2,033 research outputs found

    Ocular sarcoidosis and tuberculous lymphadenopathy: coincidence or real association

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    Tuberculosis and sarcoidosis share similarity in histopathologic findings and clinically occur in association with each other occasionally. Tuberculosis should always be ruled out before the diagnosis of sarcoidosis. But, the diagnosis is often complicated, especially in extrapulmonary cases. Here we present a case of bilateral vitreous hemorrhage with uveitis. Ocular sarcoidosis was initially diagnosed based on the characteristic ocular findings, negative results on chest radiography, tuberculosis culture, and polymerase chain reaction of aqueous, as well as simultaneous presence of panda and lambda sign on gallium-67 scans. The ocular condition improved after pars plana vitrectomy and systemic steroid therapy. However, TB lymphadenopathy but no recurrent ocular inflammation was found 6 years later. The patient received anti-TB treatment for 6 months thereafter. The eyes remained silent except cataract progression and glaucoma under two medications during this period. In conclusion, TB could occur coincidently or in association with sarcoidosis, continued follow-up is important for patients with ocular sarcoidosis

    Mesoscopic structure conditions the emergence of cooperation on social networks

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    We study the evolutionary Prisoner's Dilemma on two social networks obtained from actual relational data. We find very different cooperation levels on each of them that can not be easily understood in terms of global statistical properties of both networks. We claim that the result can be understood at the mesoscopic scale, by studying the community structure of the networks. We explain the dependence of the cooperation level on the temptation parameter in terms of the internal structure of the communities and their interconnections. We then test our results on community-structured, specifically designed artificial networks, finding perfect agreement with the observations in the real networks. Our results support the conclusion that studies of evolutionary games on model networks and their interpretation in terms of global properties may not be sufficient to study specific, real social systems. In addition, the community perspective may be helpful to interpret the origin and behavior of existing networks as well as to design structures that show resilient cooperative behavior.Comment: Largely improved version, includes an artificial network model that fully confirms the explanation of the results in terms of inter- and intra-community structur

    Holographic Anomalous Conductivities and the Chiral Magnetic Effect

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    We calculate anomaly induced conductivities from a holographic gauge theory model using Kubo formulas, making a clear conceptual distinction between thermodynamic state variables such as chemical potentials and external background fields. This allows us to pinpoint ambiguities in previous holographic calculations of the chiral magnetic conductivity. We also calculate the corresponding anomalous current three-point functions in special kinematic regimes. We compare the holographic results to weak coupling calculations using both dimensional regularization and cutoff regularization. In order to reproduce the weak coupling results it is necessary to allow for singular holographic gauge field configurations when a chiral chemical potential is introduced for a chiral charge defined through a gauge invariant but non-conserved chiral density. We argue that this is appropriate for actually addressing charge separation due to the chiral magnetic effect.Comment: 17 pages, 1 figure. v2: 18 pages, 1 figure, discussion clarified throughout the text, references added, version accepted for publication in JHE

    Comparison of contact patterns relevant for transmission of respiratory pathogens in Thailand and the Netherlands using respondent-driven sampling

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    Understanding infection dynamics of respiratory diseases requires the identification and quantification of behavioural, social and environmental factors that permit the transmission of these infections between humans. Little empirical information is available about contact patterns within real-world social networks, let alone on differences in these contact networks between populations that differ considerably on a socio-cultural level. Here we compared contact network data that were collected in the Netherlands and Thailand using a similar online respondent-driven method. By asking participants to recruit contact persons we studied network links relevant for the transmission of respiratory infections. We studied correlations between recruiter and recruited contacts to investigate mixing patterns in the observed social network components. In both countries, mixing patterns were assortative by demographic variables and random by total numbers of contacts. However, in Thailand participants reported overall more contacts which resulted in higher effective contact rates. Our findings provide new insights on numbers of contacts and mixing patterns in two different populations. These data could be used to improve parameterisation of mathematical models used to design control strategies. Although the spread of infections through populations depends on more factors, found similarities suggest that spread may be similar in the Netherlands and Thailand

    Fracturing ranked surfaces

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    Discretized landscapes can be mapped onto ranked surfaces, where every element (site or bond) has a unique rank associated with its corresponding relative height. By sequentially allocating these elements according to their ranks and systematically preventing the occupation of bridges, namely elements that, if occupied, would provide global connectivity, we disclose that bridges hide a new tricritical point at an occupation fraction p=pcp=p_{c}, where pcp_{c} is the percolation threshold of random percolation. For any value of pp in the interval pc<p≤1p_{c}< p \leq 1, our results show that the set of bridges has a fractal dimension dBB≈1.22d_{BB} \approx 1.22 in two dimensions. In the limit p→1p \rightarrow 1, a self-similar fracture is revealed as a singly connected line that divides the system in two domains. We then unveil how several seemingly unrelated physical models tumble into the same universality class and also present results for higher dimensions

