748 research outputs found

    Neurodevelopmental basis of health and disease: the 14th meeting of the International Neurotoxicology Association

    Get PDF
    Biological events in early life are key determinants of health status in adult and aging stages. The evidence for this is compelling in neurotoxicology (Grandjean and Landrigan, 2006). The complexity of the developing nervous system creates multiple targets for the adverse structural, functional and behavioral effects of toxic chemicals: from overt neuroteratogenia to subtle influences on the functional decline occur during aging. Minamata disease is the best known example of dramatic alterations in nervous system structure and function as a result of chemical exposure during development. However, the impact of low dose exposure of several other toxic compounds on endpoints such as adolescent emotional growth, cognitive function, sensory deficits or risk of suffering neurodegenerative diseases (Grandjean and Landrigan, 2006; Cannon and Greenamyre, 2011; Bellinger, 2013) is a field of knowledge that still contains more questions than answers. The effects of toxicants on later life become more and more important as life expectancy increases. In addition to understanding the effects and underlying mechanisms, we want to predict the adverse effects on the developing nervous and sensory systems. This constitutes a major challenge for neurotoxicity testing. Facing these questions, the International Neurotoxicology Association (INA) selected the theme ''Neurodevelopmental Basis of Health and Disease'' for its 14th Meeting, held in Egmond aan Zee, The Netherlands, June 2013. Detailed information on the meeting, including lists of symposia, members of the organizing and scientific committees, awardees, sponsors, and exhibitors are included elsewhere in this Special Issue (De Groot et al., 2014)

    Exo-π-bonding to an ortho-carborane hypercarbon atom: systematic icosahedral cage distortions reflected in the structures of the fluoro-, hydroxy- and amino-carboranes, 1-X-2-Ph-1,2-C2B10H10 (X = F, OH or NH2) and related anions

    Get PDF
    The structures of derivatives of phenyl-ortho-carborane bearing on the second cage hypercarbon atom a pi-donor substituent (F, OH, O-, NH2, NH- and CH2-) were investigated by NMR, X-ray crystallography and computational studies. The molecular structures of these compounds, notably their cage C1-C2 distances and the orientations of their pi-donor substituents (OH, NH2, NH- and CH2-) show remarkable and systematic variations with the degree of exo pi-bonding, which varies as expected with the pi-donor characteristics of the substituent

    The effects of an intronic polymorphism in TOMM40 and APOE genotypes in sporadic inclusion body myositis.

    Get PDF
    A previous study showed that, in carriers of the apolipoprotein E (APOE) genotype ε3/ε3 or ε3/ε4, the presence of a very long (VL) polyT repeat allele in "translocase of outer mitochondrial membrane 40" (TOMM40) was less frequent in patients with sporadic inclusion body myositis (sIBM) compared with controls and associated with a later age of sIBM symptom onset, suggesting a protective effect of this haplotype. To further investigate the influence of these genetic factors in sIBM, we analyzed a large sIBM cohort of 158 cases as part of an International sIBM Genetics Study. No significant association was found between APOE or TOMM40 genotypes and the risk of developing sIBM. We found that the presence of at least 1 VL polyT repeat allele in TOMM40 was significantly associated with about 4 years later onset of sIBM symptoms. The age of onset was delayed by 5 years when the patients were also carriers of the APOE genotype ε3/ε3. In addition, males were likely to have a later age of onset than females. Therefore, the TOMM40 VL polyT repeat, although not influencing disease susceptibility, has a disease-modifying effect on sIBM, which can be enhanced by the APOE genotype ε3/ε3

    Kinetics and Mechanism of Hydroxyapatite Crystal Dissolution in Weak Acid Buffers Using the Rotating Disk Method

    Full text link
    The dissolution rates of synthetic hydroxyapatite pellets under sink conditions were measured using the rotating disk method. The experimental data were analyzed by means of a physical model that yielded an ionic activity product of KHAP = a10Ca2+ a6 PO4 3- a2OH- = 1 × 10-124.5±1.0 that was found to govern the dissolution reaction. Also, a surface resistance factor of k' equal to about 174 sec/cm was deduced from the data.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67157/2/10.1177_00220345760550033201.pd

    Nonlinear weakly curved rod by Γ-Convergence

    Get PDF
    We present a nonlinear model of weakly curved rod, namely the type of curved rod where the curvature is of the order of the diameter of the cross-section. We use an approach analogous to the one for rods and curved rods and start from the strain energy functional of three dimensional nonlinear elasticity. We do not impose any constitutional behavior of the material and work in a general framework. To derive the model, by means of Γ-convergence, we need to set the order of strain energy (i.e., its relation to the thickness of the body h). We analyze the situation when the strain energy (divided by the order of volume) is of the order h 4. This is the same approach as the one used in Föppl-von Kármán model for plates and the analogous model for rods. The obtained model is analogous to Marguerre-von Kármán for shallow shells and its linearization is the linear shallow arch model which can be found in the literature

    Coherent states for exactly solvable potentials

    Full text link
    A general algebraic procedure for constructing coherent states of a wide class of exactly solvable potentials e.g., Morse and P{\"o}schl-Teller, is given. The method, {\it a priori}, is potential independent and connects with earlier developed ones, including the oscillator based approaches for coherent states and their generalizations. This approach can be straightforwardly extended to construct more general coherent states for the quantum mechanical potential problems, like the nonlinear coherent states for the oscillators. The time evolution properties of some of these coherent states, show revival and fractional revival, as manifested in the autocorrelation functions, as well as, in the quantum carpet structures.Comment: 11 pages, 4 eps figures, uses graphicx packag

    Взаємозв’язок великих кондратьєвських циклів розвитку економіки і системних світових конфліктів

    Get PDF
    Однією з найважливіших проблем, що постала перед сучасною наукою у зв’язку із стрімким розгортанням глобальної економічної кризи, загостренням світових конфліктів, є вироблення науково обґрунтованих «метричних» експрес прогнозів розвитку суспільства на ближчу і далеку перспективу
    corecore