216 research outputs found

    The challenge of paediatric obesity: More rhetoric than action

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    A growing body of knowledge clearly shows a rapid increase in the prevalence of childhood obesity. But in spite of the many empirically-driven research projects and more laissez-faire initiatives intent on finding ways to ensure the healthy development of our young people, translating what we know into appropriate behaviour in the home, school, and community is more difficult than it sounds. It is, therefore, not surprising this concern is attracting the attention of politicians, health professionals, and educators. This article reflects on the paediatric obesity research and argues for a more coordinated effort in addressing what could (but need not) become a major public health issue

    Measured Effects Of Liquid Distribution On Compressor Performance During Wet Gas Ingestion

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    LectureUpstream production of natural gas is commonly a mixture of both liquid and gas hydrocarbons that is separated before boosting the gas or liquid flows to higher pressure for transport. The gas-liquid mixture is known to affect the compressor performance, but it is not known if the distribution of the liquid entering the compressor affects the maximum amount of liquid that the compressor can safely ingest. The work presented in this paper determines if liquid atomization affects the compressor operation or influences the amount of liquid that can be safely ingested by the compressor, compared to non-atomized liquid. To determine the effect of atomization on compressor performance, three injection methods are used to characterize the performance for atomized and non-atomized flow. Non-atomized flow is generated by injecting liquid far upstream of the compressor to allow a natural two-phase flow regime to develop before entering the compressor. Atomized flow is generated near the compressor suction flange using liquid pressure to generate large droplets on the order of 2,000 m and gas-assisted atomization to generate droplets at least an order of magnitude less than the large droplets (100 m). Results of the work are reported in this paper to include compressor performance measurements for two rotation speeds and a range of liquid and gas flow rates. In addition, the control of the compressor during wet gas ingestion is demonstrated through movement of the compressor on the flow map. Finally, high-speed flow images of the liquid entering the compressor are qualitatively shown to illustrate the difference in injection method

    Degradation and characterization of resorbable phosphate-based glass thin-film coatings applied by radio-frequency magnetron sputtering

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    Quinternary phosphate-based glasses of up to 2.67 μm, deposited by radio-frequency magnetron sputtering, were degraded in distilled water and phosphate-buffered saline (PBS) to investigate their degradation characteristics. Magnetron- sputtered coatings have been structurally compared to their compositionally equivalent melt-quenched bulk glass counterparts. The coatings were found to have structurally variable surfaces to melt-quenched glass such that the respective bridging oxygen to nonbridging oxygen bonds were 34.2% to 65.8% versus 20.5% to 79.5%, forming metaphosphate (PO3)−(Q2) versus less soluble (P2O7)4− (Q1) and (PO4)3− (Q0), respectively. This factor led to highly soluble coatings, exhibiting a t1/2 degradation dependence in the first 2 h in distilled water, followed by a more characteristic linear profile because the subsequent layers were less soluble. Degradation was observed to preferentially occur, forming voids characteristic of pitting corrosion, which was confirmed by the use of a focused ion beam. Coating degradation in PBS precipitated a (PO3)−metaphosphate, an X-ray amorphous layer, which remained adherent to the substrate and seemingly formed a protective diffusion barrier, which inhibited further coating degradation. The implications are that while compositionally similar, sputter-deposited coatings and melt-quenched glasses are structurally dissimilar, most notably, with regard to the surface layer. This factor has been attributed to surface etching of the as-deposited coating layer during deposition and variation in the thermal history between the processes of magnetron sputtering and melt quenching

    Halococcus salifodinae sp. nov., an Archaeal Isolate from an Austrian Salt Mine

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    A novel extremely halophilic archaeon (archaebacterium) was isolated from rock salt obtained from an Austrian salt mine. The deposition of the salt is thought to have occurred during the Permian period (225 x 106 to 280 x 10(exp 6) years ago). This organism grew over a pH range of 6.8 to 9.5. Electron microscopy revealed cocci in tetrads or larger clusters. The partial 16S rRNA sequences, polar lipid composition, and menaquinone content suggested that this organism was related to members of the genus Halococcus, while the whole-cell protein patterns, the presence of several unknown lipids, and the presence of pink pigmentation indicated that it was different from previously described coccoid halophiles. We propose that this isolate should be recognized as a new species and should be named Halococcus salifodinae. The type strain is Bl(sub p) (= ATCC 51437 = DSM 8989). A chemotaxonomically similar microorganism was isolated from a British salt mine

