An artificial neural network predictor for tropospheric surface duct phenomena

International audienceIn this work, an artificial neural network (ANN) model is developed and used to predict the presence of ducting phenomena for a specific time, taking into account ground values of atmospheric pressure, relative humidity and temperature. A feed forward backpropagation ANN is implemented, which is trained, validated and tested using atmospheric radiosonde data from the Helliniko airport, for the period from 1991 to 2004. The network's quality and generality is assessed using the Area Under the Receiver Operating Characteristics (ROC) Curves (AUC), which resulted to a mean value of about 0.86 to 0.90, depending on the observation time. In order to validate the ANN results and to evaluate any further improvement options of the proposed method, the problem was additionally treated using Least Squares Support Vector Machine (LS-SVM) classifiers, trained and tested with identical data sets for direct performance comparison with the ANN. Furthermore, time series prediction and the effect of surface wind to the presence of tropospheric ducts appearance are discussed. The results show that the ANN model presented here performs efficiently and gives successful tropospheric ducts predictions

Linear functional organization of the omic embedding space

Motivation: We are increasingly accumulating complex omics data that capture different aspects of cellular functioning. A key challenge is to untangle their complexity and effectively mine them for new biomedical information. To decipher this new information, we introduce algorithms based on network embeddings. Such algorithms represent biological macromolecules as vectors in d-dimensional space, in which topologically similar molecules are embedded close in space and knowledge is extracted directly by vector operations. Recently, it has been shown that neural networks used to obtain vectorial representations (embeddings) are implicitly factorizing a mutual information matrix, called Positive Pointwise Mutual Information (PPMI) matrix. Thus, we propose the use of the PPMI matrix to represent the human protein-protein interaction (PPI) network and also introduce the graphlet degree vector PPMI matrix of the PPI network to capture different topological (structural) similarities of the nodes in the molecular network. Results: We generate the embeddings by decomposing these matrices with Nonnegative Matrix Tri-Factorization. We demonstrate that genes that are embedded close in these spaces have similar biological functions, so we can extract new biomedical knowledge directly by doing linear operations on their embedding vector representations. We exploit this property to predict new genes participating in protein complexes and to identify new cancer-related genes based on the cosine similarities between the vector representations of the genes. We validate 80% of our novel cancer-related gene predictions in the literature and also by patient survival curves that demonstrating that 93.3% of them have a potential clinical relevance as biomarkers of cancer

