1,720,975 research outputs found
Comparative Study of Acid Maltase Deficiency: Biochemical Differences Between Infantile, Childhood, and Adult Types
No full textMaltase (α-1,4-glucosidase) activity was determined at various pH values in tissues in infantile (heart, liver, skeletal muscle), childhood (heart, liver, skeletal muscle), and adult (liver, skeletal muscle, leukocytes) types of acid maltase deficiency (AMD) and in control tissues. In an infantile case of AMD, only traces of neutral maltase were present in heart, and this activity was significantly decreased in skeletal muscle and liver. In a childhood case of AMD, neutral maltase activity was decreased only in liver. No decreases of neutral maltase occurred in adult AMD tissues. An absolute decrease of leukocyte acid maltase was found in four and a relative decrease in one of five adults with AMD. A decrease in the pH 4.0/pH 6.5 ratio of leukocyte maltase activity may aid in the diagnosis of adult AMD. © 1972, American Medical Association. All rights reserved
Carnitine deficiency of human skeletal muscle with associated lipid storage myopathy: A new syndrome
No full textIn a rare myopathy muscle fibers contained myriad lipid-filled vacuoles. Homogenates of the patient's muscle oxidized fatty acids more slowly than normal (11 controls). Addition of carnitine increased the oxidation rate with the patient's muscle to the level attained by the controls with carnitine. In five separate muscle samples from the patient the mean carnitine level was less than 20 percent of that observed in 42 controls. Carnitine palmityl transferase and palmityl thiokinase levels in the patient's muscles were not depressed. The present case represents the first recognized instance of carnitine deficiency in human skeletal muscle
Adult Acid Maltase Deficiency: Abnormalities in Fibroblasts Cultured from Patients
No full textA deficiency of acid maltase but not neutral maltase was observed in cultured fibroblasts obtained from six adults with glycogen-storage myopathy associated with acid maltase deficiency (AMD). Abnormal sequestration of glycogen in membrane-bound sacs, without admixture of cytoplasmic degradation products, was found in cells of three of the six AMD cultures, but the glycogen content was normal in all six cultures. Neither a partial enzyme deficiency nor a selective absence of the enzyme from affected tissues can explain the age-dependent variants of AMD. The diagnosis of AMD in adults can be made on the basis of skin as well as muscle-biopsy specimens. Prenatal diagnosis of the adult form also should be feasible. © 1972, Massachusetts Medical Society. All rights reserved
Mitochondria-Lipid-Glycogen (MLG) Disease of Muscle: A Morphologically Regressive Congenital Myopathy
No full textMuscle biopsies of a 7-week-old girl with profound weakness of all but the ocular muscles, combined with hypotonia, hyporeflexia, hepatomegaly, macroglossia, myopathic electromyogram, and slight elevation of serum enzyme levels revealed mild glycogen and marked lipid and mitochondrial excess. Glycogen structure and anaerobic glycolysis were normal. Aldolase and pyruvate kinase levels were relatively low and the lactic dehydrogenase isoenzyme pattern resembled that of heart muscle. Subsequently the patient had normal intellectual and delayed motor development and her macroglossia disappeared. At 22 months pathologic alterations in muscle were strikingly improved and glycolytic enzyme levels and oxidation of labeled oleic acid and Krebs cycle intermediates were normal. Although still unidentified, the basic metabolic lesion is one that (1) affects mitochondria! morphology, (2) alters lipid and glycogen metabolism, (3) may improve with age, and (4) is compatible with a benign clinical course after early infancy. © 1973, American Medical Association. All rights reserved
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
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
- …
