87 research outputs found
Introduction: What we do and do not know regarding redox processes of thiols in signaling pathways
Due to their susceptibility towards redox modification, protein thiols represent primary targets for the modulation of protein activity, conformation and oligomerization. Until fairly recently, such modifications were considered âdamageâ as a result of oxidative stress, before researchers recognized their physiological importance for biologic signaling. This paradigm shift, and the associated necessity to accurately characterize and quantify the various pathways of thiol redox modifications not only for specific proteins, but also within the cellular environment, has enticed researchers to take a close look at the impact of environment and molecular (protein) structure on these reactions. This Special Issue on Redox Biology of Thiols in Signaling Pathways is the result of a workshop organized at the 2013 Annual Meeting of the Society for Free Radical Biology and Medicine in San Antonio, Texas, summarizing the contributions from many of the presenters. It will provide a stimulating synopsis on what is known, and what is not known, about the reaction mechanisms which underlie the role of thiols and oxidative processes in signaling pathways
Measurement of the Atmospheric Muon Spectrum from 20 to 3000 GeV
The absolute muon flux between 20 GeV and 3000 GeV is measured with the L3
magnetic muon spectrometer for zenith angles ranging from 0 degree to 58
degree. Due to the large exposure of about 150 m2 sr d, and the excellent
momentum resolution of the L3 muon chambers, a precision of 2.3 % at 150 GeV in
the vertical direction is achieved.
The ratio of positive to negative muons is studied between 20 GeV and 500
GeV, and the average vertical muon charge ratio is found to be 1.285 +- 0.003
(stat.) +- 0.019 (syst.).Comment: Total 32 pages, 9Figure
GDTN: Genome-Based Delay Tolerant Network Formation in Heterogeneous 5G Using Inter-UA Collaboration
This work was supported by âThe Cross-Ministry Giga KOREA Projectâ grant from the Ministry of Science, ICT and Future Planning, Korea. Also, it was in part supported by the Soonchunhyang University Research Fund.With a more Internet-savvy and sophisticated user base, there are more demands for interactive applications and services. However, it is a challenge for existing radio access networks (e.g. 3G and 4G) to cope with the increasingly demanding requirements such as higher data rates and wider coverage area. One potential solution is the inter-collaborative deployment of multiple radio devices in a 5G setting designed to meet exacting user demands, and facilitate the high data rate requirements in the underlying networks. These heterogeneous 5G networks can readily resolve the data rate and coverage challenges. Networks established using the hybridization of existing networks have diverse military and civilian applications. However, there are inherent limitations in such networks such as irregular breakdown, node failures, and halts during speed transmissions. In recent years, there have been attempts to integrate heterogeneous 5G networks with existing ad hoc networks to provide a robust solution for delay-tolerant transmissions in the form of packet switched networks. However, continuous connectivity is still required in these networks, in order to efficiently regulate the flow to allow the formation of a robust network. Therefore, in this paper, we present a novel network formation consisting of nodes from different network maneuvered by Unmanned Aircraft (UA). The proposed model utilizes the features of a biological aspect of genomes and forms a delay tolerant network with existing network models. This allows us to provide continuous and robust connectivity. We then demonstrate that the proposed network model has an efficient data delivery, lower overheads and lesser delays with high convergence rate in comparison to existing approaches, based on evaluations in both real-time testbed and simulation environment.Yeshttp://www.plosone.org/static/editorial#pee
Rock glaciers and mountain hydrology: A review
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.In mountainous regions, climate change threatens cryospheric water resources, and understanding all components of the hydrological cycle is necessary for effective water resource management. Rockglaciers are climatically more resilient than glaciers and contain potentially hydrologically valuable ice volumes, and yet havereceived lessattention, even though rock glacier hydrologicalimportance may increase under future climate warming. In synthesising data from a range of global studies, we provide the first compre-hensive evaluation of the hydrological role played by rock glaciers. Weevaluate hydrological significanceover a range of temporal and spatial scales, alongsidethe complex multiple hydrological processes with which rock glaciers can interact diurnally, seasonally, annually, decadally and both at local and regional extents.We report that although no global-extent, complete inventory for rock glaciers exists currently, recent research efforts have greatly elaborated spatialcoverage.Using these research papers,we synthe-sise information on rock glacier spatial distribution, morphometric characteristics, surface and subsurface features, ice-storage and hydrological flow dynamics, water chemistry, and future resilience, from which we provide the first comprehensive evaluation of their hydrological contribution. We identify and discuss long-, intermediate-and short-term timescales for rock glacier storage, allowing a more balanced assess-ment of the contrasting perspectives regarding the relative significance of rock glacier-derived hydrological contributions compared to other water sources.We show that further empirical observations are required to gain a deeper hydrological understanding of rock glaciers, in terms of(i) their genesis and geomorpho-logical dynamics (ii) total ice/water volume; (iii) water discharge; and (iv) water quality. Lastly, we hypothesisethat at decadal and longer timescales, under future climate warming, degradation of ice within rock glaciers may represent an increasing hydrological contribution to downstream regions, and thus in-creased hydrological significance while rock glacier water stores persist.Royal Geographical SocietyNatural Environment Research Council (NERC
Fatigue precracking and fracture toughness testing of TiAl intermetallics
The fatigue crack initiation and growth in as-cast, two-phase near gamma (#gamma#) TiAl aloys with and without 2 at% Cr were studied. Prefatigued single edge notch bend (SENB) and compact tension (CT) specimens were tested at room temperature and 700 C to determine the fracture toughness of the alloys. The effect of microstructure on the deformation, crack initiation and propagation were studied on the side and fracture surfaces of the specimens tested. The fatigue precracks generated by cyclic compression in SENB specimens were initiated at a grain boundary, grew up to 50 #mu#m in size before they became arrested. Extensive damage and microcracks of 20-30 #mu#m length were observed at the notch tip. However, both SENB and CT specimens were successfully fatigue precracked in cyclic tension. The cracks were initiated at stress intensity factor (K) levels of 9 MPa#sq root#m and 20 MPa#sq root#m in SENB and CT specimens, respectively. The fatigue cracks were then arrested after 0.8-1.0 mm growth. Crack growth occurred with increased load, with associated increased deformation particularly in the #gamma# phase, as well as crack branching and crack deviation in lamellae. SEM (Scanning Electron Microscope) examination of fracture surfaces showed that the fatigue fracture surface was not distinguishable from the rest of the fracture surface, where the fracture mode in both regions was brittle. Thus, crack initiation and growth are strongly affected by the microstructural component and the orientation of the lamellae at the notch tip. The composite-like fracture behaviour of the material with large lamellar grains leads to higher initiation toughness due to increased fracture surface roughness and crack deviation in lamellae. (orig.)Also published in Intermetallics (1996) v. 4 p. 61-69Available from TIB Hannover: RA 3251(96/E/10) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
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