1,318 research outputs found

    Human Dynamics: The Correspondence Patterns of Darwin and Einstein

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    While living in different historical era, Charles Darwin (1809-1882) and Albert Einstein (1879-1955) were both prolific correspondents: Darwin sent (received) at least 7,591 (6,530) letters during his lifetime while Einstein sent (received) over 14,500 (16,200). Before email scientists were part of an extensive university of letters, the main venue for exchanging new ideas and results. But were the communication patterns of the pre-email times any different from the current era of instant access? Here we show that while the means have changed, the communication dynamics has not: Darwin's and Einstein's pattern of correspondence and today's electronic exchanges follow the same scaling laws. Their communication belongs, however, to a different universality class from email communication, providing evidence for a new class of phenomena capturing human dynamics.Comment: Supplementary Information available at http://www.nd.edu/~network

    An orientation method with prediction and anticipation features

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    Nowadays, progress is constant and inherent to a living society. This may occur in different arenas, namely in mathematical evaluation and healthcare. Assistive technologies are a topic under this evolution, being extremely important in helping users with diminished capabilities (physical, sensory, intellectual). These technologies assist people in tasks that were difficult or impossible to execute. A common diminished task is orientation, which is crucial for the user autonomy. The adaptation to such technologies should require the minimum effort possible in order to enable the person to use devices that convey assistive functionalities. There are several solutions that help a human being to travel between two different locations, however their authors are essentially concerned with the guidance method, giving special attention to the user interface. The CogHelper system aims to overcome these systems by applying a framework of Speculative Computation, which adds a prediction feature for the next user movement giving an anticipation ability to the system. Thus, an alert is triggered before the user turn towards an incorrect path. The travelling path is also adjusted to the user preferences through a trajectory mining module.This work has been supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT - Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2013. The work of João Ramos is supported by a doctoral the FCT grant SFRH/BD/89530/2012. The work of Tiago Oliveira is also supported by the FCT grant with the reference SFRH/BD/85291/2012info:eu-repo/semantics/publishedVersio

    Speculative orientation and tracking system

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    The current progresses at the intersection of computer science and health care have the potential of greatly improving the living conditions of people with disabilities by removing obstacles that impair the normal unfolding of their everyday lives. Assistive technologies, as an application of scientific knowledge, aim to help users with their diminished capacities and, usually, imply a small adaptation from individuals so that they can use the devices that convey assistive functionalities. One of the most commonly diminished capabilities is that of spatial orientation. This is mirrored by several research works whose goal is to help human beings to travel between locations. Once set up, most of the systems featured in these research works requires changes in the configurations to be made manually in order to achieve a better adjustment to the user. In order to overcome this drawback, the work presented herein features a framework of Speculative Computation to set up the computation of the next step of a user using default values. The consequence of the application of the framework is a faster reaction to user stimuli, which may result in issuing warnings when he is likely to choose the wrong direction.This work is part-funded by ERDF - European Regional Development Fund through the COMPETE Programme (operational programme for competitiveness) and by National Funds through the FCT Fundac¸ao para a Ci ˜ encia e a Tecnologia (Portuguese Foundation for Science and ˆ Technology) within project FCOMP-01-0124-FEDER-028980 (PTDC/EEI-SII/1386/2012). The work of Joao Ramos is supported by a doctoral grant by FCT - Fundac¸ ˜ ao para a Ci ˜ encia e a ˆ Tecnologia (Portuguese Foundation for Science and Technology) SFRH/BD/89530/2012. The work of Tiago Oliveira is also supported by the FCT grant with the reference SFRH/BD/85291/- 2012.info:eu-repo/semantics/publishedVersio

    An alert mechanism for orientation systems based on Speculative computation

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    The role of assistive technologies is to help users with diminished capabilities in the fulfillment of their everyday tasks. One of such tasks is orientation. It is crucial for the autonomy of an individual and, at the same time, it is one of the most challenging tasks for an individual with cognitive disabilities. Existing solutions that tackle this problem are mostly concerned with guidance, tracking and the display of information. However, there is a dimension that has not been the object of concern in existing projects, the prediction of user actions. This work presents a Speculative Module for an orientation system that is used to alert the user for potential mistakes in his path, anticipating possible shifts in the wrong direction in critical points of the route. With this module, it becomes possible to issue warnings to the user and increase his attention so as to avoid a deviation from the correct path.This work is part-funded by ERDF - European Regional Development Fund through the COMPETE Programme (operational programme for competitiveness) and by National Funds through the FCT Fundação para a Ciência e a Tecnologia (Portuguese Foundation for Science and Technology) within project FCOMP-01-0124-FEDER- 028980 (PTDC/EEI-SII/1386/2012) and within Project Scope UID/CEC/00319/2013. The work of João Ramos is supported by a doctoral the FCT grant SFRH/BD/89530/2012. The work of Tiago Oliveira is also supported by the FCT grant with the reference SFRH/BD/85291/2012.info:eu-repo/semantics/publishedVersio

