70 research outputs found

    Numerical modeling of meteorological and topographical effects on pollen shed, dispersion, and viability

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    For open-pollinated species, the success of a pollen grain pollinating a receptive plant is a function of when it is shed, its dispersion in the atmosphere, and the chance of germination upon deposition. Most studies of pollen dispersion have focused on a source and surrounding fields in relatively flat terrain, but dispersion to distances over 20 km has been reported in regions of complex terrain. For this reason, a more detailed examination of atmospheric dispersion over long distances and the components of dispersion - shed, transport, and successful pollination - was undertaken. This dissertation uses numerical models to predict these components in order to improve simulations of dispersion over long distances. Chapter One provides an overview of work previously done in pollen dispersion. Chapter Two describes a model that uses empirical relationships between pollen release and meteorological variables to predict diurnal variations in maize pollen shed. The model captured the general pattern of shed and predicted the time of peak shed on most days. In Chapter Three, a meteorological model was combined with a Lagrangian dispersion model to predict bentgrass pollen dispersion over complex terrain. The models predicted pollen deposition in locations where outcross was previously reported over 20 km from the source. However, pollen was not predicted to be deposited on upwind slopes of mountains or in valleys more than a few kilometers from the source. Chapter Four examines how thermally-generated updrafts resulting from surface sensible heat flux and mechanically-generated updrafts associated with complex topography affect dispersion. We determined the gaps in pollen dispersion found in Chapter Three resulted from additional lift created by convergence on the windward side of mountains and thermally-induced flow that traveled up valley walls and mountain slopes. Chapter Five examines how maize pollen viability is affected when pollen grains are lifted higher in the atmospheric boundary layer. Viability was predicted to be as much as 30% higher when the atmospheric conditions along a pollen grain\u27s trajectory are used compared to estimates of viability using conditions at the Earth\u27s surface. Chapter Six summarizes the dissertation. The results of this work are expected to improve future models of pollen dispersion, leading to more accurate predictions of outcrossing. Also, the methods described here are not limited to maize or bentgrass pollen, but can be modified for applications to other biological particles that rely on atmospheric conditions for dispersion

    Predicting the dispersion and viability of maize pollen

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    High Spatial and Temporal Resolution Census Data Reveal Communities at Risk Along the Wildland-Urban Interface (WUI) in California, USA

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    We tracked census tract level population change along California\u27s wild land-urban interface (WUI) during the past decade (2010-2019), an ecological sensitive region transitioning from developed land to wilderness. Our results from Mann-Kendall analysis, a method employed for monotonic trend detection showed that about one-third (29.1%) of census tracts in California’s WUI have seen a significant population increase from 2010 to 2019, affecting 12.7% population in California. The population increase along WUI is largely driven by the sixteen counties in the San Francisco Bay Area (10) and Southern California (6). We also found that higher proportion of WUI residents in Bay Area and larger number of WUI residents in Southern California. Bay Area counties in general have a higher proportion of population living in WUI tracts with significant population increase than Southern California counties. However, the lower proportion of residents living in WUI in Southern California counties account for a much larger population. Riverside is the county with the highest number of residents living in WUI tracts that have experienced significant population increase during the past decade. These residents also account for a high proportion (29.2%) of total population in Riverside. Preliminary results showed that the increase of population along WUI is driven by the house affordability and house ownership in 16 counties of Bay Area and Southern California. These factors can still explain a significant amount of the spatial pattern if extended to all counties in California

    High Spatial and Temporal Resolution Census Data Reveals Communities at Risk Along the Wildland-Urban Interface (WUI) in California, USA

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    We tracked census tract level population change along California\u27s wild land-urban interface (WUI) during the past decade (2010-2019), an ecological sensitive region transitioning from developed land to wilderness. Our results from Mann-Kendall analysis, a method employed for monotonic trend detection showed that about one-third (29.1%) of census tracts in California’s WUI have seen a significant population increase from 2010 to 2019, affecting 12.7% population in California. The population increase along WUI is largely driven by the sixteen counties in the San Francisco Bay Area (10) and Southern California (6). We also found that higher proportion of WUI residents in Bay Area and larger number of WUI residents in Southern California. Bay Area counties in general have a higher proportion of population living in WUI tracts with significant population increase than Southern California counties. However, the lower proportion of residents living in WUI in Southern California counties account for a much larger population. Riverside is the county with the highest number of residents living in WUI tracts that have experienced significant population increase during the past decade. These residents also account for a high proportion (29.2%) of total population in Riverside. Preliminary results showed that the increase of population along WUI is driven by the house affordability and house ownership in 16 counties of Bay Area and Southern California. These factors can still explain a significant amount of the spatial pattern if extended to all counties in California

    Implementation of a novel ultrasound training programme for midwives in Malawi:A mixed methods evaluation using the RE-AIM framework

