285 research outputs found

    A Chemical study of the nutrition of swine

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    Studies of a Lacustrine-Volcanic Mars Analog Field Site with Mars-2020-like Instruments

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    On the upcoming Mars‐2020 rover two remote sensing instruments, Mastcam‐Z and SuperCam, and two microscopic proximity science instruments, SHERLOC and PIXL, will collect compositional (mineralogy, chemistry, and organics) data essential for paleoenvironmental reconstruction. The synergies between and limitations of these instruments were evaluated via study of a Mars analog field site in the Mojave Desert, using instruments approximating the data that will be returned by Mars‐2020. A ground truth dataset was generated for comparison to validate the results. The site consists of a succession of clay‐rich mudstones of lacustrine origin, interbedded tuffs, a carbonate‐silica travertine deposit, and gypsiferous mudstone strata. The major geological units were mapped successfully using simulated Mars‐2020 data. Simulated Mastcam‐Z data identified unit boundaries and Fe‐bearing weathering products. Simulated SuperCam passive shortwave infrared and green Raman data were essential in identifying major mineralogical composition and changes in lacustrine facies at distance; this was possible even with spectrally downsampled passive IR data. LIBS and simulated PIXL data discriminated and mapped major element chemistry. Simulated PIXL revealed mm‐scale zones enriched in zirconium, of interest for age dating. SHERLOC‐like data mapped sulfate and carbonate at sub‐mm scale; silicates were identified with increased laser pulses/spot or by averaging of hundreds of spectra. Fluorescence scans detected and mapped varied classes of organics in all samples, characterized further with follow‐on spatially targeted deep‐UV Raman spectra. Development of dedicated organics spectral libraries is needed to aid interpretation. Given these observations, the important units in the outcrop would be sampled and cached for sample return

    Rodent Habitat on ISS: Advances in Capability for Determining Spaceflight Effects on Mammalian Physiology

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    Rodent research is a valuable essential tool for advancing biomedical discoveries in life sciences on Earth and in space. The National Research Counsel's Decadal survey (1) emphasized the importance of expanding NASAs life sciences research to perform long duration, rodent experiments on the International Space Station (ISS). To accomplish this objective, new flight hardware, operations, and science capabilities were developed at NASA ARC to support commercial and government-sponsored research. The flight phases of two separate spaceflight missions (Rodent Research-1 and Rodent Research-2) have been completed and new capabilities are in development. The first flight experiments carrying 20 mice were launched on Sept 21, 2014 in an unmanned Dragon Capsule, SpaceX4; Rodent Research-1 was dedicated to achieving both NASA validation and CASIS science objectives, while Rodent Reesearch-2 extended the period on orbit to 60 days. Groundbased control groups (housed in flight hardware or standard cages) were maintained in environmental chambers at Kennedy Space Center. Crewmembers previously trained in animal handling transferred mice from the Transporter into Habitats under simultaneous veterinary supervision by video streaming and were deemed healthy. Health and behavior of all mice on the ISS was monitored by video feed on a daily basis, and post-flight quantitative analyses of behavior were performed. The 10 mice from RR-1 Validation (16wk old, female C57Bl6/J) ambulated freely and actively throughout the Habitat, relying heavily on their forelimbs for locomotion. The first on-orbit dissections of mice were performed successfully, and high quality RNA (RIN values>9) and liver enzyme activities were obtained, validating the quality of sample recovery. Post-flight sample analysis revealed that body weights of FLT animals did not differ from ground controls (GC) housed in the same hardware, or vivarium controls (VIV) housed in standard cages. Organ weights analyzed post-flight showed that there were no differences between FLT and GC groups in adrenal gland and spleen weights, whereas FLT thymus and liver weights exceeded those of GC. Minimal differences between the control groups (GC and VIV) were observed. In addition, Over 3,000 aliquots collected post-flight from the four groups of mice were deposited into the Ames Life Science Data Archives for the Biospecimen Sharing Program and Genelab project. New capabilities recently developed include DEXA scanning, grip strength tests and male mice. In conclusion, new capability for long duration rodent habitation of group-housed rodents was developed and includes in-flight sample collection, thus avoiding the complication of reentry. Results obtained to date reveal the possibility of striking differences between the effects of short duration vs. long duration spaceflight. This Rodent Research system enables achievement of both basic science and translational research objectives to advance human exploration of space

