We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the solar system, exploring the transient optical sky, and mapping the Milky Way. LSST will be a large, wide-field ground-based system designed to obtain repeated images covering the sky visible from Cerro Pachón in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg 2 field of view, a 3.2-gigapixel camera, and six filters (ugrizy) covering the wavelength range 320-1050 nm. The project is in the construction phase and will begin regular survey operations by 2022. About 90% of the observing time will be devoted to a deep-wide-fast survey mode that will uniformly observe a 18,000 deg 2 region about 800 times (summed over all six bands) during the anticipated 10 yr of operations and will yield a co-added map to r∼27.5. These data will result in databases including about 32 trillion observations of 20 billion galaxies and a similar number of stars, and they will serve the majority of the primary science programs. The remaining 10% of the observing time will be allocated to special projects such as Very Deep and Very Fast time domain surveys, whose details are currently under discussion. We illustrate how the LSST science drivers led to these choices of system parameters, and we describe the expected data products and their characteristics.

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Abstract. The sensitivity of the rate of energetic electron pitch angle scattering and precipitation loss in the Earth's magnetosphere due to Coulomb interactions with thermal plasma and resonant wave-particle interactions with plasmaspheric hiss, lightning-generated whistlers and VLF transmitter signals is computed for a realistic range of plasma and wave parameters. The computed scattering rates are most sensitive to the choice of mean wave frequency and the average angle of propagation; the frequency bandwidth and angular spread in propagation direction are relatively unimportant. Variations in plasma density can also strongly modulate the effectiveness of waveparticle interactions. The average intensity of plasma waves controls electron lifetimes, but has little effect on the shape of the equilibrium pitch angle distribution function. All three classes of waves must be included together with Coulomb collisions in any realistic analysis of inner magnetospheric electron scattering. The long-term energetic electron population beyond the inner belt is largely controlled by plasmaspheric hiss and, to a lesser extent, by lightning-generated whistlers, while VLF transmitter signals constitute the principal loss mechanism over the range 1.3 _< L _< 2.4. The region below L-1.3 is dominated by Coulomb collisions.

Objectives Biliary atresia (BA) frequently results in portal hypertension (PHT), complications of which lead to significant morbidity and mortality. The Childhood Liver Disease Research and Education Network (ChiLDREN) was utilized to perform a cross-sectional multi-centered analysis of PHT in children with BA. Methods BA subjects receiving medical management at a ChiLDREN site were enrolled. A priori, clinically evident PHT was defined as “definite” when there was either 1) history of a complication of PHT or 2) clinical findings consistent with PHT (both splenomegaly and thrombocytopenia). PHT was denoted as “possible” if one of the findings was present in the absence of a complication, while PHT was “absent” if none of the criteria were met. Results 163 subjects were enrolled between May 2006 and December 2009. At baseline, definite PHT was present in 49%, possible in 17% and absent in 34% of subjects. Demographics, growth and anthropometrics were similar amongst the 3 PHT categories. ALT, GGTP, and sodium levels were similar, while there were significant differences in AST, AST/ALT, albumin, total bilirubin, PT, WBC, platelet count and AST/platelet between definite and absent PHT. Thirty-four percent of those with definite PHT had either PT > 15s or albumin < 3 g/L. Conclusions Clinically definable PHT is present in two thirds of North American long-term BA survivors with their native livers. The presence of PHT is associated with measures of hepatic injury and dysfunction, although in this selected cohort the degree of hepatic dysfunction is relatively mild and growth is preserved.

(the subscripts "m" were missing), and (the two exponents were omitted).In our original numerical calculations we also omitted a term "sec era" necessary for correctly calculating the resonance condition for waves with a peak propagation angle ½m that is nonzero with respect to the local magnetic field. This error (which did affect the reported numerical results) occurred in the following three ex- 4627