267 research outputs found

    Fast Discrete Consensus Based on Gossip for Makespan Minimization in Networked Systems

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    In this paper we propose a novel algorithm to solve the discrete consensus problem, i.e., the problem of distributing evenly a set of tokens of arbitrary weight among the nodes of a networked system. Tokens are tasks to be executed by the nodes and the proposed distributed algorithm minimizes monotonically the makespan of the assigned tasks. The algorithm is based on gossip-like asynchronous local interactions between the nodes. The convergence time of the proposed algorithm is superior with respect to the state of the art of discrete and quantized consensus by at least a factor O(n) in both theoretical and empirical comparisons

    Accelerated Multi-Stage Discrete Time Dynamic Average Consensus

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    This paper presents a novel solution for the discrete time dynamic average consensus problem. Given a set of time-varying input signals over the nodes of an undirected graph, the proposed algorithm tracks, at each node, the input signals’ average. The algorithm is based on a sequence of consensus stages combined with a second order diffusive protocol. The former overcomes the need of k-th order differences of the inputs and conservation of the network state average, while the latter overcomes the trade-off between speed and accuracy of the consensus stages by just storing the previous estimate at each node. The result is a protocol that is fast, arbitrarily accurate, and robust against input noises and initializations. The protocol is extended to an asynchronous and randomized version that follows a gossiping scheme that is robust against potential delays and packet losses. We study the convergence properties of the algorithms and validate them via simulations

    Influence of calcium-sensing receptor gene on urinary calcium excretion in stone-forming patients

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    Calcium-sensing receptor (CaSR) is a plasma membrane protein that regulates tubular reabsorption of Ca. To establish its role in idiopathic hypercalciuria, the association of urinary Ca excretion with the polymorphisms of CASR gene has been studied in healthy subjects and in hypercalciuric and normocalciuric Ca stone formers. CASR exon 7 single nucleotide polymorphisms (SNP), G/T at codon 986, G/A at codon 990, and C/G at codon 1011, were evaluated by PCR amplification and direct sequencing in 97 normocalciuric stone formers, 134 hypercalciuric stone formers, and 101 normocalciuric healthy controls. Four haplotypes were defined on the basis of CASR gene SNP: haplotype 1 was characterized by the most frequent sequence; haplotypes 2, 3, or 4 by the presence of a single polymorphic variant at codon 986, 990, or 1011, respectively. The relative risk of hypercalciuria was calculated with multinomial logistic regression and was significantly increased only in individuals carrying haplotype 3 (Odds ratio, 13.0 [95% confidence interval, 1.7 to 99.4]). Accordingly, Ca excretion was higher in subjects bearing haplotype 3, whereas those bearing haplotype 2 showed a slight increase of plasma Ca concentration. Multiple regression analysis showed that haplotype 3 explained 4.1% of the total variance of Ca excretion and 12.6% of the variance explained by the variables considered in the study. In conclusion, CASR gene could be a component of the complex genetic background regulating Ca excretion. Arg990Gly polymorphism could facilitate activation of CaSR and increase Ca excretion and susceptibility to idiopathic hypercalciuria

    Gemcitabine-induced systemic capillary leak syndrome

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    Systemic capillary leak syndrome (SCLS) is a rare disorder with a high mortality rate, characterized by rapidly developing edema, weight gain and hypotension, hemoconcentration and hypoproteinemia. This syndrome is caused by sudden, reversible capillary hyperpermeability with a rapid extravasation of plasma from the intravascular to the interstitial space. Even though SCLS has been suggested to be the pathogenic mechanism for the pulmonary toxicity of gemcitabine (GCB), a new deoxycytidine analogue with structural similarities to cytosine arabinoside, a direct correlation between GCB and SCLS has never been reported. We describe a case of repeated SCLS after GCB administration in a 51-year-old male with locally-advanced non-small-cell lung cancer treated with a combination of cisplatin and GCB. The detection of GCB-induced SCLS supports the hypothesis that SCLS could be the pathogenic way of GCB pulmonary toxicity. This finding can help to better understand and treat the potentially deadly GCB-related acute respiratory distress syndrome that is being recognize

    The Roman centuriated landscape: conception, genesis and development as inferred from the Ager Tarraconensis case

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    Although centuriation was only one system of Roman land division, its impact on the landscape and its visibility in modern field arrangements make it the most commonly recognized expression of Roman landscapes. Centuriated grid systems are usually analyzed from a materialistic point of view and consequently regarded as an assertion of Roman dominance over conquered territories. In this sense, their productive function is clear. The hinterland of Tarraco (the ancient capital of the Roman province of Tarraconensis) offers one of the most clearly documented examples of multiple-grid centuriated systems. From 2006 to 2010, the Landscape Archaeology Research Group (GIAP) of the Catalan Institute of Classical Archaeology employed a wide array of digital and field methodologies at Tarraco to record the traces of centuriated land divisions and their Roman origin. Most importantly, these methods have allowed research to move beyond pure description of the traces to explore the concepts and ideas behind the making of a centuriated landscape. By using Tarraco as a case study, this article shows how centuriation was not only a system for dividing the land but also a conceptual appropriation of the landscape based on a strong mythical and religious backgroun