    ChemCam Investigation of the Last Four MSL Drill Sites in the Murray Formation, Gale Crater, Mars

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    This study utilizes ChemCam data for outcrop surfaces, drill hole walls, tailings, and dump piles in the Middle Murray Formation to investigate chemical variations with depth in the drill holes and pos-sible effects of the drilling and sample processing. This work is a continuation of similar work on drill sites at Yellowknife Bay [1], the Pahrump Hills [2], and the Stimson Formation [3]

    Maximizing Science Return from Future Rodent Experiments on the International Space Station (ISS): Tissue Preservation

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    To better understand how mammals adapt to long duration habitation in space, a system for performing rodent experiments on the ISS is under development; Rodent Research-1 is the first flight and will include validation of both on-orbit animal support and tissue preservation. To evaluate plans for on-orbit sample dissection and preservation, we simulated conditions for euthanasia, tissue dissection, and prolonged sample storage on the ISS, and we also developed methods for post-flight dissection and recovery of high quality RNA from multiple tissues following prolonged storage in situ for future science. Mouse livers and spleens were harvested under conditions that simulated nominal, on-orbit euthanasia and dissection operations including storage at -80 C for 4 months. The RNA recovered was of high quality (RNA Integrity Number, RIN(is) greater than 8) and quantity, and the liver enzyme contents and activities (catalase, glutathione reductase, GAPDH) were similar to positive controls, which were collected under standard laboratory conditions. We also assessed the impact of possible delayed on-orbit dissection scenarios (off-nominal) by dissecting and preserving the spleen (RNAlater) and liver (fast-freezing) at various time points post-euthanasia (from 5 min up to 105 min). The RNA recovered was of high quality (spleen, RIN (is) greater than 8; liver, RIN (is) greater than 6) and liver enzyme activities were similar to positive controls at all time points, although an apparent decline in select enzyme activities was evident at the latest time (105 min). Additionally, various tissues were harvested from either intact or partially dissected, frozen carcasses after storage for approximately 2 months; most of the tissues (brain, heart, kidney, eye, adrenal glands and muscle) were of acceptable RNA quality for science return, whereas some tissues (small intestine, bone marrow and bones) were not. These data demonstrate: 1) The protocols developed for future flight experiments will support science return despite delayed preservation post-euthanasia or prolonged storage, and 2) Many additional tissues for gene expression analysis can be obtained by dissection following prolonged storage of the tissue in situ at -80 C. These findings have relevance both to high value, ground-based experiments when sample collection capability is severely constrained, and to all future spaceflight experiments that entail on-orbit sample recovery by the ISS crew

    New Development in NASA's Rodent Research Hardware for Conducting Long Duration Biomedical and Basic Research in Space

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    Animal models, particularly rodents, are the foundation of pre-clinical research to understand human diseases and evaluate new therapeutics, and play a key role in advancing biomedical discoveries both on Earth and in space. The National Research Councils Decadal survey emphasized the importance of expanding NASAs life sciences research to perform long duration, rodent experiments on the International Space Station (ISS). To accomplish this objective, flight hardware, operations, and science capabilities were developed at NASA Ames Research Center (ARC) to enhance science return for both commercial (CASIS) and government-sponsored rodent research. The Rodent Research program at NASA ARC has pioneered a new research capability on the International Space Station and has progressed toward translating research to the ISS utilizing commercial rockets, collaborating with academia and science industry, while training crewmembers to assist in performing research on orbit. Throughout phases of these missions, our practices, hardware and operations have evolved from tested to developed standards, and we are able to modify and customize our procedure and operations for mission specific requirements. The Rodent Research Habitat is capable of providing a living environment for animals on ISS according to standard animal welfare requirements. Using the cameras in the Habitat, the Rodent Research team has the ability to perform daily health checks on animals, and further analyze the collected videos for behavioral studies. A recent development of the Rodent Research hardware is inclusion of enrichment, to provide the animals the ability to rest and huddle. The Enrichment Hut is designed carefully for adult mice (up to 35 week old) within animal welfare, engineering, and operations constraints. The Hut is made out of the same stainless steel mesh as the cage interior, it has an ingress and an egress to allow animals move freely, and a hinge door to allow crewmembers remove the animals easily. The Rodent Research team has also developed Live Animal Return (LAR) capability, which will be implemented during Rodent Research-5 mission for the first time. The animals will be transported from the Habitat to a Transporter, which will return on the Dragon capsule and splashes down in the Pacific Ocean. Once SpaceX retrieves the Dragon, all powered payloads will be transferred to a SeaVan and transferred to the Long Beach pier. The NASA team then receives the transporter and delivers to a PI-designated laboratory within 120 mile radius of Long Beach. This is a significant improvement allowing researchers to examine animals within 72 hrs. of reentry or to conduct recovery experiments. Together, the hardware improvements and experience that the Rodent Research team has gained working with principal investigators and ISS crew to conduct complex experiments on orbit are expanding capabilities for long duration rodent research on the ISS to achieve both basic science and biomedical objectives

