Magnetohydrodynamic properties of incompressible Meissner fluids

We consider a superconducting material that exists in the liquid state, more precisely, in which the Meissner-Ochsenfeld effect persists in the liquid state. First, we investigate how the shape of such a hypothetical Meissner liquid will adapt to accomodate for an applied external field. In particular, we analyse the case of a droplet of Meissner fluid, and compute the elongation of the droplet and its quadrupole frequency as a function of the applied field. Next, the influence of an applied field on the flow of the liquid is studied for the case of a surface wave. We derive the dispersion relation for surface waves on an incompressible Meissner fluid. We discuss some candidate realizations of the Meissner fluids and for the case of a superconducting colloid discuss which regime of wave lengths would be most affected by the Meissner effect.Comment: 12 pages, 3 figure

Status of Rockwell-ERC high efficiency solar cell programs

Programs aimed at developing large area, high efficiency GaAs heteroface cells for low concentration space applications and high concentration terrestrial applications as well as other programs aimed at developing high efficiency multicolor devices for use in similar applications are described. An additional program aimed at achieving improved power to weight ratio by parting thin film solar cells from their growth substrates prior to their incorporation into an array assembly is also described. There is potential for multiple reuse of the substrates which could lead to reduced costs for such devices. Highlights of these programs and their interrelated contributions toward the goals of reducing specific weight, volume and cost of photovoltaic space power systems are discussed. Overall goals are summarized and current programs and their funding sources are listed

Evaluation of the pathways of tropospheric nitrophenol formation using a multiphase model

International audiencePhenols are a major class of volatile organic compounds (VOC) whose reaction within, and partitioning between, the gas and liquid phases affects their lifetime within the atmosphere, the local oxidising capacity, and the extent of production of nitrophenols, which are toxic chemicals. In this work, a zero-dimension box model was constructed to quantify the relative nitration pathways, and partitioning into the liquid phase, of mono-aromatic compounds in order to help elucidate the formation pathways of 2- and 4-nitrophenol in the troposphere. The liquid phase contributed significantly to the production of nitrophenols for liquid water content (Lc) values exceeding 3×10-9, and for a range of assumed liquid droplet diameter, even though the resultant equilibrium partitioning to the liquid phase was much lower. For example, in a ''typical'' model scenario, with Lc=3×10-7, 58% of nitrophenol production occurred in the liquid phase but only 2% of nitrophenol remained there, i.e. a significant proportion of nitrophenol observed in the gas phase may actually be produced via the liquid phase. The importance of the liquid phase was enhanced at lower temperatures, by a factor ~1.5?2 at 278 K cf. 298 K. The model showed that nitrophenol production was particularly sensitive to the values of the rate coefficients for the liquid phase reactions between phenol and OH or NO3 reactions, but insensitive to the rate coefficient for the reaction between benzene and OH, thus identifying where further experimental data are required

Survey of Infections Transmissible Between Baboons and Humans, Cape Town, South Africa

Baboons on South Africa’s Cape Peninsula come in frequent contact with humans. To determine potential health risks for both species, we screened 27 baboons from 5 troops for 10 infections. Most (56%) baboons had antibodies reactive or cross-reactive to human viruses. Spatial overlap between these species poses low but potential health risks

Dynamic interpersonal therapy for moderate to severe depression: A pilot randomized controlled and feasibility trial

Background: Improving Access to Psychological Therapies (IAPT) services treat most patients in England who present to primary care with major depression. Psychodynamic psychotherapy is one of the psychotherapies offered. Dynamic Interpersonal Therapy (DIT) is a psychodynamic and mentalization-based treatment for depression. 16 sessions are delivered over approximately 5 months. Neither DIT's effectiveness relative to low-intensity treatment (LIT), nor the feasibility of randomizing patients to psychodynamic or cognitive-behavioural treatments (CBT) in an IAPT setting has been demonstrated. Methods: 147 patients were randomized in a 3:2:1 ratio to DIT (n = 73), LIT (control intervention; n = 54) or CBT (n = 20) in four IAPT treatment services in a combined superiority and feasibility design. Patients meeting criteria for major depressive disorder were assessed at baseline, mid-treatment (3 months) and post-treatment (6 months) using the Hamilton Rating Scale for Depression (HRSD-17), Beck Depression Inventory-II (BDI-II) and other self-rated questionnaire measures. Patients receiving DIT were also followed up 6 months post-completion. Results: The DIT arm showed significantly lower HRSD-17 scores at the 6-month primary end-point compared with LIT (d = 0.70). Significantly more DIT patients (51%) showed clinically significant change on the HRSD-17 compared with LIT (9%). The DIT and CBT arms showed equivalence on most outcomes. Results were similar with the BDI-II. DIT showed benefit across a range of secondary outcomes.ConclusionsDIT delivered in a primary care setting is superior to LIT and can be appropriately compared with CBT in future RCTs

