1,271 research outputs found
Specialisation in physiotherapy: A mark of maturity
Have you gained postgraduate qualifications or been invited to lecture to other physiotherapists regarding your area of practice? Do your clients present for treatment of a particular condition or area of the body? Should you be able to claim that you specialise in that particular condition or region of the body (e.g. shoulder injuries or headaches)? What defines specialisation within physiotherapy? What is a Specialist Physiotherapist
The first magnetic maps of a pre-main sequence binary star system - HD 155555
We present the first maps of the surface magnetic fields of a pre-main
sequence binary system. Spectropolarimetric observations of the young, 18 Myr,
HD 155555 (V824 Ara, G5IV + K0IV) system were obtained at the Anglo-Australian
Telescope in 2004 and 2007. Both datasets are analysed using a new binary
Zeeman Doppler imaging (ZDI) code. This allows us to simultaneously model the
contribution of each component to the observed circularly polarised spectra.
Stellar brightness maps are also produced for HD 155555 and compared to
previous Doppler images. Our radial magnetic maps reveal a complex surface
magnetic topology with mixed polarities at all latitudes. We find rings of
azimuthal field on both stars, most of which are found to be non-axisymmetric
with the stellar rotational axis. We also examine the field strength and the
relative fraction of magnetic energy stored in the radial and azimuthal field
components at both epochs. A marked weakening of the field strength of the
secondary star is observed between the 2004 and 2007 epochs. This is
accompanied by an apparent shift in the location of magnetic energy from the
azimuthal to radial field. We suggest that this could be indicative of a
magnetic activity cycle. We use the radial magnetic maps to extrapolate the
coronal field (by assuming a potential field) for each star individually - at
present ignoring any possible interaction. The secondary star is found to
exhibit an extreme tilt (~75 deg) of its large scale magnetic field to that of
its rotation axis for both epochs. The field complexity that is apparent in the
surface maps persists out to a significant fraction of the binary separation.
Any interaction between the fields of the two stars is therefore likely to be
complex also. Modelling this would require a full binary field extrapolation.Comment: 17 pages, 12 figures, accepted for publication in MNRA
A hepatitis C avidity test for determining recent and past infections in both plasma and dried blood spots
DBS testing has been used successfully to detect HCV antibody positive individuals. Determining how long someone has been infected is important for surveillance initiatives. Antibody avidity is a method that can be used to calculate recency of infection. A HCV avidity assay was evaluated for both plasma and DBS. Study design: To measure antibody avidity a commercial HCV ELISA was modified using 7 M urea. The plasma samples were split into: group 1 (recently infected N = 19), group 2 (chronic carrier N = 300) and group 3 (resolved infection N = 82). Mock DBS made from group 1 (N = 12), group 2 (N = 50), group 3 (N = 25) and two seroconverter panels were evaluated. 133 DBS taken from patients known to have a resolved infection or be a chronic carrier were also tested. The avidity assay cut-off was set at AI ≤ 30 for a recent infection. Using sequential samples the assay could detect a recent infection in the first 4–5 months from the point of infection. Most of the false positive results (AI < 30 among cases known not to have had recent infection) were detected among known resolved infections, in both the plasma and DBS; as a result, a testing algorithm has been designed incorporating both PCR and two dilution factors. The sensitivity and specificity of the assay on plasma was 100% and 99.3%, respectively, while DBS had 100% sensitivity and 98.3% specificity. The HCV avidity assay can be used to distinguish between chronic and recent infection using either plasma or DBS as the sample type
Engineering bacteria to control electron transport altering the synthesis of non-native polymer
The use of bacteria as catalysts for radical polymerisations of synthetic monomers has recently been established. However, the role of trans Plasma Membrane Electron Transport (tPMET) in modulating these processes is not well understood. We sort to study this by genetic engineering a part of the tPMET system NapC in E. coli. We show that this engineering altered the rate of extracellular electron transfer coincided with an effect on cell-mediated polymerisation using a model monomer. A plasmid with arabinose inducible PBAD promoters were shown to upregulate NapC protein upon induction at total arabinose concentrations of 0.0018% and 0.18%. These clones (E. coli(IP_0.0018%) and E. coli(IP_0.18%), respectively) were used in iron-mediated atom transfer radical polymerisation (Fe ATRP), affecting the nature of the polymerisation, than cultures containing suppressed or empty plasmids (E. coli(IP_S) and E. coli(E), respectively). These results lead to the hypothesis that EET (Extracellular Electron Transfer) in part modulates cell instructed polymerisations
