12 research outputs found

    The PY4 Mission: A Low-Cost Demonstration of CubeSat Formation-Flying Technologies

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    The PY4 mission aims to enable autonomous swarms of small spacecraft by both reducing the manufacturing cost and integration effort required for individual spacecraft, and by advancing guidance, navigation, and control algorithms that increase autonomy and reduce or eliminate the need for expensive sensor, actuator, and propulsion hardware. PY4 consists of four 1.5U CubeSats, and builds on the PyCubed open-source avionics platform and the previous V-R3x mission. To date, PY4 has successfully demonstrated high-data-rate mesh networking, precise inter-satellite ranging, range-based relative orbit determination, and magnetorquer-only sun pointing. A drag-based formation-flying experiment is also planned for an extended mission

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Dispatch From The Non-Hitech-Incented Health It World: Electronic Medication History Adoption And Utilization

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    Objective To document national trends of electronic medication history use in the ambulatory setting and describe the characteristics and predicting factors of providers who regularly use medication history transaction capabilities through their e-prescribing systems. Materials and Methods The study used provider-initiated medication history data requests, electronically sent over an e-prescribing network from all 50 states and the District of Columbia. Data from 138,000 prescribers were evaluated using multivariate analyses from 2007 to 2013. Results Medication history use showed significant growth, increasing from 8 to 850 million history requests during the study period. Prescribers on the network for \u3c5 years had a lower likelihood of requests than those on the network for 5 or more years. Although descriptive analyses showed that prescribers in rural areas were alongside e-prescribing, and requesting medication histories more often than those in large and small cities, these findings were not significant in multivariate analyses. Providers in orthopedic surgery and internal medicine had a higher likelihood of more requests than family practice prescribers, with 12% and 7% higher likelihood, respectively. Discussion Early adopters of e-prescribing have remained medication history users and have continually increased their volume of requests for medication histories. Conclusion Despite the fact that the use of medication histories through e-prescribing networks in the ambulatory care setting has not been encouraged through federal incentive programs, there has been substantial growth in the use of medication histories offered through e-prescribing networks

    Electronic Prescribing Of Controlled Substances: A Tool To Help Promote Better Patient Care

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    Objectives: The objective of this study is to present the first information available regarding enablement and use by state and area characteristics of electronic prescriptions of controlled substances (EPCS) by prescribers and pharmacy systems in the United States using 15 months of transactional data, from January 2014 to March 2015, from an e-prescribing network. Study Design and Methods: The data used in this study represent electronic transactions of controlled substances from all states and the District of Columbia, from Surescripts. Data in this analysis include prescriber enablement for EPCS, pharmacies with certified and audit-approved software enabled to receive EPCS transactions from prescribers, and number of EPCS transactions. In addition, area characteristics were determined using the Area Health Resource File to define metropolitan and non-metropolitan areas. Results: During the study period from January 2014 to March 2015, pharmacies enabled for EPCS grew minimally, from 78% to 79% nationally. National EPCS enablement among prescribers increased 3.7%, from 0.6% to 4.3%. Differences were observed between metropolitan and rural counties. The percent of transactions nationally grew from 0.16% to 1.8% during the study period, more than a 10-fold increase in transactions. Conclusions: There has been progress in the adoption and use of EPCS. However, there are marked differences at the state level and between urban and rural areas. EPCS is an important tool to help prescribers provide better care for their patients. Additionally, EPCS provides a complete electronic record of controlled substance prescriptions, critical for public health and law enforcement initiatives that address the misuse and diversion of opioid medications

    Effect of landscape diversity and crop management on the control of the millet head miner, Heliocheilus albipunctella (Lepidoptera: Noctuidae) by natural enemies

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    The pearl millet head miner, Heliocheilus albipunctella, is a major constraint to increasing crop productivity in sub-Saharan Africa. In the absence of any insecticide application by farmers, its control mostly relies on the action of natural enemies. The objective of the present study is to identify crop management and landscape features affecting biocontrol services by natural enemies. A set of 45 millet fields were selected in a 20 ∗ 20 km area in Senegal, from the analysis of high resolution satellite images (Pleiades), and hypotheses on relative abundance of millet fields and semi-natural habitats (mainly trees) in the agricultural landscape. A biocontrol service index (BSI) was computed for each field over two cropping seasons by experimentally excluding natural enemies from naturally egg-infested millet panicles. Information on crop management was collected through farmer's interviews. An information theoretical approach and model averaging were performed to rank the effect of landscape metrics on BSI at eight spatial scales (from 250 to 2000 m). The BSI was generally high (77%) but highly variable among fields (0–100%), and was greater in compound fields compared to bush fields. The BSI also increased with the abundance of tree patches and the diversity of vegetation in a 1750 m-buffer around millet fields. Results support previous studies stressing the importance of semi-natural areas and vegetation diversity to support pest regulation by natural enemies. Further research is needed to better understand relationships between agroforestry systems and biological control, to promote ecologically-intensive solutions for reducing crop losses

    Effect of isoniazid preventive therapy on risk of death in west African, HIV-infected adults with high CD4 cell counts: long-term follow-up of the Temprano ANRS 12136 trial

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