1,571 research outputs found

    Human cognition inspired procedures for part family formation based on novel Inspection Based Clustering approach

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    Human cognition based procedures are promising approaches for solving different kind or problems, and this paper addresses the part family formation problem inspired by a human cognition procedure through a graph-based approach, drawing on pattern recognition. There are many algorithms which consider nature inspired models for solving a broad range of problem types. However, there is a noticeable existence of a gap in implementing models based on human cognition, which are generally characterized by “visual thinking”, rather than complex mathematical models. Hence, the natural power of reasoning - by detecting the patterns that mimic the natural human cognition - is used in this study as this paper is based on the partial implementation of graph theory in modelling and solving issues related to the grouping of the parts to be processed by one machine, regardless of their size. The obtained results have shown that most of the problems solved by using the proposed approach have provided interesting benchmark results when compared with previous results given by GRASP (Greedy Randomized Adaptive Search Procedure) heuristics.This work has been supported by national funds through FCT - Fundacao para a Ciencia e Tecnologia - under the [UID/CEC/00319/2019] project, and under the RD Units Projects Scopes: UIDP/04077/2020 and UIDB/04077/2020, UIDP/04077/2020 and UIDB/04077/2020

    Quantitative historical hydrology in Europe

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    Received: 27 Mar 2015 – Published in Hydrol. Earth Syst. Sci. Discuss.: 30 Apr 2015 Revised: 02 Jul 2015 – Accepted: 11 Jul 2015 – Published: 10 Aug 2015In recent decades, the quantification of flood hydrological characteristics (peak discharge, hydrograph shape, and runoff volume) from documentary evidence has gained scientific recognition as a method to lengthen flood records of rare and extreme events. This paper describes the methodological evolution of quantitative historical hydrology under the influence of developments in hydraulics and statistics. In the 19th century, discharge calculations based on flood marks were the only source of hydrological data for engineering design, but were later left aside in favour of systematic gauge records and conventional hydrological procedures. In the last two decades, there has been growing scientific and public interest in understanding long-term patterns of rare floods, in maintaining the flood heritage and memory of extremes, and developing methods for deterministic and statistical application to different scientific and engineering problems. A compilation of 46 case studies across Europe with reconstructed discharges demonstrates that (1) in most cases present flood magnitudes are not unusual within the context of the last millennium, although recent floods may exceed past floods in some temperate European rivers (e.g. the Vltava and Po rivers); (2) the frequency of extreme floods has decreased since the 1950s, although some rivers (e.g. the Gardon and Ouse rivers) show a reactivation of rare events over the last two decades. There is a great potential for gaining understanding of individual extreme events based on a combined multiproxy approach (palaeoflood and documentary records) providing high-resolution time flood series and their environmental and climatic changes; and for developing non-systematic and non-stationary statistical models based on relations of past floods with external and internal covariates under natural low-frequency climate variability.G. Benito and M. J. Machado were funded by the Spanish Ministry of Economy and Competitiveness through research projects CLARIES (CGL2011-29176) and PALEOMED (CGL2014-58127-C3-1-R), and by the CSIC PIE Intramural Project (ref. 201430E003).Peer reviewe

    Thrombophilia screening: An artificial neural network approach

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    Thrombotic disorders have severe consequences for the patients and for the society in general, being one of the main causes of death. These facts reveal that it is extremely important to be preventive; being aware of how probable is to have that kind of syndrome. Indeed, this work will focus on the development of a decision support system that will cater for an individual risk evaluation with respect to the surge of thrombotic complaints. The Knowledge Representation and Reasoning procedures used will be based on an extension to the Logic Programming language, allowing the handling of incomplete and/or default data. The computational framework in place will be centered on Artificial Neural Networks.This work is funded by National Funds through the FCT – Fundação para a Ciência e a Tecnologia (Portuguese Foundation for Science and Technology) within projects PEst-OE/EEI/UI0752/2014 and PEst-OE/QUI/UI0619/2012

