Streptococcus mutans is considered the primary etiologic agent of dental caries, a global health problem that affects 60 to 90% of the population, and a leading causative agent of infective ...endocarditis. It can be divided into four different serotypes (c, e, f, and k), with serotype c strains being the most common in the oral cavity. In this study, we demonstrate that in addition to OMZ175 and B14, three other strains (NCTC11060, LM7, and OM50E) of the less prevalent serotypes e and f are able to invade primary human coronary artery endothelial cells (HCAEC). Invasive strains were also significantly more virulent than noninvasive strains in the Galleria mellonella (greater wax worm) model of systemic disease. Interestingly, the invasive strains carried an additional gene, cnm, which was previously shown to bind to collagen and laminin in vitro. Inactivation of cnm rendered the organisms unable to invade HCAEC and attenuated their virulence in G. mellonella. Notably, the cnm knockout strains did not adhere to HCAEC as efficiently as the parental strains did, indicating that the loss of the invasion phenotype observed for the mutants was linked to an adhesion defect. Comparisons of the invasive strains and their respective cnm mutants did not support a correlation between biofilm formation and invasion. Thus, Cnm is required for S. mutans invasion of endothelial cells and possibly represents an important virulence factor of S. mutans that may contribute to cardiovascular infections and pathologies.
Fisheries and aquaculture provide food and economic security, especially in the developing world, but both face challenges from infectious disease. Here, we consider management of disease issues from ...a structured decision‐making perspective to examine how infectious disease can threaten seafood production and influence management decisions. For both wild fisheries and aquaculture, disease‐management objectives generally aim to mitigate the severity and economic burden of outbreaks. General management strategies include manipulating host densities, reducing system connectivity, conserving or improving habitat, and implementing direct treatments or some other biological interventions. To inform decisions, mathematical models can be used to explore disease dynamics and to forecast the potential effectiveness of alternative management actions. Developing and implementing disease‐management strategies also involve considering uncertainties and balancing competing stakeholder interests and risk tolerances. We conclude by outlining several steps for applying structured decision making that are broadly useful to decision makers facing issues related to disease.
Dissociated primary cultures from rat telencephalon at different developmental stages were used to study the effect of basic fibroblast growth factor (FGF2) on Otx2, Dlx1, and Emx1, three homeobox ...genes expressed in different regions of the developing mammalian forebrain. At embryonic day (E)13.5. the regional pattern of expression of Otx1, Otx2, Dlx1, Dlx2, Dlx5, and Emx1 is maintained in primary culture, suggesting that cells are already committed to a regional identity at this stage. In these cultures, Otx2 is expressed by precursor cells, whereas Dlx1 and Emx1 are predominantly expressed by postmitotic cells. We found that FGF2 increased Otx2 expression within precursor cells and the total number of Otx2-expressing cells. This effect was gene-specific, dose-dependent, and temporally regulated, with larger effects at earlier stages of development (E11.5). At E13.5, the effect of FGF2 on Otx2 expression was restricted to the basal telencephalon. Our results suggest that a restricted population of neuroblasts respond to FGF2 in a temporally regulated fashion by proliferating and increasing Otx2 expression. This interaction between FGF2 and Otx2 may be important for the regulation of neurogenesis in the forebrain.
Functional abdominal pain disorders (FAPD) are the most common chronic pain conditions of childhood and are made worse by co-occurring anxiety. Our research team found that the Aim to Decrease Pain ...and Anxiety Treatment (ADAPT), a six-session coping skills program using cognitive behavioral therapy strategies, was effective in improving pain-related symptoms and anxiety symptoms compared to standard care. In follow-up, this current randomized clinical trial (RCT) aims to test potential neural mechanisms underlying the effect of ADAPT. Specifically, this two-arm RCT will explore changes in amygdalar functional connectivity (primary outcome) following the ADAPT protocol during the water loading symptom provocation task (WL-SPT). Secondary (e.g., changes in regional cerebral blood flow via pulsed arterial spin labeling MRI) and exploratory (e.g., the association between the changes in functional connectivity and clinical symptoms) outcomes will also be investigated.
We will include patients ages 11 to 16 years presenting to outpatient pediatric gastroenterology care at a midwestern children's hospital with a diagnosis of FAPD plus evidence of clinical anxiety based on a validated screening tool (the Generalized Anxiety Disorder-7 GAD-7 measure). Eligible participants will undergo baseline neuroimaging involving the WL-SPT, and assessment of self-reported pain, anxiety, and additional symptoms, prior to being randomized to a six-week remotely delivered ADAPT program plus standard medical care or standard medical care alone (waitlist). Thereafter, subjects will complete a post assessment neuroimaging visit similar in nature to their first visit.
This small scale RCT aims to increase understanding of potential neural mechanisms of response to ADAPT.
