1,720,960 research outputs found
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
Radial Glial Filopodia Motility in the developing Xenopus Laevis Optic Tectum is regulated through the cGMP-PKG1 pathway activation and is necessary for the normal function of the Excitatory Tectal Synapses
No full textRadial glia are elongated non-neuronal cells in the nervous system. They were first recognized to act as migrational scaffolds for neuroblasts. With the deepening understanding that glial cells are not passive but engaged in multilevel communication with neurons and other components of the nervous system, new functions were revealed for radial glia. Radial glia and radial glia-like cells act as progenitors for multiple cell types, form transient axo-glial synapses, guide axons and dendrites, wrap synapses and probably perform many other functions yet to be discovered. It is also likely that radial glia have similar or overlapping duties with astrocytes, especially in organisms like Xenopus laevis that do not seem to have astrocytes. Data from the Ruthazer lab has revealed that radial glia in the developing Xenopus laevis optic tectum sense excitatory neural activity and respond to it with increased motility of their filopodial processes. We aimed to better understand the mechanisms and functions for these glial dynamics. Using the techniques of tectal electroporation of DNA constructs and in vivo time-lapse imaging of the cellular interactions in the brain, we determined that cGMP and cGMP-dependent protein kinase PKG1 are implicated in translating neural NMDA receptor activity levels to glial filopodia motility. We also noticed that antagonizing mGluR5 receptor has a small effect on the filopodial motility. We manipulated glial filopodial behaviour by overexpression of modified small GTPases in glia and investigated the effects on neighboring tectal excitatory neurons by patch-clamp electrophysiology measurements. In the case of glial expression of constitutively active RhoA, glial filopodia retracted severely and both frequency and amplitude of mEPSCs were decreased. Interestingly, when expressing another small GTPase - dominant negative Rac - glial filopodia were retained but moved less, and only mEPSC frequency but not amplitude was affected in nearby neurons. This indicates that not just the mere presence of the glial filopodia but also their motility is critical for normal excitatory neuron development.Les cellules de la glie radiale sont des cellules allongées non neuronales du système nerveux. Elles ont d'abord été reconnues comme agissant à l'instar d'échafaudages pour la migration des neuroblastes. Avec l'approfondissement de la compréhension que les cellules gliales ne sont pas passives, mais engagées dans une communication à multiples niveaux avec les neurones et d'autres composants du système nerveux, de nouvelles fonctions ont été révélées pour la glie radiale. Glie radiale et cellules ressemblant aux cellules gliales radiales agissent comme des progéniteurs pour plusieurs types de cellules, forment des synapses transitoires axo-gliales, guident les axones et les dendrites, enveloppent les synapses et effectuent probablement de nombreuses autres fonctions encore à découvrir. Il est également probable que la glie radiale a des fonctions similaires ou chevauchantes avec les astrocytes, en particulier dans les organismes comme Xenopus laevis, qui ne semble pas avoir d'astrocytes. Les données du laboratoire du Dr Ruthazer ont révélé que la glie radiale dans le tectum optique de Xenopus laevis en développement ressent l'activité neurale excitatrice et y répond par une motilité accrue de ces extensions filopodiales. Nous avons cherché à mieux comprendre les mécanismes et les raisons de cette dynamique gliale.En utilisant les techniques d'électroporation tectale avec des construction d'ADN et l'imagerie in vivo à intervalle régulier pour suivre les interactions cellulaires dans le cerveau, nous avons déterminé que le GMPc et une protéine kinase GMPc-dépendante, Pkg1, sont impliqués dans l'interprétation des niveaux d'activité des récepteurs neuronaux NMDA pour réguler la motilité des filopodes gliaux. Nous avons également remarqué que le récepteur antagoniste mGluR5 a un léger effet sur la motilité filopodiale. Nous avons manipulé le comportement filopodial de la glie par la surexpression de petites GTPases modifiées dans les cellules gliales et étudié les effets sur les neurones excitateurs tectaux voisins par des mesures d'électrophysiologie patch-clamp. Dans le cas de l'expression de RhoA constitutivement active, les filopodes gliaux se rétractaient sévèrement, et à la fois la fréquence et l'amplitude des mEPSC des neurones excitateurs diminuaient. Fait intéressant, lors de l'expression gliale d'une autre petite GTPase - Rac dominant négatif – les filopodes gliaux étaient retenus mais, faits de façon à moins se déplacer, seule la fréquence des mEPSC des neurones mais pas leur amplitude étaient affectée. Cela indique que ce n'est pas simplement la présence des filopodes gliaux mais aussi leur motilité qui est essentielle pour le développement normal des neurones excitateurs
