3,998 research outputs found

    Future Plans in US Flight Missions: Using Laser Remote Sensing for Climate Science Observations

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    Laser Remote Sensing provides critical climate science observations necessary to better measure, understand, model and predict the Earth's water, carbon and energy cycles. Laser Remote Sensing applications for studying the Earth and other planets include three dimensional mapping of surface topography, canopy height and density, atmospheric measurement of aerosols and trace gases, plume and cloud profiles, and winds measurements. Beyond the science, data from these missions will produce new data products and applications for a multitude of end users including policy makers and urban planners on local, national and global levels. NASA Missions in formulation including Ice, Cloud, and land Elevation Satellite (ICESat 2) and the Deformation, Ecosystem Structure, and Dynamics of Ice (DESDynI), and future missions such as the Active Sensing of CO2 Emissions over Nights, Days and Seasons (ASCENDS), will incorporate the next generation of LIght Detection And Ranging (lidar) instruments to measure changes in the surface elevation of the ice, quantify ecosystem carbon storage due to biomass and its change, and provide critical data on CO 2 in the atmosphere. Goddard's plans for these instruments and potential uses for the resulting data are described below. For the ICESat 2 mission, GSFC is developing a micro-pulse multi-beam lidar. This instrument will provide improved ice elevation estimates over high slope and very rough areas and result in improved lead detection for sea ice estimates. Data about the sea ice and predictions related to sea levels will continue to help inform urban planners as the changes in the polar ice accelerate. DESDynI is planned to be launched in 2017 and includes both lidar and radar instruments. GSFC is responsible for the lidar portion of the DESDynI mission and is developing a scanning laser altimeter that will measure the Earth's topography, the structure of tree canopies, biomass, and surface roughness. The DESDynI lidar will also measure and predict the response of ice masses to climate change and impact on sea level. Data from the lidar will ultimately be fused with radar data products with heretofore unseen results and applications. The 3-D structure of forests is critical to understanding the impact of land use and associated landscape changes on the habitat of life forms and consequently on their biodiversity. Lidar instruments are also under development to measure trace gases in the atmospheric such as CO2 and methane. GSFC is developing an active measurement approach to determine the CO2 column density and surface pressure for the proposed ASCENDS mission. The objective of this approach is to produce data on the amounts of anthropogenic and organic CO2 in the atmosphere with sufficient accuracy to meet the needs of target users including state, federal and international users as well as policy-related legislative, regulatory, and voluntary carbon-related management groups local to international interests. In summary, NASA will continue to rely on laser remote sensing for critical climate science observations and is committed to the development of the next generation of lidar instruments for a range of applications

    Quantifying the Economic Costs of Global Warming

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    Climate change poses a threat to the well-being of people across the globe. Rising global temperatures will increase the frequency and magnitude of extreme climate events, threatening the lives and livelihoods of vulnerable people. Yet the magnitude and persistence of these economic impacts are poorly understood, making it difficult both to design equitable mitigation and adaptation strategies and to hold emitters accountable for the impacts of their emissions. In this thesis, I combine methods from detection and attribution, climate projection, and causal inference to understand the global economic consequences of past and future climate change. I show that two extreme climate events that have not been previously integrated into climate-economy analyses---heat waves and El Niño events---reduce economic growth globally. But these impacts are highly unequal across the globe: Heat waves have their greatest effects in warm regions, and El Niño events primarily harm highly teleconnected countries. As a result, these effects fall most severely on the people that have contributed least to warming, a sign of the inequities embedded in the causes and consequences of global warming. To quantitively understand these inequities and support efforts to hold major emitters accountable for the impacts of their emissions, I develop an end-to-end attribution framework that links individual emitters to the economic effects of the warming induced by their emissions. I show that warming from the emissions of high-income countries in the global North have driven billions of dollars of economic losses in low-income, low-emitting countries. I then combine this framework with my previous results on extreme heat, showing that the emissions of major fossil fuel firms have intensified heat waves, and the resulting economic penalties, across the global tropics. These first-of-their-kind results lend scientific support to emerging discussions over climate liability and loss and damage payments. More broadly, these findings together highlight the already-emerging economic threat of global warming, raising the importance of climate mitigation and adaptation in order to avoid accelerating losses to the most vulnerable people around the globe

    Studies of the effect of lipid micelles on mitochondrial malate dehydrogenase.

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    Beyond cosmopolitanism and nationalism : diasporic Chinese and neo-nationalism in China and Thailand

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    This article highlights the dynamic interaction between Chinese, Thai, and SinoThai identity construction, on the one hand, and the mutual production of domestic and international politics, on the other. It questions how nationalism and cosmopolitanism are formulated by arguing against the popular notion that a diaspora is a cosmopolitan community situated in a foreign nation. Diasporic public spheres are critically examined to show how Sino-Thai identity is produced in relation first to neo-nationalism in Thailand and China, and second in specific contexts within Thailand that call into question essential notions of Thai, Chinese, and overseas Chinese identity. Diasporas thus both construct and deconstruct the seemingly opposing forces of nationalism and cosmopolitanism. The article uses the ethnographic approach of anthropological constructivism to build on sociological constructivism's focus on national identity, norms, and formal institutions. Rather than looking to culture as a substance, the article highlights how culture takes shape in context-sensitive relations between identity and difference. This ethnographic approach encourages one to look in different places for world politics, shifting away from state actors to transnational nonstate actors, from geopolitics and international political economy to economic culture, and from law and institutions as the foundations of international society to the less formal organizations of the diasporic public sphere. Diaspora thus not only adds new data to arguments about global/local relations-it helps one question the structures of world politics that look to the opposition between cosmopolitanism and nationalism

