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1.
Bull Volcanol ; 80(5): 46, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-31258238

RESUMO

Over the last four decades, volcano observatories have adopted a number of different communication strategies for the dissemination of information on changes in volcanic behaviour and potential hazards to a wide range of user groups. These commonly include a standardised volcano alert level system (VALS), used in conjunction with other uni-valent communication techniques (such as information statements, reports and maps) and multi-directional techniques (such as meetings and telephone calls). This research, based on interviews and observation conducted 2007-2009 at the five US Geological Survey (USGS) volcano observatories, and including some of the key users of the VALS, argues for the importance of understanding how communicating volcanic hazard information takes place as an everyday social practice, focusing on the challenges of working across the boundaries between the scientific and decision-making communities. It is now widely accepted that the effective use, value and deployment of information across science-policy interfaces of this kind depend on three criteria: the scientific credibility of the information, its relevance to the needs of stakeholders and the legitimacy of both the information and the processes that produced it. Translation and two-way communication are required to ensure that all involved understand what information is credible and relevant. Findings indicate that whilst VALS play a role in raising awareness of an unfolding situation, supplementary communication techniques are crucial in facilitating situational understanding of that situation, and the uncertainties inherent to its scientific assessment, as well as in facilitating specific responses. In consequence, 'best practice' recommendations eschew further standardisation, and focus on the in situ cultivation of dialogue between scientists and stakeholders as a means of ensuring that information, and the processes through which it is produced are perceived to be legitimate by all involved.

2.
Vaccine ; 26(52): 6746-8, 2008 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-18852004

RESUMO

In 2005 the United Kingdom departments of health added 'carers' to the list of people that should be offered seasonal influenza immunisation by their general practice. We surveyed a sample of carers registered for care assistance with the charity Crossroads Caring for Carers. Over half (58%) were not aware that they are eligible for free influenza immunisation. Young carers without a chronic disease, were least likely to be offered immunisation and least likely to be immunised.


Assuntos
Cuidadores/estatística & dados numéricos , Pessoal de Saúde/estatística & dados numéricos , Imunização/estatística & dados numéricos , Vacinas contra Influenza/uso terapêutico , Adolescente , Adulto , Fatores Etários , Idoso , Pesquisas sobre Atenção à Saúde , Humanos , Vacinas contra Influenza/efeitos adversos , Pessoa de Meia-Idade , Medição de Risco , Inquéritos e Questionários , Reino Unido/epidemiologia , Adulto Jovem
3.
J Am Chem Soc ; 126(1): 18-9, 2004 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-14709038

RESUMO

The reaction between (TBP)8(Cz)Mn(III) (1) and the oxygen atom donors iodosylbenzene (PhIO) or p-cyanodimethylaniline-N-oxide (CDMANO) leads to the manganese(V)-oxo complex (TBP)8(Cz)Mn(V)O (2), which has been isolated and characterized previously. Under catalytic conditions with 1 as added catalyst and PhIO as oxidant, both sulfoxidation of PhSMe and epoxidation of cis-stilbene is observed, whereas with CDMANO no sulfoxidation takes place, suggesting that 2 is not the active oxidant. Examination of the independent reactivity of isolated 2 toward PhSMe and cis-stilbene supports this conclusion. A mechanism which relies on a novel type of oxidant involving Lewis acid activation of PhIO by the Mn(V)-oxo complex 2 accounts for these observations and is confirmed by 18O-labeling experiments.


Assuntos
Compostos de Epóxi/síntese química , Manganês/química , Metaloporfirinas/química , Porfirinas/química , Sulfóxidos/síntese química , Oxirredução , Isótopos de Oxigênio
4.
Inorg Chem ; 42(3): 859-67, 2003 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-12562200

RESUMO

The four-coordinate Ni(+) complex [PhTt(t)(Bu)]Ni(I)CO, where PhTt(t)()(Bu) = phenyltris((tert-buthylthio)methyl)borate (a tridentate thioether donor ligand), serves as a possible model for key Ni-CO reaction intermediates in the acetyl-CoA synthase (ACS) catalytic cycle. Resonance Raman, electronic absorption, magnetic circular dichroism (MCD), variable-temperature variable-field MCD, and electron paramagnetic resonance spectroscopies were utilized in conjunction with density functional theory and semiemperical INDO/S-CI calculations to investigate the ground and excited states of [PhTt(t)()(Bu)]Ni(I)CO. These studies reveal extensive Ni(+) --> CO pi-back-bonding interactions, as evidenced by a low C-O stretching frequency (1995 cm(-)(1)), a calculated C-O stretching force constant of 15.5 mdyn/A (as compared to k(CO)(free CO) = 18.7 mdyn/A), and strong Ni(+) --> CO charge-transfer absorption intensities. Calculations reveal that this high degree of pi-back-bonding is due to the fact that the Ni(+) 3d orbitals are in close energetic proximity to the CO pi acceptor orbitals. In the ACS "paramagnetic catalytic cycle", the high degree of pi-back-bonding in the putative Ni(+)-CO intermediate (the NiFeC species) is not expected to preclude methyl transfer from CH(3)-CoFeSP.


