Elastic turbulence in two-dimensional Taylor-Couette flows

We report the onset of elastic turbulence in a two-dimensional Taylor-Couette geometry using numerical solutions of the Oldroyd-B model, also performed at high Weissenberg numbers with the program OpenFOAM. Beyond a critical Weissenberg number, an elastic instability causes a supercritical transition from the laminar Taylor-Couette to a turbulent flow. The order parameter, the time average of secondary-flow strength, follows the scaling law $\Phi \propto (\mathrm{Wi} -\mathrm{Wi}_c)^{\gamma}$ with $\mathrm{Wi}_c=10$ and $\gamma = 0.45$. The power spectrum of the velocity fluctuations shows a power-law decay with a characteristic exponent, which strongly depends on the radial position. It is greater than two, which we relate to the dimension of the geometry

Treatment outcomes for children with multidrug-resistant tuberculosis: a systematic review and meta-analysis

BACKGROUND: Paediatric multidrug-resistant (MDR) tuberculosis is a public health challenge of growing concern, accounting for an estimated 15% of all global cases of MDR tuberculosis. Clinical management is especially challenging, and recommendations are based on restricted evidence. We aimed to assess existing evidence for the treatment of MDR tuberculosis in children. METHODS: We did a systematic review and meta-analysis of published and unpublished studies reporting treatment outcomes for children with MDR tuberculosis. We searched PubMed, Ovid, Embase, Cochrane Library, PsychINFO, and BioMedCentral databases up to Oct 31, 2011. Eligible studies included five or more children (aged ≤16 years) with MDR tuberculosis within a defined treatment cohort. The primary outcome was treatment success, defined as a composite of cure and treatment completion. RESULTS: We identified eight studies, which reported treatment outcomes for a total of 315 patients. We recorded much variation in the characteristics of patients and programmes. Time to appropriate treatment varied from 2 days to 46 months. Average duration of treatment ranged from 6 months to 34 months, and duration of follow-up ranged from 12 months to 37 months. The pooled estimate for treatment success was 81·67% (95% CI 72·54-90·80). Across all studies, 5·9% (95% CI 1·3-10·5) died, 6·2% (2·3-10·2) defaulted, and 39·1% (28·7-49·4) had an adverse event. The most common drug-related adverse events were nausea and vomiting. Other serious adverse events were hearing loss, psychiatric effects, and hypothyroidism. INTERPRETATION: The treatment of paediatric MDR tuberculosis has been neglected, but when children are treated outcomes can be achieved that are at least as good as those reported for adults. Programmes should be encouraged to report outcomes in children to improve the knowledge base for care, especially as new drugs become available. FUNDING: None

Thomas-Fermi Calculations of Atoms and Matter in Magnetic Neutron Stars II: Finite Temperature Effects

We present numerical calculations of the equation of state for dense matter in high magnetic fields, using a temperature dependent Thomas-Fermi theory with a magnetic field that takes all Landau levels into account. Free energies for atoms and matter are also calculated as well as profiles of the electron density as a function of distance from the atomic nucleus for representative values of the magnetic field strength, total matter density, and temperature. The Landau shell structure, which is so prominent in cold dense matter in high magnetic fields, is still clearly present at finite temperature as long as it is less than approximately one tenth of the cyclotron energy. This structure is reflected in an oscillatory behaviour of the equation of state and other thermodynamic properties of dense matter and hence also in profiles of the density and pressure as functions of depth in the surface layers of magnetic neutron stars. These oscillations are completely smoothed out by thermal effects at temperatures of the order of the cyclotron energy or higher.Comment: 37 pages, 17 figures included, submitted to Ap

Cavitation of the Ghon focus in an HIV-infected infant who acquired tuberculosis after the initiation of HAART

Tuberculosis immune reconstitution inflammatory syndrome (IRIS) may present as new or worsening cavitation. We present an HIV-infected infant in whom TB infection and subsequent cavitation of the Ghon focus appeared to coincide with immune reconstitution due to highly active antiretroviral therapy (HAART). TB-IRIS in response to infection that occurs after starting HAART has not previously been described

Development and Evaluation of an Adaptive Digital Module on Enzyme Kinetics

An adaptive module on basic enzyme kinetics was developed for first- and second-year university students. The module offers more assignments to students who have less knowledge of the theory than to more advanced students. The aim of the research was to investigate what influence students’ backgrounds have on their use and appreciation of this module. Both freshmen and second-year students showed a large variation in the number of assignments they needed to perform in order to finish the module, indicating that the module’s adaptive feature was exploited by all the students. Findings indicated that the prior knowledge was of influence of students’ motivation and perception of difficulty of the modul

Astrophysical Supercomputing with GPUs: Critical Decisions for Early Adopters

General purpose computing on graphics processing units (GPGPU) is dramatically changing the landscape of high performance computing in astronomy. In this paper, we identify and investigate several key decision areas, with a goal of simplyfing the early adoption of GPGPU in astronomy. We consider the merits of OpenCL as an open standard in order to reduce risks associated with coding in a native, vendor-specific programming environment, and present a GPU programming philosophy based on using brute force solutions. We assert that effective use of new GPU-based supercomputing facilities will require a change in approach from astronomers. This will likely include improved programming training, an increased need for software development best-practice through the use of profiling and related optimisation tools, and a greater reliance on third-party code libraries. As with any new technology, those willing to take the risks, and make the investment of time and effort to become early adopters of GPGPU in astronomy, stand to reap great benefits.Comment: 13 pages, 5 figures, accepted for publication in PAS

