Find research datasets worth reusing

openGEO-OpenFeb 2025View details →

Pou4f2/Brn3b Overexpression Promotes the Genesis of Retinal Ganglion Cell-like Projection Neurons from Late Progenitors

GEO Series GSE269337. Mus musculus. 2 samples. Type: Expression profiling by high throughput sequencing.

openGEO-OpenAug 2023View details →

Pou3f1 orchestrates a gene regulatory network controlling contralateral retinogeniculate projections [RNA-seq]

GEO Series GSE233793. Mus musculus. 19 samples. Type: Expression profiling by high throughput sequencing.

openGEO-OpenJul 2024View details →

Crnic Institute Human Trisome Project - Trisomy 21 Model Atlas: PolyA RNA-seq from adult mouse brain hippocampus

GEO Series GSE272567. Mus musculus. 17 samples. Type: Expression profiling by high throughput sequencing.

openGEO-OpenJul 2024View details →

Molecular organization of autonomic, respiratory, and spinally-projecting neurons in the mouse ventrolateral medulla

GEO Series GSE272976. Mus musculus. 16 samples. Type: Expression profiling by high throughput sequencing.

Investigation of anomalous transport in the lower thermosphere Project

&nbsp; Near-simultaneously deployed chemical tracer trails over an extended horizontal range will be used to obtain measurements of the turbulent structure function and (the pair) relative velocity distribution over a range of spatial scales covering a full decade. Trimethyl aluminum trails (TMA) released in the mesosphere and lower thermosphere have been used to trace the neutral motions over 500 times since 1958. Such releases are a simple and reliable method for obtaining horizontal velocities with good accuracy and height resolution. Deriving the diffusion characteristics is more difficult but two detailed studies of the expansion rates have been carried out. Analyses from the earlier experiments show enhanced or anomalous diffusion rates in a 10 to 15 km altitude range above the turbopause. (MAJOR) Even if only partially successful, this study is expected to contribute significantly to our understanding of turbulent motions in the atmosphere as turbulence at small scales is currently poorly understood. (MINOR) &nbsp;

Mars Technology Project

NASA&rsquo;s Mars Exploration Program (MEP) calls for a series of highly ambitious missions over the next decade and beyond. The overall goals of the MEP must be achieved with relatively low mission risk and within tightly constrained cost resources. The current overarching scientific goals of the MEP are: life, climate, geology, and preparation for human exploration. These have a common, measurable link: water. For Mars (like Earth), water is central to the planet&rsquo;s history; it is also the primary reason for interest in it as a potentially habitable world. No new proposals are being solicited or funded in FY 2012 under this project line. Proposals for Mars instrument technology development are now included in PIDDP and no new awards will be provided under the Mars Instrument Development Program (MIDP).

Advanced Multiplexed TES Arrays Project

X-ray measurements are critical for the understanding of cycles of matter and energy in the Universe, for understanding the nature of dark matter and dark energy, and for probing gravity in the extreme limit of matter accretion onto a black hole. We propose a program to mature the current x-ray microcalorimeter technology, while developing transformational technology that will enable megapixel arrays. X-ray calorimeters based on superconducting transition-edge sensors achieve the highest energy resolution of any non-dispersive detector technology. The performance of single x-ray calorimeter pixels has reached that required for many possible future missions such as IXO, RAM, and Generation-X, but further optimization is still useful. In the last years, we have made progress in developing techniques to control and engineer the properties of the superconducting transition. We propose to continue this single-pixel optimization, and to improve both the practical and theoretical understanding of the correlation between alpha, beta, and noise to identify favorable regions of parameter space for different instruments. A greater challenge is the development of mature TES x-ray calorimeter arrays with a very large number of pixels. Advances in the last several years have been significant. We have developed modestly large (256 pixel) x-ray calorimeter arrays with time-division SQUID multiplexing, and demonstrated Walsh code-division SQUID multiplexing, which has the potential to allow scaling to much larger arrays. Here we propose to extend this work, and also to introduce a new code-division SQUID multiplexing circuit with extremely compact, low-power elements. Using this approach, it is possible for the first time to fit all of the detector biasing and multiplexing elements underneath an x-ray absorber, allowing in-focal-plane multiplexing. This approach eliminates the requirement to bring leads from each pixel out of the focal plane, while reducing the power dissipati

