Fundamental studies on a heat driven lamp

A detailed theoretical study of a heat-driven lamp has been performed. This lamp uses a plasma produced in a thermionic diode. The light is produced by the resonance transition of cesium. An important result of this study is that up to 30% of the input heat is predicted to be converted to light in this device. This is a major improvement over ordinary thermionic energy converters in which only approx. 1% is converted to resonance radiation. Efficiencies and optimum inter-electrode spacings have been found as a function of cathode temperature and the radiative escape factor. The theory developed explains the operating limits of the device

Amino acids in a Fischer Tropsch type synthesis

One postulation is described for the presence of organic compounds in meteorites which states that they were formed during the condensation of the solar nebula. A viable laboratory simulation of these conditions can be modeled after the industrial Fischer Tropsch reaction, which is known to produce organic compounds called hydrocarbons. In this simulation, a mixture of carbon monoxide, hydrogen and ammonia is heated in the presence of iron meteorite. The reaction products for amino acids, a class of organic compounds important to life, were examined. A large number of these compounds is found in meteorites and other chemical evolution experiments, but only small quantities of a few amino acids were found in the present simulation work. These results are at odds with the existing literature in which many amino acids were reported

Data approximation strategies between generalized line scales and the influence of labels and spacing

Comparing sensory data gathered using different line scales is challenging. We tested whether adding internal labels to a generalized visual analog scale (gVAS) would improve comparability to a typical generalized labeled magnitude scale (gLMS). Untrained participants evaluated cheeses using one of four randomly assigned scales. Normalization to a cross‐modal standard and/or two gLMS transformations were applied to the data. Response means and distributions were lower for the gLMS than the gVAS, but no difference in resolving power was detected. The presence of labels, with or without line markings, caused categorical‐like lumping of responses. Closer low‐end label spacing for gLMS increased influenced participants to mark near higher intensity labels when they were evaluating low‐intensity samples. Although normalization reduced differences between scales, neither transformation nor normalization was supported as appropriate gLMS/gVAS approximation strategies. This study supports previous observations that neither scale offers a systematic advantage and that participant usage differences limit direct scale comparisons

Optimal discrete stopping times for reliability growth tests

Often, the duration of a reliability growth development test is specified in advance and the decision to terminate or continue testing is conducted at discrete time intervals. These features are normally not captured by reliability growth models. This paper adapts a standard reliability growth model to determine the optimal time for which to plan to terminate testing. The underlying stochastic process is developed from an Order Statistic argument with Bayesian inference used to estimate the number of faults within the design and classical inference procedures used to assess the rate of fault detection. Inference procedures within this framework are explored where it is shown the Maximum Likelihood Estimators possess a small bias and converges to the Minimum Variance Unbiased Estimator after few tests for designs with moderate number of faults. It is shown that the Likelihood function can be bimodal when there is conflict between the observed rate of fault detection and the prior distribution describing the number of faults in the design. An illustrative example is provided

Behavioral Couples Treatment for Substance Use Disorder: Secondary Effects on the Reduction of Risk for Child Abuse

Risk for child abuse was examined prior to and after behavioral couples treatment (BCT) among 61 couples in which one or both parents were diagnosed with substance use disorder (SUD). All couples were residing with one or more school-age children. Mothers and fathers completed pretreatment, post-intervention, and 6 month post-intervention follow-up assessments. Results of piecewise latent growth models tested whether the number of BCT sessions attended and number of days abstinent from drugs and alcohol influenced relationship satisfaction and its growth over time, and in turn if relationship satisfaction and change in relationship satisfaction influenced risk for child abuse. For both mothers and fathers, attending more BCT sessions lead to a direct increase in relationship satisfaction, which in turn led to stronger reductions in risk for child abuse. This effect was maintained from the post-intervention through the 6-month post-intervention follow-up. For fathers, number of days abstinent significantly influenced reduction in child abuse potential at post-intervention via relationship satisfaction. This indirect effect was not present for mothers. The overall benefits of BCT on mothers\u27 and fathers\u27 risk for child abuse suggest that BCT may have promise in reducing risk for child abuse among couples in which one or both parents have SUD

Bayes linear kinematics in the analysis of failure rates and failure time distributions

Collections of related Poisson or binomial counts arise, for example, from a number of different failures in similar machines or neighbouring time periods. A conventional Bayesian analysis requires a rather indirect prior specification and intensive numerical methods for posterior evaluations. An alternative approach using Bayes linear kinematics in which simple conjugate specifications for individual counts are linked through a Bayes linear belief structure is presented. Intensive numerical methods are not required. The use of transformations of the binomial and Poisson parameters is proposed. The approach is illustrated in two examples, one involving a Poisson count of failures, the other involving a binomial count in an analysis of failure times

Not in my back yard! Sports stadia location and the property market

In recent years sports stadia have been built in the UK, not only for their intended sporting purpose but with the twin aim of stimulating economic and physical regeneration. However, proposals to locate stadia in urban areas often prompt a negative reaction from local communities, fearing a decline in property prices. This paper will use a case study of the Millennium Stadium in Cardiff and the City of Manchester Stadium to illustrate that in contrast to this widely held belief, sports stadia can actually enhance the value of residential property. Furthermore, it will argue that stadia also contribute indirectly to property value through the creation of pride, confidence and enhanced image of an area.</p

Drosophila modifier screens to identify novel neuropsychiatric drugs including aminergic agents for the possible treatment of Parkinson's disease and depression.