    Four patients with a history of acute exacerbations of COPD: implementing the CHEST/Canadian Thoracic Society guidelines for preventing exacerbations

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    This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/ by/4.0

    Set-shifting as a component process of goal-directed problem-solving

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    In two experiments, we compared secondary task interference on Tower of London performance resulting from three different secondary tasks. The secondary tasks were designed to tap three different executive functions, namely set-shifting, memory monitoring and updating, and response inhibition. Previous work using individual differences methodology suggests that, all other things being equal, the response inhibition or memory tasks should result in the greatest interference. However, this was not found to be the case. Rather, in both experiments the set-shifting task resulted in significantly more interference on Tower of London performance than either of the other secondary tasks. Subsequent analyses suggest that the degree of interference could not be attributed to differences in secondary task difficulty. Results are interpreted in the light of related work which suggests that solving problems with non-transparent goal/subgoal structure requires flexible shifting between subgoals – a process that is held to be impaired by concurrent performance of a set-shifting task

    Molecular Evolution of Aminoacyl tRNA Synthetase Proteins in the Early History of Life

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    Aminoacyl-tRNA synthetases (aaRS) consist of several families of functionally conserved proteins essential for translation and protein synthesis. Like nearly all components of the translation machinery, most aaRS families are universally distributed across cellular life, being inherited from the time of the Last Universal Common Ancestor (LUCA). However, unlike the rest of the translation machinery, aaRS have undergone numerous ancient horizontal gene transfers, with several independent events detected between domains, and some possibly involving lineages diverging before the time of LUCA. These transfers reveal the complexity of molecular evolution at this early time, and the chimeric nature of genomes within cells that gave rise to the major domains. Additionally, given the role of these protein families in defining the amino acids used for protein synthesis, sequence reconstruction of their pre-LUCA ancestors can reveal the evolutionary processes at work in the origin of the genetic code. In particular, sequence reconstructions of the paralog ancestors of isoleucyl- and valyl- RS provide strong empirical evidence that at least for this divergence, the genetic code did not co-evolve with the aaRSs; rather, both amino acids were already part of the genetic code before their cognate aaRSs diverged from their common ancestor. The implications of this observation for the early evolution of RNA-directed protein biosynthesis are discussed.National Science Foundation (U.S.) (Grant DEB 0830024)National Science Foundation (U.S.) (Grant DEB 0936234)United States. National Aeronautics and Space Administration (NASA Postdoctoral Fellowship

    30 days wild: development and evaluation of a large-scale nature engagement campaign to improve well-being

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    There is a need to increase people’s engagement with and connection to nature, both for human well-being and the conservation of nature itself. In order to suggest ways for people to engage with nature and create a wider social context to normalise nature engagement, The Wildlife Trusts developed a mass engagement campaign, 30 Days Wild. The campaign asked people to engage with nature every day for a month. 12,400 people signed up for 30 Days Wild via an online sign-up with an estimated 18,500 taking part overall, resulting in an estimated 300,000 engagements with nature by participants. Samples of those taking part were found to have sustained increases in happiness, health, connection to nature and pro-nature behaviours. With the improvement in health being predicted by the improvement in happiness, this relationship was mediated by the change in connection to nature

    Mesoscopic effects in an agent-based bargaining model in regular lattices

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    The effect of spatial structure has been proved very relevant in repeated games. In this work we propose an agent based model where a fixed finite population of tagged agents play iteratively the Nash demand game in a regular lattice. The model extends the multiagent bargaining model by Axtell, Epstein and Young [1] modifying the assumption of global interaction. Each agent is endowed with a memory and plays the best reply against the opponent’s most frequent demand. We focus our analysis on the transient dynamics of the system, studying by computer simulation the set of states in which the system spends a considerable fraction of the time. The results show that all the possible persistent regimes in the global interaction model can also be observed in this spatial version. We also find that the mesoscopic properties of the interaction networks that the spatial distribution induces in the model have a significant impact on the diffusion of strategies, and can lead to new persistent regimes different from those found in previous research. In particular, community structure in the intratype interaction networks may cause that communities reach different persistent regimes as a consequence of the hindering diffusion effect of fluctuating agents at their borders.Spanish Ministry of Science and Innovation, references TIN2008-06464-C03-02 and CSD2010-00034 (CONSOLIDER-INGENIO 2010), and by the Junta de Castilla y Leon, references VA006A009, BU034A08 and GREX251-200
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