47 research outputs found

    Right place. Right time. Right tool: guidance for using target analysis to increase the likelihood of invasive species detection

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    In response to the National Invasive Species Council’s 2016–2018 Management Plan, this paper provides guidance on applying target analysis as part of a comprehensive framework for the early detection of and rapid response to invasive species (EDRR). Target analysis is a strategic approach for detecting one or more invasive species at a specific locality and time, using a particular method and/or technology(ies). Target analyses, which are employed across a wide range of disciplines, are intended to increase the likelihood of detection of a known target in order to maximize survey effectiveness and cost-efficiency. Although target analyses are not yet a standard approach to invasive species management, some federal agencies are employing target analyses in principle and/or in part to improve EDRR capacities. These initiatives can provide a foundation for a more standardized and comprehensive approach to target analyses. Guidance is provided for improving computational information. Federal agencies and their partners would benefit from a concerted effort to collect the information necessary to perform rigorous target analyses and make it available through open access platforms

    Adaptive risk-based targeted surveillance for foreign animal diseases at the wildlife-livestock interface

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    Animal disease surveillance is an important component of the national veterinary infrastructure to protect animal agriculture and facilitates identification of foreign animal disease (FAD) introduction. Once introduced, pathogens shared among domestic and wild animals are especially challenging to manage due to the complex ecology of spillover and spillback. Thus, early identification of FAD in wildlife is critical to minimize outbreak severity and potential impacts on animal agriculture as well as potential impacts on wildlife and biodiversity. As a result, national surveillance and monitoring programs that include wildlife are becoming increasingly common. Designing surveillance systems in wildlife or, more importantly, at the interface of wildlife and domestic animals, is especially challenging because of the frequent lack of ecological and epidemiological data for wildlife species and technical challenges associated with a lack of non-invasive methodologies. To meet the increasing need for targeted FAD surveillance and to address gaps in existing wildlife surveillance systems, we developed an adaptive risk-based targeted surveillance approach that accounts for risks in source and recipient host populations. The approach is flexible, accounts for changing disease risks through time, can be scaled from local to national extents and permits the inclusion of quantitative data or when information is limited to expert opinion. We apply this adaptive risk-based surveillance framework to prioritize areas for surveillance in wild pigs in the United States with the objective of early detection of three diseases: classical swine fever, African swine fever and foot-and-mouth disease. We discuss our surveillance framework, its application to wild pigs and discuss the utility of this framework for surveillance of other host species and diseases

    Nutritional practices and needs of resource-constrained communities as seen through the eyes of primary school teachers

