A Porphyrin-Phenylalkynyl-Based Conjugated Organic Polymer as a High-Performance Cathode for Rechargeable Organic Batteries.

Organic electrode materials (OEMs) have attracted much attention for rechargeable batteries due to their low cost, environment friendliness, flexibility, and structural versatility. Despite the above advantages, high solubility in electrolyte and low electronic conductivity remain critical limitations for the application of OEMs. In this work, the conjugated organic polymer (COP) poly([5,10,15,20-tetrakis(4-phenylalkynyl)porphyrin]Cu(II)) (PCuTPEP) is proposed as a cathode for high performance in organic lithium batteries. The polymerization inhibits the dissolution of the organic electrodes in the electrolyte, and the porphyrin and ethynyl-phenyl groups greatly expand the conjugated system and result in a high average discharge plateau at 4.0 V (vs Li+/Li). The PCuTPEP cathode exhibits a reversible discharge capacity of 119 mAh g-1 at a current of 50 mA g-1. Even at a high current density of 2.0 A g-1, excellent cycling stability up to 1000 cycles is achieved with capacity retentions of 88.5 and 90.4% at operating temperatures of 25 and 50 °C in organic lithium batteries, respectively. This study provides the approach for the development of organic cathodes for electrochemical energy storage.

Climate change is increasing the risk of a California megaflood.

Despite the recent prevalence of severe drought, California faces a broadly underappreciated risk of severe floods. Here, we investigate the physical characteristics of "plausible worst case scenario" extreme storm sequences capable of giving rise to "megaflood" conditions using a combination of climate model data and high-resolution weather modeling. Using the data from the Community Earth System Model Large Ensemble, we find that climate change has already doubled the likelihood of an event capable of producing catastrophic flooding, but larger future increases are likely due to continued warming. We further find that runoff in the future extreme storm scenario is 200 to 400% greater than historical values in the Sierra Nevada because of increased precipitation rates and decreased snow fraction. These findings have direct implications for flood and emergency management, as well as broader implications for hazard mitigation and climate adaptation activities.

Climate change increases risk of extreme rainfall following wildfire in the western United States.

Post-wildfire extreme rainfall events can have destructive impacts in the western United States. Using two climate model large ensembles, we assess the future risk of extreme fire weather events being followed by extreme rainfall in this region. By mid-21st century, in a high warming scenario (RCP8.5), we report large increases in the number of extreme fire weather events followed within 1 year by at least one extreme rainfall event. By 2100, the frequency of these compound events increases by 100% in California and 700% in the Pacific Northwest in the Community Earth System Model v1 Large Ensemble. We further project that more than 90% of extreme fire weather events in California, Colorado, and the Pacific Northwest will be followed by at least three spatially colocated extreme rainfall events within five years. Our results point to a future with substantially increased post-fire hydrologic risks across much of the western United States.

The short neuropeptide F receptor regulates olfaction-mediated foraging behavior in the oriental fruit fly Bactrocera dorsalis (Hendel).

The short neuropeptide F (sNPF) signaling system, consisting of sNPF and its receptor (sNPFR), influences many physiological processes in insects, including feeding, growth and olfactory memory. We previously showed that sNPF regulates olfactory sensitivity in the oriental fruit fly Bactrocera dorsalis (Hendel) during starvation. However, the functional analysis of sNPFR is constrained by the failure of RNA interference in this species. Here, we generated a null sNPFR mutant using the CRISPR/Cas9 system to investigate the physiological roles of this receptor in more detail. G0 adults were produced at a frequency of 60.8%, and sNPFR-/- mutants were obtained after several generations of backcrossing followed by self-crossing among heterozygous flies. We found that the mutants were significantly less successful at foraging for certain foods and showed increased foraging latency. Electroantennogram (EAG) assays indicated that the mutants had significantly lower electrophysiological responses to three tested odorants. Furthermore, qPCR data revealed the inhibition of several olfactory receptor genes, including Orco. Immunohistochemistry showed that BdsNPFR was localized in cells under the sensillum on the antennae. Based on their shape and size, the BdsNPFR+ cells differ from odorant receptor neurons (ORNs), which were labeled using a Drosophila melanogaster Orco antibody. Our data suggest that sNPFR regulates olfaction-mediated foraging behavior by mediating interactions between BdsNPFR+ cells and selected ORNs.

Future precipitation increase from very high resolution ensemble downscaling of extreme atmospheric river storms in California.

Precipitation extremes will likely intensify under climate change. However, much uncertainty surrounds intensification of high-magnitude events that are often inadequately resolved by global climate models. In this analysis, we develop a framework involving targeted dynamical downscaling of historical and future extreme precipitation events produced by a large ensemble of a global climate model. This framework is applied to extreme "atmospheric river" storms in California. We find a substantial (10 to 40%) increase in total accumulated precipitation, with the largest relative increases in valleys and mountain lee-side areas. We also report even higher and more spatially uniform increases in hourly maximum precipitation intensity, which exceed Clausius-Clapeyron expectations. Up to 85% of this increase arises from thermodynamically driven increases in water vapor, with a smaller contribution by increased zonal wind strength. These findings imply substantial challenges for water and flood management in California, given future increases in intense atmospheric river-induced precipitation extremes.