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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 91 records · Page 5

An apparatus and procedure for evaluating the toxic hazards of smoldering seating and bedding materials

An apparatus and procedure are described for evaluating the toxicity of the gases evolved from the smoldering combustion of seating and bedding materials. The method combines initiation of smoldering combustion in fabric/cushion combinations by a lighted cigarette and exposure of laboratory animals to the gases evolved. The ratio of the surface available for smoldering to the compartment volume in this apparatus is approximately five times the ratio expected in a California living room, and 100 times the ratio expected in a wide-body aircraft passenger cabin. Based on fabric/cushion combinations tested, the toxicity of gases from smoldering combustion does not appear to be a significant hazard in aircraft passenger cabins, but seems to be a basis for careful selection of materials for residential environments.

Hilado, C. J.↗

Relative toxicity of materials in fire situations

The results of toxicity testing of additional materials is presented. Relative toxicity data on polymers by generic type are presented and include wood, polyurethane flexible foam, polyvinyl chloride (PVC), acrylonitrile/butadiene/styrene (ABS), and polyisoprene (natural rubber). A second table gives relative toxicity data on fibers and fabrics including wool, nylon, rayon, polyester, and aromatic polyamide. Sulfur-containing materials seemed to exhibit the shortest times to death of laboratory animals. Some chlorine-containing polymers tended to exhibit shortest time to death also while some halogen-containing polymers gave the shortest time to incapacitation. Among fibers and fabrics, wool, silk, and polyester exhibited the shortest times to incapacitation and times to death. Difficulty in restricting generally accepted materials is discussed and attention is given to other factors important in comparing materials, such as backcoatings and relative weights.

Hilado, C. J.↗

Nutritional models for space travel from chemically defined diets

Human nutritional requirements are summarized, including recommended daily intake and maximum safe chronic intake of nutrients. The biomedical literature on various types of chemically defined diets (CDD's), which are liquid, formulated diets for enteral and total parenteral nutrition, is reviewed. The chemical forms of the nutrients in CDD's are detailed, and the compositions and sources of representative commercial CDD's are tabulated. Reported effects of CDD's in medical patients, healthy volunteers, and laboratory animals are discussed. The effects include gastrointestinal side effects, metabolic imbalances, nutrient deficiencies and excesses, and psychological problems. Dietary factors contributing to the side effects are examined. Certain human nutrient requirements have been specified more precisely as a result of long-term use of CDD's, and related studies are included. CDD's are the most restricted yet nutritionally complete diets available.

Dufour, P. A.↗

Causes of the triglyceride-lowering effect of exercise training in rats

Studies conducted with human subjects and laboratory animals have consistently shown a reduction in serum triglyceride (TG) in exercise-trained subjects. The obtained data have suggested that this decrease was due to a reduction in hepatic TG secretion. The present investigation, which was conducted with rats trained to attain a high level of spontaneous running activity, provides support for the earlier results. In addition, insights are obtained regarding the mechanism by which exercise lowers TG levels. Since the liver accounts for the vast majority of endogenous very low density lipoprotein (VLDL)-TG secretion, the fall in TG secretion rate seen in exercise-trained (ET) rats must be due to a reduction in hepatic TG secretion.

Mondon, C. E.↗

Image processing mini manual

The intent is to provide an introduction to the image processing capabilities available at the Langley Research Center (LaRC) Central Scientific Computing Complex (CSCC). Various image processing software components are described. Information is given concerning the use of these components in the Data Visualization and Animation Laboratory at LaRC.

Matthews, Christine G.↗

Data Visualization and Animation Lab (DVAL): Applications

A wide variety of software tools has been successfully used to visualize, analyze and present computational and experimental data at Langley Research Center. These tools can be categorized according to five primary uses: (1) 2-D image analysis, (2) conventional 3-D visualization, (3) volume visualization, (4) photo-realistic rendering, or (5) special purpose applications. Software is accessible in each of these categories for Langley personnel, and training or consultation can be arranged with the Data Visualization and Animation laboratory staff.

