159 research outputs found
Spatial structure of boreal woodland caribou populations in northwest Canada
Local population units (LPUs) were delineated in Canada’s recovery strategy for threatened boreal woodland caribou (Rangifer tarandus caribou). Population viability analyses central to contemporary integrated risk assessments of LPUs implicitly assume geographic closure. Several LPUs in northwest Canada, however, were in part delineated by geopolitical boundaries and/or included large areas in the absence of evidence of more finely resolved population spatial structure. We pooled >1.2 million locations from >1200 GPS or VHF-collared caribou from northeast British Columbia, northwest Alberta and southwestern Northwest Territories. Bayesian cluster analysis generated 10 alternative candidate LPUs based on a spatial cluster graph of the extent of pairwise co-occurrence of collared caribou. Up to four groups may be artifacts in as yet under-sampled areas. Four were mapped LPUs that were conserved (Prophet, Parker, Chinchaga and Red Earth). One small group between Parker and Snake-Sahtaneh known locally as the “Fort Nelson core,” and outside any mapped LPU, was also conserved. Finally, one large group, at >136000 km2, spanned all three jurisdictions and subsumed all of six delineated LPUs (Maxhamish, Snake-Sahtaneh, Calendar, Bistcho, Yates, Caribou Mountains) and part of southern Northwest Territories. These results suggest less geographic closure of LPUs than those currently delineated, but further analyses will be required to better reconcile various sources of knowledge about local population structure in this region.  
Similarity, precedent and argument from analogy
In this paper, it is shown (1) that there are two schemes for argument from analogy that seem to be competitors but are not, (2) how one of them is based on a distinctive type of similarity premise, (3) how to analyze the notion of similarity using story schemes illustrated by some cases, (4) how arguments from precedent are based on arguments from analogy, and in many instances arguments from classification, and (5) that when similarity is defined by means of episode schemes, we can get a clearer idea of how it integrates with the use of argument from classification and argument from precedent in case-based reasoning by using a dialogue structure
Towards an Intelligent Tutor for Mathematical Proofs
Computer-supported learning is an increasingly important form of study since
it allows for independent learning and individualized instruction. In this
paper, we discuss a novel approach to developing an intelligent tutoring system
for teaching textbook-style mathematical proofs. We characterize the
particularities of the domain and discuss common ITS design models. Our
approach is motivated by phenomena found in a corpus of tutorial dialogs that
were collected in a Wizard-of-Oz experiment. We show how an intelligent tutor
for textbook-style mathematical proofs can be built on top of an adapted
assertion-level proof assistant by reusing representations and proof search
strategies originally developed for automated and interactive theorem proving.
The resulting prototype was successfully evaluated on a corpus of tutorial
dialogs and yields good results.Comment: In Proceedings THedu'11, arXiv:1202.453
Integration of environment and nutrition in life cycle assessment of food items: opportunities and challenges
This report is the outcome of a consensus-building project to agree on best practices for environmental and nutritional Life Cycle Assessment (nLCA) methodology, and identify future research needs. The project involved 30 nutritional and environmental LCA researchers from 18 countries. It focused on the assessment of food items (as opposed to meals or diets).Best practice recommendations were developed to address the intended purpose of an LCA study and related modeling approach, choice of an appropriate functional unit, assessment of nutritional value, and reporting nLCA results. An nLCA study should report the quantities of as many essential nutrients as possible and aim to provide information on the nutritional quality and/or health impacts in addition to nutrient quantities. Outstanding issues requiring further research attention include: defining a minimum number of nutrients to be considered in an nLCA study; treatment of nutrients to limit; use of nutrient indexes; further development of Impact Assessment methods; representation of nutritional changes that may occur during subsequent distribution and food preparation in cradle-to-gate nLCA studies; and communication of data uncertainty and variability. More data are required for different regions (particularly developing countries); for the processing, distribution, retail, and consumption life cycle stages; and for food loss and waste. Finally, there is a need to extend nLCA methodology for the assessment of meals and diets, to consider further how to account for the multi-functionality of food in a sustainability framework, and to set nLCA studies within the context of environmental limits.These results provide a robust basis for improving nLCA methodology and applying it to identify solutions that minimize the trade-offs between nourishing populations and safeguarding the environment
Unpacking vertical and horizontal integration: childhood overweight/obesity programs and planning, a Canadian perspective
Abstract
Background
Increasingly, multiple intervention programming is being understood and implemented as a key approach to developing public health initiatives and strategies. Using socio-ecological and population health perspectives, multiple intervention programming approaches are aimed at providing coordinated and strategic comprehensive programs operating over system levels and across sectors, allowing practitioners and decision makers to take advantage of synergistic effects. These approaches also require vertical and horizontal (v/h) integration of policy and practice in order to be maximally effective.
