393 research outputs found
Socio-Economic Implications of New Information Technology
Socio-Economic Implications of New Information Technology provides not only an exploration of the relevant literature and some guidelines for further, more detailed research, but also some stimulating insights into a host of issues raised by the communications revolution
To fill or not to fill: a qualitative cross-country study on dentists' decisions in managing non-cavitated proximal caries lesions
BACKGROUND: This study aimed to identify barriers and enablers for dentists managing non-cavitated proximal caries lesions using non- or micro-invasive (NI/MI) approaches rather than invasive and restorative methods in New Zealand, Germany and the USA. METHODS: Semi-structured interviews were conducted, focusing on non-cavitated proximal caries lesions (radiographically confined to enamel or the outer dentine). Twelve dentists from New Zealand, 12 from Germany and 20 from the state of Michigan (USA) were interviewed. Convenience and snowball sampling were used for participant recruitment. A diverse sample of dentists was recruited. Interviews were conducted by telephone, using an interview schedule based on the Theoretical Domains Framework (TDF). RESULTS: The following barriers to managing lesions non- or micro-invasively were identified: patients' lacking adherence to oral hygiene instructions or high-caries risk, financial pressures and a lack of reimbursement for NI/MI, unsupportive colleagues and practice leaders, not undertaking professional development and basing treatment on what had been learned during training, and a sense of anticipated regret (anxiety about not restoring a proximal lesion in its early stages before it progressed). The following enablers were identified: the professional belief that remineralisation can occur in early non-cavitated proximal lesions and that these lesions can be arrested, the understanding that placing restorations weakens the tooth and inflicts a cycle of re-restoration, having up-to-date information and supportive colleagues and work environments, working as part of a team of competent and skilled dental practitioners who perform NI/MI (such as cleaning or scaling), having the necessary resources, undertaking ongoing professional development and continued education, maintaining membership of professional groups and a sense of professional and personal satisfaction from working in the patient's best interest. Financial aspects were more commonly mentioned by the German and American participants, while continuing education was more of a focus for the New Zealand participants. CONCLUSIONS: Decisions on managing non-cavitated proximal lesions were influenced by numerous factors, some of which could be targeted by interventions for implementing evidence-based management strategies in practice
Quasi Stable Black Holes at the Large Hadron Collider
We adress the production of black holes at LHC and their time evolution in
space times with compactified space like extra dimensions. It is shown that
black holes with life times of hundred fm/c can be produced at LHC. The
possibility of quasi-stable remnants is discussed.Comment: 4 pages, 3 figures, typos removed, omitted factors included, accepted
for publicatio
Mechanistic studies on the: N -alkylation of amines with alcohols catalysed by iridium(i) complexes with functionalised N-heterocyclic carbene ligands
Iridium(i) cyclooctadiene complexes featuring O- and N-donor functionalised NHC ligands efficiently catalyse the C-N coupling of amines with alcohols through a borrowing hydrogen mechanism. These catalysts have been applied for the N-alkylation of several aromatic and aliphatic primary amines with a range of alcohols including benzyl alcohol derivatives, straight-chain primary alcohols and secondary alcohols. The cationic complex [Ir(NCCH3)(cod){MeIm(2-methoxybenzyl)}]+ (cod = 1, 5-cyclooctadiene, MeIm = 3-methylimidazol-2-ylidene) having a rigid O-donor wingtip exhibits the best catalytic performance for the N-alkylation of aniline with benzyl alcohol giving a quantitative conversion to N-benzylaniline in 3 h. Experimental and theoretical studies at the DFT level on the N-alkylation of aniline with benzyl alcohol catalysed by the model compound [IrCl(cod)(IMe)] (IMe = 1, 3-dimethyl-imidazol-2-ylidene) support the participation of the iridium catalyst not only in the alcohol dehydrogenation and imine hydrogenation steps but also in the key step leading to the formation of the new C-N bond. Nucleophilic attack of an iridium-amido species generated in basic medium on the electrophilic aldehyde results in a hemiaminolate intermediate species from which the hemiaminal is released by alcoholysis. The free hemiaminal dehydrates to give the corresponding intermediate imine product that is hydrogenated by the iridium catalyst to the N-alkylated amine product. The iridium(i) complexes featuring functionalised NHC ligands are more active than [IrCl(cod)(IMe)] which highlights the positive influence of the functional group on the N-alkylation catalytic activity
Hybrid meson decay from the lattice
We discuss the allowed decays of a hybrid meson in the heavy quark limit. We
deduce that an important decay will be into a heavy quark non-hybrid state and
a light quark meson, in other words, the de-excitation of an excited gluonic
string by emission of a light quark-antiquark pair.
