1,438 research outputs found

    PMT37: BENEFITS OF EARLY MODELING IN DRUG DISCOVERY

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    Preference and Nutrition of Quail Breeder 16, Common Agricultural Feeds, and a Mix of Native Seeds as Northern Bobwhite Food

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    Agricultural feeds are commonly dispersed along roads or in openings as an attractant or dietary supplement for northern bobwhites (Colinus virginianus). Quail Breeder 16e is a pelletized ration specifically developed by Lyssy & Eckel Feeds for breeding bobwhites to maximize nutritive content of diets. Captive bobwhites were used to examine relative preference of the pellets, sorghum, corn, soybean, and a mix of seeds of 8 native plant species. Protein, fat, acid detergent fiber, gross energy, and mineral content of the feeds were measured and we examined changes in body mass of bobwhites fed exclusive diets of each of the five feeds. A Latin rectangle experimental design with single and multiple-offer treatments was used to compare feed preference. Sorghum was most highly preferred in both the single and multiple offering experiments. Soybeans and the pelletized ration were least preferred. The native seed mix and corn were intermediate in preference. Nutritionally, soybeans had the highest protein (40%), highest fat (19%), and highest gross energy (21 kJ/g). Bobwhites fed exclusive diets of the native seed mix exhibited the greatest increase in body mass (40%), and birds fed the sorghum diet had the greatest decrease in body mass ( 8%). Providing supplements (pelletized rations and agricultural feeds) should not take precedence over managing bobwhite habitat to produce a variety of native grasses and forbs when improving bobwhite nutrition is a management objective

    The Application of an Adult Learning Approach to Genetic Counselling: An Exploratory Study

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    The aim of this thesis was to explore the applicability of an adult learning approach to genetic counselling. This exploration commenced by reviewing the literature on genetic counselling and adult learning theory and examining the relationship between the two. Four selected transcripts of genetic counselling sessions were then analysed in two phases. The first phase included the categorisation of genetic counsellee dialogue according to the elements of a form of learning, contemplation, described by Jarvis' (1987) model of adult learning. The second phase included an examination of two aspects of the application of Jarvis' (1987) contemplation learning model which were considered to be important. One of these aspects involved searching the categorised genetic counsellee dialogue for evidence of cognitive versus affective domain material to determine if both could be accounted for. It was assumed that learners do not follow Jarvis' (1987) contemplation learning model in any sequential order. Therefore, the second phase also comprised a line by line analysis of the transcripts. This was intended to show the extent to which the genetic counsellees deviated from the sequence of the model. The review of the literature suggested there was a relationship between adult learning theory and genetic counselling, and analysis of the transcripts supported this. The analysis of the transcripts showed that Jarvis' (1987) contemplation learning model could be used to explore, discuss and understand the process genetic counsellees undergo, in both the cognitive and affective domains, but was not followed in the strict sequential order of Jarvis' (1987) model. The implications of the study for clinical practice, the education of genetic counsellors and future research are discussed