Severance, Kurt↗

The Use of NASA Light-Emitting Diode Near-Infrared Technology for Biostimulation

Studies on cells exposed to microgravity and hypergravity indicate that human cells need gravity to stimulate growth. As the gravitational force increases or decreases, the cell function responds in a linear fashion. This poses significant health risks for astronauts in long-term spaceflight. The application of light therapy with the use of NASA LEDs will significantly improve the medical care that is available to astronauts on long-term space missions. NASA LEDs stimulate the basic energy processes in the mitochondria (energy compartments) of each cell, particularly when near-infrared light is used to activate the color sensitive chemicals (chromophores, cytochrome systems) inside. Optimal LED wavelengths include 680, 730 and 880 nm and our laboratory has improved the healing of wounds in laboratory animals by using both NASA LED light and hyperbaric oxygen. Furthermore, DNA synthesis in fibroblasts and muscle cells has been quintupled using NASA LED light alone, in a single application combining 680, 730 and 880 nm each at 4 Joules per centimeter squared. Muscle and bone atrophy are well documented in astronauts, and various minor injuries occurring in space have been reported not to heal until landing on Earth. An LED blanket device may be used for the prevention of bone and muscle atrophy in astronauts. The depth of near-infrared light penetration into human tissue has been measured spectroscopically.

Whelan, Harry T.↗

Body mass, energy intake, and water consumption of rats and humans during space flight

Alteration of metabolism has been suggested as a major limiting factor to long-term space flight. In humans and primates, a negative energy balance has been reported. The metabolic response of rats to space flight has been suggested to result in a negative energy balance. We hypothesized that rats flown in space would maintain energy balance as indicated by maintenance of caloric intake and body mass gain. Further, the metabolism of the rat would be similar to that of laboratory-reared animals. We studied the results from 15 space flights lasting 4 to 19 d. There was no difference in average body weight (206 +/- 13.9 versus 206 +/- 14.8 g), body weight gain (5.8 +/- 0.48 versus 5.9 +/- 0.56 g/d), caloric intake (309 +/- 21.0 versus 309 +/- 20.1 kcal/kg of body mass per day), or water intake (200 +/- 8.6 versus 199 +/- 9.3 mL/kg of body mass per day) between flight and ground control animals. Compared with standard laboratory animals of similar body mass, no differences were noted. The observations suggested that the negative balance observed in humans and non-human primates may be due to other factors in the space-flight environment.

Non-NASA Center↗

Association between simian virus 40 and non-Hodgkin lymphoma

BACKGROUND: Non-Hodgkin lymphoma has increased in frequency over the past 30 years, and is a common cancer in HIV-1-infected patients. Although no definite risk factors have emerged, a viral cause has been postulated. Polyomaviruses are known to infect human beings and to induce tumours in laboratory animals. We aimed to identify which one of the three polyomaviruses able to infect human beings (simian virus 40 [SV40], JC virus, and BK virus) was associated with non-Hodgkin lymphoma. METHODS: We analysed systemic non-Hodgkin lymphoma from 76 HIV-1-infected and 78 HIV-1-uninfected patients, and non-malignant lymphoid samples from 79 HIV-1-positive and 107 HIV-1-negative patients without tumours; 54 colon and breast carcinoma samples served as cancer controls. We used PCR followed by Southern blot hybridisation and DNA sequence analysis to detect DNAs of polyomaviruses and herpesviruses. FINDINGS: Polyomavirus T antigen sequences, all of which were SV40-specific, were detected in 64 (42%) of 154 non-Hodgkin lymphomas, none of 186 non-malignant lymphoid samples, and none of 54 control cancers. This difference was similar for HIV-1-infected patients and HIV-1-uninfected patients alike. Few tumours were positive for both SV40 and Epstein-Barr virus. Human herpesvirus type 8 was not detected. SV40 sequences were found most frequently in diffuse large B-cell and follicular-type lymphomas. INTERPRETATION: SV40 is significantly associated with some types of non-Hodgkin lymphoma. These results add lymphomas to the types of human cancers associated with SV40.

