301 research outputs found
The Steep Spectrum Quasar PG1404+226 with ASCA, HST and ROSAT
(abridged) We present and discuss our observations of the NL quasar
PG1404+226 with ASCA and HST, and a re-analysis of our earlier observations
with ROSAT. The soft X-ray spectrum is very steep and displays an absorption
feature (edge or line at ~1.1 keV). We have applied a variety of models to the
ASCA and ROSAT spectra without finding a completely satisfactory fit, and the
identification of the edge remains uncertain. A satisfactory fit of the ASCA
spectrum assuming that the edge is produced by highly ionized iron (using the
code absori in XSPEC) is obtained with an overabundance of iron by a factor >
25 compared to solar, a suggestion supported by the extremely high equivalent
width of the Fe K_alpha line at 6.4 keV. A warm absorber model fitting the
absorption feature with NeVII-NeX edges and assuming a peculiar oxygen/neon
abundance ratio is consistent with the ROSAT data but not the ASCA data.
Finally, it is also possible that the observed edge is caused by a OVIII or
OVII edge or line, blueshifted by z_abs=0.2 to 0.5 depending on the specific
identification, as has been suggested previously for 2 other NL quasars, but
there are no other features in the UV and X-ray spectra in support of this
suggestion. Two systems of UV absorption lines, one nearly at rest in the
source frame, the other blueshifted by ~1900 km/s are identified in the HST/FOS
spectra.
Photoionization models indicate that the UV absorption and the ~1 keV
absorption are probably caused by absorbers with different physical conditions.
PG1404+226 is one more case of AGN where both UV and X-ray absorption features
are detected, thereby increasing further the significance of the previously
noted statistical association of the two types of absorbers.Comment: 11 pages, A&A in pres
Cross-cultural comparison of anxiety symptoms in Colombian and Australian children [Una comparacion transcultural de sintomas de la ansiedad en tre ninos colombianos y australianos]
Introduction: This cross-cultural study compared both the symptoms of anxiety and their severity in a community sample of children from Colombia and Australia. Method: The sample comprised 516 children (253 Australian children and 263 Colombian children), aged 8 to 12-years-old. The Spence Children’s Anxiety Scale (SCAS) was used to measure both the symptoms and levels of anxiety. Results: The results showed a significant difference in the severity of the symptoms between the children in the two countries. In general, Colombian children reported more severe symptoms than their Australian peers, however there were no difference in the types of symptoms reported by the children in the two countries. Discussion and Conclusion: The implications of these findings and their importance to cross-cultural research are discussed
Caudal Fgfr1 disruption produces localised spinal mis-patterning and a terminal myelocystocele-like phenotype in mice
Closed spinal dysraphisms are poorly understood malformations classified as neural tube (NT) defects. Several, including terminal myelocystocele, affect the low spine. We previously identified a NT closure-initiating point, Closure 5, in the distal spine of mice. Here we document equivalent morphology of the caudal-most closing posterior neuropore (PNP) in mice and humans. Closure 5 forms in a region of active FGF signalling and pharmacological FGF receptor blockade impairs its formation in cultured mouse embryos. Conditional genetic deletion of Fgfr1 in caudal embryonic tissues with Cdx2Cre diminishes neuroepithelial proliferation, impairs Closure 5 formation and delays PNP closure. After closure, the distal NT of Fgfr1-disrupted embryos dilates to form a fluid-filled sac overlying ventrally flattened spinal cord. This phenotype resembles terminal myelocystocele. Histological analysis reveals regional and progressive loss of SHH and FOXA2-positive ventral NT domains, resulting in OLIG2-labelling of the ventral-most NT. The OLIG2-domain is also subsequently lost, eventually producing a NT entirely positive for the dorsal marker PAX3. Thus, a terminal myelocystocele-like phenotype can arise after completion of NT closure with localised spinal mis-patterning caused by disruption of FGFR1 signalling
Dampness and moulds in relation to respiratory and allergic symptoms in children : results from phase two of the International Study of Asthma and Allergies in Childhood, (ISAAC Phase Two)
Many studies report that damp housing conditions are associated with respiratory symptoms. Less is known about mechanisms and possible effect modifiers. Studies of dampness in relation to allergic sensitization and eczema are scarce.
Objective We study the influence of damp housing conditions world-wide on symptoms
and objective outcomes.
Cross-sectional studies of 8–12-year-old children in 20 countries used standardized
methodology from Phase Two of the International Study of Asthma and Allergies in
Childhood (ISAAC). Symptoms of asthma, rhinitis and eczema, plus residential exposure
to dampness and moulds, were ascertained by parental questionnaires (n = 46 051). Skin
examination, skin prick tests (n = 26 967) and hypertonic saline bronchial challenge
(n = 5713) were performed. In subsamples stratified by wheeze (n = 1175), dust was sampled
and analysed for house dust mite (HDM) allergens and endotoxin.
Current exposure to dampness was more common for wheezy children (pooled
odds ratio 1.58, 95% CI 1.40–1.79) and was associated with greater symptom severity
among wheezers, irrespective of atopy. A significant (P < 0.01) adverse effect of dampness
was also seen for cough and phlegm, rhinitis and reported eczema, but not for examined
eczema, nor bronchial hyperresponsiveness. HDM sensitization was more common in
damp homes (OR 1.16, 1.03–1.32). HDM-allergen levels were higher in damp homes and
were positively associated with HDM-sensitization, but not wheeze.