    CAPSTONE: Recovery & Operations of a Tumbling Small Satellite in Deep Space

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    The Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment (CAPSTONE) satellite, deployed in July 2022, experienced a thruster anomaly in September 2022 during its Ballistic Lunar Transfer (BLT) into the Earth-Moon L2 Near Rectilinear Halo Orbit (NRHO). CAPSTONE\u27s primary mission objective to achieve and maintain NRHO serves to validate the cislunar CONOPS contemplated for NASA\u27s Lunar Gateway. Terran Orbital designed and built CAPSTONE, and serves as the operator of the on-orbit spacecraft. Advanced Space owns and operates the CAPSTONE payload and its software on behalf of NASA, as well as performs mission navigation and maneuver design. This 12U+ lunar nanosatellite contains a pump-fed hydrazine propulsion system from Stellar Exploration, enabling all orbital maneuvers and momentum management for the mission. The CAPSTONE mission is funded by the NASA Space Technology Mission Directorate (STMD) through the Small Spacecraft Technology program, and by the Human Exploration and Operations Mission Directorate (HEOMD) through the Advanced Exploration Systems program. This paper will examine the timeline, innovation, and steps taken by the spacecraft team to recover the vehicle from the thruster anomaly and the resulting high-rate tumble. The high-rate tumble was induced by a valve which became stuck open at the conclusion of Trajectory Correction Maneuver 3 (TCM-3). The timeline discussion includes initial autonomous fault recovery, the evolution of the state of the vehicle, and the recovery actions taken by a small, agile engineering team. The off-nominal attitude and thermal state was determined from a limited data set, requiring the largest assets in NASA\u27s Deep Space Network (DSN) to support communications with the vehicle. Once a determination was made that the hydrazine propellant was freezing, an assessment was made on the minimum amount of heat required to thaw propellant without placing the spacecraft in a power-negative state. The integrated spacecraft team performed root cause analysis and incrementally tested the propulsion system to recommission it in the face of an anomalous thruster valve. The recommissioning approach eventually lead to the development of a new propulsive state machine and Guidance Navigation and Control (GNC) thruster controller for detumbling. After recovering 3-axis attitude control, power and thermal stability, and establishing nominal communications, significant development and testing was required to ensure the vehicle could operate in the presence of a continued thruster anomaly. This effort enabled CAPSTONE to execute future propulsive maneuvers with an open thruster valve. The resultant updates were tested on Terran Orbital\u27s Hardware-in-the-Loop (HITL) platform in partnership with Stellar Exploration. A comparison of GNC subsystem requirements will be presented pre-and post-anomaly, based on the resulting capability and restrictions of the propulsion system to meet mission objectives. Ultimately, the spacecraft was successfully recovered from body rates exceeding 120 deg/s, allowing the CAPSTONE spacecraft to continue its mission, including successful insertion into NRHO in November 2022. An examination of the lessons learned for future deep space small satellite missions is also discussed herein

    Effects of Tanglehead Expansion on Bobwhite Habitat Use in South Texas

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    Usable space for northern bobwhite (Colinus virginianus) has been reduced across a large portion of South Texas rangelands due to the spread of non-native, invasive grasses. A native grass, tanglehead (Heteropogon contortus) has rapidly expanded its dominance in the western Sand Sheet of South Texas within the last 10-15 years. It has formed high-density monocultures, similar to non-native grasses, which are associated with losses of forb and grass diversity as well as bare ground, which are key components of bobwhite habitat. The objectives of our research were to 1) determine selection-avoidance of habitat features by bobwhites, and 2) determine the effects of tanglehead cover on vegetation characteristics. We detected 488 coveys across 20,103 ha on helicopter surveys conducted December 2014 in South Texas. We measured 6 vegetation characterstics (grass and forb species richness, vegetation height, woody-plant cover, tanglehead cover, and non-native grass cover) at all covey detections and an equal number of random locations. We developed continuous selection ratios based on probability density functions of used and random points derived using Simple Saddlepoint Approximations to determine habitat selection by bobwhites. We also used quantile regression at the 10th, 50th, and 90th quantiles to determine relationships between tanglehead and vegetation factors. Bobwhite avoided areas of high canopy cover (\u3e20%) of all invasive grasses measured. Brush cover was selected for up to 47%, after which it was avoided. We found significant negative relationships between tanglehead cover and forb and grass species richness, bare ground, and shrub cover, and a positive relationship with vegetation height at all quantiles modeled. Our results demonstrate the negative effects of increased tanglehead cover on native rangeland habitats. Further expansion by tanglehead has the potential to significantly reduce usable space for bobwhites in South Texas

