15 research outputs found
BAMMsat-on-BEXUS: A Technology and Operation Demonstration of a BioCubeSat Platform on a Stratospheric Balloon Flight Educational Program
This paper reports the current use of the REXUS/BEXUS educational program. The program allows university students across Europe to carry out scientific and technology experiments on research sounding rockets and balloons. BAMMsat-on-BEXUS (BoB) is an experiment from Cranfield University and University of Exeter performing a technology and operation demonstration of a bioCubeSat on a stratospheric balloon at an altitude of ~30km above the ground. BEXUS stands for Balloon Experiments for University Students and is realized under an agreement between the German Aerospace Centre (DLR), Swedish National Space Agency (SNSA), European Space Agency (ESA), and EuroLaunch. The term bioCubeSat could be used to refer to a nanosatellite in a CubeSat format with a biological experiment on-board. Over the last decade, a series of six bioCubeSats have been launched into orbit by NASA and a private company, SpacePharma, i.e., GeneSat, PharmaSat, O/OREOS, SporeSat, Dido-2, and EcAMSat. The BAMMsat concept (Bioscience, Astrobiology, Medicine and Material science on CubeSat) is a bioscience hardware platform which aims to advance the current state of the art technology, under development at Cranfield University, for application in LEO and beyond LEO. This generic platform can be flown as a free-flying CubeSat or hosted as a payload on a larger spacecraft. BAMMsat utilizes COTS sensors, actuators, and fluidic components to enable bioscience experiments by reproducing the features in a traditional laboratory into a miniaturized “laboratory.” It is designed to be compatible with the mass, volume, and power budget of a CubeSat payload and flexible for a broad range of applications and biological systems such as microorganisms, nematode worms, and mammalian cells cultures, including human cell cultures. The core features of BAMMsat are the ability to (i) house multiple samples, (ii) maintain samples in an appropriate local environment (ii) perturb sample fluidically, and (iv) monitor samples.
BoB aims to perform a technology and operation demonstration of the BAMMsat bioCubeSat payload in an extreme environment such as the stratosphere. The experiment is to be flown on the BEXUS30 flight campaign in October 2020 from ESRANGE Space Centre, Sweden. The stratosphere can be used as an analog of some aspect of a relevant spaceflight physical environment such as reduced pressure (near-vacuum; ~11 mbar), and temperature (-50°C). The BEXUS flight campaign could also be used as an analog of pre-flight, flight and post-flight operation similar to orbital launch campaign. For bioscience experiments, the biological samples often imposed additional requirement during pre-flight to ensure its viability. BoB will house C. elegans in a 2U pressure vessel to demonstrate its functionality to provide a controlled thermal and fluidic environment with appropriate housekeeping control. This functionality reflects the hardware capability to maintain a viable biological sample. BoB has a 3U CubeSat form factor with 2U allocated for the BAMMsat hardware and 1U allocated as the BAMMsat-on-BEXUS bus. This paper reports progress at four months before flight campaign. The paper also discusses an overview of the experiment objectives and systems design, to build a representative CubeSat that is translatable into a free-flying orbital CubeSat
A Modular Hardware and Software Architecture for a Student-Designed BioCubeSat Prototype Using Autonomous Operations
BAMMsat-on-BEXUS is a student-led project aiming to design, manufacture, and fly a CubeSat-compatible payload on a stratospheric balloon. The payload – BAMMsat (Biology, Astrobiology, Medicine, and Materials Science on satellite) – is a modular CubeSat-format laboratory termed a bioCubeSat. The mission is realized under the bilateral REXUS/BEXUS programme run by the German Aerospace Center (DLR) and the Swedish National Space Agency (SNSA), with the Swedish payload share available to students through a European Space Agency (ESA) collaboration. The core objective of the prototype payload is to perform a technology demonstration of the core bioCubeSat technology, demonstrating its capability to support biological experiments in space. Additionally, the mission aims to validate pre-flight and flight operations, with a particular focus on biological operations. This will increase TRL for future bioCubeSat spaceflight with the goal to eventually enable better and cheaper biological, pharmaceutical, and materials science research in space environments.
The BEXUS mission follows a typical space mission framework with reduced timeframe, therefore trade-offs prioritize commercial-off-the-shelf components and simple software using open-source solutions. The payload comprises a 2U pressurized laboratory payload (BAMMsat) and 1U avionics bus. The former contains experiment hardware including a Multi-Chamber Sample Disc, rotary mechanism, imager, the microfluidics system, active thermal control, and supporting avionics. The bus contains two flight computers, multiple custom avionics PCBs, and serves as the interface between BAMMsat and the BEXUS balloon gondola.
The BAMMsat-on-BEXUS prototype will likely fly in October 2021. The prototype flight should prove that the system can perform varied microfluidics operations on multiple C. elegans samples, capture detailed imagery of the samples, provide general system housekeeping and communications, and provide life support for samples, including stable temperature and pressure despite operating within an extreme temperature and near-vacuum environment.
The system and biological operations are designed to be fully automatic during flight, with some subsystems continually autonomously operating and others following sequenced events. Future work will aim for greater use of autonomous operations to reduce operating costs and enable more advanced system control, particularly for precise active thermal control and experiment sequencing. The next iteration of BAMMsat is targeting low Earth orbit missions, after further hardware upgrades and the inclusion of fluorescence microscopy and additional chemical sensors
The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance
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
New value chain Pentadesma nuts and butter from West Africa to international markets: Biological activities, health benefits, and physicochemical properties
The tallow or butter tree (Pentadesma butyracea Sabine) is a ligneous forest species of multipurpose use largely distributed in Sub-Sahara Africa. Owing to the biological properties of different parts of the tree and physicochemical properties, as well as the numerous benefits of its fruits, research on P. butyracea products, especially kernels and butter, has now gained more interest. Thus, the scientific literature revealed that Pentadesma butter is a more promising product with good physical and technological characteristics. It is traditionally preferred in households for food, medicine, and cosmetic use. Apart from the fruits, all other parts of the butter tree are used by local communities in folk medicine. The existing studies indicated that P. butyracea contains valuable health-promoting compounds such as phenolic compounds, vitamins, minerals, and essential fatty acids. P. butyracea and derived products have antioxidant, antimicrobial, anti-inflammatory, antiplasmodial, antitumor, estrogenic, anti-androgenic, and cholesterol-regulative effects. Since studies on the biological properties of the tree parts, nutritional composition, and physicochemical properties of food products from the tree have been very limited, this review attempts to summarize some results from recent investigations. Our intention in the present review was to give an overview of the biological activities of plants and an account of the potential properties of Pentadesma products (pulp, kernels, and butter) and outline the way for future relevant research to improve their state of knowledge