Strong electron correlations in cobalt valence tautomers

We have examined cobalt based valence tautomer molecules such as Co(SQ)$_2$(phen) using density functional theory (DFT) and variational configuration interaction (VCI) approaches based upon a model Hamiltonian. Our DFT results extend earlier work by finding a reduced total energy gap (order 0.6 eV) between high temperature and low temperature states when we fully relax the coordinates (relative to experimental ones). Futhermore we demonstrate that the charge transfer picture based upon formal valence arguments succeeds qualitatively while failing quantitatively due to strong covalency between the Co 3$d$ orbitals and ligand $p$ orbitals. With the VCI approach, we argue that the high temperature, high spin phase is strongly mixed valent, with about 30 % admixture of Co(III) into the predominantly Co(II) ground state. We confirm this mixed valence through a fit to the XANES spectra. Moreover, the strong electron correlations of the mixed valent phase provide an energy lowering of about 0.2-0.3 eV of the high temperature phase relative to the low temperature one. Finally, we use the domain model to account for the extraordinarily large entropy and enthalpy values associated with the transition.Comment: 10 pages, 4 figures, submitted to J. Chem. Phy

Carbon Monoxide Screening in Pregnancy: An Evaluation Study of a Plymouth Pilot Intervention

This report provides an analysis and evaluation of a National Institute for Health and Care Excellence (NICE) recommended pilot intervention which was designed to identify pregnant women exposed to carbon monoxide due to cigarette smoke and refers them to local stop smoking services (LSSS). The pilot intervention was carried out by community midwives working in two areas of Plymouth. The city has areas of social and health inequalities and the study drew on populations from a socially deprived neighbourhood and a socially affluent area. The pilot was instigated following new NICE guidance recommending that all women attending initial ante natal booking appointments with their community midwives be offered a Carbon Monoxide (CO) breath analyser screening to determine their smoking status and or exposure to other forms of CO. This evaluation study identifies the benefits and barriers associated with the implementation of the CO screening pilot. In particular, our aims were to explore any detrimental impact on the relationship between women and their community midwives, identify the impact on midwives in terms of time and resources, reveal the responses and acceptability or otherwise of the screening as perceived and experienced by the women being asked to participate during the booking appointment and finally to evaluate the success of the intervention overall in relation to the numbers of referrals made to Plymouth’s LSSS. A further aim was explore any differences in the two socio demographic areas. We adopted a mixed methods approach involving four focus group interviews with 23 midwives, a survey posted to the 258 women who attended initial antenatal booking appointments in the study areas, an online version of the survey to ascertain the views and experiences of pregnant women and new mothers nationally and an interrogation of an internet forum discussion board for mothers. A two page questionnaire consisting of 12 questions was designed and posted to women who attended the booking appointment with the midwife during the three month pilot period and the same survey was made available online. Questions were designed to elicit women’s views about the information given by the midwife in relation to the screening, whether they had agreed to participate in the CO screening process, their experiences and views about offering CO screening to pregnant women and their smoking status and those of other household members. Of the 258 questionnaires posted to women who had attended the clinic during the pilot intervention 40 completed responses were returned representing a 15.5% response rate. Only 4 responses were received from the online survey posting but an additional 484 comments posted on the Mumsnet website discussion board were analysed. Our findings show that in general there was a high degree of acceptability for the intervention. Midwives and their clients were generally in support of the screening being offered to all pregnant women. However, this support was dependent on a number of contextual factors. Women wanted to be properly informed about the screening and midwives wanted to be kept informed about the effects of the intervention on women’s smoking cessation. Initial and ongoing training of midwives in utilising the protocol and in instructing women to correct use the monitor was also very important. Trust was revealed to be a very important aspect of the relationship between women and their midwives. Some women felt that the CO screening was being used just to check whether or not they were smokers and some midwives also worried about the possible negative effects the CO screening may have on their relationships with women

Vector magnetometer design study: Analysis of a triaxial fluxgate sensor design demonstrates that all MAGSAT Vector Magnetometer specifications can be met

