101,962 research outputs found
Observing the Cosmic Web with the Sunyaev-Zel’dovich effect: from ACT to MISTRAL
No full textThis thesis work gravitates around the broad field of the large scale structure and its observation using the Sunyaev-Zel’dovich effect, an anisotropic spectral distortion of the CMB that causes a decrement in brightness when observing in the direction of an hot electron population, like the ones contained in galaxy clusters or in cosmic filaments. The first part of this thesis focuses on observing bridges between interacting clusters, i.e. filaments compressed by merging clusters, using data from the Atacama Cosmology Telescope. We survey a preliminary version of the ACT-DR6 cluster catalog in order to search for significant filaments between clusters, and to measure their average properties by stacking. The second part of this work instead focuses on observing clusters and filaments at higher resolution compared to CMB experiments, using high resolution millimeter cameras. We introduce the MISTRAL receiver and follow the steps of its development, from the laboratory calibration to the first observations at the focus of the Sardinia Radio Telescope
Cell capacity of LMDS systems in typical traffic scenarios
No full textBroadband access and multimedia technologies are expected to be primary drivers for the telecommunications market of the next few years. The increasing bandwidth needs, together with the plethora of different services and heterogeneous traffic flows, requires accurate methodologies for resource dimensioning, especially in the field of wireless technologies where efficient bandwidth usage is crucial. New methodologies need to be based on up-to-date traffic source modeling and usage scenarios. Therefore, in this article we propose a survey of statistical characterization of single traffic sources, QoS requirements and different traffic demands. When possible, we consider the aggregate traffic resulting from a large number of heavy tailed ON/OFF sources, relying on the theory of long-range dependent flows. This method is particularly useful when time- and resource-consuming simulations are needed in order to dimension the system resources, which is always the case in the multimedia scenarios of future networks. We use such a traffic framework to estimate by simulations the capacity of an LMDS system
Dual inoculation of Sorghum bicolor (L.) Moench. ssp. bicolor with arbuscular mycorrhizas and Acetobacter diazotrophicus
No full text
Roles of specialized pro-resolving lipid mediators in autophagy and inflammation
No full textAutophagy is a catabolic pathway that accounts for degradation and recycling of cellular components to extend cell survival under stress conditions. In addition to this prominent role, recent evidence indicates that autophagy is crucially involved in the regulation of the inflammatory response, a tightly controlled process aimed at clearing the inflammatory stimulus and restoring tissue homeostasis. To be efficient and beneficial to the host, inflammation should be controlled by a resolution program, since uncontrolled inflammation is the underlying cause of many pathologies. Resolution of inflammation is an active process mediated by a variety of mediators, including the so-called specialized pro-resolving lipid mediators (SPMs), a family of endogenous lipid autacoids known to regulate leukocyte infiltration and activities, and counterbalance cytokine production. Recently, regulation of autophagic mechanisms by these mediators has emerged, uncovering unappreciated connections between inflammation resolution and autophagy. Here, we summarize mechanisms of autophagy and resolution, focusing on the contribution of autophagy in sustaining paradigmatic examples of chronic inflammatory disorders. Then, we discuss the evidence that SPMs can restore dysregulated autophagy, hypothesizing that resolution of inflammation could represent an innovative approach to modulate autophagy and its impact on the inflammatory response
On the Implications of the OFF Period Distribution in two-State Traffic Models
No full textThe goal of the letter is to highlight the impact of the
inactive period distribution of an ON–OFF source on the autocor relation structure of the model. In particular, two discrete-time
ON–OFF models, both with geometric distribution of the active
period, are considered: the GeoGeo Model (GGM) and the
ParetoGeo Model (PGM), characterized by a geometric and
Pareto-like distribution of the OFF periods length, respectively.
The two models are compared in terms of their main statistical
features as well as queueing impact. The asymptotic behavior
of the autocorrelation function for the proposed PGM has been
analytically evaluated. It is shown it has a hyperbolic decay
related to the tail behavior of the OFF periods distribution
Resolvin D1 improves airway inflammation and exercise capacity in cystic fibrosis lung disease.
No full textMucus plugging and non-resolving inflammation are inherent features of cystic fibrosis (CF) that may lead to progressive lung disease and exercise intolerance, which are the main causes of morbidity and mortality for people with CF. Therefore, understanding the influence of mucus on basic mechanisms underlying the inflammatory response and identifying strategies to resolve mucus-driven airway inflammation and consequent morbidity in CF are of wide interest. Here, we investigated the effects of the proresolving lipid mediator resolvin (Rv) D1 on mucus-related inflammation as a proof-of-concept to alleviate the burden of lung disease and restore exercise intolerance in CF. We tested the effects of RvD1 on inflammatory responses of human organotypic airways and leukocytes to CF mucus and of humanized mice expressing the epithelial Na + channel (βENaC-Tg) having CF-like mucus obstruction, lung disease, and physical exercise intolerance. RvD1 reduced pathogenic phenotypes of CF-airway supernatant (ASN)-stimulated human neutrophils, including loss of L-selectin shedding and CD16. RNASeq analysis identified select transcripts and pathways regulated by RvD1 in ASN-stimulated CF bronchial epithelial cells that are involved in sugar metabolism, NF-κB activation and inflammation, and response to stress. In in vivo inflammation using βENaC TG mice, RvD1 reduced total leukocytes, PMN, and interstitial Siglec-MΦ when given at 6-8 weeks of age, and in older mice at 10-12 weeks of age, along with the decrease of pro-inflammatory chemokines and increase of anti-inflammatory IL-10. Furthermore, RvD1 treatment promoted the resolution of pulmonary exacerbation caused by Pseudomonas aeruginosa infection and significantly enhanced physical activity and energy expenditure associated with mucus obstruction, which was impaired in βENaC-Tg mice compared with wild-type. These results demonstrate that RvD1 can rectify features of CF and offer proof-of-concept for its therapeutic application in this and other muco-obstructive lung diseases
Thin Coatings of Polymer of Intrinsic Microporosity (PIM-1) Enhance Nickel Electrodeposition and Nickel-Catalyzed Hydrogen Evolution
No full textNickel nanoparticle electrodeposition is studied on flat glassy carbon (GC) or on nitrogen-doped reduced graphene oxide (rGO-N) substrates. The effects of a very thin (nominally 16 nm) layer polymer of intrinsic microporosity (PIM-1) are investigated (i) on enhancing nickel nanoparticle nucleation and growth during electrodeposition and (ii) on enhancing hydrogen evolution electrocatalysis. Beneficial effects are tentatively assigned to PIM-1 suppressing blocking effects from interfacial hydrogen bubble formation. Exploratory data suggest that in aqueous 0.5 M NaCl solution (artificial seawater) nickel nano-particles grown into a thin film of PIM-1 could be a viable electrocatalyst with an onset of hydrogen evolution only slightly negative compared to that observed for platinum nanoparticles
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