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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
Exercise induced arterial desaturation in recreationally active males at moderate altitude helps explain variability in relationship between total hemoglobin mass and VO2max
Get PDFExercise induced arterial desaturation (EIAD) occurs in a large percentage of highly trained athletes at sea-level (SL), but is extremely rare in less trained populations at SL. Altitude increases the risk for EIAD, but little research has looked at the prevalence of EIAD in recreationally active males at moderate altitude (MA). Moreover, previous research has identified a strong correlation between total hemoglobin mass (tHb) and maximal oxygen uptake (VO2max). However, no research has looked at the effect that EIAD has on the VO2max-tHb relationship. We sought to determine the prevalence of EIAD in recreationally active males at moderate altitude, and further to determine how this effected the VO2max-tHb relationship. Additionally, we looked at how tHb and EIAD influenced performance at VO2max. Six recreationally active subjects living at moderate altitude (~1655m) completed 5 separate visits. This consisted of a graded exercise test to determine VO2max, two endurance performance tasks at peak power output, and two tHb measurements using the optimized carbon monoxide rebreathing procedure. Preliminary results show that four of six subjects experienced EIAD. Additionally, while tHb alone explained a large portion of the variability in VO2max (adj r2(rel. VO2max, rel. tHb) = 0.66; adj r2(VO2max, tHb) = 0.86), adding arterial oxygen saturation (SaO2) into the model increased this relationship (adj R2(rel. VO2max, rel. tHb, SaO2) = 0.72; adj R2(VO2max, tHb, SaO2) = 0.90). No correlation was found between SaO2, tHb, and performance at VO2max. Our results demonstrate that the VO2max-tHb model can be improved by taking into account SaO2, and highlight the importance of accounting for SaO2 as well as tHb as markers for oxygen transport and whole body oxygen carrying capability in relation to VO2max.</p
Alterations in the VO2-Power Relationship above the Lactate Threshold during a Graded Bicycling Exercise Protocol
Get PDFPurpose: The purpose of this study was to examine the changes in VO2-power and energy expenditure-power relationships below (BLT) and above (ALT) the lactate threshold (LT). Methods: Thirty active subjects (15 males, 15 females) performed a graded exercise protocol on a bicycle ergometer. Initial power outputs were determined based upon subject size and training status. Workloads were increased by 30-Watt increments every 4 minutes until exhaustion. Indirect calorimetry and blood lactate measures were performed during each stage. Linear regressions were developed BLT and
ALT for VO2-power and energy expenditure-power (EE-power) relationships. Only 18 subjects (13 males, 5 females) had a sufficient number of data points BLT and ALT to adequately describe the linear regressions. Results: The individual R2
values for VO2-power and EE-power relationships at both BLT and ALT were 0.93 or higher. The mean (±SD) VO2-power slope (mlO2/min/Watt) and intercept (mlO2/min) for ALT were significantly (p<0.01) steeper and lower than the mean BLT slope and intercept (Slope: ALT = 12.7±2.9 vs. BLT = 8.8±1.7; Intercept: ALT = -146.2±617.1 vs. BLT = 656.2±186.8). The mean EE-power slope (kcal/min/Watt) and intercept (kcal/min) for ALT were significantly (p<0.01) steeper and lower than the mean BLT slope and intercept (Slope: ALT = 0.067±0.015 vs. BLT = 0.045±0.009; Intercept: ALT = -1.624±3.248 vs. BLT = 2.934±0.917). No sex effect was observed on the changes in slope or intercept for either VO2-power or EE-power. Conclusion: The relationship between power and either VO2 or energy expenditure during a graded bicycle test suggests an increased oxidative energy requirement relative to power above the lactate threshold
Alterations in the VO2-Power Relationship above the Lactate Threshold during a Graded Bicycling Exercise Protocol
Get PDFPurpose: The purpose of this study was to examine the changes in VO2-power and energy expenditure-power relationships below (BLT) and above (ALT) the lactate threshold (LT). Methods: Thirty active subjects (15 males, 15 females) performed a graded exercise protocol on a bicycle ergometer. Initial power outputs were determined based upon subject size and training status. Workloads were increased by 30-Watt increments every 4 minutes until exhaustion. Indirect calorimetry and blood lactate measures were performed during each stage. Linear regressions were developed BLT and
ALT for VO2-power and energy expenditure-power (EE-power) relationships. Only 18 subjects (13 males, 5 females) had a sufficient number of data points BLT and ALT to adequately describe the linear regressions. Results: The individual R2
values for VO2-power and EE-power relationships at both BLT and ALT were 0.93 or higher. The mean (±SD) VO2-power slope (mlO2/min/Watt) and intercept (mlO2/min) for ALT were significantly (p<0.01) steeper and lower than the mean BLT slope and intercept (Slope: ALT = 12.7±2.9 vs. BLT = 8.8±1.7; Intercept: ALT = -146.2±617.1 vs. BLT = 656.2±186.8). The mean EE-power slope (kcal/min/Watt) and intercept (kcal/min) for ALT were significantly (p<0.01) steeper and lower than the mean BLT slope and intercept (Slope: ALT = 0.067±0.015 vs. BLT = 0.045±0.009; Intercept: ALT = -1.624±3.248 vs. BLT = 2.934±0.917). No sex effect was observed on the changes in slope or intercept for either VO2-power or EE-power. Conclusion: The relationship between power and either VO2 or energy expenditure during a graded bicycle test suggests an increased oxidative energy requirement relative to power above the lactate threshold
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
Exercise induced arterial desaturation in recreationally active males at moderate altitude helps explain variability in relationship between total hemoglobin mass and VO2max
Get PDFExercise induced arterial desaturation (EIAD) occurs in a large percentage of highly trained athletes at sea-level (SL), but is extremely rare in less trained populations at SL. Altitude increases the risk for EIAD, but little research has looked at the prevalence of EIAD in recreationally active males at moderate altitude (MA). Moreover, previous research has identified a strong correlation between total hemoglobin mass (tHb) and maximal oxygen uptake (VO2max). However, no research has looked at the effect that EIAD has on the VO2max-tHb relationship. We sought to determine the prevalence of EIAD in recreationally active males at moderate altitude, and further to determine how this effected the VO2max-tHb relationship. Additionally, we looked at how tHb and EIAD influenced performance at VO2max. Six recreationally active subjects living at moderate altitude (~1655m) completed 5 separate visits. This consisted of a graded exercise test to determine VO2max, two endurance performance tasks at peak power output, and two tHb measurements using the optimized carbon monoxide rebreathing procedure. Preliminary results show that four of six subjects experienced EIAD. Additionally, while tHb alone explained a large portion of the variability in VO2max (adj r2(rel. VO2max, rel. tHb) = 0.66; adj r2(VO2max, tHb) = 0.86), adding arterial oxygen saturation (SaO2) into the model increased this relationship (adj R2(rel. VO2max, rel. tHb, SaO2) = 0.72; adj R2(VO2max, tHb, SaO2) = 0.90). No correlation was found between SaO2, tHb, and performance at VO2max. Our results demonstrate that the VO2max-tHb model can be improved by taking into account SaO2, and highlight the importance of accounting for SaO2 as well as tHb as markers for oxygen transport and whole body oxygen carrying capability in relation to VO2max.</p
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
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