132 research outputs found
Fe(III)2O3 Nanoparticle Mediated Molecular Growth and Soot Particle Inception from the Oxidative Pyrolysis of 1-Methylnaphthalene
The potential for Fe(III)2O3 nanoparticles to participate in the molecular growth and particle inception of soot from 1-methylnapthalene (1-MN) was studied in a dual-zone, high-temperature flow reactor. An iron substituted, dendrimer template was oxidized in the Zone 1 reactor to generate ~5nm Fe(III)2O3 nanoparticles, that were continually seeded to a high sooting 1-MN fuel under oxidative pyrolysis conditions. The Fe(III)2O3 nanoparticles could then influence the otherwise gas-phase reactions of 1-MN. Increased PAH formation, soot number density, soot mass yield, and soot radical intensity were observed as a result of Fe(III)2O3 nanoparticle introduction prior to soot inception. Low Temperature Matrix Isolation-Electron Paramagnetic Resonance (LTMI-EPR) spectroscopy was used to determine the superimposed signal of particulate from the oxidative pyrolysis of 1-MN. The EPR spectrum of particulate was found to be a mixture of organic carbon-centered radicals, oxygen-centered radicals, and soot. The carbon-centered radicals were identified through simulation of the hyperfine structure to be the resonance-stabilized indenyl, cyclopentadienyl, and naphthalene 1-methylene radicals. The species of iron oxide nanoparticles generated from the iron substituted dendrimer was also determined with the LTMI-EPR technique to be Fe(III)2O3 nanoparticles clusters and superoxide anion-radicals, O2•- adsorbed on nanoparticle surfaces in form of Fe (IV)-O2•-. Superoxide anion-radicals initiate radical chain reactions through abstraction of hydrogen whereas Fe(III)2O3 nanoparticles are capable of the stabilization of the initially formed radicals species. Subsequent formation of soot also resulted in a partial reduction of the Fe(III)2O3 nanoparticles. These studies contained herein suggest Fe(III)2O3 nanoparticles can mediate the formation and stabilization of resonance stabilized radicals and subsequent reactions can result in the molecular growth of PAHs into soot. At the high concentrations in the flow reactor, these resonance–stabilized free radicals can undergo surface-mediated, radical-radical, molecular growth reactions and contribute to molecular growth and soot particle inception
Patterns in reduction or cessation of drinking in Australia (2001-2013) and motivation for change
Aims: This paper examines: 1) change over time (2001-2013) in recently reducing or ceasing drinking in the Australian population, and 2) the reasons given for reducing or ceasing drinking in the most recent survey (2013); stratified by sex and age group.
Methods: Data are from five waves of the National Drug Strategy Household Survey (N=119,397). Logistic regression models with interaction terms were used to identify a shift in sex or age over time in predicting reduction or cessation of drinking, and to predict motivations for reducing or ceasing drinking by sex and age.
Results: Reports of recently reducing the quantity or frequency of drinking increased from 2001 to 2007, and remained stable between 2007 and 2013. There was a steady increase in the number of Australians reporting recently ceasing drinking from 2001 to 2013, with a significant effect for age (younger groups more likely than older groups to cease drinking in the past two waves). Reasons for reducing or ceasing drinking varied by age, with older people more likely to report health reasons, and younger people more likely to report lifestyle reasons or enjoyment.
Conclusion: Increases over time in reports of reduction or cessation of drinking due to health, lifestyle, social and enjoyment reasons, suggests that the social position of alcohol in Australia may be shifting, particularly among young people
Response to commentaries: (de)normalization of drinking and its implications for young people, sociality, culture and epidemiology
The beginning of time? Evidence for catastrophic drought in Baringo in the early nineteenth century
New developments in the collection of palaeo-data over the past two decades have transformed our understanding of climate and environmental history in eastern Africa. This article utilises instrumental and proxy evidence of historical lake-level fluctuations from Baringo and Bogoria, along with other Rift Valley lakes, to document the timing and magnitude of hydroclimate variability at decadal to century time scales since 1750. These data allow us to construct a record of past climate variation not only for the Baringo basin proper, but also across a sizable portion of central and northern Kenya. This record is then set alongside historical evidence, from oral histories gathered amongst the peoples of northern Kenya and the Rift Valley and from contemporary observations recorded by travellers through the region, to offer a reinterpretation of human activity and its relationship to environmental history in the nineteenth century. The results reveal strong evidence of a catastrophic drought in the early nineteenth century, the effects of which radically alters our historical understanding of the character of settlement, mobility and identity within the Baringo–Bogoria basin
Response to commentaries: (de)normalization of drinking and its implications for young people, sociality, culture and epidemiology
Commentar
The Concussion Recognition Tool 5th Edition (CRT5): Background and rationale
The Concussion Recognition Tool 5 (CRT5) is the most recent revision of the Pocket Sport Concussion Assessment Tool 2 that was initially introduced by the Concussion in Sport Group in 2005. The CRT5 is designed to assist non-medically trained individuals to recognise the signs and symptoms of possible sport-related concussion and provides guidance for removing an athlete from play/sport and to seek medical attention. This paper presents the development of the CRT5 and highlights the differences between the CRT5 and prior versions of the instrument
Consensus Statement on Concussion in Sportâ The 4th International Conference on Concussion in Sport Held in Zurich, November 2012
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147044/1/pmr2255.pd
Why is adolescent drinking declining? A systematic review and narrative synthesis
Background: Adolescent drinking has declined across many developed countries from the turn of the century. The aim of this review is to explore existing evidence examining possible reasons for this decline.
