110 research outputs found
Investigating Mineral Stability under Venus Conditions: A Focus on the Venus Radar Anomalies
Radar studies of the surface of Venus have identified regions with high radar reflectivity concentrated in the Venusian highlands: between 2.5 and 4.75 km above a planetary radius of 6051 km, though it varies with latitude. Previous research has proposed several theories on the source of these anomalies, including increased surface roughness, metallic materials with higher dielectric constants, or ferroelectric materials. Prior work suggests several processes that could be the origin of these anomalies, such as surface-atmospheric interactions or low lying clouds or fog. Alternatively, these anomalies could result from a semi-metallic compound trapped at the cooler conditions in the highlands, likely forming as a snow or frost. If this were the case, the compound would be expected to precipitate out of a low cloud layer.
While theoretical studies have been beneficial towards determining the source of these anomalies, few experimental investigations have been done to validate these theories. In this dissertation, several minerals, chosen by their likely presence on Venus, were investigated to determine their stability under Venusian conditions, including temperature, pressure and atmospheric composition. Analysis of the empirical data enabled the identification of potential mineral source(s) of the radar-bright anomalies
The Prospect of Detecting Volcanic Signatures on an ExoEarth Using Direct Imaging
The James Webb Space Telescope (JWST) has provided the first opportunity to
study the atmospheres of terrestrial exoplanets and estimate their surface
conditions. Earth-sized planets around Sun-like stars are currently
inaccessible with JWST however, and will have to be observed using the next
generation of telescopes with direct imaging capabilities. Detecting active
volcanism on an Earth-like planet would be particularly valuable as it would
provide insight into its interior, and provide context for the commonality of
the interior states of Earth and Venus. In this work we used a climate model to
simulate four exoEarths over eight years with ongoing large igneous province
eruptions with outputs ranging from 1.8-60 Gt of sulfur dioxide. The
atmospheric data from the simulations were used to model direct imaging
observations between 0.2-2.0 m, producing reflectance spectra for every
month of each exoEarth simulation. We calculated the amount of observation time
required to detect each of the major absorption features in the spectra, and
identified the most prominent effects that volcanism had on the reflectance
spectra. These effects include changes in the size of the O, O, and
HO absorption features, and changes in the slope of the spectrum. Of these
changes, we conclude that the most detectable and least ambiguous evidence of
volcanism are changes in both O absorption and the slope of the spectrum.Comment: 13 pages, 5 figures, 4 tables, Accepted for publication in AJ
(September 26, 2023
Impact of in utero drug exposure on neonates requiring ECMO: A retrospective cohort study
The incidence of in utero drug exposure (IUDE) and neonatal extracorporeal membrane oxygenation (ECMO) utilization have both increased over the past decade. However, there are no studies to date that examine the impact that IUDE has on neonates requiring ECMO. In this retrospective cohort study, we compared the clinic course and outcomes of neonates who were placed on ECMO with IUDE vs. neonates without IUDE. Analysis included data extracted from medical records from all neonatal ECMO runs between January 2014 and January 2021 at the University of Kentucky Children's Hospital. A total of 56 neonatal patients were placed on ECMO during this time period and there were a total of 57 ECMO runs. Nearly one-third of neonates (16) had documented IUDE. There were no differences in gestational age, length of ECMO run, survival to discharge, or number of major complications while on ECMO in the neonates with IUDE compared to those without. In contrast, greater use of sedative and analgesic adjuvant medications during ECMO was required for IUDE-ECMO cases (pâ<â0.01). Trending results indicated that post-ECMO feeding complications and total hospitalization length were also greater in the IUDE-ECMO group. These findings illustrate the complex influence of prenatal drug exposures on neonatal patient care and warrant the development of clinical care strategies optimized for this unique patient group
Yeast:One cell, one reference sequence, many genomes?
