Skip to main content
Home

Navigation Menu

  • Back
  • About
    • Back
    • About

      Contact Us

      Business Address
      5241 Broad Branch Rd. NW

      Washington , DC 20015
      United States place Map
      Call Us (202) 387-640
    • Who We Are
      • Back
      • Leadership
      • Board & Advisory Committee
      • Initiatives
      • Financial Stewardship
      • Awards & Accolades
      • History
    • Connect with Us
      • Back
      • Outreach & Education
      • Newsletter
      • Yearbook
    • Working at Carnegie

    Contact Us

    Business Address
    5241 Broad Branch Rd. NW

    Washington , DC 20015
    United States place Map
    Call Us (202) 387-6400
  • Research
    • Back
    • Research Areas & Topics
    • Research Areas & Topics
      • Back
      • Research Areas
      • From genomes to ecosystems and from planets to the cosmos, Carnegie Science is an incubator for cutting-edge, interdisciplinary research.
      • Astronomy & Astrophysics
        • Back
        • Astronomy & Astrophysics
        • Astrophysical Theory
        • Cosmology
        • Distant Galaxies
        • Milky Way & Stellar Evolution
        • Planet Formation & Evolution
        • Solar System & Exoplanets
        • Telescope Instrumentation
        • Transient & Compact Objects
      • Earth Science
        • Back
        • Earth Science
        • Experimental Petrology
        • Geochemistry
        • Geophysics & Geodynamics
        • Mineralogy & Mineral Physics
      • Ecology
        • Back
        • Ecology
        • Atmospheric Science & Energy
        • Adaptation to Climate Change
        • Water Quality & Scarcity
      • Genetics & Developmental Biology
        • Back
        • Genetics & Developmental Biology
        • Adaptation to Climate Change
        • Developmental Biology & Human Health
        • Genomics
        • Model Organism Development
        • Nested Ecosystems
        • Symbiosis
      • Matter at Extreme States
        • Back
        • Matter at Extreme States
        • Extreme Environments
        • Extreme Materials
        • Mineralogy & Mineral Physics
      • Planetary Science
        • Back
        • Planetary Science
        • Astrobiology
        • Cosmochemistry
        • Mineralogy & Mineral Physics
        • Planet Formation & Evolution
        • Solar System & Exoplanets
      • Plant Science
        • Back
        • Plant Science
        • Adaptation to Climate Change
        • Nested Ecosystems
        • Photosynthesis
        • Symbiosis
    • Divisions
      • Back
      • Divisions
      • Biosphere Sciences & Engineering
        • Back
        • Biosphere Sciences & Engineering
        • About

          Contact Us

          Business Address
          5241 Broad Branch Rd. NW

          Washington , DC 20015
          United States place Map
          Call Us (202) 387-640
        • Research
        • Culture
        • Path to Pasadena
      • Earth & Planets Laboratory
        • Back
        • Earth & Planets Laboratory
        • About

          Contact Us

          Business Address
          5241 Broad Branch Rd. NW

          Washington , DC 20015
          United States place Map
          Call Us (202) 387-640
        • Research
        • Culture
        • Campus
      • Observatories
        • Back
        • Observatories
        • About

          Contact Us

          Business Address
          5241 Broad Branch Rd. NW

          Washington , DC 20015
          United States place Map
          Call Us (202) 387-640
        • Research
        • Culture
        • Campus
    • Instrumentation
      • Back
      • Instrumentation
      • Our Telescopes
        • Back
        • Our Telescopes
        • Magellan Telescopes
        • Swope Telescope
        • du Pont Telescope
      • Observatories Machine Shop
      • EPL Research Facilities
      • EPL Machine Shop
      • Mass Spectrometry Facility
      • Advanced Imaging Facility
  • People
    • Back
    • People
      Observatory Staff

      Featured Staff Member

      Staff Member

      Staff Member

      Professional Title

      Learn More
      Observatory Staff

      Search For

    • Search All People
      • Back
      • Staff Scientists
      • Leadership
      • Biosphere Science & Engineering People
      • Earth & Planets Laboratory People
      • Observatories People
    Observatory Staff
    Dr. Allan Spradling
    Staff Scientist, Emeritus Director

    Featured Staff Member

    Allan Spradling portait

    Dr. Allan Spradling - HHMI

    Staff Scientist, Emeritus Director

    Learn More
    Observatory Staff
    Dr. Allan Spradling
    Staff Scientist, Emeritus Director

    Allan Spradling and his team focus on the biology of reproduction, particularly oogenesis — the process of egg formation.

