237 research outputs found

    Effectiveness of segment routing technology in reducing the bandwidth and cloud resources provisioning times in network function virtualization architectures

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    Network Function Virtualization is a new technology allowing for a elastic cloud and bandwidth resource allocation. The technology requires an orchestrator whose role is the service and resource orchestration. It receives service requests, each one characterized by a Service Function Chain, which is a set of service functions to be executed according to a given order. It implements an algorithm for deciding where both to allocate the cloud and bandwidth resources and to route the SFCs. In a traditional orchestration algorithm, the orchestrator has a detailed knowledge of the cloud and network infrastructures and that can lead to high computational complexity of the SFC Routing and Cloud and Bandwidth resource Allocation (SRCBA) algorithm. In this paper, we propose and evaluate the effectiveness of a scalable orchestration architecture inherited by the one proposed within the European Telecommunications Standards Institute (ETSI) and based on the functional separation of an NFV orchestrator in Resource Orchestrator (RO) and Network Service Orchestrator (NSO). Each cloud domain is equipped with an RO whose task is to provide a simple and abstract representation of the cloud infrastructure. These representations are notified of the NSO that can apply a simplified and less complex SRCBA algorithm. In addition, we show how the segment routing technology can help to simplify the SFC routing by means of an effective addressing of the service functions. The scalable orchestration solution has been investigated and compared to the one of a traditional orchestrator in some network scenarios and varying the number of cloud domains. We have verified that the execution time of the SRCBA algorithm can be drastically reduced without degrading the performance in terms of cloud and bandwidth resource costs

    Insight on collagen self-assembly mechanisms by coupling molecular dynamics and UV spectroscopy techniques

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    Self-assembly of rat tail collagen type I was investigated by means of turbidity measurements and molecular dynamics simulations. Turbidity curves collected at different pH values show that the rate of aggregation was not linear in dependence from pH, with the fastest kinetics at pH 5.0 and the lowest at neutral pH. MD simulations were carried out on two regions with different hydropathicity, monitoring the aggregation of up to four staggered tropocollagen fragments at different ionic strength. At physiological conditions, association of lowly charged regions occurs more easily than for highly charged ones, the latter seeming to aggregate in a sequential way. The first contacts indicate for both regions that the driving force is hydrophobic, the electrostatic contribution becoming relevant at short distance. The direct inter-tropocollagen H-bonds confirm that fibrillogenesis is driven by loss of surface water from the monomers and involves in large percentage hydroxyproline residues. Low ionic strength dynamics leads to the formation of incorrect assemblies, driven by not shielded pairwise charge interactions

    Creation of a Scholars Program in Dental Leadership (SPDL) for Dental and Dental Hygiene Students

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153552/1/jddj0022033720097310tb04805x.pd

    Dynamic in-network classification for service function chaining ready SDN networks

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    Service Function Chaining (SFC) paradigm consists in steering traffic flows through an ordered set of Service Functions (SFs) so that to realize complex end to end services. SFC architecture introduces all the logical functions that need to be developed in order to provide the required service. The SFC overlay infrastructure can be built on top of many different underlay network technologies. The high flexibility and centrally controlled feature of Software Defined Networking (SDN), make SDN networks to be a perfect underlay to build the SFC architecture. Due to Ternary Content Address Memory (TCAM) limited size, SDN switches have a limitation in the number of flow rules that can be hosted. This constraint is particularly penalizing in case of the SFC classifier function, since it requires to manage a high number of different flows. The limitation imposed by the TCAM size on the SFC classifier can be a bottleneck for the number of SFC requests that the SDN-based SFC architecture can handle. In this paper we define the Dynamic Chain Request Classification Offloading (D-CRCO) problem, as the one of maximizing the number of accepted SFC requests, having the possibility of: i) implement the SFC classifier also in a node that is internal to the SDN-based SFC domain, and ii) install classification rules in a reactive fashion. Furthermore, we propose the Dynamic Nearest Node (DNN) heuristic to solve the D-CRCO problem. Performance evaluation shows that by using DNN heuristic it is possible to triple the number of accepted requests, with respect to existing solutions