Non-thermal microwave effects on chicken foetuses during organogenesis

Σκοπός της πειραματικής αυτής εργασίας είναι η διερεύνηση των αποτελεσμάτων έκθεσης παλμικά διαμορφωμένης (Pulse Modulated, FW) και αδιαμόρφωτης (Continuous Wave, CW) μικροκυματικής ακτινοβολίας, πολύ χαμηλής ισχύος, σε έμβρυα όρνιθας στην οργανογένεση. Χρησιμοποιήθηκαν 496 γονιμοποιημένα αυγά όρνιθας από τα οποία τα 380 εκτέθηκαν σε ακτινοβολία, ενώ τα 116 χρησιμοποιήθηκαν ως μάρτυρες. Τα πρώτα εκτέθηκαν σε "μη θερμική" πυκνότητα μικροκυματικής ισχύος στάθμης 8,8 uW/cm2 (SAR= 1,16 mW/Kg) στη συχνότητα 9,152 GHz, από την 3η ως τη 10η ημέρα της επώασης συνεχώς. Από τα αυγά αυτά 172 εκτέθηκαν σε CW, ενώ 208 σε PW. Στα αυγά-μάρτυρες έγιναν όλες οι κινήσεις της έκθεσης χωρίς όμως να εκτεθούν σε ακτινοβολία. Στο τέλος της επώασης τόσο τα έμβρυα των πειραματικών αυγών όσο και των αυγών-μαρτυρων εξετάστηκαν μακροσκοπικά και μικροσκοπικά. Τα έμβρυα που προέκυψαν από τα αυγά τα οποία εκτέθηκαν σε μικροκύματα, παρουσίασαν συγγενείς ανωμαλίες (καθυστέρηση ανάπτυξης και σοβαρές διαμαρτίες) καθώς και πρώιμους και όψιμους εμβρυϊκούς θανάτους. Το ποσοστό των προσβεβλημένων εμβρύων έφτασε στο 62,78% στα εκτεθέντα σε αδιαμόρφωτα και στο 47,12% στα εκτεθέντα σε παλμικά διαμορφωμένα κύματα. Το αντίστοιχο ποσοστό στους μάρτυρες ήταν ιδιαίτερα μικρό και έφτασε μόλις το 3,44%. Τα αποτελέσματα αυτά, τα οποία αξιολογήθηκαν στατιστικά, στηρίξουν την άποψη, ότι in ovo έκθεση εμβρύων όρνιθας σε μικροκυματική ακτινοβολία πολύ χαμηλής -μη θερμικής- πυκνότητας ισχύος, κατά την οργανογένεση, προκαλεί δυσμενείς επιδράσεις στην ανάπτυξη τους.The purpose of this work is το investigate possible effects of pulse-modulated (PW) and non-modulated (CW) low power density microwave radiation on chicken foetuses during organogenesis. A total of 496 fertilised chicken eggs were used in this study; 380 of diem as experimental material and 116 as controls. The experimental eggs were exposed to a non-thermal power density of 8.8 uW/cm2 (SAR= 1.16 mW/Kg) radiation at 9.152 GHz, from the 3rd to the 10th day of incubation, continuously. 172 eggs were irradiated by CW whereas 208 eggs by PW. The controls were sham-exposed. The foetuses of the experimental eggs and of the controls were macro- and microscopically examined at the end of their incubation. In 62.78% of CW-irradiated, 47.12% of PWirradiated and only in 3.44% of the sham-exposed fetuses abnormalities (development retardation and severe malformations) and embryonic and foetal deaths (embryonic and foetal) were observed. The differences in the effects caused by CW and PW irradiation were statistically evaluated. These results support the aspect that very low power density microwaves applied to the chicken foetuses, in ovo during organogenesis, may cause abnormal development

Investigating the effect of child maltreatment on early adolescent peer-on-peer sexual aggression: testing a multiple mediator model in a non-incarcerated sample of Danish adolescents

Objective: The aim of the present study was to investigate the relationship between child maltreatment and severe early adolescent peer-on-peer sexual aggression, using a multiple mediator model. Methods: The study comprised 330 male Grade 9 students with a mean age of 14.9 years (SD=0.5). Results: Estimates from the mediation model indicated significant indirect effects of child physical abuse on sexual aggression via peer influence and insecure-hostile masculinity. No significant total effect of child sexual abuse and child neglect on sexual aggression was found. Conclusions: Findings of the present study identify risk factors that are potentially changeable and therefore of value in informing the design of prevention programs aiming at early adolescent peer-on-peer sexual aggression in at-risk youth

To retain or remove the syndesmotic screw: a review of literature

Introduction: Syndesmotic positioning screws are frequently placed in unstable ankle fractures. Many facets of adequate placement techniques have been the subject of various studies. Whether or not the syndesmosis screw should be removed prior to weight-bearing is still debated. In this study, the recent literature is reviewed concerning the need for removal of the syndesmotic screw. Materials and methods: A comprehensive literature search was conducted in the electronic databases of the Cochrane Library, Pubmed Medline and EMbase from January 2000 to October 2010. Results: A total of seven studies were identified in the literature. Most studies found no difference in outcome between retained or removed screws. Patients with screws that were broken, or showed loosening, had similar or improved outcome compared to patients with removed screws. Removal of the syndesmotic screws, when deemed necessary, is usually not performed before 8-12 weeks. Conclusion: There is paucity in randomized controlled trials on the absolute need for removal of the syndesmotic screw. However, current literature suggests that it might be reserved for intact screws that cause hardware irritation or reduced range of motion after 4-6 months