    Search For

    Search All Staff
  • Events
    • Back
    • Events
    • Search All Events
      • Back
      • Biosphere Science & Engineering Events
      • Earth & Planets Laboratory Events
      • Observatories Events

    Upcoming Events

    Events

    Events

    People sit on the shore at sunset.
    Workshop

    Seventh Workshop on Trait-based Approaches to Ocean Life

    Pacific Grove, CA

    August 4

    9:00pm PDT

    A gray-true color Mercury next to a colorized Mercury that combines visible and near infrared light to highlight the differences in surface composition.
    Public Program

    Mercury beyond MESSENGER: Recent Progress from the Earth and Planets Laboratory

    Anne Pommier, Staff Scientist, EPL

    June 5

    6:30pm EDT

    brian-yurasits-EQlwRGr5sqk-unsplash.jpg
    Seminar

    Microenvironmental ecology and symbiosis

    Dr. Michael Kühl

    May 14

    11:00am PDT

  • News
    • Back
    • News
    • Search All News
      • Back
      • Biosphere Science & Engineering News
      • Earth & Planets Laboratory News
      • Observatories News
      • Carnegie Science News
    News

    Recent News

    News

    Read all News
    Vera Rubin at Carnegie Science’s former Department of Terrestrial Magnetism, now part of the Earth and Planets Laboratory, in 1972 usi
    Breaking News
    June 18, 2025

    10 Iconic Photographs of Vera Rubin

    A gray-true color Mercury next to a colorized Mercury that combines visible and near infrared light to highlight the differences in surface composition.
    Breaking News
    June 17, 2025

    Inside Mercury: What Experimental Geophysics Is Revealing About Our Strangest Planet

    Vera Rubin at Lowell Observatory, 69-inch [i.e., 72-inch] Telescope (Kent Ford in white helmet)
    Breaking News
    June 17, 2025

    Things Named After Carnegie Astronomer Vera Rubin

  • Donate
    • Back
    • Donate
      - ,

    • Make a Donation
      • Back
      • Support Scientific Research
      • The Impact of Your Gift
      • Planned Giving
    Jo Ann Eder

    I feel passionately about the power of nonprofits to bolster healthy communities.

    - Jo Ann Eder , Astronomer and Alumna

    Header Text

    Postdoctoral alumna Jo Ann Eder is committed to making the world a better place by supporting organizations, like Carnegie, that create and foster STEM learning opportunities for all. 

