594 research outputs found

    Axonal maintenance, glia, exosomes, and heat shock proteins

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    © The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in F1000Research 5 (2016): 205, doi:10.12688/f1000research.7247.1.Of all cellular specializations, the axon is especially distinctive because it is a narrow cylinder of specialized cytoplasm called axoplasm with a length that may be orders of magnitude greater than the diameter of the cell body from which it originates. Thus, the volume of axoplasm can be much greater than the cytoplasm in the cell body. This fact raises a logistical problem with regard to axonal maintenance. Many of the components of axoplasm, such as soluble proteins and cytoskeleton, are slowly transported, taking weeks to months to travel the length of axons longer than a few millimeters after being synthesized in the cell body. Furthermore, this slow rate of supply suggests that the axon itself might not have the capacity to respond fast enough to compensate for damage to transported macromolecules. Such damage is likely in view of the mechanical fragility of an axon, especially those innervating the limbs, as rapid limb motion with high impact, like running, subjects the axons in the limbs to considerable mechanical force. Some researchers have suggested that local, intra-axonal protein synthesis is the answer to this problem. However, the translational state of axonal RNAs remains controversial. We suggest that glial cells, which envelop all axons, whether myelinated or not, are the local sources of replacement and repair macromolecules for long axons. The plausibility of this hypothesis is reinforced by reviewing several decades of work on glia-axon macromolecular transfer, together with recent investigations of exosomes and other extracellular vesicles, as vehicles for the transmission of membrane and cytoplasmic components from one cell to another.Harold Gainer’s contribution to this research was supported by the Intramural Research Program of the NINDS, NIH

    Hollywood, African Consolidated Films, and "bioskoopbeskawing," or bioscope culture : aspects of American culture in Cape Town, 1945-1960

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    Bibliography: leaves 270-279.This thesis examines the deep-rooted history and structure of American culture in South Africa during the twentieth century. It examines one aspect of that cultural penetration in particular, the cinema industry, in Cape Town, a region ofpredominantIy British influence, in order to illustrate a process in which America displaced Great Britain as South Africa's political, economic, and cultural centre. Based on a wide range of unpublished government documents, oral interviews, periodicals, and a survey of motion pictures in Cape Town between 1946 and 1960, this thesis illustrates that not only did American images and products dominate the South African market, but American methods of mass marketing and advertising intensified South Africa's development of a consumer culture

    Low-speed investigation of effects of wing leading- and trailing-edge flap deflections and canard incidence on a fighter configuration equipped with a forward-swept wing

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    An advanced fighter configuration with a forward-swept wing of aspect ratio 3.28 is tested in the Langley 7 by 10 Foot High Speed Tunnel at a Mach number of 0.3. The wing has 29.5 degrees of forward sweep of the quarter chord line and is equipped with 15 percent chord leading edge and 30 percent chord trailing edge flaps. The canard is sweptback 45 degrees. Tests were made through a range of angle of attack from about -2 degrees to 22 degrees. Deflecting the flaps significantly improves the lift drag characteristics at the higher angles of attack. The canard is able to trim the configurations with different flap deflections over most of the range of angle of attack. The penalty in maximum lift coefficient due to trimming is about 0.10

    An intraorganizational model for developing and spreading quality improvement innovations

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    BACKGROUND Recent policy reforms encourage quality improvement (QI) innovations in primary care, but practitioners lack clear guidance regarding spread inside organizations. PURPOSE We designed this study to identify how large organizations can facilitate intraorganizational spread of QI innovations. METHODOLOGY/APPROACH We conducted ethnographic observation and interviews in a large, multispecialty, community-based medical group that implemented three QI innovations across 10 primary care sites using a new method for intraorganizational process development and spread. We compared quantitative outcomes achieved through the group's traditional versus new method, created a process model describing the steps in the new method, and identified barriers and facilitators at each step. FINDINGS The medical group achieved substantial improvement using its new method of intraorganizational process development and spread of QI innovations: standard work for rooming and depression screening, vaccine error rates and order compliance, and Pap smear error rates. Our model details nine critical steps for successful intraorganizational process development (set priorities, assess the current state, develop the new process, and measure and refine) and spread (develop support, disseminate information, facilitate peer-to-peer training, reinforce, and learn and adapt). Our results highlight the importance of utilizing preexisting organizational structures such as established communication channels, standardized roles, common workflows, formal authority, and performance measurement and feedback systems when developing and spreading QI processes inside an organization. In particular, we detail how formal process advocate positions in each site for each role can facilitate the spread of new processes. PRACTICE IMPLICATIONS Successful intraorganizational spread is possible and sustainable. Developing and spreading new QI processes across sites inside an organization requires creating a shared understanding of the necessary process steps, considering the barriers that may arise at each step, and leveraging preexisting organizational structures to facilitate intraorganizational process development and spread.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial License 4.0 (CCBY-NC), where it is permissible to download, share, remix, transform, and buildup the work provided it is properly cited. The work cannot be used commercially
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