1,720,956 research outputs found
The effect of wounding and mechanical stress in kiwifruit ripening mechanism
No full textMechanical stress of kiwifruits (Actinidia chinensis var. deliciosa (A.Chev.) A. Chev.) is a very common phenomenon which is directly related to fruit quality and postharvest losses. Although of major importance, the knowledge regarding the role of mechanical stresses in kiwifruit metabolism is very limited. Ιn the present study, the post-harvest effect of wounding in 'Hayward' kiwifruit variety was investigated using high-throughput molecular analyzes such as metabolomics and transcriptomics. Two experimental approaches were used that reflect two different types of injury/stress. In the first experimental approach, after harvest, fruits were artificially injured by inserting a needle to a depth of one centimeter and their ripening characteristics were evaluated for the period of 8 days of ripening at room temperature. According to the results, wounding promoted fruit ripening, as demonstrated by changes in fruit firmness, ethylene production and respiration activity determined periodically during a ripening period of 8 days at room temperature. Calcium imaging using fluorescent probe Fluo-3 AM revealed spatial dynamics of Ca2+ signaling in the wounding area following 8 days of ripening. Several sugars including fructose, glucose, and sucrose as well as organic acids such as citric, succinic and galacturonic acid were increased by wounding. Gene expression analysis of the wounded fruit showed increased expression of genes that mainly involved in defense response, calcium ion binding, TCA cycle, sugars, secondary metabolism, lipid processing and pectin degradation, as well as in ethylene and auxin synthesis. Moreover, genes related to aquaporins, were down-regulated in fruit exposed to wounding. In the second experimental approach, compression force (147.1 N) was applied, during harvest as well as after short (14 days) or long (3 months) cold storage (0℃). Using several experimental approaches, we documented that the applied compression-imposed stress conditions and induced the fruit ripening process at room temperature (20℃). Fluorescent antibody labeling showed that arabinogalactan proteins and xyloglucans were altered due to compression, while gel diffusion assay indicated that pectin methylesterase activity was reduced by the long cold exposure. Intracellular Fluo-3 AM-dependent Ca2+ signals were detected in proximal to the main compressed fruit areas just after mechanical treatment. Several primary metabolites changed in cold stored pericarp and placenta tissues after 8 hours of compression treatment while transcriptomic data, also, disclosed numerous genes, which are mainly involved in sugar metabolism, TCA cycle, cell wall, ethylene and hormones signaling, that were affected by mechanical stress in pericarp and especially in placenta. We also detected potential transcription factors, including bZIP53, WRKY40 and GATA17, that are involved in compression stress while meta-data analysis enabled identification of several transcription factors that regulated by both compression and wounding in kiwifruit. The meta-analysis of all the transcriptional and metabolic data, for the two types of stress, and more specifically for the pericarp tissue, enabled identification of several commonly expressed genes and TFs that regulated by both compression and wounding in kiwifruit. Overall, the results of the present study provide a first characterization of the changes involved in kiwifruit mechanical stress and provide important insights into the molecular basis of this phenomenon.