Capturing indigenous knowledge of small grain production

Many Iowa farmers lack the knowledge base to grow small grains successfully. This grant supported visits and interviews with farmers across Iowa during small grains field operations in 2014. The goal was to capture the nuts and bolts of small grains production in both conventional and organic systems to facilitate greater adoption of these sustainable systems

Farming for ecosystem services: A case study of multifunctional agriculture in Iowa, U.S.A

Agriculture in the United States faces major challenges for the 21st Century; it is at a pivotal stage in terms of integrating societal demands for sustainability and enhanced quality of life from agricultural lands. A growing understanding that farms play key roles in provisioning a wide range of ecosystem services is converging with a surge in public interest in the sustainability of farming and food systems. Farmers in the US Corn Belt are being solicited to manage for an increasingly complex and expanding suite of production and environmental benefits. However, managing landscapes for multiple objectives presents a major challenge and inherently increases management complexity. A critical challenge lies in defining an appropriate set of agriculture and environmental objectives for management across spatial scales. The goal of this research was to analyze the degree to which there is a capacity to manage agricultural landscapes for multiple ecosystem services with existing and emerging agricultural management practices. I addressed this goal by conducting a case study with stakeholders representing agricultural and environmental interests in Iowa, U.S.A., through a mixed methods approach utilizing the Delphi survey technique and in-person interviews with photo elicitation. This thesis presents the case study results regarding the relationship between ecosystem services and agricultural land management; identifies farm scale management practices that are most promising for achieving ecosystem service objectives across scales; and, additionally, presents a portfolio of landscape visualizations depicting scenarios of land management alternatives

Simulating radiative shocks in nozzle shock tubes

We use the recently developed Center for Radiative Shock Hydrodynamics (CRASH) code to numerically simulate laser-driven radiative shock experiments. These shocks are launched by an ablated beryllium disk and are driven down xenon-filled plastic tubes. The simulations are initialized by the two-dimensional version of the Lagrangian Hyades code which is used to evaluate the laser energy deposition during the first 1.1ns. The later times are calculated with the CRASH code. This code solves for the multi-material hydrodynamics with separate electron and ion temperatures on an Eulerian block-adaptive-mesh and includes a multi-group flux-limited radiation diffusion and electron thermal heat conduction. The goal of the present paper is to demonstrate the capability to simulate radiative shocks of essentially three-dimensional experimental configurations, such as circular and elliptical nozzles. We show that the compound shock structure of the primary and wall shock is captured and verify that the shock properties are consistent with order-of-magnitude estimates. The produced synthetic radiographs can be used for comparison with future nozzle experiments at high-energy-density laser facilities.Comment: submitted to High Energy Density Physic

Using Delphi to Track Shifts in Meanings of Scientific Concepts in a Long-term, Expert-lay Collaboration on Sustainable Agriculture Research in the Midwest

Dilemmas for ongoing expert-lay collaborations for agricultural conservation include divergence of meaning of new scientific concepts. Delphi method documented stakeholders’ understandings of a new term, “ecosystem services.” Flood mitigation and pest management benefits as ecosystem service attributes were ranked lower by stakeholders than anticipated by scientists. Recreation and aesthetics, and food production, were ranked higher

A systematic search for close supermassive black hole binaries in the Catalina Real-Time Transient Survey

Hierarchical assembly models predict a population of supermassive black hole (SMBH) binaries. These are not resolvable by direct imaging but may be detectable via periodic variability (or nanohertz frequency gravitational waves). Following our detection of a 5.2 year periodic signal in the quasar PG 1302-102 (Graham et al. 2015), we present a novel analysis of the optical variability of 243,500 known spectroscopically confirmed quasars using data from the Catalina Real-time Transient Survey (CRTS) to look for close (< 0.1 pc) SMBH systems. Looking for a strong Keplerian periodic signal with at least 1.5 cycles over a baseline of nine years, we find a sample of 111 candidate objects. This is in conservative agreement with theoretical predictions from models of binary SMBH populations. Simulated data sets, assuming stochastic variability, also produce no equivalent candidates implying a low likelihood of spurious detections. The periodicity seen is likely attributable to either jet precession, warped accretion disks or periodic accretion associated with a close SMBH binary system. We also consider how other SMBH binary candidates in the literature appear in CRTS data and show that none of these are equivalent to the identified objects. Finally, the distribution of objects found is consistent with that expected from a gravitational wave-driven population. This implies that circumbinary gas is present at small orbital radii and is being perturbed by the black holes. None of the sources is expected to merge within at least the next century. This study opens a new unique window to study a population of close SMBH binaries that must exist according to our current understanding of galaxy and SMBH evolution.Comment: 29 pages, 10 figures, accepted for publication in MNRAS - this version contains extended table and figur

