3,654 research outputs found
Jet-related Excitation of the [CII] Emission in the Active Galaxy NGC 4258 with SOFIA
We detect widespread [CII]157.7um emission from the inner 5 kpc of the active
galaxy NGC 4258 with the SOFIA integral field spectrometer FIFI-LS. The
emission is found associated with warm H2, distributed along and beyond the end
of southern jet, in a zone known to contain shock-excited optical filaments. It
is also associated with soft X-ray hot-spots, which are the counterparts of the
`anomalous radio arms' of NGC~4258, and a 1 kpc-long filament on the minor axis
of the galaxy which contains young star clusters. Palomar-CWI H-alpha integral
field spectroscopy shows that the filament exhibits non-circular motions within
NGC 4258. Many of the [CII] profiles are very broad, with the highest line
width, 455 km/s, observed at the position of the southern jet bow-shock.
Abnormally high ratios of L([CII])/L(FIR) and L([CII])/L(PAH7.7um) are found
along and beyond the southern jet and in the X-ray hotspots. These are the same
regions that exhibit unusually large intrinsic [CII] line widths. This suggests
that the [CII] traces warm molecular gas in shocks and turbulence associated
with the jet. We estimate that as much as 40% (3.8 x 10^39 erg/s) of the total
[CII] luminosity from the inner 5 kpc of NGC 4258 arises in shocks and
turbulence (< 1% bolometric luminosity from the active nucleus), the rest being
consistent with [CII] excitation associated with star formation. We propose
that the highly-inclined jet is colliding with, and being deflected around,
dense irregularities in a thick disk, leading to significant energy dissipation
over a wide area of the galaxy.Comment: Accepted for Publication in the Astrophysical Journal Oct 29 201
THE EFFECT OF ROUNDING ON THE PROBABILITY DISTRIBUTION OF REGRADING IN THE U.S. PEANUT INDUSTRY
This article determines the effect of rounding (pointing-off) of grade percentages to the nearest whole number on the probability distribution of regrading in the peanut industry. Results show that rounding causes graders to have to regrade an extra 4% of samples even when they follow all directions and make no mistakes. When rounding was not used, the sample weight had little effect on the probability of regrading. With rounding, the probability of regrading was reduced by beginning with a larger than 500-gram sample. Thus, rounding provides an incentive to take overweight samples in order to avoid regrading. Overweight samples can overestimate the value of peanuts. A low-cost way to improve peanut grading accuracy would be to round to tenths rather than whole numbers.grading, normal-jump distribution, peanuts, regrading, rounding, Crop Production/Industries,
âOur Storiesâ: First-year Learning Communities Students Reflections on the Transition to College
Analysis of diverse first-year and first-generation learning communities studentsâ reflective narratives shows this population of students at an urban commuter college of technology face significant challenges in the transition into college. Designed to assist in this transition, the âOur Storiesâ digital writing project incorporates reflective writing in the long established, yet recently revitalized, learning communities program. Through analysis of the âOur Storiesâ project, we examine how the structure of our learning communities program, together with writing on an open digital platform, builds community and has the potential to positively influence students as they identify, and begin to make sense, of the social, emotional, and bureaucratic challenges in their transition into college. The role of peer mentors, faculty and administrators in this project is discussed
