618 research outputs found

    Uptake and early removals of Implanon NXT in South Africa: Perceptions and attitudes of healthcare workers

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    Background. The South African (SA) government introduced Implanon NXT, a long-acting subdermal contraceptive implant, in 2014 to expand contraceptive choice. Following an initial high uptake, its use declined considerably amid reports of early removals and frequent side-effects. We examine providers’ perceptions of training and attitudes towards Implanon NXT, as well as their views on the causes of early removals and the impact on the implant service. Objective. To assess healthcare providers’ perceptions and attitudes towards implant services in SA. Methods. In-depth interviews were conducted with eight nurses providing implant services in public facilities in Gauteng and North West Province. Emerging themes were identified, manually coded and thematically analysed following an interpretivism approach. Results. Nurses lacked confidence in providing implant services effectively, particularly removals, which they ascribed to the brief, cascade-type training received. Nurses generally held negative views towards the method. They also reported that side-effects are the most common reason for early removals – particularly irregular bleeding – and that men often do not support their partners who use the method. Lastly, it was found that providers require guidance on counselling regarding the method and standardised guidelines on the management of side-effects. Conclusion. Retraining and support of providers are needed to address competency gaps and negative attitudes towards the method. Assessment of providers’ readiness to perform removal procedures is also important. Finally, effective plans are necessary to improve implant continuation rates, especially among women whose partners are unsupportive.S Afr Med J 2017;107(10):822-82

    Gaps in monitoring systems for Implanon NXT services in South Africa: An assessment of 12 facilities in two districts

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    Background. Implanon NXT, a long-acting subdermal contraceptive implant, was introduced in South Africa (SA) in early 2014 as part of an expanded contraceptive method mix. After initial high levels of uptake, reports emerged of frequent early removals and declines in use. Monitoring of progress and challenges in implant service delivery could identify aspects of the programme that require strengthening. Objectives. To assess data management and record keeping within implant services at primary care facilities. Methods. We developed a checklist to assess the tools used for monitoring implant services and data reporting to district offices. The checklist was piloted in seven facilities. An additional six high-volume and six low-volume implant insertion clinics in the City of Johannesburg (CoJ), Gauteng Province, and the Dr Kenneth Kaunda District, North West Province, were selected for assessment. Results. All 12 facilities completed a Daily Head Count Register, which tallied the number of clients attending the clinic, but not information about implant use. A more detailed Tick Register recorded services that clinic attendees received, with nine documenting number of implant insertions and six implant removals. A more specific tool, an Insertion Checklist, collected data on insertion procedures and client characteristics, but was only used in CoJ (five of six facilities). Other registers, which were developed de novo by staff at individual facilities, captured more detailed information about insertions and removals, including reasons. Five of six low-volume insertion facilities used these registers, but only three of six high-volume facilities. No facilities used the form specifically developed by the National Department of Health for implant pharmacovigilance. Nine of 12 clinics reported data on numbers of insertions to the district office, six reported removals and none provided data on reasons for removals. Conclusion. For data to inform effective decision-making and quality improvement in implant services in SA, standardised reporting guidelines and data collection tools are needed, reinforced by staff training and quality assessment of data collection. Staff often took the initiative to fill gaps in reporting systems. Current systems are unable to accurately monitor uptake or discontinuation, or identify aspects of services requiring strengthening. Lack of pharmacovigilance data is especially concerning. Deficiencies noted in these monitoring systems may be common to family planning services more broadly, which warrants investigation.S Afr Med J 2017;107(10):827-831

    User perspectives on Implanon NXT in South Africa: A survey of 12 public-sector facilities

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    Background. Implanon NXT, a long-acting reversible contraceptive, was introduced in South Africa (SA) in early 2014, aiming to expand the method mix and increase its effectiveness. Initial uptake was high, but has since declined considerably. In these early years after the implant’s introduction, it is important to identify reasons for the decline, and remedy gaps in services. Objectives. To determine periods of use, reasons for the use and early removal of the implant Implanon NXT. Methods. In 2016, we recruited 152 women from six clinics in the City of Johannesburg, and six in North West Province, SA. A semistructured interview was administered to 91 women currently using the implant and 61 previous users. We examined user perspectives, factors influencing women’s experiences with the implant and reasons for discontinuation. Results. The participants’ mean age was 30 years, with only 15% aged <25. Implant uptake was motivated by convenience (less frequent visits required than for short-acting methods) and by favourable views of the method among friends, family and healthcare providers. Only about a quarter of women recalled being counselled pre-insertion about implant effectiveness, and half about side-effects pre-insertion. Among discontinuers, the median time to device removal was 8 months (interquartile range 6 - 12), and this was primarily as a result of sideeffects (90%), especially bleeding-pattern changes and headaches. Removals were most common among married and cohabiting women, often ascribed to the effects of bleeding on their sexual relationships. Rumours and misinformation contributed to some removals. Overall, women’s experiences with the implant were rated ‘good’ or ‘very good’ by 74% of those continuing use, many of whom reported not having experienced any side-effects or that these had diminished over time. Conclusion. Levels of acceptability among continuing users were high, mainly linked to the method’s convenience. While early favourable views drove uptake, negative perceptions, if unaddressed, may now undermine services. Deficiencies in counselling around effectiveness and side-effects may extend to contraceptive services more generally. Women require more intensive support when experiencing sideeffects, including effective systematic approaches to ameliorating bleeding and headaches. Implant services could specifically target young women and first-time contraceptive users. These actions together could reverse the persistent decline in implant use in SA. S Afr Med J 2017;107(10):815-82

