Canonical heights on the jacobians of curves of genus 2 and the infinite descent

We give an algorithm to compute the canonical height on a Jacobian of a curve of genus 2. The computations involve only working with the Kummer surface and so lengthy computations with divisors in the Jacobian are avoided. We use this height algorithm to give an algorithm to perform the infinite descent stage of computing the Mordell-Weil group. This last stage is performed by a lattice enlarging procedure

Modulation of neurosteroid potentiation by protein kinases at synaptic- and extrasynaptic-type GABAA receptors.

GABAA receptors are important for inhibition in the CNS where neurosteroids and protein kinases are potent endogenous modulators. Acting individually, these can either enhance or depress receptor function, dependent upon the type of neurosteroid or kinase and the receptor subunit combination. However, in vivo, these modulators probably act in concert to fine-tune GABAA receptor activity and thus inhibition, although how this is achieved remains unclear. Therefore, we investigated the relationship between these modulators at synaptic-type α1β3γ2L and extrasynaptic-type α4β3δ GABAA receptors using electrophysiology. For α1β3γ2L, potentiation of GABA responses by tetrahydro-deoxycorticosterone was reduced after inhibiting protein kinase C, and enhanced following its activation, suggesting this kinase regulates neurosteroid modulation. In comparison, neurosteroid potentiation was reduced at α1β3(S408A,S409A)γ2L receptors, and unaltered by PKC inhibitors or activators, indicating that phosphorylation of β3 subunits is important for regulating neurosteroid activity. To determine whether extrasynaptic-type GABAA receptors were similarly modulated, α4β3δ and α4β3(S408A,S409A)δ receptors were investigated. Neurosteroid potentiation was reduced at both receptors by the kinase inhibitor staurosporine. By contrast, neurosteroid-mediated potentiation at α4(S443A)β3(S408A,S409A)δ receptors was unaffected by protein kinase inhibition, strongly suggesting that phosphorylation of α4 and β3 subunits is required for regulating neurosteroid activity at extrasynaptic receptors. Western blot analyses revealed that neurosteroids increased phosphorylation of β3(S408,S409) implying that a reciprocal pathway exists for neurosteroids to modulate phosphorylation of GABAA receptors. Overall, these findings provide important insight into the regulation of GABAA receptors in vivo, and into the mechanisms by which GABAergic inhibitory transmission may be simultaneously tuned by two endogenous neuromodulators

Soil microstructure and electron microscopy

As part of the process of comparing Martian soils with terrestial soils, high resolution electron microscopy and associated techniques should be used to examine the finer soil particles, and various techniques of electron and optical microscopy should be used to examine the undisturbed structure of Martian soils. To examine the structure of fine grained portions of the soil, transmission electron microscopy may be required. A striking feature of many Martian soils is their red color. Although the present-day Martian climate appears to be cold, this color is reminiscent of terrestial tropical red clays. Their chemical contents are broadly similar

Commencing creditors' voluntary liquidations

published_or_final_versio

公司的權力劃分問題

published_or_final_versio

Evidence for orbital motion of CW Leonis from ground-based astrometry

© 2017 The Authors.Recent Atacama Large Millimeter/submillimeter Array (ALMA) observations indicate that CW Leo, the closest carbon-rich asymptotic giant branch star to Sun, might have a low-mass stellar companion. We present archival ground-based astrometric measurements of CW Leo obtained within the context of the Torino Parallax Program and with > 6 yr (1995-2001) of time baseline. The residuals to a single-star solution show significant curvature, and they are strongly correlatedwith thewell-known I-band photometric variations due to stellar pulsations. We describe successfully the astrometry of CW Leo with a variability-induced motion (VIM) + acceleration model. We obtain proper motion and parallax of the centre-of-mass of the binary, the former in fair agreement with recent estimates, the latter at the near end of the range of inferred distances based on indirect methods. The VIM + acceleration model results allow us to derive a companion mass in agreement with that inferred by ALMA, they point towards a somewhat longer period than implied by ALMA, but are not compatible with much longer period estimates. These data will constitute a fundamental contribution towards the full understanding of the orbital architecture of the system when combined with Gaia astrometry, providing an ~25 yr time baseline.Peer reviewe