A Subset of Pemphigus Foliaceus Patients Exhibits Pathogenic Autoantibodies Against Both Desmoglein-1 and Desmoglein-3
In pemphigus vulgaris the major pathogenic antibody binds desmoglein-3, and mediates mucosal disease. Development of cutaneous disease is associated with acquisition of antibodies to desmoglein-1. In pemphigus foliaceus, and its endemic form, fogo selvagem by contrast, the major pathogenic antibody recognizes desmoglein-1 and mediates cutaneous disease only. In this study, we sought to determine the prevalence of antibodies to desmoglein-3 in patients with pemphigus foliaceus and fogo selvagem. We produced recombinant desmoglein-1 and desmoglein-3, and used them in highly sensitive and specific enzyme-linked immunosorbent assays, as well as immunoprecipitation assays. We detected antibodies to desmoglein-3 in 19 of 276 patients with pemphigus foliaceus and fogo selvagem, who had cutaneous disease only. We showed that these antibodies to desmoglein-3 could be absorbed in a concentration-dependent manner by desmoglein-3 but not by desmoglein-1. Also antibodies to desmoglein-1 could be absorbed in a concentration-dependent manner by desmoglein-1 but not desmoglein-3. This suggests that two separate species of antibody are present rather than one antibody capable of cross-reacting with both desmoglein-1 and desmoglein-3. Finally, it was shown that affinity-purified antibodies to desmoglein-3 from patients with pemphigus foliaceus and fogo selvagem induced a pemphigus vulgaris-like skin disease in mice by passive transfer. These results suggest that a subset of patients with pemphigus foliaceus and fogo selvagem have antibodies to desmoglein-3 that may be involved in the pathogenesis of their cutaneous disease
The Spatial Extent of (U)LIRGs in the Mid-Infrared. II. Feature Emission
We present results from the second part of our analysis of the extended
mid-infrared (MIR) emission of the Great Observatories All-Sky LIRG Survey
(GOALS) sample based on 5-14 micron low-resolution spectra obtained with the
IRS on Spitzer. We calculate the fraction of extended emission as a function of
wavelength for all galaxies in the sample, FEE_lambda, and spatially separate
the MIR spectrum of galaxies into their nuclear and extended components.
We find that the [NeII] emission line is as compact as the hot dust MIR
continuum, while the polycyclic aromatic hydrocarbon (PAH) emission is more
extended. The 6.2 and 7.7 micron PAH emission is more compact than that of the
11.3 micron PAH, which is consistent with the formers being enhanced in a more
ionized medium. The presence of an AGN or a powerful nuclear starburst
increases the compactness of the hot dust MIR continuum, but has a negligible
effect on the spatial extent of the PAH emission on kpc-scales. Globally, the
spectra of the extended emission component are homogeneous for all galaxies in
GOALS. This suggests that the physical properties of star formation taking
place at distances farther than 1.5 kpc from the nuclei of (U)LIRGs are very
similar, resembling local star-forming galaxies with L_IR < 10^11 Lsun, as well
as star formation-dominated ULIRGs at z~2. In contrast, the MIR spectra of the
nuclear component of local (U)LIRGs are very diverse. This implies that the
observed variety of their integrated MIR properties arise, on average, only
from the processes that are taking place in their cores.Comment: 16 pages, 7 figures, accepted for publication in Ap
Uplink Non-Orthogonal Multiple Access with Finite-Alphabet Inputs
This paper focuses on the non-orthogonal multiple access (NOMA) design for a
classical two-user multiple access channel (MAC) with finite-alphabet inputs.
