1,889 research outputs found
Sources of nitrogen for winter wheat in organic cropping systems
No full textIn organic cropping systems, legumes, cover crops, residue incorporation, and manure application are used to maintain soil fertility, but the contributions of these management practices to soil nitrogen (N) supply remain obscure. We examined potential sources of N for winter wheat (Triticum aestivum L.) in four experimental cropping systems established in 1997 on three soil types. Three of the four systems were under organic management. Topsoil N, depth of the A horizon, and cumulated inputs of N since 1997 were determined at plot level. Labile soil N pools (mineral N, potentially mineralizable N [PMN], microbial biomass N [MBN]) were monitored during two growth periods; at one site, biomass C/N ratios were also determined. Soil for labile N analysis was shielded from N inputs during spring application to isolate cumulated system effects. PMN and MBN were correlated across all sites and rotations (r2=0.72). The MBN corresponded to 46-85, 85-145 and 74-172 kg N ha-1 at the three sites and differed significantly between cropping systems, but MBN could not explain differences in wheat grain N yields. Instead, a multiple linear regression model explained 76 and 82% of the variation in grain N yields in organic cropping systems in 2007 and 2008, showing significant effects of, respectively, topsoil N, depth of A horizon, cumulated inputs of N, and N applied to winter wheat in manure. Thus, soil properties, and past and current management all contributed to winter wheat N supply
The IPHAS catalogue of H alpha emission-line sources in the northern Galactic plane
No full textWe present a catalogue of point-source H alpha emission-line objects selected from the INT/WFC Photometric Ha Survey (IPHAS) of the northern Galactic plane. The catalogue covers the magnitude range 13 <= r' <= 19.5 and includes Northern hemisphere sources in the Galactic latitude range -5 degrees < b < 5 degrees. It is derived from similar to 1500 deg(2) worth of imaging data, which represents 80 per cent of the final IPHAS survey area. The electronic version of the catalogue will be updated once the full survey data become available. In total, the present catalogue contains 4853 point sources that exhibit strong photometric evidence for Ha emission. We have so far analysed spectra for similar to 300 of these sources, confirming more than 95 per cent of them as genuine emission-line stars. A wide range of stellar populations are represented in the catalogue, including early-type emission-line stars, active late-type stars, interacting binaries, young stellar objects and compact nebulae.
The spatial distribution of catalogue objects shows overdensities near sites of recent or current star formation, as well as possible evidence for the warp of the Galactic plane. Photometrically, the incidence of Ha emission is bimodally distributed in (r' - i'). The blue peak is made up mostly of early-type emission-line stars, whereas the red peak may signal an increasing contribution from other objects, such as young/active low-mass stars. We have cross-matched our H alpha-excess catalogue against the emission-line star catalogue of Kohoutek & Wehmeyer, as well as against sources in SIMBAD. We find that fewer than 10 per cent of our sources can be matched to known objects of any type. Thus IPHAS is uncovering an order of magnitude more faint (r' > 13) emission-line objects than were previously known in the Milky Way
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Focus on forestry ; vol. 3, no. 1 (Winter 1990)
No full textFocus on Forestry is published three times each year (Fall, Winter, Spring) by the College of Forestry, Oregon State University.KEYWORDS: plant genetics biotechnology, Dennis Isaacson, Environmental Remote Sensing Applications Laboratory (ERSAL), Steven Strauss, McGillivray's warbler, snags, Norman Johnson, James Funck, wood products manufacturing, John Sessions, Weyerhaeuser, George Brown, Rexford Resler, gestalt, Bill Atkinson, Bill McComb, gypsy moth, John Beuter, Brian Greber, John Tappeiner, forestry enrollment, wildlife habitat, Jim Krygier, David Butler, Jeff Garver, Bacillus thuringiensis (B.t.), Barbara Yoder, Douglas-fir, Terry Luther, Carl Stoltenberg, machine vision, NASA fellowship, Charles Brunner, Gifford Pinchot Medal, William Ripple, timber projections, McDonald Research Forest, Warm Springs Indian Reservation, Richard Waring, Oregon Transect Terrestrial Ecosystem Research (OTTER
The distribution of basal motion beneath a High Arctic polythermal glacier
No full textThe longitudinal pattern of surface velocity of a large, predominantly colds polythermal glacier (John Evans Glacier, Ellesmere Island, Canada) was measured over summer and winter periods. In the accumulation and upper ablation areas, where ice is predominantly cold-based, summer velocities were slightly higher than overwinter velocities. Predicted velocities due to ice deformation alone in these areas closely matched these observations in the winter, with limited basal motion likely in the summer. In the lower ablation area, where ice is likely warm-based, measured summer velocities were up to double overwinter velocities. Predicted ice deformation could not account for all of these measured velocities in either summer or winter. This suggests that basal motion occurs throughout the year over at least part of the lower ablation area. This finding is supported by radio-echo sounding, subglacial drainage reconstructions and analyses of early-summer meltwater chemistry, which suggest that subglacial water is present throughout the year in this region. In Summer, basal motion may account for up to 75% of the total surface velocity throughout the lower ablation area. The inferred rate of basal motion increases sharply directly below a set of moulins by which most surface meltwater reaches the glacier bed
Uptake of WmCSV by the efficient transmitter <i>Bemisia tabaci</i> 63 and the poor transmitter <i>B. tabaci</i> 95.