    Estatura e maturac¸ão sexual em meninas com artrite idiopática juvenil

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    Objective: To evaluate height, sexual maturation, and the difference between final and expected height in girls with juvenile idiopathic arthritis and no glucocorticoid treatment for at least six months, as compared to a group of healthy girls. Methods: This cross-sectional study involved 44 girls with juvenile idiopathic arthritis, diagnosed according to the International League of Associations for Rheumatology criteria, and 59 healthy controls aged between 8 and 18 (incomplete) years with no comorbid chronic diseases. Demographic data were collected from all participants, and disease and treatment variables were compiled for the patient group. Anthropometric measurements were converted into Z-scores based on World Health Organization standards. Sexual maturation was classified according to Tanner stages. Results: Body mass index and height Z-scores were lower in girls with juvenile idiopathic arthritis as compared to control participants. These values differed significantly in Tanner stage II. Three (6.8%) girls with juvenile idiopathic arthritis had height-for-age Z-scores <−2 (short stature). Girls with polyarticular juvenile idiopathic arthritis and higher cumulative glucocorticoid doses were significantly more likely to present with short stature. The percentage of prepubertal girls in the juvenile idiopathic arthritis group was significantly higher than that observed in the control group, (p = 0.012). Age of menarche, adult height, and the difference between actual and expected height did not differ between groups. Conclusion: These findings suggest that even six months after the suspension of glucocorticoid treatment, children with polyarticular/systemic juvenile idiopathic arthritis subtypes are still susceptible to low height and delayed puberty.Objetivo: Avaliar a estatura, maturac¸ão sexual e a diferenc¸a entre a estatura final e a esperada em meninas com artrite idiopática juvenil (AIJ) sem tratamento com glicocorticoides por pelo menos seis meses, em comparac¸ão com um grupo de meninas saudáveis. Métodos: Este estudo transversal avaliou 44 meninas com artrite idiopática juvenil, diagnosticadas de acordo com os critérios da International League of Associations for Rheumatology e 59 controles saudáveis, entre oito e 18 anos (incompletos) sem comorbidades por doenc¸as crônicas. Os dados demográficos foram coletados de todos os participantes e as variáveis de doenc¸a e tratamento foram compiladas para o grupo de pacientes. As medidas antropométricas foram convertidas em escores-z com base nos padrões da Organizac¸ão Mundial da Saúde. A maturac¸ão sexual foi classificada de acordo com os estágios de Tanner. Resultados: Índice de massa corporal e escores-z de estatura foram menores em meninas com artrite idiopática juvenil em comparac¸ão com os participantes-controle. Esses valores diferiram significativamente no estágio II de Tanner. Três (6,8%) meninas com artrite idiopática juvenil tinham escores-z de estatura para idade < -2 (baixa estatura). Meninas com artrite idiopática juvenil poliarticular e doses cumulativas de glicocorticoides foram significativamente mais propensas a apresentar baixa estatura. A porcentagem de meninas pré-púberes no grupo artrite idiopática juvenil foi significativamente maior do que a observada no grupo controle (p = 0,012). A idade da menarca, a estatura adulta e a diferenc¸a entre a estatura real e a esperada não diferiram entre os grupos. Conclusão: Esses achados sugerem que, mesmo após seis meses da suspensão do tratamento com glicocorticoides, as crianc¸as com os subtipos poliarticular/sistêmico de AIJ ainda são suscetíveis a baixa estatura e atraso na puberdade

    Influence of preparation procedures on the phenolic content, antioxidant and antidiabetic activities of green and black teas

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    The influence of common tea preparation procedures (temperature, infusion time, consumption time interval and tea bag/loose-leaf) and the type of water used, on the total phenolic content (TPC), the radical scavenging activity and the alpha-glucosidase inhibitory activity were assessed. Higher TPC and antioxidant activity were obtained when using lower mineralized waters. Tea bags also evidenced higher antioxidant activity than loose-leaf samples. Under the same conditions (90 degrees C and five minutes of infusion time) green tea contains almost twice the quantity of polyphenols and the free radical scavenging ability of black tea. In the alpha-glucosidase assay all infusions were active (97-100 %). Furthermore, HPLC allowed to identify some of the polyphenols present in both teas and to monitor their composition change with time. After twenty-four hours, the antioxidant activity was maintained without significant changes, but a small decrease in enzyme inhibition was observed, although this activity was still very high.info:eu-repo/semantics/publishedVersio

    Electrons in Dry DNA from Density Functional Calculations

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    The electronic structure of an infinite poly-guanine - poly-cytosine DNA molecule in its dry A-helix structure is studied by means of density-functional calculations. An extensive study of 30 nucleic base pairs is performed to validate the method. The electronic energy bands of DNA close to the Fermi level are then analyzed in order to clarify the electron transport properties in this particularly simple DNA realization, probably the best suited candidate for conduction. The energy scale found for the relevant band widths, as compared with the energy fluctuations of vibrational or genetic-sequence origin, makes highly implausible the coherent transport of electrons in this system. The possibility of diffusive transport with sub-nanometer mean free paths is, however, still open. Information for model Hamiltonians for conduction is provided.Comment: 8 pages, 4 figure