    Learn more arrow_forward
  • Home

Abstract
Plans for decarbonized electricity systems rely on projections of highly uncertain future technology costs. We use a stylized model to investigate the influence of future cost uncertainty, as represented by different projections in the National Renewable Energy Laboratory 2021 Annual Technology Baseline dataset, on technology mixes comprising least-cost decarbonized electricity systems. Our analysis shows that given the level of future cost uncertainty as represented by these projections, it is not possible to predict with confidence which technologies will play a dominant role in future least-cost carbon emission-free energy systems. Successful efforts to reduce costs of individual technologies may or may not lead to system cost reductions and widespread deployments, depending on the success of cost-reduction efforts for competing and complementary technologies. These results suggest a portfolio approach to reducing technology costs. Reliance on uncertain cost breakthroughs risks costly outcomes. Iterative decision-making with learning can help mitigate these risks.
View Full Publication open_in_new
Abstract
Efforts to make food systems more sustainable have emphasized reducing adverse environmental impacts of agriculture. In contrast, chemical and biological processes that could produce food without agriculture have received comparatively little attention or resources. Although there is a possibility that someday a wide array of attractive foods could be produced chemosynthetically, here we show that dietary fats could be synthesized with <0.8 g CO2-eq kcal(-1), which is much less than the >1.5 g CO2-eq kcal(-1) now emitted to produce palm oil in Brazil or Indonesia. Although scaling up such synthesis could disrupt agricultural economies and depend on consumer acceptance, the enormous potential reductions in greenhouse gas emissions as well as in land and water use represent a realistic possibility for mitigating the environmental footprint of agriculture over the coming decade.
View Full Publication open_in_new
Abstract
The 2022 Indus floods in Pakistan underscore the urgency of adapting to more frequent and severe natural disasters in a warming world. Post-disaster reconstruction offers a chance to built-in adaptation measures, but identifying feasible and cost-effective adaptation options is challenging, especially in data-scarce regions. Here we employ a high-resolution rapid assessment of flood stages combined with demographic data to identify adaptation opportunities and costs for the Indus floodplains. Under a plausible set of assumptions, we find that rebuilding houses in a flood-proof, elevated manner ('moving up') or (temporary) relocation ('moving over') could have protected 13%, respectively 16% of people affected during the 2022 floods, while the remaining 70% of people were exposed to shallow water levels that could have been addressed with low-cost adaptation. Implementing these measures during ongoing reconstruction could be an effective adaptation to future floods but will come with substantial costs. Rebuilding in a flood-proofed manner ('moving up') alone would already increase costs by 26%-63% ($1.5bn-$3.6bn) compared to estimated reconstruction costs without adaptation ($5.8bn). Additional costs would be incurred by relocation and adaptation of other infrastructure. The absence of local flood stage and socio-economic data creates uncertainty and points to future research avenues. Yet, our prototype approach demonstrates the value of rapid assessments for guiding post-disaster adaptation of livelihoods to future floods.
View Full Publication open_in_new
Abstract
Potential temporal and causal connections among various geologic events have long been discussed in the geological literature. More recently, signs of common periodicities in these episodes have been reported. In this study of correlation and cyclicity of geologic occurrences, we review and synthesize previous work, and utilize the newest data for various major events over the the last 260 My. These include, 1) high-quality radio-isotopic age determinations (U-Pb zircon and 40Ar/39Ar) for continental flood-basalt (CFB) eruptions; 2) the dates of widespread intervals of ocean anoxia; 3) the latest published dates of marine and non-marine extinction events, 4) hyper-thermal climate intervals and 5) the occurrences of stratigraphic Hg anomalies, and non-radiogenic Os -isotope anomalies as potential proxies for large-scale basaltic volcanism. Times of at least 13 of 17 intervals of anoxic oceans are marked by stratigraphic Hg-anomalies, pointing to contemporaneous LIP eruptions, and 5 anoxic intervals in the warm Cretaceous Period are correlated with marine Os-isotope ratios suggesting potential LIP hydrothermal activity. Nine of the ocean-anoxic intervals are thus far correlated with times of marine-extinction episodes, and 8 of those anoxia/extinction co-events are significantly correlated with the ages of the well-dated CFB eruptions. Seven of the marine-extinction events and associated CFB volcanism are coeval