1,959 research outputs found

    Applying Conservation Genomic Techniques to Guide Management of the Reticulated Flatwoods Salamander (Ambystoma bishopi)

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    The Reticulated flatwoods salamander (Ambystoma bishopi) is a federally endangered amphibian endemic to the longleaf-pine ecosystem of the southeastern U.S. This study used analyses of single-nucleotide polymorphism (SNP) data, collected from 2,255 unique individuals across 5 breeding seasons, spread across the known extant range of A. bishopi, to characterize the genetic diversity and demographics of populations, genetic relationships among populations, and patterns and spatial extents of gene flow, and to evaluate potential effects of management on A. bishopi’s resiliency. Population structure was strongly hierarchical, with individual breeding ponds (n = 38) acting as semi-connected subpopulations within five regional metapopulations (Mayhaw in Georgia; Oglesby, Eastbay, Garcon, and Escribano in Florida). Likewise, gene flow among populations was scale-dependent: negligible genetic differentiation, indicative of high gene flow, was observed only between pairs of ponds separated by \u3c 0.5 km, whereas between 0.5 and 5 km I observed steep genetic isolation by distance, and beyond 5 km genetic differentiation was generally high and only weakly related to distance. Across several breeding seasons, the effective number of breeders (Nb) per pond per year averaged 26 individuals (range 4 to 104). Larger-area, slower-drying ponds located closer to other occupied ponds exhibited larger Nb and greater genetic diversity. Based on genetically-reconstructed pedigrees, the ongoing headstarting program at Escribano successfully captured 97.9% of the estimated total number of alleles, but only 63% of the total number families, in each cohort. Based on these results, I recommend the following: 1) Given its genetic distinctiveness, Georgia populations merit elevated priority for protection and restoration. 2) Resiliency and redundancy (a la the species’ recovery plan) should be assessed at the spatial grain of individual breeding ponds. 3) Attempts to restore habitat connectivity should consider dispersal over distances \u3e 500 m to be relatively unlikely. 4) Finally, to the extent that headstarted individuals are used to augment existing or introduce new populations, managers should consider the potential risks of founder effects, and reduce these risks by creating genetically and demographically diverse headstart samples, for example by maximizing the diversity of egg/larva collections over time and space within ponds

    Extreme Events in a Globalized Food System

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    Our food systems are complex and globally interdependent and are presently struggling to feed the world’s population. As population grows and the world becomes increasingly unstable and subject to shocks, it is imperative that we acknowledge the systemic nature of our food system and enhance its resilience

    Systemic risks emerging from global climate hotspots and their impacts on Europe

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    In a globalized world, Europe is increasingly affected by climate change events beyond its borders that propagate through our interconnected systems impacting the socio-economic welfare in Europe. The REmote Climate Effects and their Impact on European sustainability, Policy and Trade (RECEIPT) project uses a novel stakeholder-driven storytelling approach that maps representative connections between remote climate hazards such as droughts or hurricanes and European socio-economic activities in the agricultural, finance, development, shipping and manufacturing sectors. As part of RECEIPT, this work focuses on systemic risks in global climate risk hotspots and their knock-on effects on the European economy. In five stakeholder workshops, expert elicitation methods are used to identify and map sector- and storyline-specific systemic risks: interlinkages between different events, hidden causes and consequences, potential feedback loops, uncertainties and other systemic risk characteristics will be investigated. A special focus lies on “gray rhino” events, “foreseeable random surprises” that follow clear warning signs but are only known to a smaller group of people. Results reveal sector-specific “topographies of risk” within the storylines identified by stakeholders

    A W:B4C multilayer phase retarder for broadband polarization analysis of soft x-ray radiation \ud

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    A W:B4C multilayer phase retarder has been designed and characterized which shows a nearly constant phase retardance between 640 and 850 eV photon energies when operated near the Bragg condition. This freestanding transmission multilayer was used successfully to determine, for the first time, the full polarization vector at soft x-ray energies above 600 eV, which was not possible before due to the lack of suitable optical elements. Thus, quantitative polarimetry is now possible at the 2p edges of the magnetic substances Fe, Co, and Ni for the benefit of magnetic circular dichroism spectroscopy employing circularly polarized synchrotron radiatio

    Systemic risk and compound vulnerability impact pathways of food insecurity in Somalia

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    In a strongly interconnected world, extreme and compound events pose systemic risks to food security and populations already vulnerable to the impacts of climate change. Pre-existing vulnerabilities can also compound, interfering with adaptation strategies and affecting human migration patterns. While some drivers of compound vulnerability are known on a normative level, there remains a critical gap on the relationship between drivers of vulnerability systemic risk, and food insecurity outcomes. We use a systemic risk impact pathway (SRIP) model to gain data-driven insights on the drivers of systemic risk and the impacts on food insecurity in Somalia. By applying data on extreme weather and food insecure internally displaced populations from 2011 to 2019 we isolate different components of vulnerability and show how they compound and relate to systemic risk drivers. Our findings contribute to the empirical evidence on limits to adaptation indicating that systemic risk impacts compound vulnerabilities and act as adaptation ‘roadblocks’ for food security. We argue that a systems design can provide guardrails to resilience opportunities where compound vulnerabilities overstretch fragile resilience levels.publishedVersio

    Research Sites of the H2STORE Project and the Relevance of Lithological Variations for Hydrogen Storage at Depths

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    AbstractThe H2STORE collaborative project investigates potential geohydraulic, petrophysical, mineralogical, microbiological and geochemical interactions induced by the injection of hydrogen into depleted gas reservoirs and CO2- and town gas storage sites. In this context the University of Jena performs mineralogical and geochemical investigations on reservoir and cap rocks to evaluate the relevance of preferential sedimentological features, which will control fluid (hydrogen) pathways, thus provoking fluid-rock interactions and related variations in porosity and permeability. Thereby reservoir sand- and sealing mudstones of different composition, sampled from distinct depths (different: pressure/temperature conditions) of five German locations are analysed. In combination with laboratory experiments the results will enable the characterization of specific mineral reactions at different physico-chemical conditions and geological settings
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