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61.
As group applications are becoming widespread, efficient network utilization becomes a growing concern. Multicast transmission represents a necessary lower network service for the wide diffusion of new multimedia network applications. Multicast transmission may use network resources more efficiently than multiple point-to-point messages; however, creating optimal multicast trees (Steiner Tree Problem in networks) is prohibitively expensive. This paper proposes a distributed algorithm for the heuristic solution of the Steiner Tree Problem, allowing the construction of effective distribution trees using a coordination protocol among the network nodes. Furthermore, we propose a novel distributed technique for dynamically updating the multicast tree. The approach proposed has been implemented and extensively tested both in simulation, and on experimental networks. Performance evaluation indicates that the distributed algorithm performs as well as the centralized version, providing good levels of convergence time and communication complexity. 相似文献
62.
Ian Stoppa Casimiro Luca Gigliotti Nausicaa Clemente Deepika Pantham Chiara Dianzani Chiara Monge Chiara Puricelli Roberta Rolla Salvatore Sutti Filippo Ren Renzo Boldorini Elena Boggio Umberto Dianzani 《International journal of molecular sciences》2022,23(13)
Background: ICOS and its ligand ICOSL are immune receptors whose interaction triggers bidirectional signals that modulate the immune response and tissue repair. Aim: The aim of this study was to assess the in vivo effects of ICOSL triggering by ICOS-Fc, a recombinant soluble form of ICOS, on skin wound healing. Methods: The effect of human ICOS-Fc on wound healing was assessed, in vitro, and, in vivo, by skin wound healing assay using ICOS−/− and ICOSL−/− knockout (KO) mice and NOD-SCID-IL2R null (NSG) mice. Results: We show that, in wild type mice, treatment with ICOS-Fc improves wound healing, promotes angiogenesis, preceded by upregulation of IL-6 and VEGF expression; increases the number of fibroblasts and T cells, whereas it reduces that of neutrophils; and increases the number of M2 vs. M1 macrophages. Fittingly, ICOS-Fc enhanced M2 macrophage migration, while it hampered that of M1 macrophages. ICOS−/− and ICOSL−/− KO, and NSG mice showed delayed wound healing, and treatment with ICOS-Fc improved wound closure in ICOS−/− and NSG mice. Conclusion: These data show that the ICOS/ICOSL network cooperates in tissue repair, and that triggering of ICOSL by ICOS-Fc improves cutaneous wound healing by increasing angiogenesis and recruitment of reparative macrophages. 相似文献
63.
The generation of realistic spatio-temporal trajectories of human mobility is of fundamental importance in a wide range of applications, such as the developing of protocols for mobile ad-hoc networks or what-if analysis in urban ecosystems. Current generative algorithms fail in accurately reproducing the individuals’ recurrent schedules and at the same time in accounting for the possibility that individuals may break the routine during periods of variable duration. In this article we present Ditras (DIary-based TRAjectory Simulator), a framework to simulate the spatio-temporal patterns of human mobility. Ditras operates in two steps: the generation of a mobility diary and the translation of the mobility diary into a mobility trajectory. We propose a data-driven algorithm which constructs a diary generator from real data, capturing the tendency of individuals to follow or break their routine. We also propose a trajectory generator based on the concept of preferential exploration and preferential return. We instantiate Ditras with the proposed diary and trajectory generators and compare the resulting algorithm with real data and synthetic data produced by other generative algorithms, built by instantiating Ditras with several combinations of diary and trajectory generators. We show that the proposed algorithm reproduces the statistical properties of real trajectories in the most accurate way, making a step forward the understanding of the origin of the spatio-temporal patterns of human mobility. 相似文献
64.