No full text<p>Virus concentrations were analyzed by qPCR in composite samples of 100 whiteflies of <i>B. tabaci</i> 63 (<i>B.t.</i> 63) and <i>B. tabaci</i> 95 (<i>B.t.</i> 95) after a six hour starvation over an acquisition access period of five days (two technical replicates). Median values of virus concentrations were calculated assuming 100 ng DNA as an average DNA content of an individual whitefly. Three independent experiments were performed.</p
The design of an intuitive interface for the GyBAR: Simplifying the controls of a balance assistance device for optimal adoption by physical therapists
No full textAccording to the WHO, falls are responsible for over 38 million disability-adjusted life years lost each year, globally. Additionally, an estimated 684.000 individuals die of falling each year, making it the second leading cause of unintentional death. One of the most effective physical activity interventions to reduce the risk of falling, is targeted exercise that safely challenges balance. One tool, that is currentlybeing developed, which can aid physical therapists with these interventions is the GyBAR. A wearable device that uses gyroscopes to apply moments to the patient. This can be used to either provide balance assistance or challenge balance by applying perturbations. The goal of this research was to develop an interface for the GyBAR. The interface should contribute to the acceptance of the GyBAR. This can be achieved by an excellent perceived ease of use, which combined with perceived usefulnessare indicators for the Technology Acceptance Model (TAM). The interface inspired by a Voodoo-doll was developed by going through the following design process steps; the creation of a list of requirements; a brainstorm to generate ideas; the development of three concepts; and the selection and development of one concept into a prototype. The Voodoo Doll controls the GyBAR by a handheld model of the patient, which can be manipulated and translates the movements of the model to the actual patient. User tests were performed to validate the design. With a SUS-score of 82.81 (SD=7.48), which is within the 90-95 percentile, it can be concluded that the interface has an excellent perceived ease of use. Further development is encouraged are several recommendations for points of improvement are given.Biomedical Engineerin
Efficacy of Bacillus thuringiensis var.galleriae Berliner and selected insecticides on cotton bollworm, Earias vitella
No full textCotton, an important cash crop of tropical world, is attacked by many insects. Earias vitella is a major pest in winter crop.Bio-efficacy of B.t, var galleriae as Spicturin®, was evaluated in comparison with insecticides. Two field experimentswere conducted winter and summer seasons with the cotton cultivar LRA- 5166 to assess the efficacy of B.t. on Earias spp. in combination with the insecticides like endosulfan (0.035 %), quinalphos (0.025%), fenvalerate (0.01%) and diflubenzuron (0.075%),endosulfan (0.035%) in combination with B.t.g. @ 3 l/ha was found to be the best in reducingthe boll damage.The damage to the larva tissues is illustrated with thin sections of diseased larva after fixing in blackwax, microtomy sectioning and light microscopy. Cracks in gut lining, damage to gut lumen, epidermis and epithelialcells, basement membrane, musculosa , peritrophic membrane were observed and support the successful pathogenesisand mortality of treated larvae.
Keywords: Cotton, boll worm, Earias, Bacillus, squares, pathogenei
Asylum policy and housing for asylum seekers in the EU – A look at Malta’s open centres for asylum seekers
No full textReservoir Management and Optimization of the Mitsue Gilwood Sand Unit #1 Horizontal Hydrocarbon Miscible Flood
No full textThe new port infrastructure: strategic design of a container data platform for Port of Rotterdam
No full textSea ports are undergoing a digital transformation, which can offer benefits for many involved stakeholders in the logistic chain. In order to stay relevant, Port of Rotterdam (PoR) should invest in developing new port infrastructure; digital connections that facilitate data exchange between logistic chain stakeholders. A strategic digital opportunity was found for PoR, design a platform that is focused on container data, which contributes to the competitive position of the port of Rotterdam and the business model of PoR. The thesis explores the design of the platform Cadex, a data platform that facilitates cargo data exchange between data suppliers, e.g. terminals and data demanders, shippers. Cadex offers shippers real-time data about their containers that enables shippers to act upon containers that deviate from the planned schedule. By making cargo data easy accessible it could save shippers significant costs that come with transport, the deprecation of their goods, the management of their logistics and their inventory. Especially in time sensitive trade, like fresh goods or factory parts this data is valuable. In addition, it could also contribute to a lower carbon footprint of shipments. The platform enables users to get data directly from the data owners (data supplies) like sea-port terminals and hinterland terminals and can therefore be labeled as reliable data. The data suppliers benefit from the revenue model the platform offers for their data and they are allowed to set their own asking price for this data, furthermore they benefit from the data they receive about their clients. PoR would directly benefit from the data exchange by charging a percentage of the price. In addition, PoR receives historical data about its clients, which improves their knowledge about the clients they serve and could be input for improvements in the port of Rotterdam. Moreover, a better customer service is offered to shippers that make use of the port of Rotterdam. The new port infrastructure Cadex offers, could improve the score of the port Rotterdam on the selection criteria and therefore, contribute to a higher competitive position. Developing this new port infrastructure is a long-term investment since the connections hold value. Once built, the infrastructure can be reused by other parties or other digital purposes with some adjustments. This makes PoR a relevant party in the digital transition. Without this new port infrastructure, PoR is more likely to be bypassed by other competing players who will reap the benefits of the digital transformation in sea-ports.Strategic Product Desig
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