1,720,984 research outputs found
Sviluppo del sistema radicale nelle piante: dal livello cellulare a quello ecosistemico
No full textIl cambiamento climatico sta modificando in profondità i processi di crescita delle piante e il funzionamento degli ecosistemi. Tuttavia, la maggior parte delle conoscenze disponibili si concentra ancora sui tratti epigei, mentre le risposte dell’apparato radicale restano meno indagate. Questa tesi intende colmare tale lacuna, affrontando il tema su più livelli biologici — cellulare, individuale ed ecosistemico — per comprendere come le radici reagiscano agli stress ambientali e alle diverse pratiche gestionali.
Sul piano cellulare, gli esperimenti condotti su Populus nigra L. hanno messo in luce risposte divergenti del cambio vascolare in condizioni di siccità e calore combinati. Il cambio radicale ha mantenuto un’elevata attività e mostrato capacità di recupero dopo il rewatering, mentre quello del fusto ha evidenziato una minore resilienza, segnalando un’elevata plasticità organo-specifica nella crescita secondaria.
A livello della pianta individuale, il biochar è stato valutato come possibile sostituto sostenibile della torba nei substrati vivaistici. I risultati hanno indicato che la morfologia radicale non differiva significativamente rispetto alla torba, ma lo stato idrico fogliare risultava migliore, suggerendo un duplice beneficio: incrementare la performance delle piante e, allo stesso tempo, ridurre l’impronta ambientale dell’orticoltura.
Infine, a scala ecosistemica, lo studio condotto su Pistacia lentiscus negli ambienti mediterranei ha mostrato come fattori quali la competizione, la successione secondaria e il clima contribuiscano a modellare la crescita di radici e fusti. Le analisi dei tratti funzionali delle radici fini e delle foglie hanno inoltre evidenziato strategie sia convergenti sia divergenti per l’acquisizione delle risorse e la tolleranza agli stress.
Nel complesso, i risultati sottolineano come la resilienza delle piante non possa essere spiegata considerando un singolo organo o una sola scala di analisi. Solo un approccio integrato, che tenga conto congiuntamente dei tratti epigei e ipogei, consente di cogliere le differenze che influenzano crescita, sopravvivenza e allocazione del carbonio. Collegando i processi cellulari, le strategie specifiche degli organi e le dinamiche degli ecosistemi, questa tesi propone un quadro interpretativo olistico per prevedere le risposte delle piante e degli ecosistemi ai cambiamenti globali. Tale prospettiva risulta fondamentale per migliorare la gestione forestale, promuovere pratiche orticole prive di torba e garantire la conservazione dei servizi ecosistemici in scenari di riscaldamento climatico e risorse sempre più limitate.Climate is profoundly reshaping plant growth and ecosystem functioning, yet much of our current knowledge relies on aboveground traits, leaving belowground responses underexplored. This dissertation addresses this gap by integrating analyses at multiple biological scales—cellular, individual, and ecosystem levels—to investigate how roots respond to environmental stresses and management practices.
At the cellular level, experiments on Populus nigra L. revealed contrasting responses of the vascular cambium under combined heat and drought stress. Root cambium maintained higher activity and showed recovery capacity after rewatering, while stem cambium exhibited impaired resilience, underscoring organ-specific plasticity in secondary growth. At the individual level, biochar was tested as a sustainable alternative to peat in nursery growing media. Results demonstrated comparable root morphology to peat substrates, but improved leaf water status, highlighting biochar’s dual role in promoting plant performance and reducing the environmental footprint of horticulture. At the ecosystem level, studies on Pistacia lentiscus across the Mediterranean ecosystem illustrated how competition, secondary succession, and climate interact to shape root and shoot growth dynamics. Fine root and leaf trait analyses further revealed both convergent and divergent strategies in resource acquisition and stress tolerance.
Together, these findings demonstrate that plant resilience cannot be fully understood by focusing on a single organ or scale. Instead, integrating above- and belowground perspectives reveals differences that critically impact growth, survival, and carbon allocation. By linking cellular processes, organ-specific strategies, and ecosystem dynamics, this thesis advances a holistic framework for predicting plant and ecosystem responses to global change. Such an approach is essential for improving forest management, guiding peat-free horticultural practices, and enhancing our knowledge to preserve ecosystem services in a warming and resource-limited world
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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
Resting state network dynamic reconfiguration and neuropsychological functioning in temporal lobe epilepsy: An HD-EEG investigation
No full textTemporal lobe epilepsy (TLE) is nowadays considered a network disorder impacting several cognitive domains. In this work we investigated dynamic network reconfiguration differences in patients with unilateral TLE compared to a healthy control group, focusing on two connectivity indices: flexibility and integration. We apply these indices for the first time to high-density EEG source-based functional connectivity. We observed that patients with TLE exhibited significantly lower flexibility than healthy controls in the Control, Default Mode and Attentive Dorsal networks, expressed in the delta, theta and alpha bands. In addition, patients with TLE displayed greater integration values across the majority of the resting state networks, especially in the delta, theta and gamma bands. Relevantly, a higher integration index in the Control, Attentive Dorsal and Visual networks in the delta band was correlated with lower performance in visual attention and executive functions. Moreover, a greater integration index in the gamma band of the Control, Somatomotor and Temporoparietal networks was related to lower long-term memory performance. These results suggest that patients with TLE display dysregulated network reconfiguration, with lower flexibility in the brain areas related to cognitive control and attention, together with excessive inter-network communication (integration index). Finally, the correlation between network integration and the reduced cognitive performance suggests a potential mechanism underlying specific alterations in neuropsychological profile of patients with TLE
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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