1,720,959 research outputs found
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
DISSECTING THE NEURAL CIRCUITRY BEHIND SOCIAL DECISION-MAKING PROCESSES BY DIRECT AND OBSERVATIONAL LEARNING
Get PDFGli esseri umani sono animali sociali che raramente vivono in completo isolamento. Pertanto, le nostre decisioni spesso prendono la forma di decisioni sociali, che riguardano altri interlocutori e possibilmente vengono influenzate da essi. I processi decisionali possono portare, a loro volta, a manifestazioni sociali rilevanti come i comportamenti altruistici o egoistici, i quali determinano in modo significativo la nostra società. Gli esseri umani possono apprendere questi comportamenti attraverso l'apprendimento diretto o attraverso l'osservazione degli altri, che prende il nome di apprendimento osservativo. Tuttavia, i fondamenti neurobiologici alla base delle scelte altruistiche o egoistiche, sia attraverso l'apprendimento diretto che attraverso l'osservazione, non sono ancora chiari. Negli ultimi anni, molti studi hanno descritto in animali non umani, inclusi i roditori, comportamenti che possono assomigliare all’altruismo. Inoltre, i roditori sono in grado di apprendere task spaziali e affettivi anche osservando i loro simili. Pertanto, i roditori offrono la possibilità di analizzare in dettaglio le basi neurali dei processi decisionali sociali sia quando queste vengono apprese tramite apprendimento diretto sia tramite osservazione.
Per il mio progetto di dottorato, abbiamo sviluppato un task decisionale in ambito sociale (SDM) in cui i topi possono decidere se condividere (scelta altruistica) o no (scelta egoistica) una ricompensa con i loro conspecifici. Abbiamo osservato che i topi maschi adulti, nel complesso, preferivano condividere la ricompensa con i loro conspecifici. Tuttavia, la preferenza per le scelte altruistiche è stata modulata da fattori interni ed esterni come il sesso, la familiarità, la motivazione, l'empatia e la dominanza sociale. Inoltre, le nostre manipolazioni chemogenetiche inibitorie hanno dimostrato che l'amigdala basolaterale (BLA) è coinvolta nella formazione di una preferenza altruistica. In particolare, i neuroni BLA che proiettano alla regione prelimbica (PL) della corteccia prefrontale hanno mediato lo sviluppo di una preferenza per le scelte altruistiche, mentre le proiezioni da PL a BLA hanno determinato decisioni più egoistiche.
Abbiamo anche dimostrato che i topi sono in grado di acquisire il task del SDM attraverso l'osservazione dei loro simili. In particolare, i topi che hanno osservato il task hanno mostrato prestazioni migliori rispetto ai loro compagni senza osservazione. A livello neurale, l'ippocampo dorsale (dCA1) si è dimostrato fondamentale per l'acquisizione dei processi decisionali sociali attraverso l'osservazione degli altri. Infatti, il silenziamento della regione dCA1, nonostante non abbia compromesso l’apprendimento procedurale del nostro task, ha rallentato considerevolmente la creazione di una preferenza sociale attraverso l’osservazione. Quindi, questo progetto di dottorato fa luce sui circuiti neurali alla base dei processi decisionali sociali tramite l'apprendimento diretto o osservazionale, con rilevanza per patologie come i disturbi neuropsichiatrici o neurodegenerativi spesso associati a disfunzioni sociali, inclusi i deficit decisionali sociali.Humans are social animals that rarely live in complete isolation. Thus, human decisions often take the form of social decisions, regarding other social agents and possibly influenced by them. Social decision-making processes can lead, in turn, to relevant social manifestations such as altruistic or selfish behaviors that significantly determine our society. Humans can learn these behaviors by direct experience (ie, direct learning) or through the observation of others (ie, observational learning). However, the neurobiology underlying altruistic or selfish choices, either by direct or observational learning, is still unclear. In recent years, many studies described social decision-making processes and associated behaviors such as altruistic-like behaviors in nonhuman animals, including rodents. Moreover, rodents are able to learn spatial and affective tasks also by observing their similars. Thus, rodents offer the possibility to dissect in detail the neural bases of social decision-making processes either when these are learned by direct or observational learning.
