1,851 research outputs found
IRAM and Gaia views of multi-episodic star formation in IC1396A:The origin and dynamics of the Class 0 protostar at the edge of an HII region
(Abridged) IC1396A is a cometary globule containing the Class 0 source IC1396A-PACS-1. We use IRAM 30m and Gaia DR2 data to explore the star-formation history of IC1396A and investigate the possibilities of triggered star formation. IRAM and Herschel continuum data reveal dust temperatures and column densities. Heterodyne data reveal the velocity structure of the gas. Gaia DR2 proper motions for the stars complete the kinematics of the region. IC1396A-PACS-1 shows molecular emission similar to a hot corino with warm carbon chain chemistry, and is surrounded by gas at velocities significantly different from the velocities of the Tr37 cluster. Combining the velocity, column density, and temperature information and Gaia DR2 kinematics, we confirm that IC1396A has suffered various episodes of star formation. IC1396A-PACS-1 is probably the last intermediate-mass protostar that will form within IC1396A, showing evidence of triggering by radiative driven implosion. Chemical signatures place IC1396A-PACS-1 among the youngest protostars known. Gaia DR2 data reveal velocities in the plane of the sky 4km/s for IC1396A with respect to Tr37. The total velocity difference (8 km/s) between the Tr37 cluster and IC1396A is too small for IC1396A to have undergone substantial rocket acceleration, which imposes constraints on the distance to the ionizing source in time and the possibilities of triggered star formation. The three stellar populations in the globule reveal that objects located within relatively close distances (<0.5pc) can be formed in various episodes within a 1-2 Myr period. We expect substantial differences in initial conditions for the resulting objects and their protoplanetary disks, which may affect their evolution. Finally, evidence for short-range feedback from the embedded protostars and, in particular, the A-type star V390 Cep is also observed
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Aspects of the Release of Superoxide by Leukocytes, and a Means by Which This Is Switched Off
Although great progress has been made in understanding the respiratory burst of leukocytes that produce superoxide (O2-), it is possible that a component or components, might have been overlooked. Furthermore, O2- production and its sequels, though cardinal in bactericidal action, might ultimately be damaging to the host's own cells. It is important, therefore, that a biologic mechanism exist to turn off O2- production by stimulated leukocytes. This article offers evidence that methoxatin (PQQ), a redox-cycling orthoquinone, might be involved in O2- production by leukocytes. This is based on the fact that inhibitors of O2- production, such as diphenylene iodonium (DPI) and 4,5-dimethylphenylene diamine (DIMPDA), were shown to sequester PQQ in leukocytes, i.e., to form adducts with that substance. Addition of PQQ to cells blocked with the inhibitors partially restored O2- release. With respect to turning off cellular O2- release, a factor was observed to be released to the medium by old macrophages (14 days old, but not by those less than 7 days old). Such conditioned medium, when added to stimulated neutrophils or macrophages, blocked O2- release. This factor was sensitive to proteases, exhibited molecular sizes of 3 and 11 kDa, and its action was independent of the nature of the stimulus applied to the leukocytes. It was partially purified by column (sizing) chromatography and HPLC. It seems to be a general modulator of the release of reactive oxygen species by phagocytes and is irrespective of phagocytic cellular type, or species from which the cells were derived
The \u3cem\u3eChlamydomonas\u3c/em\u3e Genome Reveals the Evolution of Key Animal and Plant Functions
Chlamydomonas reinhardtii is a unicellular green alga whose lineage diverged from land plants over 1 billion years ago. It is a model system for studying chloroplast-based photosynthesis, as well as the structure, assembly, and function of eukaryotic flagella (cilia), which were inherited from the common ancestor of plants and animals, but lost in land plants. We sequenced the ∼120-megabase nuclear genome of Chlamydomonas and performed comparative phylogenomic analyses, identifying genes encoding uncharacterized proteins that are likely associated with the function and biogenesis of chloroplasts or eukaryotic flagella. Analyses of the Chlamydomonas genome advance our understanding of the ancestral eukaryotic cell, reveal previously unknown genes associated with photosynthetic and flagellar functions, and establish links between ciliopathy and the composition and function of flagella
Looking beyond LCI: Multiple breath washout phase III slope derived indices and their application in chronic respiratory disease in children
The multiple breath washout (MBW) test is widely reported in the context of Lung Clearance Index (LCI). LCI reflects global ventilation inhomogeneity but does not provide information regarding the localization of disease along the respiratory tree. The MBW-derived normalized phase III slope (SnIII) indices (Scond and Sacin), instead, can distinguish between convective-dependent and diffusion-convection-dependent ventilation inhomogeneity considered to occur within the conductive and acinar airways, respectively. In cystic fibrosis, Scond tends to become abnormal even earlier than LCI and spirometry. The value of Scond and Sacin in clinical practice has been recently explored in other respiratory conditions, including asthma, primary ciliary dyskinesia, bronchopulmonary dysplasia, bronchiolitis obliterans, and sickle cell disease. In this narrative review we offer an overview on the theoretical background, potentialities, and limitations of SnIII analysis in children, including challenges and feasibility aspects. Moreover, we summarize current evidence on the use of SnIII-derived indices across different groups of pediatric chronic respiratory disease and we highlight the gaps in knowledge that need to be addressed in future studies
Classifying Single Stars and Spectroscopic Binaries Using Optical Stellar Templates
Stellar spectral classification is a fundamental tool of modern astronomy,
providing insight into physical characteristics such as effective temperature,
surface gravity, and metallicity. Accurate and fast spectral typing is an
integral need for large all-sky spectroscopic surveys like the SDSS and LAMOST.