    Robotic Wireless Sensor Networks

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    In this chapter, we present a literature survey of an emerging, cutting-edge, and multi-disciplinary field of research at the intersection of Robotics and Wireless Sensor Networks (WSN) which we refer to as Robotic Wireless Sensor Networks (RWSN). We define a RWSN as an autonomous networked multi-robot system that aims to achieve certain sensing goals while meeting and maintaining certain communication performance requirements, through cooperative control, learning and adaptation. While both of the component areas, i.e., Robotics and WSN, are very well-known and well-explored, there exist a whole set of new opportunities and research directions at the intersection of these two fields which are relatively or even completely unexplored. One such example would be the use of a set of robotic routers to set up a temporary communication path between a sender and a receiver that uses the controlled mobility to the advantage of packet routing. We find that there exist only a limited number of articles to be directly categorized as RWSN related works whereas there exist a range of articles in the robotics and the WSN literature that are also relevant to this new field of research. To connect the dots, we first identify the core problems and research trends related to RWSN such as connectivity, localization, routing, and robust flow of information. Next, we classify the existing research on RWSN as well as the relevant state-of-the-arts from robotics and WSN community according to the problems and trends identified in the first step. Lastly, we analyze what is missing in the existing literature, and identify topics that require more research attention in the future

    Solving the Task Variant Allocation Problem in Distributed Robotics

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    We consider the problem of assigning software processes (or tasks) to hardware processors in distributed robotics environments. We introduce the notion of a task variant, which supports the adaptation of software to specific hardware configurations. Task variants facilitate the trade-off of functional quality versus the requisite capacity and type of target execution processors. We formalise the problem of assigning task variants to processors as a mathematical model that incorporates typical constraints found in robotics applications; the model is a constrained form of a multi-objective, multi-dimensional, multiple-choice knapsack problem. We propose and evaluate three different solution methods to the problem: constraint programming, a constructive greedy heuristic and a local search metaheuristic. Furthermore, we demonstrate the use of task variants in a real instance of a distributed interactive multi-agent navigation system, showing that our best solution method (constraint programming) improves the system’s quality of service, as compared to the local search metaheuristic, the greedy heuristic and a randomised solution, by an average of 16, 31 and 56% respectively

    BAG3: a multifaceted protein that regulates major cell pathways

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    Bcl2-associated athanogene 3 (BAG3) protein is a member of BAG family of co-chaperones that interacts with the ATPase domain of the heat shock protein (Hsp) 70 through BAG domain (110–124 amino acids). BAG3 is the only member of the family to be induced by stressful stimuli, mainly through the activity of heat shock factor 1 on bag3 gene promoter. In addition to the BAG domain, BAG3 contains also a WW domain and a proline-rich (PXXP) repeat, that mediate binding to partners different from Hsp70. These multifaceted interactions underlie BAG3 ability to modulate major biological processes, that is, apoptosis, development, cytoskeleton organization and autophagy, thereby mediating cell adaptive responses to stressful stimuli. In normal cells, BAG3 is constitutively present in a very few cell types, including cardiomyocytes and skeletal muscle cells, in which the protein appears to contribute to cell resistance to mechanical stress. A growing body of evidence indicate that BAG3 is instead expressed in several tumor types. In different tumor contexts, BAG3 protein was reported to sustain cell survival, resistance to therapy, and/or motility and metastatization. In some tumor types, down-modulation of BAG3 levels was shown, as a proof-of-principle, to inhibit neoplastic cell growth in animal models. This review attempts to outline the emerging mechanisms that can underlie some of the biological activities of the protein, focusing on implications in tumor progression

    Advanced health information technologies to engage parents, clinicians, and community nutritionists in coordinating responsive parenting care: Descriptive case series of the women, infants, and children enhancements to early healthy lifestyles for baby (WEE Baby) care randomized controlled trial

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    Background: Socioeconomically disadvantaged newborns receive care from primary care providers (PCPs) and Women, Infants, and Children (WIC) nutritionists. However, care is not coordinated between these settings, which can result in conflicting messages. Stakeholders support an integrated approach that coordinates services between settings with care tailored to patient-centered needs. Objective: This analysis describes the usability of advanced health information technologies aiming to engage parents in self-reporting parenting practices, integrate data into electronic health records to inform and facilitate documentation of provided responsive parenting (RP) care, and share data between settings to create opportunities to coordinate care between PCPs and WIC nutritionists. Methods: Parents and newborns (dyads) who were eligible for WIC care and received pediatric care in a single health system were recruited and randomized to a RP intervention or control group. For the 6-month intervention, electronic systems were created to facilitate documentation, data sharing, and coordination of provided RP care. Prior to PCP visits, parents were prompted to respond to the Early Healthy Lifestyles (EHL) self-assessment tool to capture current RP practices. Responses were integrated into the electronic health record and shared with WIC. Documentation of RP care and an 80-character, free-text comment were shared between WIC and PCPs. A care coordination opportunity existed when the dyad attended a WIC visit and these data were available from the PCP, and vice versa. Care coordination was demonstrated when WIC or PCPs interacted with data and documented RP care provided at the visit. Results: Dyads (N=131) attended 459 PCP (3.5, SD 1.0 per dyad) and 296 WIC (2.3, SD 1.0 per dyad) visits. Parents completed the EHL tool prior to 53.2% (244/459) of PCP visits (1.9, SD 1.2 per dyad), PCPs documented provided RP care at 35.3% (162/459) of visits, and data were shared with WIC following 100% (459/459) of PCP visits. A WIC visit followed a PCP visit 50.3% (231/459) of the time; thus, there were 1.8 (SD 0.8 per dyad) PCP to WIC care coordin
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