13,453 research outputs found
The development of an unconventional food regeneration process: Quantifying the nutritional components of a model methylotrophic yeast
A hybrid chemical/biological approach to unconventional food regeneration is discussed. Carbon dioxide and water, the major wastes of human metabolism would be converted to methanol by one of several physiochemical processes available (thermal, photocatalytic, etc.). Methanol is then used to supply carbon and energy for the culture of microorganisms which in turn produce biological useful basic food stuffs for human nutrition. Our work has focused on increasing the carbohydrate levels of a candidate methylotrophic yeast to more nearly coincide with human nutritional requirements. Yeasts were chosen due to their high carbohydrate levels compared to bacteria and their present familiarity in the human diet. The initial candidate yeast studied was a thermotolerant strain of Hansenula polymor pha, DL-1. The quantitative results that permit an evaluation of the overall efficiency in hybrid chemical/biological food production schemes are discussed. A preliminary evaluation of the overall efficiency of such schemes is also discussed
An Online Educational Program Improves Pediatric Oncology Nursesâ Knowledge, Attitudes, and Spiritual Care Competence
This study evaluated the potential impact of an online spiritual care educational program on pediatric nursesâ attitudes toward and knowledge of spiritual care and their competence to provide spiritual care to children with cancer at the end of life. It was hypothesized that the intervention would increase nursesâ positive attitudes toward and knowledge of spiritual care and increase nursesâ level of perceived spiritual care competence. A positive correlation was expected between change in nursesâ perceived attitudes toward and knowledge of spiritual care and change in nursesâ perceived spiritual care competence. A prospective, longitudinal design was employed, and analyses included one-way repeated-measures analysis of variance, linear regression, and partial correlation. Statistically significant differences were found in nursesâ attitudes toward and knowledge of spiritual care and nursesâ perceived spiritual care competence. There was a positive relationship between change scores in nursesâ attitudes toward and knowledge of spiritual care and nursesâ spiritual care competence. Online spiritual care educational programs may exert a lasting impact on nursesâ attitudes toward and knowledge of spiritual care and their competence to provide spiritual care to children with cancer at the end of life. Additional studies are required to evaluate the direct effects of educational interventions patient outcomes
Continuous collection of volatiles produced by <i>Streptomyces</i> grown on oatmeal agar by headspace extraction and GC-MS
Psychosocial and behavioural correlates of attitudes towards antiretroviral therapy (ART) in a sample of South African mineworkers
Despite being one of the worst affected sectors in South Africa, the mining sector has proven to be one of the most active in intervention efforts in the fight against HIV and AIDS (Ellis, 2007). Owing to low uptake rates of antiretroviral therapy (ART) in mining companies in recent years (Connelly & Rosen, 2006) and the positive relationship between attitudes towards ART and ART uptake (Cooper et al., 2002; Horne, Cooper, Gellaitry, Leake, & Fisher, 2007), this study sought to describe and investigate the psychosocial and behavioural correlates of attitudes towards ART in a sample of South African mineworkers. A total of 806 mineworkers from a large South African mine participated in this quantitative study. Despite a high rate of HIV testing behaviour (83.0%) as well as favourable attitudes towards ART, analysis indicated that temporary employees and contractors were more vulnerable in terms of HIV risk, HIV testing behaviours and ART knowledge and attitudes. Employees who had more positive attitudes towards ART were more knowledgeable of ART and, importantly, had a more favourable attitude towards the mineâs HIV/AIDS treatment programme. These findings are discussed in relation to the low ART uptake rates in this context and recommendations for the improvement of ART uptake amongst employees at this mining site.Keywords: mining sector, workplace, ART uptake, attitudes.Le secteur minier reste lâun des secteurs les plus affectĂ©s par le VIH et SIDA en Afrique du Sud et aussi lâun des plus actifs dans la lutte contre la maladie (Ellis, 2007). En raison du faible taux dâutilisation de la thĂ©rapie antirĂ©trovirale (ART) dans les annĂ©es rĂ©centes par des compagnies miniĂšres (Connelly & Rosen, 2006) et les attitudes positives envers ART et ART absorption (Cooper et al., 2002; Horne, Cooper, Gellaitry, Leake, & Fisher, 2007) pour trouver des solutions pour les malades du VIH/SIDA, cette Ă©tude ĂĄ pour objectif dâexaminer les comportements psychosociaux et le traitement de la thĂ©rapie antirĂ©trovirale dâun groupe de mineurs Sud-Africains. Huit cent six mineurs Sud-Africains ont participĂ© Ă cette Ă©tude quantitative. Soit un taux de dĂ©pistage VIH Ă©levĂ© (83.0%) et des attitudes trĂšs favorables envers ART, les analyses indiquent quâen termes de risque du VIH les employĂ©s temporaires et les entrepreneurs sont plus exposĂ©s ĂĄ la maladie. Mais cependant, les employĂ©s qui sont bien informĂ©s de la mĂ©thode ART grĂące Ă la connaissance et Ă lâinformation bĂ©nĂ©ficient dâun programme de traitement contre le VIH/SIDA. Ces rĂ©sultats font lâobjet de discussion sur le faible taux dâART dans ce contexte et quelques recommandations et amĂ©liorations de lâabsorption de lâART pour les employĂ©s de ce site minier
Verification of State/Event Systems by Quotienting