A consistent association of dampness with respiratory and other symptoms
was found in both affluent and non-affluent countries, among both atopic and non-atopic
children. HDM exposure and sensitization may contribute, but the link seems to be related
principally to non-atopic mechanisms.peer-reviewe
Analysis of the 24-Hour Activity Cycle: An illustration examining the association with cognitive function in the Adult Changes in Thought (ACT) Study
The 24-hour activity cycle (24HAC) is a new paradigm for studying activity
behaviors in relation to health outcomes. This approach captures the
interrelatedness of the daily time spent in physical activity (PA), sedentary
behavior (SB), and sleep. We illustrate and compare the use of three popular
approaches, namely isotemporal substitution model (ISM), compositional data
analysis (CoDA), and latent profile analysis (LPA) for modeling outcome
associations with the 24HAC. We apply these approaches to assess an association
with a cognitive outcome, measured by CASI item response theory (IRT) score, in
a cohort of 1034 older adults (mean [range] age = 77 [65-100]; 55.8% female;
90% White) who were part of the Adult Changes in Thought (ACT) Activity
Monitoring (ACT-AM) sub-study. PA and SB were assessed with thigh-worn activPAL
accelerometers for 7 days. We highlight differences in assumptions between the
three approaches, discuss statistical challenges, and provide guidance on
interpretation and selecting an appropriate approach. ISM is easiest to apply
and interpret; however, the typical ISM model assumes a linear association.
CoDA specifies a non-linear association through isometric logratio
transformations that are more challenging to apply and interpret. LPA can
classify individuals into groups with similar time-use patterns. Inference on
associations of latent profiles with health outcomes need to account for the
uncertainty of the LPA classifications which is often ignored. The selection of
the most appropriate method should be guided by the scientific questions of
interest and the applicability of each model's assumptions. The analytic
results did not suggest that less time spent on SB and more in PA was
associated with better cognitive function. Further research is needed into the
health implications of the distinct 24HAC patterns identified in this cohort.Comment: 51 pages, 11 tables, 8 figure
Evaluation of Pelvic Floor Symptoms and Sexual Function in Primiparous Women Who Underwent Operative Vaginal Delivery Versus Cesarean Delivery for Second-Stage Arrest
This study aimed to compare the prevalence and severity of pelvic floor symptoms and sexual function at 1 year postpartum in women who underwent either operative vaginal delivery (OVD) or cesarean delivery (CD) for second-stage arrest
Light inactivation of water transport and protein–protein interactions of aquaporin–Killer Red chimeras
Aquaporins (AQPs) have a broad range of cellular and organ functions; however, nontoxic inhibitors of AQP water transport are not available. Here, we applied chromophore-assisted light inactivation (CALI) to inhibit the water permeability of AQP1, and of two AQP4 isoforms (M1 and M23), one of which (M23) forms aggregates at the cell plasma membrane. Chimeras containing Killer Red (KR) and AQPs were generated with linkers of different lengths. Osmotic water permeability of cells expressing KR/AQP chimeras was measured from osmotic swelling–induced dilution of cytoplasmic chloride, which was detected using a genetically encoded chloride-sensing fluorescent protein. KR-AQP1 red fluorescence was bleached rapidly (∼10% per second) by wide-field epifluorescence microscopy. After KR bleaching, KR-AQP1 water permeability was reduced by up to 80% for the chimera with the shortest linker. Remarkably, CALI-induced reduction in AQP4-KR water permeability was approximately twice as efficient for the aggregate-forming M23 isoform; this suggests intermolecular CALI, which was confirmed by native gel electrophoresis on cells coexpressing M23-AQP4-KR and myc-tagged M23-AQP4. CALI also disrupted the interaction of AQP4 with a neuromyelitis optica autoantibody directed against an extracellular epitope on AQP4. CALI thus permits rapid, spatially targeted and irreversible reduction in AQP water permeability and interactions in live cells. Our data also support the utility of CALI to study protein–protein interactions as well as other membrane transporters and receptors
TOI-4201: An Early M-dwarf Hosting a Massive Transiting Jupiter Stretching Theories of Core-Accretion
We confirm TOI-4201 b as a transiting Jovian mass planet orbiting an early M
dwarf discovered by the Transiting Exoplanet Survey Satellite. Using ground
based photometry and precise radial velocities from NEID and the Planet Finder
Spectrograph, we measure a planet mass of 2.59 M,
making this one of the most massive planets transiting an M-dwarf. The planet
is 0.4\% the mass of its 0.63 M host and may have a heavy
element mass comparable to the total dust mass contained in a typical Class II
disk. TOI-4201 b stretches our understanding of core-accretion during the
protoplanetary phase, and the disk mass budget, necessitating giant planet
formation to either take place much earlier in the disk lifetime, or perhaps
through alternative mechanisms like gravitational instability.Comment: To be submitted to AAS journals on 14th July 202
Obstetric Sphincter Injury Interacts With Diarrhea and Urgency to Increase the Risk of Fecal Incontinence in Women With Irritable Bowel Syndrome
To confirm that fecal urgency and diarrhea are independent risk factors for fecal incontinence (FI), to identify obstetrical risk factors associated with FI in women with IBS (irritable bowel syndrome), and to determine whether obstetric anal sphincter injuries interact with diarrhea or urgency to explain the occurrence of FI
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