Luca Dall’Asta Ignacio Alvarez-Hamelin Alain Barrat Alexei Vázquez Alessandro Vespignani 《Theoretical computer science》2006
Mapping the Internet generally consists in sampling the network from a limited set of sources by using traceroute-like probes. This methodology, akin to the merging of different spanning trees to a set of destination, has been argued to introduce uncontrolled sampling biases that might produce statistical properties of the sampled graph which sharply differ from the original ones. In this paper, we explore these biases and provide a statistical analysis of their origin. We derive an analytical approximation for the probability of edge and vertex detection that exploits the role of the number of sources and targets and allows us to relate the global topological properties of the underlying network with the statistical accuracy of the sampled graph. In particular, we find that the edge and vertex detection probability depends on the betweenness centrality of each element. This allows us to show that shortest path routed sampling provides a better characterization of underlying graphs with broad distributions of connectivity. We complement the analytical discussion with a throughout numerical investigation of simulated mapping strategies in network models with different topologies. We show that sampled graphs provide a fair qualitative characterization of the statistical properties of the original networks in a fair range of different strategies and exploration parameters. Moreover, we characterize the level of redundancy and completeness of the exploration process as a function of the topological properties of the network. Finally, we study numerically how the fraction of vertices and edges discovered in the sampled graph depends on the particular deployements of probing sources. The results might hint the steps toward more efficient mapping strategies. 相似文献
65.
Silvio Borrelli Ida Matarazzo Eugenio Lembo Laura Peccarino Claudia Annoiato Maria Rosaria Scognamiglio Andrea Foderini Chiara Ruotolo Aldo Franculli Federica Capozzi Pavlo Yavorskiy Fatme Merheb Michele Provenzano Gaetano La Manna Luca De Nicola Roberto Minutolo Carlo Garofalo 《International journal of molecular sciences》2022,23(12)
Increasing potassium intake ameliorates blood pressure (BP) and cardiovascular (CV) prognoses in the general population; therefore the World Health Organization recommends a high-potassium diet (90–120 mEq/day). Hyperkalaemia is a rare condition in healthy individuals due to the ability of the kidneys to effectively excrete dietary potassium load in urine, while an increase in serum K+ is prevalent in patients with chronic kidney disease (CKD). Hyperkalaemia prevalence increases in more advanced CKD stages, and is associated with a poor prognosis. This scenario generates controversy on the correct nutritional approach to hyperkalaemia in CKD patients, considering the unproven link between potassium intake and serum K+ levels. Another concern is that drug-induced hyperkalaemia leads to the down-titration or withdrawal of renin-angiotensin system inhibitors (RASI) and mineralocorticoids receptors antagonists (MRA) in patients with CKD, depriving these patients of central therapeutic interventions aimed at delaying CKD progression and decreasing CV mortality. The new K+-binder drugs (Patiromer and Sodium-Zirconium Cyclosilicate) have proven to be adequate and safe therapeutic options to control serum K+ in CKD patients, enabling RASI and MRA therapy, and possibly, a more liberal intake of fruit and vegetables. 相似文献
66.
Silvia Carra Germano Gaudenzi Alessandra Dicitore Maria Celeste Cantone Alice Plebani Davide Saronni Silvia Zappavigna Michele Caraglia Alessia Candeo Andrea Bassi Luca Persani Giovanni Vitale 《International journal of molecular sciences》2022,23(15)
Lung carcinoids are neuroendocrine tumors that comprise well-differentiated typical (TCs) and atypical carcinoids (ACs). Preclinical models are indispensable for cancer drug screening since current therapies for advanced carcinoids are not curative. We aimed to develop a novel in vivo model of lung carcinoids based on the xenograft of lung TC (NCI-H835, UMC-11, and NCI-H727) and AC (NCI-H720) cell lines and patient-derived cell cultures in Tg(fli1a:EGFP)y1 zebrafish embryos. We exploited this platform to test the anti-tumor activity of sulfatinib. The tumorigenic potential of TC and AC implanted cells was evaluated by the quantification of tumor-induced angiogenesis and tumor cell migration as early as 24 h post-injection (hpi). The characterization of tumor-induced angiogenesis was performed in vivo and in real time, coupling the tumor xenograft with selective plane illumination microscopy on implanted zebrafish embryos. TC-implanted cells displayed a higher pro-angiogenic potential compared to AC cells, which inversely showed a relevant migratory behavior within 48 hpi. Sulfatinib inhibited tumor-induced angiogenesis, without affecting tumor cell spread in both TC and AC implanted embryos. In conclusion, zebrafish embryos implanted with TC and AC cells faithfully recapitulate the tumor behavior of human lung carcinoids and appear to be a promising platform for drug screening. 相似文献
67.
