XESS: The XML expert system shell

The XML Expert System Shell (XESS) was designed to alleviate some of the difficulties associated with translating a knowledge base from one expert system to another. The major goal of XESS is to allow programmers to model an expert system, complete with traditional facts and rules, in an XML-based language that leverages the universally understood terms used when teaching artificial intelligence to students. XML, the extensible markup language, is a text-based standard for information interchange between disparate systems1; it was originally designed to represent data in an easily parsable, human readable format2. While some extensions of the XML specification, particularly the Simple Object Access Protocol (SOAP), have long since abandoned human readability, the core XML specification is still used frequently to produce documents that can easily be exchanged between computational platforms and created or understood by human beings. The XESS-XML language inherits all of the usability of XML; it can be edited by hand in any text editor, is human readable, and can be parsed using XML parsers commonly available in any modern programming language. The XML Schema specification provides a mechanism for explicitly defining the content of an XML document so that a document can be validated3,4,5. XML schemas specify the make-up of an XML document in exacting detail6, using a pseudo-object-oriented syntax to specify exactly which entities are allowed in the document, the attributes of those entities, where they are allowed in the document, and how often they may occur. The XESS-XML language is defined as a fully extensible XML Schema, which can be used to validate any knowledge base written in the language. The Schema provides entities for common facts (e.g. predictes, structs) and a robust syntax for expressing rules in an if-then-else format, as well as the actions that should be taken in the event that a rule is fired. Additionally, because XML schemas are fully extensible, the XESS schema may be extended to add additional functionality such as support for fuzzy logic, new clause types, or new actions to be taken when rules are fired. In addition to the XML language, XESS also includes an object oriented interpreter specification that defines a robust set of language independent APIs for interacting with the expert system. This interpreter specification is meant to set expectations, both for XESS developers and users, as to the features provided by the XESS API regardless of the language in which the interpreter has been implemented. As part of the specification, the XESS API also provides object oriented definitions for XESS plug-ins; a plug-in is capable of translating from an XESS document to the native language of a specific expert system shell in a generic way (i.e. not specific to any one rule set) and back again. This allows users to express custom expert system shells in the XESS-XML language, parse them using an XESS interpreter written in any language, and translate them to a specific expert system shell through the use of an XESS plug-in without needing to learn the specific expert system shell language or rewriting the knowledge base once for each shell tested

Canadian Arctic Tide Measurement Techniques and Results

About 10 years ago the Canadian Hydrographic Service recognized the need for a planned approach to completing tide and current surveys of the Canadian Arctic Archipelago in order to meet the requirements of marine shipping and construction industries as well as the needs of environmental studies related to resource development. Therefore, a program of tidal surveys was begun which has resulted in a data base of tidal records covering most of the Archipelago. In this paper the problems faced by tidal surveyors and others working in the harsh Arctic environment are described and the variety of equipment and techniques developed for short, medium and long-term deployments are reported. The tidal characteristics throughout the Archipelago, determined primarily from these surveys, are briefly summarized. It was also recognized that there would be a need for real time tidal data by engineers, surveyors and mariners. Since the existing permanent tide gauges in the Arctic do not have this capability, a project was started in the early 1980’s to develop and construct a new permanent gauging system. The first of these gauges was constructed during the summer of 1985 and is described

Individual-Based Modeling: Mountain Pine Beetle Seasonal Biology in Response to Climate

Over the past decades, as significant advances were made in the availability and accessibility of computing power, individual-based models (IBM) have become increasingly appealing to ecologists (Grimm 1999). The individual-based modeling approachprovides a convenient framework to incorporate detailed knowledge of individuals and of their interactions within populations (Lomnicki 1999). Variability among individuals is essential to the success of populations that are exposed to changing environments, and because natural selection acts on this variability, it is an essential component of population performance. © Springer International Publishing Switzerland 2015

Age differences in brain activity during emotion processing: reflections of age-Related decline or increased emotion regulation?

