1,314 research outputs found
Rejuvenating Power Spectra II: the Gaussianized galaxy density field
We find that, even in the presence of discreteness noise, a Gaussianizing
transform (producing a more-Gaussian one-point distribution) reduces
nonlinearities in the power spectra of cosmological matter and galaxy density
fields, in many cases drastically. Although Gaussianization does increase the
effective shot noise, it also increases the power spectrum's fidelity to the
linear power spectrum on scales where the shot noise is negligible.
Gaussianizing also increases the Fisher information in the power spectrum in
all cases and resolutions, although the gains are smaller in redshift space
than in real space. We also find that the gain in cumulative Fisher information
from Gaussianizing peaks at a particular grid resolution that depends on the
sampling level.Comment: Slight changes to match version accepted to ApJ. 7 pages, 8 figure
Novel Academic Tabletop 2022 (NAT22): A dynamic dice-based emergency medicine education tool
Gamification is an effective teaching tool that improves engagement and knowledge retention. Tabletop role-playing games are dynamic games that use random chance and foster player/leader partnership. To date, there are no teaching tools that mimic dynamic or unpredictable patient presentations. This style of game may work well as a tool for medical education in a simulation-based modality. In this report, we document the rules, materials, and training required to reproduce a hybrid game created to combine facets of simulation and tabletop role-playing games (TRPGs) to create a dynamic medical education tool. After testing the game for flaws and fluidity of gameplay, we plan to collect data evaluating emergency medicine residents\u27 enjoyability and knowledge retention. In this article, we describe a novel TRPG simulation hybrid game that we hypothesize will improve learner enjoyability/engagement and have similar educational benefits to standard medical education
Characteristics of surface-water flows in the ridge and slough landscape of Everglades National Park: implications for particulate transport
Over the last one hundred years, compartmentalization and water management activities have reduced water flow to the ridge and slough landscape of the Everglades. As a result, the once corrugated landscape has become topographically and vegetationally uniform. The focus of this study was to quantify variation in surface flow in the ridge and slough landscape and to relate flow conditions to particulate transport and deposition. Over the 2002–2003 and 2003–2004 wet seasons, surface velocities and particulate accumulation were measured in upper Shark River Slough in Everglades National Park. Landscape characteristics such as elevation, plant density and biomass also were examined to determine their impact on flow characteristics and material transport. The results of this study demonstrate that the release of water during the wet season not only increases water levels, but also increased flow speeds and particulate transport and availability. Further, flow speeds were positively and significantly correlated with water level thereby enhancing particulate transport in sloughs relative to ridges especially during peak flow periods. Our results also indicate that the distribution of biomass in the water column, including floating plants and periphyton, affects velocity magnitude and shape of vertical profiles, especially in the sloughs where Utricularia spp. and periphyton mats are more abundant. Plot clearing experiments suggest that the presence of surface periphyton and Utricularia exert greater control over flow characteristics than the identity (i.e., sawgrass or spike rush) or density of emergent macrophytes, two parameters frequently incorporated into models describing flow through vegetated canopies. Based on these results, we suggest that future modeling efforts must take the presence of floating biomass, such as Utricularia, and presence of periphyton into consideration when describing particulate transport
First-time Diabetic Ketoacidosis in Type 2 Diabetics with COVID-19 Infection: A Novel Case Series
Background: SARS-CoV-2 is a novel coronavirus first diagnosed in US hospitals in January 2020. Typical presenting symptoms include fever, dry cough, dyspnea, and hypoxia. However, several other symptoms have been reported, including fatigue, weakness, diarrhea, and abdominal pain. We have identified a series of patients with diabetic ketoacidosis (DKA) likely precipitated by COVID-19.
Case Series: We describe five patients with previously known type 2 diabetes and no history of DKA, who presented to the emergency department with new-onset DKA and COVID-19.
Why should an emergency physician be aware of this?: Diabetes mellitus is a known risk factor for poor outcomes in viral respiratory illnesses, including COVID-19. Infection may precipitate DKA in patients with type 2 diabetes. Aggressive management of these patients is recommended; however, management guidelines have not yet been put forth for this unique subset of patients
CD248+ stromal cells are associated with progressive chronic kidney disease
Stromal fibroblasts are the primary cells of the kidney that produce fibrotic matrix. CD248 is a stromal marker expressed on fibroblasts and pericytes within the human kidney. Here, we tested whether CD248 expression in the kidney colocalizes with fibrosis and if it is associated with known determinants of chronic kidney disease (CKD). CD248 expression was located and quantified in situ by immunohistochemistry in kidney biopsies from 93 patients with IgA nephropathy and compared with 22 archived biopsies encompassing normal kidney tissue as control. In normal kidney tissue, CD248 was expressed by resident pericytes, stromal fibroblasts, and was upregulated in human CKD. The expression was linked to known determinants of renal progression. This relationship was maintained in a multivariate analysis with CD248 expression linked to renal survival. CD248 was expressed by a population of α-smooth muscle actin (SMA)+ myofibroblasts and α-SMA− stromal cells but not expressed on CD45+ leukocytes. Thus, CD248 defines a subset of stromal cells, including but not limited to some myofibroblasts, linked to albuminuria and tubulointerstitial damage during tissue remodeling in CKD
Prog imperfective drift in ancient Greek? Reconsidering eimi 'be' with present participle
In this paper, I reconsider the diachrony of the Ancient Greek periphrastic construction of eimi 'be' with present participle by means of Bertinetto’s recently proposed model for the development of progressive grams (a process called ‘PROG imperfective drift’). While Bertinetto’s proposal sheds new light on the diachronic development of the construction, at the same time the evidence from Ancient Greek brings to light the need for modification and further refinement of the model (most importantly with regard to the role of what I call the ‘stative’ function, next to the diachronic source(s) of the construction). I furthermore show that eimi with present participle never fully developed a (focalized) progressive function, which can be explained in terms of ‘constructional competition’
LUCIFER@LBT view of star-forming galaxies in the cluster 7C 1756+6520 at z~1.4
Galaxy clusters are key places to study the contribution of {\it nature}
(i.e. mass, morphology) and {\it nurture} (i.e.environment) in the formation
and evolution of galaxies. Recently, a number of clusters at z1, i.e.