\u3ci\u3eDalea villosa\u3c/i\u3e ‘Sandhills Satin

Daleas (prairie-clovers) are annual or perennial, warm season legumes found from southern Canada to South America (Barneby, 1977). They are an important group of legumes in native grasslands of the Great Plains. The genus name Dalea L. is in honor of Samuel Dale, an English botanist (1659–1739). Until recently, these plants were classified in the genus Petalostemon Michx. (Weber, 1990). The prairie-clovers have potential as attractive garden ornamental plants in addition to their importance as constituents of prairies and pastures. They have uses, along with other native species, for beautification of roadsides, rest areas, parks, and recreation areas, and for soil stabilization (Salac et al., 1978). Daleas are common in the Nebraska Sandhills, an area in central Nebraska extending into South Dakota, consisting of almost 50,000 Km2. It is one of the largest grass-stabilized sand dune regions in the world. The Sandhills area has many unique or special plants, such as Penstemon haydenii S. Wats. and Lithospermum caroliniense (Walter) MacMill (Bleed and Flowerday, 1989). Dalea villosa (Nuttall) Sprengel, commonly known as silky prairie-clover, typically grows in moderately moist to dry sandy soils in disturbed sites, along right-of-ways, and in margins of sandy, wind-eroded blowouts (Farrar, 1990; Great Plains Flora Association, 1986). It has numerous, often horizontal to drooping flowering heads with pinkish-rose colored flowers. Flower spikes are solitary at ends of short branches near the top of the plant (Stubbendieck et al., 1989). Flowers are minute with five protruding yellow stamens encircling a spike up to 10 cm long (Farrar, 1990). Flowers mature acropetally and the fruit is a pod 2.5 to 3 mm long (Barneby, 1977). Plants flower from July to August, depending on location. It has one to several erect, branching stems and a reddish-orange taproot. A compact arching growth habit and an abundance of attractive, silvery, compound leaves give an appearance quite different from other species of the genus (Farrar, 1990). It has numerous alternate, odd-pinnately compound leaves, up to 2 to 4 cm long, with 11 to 25 leaflets, narrowly elliptic and 5 to 11 mm long (Great Plains Flora Association, 1986). Stems and leaves are silvery-green with short, white hairs (Farrar, 1990). Leaves are dotted with glands on the lower surface. The species is found from Manitoba to central Texas and from western Wisconsin to eastern Colorado (Barneby, 1977)

\u3ci\u3eDalea villosa\u3c/i\u3e ‘Sandhills Satin

Daleas (prairie-clovers) are annual or perennial, warm season legumes found from southern Canada to South America (Barneby, 1977). They are an important group of legumes in native grasslands of the Great Plains. The genus name Dalea L. is in honor of Samuel Dale, an English botanist (1659–1739). Until recently, these plants were classified in the genus Petalostemon Michx. (Weber, 1990). The prairie-clovers have potential as attractive garden ornamental plants in addition to their importance as constituents of prairies and pastures. They have uses, along with other native species, for beautification of roadsides, rest areas, parks, and recreation areas, and for soil stabilization (Salac et al., 1978). Daleas are common in the Nebraska Sandhills, an area in central Nebraska extending into South Dakota, consisting of almost 50,000 Km2. It is one of the largest grass-stabilized sand dune regions in the world. The Sandhills area has many unique or special plants, such as Penstemon haydenii S. Wats. and Lithospermum caroliniense (Walter) MacMill (Bleed and Flowerday, 1989). Dalea villosa (Nuttall) Sprengel, commonly known as silky prairie-clover, typically grows in moderately moist to dry sandy soils in disturbed sites, along right-of-ways, and in margins of sandy, wind-eroded blowouts (Farrar, 1990; Great Plains Flora Association, 1986). It has numerous, often horizontal to drooping flowering heads with pinkish-rose colored flowers. Flower spikes are solitary at ends of short branches near the top of the plant (Stubbendieck et al., 1989). Flowers are minute with five protruding yellow stamens encircling a spike up to 10 cm long (Farrar, 1990). Flowers mature acropetally and the fruit is a pod 2.5 to 3 mm long (Barneby, 1977). Plants flower from July to August, depending on location. It has one to several erect, branching stems and a reddish-orange taproot. A compact arching growth habit and an abundance of attractive, silvery, compound leaves give an appearance quite different from other species of the genus (Farrar, 1990). It has numerous alternate, odd-pinnately compound leaves, up to 2 to 4 cm long, with 11 to 25 leaflets, narrowly elliptic and 5 to 11 mm long (Great Plains Flora Association, 1986). Stems and leaves are silvery-green with short, white hairs (Farrar, 1990). Leaves are dotted with glands on the lower surface. The species is found from Manitoba to central Texas and from western Wisconsin to eastern Colorado (Barneby, 1977)

Retooling existing tuberculosis drugs for children.

Please help populate SUNScholar with the full text of SU research output. Also - should you need this item urgently, please send us the details and we will try to get hold of the full text as quick possible. E-mail to [email protected]. Thank you.Journal Articles (subsidised)Geneeskunde en GesondheidswetenskappePediatrie En Kindergesondhei