The design of the vector magnetometer selected for analysis is capable of exceeding the required accuracy of 5 gamma per vector field component. The principal elements that assure this performance level are very low power dissipation triaxial feedback coils surrounding ring core flux-gates and temperature control of the critical components of two-loop feedback electronics. An analysis of the calibration problem points to the need for improved test facilities

Hyperspherical Harmonics, Separation of Variables and the Bethe Ansatz

The relation between solutions to Helmholtz's equation on the sphere $S^{n-1}$ and the [{\gr sl}(2)]^n Gaudin spin chain is clarified. The joint eigenfuctions of the Laplacian and a complete set of commuting second order operators suggested by the $R$--matrix approach to integrable systems, based on the loop algebra \wt{sl}(2)_R, are found in terms of homogeneous polynomials in the ambient space. The relation of this method of determining a basis of harmonic functions on $S^{n-1}$ to the Bethe ansatz approach to integrable systems is explained.Comment: 14 pgs, Plain Tex, preprint CRM--2174 (May, 1994

Anemia as a risk factor and therapeutic target in heart failure

Anemia has recently been recognized as an important comorbid condition and potentially novel therapeutic target in patients with heart failure (HF). Anemia is common in HF patients, with a prevalence ranging from 4% to 55% depending on the population studied. Multiple potential mechanisms of interaction exist between anemia and the clinical syndrome of HF, including hemodilution, inflammatory activation, renal insufficiency, and malnutrition. A growing body of literature from observational databases and clinical trials suggests that anemia is an independent risk factor for adverse outcomes in patients with HF. Although preliminary data suggest that treatment of anemia may result in significant symptomatic improvement in HF, aggressive treatment of anemia may also be associated with increased risk of hypertension or thrombosis. Multiple ongoing studies will provide definitive data on the balance of risks and benefits of anemia treatment in chronic HF

Fracture toughness of the cancellous bone of FNF femoral heads in relation to its microarchitecture

This study considers the relationship between microarchitecture and mechanical properties for cancellous bone specimens collected from a cohort of patients who had suffered fractured necks of femur. OP is an acute skeletal condition with huge socioeconomic impact [1] and it is associated with changes in both bone quantity and quality [2], which affect greatly the strength and toughness of the tissue [3].Support was provided by the EPSRC (EP/K020196: Point-ofCare High Accuracy Fracture Risk Prediction), the UK Department of Transport under the BOSCOS (Bone Scanning for Occupant Safety) project, and approved by Gloucester and Cheltenham NHS Trust hospitals under ethical consent (BOSCOS – Mr. Curwen CI REC ref 01/179G)

Feedback and Fluctuations in a Totally Asymmetric Simple Exclusion Process with Finite Resources

We revisit a totally asymmetric simple exclusion process (TASEP) with open boundaries and a global constraint on the total number of particles [Adams, et. al. 2008 J. Stat. Mech. P06009]. In this model, the entry rate of particles into the lattice depends on the number available in the reservoir. Thus, the total occupation on the lattice feeds back into its filling process. Although a simple domain wall theory provided reasonably good predictions for Monte Carlo simulation results for certain quantities, it did not account for the fluctuations of this feedback. We generalize the previous study and find dramatically improved predictions for, e.g., the density profile on the lattice and provide a better understanding of the phenomenon of "shock localization."Comment: 11 pages, 3 figures, v2: Minor change

Far-infrared vibrational properties of linear C60 polymers: A comparison between neutral and charged materials

We report the far-infrared transmittance spectrum of a pure phase of the orthorhombic high-temperature and high-pressure C-60 polymer and compare the results with a previously published spectrum of the charged RbC60 orthorhombic polymer. Assignments for both spectra are made with the aid of first-principles quantum molecular dynamics simulations of the two materials. We find that the striking spectral differences between the neutral and charged linear fullerene polymers can be fully accounted for by charge effects on the C-60 ball