Individual Nanostructures in an Epsilon-Near-Zero Material Probed with 3D-Sculpted Light

Epsilon-near-zero (ENZ) materials, i.e., materials with vanishing real part of the permittivity, have become an increasingly desirable platform for exploring linear and nonlinear optical phenomena in nanophotonic and on-chip environments. ENZ materials inherently enhance electric fields for properly chosen interaction scenarios, host extreme nonlinear optical effects, and lead to other intriguing phenomena. To date, studies in the optical domain mainly focused on nanoscopically thin films of ENZ materials and their interaction with light and other nanostructured materials. Here, the optical response of individual nanostructures milled into an ENZ material are explored both experimentally and numerically. For the study, 3D structured light beams are employed, allowing for the full utilization of polarization-dependent field enhancements enabled by a tailored illumination and a vanishing permittivity. This study reveals the underlying intricate interaction mechanisms and showcase the polarization-dependent controllability, paving the way towards experiments in the nonlinear optical regime where the presented effects will enable polarization-controlled nonlinear refractive index based ultra-fast switching on the single nanostructure level.Comment: 7 pages, 8 figure

LSST Science Book, Version 2.0

A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of the exciting science opportunities of the next decade. The Large Synoptic Survey Telescope (LSST) will have an effective aperture of 6.7 meters and an imaging camera with field of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over 20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a total point-source depth of r~27.5. The LSST Science Book describes the basic parameters of the LSST hardware, software, and observing plans. The book discusses educational and outreach opportunities, then goes on to describe a broad range of science that LSST will revolutionize: mapping the inner and outer Solar System, stellar populations in the Milky Way and nearby galaxies, the structure of the Milky Way disk and halo and other objects in the Local Volume, transient and variable objects both at low and high redshift, and the properties of normal and active galaxies at low and high redshift. It then turns to far-field cosmological topics, exploring properties of supernovae to z~1, strong and weak lensing, the large-scale distribution of galaxies and baryon oscillations, and how these different probes may be combined to constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at http://www.lsst.org/lsst/sciboo

Genome-Wide Search for Gene-Gene Interactions in Colorectal Cancer

Genome-wide association studies (GWAS) have successfully identified a number of single-nucleotide polymorphisms (SNPs) associated with colorectal cancer (CRC) risk. However, these susceptibility loci known today explain only a small fraction of the genetic risk. Gene-gene interaction (GxG) is considered to be one source of the missing heritability. To address this, we performed a genome-wide search for pair-wise GxG associated with CRC risk using 8,380 cases and 10,558 controls in the discovery phase and 2,527 cases and 2,658 controls in the replication phase. We developed a simple, but powerful method for testing interaction, which we term the Average Risk Due to Interaction (ARDI). With this method, we conducted a genome-wide search to identify SNPs showing evidence for GxG with previously identified CRC susceptibility loci from 14 independent regions. We also conducted a genome-wide search for GxG using the marginal association screening and examining interaction among SNPs that pass the screening threshold (p<$10^{−4}$). For the known locus rs10795668 (10p14), we found an interacting SNP rs367615 (5q21) with replication p = 0.01 and combined p = 4.19×$10^{−8}$. Among the top marginal SNPs after LD pruning (n = 163), we identified an interaction between rs1571218 (20p12.3) and rs10879357 (12q21.1) (nominal combined p = 2.51×$10^{−6}$; Bonferroni adjusted p = 0.03). Our study represents the first comprehensive search for GxG in CRC, and our results may provide new insight into the genetic etiology of CRC

A Large U3 Deletion Causes Increased In Vivo Expression From a Nonintegrating Lentiviral Vector

The feasibility of employing nonintegrating lentiviral vectors has been demonstrated by recent studies showing the ability of nonintegrating lentiviral vectors to maintain transgene expression in vitro and in vivo. Furthermore, HIV-1 vectors packaged with a mutated integrase were able to correct retinal disease in a mouse model. Interestingly, these results differ from earlier studies in which first-generation nonintegrating lentiviral vectors yielded insignificant levels of transduction. However, to date a rigorous characterization of transgene expression from the currently used self-inactivating (SIN) nonintegrating lentiviral vectors has not been published. Here we characterize transgene expression from SIN nonintegrating lentiviral vectors. Overall, we found that nonintegrating vectors express transgenes at a significantly lower level than their integrating counterparts. Expression from nonintegrating vectors was improved upon introducing a longer deletion in the vector’s U3 region. A unique shuttle-vector assay indicated that the relative abundance of the different episomal forms was not altered by the longer U3 deletion. Interestingly, the longer U3 deletion did not enhance expression in the corpus callosum of the rat brain, suggesting that the extent of silencing of episomal transcription is influenced by tissue-specific factors. Finally, and for the first time, episomal expression in the mouse liver was potent and sustained