Methods: We conducted systematic searches across five databases: Medline, PsycINFO, CINAHL, Informit Health and Scopus. Studies were included if association between declining alcohol consumption and potential explanatory factors were measured over time. Narrative synthesis was undertaken due to substantial methodological heterogeneity in these studies.
Results: 17 studies met the inclusion criteria. Five studies found moderate evidence for changes in parental practices as a potential cause for the decline. Five studies that examined whether alcohol policy changes influenced the decline found weak evidence of association. Three studies explored whether alcohol use has been substituted by illicit substances but no evidence was found. Two studies examined the effect of a weaker economy; both identified increase in adolescent alcohol use during times of economic crisis. One study indicated that changes in exposure to alcohol advertising were positively associated with the decline and another examined the role of immigration of non-drinking populations but found no evidence of association. One study tested participation in organised sports and party lifestyle as a potential cause but did not use robust analytical methods and therefore did not provide strong evidence of association for the decline.
Conclusions: The most robust and consistent evidence was identified for shifts in parental practices. Further research is required using robust analytical methods such as ARIMA modelling techniques and utilising cross-national data
Consensus statement on concussion in sport—the 5 th international conference on concussion in sport held in Berlin, October 2016
The 2017 Concussion in Sport Group (CISG) consensus statement is designed to build on the principles outlined in the previous statements1–4 and to develop further conceptual understanding of sport-related concussion (SRC) using an expert consensus-based approach. This document is developed for physicians and healthcare providers who are involved in athlete care, whether at a recreational, elite or professional level. While agreement exists on the principal messages conveyed by this document, the authors acknowledge that the science of SRC is evolving and therefore individual management and return-to-play decisions remain in the realm of clinical judgement. This consensus document reflects the current state of knowledge and will need to be modified as new knowledge develops. It provides an overview of issues that may be of importance to healthcare providers involved in the management of SRC. This paper should be read in conjunction with the systematic reviews and methodology paper that accompany it. First and foremost, this document is intended to guide clinical practice; however, the authors feel that it can also help form the agenda for future research relevant to SRC by identifying knowledge gaps
Muscle Logic: New Knowledge Resource for Anatomy Enables Comprehensive Searches of the Literature on the Feeding Muscles of Mammals
Background: In recent years large bibliographic databases have made much of the published literature of biology available for searches. However, the capabilities of the search engines integrated into these databases for text-based bibliographic searches are limited. To enable searches that deliver the results expected by comparative anatomists, an underlying logical structure known as an ontology is required. Development and Testing of the Ontology Here we present the Mammalian Feeding Muscle Ontology (MFMO), a multi-species ontology focused on anatomical structures that participate in feeding and other oral/pharyngeal behaviors. A unique feature of the MFMO is that a simple, computable, definition of each muscle, which includes its attachments and innervation, is true across mammals. This construction mirrors the logical foundation of comparative anatomy and permits searches using language familiar to biologists. Further, it provides a template for muscles that will be useful in extending any anatomy ontology. The MFMO is developed to support the Feeding Experiments End-User Database Project (FEED, https://feedexp.org/), a publicly-available, online repository for physiological data collected from in vivo studies of feeding (e.g., mastication, biting, swallowing) in mammals. Currently the MFMO is integrated into FEED and also into two literature-specific implementations of Textpresso, a text-mining system that facilitates powerful searches of a corpus of scientific publications. We evaluate the MFMO by asking questions that test the ability of the ontology to return appropriate answers (competency questions). We compare the results of queries of the MFMO to results from similar searches in PubMed and Google Scholar. Results and Significance Our tests demonstrate that the MFMO is competent to answer queries formed in the common language of comparative anatomy, but PubMed and Google Scholar are not. Overall, our results show that by incorporating anatomical ontologies into searches, an expanded and anatomically comprehensive set of results can be obtained. The broader scientific and publishing communities should consider taking up the challenge of semantically enabled search capabilities
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