Measuring co-authorship and networking-adjusted scientific impact

Appraisal of the scientific impact of researchers, teams and institutions with productivity and citation metrics has major repercussions. Funding and promotion of individuals and survival of teams and institutions depend on publications and citations. In this competitive environment, the number of authors per paper is increasing and apparently some co-authors don't satisfy authorship criteria. Listing of individual contributions is still sporadic and also open to manipulation. Metrics are needed to measure the networking intensity for a single scientist or group of scientists accounting for patterns of co-authorship. Here, I define I1 for a single scientist as the number of authors who appear in at least I1 papers of the specific scientist. For a group of scientists or institution, In is defined as the number of authors who appear in at least In papers that bear the affiliation of the group or institution. I1 depends on the number of papers authored Np. The power exponent R of the relationship between I1 and Np categorizes scientists as solitary (R>2.5), nuclear (R=2.25-2.5), networked (R=2-2.25), extensively networked (R=1.75-2) or collaborators (R<1.75). R may be used to adjust for co-authorship networking the citation impact of a scientist. In similarly provides a simple measure of the effective networking size to adjust the citation impact of groups or institutions. Empirical data are provided for single scientists and institutions for the proposed metrics. Cautious adoption of adjustments for co-authorship and networking in scientific appraisals may offer incentives for more accountable co-authorship behaviour in published articles.Comment: 25 pages, 5 figure

An innovative data mining procedure, using clean algorithm and factor analysis, for irregularly sampled temporal environmental data sets

Οι περιβαλλοντικές βάσεις δεδομένων συχνά αντιμετωπίζουν τα προβλήματα της άτακτης δειγματοληψίας στον χρόνο και της έλλειψης μετρήσεων για κάποιες περιόδους. Το γεγονός αυτό εμποδίζει τη χρήση των κλασικών μεθόδων ανάλυσης χρονοσειρών, οι οποίες απαιτούν σταθερό χρονικό βήμα ενώ ταυτόχρονα τα χρονικά κενά εισάγουν δυσκολίες στην χρήση των περισσοτέρων μεθόδων πολυδιάστατης σταπστικής ανάλυσης. Η παρούσα εργασία προτείνει ένα πλήρες μεθοδολογικό σχήμα ανάλυσης χρονικών περιβαλλονπκών δεδομένων με δειγματοληπτική ανομοιογένεια, στο οποίο γίνεται χρήση του αλγορίθμου CLEAN και της Παραγοντικής ανάλυσης (Factor Analysis). Ο αλγόριθμος CLEAN έχει την ικανότητα να αναπλάθει τις αρχικές χρονοσειρές της βάσης δεδομένων χρησιμοποιώντας φασματική ανάλυση και να δημιουργεί καινούργιες με σταθερό χρονικό βήμα και έλλειψη κενών. Λαμβάνει χώρα δηλαδή τόσο συμπλήρωση των κενών τ?/ς βάσης, όσο και «εξυγίανση» της δειγματοληψίας της. Η παραγοντική ανάλυση ομαδοποιεί τις μεταβλητές, ανάλογα με τον περιβαλλοντικό μηχανισμό από τον οποίο κάθε μια ελέγχεται και επιπλέον αποκαλύπτει τη χαρακτηριστική χρονική διακύμανση της κάθε ομάδας. Το συγκεκριμένο μεθοδολογικό σχήμα εφαρμόστηκε με πλήρη επιτυχία σε μια βάση υδροχημικών δεδομένων μεγάλης χρονικής περιόδου (1980-94) στον ποταμό ΣτρυμόναEnvironmental data are often irregularly collected in the time domain due to various reasons which affect the field sampling schedule. As a result, data sets with uneven time step and time periods with no measurements are frequently built. Many problems occur in such data sets when processed owing to that neither statistical nor spectral analysis methods can easily be applied to them without any specific pre-treatment. In our study it is demonstrated a unified methodological scheme especially designed to deal with incomplete and unevenly sampled temporal data sets. This method consists of the CLEAN algorithm and the Factor analysis. The proposed methodology is successfully applied to data sets that belong to two sampling sites of the Greek river Strimona

