1,525 research outputs found
Optimal strategies for regional cultivar testing
In undertaking cultivar trials, the variability of the response of the cultivars to the different environments in which they are grown introduces the possibility of release errors and non‐release errors in the decisions made on the basis of the trial results. In this article a model is developed that accounts for the economic costs of those errors as well as the costs of operating the trials, and enables the features of the optimal cultivar testing program to be identified. The model is illustrated by application to wheat cultivar trials in central and southern NSW.Crop Production/Industries,
Integrated monitoring of water allocation reform in South Africa
South Africa faces significant inequities in the allocation of water for productive purposes. Water allocation is one component of a wider government mandate to address the inequities of the past. Water allocation reform is being implemented by the South African Department of Water Affairs and Forestry (DWAF), through the Water Allocation Reform (WAR) Programme. This paper presents an approach for determining indicators that can be used to monitor targets for WAR and for prioritising areas for specific WAR interventions. The approach integrates water use data with environmental, economic and equity data to provide a holistic picture of the progress and benefits of WAR. Limitations of the approach are discussed, specifically related to the data on which the indicators are based. The development of data for the equity indicator presents specific challenges which are discussed through examples from its application in four case study areas.Keywords: monitoring, water allocation reform, equity, indicators, South Afric
Statistical methods for analysis of multi-harvest data from perennial pasture variety selection trials
Variety selection in perennial pasture crops involves identifying best varieties from data collected from multiple harvest times in field trials. For accurate selection, the statistical methods for analysing such data need to account for the spatial and temporal correlation typically present. This paper provides an approach for analysing multi-harvest data from variety selection trials in which there may be a large number of harvest times. Methods are presented for modelling the variety by harvest effects while accounting for the spatial and temporal correlation between observations. These methods provide an improvement in model fit compared to separate analyses for each harvest, and provide insight into variety by harvest interactions. The approach is illustrated using two traits from a lucerne variety selection trial. The proposed method provides variety predictions allowing for the natural sources of variation and correlation in multi-harvest data
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Landscapes of progress: the place of physical geography in Scottish Enlightenment accounts of stadial theory
The aim of this thesis is to explore the place of physical geography in Scottish Enlightenment accounts of stadial theory. It does this through examining the historical works of the following authors: Adam Ferguson, Henry Home, (Lord Kames), John Millar and Adam Smith. Stimulated by the 1748 publication of Montesquieu’s Spirit of the Laws each of these individuals presented distinctive explanations for historical progress. Conventional interpretations of Scottish Enlightenment accounts of stadial theory have tended to stress how these were informed by debates over moral conduct and political practice in line with the rise of commercial society. However, these approaches have neglected to consider the place of physical geography within Scottish Enlightenment accounts of historical progress. Consequently, this thesis aims to amend this picture and demonstrate how physical geography provided further insight into the arguments deployed by stadial theorists. This thesis will therefore be structured in the following way. In the introductory chapter, the focus will be on Montesquieu’s understanding of physical geography within the Spirit of the Laws, in demonstrating that his account provided key insights into the differences between European and Asiatic societies which Scottish Enlightenment authors would draw from in order to develop their individual arguments. The second chapter will focus on the work of Adam Ferguson and his An Essay on the History of Civil Society. In the process, it will demonstrate how he used physical geography to illustrate the way social stability was rooted in civic virtue. In the third chapter, Henry Home’s (Lord Kames) Sketches of the History of Man will be examined. It will be argued that physical geography allowed Kames to demonstrate a sceptical interpretation of societal progress which culminated in an ambiguous view of humanity. The final chapter considers the place of physical geography in Adam Smith’s Lectures on Jurisprudence and the Wealth of Nations. In addition to this, this chapter will consider the work of John Millar as an example of the legacy of Smith’s argument and how it informed accounts of physical geography in stadial theory written after the Lectures. Doing so it demonstrates Smith’s understanding of physical geography to be concerned with the way historical progress was conditioned by local influences. This thesis will therefore argue that physical geography provides a way of viewing Scottish Enlightenment accounts of stadial theory which use the premise that societal development was intrinsically linked to a range of physical factors including location, climate, topography and fertility
Is Screening of Intestinal Foregut Anatomy in Heterotaxy Patients Really Necessary? : A Systematic Review in Search of the Evidence
