Search for: All records

Summary The restoration of terrestrial ecosystems often requires the reestablishment of plant communities, but restorations often overlook microbial communities, which directly and indirectly structure plant diversity. Legacies of anthropogenic disturbance radically alter microbial diversity and, contrary to previous assumptions, the natural recovery of microbial communities is not guaranteed, even after decades. This necessitates established and novel forms of microbial restoration, such as the addition of key microbial taxa to boost plant diversity and ecosystem functioning. Here, we review why anthropogenically disturbed microbial communities need restoration, the positive outcomes of doing so for plant conservation, community dynamics, and ecosystem functioning, and best practices when taking these approaches. We also highlight knowledge gaps in this emerging field, such as the mechanisms underlying successful microbially based restoration of plant communities, how shifting climate conditions will impact global microbiomes, and the potential for off‐target effects. Our goal is to shift the perspective of microbes as passive measures of restoration success to the restoration of microbial communities as a major objective and driver of restoration outcomes. 

Summary Plant microbiomes have the potential to mitigate the impacts of climate change, yet both the complexity of climate change and the complexity of plant–microbe interactions make applications and future predictions challenging. Here, we embrace this complexity, reviewing how different aspects of climate change influence beneficial plant–microbe interactions and how advances in theory, tools, and applications may improve understanding and predictability of climate change effects on plants, microbiomes, and their roles within ecosystems. New advances include consideration of (1) interactions among climate stressors, such as more variable precipitation regimes combined with warmer mean temperature; (2) mechanisms that promote the stability of microbiome functions; (3) legacies of stress affecting the functionality of microbial communities under future stress; and (4) temporally repeated plant–microbe interactions or feedbacks. We also identify key gaps in each of these areas and spotlight the need for more research bridging molecular biology and ecology to develop a more mechanistic understanding of how climate change shapes beneficial microbe–plant interactions. 

The IceCube Upgrade is an extension of the existing IceCube Neutrino Observatory and will be deployed in the 2025–2026 austral summer. It will significantly improve the sensitivity of the detector to atmospheric neutrino oscillations. The existing 86-string IceCube array contains a dense in-fill known as DeepCore which is optimized to measure neutrinos with energies down to a few GeV. The IceCube Upgrade will consist of seven new densely instrumented strings placed within the DeepCore volume to further enhance the performance in the GeV energy range. The additional strings will feature new optical modules, each containing multiple photomultiplier tubes (PMTs), in contrast to the existing modules that each contain a single PMT. This will more than triple the number of PMT channels with respect to the current IceCube configuration, allowing for improved detection efficiency and reconstruction performance at GeV energies. We describe necessary updates to simulation, event selection, and reconstruction to accommodate the higher data rates observed by the upgraded detector and the addition of multi-PMT modules. We determine the expected sensitivity of the IceCube Upgrade to the atmospheric neutrino oscillation parameters ${\sin }^2{\theta }_{23}$and $\mathrm{\Delta }{m}_{32}^2$, the appearance of tau neutrinos and the neutrino mass ordering. The IceCube Upgrade will provide neutrino oscillation measurements that are of similar precision to those from accelerator experiments, while providing complementarity by probing higher energies and longer baselines, and with different sources of systematic uncertainties. 

Abstract Recently, IceCube reported neutrino emission from the Seyfert galaxy NGC 1068. Using 13.1 yr of IceCube data, we present a follow-up search for neutrino sources in the northern sky. NGC 1068 remains the most significant neutrino source among 110 preselected gamma-ray emitters while also being spatially compatible with the most significant location in the northern sky. Its energy spectrum is characterized by an unbroken power-law with spectral indexγ = 3.4 ± 0.2. Consistent with previous results, the observed neutrino flux exceeds its gamma-ray counterpart by at least 2 orders of magnitude. Motivated by this disparity and the high X-ray luminosity of the source, we selected 47 X-ray-bright Seyfert galaxies from the Swift/BAT spectroscopic survey that were not included in the list of gamma-ray emitters. When testing this collection for neutrino emission, we observe a 3.3σexcess from an ensemble of 11 sources, with NGC 1068 excluded from the sample. Our results strengthen the evidence that X-ray-bright cores of active galactic nuclei are neutrino emitters. 

Abstract The IceCube Neutrino Observatory has observed extragalactic astrophysical neutrinos with an apparently isotropic distribution. Only a small fraction of the observed astrophysical neutrinos can be explained by known sources. Neutrino production is thought to occur in energetic environments that are ultimately powered by the gravitational collapse of dense regions of the large-scale mass distribution in the universe. Whatever their identity, neutrino sources likely trace this large-scale mass distribution. The clustering of neutrinos with a tracer of the large-scale structure may provide insight into the distribution of neutrino sources with respect to redshift and the identity of neutrino sources. We implement a two-point angular cross correlation of the Northern sky track events with an infrared galaxy catalog derived from the Wide-field Infrared Survey Explorer (WISE) and Two Micron All Sky Survey (2MASS) source catalogs, which trace the nearby large-scale structure. No statistically significant correlation is found between the neutrinos and this infrared galaxy catalog. We find that ≤54% of the diffuse muon neutrino flux can be attributed to sources correlated with the galaxy catalog with 90% confidence. Additionally, when assuming that the neutrino source comoving density evolves following a power law in redshift,dN_s/dV ∝ (1 + z)^k, we find that sources with negative evolution, in particulark < −1.75, are disfavored at the 90% confidence level.