The Kuiper Belt hosts a swarm of distant, icy objects ranging in size from small, primordial planetesimals to much larger, highly evolved objects, representing a whole new class of previously ...unexplored cryogenic worlds. Pluto, the largest among them, along with its system of five satellites, has been revealed by NASAs New Horizons spacecraft flight through the system in July 2015, nearly a decade after its launch.
The Pluto system was recently explored by NASA's New Horizons spacecraft, making closest approach on 14 July 2015. Pluto's surface displays diverse landforms, terrain ages, albedos, colors, and ...composition gradients. Evidence is found for a water-ice crust, geologically young surface units, surface ice convection, wind streaks, volatile transport, and glacial flow. Pluto's atmosphere is highly extended, with trace hydrocarbons, a global haze layer, and a surface pressure near 10 microbars. Pluto's diverse surface geology and long-term activity raise fundamental questions about how small planets remain active many billions of years after formation. Pluto's large moon Charon displays tectonics and evidence for a heterogeneous crustal composition; its north pole displays puzzling dark terrain. Small satellites Hydra and Nix have higher albedos than expected.
We explored whether breast cancer outcomes are associated with endoxifen and other metabolites of tamoxifen and examined potential correlates of endoxifen concentration levels in serum including ...cytochrome P450 2D6 (CYP2D6) metabolizer phenotype and body mass index (BMI). Concentration levels of tamoxifen, endoxifen, 4‐hydroxytamoxifen (4OH‐tamoxifen), and N‐desmethyltamoxifen (ND‐tamoxifen) were measured from samples taken from 1,370 patients with estrogen receptor (ER)‐positive breast cancer who were participating in the Women's Healthy Eating and Living (WHEL) Study. We tested these concentration levels for possible associations with breast cancer outcomes and found that breast cancer outcomes were not associated with the concentration levels of tamoxifen, 4‐hydroxytamoxifen, and ND‐tamoxifen. For endoxifen, a threshold was identified, with women in the upper four quintiles of endoxifen concentration appearing to have a 26% lower recurrence rate than women in the bottom quintile (hazard ratio (HR) = 0.74; 95% confidence interval (CI), (0.55–1.00)). The predictors of this higher‐risk bottom quintile were poor/intermediate metabolizer genotype, higher BMI, and lower tamoxifen concentrations as compared with the mean for the cohort as a whole. This study suggests that there is a minimal concentration threshold above which endoxifen is effective against the recurrence of breast cancer and that ~80% of tamoxifen takers attain this threshold.
Clinical Pharmacology & Therapeutics (2011) 89 5, 718–725. doi:10.1038/clpt.2011.32
NASA's New Horizons spacecraft will conduct a close flyby of the cold-classical Kuiper Belt Object (KBO) designated (486958) 2014 MU69 on 2019 January 1. At a heliocentric distance of 44 au, "MU69" ...will be the most distant object ever visited by a spacecraft. To enable this flyby, we have developed an extremely high-precision orbit fitting and uncertainty processing pipeline, making maximal use of the Hubble Space Telescope's Wide Field Camera 3 (WFC3) and pre-release versions of the ESA Gaia Data Release 2 (DR2) catalog. This pipeline also enabled successful predictions of a stellar occultation by MU69 in 2017 July. We describe how we process the WFC3 images to match the Gaia DR2 catalog, extract positional uncertainties for this extremely faint target (typically 140 photons per WFC3 exposure), and translate those uncertainties into probability distribution functions for MU69 at any given time. We also describe how we use these uncertainties to guide New Horizons, plan stellar occultions of MU69, and derive MU69's orbital evolution and long-term stability.
Plants deploy cell-surface and intracellular leucine rich-repeat domain (LRR) immune receptors to detect pathogens
. LRR receptor kinases and LRR receptor proteins at the plasma membrane recognize ...microorganism-derived molecules to elicit pattern-triggered immunity (PTI), whereas nucleotide-binding LRR proteins detect microbial effectors inside cells to confer effector-triggered immunity (ETI). Although PTI and ETI are initiated in different host cell compartments, they rely on the transcriptional activation of similar sets of genes
, suggesting pathway convergence upstream of nuclear events. Here we report that PTI triggered by the Arabidopsis LRR receptor protein RLP23 requires signalling-competent dimers of the lipase-like proteins EDS1 and PAD4, and of ADR1 family helper nucleotide-binding LRRs, which are all components of ETI. The cell-surface LRR receptor kinase SOBIR1 links RLP23 with EDS1, PAD4 and ADR1 proteins, suggesting the formation of supramolecular complexes containing PTI receptors and transducers at the inner side of the plasma membrane. We detected similar evolutionary patterns in LRR receptor protein and nucleotide-binding LRR genes across Arabidopsis accessions; overall higher levels of variation in LRR receptor proteins than in LRR receptor kinases are consistent with distinct roles of these two receptor families in plant immunity. We propose that the EDS1-PAD4-ADR1 node is a convergence point for defence signalling cascades, activated by both surface-resident and intracellular LRR receptors, in conferring pathogen immunity.
We report the detection of ammonia (NH
) on Pluto's surface in spectral images obtained with the New Horizons spacecraft that show absorption bands at 1.65 and 2.2 μm. The ammonia signature is ...spatially coincident with a region of past extensional tectonic activity (Virgil Fossae) where the presence of H
O ice is prominent. Ammonia in liquid water profoundly depresses the freezing point of the mixture. Ammoniated ices are believed to be geologically short lived when irradiated with ultraviolet photons or charged particles. Thus, the presence of NH
on a planetary surface is indicative of a relatively recent deposition or possibly through exposure by some geological process. In the present case, the areal distribution is more suggestive of cryovolcanic emplacement, however, adding to the evidence for ongoing geological activity on Pluto and the possible presence of liquid water at depth today.
PDF
