7,187 research outputs found
Post-aragonite phases of CaCO at lower mantle pressures
The stability, structure and properties of carbonate minerals at lower mantle
conditions has significant impact on our understanding of the global carbon
cycle and the composition of the interior of the Earth. In recent years, there
has been significant interest in the behavior of carbonates at lower mantle
conditions, specifically in their carbon hybridization, which has relevance for
the storage of carbon within the deep mantle. Using high-pressure synchrotron
X-ray diffraction in a diamond anvil cell coupled with direct laser heating of
CaCO using a CO laser, we identify a crystalline phase of the
material above 40 GPa corresponding to a lower mantle depth of around 1,000
km which has first been predicted by \textit{ab initio} structure
predictions. The observed carbon hybridized species at 40 GPa is
monoclinic with symmetry and is stable up to 50 GPa, above which it
transforms into a structure which cannot be indexed by existing known phases. A
combination of \textit{ab initio} random structure search (AIRSS) and
quasi-harmonic approximation (QHA) calculations are used to re-explore the
relative phase stabilities of the rich phase diagram of CaCO. Nudged
elastic band (NEB) calculations are used to investigate the reaction mechanisms
between relevant crystal phases of CaCO and we postulate that the mineral
is capable of undergoing - hybridization change purely in the
structure forgoing the accepted post-aragonite structure.Comment: 12 pages, 8 figure
Solar flares and their associated processes
The evolution of the solar neutrino flux which is described by the wave
function
is examined. Our treatment of the problem holds for any standard model (SM)
extensions possessing nonzero dipole magnetic and anapole moments. When the
solar neutrino flux moves through the solar flare (SF) region in the preflare
period, then it undergoes the additional (compared with the SM) resonance
conversions. As a result, the weakening the electron neutrinos flux takes
place. On the other hand, existence of the additional resonances lead to
appearance of the and neutrinos
that could be detected by the terrestrial detectors.
The hypothesis of the -induced -decays is also discussed.
According to it, before the large SF, decreasing the -decay rate for
some elements takes place. The possible influence of the electron antineutrino
flux produced in the superflares on the regime of the hypothetical georeactor
is considered.Comment: 11 pages. arXiv admin note: text overlap with arXiv:hep-ph/0401221 by
other author
Learning from people with long-term conditions: new insights for governance in primary health care
Internationally, system-wide changes to the structures and systems governing health care aim to improve outcomes for patients, quality of care and access to services. The introduction of top-down centrally driven solutions to governance of health care, at the same time as increasing policy emphasis on greater ‘bottom up’ patient and public involvement in all aspects of health care, has set up complex tensions for policy implementation and health care practice. This paper explores the interplay of these agendas in the context of changes in primary health care services provided by the National Health Service (NHS) in England. Specifically, it looks at an example of service user involvement in a study (the PEGI study) of professional response to changes in the governance and incentives in the care of people with long-term conditions. This qualitative study was conducted in three Primary Care Trust sites in England. Service users influenced and guided the study throughout. In-depth interviews with 56 health and social care professionals engaged in the development of local policies and the delivery of care for people with complex long-term illness drew on vignettes developed by 32 members from three Service User Reference Groups (SURG). Themes generated by the cross case analysis were validated through these SURG groups. The findings presented here focus on four themes about risk and comparison of professionals’/service users’ perspectives of the issues: managing risks/consistent support, the risks of letting go/feeling in control, professionalism/helping people to help themselves, and managing expectations/professionals losing out. Service user involvement added value by: validating understandings of governance, framing debates to focus on what matters at the point of care, and enabling perspective sharing and interaction. We suggest that more collaborative forms of governance in health care, that take account of service user perspectives and enable interaction with professional groups, could help to validate processes of quality assurance and provide motivation for continuous quality improvement. We offer a model for ‘opening up’ collaborative projects to evaluation and appraisal and a process for critical reflection of the interrelationships between the PEGI study context, researcher issues, methods/approach and outcomes/impact of service user involvement
Synthesis of novel monomers containing the trifluorovinylidene group and the cyanato group and polymers thereof
Novel hybrid monomers containing both the aryltrifluorovyinyloxyether-group (TFVE-group) and the cyanato-group, their synthesis, and the synthesis of polymers made from these new hybrid monomers are disclosed
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Is Sacral Extension a Risk Factor for Early Proximal Junctional Kyphosis in Adult Spinal Deformity Surgery?
