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On the quasi-periodic nature of magnetopause flux transfer events
The recurrence rate of flux transfer events (FTEs) observed near the dayside magnetopause is discussed. A survey of magnetopause observations by the ISEE satellites shows that the distribution of the intervals between FTE signatures has a mode value of 3 min, but is highly skewed, having upper and lower decile values of 1.5 min and 18.5 min, respectively. The mean value is found to be 8 min, consistent with previous surveys of magnetopause data. The recurrence of quasi-periodic events in the dayside auroral ionosphere is frequently used as evidence for an association with magnetopause FTEs, and the distribution of their repetition intervals should be matched to that presented here if such an association is to be confirmed. A survey of 1 year's 15-s data on the interplanetary magnetic field (IMF) suggests that the derived distribution could arise from fluctuations in the IMF Bz component, rather than from a natural oscillation frequency of the magnetosphere-ionosphere system
QCD coherence in the structure function and associated distributions at small
We recall the origin of angular ordering of soft parton emission in the
region of small and show that this coherent structure can be detected in
associated distributions. For structure functions at small and at fixed
transverse momentum the angular ordering is masked because of the complete
inclusive cancellations of collinear singularities for \xt0. Therefore, in this
case the dependence on the hard scale is lost and the angular ordered region
becomes equivalent to multi-Regge region in which all transverse momenta are of
the same order. In this limit one derives the BFKL equation. In general such a
complete cancellation does not hold for the associated distributions at small
. The calculation, which requires an analysis without any collinear
approximation, is done by extending to small the soft gluon factorization
techniques largely uses in the region of large . Since one finds angular
ordering in the both regions of small and large , one can formulate a
unified evolution equation for the structure function, a unified coherent
branching and jet algorithm which allows the calculation of associated
distributions in all regions. Such a unified formulation valid for all
is presented and compared with usual treatments. In particular we show that the
associated distributions at small are sensitive to coherence. By replacing
angular ordering with the multi-Regge region one neglects large singular
contributions in the associated distributions.Comment: LaTeX file of 27 page
Involvement of polyaminaes in the pancreatic microcirculatory and protective effects of EGF in acute experimental pancreatitis
Blockade of NK-1 receptors attenuates I/R intestinal mucosa injury but is not affecting myolectric activity of the small intestine
Synthesis and crystal structure of a new armed-tetraazacrown ether and its liquid membrane transport of alkali metal cations
Expression of TdT in Myoepithelial Cells: Investigation in Breasts, Sweat Glands, and Salivary Lesions Emphasizing the Never-Documented Immunohistochemical Findings
Flexible, Strain Gated Logic Transducer Arrays Enabled by Initializing Surface Instability on Elastic Bilayers
Developing flexible sensors with a high strain sensing range could enable widespread downstream applications, by allowing intimate, mechanically conformable integration with soft biological tissues. By characterizing interconnected metal electrode arrays on super-flexible substrates, we have established a surface deformation control strategy of an array of strain transducers. The strain gated switches are capable of measuring various compressive strains (up to 60%) by bringing metal electrodes into self-contact via creasing elastic instability beyond a threshold substrate strain. The designed devices have been developed to explore the geometry design effect on the electrode-elastomer “stiff film on soft elastomer” surface deformation. The enabled transducer array yielded a stepwise strain-electrical resistance switching mechanism which opens up the potential of future interconnected sensor array type of super-compressible devices
Abnormal Alzheimer-like phosphorylation of tau-protein by cyclin-dependent kinases cdk2 and cdk5
We have shown earlier that certain proline-directed kinases such as MAP kinase or GSK-3 can phosphorylate tau protein in an abnormal manner reminiscent of tau from Alzheimer paired helical filaments [Drewes et al. (1992); Mandelkow et al. (1992)]. Both kinases are abundant in brain tissue and associate physically with microtubules through several cycles of assembly and disassembly. In this report we show that cdk2/cyclinA incorporates ≈5 P, into recombinant tau, and that it also induces the M r shift and antibody reactivity typical of Alzheimer tau. However, since there is no cdk2 in brain [Meyerson et al. (1992)] we looked for other members of this family of kinases. Using an antibody against the conserved N-terminus we isolated a cdk-like kinase from brain which was capable of inducing the Alzheimer-like characteristics in tau by phosphorylation. Its size (31 kDa), target specificity (proline-directed), Chromatographic behavior, and abundance in brain suggest that this kinase is similar or identical to the neuronal cdc2-like kinase nclk alias PSSARLE or cdk5 [Hellmich et al. (1992); Meyerson et al. (1992); Xiong et al. (1992); Tsai et al. (1993)]. This was confirmed by an antibody specific for cdk5. Like MAP kinase and GSK-3, this kinase is physically associated with microtubules and can be enriched by cycles of microtubule assembly and disassembly. Thus, cdk5 should be regarded as another kinase that could be held responsible for the changes in tau protein during Alzheimer disease progression