2,299 research outputs found
Selective amplification of glucocorticoid anti-inflammatory activity through synergistic multi-target action of a combination drug
A Thirty Kiloparsec Chain of "Beads on a String" Star Formation Between Two Merging Early Type Galaxies in the Core of a Strong-Lensing Galaxy Cluster
New Hubble Space Telescope ultraviolet and optical imaging of the
strong-lensing galaxy cluster SDSS J1531+3414 (z=0.335) reveals two centrally
dominant elliptical galaxies participating in an ongoing major merger. The
interaction is at least somewhat rich in cool gas, as the merger is associated
with a complex network of nineteen massive superclusters of young stars (or
small tidal dwarf galaxies) separated by ~1 kpc in projection from one another,
combining to an estimated total star formation rate of ~5 solar masses per
year. The resolved young stellar superclusters are threaded by narrow H-alpha,
[O II], and blue excess filaments arranged in a network spanning ~27 kpc across
the two merging galaxies. This morphology is strongly reminiscent of the
well-known "beads on a string" mode of star formation observed on kpc-scales in
the arms of spiral galaxies, resonance rings, and in tidal tails between
interacting galaxies. Nevertheless, the arrangement of this star formation
relative to the nuclei of the two galaxies is difficult to interpret in a
dynamical sense, as no known "beads on a string" systems associated with
kpc-scale tidal interactions exhibit such lopsided morphology relative to the
merger participants. In this Letter we present the images and follow-up
spectroscopy, and discuss possible physical interpretations for the unique
arrangement of the young stellar clusters. While we suggest that this
morphology is likely to be dynamically short-lived, a more quantitative
understanding awaits necessary multiwavelength follow-up, including optical
integral field spectroscopy, ALMA sub-mm interferometry, and Chandra X-ray
imaging.Comment: 7 pages, 4 figures, accepted for publication in ApJ Letters. High
resolution images of the cluster can be found at
http://hubblesite.org/news/2014/2
Neighbor-directed histidine N (Ï„)-alkylation: A route to imidazolium-containing phosphopeptide macrocycles
Our recently discovered, selective, on-resin route to N(Ï„)-alkylated imidazolium-containing histidine residues affords new strategies for peptide mimetic design. In this, we demonstrate the use of this chemistry to prepare a series of macrocyclic phosphopeptides, in which imidazolium groups serve as ring-forming junctions. Interestingly, these cationic moieties subsequently serve to charge-mask the phosphoamino acid group that directed their formation. Neighbor-directed histidine N(Ï„)-alkylation opens the door to new families of phosphopeptidomimetics for use in a range of chemical biology contexts.National Institutes of Health (U.S.) (Grants ES015339 and GM104047
Pattern Transfer of Sub-10 nm Features via Tin-Containing Block Copolymers
Tin-containing block copolymers were investigated as materials for nanolithographic applications. Poly(4-trimethylstannylstyrene-block-styrene) (PSnS-PS) and poly(4-trimethylstannylstyrene-block-4-methoxystyrene) (PSnS-PMOST) synthesized by reversible addition–fragmentation chain transfer polymerization form lamellar domains with periodicities ranging from 18 to 34 nm. Thin film orientation control was achieved by thermal annealing between a neutral surface treatment and a top coat. Incorporation of tin into one block facilitates pattern transfer into SiO_2 via a two-step etch process utilizing oxidative and fluorine-based etch chemistries
Validation of the BEEM rater scale: An instrument to define the “best evidence for Emergency Medicine
HST NIR Snapshot Survey of 3CR Radio Source Counterparts II: An Atlas and Inventory of the Host Galaxies, Mergers and Companions
We present the second part of an H-band (1.6 microns) atlas of z<0.3 3CR
radio galaxies, using the Hubble Space Telescope Near Infrared Camera and
Multi-Object Spectrometer (HST NICMOS2). We present new imaging for 21 recently
acquired sources, and host galaxy modeling for the full sample of 101
(including 11 archival) -- an 87% completion rate. Two different modeling
techniques are applied, following those adopted by the galaxy morphology and
the quasar host galaxy communities. Results are compared, and found to be in
excellent agreement, although the former breaks down in the case of strongly
nucleated sources. Companion sources are tabulated, and the presence of
mergers, tidal features, dust disks and jets are catalogued. The tables form a
catalogue for those interested in the structural and morphological dust-free
host galaxy properties of the 3CR sample, and for comparison with morphological
studies of quiescent galaxies and quasar host galaxies. Host galaxy masses are
estimated, and found to typically lie at around 2*10^11 solar masses. In
general, the population is found to be consistent with the local population of
quiescent elliptical galaxies, but with a longer tail to low Sersic index,
mainly consisting of low-redshift (z<0.1) and low-radio-power (FR I) sources. A
few unusually disky FR II host galaxies are picked out for further discussion.
Nearby external sources are identified in the majority of our images, many of
which we argue are likely to be companion galaxies or merger remnants. The
reduced NICMOS data are now publicly available from our website
(http://archive.stsci.edu/prepds/3cr/)Comment: ApJS, 177, 148: Final version; includes revised figures 1, 15b, and
section 7.5 (and other minor changes from editing process. 65 pages, inc. 17
figure
Ribosomal protein S6 mRNA is a biomarker upregulated in multiple sclerosis, downregulated by interferon treatment, and affected by season
Background
The Development and Initial Validation of a Measure of Coaching Behaviors in a Sample of Soldiers Under Training
In this article we outline a model of coaching that is conceptually grounded in workplace and sport coaching literature and present 2 studies conducted to test this model: the extent that coaching behaviors are present in a military training setting, and their association with performance-related outcomes. Following an extensive review of literature and rigorous development and validation procedures the 28-item Military Coaching Behavior Scale was tested. The measure showed good content and predictive validity for 2 dependent variables (satisfaction and resilience). We concluded that the Military Coaching Behavior Scale offers a psychometrically sound, brief, and easy-to-administer measure of high-performance coaching behavior
A Science-Based Policy for Managing Free-Roaming Cats
Free-roaming domestic cats (i.e., cats that are owned or unowned and are considered ‘at large’) are globally distributed non-native species that have marked impacts on biodiversity and human health. Despite clear scientific evidence of these impacts, free-roaming cats are either unmanaged or managed using scientifically unsupported and ineffective approaches (e.g., trap-neuter-release [TNR]) in many jurisdictions around the world. A critical first initiative for effective, science-driven management of cats must be broader political and legislative recognition of free-roaming cats as a non-native, invasive species. Designating cats as invasive is important for developing and implementing science-based management plans, which should include efforts to prevent cats from becoming free-roaming, policies focused on responsible pet ownership and banning outdoor cat feeding, and better enforcement of existing laws.
Using a science-based approach is necessary for responding effectively to the politically charged and increasingly urgent issue of managing free-roaming cat populations
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