3,324 research outputs found

    Plant Atrium System for Food Production in NASA's Deep Space Habitat Tests

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    In preparation for future human exploration missions to space, human habitat designs and concepts need to be tested to assess integration issues, power requirements, crew operations, and technology I subsystem performance. One potential subsystem for early habitats is supplemental food production. Fresh foods, such as vegetables and small fruits, could be harvested on a continuous basis to improve the diet and quality of life. The system would need to fit conveniently into the habitat and not interfere with other components or operations. To test this concept, a plant growing "atrium" was designed to surround the lift between the lower and upper modules of the Deep Space Habitat and deployed at NASA DRA TS test site in 2011 and at NASA's JSC in 20I2. With this approach, un-utilized volume provided an area for vegetable growth. For the 20 II test, mizuna, lettuce, basil, radish and sweetpotato plants were grown in trays using commercially available red I blue LED light fixtures. Seedlings were transplanted into the atrium and cared for by the crew. Plants were then harvested two weeks later following completion of the test. In 20I2, mizuna, lettuce, and radish plants were grown similarly but under flat panel banks of white LEDs. In 20 I2, the crew went through plant harvesting, including sanitizing the leafy greens and radishes, which were then consumed. Each test demonstrated successful production of vegetables within a functional hab module. The round red I blue LEDs for the 20Il test lighting cast a purple light in the hab, and were less uniformly distributed over the plant trays. The white LED panels provided broad spectrum light with more uniform distribution. Post-test questionnaires showed that the crew enjoyed tending and consuming the plants, and that the white LED light in 2012 provided welcome extra light for the main hab area

    TCT-142 Clinical Characteristics and Outcomes of Patients Undergoing Transcatheter Aortic Valve Replacement With STS PROM of ≤3%

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    Background Transcatheter aortic valve replacement (TAVR) is the preferred treatment for most patients with aortic stenosis deemed at intermediate or higher risk for surgical aortic valve replacement (SAVR). Determination of the risk of SAVR is mainly based on the Society of Thoracic Surgeons (STS) risk calculator. However, federal regulations permit the heart team latitude to offer TAVR for patients with ≤3% predicted risk of mortality (PROM) whose perceived risk is not adequately accounted for by the STS risk model. Limited data is available on the clinical characteristics and outcomes of these patients Methods The study group involved 2,539 patients who underwent TAVR from 2013 to 2017 within 7 hospitals in 5 Western states in the Providence St. Joseph Health system. The local TAVR site staff completed surveys identifying the clinical factors driving the heart team\u27s decision to proceed with TAVR. Clinical data was also collected per the TVT registry requirements. Results We identified 332 TAVR patients with STS PROM ≤3% and 2,207 patients with STS PROM \u3e3%. The percentage of TAVR patients with an STS PROM increased over time from 5.1% in 2013 to 16.6% in 2017. The most common factors (≥1 possible) influencing the heart team\u27s decision to proceed with TAVR in the ≤3% STS PROM group were frailty (63%), hostile chest (23%), severe lung disease (14%), morbid obesity (10%), and liver disease (8%). The baseline characteristics and outcomes of both groups are listed in the Table. Conclusion The proportion of TAVR patients with STS PROM ≤3% tripled from 2013 to 2017. In comparison to those with STS PROM \u3e3%, they were younger and more often men. The most common reasons driving the decision to favor TAVR over SAVR were frailty, hostile chest, and severe lung disease. TAVR patients with STS PROM ≤3% had shorter hospital stays and were more likely to be alive at 1 year

    Noninflammatory Changes of Microglia Are Sufficient to Cause Epilepsy.

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    Microglia are well known to play a critical role in maintaining brain homeostasis. However, their role in epileptogenesis has yet to be determined. Here, we demonstrate that elevated mTOR signaling in mouse microglia leads to phenotypic changes, including an amoeboid-like morphology, increased proliferation, and robust phagocytosis activity, but without a significant induction of pro-inflammatory cytokines. We further provide evidence that these noninflammatory changes in microglia disrupt homeostasis of the CNS, leading to reduced synapse density, marked microglial infiltration into hippocampal pyramidal layers, moderate neuronal degeneration, and massive proliferation of astrocytes. Moreover, the mice thus affected develop severe early-onset spontaneous recurrent seizures (SRSs). Therefore, we have revealed an epileptogenic mechanism that is independent of the microglial inflammatory response. Our data suggest that microglia could be an opportune target for epilepsy prevention

    The acquisition of Sign Language: The impact of phonetic complexity on phonology

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    Research into the effect of phonetic complexity on phonological acquisition has a long history in spoken languages. This paper considers the effect of phonetics on phonological development in a signed language. We report on an experiment in which nonword-repetition methodology was adapted so as to examine in a systematic way how phonetic complexity in two phonological parameters of signed languages — handshape and movement — affects the perception and articulation of signs. Ninety-one Deaf children aged 3–11 acquiring British Sign Language (BSL) and 46 hearing nonsigners aged 6–11 repeated a set of 40 nonsense signs. For Deaf children, repetition accuracy improved with age, correlated with wider BSL abilities, and was lowest for signs that were phonetically complex. Repetition accuracy was correlated with fine motor skills for the youngest children. Despite their lower repetition accuracy, the hearing group were similarly affected by phonetic complexity, suggesting that common visual and motoric factors are at play when processing linguistic information in the visuo-gestural modality

    Heterogenized Iridium Water-Oxidation Catalyst from a Silatrane Precursor

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    A pentamethylcyclopentadienyl (Cp*) iridium water-oxidation precatalyst was modified to include a silatrane functional group for covalent attachment to metal oxide semiconductor surfaces. The heterogenized catalyst was found to perform electrochemically driven water oxidation at an overpotential of 462 mV with a turnover number of 304 and turnover frequency of 0.035 s^(–1) in a 0.1 M KNO3 electrolyte at pH 5.8. Computational modeling of the experimental IR spectra suggests that the catalyst retains its Cp* group during the first hour of catalysis and likely remains monomeric

    Lithium isotope evidence for enhanced weathering and erosion during the Paleocene-Eocene Thermal Maximum

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    The Paleocene-Eocene Thermal Maximum (PETM; ~55.9 Ma) was a geologically rapid warming period associated with carbon release, which caused a marked increase in the hydrological cycle. Here, we use lithium (Li) isotopes to assess the global change in weathering regime, a critical carbon drawdown mechanism, across the PETM. We find a negative Li isotope excursion of ~3‰ in both global seawater (marine carbonates) and in local weathering inputs (detrital shales). This is consistent with a very large delivery of clays to the oceans or a shift in the weathering regime toward higher physical erosion rates and sediment fluxes. Our seawater records are best explained by increases in global erosion rates of ~2× to 3× over 100 ka, combined with model-derived weathering increases of 50 to 60% compared to prewarming values. Such increases in weathering and erosion would have supported enhanced carbon burial, as both carbonate and organic carbon, thereby stabilizing climate
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