Nyborgdegn8556

We also highlight how plausible future improvements in energy crop yields and biorefining technology together with CCS would achieve mitigation potential 4 and 15 times greater than forest and grassland restoration, respectively. Finally, we show that recent estimates of induced land use change are small relative to the opportunities for improving system performance that we quantify here. While climate and other ecosystem service benefits cannot be taken for granted from cellulosic biofuel deployment, our scenarios illustrate how conventional and carbon-negative biofuel systems could make a near-term, robust, and distinctive contribution to the climate challenge.The correct distribution and trafficking of proteins are essential for all organisms. Eukaryotes evolved a sophisticated trafficking system which allows proteins to reach their destination within highly compartmentalized cells. One eukaryotic hallmark is the attachment of a glycosylphosphatidylinositol (GPI) anchor to C-terminal ω-peptides, which are used as a zip code to guide a subset of membrane-anchored proteins through the secretory pathway to the plasma membrane. In fungi, the final destination of many GPI-anchored proteins is their outermost compartment, the cell wall. Enzymes of the Dfg5 subfamily catalyze the essential transfer of GPI-anchored substrates from the plasma membrane to the cell wall and discriminate between plasma membrane-resident GPI-anchored proteins and those transferred to the cell wall (GPI-CWP). We solved the structure of Dfg5 from a filamentous fungus and used in crystallo glycan fragment screening to reassemble the GPI-core glycan in a U-shaped conformation within its binding pocket. selleck The resulting model of the membrane-bound Dfg5•GPI-CWP complex is validated by molecular dynamics (MD) simulations and in vivo mutants in yeast. The latter show that impaired transfer of GPI-CWPs causes distorted cell-wall integrity as indicated by increased chitin levels. The structure of a Dfg5•β1,3-glycoside complex predicts transfer of GPI-CWP toward the nonreducing ends of acceptor glycans in the cell wall. In addition to our molecular model for Dfg5-mediated transglycosylation, we provide a rationale for how GPI-CWPs are specifically sorted toward the cell wall by using GPI-core glycan modifications.Neurofibromin gene (NF1) mutation causes neurofibromatosis type 1 (NF1), a disorder in which brain white matter deficits identified by neuroimaging are common, yet of unknown cellular etiology. In mice, Nf1 loss in adult oligodendrocytes causes myelin decompaction and increases oligodendrocyte nitric oxide (NO) levels. Nitric oxide synthase (NOS) inhibitors rescue this pathology. Whether oligodendrocyte pathology is sufficient to affect brain-wide structure and account for NF1 imaging findings is unknown. Here we show that Nf1 gene inactivation in adult oligodendrocytes (Plp-Nf1fl/+ mice) results in a motor coordination deficit. Magnetic resonance imaging in awake mice showed that fractional anisotropy is reduced in Plp-Nf1fl/+ corpus callosum and that interhemispheric functional connectivity in the motor cortex is also reduced, consistent with disrupted myelin integrity. Furthermore, NOS-specific inhibition rescued both measures. These results suggest that oligodendrocyte defects account for aspects of brain dysfunction in NF1 that can be identified by neuroimaging and ameliorated by NOS inhibition.Nuclides synthesized in massive stars are ejected into space via stellar winds and supernova explosions. The solar system (SS) moves through the interstellar medium and collects these nucleosynthesis products. One such product is 60Fe, a radionuclide with a half-life of 2.6 My that is predominantly produced in massive stars and ejected in supernova explosions. Extraterrestrial 60Fe has been found on Earth, suggesting close-by supernova explosions ∼2 to 3 and ∼6 Ma. Here, we report on the detection of a continuous interstellar 60Fe influx on Earth over the past ∼33,000 y. This time period coincides with passage of our SS through such interstellar clouds, which have a significantly larger particle density compared to the local average interstellar medium embedding our SS for the past few million years. The interstellar 60Fe was extracted from five deep-sea sediment samples and accelerator mass spectrometry was used for single-atom counting. The low number of 19 detected atoms indicates a continued but low influx of interstellar 60Fe. The measured 60Fe time profile over the 33 ky, obtained with a time resolution of about ±9 ky, does not seem to reflect any large changes in the interstellar particle density during Earth's passage through local interstellar clouds, which could be expected if the local cloud represented an isolated remnant of the most recent supernova ejecta that traversed the Earth ∼2 to 3 Ma. The identified 60Fe influx may signal a late echo of some million-year-old supernovae with the 60Fe-bearing dust particles still permeating the interstellar medium.A long-lasting challenge in neuroscience has been to find a set of principles that could be used to organize the brain into distinct areas with specific functions. Recent studies have proposed the orderly progression in the time constants of neural dynamics as an organizational principle of cortical computations. However, relationships between these timescales and their dependence on response properties of individual neurons are unknown, making it impossible to determine how mechanisms underlying such a computational principle are related to other aspects of neural processing. Here, we developed a comprehensive method to simultaneously estimate multiple timescales in neuronal dynamics and integration of task-relevant signals along with selectivity to those signals. By applying our