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    In hierdie artikel bespreek ons die persepsies van onderwysers (n = 45) wat betref die voedingpraktyke van ’n steekproef laerskoolleerders en hul gesinne in ’n hulpbron-arm gemeenskap. Ons fokus spesifiek op die behoeftes, praktyke en verwagtings ten opsigte van die gebruik van voedsel, wat die produksie, keuse en voorbereiding van voedsel impliseer. Ons studie vorm die eerste deel van ’n groter institusionele navorsingprojek. Vir die doel van ons studie het ons deelnemende refleksie en aksie-gebaseerde werkwinkels gehou om data te genereer en tydens die interpretasie van bevindinge op interpretivisme staatgemaak. Hierdie studie beklemtoon die behoeftes van hulpbron-arm en werklose gemeenskapslede wat dikwels genoodsaak is om teen verlaagde pryse voedsel te koop waarvan die kwaliteit nie optimaal is nie. ’n Verskraalde ontbyt, middagete of aandete waarvan die keuse algemeen beperk is tot swart tee, pap en een of twee snye ou brood, bevestig die manifestasies van armoede in hulpbron-arm gemeenskappe. Maaltye is dikwels beperk tot groot hoeveelhede koolhidrate, min groente, ingelegde vis, pap met inkomazi en marog. Hoenderpote en afval vul soms die spyskaart aan. Onderwysers beklemtoon die feit dat gemeenskapslede tipies op skenkings van werkgewers, kerke en kruidenierswinkels staatmaak om hul voedselbegroting aan te vul. Onderwysers fokus verder op die behoeftes aan opleiding vir gemeenskapslede. Na hulle mening moet gemeenskappe ingelig word oor voedselproduksie, groentetuine, die wyses waarop die kwaliteit van grond bepaal kan word, besproeiing en die toepassing van volhoubare wisselbou. Die artikel word afgesluit met uitvoerbare en leersame wenke vir die opleiding van landelike gemeenskappe. Op grond van dié navorsingsbevindinge word ’n intervensieprogram tans ontwikkel, met die doel om dit in die onderskeie deelnemende skole te implementeer ter bevordering van gesonde voedselverwante gedrag en welsyn.In this article we discuss the perceptions teachers (n = 45) have regarding the nutritional practices of a sample of primary school learners and their families in a resource-constrained community. We specifically focus on the needs, practices and expectations related to food consumption, which implies food production, food choice and food preparation. Our study forms the first part of a more comprehensive institutional research project. For the purpose of our study we utilised participatory reflection and action-based workshops with the participants in order to generate data, and employed interpretivism to interpret the findings. This study emphasises the need of resource-constrained and unemployed community members, who are often forced to purchase food as a reduced cost of which the quality is not optimal. An attenuated breakfast, lunch or dinner where choices are often limited to black tea, porridge and one or two slices of stale bread, confirms the manifestations of poverty in resource-constrained communities. Meals are often limited to large quantities of carbohydrates, few vegetables, canned fish, porridge with inkomazi and marog. Chicken feet and tripe may supplement the menu. Teachers emphasise the fact that community members typically rely on donations from employers, churches and grocery stores in order to supplement their food budget. Teachers furthermore focus on the needs of community members to be educated. In their view community members need to be informed in respect of food production, vegetable gardens, techniques of determining the quality of soil, irrigation and the application of sustainable crop rotation. The article concludes with achievable and informative ideas for educating rural communities. Based on these research findings an intervention programme is currently being developed, with the purpose of implementing the intervention in the various participating schools in support of healthy nutrition-related behaviour and well-being.This article forms part of a more comprehensive institutional research project, namely: ‘Schools as sites for social change: Facilitating adjusted behaviour in resource-constrained communities by empowering children’, funded by the Institute for Food, Nutrition and Well-being, University of Pretoria.The Institute for Food, Nutrition and Well-being, University of Pretoriahttp://www.satnt.ac.zaam2014gv201

    Students' Learning Strategies With Multiple Representations: Explanations of the Human Breathing Mechanism

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    The purpose of this study was to understand how students utilized multiple representations to learn and explain science concepts, in this case the human breathing mechanism. The study was conducted with Grade 11 students in a human biology class. Semistructured interviews and a two-tier diagnostic test were administered to evaluate students’ learning strategies of integrating multiple representations. The functions of multiple representations (complementary, constraining, and deeper understanding) suggested by Ainsworth (2008) were adapted as the analytical framework to better describe the participating students’ learning strategies with multiple representations (access complementary information, apply one representation to interpret the other, and evaluate representations). The categorization of students’ learning strategies facilitated interpreting their diverse understanding in relation to the multiple representations. In addition to a summary of students’ learning strategies, three case examples are presented to show how the framework was applied in the analysis and to discuss how the learning strategies interacted with students’

    Tetrabenzoporphyrin and -mono-, - Cis -di- and tetrabenzotriazaporphyrin derivatives: Electrochemical and spectroscopic implications of meso CH Group replacement with nitrogen