Direct Energy Conversion for Nuclear Propulsion at Low Specific Mass Project

Low specific mass (&lt; 3&nbsp; kg/kW) in-space electric power and propulsion can drastically alter the paradigm for exploration of the Solar System, changing human Mars exploration from a 3-year epic event to an annual expedition.&nbsp;&nbsp; A specific mass of ~1 kg/kW can enable 1-year round-trips to Mars, regardless of alignment, with the same launch mass to low Earth orbit (350 mT) estimated by the Mars Design Reference Architecture 5.0 study for a 3-year conjunction mission. Key to achieving such a propulsion capability is the ability to convert, at high efficiency and with only minimal losses rejected as heat via radiators, the energy of charged particle reaction products originating from an advanced fission or aneutronic fusion source directly into electricity conditioned as required to power an electric thruster.&nbsp; The TWDEC concept accomplishes this by converting particle beam energy into radio frequency (RF) alternating current electrical power, such as can be used to heat the propellant in a plasma thruster.This project is core to the development of multi-MW power for electric propulsion.&nbsp; The technology developed will enable high power systems which have specific mass in the low single-digits and which are sun-independent, require no neutron shielding, and produce no radioactive waste.&nbsp; The power levels and specific mass this technology could provide will, when combined with either high-efficiency Q-thrusters or VASIMR-class plasma thrusters, enable rapid human missions to Mars and beyond.&nbsp;&nbsp;&nbsp;&nbsp; Project Infusion Path: Low specific mass (a &ndash; kg/kWe) in-space electric power and propulsion can drastically alter the paradigm for exploration of the Solar System, changing human Mars exploration from a 3-year epic event to an annual expedition.&nbsp;&nbsp; An a of ~1 kg/kWe can enable 1-year round-trips to Mars, regardless of opportunity, with the same launch mass to low Earth orbit (350 mT) estimated by the Mars Design Reference Architecture 5.0 study for a 3-year conjunction mission. Key to achieving such a propulsion capability is the ability to convert, at high efficiency and with only minimal losses rejected as heat via radiators, the energy of charged particle reaction products originating from an aneutronic fusion source directly into electricity conditioned as required to power an electric thruster. The TWDEC concept (originally conceived in Japan in the 1990&rsquo;s for terrestrial fusion applications) accomplishes this by converting particle beam energy into radio frequency (RF) alternating current electrical power, such as can be used to heat the propellant in a VASIMR-class plasma thruster. In a more advanced concept (explored in a 2012 Phase 1 NASA Innovative Advanced Concepts (NIAC) project), the TWDEC could also be utilized to condition the particle beam such that it may transfer directed kinetic energy to a target propellant plasma for the purpose of increasing thrust and optimizing the specific impulse.&nbsp; While other government agencies and/or industry partners are pursuing aneutronic fusion reactors and plasma propulsion, NASA JSC is the only entity advancing this core energy conversion technology. With successful development of this system by NASA and its partners, an intermediate NASA infusion step would demonstrate megawatt-class aneutronic fusion, TWDEC, and electric propulsion (e.g., Q-thruster, VASIMR) systems on robotic missions to the Jovian moons.&nbsp; Human vehicle system development would then integrate such systems into the &ldquo;ultimate&rdquo; NASA application:&nbsp; sustainable, routine human exploration of Mars and, with successful Q-thruster development, beyond.Project Infusion Path:Low specific mass (a &ndash; kg/kWe) in-spac

Georeferenced U.S. County-Level Population Projections, Total and by Sex, Race and Age, Based on the SSPs, 2020-2100

The Georeferenced U.S. County-Level Population Projections, Total and by Sex, Race and Age, Based on the SSPs, 2020-2100 consists of county-level population projection scenarios of total population, and by age, sex, and race in five-year intervals for all U.S. counties for the period 2020 - 2100. These data have numerous potential uses and can serve as inputs for addressing questions involving sub-national demographic change in the United States in the near, middle- and long-term.

Research on Ocean-Atmosphere Variability and Ecosystem Response in the Ross Sea (ROAVERRS) Project

Measurements taken off the Antarctic coast in the Ross Sea between 1996 and 1998 under the Research on Ocean-Atmosphere Variability and Ecosystem Response in the Ross Sea (ROAVERRS).