Discussion
This paper examines v/h integration of interventions for childhood overweight/obesity prevention and reduction from a Canadian perspective. It describes the implications of v/h integration for childhood overweight and obesity prevention, with examples of interventions where v/h integration has been implemented. An application of a conceptual framework for structuring v/h integration of an overweight/obesity prevention initiative is presented. The paper concludes with a discussion of the implications of vertical/horizontal integration for policy, research, and practice related to childhood overweight and obesity prevention multiple intervention programs.
Summary
Both v/h integration across sectors and over system levels are needed to fully support multiple intervention programs of the complexity and scope required by obesity issues. V/h integration requires attention to system structures and processes. A conceptual framework is needed to support policy alignment, multi-level evaluation, and ongoing coordination of people at the front lines of practice. Using such tools to achieve integration may enhance sustainability, increase effectiveness of prevention and reduction efforts, decrease stigmatization, and lead to new ways to relate the environment to people and people to the environment for better health for children
A comprehensive analysis of rare genetic variation in amyotrophic lateral sclerosis in the UK.
Amyotrophic lateral sclerosis is a progressive neurodegenerative disease of motor neurons. About 25 genes have been verified as relevant to the disease process, with rare and common variation implicated. We used next generation sequencing and repeat sizing to comprehensively assay genetic variation in a panel of known amyotrophic lateral sclerosis genes in 1126 patient samples and 613 controls. About 10% of patients were predicted to carry a pathological expansion of the C9orf72 gene. We found an increased burden of rare variants in patients within the untranslated regions of known disease-causing genes, driven by SOD1, TARDBP, FUS, VCP, OPTN and UBQLN2. We found 11 patients (1%) carried more than one pathogenic variant (P = 0.001) consistent with an oligogenic basis of amyotrophic lateral sclerosis. These findings show that the genetic architecture of amyotrophic lateral sclerosis is complex and that variation in the regulatory regions of associated genes may be important in disease pathogenesis
A log-normal spectral analysis of inorganic grain-size distributions from a Canadian boreal lake core: Towards refining depositional process proxy data from high latitude lakes
Better methods for interpreting grain size spectra will enhance current understanding of past transport–depositional processes. A high-resolution inorganic grain-size dataset has been measured from a freeze core extracted from ‘Alberta Lake E’ a boreal fresh water lake 40 km east of the Athabasca Oil Sands in north-eastern Alberta, Canada. The grain-size spectra are remarkably consistent throughout the core, exhibiting a structure comprising six persistent grain-size distributions below ca 250 μm, plus a rare medium-sand distribution. Automated deconvolution of the grain-size spectra produced poor results. Constraining the modes of two of the distributions produced deconvolution solutions that were statistically excellent and consistent with the structure of each spectrum. Statistical analysis of the ‘constrained’ solutions indicates that deconvolution successfully extracted independent grain-size populations. Conversely, the multimodal spectra generate traditional measures (for example, mean grain size) that are inconsistent combinations of different individual populations, and thus are poor proxies of transport–depositional processes. Alberta Lake E is situated in a boreal wetland landscape where sediment delivery is dominated by overland flow transport during spring melt. This context means that the Alberta Lake E grain-size spectra can be interpreted to reflect: (i) a bedload component transported during short-duration high discharge events that reflect the intensity of the melt; and (ii) a finer suspended load component representing material whose magnitude is controlled by the volume of the spring melt. Stratigraphically, bedload and suspended load populations demonstrate different short-wavelength and long-wavelength cyclicity, suggesting that spring melt is likely to be driven by cyclic external forcing factors. The links between the grain-size spectra and spring melt have potential for generating proxy records that better capture the external controls over spring melt in boreal systems, and the risks associated with these energetic hydrodynamics. This is exemplified by the coarsest Alberta Lake E distributions, which indicate that more intense spring melt dynamics occurred in pre-historical times
Arsenic in freshwater systems: Influence of eutrophication on occurrence, distribution, speciation, and bioaccumulation
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
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