Assuntos
Acetato-CoA Ligase/metabolismo , Níquel/química , Compostos Organometálicos/síntese química , Acetato-CoA Ligase/química , Catálise , Espectroscopia de Ressonância de Spin Eletrônica , Ligantes , Modelos Químicos , Conformação Molecular , Estrutura Molecular
5.
J Am Chem Soc ; 124(51): 15170-1, 2002 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-12487581

RESUMO

The synthesis and characterization of an oxomanganese(V) corrolazine, (TBP)8(Cz)Mn(V)O (2), are reported. This remarkably stable high-valent complex is obtained from the stoichiometric reaction of (TBP)8(Cz)Mn(III) (1) with m-CPBA and is easily purified by standard chromatographic methods on silica gel at room temperature. Complex 2 exhibits a diamagnetic 1H NMR spectrum indicative of a low-spin d2 Mn(V)O species. LDI-TOFMS of 2 shows the predicted isotopic envelope at m/z 1426.8. This envelope shifts to higher mass as expected after the facile exchange of the terminal oxo group with H218O. The resonance Raman spectrum of 2 either in solution or in the solid state shows a strongly enhanced Raman band for the stretching mode of the Mn-oxo bond, which also shifts as expected upon 18O substitution: 2(16O), 979 cm-1; 2(18O), 938 cm-1 (in CH2Cl2). Initial reactivity studies show that 2 rapidly transfers the terminal oxo ligand to PPh3, resulting in the quantitative formation of OPPh3 and concomitant reduction of 2 back to 1. Complex 2 is the first example of an oxomanganese(V)-porphyrinoid complex that can be isolated at room temperature.


Assuntos
Manganês/química , Metaloporfirinas/química , Metaloporfirinas/síntese química , Espectrofotometria Ultravioleta , Análise Espectral Raman
6.
J Am Chem Soc ; 124(46): 13842-55, 2002 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-12431115

RESUMO

Spectroscopic and density functional theory (DFT) electronic structure computational studies on a binuclear bis-mu-oxo bridged (Ni(3+))(2) complex, [(PhTt(t(Bu))(2)Ni(2)(mu-O)(2)] (1), where (PhTt(t(Bu)) represents phenyl-tris((tert-butylthio)methyl)borate, are presented and discussed. These studies afford a detailed description of the Ni(2)O(2) core electronic structure in bis-mu-oxo (Ni(3+))(2) dimers and provide insight into the possible role of the (PhTt(t(Bu)) thioether ligand in the formation of 1 from a Ni(1+) precursor by O(2) activation. From a normal coordinate analysis of resonance Raman data, a value of k(Ni)(-)(O) = 2.64 mdyn/A is obtained for the Ni-O stretch force constant for 1. This value is smaller than k(Cu)(-)(O) = 2.82-2.90 mdyn/A obtained for bis-mu-oxo (Cu(3+))(2) dimers possessing nitrogen donor ligands, indicating a reduced metal-oxo bond strength in 1. Electronic absorption and magnetic circular dichroism spectroscopic techniques permit identification of several O-->Ni and S-->Ni charge transfer (CT) transitions that are assigned on the basis of DFT calculations. The dominant O-->Ni CT transition of 1 occurs at 17 700 cm(-)(1), red-shifted by approximately 7000 cm(-)(1) relative to the corresponding transition in bis-mu-oxo (Ni(3+))(2) dimers with nitrogen donor ligands. This red-shift along with the relatively low value of k(Ni)(-)(O) are due primarily to the presence of the thioether ligands in 1 that greatly affect the compositions of the Ni(2)O(2) core MOs. This unique property of the thioether ligand likely contributes to the reactivity of the Ni center in the precursor [(PhTt(t(Bu))Ni(1+)CO] toward O(2). DFT computations reveal that conversion of a hypothetical side-on peroxo (Ni(2+))(2) dimer, [(PhTt(t(Bu))(2)Ni(2)(mu-eta(2):eta(2)-O(2))], to the bis-mu-oxo (Ni(3+))(2) dimer 1 is energetically favorable by 32 kcal/mol and occurs without a significant activation energy barrier (DeltaH++) = 2 kcal/mol).

7.
J Am Chem Soc ; 124(33): 9668-9, 2002 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-12175200

RESUMO

The potential of 1s2p resonant inelastic (Raman) X-ray scattering (RIXS) is demonstrated for a series of Ni coordination complexes. In this technique, incident and scattered photon energies lie in the hard X-ray range (>5 keV). The 1s2p RIXS contour plots provide information that is complementary to K-edge and L-edge spectroscopy. RIXS spectroscopy promises to be a valuable probe of electronic structure


Assuntos
Níquel/química , Compostos Organometálicos/química , Análise Espectral Raman/métodos , Oxirredução , Espalhamento de Radiação , Raios X
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