We consider practical quadrature amplitude modulation (QAM) constellations at
both transmitters, the sizes of which are assumed to be not necessarily
identical. We propose to maximize the minimum Euclidean distance of the
received sum-constellation with a maximum likelihood (ML) detector by adjusting
the scaling factors (i.e., instantaneous transmitted powers and phases) of both
users. The formulated problem is a mixed continuous-discrete optimization
problem, which is nontrivial to resolve in general. By carefully observing the
structure of the objective function, we discover that Farey sequence can be
applied to tackle the formulated problem. However, the existing Farey sequence
is not applicable when the constellation sizes of the two users are not the
same. Motivated by this, we define a new type of Farey sequence, termed punched
Farey sequence. Based on this, we manage to achieve a closed-form optimal
solution to the original problem by first dividing the entire feasible region
into a finite number of Farey intervals and then taking the maximum over all
the possible intervals. The resulting sum-constellation is proved to be a
regular QAM constellation of a larger size. Moreover, the superiority of NOMA
over time-division multiple access (TDMA) in terms of minimum Euclidean
distance is rigorously proved. Furthermore, the optimal rate allocation among
the two users is obtained in closed-form to further maximize the obtained
minimum Euclidean distance of the received signal subject to a total rate
constraint. Finally, simulation results are provided to verify our theoretical
analysis and demonstrate the merits of the proposed NOMA over existing
orthogonal and non-orthogonal designs.Comment: Submitted for possible journal publicatio
Two-dimensional gel proteome reference map of blood monocytes
BACKGROUND: Blood monocytes play a central role in regulating host inflammatory processes through chemotaxis, phagocytosis, and cytokine production. However, the molecular details underlying these diverse functions are not completely understood. Understanding the proteomes of blood monocytes will provide new insights into their biological role in health and diseases. RESULTS: In this study, monocytes were isolated from five healthy donors. Whole monocyte lysates from each donor were then analyzed by 2D gel electrophoresis, and proteins were detected using Sypro Ruby fluorescence and then examined for phosphoproteomes using ProQ phospho-protein fluorescence dye. Between 1525 and 1769 protein spots on each 2D gel were matched, analyzed, and quantified. Abundant protein spots were then subjected to analysis by mass spectrometry. This report describes the protein identities of 231 monocyte protein spots, which represent 164 distinct proteins and their respective isoforms or subunits. Some of these proteins had not been previously characterized at the protein level in monocytes. Among the 231 protein spots, 19 proteins revealed distinct modification by protein phosphorylation. CONCLUSION: The results of this study offer the most detailed monocyte proteomic database to date and provide new perspectives into the study of monocyte biology
Production of Toxic Volatile Trimethylbismuth by the Intestinal Microbiota of Mice
The biotransformation of metals and metalloids into their volatile methylated derivatives by microbes growing under anaerobic conditions (e.g., the mammalian intestinal microbiota) plays an important role in spreading these compounds in the environment. In this paper, we could show that the presence of an intact intestinal microbiota of mice provides the conditio sine qua non for the production of these mostly toxic derivatives. To document the indispensible role of the intestinal microbiota in methylating metals and metalloids to volatile derivatives under in vivo conditions, we compared the methylation capability of conventionally raised (CONV) and germ-free (GF) B6-mice fed with chow containing colloidal bismuth subcitrate (CBS) as the starting material for the formation of volatile methylated metal(loid)s. Permethylated volatile trimethylbismuth ((CH3)3Bi) was only detected in the blood of the conventionally raised mice. Concomitantly, a higher bismuth concentration was found in organs such as liver, lung, testicles, and brain of the CONV mice as compared to those of GF mice (P > 0.01), strongly suggesting a correlation between the intestinal biomethylation of bismuth and its accumulation in mammalian tissues
N-body simulation of the Stephan's Quintet
The evolution of compact groups of galaxies may represent one of the few
places in the nearby universe in which massive galaxies are being forged
through a complex set of processes involving tidal interaction, ram-pressure
stripping, and perhaps finally "dry-mergers" of galaxies stripped of their cool
gas. Using collisionless N-body simulations, we propose a possible scenario for
the formation of one of the best studied compact groups: Stephan's Quintet. We
define a serial approach which allows us to consider the history of the group
as sequence of galaxy-galaxy interactions seen as relatively separate events in
time, but chained together in such a way as to provide a plausible scenario
that ends in the current configuration of the galaxies. By covering a large set
of parameters, we claim that it is very unlikely that both major tidal tails of
the group have been created by the interaction between the main galaxy and a
single intruder. We propose instead a scenario based on two satellites orbiting
the main disk, plus the recent involvement of an additional interloper, coming
from the background at high speed. This purely N-body study of the quintet will
provide a parameter-space exploration of the basic dynamics of the group that
can be used as a basis for a more sophisticated N-body/hydrodynamic study of
the group that is necessary to explain the giant shock structure and other
purely gaseous phenomena observed in both the cold, warm and hot gas in the
group.Comment: 13 pages, 13 figures. Accepted for publication in Ap
Effect of extending conjugation via thiophene-based oligomers on the excited state electron transfer rates to ZnO nanocrystals
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