Ο τραυματισμός των καρπών της ακτινιδιάς αποτελεί συχνό φαινόμενο κατά τη συγκομιδή και τη μετασυλλεκτική τους διαχείριση με αποτέλεσμα να επηρεάζεται άμεσα η διαδικασία της ωρίμανσής τους. Αυτό έχει ως συνέπεια να υποβαθμίζεται η ποιότητα των καρπών γεγονός που επιφέρει σημαντικές οικονομικές απώλειες. Η γνώση αναφορικά με το ρόλο των μηχανικών καταπονήσεων στο μεταβολισμό των ακτινιδίων και οι μηχανισμοί που τους διέπουν είναι περιορισμένη. Στην παρούσα διδακτορική διατριβή διερευνήθηκε η μετασυλλεκτική επίδραση του τραυματισμού σε καρπούς ακτινιδιάς ποικιλίας ‘Hayward’ χρησιμοποιώντας αναλύσεις των φυσιολογικών χαρακτηριστικών και μοριακές τεχνικές υψηλής απόδοσης, όπως μεταβολομική και τρανσκριπτομική. Χρησιμοποιήθηκαν δυο πειραματικές προσεγγίσεις, ήτοι «τεχνητός τραυματισμός» και «δύναμη συμπίεσης» που αντικατοπτρίζουν δυο διαφορετικούς τύπους τραυματισμού/μηχανικής καταπόνησης. Κατά τον τεχνητό τραυματισμό, εισήχθη βελόνα σε βάθος ενός εκατοστού και μελετήθηκαν τα χαρακτηριστικά ωρίμανσης για την χρονική περίοδο των 8 ημερών ωρίμανσης των καρπών σε θερμοκρασία δωματίου (0oC). Παρατηρήθηκε επαγωγή της ωρίμανσης στους τραυματισμένους καρπούς που αποτυπώθηκε με μεταβολές στη συνεκτικότητα, την αναπνευστική δραστηριότητα και την παραγωγή του αιθυλενίου. Επιπλέον, η χρώση του ασβεστίου (Ca2+) με χρήση δείκτη φθορισμού Fluo-3 AM εντόπισε χωρικά το Ca2+ στην περιοχή του τεχνητού τραυματισμού μετά από 8 ημέρες ωρίμανσης. Επιπρόσθετα, η μεταβολομική ανάλυση έδειξε ότι πολλά σάκχαρα, συμπεριλαμβανομένης της φρουκτόζης, της γλυκόζης και της σακχαρόζης, καθώς και οργανικά οξέα όπως το κιτρικό, και το γαλακτουρονικό οξύ αυξήθηκαν κατά τον τραυματισμό. Μέσω της μαζικής ανάλυσης της γονιδιακής έκφρασης των τραυματισμένων ακτινιδίων διαπιστώθηκε η αυξημένη έκφραση γονιδίων που εμπλέκονται στην αμυντική απόκριση, τη σύνδεση ιόντων ασβεστίου, τον κύκλο του κιτρικού οξέος, τα σάκχαρα, το δευτερογενή μεταβολισμό, τον μεταβολισμό των λιπιδίων, την αποικοδόμηση της πηκτίνης και τη βιοσύνθεση και διαμεταγώγηση του αιθυλενίου και της αυξίνης. Αντίθετα, γονίδια που σχετίζονται με τις υδατοπορίνες, παρουσίασαν μειωμένη έκφραση στους τραυματισμένους καρπούς. Κατά τη μηχανική συμπίεση, εφαρμόσθηκε δύναμη 15 kg, κατά τη συγκομιδή των καρπών καθώς και μετά από τη βραχεία (14 ημέρες) ή τη μακρά (3 μήνες) ψυχρή συντήρησή τους (0℃). Τα αποτελέσματα έδειξαν ότι και αυτός ο τύπος τραυματισμού προκάλεσε επαγωγή της ωρίμανσης. Επιπλέον, η σήμανση φθοριζόντων αντισωμάτων, που σχετίζονται με το κυτταρικό τοίχωμα, έδειξε ότι οι πρωτεΐνες αραβινογαλακτάνης και οι ξυλογλυκάνες μεταβλήθηκαν λόγω της συμπίεσης, ενώ η δράση της πηκτινομεθυλεστεράσης μειώθηκε μετά από μακρά ψυχρή συντήρηση. Επιπλέον, ενδοκυτταρικά σήματα ασβεστίου ανιχνεύθηκαν κοντά στις περιοχές συμπίεσης των ακτινιδίων αμέσως μετά τη μηχανική επεξεργασία. Αρκετοί πρωτογενείς μεταβολίτες παρουσίασαν μικρή διαφοροποίηση ενώ η τρανσκριπτομική ανάλυση ανέδειξε πολυάριθμα γονίδια, που εμπλέκονται σε βασικές λειτουργίες όπως στο μεταβολισμό των σακχάρων, τον κύκλο του κιτρικού οξέος, το κυτταρικό τοίχωμα, το αιθυλένιο και τις φυτο-ορμόνες, και επηρεάστηκαν από μηχανική καταπόνηση στο περικάρπιο και ιδιαίτερα στον πλακούντα. Επιπλέον, εντοπίσθηκαν πιθανοί μεταγραφικοί παράγοντες, συμπεριλαμβανομένων των bZIP53, WRKY40 και GATA17, που εμπλέκονται στην καταπόνηση κατά τη συμπίεση. Η μέτα-ανάλυση του συνόλου των μεταγραφικών δεδομένων για τον ιστό του περικαρπίου, ανέδειξε την ύπαρξη πολλών κοινώς εκφραζόμενων γονιδίων και μεταγραφικών παραγόντων σε συνθήκες τραυματισμού/μηχανικής καταπόνησης. Συνολικά, τα αποτελέσματα της παρούσας διδακτορικής διατριβής παρέχουν έναν πρώτο χαρακτηρισμό των μεταβολών που εμπλέκονται στον τραυματισμό των καρπών ακτινιδιάς και παρέχουν σημαντικές πληροφορίες για τη μοριακή βάση της μηχανικής καταπόνησης στους καρπούς ακτινιδιάς
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
- …
