434 research outputs found
Intra- and interspecies interactions between prion proteins and effects of mutations and polymorphisms
Recently, crystallization of the prion protein in a dimeric form was reported. Here we show that native soluble homogenous FLAG-tagged prion proteins from hamster, man and cattle expressed in the baculovirus system are predominantly dimeric. The PrP/PrP interaction was confirmed in Semliki Forest virus-RNA transfected BHK cells co-expressing FLAG- and oligohistidine-tagged human PrP. The yeast two-hybrid system identified the octarepeat region and the C-terminal structured domain (aa90-aa230) of PrP as PrP/PrP interaction domains. Additional octarepeats identified in patients suffering from fCJD reduced (wtPrP versus PrP+90R) and completely abolished (PrP+90R versus PrP+90R) the PrP/PrP interaction in the yeast two-hybrid system. In contrast, the Met/Val polymorphism (aa129), the GSS mutation Pro102Leu and the FFI mutation Asp178Asn did not affect PrP/PrP interactions. Proof of interactions between human or sheep and bovine PrP, and sheep and human PrP, as well as lack of interactions between human or bovine PrP and hamster PrP suggest that interspecies PrP interaction studies in the yeast two-hybrid system may serve as a rapid pre-assay to investigate species barriers in prion diseases
Time delay occultation data of the Helios spacecraft for probing the electron density distribution in the solar corona
S-band time delay measurements were collected from the spacecraft Helios A and B during three solar occultations in 1975/76 within heliocentric distances of about 3 and 215 earth radius in terms of range, Doppler frequency shift, and electron content. Characteristic features of measurement and data processing are described. Typical data sets are discussed to probe the electron density distribution near the sun (west and east limb as well) including the outer and extended corona. Steady-state and dynamical aspects of the solar corona are presented and compared with earth-bound-K-coronagraph measurements. Using a weighted least squares estimation, parameters of an average coronal electron density profile are derived in a preliminary analysis to yield electron densities at r = 3, 65, 215 earth radius. Transient phenomena are discussed and a velocity of propagation v is nearly equal to 900 km/s is determined for plasma ejecta from a solar flare observed during an extraordinary set of Helios B electron content measurements
Could resource rents finance universal access to infrastructure? A first exploration of needs and rents
It is often argued that, ethically, resource rents should accrue to all citizens. Yet, in reality, the rents from exploiting national resources are often concentrated in the hands of a few. If resource rents were to be taxed, on the other hand, substantial amounts of public money could be raised and used to cover the population's infrastructure needs, such as access to electricity, water, sanitation, communication technology and roads, which all play important roles in a nation's economic development process. Here, the authors examine to what extent existing resource rents could be used to provide universal access to these infrastructures
Carbon Pricing Revenues Could Close Infrastructure Access Gaps
Introducing a price on greenhouse gas emissions would not only contribute to reducing the risk of dangerous anthropogenic climate change, but would also generate substantial public revenues. Some of these revenues could be used to cover investment needs for infrastructure providing access to water, sanitation, electricity, telecommunications, and transport. In this way, emission pricing could promote sustainable socio-economic development by safeguarding the stability of natural systems which constitute the material basis of economies, while at the same time providing public goods that are essential for human well-being. For a scenario that is consistent with limiting global warming to below 2°C, we find that domestic carbon pricing (without redistribution of revenues across countries) has substantial potential to close existing access gaps for water, sanitation, electricity, and telecommunication. However, for the majority of countries carbon pricing revenues would not be sufficient to pave all unpaved roads, and for most countries in Sub-Saharan Africa they would be insufficient to provide universal access to all types of infrastructure except water. If some fraction of the global revenues of carbon pricing is redistributed, e.g., via the Green Climate Fund, more ambitious infrastructure access goals could be achieved in developing countries. Our paper also bears relevance for the design of climate finance mechanisms, as it suggests that supporting carbon pricing policies instead of project based finance might not only permit cost-efficient emission reductions, but also leverage public revenues to promote human development goals
A Parsec-Scale Galactic 3D Dust Map out to 1.25 kpc from the Sun
High-resolution 3D maps of interstellar dust are critical for probing the
underlying physics shaping the structure of the interstellar medium, and for
foreground correction of astrophysical observations affected by dust. We aim to
construct a new 3D map of the spatial distribution of interstellar dust
extinction out to a distance of 1.25 kpc from the Sun. We leverage distance and
extinction estimates to 54 million nearby stars derived from the Gaia BP/RP
spectra. Using the stellar distance and extinction information, we infer the
spatial distribution of dust extinction. We model the logarithmic dust
extinction with a Gaussian Process in a spherical coordinate system via
Iterative Charted Refinement and a correlation kernel inferred in previous
work. We probe our 661 million dimensional posterior distribution using the
variational inference method MGVI. Our 3D dust map achieves an angular
resolution of 14' (Nside = 256). We sample the dust extinction in 516 distance
bins spanning 69 pc to 1250 pc. We obtain a maximum distance resolution of 0.4
pc at 69 pc and a minimum distance resolution of 7 pc at 1.25 kpc. Our map
resolves the internal structure of hundreds of molecular clouds in the solar
neighborhood and will be broadly useful for studies of star formation, Galactic
structure, and young stellar populations. It is available for download in a
variety of coordinate systems at https://doi.org/10.5281/zenodo.8187943 and can
also be queried via the publicly available dustmaps Python package
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The low cost of geological assessment for underground CO2 storage: Policy and economic implications
The costs for carbon dioxide (CO{sub 2}) capture and storage (CCS) in geologic formations is estimated to be 25-60/t CO{sub 2} for power plant applications followed by CO{sub 2} transport and storage, estimated at 0.1/t CO{sub 2} or less as these costs are spread out over the many millions of tons likely to be injected into a field over many decades. Geologic assessments include information central to capacity prediction, risk estimation for the target intervals, and development facilities engineering. Since assessment costs are roughly 2 orders of magnitude smaller than capture costs, and assessment products carry other tangible societal benefits such as improved accuracy in fossil fuel and ground water reserves estimates, government or joint private/public funding of major assessment initiatives should underpin early policy choices regarding CO{sub 2} storage deployment and should serve as a point of entry for policy makers and regulators. Early assessment is also likely to improve the knowledge base upon which the first commercial CCS deployments will rest.
Marginalization of end-use technologies in energy innovation for climate protection
Mitigating climate change requires directed innovation efforts to develop and deploy energy technologies. Innovation activities are directed towards the outcome of climate protection by public institutions, policies and resources that in turn shape market behaviour. We analyse diverse indicators of activity throughout the innovation system to assess these efforts. We find efficient end-use technologies contribute large potential emission reductions and provide higher social returns on investment than energy-supply technologies. Yet public institutions, policies and financial resources pervasively privilege energy-supply technologies. Directed innovation efforts are strikingly misaligned with the needs of an emissions-constrained world. Significantly greater effort is needed to develop the full potential of efficient end-use technologies
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The missing economic risks in assessments of climate change impacts
In order to make well-informed decisions on climate change action, leaders need to understand clearly the nature and magnitude of the risks to lives and livelihoods that are being created by climate change. Unfortunately, much of the technical advice and recommendations about these risks incorporate assessments of the economic implications that omit or underplay the largest potential impacts of climate change.
This policy insight seeks to identify and draw attention to these missing and under-represented risks. The authors also discuss how populations might fare in light of their potential to adapt in the face of these risks. When the risks are taken into account, the case for strong, deliberate and urgent action to reduce greenhouse gas emissions becomes even more compelling
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