5,328 research outputs found

    Using Pattern Languages in Participatory Design

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    In this paper, we examine the contribution that pattern languages could make to user participation in the design of interactive systems, and we report on our experiences of using pattern languages in this way. In recent years, there has been a growing interest in the use of patterns and pattern languages in the design of interactive systems. Pattern languages were originally developed by the architect, Christopher Alexander, both as a way of understanding the nature of building designs that promote a ‘humane’ or living built environment; and as a practical tool to aid in participatory design of buildings. Our experience suggests that pattern languages do have considerable potential to support participatory design in HCI, but that many pragmatic issues remain to be resolved

    Using pattern languages in participatory design

    Get PDF
    In this paper, we examine the contribution that pattern languages could make to user participation in the design of interactive systems, and we report on our experiences of using pattern languages in this way. In recent years, there has been a growing interest in the use of patterns and pattern languages in the design of interactive systems. Pattern languages were originally developed by the architect, Christopher Alexander, both as a way of understanding the nature of building designs that promote a ‘humane’ or living built environment; and as a practical tool to aid in participatory design of buildings. Our experience suggests that pattern languages do have considerable potential to support participatory design in HCI, but that many pragmatic issues remain to be resolved.</p

    Biodiversity and ecosystem function in soil

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    1. Soils are one of the last great frontiers for biodiversity research and are home to an extraordinary range of microbial and animal groups. Biological activities in soils drive many of the key ecosystem processes that govern the global system, especially in the cycling of elements such as carbon, nitrogen and phosphorus. 2. We cannot currently make firm statements about the scale of biodiversity in soils, or about the roles played by soil organisms in the transformations of organic materials that underlie those cycles. The recent UK Soil Biodiversity Programme (SBP) has brought a unique concentration of researchers to bear on a single soil in Scotland, and has generated a large amount of data concerning biodiversity, carbon flux and resilience in the soil ecosystem. 3. One of the key discoveries of the SBP was the extreme diversity of small organisms: researchers in the programme identified over 100 species of bacteria, 350 protozoa, 140 nematodes and 24 distinct types of arbuscular mycorrhizal fungi. Statistical analysis of these results suggests a much greater 'hidden diversity'. In contrast, there was no unusual richness in other organisms, such as higher fungi, mites, collembola and annelids. 4. Stable-isotope (C-13) technology was used to measure carbon fluxes and map the path of carbon through the food web. A novel finding was the rapidity with which carbon moves through the soil biota, revealing an extraordinarily dynamic soil ecosystem. 5. The combination of taxonomic diversity and rapid carbon flux makes the soil ecosystem highly resistant to perturbation through either changing soil structure or removing selected groups of organisms

    Diversity of free-living ciliates in the sandy sediment of a Spanish stream in winter

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    This study had two objectives: to determine the number of (phenotypic) ciliate species co-existing in 1 m2 of sandy river sediment at a maximum temperature of 4 "C; and to determine the ecological mechanism(s) facilitating their co-existence. The ciliate community was diverse (65 species [8 of which are new], belonging to 50 genera, from 17 orders). The sediment supported a superficial mat of diatoms (> 30 species). These served as food for at least 16 ciliate species. The size frequency distribution of ingested diatoms was almost identical to that for the diatoms in the sediment: thus the probability of a diatom being ingested appears to be a simple function of its relative abundance. Two factors were probably important for the co-existence of ciliate species : wide variation in cell size and shape enabled them to occupy most habitats; and they deployed a variety of feeding mechanisms to consume the variety of microbial food types. Taken as a whole, the ciliate community was capable of feeding on all microbes, including other protozoa, up to a size of about 80 pm. Considering the broad diversity of ciliate habitats available within 1 m2, the importance of physical transport processes in the river basin, and the known cosmopolitan distribution of many ciliate species, it is believed likely that the species richness we recorded is representative of the expanse of sandy sediment in this river, on this occasion

    Total Cross Sections for Neutron Scattering

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    Measurements of neutron total cross-sections are both extensive and extremely accurate. Although they place a strong constraint on theoretically constructed models, there are relatively few comparisons of predictions with experiment. The total cross-sections for neutron scattering from 16^{16}O and 40^{40}Ca are calculated as a function of energy from 5070050-700~MeV laboratory energy with a microscopic first order optical potential derived within the framework of the Watson expansion. Although these results are already in qualitative agreement with the data, the inclusion of medium corrections to the propagator is essential to correctly predict the energy dependence given by the experiment.Comment: 10 pages (Revtex 3.0), 6 fig

