6,260 research outputs found

    Systems, interactions and macrotheory

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    A significant proportion of early HCI research was guided by one very clear vision: that the existing theory base in psychology and cognitive science could be developed to yield engineering tools for use in the interdisciplinary context of HCI design. While interface technologies and heuristic methods for behavioral evaluation have rapidly advanced in both capability and breadth of application, progress toward deeper theory has been modest, and some now believe it to be unnecessary. A case is presented for developing new forms of theory, based around generic “systems of interactors.” An overlapping, layered structure of macro- and microtheories could then serve an explanatory role, and could also bind together contributions from the different disciplines. Novel routes to formalizing and applying such theories provide a host of interesting and tractable problems for future basic research in HCI

    A rapid and low-cost DNA extraction method for isolating Escherichia coli DNA from animal stools

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    The price of commercial DNA extraction methods makes the routine use of polymerase chain reaction amplification (PCR) based methods rather costly for scientists in developing countries. A guanidium thiocayante-based DNA extraction method was investigated in this study for the isolation of Escherichia coli (E. coli) DNA from goat, chicken, pig, cow and human stool samples. Two versions of the lysis buffer, with and without _-casein, were tested to alleviate PCR inhibition associated with DNA isolated from stool samples. Results obtained show that, this method using the lysis buffer containing _-casein, produces PCR ready DNA at a fraction of the cost of commercial DNA extraction kits & copy; 2011 Academic Journals

    Recovering Grammar Relationships for the Java Language Specification

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    Grammar convergence is a method that helps discovering relationships between different grammars of the same language or different language versions. The key element of the method is the operational, transformation-based representation of those relationships. Given input grammars for convergence, they are transformed until they are structurally equal. The transformations are composed from primitive operators; properties of these operators and the composed chains provide quantitative and qualitative insight into the relationships between the grammars at hand. We describe a refined method for grammar convergence, and we use it in a major study, where we recover the relationships between all the grammars that occur in the different versions of the Java Language Specification (JLS). The relationships are represented as grammar transformation chains that capture all accidental or intended differences between the JLS grammars. This method is mechanized and driven by nominal and structural differences between pairs of grammars that are subject to asymmetric, binary convergence steps. We present the underlying operator suite for grammar transformation in detail, and we illustrate the suite with many examples of transformations on the JLS grammars. We also describe the extraction effort, which was needed to make the JLS grammars amenable to automated processing. We include substantial metadata about the convergence process for the JLS so that the effort becomes reproducible and transparent

    Modeling the iron oxides and oxyhydroxides for the prediction of environmentally sensitive phase transformations

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    Iron oxides and oxyhydroxides are challenging to model computationally as competing phases may differ in formation energies by only several kJ/mol, they undergo magnetization transitions with temperature, their structures may contain partially occupied sites or long-range ordering of vacancies, and some loose structures require proper description of weak interactions such as hydrogen bonding and dispersive forces. If structures and transformations are to be reliably predicted under different chemical conditions, each of these challenges must be overcome simultaneously, while preserving a high level of numerical accuracy and physical sophistication. Here we present comparative studies of structure, magnetization, and elasticity properties of iron oxides and oxyhydroxides using density functional theory calculations with plane-wave and locally-confined-atomic-orbital basis sets, which are implemented in VASP and SIESTA packages, respectively. We have selected hematite, maghemite, goethite, lepidocrocite, and magnetite as model systems from a total of 13 known iron oxides and oxyhydroxides; and use same convergence criteria and almost equivalent settings in order to make consistent comparisons. Our results show both basis sets can reproduce the energetic stability and magnetic ordering, and are in agreement with experimental observations. There are advantages to choosing one basis set over the other, depending on the intended focus. In our case, we find the method using PW basis set most appropriate, and combine our results to construct the first phase diagram of iron oxides and oxyhydroxides in the space of competing chemical potentials, generated entirely from first principlesComment: 46 pages - Accepted for publication in PRB (19 journal pages), January 201

    Aborsie: ’n Juridiese, etiese en regsetiese vraagstuk

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    In die geledere van skokkende en onetiese dade in die menslike samelewing, beklee aborsie ’n besondere plek. Vir wetenskaplike doeleindes kan aborsie oor die algemeen gedefinieer word as die skeiding van of afdrywing uit die moederlyf van die „produk” van konsepsie, synde ’n fetus (Geldenhuys, 1974:11; O’Donovan 1975:2). ’n Verdere element van die definisie, wat die blote afdrywing van die vrug gewoonlik kwalifiseer, is dat die fetus, met betrekking tot nageboortelike lewe gesproke, nie lewensvatbaar moes gewees het nie. Met die byvoeging van hierdie element tot die eie definisie word tans egter vertoef ten einde eers die belangrike vraag wanneer lewe ontstaan, te beantwoord

    Schizophrenia and the progression of emotional expression in relation to others

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    Gaining an improved understanding of people diagnosed with schizophrenia has the potential to influence priorities for therapy. Psychosis is commonly understood through the perspective of the medical model. However, the experience of social context surrounding psychosis is not well understood. In this research project we used a phenomenological methodology with a longitudinal design to interview 7 participants across a 12-month period to understand the social experiences surrounding psychosis. Eleven themes were explicated and divided into two phases of the illness experience: (a) transition into emotional shutdown included the experiences of not being acknowledged, relational confusion, not being expressive, detachment, reliving the past, and having no sense of direction; and (b) recovery from emotional shutdown included the experiences of being acknowledged, expression, resolution, independence, and a sense of direction. The experiential themes provide clinicians with new insights to better assess vulnerability, and have the potential to inform goals for therapy
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