Twitter Marketing Research

Research Objective: • To examine the relationship between usage rates for individuals ages 46 and up, versus other similar social media platforms. • Are adults aged 46+ using Facebook at a disproportionate rate to Twitter? • What atmosphere/content is the 46+ age demographic seeking when surfing social media? • What can Twitter marketing do to improve brand image among older potential users

Measuring pathways to care in first-episode psychosis : a systematic review

Background Adequately understanding and measuring pathways to care is a prerequisite for early detection and effective treatment of first-episode psychosis. Method We conducted a systematic review of studies on pathways to care in first-episode psychosis to establish what measures currently exist to assess pathways in first-episode psychosis and to compare these measures. Results We identified 15 studies which had used six different measures of pathways to care. Differences in aims, methodology and lack of psychometric data did not allow a direct comparison of pathways measures but certain common themes emerged. Discussion Pathways to care in first-episode psychosis are diverse and varied. There is no measure with established psychometric properties that has been devised on a well-developed theoretical or conceptual framework and had its psychometric properties established. The conflict between exploring the patient's narrative and journey through the healthcare system and developing an empirical measure of pathways with optimal outcomes has hindered the development of such a measure

The influence of the atmospheric boundary layer on nocturnal layers of noctuids and other moths migrating over southern Britain

Insects migrating at high altitude over southern Britain have been continuously monitored by automatically-operating, vertical-looking radars over a period of several years. During some occasions in the summer months, the migrants were observed to form well-defined layer concentrations, typically at heights of 200-400 m, in the stable night-time atmosphere. Under these conditions, insects are likely to have control over their vertical movements and are selecting flight heights which are favourable for long-range migration. We therefore investigated the factors influencing the formation of these insect layers by comparing radar measurements of the vertical distribution of insect density with meteorological profiles generated by the UK Met. Office’s Unified Model (UM). Radar-derived measurements of mass and displacement speed, along with data from Rothamsted Insect Survey light traps provided information on the identity of the migrants. We present here three case studies where noctuid and pyralid moths contributed substantially to the observed layers. The major meteorological factors influencing the layer concentrations appeared to be: (a) the altitude of the warmest air, (b) heights corresponding to temperature preferences or thresholds for sustained migration and (c), on nights when air temperatures are relatively high, wind-speed maxima associated with the nocturnal jet. Back-trajectories indicated that layer duration may have been determined by the distance to the coast. Overall, the unique combination of meteorological data from the UM and insect data from entomological radar described here show considerable promise for systematic studies of high-altitude insect layering

Wide-Field Infrared Survey Explorer Science Payload Update

The Wide Field Infrared Survey Explorer is a NASA Medium Class Explorer mission to perform a high-sensitivity, high resolution, all-sky survey in four infrared wavelength bands. The science payload is a 40 cm aperture cryogenically cooled infrared telescope with four 10242 infrared focal plane arrays covering from 2.8 to 26 μm. Mercury cadmium telluride (MCT) detectors are used for the 3.3 μm and 4.6 μm channels, and Si:As detectors are used for the 12 μm and 23 μm wavelength channels. A cryogenic scan mirror freezes the field of view on the sky over the 9.9-second frame integration time. A two-stage solid hydrogen cryostat provides cooling to temperatures less than 17 K and 8.3 K at the telescope and Si:As focal planes, respectively. The science payload collects continuous data on orbit for the seven-month baseline mission with a goal to support a year-long mission, if possible. As of the writing of this paper, the payload subassemblies are complete, and the payload has begun integration and test. This paper provides a payload overview and discusses instrument status and performance