    IL-7R-mediated signaling in T-cell acute lymphoblastic leukemia: an update

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    © 2018 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/BY-NC-ND/4.0/)Interleukin 7 (IL-7) and its receptor (IL-7R, a heterodimer of IL-7Rα and γc) are essential for normal lymphoid development. In their absence, severe combined immunodeficiency occurs. By contrast, excessive IL-7/IL-7R-mediated signaling can drive lymphoid leukemia development, disease acceleration and resistance to chemotherapy. IL-7 and IL-7R activate three main pathways: STAT5, PI3K/Akt/mTOR and MEK/Erk, ultimately leading to the promotion of leukemia cell viability, cell cycle progression and growth. However, the contribution of each of these pathways towards particular functional outcomes is still not completely known and appears to differ between normal and malignant states. For example, IL-7 upregulates Bcl-2 in a PI3K/Akt/mTOR-dependent and STAT5-independent manner in T-ALL cells. This is a 'symmetric image' of what apparently happens in normal lymphoid cells, where PI3K/Akt/mTOR does not impact on Bcl-2 and regulates proliferation rather than survival. In this review, we provide an updated summary of the knowledge on IL-7/IL-7R-mediated signaling in the context of cancer, focusing mainly on T-cell acute lymphoblastic leukemia, where this axis has been more extensively studied.Publication costs were supported by LISBOA-01-0145-FEDER-007391, project cofunded by FEDER, through POR Lisboa2020 Programa Operacional Regional de Lisboa, PORTUGAL 2020, and Fundação para a Ciência e a Tecnologia (FCT, Portugal). The research work in JTB's lab related to the present review was supported by the grants FAPESP/20015/2014 and PTDC/MEC-HEM/31588/2017, from FCT; and by the consolidator grant ERC CoG-648455 from the European Research Council, under the European Union's Horizon 2020 research and innovation programme. JTB is an FCT investigator (consolidator). MLO is a LisbonBioMed PhD student and received a fellowship from FCT. PA received a PhD fellowship from the EU Marie Sklodowska-Curie ITN Protein Conjugates.info:eu-repo/semantics/publishedVersio

    Measured data of Drosophila melanogaster (Diptera Drosophilidae) development and learning and memory behaviour after copper exposition

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    This article presents the statistical analysis data from Drosophila melanogaster development (from larvae to adult) and learning and memory retention behavior of a Pavlovian conditioning in male and female flies exposed to copper. While the full data sets are available In the article: Copper decrease associative learning and memory in D. melanogaster, this data-in-brief article includes the detailed statistical analysis performed. Data demonstrates Statistica Software analysis between the subject part of the analysis: 2 treatments x 2 sexes x 2 ages and within subject part of the analysis: 2 treatments x 2 sex x 2 ages x 4 times, repeated measures

    Avaliação da qualidade ecológica de rios portugueses (Projecto AQUARIPORT): síntese dos resultados referentes à análise das comunidades de macroinvertebrados bentónicos

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    O projecto AQUARIPORT serve de base ao Programa Nacional de Monitorização de sistemas aquáticos e tem como objectivos (1) a recolha de informação base de suporte ao ordenamento dos recursos piscícolas nacionais; (2) o desenvolvimento e a implementação de índices bióticos, baseados na ictiofauna e nos macroinvertebrados bentónicos, que permitam a avaliação da qualidade ecológica de rios no enquadramento nos princípios da Directiva Quadro da Água. Neste âmbito, avalia-se, com base nas comunidades de macroinvertebrados, a integridade ecológica de 107 pontos localizados nas bacias hidrográficas dos rios Douro, Minho, Lima, Mondego, Vouga, Tejo, Sado, Mira e Guadiana das Ribeiras do Oeste e do Algarve. Complementarmente às amostragens de macroinvertebrados também se avalia a condição ambiental de cada ponto amostrado (e.g., estrutura da zona ripícola, substrato do leito, largura do rio, perturbações antropogénicas, condutividade, temperatura, oxigénio dissolvido). Com base nas famílias de macroinvertebrados presentes foram determinados para cada ponto os valores do índice biótico IBMWP. Verificou-se que em 62,3% dos pontos amostrados predominam grupos mais intolerantes à degradação ambiental o que indica que estes locais possuem boa qualidade ambiental (Classes I e II). 24,6% apresentam degradação moderada (Classe III). A qualidade ambiental dos restantes 13,1% encontra-se muito a fortemente degradada, uma vez que os grupos tolerantes ou muito tolerantes à degradação ambiental são dominantes (Classes IV e V). Os parâmetros morfológicos e ambientais que influenciam significativamente a composição das comunidades de macroinvertebrados, são a condutividade, profundidade e largura média do curso de água, presença de hidrófitos, intensidade da urbanização nas áreas circundantes, características do substrato e da mata rípícola

