21,944 research outputs found

    A Monte Carlo Approach to Measure the Robustness of Boolean Networks

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    Emergence of robustness in biological networks is a paramount feature of evolving organisms, but a study of this property in vivo, for any level of representation such as Genetic, Metabolic, or Neuronal Networks, is a very hard challenge. In the case of Genetic Networks, mathematical models have been used in this context to provide insights on their robustness, but even in relatively simple formulations, such as Boolean Networks (BN), it might not be feasible to compute some measures for large system sizes. We describe in this work a Monte Carlo approach to calculate the size of the largest basin of attraction of a BN, which is intrinsically associated with its robustness, that can be used regardless the network size. We show the stability of our method through finite-size analysis and validate it with a full search on small networks.Comment: on 1st International Workshop on Robustness and Stability of Biological Systems and Computational Solutions (WRSBS

    MotionDesigner: Augmented artistic performances with kinect-based human body motion tracking

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    In the last two decades the use of technology in art projects has proliferated, as is the case of the interactive projections based on movement used in artistic performances and installations. However, the artists responsible for creating this work typically have to rely on computer experts to implement this type of interactive systems. The tool herein presented, MotionDesigner, intends to assist the design of these systems by providing artists with higher levels of autonomy and efficiency during the creative process, allowing them to specify the rules by which a human body interacts with both the audio and the visuals used in their interactive art work. The presented tool relies on an RGB-D camera to modulate the multimedia content according to the performer’s body motion. MotionDesigner is extensible so as to accommodate additions required by artists. The tool has been tested with dancers, choreographers, and architects. Results show that MotionDesigner is a valuable aid to artists, working as a catalyst of their creative process.info:eu-repo/semantics/acceptedVersio

    Sanitizing the fortress: protection of ant brood and nest material by worker antibiotics

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    Social groups are at particular risk for parasite infection, which is heightened in eusocial insects by the low genetic diversity of individuals within a colony. To combat this, adult ants have evolved a suite of defenses to protect each other, including the production of antimicrobial secretions. However, it is the brood in a colony that are most vulnerable to parasites because their individual defenses are limited, and the nest material in which ants live is also likely to be prone to colonization by potential parasites. Here, we investigate in two ant species whether adult workers use their antimicrobial secretions not only to protect each other but also to sanitize the vulnerable brood and nest material. We find that, in both leaf-cutting ants and weaver ants, the survival of the brood was reduced and the sporulation of parasitic fungi from them increased, when the workers nursing them lacked functional antimicrobial-producing glands. This was the case for both larvae that were experimentally treated with a fungal parasite (Metarhizium) and control larvae which developed infections of an opportunistic fungal parasite (Aspergillus). Similarly, fungi were more likely to grow on the nest material of both ant species if the glands of attending workers were blocked. The results show that the defense of brood and sanitization of nest material are important functions of the antimicrobial secretions of adult ants and that ubiquitous, opportunistic fungi may be a more important driver of the evolution of these defenses than rarer, specialist parasites

    An 11-year-old boy with pharyngitis and cough: Lemierre syndrome

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    The authors present the case of an 11-year-old boy with pharyngitis, treated with amoxicillin, that worsened on day 7, with cough, high fever and refusal to eat. Lethargy and respiratory distress were noted. Based on radiographic findings of bilateral infiltrates he was diagnosed with pneumonia and started on intravenous ampicillin and erythromycin. Two days later he complained of right-sided neck pain and a palpable mass was identified. An ultrasound showed partial thrombosis of the right internal jugular vein and a lung CT scan revealed multiple septic embolic lesions. Lemierre syndrome was diagnosed, antibiotic treatment adjusted and anticoagulation started. A neck CT-scan showed a large parapharyngeal abscess. His clinical condition improved gradually and after 3 weeks of intravenous antibiotics he was discharged home on oral treatment. This case illustrates the importance of diagnosing Lemierre syndrome in the presence of pharyngitis with localised neck pain and respiratory distress, to prevent potentially fatal complications

    Intangibles as innovative drivers for competitive businesses

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    This paper aims to identify the impact of intangible resources as drivers of firms’ performance and profitability, in the major technological firms in the world. Using information from the major technological firms for a four years economic period, a set of intellectual capital proxies were identified and regressed against the major performance and profitability indicators. The regression model embodies a set of knowledge-based resources intangible (e.g. goodwill, licenses and patents, software and R&D, and advertising expenses) and human capital proxies, aiming to identify potential disaggregated effects of intangibles those key performance indicators. Broadly, results suggest the existence of effective isolated effect for some variables, in particular for intangibles recognized in the financial reporting. Furthermore, this research also suggests that the capitalization of intangible resources can be associated with region and corresponding accounting standards used in the preparation of the financial reporting.info:eu-repo/semantics/acceptedVersio

    DigitalPinDirector: A digital pinscreen editor for images and realtime animation in low cost personal computers

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    This paper presents the main characteristics of the traditional Pinscreen, the way it works, its problems and results achieved. The first Digital Pinscreen system is presented, along with its main characteristics and limitations. The rest of the paper describes and presents the DigitalPinDirector: a system that enables a full and true creative access to the unique visual and animation characteristics of the Pinscreen.info:eu-repo/semantics/publishedVersio

    Impact of biofilms in simulated drinking water and urban heat supply systems

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    Biofouling and biocorrosion were studied in drinking water and heating water systems by forming biofilms on steel and on polymethylmetacrylate. In the drinking water system, biofilm development was more significant on corroded surfaces, suggesting that in these conditions they were largely protected from disinfection, probably because of sheltering and chlorine demand by corrosion products. In the urban heat supply system, results suggest a higher biofilm activity at lower pH. Sulphate-reducing bacteria were detected in the urban heating biofilms, but little corrosion was observed on steel coupons. Results indicate that surface and bulk medium properties, as well as bacterial diversity are determinant parameters when studying biofouling and biocorrosion.Cirius – Danish Centre for International Cooperation and Mobility in Education and Trainin
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