53 research outputs found

    Model study of adsorbed metallic quantum dots: Na on Cu(111)

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    We model electronic properties of the second monolayer Na adatom islands (quantum dots) on the Cu(111) surface covered homogeneously by the first Na monolayer. An axially-symmetric three-dimensional jellium model, taking into account the effects due to the first Na monolayer and the Cu substrate, has been developed. The electronic structure is solved within the local-density approximation of the density-functional theory using a real-space multigrid method. The model enables the study of systems consisting of thousands of Na-atoms. The results for the local density of states are compared with differential conductance (dI/dVdI/dV) spectra and constant current topographs from Scanning Tunneling Microscopy.Comment: 10 pages, 8 figures. For better quality figures, download http://www.fyslab.hut.fi/~tto/cylart1.pd

    Collaborative creativity: The Music Room

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    In this paper, we reflect on our experience of designing, developing and evaluating interactive spaces for collaborative creativity. In particular, we are interested in designing spaces which allow everybody to compose and play original music. The Music Room is an interactive installation where couples can compose original music by moving in the space. Following the metaphor of love, the music is automatically generated and modulated in terms of pleasantness and intensity, according to the proxemics cues extracted from the visual tracking algorithm. The Music Room was exhibited during the EU Researchers' Night in Trento, Italy

    Somatic diversification of variable lymphocyte receptors in the agnathan sea lamprey

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    Although jawless vertebrates are apparently capable of adaptive immune responses, they have not been found to possess the recombinatorial antigen receptors shared by all jawed vertebrates. Our search for the phylogenetic roots of adaptive immunity in the lamprey has instead identified a new type of variable lymphocyte receptors (VLRs) composed of highly diverse leucine-rich repeats (LRR) sandwiched between amino- and carboxy-terminal LRRs. An invariant stalk region tethers the VLRs to the cell surface by means of a glycosyl-phosphatidyl-inositol anchor. To generate rearranged VLR genes of the diversity necessary for an anticipatory immune system, the single lamprey VLR locus contains a large bank of diverse LRR cassettes, available for insertion into an incomplete germline VLR gene. Individual lymphocytes express a uniquely rearranged VLR gene in monoallelic fashion. Different evolutionary strategies were thus used to generate highly diverse lymphocyte receptors through rearrangement of LRR modules in agnathans ( jawless fish) and of immunoglobulin gene segments in gnathostomes ( jawed vertebrates).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62870/1/nature02740.pd

    Uniaxial versus biaxial character of nematic equilibria in three dimensions

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    We study global minimizers of the Landau–de Gennes (LdG) energy functional for nematic liquid crystals, on arbitrary three-dimensional simply connected geometries with topologically non-trivial and physically relevant Dirichlet boundary conditions. Our results are specific to an asymptotic limit coined in terms of a dimensionless temperature and material-dependent parameter, t and some constraints on the material parameters, and we work in the t→∞ limit that captures features of the widely used Lyuksyutov constraint (Kralj and Virga in J Phys A 34:829–838, 2001). We prove (i) that (re-scaled) global LdG minimizers converge uniformly to a (minimizing) limiting harmonic map, away from the singular set of the limiting map; (ii) we have points of maximal biaxiality and uniaxiality near each singular point of the limiting map; (iii) estimates for the size of “strongly biaxial” regions in terms of the parameter t. We further show that global LdG minimizers in the restricted class of uniaxial Q-tensors cannot be stable critical points of the LdG energy in this limit

    A systematic review of non-invasive modalities used to identify women with anal incontinence symptoms after childbirth

