1,721,019 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
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
Disparate and parallel craniofacial climatic adaptations in native populations of Asia, North America, and South America
No full textUnderstanding the impact that climate had in shaping cranial variation is critical for inferring the evolutionary mechanisms that played a role in human diversification. Here, we provide a comprehensive study aiming to analyze the association between climate and cranial variation of high latitude populations living in temperate to cold environments of Asia, North America, and South America. For this, we compiled a large morphometric dataset (N = 2633), which was combined with climatic and genomic data. We tested the influence of climate on the facial skeleton, nasal protrusion, and cranial vault and through multiple statistical tests at two geographical scales: intracontinental and intercontinental. We show that populations living in cold areas share a morphological pattern characterized by an increase in nasal height, facial and orbital heights and widths, a decrease in facial protrusion, and larger, longer, and lower cranial vaults. There are also distinctive features; populations from north Asia present the tallest noses, largest faces, and cranial vaults of the whole sample. Nasal breadth dimensions show small values in Asians, large values in South Americans, and non-significant changes in arctic North America. The morphological pattern in populations living at high latitude may be the result of parallel adaptation, as supported by physiological, morphometric, ecological, and genetic explanations, while the differences in magnitude and phenotypic expression could be due to the diverse population histories, severity of climate, and cultural strategies. Overall, our study shows that climate is a relevant factor shaping modern human morphology and it should be considered when studying modern human evolution and diversification
Diet and Dental Health: Differential Diets of the Middle Horizon (CE 400-1000) in San Pedro de Atacama, Northern Chile
Get PDFThis research utilizes dental health data from three archaeological sites from the Middle Horizon (AD 400-1000) period in the Atacama oases of northern Chile: Coyo 3, Quitor 6, Solcor 3 elite, and Solcor 3 non-elite. The Middle Horizon is characterized in the Andes by the establishment of the Tiwanaku State, which exerted political and economic influence in much of the South-Central Andes, which is explored here using the two Solcor 3 sites. In this thesis, I analyze the aspects of oral health of the population using the prevalence of dental caries, abscesses, tooth loss, and occlusal wear. I calculated the frequency of each type of dental pathology for males, females, and the total population for different parts of the dental arcade, to test if there are significant differences in oral health, and therefore in dietary practices, between the sites. The dental arcade was divided into six sections: anterior, posterior, superior, inferior, right, and left. Then, using statistical tests of Chi-Square and Analysis of Variance, I tested for significant differences between each section and between sexes. I found that there was a significant difference in total presence of dental pathological conditions throughout the entire dental arcade between males and females at all sites, showing a possible difference in diet between the sexes. In addition, all sites had significant differences between the posterior and anterior sections of the dental arcade and two sites, Coyo 3 and Quitor 6, had significant differences between the superior and inferior sections of the dental arcade when all dental conditions were considered. The Solcor 3 Pre-Tiwanaku and Solcor 3 Tiwanaku individuals had similar rates of abscesses and antemortem tooth loss, but significantly different rates of caries, possibly suggesting a change in diet after the establishment of the Tiwanaku state.No embargoAcademic Major: Anthropological Science
Variation in the Cranial Morphology of Hominin Specimens: Geographic Distinctions
No full textMorphological variation has been widely used to identify differences between hominins and define their species. Despite this accumulated work, there is little consensus regarding the definition of most hominin species, which has significantly impacted our understanding of hominin relationships. Therefore, it is important to better contextualize the morphological variation seen among hominin fossil crania, to better understand species morphological boundaries and evaluate the significance of geographic dispersion within species. To explore hominin morphological variation, we collected 29 cranial linear measurements from 162 specimens from the literature. We excluded specimens and variables with more than 35% of missing values, resulting in 111 specimens and 17 measurements, divided into 15 species. The Homo species were further divided by geographic regions, resulting in 24 groups. We used linear discriminant analysis to explore morphological affinities among