An innovative data mining procedure, using clean algorithm and factor analysis, for irregularly sampled temporal environmental data sets

Οι περιβαλλοντικές βάσεις δεδομένων συχνά αντιμετωπίζουν τα προβλήματα της άτακτης δειγματοληψίας στον χρόνο και της έλλειψης μετρήσεων για κάποιες περιόδους. Το γεγονός αυτό εμποδίζει τη χρήση των κλασικών μεθόδων ανάλυσης χρονοσειρών, οι οποίες απαιτούν σταθερό χρονικό βήμα ενώ ταυτόχρονα τα χρονικά κενά εισάγουν δυσκολίες στην χρήση των περισσοτέρων μεθόδων πολυδιάστατης σταπστικής ανάλυσης. Η παρούσα εργασία προτείνει ένα πλήρες μεθοδολογικό σχήμα ανάλυσης χρονικών περιβαλλονπκών δεδομένων με δειγματοληπτική ανομοιογένεια, στο οποίο γίνεται χρήση του αλγορίθμου CLEAN και της Παραγοντικής ανάλυσης (Factor Analysis). Ο αλγόριθμος CLEAN έχει την ικανότητα να αναπλάθει τις αρχικές χρονοσειρές της βάσης δεδομένων χρησιμοποιώντας φασματική ανάλυση και να δημιουργεί καινούργιες με σταθερό χρονικό βήμα και έλλειψη κενών. Λαμβάνει χώρα δηλαδή τόσο συμπλήρωση των κενών τ?/ς βάσης, όσο και «εξυγίανση» της δειγματοληψίας της. Η παραγοντική ανάλυση ομαδοποιεί τις μεταβλητές, ανάλογα με τον περιβαλλοντικό μηχανισμό από τον οποίο κάθε μια ελέγχεται και επιπλέον αποκαλύπτει τη χαρακτηριστική χρονική διακύμανση της κάθε ομάδας. Το συγκεκριμένο μεθοδολογικό σχήμα εφαρμόστηκε με πλήρη επιτυχία σε μια βάση υδροχημικών δεδομένων μεγάλης χρονικής περιόδου (1980-94) στον ποταμό ΣτρυμόναEnvironmental data are often irregularly collected in the time domain due to various reasons which affect the field sampling schedule. As a result, data sets with uneven time step and time periods with no measurements are frequently built. Many problems occur in such data sets when processed owing to that neither statistical nor spectral analysis methods can easily be applied to them without any specific pre-treatment. In our study it is demonstrated a unified methodological scheme especially designed to deal with incomplete and unevenly sampled temporal data sets. This method consists of the CLEAN algorithm and the Factor analysis. The proposed methodology is successfully applied to data sets that belong to two sampling sites of the Greek river Strimona

Air transport liberalisation and airport dependency: developing a composite index

Air transport liberalisation in Europe has produced some major changes to the networks operated by airlines and the services available at airports. Within this context the degree of airport dependency in terms of market, spatial and temporal concentration is important to know from an economic geography and risk management perspective. A composite index called the Airport Dependency Index (ADI) is developed to measure airport dependency based on the concept of the relative Gini coefficient. Liberalisation has had varying impacts depending on the size and type of airport and so a comparison is made of the degree of dependency at a large sample of European airports using the ADI. The ADI has the potential to provide insight on the sustainability and worthiness of financing airport projects, and on whether airports should diversify further their activities by investing in the growth and expansion of their network

Control-Barrier-Aided Teleoperation with Visual-Inertial SLAM for Safe MAV Navigation in Complex Environments