    Studies of a Lacustrine-Volcanic Mars Analog Field Site with Mars-2020-like Instruments

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    On the upcoming Mars‐2020 rover two remote sensing instruments, Mastcam‐Z and SuperCam, and two microscopic proximity science instruments, SHERLOC and PIXL, will collect compositional (mineralogy, chemistry, and organics) data essential for paleoenvironmental reconstruction. The synergies between and limitations of these instruments were evaluated via study of a Mars analog field site in the Mojave Desert, using instruments approximating the data that will be returned by Mars‐2020. A ground truth dataset was generated for comparison to validate the results. The site consists of a succession of clay‐rich mudstones of lacustrine origin, interbedded tuffs, a carbonate‐silica travertine deposit, and gypsiferous mudstone strata. The major geological units were mapped successfully using simulated Mars‐2020 data. Simulated Mastcam‐Z data identified unit boundaries and Fe‐bearing weathering products. Simulated SuperCam passive shortwave infrared and green Raman data were essential in identifying major mineralogical composition and changes in lacustrine facies at distance; this was possible even with spectrally downsampled passive IR data. LIBS and simulated PIXL data discriminated and mapped major element chemistry. Simulated PIXL revealed mm‐scale zones enriched in zirconium, of interest for age dating. SHERLOC‐like data mapped sulfate and carbonate at sub‐mm scale; silicates were identified with increased laser pulses/spot or by averaging of hundreds of spectra. Fluorescence scans detected and mapped varied classes of organics in all samples, characterized further with follow‐on spatially targeted deep‐UV Raman spectra. Development of dedicated organics spectral libraries is needed to aid interpretation. Given these observations, the important units in the outcrop would be sampled and cached for sample return

    Should We Track Migrant Households When Collecting Household Panel Data?:Household Relocation, Economic Mobility and Attrition Biases in the Rural Philippines

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    Based on household panel data that tracked migrant households (with an additional survey cost of 17 percent), this article describes behavior of household relocation and quantifies the extent of attrition biases in estimating the determinants of percapita household consumption and of its growth rate. Many households relocate for non-economic reasons, and to rural destinations, while the small number of urban migrants improved their wellbeing faster than did others. Such heterogeneity among migrants may be a reason behind the negligible attrition biases caused by the omission of migrants, in the inference on the average behavioral coefficients among the original population

    Mars Hand Lens Imager (MAHLI) Efforts and Observations at the Rocknest Eolian Sand Shadow in Curiosity's Gale Crater Field Site

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    The Mars Science Laboratory (MSL) mission is focused on assessing the past or present habitability of Mars, through interrogation of environment and environmental records at the Curiosity rover field site in Gale crater. The MSL team has two methods available to collect, process and deliver samples to onboard analytical laboratories, the Chemistry and Mineralogy instrument (CheMin) and the Sample Analysis at Mars (SAM) instrument suite. One approach obtains samples by drilling into a rock, the other uses a scoop to collect loose regolith fines. Scooping was planned to be first method performed on Mars because materials could be readily scooped multiple times and used to remove any remaining, minute terrestrial contaminants from the sample processing system, the Collection and Handling for In-Situ Martian Rock Analysis (CHIMRA). Because of this cleaning effort, the ideal first material to be scooped would consist of fine to very fine sand, like the interior of the Serpent Dune studied by the Mars Exploration Rover (MER) Spirit team in 2004 [1]. The MSL team selected a linear eolian deposit in the lee of a group of cobbles they named Rocknest (Fig. 1) as likely to be similar to Serpent Dune. Following the definitions in Chapter 13 of Bagnold [2], the deposit is termed a sand shadow. The scooping campaign occurred over approximately 6 weeks in October and November 2012. To support these activities, the Mars Hand Lens Imager (MAHLI) acquired images for engineering support/assessment and scientific inquiry
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