2,567 research outputs found
NETEMBED: A Network Resource Mapping Service for Distributed Applications
Emerging configurable infrastructures such as large-scale overlays and grids, distributed testbeds, and sensor networks comprise diverse sets of available computing resources (e.g., CPU and OS capabilities and memory constraints) and network conditions (e.g., link delay, bandwidth, loss rate, and jitter) whose characteristics are both complex and time-varying. At the same time, distributed applications to be deployed on these infrastructures exhibit increasingly complex constraints and requirements on resources they wish to utilize. Examples include selecting nodes and links to schedule an overlay multicast file transfer across the Grid, or embedding a network experiment with specific resource constraints in a distributed testbed such as PlanetLab. Thus, a common problem facing the efficient deployment of distributed applications on these infrastructures is that of "mapping" application-level requirements onto the network in such a manner that the requirements of the application are realized, assuming that the underlying characteristics of the network are known. We refer to this problem as the network embedding problem. In this paper, we propose a new approach to tackle this combinatorially-hard problem. Thanks to a number of heuristics, our approach greatly improves performance and scalability over previously existing techniques. It does so by pruning large portions of the search space without overlooking any valid embedding. We present a construction that allows a compact representation of candidate embeddings, which is maintained by carefully controlling the order via which candidate mappings are inserted and invalid mappings are removed. We present an implementation of our proposed technique, which we call NETEMBED – a service that identify feasible mappings of a virtual network configuration (the query network) to an existing real infrastructure or testbed (the hosting network). We present results of extensive performance evaluation experiments of NETEMBED using several combinations of real and synthetic network topologies. Our results show that our NETEMBED service is quite effective in identifying one (or all) possible embeddings for quite sizable queries and hosting networks – much larger than what any of the existing techniques or services are able to handle.National Science Foundation (CNS Cybertrust 0524477, NSF CNS NeTS 0520166, NSF CNS ITR 0205294, EIA RI 0202067
In Vitro Impact of Triatomine Salivary Glands Extracts Introduced to Endothelial Cells
Chagas Disease (AKA Trypanosomiasis) is caused by biting/feeding behavior from the arthropod vector Triatoma (subfamily of Reduviidae family), that house the endoparasite Trypanosoma cruzi, which can then be passed to human and mammalian hosts (Schmidt, et al., 2011). Resources are currently being utilized to help minimize the effects and susceptibility of Chagas within endemic areas. Previous research has demonstrated that there are biochemical interactions between specific Triatoma salivary proteins and host cells (Ribeiro, Assumpção, Van Pham, Francischetti, & Reisenman, 2012).This study examined the interactions made from salivary proteins procured from the T. sanguisuga and T. indictiva species with the expression of two glycoproteins, fibronectin (angiogenic) and thrombospondin (antiangiogenic) when exposed to Human Umbilical Vein Endothelial Cells (HUVECs)
Cytokines Gene Expression on Macrophages Exposed to Triatoma Salivary Gland Extracts
Triatoma sanguisuga and Triatoma Indictiva are vectors of Chagas disease. These two vectors goes to the host and bites down to feed on blood, which is necessary for the egg laying process. The disease however is not spread through their bite, but through their feces. When they become full of blood, they defecate and that is where the parasite is. The parasite is then introduced into the skin when the host scratches at the bite and feces enter the skin. An estimated 8 million people worldwide are infected with T Cruzi, and the United States has the 7th highest prevalence of Chagas infections. The Macrophages produces cytokines including TNF (Tumoral Necrosis Factor), IL-10 and IL-18 in responses to danger or infections, the function include tissue inflammation and destruction
Foreland basins: lithospheric flexure, plate strength and regional stratigraphy
Foreland basin subsidence through time is reproduced in this study, as the flexure of an elastic beam in an inviscid fluid under the vertical stress, caused by discrete-distributed loads. Thus, seismostratigraphic data from the Timor Sea peripheral foreland basin, in northwestern Australia, and the Putumayo retroarc foreland basin in the Colombian Andes, are forward modeled, at chronostratigraphic intervals, to assess the evolving geodynamic conditions of the basins. Results show that the accommodation in foreland basins varies as the depositional basement is vertically adjusted according to the regionally isostatic compensation of the lithosphere. Distributed tectonic (thrust belts) and sedimentary loads that act independently but consecutively during tectono-stratigraphic events, throughout the evolution of foreland basins, control the deflection of the plate that forms the foredeep of these depocenters. Accordingly, the loads limit the amount and distribution of available space for sedimentation. Results also reduce the role of eustasy to only 2 to 6% of the total accommodation, even in marine foreland depocenters. The strength of the plate remains invariable during the evolution of the basin at time scales of 106 to 107 m.y. Asymmetrical flexure, produced by oblique plate convergence, induces diachronuous and local marine cycles at basin scale (100’s of km). Stratigraphic development of non-marine foreland basins is more likely to respond to the evolution of the equilibrium-profile during basin history