In this paper, we consider a Micro Aerial Vehicle (MAV) system teleoperated by a non-expert and introduce a perceptive safety filter that leverages Control Barrier Functions (CBFs) in conjunction with Visual-Inertial Simultaneous Localization and Mapping (VI-SLAM) and dense 3D occupancy mapping to guarantee safe navigation in complex and unstructured environments. Our system relies solely on onboard IMU measurements, stereo infrared images, and depth images and autonomously corrects teleoperated inputs when they are deemed unsafe. We define a point in 3D space as unsafe if it satisfies either of two conditions: (i) it is occupied by an obstacle, or (ii) it remains unmapped. At each time step, an occupancy map of the environment is updated by the VI-SLAM by fusing the onboard measurements, and a CBF is constructed to parameterize the (un)safe region in the 3D space. Given the CBF and state feedback from the VI-SLAM module, a safety filter computes a certified reference that best matches the teleoperation input while satisfying the safety constraint encoded by the CBF. In contrast to existing perception-based safe control frameworks, we directly close the perception-action loop and demonstrate the full capability of safe control in combination with real-time VI-SLAM without any external infrastructure or prior knowledge of the environment. We verify the efficacy of the perceptive safety filter in real-time MAV experiments using exclusively onboard sensing and computation and show that the teleoperated MAV is able to safely navigate through unknown environments despite arbitrary inputs sent by the teleoperator.Comment: Accepted to the IEEE International Conference on Robotics and Automation (ICRA) 2024, 7 pages, 7 figures, supplementary video is available at https://youtu.be/rCxbWY4PIfQ?si=DC-9mg7g1WooNda

The role of the humoral immune response to Clostridium difficile toxins A and B in susceptibility to C. difficile infection: a case-control study

Antibody levels to Clostridium difficile toxin A (TcdA), but not toxin B (TcdB), have been found to determine risk of C. difficile infection (CDI). Historically, TcdA was thought to be the key virulence factor; however the importance of TcdB in disease is now established. We re-evaluated the role of antibodies to TcdA and TcdB in determining patient susceptibility to CDI in two separate patient cohorts. In contrast to earlier studies, we find that CDI patients have lower pre-existing IgA titres to TcdB, but not TcdA, when compared to control patients. Our findings suggest that mucosal immunity to TcdB may be important in the early stages of infection and identifies a possible target for preventing CDI progression

Gramene 2018: unifying comparative genomics and pathway resources for plant research

Gramene (http://www.gramene.org) is a knowledgebase for comparative functional analysis in major crops and model plant species. The current release, #54, includes over 1.7 million genes from 44 reference genomes, most of which were organized into 62,367 gene families through orthologous and paralogous gene classification, whole-genome alignments, and synteny. Additional gene annotations include ontology-based protein structure and function; genetic, epigenetic, and phenotypic diversity; and pathway associations. Gramene's Plant Reactome provides a knowledgebase of cellular-level plant pathway networks. Specifically, it uses curated rice reference pathways to derive pathway projections for an additional 66 species based on gene orthology, and facilitates display of gene expression, gene-gene interactions, and user-defined omics data in the context of these pathways. As a community portal, Gramene integrates best-of-class software and infrastructure components including the Ensembl genome browser, Reactome pathway browser, and Expression Atlas widgets, and undergoes periodic data and software upgrades. Via powerful, intuitive search interfaces, users can easily query across various portals and interactively analyze search results by clicking on diverse features such as genomic context, highly augmented gene trees, gene expression anatomograms, associated pathways, and external informatics resources. All data in Gramene are accessible through both visual and programmatic interfaces

A Reporter Screen in a Human Haploid Cell Line Identifies CYLD as a Constitutive Inhibitor of NF-κB

The development of forward genetic screens in human haploid cells has the potential to transform our understanding of the genetic basis of cellular processes unique to man. So far, this approach has been limited mostly to the identification of genes that mediate cell death in response to a lethal agent, likely due to the ease with which this phenotype can be observed. Here, we perform the first reporter screen in the near-haploid KBM7 cell line to identify constitutive inhibitors of NF-κB. CYLD was the only currently known negative regulator of NF-κB to be identified, thus uniquely distinguishing this gene. Also identified were three genes with no previous known connection to NF-κB. Our results demonstrate that reporter screens in haploid human cells can be applied to investigate the many complex signaling pathways that converge upon transcription factors

