217 research outputs found

    Reducing insecticide use in broad-acre grains production: An Australian study

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    Prophylactic use of broad-spectrum insecticides is a common feature of broad-acre grains production systems around the world. Efforts to reduce pesticide use in these systems have the potential to deliver environmental benefits to large areas of agricultural land. However, research and extension initiatives aimed at decoupling pest management decisions from the simple act of applying a cheap insecticide have languished. This places farmers in a vulnerable position of high reliance on a few products that may lose their efficacy due to pests developing resistance, or be lost from use due to regulatory changes. The first step towards developing Integrated Pest Management (IPM) strategies involves an increased efficiency of pesticide inputs. Especially challenging is an understanding of when and where an insecticide application can be withheld without risking yield loss. Here, we quantify the effect of different pest management strategies on the abundance of pest and beneficial arthropods, crop damage and yield, across five sites that span the diversity of contexts in which grains crops are grown in southern Australia. Our results show that while greater insecticide use did reduce the abundance of many pests, this was not coupled with higher yields. Feeding damage by arthropod pests was seen in plots with lower insecticide use but this did not translate into yield losses. For canola, we found that plots that used insecticide seed treatments were most likely to deliver a yield benefit; however other insecticides appear to be unnecessary and economically costly. When considering wheat, none of the insecticide inputs provided an economically justifiable yield gain. These results indicate that there are opportunities for Australian grain growers to reduce insecticide inputs without risking yield loss in some seasons. We see this as the critical first step towards developing IPM practices that will be widely adopted across intensive production systems. © 2014 Macfadyen et al

    Coulomb Blockade in low mobility nanometer size Si:MOSFETs

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    We investigate coherent transport in Si:MOSFETs with nominal gate lengths 50 to 100nm and various widths at very low temperature. Independent of the geometry, localized states appear when G=e^{2}/h and transport is dominated by resonant tunnelling through a single quantum dot formed by an impurity potential. We find that the typical size of the relevant impurity quantum dot is comparable to the channel length and that the periodicity of the observed Coulomb blockade oscillations is roughly inversely proportional to the channel length. The spectrum of resonances and the nonlinear I-V curves allow to measure the charging energy and the mean level energy spacing for electrons in the localized state. Furthermore, we find that in the dielectric regime, the variance var(lng) of the logarithmic conductance lng is proportional to its average value consistent with one-electron scaling models.Comment: 4 pages, 4 figure

    Magnetic and intruder rotational bands in (113)In

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    ©2005 American Physical SocietyExcited states in ¹¹³In were populated via the reactions ¹⁰⁰Mo(¹⁸O,p4n)¹¹³In and ¹¹⁰Pd(7Li,4n)¹¹³In. The two known ΔJ = 2 intruder bands, based on the πg7/2 ⊗ d5/2 and πh11/2 orbitals, have been extended by 8¯h to spins (49/2+)¯h and (55/2−)¯h, respectively. The previous finding of three sequences of ΔJ = 1 γ -ray transitions has been confirmed. A self-consistent cranked shell-model calculation gives a good description of the contrasting alignment patterns of the two ΔJ = 2 intruder bands. The intruder bands, the known sequences ofM1 transitions, and spherical levels together represent a coexistence of three different excitation modes in this nucleus.S. Naguleswaran, R. S. Chakrawarthy, U. Garg, K. L. Lamkin, G. Smith, J. C. Walpe, A. Galindo-Uribarri, V. P. Janzen, D. C. Radford, R. Kaczarowski, D. B. Fossan, D. R. Lafosse, P. Vaska, Ch. Droste, T. Morek, S. Pilotte, J. DeGraaf, T. Drake, and R. Wys

    Low-lying quadrupole collective states of the light and medium Xenon isotopes

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    Collective low lying levels of light and medium Xenon isotopes are deduced from the Generalized Bohr Hamiltonian (GBH). The microscopic seven functions entering into the GBH are built from a deformed mean field of the Woods-Saxon type. Theoretical spectra are found to be close to the ones of the experimental data taking into account that the calculations are completely microscopic, that is to say, without any fitting of parameters.Comment: 8 pages, 4 figures, 1 tabl

