608 research outputs found
Development of Computational Spectroscopic Methods for the Analysis of Molecular Reactions
The overarching aim of this thesis is to develop new methodologies for the spectroscopic analysis of dissociative molecular reactions. The reversible reaction SiH2 +SiH4→Si2H6 was chosen as a test system. The first ro-vibration linelist for the electronic ground state (X̃ 1A1) of SiH2 has been produced using the ExoMol procedure. The linelist is suitable for temperatures up to 2000 K, wavenumber range 0–10 000 cm−1 and rotational excitation up to J = 51. A new refined potential energy surface and a new ab initio dipole moment surface for SiH2 have been produced for the first time. Next, using the SiH2 linelist as a reference spectrum, the computational methodologies for modelling spectra of polyatomic molecules produced in reactive or dissociative environments were developed. Two approaches for modelling the disequilibrium vibrational populations are introduced: a simplistic 1D approach based on the harmonic approximation and a full 3D model incorporating accurate vibrational wavefunctions computed with the TROVE (Theoretical ROVibrational Energy) program. The developed methodologies use the accurate and extensive ro-vibrational ExoMol linelists and allow a full and systematic analysis of the vibrational spectra for dissociated species. The developed 1D methodology was used to model the emission spectra of di- and triatomic molecules formed via the dissociation of formamide, and the results compared with the experimental spectra. The fragments modelled include CO, N2 , CN, CO2 , and HCN. A further bi-temperature approach was introduced in order to fully and correctly model all fragments. The computational methodologies developed here produced an excellent agreement with experiment and our theoretical analysis is directly responsible for the determination of a experimental self-absorption within the CO2 spectrum that had remained unnoticed until this work. Finally, the SiH2 linelist was used to investigate the rotational energy level clustering of silylene for the first time, and the critical total angular momentum quantum number determined to be Jcr. ≈ 17
The high-temperature rotation-vibration spectrum and rotational clustering of silylene (SiH)
A rotation-vibration line list for the electronic ground state
() of SiH is presented. The line list, named CATS, is
suitable for temperatures up to 2000 K and covers the wavenumber range 0 -
10,000 cm(wavelengths m) for states with rotational
excitation up to . Over 310 million transitions between 593 804 energy
levels have been computed variationally with a new empirically refined
potential energy surface, determined by refining to 75 empirical term values
with and a newly computed high-level ab initio dipole moment surface.
This is the first, comprehensive high-temperature line list to be reported for
SiH and it is expected to aid the study of silylene in plasma physics,
industrial processes and possible astronomical detection. Furthermore, we
investigate the phenomenon of rotational energy level clustering in the
spectrum of SiH. The CATS line list is available from the ExoMol database
(www.exomol.com) and the CDS database
Do UK universities communicate their brands effectively through their websites?
This paper attempts to explore the effectiveness of UK universities’ websites. The area of branding in higher education has received increasing academic investigation, but little work has researched how universities demonstrate their brand promises through their websites. The quest to differentiate through branding can be challenging in the university context, however. It is argued that those institutions that have a strong distinctive image will be in a better position to face a changing future. Employing a multistage methodology, the web pages of twenty UK universities were investigated by using a combination of content and multivariable analysis. Results indicated ‘traditional values’ such as teaching and research were often well communicated in terms of online brand but ‘emotional values’ like social responsibility and the universities’ environments were less consistently communicated, despite their increased topicality. It is therefore suggested that emotional values may offer a basis for possible future online differentiation
An exploratory cluster randomised controlled trial of knowledge translation strategies to support evidence-informed decision-making in local governments (The KT4LG study)
Background: Childhood overweight and obesity is the most prevalent and, arguably, politically complex child health problem internationally. Governments, communities and industry have important roles to play, and are increasingly expected to deliver an evidence-informed system-wide prevention program. However, efforts are impeded by a lack of organisational access to and use of research evidence. This study aims to identify feasible, acceptable and ideally, effective knowledge translation (KT) strategies to increase evidence-informed decision making in local governments, within the context of childhood obesity prevention as a national policy priority.Methods/Design: This paper describes the methods for KT4LG, a cluster randomised controlled trial which is exploratory in nature, given the limited evidence base and methodological advances. KT4LG aims to examine a program of KT strategies to increase the use of research evidence in informing public health decisions in local governments. KT4LG will also assess the feasibility and acceptability of the intervention. The intervention program comprises a facilitated program of evidence awareness, access to tailored research evidence, critical appraisal skills development, networking and evidence summaries and will be compared to provision of evidence summaries alone in the control program. 28 local governments were randomised to intervention or control, using computer generated numbers, stratified by budget tertile (high, medium or low). Questionnaires will be used to measure impact, costs, and outcomes, and key informant interviews will be used to examine processes, feasibility, and experiences. Policy tracer studies will be included to examine impact of intervention on policies within relevant government policy documents.Discussion: Knowledge translation intervention studies with a focus on public health and prevention are very few in number. Thus, this study will provide essential data on the experience of program implementation and evaluation of a system-integrated intervention program employed within the local government public health context. Standardised programs of system, organisational and individual KT strategies have not been described or rigorously evaluated. As such, the findings will make a significant contribution to understanding whether a facilitated program of KT strategies hold promise for facilitating evidence-informed public health decision making within complex multisectoral government organisations.<br /
The Conceptualization and Measurement of Comorbidity: A Review of the Interprofessional Discourse