We discuss the study of hadronic decays from the lattice in the heavy quark
limit and apply this approach to explore the transitions from a spin-exotic
hybrid to and where is a scalar meson. We obtain a
signal for the transition emitting a scalar meson and we discuss the
phenomenological implications.Comment: 18 pages, LATEX, 3 ps figure
Black Hole Chromosphere at the LHC
If the scale of quantum gravity is near a TeV, black holes will be copiously
produced at the LHC. In this work we study the main properties of the light
descendants of these black holes. We show that the emitted partons are closely
spaced outside the horizon, and hence they do not fragment into hadrons in
vacuum but more likely into a kind of quark-gluon plasma. Consequently, the
thermal emission occurs far from the horizon, at a temperature characteristic
of the QCD scale. We analyze the energy spectrum of the particles emerging from
the "chromosphere", and find that the hard hadronic jets are almost entirely
suppressed. They are replaced by an isotropic distribution of soft photons and
hadrons, with hundreds of particles in the GeV range. This provides a new
distinctive signature for black hole events at LHC.Comment: Incorporates changes made for the version to be published in Phys.
Rev. D. Additional details provided on the effect of the chromosphere in
cosmic ray shower
Children’s rights in their oral health care: How responsive are oral health professionals to children’s rights
Research on children’s rights in oral health care is lacking, and this study aims to partially fill this gap. In 2015, we conducted research in one region of New Zealand using video methods to explore the rights of 22 children during a specific oral health treatment, the placement of stainless steel crowns. Our findings show that many children did not receive a professional standard of care, there were gaps in the delivery and standard of care, and there were numerous examples of children’s rights’ violations. At the same time, however, some of the children’s dental practitioners’ (CDPs) actions may have been acceptable practice within the profession if children’s rights have not yet fully been embedded into the practice of oral health care workers. We conclude with a discussion of the implications of our findings and suggestions for a more rights based standard of oral health care
Classical and Quantum Decay of Oscillatons: Oscillating Self-Gravitating Real Scalar Field Solitons
The oscillating gravitational field of an oscillaton of finite mass M causes
it to lose energy by emitting classical scalar field waves, but at a rate that
is non-perturbatively tiny for small GMm, where m is the scalar field mass:
d(GM)/dt ~ -3797437.776333015 e^[-39.433795197160163/(GMm)]/(GMm)^2.
Oscillatons also decay by the quantum process of the annihilation of scalarons
into gravitons, which is only perturbatively small in GMm, giving by itself
d(GM)/dt ~ - 0.008513223934732692 G m^2 (GMm)^5. Thus the quantum decay is
faster than the classical one for Gmm < 39.4338/[ln(1/Gm^2)}-7ln(GMm)+19.9160].
The time for an oscillaton to decay away completely into free scalarons and
gravitons is ~ 2/(G^5 m^11) ~ 10^324 yr (1 meV/m)^11. Oscillatons of more than
one real scalar field of the same mass generically asymptotically approach a
static-geometry U(1) boson star configuration with GMm = GM_0 m, at the rate
d(GM/c^3)/dt ~ [(C/(GMm)^4)e^{-alpha/(GMm)}+Q(m/m_{Pl})^2(GMm)^3]
[(GMm)^2-(GM_0 m)^2], with GM_0 m depending on the magnitudes and relative
phases of the oscillating fields, and with the same constants C, alpha, and Q
given numerically above for the single-field case that is equivalent to GM_0 m
= 0.Comment: 75 pages, LaTe
Quantum Radiation from a 5-Dimensional Rotating Black Hole
We study a massless scalar field propagating in the background of a
five-dimensional rotating black hole. We showed that in the Myers-Perry metric
describing such a black hole the massless field equation allows the separation
of variables. The obtained angular equation is a generalization of the equation
for spheroidal functions. The radial equation is similar to the radial
Teukolsky equation for the 4-dimensional Kerr metric. We use these results to
quantize the massless scalar field in the space-time of the 5-dimensional
rotating black hole and to derive expressions for energy and angular momentum
fluxes from such a black hole.Comment: references added, accepted for publication in Physical Review
- …