    Cleaning activity among Labridae in the Azores: the rainbow wrasse Coris julis and the Azorean blue wrasse Centrolabrus caeruleus

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    Copyright © Cambridge University Press 2009.Cleaning interactions among the rainbow wrasse Coris julis and the azorean blue wrasse Centrolabrus caeruleus are presented with photographic registers, as well as the first record of the latter cleaning conspecifics from Azorean shallow rocky reefs

    Creating new functional biomaterials: construction and production of Bone Morphogenetic 2-ELP hybrid proteins

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    Bone morphogenetic protein 2 (BMP-2) is a potent osteoinductive cytokine from the TGF-β superfamily that triggers the development of stem cells into osteoblasts. Its therapeutic interest has led to the development of various production systems for recombinant variables of BMP-2. Production has been achieved in expression systems ranging from animal cells to bacteria, but is always associated with three major drawbacks: low production rates (in animal cells), low activity (bacterial cells) and low solubility due to aggregation in inclusion bodies (bacterial cells) [1]. In this study we have developed a strategy to overcome the low production levels as well as the insolubility of BMP-2 in E. coli by fusing it with an elastin like polymer (ELP). This recombinant ELP, based on repetitions of the main monomer VPAVG, displays no measurable cytotoxicity [2] and exhibits thermoresponsive properties as well as hysteresis behaviour [3]. By exploring this thermal responsiveness we are able to purify the fusion protein using a simple and low cost method and thus avoid expensive chromatographic techniques. The mature human-BMP2 domain was cloned in frame to the N-terminus of the (VPAVG)n (n = 60 or 220) polymers. The production of the genetic constructs was achieved in E. coli BL21 (DE3) with Lysogeny Broth (LB) supplemented with lactose for auto-induction. Purification of the hybrid BMP2:(VPAVG)n polymers was accomplished by exploring the thermal responsiveness of the ELP tail. Physical and chemical characterization as well as bioactivity studies of both constructs are currently in progress. 1. Bessa P. C., Casal M., Reis R. L. (2008) “Bone morphogenetic proteins in tissue engineering: the road from laboratory to the clinic, part I (Basic concepts)”, Journal of tissue engineering and regenerative medicine 2, 1-13; 2. Bessa, P., Machado, R., Nürnberger , S., Dopler, D., Banerjee, A., Cunha, A. M., Rodríguez-Cabello, C., Redl, H., van Griensven, M., Reis, R.L., Casal, M. 2010. Thermoresponsive self-assembled elastin-based nanoparticles for delivery of BMPs. Journal of Controlled Release 142: 312–318. 3. Machado R., Ribeiro A., Padrão J., Silva D., Nobre A., Teixeira J., Arias F., Cunha A., Rodroguez-Cabello J., Casal M. (2009) “Exploiting the natural ocurring elastin: construction, production and characterization of a recombinant thermoplastic protein-based polymer”, Journal of Nano Research, 6, 133-145

    A bibliometric review and analysis of traffic lights optimization

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    The significant increase in the number of vehicles in urban areas emerges the challenge of urban mobility. Researchers in this area suggest that most daily delays in urban travel times are caused by intersections, which could be reduced if the traffic lights at these intersections were more efficient. The use of simulation for real intersections can be effective in optimizing the cycle times and improving the traffic light timing to coordinate vehicles passing through intersections. From these themes emerge the research questions: How are the existing approaches (optimization techniques and simulation) to managing traffic lights smartly? What kind of data (offline and online) are used for traffic lights optimization? How beneficial is it to propose an optimization approach to the traffic system? This paper aims to answer these questions, carried out through a bibliometric literature review. In total, 93 articles were analyzed. The main findings revealed that the United States and China are the countries with the most studies published in the last ten years. Moreover, Particle Swarm Optimization is a frequently used approach, and there is a tendency for studies to perform optimization of real cases by real-time data, showing that the praxis of smart cities has resorted to smart traffic lights.This work has been supported by FCT— Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020 and the project “Integrated and Innovative Solutions for the well-being of people in complex urban centers” within the Project Scope NORTE-01-0145-FEDER-000086
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