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    Nonperipherally hexyl-substituted metal-free tetrabenzoporphyrin (2H-TBP, 1a) tetrabenzomonoazaporphyrin (2H-TBMAP, 2a), tetrabenzo-cis-diazaporphyrin (2H-TBDAP, 3a), tetrabenzotriazaporphyrin (2H-TBTAP, 4a), and phthalocyanine (2H-Pc, 5a), as well as their copper complexes (1b-5b), were synthesized. As the number of meso nitrogen atoms increases from zero to four, Îmax of the Q-band absorption peak becomes red-shifted by almost 100 nm, and extinction coefficients increased at least threefold. Simultaneously the blue-shifted Soret (UV) band substantially decreased in intensity. These changes were related to the relative electron-density of each macrocycle expressed as the group electronegativity sum of all meso N and CH atom groups, âχR. X-ray photoelectron spectroscopy differentiated between the three different types of macrocyclic nitrogen atoms (the Ninner, (NH)inner, and Nmeso) in the metal-free complexes. Binding energies of the Nmeso and Ninner,Cu atoms in copper chelates could not be resolved. Copper insertion lowered especially the cathodic redox potentials, while all four observed redox processes occurred at larger potentials as the number of meso nitrogens increased. Computational chemical methods using density functional theory confirmed 1b to exhibit a Cu(II) reduction prior to ring-based reductions, while for 2b, Cu(II) reduction is the first reductive step only if the nonperipheral substituents are hydrogen. When they are methyl groups, it is the second reduction process; when they are ethyl, propyl, or hexyl, it becomes the third reductive process. Spectro-electrochemical measurements showed redox processes were associated with a substantial change in intensity of at least two main absorbances (the Q and Soret bands) in the UV spectra of these compounds

    The neutron and its role in cosmology and particle physics

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    Experiments with cold and ultracold neutrons have reached a level of precision such that problems far beyond the scale of the present Standard Model of particle physics become accessible to experimental investigation. Due to the close links between particle physics and cosmology, these studies also permit a deep look into the very first instances of our universe. First addressed in this article, both in theory and experiment, is the problem of baryogenesis ... The question how baryogenesis could have happened is open to experimental tests, and it turns out that this problem can be curbed by the very stringent limits on an electric dipole moment of the neutron, a quantity that also has deep implications for particle physics. Then we discuss the recent spectacular observation of neutron quantization in the earth's gravitational field and of resonance transitions between such gravitational energy states. These measurements, together with new evaluations of neutron scattering data, set new constraints on deviations from Newton's gravitational law at the picometer scale. Such deviations are predicted in modern theories with extra-dimensions that propose unification of the Planck scale with the scale of the Standard Model ... Another main topic is the weak-interaction parameters in various fields of physics and astrophysics that must all be derived from measured neutron decay data. Up to now, about 10 different neutron decay observables have been measured, much more than needed in the electroweak Standard Model. This allows various precise tests for new physics beyond the Standard Model, competing with or surpassing similar tests at high-energy. The review ends with a discussion of neutron and nuclear data required in the synthesis of the elements during the "first three minutes" and later on in stellar nucleosynthesis.Comment: 91 pages, 30 figures, accepted by Reviews of Modern Physic

    Iterative Models for Early Detection of Invasive Species across Spread Pathways

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    Species distribution models can be used to direct early detection of invasive species, if they include proxies for invasion pathways. Due to the dynamic nature of invasion, these models violate assumptions of stationarity across space and time. To compensate for issues of stationarity, we iteratively update regionalized species distribution models annually for European gypsy moth (Lymantria dispar dispar) to target early detection surveys for the USDA APHIS gypsy moth program. We defined regions based on the distances from the invasion spread front where shifts in variable importance occurred and included models for the non-quarantine portion of the state of Maine, a short-range region, an intermediate region, and a long-range region. We considered variables that represented potential gypsy moth movement pathways within each region, including transportation networks, recreational activities, urban characteristics, and household movement data originating from gypsy moth infested areas (U.S. Postal Service address forwarding data). We updated the models annually, linked the models to an early detection survey design, and validated the models for the following year using predicted risk at new positive detection locations. Human-assisted pathways data, such as address forwarding, became increasingly important predictors of gypsy moth detection in the intermediate-range geographic model as more predictor data accumulated over time (relative importance = 5.9%, 17.36%, and 35.76% for 2015, 2016, and 2018, respectively). Receiver operating curves showed increasing performance for iterative annual models (area under the curve (AUC) = 0.63, 0.76, and 0.84 for 2014, 2015, and 2016 models, respectively), and boxplots of predicted risk each year showed increasing accuracy and precision of following year positive detection locations. The inclusion of human-assisted pathway predictors combined with the strategy of iterative modeling brings significant advantages to targeting early detection of invasive species. We present the first published example of iterative species distribution modeling for invasive species in an operational context
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