Recharge Net Metering To Enhance Groundwater Sustainability

Groundwater sustainability depends on balancing aquifer inflows and outflows. Extraction (pumping of groundwater, typically for human use) and recharge (inflow of water to an aquifer from the land surface and streams) are central components of this water balance. Often, increasing demands for groundwater are exacerbated by stresses on limited surface water supplies. Changes in land use and shifting climate can result in less infiltration of precipitation into the ground, reducing recharge. Increasing water scarcity has led to increased pumping, and in turn, unsustainable management of groundwater in many basins, resulting in depleted supplies, degraded water quality, and other impacts. Conservation strategies have reduced demand in some basins, and there are also opportunities for increasing recharge; both strategies can help to tip the water balance towards sustainability. Natural recharge occurs across the landscape, in forests and fields, and below rivers and streams; it is a fundamental hydrologic process that is difficult to measure or control because it varies so greatly in location and timing. Managed aquifer recharge (MAR) is a set of techniques used to improve groundwater conditions by routing more surface water into aquifers. MAR can be applied at many scales, from street corner swales to regional systems. MAR based on the distributed collection of stormwater (distributed MAR) can be accomplished at an intermediate scale, generating hundreds to thousands of acre-feet/year of infiltration benefit. The promise of distributed MAR stems from its modest cost, and comparative simplicity of design and operation. Distributed MAR projects can be developed on private or public land across a groundwater basin, potentially generating more total benefit than smaller scale installations, and with less cost and complexity than regional MAR systems. A key challenge for developing distributed MAR projects lies in creating incentives that will motivate landowners, tenants, and other stakeholders to participate. Distributed MAR projects can be funded by a limited number of private participants, but public benefits may accrue more broadly. Developing and implementing policies to encourage the creation and operation of distributed MAR systems is a challenge at the frontier of groundwater management.</p

Hydrogen-Based Metabolism as an Ancestral Trait in Lineages Sibling to the Cyanobacteria

© 2019, The Author(s). The evolution of aerobic respiration was likely linked to the origins of oxygenic Cyanobacteria. Close phylogenetic neighbors to Cyanobacteria, such as Margulisbacteria (RBX-1 and ZB3), Saganbacteria (WOR-1), Melainabacteria and Sericytochromatia, may constrain the metabolic platform in which aerobic respiration arose. Here, we analyze genomic sequences and predict that sediment-associated Margulisbacteria have a fermentation-based metabolism featuring a variety of hydrogenases, a streamlined nitrogenase, and electron bifurcating complexes involved in cycling of reducing equivalents. The genomes of ocean-associated Margulisbacteria encode an electron transport chain that may support aerobic growth. Some Saganbacteria genomes encode various hydrogenases, and others may be able to use O2 under certain conditions via a putative novel type of heme copper O2 reductase. Similarly, Melainabacteria have diverse energy metabolisms and are capable of fermentation and aerobic or anaerobic respiration. The ancestor of all these groups may have been an anaerobe in which fermentation and H2 metabolism were central metabolic features. The ability to use O2 as a terminal electron acceptor must have been subsequently acquired by these lineages

Standardizing data reporting in the research community to enhance the utility of open data for SARS-CoV-2 wastewater surveillance

SARS-CoV-2 RNA detection in wastewater is being rapidly developed and adopted as a public health monitoring tool worldwide. With wastewater surveillance programs being implemented across many different scales and by many different stakeholders, it is critical that data collected and shared are accompanied by an appropriate minimal amount of meta-information to enable meaningful interpretation and use of this new information source and intercomparison across datasets. While some databases are being developed for specific surveillance programs locally, regionally, nationally, and internationally, common globally-adopted data standards have not yet been established within the research community. Establishing such standards will require national and international consensus on what meta-information should accompany SARS-CoV-2 wastewater measurements. To establish a recommendation on minimum information to accompany reporting of SARS-CoV-2 occurrence in wastewater for the research community, the United States National Science Foundation (NSF) Research Coordination Network on Wastewater Surveillance for SARS-CoV-2 hosted a workshop in February 2021 with participants from academia, government agencies, private companies, wastewater utilities, public health laboratories, and research institutes. This report presents the primary two outcomes of the workshop: (i) a recommendation on the set of minimum meta-information that is needed to confidently interpret wastewater SARS-CoV-2 data, and (ii) insights from workshop discussions on how to improve standardization of data reporting