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
Mitigation translocation of protected plant species and its evaluation in Estonia on the example of Cypripedium calceolus
No full textMagistritöö
Keskkonnakorralduse ja -poliitika õppekavalArendustegevus avaldab üha suuremat survet looduslikele elupaikadele ja liikidele, mille tagajärgedeks on elupaikade kadu ja killustumine ning liikide levikualade ja arvukuse vähenemine. Eriti haavatavad on kaitsealused liigid. Kaitsealuste taimeliikide osas rakendatakse arendustegevuse lubamisel leevendava meetmena ümberasustamist, mis peaks tagama isendite säilimise, kuid mille tulemuslikkus on sageli küsitav või vähe uuritud. Magistritöö eesmärk on kirjeldada Eestis kehtestatud kaitsealuste taimede ümberasustamise regulatsiooni, tutvustada ja analüüsida praktilisi näiteid ning analüüsida ümberasustamise edukust kauni kuldkinga näitel Võõbu-Mäo lõigu teeprojektis. Töö uurimisobjektiks on 2019. aastal toimunud kauni kuldkinga ümberasustamine ja sellele järgnenud viie aasta seire andmed. Töös on kasutatud kvantitatiivset uurimismeetodit. Analüüsitud on kauni kuldkinga elumust pärast ümberasustamist ning peamisi liigi elujõulisuse näitajaid ja nende muutusi viie aasta jooksul. Lisaks on analüüsitud elumust seitsme teise Eestis toimunud käpaliste ümberasustamise puhul. Tulemused näitavad, et kauni kuldkinga elujõulisuse näitajad on olnud kõikuvad pärast ümberasustamist, nii õitsvate võsude osakaalu kui võsude koguarvu vaates, ning lõplike järelduste tegemiseks on vaja jätkata seiretega seni, kuni on võimalik hinnata ümberasustatud populatsiooni taastootmist, mis on olulisem üksikute isendite elujõust. Teised Eesti käpalistega seotud ümberasustamised on elumuse poolest olnud samuti kõikuvad (elumus esimesel aastal pärast ümberasustamist 50-100%, langedes teatud juhtudel kolmandaks aastaks nulli). Võõbu-Mäo lõigu teeprojekti alalt ümberasustatud kauni kuldkinga elumus oli esimesel aastal pärast ümberistutamist 99% ja viiendal aastal 94%, mis on võrdluses teiste maade kogemustega kõrge näitaja ja võimaldab ümberasustamist hinnata leevendava meetmena liigi puhul sobivaks olulise avaliku huviga projektide lubamisel. Siiski tuleks võrreldes varasemaga praktikaga ümberasustamise loas seada selged eesmärgid ümberasutamise edukusele, vajadusel sätestada hooldusülesanded ning määrata piisav seireperiood, mis võimaldab pädevalt hinnata ümberasustamise edukust.Development activities are placing increasing pressure on natural habitats and species, leading to habitat loss, fragmentation, and declines in species distribution and abundance. Protected species are especially vulnerable. In the case of protected plant species, translocation is often employed as a mitigation measure when permitting development projects, aiming to preserve individual specimens. However, the effectiveness of such measures is frequently uncertain or inadequately studied. This thesis examines the regulatory framework governing the translocation of protected plant species in Estonia, presents and analyses practical case studies, and evaluates the success of translocation efforts through a focused case study on Cypripedium calceolus (lady’s slipper orchid) in the Võõbu–Mäo road construction project. The study is based on the 2019 translocation of C. calceolus and five years of subsequent monitoring data. A quantitative research approach is employed to assess the survival and viability of the translocated population, including key indicators of population health and their changes over time. The thesis also considers the outcomes of seven additional orchid translocations conducted in Estonia. Results indicate fluctuating viability indicators for C. calceolus post-translocation, particularly in the proportion of flowering shoots and total shoot numbers. Ongoing monitoring is essential to evaluate long-term reproductive success, which is more indicative of population viability than individual survival alone. Other orchid translocations in Estonia have shown similarly fluctuating survival rates, with initial survival rates ranging from 50% to 100%, and in some cases declining to zero within three years. The survival rate of C. calceolus translocated from the Võõbu–Mäo road project area was 99% in the first year and 94% in the fifth year—figures that are high compared to international experiences and suggest that translocation can serve as a viable mitigation measure for projects of significant public interest. However, compared to previous practices, clearer objectives for translocation success should be defined in the legal permit, maintenance obligations should be stipulated if necessary, and an adequate monitoring period should be set to allow for a competent assessment of the translocation's success
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
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