A rather new approach towards compositional verification of concurrent systems is the quotient technique, where components are gradually removed from the concurrent system while transforming the specification accordingly. When the intermediate specifications can be kept small using heuristics for minimization, the state explosion problemis avoided and there are already promising experimental results for systems with an interleaving semantics, including real-time systems. This paper extends the quotienting approach to deal with a synchronous framework in the shape of state/event systems. A state/event system is a concurrent system with a set of interdependent components operating synchronously according to stimuli (input events) provided by an environment while producing output events in return for the environment. A compositional modal logic M suitable for expressing general safety and liveness properties subsystems is introduced. A quotient construction for building components from a state/event system into the specification is presented and heuristics for minimizing formulae are proposed. The techniques are demonstrated on an example. The correctness of the techniques are justified by proofs in an appendix
Second Overtone Pulsators Among Delta Scuti Stars
We investigate the modal stability of stellar models at masses and luminosity
levels corresponding to post main sequence luminous delta scuti pulsators. The
envelope models have been computed at fixed mass value, luminosity level and
chemical composition (Y=0.28, Z=0.02). According to a nonlinear approach to
radial oscillations the present investigation predicts the occurrence of stable
second overtone pulsators for the first time. The shape of both light and
velocity curves are presented and discussed, providing a useful tool for the
identification of second overtone pulsators among the known groups of radially
pulsating stars. The period ratios of mixed mode pulsators obtained by
perturbing the first and the second overtone radial eigenfunctions are in
agreement with observative values. Finally, the physical structure and the
dynamical properties of second overtone pulsators are discussed in detail. The
role played by the nodal lines in the destabilization of second overtone
pulsators is also pointed out.Comment: 20 pages, 11 Postscript figures, uses aaspp4.sty and tighten.st
Metallicities for Double Mode RR Lyrae in the Large Magellanic Cloud
Metallicities for six double mode RR Lyrae's (RRd's) in the Large Magellanic
Cloud have been estimated using the DeltaS method. The derived [Fe/H] values
are in the range [Fe/H] = -1.09 to -1.78 (or -0.95 to -1.58, adopting a
different calibration of [Fe/H] vs DeltaS). Two stars in our sample are at the
very metal rich limit of all RRd's for which metal abundance has been
estimated, either by direct measure (for field objects) or on the basis of the
hosting system (for objects in globular clusters or external galaxies). These
metal abundances, coupled with mass determinations from pulsational models and
the Petersen diagram, are used to compare the mass-metallicity distribution of
field and cluster RR Lyrae variables. We find that field and cluster RRd's seem
to follow the same mass-metallicity distribution, within the observational
errors, strengthening the case for uniformity of properties between field and
cluster variables At odds to what is usually assumed, we find no significative
difference in mass for RR Lyrae's in globular clusters of different metallicity
and Oosterhoff types, or there may even be a difference contrary to the
commonly accepted one, depending on the metallicity scale adopted to derive
masses. This ``unusual'' result for the mass-metallicity relation is probably
due, at least in part, to the inclusion of updated opacity tables in the
computation of metal-dependent pulsation models.Comment: 33 pages, 7 figures, uses aastex, accepted for publication in A
2015 Update on Acute Adverse Reactions to Gadolinium based Contrast Agents in Cardiovascular MR. Large Multi-National and Multi-Ethnical Population Experience With 37788 Patients From the EuroCMR Registry
Objectives: Specifically we aim to demonstrate that the results of our earlier safety data hold true in this much larger multi-national and multi-ethnical population. Background: We sought to re-evaluate the frequency, manifestations, and severity of acute adverse reactions associated with administration of several gadolinium- based contrast agents during routine CMR on a European level. Methods: Multi-centre, multi-national, and multi-ethnical registry with consecutive enrolment of patients in 57 European centres. Results: During the current observation 37788 doses of Gadolinium based contrast agent were administered to 37788 patients. The mean dose was 24.7Â ml (range 5â80Â ml), which is equivalent to 0.123Â mmol/kg (range 0.01 - 0.3Â mmol/kg). Forty-five acute adverse reactions due to contrast administration occurred (0.12Â %). Most reactions were classified as mild (43 of 45) according to the American College of Radiology definition. The most frequent complaints following contrast administration were rashes and hives (15 of 45), followed by nausea (10 of 45) and flushes (10 of 45). The event rate ranged from 0.05Â % (linear non-ionic agent gadodiamide) to 0.42Â % (linear ionic agent gadobenate dimeglumine). Interestingly, we also found different event rates between the three main indications for CMR ranging from 0.05Â % (risk stratification in suspected CAD) to 0.22Â % (viability in known CAD). Conclusions: The current data indicate that the results of the earlier safety data hold true in this much larger multi-national and multi-ethnical population. Thus, the âoff-labelâ use of Gadolinium based contrast in cardiovascular MR should be regarded as safe concerning the frequency, manifestation and severity of acute events
Beat Cepheids as Probes of Stellar and Galactic Metallicity
The mere location of a Beat Cepheid model in a Period Ratio vs. Period
diagram (Petersen diagram) puts very tight constraints on its metallicity Z.
The Beat Cepheid Peterson diagrams are revisited with linear nonadiabatic
turbulent convective models, and their accuracy as a probe for stellar
metallicity is evaluated. They are shown to be largely independent of the
helium content Y, and they are also only weakly dependent on the
mass-luminosity relation that is used in their construction. However, they are
found to show sensitivity to the relative abundances of the elements that are
lumped into the metallicity parameter Z. Rotation is estimated to have but a
small effect on the 'pulsation metallicities'. A composite Petersen diagram is
presented that allows one to read off upper and lower limits on the metallicity
Z from the measured period P0 and period ratio P1/P0.Comment: 9 pages, 12 color figures (black and white version available from 1st
author's website). With minor revisions. to appear in Ap
- âŠ