6 research outputs found
CANDELS: The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey
The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS)
is designed to document the first third of galactic evolution, over the
approximate redshift (z) range 8--1.5. It will image >250,000 distant galaxies
using three separate cameras on the Hubble Space Telescope, from the
mid-ultraviolet to the near-infrared, and will find and measure Type Ia
supernovae at z>1.5 to test their accuracy as standardizable candles for
cosmology. Five premier multi-wavelength sky regions are selected, each with
extensive ancillary data. The use of five widely separated fields mitigates
cosmic variance and yields statistically robust and complete samples of
galaxies down to a stellar mass of 10^9 M_\odot to z \approx 2, reaching the
knee of the ultraviolet luminosity function (UVLF) of galaxies to z \approx 8.
The survey covers approximately 800 arcmin^2 and is divided into two parts. The
CANDELS/Deep survey (5\sigma\ point-source limit H=27.7 mag) covers \sim 125
arcmin^2 within GOODS-N and GOODS-S. The CANDELS/Wide survey includes GOODS and
three additional fields (EGS, COSMOS, and UDS) and covers the full area to a
5\sigma\ point-source limit of H \gtrsim 27.0 mag. Together with the Hubble
Ultra Deep Fields, the strategy creates a three-tiered "wedding cake" approach
that has proven efficient for extragalactic surveys. Data from the survey are
nonproprietary and are useful for a wide variety of science investigations. In
this paper, we describe the basic motivations for the survey, the CANDELS team
science goals and the resulting observational requirements, the field selection
and geometry, and the observing design. The Hubble data processing and products
are described in a companion paper.Comment: Submitted to Astrophysical Journal Supplement Series; Revised
version, subsequent to referee repor
Mitochondrial Phosphate–Carrier Deficiency: A Novel Disorder of Oxidative Phosphorylation
The mitochondrial phosphate carrier SLC25A3 transports inorganic phosphate into the mitochondrial matrix, which is essential for the aerobic synthesis of adenosine triphosphate (ATP). We identified a homozygous mutation—c.215G→A (p.Gly72Glu)—in the alternatively spliced exon 3A of this enzyme in two siblings with lactic acidosis, hypertrophic cardiomyopathy, and muscular hypotonia who died within the 1st year of life. Functional investigation of intact mitochondria showed a deficiency of ATP synthesis in muscle but not in fibroblasts, which correlated with the tissue-specific expression of exon 3A in muscle versus exon 3B in fibroblasts. The enzyme defect was confirmed by complementation analysis in yeast. This is the first report of patients with mitochondrial phosphate–carrier deficiency
Trochammina
The ecostratigraphic analysis of foraminiferal assemblages from Upper Pliensbachian to Lower Toarcian (Lower Jurassic) mudstones, siltstones and black shales from northern Siberia allows for a better understanding of the response to the benthic biotic crisis related to the Toarcian Oceanic Anoxic Event in a high latitude context. The assemblages were dominated by agglutinated taxa with extremely low diversity values and dominance of Trochammina. These features suggest that the foraminiferal assemblages were adapted to restricted conditions, where the main limiting factors were salinity and oxygen degree. The opportunist behaviour of Trochammina enabled this genus to survive and adapt to unfavourable conditions. Trochammina proliferated in relation to the sea-level fall and probable changes in salinity in the Arctic palaeobasin during the Margaritatus Chron and at the beginning of the Viligaensis Chron (Late Pliensbachian). Another Trochammina proliferation is associated with the initial development of the restricted oxygen conditions related to the Toarcian Oceanic Anoxic Event