620 research outputs found
Changing fertilizer management practices in sugarcane production: cane grower survey insights
Improved fertilizer management practice in sugarcane production is a key component in plans to improve Great Barrier Reef (GBR) water quality. Research focused on understanding wider systemic factors that drive behavioral change in agriculture is currently limited, with the domi-nant focus on individual farmer and psychosocial factors. Adopting a wider systems perspective, this study examines farming behavior change and the role of supporting services among 238 sugarcane growers (74,597 hectares) in Queenslandâs Wet Tropics region who completed surveys reporting on changes in the method they used to calculate fertilizer application rates, along with information on their farm business, socio-demographics and self-reported importance ratings on a variety of topics. Informed by the Theory of Planned Behavior., ssurvey data are analyzed us-ing regression models to identify factors influencing the change from traditional to improved practice, and early adoption of improved practice. Results indicate growers were less likely to change fertilizer practice if they regarded maintaining good relationships with other local growers as being extremely important, had off-farm income, or had not attended a govern-ment-funded fertilizer management workshop in the five years preceding the survey. Similar drivers acted to promote or delay early adoption of improved practice. Results demonstrate the influence of government-funded services to support practice change
Toward a descriptive model of solar particles in the heliosphere
During a workshop on the interplanetary charged particle environment held in 1987, a descriptive model of solar particles in the heliosphere was assembled. This model includes the fluence, composition, energy spectra, and spatial and temporal variations of solar particles both within and beyong 1 AU. The ability to predict solar particle fluences was also discussed. Suggestions for specific studies designed to improve the basic model were also made
Applications of Bayesian Networks as Decision Support Tools for Water Resource Management under Climate Change and Socio-Economic Stressors: A Critical Appraisal
Bayesian networks (BNs) are widely implemented as graphical decision support tools which use probability inferences to generate âwhat if?â and âwhich is best?â analyses of potential management options for water resource management, under climate change and socio-economic stressors. This paper presents a systematic quantitative literature review of applications of BNs for decision support in water resource management. The review quantifies to what extent different types of data (quantitative and/or qualitative) are used, to what extent optimization-based and/or scenario-based approaches are adopted for decision support, and to what extent different categories of adaptation measures are evaluated. Most reviewed publications applied scenario-based approaches (68%) to evaluate the performance of management measures, whilst relatively few studies (18%) applied optimization-based approaches to optimize management measures. Institutional and social measures (62%) were mostly applied to the management of water-related concerns, followed by technological and engineered measures (47%), and ecosystem-based measures (37%). There was no significant difference in the use of quantitative and/or qualitative data across different decision support approaches (p = 0.54), or in the evaluation of different categories of management measures (p = 0.25). However, there was significant dependence (p = 0.076) between the types of management measure(s) evaluated, and the decision support approaches used for that evaluation. The potential and limitations of BN applications as decision support systems are discussed along with solutions and recommendations, thereby further facilitating the application of this promising decision support tool for future research priorities and challenges surrounding uncertain and complex water resource systems driven by multiple interactions amongst climatic and non-climatic changes. View Full-Tex
Aquaculturists preference heterogeneity towards wetland ecosystem services : a latent class discrete choice model
The fundamental objective of discrete Choice Experiments (CEs) model or Choice Modelling (CM) is to understand
the behavioural processes among individuals which drive the choice decisions based on selected attributes and
choice options. Preferences may differ among individuals triggered by their specific characteristics such as sociodemographics,
constraints and attitudes. Preferences could also vary among groups and within a particular group by
forming different segments of groups or subgroups. The Latent Class (LC) model is a distinctive approach which can
accommodate preference heterogeneity where preferences are assumed to be relatively homogenous within the segments,
but substantially different between the segments. This LC model was applied to account for preference heterogeneity
among aquaculturists in the Setiu Wetlands, Terengganu. Currently, fish cage culture is the main socio-economic activity
which imposes considerable impacts on the wetland ecosystem and thus affect its ability to deliver ecosystem service
outcomes to other stakeholder groups. This research quantifies the aquaculturistsâ preferences heterogeneity with regard
to the ecosystem impacts under different management scenarios. The existence of sub-divisions of preferences within the
stakeholder subgroups was tested. This study revealed three latent classes or segments which show relatively distinct
sets of preferences. Segment 1 shows a strong preference for higher harvest rates, a moderately strong preference
for higher fisheries income and a moderately strong preference for lower shellfish collections. Segment 2 shows a
moderately strong linear preference for higher harvest rates and a very strong preference for retaining the status quo.
