1,720,979 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
Beyond the sweetness
No full textWe refer to the thought-provoking article "WHO cancer arm deems aspartame 'possible carcinogen'; consumption limits unchanged"(The Star, July 14; online at bit.ly/aspartamewho), which emphasised our shared concern over the health implications of the use of non-nutritive sweeteners such as aspartame and sucralose in Malaysia
Contamination of nuclear fractions with plasma membrane lipid rafts
No full textSubcellular fractionation is central to a range of cell biological, biochemical and proteomic studies. Purification of nuclear-enriched fractions is critical for studies on nuclear structure and function. Here we show that detergent-based nuclear isolation methods cause the redistribution of proteins associated with plasma membrane lipid rafts into nuclear fractions. The glycosylphosphatidylinositol (GPI)-anchored prion protein (PrPC) and a GPI-anchored construct of angiotensin converting enzyme (GPI-ACE), as well as the lipid raft markers flotillin-1 and -2, were present in the nuclear fractions derived using three different subcellular fractionation protocols. Incubation of intact cells with bacterial phosphatidylinositol-specific phospholipase C (PI-PLC), which cleaves GPI-anchored proteins from the cell surface, significantly reduced the amount of PrPC and GPI-ACE in the nuclear fraction. Buoyant sucrose density gradient centrifugation in the presence of Triton X-100 of the nuclear fraction resulted in a significant proportion of the GPI-anchored proteins being recovered in the low density lipid raft fractions. These data indicate that the nuclear fraction isolated using such subcellular fractionation protocols is contaminated with components of plasma membrane lipid rafts and raises questions as to the integrity of the nuclear fraction isolated by such protocols for use in detailed cell biological studies and proteomics analysis. © 2007 Wiley-VCH Verlag GmbH & Co. KGaA
Gender Differences in Body Image Perception among Northern Malaysian Tertiary Students
No full textAims: This study examined the association of socio-cultural and psychological factors with body shape concern, perception and body weight perception among tertiary students of Northern Malaysia. Study Design: This is a cross-sectional study. Place and Duration of Study: Universiti and Kolej Tunku Abdul Rahman (UTAR and KTAR), Perak campuses, between August 2011 and January 2012. Methodology: A total of 1003 students were recruited (M = 431, F = 572; mean age 19.96 ± 1.51) and their body image perception were assessed using Body Shape Concern Questionnaire, Body Weight Perception Questionnaire, Body Shape Perception Questionnaire (Stunkard Silhouette Chart), Multidimensional Body Self Relations Questionnaire (MBSRQ), Rosenberg’s Self-Esteem Scale (RSE) and Quality of Life measurement. Results: More females than males had problems with their body shape, where more females desired a thinner body size and vice versa for males. There was misperception of opposite sex’s perception of attractive body shape, where males chose a larger figure for attractive body shape of female compared to females themselves, and vice versa. Overweight students had significantly lower parental/peer acceptance, higher body shape satisfaction and hence lower body weight/shape anxiety, and made lesser body shape comparison compared to other counterparts. Quality of life and self-esteem were significantly negatively correlated with body satisfaction. Conclusion: Male and female Malaysian tertiary students were concerned with their body shape and perceived their body weight/shape differently
Contamination of nuclear fractions with plasma membrane lipid rafts
No full textSubcellular fractionation is central to a range of cell biological, biochemical and proteomic studies. Purification of nuclear-enriched fractions is critical for studies on nuclear structure and function. Here we show that detergent-based nuclear isolation methods cause the redistribution of proteins associated with plasma membrane lipid rafts into nuclear fractions. The glycosylphosphatidylinositol (GPI)-anchored prion protein (PrPC) and a GPI-anchored construct of angiotensin converting enzyme (GPI-ACE), as well as the lipid raft markers flotillin-1 and -2, were present in the nuclear fractions derived using three different subcellular fractionation protocols. Incubation of intact cells with bacterial phosphatidylinositol-specific phospholipase C (PI-PLC), which cleaves GPI-anchored proteins from the cell surface, significantly reduced the amount of PrPC and GPI-ACE in the nuclear fraction. Buoyant sucrose density gradient centrifugation in the presence of Triton X-100 of the nuclear fraction resulted in a significant proportion of the GPI-anchored proteins being recovered in the low density lipid raft fractions. These data indicate that the nuclear fraction isolated using such subcellular fractionation protocols is contaminated with components of plasma membrane lipid rafts and raises questions as to the integrity of the nuclear fraction isolated by such protocols for use in detailed cell biological studies and proteomics analysis. © 2007 Wiley-VCH Verlag GmbH & Co. KGaA
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
- …