    A Tale of Two Current Sheets

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    I outline a new model of particle acceleration in the current sheet separating the closed from the open field lines in the force-free model of pulsar magnetospheres, based on reconnection at the light cylinder and "auroral" acceleration occurring in the return current channel that connects the light cylinder to the neutron star surface. I discuss recent studies of Pulsar Wind Nebulae, which find that pair outflow rates in excess of those predicted by existing theories of pair creation occur, and use those results to point out that dissipation of the magnetic field in a pulsar's wind upstream of the termination shock is restored to life as a viable model for the solution of the "σ\sigma" problem as a consequence of the lower wind 4-velocity implied by the larger mass loading.Comment: 17 pages, 6 figures, Invited Review, Proceedings of the "ICREA Workshop on The High-Energy Emission from Pulsars and their Systems", Sant Cugat, Spain, April 12-16, 201

    Noninvasive diffusion magnetic resonance imaging of brain tumour cell size for the early detection of therapeutic response

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    Cancer cells differ in size from those of their host tissue and are known to change in size during the processes of cell death. A noninvasive method for monitoring cell size would be highly advantageous as a potential biomarker of malignancy and early therapeutic response. This need is particularly acute in brain tumours where biopsy is a highly invasive procedure. Here, diffusion MRI data were acquired in a GL261 glioma mouse model before and during treatment with Temozolomide. The biophysical model VERDICT (Vascular Extracellular and Restricted Diffusion for Cytometry in Tumours) was applied to the MRI data to quantify multi-compartmental parameters connected to the underlying tissue microstructure, which could potentially be useful clinical biomarkers. These parameters were compared to ADC and kurtosis diffusion models, and, measures from histology and optical projection tomography. MRI data was also acquired in patients to assess the feasibility of applying VERDICT in a range of different glioma subtypes. In the GL261 gliomas, cellular changes were detected according to the VERDICT model in advance of gross tumour volume changes as well as ADC and kurtosis models. VERDICT parameters in glioblastoma patients were most consistent with the GL261 mouse model, whilst displaying additional regions of localised tissue heterogeneity. The present VERDICT model was less appropriate for modelling more diffuse astrocytomas and oligodendrogliomas, but could be tuned to improve the representation of these tumour types. Biophysical modelling of the diffusion MRI signal permits monitoring of brain tumours without invasive intervention. VERDICT responds to microstructural changes induced by chemotherapy, is feasible within clinical scan times and could provide useful biomarkers of treatment response

    Global Burden of Sickle Cell Anaemia in Children under Five, 2010-2050: Modelling Based on Demographics, Excess Mortality, and Interventions

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    The global burden of sickle cell anaemia (SCA) is set to rise as a consequence of improved survival in high-prevalence low- and middle-income countries and population migration to higher-income countries. The host of quantitative evidence documenting these changes has not been assembled at the global level. The purpose of this study is to estimate trends in the future number of newborns with SCA and the number of lives that could be saved in under-five children with SCA by the implementation of different levels of health interventions.First, we calculated projected numbers of newborns with SCA for each 5-y interval between 2010 and 2050 by combining estimates of national SCA frequencies with projected demographic data. We then accounted for under-five mortality (U5m) projections and tested different levels of excess mortality for children with SCA, reflecting the benefits of implementing specific health interventions for under-five patients in 2015, to assess the number of lives that could be saved with appropriate health care services. The estimated number of newborns with SCA globally will increase from 305,800 (confidence interval [CI]: 238,400-398,800) in 2010 to 404,200 (CI: 242,500-657,600) in 2050. It is likely that Nigeria (2010: 91,000 newborns with SCA [CI: 77,900-106,100]; 2050: 140,800 [CI: 95,500-200,600]) and the Democratic Republic of the Congo (2010: 39,700 [CI: 32,600-48,800]; 2050: 44,700 [CI: 27,100-70,500]) will remain the countries most in need of policies for the prevention and management of SCA. We predict a decrease in the annual number of newborns with SCA in India (2010: 44,400 [CI: 33,700-59,100]; 2050: 33,900 [CI: 15,900-64,700]). The implementation of basic health interventions (e.g., prenatal diagnosis, penicillin prophylaxis, and vaccination) for SCA in 2015, leading to significant reductions in excess mortality among under-five children with SCA, could, by 2050, prolong the lives of 5,302,900 [CI: 3,174,800-6,699,100] newborns with SCA. Similarly, large-scale universal screening could save the lives of up to 9,806,000 (CI: 6,745,800-14,232,700) newborns with SCA globally, 85% (CI: 81%-88%) of whom will be born in sub-Saharan Africa. The study findings are limited by the uncertainty in the estimates and the assumptions around mortality reductions associated with interventions.Our quantitative approach confirms that the global burden of SCA is increasing, and highlights the need to develop specific national policies for appropriate public health planning, particularly in low- and middle-income countries. Further empirical collaborative epidemiological studies are vital to assess current and future health care needs, especially in Nigeria, the Democratic Republic of the Congo, and India