species and groups. The results show significant overlap between late Homo species irrespective of their geographic regions. Paranthropus and Australopithecus are distinct from late Homo, and H. habilis and rudolfensis occupy intermediary positions. The similarities in cranial morphological measurements observed within Homo across geographic boundaries support a greater need for broad species definition within the genus, with relatively small morphological changes among them. Nevertheless, Homo habilis and rudolfensis are clearly distinct from other Homo species, and our results support the separation of the Paranthropus and Australopithecus genera. These results are relevant to discuss the validity of species nomenclatures adopted in the past, given that over 70 different species names have been suggested for hominin fossils in the past.A one-year embargo was granted for this item.Academic Major: Anthropological SciencesAcademic Major: Histor
Biodistance Analysis of North and South American Populations
Get PDFThis project was awarded third place in "History of People and Art" at the 2018 Richard J. And Martha D. Denman Undergraduate Research ForumArchaeological evidence suggests that humans were already present in both North and South America by 12.5-11.5 kyr BP. However, the number of waves and routes from Asia are much debated, and the early (~12 kya) settlement in Brazil bring into question previous ideas about human migration into the region. Given the debate surrounding this topic, it is important to understand the genetic diversity between North and South Americans. In this project, I used biodistance analysis to explore the cranial morphological variation observed in the New World, and how this variation is structured between the two American continents. Human craniometrics data from previous studies (Hanihara, 1996; Herrera, et al., 2017; Hubbe, et al., 2014; Hubbe, et al., 2015; Neves et al., 2013) was used to create a detailed understanding of the biological variation of the region. These data cover populations in North America (USA and Mexico) and South America (Brazil, Colombia, and Peru), as well as comparative series from Asia and Australo- Melanesia. Results show that Atlantic South America exhibits the highest Fst value (0.15) out of all groups analyzed. Whereas the Andean (0.068), North Americans (0.07), and East Asian (0.077) populations have the lowest Fst values. These findings reveal high genetic diversity of South American groups and calls into question the validity of grouping North and South Americans in genetic studies.This project was funded by a scholarship from the Ohio State University College of Arts and Sciences Honors undergraduate Research Scholarship.No embargoAcademic Major: Anthropolog
The Accuracy of Age Estimation Using Transition Analysis in the Hamann-Todd Collection
Get PDFTrying to reconstruct the demographic parameters of past populations using skeletal data is challenging for several reasons. First, skeletal traits are proxy to biological age, which does not always reflect chronological age. Second, different parts of the skeleton age at different rates, making age estimation problematic when based on methods that only incorporate a few anatomical features. A proposed solution to address this limitation is transition analysis (TA), a multifactorial method of age estimation that incorporates information from the pubic symphysis, iliac auricular area, and cranial sutures. However, despite its methodological refinement, TA has been shown to have varying degrees of accuracy when applied to different known-age skeletal samples. This thesis contributes to the discussion about TA's accuracy by estimating the age for 221 individuals from the Hamann-Todd Collection. We contrasted the maximum likelihood estimates generated through TA to the known ages, and analyzed the absolute error for the entire sample, as well as according to sex and ancestry. Estimates show an average absolute error of 11.6 (SD=10.3) years, with white individuals' average absolute errors (14.1 years) being significantly higher than black individuals' (9.1 years; Independent Samples T-Test p<0.001). There are no significant differences in the absolute errors between sexes (males = 11.2; females = 12.1; Independent Samples T-Test p=0.526). A weak to moderate positive correlation was found between known age and absolute error for white males (R2=0.3688; p<0.001), white females (R2=0.2590; p<0.001), and black males (R2=0.1379; p=0.006). The accuracy of transition analysis age estimates varied when each anatomical region was analyzed independently, but the combination of all three anatomical regions yielded the most accurate age estimates. These findings further support that TA accuracy depends on the prior distribution used and that in the case of the Hamann-Todd Collection, the accuracy for white individuals is more influenced by this limitation than when black individuals are analyzed.No embargoAcademic Major: Anthropological Science
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
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