences in clinical outcomes were observed. Conclusions While implementation of a phenotypic RDT + ASP can improve time to IPT, close coordination with Clinical Microbiology and continued ASP follow up are needed to optimize therapy. Although uncommon, the potential for erroneous ASP recommendations to de-escalate to inactive therapy following RDT results warrants further investigation.


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