Segment 3 shows a perplexing set of significant preferences for increasing harvest rates and a modest preference for
higher fisheries income. In direct contrast to Segment 2, Segment 3 shows a very strong aversion to retaining the status
quo. The results of aquaculturistsâ preferences for delivery of different ecosystem services in Setiu Wetlands suggest
that Latent Class Model (LCM) could be applied successfully in a Malaysian setting. The success of the LC model is
evidenced by the high level of fit obtained from the best fitting models. The main finding of this research suggests that
a good understanding of the main research objective, familiarity with the research area and carefully designed choice
set, as well as employing appropriately trained enumerators are the main factors that particularly contribute to a
successful application of the LC model in a developing country setting
Y Dwarf Trigonometric Parallaxes from the Spitzer Space Telescope
Y dwarfs provide a unique opportunity to study free-floating objects with masses <30 M_(Jup) and atmospheric temperatures approaching those of known Jupiter-like exoplanets. Obtaining distances to these objects is an essential step toward characterizing their absolute physical properties. Using Spitzer's Infrared Array Camera (IRAC) [4.5] images taken over baselines of ~2â7 years, we measure astrometric distances for 22 late-T and early Y dwarfs, including updated parallaxes for 18 objects and new parallax measurements for 4 objects. These parallaxes will make it possible to explore the physical parameter space occupied by the coldest brown dwarfs. We also present the discovery of six new late-T dwarfs, updated spectra of two T dwarfs, and the reclassification of a new Y dwarf, WISE J033605.04â014351.0, based on Keck/NIRSPEC J-band spectroscopy. Assuming that effective temperatures are inversely proportional to absolute magnitude, we examine trends in the evolution of the spectral energy distributions of brown dwarfs with decreasing effective temperature. Surprisingly, the Y dwarf class encompasses a large range in absolute magnitude in the near- to mid-infrared photometric bandpasses, demonstrating a larger range of effective temperatures than previously assumed. This sample will be ideal for obtaining mid-infrared spectra with the James Webb Space Telescope because their known distances will make it easier to measure absolute physical properties
The narrative self, distributed memory, and evocative objects
In this article, I outline various ways in which artifacts are interwoven with autobiographical memory systems and conceptualize what this implies for the self. I first sketch the narrative approach to the self, arguing that who we are as persons is essentially our (unfolding) life story, which, in turn, determines our present beliefs and desires, but also directs our future goals and actions. I then argue that our autobiographical memory is partly anchored in our embodied interactions with an ecology of artifacts in our environment. Lifelogs, photos, videos, journals, diaries, souvenirs, jewelry, books, works of art, and many other meaningful objects trigger and sometimes constitute emotionally-laden autobiographical memories. Autobiographical memory is thus distributed across embodied agents and various environmental structures. To defend this claim, I draw on and integrate distributed cognition theory and empirical research in human-technology interaction. Based on this, I conclude that the self is neither defined by psychological states realized by the brain nor by biological states realized by the organism, but should be seen as a distributed and relational construct
Neutrino and Antineutrino Inclusive Charged-current Cross Section Measurements with the MINOS Near Detector
The energy dependence of the neutrino-iron and antineutrino-iron inclusive
charged-current cross sections and their ratio have been measured using a
high-statistics sample with the MINOS Near Detector exposed to the NuMI beam
from the Main Injector at Fermilab. Neutrino and antineutrino fluxes were
determined using a low hadronic energy subsample of charged-current events. We
report measurements of neutrino-Fe (antineutrinoFe) cross section in the energy
range 3-50 GeV (5-50 GeV) with precision of 2-8% (3-9%) and their ratio which
is measured with precision 2-8%. The data set spans the region from low energy,
where accurate measurements are sparse, up to the high-energy scaling region
where the cross section is well understood.Comment: accepted by PR
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New constraints on muon-neutrino to electron-neutrino transitions in MINOS
This paper reports results from a search for ν_Îź â ν_e transitions by the MINOS experiment based on a 7Ă10^(20) protons-on-target exposure. Our observation of 54 candidate ν_e events in the far detector with a background of 49.1Âą7.0(stat)Âą2.7(syst) events predicted by the measurements in the near detector requires 2sin^2(2θ_(13))sin^2θ_(23)<0.12(0.20) at the 90% C.L. for the normal (inverted) mass hierarchy at δ_(CP)=0. The experiment sets the tightest limits to date on the value of θ_(13) for nearly all values of δ_(CP) for the normal neutrino mass hierarchy and maximal sin^2(2θ_(23))
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Search for sterile neutrino mixing in the MINOS long-baseline experiment
A search for depletion of the combined flux of active neutrino species over a 735 km baseline is reported using neutral-current interaction data recorded by the MINOS detectors in the NuMI neutrino beam. Such a depletion is not expected according to conventional interpretations of neutrino oscillation data involving the three known neutrino flavors. A depletion would be a signature of oscillations or decay to postulated noninteracting sterile neutrinos, scenarios not ruled out by existing data. From an exposure of 3.18Ă10^(20) protons on target in which neutrinos of energies between âź500ââMeV and 120 GeV are produced predominantly as ν_Îź, the visible energy spectrum of candidate neutral-current reactions in the MINOS far detector is reconstructed. Comparison of this spectrum to that inferred from a similarly selected near-detector sample shows that of the portion of the ν_Îź flux observed to disappear in charged-current interaction data, the fraction that could be converting to a sterile state is less than 52% at 90% confidence level (C.L.). The hypothesis that active neutrinos mix with a single sterile neutrino via oscillations is tested by fitting the data to various models. In the particular four-neutrino models considered, the mixing angles θ_(24) and θ_(34) are constrained to be less than 11° and 56° at 90% C.L., respectively. The possibility that active neutrinos may decay to sterile neutrinos is also investigated. Pure neutrino decay without oscillations is ruled out at 5.4 standard deviations. For the scenario in which active neutrinos decay into sterile states concurrently with neutrino oscillations, a lower limit is established for the neutrino decay lifetime Ď_3/m_3>2.1Ă10^(-12)âs/eV at 90% C.L
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