    MHD models of Pulsar Wind Nebulae

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    Pulsar Wind Nebulae (PWNe) are bubbles or relativistic plasma that form when the pulsar wind is confined by the SNR or the ISM. Recent observations have shown a richness of emission features that has driven a renewed interest in the theoretical modeling of these objects. In recent years a MHD paradigm has been developed, capable of reproducing almost all of the observed properties of PWNe, shedding new light on many old issues. Given that PWNe are perhaps the nearest systems where processes related to relativistic dynamics can be investigated with high accuracy, a reliable model of their behavior is paramount for a correct understanding of high energy astrophysics in general. I will review the present status of MHD models: what are the key ingredients, their successes, and open questions that still need further investigation.Comment: 18 pages, 5 figures, Invited Review, Proceedings of the "ICREA Workshop on The High-Energy Emission from Pulsars and their Systems", Sant Cugat, Spain, April 12-16, 201

    Hemoglobin E syndromes in Pakistani population

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    <p>Abstract</p> <p>Background</p> <p>Hemoglobin E is an important hemoglobin variant with a worldwide distribution. A number of hemoglobinopathies have been reported from Pakistan. However a comprehensive description of hemoglobin E syndromes for the country was never made. This study aimed to describe various hemoglobin E disorders based on hematological parameters and chromatography. The sub-aim was to characterize hemoglobin E at molecular level.</p> <p>Methods</p> <p>This was a hospital based study conducted prospectively for a period of one year extending from January 1 to December 31, 2008. EDTA blood samples were analyzed for completed blood counts and hemoglobin variants through automated hematology analyzer and Bio-Rad beta thalassaemia short program respectively. Six samples were randomly selected to characterize HbE at molecular level through RFLP-PCR utilizing <it>Mnl</it>I restriction enzyme.</p> <p>Results</p> <p>During the study period, 11403 chromatograms were analyzed and Hb E was detected in 41 (or 0.36%) samples. Different hemoglobin E syndromes identified were HbEA (n = 20 or 49%), HbE/β-thalassemia (n = 14 or 34%), HbEE (n = 6 or 15%) and HbE/HbS (n = 1 or 2%). Compound heterozygosity for HbE and beta thalassaemia was found to be the most severely affected phenotype. RFLP-PCR utilizing <it>Mnl</it>I successfully characterized HbE at molecular level in six randomly selected samples.</p> <p>Conclusions</p> <p>Various HbE phenotypes are prevalent in Pakistan with HbEA and HbE/β thalassaemia representing the most common syndromes. Chromatography cannot only successfully identify hemoglobin E but also assist in further characterization into its phenotype including compound heterozygosity. Definitive diagnosis of HbE can easily be achieved through RFLP-PCR.</p

    Comparative Population Genetics of the Immunity Gene, Relish: Is Adaptive Evolution Idiosyncratic?

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    The frequency of adaptive evolution acting on common loci in distant lineages remains an outstanding question in evolutionary biology. We asked whether the immunity factor, Relish, a gene with a history of directional selection in Drosophila simulans, shows evidence of a similar selective history in other Drosophila species. We found only weak evidence of recurrent adaptive protein evolution at the Relish locus in three sister species pairs, suggesting that this key component of the insect immune system has an idiosyncratic evolutionary history in Drosophila

    Modelling Visual Neglect: Computational Insights into Conscious Perception

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    Background: Visual neglect is an attentional deficit typically resulting from parietal cortex lesion and sometimes frontal lesion. Patients fail to attend to objects and events in the visual hemifield contralateral to their lesion during visual search. Methodology/Principal Finding: The aim of this work was to examine the effects of parietal and frontal lesion in an existing computational model of visual attention and search and simulate visual search behaviour under lesion conditions. We find that unilateral parietal lesion in this model leads to symptoms of visual neglect in simulated search scan paths, including an inhibition of return (IOR) deficit, while frontal lesion leads to milder neglect and to more severe deficits in IOR and perseveration in the scan path. During simulations of search under unilateral parietal lesion, the model’s extrastriate ventral stream area exhibits lower activity for stimuli in the neglected hemifield compared to that for stimuli in the normally perceived hemifield. This could represent a computational correlate of differences observed in neuroimaging for unconscious versus conscious perception following parietal lesion. Conclusions/Significance: Our results lead to the prediction, supported by effective connectivity evidence, that connections between the dorsal and ventral visual streams may be an important factor in the explanation of perceptua
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