    Mechanical, structural and dissolution properties of heat treated thin-film phosphate based glasses

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    Here we show the deposition of 2.7 μm thick phosphate based glass films produced by magnetron sputtering, followed by post heat treatments at 500 °C. Variations in degradation properties pre and post heat treatment were attributed to the formation of Hematite crystals within a glass matrix, iron oxidation and the depletion of hydrophilic P-O-P bonds within the surface layer. As deposited and heat treated coatings showed interfacial tensile adhesion in excess of 73.6 MPa; which surpassed ISO and FDA requirements for HA coatings. Scratch testing of coatings on polished substrates revealed brittle failure mechanisms, amplified due to heat treatment and interfacial failure occurring from 2.3 to 5.0 N. Coatings that were deposited onto sandblasted substrates to mimic commercial implant surfaces, did not suffer from tensile cracking or trackside delamination showing substantial interfacial improvements to between 8.6 and 11.3 N. An exponential dissolution rate was observed from 0 to 2 h for as deposited coatings, which was eliminated via heat treatment. From 2 to 24 h ion release rates ordered P > Na > Mg > Ca > Fe whilst all coatings exhibited linear degradation rates, which reduced by factors of 2.4–3.0 following heat treatments

    Rural health systems in Oklahoma: What is a community health center

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    The Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311

    Independent and complementary bio-functional effects of CuO and Ga2O3 incorporated as therapeutic agents in silica- and phosphate-based bioactive glasses

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    The incorporation of therapeutic-capable ions into bioactive glasses (BGs), either based on silica (SBGs) or phosphate (PBGs), is currently envisaged as a proficient path for facilitating bone regeneration. In conjunction with this view, the single and complementary structural and bio-functional roles of CuO and Ga2O3 (in the 2–5 mol% range) were assessed, by deriving a series of SBG and PBG formulations starting from the parent glass systems, FastOs®BG – 38.5SiO2—36.1CaO—5.6P2O5—19.2MgO—0.6CaF2, and 50.0P2O5—35.0CaO—10.0Na2O—5.0 Fe2O3 (mol%), respectively, using the process of melt-quenching. The inter-linked physico-chemistry – biological response of BGs was assessed in search of bio-functional triggers. Further light was shed on the structural role – as network former or modifier – of Cu and Ga, immersed in SBG and PBG matrices. The preliminary biological performance was surveyed in vitro by quantification of Cu and Ga ion release under homeostatic conditions, cytocompatibility assays (in fibroblast cell cultures) and antibacterial tests (against Staphylococcus aureus). The similar (Cu) and dissimilar (Ga) structural roles in the SBG and PBG vitreous networks governed their release. Namely, Cu ions were leached in similar concentrations (ranging from 10–35 ppm and 50–110 ppm at BG doses of 5 and 50 mg/mL, respectively) for both type of BGs, while the release of Ga ions was 1–2 orders of magnitude lower in the case of SBGs (i.e., 0.2–6 ppm) compared to PBGs (i.e., 9–135 ppm). This was attributed to the network modifier role of Cu in both types of BGs, and conversely, to the network former (SBGs) and network modifier (PBGs) roles of Ga. All glasses were cytocompatible at a dose of 5 mg/mL, while at the same concentration the antimicrobial efficiency was found to be accentuated by the coupled release of Cu and Ga ions from SBG. By collective assessment, the most prominent candidate material for the further development of implant coatings and bone graft substitutes was delineated as the 38.5SiO2—34.1CaO—5.6P2O5—16.2MgO—0.6CaF2—2.0CuO—3.0Ga2O3 (mol%) SBG system, which yielded moderate Cu and Ga ion release, excellent cytocompatibility and marked antibacterial efficacy.publishe

    Northeastern united states species treated with copper-based preservatives: Durability in mississippi stake tests