with extinctions of non-marine vertebrates, supporting global catastrophic volcano-climatic episodes devastating both marine and terrestrial environments.New digital circular spectral analyses revealed significant underlying cycles of-32.5 My and -26.2 My in the ages of the anoxic events and marine extinctions. Spectral analysis of the latest high-quality ages of the CFBs resulted in similar significant periodicities of 32.8 My and 12.9 My (-26.2/2 My harmonic). High-frequency periods at various harmonics appear at-6.4 My, 8.4 My and 9.7 My in each of the three spectra.These findings support a multi-factor extinction scenario in which release of massive amounts of CO2 and perhaps CH4 mostly from CFB magmas (and in some cases sub-volcanic intrusions into carbon-rich deposits), led to very warm climate intervals with near-lethal to lethal hyper-thermal conditions on land and in the sea. Concurrent release of halogens from CFB eruptions could also have decimated the global ozone layer. In many cases, the warm oceans became acidic, and developed anoxic to euxinic conditions, even up to the ocean surface, contributing to the causes of the marine extinctions. Additionally, four extinction events (late Eocene, end -Cretaceous, end-Jurassic and mid-Norian) correlate closely with the ages of the 4 largest impacts (craters >= 100 km in diameter) over the same period, capable of producing severe climatic effects and extinctions.The potential dominant underlying-33-My and 26-My cycles, reported in these and other correlated tectonic, climatic, and biotic events over the last 260 My and beyond, are likely related to the Earth's tectonic-volcanic rhythms, but the similarities with known Milankovitch Earth orbital periods and their amplitude modulations, and with known Galactic cycles, suggest that, contrary to conventional wisdom, the geological events and cycles may be paced by astronomical factors.
View Full Publication open_in_new
Abstract
Movement of radioactive isotopes in the phloem tissue was investigated by the stripping technic similar to that used by Stout and Hoagland, i.e., the bark was separated from the wood and a piece of paraffined paper was inserted between them. When P32 was introduced to the leaves, it moved both upward and downward chiefly through the phloem tissue. C14 invariably moved in the phloem when supplied to the leaves in the form of C14O2. The simultaneous movement of these 2 radioactive tracers in opposite directions in the phloem was studied by supplying them separately to the leaves at each end of a stripped area. Their radioactivities were separated by the dry combustion method. Radioactivity due to C14 was re-covered in the BaCO3 fraction, while that due to P32 was re-tained in the ash. By carrying out this expt. under continuous light for a short period of time, considerable amt. of both P32 and C14 were found in the phloem of the stripped area. This is considered to be conclusive evidence for the simultaneous movement of P32 and C14 in opposite directions in the phloem tissue.
View Full Publication open_in_new
Abstract
The Hill reaction was followed by the reduction of an oxidation-reduction dye, 2, 6-dichlorophenol indophenol. Samples of the mixture of the dye and chloroplasts were exposed to monochromatic light obtained from a Wood replica grating monochro-mator. The degree of dye reduction produced by exposure was measured with a Beckman spectrophotometer at the wave length corresponding to the absorption peak of the dye. The action spectrum of this reaction was obtained by plotting the effectiveness of light against wave length. This curve was compared with the absorption spectrum of chloroplast suspension and the photosynthetic action spectra of Chlorella and Ulva. Quantum requirement for this reaction was calculated. All findings are consistent with the view that Hill reaction is identical with the primary photochemical step of photosynthesis. The action spectrum of this reaction thus may be interpreted as a measure of the spectrum effectiveness for the photosynthetic process in chlorophasts of a higher plant.
View Full Publication open_in_new
Abstract
Cuttings of garnet peridotite were collected between 603.2 and 683.5 in in the CCSD at Donghai. Minerals were separated by various methods and handpicked under a binocular microscope. The selected minerals were identified by SEM-EDS, microprobe, Laser Raman, and EDXD ( Synchrontron X-ray Diffraction). A number of unusual minerals have been recognized from the cuttings, e. g., moissanite, w stite, native Fe, native Cr, native Ni, native An, native Cu, native Al, taenite, kamacite, Ni-Fe-Cr alloy, Ni-Fe alloy, Fe-Cr alloy, Si-Fe alloy (Fe3Sgamma), and Co-Ni alloy. Two grains of Fe2P alloy (barringerite), have also been found. They are spheroidal in shape, with diameters of about 200 mu m, and they have identical hexagonal structures with cell parameters of a = 5.877 angstrom, c = 3.437 angstrom, and a: c = 1 :0.5848. They belong to space group P62m. This mineral, which is similar in structure and composition to artificial Fe2P (ICDD 83-2337), has previously only been found in meteorites. This is the first reported natural terrestrial occurrence of barringerite. Further study on its genesis and formational conditions is underway.
