177 research outputs found
SNS programming environment user's guide
The computing environment is briefly described for the Supercomputing Network Subsystem (SNS) of the Central Scientific Computing Complex of NASA Langley. The major SNS computers are a CRAY-2, a CRAY Y-MP, a CONVEX C-210, and a CONVEX C-220. The software is described that is common to all of these computers, including: the UNIX operating system, computer graphics, networking utilities, mass storage, and mathematical libraries. Also described is file management, validation, SNS configuration, documentation, and customer services
Two P domain potassium channels in GtoPdb v.2021.2
The 4TM family of K channels mediate many of the background potassium currents observed in native cells. They are open across the physiological voltage-range and are regulated by a wide array of neurotransmitters and biochemical mediators. The pore-forming α-subunit contains two pore loop (P) domains and two subunits assemble to form one ion conduction pathway lined by four P domains. It is important to note that single channels do not have two pores but that each subunit has two P domains in its primary sequence; hence the name two P domain, or K2P channels (and not two-pore channels). Some of the K2P subunits can form heterodimers across subfamilies (e.g. K2P3.1 with K2P9.1). The nomenclature of 4TM K channels in the literature is still a mixture of IUPHAR and common names. The suggested division into subfamilies, described in the More detailed introduction, is based on similarities in both structural and functional properties within subfamilies and this explains the "common abbreviation" nomenclature in the tables below
RELICS: Strong Lens Models for Five Galaxy Clusters From the Reionization Lensing Cluster Survey
Strong gravitational lensing by galaxy clusters magnifies background
galaxies, enhancing our ability to discover statistically significant samples
of galaxies at z>6, in order to constrain the high-redshift galaxy luminosity
functions. Here, we present the first five lens models out of the Reionization
Lensing Cluster Survey (RELICS) Hubble Treasury Program, based on new HST
WFC3/IR and ACS imaging of the clusters RXC J0142.9+4438, Abell 2537, Abell
2163, RXC J2211.7-0349, and ACT-CLJ0102-49151. The derived lensing
magnification is essential for estimating the intrinsic properties of
high-redshift galaxy candidates, and properly accounting for the survey volume.
We report on new spectroscopic redshifts of multiply imaged lensed galaxies
behind these clusters, which are used as constraints, and detail our strategy
to reduce systematic uncertainties due to lack of spectroscopic information. In
addition, we quantify the uncertainty on the lensing magnification due to
statistical and systematic errors related to the lens modeling process, and
find that in all but one cluster, the magnification is constrained to better
than 20% in at least 80% of the field of view, including statistical and
systematic uncertainties. The five clusters presented in this paper span the
range of masses and redshifts of the clusters in the RELICS program. We find
that they exhibit similar strong lensing efficiencies to the clusters targeted
by the Hubble Frontier Fields within the WFC3/IR field of view. Outputs of the
lens models are made available to the community through the Mikulski Archive
for Space TelescopesComment: Accepted to Ap
Scientific issues related to the cytology proficiency testing regulations
The member organizations of the Cytology Education and Technology Consortium believe there are significant flaws in current cytology proficiency testing regulations. The most immediate needed modifications include lengthening the required testing interval, utilizing stringently validated and continuously monitored slides, changing the grading scheme, and changing the focus of the test from the individual to laboratory level testing. Integration of new computer-assisted and located-guided screening technologies into the testing protocols is necessary for the testing protocol to be compliant with the law
RELICS: High-Resolution Constraints on the Inner Mass Distribution of the z=0.83 Merging Cluster RXJ0152.7-1357 from strong lensing
Strong gravitational lensing (SL) is a powerful means to map the distribution
of dark matter. In this work, we perform a SL analysis of the prominent X-ray
cluster RXJ0152.7-1357 (z=0.83, also known as CL 0152.7-1357) in \textit{Hubble
Space Telescope} images, taken in the framework of the Reionization Lensing
Cluster Survey (RELICS). On top of a previously known galaxy multiply
imaged by RXJ0152.7-1357, for which we identify an additional multiple image,
guided by a light-traces-mass approach we identify seven new sets of multiply
imaged background sources lensed by this cluster, spanning the redshift range
[1.79-3.93]. A total of 25 multiple images are seen over a small area of ~0.4
, allowing us to put relatively high-resolution constraints on the
inner matter distribution. Although modestly massive, the high degree of
substructure together with its very elongated shape make RXJ0152.7-1357 a very
efficient lens for its size. This cluster also comprises the third-largest
sample of z~6-7 candidates in the RELICS survey. Finally, we present a
comparison of our resulting mass distribution and magnification estimates with
those from a Lenstool model. These models are made publicly available through
the MAST archive.Comment: 15 Pages, 7 Figures, 4 Tables Accepted for publication in Ap
Genome-wide expression analyses of Campylobacter jejuni NCTC11168 reveals coordinate regulation of motility and virulence by flhA.