Despite the fact that physical health and cognitive abilities decline with aging, the ability to regulate emotion remains stable and in some aspects improves across the adult life span. Older adults also show a positivity effect in their attention and memory, with diminished processing of negative stimuli relative to positive stimuli compared with younger adults. The current paper reviews functional magnetic resonance imaging studies investigating age-related differences in emotional processing and discusses how this evidence relates to two opposing theoretical accounts of older adults’ positivity effect. The aging-brain model [Cacioppo et al. in: Social Neuroscience: Toward Understanding the Underpinnings of the Social Mind. New York, Oxford University Press, 2011] proposes that older adults’ positivity effect is a consequence of age-related decline in the amygdala, whereas the cognitive control hypothesis [Kryla-Lighthall and Mather in: Handbook of Theories of Aging, ed 2. New York, Springer, 2009; Mather and Carstensen: Trends Cogn Sci 2005;9:496–502; Mather and Knight: Psychol Aging 2005;20:554–570] argues that the positivity effect is a result of older adults’ greater focus on regulating emotion. Based on evidence for structural and functional preservation of the amygdala in older adults and findings that older adults show greater prefrontal cortex activity than younger adults while engaging in emotion-processing tasks, we argue that the cognitive control hypothesis is a more likely explanation for older adults’ positivity effect than the aging-brain model

A Review of the Participation of Smallholder Farmers in Land-based Carbon Payment Schemes

There is renewed interest in the engagement of smallholder farmers in carbon markets. This follows in the wake of commitments by governments and companies to reduce or avoid the release of greenhouse gases. It is well known that soil can store large amounts of carbon, and soil stewardship offers a means to harness this potential. However, issues around permanence and scaling in smallholder farmer systems must be addressed if progress is to be made in this area. In this review, we examine the engagement of smallholder farmers in carbon sequestration payment schemes that promote sustainable land management (SLM). Drawing on a review of documents from carbon payment projects, interviews with key informants, and scientific literature, we highlight approaches for smallholder engagement along the project cycle, identify key barriers to participation, and outline options to enhance farmers’ agency. In assessing a total of ten projects, we observe considerable variation in participation across the projects. Project design tools classified as co-decision tools were common, with 60 % of projects reporting the use of individualised land management plans, 30 % the use of participatory rural appraisals (PRAs) and 10 % participatory mapping. However, few projects featured detailed frameworks for the incorporation of community feedback. The key informant interviews and literature review revealed that low carbon revenues, insecure land tenure, and high transaction costs are the primary barriers to participation, placing disproportionate pressure on marginalised households. Further, designing and implementing rigorous, participatory, and cost-effective monitoring reporting and verification (MRV) methodologies remains a challenge for many project proponents. We also find that flexible contracts can foster broad participation by including details that are attractive to mallholders such as longer terms, local contract providers and low-cost SLM measures. Projects that strengthen community institutions and social capital can stimulate participation among the marginalised, reduce transaction costs, and promote equity as well as smallholder agency. Engagement with communitybased organisations or other civil society actors can facilitate communication between project proponents and farmers, bolster farmers’ bargaining power, and reduce transaction costs during implementation

Elemental spatial and temporal association formation in left temporal lobe epilepsy

The mesial temporal lobe (MTL) is typically understood as a memory structure in clinical settings, with the sine qua non of MTL damage in epilepsy being memory impairment. Recent models, however, understand memory as one of a number of higher cognitive functions that recruit the MTL through their reliance on more fundamental processes, such as “self-projection” or “association formation”. We examined how damage to the left MTL influences these fundamental processes through the encoding of elemental spatial and temporal associations. We used a novel fMRI task to image the encoding of simple visual stimuli, either rich or impoverished, in spatial or spatial plus temporal information. Participants included 14 typical adults (36.4 years, sd. 10.5 years) and 14 patients with left mesial temporal lobe damage as evidenced by a clinical diagnosis of left temporal lobe epilepsy (TLE) and left MTL impairment on imaging (34.3 years, sd. 6.6 years). In-scanner behavioral performance was equivalent across groups. In the typical group whole-brain analysis revealed highly significant bilateral parahippocampal activation (right > left) during spatial associative processing and left hippocampal/parahippocampal deactivation in joint spatial-temporal associative processing. In the left TLE group identical analyses indicated patients used MTL structures contralateral to the seizure focus differently and relied on extra-MTL regions to a greater extent. These results are consistent with the notion that epileptogenic MTL damage is followed by reorganization of networks underlying elemental associative processes. In addition, they provide further evidence that task-related fMRI deactivation can meaningfully index brain function. The implications of these findings for clinical and cognitive neuropsychological models of MTL function in TLE are discussed

The Insertion and Transport of Anandamide in Synthetic Lipid Membranes Are Both Cholesterol-Dependent