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    IntroductionDespite recommendation that all women receive an ultrasound in pregnancy prior to 24 weeks', this remains unavailable to many women in low-income countries where trained practitioners are scarce. Although many programmes have demonstrated efficacy, few have achieved longterm sustainability, with a lack of information about how best to implement such programmes. This mixed-methods study aimed to evaluate the implementation of a novel education package to teach ultrasound-naive midwives in Malawi basic obstetric ultrasound, assessing its impact in the context of the Reach, Effectiveness, Adoption, Implementation and Maintenance (RE-AIM) framework.MethodsThe study ran across six sites in Malawi between October 2020 and June 2021, encompassing three phases; pre-implementation, implementation and post-implementation. Twenty nine midwives underwent a bespoke education package with matched pre and post course surveys assessed their knowledge, attitudes and confidence and "hands on" assessments evaluating practical skills. Training evaluation forms and in-depth interviews explored their satisfaction with the package, with repeat assessment and remote image review evaluating maintenance of skills.Results28/29 midwives completed the training, with significant increases in knowledge, confidence and practical skills. Adherence to the education package varied, however many changes to the proposed methodology were adaptive and appeared to facilitate the efficacy of the programme. Unfortunately, despite reporting approval regarding the training itself, satisfaction regarding supervision and follow up was mixed, reflecting the difficulties encountered with providing ongoing in-person and remote support.ConclusionThis programme was successful in improving trainees' knowledge, confidence and skill in performing basic obstetric ultrasound, largely on account of an adaptive approach to implementation. The maintenance of ongoing support was challenging, reflected by trainee dissatisfaction. By evaluating the success of this education package based on its implementation and not just its efficacy, we have generated new insights into the barriers to sustainable upscale, specifically those surrounding maintenance

    Midwife‐Led Ultrasound Scanning to Date Pregnancy in Malawi: Development of a Novel Training Program

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    The use of ultrasound to determine gestational age is fundamental to the optimum management of pregnancy and is recommended for all women by the World Health Organization. However, this modality remains unavailable to many women in low-income countries where trained practitioners are scarce. Although previous initiatives have demonstrated efficacy in training midwives and technicians to perform antenatal ultrasound, these programs have often been too long and too complex to be realistic within the specific constraints of this context, highlighting the need for a novel and pragmatic approach. We describe the development and piloting of a bespoke course to teach midwives 3 fundamental components of early antenatal ultrasound scanning: (1) to identify the number of fetuses, (2) to confirm fetal viability, and (3) to determine gestational age. Having established that 5 days is insufficient, we propose that the minimum duration required to train ultrasound-naive midwives to competency is 10 days. Our completed program therefore consists of one and one-half days of didactic teaching, followed by 8 and one-half days of supervised hands-on practical training in which trainees are assessed on their skills. This package has subsequently been successfully implemented across 6 sites in Malawi, where 28 midwives have achieved competency. By describing the processes involved in our cross-continental collaboration, we explain how unexpected challenges helped shape and improve our program, demonstrating the value of preimplementation piloting and a pragmatic and adaptive approach

    Training in Ultrasound to Determine Gestational Age (TUDA): Evaluation of a Novel Education Package to Teach Ultrasound-Naive Midwives Basic Obstetric Ultrasound in Malawi

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    IntroductionAlthough ultrasound to determine gestational age is fundamental to the optimum management of pregnancy and is recommended for all women by the World Health Organisation, it remains unavailable to many women in low-income countries where trained practitioners are scarce. This study aimed to evaluate a novel, context-specific education package to teach midwives basic obstetric ultrasound, including the determination of gestational age by measurement of fetal femur length.MethodsThe study was conducted across six sites in Malawi in January 2021. Following a virtual “training of the trainers”, local teams delivered a 10-day programme encompassing both didactic and “hands on” components. Matched pre and post course tests assessed participants' knowledge of key concepts, with Objective Structured Clinical Examinations used to evaluate practical skills. To achieve a pass, trainees were required to establish the gestational age to within ±7 days of an experienced practitioner and achieve an overall score of &amp;gt;65% on five consecutive occasions. A matched pre and post course survey explored participants' attitudes and confidence in performing ultrasound examinations.ResultsOf the 29 midwives who participated, 28 finished the programme and met the criteria specified to pass. 22 midwives completed the matched knowledge tests, with the mean (SD) score increasing from 10.2 (3.3) to 18 (2.5) after training (P &amp;lt;0.0001). Mean difference 7.9, 95% CI 6.5–9.2. Midwives passed 87% of the Observed Structured Clinical Examinations, establishing the gestational age to within ±7 days of an experienced practitioner in 89% of assessments. Beliefs regarding the importance of antenatal ultrasound increased post course (p = 0.02), as did confidence in performing ultrasound examinations (p &amp;lt;0.0001).ConclusionThis study demonstrates not only that ultrasound-naive practitioners can be taught to perform basic obstetric ultrasound dating scans, confidently and competently, after 10 days of training, but also that local teams can be orientated to successfully deliver the programme virtually. Previous ultrasound training initiatives, while often more comprehensive in their syllabus, have been of considerably longer duration and this is likely to be a barrier to upscaling opportunities. We propose that this focused training increases the potential for widescale and sustainable implementation.</jats:sec

