On acceleration of Krylov-subspace-based Newton and Arnoldi iterations for incompressible CFD: replacing time steppers and generation of initial guess

We propose two techniques aimed at improving the convergence rate of steady state and eigenvalue solvers preconditioned by the inverse Stokes operator and realized via time-stepping. First, we suggest a generalization of the Stokes operator so that the resulting preconditioner operator depends on several parameters and whose action preserves zero divergence and boundary conditions. The parameters can be tuned for each problem to speed up the convergence of a Krylov-subspace-based linear algebra solver. This operator can be inverted by the Uzawa-like algorithm, and does not need a time-stepping. Second, we propose to generate an initial guess of steady flow, leading eigenvalue and eigenvector using orthogonal projection on a divergence-free basis satisfying all boundary conditions. The approach, including the two proposed techniques, is illustrated on the solution of the linear stability problem for laterally heated square and cubic cavities

Community knowledge, perceptions and practices on malaria in Mpwapwa District, central Tanzania

A study on community knowledge, attitudes and perception on malaria and its management was conducted in Mpwapwa district of central Tanzania in January-February 2001. Six villages, three with health facilities (Kibakwe, Makose and Mwanawota) and three without health facilities (Chogola, Kidenge and Wangi) lying between 975 and 1859 m above sea level were selected for the study. According to most respondents, the general health problems for adults in the district included malaria, diarrhoea, typhoid fever and pneumonia. Malaria, pneumonia and diarrhoea were the major health problems among children. Among pregnant women, malaria, abortions and diarrhoea were identified as the major public health problems in the district. In the view of most of villagers, malaria was the cause of most fevers and convulsions at low and intermediate altitudes. Cold weather was considered as the main predisposing factor to most of the fevers experienced in the highland villages. The common antimalarial drugs used in Mpwapwa district were chloroquine and quinine. The cost of antimalarial drugs ranged between TShs. 10/- and 20/- for one tablet of chloroquine, 600/- for chloroquine syrup, and 320/- for a single dose of chloroquine injection. However, shortage of drugs was frequently encountered in most of the health facilities. Traditional medicine practitioners were most frequently consulted for cases of convulsions in the district. Our findings showed that only 2.1% of the children in the district were sleeping under mosquito nets. The use of mosquito net was common among individuals living in the villages with health facilities than in those without health facilities. Generally, most respondents considered long distances to health facilities and inability to pay for health services as the main constraints in obtaining proper health care. Tanzania Health Research Bulletin Vol.6(2) 2004: 37-4

The relationship between malaria parasitaemia and availability of healthcare facility in Mpwapwa District, central Tanzania

A study was carried out in six villages located at different altitudes in Mpwapwa district of central Tanzania to determine malaria parasitaemia and transmission levels in villages with or without health care facilities. A total of 1119 schoolchildren (age= 5.9-12.3 years) were examined for malaria parasitaemia. Plasmodium falciparum was the predominant malaria species accounting for 92.8% of all species. The average malaria prevalence rate among schoolchildren was 25.8% (range 1.5-53.8%). The geometric mean parasite densities for P. falciparum was 361 (N= 286). Higher malaria prevalence was observed in villages at lower (1500m) altitudes. Schoolchildren in areas with health care facilities were less at risk of acquiring malaria by 33.4% as compared with those living in areas without health facilities. Mean packed cell volume in schoolchildren was 38.5% (range= 35.2-41.0%). Splenomegaly was observed in 18.1% (0-40.2%) of the schoolchildren examined and it was higher among those in villages without health care facilities. Anopheles gambiae sensu lato was the only malaria vector found in the district and was found in all villages and at all altitudes. Sporozoite rate in An. gambiae s.l. ranged from 0-10.5%, with the lowland villages recording the highest rates. This study indicates that altitude and geographical accessibility to healthcare service are important determinants of malaria infection among rural communities in Tanzania. Keywords: malaria, schoolchildren, altitudes, health care facility, Tanzania Tanzania Health Research Bulletin Vol. 8(1) 2006: 22-2

Efficacy of electronic apex locators in comparison with intraoral radiographs in working length determination- a systematic review and meta-analysis.

BACKGROUND: Successful endodontic treatment needs accurate determination of working length (WL). Electronic apex locators (EALs) were presented as an alternative to radiographic methods; and since then, they have evolved and gained popularity in the determination of WL. However, there is insufficient evidence on the post-operative pain, adequacy, and accuracy of EALs in determining WL. OBJECTIVE: The systematic review and meta-analysis aims to gather evidence regarding the effectiveness of EALs for WL determination when compared to different imaging techniques along with postoperative pain associated with WL determination, the number of radiographs taken during the procedure, the time taken, and the adverse effects. METHODS: For the review, clinical studies with cross-over and parallel-arm randomized controlled trials (RCTs) were searched in seven electronic databases, followed by cross-referencing of the selected studies and related research synthesis. Risk of bias (RoB) assessment was carried out with Cochrane's RoB tool and a random-effects model was used. The meta-analysis was performed with the RevMan software 5.4.1. RESULTS: Eleven eligible RCTs were incorporated into the review and eight RCTs into the meta-analysis, of which five had high RoB and the remaining six had unclear RoB. Following meta-analysis, no significant difference in postoperative pain was found among the EAL and radiograph groups (SMD 0.00, CI .29 to .28, 354 participants; P value = 0.98). Radiograph group showed better WL accuracy (SMD 0.55, CI .11 to .99, 254 participants; P value = 0.02), while the EAL group had 10% better WL adequacy (RR 1.10, CI 1.03-1.18, 573 participants; P value = 0.006). CONCLUSION: We found very low-certainty evidence to support the efficacy of different types of EAL compared to radiography for the outcomes tested. We were unable to reach any conclusions about the superiority of any type of EAL. Well-planned RCTs need to be conducted by standardizing the outcomes and outcome measurement methods