We examined two variants of the genome-sequenced strain, Campylobacter jejuni NCTC11168, which show marked differences in their virulence properties including colonization of poultry, invasion of Caco-2 cells, and motility. Transcript profiles obtained from whole genome DNA microarrays and proteome analyses demonstrated that these differences are reflected in late flagellar structural components and in virulence factors including those involved in flagellar glycosylation and cytolethal distending toxin production. We identified putative sigma(28) and sigma(54) promoters for many of the affected genes and found that greater differences in expression were observed for sigma(28)-controlled genes. Inactivation of the gene encoding sigma(28), fliA, resulted in an unexpected increase in transcripts with sigma(54) promoters, as well as decreased transcription of sigma(28)-regulated genes. This was unlike the transcription profile observed for the attenuated C. jejuni variant, suggesting that the reduced virulence of this organism was not entirely due to impaired function of sigma(28). However, inactivation of flhA, an important component of the flagellar export apparatus, resulted in expression patterns similar to that of the attenuated variant. These findings indicate that the flagellar regulatory system plays an important role in campylobacter pathogenesis and that flhA is a key element involved in the coordinate regulation of late flagellar genes and of virulence factors in C. jejuni
EPOCHS VII: Discovery of high redshift () AGN candidates in JWST ERO and PEARLS data
We present an analysis of a sample of robust high redshift galaxies selected
photometrically from the `blank' fields of the Prime Extragalactic Areas for
Reionization Science (PEARLS) survey and Early Release Observations (ERO) data
of the James Webb Space Telescope (JWST) with the aim of selecting candidate
high redshift active galactic nuclei (AGN). Sources were identified from the
parent sample using a threefold selection procedure, which includes spectral
energy distribution (SED) fitting to identify sources that are best fitted by
AGN SED templates, a further selection based on the relative performance of AGN
and non-AGN models, and finally morphological fitting to identify compact
sources of emission, resulting in a purity-oriented procedure. Using this
procedure, we identify a sample of nine AGN candidates at , from
which we constrain their physical properties as well as measure a lower bound
on the AGN fraction in this redshift range of \%. As this is an
extreme lower limit due to our focus on purity and our SEDs being calibrated
for unobscured Type 1 AGN, this demonstrates that AGN are perhaps quite common
at this early epoch. The rest-frame UV colors of our candidate objects suggest
that these systems are potentially candidate obese black hole galaxies (OBG),
or AGN with very little galaxy component. We also investigate emission from our
sample sources from fields overlapping with Chandra and VLA surveys, allowing
us to place X-ray and 3 GHz radio detection limits on our candidates. Of note
is a candidate source exhibiting an abrupt morphological shift in
the reddest band as compared to the bluer bands, indicating a potential merger
or an unusually strong outflow.Comment: Submitted to MNRAS, 12 pages, 11 figures, typos correcte
EPOCHS IX. When cosmic dawn breaks: Evidence for evolved stellar populations in galaxies from PEARLS GTO and public NIRCam imaging
The presence of evolved stars in high-redshift galaxies can place valuable
indirect constraints on the onset of star formation in the Universe. Thus we
use PEARLS GTO and public NIRCam photometric data to search for Balmer-break
candidate galaxies at . We find that our Balmer-break candidates at
tend to be older (115 Myr), have lower inferred [O III] +
H emission line equivalent widths (120 \r{A}), have lower specific star
formation rates (6 Gyr) and redder UV slopes () than our
control sample of galaxies. However, these trends all become less strong at , where the F444W filter now probes the strong rest-frame optical
emission lines, thus providing additional constraints on the current star
formation activity of these galaxies. Indeed, the bursty nature of Epoch of
Reionisation galaxies can lead to a disconnect between their current SED
profiles and their more extended star-formation histories. We discuss how
strong emission lines, the cumulative effect of weak emission lines, dusty
continua and AGN can all contribute to the photometric excess seen in the
rest-frame optical, thus mimicking the signature of a Balmer break. Additional
medium-band imaging will thus be essential to more robustly identify
Balmer-break galaxies. However, the Balmer break alone cannot serve as a
definitive proxy for the stellar age of galaxies, being complexly dependent on
the star-formation history. Ultimately, deep NIRSpec continuum spectroscopy and
MIRI imaging will provide the strongest indirect constraints on the formation
era of the first galaxies in the Universe, thereby revealing when cosmic dawn
breaks.Comment: 25 pages, 16 figures, 2 tables. Updated to published version in MNRA
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