    Animal studies on Spacelab-3

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    The flight of two squirrel monkeys and 24 rates on Spacelab-3 was the first mission to provide hand-on maintenance on animals in a laboratory environment. With few exceptions, the animals grew and behaved normally, were free of chronic stress, and differed from ground controls only for gravity-dependent parameters. One of the monkeys exhibited symptoms of space sickness similar to those observed in humans, which suggests squirrel monkeys may be good models for studying the space-adaptation syndrome. Among the wide variety of parameters measured in the rats, most notable was the dramatic loss of muscle mass and increased fragility of long bones. Other interesting rat findings were those of suppressed interferon production by spleen cells, defective release of growth hormone by somatotrophs, possible dissociation of circadian pacemakers, changes in hepatic lipid and carbohydrate metabolism, and hypersensitivity of marrow cells to erythopoietin. These results portend a strong role for animals in identifying and elucidating the physiological and anatomical responses of mammals to microgravity

    Textualizing Cultures: Thinking beyond the MIT Controversy

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    Spinal V2b neurons reveal a role for ipsilateral inhibition in speed control

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    The spinal cord contains a diverse array of interneurons that govern motor output. Traditionally, models of spinal circuits have emphasized the role of inhibition in enforcing reciprocal alternation between left and right sides or flexors and extensors. However, recent work has shown that inhibition also increases coincident with excitation during contraction. Here, using larval zebrafish, we investigate the V2b (Gata3+) class of neurons, which contribute to flexor-extensor alternation but are otherwise poorly understood. Using newly generated transgenic lines we define two stable subclasses with distinct neurotransmitter and morphological properties. These V2b subclasses synapse directly onto motor neurons with differential targeting to speed-specific circuits. In vivo, optogenetic manipulation of V2b activity modulates locomotor frequency: suppressing V2b neurons elicits faster locomotion, whereas activating V2b neurons slows locomotion. We conclude that V2b neurons serve as a brake on axial motor circuits. Together, these results indicate a role for ipsilateral inhibition in speed control

    MARINE CORPS OFFICER ATTITUDES TOWARD THE REPEAL OF "DON'T ASK, DON'T TELL"

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    "Don't Ask, Don't Tell" (DADT) prohibited gays from serving openly in the military from December 1993 to September 2011. The present study, conducted over one year after DADTs repeal, utilized a survey of attitudes toward DADT that was previously administered to Marine Corps officers at the Naval Postgraduate School (NPS) in 1999, 2004, and 2010. This survey, re-administered to NPS Marine officers in November 2012, addressed the following areas policy, cohesion, leadership, tolerance, unit effectiveness, and military readiness. A comparison of results from the four surveys shows a clear trend of increasing acceptance toward homosexuals in the military. Levels of acceptance tended to vary by Military Occupational Specialty and length of service. Additionally, many Marine officers continued to express concern about habitability and personal comfort. These and other issues were further explored with Marine officers in three focus-group sessions. Overall, study results indicated strong agreement that the current policy protects the rights of all Marines, regardless of sexual orientation. Finally, Marine officers expressed confidence that the training they received adequately prepared them to execute the repeal of DADT. The thesis includes appendices with survey trend data from 1999 to 2012 and response frequencies from a concurrent survey of Navy officers.http://archive.org/details/marinecorpsoffic1094532802Captain, United States Marine Corps;Lieutenant Commander, United States NavyApproved for public release; distribution is unlimited

    In vivo Dopamine Efflux is Decreased in Striatum of both Fragment (R6/2) and Full-Length (YAC128) Transgenic Mouse Models of Huntington's Disease

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    Huntington's disease (HD) is characterized by numerous alterations within the corticostriatal circuitry. The striatum is innervated by a dense array of dopaminergic (DA) terminals and these DA synapses are critical to the proper execution of motor functions. As motor disturbances are prevalent in HD we examined DA neurotransmission in the striatum in transgenic (tg) murine models of HD. We used in vivo microdialysis to compare extracellular concentrations of striatal DA in both a fragment (R6/2) model, which displays a rapid and severe phenotype, and a full-length (YAC128) model that expresses a more progressive phenotype. Extracellular striatal DA concentrations were significantly reduced in R6/2 mice and decreased concomitantly with age-dependent increasing motor impairments on the rotarod task (7, 9, and 11 weeks). In a sample of 11-week-old R6/2 mice, we also measured tissue concentrations of striatal DA and found that total levels of DA were significantly depleted. However, the loss of total DA content (<50%) was insufficient to account for the full extent of DA depletion in the extracellular fluid (ECF; ∼75%). We also observed a significant reduction in extracellular DA concentrations in the striatum of 7-month-old YAC128 mice. In a separate set of experiments, we applied d-amphetamine (AMPH; 10 μm) locally into the striatum to stimulate the release of intracellular DA into the ECF. The AMPH-induced increase in extracellular DA levels was significantly blunted in 9-week-old R6/2 mice. There also was a decrease in AMPH-stimulated DA efflux in 7-month-old YAC128 mice in comparison to WT controls, although the effect was milder. In the same cohort of 7-month-old YAC128 mice we observed a significant reduction in the total locomotor activity in response to systemic AMPH (2 mg/kg). Our data demonstrate that extracellular DA release is attenuated in both a fragment and full-length tg mouse model of HD and support the concept of DA involvement in aspects of the syndrome

    There\u27s Only One Story The Roses Tell

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    https://digitalcommons.library.umaine.edu/mmb-vp/6643/thumbnail.jp
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