    Informing prevention of stillbirth and preterm birth in Malawi:development of a minimum dataset for health facilities participating in the DIPLOMATIC collaboration

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    OBJECTIVE: The global research group, DIPLOMATIC (Using eviDence, Implementation science, and a clinical trial PLatform to Optimise MATernal and newborn health in low Income Countries), aims to reduce stillbirths and preterm births and optimise outcomes for babies born preterm. Minimum datasets for routine data collection in healthcare facilities participating in DIPLOMATIC (initially in Malawi) were designed to assist understanding of baseline maternal and neonatal care processes and outcomes, and facilitate evaluation of improvement interventions and pragmatic clinical trials. DESIGN: Published and grey literature was reviewed alongside extensive in-country consultation to define relevant clinical best practice guidance, and the existing local data and reporting infrastructure, to identify requirements for the minimum datasets. Data elements were subjected to iterative rounds of consultation with topic experts in Malawi and Scotland, the relevant Malawian professional bodies and the Ministry of Health in Malawi to ensure relevance, validity and feasibility. SETTING: Antenatal, maternity and specialist neonatal care in Malawi. RESULTS: The resulting three minimum datasets cover the maternal and neonatal healthcare journey for antenatal, maternity and specialist neonatal care, with provision for effective linkage of records for mother/baby pairs. They can facilitate consistent, precise recording of relevant outcomes (stillbirths, preterm births, neonatal deaths), risk factors and key care processes. CONCLUSIONS: Poor quality routine data on care processes and outcomes constrain healthcare system improvement. The datasets developed for implementation in DIPLOMATIC partner facilities reflect, and hence support delivery of, internationally agreed best practice for maternal and newborn care in low-income settings. Informed by extensive consultation, they are designed to integrate with existing local data infrastructure and reporting as well as meeting research data needs. This work provides a transferable example of strengthening data infrastructure to underpin a learning healthcare system approach in low-income settings.DIPLOMATIC is funded by the UK National Institute for Health Research

    Implementation of a novel ultrasound training programme for midwives in Malawi: A mixed methods evaluation using the RE-AIM framework

    Get PDF
    INTRODUCTION: Despite recommendation that all women receive an ultrasound in pregnancy prior to 24 weeks', this remains unavailable to many women in low-income countries where trained practitioners are scarce. Although many programmes have demonstrated efficacy, few have achieved longterm sustainability, with a lack of information about how best to implement such programmes. This mixed-methods study aimed to evaluate the implementation of a novel education package to teach ultrasound-naive midwives in Malawi basic obstetric ultrasound, assessing its impact in the context of the Reach, Effectiveness, Adoption, Implementation and Maintenance (RE-AIM) framework. METHODS: The study ran across six sites in Malawi between October 2020 and June 2021, encompassing three phases; pre-implementation, implementation and post-implementation. Twenty nine midwives underwent a bespoke education package with matched pre and post course surveys assessed their knowledge, attitudes and confidence and "hands on" assessments evaluating practical skills. Training evaluation forms and in-depth interviews explored their satisfaction with the package, with repeat assessment and remote image review evaluating maintenance of skills. RESULTS: 28/29 midwives completed the training, with significant increases in knowledge, confidence and practical skills. Adherence to the education package varied, however many changes to the proposed methodology were adaptive and appeared to facilitate the efficacy of the programme. Unfortunately, despite reporting approval regarding the training itself, satisfaction regarding supervision and follow up was mixed, reflecting the difficulties encountered with providing ongoing in-person and remote support. CONCLUSION: This programme was successful in improving trainees' knowledge, confidence and skill in performing basic obstetric ultrasound, largely on account of an adaptive approach to implementation. The maintenance of ongoing support was challenging, reflected by trainee dissatisfaction. By evaluating the success of this education package based on its implementation and not just its efficacy, we have generated new insights into the barriers to sustainable upscale, specifically those surrounding maintenance

    GA4GH: International policies and standards for data sharing across genomic research and healthcare.

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    The Global Alliance for Genomics and Health (GA4GH) aims to accelerate biomedical advances by enabling the responsible sharing of clinical and genomic data through both harmonized data aggregation and federated approaches. The decreasing cost of genomic sequencing (along with other genome-wide molecular assays) and increasing evidence of its clinical utility will soon drive the generation of sequence data from tens of millions of humans, with increasing levels of diversity. In this perspective, we present the GA4GH strategies for addressing the major challenges of this data revolution. We describe the GA4GH organization, which is fueled by the development efforts of eight Work Streams and informed by the needs of 24 Driver Projects and other key stakeholders. We present the GA4GH suite of secure, interoperable technical standards and policy frameworks and review the current status of standards, their relevance to key domains of research and clinical care, and future plans of GA4GH. Broad international participation in building, adopting, and deploying GA4GH standards and frameworks will catalyze an unprecedented effort in data sharing that will be critical to advancing genomic medicine and ensuring that all populations can access its benefits
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