2,162 research outputs found
Eosinophilic bronchitis, eosinophilic granuloma, and eosinophilic bronchopneumopathy in 75 dogs (2006-2016).
BackgroundEosinophilic lung disease is a poorly understood inflammatory airway disease that results in substantial morbidity.ObjectiveTo describe clinical findings in dogs with eosinophilic lung disease defined on the basis of radiographic, bronchoscopic, and bronchoalveolar lavage fluid (BAL) analysis. Categories included eosinophilic bronchitis (EB), eosinophilic granuloma (EG), and eosinophilic bronchopneumopathy (EBP).AnimalsSeventy-five client owned dogs.MethodsMedical records were retrospectively reviewed for dogs with idiopathic BAL fluid eosinophilia. Information abstracted included duration and nature of clinical signs, bronchoscopic findings, and laboratory data. Thoracic radiographs were evaluated for the pattern of infiltrate, bronchiectasis, and lymphadenomegaly.ResultsThoracic radiographs were normal or demonstrated a bronchial pattern in 31 dogs assigned a diagnosis of EB. Nine dogs had intraluminal mass lesions and were bronchoscopically diagnosed with EG. The remaining 35 dogs were categorized as having EBP based on radiographic changes, yellow green mucus in the airways, mucosal changes, and airway collapse. Age and duration of cough did not differ among groups. Dogs with EB were less likely to have bronchiectasis or peripheral eosinophilia, had lower total nucleated cell count in BAL fluid, and lower percentage of eosinophils in BAL fluid compared to dogs in the other 2 groups. In contrast to previous reports, prolonged survival (>55βmonths) was documented in dogs with EG.Conclusions and clinical importanceDogs with eosinophilic lung disease can be categorized based on imaging, bronchoscopic and BAL fluid cytologic findings. Further studies are needed to establish response to treatment in these groups
Slowest first passage times, redundancy, and menopause timing
Biological events are often initiated when a random "searcher" finds a
"target," which is called a first passage time (FPT). In some biological
systems involving multiple searchers, an important timescale is the time it
takes the slowest searcher(s) to find a target. For example, of the hundreds of
thousands of primordial follicles in a woman's ovarian reserve, it is the
slowest to leave that trigger the onset of menopause. Such slowest FPTs may
also contribute to the reliability of cell signaling pathways and influence the
ability of a cell to locate an external stimulus. In this paper, we use extreme
value theory and asymptotic analysis to obtain rigorous approximations to the
full probability distribution and moments of slowest FPTs. Though the results
are proven in the limit of many searchers, numerical simulations reveal that
the approximations are accurate for any number of searchers in typical
scenarios of interest. We apply these general mathematical results to models of
ovarian aging and menopause timing, which reveals the role of slowest FPTs for
understanding redundancy in biological systems. We also apply the theory to
several popular models of stochastic search, including search by diffusive,
subdiffusive, and mortal searchers.Comment: 55 pages, 7 figure
The extent of chemically enriched gas around star-forming dwarf galaxies
Supernova driven winds are often invoked to remove chemically enriched gas
from dwarf galaxies to match their low observed metallicities. In such shallow
potential wells, outflows may produce massive amounts of enriched halo gas
(circum-galactic medium or CGM) and pollute the intergalactic medium (IGM).
Here, we present a survey of the CGM and IGM around 18 star-forming field
dwarfs with stellar masses of at .
Eight of these have CGM probed by quasar absorption spectra at projected
distances, , less than the host virial radius, . Ten are probed
in the surrounding IGM at . The absorption measurements
include neutral hydrogen, the dominant silicon ions for diffuse cool gas
( K; Si II, Si III, and Si IV), moderately ionized carbon (C IV),
and highly ionized oxygen (O VI). Metal absorption from the CGM of the dwarfs
is less common and weaker compared to massive star-forming
galaxies though O VI absorption is still common. None of the dwarfs probed at
have definitive metal-line detections. Combining the
available silicon ions, we estimate that the cool CGM of the dwarfs accounts
for only of the expected silicon budget from the yields of supernovae
associated with past star-formation. The highly ionized O VI accounts for
of the oxygen budget. As O VI traces an ion with expected
equilibrium ion fractions of , the highly ionized CGM may
represent a significant metal reservoir even for dwarfs not expected to
maintain gravitationally shock heated hot halos.Comment: Accepted to ApJL, 10 pages, 3 figures, 2 tables. Please contact the
corresponding author for additional column density measurements if needed. v3
includes additional references and clarification in the introductio
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