10,806 research outputs found
The applicability, efficacy and risks of natural sequence farming in the dryland agricultural zone of south west Western Australia
Natural sequence farming (NSF) is an approach to restoring degraded agricultural land, developed by Peter Andrews on his property Tarwyn Park in New South Wales. The approach aims to rehydrate the landscape by slowing the movement of water with a series of structures and then using this water to drive plant growth and improve soil function.
The Department of Primary Industries and Regional Development engaged the University of Western Australia to review the applicability, efficacy and risks associated with using NSF principles and practices in the south-west dryland agricultural zone in Western Australia. The review has combined information from the literature, relevant case studies and findings from interviews with knowledge holders and stakeholders.
The review identified that NSF might be suitable or applicable for: the rejuvenated and steeply sloped catchments near the Darling Scarp of the Avon Basin (e.g. Toodyay, Northam, York areas) areas of the Chapman Valley (Sugarloaf System) the higher rainfall and hydrologically connected catchments draining to the coast from Perth to Esperance (the south-west and south coastal areas of WA) limited areas of sandplain systems in the Swan Coastal Plain and Perth Basin with no salinity risk applying with caution in sandplain systems in the medium rainfall zone with no present surface salinity issues (e.g. Meckering and Wongan Hills area), and on skeletal soils in rejuvenated systems where rainfall is above 350 mm, and some similar land systems along the south coast.
However, in relation to dryland salinity, NSF interventions in most hydrozones are considered likely to exacerbate current salinity risk. The impact on water erosion was assessed as depending on site-specific factors such as the scale, design and quality of construction for flow control structures on hillslopes and in-channel leaky weirs. Increased groundcover will likely improve the land condition in relation to raindrop impact and related water erosion
Covariant Helicity-Coupling Amplitudes: A New Formulation
We have worked out covariant amplitudes for any two-body decay of a resonance
with an arbitrary non-zero mass, which involves arbitrary integer spins in the
initial and the final states. One key new ingredient for this work is the
application of the total intrinsic spin operator which is given
directly in terms of the generators of the Poincar\'e group.
Using the results of this study, we show how to explore the Lorentz factors
which appear naturally, if the momentum-space wave functions are used to form
the covariant decay amplitudes. We have devised a method of constructing our
covariant decay amplitudes, such that they lead to the Zemach amplitudes when
the Lorentz factors are set one
The Indo-U.S. Library of Coude Feed Stellar Spectra
We have obtained spectra for 1273 stars using the 0.9m Coud\'e Feed telescope
at Kitt Peak National Observatory. This telescope feeds the coud\'e
spectrograph of the 2.1m telescope. The spectra have been obtained with the #5
camera of the coud\'e spectrograph and a Loral 3K X 1K CCD. Two gratings have
been used to provide spectral coverage from 3460 \AA to 9464 \AA, at a
resolution of 1\AA FWHM and at an original dispersion of 0.44 \AA/pixel.
For 885 stars we have complete spectra over the entire 3460 \AA to 9464 \AA
wavelength region (neglecting small gaps of 50 \AA), and partial spectral
coverage for the remaining stars. The 1273 stars have been selected to provide
broad coverage of the atmospheric parameters T, log g, and [Fe/H], as
well as spectral type. The goal of the project is to provide a comprehensive
library of stellar spectra for use in the automated classification of stellar
and galaxy spectra and in galaxy population synthesis. In this paper we discuss
the characteristics of the spectral library, viz., details of the observations,
data reduction procedures, and selection of stars. We also present a few
illustrations of the quality and information available in the spectra. The
first version of the complete spectral library is now publicly available from
the National Optical Astronomy Observatory (NOAO) via FTP and HTTP.Comment: 18 pages, 6 figures, 4 table
Teaching Environmental Management Competencies Online: Towards “Authentic” Collaboration?
