358 research outputs found
Blood Lipids in Progressive Muscular Dystrophy
Muscular dystrophy is a heredofamilial disease characterized by primary degeneration of certain groups of voluntary muscles. Although several forms of the disease are recognized clinically the basic metabolic defect is probably the same in all cases, regardless of the outward manifestations. In many instances it appears that the genetic defect is sex-linked, while in others it is not. All of the members of a given family may not show the obvious signs of disease, but if a careful study is made the non-affected members often show more or less subtle and asymptomatic defects which may be characterized as abortive forms of the disease. In experimental animals a type of dystrophy may he produced by diets which are deficient in vitamin E, and the resulting dystrophy is accompanied by a markedly increased oxygen consumption of even the resting muscle. At the same time the urine of dystrophic animals, like the urine of dystrophic humans, contains large amounts of creatine and very little creatinine. Since creatine phosphate is intimately involved in the metabolism of skeletal muscle, loss of this vital intermediate is completely in line with the obvious muscular wasting. Attempts at alleviation of human disease by vitamin E therapy have been disappointing. While vitamin E, alone or with inositol (1), corrects the creatinuria, the other degenerative changes are not altered from their progressive course. For the past ten years we have been engaged in cataloging the electrophoretic patterns of serum and plasma proteins in a variety of diseases, and our interest in muscular dystrophy was recently stimulated by receipt of several samples of serum and plasma as part of this general project. It was observed that the few samples then available were distinctly lactescent or chylous in appearance. Investigation of successive samples from a larger number of individuals indicated that this was a general observation. In some instances post-absorbtive samples were sufficiently opaque to completely obscure large newsprint held directly behind the sample tube (Figure 1). The striking appearance of the samples lead us to investigate the content of some lipoid components. Our findings in this connection constitute the basis of the present report
Accuracy and Precision of Age Estimates for Pallid Sturgeon from Pectoral Fin Rays
Accurate age information is critical to the biological understanding and management of most fish species, but particularly for species of concern, such as the pallid sturgeon Scaphirhynchus albus. The accuracy and precision of pallid sturgeon age estimates from pectoral fin ray sections has never been established, yet all accumulated age information for the species was collected using this technique. To examine the accuracy and precision of age estimates, 16 pectoral fin ray samples from age-6 pallid sturgeon were obtained from Gavins Point National Fish Hatchery, South Dakota. The fin rays were sectioned, mounted, and independently examined twice by each of two readers. Only 28.1% of the age estimates accurately reflected the known age of the fish. Multiple readings of the same sample by the same reader (within-reader precision) only agreed 25% of the time, differences being as great as 5 years between the two estimates. Between-reader agreement was 46.9%, the two readers\u27 estimates of the same fish differing by as much as 2 years. Because of low accuracy and precision, estimated ages from pallid sturgeon pectoral fin rays should be viewed with caution
Direct observations of submarine melt and subsurface geometry at a tidewater glacier
Ice loss from the world’s glaciers and ice sheets contributes to sea level rise, influences
ocean circulation, and affects ecosystem productivity. Ongoing changes in glaciers and
ice sheets are driven by submarine melting and iceberg calving from tidewater glacier
margins.Ice loss from the world’s glaciers and ice sheets contributes to sea level rise, influences
ocean circulation, and affects ecosystem productivity. Ongoing changes in glaciers and
ice sheets are driven by submarine melting and iceberg calving from tidewater glacier
margins. However, predictions of glacier change largely rest on unconstrained theory for
submarine melting. Here, we use repeat multibeam sonar surveys to image a subsurface
tidewater glacier face and document a time-variable, three-dimensional geometry linked
to melting and calving patterns. Submarine melt rates are high across the entire ice face over
both seasons surveyed and increase from spring to summer. The observed melt rates are up
to two orders of magnitude greater than predicted by theory, challenging current simulations of
ice loss from tidewater glaciers.Department of Earth Sciences, University of Oregon,
Eugene, OR 97403, USA. 2
College of Earth, Ocean, and
Atmospheric Sciences, Oregon State University, Corvallis, OR
97331, USA. 3
Department of Natural Sciences, University of
Alaska Southeast, Juneau, AK 99801, USA. 4
Institute for
Geophysics, University of Texas at Austin, Austin, TX 78758,
USA. 5
Department of Marine Sciences, University of North
Carolina, Chapel Hill, NC 27599, USA. 6
Geophysical Institute,
University of Alaska Fairbanks, Fairbanks, AK 99775, USA.