    Culex quinquefasciatus mosquitoes do not support replication of Zika virus

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    The rapid spread of Zika virus (ZIKV) in the Americas raised many questions about the role of Culex quinquefasciatus mosquitoes in transmission, in addition to the key role played by the vector Aedes aegypti. Here we analysed the competence of Cx. quinquefasciatus (with or without Wolbachia endosymbionts) for a ZIKV isolate. We also examined the induction of RNA interference pathways after viral challenge and the production of small virus-derived RNAs. We did not observe any infection nor such small virus-derived RNAs, regardless of the presence or absence of Wolbachia. Thus, Cx. quinquefasciatus does not support ZIKV replication and Wolbachia is not involved in producing this phenotype. In short, these mosquitoes are very unlikely to play a role in transmission of ZIKV

    The effect of insulin-loaded chitosan particle-aggregated scaffolds in chondrogenic differentiation

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    Osteochondral defect repair requires a tissue engineering approach that aims at mimicking the physiological properties and structure of two different tissues (cartilage and bone) using a scaffold–cell construct. One ideal approach would be to engineer in vitro a hybrid material using a single-cell source. For that purpose, the scaffold should be able to provide the adequate biochemical cues to promote the selective but simultaneous differentiation of both tissues. In this work, attention was paid primarily to the chondrogenic differentiation by focusing on the development of polymeric systems that provide biomolecules release to induce chondrogenic differentiation. For that, different formulations of insulin-loaded chitosan particle–aggregated scaffolds were developed as a potential model system for cartilage and osteochondral tissue engineering applications using insulin as a potent bioactive substance known to induce chondrogenic differentiation. The insulin encapsulation efficiency was shown to be high with values of 70.37!0.8%, 84.26!1.76%, and 87.23!1.58% for loadings of 0.05%, 0.5%, and 5%, respectively. The in vitro release profiles were assessed in physiological conditions mimicking the cell culture procedures and quantified by Micro-BCA! protein assay. Different release profiles were obtained that showed to be dependent on the initial insulin-loading percentage. Further, the effect on prechondrogenic ATDC5 cells was investigated for periods up to 4 weeks by studying the influence of these release systems on cell morphology, DNA and glycosaminoglycan content, histology, and gene expression of collagen types I and II, Sox-9, and aggrecan assessed by real-time polymerase chain reaction. When compared with control conditions (unloaded scaffolds cultured with the standard chondrogenic-inducing medium), insulin-loaded scaffolds upregulated the Sox-9 and aggrecan expression after 4 weeks of culture. From the overall results, it is reasonable to conclude that the developed loaded scaffolds when seeded with ATDC5 can provide biochemical cues for chondrogenic differentiation. Among the tested formulations, the higher insulin-loaded system (5%) was the most effective in promoting chondrogenic differentiation.The authors would like to acknowledge the Portuguese Foundation for Science and Technology for the Ph. D. Grant to Patricia B. Malafaya (SFRH/BD/11155/2002). This work was partially supported and carried out under the scope of the European STREP Project HIPPOCRATES (NMP3-CT-2003-505758) and European NoE EXPERTISSUES (NMP3CT-2004-500283). The authors also like to acknowledge the Life and Health Sciences Research Institute (ICVS), University of Minho, for the use of their facilities, namely, to Luis Martins for histological sections slicing and H&E stain processing

    Bacteriocin production of the probiotic Lactobacillus acidophilus KS400

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    In the last years, the use of probiotics, including Lactobacillus species, has received much attention to prevent and treat vaginal disorders. These species have been described as having the ability to colonize the epithelial surface and produce antimicrobial metabolites that are able to control the remaining vaginal microflora. This study aimed to identify and characterize, for the first time, a bacteriocin natively produced by Lactobacillus acidophilus KS400 (probiotic strain from Gynoflor®-Medinova AG, Switzerland) and its antimicrobial activity against relevant urogenital pathogens. After organic acids and hydrogen peroxide neutralization in the fermented Lactobacillus acidophilus KS400 culture medium, bacteriocin activity was tested against the indicator microorganism Lactobacillus delbrueckii ATCC9649. The fermentation of Lactobacillus acidophilus KS400 for bacteriocin production was carried out in batch mode, and its antimicrobial activity, optical density and pH were monitored. After production and extraction, the bacteriocin molecular weight was estimated by electrophoresis and tested against vaginal pathogenic microorganisms. As described for other bacteriocins, batch fermentation profiles indicated that bacteriocin production occurs during the exponential growth phase of the lactobacilli, and declines during their stationary growth phase. The molecular weight of the bacteriocin is approximately 7.5 kDa. The bacteriocin containing protein extract was shown to inhibit the growth of Gardnerella vaginalis, Streptococcus agalactiae, Pseudomonas aeruginosa and the indicator strain Lactobacillus delbrueckii ATCC9649. We conclude that L. acidophilus KS400 produces bacteriocin with antimicrobial activity against relevant urogenital pathogens.Project POCI-01-0145-FEDER-007491; Medinovainfo:eu-repo/semantics/publishedVersio
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