Survival of Escherichia coli 0157:H7 in Feta cheese during storage

Η επιβίωση της Escherichia coli 0157:Η7 σε τυρίφέτα και στην άλμη της μελετήθηκε στη διάρκεια της συντήρησηςστους 4°C και 12°C. Η επιμόλυνση του τυριού έγινε με την προσθήκη5.3 log10CFU/ml της Ε. coli Ol57:Η7 στην άλμη. Η E. Coli0157:Η7 ήταν ανιχνεύσιμη στην άλμη με ενοφθαλμισμό στο υπόστρωμαSMAC μέχρι την 40η και 32η μέρα κατά τη συντήρηση τηςστους 4°C και 12°C αντίστοιχα, ενώ έπειτα απο εμπλουτισμό καιστη συνέχεια σπορά στο υπόστρωμα SMAC μέχρι την 44η και 36ημέρα στους 4°C και 12°C αντίστοιχα. Η E. coli 0157:Η7 στη φέταήταν ανιχνεύσιμη στο υπόστρωμα SMAC μέχρι την 44η και 38η μέρακατά τη συντήρηση στους 4°C και 12°C, ενώ έπειτα απο εμπλουτισμόκαι στη συνέχεια σπορά στο υπόστρωμα SMAC μέχριτην 50η και 42η μέρα στους 4°C και 12°C αντίστοιχα. Τα αποτελέσματαέδειξαν ότι η Ε. coli Ol57:Η7 επέζησε για μεγαλύτερο διάστημαστη φέτα από ότι στην άλμη και για τις δυο θερμοκρασίεςσυντήρησης αν και η διαφορά αυτή ήταν μικρή. Η επιβίωση της Ε.co/i0157:H7 τόσο στη φέτα όσο και στην άλμη ήταν μεγαλύτερηστους 4°C παρά στους 12°C .The survival of E. co/i0157:H7 in Feta cheese and the brine used after 2 months ripening of cheese, was studied during storage at 4°C and 12°C. An inoculum of 5.3 log10CFU/ml of E. coli Ol57:H7 was added in brine, for the contamination with the pathogen of Feta cheese. E. coli Ol 57:H7 was detectable in brine by direct plating on SMAC up to 40th day and 32th day during its storage at 4°C and 12°C respectively, while by enrichment and following plating on SMAC up to 44th day (4°C) and 36th day (12°C). The E. coli 0157:H7 was detectable in Feta by direct plating on SMAC up to 44th day (4°C) and 38th day (12°C), while by enrichment and following plating on SMAC up to 50th day (4°C) and 42th day (12°C). The results showed that E. coli Ol57:H7 survived longer in Feta than in its brine, for both storage temperatures but the difference was very low. The survival of E. coli 0157:H7 in feta and brine was longer during the storage at 4°C than at 12°C

Early childhood pedagogies: spaces for young children to flourish

This paper introduces the Special Issue of Early Child Development and Care focused on Early Childhood Pedagogy. It opens by considering past and present discourses concerning early childhood pedagogy, and focus is given to established philosophical underpinnings in the field and their translation to contemporary guidance, alongside research and policy. It is argued that early childhood pedagogy is a contested, complex and diverse space, yet these factors are entirely appropriate for supporting young children to flourish as valued individuals in different contexts. Building on this argument, it is posited that it may be more appropriate to discuss early childhood pedagogies rather than early childhood pedagogy. The paper goes on to critique a range of established early childhood pedagogies, before introducing 18 papers from across the world that make exciting new contributions to the discourse. It is intended that this collection will inspire new debates and fresh endeavours concerning early childhood pedagogies