Older adults respond better to psychological therapy than working-age adults: evidence from a large sample of mental health service attendees.

BACKGROUND: Older adults commonly experience depression and anxiety, yet are under-represented in psychological treatment services. There is uncertainty about the outcomes from psychological therapies for older adults relative to working-age adults. This study explored: pre-treatment differences between older and working-age patients with depression or anxiety disorders; whether outcomes from psychological therapy differ between groups controlling for pre-treatment clinical severity, functioning, and socio-demographics; and whether the impact of a long-term condition (LTC) on outcome differs by age. METHODS: Data on >100,000 patients treated with psychological therapies in eight Improving Access to Psychological Therapies services were analyzed. We compared pre-treatment characteristics and therapy outcomes for older (≥65 years) and working-age (18-64 years) patients, and investigated associations between age and outcomes. RESULTS: Older adults had less severe clinical presentations pre-treatment. In adjusted models older adults were more likely to reliably recover (OR=1.33(95%CI=1.24-1.43)), reliably improve (OR=1.34(95%CI =1.24-1.45)), and attrition was less likely (OR=0.48(95%CI =0.43-0.53)). Effects were more pronounced in patients with anxiety disorders compared to depression. Having an LTC was associated with a much lower likelihood of reliable recovery for working-age patients but had only a modest effect for older adults. LIMITATIONS: There are potential selection biases affecting the characteristics of older people attending these services. Residual confounding cannot be ruled out due to limits on data available. CONCLUSIONS: Older adults experienced better outcomes from psychological treatments than working-age adults. Given the deleterious effects if mental health conditions go untreated, increasing access to psychological therapies for older people should be an international priority

A retrospective evaluation of the impact of a dedicated obstetric and neonatal transport service on transport times within an urban setting

OBJECTIVE:To determine whether the establishment of a dedicated obstetric and neonatal flying squad resulted in improved performance within the setting of a major metropolitan area.DESIGN AND SETTING:The Cape Town metropolitan service of the Emergency Medical Services was selected for a retrospective review of the transit times for the newly implemented Flying Squad programme. Data were imported from the Computer Aided Dispatch programme. Dispatch, Response, Mean Transit and Total Pre-hospital times relating to the obstetric and neonatal incidents was analysed for 2005 and 2008. RESULTS: There was a significant improvement between 2005 and 2008 in all incidents evaluated. Flying Squad dispatch performance improved from 11.7% to 46.6% of all incidents dispatched within 4 min (p < 0.0001). Response time performance at the 15-min threshold did not demonstrate a statistically significant improvement (p = 0.4), although the improvement in the 30-min performance category was statistically significant in both maternity and neonatal incidents. Maternity incidents displayed the greatest improvement with the 30-min performance increasing from 30.3% to 72.9%. The analysis of the mean transit times demonstrated that neonatal transfers displayed the longest status time in all but one of the categories. Even so, the introduction of the Flying Squad programme resulted in a reduction in a total pre-hospital time from 177 to 128 min. CONCLUSION: The introduction of the Flying Squad programme has resulted in significant improvement in the transit times of both neonatal and obstetric patients. In spite of the severe resource constraints facing developing nations, the model employed offers significant gains

Evaluation of the pathways of tropospheric nitrophenol formation from benzene and phenol using a multiphase model