Synthesis of methacrylate-terminated block copolymers with reduced transesterification by controlled ring-opening polymerization
This work presents a robust method to achieve the synthesis of low molecular weight polyesters 26 via ring-opening polymerization (ROP) initiated by 2-hydroxyethyl-methacrylate (HEMA) 27 when using triazabicyclodecene (TBD) as catalyst. The effect that the HEMA:TBD ratio has 28 upon the final reaction rate and final polymer molecular architecture is discussed. The optimum 29 HEMA:TBD ratio and reaction conditions required to minimize competing transesterification 30 reactions were determined, in order to synthesize successfully the target ROP macromonomer 31 species containing only a single 2-methacryloyloxyethyl end-group. Additionally, to confirm 32 the terminal end-group fidelity of the product macromonomers and confirm TBD utility for 33 block copolymer manufacture, a small series of di-block polyesters were synthesized using 34 TBD and shown to exhibit good control over the final polymer structure whilst negating the 35 side transesterification reactions, irrespective of the monomers used
Birefringence of interferential mirrors at normal incidence Experimental and computational study
In this paper we present a review of the existing data on interferential
mirror birefringence. We also report new measurements of two sets of mirrors
that confirm that mirror phase retardation per reflection decreases when mirror
reflectivity increases. We finally developed a computational code to calculate
the expected phase retardation per reflection as a function of the total number
of layers constituting the mirror. Different cases have been studied and we
have compared computational results with the trend of the experimental data.
Our study indicates that the origin of the mirror intrinsic birefringence can
be ascribed to the reflecting layers close to the substrate.Comment: To be published in Applied Physics
Population coverage of artemisinin-based combination treatment in children younger than 5 years with fever and Plasmodium falciparum infection in Africa, 2003–2015: a modelling study using data from national surveys
Background Artemisinin-based combination therapies (ACTs) are the most effective treatment for uncomplicated
Plasmodium falciparum malaria infection. A commonly used indicator for monitoring and assessing progress in
coverage of malaria treatment is the proportion of children younger than 5 years with reported fever in the previous
14 days who have received an ACT. We propose an improved indicator that incorporates parasite infection status (as
assessed by a rapid diagnostic test [RDT]), which is available in recent household surveys. In this study we estimated
the annual proportion of children younger than 5 years with fever and a positive RDT in Africa who received an ACT
in 2003–15.
Methods Our modelling study used cross-sectional data on treatment for fever and RDT status for children younger
than 5 years compiled from all nationally available representative household surveys (the Malaria Indicator Surveys,
Demographic and Health Surveys, and Multiple Indicator Cluster Surveys) across sub-Saharan Africa between 2003
and 2015. Estimates for the proportion of children younger than 5 years with a fever within the previous 14 days and
P falciparum infection assessed by RDT who received an ACT were incorporated in a generalised additive mixed
model, including data on ACT distributions, to estimate coverage across all countries and time periods. We did
random effects meta-analyses to examine individual, household, and community effects associated with ACT coverage.
Findings We obtained data on 201 704 children younger than 5 years from 103 surveys (22 MIS, 61 DHS, and 20 MICS)
across 33 countries. RDT results were available for 40 of these surveys including 40 261 (20%) children, and we
predicted RDT status for the remaining 161 443 (80%) children. Our results showed that ACT coverage in children
younger than 5 years with a fever and P falciparum infection increased across sub-Saharan Africa in 2003–15, but even
in 2015, only 19·7% (95% CI 15·6–24·8) of children younger than 5 years with a fever and P falciparum infection
received an ACT. In meta-analyses, children younger than 5 years were more likely to receive an ACT for fever and
P falciparum infection if they lived in an urban area (vs rural area; odds ratio [OR] 1·18, 95% CI 1·06–1·31), had
household wealth above the national median (vs wealth below the median; OR 1·26, 1·16–1·39), had a caregiver with
any education (vs no education; OR 1·31, 1·22–1·41), had a household insecticide-treated net (ITN; vs no ITN; OR 1·21,
1·13–1·29), were older than 2 years (vs ≤2 years; OR 1·09, 1·01–1·17), or lived in an area with a higher mean
P falciparum prevalence in children aged 2–10 years (OR 1·12, 1·02–1·23). In the subgroup of children for whom
treatment was sought, those who sought treatment in the public sector were more likely to receive an ACT (vs the
private sector; OR 3·18, 2·67–3·78).