Q-thruster Breadboard Campaign Project

Q-thruster technology is a mission enabling form of electric propulsion and is already being traded by NASA&#39;s Concept Architecture Team (CAT) &amp; Human Space Flight (HSF) Architecture Team (HAT) as an electric propulsion effector for Asteroid Recovery Vehicle (ARV) mission extensibility options out to Mars.&nbsp; The Nuclear Electric Propulsion mission allows for rapid transit while allowing for a heavy, more near-term reactor design and the Solar Electric Propulsion mission allows for a power starved approach with similar mission durations to Design Reference Architecture - DRA 5.0 that would not be possible without the Q-thruster technology.

Space Mission Human Reliability Analysis (HRA) Project

The purpose of this project is to extend current ground-based Human Reliability Analysis (HRA) techniques to a long-duration, space-based tool to more effectively predict the risk associated with human actions on long-duration missions.&nbsp; By doing so, the agency will be able to focus resources on the risk drivers, such as specific training, conditioning, procedures, exercising, etc. for these future missions.&nbsp; NASA uses Probabilistic Risk Assessments (PRAs) to assess the probability of Loss of Crew (LOC) and Loss of Mission (LOM).&nbsp; PRAs take into account multiple contributing factors and their interactions, such as how the crew, software, and hardware work together to achieve mission objectives.&nbsp; HRA is used to assess the human contribution to risk in PRAs.&nbsp; Current HRA techniques were developed for ground applications using Earth based human reliability data to estimate human error probability.&nbsp; These ground-based HRA techniques have been shown to be a reasonable tool for short-duration space missions, such as Space Shuttle and lunar fly-bys.&nbsp; However, longer-duration beyond Earth orbit missions, such as asteroid and Mars missions, will require crews to be in space for 400 to 900 days with periods of extended autonomy and self-sufficiency.&nbsp; Current indications show higher risk due to fatigue, physiological effects due to extended low gravity environments, and others, which may impact HRA predictions by affecting the crew&rsquo;s cognitive abilities, as well as their physiology, and yield a higher probability for LOC and LOM (e.g. early return).&nbsp; PRAs will need to account for these effects in order to provide management, designers, and the crew our best estimate of risk.With the funding of this IR&amp;D project over the next three years, Safety &amp; Mission Assurance (S&amp;MA) will collaborate with Human Health &amp; Performance (HH&amp;P) to establish what is currently used to assess human reliability for human space programs, identify human performance factors that may be sensitive to long duration space flight, collect available historical data, and update current tools to account for performance shaping factors believed to be important to such missions.&nbsp; JSC&rsquo;s Human System Integration (HSI) initiative is a work in progress to better understand how the crew, software, and hardware work together and ensure that HSI is accounted for in future space mission designs.&nbsp;

Entry Systems Modeling (ESM) Project

Cutting edge customer driven research in two areas:Aerosciences, including the completion and delivery of two new aerothermal CFD codes, a first ever validated shock layer radiation model, and an experimental validationdatabase, at flight-relevant enthalpy, for current and future generations.EDL Materials, including the&nbsp;development and delivery of two&nbsp;new flexible TPS systems to&nbsp;enable HIAD missions, vastly&nbsp;improved ablator modeling&nbsp;capability, and improved&nbsp;polymer resins&nbsp;to enhance or enable&nbsp;future developments&nbsp;in woven, flexible and&nbsp;conformal thermal&nbsp;protection systems.

Integrated LED/Imaging Illumination Panels Demonstrated within a Small Plant Growth Chamber Project

LED light sources are ideal for plant growth systems. However, commercially available multi-color LED illumination panels are designed and manufactured to produce a single particular illumination. These panels have very specific LED colors arranged in a very specific fashion. This limits the amount of color mixing, intensity variation, and spatial arrangement that is possible, precluding passive precision illumination. There is no feedback mechanism to detect spectral shifts caused by LED aging and additionally, there is no mechanism to modulate LEDs. It is also not possible to integrate an imaging system into these panels. Furthermore, these panels are commonly operated using high voltage AC power sources, which is not ideal in a potentially wet environment. Therefore, to address these issues, custom LED illumination panels were designed and developed for this project&rsquo;s plant growth chamber.A systematic approach was taken to determine the general size, specifications, and shape of a portable plant growth unit. Once the general size and shape were finalized, the detailed design of the support structure, aeroponics, and lighting subsystems were developed. Particular attention was given to heat transfer and the expected LED thermal environment.&nbsp; Additionally, a&nbsp;computational analysis was performed to determine optimal LED nodes placement so that two different uniform illumination fields could be yielded:&nbsp; (1) for germinating plants, lower intensity light, and (2) for larger maturing plants, a brighter one.&nbsp; Also, aeroponic studies were reviewed to identify an efficient and user-friendly system that would require minimal user involvement.