The genome of Saccharomyces cerevisiae â brewerâs or bakerâs yeast â was the first eukaryotic genome to be sequenced in 1996. The identity of that yeast genome has been not just a product of sequencing, but also of its use after sequencing and particularly of its mobilization in scientific literature. We ask âwhat is the yeast genome?â as an empirical question by investigating âthe yeast genomeâ as a discursive entity. Analyzing publications that followed sequencing points to several âyeast genomesâ existing side-by-side: genomes as physical molecules, digital texts, and a historic event. Resolving this unified-yet-multiple âgenomeâ helps make sense of contemporary developments in yeast genomics such as the synthetic yeast project, in which apparently âthe sameâ genome occupies multiple roles and locations, and points to the utility of examining specific non-human genomes independent of the Human Genome Project
Is living in a household with children associated with SARS-CoV-2 seropositivity in adults? Results from the Swiss national seroprevalence study Corona Immunitas.
BACKGROUND
We aimed to determine whether living in a household with children is associated with SARS-CoV-2 seropositivity in adults and investigated interacting factors that may influence this association.
METHODS
SARS-CoV-2 serology testing was performed in randomly selected individuals from the general population between end of October 2020 and February 2021 in 11 cantons in Switzerland. Data on sociodemographic and household characteristics, employment status, and health-related history was collected using questionnaires. Multivariable logistic regression was used to examine the association of living with children <18 years of age (number, age group) and SARS-CoV-2 seropositivity. Further, we assessed the influence of reported non-household contacts, employment status, and gender.
RESULTS
Of 2393 working age participants (18-64 years), 413 (17.2%) were seropositive. Our results suggest that living with children and SARS-CoV-2 seropositivity are likely to be associated (unadjusted odds ratio (OR) 1.22, 95% confidence interval [0.98-1.52], adjusted OR 1.25 [0.99-1.58]). A pattern of a positive association was also found for subgroups of children aged 0-11 years (OR 1.21 [0.90-1.60]) and 12-17 years (OR 1.14 [0.78-1.64]). Odds of seropositivity were higher with more children (OR 1.14 per additional child [1.02-1.27]). Men had higher risk of SARS-CoV-2 infection when living with children than women (interaction: OR 1.74 [1.10-2.76]).
CONCLUSIONS
In adults from the general population living with children seems associated with SARS-CoV-2 seropositivity. However, child-related infection risk is not the same for every subgroup and depends on factors like gender. Further factors determining child-related infection risk need to be identified and causal links investigated.
TRIAL REGISTRATION
https://www.isrctn.com/ISRCTN18181860
Is living in a household with children associated with SARS-CoV-2 seropositivity in adults? Results from the Swiss national seroprevalence study Corona Immunitas
BACKGROUND: We aimed to determine whether living in a household with children is associated with SARS-CoV-2 seropositivity in adults and investigated interacting factors that may influence this association.
METHODS: SARS-CoV-2 serology testing was performed in randomly selected individuals from the general population between end of October 2020 and February 2021 in 11 cantons in Switzerland. Data on sociodemographic and household characteristics, employment status, and health-related history was collected using questionnaires. Multivariable logistic regression was used to examine the association of living with children <18 years of age (number, age group) and SARS-CoV-2 seropositivity. Further, we assessed the influence of reported non-household contacts, employment status, and gender.
RESULTS: Of 2393 working age participants (18-64 years), 413 (17.2%) were seropositive. Our results suggest that living with children and SARS-CoV-2 seropositivity are likely to be associated (unadjusted odds ratio (OR) 1.22, 95% confidence interval [0.98-1.52], adjusted OR 1.25 [0.99-1.58]). A pattern of a positive association was also found for subgroups of children aged 0-11 years (OR 1.21 [0.90-1.60]) and 12-17 years (OR 1.14 [0.78-1.64]). Odds of seropositivity were higher with more children (OR 1.14 per additional child [1.02-1.27]). Men had higher risk of SARS-CoV-2 infection when living with children than women (interaction: OR 1.74 [1.10-2.76]).
CONCLUSIONS: In adults from the general population living with children seems associated with SARS-CoV-2 seropositivity. However, child-related infection risk is not the same for every subgroup and depends on factors like gender. Further factors determining child-related infection risk need to be identified and causal links investigated
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