International audiencePhenols are a major class of volatile organic compounds (VOC) whose reaction within, and partitioning between, the gas and liquid phases affects their lifetime within the atmosphere, the local oxidising capacity, and the extent of production of nitrophenols, which are toxic chemicals. In this work, a zero-dimension box model was constructed to quantify the relative importance of different nitration pathways, and partitioning into the liquid phase, of mono-aromatic compounds in order to help elucidate the formation pathways of 2- and 4-nitrophenol in the troposphere. The liquid phase contributed significantly to the production of nitrophenols for liquid water content (Lc) values exceeding 3x10-9, and for a range of assumed liquid droplet diameter, even though the resultant equilibrium partitioning to the liquid phase was much lower. For example, in a "typical" model scenario, with Lc=3x10-7, 58% of nitrophenol production occurred in the liquid phase but only 2% of nitrophenol remained there, i.e. a significant proportion of nitrophenol observed in the gas phase may actually be produced via the liquid phase. The importance of the liquid phase was enhanced at lower temperatures, by a factor ~1.5-2 at 278K c.f. 298K. The model showed that nitrophenol production was particularly sensitive to the values of the rate coefficients for the liquid phase reactions between phenol and OH or NO3 reactions, but insensitive to the rate coefficient for the reaction between benzene and OH, thus identifying where further experimental data are required

Barriers to recruitment when conducting a commissioned randomised controlled trial of medication versus psychological therapy for generalised anxiety disorder: some lessons learned

Background Poor recruitment is the most common reason for premature discontinuation of randomised controlled trials (RCTs). An RCT of medication versus psychological therapy for generalised anxiety disorder (GAD) was discontinued prematurely by the UK National Institute of Health Research funders because of recruitment failure. In order to inform future research studies, this article explores the reasons for poor recruitment and aspects which could have been improved. Methods The trial recruited participants via psychological well-being practitioners (PWPs) employed within local Improving Assess to Psychological Therapies (IAPT) services at four sites in England. For this study, we initially examined the recruitment data to identify reasons why potential participants were reluctant to participate in the trial. We then investigated reasons the PWPs did not identify more potential participants. Finally, we performed retrospective analyses of a computerised clinical records system used by the IAPT services in this study. These analyses aimed to establish the number of potential participants who had not been approached about the trial as well as whether there were additional factors affecting the numbers of people who might be eligible to take part. Data were obtained for all patients assessed during the period from the date on which recruitment commenced until the closure of the trial. Results Three quarters of those patients identified as possibly suitable for the trial declined to take part; the great majority did so because they did not want to be randomly assigned to receive medication. Our retrospective database analyses showed that only around 12% of potentially eligible patients for the trial were identified by the PWPs at the pilot sites. The results also indicated that only 5% of those noted at entry to the IAPT services to have a score of at least 10 on the GAD-7 questionnaire (a self-completed questionnaire with high sensitivity and specificity for GAD) would have been eligible for the trial. Conclusions Our findings suggest that poor recruitment to RCTs can be significantly affected by participants’ treatment preferences and by factors influencing the recruiting clinicians. It may also be important not to include too many restrictions on inclusion criteria for pragmatic trials aiming for generalisable results

Experimentally determined Henry's Law coefficients of phenol, 2-methylphenol and 2-nitrophenol in the temperature range 281-302 K

The Henry’s Law coefficient is a key physical parameter in the partitioning, and hence environmental fate, of a chemical species between air and water. Despite the acknowledged polluting potential of phenol, 2-methylphenol (o-cresol) and 2-nitrophenol, there is extremely poor agreement in the literature of their Henry’s law coefficients and, in particular, no apparent systematic measurement of the variation with temperature. Here a temperature controlled column-stripping method was employed to determine the Henry's Law coefficients for these compounds over the temperature range 281-302 K. Coefficients were derived from regression fits to the observed rates of loss from the liquid phase as a function of column depth in order explicitly to take account of potential non-attainment of equilibrium between liquid and gas phases. Temperature dependent expressions summarising the Henry's Law coefficient of phenol, o-cresol and 2-nitrophenol over the stated temperature range are ln H (/ M atm-1) = 5850/T - 11.6, ln H (/ M atm-1) = 6680/T - 15.4 and ln H (/ M atm-1) = 6270/T - 16.6, respectively (to within 15% of all measured values in this work). A thorough comparison with previous literature-published values has been undertaken