HNX/DragonTIGER Instrument Development Project

Precisely identifying the species of cosmic-ray nuclei detected by a satellite or balloon instrument requires the use of several complementary detector systems. In particular, determining the nuclear charge of an incident nucleus, and so the element to which it belongs, requires precise measurements of the differential energy loss of the particle passing through a well-characterized layer of material, the velocity of the particle, and its trajectory. The goal of this project is to improve detectors for these measurements.

Advancement and New Optimizations of Microcalorimeter Arrays for High-Resolution Imaging X-ray Spectroscopy Project

"We propose to continue our successful research program in developing x-ray microcalorimeter arrays for astrophysics. This development will directly benefit not only the International X-ray Observatory (IXO), but also other possible mission concepts. We will investigate various array and pixel optimizations such as would be needed for large arrays for surveys, or arrays of fast pixels optimized for neutron star burst spectroscopy. The main emphasis of our research will be the further development of arrays of superconducting transition-edge sensors (TES) for imaging x-ray spectroscopy. We have developed a TES pixel that achieves better than 2.5-eV resolution at 6 keV, and arrays of such pixels that are sufficiently uniform in characteristics as to permit common biasing without significant compromises in the operation of any pixel. We are also making arrays of position sensitive TES pixels that show promise for use on IXO. We propose to advance both the single-pixel and position-sensitive arrays so that we can produce arrays suitable for subsystem-level read-out demonstrations of the IXO X-ray Microcalorimeter Spectrometer focal plane. Additionally, we propose to re-evaluate out successful pixel design which, while certainly suitable for use in developing the architecture of arrays and addressing detector systems issues, is not necessarily the final optimization. The performance of a TES depends on the functional form of the current, temperature, and magnetic-field dependence of the resistive transition, and also on the noise at each point on this transition surface. The parameters that describe this transition surface occupy a large phase space, and we have only probed a small portion of it. We propose to fabricate a series of test devices to explore other parts of the phase space and to learn how to engineer the superconducting transition. Recently, our understanding of the physical effects governing the observed resistive transitions has improved, th

Gamma-Ray Imager Polarimeter for Solar Flares Project

We propose here to develop the Gamma-Ray Imager/Polarimeter for Solar flares (GRIPS), the next-generation instrument for high-energy solar observations. GRIPS will provide a nearoptimal combination of high-resolution imaging, spectroscopy, and polarimetry of solar-flare gamma-ray/hard X-ray emissions from ~20 keV to &gt;~10 MeV (see Table 1). The key new technology (already developed for non-solar astrophysics by collaborator Steven Boggs) is that of a 3D position-sensitive germanium detector (3D-GeD) that allows the position and energy deposition of every photon interaction to be recorded individually, even within the same detector. With the 3D-GeDs, GRIPS can use a new single-grid imaging system, called the Multi- Pitch Rotating Modulator (MPRM), that provides a near-ideal point response function with twice the throughput per cm2 of detector area compared to the rotating modulation collimator (RMC) imaging of RHESSI. In addition, since Compton scattering (the dominant interaction at &gt;~150 keV) of the incident photons can be tracked by the 3D-GeDs, much of the background can be rejected and the polarization of photons can be determined. The proposed balloon-borne GRIPS consists of a Spectrometer/Polarimeter with sixteen 3DGeDs in four stacked 2_2 planes, together with a single rotating MPRM grid placed 8 meters away, to provide a full-Sun field-of-view and angular resolution (12.5-arcsec FWHM at gamma ray energies) sufficient to separate the footpoints of 2.2 MeV sources for almost all flares. The spacecraft-borne version of GRIPS is envisioned to have sixty-four 3D-GeDs in four stacked 4_4 planes, together with a single grid ~20 meters away, in a spinning spacecraft. Such a space GRIPS would provide a tremendous leap forward for high-energy solar physics, with order of magnitude increases in effective area for gamma-ray line (and hard X-ray) imaging, and much better angular resolution and image quality (see Table 1). A space GRIPS will allow the 0.511 MeV positron-annihilation line and the weaker prompt nuclear de-excitation lines to be imaged for the first time. Together with line shifts and shapes from the simultaneous high-resolution spectroscopy, such an instrument will provide powerful new diagnostics of the flare energy release and particle acceleration process. Furthermore, precise polarization measurements would be obtained for the first time to constrain models and determine beaming of energetic electrons.