    The Vehicle, Fall 1993

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    Table of Contents 7/10ths SynthesisPeter F. Essigpage 5 Aug 1992 (My Small Catechism)Jon Montgomerypage 6 Chaos Is-J. Dylan McNeillpage 7 UntouchedTraci Williamspage 8 The JustificationJohn C. Carminepage 8 LincolnJon Montgomerypage 9 Untitled (Photo)Nicole Niemanpage 10 Park PoemJohn Brillhartpage 11 SmokeJulia Ann Canhampage 12 Warming the BenchAnn Moutraypage 12 Cereal KillerJay Harnackpage 13 The Dutiful SonsTom McGrathpage 14 UntitledCatherine DeGraafpage 17 7-up bottleWalt Howardpage 17 BreedDan Trutterpage 18 An Argument Against LoveTony Martinezpage 19 UntitledT. Scott Laniganpage 19 Glassblowers BallStephanie Franzenpage 20 Portrait of a Young GirlJohn C. Carminepage 20 Untitled (artwork)Dan Trutterpage 21 Death of a FriendLizabeth Kulkapage 22 Submission BluesMartin Paul Brittpage 23 To the Fourteen Year Old SuicideScott Langenpage 23 The Flabby PilgrimTom McGrathpage 24 The Fall of ImmortalityBrian Wheelerpage 25 Merging with AirThom Schnarrepage 26 UntitledCatherine DeGraafpage 27 Tree FishSandra Beauchamppage 28 Country SlumberJ. Dylan McNeillpage 29 Untitled (artwork)Dan Trutterpage 33 Authors\u27 Pagepage 34https://thekeep.eiu.edu/vehicle/1060/thumbnail.jp

    An exploratory study of Muslim adolescents' views on sexuality: Implications for sex education and prevention

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    <p>Abstract</p> <p>Background</p> <p>This paper describes the results of an exploratory qualitative study on Muslim adolescents' views on sexuality in the Netherlands.</p> <p>Methods</p> <p>Data were gathered from an Internet forum on which 44 Muslim and 33 non-Muslim adolescents discussed sexuality as it relates to Islam. These discussions were subsequently analyzed for content using Nvivo 2.0.</p> <p>Results</p> <p>Our analysis revealed several issues that are relevant for the design of future sex education programs targeting Muslim youth. Apart from some expected outcomes regarding, for example, taboos on sexuality, sex outside marriage, abortion, homosexuality and conservative gender roles, our analyses showed that in cases of disputes 1) discussions were polarized, 2) opponents used the same Qur'anic passages to support their views, and 3) the authority of an Imam was questioned when his interpretation of Qur'anic passages was not in line with the views of participants.</p> <p>Conclusions</p> <p>Our findings show that current approaches to sex education among Muslim youth are likely to be unsuccessful given the rigidity of sexual norms in Muslim society. In addition, we also identified new barriers to sex education among Muslim youth (e.g. lack of respect for an Imam who opposes a youth's views on sexuality).</p

    Effects of Vegetation, Corridor Width and Regional Land Use on Early Successional Birds on Powerline Corridors

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    Powerline rights-of-way (ROWs) often provide habitat for early successional bird species that have suffered long-term population declines in eastern North America. To determine how the abundance of shrubland birds varies with habitat within ROW corridors and with land use patterns surrounding corridors, we ran Poisson regression models on data from 93 plots on ROWs and compared regression coefficients. We also determined nest success rates on a 1-km stretch of ROW. Seven species of shrubland birds were common in powerline corridors. However, the nest success rates for prairie warbler (Dendroica discolor) and field sparrow (Spizella pusilla) were <21%, which is too low to compensate for estimated annual mortality. Some shrubland bird species were more abundant on narrower ROWs or at sites with lower vegetation or particular types of vegetation, indicating that vegetation management could be refined to favor species of high conservation priority. Also, several species were more abundant in ROWs traversing unfragmented forest than those near residential areas or farmland, indicating that corridors in heavily forested regions may provide better habitat for these species. In the area where we monitored nests, brood parasitism by brown-headed cowbirds (Molothrus ater) occurred more frequently close to a residential area. Although ROWs support dense populations of shrubland birds, those in more heavily developed landscapes may constitute sink habitat. ROWs in extensive forests may contribute more to sustaining populations of early successional birds, and thus may be the best targets for habitat management