Non-NASA Center↗

Invited review: what do we know about the effects of spaceflight on bone?

This review of the peer-reviewed literature focuses on the effects of spaceflight on bone. Studies performed in humans and laboratory animals have revealed abnormalities in bone and mineral metabolism that suggest that long-duration spaceflight will have detrimental effects on the skeleton. However, because of large gaps in our knowledge, it is not presently possible to estimate the magnitude of the health risk, individual variations in risk, effective countermeasures, or mechanism(s) of action. Specific recommendations are made for future research to ascertain risk and develop appropriate countermeasures.

NASA Discipline Musculoskeletal↗

VESGEN Software for Mapping and Quantification of Vascular Regulators

VESsel GENeration (VESGEN) Analysis is an automated software that maps and quantifies effects of vascular regulators on vascular morphology by analyzing important vessel parameters. Quantification parameters include vessel diameter, length, branch points, density, and fractal dimension. For vascular trees, measurements are reported as dependent functions of vessel branching generation. VESGEN maps and quantifies vascular morphological events according to fractal-based vascular branching generation. It also relies on careful imaging of branching and networked vascular form. It was developed as a plug-in for ImageJ (National Institutes of Health, USA). VESGEN uses image-processing concepts of 8-neighbor pixel connectivity, skeleton, and distance map to analyze 2D, black-and-white (binary) images of vascular trees, networks, and tree-network composites. VESGEN maps typically 5 to 12 (or more) generations of vascular branching, starting from a single parent vessel. These generations are tracked and measured for critical vascular parameters that include vessel diameter, length, density and number, and tortuosity per branching generation. The effects of vascular therapeutics and regulators on vascular morphology and branching tested in human clinical or laboratory animal experimental studies are quantified by comparing vascular parameters with control groups. VESGEN provides a user interface to both guide and allow control over the users vascular analysis process. An option is provided to select a morphological tissue type of vascular trees, network or tree-network composites, which determines the general collections of algorithms, intermediate images, and output images and measurements that will be produced.

Parsons-Wingerter, Patricia A.↗

Globalizing animal care and use: making the dream a reality

What will drive the globalization of animal care in the 21st century? Will targeted concerns from privately funded groups be the motivating factors? Will the threat of disease, and the concomitant hue and cry from a threatened public, be responsible for bringing nations together to collaborate on rules and regulations? The author, who is responsible for the animal use protocols on NASA's space station, explains why globalization on Planet Earth may be guided by what happens in outer space.

Animal Welfare/standards↗

SU-F-T-670: From the OR to the Radiobiology Lab: The Journey of a Small X-Ray Source

Purpose: Irradiation of small animal tumor models within laboratories is vital to radiobiological experiments. Often the animals are not able to be brought back into the lab after being taken out for irradiation. Cell biology laboratories benefit from irradiation capability available around the clock without regard to patient load in an associated radiotherapy clinic. Commercial systems are available, but bulky and expensive. Methods: An intraoperative kV irradiation system (IntraBeam™) designed to deliver spherical dose distributions to surgical cavities has been repurposed for the irradiation of cell plates and small laboratory animals. An applicator has been altered to allow for simple, open fields. Special collimators are being developed. BEAMnrc Monte Carlo simulations with the “NRC swept BEAM” source model have been performed to characterize the dose distributions, to develop optimal collimators and as basis for dose prescription. Measurements with radiochromic film and with an ionization chamber were performed to characterize the beam and to validate the simulations. Results: Using its highest setting (50 kV and 40 µA) the x-ray unit is capable of delivering dose rates over 1 Gy/min homogeneously to standard cell plates even without an optimized collimator. Smaller areas (tumors in animals) can be irradiated with significantly higher dose rates (> 20 Gy/min) depending on distance of the source to the tumor. The HVL was found to be 0.21 mm Al which means the shielding requirements for the device are easily achievable in the lab. Conclusion: A mobile irradiation facility is feasible. It will allow easier access to radiation for radiobiology experiments. The modified system is versatile in that for cell plates homogenous irradiations can be achieved through distance from the source, while for high dose rate small field irradiations the source can be brought in close proximity to the target.