Learning Programming with Educational Robotics: Towards an Integrated Approach

Despite the fact that it has been a few years since robotics entered the school and offered new learning opportunities, educational robotics usually is offered in the context of extra-curricular activity (e.g. a “club”) which addresses a limited number of students and participation is based on student personal interest. In this paper we explore the potential of ER when it is integrated in the typical school curriculum. In the study we report here, we integrated ER in the computer science curriculum and all students of a 9th grade class engaged with robotics activities. The rationale underlying the study is that robotics can be used as a medium to motivate students in engaging with programming and support them to negotiate real life problems. Analysis of the data collected, indicate that ER when integrated with the computer science curriculum, can create a rich learning environment where programming is contextualized and students are highly motivated to engage and negotiate important STEM concepts

Leo Strauss and International Relations: The politics of modernity's abyss

This article argues that an engagement with the political philosophy of Leo Strauss is of considerable value in International Relations (IR), in relation to the study of both recent US foreign policy and contemporary IR theory. The question of Straussian activities within and close to the foreign policy-making establishment in the United States during the period leading up to the 2003 invasion of Iraq has been the focus of significant scholarly and popular attention in recent years. This article makes the case that several individuals influenced by Strauss exercised considerable influence in the fields of intelligence production, the media and think tanks, and traces the ways in which elements of Strauss’ thought are discernible in their interventions in these spheres. It further argues that Strauss’ political philosophy is of broader significance for IR insofar as it can be read as a securitising response to the dangers he associated with the foundationlessness of the modern condition. The article demonstrates that the politics of this response are of crucial importance for contemporary debates between traditional and critical IR theorists

Materializing digital collecting: an extended view of digital materiality

If digital objects are abundant and ubiquitous, why should consumers pay for, much less collect them? The qualities of digital code present numerous challenges for collecting, yet digital collecting can and does occur. We explore the role of companies in constructing digital consumption objects that encourage and support collecting behaviours, identifying material configuration techniques that materialise these objects as elusive and authentic. Such techniques, we argue, may facilitate those pleasures of collecting otherwise absent in the digital realm. We extend theories of collecting by highlighting the role of objects and the companies that construct them in materialising digital collecting. More broadly, we extend theories of digital materiality by highlighting processes of digital material configuration that occur in the pre-objectification phase of materialisation, acknowledging the role of marketing and design in shaping the qualities exhibited by digital consumption objects and consequently related consumption behaviours and experiences

Reporting quality of scoping reviews in endodontics: A meta‐research study

Objectives: To evaluate the reporting quality of Scoping Reviews (ScRs) in endodontics according to the PRISMA Extension Checklist for Scoping Reviews (PRISMA‐ScR) and to analyse their association with a range of publication and methodological/reporting characteristics. Methods: Pubmed, Scopus, and Web of Science databases were searched up to 31 January 2024 to identify scoping reviews in the field of endodontics. An additional search was performed in three leading endodontic journals. Study selection and appraising the quality of the studies was carried out independently by two reviewers. Each of the 20 PRISMA‐ScR items were allocated a score of either 0, 0.5 or 1 to reflect the completeness of the reporting. An item‐specific and overall percentage reporting quality score was calculated and reported through descriptive statistics across a range of publication, as well as methodological/reporting characteristics. A univariable and multivariable quantile regression was performed to identify the effect of publication and methodological/reporting characteristics (year of publication, journal, inclusion of an appropriate reporting guideline, and study registration) on the overall percentage reporting quality score. Association of reporting quality score with publication characteristics was then investigated. Results: A total of 40 ScRs were identified and included for appraisal. Most of the studies were published from 2021 onwards. The overall median reporting quality score was 86%. The most frequent items not included in the studies were: a priori protocol registration (22/40 compliant; 55%), and reporting of funding (16/40 compliant; 40%). Other key elements that were inadequately reported were the abstract (7/40 compliant; 18%), the rationale and justification of the ScR (21/40 compliant; 52%) and the objectives of the study (18/40 compliant; 45%). Studies that adhered to appropriate reporting guidelines were associated with greater reporting quality scores (β‐coefficient: 10; 95%CI: 1.1, 18.9; p = .03). ScRs with protocols registered a priori had significantly greater reporting quality scores (β‐coefficient: 12.5; 95%CI: 6.1, 18.9; p < .001), compared with non‐registered reviews. Conclusions: The reporting quality of the ScRs in endodontics varied and was greater when the ScR protocols were registered a priori and when the authors adhered to reporting guidelines