6,662 research outputs found

    DNA vaccines for emerging infectious diseases: what if?

    Get PDF
    A novel and powerful method for vaccine research, colloquially known as DNA vaccines, involves the deliberate introduction into tissues of a DNA plasmid carrying an antigen-coding gene that transfects cells in vivo and results in an immune response. DNA vaccines have several distinct advantages, which include ease of manipulation, use of a generic technology, simplicity of manufacture, and chemical and biological stability. In addition, DNA vaccines are a great leveler among re-searchers around the world because they provide unprecedented ease of experi-mentation. To facilitate diffusion of information, an Internet site has been established called THE DNA VACCINE WEB (URL:http://www.genweb.com/dnavax/dnavax.html). In this review, a brief survey is undertaken of the experimental models and preclinical work on DNA vaccines to contribute to a greater awareness of the possibilities for emerging infectious diseases

    Spacelab energetic ion mass spectrometer

    Get PDF
    Basic design criteria are given for an ion mass spectrometer for use in studying magnetospheric ion populations. The proposed instrument is composed of an electrostatic analyzer followed by a magnetic spectrometer and simultaneously measures the energy per unit and mass per unit charge of the ion species. An electromagnet is used for momentum analysis to extend the operational energy range over a much wider domain than is possible with the permanent magnets used in previous flights. The energetic ion source regions, ion energization mechanisms, field line tracing, coordinated investigations, and orbit considerations are discussed and operations of the momentum analyzer and of the electrostatic energy analyzer are examined

    Detectability of the First Cosmic Explosions

    Full text link
    We present a fully self-consistent simulation of a synthetic survey of the furthermost cosmic explosions. The appearance of the first generation of stars (Population III) in the Universe represents a critical point during cosmic evolution, signaling the end of the dark ages, a period of absence of light sources. Despite their importance, there is no confirmed detection of Population III stars so far. A fraction of these primordial stars are expected to die as pair-instability supernovae (PISNe), and should be bright enough to be observed up to a few hundred million years after the big bang. While the quest for Population III stars continues, detailed theoretical models and computer simulations serve as a testbed for their observability. With the upcoming near-infrared missions, estimates of the feasibility of detecting PISNe are not only timely but imperative. To address this problem, we combine state-of-the-art cosmological and radiative simulations into a complete and self-consistent framework, which includes detailed features of the observational process. We show that a dedicated observational strategy using 8\lesssim 8 per cent of total allocation time of the James Webb Space Telescope mission can provide us up to 915\sim 9-15 detectable PISNe per year.Comment: 9 pages, 8 figures. Minor corrections added to match published versio

    The Enigma of the “Jumping Frenchmen of Maine”

    Get PDF
    The “Jumping Frenchmen of Maine” exhibited unusual reactions when startled, and they became a component of local folklore in northern New England during the late nineteenth century. Medical scientists of the time examined the condition, but came to no definite conclusions. Modern scientists in the late twentieth century also disagreed on its origins. The syndrome appears to have resulted from the unique social and environmental factors peculiar to the logging camps of the time. Stephen R. Whalen has a Ph.D. in history from the University of Maine. Retired from public school teaching, he is currently a member of the History Department at Castleton State College in Castleton, Vermont. Robert E. Bartholomew, a former journalist in New York state, has a Ph.D. from James Cook University in Australia. He is the author of LITTLE GREEN MEN, MEOWING NUNS AND HEADHUNTING PANICS: A STUDY OF MASS PSYCHOGENIC ILLNESS AND SOCIAL DELUSION (Mc- Farland, 2001)

    Ziram activates mitogen-activated protein kinases and decreases cytolytic protein levels in human natural killer cells

    Get PDF
    Human natural killer (NK) cells are central in immune defense with their ability to lyse tumor cells and virally infected cells. Tumor formation and viral infection may increase if NK cytotoxic function is disrupted. Ziram (zinc dithiocarbamate) is used as an accelerating agent in the production of latex and to protect various fruits and vegetables from fungal infection. Previously, we have shown that exposure to ziram inhibits NK lytic function. Butyltin environmental contaminants, which also inhibit NK lytic function, cause rapid activations of mitogen-activated protein kinases (MAPKs) and decreases in expression of the cytolytic proteins granzyme B and perforin (after 24 h) in exposed NK cells. MAPKs are important regulators of the lytic response of NK cells, and spurious activation of these enzymes by contaminants would leave the NK cells unable to respond to appropriate targets. This study examined the effects of ziram exposures on MAPKs (p44/42, p38, and c-jun-N-terminal kinase) and on levels of cytolytic proteins. Ten-minute to 6-h exposures of NK cells to ziram caused activation of MAPKs, p44/42, and p38. Exposure to ziram for 24 h caused a decrease in granzyme B and perforin levels. MAPK inhibitors were able to prevent these ziram-induced decreases in granzyme B and perforin. These results suggest that ziram-induced MAPK activation is at least in part responsible for decreased cytolytic function in ziram-exposed NK cells. Furthermore, the results indicate that these changes are in common with other environmental contaminants that have been shown to decrease NK lytic function

    "I'm a bit concerned" - early actions and psychological constructions in a child protection helpline

    Get PDF
    This article analyzes early actions in 50 calls reporting cases of abuse to a national child protection helpline in the UK (the National Society for the Prevention of Cruelty to Children Helpline, NSPCC). It focuses on the early turns in the caller's reason for call, in particular, a class of constructions in which the caller describes himself or herself as "concerned about x" (or similar). Analysis of the corpus of calls suggests concern constructions are canonical early elements of the reason-for-call sequence. Concern constructions (a) are oriented to a pre-move in the caller's reason for call, (b) project the unpacking of concerns in a way oriented to the NSPCCs institutional role, (c) attend to epistemological asymmetries between caller and call taker and remove the requirement for disaffiliative next actions such as asking for the basis of claims, (d) provide a way for the Child Protection Officer to take abuse claims seriously while not presupposing their truth, and (e) display an appropriate caller stance. These observations are supported by an analysis of deviant cases. The broader implications of this study for the relation between psychology, interaction, and institutions are discussed

    Effects of ziram on tumor-cell-binding capacity, cell-surface marker expression, and ATP levels of human natural killer cells

    Get PDF
    Human natural killer (NK) cells are central in immune defense against tumor and virally infected cells. Ziram is used as an accelerating agent in latex production and as an agricultural fungicide. Previous studies showed that continuous exposure to ziram inhibits NK lytic function. Additionally, they showed that a brief (1 h) exposure to ziram caused persistent loss of lytic function. This study examined whether decreases in lytic function were accompanied by decreases in the target-binding function of NK cells and found that some, but not all, exposures to ziram caused significant decreases in binding function. Ziram exposures that caused a loss of binding function were examined for effects on expression of key NK cell-surface proteins needed for binding to targets. Exposure to 2 μM ziram for 1 h followed by 24 or 48 h in ziram-free media decreased CD16 expression, but no other exposures caused decreases in cell-surface proteins. As decreases in adenosine triphosphate (ATP) could be in part responsible for loss of lytic function, the effect of ziram exposures on ATP levels of NK cells were examined. Certain ziram exposures decreased ATP levels in NK cells, but a decrease in ATP was not necessarily associated with a decrease in lytic function. The results indicate that ziram-induced losses of lytic function cannot be fully explained by alteration in binding, cell-surface protein expression, or ATP levels
    corecore