Small molecules that increase the presynaptic function of aminergic cells may provide neuroprotection in Parkinson's disease (PD) as well as treatments for attention deficit hyperactivity disorder (ADHD) and depression. Model genetic organisms such as Drosophila melanogaster may enhance the detection of new drugs via modifier or 'enhancer/suppressor' screens, but this technique has not been applied to processes relevant to psychiatry. To identify new aminergic drugs in vivo, we used a mutation in the Drosophila vesicular monoamine transporter (dVMAT) as a sensitized genetic background and performed a suppressor screen. We fed dVMAT mutant larvae ∼ 1000 known drugs and quantitated rescue (suppression) of an amine-dependent locomotor deficit in the larva. To determine which drugs might specifically potentiate neurotransmitter release, we performed an additional secondary screen for drugs that require presynaptic amine storage to rescue larval locomotion. Using additional larval locomotion and adult fertility assays, we validated that at least one compound previously used clinically as an antineoplastic agent potentiates the presynaptic function of aminergic circuits. We suggest that structurally similar agents might be used to development treatments for PD, depression and ADHD, and that modifier screens in Drosophila provide a new strategy to screen for neuropsychiatric drugs. More generally, our findings demonstrate the power of physiologically based screens for identifying bioactive agents for select neurotransmitter systems

Therapeutic drug monitoring (TDM) of atazanavir in pregnancy

Purpose of the study: Pregnant women experience physiological changes during pregnancy resulting in clinically significant alterations in antiretroviral pharmacokinetics (PK). Therefore, achieving and maintaining optimal plasma concentrations of antiretroviral drugs is essential for maternal health and minimising the risk of mother-to-child transmission of HIV. The aim of this study is to describe atazanavir/ritonavir (ATV/r) PK during pregnancy. Methods: Pregnant HIV-positive women received ATV/r as part of their routine pre-natal care. Demographic and clinical data were collected, and ATV plasma concentrations [ATV] were determined in the first (T1), second (T2) and third (T3) trimester using HPLC-MS/MS (LLQ=0.05 &#x00B5;g/mL). Postpartum (PP) sampling was performed where applicable. Antepartum (AP) and PP PK parameters were compared using a one-way ANOVA. Summary of results: From January 2007, 44 women (37 black African) were enrolled in the study. All received ATV/r at a standard dose of 1 tablet once daily (300/100 mg od). 24 women were receiving ART prior to pregnancy, and 20 women initiated ATV/r during pregnancy. Median (range) gestation at treatment initiation in these patients was 23.5 weeks (7&#x2013;35). At the time nearest to delivery 31 patients had an undetectable plasma viral load (pVL), 6 patients had detectable pVL and 2 were unavailable. [ATV] were determined in 11/44 (T1); 25/44 (T2); 35/44 (T3) and 28/44 (PP) patients. Time of TDM sampling, gestation time and [ATV] (geometric mean; 95% CI) are given in the Table. 6 patients were either below or approaching the ATV MEC (0.15 &#x00B5;g/mL) during pregnancy; of these, 4/6 achieved undetectable pVL at the time of delivery (1=pVL of 291 copies/mL; 1 unavailable). [ATV] were significantly lower at T2/T3 relative to T1/PP. Equally, in a paired analysis of 28 patients (T2/T3 vs. PP), [ATV] were significantly reduced at T2/T3 (P=0.003). Conclusions: This study represents one of the larger cohorts of women undergoing TDM for ATV in pregnancy. Lower [ATV] were seen in T2 and T3 when compared to T1. However, such findings were not associated with viral breakthrough or HIV transmissions. Nonetheless, careful monitoring of women in pregnancy is required, and if there is concern for inadequate levels, dose adjustment of ATV upward from 300 mg to 400 mg may be an option

A Functional Link Between Bir1 and the <i>Saccharomyces cerevisiae</i> Ctf19 Kinetochore Complex Revealed Through Quantitative Fitness Analysis

The chromosomal passenger complex (CPC) is a key regulator of eukaryotic cell division, consisting of the protein kinase Aurora B/Ipl1 in association with its activator (INCENP/Sli15) and two additional proteins (Survivin/Bir1 and Borealin/Nbl1). Here, we report a genome-wide genetic interaction screen in Saccharomyces cerevisiae using the bir1-17 mutant, identifying through quantitative fitness analysis deletion mutations that act as enhancers and suppressors. Gene knockouts affecting the Ctf19 kinetochore complex were identified as the strongest enhancers of bir1-17, while mutations affecting the large ribosomal subunit or the mRNA nonsense-mediated decay pathway caused strong phenotypic suppression. Thus, cells lacking a functional Ctf19 complex become highly dependent on Bir1 function and vice versa. The negative genetic interaction profiles of bir1-17 and the cohesin mutant mcd1-1 showed considerable overlap, underlining the strong functional connection between sister chromatid cohesion and chromosome biorientation. Loss of some Ctf19 components, such as Iml3 or Chl4, impacted differentially on bir1-17 compared with mutations affecting other CPC components: despite the synthetic lethality shown by either iml3∆ or chl4∆ in combination with bir1-17, neither gene knockout showed any genetic interaction with either ipl1-321 or sli15-3. Our data therefore imply a specific functional connection between the Ctf19 complex and Bir1 that is not shared with Ipl1