    Pattern languages in HCI: A critical review

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    This article presents a critical review of patterns and pattern languages in human-computer interaction (HCI). In recent years, patterns and pattern languages have received considerable attention in HCI for their potential as a means for developing and communicating information and knowledge to support good design. This review examines the background to patterns and pattern languages in HCI, and seeks to locate pattern languages in relation to other approaches to interaction design. The review explores four key issues: What is a pattern? What is a pattern language? How are patterns and pattern languages used? and How are values reflected in the pattern-based approach to design? Following on from the review, a future research agenda is proposed for patterns and pattern languages in HCI

    Effectiveness of a simple lymphoedema treatment regimen in podoconiosis management in southern Ethiopia: one year follow-up

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    Background: Podoconiosis is a non-filarial elephantiasis caused by long-term barefoot exposure to volcanic soils in endemic areas. Irritant silicate particles penetrate the skin, causing a progressive, debilitating lymphoedema of the lower leg, often starting in the second decade of life. A simple patient-led treatment approach appropriate for resource poor settings has been developed, comprising (1) education on aetiology and prevention of podoconiosis, (2) foot hygiene (daily washing with soap, water and an antiseptic), (3) the regular use of emollient, (4) elevation of the limb at night, and (5) emphasis on the consistent use of shoes and socks. Methodology/Principal Findings: We did a 12-month, non-comparative, longitudinal evaluation of 33 patients newly presenting to one clinic site of a non-government organization (the Mossy Foot Treatment & Prevention Association, MFTPA) in southern Ethiopia. Outcome measures used for the monitoring of disease progress were (1) the clinical staging system for podoconiosis, and (2) the Amharic Dermatology Life Quality Index (DLQI), both of which have been recently validated for use in this setting. Digital photographs were also taken at each visit. Twenty-seven patients completed follow up. Characteristics of patients completing follow-up were not significantly different to those not. Mean clinical stage and lower leg circumference decreased significantly (mean difference -0.67 (95% CI -0.38 to -0.96) and -2.00 (95% CI -1.26 to -2.74), respectively, p<0.001 for both changes). Mean DLQI diminished from 21 (out of a maximum of 30) to 6 (p<0.001). There was a non-significant change in proportion of patients with mossy lesions (p = 0.375). Conclusions/Significance: This simple, resource-appropriate regimen has a considerable impact both on clinical progression and self-reported quality of life of affected individuals. The regimen appears ideal for scaling up to other endemic regions in Ethiopia and internationally. We recommend that further research in the area include analysis of cost-effectiveness of the regimen

    Predicting total reaction cross sections for nucleon-nucleus scattering

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    Nucleon total reaction and neutron total cross sections to 300 MeV for 12C and 208Pb, and for 65 MeV spanning the mass range, are predicted using coordinate space optical potentials formed by full folding of effective nucleon-nucleon interactions with realistic nuclear ground state densities. Good to excellent agreement is found with existing data.Comment: 10 pages, 4 figure

    High-Precision Measurement of the 19Ne Half-Life and Implications for Right-Handed Weak Currents

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    We report a precise determination of the 19Ne half-life to be T1/2=17.262±0.007T_{1/2} = 17.262 \pm 0.007 s. This result disagrees with the most recent precision measurements and is important for placing bounds on predicted right-handed interactions that are absent in the current Standard Model. We are able to identify and disentangle two competing systematic effects that influence the accuracy of such measurements. Our findings prompt a reassessment of results from previous high-precision lifetime measurements that used similar equipment and methods.Comment: 5 pages and 5 figures. Paper accepted for publication in Phys. Rev. Let

    Control over phase separation and nucleation using a laser-tweezing potential

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    Control over the nucleation of new phases is highly desirable but elusive. Even though there is a long history of crystallization engineering by varying physicochemical parameters, controlling which polymorph crystallizes or whether a molecule crystallizes or forms an amorphous precipitate is still a poorly understood practice. Although there are now numerous examples of control using laser-induced nucleation, the absence of physical understanding is preventing progress. Here we show that the proximity of a liquid–liquid critical point or the corresponding binodal line can be used by a laser-tweezing potential to induce concentration gradients. A simple theoretical model shows that the stored electromagnetic energy of the laser beam produces a free-energy potential that forces phase separation or triggers the nucleation of a new phase. Experiments in a liquid mixture using a low-power laser diode confirm the effect. Phase separation and nucleation using a laser-tweezing potential explains the physics behind non-photochemical laser-induced nucleation and suggests new ways of manipulating matter
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