SCUBA observations of the Horsehead Nebula - what did the horse swallow?

We present observations taken with SCUBA on the JCMT of the Horsehead Nebula in Orion (B33), at wavelengths of 450 and 850 \mum. We see bright emission from that part of the cloud associated with the photon-dominated region (PDR) at the `top' of the horse's head, which we label B33-SMM1. We characterise the physical parameters of the extended dust responsible for this emission, and find that B33-SMM1 contains a more dense core than was previously suspected. We compare the SCUBA data with data from the Infrared Space Observatory (ISO) and find that the emission at 6.75-\mum is offset towards the west, indicating that the mid-infrared emission is tracing the PDR while the submillimetre emission comes from the molecular cloud core behind the PDR. We calculate the virial balance of this core and find that it is not gravitationally bound but is being confined by the external pressure from the HII region IC434, and that it will either be destroyed by the ionising radiation, or else may undergo triggered star formation. Furthermore we find evidence for a lozenge-shaped clump in the `throat' of the horse, which is not seen in emission at shorter wavelengths. We label this source B33-SMM2 and find that it is brighter at submillimetre wavelengths than B33-SMM1. SMM2 is seen in absorption in the 6.75-\mum ISO data, from which we obtain an independent estimate of the column density in excellent agreement with that calculated from the submillimetre emission. We calculate the stability of this core against collapse and find that it is in approximate gravitational virial equilibrium. This is consistent with it being a pre-existing core in B33, possibly pre-stellar in nature, but that it may also eventually undergo collapse under the effects of the HII region.Comment: 11 pages, 6 figures, accepted by MNRA

Molecular gas freeze-out in the pre-stellar core L1689B

C17O (J=2-1) observations have been carried out towards the pre-stellar core L1689B. By comparing the relative strengths of the hyperfine components of this line, the emission is shown to be optically thin. This allows accurate CO column densities to be determined and, for reference, this calculation is described in detail. The hydrogen column densities that these measurements imply are substantially smaller than those calculated from SCUBA dust emission data. Furthermore, the C17O column densities are approximately constant across L1689B whereas the SCUBA column densities are peaked towards the centre. The most likely explanation is that CO is depleted from the central regions of L1689B. Simple models of pre-stellar cores with an inner depleted region are compared with the results. This enables the magnitude of the CO depletion to be quantified and also allows the spatial extent of the freeze-out to be firmly established. We estimate that within about 5000 AU of the centre of L1689B, over 90% of the CO has frozen onto grains. This level of depletion can only be achieved after a duration that is at least comparable to the free-fall timescale.Comment: MNRAS letters. 5 pages, 5 figure

Inter-row Robot Navigation using 1D Ranging Sensors

In this paper a fuzzy logic navigation controller for an inter-row agricultural robot is developed and evaluated in laboratory settings. The controller receives input from one-dimensional (1D) ranging sensors on the robotic platform, and operated on ten fuzzy rules for basic row-following behavior. The control system was implemented on basic hardware for proof of concept and operated on a commonly available microcontroller development platform and open source software libraries. The robot platform used for experimentation was a small tracked vehicle with differential steering control. Fuzzy inferencing and defuzzification, step response and cross track error were obtained from the test conducted to characterize the transient and steady state response of the controller. Controller settling times were within 4 seconds. Steady state centering errors for smooth barrier navigation were found to be within 3.5% of center for 61 cm wide solid barrier tests, and within 38% for simulated 61 cm corn row tests

Inter-row Robot Navigation using 1D Ranging Sensors

In this paper a fuzzy logic navigation controller for an inter-row agricultural robot is developed and evaluated in laboratory settings. The controller receives input from one-dimensional (1D) ranging sensors on the robotic platform, and operated on ten fuzzy rules for basic row-following behavior. The control system was implemented on basic hardware for proof of concept and operated on a commonly available microcontroller development platform and open source software libraries. The robot platform used for experimentation was a small tracked vehicle with differential steering control. Fuzzy inferencing and defuzzification, step response and cross track error were obtained from the test conducted to characterize the transient and steady state response of the controller. Controller settling times were within 4 seconds. Steady state centering errors for smooth barrier navigation were found to be within 3.5% of center for 61 cm wide solid barrier tests, and within 38% for simulated 61 cm corn row tests

Quantification of Temporal and Spatial Dynamics of Bean pod mottle virus at Different Spatial Scales

Bean pod mottle virus (BPMV) is the most prevalent virus infecting soybean (Glycine max) in the United States; however, the temporal and spatial dynamics in BPMV at varying spatial scales has not been elucidated. To quantify the temporal and spatial dynamics of BPMV at a field scale, a quadrat-based method was developed in which six soybean rows, each consisting of 30-cm-long quadrats, were established within soybean cv. NE3001 field plots (i.e., 150 quadrats per plot) in BPMV-inoculated and non-inoculated plots. Quadrats were sampled by selecting the youngest fully expanded leaflet from each of four plants within each quadrat beginning 25 days after planting, and continued at 8- to 11- day intervals until crop senescence. Leaf sap was extracted from each 4-leaflet (bulked) sample (from each quadrat), and tested for presence of the BPMV by ELISA. Quadrat position (plot, row, and quadrat number) and the date of sampling that each quadrat first tested positive for BPMV was recorded and mapped. The rate of BPMV incidence in 2006 ranged from 0.09 to 0.12 logits/day, indicating that BPMV incidence was doubling every 5.3 to 7.7 days in 2006. Doubling times for BPMV incidence in 2007 were slower, ranging from 17.3 to 34.7 days. Analysis of spatial patterns using ordinary runs revealed that BPMV-infected quadrats were predominantly clustered within both BPMV-inoculated and non-inoculated plots throughout both growing seasons. In addition to within field plot studies, a threeyear statewide disease survey (2005-2007) was conducted in Iowa to quantify county and field scale BPMV prevalence and incidence by systematically selecting 30 plants/soybean field (8 to 16 soybean fields per county). Leaf samples were then tested for BPMV by ELISA and county-level BPMV incidence maps were generated using ArcGIS software. End-of-season BPMV prevalence was 39/96 counties in 2005 (40%), 90/99 counties in 2006 (90.1%), and 74/99 counties in 2007 (74.7%). The incidence of BPMV within Iowa counties ranged from 0 to 100% and BPMV incidence significantly increased statewide from north to south. Spatial autocorrelation (dependence) analysis using Moran’s I revealed clustering for BPMV incidence among Iowa counties, indicating that BPMV incidence among counties was not random. The elucidation of the within-field temporal and spatial dynamics of BPMV and the statewide geographic distribution of BPMV in Iowa has important implications with regards to sampling, plant disease forensics, BPMV management, and risk prediction of BPMV