View Full Publication open_in_new
Abstract
To evaluate the feasibility and capability of using filter-feeding bivalves as biofilters for organic waste derived from fish faeces and feed wastage in marine fish culture activities, a polyculture system comprising fish and green-lipped mussels Perna viridis was developed by transplantation of mussels into fish cages. As a control, mussels from the same population were simultaneously transplanted to a distant reference site free of effects from fish farming activities. After 3 mo acclimation, samples of mussel tissue, particulate organic matter (POM), fish feed and fish faeces were collected for measurements of carbon and nitrogen isotopic ratios and fatty acid profiles. Enrichment of C-13 and N-15 in mussel tissue collected inside the fish cages as compared to those at the reference site indicated the uptake and assimilation of isotopically heavier fish feed and fish faeces. Compared with mussels from the reference site, the pattern of fatty acid profiles and single fatty acids of mussels in fish cages also tended to be closer to fatty acid profiles of fish feed from fish farms. Based on the concentration-weighted isotope mixing model, the proportions of mussel biomass assimilated from POM, fish feed and fish faeces to mussel dietary consumption were 68.3, 27.5 and 4.2%, respectively. The direct uptake of organic waste from fish farms by filter-feeding mussels is different to their consumption of phytoplanktonic biomass, because the nutrient flux is shifted between these 2 distinct pathways.
View Full Publication open_in_new
Abstract
E7, a single domain Family 33 cellulose binding module (CBM) protein, and E8, a non-catalytic, three-domain protein consisting of a Family 33 CBM, a FNIII domain, followed by a Family 2 CBM, were cloned, expressed, purified, and characterized. Western blots showed that E7 and E8 were induced and secreted when Thermobifida fusca was grown on cellobiose, Solka floc, switchgrass, or alfalfa as well as on beta-1,3 linked glucose molecules such as laminaribiose or pachyman. E8 bound well to alpha- and beta-chitin and bacterial microcrystalline cellulose (BMCC) at all pHs tested. E7 bound strongly to P-chitin, less well to a-chitin and more weakly to BMCC than E8. Filter paper binding assays showed that E7 was 28% bound, E8 was 39% bound, a purified CBM2 binding domain from Cel6B was 88% bound, and only 5% of the Cel5A catalytic domain was bound. A C-terminal 6 x His tag influenced binding of both E7 and E8 to these substrates. Filter paper activity assays showed enhanced activity of T. fusca cellulases when E7 or E8 was present. This effect was observed at very low concentrations of cellulases or at very long times into the reaction and was mainly independent of the type of cellulase and the number of cellulases in the mixture. E8, and to a lesser extent E7, significantly enhanced the activity of Serratia marscescens Chitinase C on beta-chitin.
View Full Publication open_in_new
Abstract
We have previously described the creation and analysis of a Notch1 activity-trap mouse line, Notch1 intramembrane proteolysis-Cre6MT or N1IP::Cre(LO), that marked cells experiencing relatively high levels of Notch1 activation. Here, we report and characterize a second line with improved sensitivity (N1IP::Cre(HI)) to mark cells experiencing lower levels of Notch1 activation. This improvement was achieved by increasing transcript stability and by restoring the native carboxy terminus of Cre, resulting in a five- to tenfold increase in Cre activity. The magnitude of this effect probably impacts Cre activity in strains with carboxy-terminal Ert2 fusion. These two trap lines and the related line N1IP::Cre(ERT2) form a complementary mapping tool kit to identify changes in Notch1 activation patterns in vivo as the consequence of genetic or pharmaceutical intervention, and illustrate the variation in Notch1 signal strength from one tissue to the next and across developmental time.
View Full Publication open_in_new

Pagination

  • Previous page chevron_left
  • …
  • Page 140
  • Page 141
  • Page 142
  • Page 143
  • Current page 144
  • Page 145
  • Page 146
  • Page 147
  • Page 148
  • …
  • Next page chevron_right
Subscribe to

Get the latest

Subscribe to our newsletters.

Privacy Policy
Home
  • Instagram instagram
  • Twitter twitter
  • Youtube youtube
  • Facebook facebook

Science

  • Biosphere Sciences & Engineering
  • Earth & Planets Laboratory
  • Observatories
  • Research Areas
  • Strategic Initiatives

Legal

  • Financial Statements
  • Conflict of Interest Policy
  • Privacy Policy

Careers

  • Working at Carnegie
  • Scientific and Technical Jobs
  • Postdoctoral Program
  • Administrative & Support Jobs
  • Carnegie Connect (For Employees)

Contact Us

  • Contact Administration
  • Media Contacts

Business Address

5241 Broad Branch Rd. NW

Washington, DC 20015

place Map

© Copyright Carnegie Science 2025