60 APPLIED LIFE SCIENCES↗

Prototype Laboratory Concept

The prototype laboratory concept was developed to simplify the laboratory design process, and should be considered for use as a new laboratory design methodology. Many developing countries lack adequate public and animal health laboratories and typically do not have the economic means and the design and construction expertise to build a laboratory on their own. These countries rely on international sponsors to provide the funds necessary to design and construct a laboratory. However, these international sponsors are often located far away, making travel back and forth difficult, which leads to an increase in overall costs and delays for the project. The prototype laboratory concept and design methodology were developed to streamline the design process, saving time and money, while also minimizing the number of errors that typically arise using a traditional design process by providing well considered design decisions in advance of the project. By solving numerous detailed design issues early, this methodology will allow the time, attention and energies of the design team to be focused on addressing the specific needs of the end users, the unique design challenges related to a given site and scientific program, and the biosafety and biosecurity risks associated with the scientific activities planned to be conducted in the facility. While the concept could be expanded to cover other types of laboratories to date, it has primarily focused on supporting the implementation of good laboratory design best practices for infectious disease diagnostic and research laboratories for both the human and animal health sectors. This report presents the laboratory design concept and details associated with the modular layouts. It builds on the work previously provided in the interim prototype laboratory concept report delivered to the Cooperative Biological Engagement Program (CBEP) at the Defense Threat Reduction Agency (DTRA) in 2014. This report includes a number of revised and additional module layouts, more detailed information regarding laboratory finishes and equipment, engineering service information, electrical and lighting layouts, plumbing service information and two mechanical service options for each prototype module. Additionally, this report also includes a description of a cost estimating tool that will accompany this report and allow funding agencies to generate an approximate cost for the construction of a laboratory that utilizes the prototype laboratory concept modules. This report is intended to serve a complete document and includes all relevant information from the 2014 prototype laboratory concept report.

42 ENGINEERING↗

Effects of muscle atrophy on motor control

As a biological tissue, muscle adapts to the demands of usage. One traditional way of assessing the extent of this adaptation has been to examine the effects of an altered-activity protocol on the physiological properties of muscles. However, in order to accurately interpret the changes associated with an activity pattern, it is necessary to employ an appropriate control model. A substantial literature exists which reports altered-use effects by comparing experimental observations with those from animals raised in small laboratory cages. Some evidence suggests that small-cage-reared animals actually represent a model of reduced use. For example, laboratory animals subjected to limited physical activity have shown resistance to insulin-induced glucose uptake which can be altered by exercise training. This project concerned itself with the basic mechanisms underlying muscle atrophy. Specifically, the project addressed the issue of the appropriateness of rats raised in conventional-sized cages as experimental models to examine this phenomenon. The project hypothesis was that rats raised in small cages are inappropriate models for the study of muscle atrophy. The experimental protocol involved: 1) raising two populations of rats, one group in conventional (small)-sized cages and the other group in a much larger (133x) cage, from weanling age (21 days) through to young adulthood (125 days); 2) comparison of size- and force-related characteristics of selected test muscles in an acute terminal paradigm.

Stuart, D. G.↗

The Language Research Center's Computerized Test System for environmental enrichment and psychological assessment