    CAPSTONE: A CubeSat Pathfinder for the Lunar Gateway Ecosystem

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    The cislunar environment is about to get much busier and with this increase in traffic comes an increase in the demand for limited resources such as Earth based tracking of and communications with assets operating in and around the Moon. With the number of NASA, commercial, and international missions to the Moon growing rapidly in the next few years, the need to make these future endeavors as efficient as possible is a challenge that is being solved now. Advanced Space is aiming to mitigate these resource limitations by enabling the numerous spacecraft in the cislunar environment to navigate autonomously and reduce the need for oversubscribed ground assets for navigation and maneuver planning. Scheduled to launch on a Rocket Lab Electron in October 2021, the Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment (CAPSTONE) mission will leverage a 12U CubeSat to demonstrate both the core software for the Cislunar Autonomous Positioning System (CAPS) as well as a validation of the mission design and operations of the Near Rectilinear Halo Orbit (NRHO) that NASA has baselined for the Artemis Lunar Gateway architecture. Currently being developed in a Phase III of NASA’s SBIR program, our CAPS software will allow missions to manage themselves and enable more critical communications to be prioritized between Earth and future cislunar missions without putting these missions at increased risk. CAPSTONE is the pathfinder mission for NASA’s Artemis program. The overall mission will include collaboration with the Lunar Reconnaissance Orbiter (LRO) operations team at NASA Goddard Space Flight Center to demonstrate inter-spacecraft ranging between the CAPSTONE spacecraft and LRO and with the NASA Gateway Operations team at NASA Johnson Space Center to inform the requirements and autonomous mission operations approach for the eventual Gateway systems. Critical success criteria for CAPSTONE in this demonstration are a transfer to and arrival into an NRHO, semi-autonomous operations and orbital maintenance of a spacecraft in an NRHO, collection of inter-spacecraft ranging data, and execution of the CAPS navigation software system on-board the CAPSTONE spacecraft. Advanced Space along with our partners at NASA’s Space Technology Mission Directorate, Advanced Exploration Systems, Launch Services Program, NASA Ames Small Spacecraft Office, Tyvak Nano-Satellite Systems and Rocket Lab, envision the CAPSTONE mission as a key enabler of both NASA’s Gateway operations involving multiple spacecraft and eventually the ever-expanding commercial cislunar economy. This low cost, high value mission will demonstrate an efficient low energy orbital transfer to the lunar vicinity and an insertion and operations approach to the NRHO that ultimately will demonstrate a risk reducing validation of key exploration operations and technologies required for the ultimate success of NASA’s lunar exploration plans, including the planned human return to the lunar surface. This presentation will include the current mission status (which would include the launch and early mission operations), the operations plan for the NRHO, and lessons learned to date in order to inform future CubeSat pathfinders in support of national exploration and scientific objectives

    Population Response of Three Quail Species to Habitat Restoration in South Texas

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    Maintaining and increasing usable space is paramount for maintaining and increasing wild quail. Aside from weather and other factors that can temporarily reduce densities, range-wide, no factor has as much influence on quail populations as the amount of habitat present across the landscape. In the field of quail management, ‘‘bad news’’ is the norm, as many articles begin by explaining how a select species has declined. Here we provide good news and use 4 empirical examples of population increases for 3 quail species following creation of usable space and restoration of patch connectivity. From 2008–2014, a suite of independent projects aimed at increasing usable space for quail was initiated across South Texas. These projects included 3 focused on northern bobwhites (Colinus virginianus), 1 focused on scaled quail (Callipepla squamata), and 1 landowner-executed project focused on Montezuma quail (Cyrtonyx montezumae). Through the correction of attributes limiting habitat, bobwhite numbers increased 22–378% across 2 studies. On one particular study site, native grassland restoration resulted in the colonization of bobwhites from adjacent areas to 1 bobwhite/1.2 ha from nearly 0. For scaled quail in South Texas, reducing buffelgrass standing crop via grazing from about 2,240 kg/ha to 1,008 kg/ha resulted in the recolonization of a previously unoccupied habitat patch to a density of 1 scaled quail/6 ha. Finally, clearing monotypic stands of the invasive native plant, ash juniper (Juniperus ashei) in the Edwards Plateau of Texas, resulted in the reestablishment of native grasses and forbs and thus recolonization by Montezuma quail from nearby areas. Although habitat restoration and management can be a painstaking and lengthy process, addressing limiting factors to quail occupancy is the only known way to increase wild quail populations. We hope that highlighting these particular studies will provide inspiration to those interested in restoring and increasing quail across the US