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    This paper reports on the ground-contact durability of lesser-used wood species of the northeastern United States after treatment with copper-based preservatives. Stakes (19 by 19 by 457 mm) cut from balsam-fir (Abies balsamea), eastern hemlock (Tsuga canadensis), eastern spruce (mixture of Picea glauca, Picea mariana and Picea rubens), red maple (Acer rubrum) or eastern white pine (Pinus strobus) were treated with one of four concentrations of chromated copper arsenate type C (CCA-C), copper citrate (CC), alkaline copper quat type C (ACQ-C) or copper azole type A (CBA-A) and placed into the ground at a test site in southern Mississippi. Similarly treated southern pine (Pinus spp.) stakes were included for comparison. The stakes were rated for decay and termite attack after 1, 2, 3, 4, 5, 8, 10 and 12 years. Eastern white pine and incised eastern hemlock and balsam-fir had durability similar to southern pine when treated with CCA or the other copper-based preservatives. Eastern spruce was less durable than the other softwood species, apparently because of low preservative uptake. Red maple had the least durability at all retentions and for all preservatives. This study indicates that several northeastern softwoods can be adequately durable when pressure-treated with CCA-C or copper-based preservatives

    Student nurse selection and predictability of academic success : the Multiple Mini Interview project

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    BACKGROUND: With recent reports of public enquiries into failure to care, universities are under pressure to ensure that candidates selected for undergraduate nursing programmes demonstrate academic potential as well as characteristics and values such as compassion, empathy and integrity. The Multiple Mini Interview (MMI) was used in one university as a way of ensuring that candidates had the appropriate numeracy and literacy skills as well as a range of communication, empathy, decision-making and problem-solving skills as well as ethical insights and integrity, initiative and team-work. OBJECTIVES: To ascertain whether there is evidence of bias in MMIs (gender, age, nationality and location of secondary education) and to determine the extent to which the MMI is predictive of academic success in nursing. DESIGN: A longitudinal retrospective analysis of student demographics, MMI data and the assessment marks for years 1, 2 and 3. SETTINGS: One university in southwest London. PARTICIPANTS: One cohort of students who commenced their programme in September 2011, including students in all four fields of nursing (adult, child, mental health and learning disability). METHODS: Inferential statistics and a Bayesian Multilevel Model. RESULTS: MMI in conjunction with MMI numeracy test and MMI literacy test shows little or no bias in terms of ages, gender, nationality or location of secondary school education. Although MMI in conjunction with numeracy and literacy testing is predictive of academic success, it is only weakly predictive. CONCLUSIONS: The MMI used in conjunction with literacy and numeracy testing appears to be a successful technique for selecting candidates for nursing. However, other selection methods such as psychological profiling or testing of emotional intelligence may add to the extent to which selection methods are predictive of academic success on nursing

    Gallium incorporation into phosphate based glasses: bulk and thin film properties

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    The osteogenic ions Ca2+, P5+, Mg2+, and antimicrobial ion Ga3+ were homogenously dispersed into a 1.45 mum thick phosphate glass coating by plasma assisted sputtering onto CP grade titanium. The objective was to deliver therapeutic ions in orthopedic/dental implants such as hip prosthesis or dental screws. The hardness 4.7 GPa and elastic modulus 69.7 GPa, of the coating were comparable to plasma sprayed hydroxyapatite/dental enamel, whilst superseding femoral cortical bone. To investigate the manufacturing challenge of translation from a target to vapour condensed coating, structural/compositional properties of the target (P51MQ) were compared to the coating (P40PVD) and a melt-quenched equivalent (P40MQ). Following condensation from P51MQ to P40PVD, P2O5 content reduced from 48.9 to 40.5 mol%. This depolymerisation and reduction in the P-O-P bridging oxygen content as determined by 31P-NMR, FTIR and Raman spectroscopy techniques was attributed to a decrease in the P2O5 network former and increases in alkali/alkali-earth cations. P40PVD appeared denser (3.47 vs. 2.70 g cm-3) and more polymerised than it’s compositionally equivalent P40MQ, showing that structure/ mechanical properties were affected by manufacturing route
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