ClinicalTrials.gov registration: NCT03518216.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
Galaxy formation and evolution are regulated by the feedback from galactic winds. Absorption lines provide the most widely available probe of winds. However, since most data only provide ...information integrated along the line of sight, they do not directly constrain the radial structure of the outflows. In this paper, we present a method to directly measure the gas electron density in outflows (
n
e
), which in turn yields estimates of outflow cloud properties (e.g., density, volume filling factor, and sizes/masses). We also estimate the distance (
r
n
) from the starburst at which the observed densities are found. We focus on 22 local star-forming galaxies primarily from the COS Legacy Archive Spectroscopic SurveY (CLASSY). In half of them, we detect absorption lines from fine-structure excited transitions of Si
ii
(i.e., Si
ii
*). We determine
n
e
from relative column densities of Si
ii
and Si
ii
*, given Si
ii
* originates from collisional excitation by free electrons. We find that the derived
n
e
correlates well with the galaxy’s star formation rate per unit area. From photoionization models or assuming the outflow is in pressure equilibrium with the wind fluid, we get
r
n
∼ 1–2
r
*
or ∼5
r
*
, respectively, where
r
*
is the starburst radius. Based on comparisons to theoretical models of multiphase outflows, nearly all of the outflows have cloud sizes large enough for the clouds to survive their interaction with the hot wind fluid. Most of these measurements are the first ever for galactic winds detected in absorption lines and, thus, will provide important constraints for future models of galactic winds.
Abstract
Ly
α
line profiles are a powerful probe of interstellar medium (ISM) structure, outflow speed, and Lyman-continuum escape fraction. In this paper, we present the Ly
α
line profiles of the ...Cosmic Origins Spectrograph (COS) Legacy Archive Spectroscopic SurveY, a sample rich in spectroscopic analogs of reionization-era galaxies. A large fraction of the spectra show a complex profile, consisting of a double-peaked Ly
α
emission profile in the bottom of a damped, Ly
α
absorption trough. Such profiles reveal an inhomogeneous ISM. We successfully fit the damped Ly
α
absorption and the Ly
α
emission profiles separately, but with complementary covering factors, a surprising result because this approach requires no Ly
α
exchange between high-
N
H
i
and low-
N
H
i
paths. The combined distribution of column densities is qualitatively similar to the bimodal distributions observed in numerical simulations. We find an inverse relation between Ly
α
peak separation and the O
iii
/O
ii
flux ratio, confirming that the covering fraction of Lyman-continuum-thin sightlines increases as the Ly
α
peak separation decreases. We combine measurements of Ly
α
peak separation and Ly
α
red peak asymmetry in a diagnostic diagram, which identifies six Lyman-continuum leakers in the COS Legacy Archive Spectrocopy SurveY (CLASSY) sample. We find a strong correlation between the Ly
α
trough velocity and the outflow velocity measured from interstellar absorption lines. We argue that greater vignetting of the blueshifted Ly
α
peak, relative to the redshifted peak, is the source of the well-known discrepancy between shell-model parameters and directly measured outflow properties. The CLASSY sample illustrates how scattering of Ly
α
photons outside the spectroscopic aperture reshapes Ly
α
profiles because the distances to these compact starbursts span a large range.
Abstract
We report the results of analyses of galactic outflows in a sample of 45 low-redshift starburst galaxies in the COS Legacy Archive Spectroscopic SurveY (CLASSY), augmented by five additional ...similar starbursts with Cosmic Origins Spectrograph (COS) data. The outflows are traced by blueshifted absorption lines of metals spanning a wide range of ionization potential. The high quality and broad spectral coverage of CLASSY data enable us to disentangle the absorption due to the static interstellar medium (ISM) from that due to outflows. We further use different line multiplets and doublets to determine the covering fraction, column density, and ionization state as a function of velocity for each outflow. We measure the outflow’s mean velocity and velocity width, and find that both correlate in a highly significant way with the star formation rate, galaxy mass, and circular velocity over ranges of four orders of magnitude for the first two properties. We also estimate outflow rates of metals, mass, momentum, and kinetic energy. We find that, at most, only about 20% of silicon created and ejected by supernovae in the starburst is carried out in the warm phase we observe. The outflows’ mass-loading factor increases steeply and inversely with both circular and outflow velocity (log–log slope ∼−1.6), and reaches ∼10 for dwarf galaxies. We find that the outflows typically carry about 10%–100% of the momentum injected by massive stars and about 1%–20% of the kinetic energy. We show that these results place interesting constraints on, and new insights into, models and simulations of galactic winds.
Tender nodules on the extremities James, Alaina J; Bender, Matthew M; Chen, Alice J ...
Dermatology online journal,
12/2003, Letnik:
9, Številka:
5
Journal Article
PDF