*Corresponding author. Email: [email protected]
†Present address: Department of Marine and Coastal Sciences,
Rutgers University, New Brunswick, NJ 08901, USA.Ye
Population regulation in lake whitefish, Coregonus clupeaformis (Mitchill)
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73745/1/j.1095-8649.1981.tb03822.x.pd
Neuropsychological intervention in kindergarten children with subtyped risks of reading retardation
Kindergarten children at risk of developing language problems were administered the Florida Kindergarten Screening Battery. A principal components analysis revealed a verbal and a visual-spatial component and subsequent discriminant function analyses a high verbal/low visual-spatial group (LAL: Latent L) and a high visual-spatial/low verbal group (LAP: Latent P). LAL- and LAP-children were considered at risk for developing an L- or P-type of dyslexia, respectively. As is common practice with children suffering from manifest L- or Pdyslexia, the LAL- and LAP-kindergartners received right and left hemisphere stimulation, respectively. The outcomes were compared with those of bilateral hemispheric stimulation and no intervention. Reading tests were administered in primary school Grades 1 and 5/6; teachers' evaluation of reading took place in Grade 5/6. Overall, the LAL- and LAP- groups showed significant backwardness in word and text reading, both at early and late primary school. Types of intervention made a difference though: not significantly backward in early word, late word, and late text reading were the LAL-children who had received right hemisphere stimulation. Nonintervened LAP-children did not show significant backwardness in early word reading and late text reading, nor did LAP-children who had received left hemisphere or bilateral stimulation. Early text reading was not affected by any treatment. Teacher's evaluations were in support of these findings. Copyright © 2005 by The International Dyslexia Association®
How Subjective Is the Subject?
This article re-examines the issue of grammatical relations in Mandarin Chinese in light of the results of recent large-scale typological research on grammatical relations (henceforth GRs) worldwide. Specifically, it discusses three syntactic operations and constructions that are cross-linguistically relevant to the definition of grammatical relations, namely relativisation, reflexivisation, and quantifier float. The study adopts a strictly language-internal typological approach and avails itself of natural linguistic data or sentences sanity-checked by native speakers. The aim of this paper is twofold: first, it explores the hypothesis that, in line with various other languages, GRs in Mandarin Chinese are construction-specific. Second, it proposes an alternative approach capable of explaining the conflicting evidence often pointed out in the literature on GRs and subjecthood in Mandarin Chinese
Dynamic Models of Language Evolution: The Linguistic Perspective
Language is probably the key defining characteristic of humanity, an immensely powerful tool which provides its users with an infinitely expressive means of representing their complex thoughts and reflections, and of successfully communicating them to others. It is the foundation on which human societies have been built and the means through which humanity’s unparalleled intellectual and technological achievements have been realized. Although we have a natural intuitive understanding of what a language is, the specification of a particular language is nevertheless remarkably difficult, if not impossible, to pin down precisely. All languages contain many separate yet integral systems which work interdependently to allow the expression of our thoughts and the interpretation of others’ expressions: each has, for instance, a set of basic meaningless sounds (e.g. [e], [l], [s]) which can be combined to make different meaningful words and parts of words (e.g. else, less, sell, -less ); these meaningful units can be combined to make complex words (e.g. spinelessness, selling ), and the words themselves can then be combined in very many complex ways into phrases, clauses and an infinite number of meaningful sentences; finally each of these sentences can be interpreted in dramatically different ways, depending on the contexts in which it is uttered and on who is doing the interpretation. Languages can be analysed at any of these different levels, which make up many of the sub-fields of linguistics, and the primary job of linguistic theorists is to try to explain the rules which best explain these complex combinations
Interaction of PLP with GFP-MAL2 in the Human Oligodendroglial Cell Line HOG
The velocity of the nerve impulse conduction of vertebrates relies on the myelin sheath, an electrically insulating layer that surrounds axons in both the central and peripheral nervous systems, enabling saltatory conduction of the action potential. Oligodendrocytes are the myelin-producing glial cells in the central nervous system. A deeper understanding of the molecular basis of myelination and, specifically, of the transport of myelin proteins, will contribute to the search of the aetiology of many dysmyelinating and demyelinating diseases, including multiple sclerosis. Recent investigations suggest that proteolipid protein (PLP), the major myelin protein, could reach myelin sheath by an indirect transport pathway, that is, a transcytotic route via the plasma membrane of the cell body. If PLP transport relies on a transcytotic process, it is reasonable to consider that this myelin protein could be associated with MAL2, a raft protein essential for transcytosis. In this study, carried out with the human oligodendrocytic cell line HOG, we show that PLP colocalized with green fluorescent protein (GFP)-MAL2 after internalization from the plasma membrane. In addition, both immunoprecipitation and immunofluorescence assays, indicated the existence of an interaction between GFP-MAL2 and PLP. Finally, ultrastructural studies demonstrated colocalization of GFP-MAL2 and PLP in vesicles and tubulovesicular structures. Taken together, these results prove for the first time the interaction of PLP and MAL2 in oligodendrocytic cells, supporting the transcytotic model of PLP transport previously suggested
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