method to neural and behavioral data during a dynamic decision-making task, we found that most neurons exhibited multiple timescales in their response, which consistently increased from parietal to prefrontal and cingulate cortex. While predicting rates of behavioral adjustments, these timescales were not correlated across individual neurons in any cortical area, resulting in independent parallel hierarchies of timescales. Additionally, none of these timescales depended on selectivity to task-relevant signals. Our results not only suggest the existence of multiple canonical mechanisms for increasing timescales of neural dynamics across cortex but also point to additional mechanisms that allow decorrelation of these timescales to enable more flexibility.The COVID-19 pandemic is causing a catastrophic increase in US mortality. How does the scale of this pandemic compare to another US catastrophe racial inequality? Using demographic models, I estimate how many excess White deaths would raise US White mortality to the best-ever (lowest) US Black level under alternative, plausible assumptions about the age patterning of excess mortality in 2020. I find that 400,000 excess White deaths would be needed to equal the best mortality ever recorded among Blacks. For White mortality in 2020 to reach levels that Blacks experience outside of pandemics, current COVID-19 mortality levels would need to increase by a factor of nearly 6. Moreover, White life expectancy in 2020 will remain higher than Black life expectancy has ever been unless nearly 700,000 excess White deaths occur. Even amid COVID-19, US White mortality is likely to be less than what US Blacks have experienced every year. I argue that, if Black disadvantage operates every year on the scale of Whites' experience of COVID-19, then so too should the tools we deploy to fight it. Our imagination should not be limited by how accustomed the United States is to profound racial inequality.Nutrients released through herbivore feces have the potential to influence plant-available nutrients and affect primary productivity. However, herbivore species use nutrients in set stoichiometric ratios that vary with body size. Such differences in the ratios at which nutrients are used leads to differences in the ratios at which nutrients are deposited through feces. Thus, local environmental factors that affect the average body size of an herbivore community (such as predation risk and food availability) influence the ratios at which fecal nutrients are supplied to plants. Here, we assess the relationship between herbivore body size and the nitrogen-to-phosphorus ratios of herbivore feces. link2 We examine how shifts in the average body size of an herbivore community alter the ratios at which nitrogen and phosphorus are supplied to plants and test whether such differences in the stoichiometry of nutrient supply propagate through plants. We show that dung from larger-bodied herbivores contain lower quantities of phosphorus per unit mass and were higher in NP ratio. We demonstrate that spatial heterogeneity in visibility (a proxy for predation risk and/or food availability) and rainfall (a proxy for food availability), did not affect the overall amount of feces deposited but led to changes in the average body size of the defecating community. Feces deposited in areas of higher rainfall and reduced visibility originated from larger herbivores and were higher in NP ratios. This indicates that processes that change the size distribution of herbivore communities, such as predation or size-biased extinction, have the potential to alter the nutrient landscape for plants.Major environmental functions and human needs critically depend on water. In regions of the world affected by water scarcity economic activities can be constrained by water availability, leading to competition both among sectors and between human uses and environmental needs. While the commodification of water remains a contentious political issue, the valuation of this natural resource is sometime viewed as a strategy to avoid water waste. Likewise, water markets have been invoked as a mechanism to allocate water to economically most efficient uses. link3 The value of water, however, remains difficult to estimate because water markets and market prices exist only in few regions of the world. Despite numerous attempts at estimating the value of water in the absence of markets (i.e., the "shadow price"), a global spatially explicit assessment of the value of water in agriculture is still missing. Here we propose a data-parsimonious biophysical framework to determine the value generated by water in irrigated agriculture and highlight its global spatiotemporal patterns. We find that in much of the world the actual crop distribution does not maximize agricultural water value.The fusiform face area responds selectively to faces and is causally involved in face perception. How does face-selectivity in the fusiform arise in development, and why does it develop so systematically in the same location across individuals? Preferential cortical responses to faces develop early in infancy, yet evidence is conflicting on the central question of whether visual experience with faces is necessary. Here, we revisit this question by scanning congenitally blind individuals with fMRI while they haptically explored 3D-printed faces and other stimuli. We found robust face-selective responses in the lateral fusiform gyrus of individual blind participants during haptic exploration of stimuli, indicating that neither visual experience with faces nor fovea-biased inputs is necessary for face-selectivity to arise in the lateral fusiform gyrus. Our results instead suggest a role for long-range connectivity in specifying the location of face-selectivity in the human brain.