Giulia Poli Consuelo Fabi Chiara Sugoni Marina Maria Bellet Claudio Costantini Giovanni Luca Stefano Brancorsini 《International journal of molecular sciences》2022,23(9)
Varicocele (VC) is the most common abnormality identified in men evaluated for hypofertility. Increased levels of reactive oxygen species (ROS) and reduced antioxidants concentrations are key contributors in varicocele-mediated hypofertility. Moreover, inflammation and alterations in testicular immunity negatively impact male fertility. In particular, NLRP3 inflammasome activation was hypothesized to lead to seminal inflammation, in which the levels of specific cytokines, such as IL-1β and IL-18, are overexpressed. In this review, we described the role played by oxidative stress (OS), inflammation, and NLRP3 inflammasome activation in VC disease. The consequences of ROS overproduction in testis, including inflammation, lipid peroxidation, mitochondrial dysfunction, chromatin damage, and sperm DNA fragmentation, leading to abnormal testicular function and failed spermatogenesis, were highlighted. Finally, we described some therapeutic antioxidant strategies, with recognized beneficial effects in counteracting OS and inflammation in testes, as possible therapeutic drugs against varicocele-mediated hypofertility. 相似文献
68.
Nowadays two main approaches are being pursued to reduce energy consumption of networks: the use of sleep modes in which devices enter a low-power state during inactivity periods, and the adoption of energy proportional mechanisms where the device architecture is designed to make energy consumption proportional to the actual load. Common to all the proposals is the evaluation of energy saving performance by means of simulation or experimental evidence, which typically consider a limited set of benchmarking scenarios. 相似文献
69.
Chiara Manneschi Paola Fanzio Elena Angeli Giuseppe Firpo Luca Ceseracciu Valentina Mussi Luca Repetto Ugo Valbusa 《Microfluidics and nanofluidics》2013,14(1-2):21-30
Peculiar transport phenomena appear at nanoscale, since surface effects strongly affect the behaviour of fluids. Electrostatic and steric interactions, capillary forces and entropic effects play a key role in the behaviour of fluids and biomolecules. Since these effects strongly depend on the size of the nanofluidic system, a careful characterization of the fluidic environment is necessary. Moreover, the possibility to dynamically modulate the size of nanochannels is very appealing in the field of biomolecule manipulation. Recently, we have developed a lab-on-chip made of poly(dimethylsiloxane) (PDMS). This polymeric device is based on a tuneable nanochannel able to dynamically change its dimension in order to fit the application of interest. In fact, a mechanical compression applied on the top of the elastomeric device squeezes the nanochannel, reducing the channel cross section and allowing a dynamical optimization of the nanostructures. In this paper, this squeezing process is fully characterized both numerically and experimentally. This analysis provides information on the reduction of the nanochannel dimensions induced by compression as a function of the work of adhesion and of the stiffness of the materials composing the device. Moreover, calculations demonstrate the possibility to predict the change of the nanochannel size and shape induced by the compression. The possibility to dynamically tune the channel size opens up new opportunities in biomolecular sensing or sieving and in the study of new hydrodynamics effects. 相似文献
70.
项目地点:沙特阿拉伯利雅得项目类型:建筑(住宅)开工日期:未知该项目获2005年豪瑞可持续建筑大奖赛非洲中东地区提名奖 相似文献