1,471 research outputs found
Measurement of a topological edge invariant in a microwave network
We report on the measurement of topological invariants in an electromagnetic
topological insulator analog formed by a microwave network, consisting of the
winding numbers of scattering matrix eigenvalues. The experiment can be
regarded as a variant of a topological pump, with non-zero winding implying the
existence of topological edge states. In microwave networks, unlike most other
systems exhibiting topological insulator physics, the winding can be directly
observed. The effects of loss on the experimental results, and on the
topological edge states, is discussed.Comment: 10 pages, 10 figure
Genetic diversity in Anthurium andraeanum cultivars in Mauritius
Anthurium andraeanum is an important ornamental in the flower industry in Mauritius. Classical phenotype methods of identification, although still very useful, are difficult to use between very closely related Anthurium cultivars. The objectives of this study were to assess the genetic diversity of 12 A. andraeanum cultivars in Mauritius using random amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) markers and identify cultivar specific markers for the genetic profiling of A. andraeanum cultivars. Polymorphism among the 12 cultivars was assessed using RAPD and ISSR primers. Reproducible results were used for statistical analysis. The presence and absence of bands were scored as 1 and 0, respectively to form a matrix from which a dendrogram was obtained using NTSYS. Dendrograms were obtained from matrices derived from RAPD and ISSR analyses to give an estimate of the genetic distance between the tested cultivars. Both ISSR and RAPD were found to be useful tools in differentiating locally grown A. andraeanum.Key words: Anthurium andraeanum, RAPD, ISSR, genetic diversity, cluster analysis
Strengthening implant provision and acceptance in South Africa with the ‘Any woman, any place, any time’ approach: An essential step towards reducing unintended pregnancies
Progress in reducing unintended pregnancies in South Africa is slow. The implant, introduced in 2014, expanded the range of available longacting reversible contraceptives (LARCs) and held much promise. Uptake, however, has declined precipitously, in spite of its ‘unmatched effectiveness’ and high levels of satisfaction for most users. We propose policy and provider interventions to raise implant use, underscored by a ‘LARC-first’ approach. Contraceptive counselling should focus on the particular benefits of LARCs and methods be presented in order of effectiveness. Moreover, implants hold particular advantages for certain groups, especially adolescents and young women, in whom it is considered first-line contraception. Provision of immediate postpartum and post-abortion implants is safe and highly acceptable, yet remains under-utilised. Implant services at HIV and tuberculosis clinics are a key priority, as is inclusion of LARC provision within school health services. Implants could also be delivered by existing mobile outreach services, for example in sex worker programmes. Services could be built around nurses dedicated solely to providing implants, with other health workers receiving brief refresher training. Women who experience side-effects, especially abnormal bleeding, require timely interventions, following a standardised protocol, including use of medications. Encouraging return for side-effects, follow-up phone calls and home visits would raise continuation rates. Removal services require doctor support or designated nurses at specific centres. Limited access to removal services, health workers’ resistance or botched procedures will further undermine implant provision. Rapid implant demonstration projects in postpartum wards, schools, outreach services and by dedicated providers may rapidly advance the field. Together, the actions outlined here will ensure that the implant fulfils its potential and reinvigorates family planning services
Cost and impact of scaling up interventions to save lives of mothers and children: taking South Africa closer to MDGs 4 and 5
KIMBACKGROUND:South Africa has made substantial progress on child and maternal mortality, yet many avoidable deaths of mothers and children still occur. This analysis identifies priority interventions to be scaled up nationally and projects the potential maternal and child lives saved.
DESIGN: We modelled the impact of maternal, newborn and child interventions using the Lives Saved Tools Projections to 2015 and used realistic coverage increases based on expert opinion considering recent policy change, financial and resource inputs, and observed coverage change. A scenario analysis was undertaken to test the impact of increasing intervention coverage to 95%.
RESULTS:By 2015, with realistic coverage, the maternal mortality ratio (MMR) can reduce to 153 deaths per 100,000 and child mortality to 34 deaths per 1,000 live births. Fifteen interventions, including labour and delivery management, early HIV treatment in pregnancy, prevention of mother-to-child transmission and handwashing with soap, will save an additional 9,000 newborns and children and 1,000 mothers annually. An additional US7 per capita) will be required annually to scale up these interventions. When intervention coverage is increased to 95%, breastfeeding promotion becomes the top intervention, the MMR reduces to 116 and the child mortality ratio to 23
Incisional Hernia: Experience in a single surgical unit
Background: Incisional hernias are a common problem in general surgery and they have a varied aetiology. The aim of this study was to document a single unit experience with the management of incisional hernias at King Edward VIII Hospital, Durban, South Arica.Patients and Methods: This was a prospective audit of incisional hernias in a single surgical unit from January 2001 to May 2004. All patients underwent open repair. Clinical data and intra-operative findings were documented.Results: A total number of 77 patients were seen of which 70 were female. Fifty three (68.8%) and 24 (31.2%) of patients underwent elective and emergency surgery respectively. A total of 56 patients had previously undergone gynaecological surgery compared to 21 who had undergone general surgery. There was a documented history of previous sepsis in 4 (7%) of patients. There was 1 sheath defect in 36 patients, 2 defects in 9 patients, 3 defects in 10 patients, 4 or more defects in 9 cases. In 55 patients the original suture could not be identified. Gangrenous bowel was present in 3 patients. Only 3 (3.9%) of the patients had a mesh repair. The rest (96.1%) underwent tissue repair. Morbidity rate was 17% and there were no deaths. Five patients needed management in the ICU. Hospital stay was 8 + 11 yearsConclusion: Most incisional hernias followed gynaecological surgery. There was no evidence of a nonabsorbable suture having been used at the original operation in over half of the patients. We recommend that meticulous technique is essential in closing the abdominal incision
Mental health policy: Options for South Africa
This paper emphasizes the need for mental health professionals to become involved in developing mental health policies in South Africa. In particular, it examines three options that are currently the focus of attention with respect to national health options, i.e. a free market system, a national health service (NHS) and a national health insurance system (NHIS). While the paper does not provide support for any one of these options it does attempt to investigate some of the implications of each option for the funding and delivery of mental health care
Guidance on Performing Focused Ethnographies with an Emphasis on Healthcare Research
Focused ethnographies can have meaningful and useful application in primary care, community, or hospital healthcare practice, and are often used to determine ways to improve care and care processes. They can be pragmatic and efficient ways to capture data on a specific topic of importance to individual clinicians or clinical specialties. While many examples of focused ethnographies are available in the literature, there is a limited availability of guidance documents for conducting this research. This paper defines focused ethnographies, locates them within the ethnographic genre, justifies their use in healthcare research, and outlines the methodological processes including those related to sampling, data collection and maintaining rigour. It also identifies and provides a summary of some recent focused ethnographies conducted in healthcare research. While the emphasis is placed on healthcare research, focused ethnographies can be applicable to any discipline whenever there is a desire to explore specific cultural perspectives held by sub - groups of people within a context - specific and problem - focused framework
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