Objective: (1) Is screening of intestinal rotational anatomy obligatory in “asymptomatic” patients with heterotaxy? (2) Does detection of an anomaly warrant surgical correction? Summary of Background Data: Heterotaxy is an abnormal arrangement of thoraco-abdominal viscera across a left-to-right axis. Intestinal rotational anomalies are frequent among patients with heterotaxy, but debate exists as to whether they are benign in nature, requiring careful observation alone, or if surgical correction is warranted to prevent obstruction or midgut volvulus. Methods: A systematic review [according to PRISMA guidelines] was conducted using CINAHL, EMBASE, Medline, and Cochrane Databases. Article quality was assessed using MINORS criteria. Conference proceedings and unpublished data were screened additionally. Results: Nineteen studies met the eligibility criteria but reporting was adequate for 9. All were observational studies. These included a total of 414 patients managed expectantly, that is, “asymptomatic patients” in whom no intestinal rotation screening was undertaken (group A), 191 cases in whom screening was performed routinely (group B), and 92 patients considered “symptomatic” of potential rotational anomalies and therefore underwent imaging or laparotomy (group C). In group A, 1 patient developed symptoms attributable to malrotation in whom laparotomy confirmed the diagnosis (0.24%). Among groups B and C, 151 had Ladd's operations (53%) and 14 cases of malrotation with obstruction or volvulus were described (4.9%), of which 2 “symptomatic patients” died before laparotomy. Overall surgical complication rate was 17% with 30-day mortality rate of 2.6% to 4.6%. Conclusion: The evidence base for screening “asymptomatic” patients is weak especially considering the life-limiting comorbidities
Seventy years of sex education in Health Education Journal: a critical review
This paper examines key debates and perspectives on sex education in Health Education Journal (HEJ), from the date of the journal’s first publication in March 1943 to the present day. Matters relating to sexuality and sexual health are revealed to be integral to HEJ’s history. First published as Health and Empire (1921 – 1942), a key purpose of the journal since its inception has been to share information on venereal disease and its prevention within the UK and across the former British Empire. From 1943 to the present day, discussions on sex education in the newly-christened HEJ both reflect and respond to evolving socio-cultural attitudes towards sexuality in the UK. Changing definitions of sex education across the decades are examined, from the prevention of venereal disease and moral decline in war-time Britain in the 1940s, to a range of responses to sexual liberation in the 1960s and 1970s; from a focus on preventing sexually-transmitted infections, teenage pregnancy and HIV in the 1980s, to the provision of sexual health services alongside sex education in the 2000s. Over the past 70 years, a shift from prevention of pre-marital sexual activity to the management of its outcomes is apparent; however, while these changes over time are notable, perhaps the most striking findings of this review are the continuities in arguments for and against the discussion of sexual issues. After more than 70 years of debate, it would seem that there is little consensus concerning motivations for and the content of sex education
Coexistence and Survival in Conservative Lotka-Volterra Networks
Analyzing coexistence and survival scenarios of Lotka-Volterra (LV) networks in which the total biomass is conserved is of vital importance for the characterization of long-term dynamics of ecological communities. Here, we introduce a classification scheme for coexistence scenarios in these conservative LV models and quantify the extinction process by employing the Pfaffian of the network's interaction matrix. We illustrate our findings on global stability properties for general systems of four and five species and find a generalized scaling law for the extinction time
Optimizing Umkehr Ozone Profile Retrievals
NOAA Dobson Umkehr ozone profile records have been collected since the 1970s. Umkehr ozone profiles are used to monitor stratospheric ozone recovery predicted to occur by the 2050s. Current operational Dobson Umkehr profile algorithms produce data that have uncertainty on the order of ~ 5 % in the stratosphere. However, when large volcanic eruptions inject aerosols into the stratosphere, the errors can be as large as 70 %. In order to evaluate Umkehr records for aerosol-related and instrumental artifacts, we compare observations with a Hindcast simulation of the NASA Merra-2 Global Modeling Initiative (GMI) Replay (M2GMI, Orbe et al, 2017; Wargan et al, 2018) and Chemistry Transport Model (GMI CTM, Strahan et al, 2013, Strahan et al, 2016). The biases found between the models and observations are summarized for each Dobson calibration and volcanic eruption period, thus providing a reference tool for homogenization of the Umkehr time series and removal of volcanic aerosol errors
Spectroscopic investigation of quantum confinement effects in ion implanted silicon-on-sapphire films
Crystalline Silicon-on-Sapphire (SOS) films were implanted with boron (B)
and phosphorous (P) ions. Different samples, prepared by varying the ion
dose in the range to 5 x and ion energy in the range
150-350 keV, were investigated by the Raman spectroscopy, photoluminescence
(PL) spectroscopy and glancing angle x-ray diffraction (GAXRD). The Raman
results from dose dependent B implanted samples show red-shifted and
asymmetrically broadened Raman line-shape for B dose greater than
ions cm. The asymmetry and red shift in the Raman line-shape is
explained in terms of quantum confinement of phonons in silicon nanostructures
formed as a result of ion implantation. PL spectra shows size dependent visible
luminescence at 1.9 eV at room temperature, which confirms the presence
of silicon nanostructures. Raman studies on P implanted samples were also
done as a function of ion energy. The Raman results show an amorphous top SOS
surface for sample implanted with 150 keV P ions of dose 5 x ions
cm. The nanostructures are formed when the P energy is increased to
350 keV by keeping the ion dose fixed. The GAXRD results show consistency with
the Raman results.Comment: 9 Pages, 6 Figures and 1 Table, \LaTex format To appear in
SILICON(SPRINGER
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