•We present a new, transparent and replicable model-driven method to predict the onset of food crises across the world.•We apply the model to Malawi, a country with persistent chronic and acute food ...security problems.•Leveraging readily available data, our model substantially improves over the status quo global methods of prediction.•Our best forecasts predict the out-of-sample food security status for between 65 and 88 percent of village clusters.•Our analysis and results demonstrate the potential gains to real-time food security modeling.
Globally, over 800 million people are food insecure. Current methods for identifying food insecurity crises are not based on statistical models and fail to systematically incorporate readily available data on prices, weather, and demographics. As a result, policymakers cannot rapidly identify food insecure populations. These problems delay responses to mitigate hunger. We develop a replicable, near real-time model incorporating spatially and temporally granular market data, remotely-sensed rainfall and geographic data, and demographic characteristics. We train the model on 2010–2011 data from Malawi and forecast 2013 food security. Our model correctly identifies the food security status of 83 to 99% of the most food insecure village clusters in 2013, depending on the food security measure, while the prevailing approach correctly identifies between 0 and 10%. Our results show the power of modeling food insecurity to provide early warning and suggest model-driven approaches could dramatically improve food insecurity crisis response.
This Letter reports the results from a haloscope search for dark matter axions with masses between 2.66 and 2.81 μeV. The search excludes the range of axion-photon couplings predicted by plausible ...models of the invisible axion. This unprecedented sensitivity is achieved by operating a large-volume haloscope at subkelvin temperatures, thereby reducing thermal noise as well as the excess noise from the ultralow-noise superconducting quantum interference device amplifier used for the signal power readout. Ongoing searches will provide nearly definitive tests of the invisible axion model over a wide range of axion masses.
The vulnerability of coastal systems to hazards such as storms and sea-level rise is typically characterized using a combination of ground and manned airborne systems that have limited spatial or ...temporal scales. Structure-from-motion (SfM) photogrammetry applied to imagery acquired by unmanned aerial systems (UAS) offers a rapid and inexpensive means to produce high-resolution topographic and visual reflectance datasets that rival existing lidar and imagery standards. Here, we use SfM to produce an elevation point cloud, an orthomosaic, and a digital elevation model (DEM) from data collected by UAS at a beach and wetland site in Massachusetts, USA. We apply existing methods to (a) determine the position of shorelines and foredunes using a feature extraction routine developed for lidar point clouds and (b) map land cover from the rasterized surfaces using a supervised classification routine. In both analyses, we experimentally vary the input datasets to understand the benefits and limitations of UAS-SfM for coastal vulnerability assessment. We find that (a) geomorphic features are extracted from the SfM point cloud with near-continuous coverage and sub-meter precision, better than was possible from a recent lidar dataset covering the same area; and (b) land cover classification is greatly improved by including topographic data with visual reflectance, but changes to resolution (when <50 cm) have little influence on the classification accuracy.
Forecasting biogeomorphological conditions for barrier islands is critical for informing sea‐level rise (SLR) planning, including management of coastal development and ecosystems. We combined five ...probabilistic models to predict SLR‐driven changes and their implications on Fire Island, New York, by 2050. We predicted barrier island biogeomorphological conditions, dynamic landcover response, piping plover (Charadrius melodus) habitat availability, and probability of storm overwash under three scenarios of shoreline change (SLC) and compared results to observed 2014/2015 conditions. Scenarios assumed increasing rates of mean SLC from 0 to 4.71 m erosion per year. We observed uncertainty in several morphological predictions (e.g., beach width, dune height), suggesting decreasing confidence that Fire Island will evolve in response to SLR as it has in the past. Where most likely conditions could be determined, models predicted that Fire Island would become flatter, narrower, and more overwash‐prone with increasing rates of SLC. Beach ecosystems were predicted to respond dynamically to SLR and migrate with the shoreline, while marshes lost the most area of any landcover type compared to 2014/2015 conditions. Such morphological changes may lead to increased flooding or breaching with coastal storms. However—although modest declines in piping plover habitat were observed with SLC—the dynamic response of beaches, flatter topography, and increased likelihood of overwash suggest storms could promote suitable conditions for nesting piping plovers above what our geomorphology models predict. Therefore, Fire Island may offer a conservation opportunity for coastal species that rely on early successional beach environments if natural overwash processes are encouraged.