corresponding to the first epochs of the cluster formation, has been discovered
and confirmed spectroscopically. We present new observations obtained with the
{\sc LUCIFER} spectrograph at Large Binocular Telescope (LBT) of a sample of
star-forming galaxies associated with a large scale structure around the radio
galaxy 7C1756+6520 at z=1.42. Combining our spectroscopic data and the
literature photometric data, we derived some of the properties of these
galaxies: star formation rate, metallicity and stellar mass. With the aim of
analyzing the effect of the cluster environment on galaxy evolution, we have
located the galaxies in the plane of the so-called Fundamental Metallically
Relation (FMR), which is known not to evolve with redshift up to z for
field galaxies, but it is still unexplored in rich environments at low and high
redshift. We found that the properties of the galaxies in the cluster 7C
1756+6520 are compatible with the FMR which suggests that the effect of the
environment on galaxy metallicity at this early epoch of cluster formation is
marginal. As a side study, we also report the spectroscopic analysis of a
bright AGN, belonging to the cluster, which shows a significant outflow of gas.Comment: Accepted for publication by MNRAS, 10 pages, 6 figures, 3 table
Supermassive Black Holes and Their Environments
We make use of the first high--resolution hydrodynamic simulations of
structure formation which self-consistently follows the build up of
supermassive black holes introduced in Di Matteo et al. (2007) to investigate
the relation between black holes (BH), host halo and large--scale environment.
There are well--defined relations between halo and black hole masses and
between the activities of galactic nuclei and halo masses at low redshifts. A
large fraction of black holes forms anti--hierarchically, with a higher ratio
of black hole to halo mass at high than at low redshifts. At , we predict
group environments (regions of enhanced local density) to contain the highest
mass and most active (albeit with a large scatter) BHs while the rest of the BH
population to be spread over all densities from groups to filaments and voids.
Density dependencies are more pronounced at high rather than low redshift.
These results are consistent with the idea that gas rich mergers are likely the
main regulator of quasar activity. We find star formation to be a somewhat
stronger and tighter function of local density than BH activity, indicating
some difference in the triggering of the latter versus the former. There exists
a large number of low--mass black holes, growing slowly predominantly through
accretion, which extends all the way into the most underdense regions, i.e. in
voids.Comment: 18 pages, 15 Figures, accepted for publication in MNRA
Recommended from our members
Polar and Magnetic Mn2FeMO6 (M = Nb, Ta) with LiNbO3-type Structure - High Pressure Synthesis
Polar oxides are of much interest in materials science and engineering. Their symmetry-dependent properties such as ferroelectricity/multiferroics, piezoelectricity, pyroelectricity, and second-order harmonic generation (SHG) effect are important for technological applications. However, polar crystal design and synthesis is challenging, because multiple effects, such as steric or dipole-dipole interactions, typically combine to form non-polar structures; so the number of known polar materials, especially polar magnetoelectric materials, is still severely restricted. Therefore, it is necessary for the material science community to develop new strategies to create these materials
Quasar induced galaxy formation: a new paradigm ?
We discuss observational evidence that quasars play a key role in the
formation of galaxies starting from the detailed study of the quasar
HE0450-2958 and extending the discussion to a series of converging evidence
that radio jets may trigger galaxy formation. The direct detection with VISIR
at the ESO-VLT of the 7 kpc distant companion galaxy of HE0450-2958 allows us
to spatially separate the sites of quasar and star formation activity in this
composite system made of two ultra-luminous infrared galaxies (ULIRGs). No host
galaxy has yet been detected for this quasar, but the companion galaxy stellar
mass would bring HE0450-2958 in the local M(BH)-M(stellar bulge) relation if it
were to merge with the QSO. This is bound to happen because of their close
distance (7 kpc) and small relative velocity (~60-200 km/s). We conclude that
we may be witnessing the building of the M(BH)-M(stellar bulge) relation, or at
least of a major event in that process. The star formation rate (~340 Msun/yr),
age (40-200 Myr) and stellar mass ([5-6]x10^10 Msun) are consistent with
jet-induced formation of the companion galaxy. We suggest that HE0450-2958 may
be fueled in fresh material by cold gas accretion from intergalactic filaments.
We map the projected galaxy density surrounding the QSO as a potential tracer
of intergalactic filaments and discuss a putative detection. Comparison to
other systems suggests that inside-out formation of quasar host galaxies and
jet-induced galaxy formation may be a common process. Two tests are proposed
for this new paradigm: (1) the detection of offset molecular gas or dust
emission with respect to the position of distant QSOs, (2) the delayed
formation of host galaxies as a result of QSO activity, hence the two step
building of the M(BH)/M(stellar bulge) ratio.Comment: 15 pages, 8 figures, accepted for publication in Astronomy and
Astrophysics (with minor corrections
- …