The Benedum Collaborative Model of Teacher Education Student Handbook

The College of Human Resources & Education welcomes you as students in the Five-Year Teacher Education Program. You will find that your experiences in the Benedum Collaborative will prepare you well as you begin your work in the teaching profession. Our partnership with the professional development schools in the Collaborative provides the setting for clinical experiences that build on your course work at West Virginia University

Quantifying the Within-Field Temporal and Spatial Dynamics of Bean pod mottle virus in Soybean

The prevalence and incidence of Bean pod mottle virus (BPMV) have been reported to be on the increase in the United States but little is known about the temporal and spatial dynamics of this virus within soybean (Glycine max) fields. A quadrat-based sampling method was developed to quantify the within-field spread of BPMV in soybean in 2006 and 2007. Twenty-five 30-cm-long quadrats were established within each row of soybean in field plots consisting of six rows, each 7.6 m long and spaced 0.76 m apart. Four treatments were used to influence the temporal and spatial dynamics of BPMV epidemics. Treatments were: (i) establishment of a point source of BPMV inoculum within soybean plots; (ii) lambda-cyhalothrin insecticide applied at the V1 and R2 growth stages; (iii) establishment of a BPMV inoculum point source, plus the application of foliar insecticide sprays at the V1 and R2 growth stages; and (iv) a nontreated, noninoculated control. All quadrats (census) were sampled beginning 25 days after planting; sampling continued every 8 to 11 days until plants were senescent. Sap from leaf samples was extracted and tested for BPMV by enzyme-linked immunosorbent assay. The incidence of BPMV per treatment was plotted against time to produce BPMV incidence curves for temporal analyses. In addition, positions of BPMV-positive quadrats were mapped for spatial analyses. BPMV was detected within soybean plots on the first sampling date in 2006 (30 May) and on the second sampling date in 2007 (21 June). The rate of BPMV temporal spread within treatments ranged from 0.11 to 0.13 logits/day in 2006 and from 0.05 to 0.07 logits/day in 2007. Doubling times for BPMV incidence among treatments ranged from 5.4 to 6.4 days in 2006 and from 10.0 to 14.1 days in 2007. Soybean plots that had the earliest dates of BPMV detection within quadrats (x) also had the highest BPMV incidence (y) at the end of the growing season (R2 = 66.5 and 70.4% for 2006 and 2007, respectively). Spatial analyses using ordinary runs, black-white join-counts, and spatial autocorrelation revealed highly aggregated spatial patterns of BPMV-infected quadrats over time. Bean leaf beetle population densities were linearly related to BPMV incidence (P \u3c 0.0001) in both years, indicating that BPMV epidemics were greatly influenced by bean leaf beetle population density. To our knowledge, this is the first study to quantify the seasonal temporal and spatial dynamics of BPMV spread within soybean

Agricultural Field Robotics for Plant Data Acquisition

As the demand for food increases, we are presented with the challenge of producing food more efficiently. With the help of agricultural robots it will be possible to achieve greater yields by the application of seeds, fertilizers and chemicals in the most efficient way possible. With more advanced robotic systems accurate crop data can be obtained to improve farming products and techniques. Flex-Row is a medium sized agricultural robotic platform built for autonomously traversing through rough fields during multiple crop growing stages. This platform consisting of a flexible frame with the ability to vary both width and height will initially be implemented with sensors to monitor production plants throughout the growing season. Furthermore, the robot will perform low draft applications such as spraying. The intended goal for this project is to develop a tele-operated platform that can be automated in the future. Inter-Row is a much smaller robot designed specifically for plant data acquisition. Tall height is not needed as it individually scans each plant a few cm from the base of the plant. The robot will help eliminate the need for manual labor when counting number of plants per row, which is beneficial on a large acreage field. Advisor: Dr. Santosh K. Pitl

LoanSTAR Energy Auditing: Update and Changes

Annual savings identified by detailed LoanSTAR audits during the period January, 1989 -December, 1991 are $13.7 million with an investment cost of$46.1 million. These savings represent retrofit projects in state-owned buildings, local government-owned facilities, and independent school districts, accounting for 80%, 16%, and 4% of the investment cost, respectively. A summary of retrofit projects by type is presented and modifications to chillers and chilled water systems account for 26% of the savings and 32% of the cost, followed by lighting retrofits which account for 24% of the savings and 24% of the cost. The Governor's Energy Office has implemented changes to simplify the audit process by eliminating some calculations. Independent calculations and maintenance and operating procedures calculations are no longer required, and some retrofit projects may depend on standard paybacks to identify cost savings