Phenotypic biomonitoring using multivariate £ow cytometric analysis of multi-stained microorganisms

Abstract A new method for monitoring phenotypic profiles of pure cultures and complex microbial communities was evaluated. The approach was to stain microorganisms with a battery of fluorescent dyes prior to flow cytometry analysis (FCM) and to analyse the data using multivariate methods, including principal component analysis and partial least squares. The FCM method was quantitatively evaluated using different mixtures of pure cultures as well as microbial communities. The results showed that the method could quantitatively and reproducibly resolve both populations and communities of microorganisms with 5% abundance in a diverse microbial background. The feasibility of monitoring complex microbial communities over time during the biodegradation of naphthalene using the FCM method was demonstrated. The biodegradation of naphthalene occurred to differing extents in microcosms representing three different types of aromatic-contaminated groundwater and a sample of bio-basin water. The FCM method distinguished each of these four microbial communities. The phenotypic profiles were compared with genotypic profiles generated by random-amplified polymorphic DNA analysis. The genotypic profiles of the microbial communities described only the microbial composition, and not their functional change, whereas the phenotypic profiles seemed to contain information on both the composition and the functional change of the microorganisms. Furthermore, event analysis of the FCM data showed that microbial communities with initially differing compositions could converge towards a similar composition if they had a capacity for high levels of degradation, whereas microbial communities with similar initial compositions could diverge if they differed in biodegrading ability.

Monitoring iron chelation effect in hearts of thalassaemia patients with improved sensitivity using reduced transverse relaxation rate (RR2)

Posters - Myocardial Viability: Human Models: No. 3660Accurate MRI characterization of myocardial iron is needed to improve the diagnosis and management of thalassaemia patients with transfusional iron overload. This study aimed to demonstrate that a new transverse relaxation index, the reduced R2 (RR2) that is estimated from non-monoexponential multi-echo CPMG signal decay and sensitive to ferritin iron, could detect the myocardial iron changes immediately following 1-week iron chelation suspension in thalassaemia patients at 3T.postprin

On the interplay between Babai and Černý’s conjectures

Motivated by the Babai conjecture and the Černý conjecture, we study the reset thresholds of automata with the transition monoid equal to the full monoid of transformations of the state set. For automata with n states in this class, we prove that the reset thresholds are upperbounded by 2n2 -6n + 5 and can attain the value (Formula presented). In addition, we study diameters of the pair digraphs of permutation automata and construct n-state permutation automata with diameter (formula presented). © Springer International Publishing AG 2017

Inner-sphere oxidation of ternary iminodiacetatochromium(III) complexes involving DL-valine and L-arginine as secondary ligands. Isokinetic relationship for the oxidation of ternary iminodiacetato-chromium(III) complexes by periodate

<p>Abstract</p> <p>Background</p> <p>In this paper, the kinetics of oxidation of [Cr^III(HIDA)(Val)(H₂O)₂]⁺and [Cr^III(HIDA)(Arg)(H₂O)₂]⁺(HIDA = iminodiacetic acid, Val = DL-valine and Arg = L-arginine) were studied. The choice of ternary complexes was attributed to two considerations. Firstly, in order to study the effect of the secondary ligands DL-valine and L-arginine on the stability of binary complex [Cr^III(HIDA)(IDA)(H₂O)] towards oxidation. Secondly, transition metal ternary complexes have received particular focus and have been employed in mapping protein surfaces as probes for biological redox centers and in protein capture for both purification and study.</p> <p>Results</p> <p>The results have shown that the reaction is first order with respect to both [IO₄^-] and the complex concentration, and the rate increases over the pH range 2.62 – 3.68 in both cases. The experimental rate law is consistent with a mechanism in which both the deprotonated forms of the complexes [Cr^III(IDA)(Val)(H₂O)₂] and [Cr^III(IDA)(Arg)(H₂O)₂] are significantly more reactive than the conjugate acids. The value of the intramolecular electron transfer rate constant for the oxidation of [Cr^III(HIDA)(Arg)(H₂O)₂]⁺, <it>k</it>₃(1.82 × 10^-3s^-1), is greater than the value of <it>k</it>₁(1.22 × 10^-3s^-1) for the oxidation of [Cr^III(HIDA)(Val)(H₂O)₂]⁺at 45.0°C and <it>I </it>= 0.20 mol dm^-3. It is proposed that electron transfer proceeds through an inner-sphere mechanism <it>via </it>coordination of IO₄^-to chromium(III).</p> <p>Conclusion</p> <p>The oxidation of [Cr^III(HIDA)(Val)(H₂O)₂]⁺and [Cr^III(HIDA)(Arg)(H₂O)₂]⁺by periodate may proceed through an inner-sphere mechanism via two electron transfer giving chromium(VI). The value of the intramolecular electron transfer rate constant for the oxidation of [Cr^III(HIDA)(Arg)(H₂O)₂]⁺, <it>k</it>₃, is greater than the value of <it>k</it>₁for the oxidation of [Cr^III(HIDA)(Val)(H₂O)₂]⁺. A common mechanism for the oxidation of ternary iminodiacetatochromium(III) complexes by periodate is proposed, and this is supported by an excellent isokinetic relationship between ΔH* and ΔS* values for these reactions.</p

Set optimization - a rather short introduction

Recent developments in set optimization are surveyed and extended including various set relations as well as fundamental constructions of a convex analysis for set- and vector-valued functions, and duality for set optimization problems. Extensive sections with bibliographical comments summarize the state of the art. Applications to vector optimization and financial risk measures are discussed along with algorithmic approaches to set optimization problems