3,867 research outputs found
Support Requirements and Effects of Supervision on Telephone Counsellors
The aim of this research was to examine the effects of the implementation of direct one-on-one supervision in a prominent telephone counselling organization and the support requirements of their telephone counsellors. Ninety-three telephone counsellors participated in this research. The results showed that more experienced telephone counsellors were more satisfied than less experienced telephone counsellors with the support offered by the organization. Furthermore, female telephone counsellors showed significantly more satisfaction with the support offered by the organisation than their male counterparts. Implications of these findings are discussed in relation to the organisation and other helping organisations within the wider community
Target product profiles for protecting against outdoor malaria transmission.
BACKGROUND\ud
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Long-lasting insecticidal nets (LLINs) and indoor residual sprays (IRS) have decimated malaria transmission by killing indoor-feeding mosquitoes. However, complete elimination of malaria transmission with these proven methods is confounded by vectors that evade pesticide contact by feeding outdoors.\ud
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METHODS\ud
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For any assumed level of indoor coverage and personal protective efficacy with insecticidal products, process-explicit malaria transmission models suggest that insecticides that repel mosquitoes will achieve less impact upon transmission than those that kill them outright. Here such models are extended to explore how outdoor use of products containing either contact toxins or spatial repellents might augment or attenuate impact of high indoor coverage of LLINs relying primarily upon contact toxicity.\ud
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RESULTS\ud
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LLIN impact could be dramatically enhanced by high coverage with spatial repellents conferring near-complete personal protection, but only if combined indoor use of both measures can be avoided where vectors persist that prefer feeding indoors upon humans. While very high levels of coverage and efficacy will be required for spatial repellents to substantially augment the impact of LLINs or IRS, these ambitious targets may well be at least as practically achievable as the lower requirements for equivalent impact using contact insecticides.\ud
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CONCLUSIONS\ud
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Vapour-phase repellents may be more acceptable, practical and effective than contact insecticides for preventing outdoor malaria transmission because they need not be applied to skin or clothing and may protect multiple occupants of spaces outside of treatable structures such as nets or houses
Tumorigenic 3T3 cells maintain an alkaline intracellular pH under physiological conditions.
CFS prediction of winter persistent inversions in the Intermountain Region
A recent study by Gillies and others of persistent inversion events in the Intermountain West of the United States found a substantive linkage between the intraseasonal oscillation (ISO) and the development of persistent inversion events. Given that NCEP’s Climate Forecast System (CFS) has demonstrated skill in the prediction of the ISO as far out as 1 month, it was decided to examine the CFS forecast’s capability in the prediction of such winter persistent inversions. After initial analysis, a simple regression scheme is proposed that is coupled to the CFS output of geopotential height as a way to predict the occurrence of persistent inversion events for Salt Lake City, Utah. Analysis of the CFS hindcasts through the period 1981–2008 indicates that the regression coupled with the CFS can predict persistent inversion events with lead times of up to 4 weeks. The adoption of this coupled regression–CFS prediction may improve the forecasting of persistent inversion events in the Intermountain West, which is currently restricted to the more limited time span (;10 days) of medium-range weather forecast models
Polyisobutylene-paclitaxel conjugates with pendant carboxylic acids and polystyrene chains: Towards multifunctional stent coatings with slow drug release
Drug-eluting stents are used in the treatment of atherosclerosis, where the incorporation of anti-proliferative or anti-inflammatory drugs decreases the rate of restenosis, the recurrence of artery narrowing. However, these stents can suffer from limitations such as drug depletion and delamination of the drug-eluting coating from the stent surface. Described here is an approach aimed at addressing these issues. Starting from a maleic anhydride adduct of polyisobutylene (PIB) prepared from butyl rubber, ring opening using paclitaxel (PTX) or a combination of PTX and polystyrene (PS) afforded covalent conjugates of PTX and PIB or PIB-PS graft copolymers bearing pendant carboxylic acids. When coated on stainless steel, the drug release was slower than that from a control coating that ressembles a clinical formulation comprising a physical mixture of a PS-PIB-PS triblock copolymer (SIBS) and PTX. The PTX conjugates also exhibited enhanced adhesion to stainless steel and increased tensile strength in comparison with the starting rubber. Cytotoxicity assays indicated that the materials did not leach toxic levels of PTX into cell culture media. Nevertheless, they were capable of inhibiting the adhesion and proliferation of C2C12 cells on their surfaces. These properties are advantageous for the potential application of the materials as stent coatings
Ph-sensitive chitosan nanoparticles for salivary protein delivery
