9 research outputs found
A New Concept for Direct Imaging and Spectral Characterization of Exoplanets in Multi-planet Systems
We present a novel method for direct detection and characterization of
exoplanets from space. This method uses four collecting telescopes, combined
with phase chopping and a spectrometer, with observations on only a few
baselines rather than on a continuously rotated baseline. Focusing on the
contiguous wavelength spectra of typical exoplanets, the (u, v) plane can be
simultaneously and uniformly filled by recording the spectrally resolved
signal. This concept allows us to perfectly remove speckles from reconstructed
images. For a target comprising a star and multiple planets, observations on
three baselines are sufficient to extract the position and spectrum of each
planet. Our simulations show that this new method allows us to detect an analog
Earth around a Sun-like star at 10 pc and to acquire its spectrum over the
wavelength range from 8 to 19 {\mu}m with a high spectral resolution of 100.
This method allows us to fully characterize an analog Earth and to similarly
characterize each planet in multi-planet systems.Comment: 10 pages, 12 figure
Mutations in the iodotyrosine deiodinase gene and hypothyroidism
DEHAL1 has been identified as the gene encoding iodotyrosine deiodinase in the thyroid, where it controls the reuse of iodide for thyroid hormone synthesis. We screened patients with hypothyroidism who had features suggestive of an iodotyrosine deiodinase defect for mutations in DEHAL1. Two missense mutations and a deletion of three base pairs were identified in four patients from three unrelated families; all the patients had a dramatic reduction of in vitro activity of iodotyrosine deiodinase. Patients had severe goitrous hypothyroidism, which was evident in infancy and childhood. Two patients had cognitive deficits due to late diagnosis and treatment. Thus, mutations in DEHAL1 led to a deficiency in iodotyrosine deiodinase in these patients. Because infants with DEHAL1 defects may have normal thyroid function at birth, they may be missed by neonatal screening programs for congenital hypothyroidism. Copyrigh