5,466 research outputs found
Walls talk: Microbial biogeography of homes spanning urbanization.
Westernization has propelled changes in urbanization and architecture, altering our exposure to the outdoor environment from that experienced during most of human evolution. These changes might affect the developmental exposure of infants to bacteria, immune development, and human microbiome diversity. Contemporary urban humans spend most of their time indoors, and little is known about the microbes associated with different designs of the built environment and their interaction with the human immune system. This study addresses the associations between architectural design and the microbial biogeography of households across a gradient of urbanization in South America. Urbanization was associated with households' increased isolation from outdoor environments, with additional indoor space isolation by walls. Microbes from house walls and floors segregate by location, and urban indoor walls contain human bacterial markers of space use. Urbanized spaces uniquely increase the content of human-associated microbes-which could increase transmission of potential pathogens-and decrease exposure to the environmental microbes with which humans have coevolved
Implementation of a rapid learning platform: predicting 2-year survival in laryngeal carcinoma patients in a clinical setting
Background and Purpose To improve quality and personalization of oncology health care, decision aid tools are needed to advise physicians and patients. The aim of this work is to demonstrate the clinical relevance of a survival prediction model as a first step to multi institutional rapid learning and compare this to a clinical trial dataset. Materials and Methods Data extraction and mining tools were used to collect uncurated input parameters from Illawarra Cancer Care Centre\u27s (clinical cohort) oncology information system. Prognosis categories previously established from the Maastricht Radiation Oncology (training cohort) dataset, were applied to the clinical cohort and the radiotherapy only arm of the RTOG-9111 (trial cohort). Results Data mining identified 125 laryngeal carcinoma patients, ending up with 52 patients in the clinical cohort who were eligible to be evaluated by the model to predict 2-year survival and 177 for the trial cohort. The model was able to classify patients and predict survival in the clinical cohort, but for the trial cohort it failed to do so. Conclusions The technical infrastructure and model is able to support the prognosis prediction of laryngeal carcinoma patients in a clinical cohort. The model does not perform well for the highly selective patient population in the trial cohort
Cation distribution in manganese cobaltite spinels Co3āxMnxO4 (0 ā¤ x ā¤ 1) determined by thermal analysis
Thermogravimetric analysis was used in order to study the reduction in air of submicronic powders of Co3āx Mn x O4 spinels, with 0 ā¤ x ā¤ 1. For x = 0 (i.e. Co3O4), cation reduction occurred in a single step. It involved the CoIII ions at the octahedral sites, which were reduced to Co2+ on producing CoO. For 0 < x ā¤ 1, the reduction occurred in two stages at increasing temperature with increasing amounts of manganese. The first step corresponded to the reduction of octahedral CoIII ions and the second was attributed to the reduction of octahedral Mn4+ ions to Mn3+. From the individual weight losses and the electrical neutrality of the lattice, the CoIII and Mn4+ ion concentrations were calculated. The distribution of cobalt and manganese ions present on each crystallographic site of the spinel was determined. In contrast to most previous studies that took into account either CoIII and Mn3+ or Co2+, CoIII and Mn4+ only, our thermal analysis study showed that Co2+/CoIII and Mn3+/Mn4+ pairs occupy the octahedral sites. These results were used to explain the resistivity measurements carried out on dense ceramics prepared from our powders sintered at low temperature (700ā750 Ā°C) in a Spark Plasma Sintering apparatus
Determination of the Axial-Vector Weak Coupling Constant with Ultracold Neutrons
A precise measurement of the neutron decay -asymmetry has been
carried out using polarized ultracold neutrons (UCN) from the pulsed spallation
UCN source at the Los Alamos Neutron Science Center (LANSCE). Combining data
obtained in 2008 and 2009, we report , from which we determine the ratio of the
axial-vector to vector weak coupling of the nucleon .Comment: 5 pages, 2 figure
First direct constraints on Fierz interference in free neutron decay
Precision measurements of free neutron -decay have been used to
precisely constrain our understanding of the weak interaction. However the
neutron Fierz interference term , which is particularly sensitive to
Beyond-Standard-Model tensor currents at the TeV scale, has thus far eluded
measurement. Here we report the first direct constraints on this term, finding
,
consistent with the Standard Model. The uncertainty is dominated by absolute
energy reconstruction and the linearity of the beta spectrometer energy
response
A pragmatic randomized controlled trial of multi-dose oral ondansetron for pediatric gastroenteritis (the DOSE-AGE study): statistical analysis plan.