    Small Angle X-ray Scattering From Lipid-bound Myelin Basic Protein In Solution

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    The structure of myelin basic protein (MBP), purified from the myelin sheath in both lipid-free (LF-MBP) and lipid-bound (LB-MBP) forms, was investigated in solution by small angle x-ray scattering. The water-soluble LF-MBP, extracted at pH 7.0. Under all conditions, the scattering from the two protein forms was different, indicating different molecular shapes. For the LB-MBP, well-defined scattering curves were obtained, suggesting that the protein had a unique, compact (but not globular) structure. Furthermore, these data were compatible with earlier results from molecular modeling calculations on the MBP structure which have been refined by us. In contrast, the LF-MBP data were in accordance with the expected open-coil conformation. 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    The complex TIE between macrophages and angiogenesis

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    Macrophages are primarily known as phagocytic immune cells, but they also play a role in diverse processes, such as morphogenesis, homeostasis and regeneration. In this review, we discuss the influence of macrophages on angiogenesis, the process of new blood vessel formation from the pre-existing vasculature. Macrophages play crucial roles at each step of the angiogenic cascade, starting from new blood vessel sprouting to the remodelling of the vascular plexus and vessel maturation. Macrophages form promising targets for both pro- and anti-angiogenic treatments. However, to target macrophages, we will first need to understand the mechanisms that control the functional plasticity of macrophages during each of the steps of the angiogenic cascade. Here, we review recent insights in this topic. Special attention will be given to the TIE2-expressing macrophage (TEM), which is a subtype of highly angiogenic macrophages that is able to influence angiogenesis via the angiopoietin-TIE pathway

    Angiogenesis induced by tumor necrosis factor-agr; is mediated by α4 integrins

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    Tumor necrosis factor-α (TNF-α) and fibroblast growth factor-2 (FGF-2 or bFGF) are potent stimulators of angiogenesis. TNF-α, but not FGF-2, can induce the expression of vascular cell adhesion molecule-1 (VCAM-1) on the surface of endothelial cells. The soluble form of VCAM-1 has recently been demonstrated to function as an angiogenic mediator. Here we demonstrate that monoclonal antibodies directed against VCAM-1 or its α4 integrin counter-receptor inhibited TNF-α-induced endothelial cell migration in vitro. Angiogenesis induced in vivo in rat corneas by TNF-α was inhibited by a neutralizing antibody directed against the rat α4 integrin subunit. A peptide antagonist of the a4 integrins blocked TNF-α-induced endothelial cell migration in vitro and angiogenesis in rat corneas in vivo. No inhibition by the antibodies or peptide antagonist was observed either in vitro or in vivo when FGF-2 was used as the stimulus. The peptide antagonist did not inhibit TNF-a binding to its receptor nor did it block the function of αvÎČ3, an integrin previously implicated in TNF-a and FGF-2 mediated angiogenesis. These results demonstrate that angiogenic processes induced by TNF-α are mediated in part by agr;4 integrins possibly by a mechanism involving the induction of soluble VCAM-1.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41761/1/10456_2004_Article_188219.pd

    Informal and formal reconciliation strategies of older peoples’ working carers: the European carers@work project

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    Faced with a historically unprecedented process of demographic ageing, many European societies implemented pension reforms in recent years to extend working lives. Although aimed at rebalancing public pension systems, this approach has the unintended side effect that it also extends the number of years in which working carers have to juggle the conflicting demands of employment and caregiving. This not only impinges on working carers’ well-being and ability to continue providing care but also affects European enterprises’ capacity to generate growth which increasingly relies on ageing workforces. The focus of this paper will thus be a cross-national comparison of individual reconciliation strategies and workplace-related company policies aimed at enabling working carers to reconcile both conflicting roles in four different European welfare states: Germany, Italy, Poland, and the United Kingdom
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