Salivary proteins such as histatins (HTNs) have demonstrated critical biological functions directly related to tooth homeostasis and prevention of dental caries. However, HTNs are susceptible to the high proteolytic activities in the oral environment. Therefore, pH-sensitive chitosan nanoparti-cles (CNs) have been proposed as potential carriers to protect proteins from enzymatic degradation at physiological salivary pH. Four different types of chitosan polymers were investigated and the optimal formulation had good batch to batch reproducibility, with an average hydrodynamic diame-ter of 144 ± 6 nm, a polydispersity index of 0.15 ± 0.04, and a zeta potential of 18 ± 4 mV at a final pH of 6.3. HTN3 encapsulation and release profiles were characterized by cationic polyacrylamide gel electrophoresis. The CNs successfully encapsulated HTN3 and selectively swelled at acidic pH to facilitate HTN3 release. Protection of HTN3 against enzymatic degradation was investigated in diluted whole saliva. HTN3 encapsulated in the CNs had a prolonged survival time compared to the free HTN3. CNs with and without HTN3 also successfully reduced biofilm weight and bacterial viability. The results of this study have demonstrated the suitability of CNs as potential protein carriers for oral applications, especially for complications occurring at acidic conditions
Single particle multipole expansions from Micromagnetic Tomography
Micromagnetic tomography aims at reconstructing large numbers of individual
magnetizations of magnetic particles from combining high-resolution magnetic
scanning techniques with micro X-ray computed tomography (microCT). Previous
work demonstrated that dipole moments can be robustly inferred, and
mathematical analysis showed that the potential field of each particle is
uniquely determined. Here, we describe a mathematical procedure to recover
higher orders of the magnetic potential of the individual magnetic particles in
terms of their spherical harmonic expansions (SHE). We test this approach on
data from scanning superconducting quantum interference device microscopy and
microCT of a reference sample. For particles with high signal-to-noise ratio of
the magnetic scan we demonstrate that SHE up to order can be robustly
recovered. This additional level of detail restricts the possible internal
magnetization structures of the particles and provides valuable rock magnetic
information with respect to their stability and reliability as paleomagnetic
remanence carriers. Micromagnetic tomography therefore enables a new approach
for detailed rock magnetic studies on large ensembles of individual particles.Comment: 21 pages, 4 Figures, 3 Tables. For Supplemental Material see
"Ancillary files" in this arxiv websit
Standard and derived Planck quantities: selected analysis and derivations
We provide an overview of the fundamental units of physical quantities
determined naturally by the values of fundamental constants of nature. We
discuss a comparison between the 'Planck units', now widely used in theoretical
physics and the pre-quantum 'Stoney units' in which, instead of the Planck
constant, the charge of the electron is used with very similar quantitative
results. We discuss some of the physical motivation for these special units,
attributed much after they were introduced, and also put forth a summary of the
arguments supporting various cases for making specific physical interpretations
of the meanings of some of these units. The new aspects we discuss are a
possible physical basis for the Stoney units, their link to the Planck units,
and also the importance of Planck units for thermodynamical quantities in the
context of quantum gravity.Comment: 22 pages, 1 tabl
Structure and soft magnetic properties of sputter deposited MnZn-ferrite films
In this paper we report the soft magnetic properties of thin films of sputtered MnZn ferrite deposited on thermally oxidized Si substrates. A high deposition temperature, 600¿°C, together with the addition of water vapor to the sputtering gas was found to improve the initial ac permeability, µ. The highest value obtained was approximately 30. For MnZn-ferrite films with much larger grain sizes, as obtained by deposition on a polycrystalline Zn-ferrite substrate, a µ of 100 was obtained. The results are discussed in terms of the so-called nonmagnetic grain boundary model
A qualitative study of the views of patients with long-term conditions on family doctors in Hong Kong
<b>Background</b> Primary care based management of long-term conditions (LTCs) is high on the international healthcare agenda, including the Asia-Pacific region. Hong Kong has a 'mixed economy' healthcare system with both public and private sectors with a range of types of primary care doctors. Recent Hong Kong Government policy aims to enhance the management of LTCs in primary care possibly based on a 'family doctor' model. Patients' views on this are not well documented and the aim of the present study was to explore the views of patients with LTCs on family doctors in Hong Kong.<p></p>
<b>Methods</b> The views of patients (with a variety of LTCs) on family doctors in Hong Kong were explored. Two groups of participants were interviewed; a) those who considered themselves as having a family doctor, b) those who considered themselves as not having a family doctor (either with a regular primary care doctor but not a family doctor or with no regular primary care doctor). In-depth individual semi-structured interviews were carried out with 28 participants (10 with a family doctor, 10 with a regular doctor, and 8 with no regular doctor) and analysed using the constant comparative method.<p></p>
<b>Results</b> Participants who did not have a family doctor were familiar with the concept but regarded it as a 'luxury item' for the rich within the private healthcare system. Those with a regular family doctor (all private) regarded having one as important to their and their family's health. Participants in both groups felt that as well as the more usual family medicine specialist or general practitioner, traditional Chinese medicine practitioners also had the potential to be family doctors. However most participants attended the public healthcare system for management of their LTCs whether they had a family doctor or not. Cost, perceived need, quality, trust, and choice were all barriers to the use of family doctors for the management of their LTCs.<p></p>
<b>Conclusions</b> Important barriers to the adoption of a 'family doctor' model of management of LTCs exist in Hong Kong. Effective policy implementation seems unlikely unless these complex barriers are addressed
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