Poverty Mapping Project: Global Subnational Infant Mortality Rates

The Poverty Mapping Project: Global Subnational Infant Mortality Rates data set consists of estimates of infant mortality rates for the year 2000. The infant mortality rate for a region or country is defined as the number of children who die before their first birthday for every 1,000 live births. The data products include a shapefile (vector data) of rates, grids (raster data) of rates (per 10,000 live births in order to preserve precision in integer format), births (the rate denominator) and deaths (the rate numerator), and a tabular data set of the same and associated data. Over 10,000 national and subnational Units are represented in the tabular and grid data sets, while the shapefile uses approximately 1,000 Units in order to protect the intellectual property of source data sets for Brazil, China, and Mexico. This data set is produced by the Columbia University Center for International Earth Science Information Network (CIESIN).

A Mission Simulation and Evaluation Platform for Terrestrial Hydrology using the NASA Land Information System (LIS) Project

Develop a mission simulation and evaluation platform for terrestrial hydrology missions by creating an end-to-end observation system simulation experiment (OSSE) platform by using NASA LIS&rsquo; data assimilation, optimization, and uncertainty estimation tools.&nbsp; This platform will enable: Quantifying the impact of observations through a variety of OSSE configurations and evaluation metrics related to terrestrial hydrologic science and applications Improving the use of products for end-use applications and science, and quantifying the mission risks for GPM and GRACE-II

Expandable Variable-Autonomy Architecture Project

Effective multi-level autonomous piloting systems require integration with safety-critical functions. The Expandable Variable-Autonomy Architecture&nbsp;(EVAA)&nbsp;project seeks to develop a hierarchal autonomous system framework that will depend on deterministic systems with higher authority to protect against catastrophic piloting faults and allow a lower level certification for the machine learning sub-systems. The multi-layered approach provides the framework for analytical systems that can learn, predict, and adapt to both routine and emergency situations.&nbsp;The objective of the project is to develop an autonomous piloting system based on analytical and learning algorithms that are capable of making effective decisions, in both nominal and potentially catastrophic situations. This will develop a safety critical framework for certification of complex autonomous systems where a small but sufficient number of levels. The system will be integrated with a certified safety critical decision makers (such as vehicle health monitoring, collision avoidance, loss of control avoidance and restricts commands of higher level critical decision makers not certified to level A software. The project will integrate these systems onto a quad-rotor micro-UAV for inexpensive and quick flight testing of concepts and develop customized, low power hardware to house the control and decision making algorithms.ASSUMPTIONS AND LIMITATIONS: The purpose of this CIF project is not to develop a full scale aircraft capable of these types of advancements, but only to develop a piloting system which make them possible. Initially, decisions associated with &ldquo;where to fly&rdquo; will be focused on and integrated into the algorithms. For this slice of the pie, the system will be required to navigate a potentially changing dense urban landscape. Routes will be planned based on time, distance, and potential risk. Additionally, terrain and obstacle avoidance algorithms will restrict these activities based on preloaded obstacle and terrain maps. Additionally, off nominal conditions such as loss of motor or other non-pre-programmed events will cause the aircraft to select landing or crashing locations based on population density maps, location of buildings, and other information. A hangar or small area will be turned into the urban city-center mockup with maps created of the mockup to facilitate flight test of concepts.Work to date: The hierarchical decision chain and framework, hardware, and embedded processing related to ground collision avoidance is in place for a sub-scale platform. Flight tests on a quad-rotor model helicopter demonstrated successful limitation of flight decisions when facing imminent ground collision.&nbsp;Looking ahead: The team is developing a full set of safety-critical functions for the sub-scale platforms and working to scale up to larger UAVs.&nbsp;Partners: University of California at Berkeley and Stanford University are developing algorithms, and the FAA is participating in the certification process.&nbsp;Benefits&nbsp;<ul><li>Increases safety: Integration of safety-critical functions improves outcomes in emergency situations.&nbsp;</li><li>Certifiable: Removal of safety-critical functions from the autonomous control enables adaptable processes to be certified to a lower level.&nbsp;</li></ul>Applications&nbsp;<ul><li>UAVs and unmanned submersibles&nbsp;</li><li>Autonomous rail transport&nbsp;</li><li>Deep space exploration&nbsp;</li><li&g