Copyright © 2013 Salimah H. Meghani et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background. Chronic medical conditions often occur in combination. Understanding underlying mechanisms causing diseases and their interactions may make it possible to address multiple complex conditions with single or consolidated treatment approaches and improve patients’ health outcomes while reducing costs. Objectives. We present a synthesis of the current interprofessional discourse on the issues surrounding comorbidities. Methods. A targeted review of the literature was conducted using published editorials, commentaries, and review articles. Results. Errors in conceptualization and measurement plague our current understanding of comorbidities. Two potential paths to generating knowledge involve the use of etiological or epidemiological approach. An etiological approach investigates the risk factors and underlying mechanisms potentially leading to consolidation of diagnosis and treatments. Because of the rudimentary stage of knowledge development in this area, this approach will require time and significant research investments. In contrast, the epidemiological approach relies on statistical identification of disease entities that cooccur beyond random chance; this approach carries an accompanying risk of diagnostic and treatment proliferation. Discussion. The concept of comorbidity, its nature, and measurement is in need of meaningful debate by the scientific and clinical communities. Recommendations in the domains of conceptualization, research, and measurement are discussed
'To live and die [for] Dixie': Irish civilians and the Confederate States of America
Around 20,000 Irishmen served in the Confederate army in the Civil War. As a result, they left behind, in various Southern towns and cities, large numbers of friends, family, and community leaders. As with native-born Confederates, Irish civilian support was crucial to Irish participation in the Confederate military effort. Also, Irish civilians served in various supporting roles: in factories and hospitals, on railroads and diplomatic missions, and as boosters for the cause. They also, however, suffered in bombardments, sieges, and the blockade. Usually poorer than their native neighbours, they could not afford to become 'refugees' and move away from the centres of conflict. This essay, based on research from manuscript collections, contemporary newspapers, British Consular records, and Federal military records, will examine the role of Irish civilians in the Confederacy, and assess the role this activity had on their integration into Southern communities. It will also look at Irish civilians in the defeat of the Confederacy, particularly when they came under Union occupation. Initial research shows that Irish civilians were not as upset as other whites in the South about Union victory. They welcomed a return to normalcy, and often 'collaborated' with Union authorities. Also, Irish desertion rates in the Confederate army were particularly high, and I will attempt to gauge whether Irish civilians played a role in this. All of the research in this paper will thus be put in the context of the Drew Gilpin Faust/Gary Gallagher debate on the influence of the Confederate homefront on military performance. By studying the Irish civilian experience one can assess how strong the Confederate national experiment was. Was it a nation without a nationalism
Mindfulness based cognitive therapy improves frontal control in bipolar disorder: a pilot EEG study
<p>Abstract</p> <p>Background</p> <p>Cognitive processing in Bipolar Disorder is characterized by a number of attentional abnormalities. Mindfulness Based Cognitive Therapy combines mindfulness meditation, a form of attentional training, along with aspects of cognitive therapy, and may improve attentional dysfunction in bipolar disorder patients.</p> <p>Methods</p> <p>12 euthymic BD patients and 9 control participants underwent record of electroencephalography (EEG, band frequency analysis) during resting states (eyes open, eyes closed) and during the completion of a continuous performance task (A-X version, EEG event-related potential (ERP) wave component analysis). The individuals with BD completed an 8-week MBCT intervention and record of EEG was repeated.</p> <p>Results</p> <p>(1) Brain activity, individuals with BD showed significantly decreased theta band power, increased beta band power, and decreased theta/beta ratios during the resting state, eyes closed, for frontal and cingulate cortices. Post MBCT intervention improvement over the right frontal cortex was seen in the individuals with BD, as beta band power decreased. (2) Brain activation, individuals with BD showed a significant P300-like wave form over the frontal cortex during the cue. Post MBCT intervention the P300-like waveform was significantly attenuated over the frontal cortex.</p> <p>Conclusions</p> <p>Individuals with BD show decreased attentional readiness and activation of non-relevant information processing during attentional processes. These data are the first that show, MBCT in BD improved attentional readiness, and attenuated activation of non-relevant information processing during attentional processes.</p
Ocean Acidification at High Latitudes: Potential Effects on Functioning of the Antarctic Bivalve Laternula elliptica
Ocean acidification is a well recognised threat to marine ecosystems. High
latitude regions are predicted to be particularly affected due to cold waters
and naturally low carbonate saturation levels. This is of concern for organisms
utilising calcium carbonate (CaCO3) to generate shells or skeletons.
Studies of potential effects of future levels of pCO2 on high latitude
calcifiers are at present limited, and there is little understanding of their
potential to acclimate to these changes. We describe a laboratory experiment
to compare physiological and metabolic responses of a key benthic bivalve, Laternula
elliptica, at pCO2 levels of their natural environment
(430 µatm, pH 7.99; based on field measurements) with those predicted
for 2100 (735 µatm, pH 7.78) and glacial levels (187 µatm, pH
8.32). Adult L. elliptica basal metabolism (oxygen consumption
rates) and heat shock protein HSP70 gene expression levels
increased in response both to lowering and elevation of pH. Expression of
chitin synthase (CHS), a key enzyme involved in synthesis
of bivalve shells, was significantly up-regulated in individuals at pH 7.78,
indicating L. elliptica were working harder to calcify in
seawater undersaturated in aragonite (ΩAr = 0.71),
the CaCO3 polymorph of which their shells are comprised. The different
response variables were influenced by pH in differing ways, highlighting the
importance of assessing a variety of factors to determine the likely impact
of pH change. In combination, the results indicate a negative effect of ocean
acidification on whole-organism functioning of L. elliptica
over relatively short terms (weeks-months) that may be energetically difficult
to maintain over longer time periods. Importantly, however, the observed changes
in L. elliptica CHS gene expression provides evidence for
biological control over the shell formation process, which may enable some
degree of adaptation or acclimation to future ocean acidification scenarios
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