BACKGROUND: Acute gastroenteritis is a leading cause of emergency department visits and hospitalizations among children in North America. Oral-rehydration therapy is recommended for children with mild-to-moderate dehydration, but children who present with vomiting are frequently offered intravenous rehydration in the emergency department (ED). Recent studies have demonstrated that the anti-emetic ondansetron can reduce vomiting, intravenous rehydration, and hospitalization when administered in the ED to children with dehydration. However, there is little evidence of additional benefit from prescribing ondansetron beyond the initial ED dose. Moreover, repeat dosing may increase the frequency of diarrhea. Despite the lack of evidence and potential adverse side effects, many physicians across North America provide multiple doses of ondansetron to be taken following ED disposition. Thus, the Multi-Dose Oral Ondansetron for Pediatric Gastroenteritis (DOSE-AGE) trial will evaluate the effectiveness of prescribing multiple doses of ondansetron to treat acute gastroenteritis-associated vomiting. This article specifies the statistical analysis plan (SAP) for the DOSE-AGE trial and was submitted before the outcomes of the study were available for analysis.
METHODS/DESIGN: The DOSE-AGE study is a phase III, 6-center, placebo-controlled, double-blind, parallel design randomized controlled trial designed to determine whether participants who are prescribed multiple doses of oral ondansetron to administer, as needed, following their ED visit have a lower incidence of experiencing moderate-to-severe gastroenteritis, as measured by the Modified Vesikari Scale score, compared with a placebo. To assess safety, the DOSE-AGE trial will investigate the frequency and maximum number of diarrheal episodes following ED disposition, and the occurrence of palpitations, pre-syncope/syncope, chest pain, arrhythmias, and serious adverse events. For the secondary outcomes, the DOSE-AGE trial will investigate the individual elements of the Modified Vesikari Scale score and caregiver satisfaction with the therapy.
DISCUSSION: The DOSE-AGE trial will provide evidence on the effectiveness of multiple doses of oral ondansetron, taken as needed, following an initial ED dose in children with acute gastroenteritis-associated vomiting. The data from the DOSE-AGE trial will be analyzed using this SAP. This will reduce the risk of producing data-driven results and bias in our reported outcomes. The DOSE-AGE study was registered on ClinicalTrials.gov on February 22, 2019.
TRIAL REGISTRATION: ClinicalTrials.gov NCT03851835 . Registered on 22 February 2019
New result for the neutron -asymmetry parameter from UCNA
The neutron -decay asymmetry parameter defines the correlation
between the spin of the neutron and the momentum of the emitted electron, which
determines , the ratio of the axial-vector to
vector weak coupling constants. The UCNA Experiment, located at the Ultracold
Neutron facility at the Los Alamos Neutron Science Center, is the first to
measure such a correlation coefficient using ultracold neutrons (UCN).
Following improvements to the systematic uncertainties and increased
statistics, we report the new result which yields . Combination with the previous UCNA result and
accounting for correlated systematic uncertainties produces
and .Comment: 9 pages, 7 figures, updated to as-published versio
Search for neutron dark decay: nāāāĻā+āeāŗeā»
In January, 2018, Fornal and Grinstein proposed that a previously unobserved neutron decay branch to a dark matter particle (Ļ) could account for the discrepancy in the neutron lifetime observed in two different types of experiments. One of the possible final states discussed includes a single Ļ along with an eāŗeā» pair. We use data from the UCNA (Ultracold Neutron Asymmetry) experiment to set limits on this decay channel. Coincident electron-like events are detected with ā¼ 4Ļ acceptance using a pair of detectors that observe a volume of stored Ultracold Neutrons (UCNs). We use the timing information of coincidence events to select candidate dark sector particle decays by applying a timing calibration and selecting events within a physically-forbidden timing region for conventional n ā p + eā» + Ī½Ģ
_e decays. The summed kinetic energy (E_(eāŗeā»)) from such events is reconstructed and used to set limits, as a function of the Ļ mass, on the branching fraction for this decay channel
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