Plain Language Summary
Predicting a barrier island's future characteristics is important for planning, particularly given that these areas contain habitats used by threatened and endangered species and are popular sites for housing and recreation. In this study, we combined five models to predict barrier island characteristics like elevation, beach width, and dune height under three rates of shoreline erosion at Fire Island, New York. Models were also used to predict how likely parts of the island were to be permanently flooded by sea‐level rise or to experience overwash with storms, where waves move sand deeper into the island. We found that Fire Island would likely become narrower and flatter while experiencing more overwash with storms as rates of shoreline erosion increase. These changes may lead to more flooding in housing communities and businesses on the island. However, models also predicted that beach habitats used by shorebirds like the piping plover would not flood permanently. Instead, they would move as the shoreline changes position as long as human structures like buildings or seawalls do not block sand movement. This migration of beaches and sand is important, as it also allows a barrier island to evolve and survive with rising sea levels.
Key Points
With increasing shoreline erosion and landward retreat, Fire Island was predicted to become flatter, narrower, and more overwash‐prone
Beaches are expected to be least impacted and to replace other landcover types as they migrate with the shoreline
Habitats used by piping plovers are expected to persist as long as development and stabilization structures do not limit beach migration
Treatment of municipal landfill leachate was investigated/compared using sequencing batch and continuous flow upflow anaerobic sludge blanket (UASB) reactors. All reactors were operated at organic ...loading rates (OLRs) between 0.6–19.7 gCOD/l d. Performance of the continuous UASB and sequencing batch UASB reactors were very similar at low and intermediate OLRs. Continuous UASB reactors performed more favorably at the higher OLRs than the sequencing batch UASB (AnSBR) system. The sequencing batch UASB reactor had soluble chemical oxygen demand (COD) removal efficiencies ranging between 71% and 92% at hydraulic retention times (HRT) of 24, 18 and 12 h with dilute to concentrated leachate feed. For the continuous UASB reactor, soluble COD removal efficiency was consistently between 77% and 91% for all HRTs and feed concentrations. At high OLRs and fill to react ratios of 0.5, the AnSBR system showed signs of system failure. In order to ensure successful AnSBR treatment of municipal landfill leachate the specific organic loading rate during the fill cycle (SOLR
fill) should not exceed 3 g COD/g VSS d. Both systems effectively resulted in a reduction in Microtox
® toxicity levels following treatment. Municipal leachate treated by either continuous or sequencing batch UASB reactor was not suitable for direct disposal into the sewerage according to Municipal Sewer Regulations. A post treatment option such as membrane filtration would be required.
Extracellular vesicles (EVs) represent a next generation drug delivery system that combines nanoparticle size with extraordinary ability to cross biological barriers, reduced immunogenicity, and low ...offsite toxicity profiles. A successful application of this natural way of delivering biological compounds requires deep understanding EVs intrinsic properties inherited from their parent cells. Herein, EVs released by cells of different origin, with respect to drug delivery to the brain for treatment of neurodegenerative disorders, are evaluated. The morphology, size, and zeta potential of EVs secreted by primary macrophages (mEVs), neurons (nEVs), and astrocytes (aEVs) are examined by nanoparticle tracking analysis (NTA), dynamic light scattering (DLS), cryogenic transmission electron microscopy (cryoTEM), and atomic force microscopy (AFM). Spherical nanoparticles with average size 110–130 nm and zeta potential around −20 mV are identified for all EVs types. mEVs show the highest levels of tetraspanins and integrins compared with nEVs and aEVs, suggesting superior adhesion and targeting to the inflamed tissues by mEVs. Strikingly, aEVs are preferentially taken up by neuronal cells in vitro, followed by mEVs and nEVs. Nevertheless, the brain accumulation levels of mEVs in a transgenic mouse model of Parkinson's disease are significantly higher than those of nEVs or aEVs. Therefore, mEVs are suggested as the most promising nanocarrier system for drug delivery to the brain.
Herein, a novel platform for brain delivery of therapeutics based on extracellular vesicles (EVs) for enabling a broader array for treatment of neurodegenerative disorders is developed. EVs may inherit at some extent properties of their parent cells. The data indicate that EVs released by inflammatory‐response cells, macrophages, are the most promising candidates for delivery of therapeutics to the inflamed brain.
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