Study designRetrospective cohort study.PurposeTo investigate the role of sacral extension (SE) for the development of proximal junctional kyphosis (PJK) in adult spinal deformity (ASD) surgery.Overview of literatureThe development of PJK is multifactorial and different risk factors have been identified. Of these, there is some evidence that SE also affects the development of PJK, but data are insufficient.MethodsUsing a combined database comprising two propensity-matched groups of fusions following ASD surgery, one with fixation to S1 or S1 and the ilium (SE) and one without SE but with a lower instrumented vertebra of L5 or higher (lumbar fixation, LF), PJK and the role of further parameters were analyzed. The propensity-matched variables included age, the upper-most instrumented vertebra (UIV), preoperative sagittal alignment, and the baseline to one year change of the sagittal alignment.ResultsPropensity matching led to two groups of 89 patients each. The UIV, pelvic incidence minus lumbar lordosis, sagittal vertical axis, pelvic tilt, age, and body mass index were similar in both groups (p >0.05). The incidence of PJK at postoperative one year was similar for SE (30.3%) and LF (22.5%) groups (p =0.207). The PJK angle was comparable (p =0.963) with a change of -8.2° (SE) and -8.3° (LF) from the preoperative measures (p =0.954). A higher rate of PJK after SE (p =0.026) was found only in the subgroup of patients with UIV levels between T9 and T12.ConclusionsInstrumentation to the sacrum with or without iliac extension did not increase the overall risk of PJK. However, an increased risk for PJK was found after SE with UIV levels between T9 and T12
Can Protostellar Jets Drive Supersonic Turbulence in Molecular Clouds?
Jets and outflows from young stellar objects are proposed candidates to drive
supersonic turbulence in molecular clouds. Here, we present the results from
multi-dimensional jet simulations where we investigate in detail the energy and
momentum deposition from jets into their surrounding environment and quantify
the character of the excited turbulence with velocity probability density
functions. Our study include jet--clump interaction, transient jets, and
magnetised jets. We find that collimated supersonic jets do not excite
supersonic motions far from the vicinity of the jet. Supersonic fluctuations
are damped quickly and do not spread into the parent cloud. Instead subsonic,
non-compressional modes occupy most of the excited volume. This is a generic
feature which can not be fully circumvented by overdense jets or magnetic
fields. Nevertheless, jets are able to leave strong imprints in their cloud
structure and can disrupt dense clumps. Our results question the ability of
collimated jets to sustain supersonic turbulence in molecular clouds.Comment: 33 pages, 18 figures, accepted by ApJ, version with high resolution
figures at:
http://www.ita.uni-heidelberg.de/~banerjee/publications/jet_paper.pd
Seasonal patterns of oral antihistamine and intranasal corticosteroid purchases from Australian community pharmacies : a retrospective observational study
Acknowledgments The abstract of this paper was presented at the Respiratory Effectiveness Group 2016 Annual Summit as a poster presentation with interim findings. The poster’s abstract was published in “Poster Abstracts” in The Journal of Thoracic Disease (Vol. 8, Supplement 5, 5 July 2016). http://jtd.amegroups.com/article/view/8504.Peer reviewedPublisher PD
Molecular characterization, tissue expression and sequence variability of the barramundi (Lates calcarifer) myostatin gene
Background: Myostatin (MSTN) is a member of the transforming growth factor-β superfamily that negatively regulates growth of skeletal muscle tissue. The gene encoding for the MSTN peptide is a consolidate candidate for the enhancement of productivity in terrestrial livestock. This gene potentially represents an important target for growth improvement of cultured finfish.\ud
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Results: Here we report molecular characterization, tissue expression and sequence variability of the barramundi (Lates calcarifer) MSTN-1 gene. The barramundi MSTN-1 was encoded by three exons 379, 371 and 381 bp in length and translated into a 376-amino acid peptide. Intron 1 and 2 were 412 and 819 bp in length and presented typical GT...AG splicing sites. The upstream region contained cis-regulatory elements such as TATA-box and E-boxes. A first assessment of sequence variability suggested that higher mutation rates are found in the 5' flanking region with several SNP's present in this species. A putative micro RNA target site has also been observed in the 3'UTR (untranslated region) and is highly conserved across teleost fish. The deduced amino acid sequence was conserved across vertebrates and exhibited characteristic conserved putative functional residues including a cleavage motif of proteolysis (RXXR), nine cysteines and two glycosilation sites. A qualitative analysis of the barramundi MSTN-1 expression pattern revealed that, in adult fish, transcripts are differentially expressed in various tissues other than skeletal muscles including gill, heart, kidney, intestine, liver, spleen, eye, gonad and brain.\ud
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Conclusion: Our findings provide valuable insights such as sequence variation and genomic information which will aid the further investigation of the barramundi MSTN-1 gene in association with growth. The finding for the first time in finfish MSTN of a miRNA target site in the 3'UTR provides an opportunity for the identification of regulatory mutations on the expression of this gene
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