In the spring of 1987, we undertook to provide environmental enrichment to nonhuman primate subjects in ways that would complement and even contribute to the bio-behaviorial science that justified the monkeys' captivity. Of course, the psychological well-being of captive primates--and indeed all research species-- has been an area of intense research activity since the 1985 amendment of the Animal Welfare Act. This mandate for researchers to ensure the psychological, as well as physical, fitness of experimental animals catalyzed the humane and scientific interests of the research community. The contemporary literature is replete with proposed means both of assaying and of providing enrichment and well-being. Notwithstanding, consensus on either assessment or intervention has yet to be reached. The paradigm we employed was modelled after successful efforts with chimpanzees. An automated test system was constructed in which subjects responded to computer tasks by manipulating a joystick. The tasks, interactive game-like versions of many of the classic testing paradigms of cognitive and comparative psychology, permitted the controlled presentation of stimuli and demands without the required presence of a human experimenter. Despite significant barriers to the success, rhesus monkeys (Macaca mulatta) and a variety of other primate species (including, of course, humans) have mastered the skills necessary for testing in this paradigm. Previous experiments have illustrated the utility of the test system for addressing questions of learning, memory, attention, perception, and motivation. Additional data have been reported to support the contention that the Language Research Center's Computerized Test System (LRC-CTS) serves its other raison d'etre--providing environmental enrichment and assessing psychological well-being. This paper is designed to augment previous descriptions of the technology and the paradigm for scientists and caretakers interested in environmental enrichment and performance assessment with primates.

Non-NASA Center↗

Hindlimb Suspension (HLS) in Rodents for the Study of Intracranial Pressure, Molecular and Histologic Changes in the Eye, and CSF Production Regulation and Resorption: A Status Report of Two Studies

This status report corresponds to two studies tied to an animal experiment being executed at the University of California Davis (Charles Fuller's laboratory). The animal protocol uses the well-documented rat hindlimb suspension (HLS) model, to examine the relationship between cephalic fluid shifts and the regulation of intracranial (ICP) and intraocular (IOP) pressures as well as visual system structure and function. Long Evans rats are subjected to HLS durations of 7, 14, 28 and 90 days. Subgroups of the 90-day animals are studied for recovery periods of 7, 14, 28 or 90 days. All HLS subjects have age-matched cage controls. Various animal cohorts are planned for this study: young males, young females and old males. In addition to the live measures (ICP by telemetry, IOP and retinal parameters by optical coherence tomography) which are shared with the Fuller study, the specific outcomes for this study include: -Gene expression analysis of the retina -Histologic analysis - Analysis of the microvasculature of retina flat mounts by NASA's VESsel GENeration Analysis (VESGEN) Software. To date, the young male and female cohorts are being completed. Due to the need to keep technical variation to a minimum, the histologic and genomic analyses have been delayed until all samples from each cohort are available and can be processed in a single batch per cohort. The samples received so far correspond to young males sacrificed at 7,14, 28 and 90 days of HLS and at 90 days of recovery; and from young females sacrificed at 7, 14 and 28 of HLS. A complementary study titled: "A gene expression and histologic approach to the study of cerebrospinal fluid (CSF) production and outflow in hindlimb suspended rats" seeks to study the molecular components of CSF production and outflow modulation as a result of HLS, bringing a molecular and histologic approach to investigate genome wide expression changes in the arachnoid villi and choroid plexus of HLS rats compared to rats in normal posture.

Theriot, C. A.↗

Optimization of Diode Laser System to Treat Benign Prostate Hyperplasia Final Report CRADA No. TSB-1154-95

Benign prostate hyperplasia (BPH) is a pervasive condition of enlargement of the male prostate gland which leads to several urinary difficulties ranging from hesitancy to incontinence to kidney dysfunction in severe cases. Currently the most common therapy is transurethral resection of the prostate (TURP) utilizing an electrosurgical device. Although TURP is largely successful, new BPH therapy methods are desired to reduce the cost and recovery time, improve the success rate, and reduce side effects. Recently, lasers have been introduced for this purpose. Indigo Medical Inc. is currently engaged in the development, testing, and preparation for sales of a new diode laser based BPH therapy system. The development is based on laboratory experiments, animal studies, and a limited FDA-approved clinical trial in the US and in other countries. The addition of sophisticated numerical modeling, of the sort that has been highly developed at Lawrence Livermore National Laboratory, can greatly aid in the design of the system and treatment protocol. The benefits to DOE include the maintenance and advancement of numerical modeling expertise in radiation-matter interactions of the sort essential for the stockpile stewardship, inertial confinement fusion, and advanced manufacturing, and the push on advanced scientific computational methods, ultimately in areas such as 3-D transport.

42 ENGINEERING↗