Environmental Management (EM) is taught in many Higher Education Institutions in the UK. Most this provision is studied full-time on campuses by younger adults preparing themselves for subsequent employment, but not necessarily as environmental managers, and this experience can be very different from the complexities of real-life situations. This formal academic teaching or initial professional development in EM is supported and enhanced by training and continuing professional development from the major EM Institutes in the UK orientated to a set of technical and transferable skills or competencies expected of professional practitioners. In both cases there can be a tendency to focus on the more tractable, technical aspects of EM which are important, but may prove insufficient for EM in practice. What is also necessary, although often excluded, is an appreciation of, and capacity to deal with, the messiness and unpredictability of real world EM situations involving many different actors and stakeholders with multiple perspectives and operating to various agendas. Building on the work of Reeves, Herrington and Oliver (2002), we argue that EM modules need to include the opportunity to work towards the practice of authentic activities with group collaboration as a key pursuit. This paper reports on a qualitative study of our experiences with a selected sample taken from two on-line undergraduate EM modules for second and third year students (referred to respectively as Modules A and B) at the Open University, UK where online collaboration was a key component. Our tentative findings indicate that on-line collaboration is difficult to ensure as a uniform experience and that lack of uniformity reduces its value as an authentic experience. Whilst it can provide useful additional skills for EM practitioners the experience is uneven in the student body and often requires more time and support to engage with than originally planned
Proposed direct test of a certain type of noncontextuality in quantum mechanics
The noncontextuality of quantum mechanics can be directly tested by measuring
two entangled particles with more than two outcomes per particle. The two
associated contexts are "interlinked" by common observables.Comment: 9 pages 2 figure
Novel 2-amino-isoflavones exhibit aryl hydrocarbon receptor agonist or antagonist activity in a species/cell-specific context
The aryl hydrocarbon receptor (AhR) mediates the induction of a variety of xenobiotic metabolism genes. Activation of the AhR occurs through binding to a group of structurally diverse compounds, most notably dioxins, which are exogenous ligands. Isoflavones are part of a family which include some well characterised endogenous AhR ligands. This paper analysed a novel family of these compounds, based on the structure of 2-amino-isoflavone. Initially two luciferase-based cell models, mouse H1L6.1c2 and human HG2L6.1c3, were used to identify whether the compounds had AhR agonistic and/or antagonistic properties. This analysis showed that some of the compounds were weak agonists in mouse and antagonists in human. Further analysis of two of the compounds, Chr-13 and Chr-19, was conducted using quantitative real-time PCR in rat H4IIE and human MCF-7 cells. The results indicated that Chr-13 was an agonist in rat but an antagonist in human cells. Chr-19 was shown to be an agonist in rat but more interestingly, a partial agonist in human. Luciferase induction results not only revealed that subtle differences in the structure of the compound could produce species-specific differences in response but also dictated the ability of the compound to be an AhR agonist or antagonist. Substituted 2-amino-isoflavones represent a novel group of AhR ligands that must differentially interact with the AhR ligand binding domain to produce their species-specific agonist or antagonist activity and future ligand binding analysis and docking studies with these compounds may provide insights into the differential mechanisms of action of structurally similar compounds
Macrorealism from entropic Leggett-Garg inequalities
We formulate entropic Leggett-Garg inequalities, which place constraints on
the statistical outcomes of temporal correlations of observables. The
information theoretic inequalities are satisfied if macrorealism holds. We show
that the quantum statistics underlying correlations between time-separated spin
component of a quantum rotor mimics that of spin correlations in two spatially
separated spin- particles sharing a state of zero total spin. This brings
forth the violation of the entropic Leggett-Garg inequality by a rotating
quantum spin- system in similar manner as does the entropic Bell inequality
(Phys. Rev. Lett. 61, 662 (1988)) by a pair of spin- particles forming a
composite spin singlet state.Comment: 5 pages, RevTeX, 2 eps figures, Accepted for publication in Phys.
Rev.
The art of making the right exception to the “rule”: Nurses' experiences with drug dispensing in nursing homes
Nurses are key professionals in ensuring safe drug management in nursing homes, and their practice is regulated by a number of guidelines. The present study aimed to explore nurses’ experiences of dispensing drugs to older people in nursing homes by using an exploratory qualitative design. Focus group interviews were conducted in three nursing homes in central Norway; the data were analyzed using qualitative content analysis. The results indicated that drug dispensing was perceived as a complicated process during which both anticipated and unforeseen challenges arose that influenced the nurses’ abilities to follow professional standards. In these situations, the nurses had to apply their knowledge and make various adjustments based on conditions in the organization and the needs of individual patients. The findings have implications for facilitating nurses’ working conditions and resources to avoid drug administration that limit the discretion of nurses and threaten patient safety in nursing homes.publishedVersio
- …