Interpretation Despite progress during the 2003–15 malaria programme, ACT treatment for children with malaria
remains unacceptably low. More work is needed at the country level to understand how health-care access, service
delivery, and ACT supply might be improved to ensure appropriate treatment for all children with malaria
A crossover randomised controlled trial of oral mandibular advancement devices for obstructive sleep apnoea-hypopnoea (TOMADO)
Rationale Mandibular advancement devices (MADs)
are used to treat obstructive sleep apnoea-hypopnoea
syndrome (OSAHS) but evidence is lacking regarding
their clinical and cost-effectiveness in less severe disease.
Objectives To compare clinical- and cost-effectiveness
of a range of MADs against no treatment in mild to
moderate OSAHS.
Measurements and methods This open-label,
randomised, controlled, crossover trial was undertaken at
a UK sleep centre. Adults with Apnoea-Hypopnoea Index
(AHI) 5–<30/h and Epworth Sleepiness Scale (ESS) score
≥9 underwent 6 weeks of treatment with three nonadjustable
MADs: self-moulded (SleepPro 1; SP1);
semi-bespoke (SleepPro 2; SP2); fully-bespoke MAD
(bMAD); and 4 weeks no treatment. Primary outcome
was AHI scored by a polysomnographer blinded to
treatment. Secondary outcomes included ESS, quality of
life, resource use and cost.
Main results 90 patients were randomised and 83
were analysed. All devices reduced AHI compared with
no treatment by 26% (95% CI 11% to 38%, p=0.001)
for SP1, 33% (95% CI 24% to 41%) for SP2 and 36%
(95% CI 24% to 45%, p<0.001) for bMAD. ESS was
1.51 (95% CI 0.73 to 2.29, p<0.001, SP1) to 2.37
(95% CI 1.53 to 3.22, p<0.001, bMAD) lower than no
treatment (p<0.001 for all). Compliance was lower for
SP1, which was the least preferred treatment at trial exit.
All devices were cost-effective compared with no
treatment at a £20 000/quality-adjusted life year (QALY)
threshold. SP2 was the most cost-effective up to
£39 800/QALY.
Conclusions Non-adjustable MADs achieve clinically
important improvements in mild to moderate OSAHS and
are cost-effective
Oxygen-Tolerant RAFT Polymerization Initiated by Living Bacteria
Living organisms can synthesize a wide range of macromolecules from a small set of natural building blocks, yet there is potential for even greater materials diversity by exploiting biochemical processes to convert unnatural feedstocks into new abiotic polymers. Ultimately, the synthesis of these polymers in situ might aid the coupling of organisms with synthetic matrices, and the generation of biohybrids or engineered living materials. The key step in biohybrid materials preparation is to harness the relevant biological pathways to produce synthetic polymers with predictable molar masses and defined architectures under ambient conditions. Accordingly, we report an aqueous, oxygen-tolerant RAFT polymerization platform based on a modified Fenton reaction, which is initiated by Cupriavidus metallidurans CH34, a bacterial species with iron-reducing capabilities. We show the synthesis of a range of water-soluble polymers under normoxic conditions, with control over the molar mass distribution, and also the production of block copolymer nanoparticles via polymerization-induced self-assembly. Finally, we highlight the benefits of using a bacterial initiation system by recycling the cells for multiple polymerizations. Overall, our method represents a highly versatile approach to producing well-defined polymeric materials within a hybrid natural-synthetic polymerization platform and in engineered living materials with properties beyond those of biotic macromolecules
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