For my PhD project, we developed a social decision-making task (SDM) in which
mice can decide whether to keep for themselves (ie, selfish choice) or share a reward with their conspecifics (ie, altruistic choice). We found that adult male mice overall preferred to share food with their similars. However, preference for altruistic choices was modulated by internal and external determinants such as sex, familiarity, motivation, empathy and social dominance. Besides, our inhibitory chemogenetic manipulations demonstrated that the basolateral amygdala (BLA) is involved in the establishment of altruistic decisions. In particular, BLA neurons projecting to the prelimbic (PL) region of the prefrontal cortex mediated the development of a preference for altruistic choices, whereas PL projections to the BLA produced a drift towards selfish acts.
We also revealed that mice were able to acquire the SDM through observation. In particular, observer mice showed an enhanced performance compared to their conspecific demonstrators. At the neural level, we found that the dorsal region of the hippocampus (dCA1) was fundamental for the acquisition of social decision-making processes through others’ observation. Indeed, dCA1 silencing, while did not compromise the procedural learning of the SDM task, considerably slowed the establishment of a clear social preference through observation. Then, this PhD project sheds light on the neural circuitry underlying social decision-making processes either by direct or observational learning, with relevance to pathologies such as neuropsychiatric or neurodegenerative disorders often associated with social dysfunction, including social decision-making deficits
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
“Can someone tell me the way” : A study on human wayfinding behaviour under incorrect information
No full textFinding the right path is a key aspect for successful navigation through the environment, with technologies such as the Global Positioning System (GPS) having improved this. However, human navigators can still be met with incorrect information either from devices or peers. The literature on how individuals then successfully navigate is limited. The current study attempts to fill in some of the gaps, assessing both individual and group differences. The navigation performance of twenty-five young adults was tested using a Virtual Environment (VE) built with Unreal Engine 4. Participants’ self-assessment of spatial ability, trait anxiety, and wayfinding preferences was further assessed through a series of pre- and post-test measures. Using quantitative data analysis, no significant differences in wayfinding strategies when given incorrect information were found and furthermore there was no interaction between trait anxiety and navigational performance. However, participants in general experienced increased difficulty when the incorrect information given was with regards to landmarks. Furthermore, males had decreased accuracy compared to females but only when given incorrect turn information. Even with this lower performance in terms of accuracy, males still rated themselves higher with regards to spatial ability. These results are particularly interesting for human navigation research and might be used to improve GPS-devices or other technology used for navigation (e.g. taking into account gender differences). Further research is needed due to some limitations present in the current study including a limited sample size.Att hitta rätt väg är grunden för att lyckas hitta rätt väg genom sin omgivning och modern teknologi som GPSen (Global positioning system) har förbättrat detta. Dock så kan en mänsklig navigatör fortfarande presenteras med felaktig information, vare sig det är från teknologiska enheter eller andra individer. Den litteratur som är tillgänglig angående hur folk anpassar sig till detta och ändå försöker finna rätt väg är begränsad. Denna studie är till för att fylla denna kunskapslucka, både på individuell och på gruppnivå. 25 unga vuxnas navigationsförmågor undersöktes med hjälp av en virtuell miljö skapad i Unreal Engine 4. Deltagarna självutvärderade också sina spatiala förmågor, ångestbenägenhet samt preferenser när det kommer till att utforska och hitta rätt väg. Något som i sin tur komplementerades både före och efter själva experimentet. Kvantitativ dataanalys uppvisade inga märkbara skillnader i navigeringsstrategier när felaktig information hade getts och ingen koppling kunde etableras mellan ångestbenägenhet och prestation. Det fanns dock en trend i upplevda svårigheter när felaktig information angående milstolpar angavs. Män presterade sämre med lägre precision än kvinnor vid missvisande information om svängtillfälle. Men trots detta hade männen en tendens att betygsätta sin spatiala förmåga högre än kvinnor. Dessa resultat är av specifikt intresse för forskning inom navigation och kan användas till att förbättra GPS-enheter samt annan teknologi som utnyttjas för liknande syften (t.ex. för att ta hänsyn till könsskillnaderna). Men mer forskning krävs på grund av vissa begränsningar i undersökningen, inklusive en begränsad provstorlek
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
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