    CAPSTONE: A Summary of Flight Operations to Date in the Cislunar Environment

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    The cislunar environment is about to get much busier and with this increase in traffic comes an increase in the demand for limited resources such as Earth based tracking of and communications with assets operating in and around the Moon. With the number of NASA, commercial, and international missions to the Moon growing rapidly, the need to make these future endeavors as efficient as possible is a challenge that is being solved now. Advanced Space is aiming to mitigate these resource limitations by enabling spacecraft in the cislunar environment to navigate autonomously and reduce the need for oversubscribed ground assets for navigation and maneuver planning. Launched in June 2022, the Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment (CAPSTONE) mission utilizes a 12U CubeSat to demonstrate both the core software for the Cislunar Autonomous Positioning System (CAPS) as well as a validation of the mission design and operations of the Near Rectilinear Halo Orbit (NRHO) that NASA has baselined for the Artemis Lunar Gateway architecture. The CAPS software enables cislunar missions to manage their navigation functions themselves and reduces the reliance on Earth based tracking requirements without putting these missions at increased risk. Upon arrival in the NRHO, the CAPSTONE spacecraft will soon initiate its navigation demonstration mission in collaboration with the Lunar Reconnaissance Orbiter (LRO) operations team at NASA’s Goddard Space Flight Center to demonstrate autonomous inter-spacecraft ranging and autonomous navigation between the CAPSTONE spacecraft and LRO. Critical success criteria for CAPSTONE in this demonstration are 1) semi-autonomous operations and orbital maintenance of a spacecraft in an NRHO, 2) collection of inter-spacecraft ranging data, and 3) execution of the CAPS navigation software system in autonomous mode on-board the CAPSTONE spacecraft. Additionally, CAPSTONE continues to demonstrate an innovative one-way ranging navigation approach utilizing a Chip Scale Atomic Clock (CSAC), unique firmware installed on the Iris radio, and onboard autonomous navigation algorithms developed JPL an implemented by Advanced Space. Advanced Space, along with our partners at NASA’s Space Technology Mission Directorate, (STMD), Advanced Exploration Systems (AES), Launch Services Program (LSP), NASA Ames’ Small Spacecraft Office, the Jet Propulsion Lab (JPL), Terran Orbital and Rocket Lab, envision the CAPSTONE mission as a key enabler of both NASA’s upcoming Gateway operations involving multiple spacecraft and eventually the ever-expanding commercial cislunar economy. Over the next 21 months, CAPSTONE will demonstrate an efficient low energy orbital transfer to the lunar vicinity, an insertion into the NRHO, and a risk reducing validation of key exploration operations and technologies required for the ultimate success of NASA’s lunar exploration plans. This paper includes an overview of the mission, the current mission operational status, lessons learned from the launch, lunar transfer, and insertion into the NRHO, an overview of operations plan for the NRHO, and other lessons learned to date in order to inform future missions in support of national exploration and scientific objectives

    CAPSTONE: A Summary of a Highly Successful Mission in the Cislunar Environment

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    NASA, Advanced Space, Terran Orbital, Rocket Lab, Stellar Exploration, JPL, the Space Dynamics Lab, and Tethers Unlimited have partnered to successfully develop, launch, and operate the Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment (CAPSTONE) mission, which is serving as a pathfinder for Near Rectilinear Halo Orbit (NHRO) operations around the Moon. This low-cost, high-value mission has demonstrated an efficient, low-energy orbital transfer to the Moon and a successful insertion into the Near Rectilinear Halo Orbit (NRHO), the intended orbit for NASA\u27s Gateway lunar orbital platform. The mission is now demonstrating operations within the NRHO that ultimately will serve to reduce risk and validate key exploration operations and technologies required for the future success of NASA\u27s lunar exploration plans, including the planned human return to the lunar surface. Over the next 9+ months, CAPSTONE will continue to validate these key operations and navigation technologies required for the success of NASA\u27s lunar exploration plans. This paper will include an overview of the current mission status, lessons learned from the launch, transfer, and insertion into the NRHO, a summary of the challenges encountered thus far, and an overview of the successful mission operations technology demonstrations thus far
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