    Rye kernel breakfast increases satiety in the afternoon - an effect of food structure

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    <p>Abstract</p> <p>Background</p> <p>The structure of whole grain cereals is maintained to varying degrees during processing and preparation of foods. Food structure can influence metabolism, including perceived hunger and satiety. A diet that enhances satiety per calorie may help to prevent excessive calorie intake. The objective of this work was to compare subjective appetite ratings after consumption of intact and milled rye kernels.</p> <p>Methods</p> <p>Two studies were performed using a randomized, cross-over design. Ratings for appetite (hunger, satiety and desire to eat) were registered during an 8-h period after consumption of whole and milled rye kernels prepared as breads (study 1, n = 24) and porridges (study 2, n = 20). Sifted wheat bread was used as reference in both study parts and the products were eaten in iso-caloric portions with standardized additional breakfast foods. Breads and porridges were analyzed to determine whether structure (whole vs. milled kernels) effected dietary fibre content and composition after preparation of the products. Statistical evaluation of the appetite ratings after intake of the different breakfasts was done by paired t-tests for morning and afternoon ratings separately, with subjects as random effect and type of breakfast and time points as fixed effects.</p> <p>Results</p> <p>All rye breakfasts resulted in higher satiety ratings in the morning and afternoon compared with the iso-caloric reference breakfast with sifted wheat bread. Rye bread with milled or whole kernels affected appetite equally, so no effect of structure was observed. In contrast, after consumption of the rye kernel breakfast, satiety was increased and hunger suppressed in the afternoon compared with the milled rye kernel porridge breakfast. This effect could be related to structural differences alone, because the products were equal in nutritional content including dietary fibre content and composition.</p> <p>Conclusions</p> <p>The study demonstrates that small changes in diet composition such as cereal grain structure have the potential to effect feelings of hunger and satiety.</p> <p>Trial registration</p> <p>This trial was registered at clinicaltrials.gov as <a href="http://www.clinicaltrials.gov/ct2/show/NCT01042418">NCT01042418</a>.</p

    Mapping Migratory Bird Prevalence Using Remote Sensing Data Fusion

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    This is the publisher’s final pdf. The published article is copyrighted by the Public Library of Science and can be found at: http://www.plosone.org/home.action.Background: Improved maps of species distributions are important for effective management of wildlife under increasing anthropogenic pressures. Recent advances in lidar and radar remote sensing have shown considerable potential for mapping forest structure and habitat characteristics across landscapes. However, their relative efficacies and integrated use in habitat mapping remain largely unexplored. We evaluated the use of lidar, radar and multispectral remote sensing data in predicting multi-year bird detections or prevalence for 8 migratory songbird species in the unfragmented temperate deciduous forests of New Hampshire, USA. \ud \ud Methodology and Principal Findings: A set of 104 predictor variables describing vegetation vertical structure and variability from lidar, phenology from multispectral data and backscatter properties from radar data were derived. We tested the accuracies of these variables in predicting prevalence using Random Forests regression models. All data sets showed more than 30% predictive power with radar models having the lowest and multi-sensor synergy ("fusion") models having highest accuracies. Fusion explained between 54% and 75% variance in prevalence for all the birds considered. Stem density from discrete return lidar and phenology from multispectral data were among the best predictors. Further analysis revealed different relationships between the remote sensing metrics and bird prevalence. Spatial maps of prevalence were consistent with known habitat preferences for the bird species. \ud \ud Conclusion and Significance: Our results highlight the potential of integrating multiple remote sensing data sets using machine-learning methods to improve habitat mapping. Multi-dimensional habitat structure maps such as those generated from this study can significantly advance forest management and ecological research by facilitating fine-scale studies at both stand and landscape level
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