Neuronal in vitro impact of Amblyommaamericanumsalivary glands extracts
When a tick feeds off a host, the salivary glands of the tick excrete saliva to assist the tick in feeding (1). The reason saliva assists the tick in consuming its blood meal is due to its immunosuppressive, anti-inflammatory, and anti-coagulant properties (2).Tick salivary glands also play an important role in the transmission of tick-borne pathogens (3). We wanted to investigate the effect of tick salivary gland extracts (SGE) on human neurons. For our experiment, the organism whose salivary gland extract we used was the Amblyomma americanum. We compared the effects of salivary gland extract from ticks collected in the field and ticks reared in a lab colony. Our results showed that the salivary gland extract from the two types of ticks affected the neurons differently, and the salivary gland extract of the field tick was more damaging to the neurons. This indicates that SGE from field ticks, together with infectious agents, could result in a more severe neuronal impairment in a human host than the infectious agent alone
Encuadres retĂłrico-polĂticos en la ley de vĂctimas y restituciĂłn de tierras en Colombia
The Law 1448 of Victims and Land Restitution, in force since January 2012, is one of the main flagship programmes of the reelected Colombian President Juan Manuel Santos aimed at settling an historical debt with the victims of the armed conflict. Drawing on qualitative analysis, the article identifies competing rhetorical frames embedded in the discursive strategies of politicians, economic groups, academics, NGOs and FARC. The Article illustrates the contribution of rhetorical analysis to framing analysis. At the same time, it argues for the effectiveness of frames when these are based on tropes and rhetorical figures such as the metaphor and the irony, whose argumentative schemes result from a critic and creative exercise contributing to unveil the truth
Explaining and predicting the single channel versus multi-channel consumer: the case of an embarrassing product
The fundamental purpose of this thesis was to determine how effective is the theory of planned behaviour (TPB) to predict and explain shopping for embarrassing products in single and multi-channel. This is important because multi-channel consumers buy more, the question is why (Neslin, Grewal et al. 2006). The question was answered by comparing consumer behaviour in three different channels: drugstore, internet and multi-channel.
The Theory of Planned Behaviour (TPB) has been successful to predict intentions for a wide variety of products and behaviours. However, little is known about how effective it is when the behaviour under study is influenced by the emotion of embarrassment. Similarly, the TPB is parsimonious and has a good predictive power; nevertheless, this thesis identified that the TPB could be more effective if it considered: (1) the role of positive and negative emotions (2) other determinants of choice like personality and demographics (3) variables that are useful to make marketing decisions like the synergistic effect of brands, retailers and channels (4) variables that explain consumer response like approach and avoidance.
To provide a comprehensive theoretical framework that is able to understand single and multi-channel, this thesis integrated the TPB within the Stimulus-Organism-Response (S-O-R) framework.
To evaluate the proposed model, the study used a context and target product that resonated with the theory: the purchase of Regaine (a hair loss product that is embarrassing to buy) in Boots (a well-known UK. multi-channel drugstore). The embarrassing nature of Regaine created differences in the importance that variables play in each channel.
The results were analysed using partial least squares structural equation modelling (PLS-SEM) and the three shopping environments were compared using multi-group analysis (MGA).
The effectiveness of the TPB was improved. The variance explained (R² to intention) was 73 percent for the drugstore, 67 percent for the internet and 54 percent for multi-channel. However, subjective norm (SN) was the only factor that achieved significance for the three shopping environments. Personality and demographic factors had a low but significant moderating effect on intention.
This thesis built on a series of contributions in different areas, such as the TPB, attitudes, subjective norm, perceived behavioural control, embarrassing products, multi-channel, marketing, emotions, personality and demographics.
Future research should expand this thesis to other embarrassing products, industries and social media settings
Photosystem II is a chimera of reaction centers
A complete scenario for the evolution of photosynthesis must account for the origin and diversification of photochemical reaction centers. Two lively debated questions are how the distinct types of reaction centers evolved and how cyanobacteria acquired two distinct reaction centers—Photosystem I and Photosystem II—in the path towards the origin of light-driven water oxidation, or in other words, towards the evolution of oxygenic photosynthesis (Hohmann-Marriott and Blankenship 2011; Fischer et al. 2016). Here I show how the chimeric structure of Photosystem II provides unambiguous answer to these questions
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