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    © 2018, The International Urogynecological Association. Introduction and hypothesis: Anal incontinence following childbirth is prevalent and has a significant impact upon quality of life (QoL). Currently, there is no standard assessment for women after childbirth to identify these symptoms. This systematic review aimed to identify non-invasive modalities used to identify women with anal incontinence following childbirth and assess response and reporting rates of anal incontinence for these modalities. Methods: Ovid Medline, Allied and Complementary Medicine Database (AMED), Cumulative Index of Nursing and Allied Health Literature (CINAHL), Cochrane Collaboration, EMBASE and Web of Science databases were searched for studies using non-invasive modalities published from January 1966 to May 2018 to identify women with anal incontinence following childbirth. Study data including type of modality, response rates and reported prevalence of anal incontinence were extracted and critically appraised. Results: One hundred and nine studies were included from 1602 screened articles. Three types of non-invasive modalities were identified: validated questionnaires/symptom scales (n = 36 studies using 15 different instruments), non-validated questionnaires (n = 50 studies) and patient interviews (n = 23 studies). Mean response rates were 92% up to 6 weeks after childbirth. Non-personalised assessment modalities (validated and non-validated questionnaires) were associated with reporting of higher rates of anal incontinence compared with patient interview at all periods of follow-up after childbirth, which was statistically significant between 6 weeks and 1 year after childbirth (p < 0.05). Conclusions: This systematic review confirms that questionnaires can be used effectively after childbirth to identify women with anal incontinence. Given the methodological limitations associated with non-validated questionnaires, assessing all women following childbirth for pelvic-floor symptomatology, including anal incontinence, using validated questionnaires should be considered

    Molecular and functional properties of P2X receptors—recent progress and persisting challenges

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    Can a Genetic Algorithm Think like a Composer?

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    There has now been a substantial body of work utilising Genetic Algorithms (GA) for the purpose of musical composition. A common point of discussion is how far GAis can simulate not just the musical output of human composers, but also the process of composing itself. This paper begins by discussing the suitability of using a GA for composition, and goes on to describe a generative music system (by the author), that utilises a domain specific, knowledge rich GA. The system acts on a supplied 2-bar musical phrase (up to 4 parts), and evolves musical fragments towards a supplied target. The aim is to provide interim points on the evolutionary path, which represents a “newi musical ideas audibly based on the supplied fragments. The paper concludes that the system is able to model at least part of the creative process of composition, and is effective at producing musically successful results. (Audio download sources of its output are included to support this conclusion). The system was used to generate music included in an interactive installation work, exhibited at Brighton Arts Festival 2002, and other applications under developed that use the algorithm are discussed

    Automatic Evolutionary Music Composition Based on Multi-objective Genetic Algorithm

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    The impact of trained radiographers as concurrent readers on performance and reading time of experienced radiologists in the UK Lung Cancer Screening (UKLS) trial.

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    OBJECTIVES: To compare radiologists' performance reading CTs independently with their performance using radiographers as concurrent readers in lung cancer screening. METHODS: 369 consecutive baseline CTs performed for the UK Lung Cancer Screening (UKLS) trial were double-read by radiologists reading either independently or concurrently with a radiographer. In concurrent reading, the radiologist reviewed radiographer-identified nodules and then detected any additional nodules. Radiologists recorded their independent and concurrent reading times. For each radiologist, sensitivity, average false-positive detections (FPs) per case and mean reading times for each method were calculated. RESULTS: 694 nodules in 246/369 (66.7%) studies comprised the reference standard. Radiologists' mean sensitivity and average FPs per case both increased with concurrent reading compared to independent reading (90.8 ± 5.6% vs. 77.5 ± 11.2%, and 0.60 ± 0.53 vs. 0.33 ± 0.20, respectively; p < 0.05 for 3/4 and 2/4 radiologists, respectively). The mean reading times per case decreased from 9.1 ± 2.3 min with independent reading to 7.2 ± 1.0 min with concurrent reading, decreasing significantly for 3/4 radiologists (p < 0.05). CONCLUSIONS: The majority of radiologists demonstrated improved sensitivity, a small increase in FP detections and a statistically significantly reduced reading time using radiographers as concurrent readers. KEY POINTS: • Radiographers as concurrent readers could improve radiologists' sensitivity in lung nodule detection. • An increase in false-positive detections with radiographer-assisted concurrent reading occurred. • The false-positive detection rate was still lower than reported for computer-aided detection. • Concurrent reading with radiographers was also faster than single reading. • The time saved per case using concurrently reading radiographers was relatively modest.The UKLS has received funding from the National Institute for Health Research, Health Technology Assessment (NIHR HTA)
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