International audienceBackground: Anandamide is a lipid neurotransmitter which belongs to a class of molecules termed the endocannabinoids involved in multiple physiological functions. Anandamide is readily taken up into cells, but there is considerable controversy as to the nature of this transport process (passive diffusion through the lipid bilayer vs. involvement of putative proteic transporters). This issue is of major importance since anandamide transport through the plasma membrane is crucial for its biological activity and intracellular degradation. The aim of the present study was to evaluate the involvement of cholesterol in membrane uptake and transport of anandamide.Methodology/Principal Findings: Molecular modeling simulations suggested that anandamide can adopt a shape that is remarkably complementary to cholesterol. Physicochemical studies showed that in the nanomolar concentration range, anandamide strongly interacted with cholesterol monolayers at the air-water interface. The specificity of this interaction was assessed by: i) the lack of activity of structurally related unsaturated fatty acids (oleic acid and arachidonic acid at 50 nM) on cholesterol monolayers, and ii) the weak insertion of anandamide into phosphatidylcholine or sphingomyelin monolayers. In agreement with these data, the presence of cholesterol in reconstituted planar lipid bilayers triggered the stable insertion of anandamide detected as an increase in bilayer capacitance. Kinetics transport studies showed that pure phosphatidylcholine bilayers were weakly permeable to anandamide. The incorporation of cholesterol in phosphatidylcholine bilayers dose-dependently stimulated the translocation of anandamide.Conclusions/Significance: Our results demonstrate that cholesterol stimulates both the insertion of anandamide into synthetic lipid monolayers and bilayers, and its transport across bilayer membranes. In this respect, we suggest that besides putative anandamide protein-transporters, cholesterol could be an important component of the anandamide transport machinery. Finally, this study provides a mechanistic explanation for the key regulatory activity played by membrane cholesterol in the responsiveness of cells to anandamide

A Follow-Up of the Multicenter Collaborative Study on HIV-1 Drug Resistance and Tropism Testing Using 454 Ultra Deep Pyrosequencing

Background: Ultra deep sequencing is of increasing use not only in research but also in diagnostics. For implementation of ultra deep sequencing assays in clinical laboratories for routine diagnostics, intra- and inter-laboratory testing are of the utmost importance. Methods: A multicenter study was conducted to validate an updated assay design for 454 Life Sciences’ GS FLX Titanium system targeting protease/reverse transcriptase (RTP) and env (V3) regions to identify HIV-1 drug-resistance mutations and determine co-receptor use with high sensitivity. The study included 30 HIV-1 subtype B and 6 subtype non-B samples with viral titers (VT) of 3,940–447,400 copies/mL, two dilution series (52,129–1,340 and 25,130–734 copies/mL), and triplicate samples. Amplicons spanning PR codons 10–99, RT codons 1–251 and the entire V3 region were generated using barcoded primers. Analysis was performed using the GS Amplicon Variant Analyzer and geno2pheno for tropism. For comparison, population sequencing was performed using the ViroSeq HIV-1 genotyping system. Results: The median sequencing depth across the 11 sites was 1,829 reads per position for RTP (IQR 592–3,488) and 2,410 for V3 (IQR 786–3,695). 10 preselected drug resistant variants were measured across sites and showed high inter-laboratory correlation across all sites with data (P20% were missed, variants 2–10% were detected at most sites (even at low VT), and variants 1–2% were detected by some sites. All mutations detected by population sequencing were also detected by UDS. Conclusions: This assay design results in an accurate and reproducible approach to analyze HIV-1 mutant spectra, even at variant frequencies well below those routinely detectable by population sequencing

Observation of Orbitally Excited B_s Mesons

We report the first observation of two narrow resonances consistent with states of orbitally excited (L=1) B_s mesons using 1 fb^{-1} of ppbar collisions at sqrt{s} = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. We use two-body decays into K^- and B^+ mesons reconstructed as B^+ \to J/\psi K^+, J/\psi \to \mu^+ \mu^- or B^+ \to \bar{D}^0 \pi^+, \bar{D}^0 \to K^+ \pi^-. We deduce the masses of the two states to be m(B_{s1}) = 5829.4 +- 0.7 MeV/c^2 and m(B_{s2}^*) = 5839.7 +- 0.7 MeV/c^2.Comment: Version accepted and published by Phys. Rev. Let