Here, we present the next version of PyHammer, stellar spectral classification
software that uses optical spectral templates and spectral line index
measurements. PyHammer v2.0 extends the classification power to include carbon
(C) stars, DA white dwarf (WD) stars, and also double-lined spectroscopic
binaries (SB2). This release also includes a new empirical library of
luminosity-normalized spectra that can be used to flux calibrate observed
spectra, or to create synthetic SB2 spectra. We have generated physically
reasonable SB2 combinations as templates, adding to PyHammer the ability to
spectrally type SB2s. We test classification success rates on SB2 spectra,
generated from the SDSS, across a wide range of spectral types and
signal-to-noise ratios. Within the defined range of pairings described, more
than of SB2s are correctly classified.Comment: 16 pages, 7 figures, 4 tables; accepted to ApJ
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Pulmonary function deficits in newborn screened infants with cystic fibrosis managed with standard UK care are mild and transient
With the advent of novel designer molecules for cystic fibrosis (CF) treatment, there is huge need for early-life clinical trial outcomes, such as infant lung function (ILF). We investigated the degree and tracking of ILF abnormality during the first 2 years of life in CF newborn screened infants.
Forced expiratory volume in 0.5 s (FEV₀.₅), lung clearance index (LCI) and plethysmographic functional residual capacity were measured at ∼3 months, 1 year and 2 years in 62 infants with CF and 34 controls.
By 2 years there was no significant difference in FEV₀.₅ z-score between CF and controls, whereas mean LCI z-score was 0.81 (95% CI 0.45–1.17) higher in CF. However, there was no significant association between LCI z-score at 2 years with either 3-month or 1-year results. Despite minimal average group changes in any ILF outcome during the second year of life, marked within-subject changes occurred. No child had abnormal LCI or FEV₀.₅ on all test occasions, precluding the ability to identify “high-risk” infants in early life.
In conclusion, changes in lung function are mild and transient during the first 2 years of life in newborn screened infants with CF when managed according to a standardised UK treatment protocol. Their potential role in tracking disease to later childhood will be ascertained by ongoing follow-up
A note on comonotonicity and positivity of the control components of decoupled quadratic FBSDE
In this small note we are concerned with the solution of Forward-Backward
Stochastic Differential Equations (FBSDE) with drivers that grow quadratically
in the control component (quadratic growth FBSDE or qgFBSDE). The main theorem
is a comparison result that allows comparing componentwise the signs of the
control processes of two different qgFBSDE. As a byproduct one obtains
conditions that allow establishing the positivity of the control process.Comment: accepted for publicatio
Health, behavior, and social outcomes among offspring of parents with criminal convictions: a register‐based study from Sweden
Background: There is currently insufficient understanding of the health and behavior of children whose parents engage in criminal behavior. We examined associations between parental criminal convictions and wide range of offspring health, behavioral, and social outcomes by age 18 in a large, national sample, aiming to get a comprehensive picture of the risks among children of offending parents. Methods: We studied 1,013,385 individuals born in Sweden between 1987 and 1995, and their parents. Using data from several longitudinal nationwide registers, we investigated parental convictions and 85 offspring outcomes until the end of 2013, grouped into birth‐related conditions, psychiatric and somatic disorders, accidents and injuries, mortality, school achievement, violent victimization, and criminality. Cox proportional hazards regression and logistic regression models were used to examine the associations. The role of genetic factors in intergenerational associations was studied in children‐of‐siblings analyses. We also examined the co‐occurrence of multiple outcomes using Poisson regression. Results: A total of 223,319 (22.0%) individuals had one parent convicted and 31,241 (3.1%) had both parents convicted during the first 18 years of their life. The strongest associations were found between parental convictions and offspring behavioral problems, substance use disorders, poor school achievement, violent victimization, and criminality, with an approximately 2 to 2.5‐fold increased risk in children with one convicted parent and 3‐ to 4‐fold increased risk in children with two convicted parents. The risks were particularly elevated among children of incarcerated parents with a history of violent convictions. The associations appeared to be at least partly explained by genetic influences. Parental convictions were also associated with an increased likelihood of experiencing multiple outcomes. Conclusions: Our findings help to calibrate the risks of a wide range of adverse outcomes associated with parental convictions and may be used to guide prevention efforts and identify key areas for future research
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