26 research outputs found
Paleoearthquakes and slip rates of the North Tabriz Fault, NW Iran: preliminary results
The North Tabriz Fault is a major seismogenic fault in NW Iran. The last damaging earthquakes on this fault
occurred in 1721, rupturing the southeastern fault segment, and in 1780, rupturing the northwestern one. The
understanding of the seismic behavior of this fault is critical for assessing the hazard in Tabriz, one of the major
cities of Iran; the city suffered major damage in both the 1721 and 1780 events. Our study area is located on the
northwestern fault segment, west of the city of Tabriz. We performed geomorphic and trenching investigations,
which allowed us to recognize evidence for repeated faulting events since the Late Pleistocene. From the trenches,
we found evidence for at least four events during the past 3.6 ka, the most recent one being the 1780 earthquake.
On the basis of different approaches, horizontal slip per event and slip rates are found in the ranges of 4 ± 0.5 m
and 3.1-6.4 mm/yr, respectively. We also attempted an estimate of the average recurrence intervals which appears
to be in the range 350-1430 years, with a mean recurrence interval of 821 ± 176 years. On the basis of these results,
the northwestern segment of the North Tabriz Fault does not appear to present a major seismic potential for
the near future, however, not enough is known about the southeastern segment of the fault to make a comparable
conclusion
Paleoearthquakes and slip rates of the North Tabriz Fault, NW Iran: preliminary results
The North Tabriz Fault is a major seismogenic fault in NW Iran. The last damaging earthquakes on this fault occurred in 1721, rupturing the southeastern fault segment, and in 1780, rupturing the northwestern one. The understanding of the seismic behavior of this fault is critical for assessing the hazard in Tabriz, one of the major cities of Iran; the city suffered major damage in both the 1721 and 1780 events. Our study area is located on the northwestern fault segment, west of the city of Tabriz. We performed geomorphic and trenching investigations, which allowed us to recognize evidence for repeated faulting events since the Late Pleistocene. From the trenches, we found evidence for at least four events during the past 3.6 ka, the most recent one being the 1780 earthquake. On the basis of different approaches, horizontal slip per event and slip rates are found in the ranges of 4 ± 0.5 m and 3.1-6.4 mm/yr, respectively. We also attempted an estimate of the average recurrence intervals which appears to be in the range 350-1430 years, with a mean recurrence interval of 821 ± 176 years. On the basis of these results, the northwestern segment of the North Tabriz Fault does not appear to present a major seismic potential for the near future, however, not enough is known about the southeastern segment of the fault to make a comparable conclusion
Platelet clearance via shear-induced unfolding of a membrane mechanoreceptor
Mechanisms by which blood cells sense shear stress are poorly characterized. In platelets, glycoprotein (GP)Ib-IX receptor complex has been long suggested to be a shear sensor and receptor. Recently, a relatively unstable and mechanosensitive domain in the GPIba subunit of GPIb-IX was identified. Here we show that binding of its ligand, von Willebrand factor, under physiological shear stress induces unfolding of this mechanosensory domain (MSD) on the platelet surface. The unfolded MSD, particularly the juxtamembrane ⏠Trigger' sequence therein, leads to intracellular signalling and rapid platelet clearance. These results illustrate the initial molecular event underlying platelet shear sensing and provide a mechanism linking GPIb-IX to platelet clearance. Our results have implications on the mechanism of platelet activation, and on the pathophysiology of von Willebrand disease and related thrombocytopenic disorders. The mechanosensation via receptor unfolding may be applicable for many other cell adhesion receptors
Paleoearthquakes and slip rates of the North Tabriz Fault, NW Iran: preliminary results
The North Tabriz Fault is a major seismogenic fault in NW Iran. The last damaging earthquakes on this fault occurred in 1721, rupturing the southeastern fault segment, and in 1780, rupturing the northwestern one. The understanding of the seismic behavior of this fault is critical for assessing the hazard in Tabriz, one of the major cities of Iran; the city suffered major damage in both the 1721 and 1780 events. Our study area is located on the northwestern fault segment, west of the city of Tabriz. We performed geomorphic and trenching investigations, which allowed us to recognize evidence for repeated faulting events since the Late Pleistocene. From the trenches, we found evidence for at least four events during the past 3.6 ka, the most recent one being the 1780 earthquake. On the basis of different approaches, horizontal slip per event and slip rates are found in the ranges of 4 ± 0.5 m and 3.1-6.4 mm/yr, respectively. We also attempted an estimate of the average recurrence intervals which appears to be in the range 350-1430 years, with a mean recurrence interval of 821 ± 176 years. On the basis of these results, the northwestern segment of the North Tabriz Fault does not appear to present a major seismic potential for the near future, however, not enough is known about the southeastern segment of the fault to make a comparable conclusion
Performance analysis for energy harvesting communication protocols with fixed rate transmission
Accommodation of Arabia-Eurasia convergence in the Zagros-Makran transfer zone, SE Iran: A transition between collision and subduction through a young deforming system
International audienceAt Iranian longitude, the Arabian plate is moving northward relative to Eurasia (âŒ20 mm yr-1 according to GPS). To the east, this relative motion is accommodated by northward subduction under the E-W Makran emerged accretionary prism. To the west, it is accommodated partly by the Zagros fold-and-thrust belt and partly by the Alborz/Kopet Dagh deforming zones further north. This work investigates the NNW striking transition zone that connects Zagros and Makran: the Minab-Zendan fault system. Satellite images, and structural and geomorphic field observations show a distributed deformation pattern covering a wide domain. Five north to NW trending major faults were identified. They exhibit evidence for late Quaternary reverse right-lateral slip, and correspond to two distinct fault systems: the western one transferring the Zagros deformation to the Makran prism, and the eastern one northward transferring the deformation to the Alborz/Kopet Dagh. Tectonic study and fault slip vector analyses indicate that two distinct tectonic regimes have occurred successively since the Miocene within a consistent regional NE trending compression: (1) an upper Miocene to Pliocene tectonic regime characterized by partitioned deformation, between reverse faulting and en echelon folding; (2) a NE trending Ï1 axis transpressional regime homogeneously affecting the region since upper Pliocene. The change is contemporaneous with major tectonic reorganization regionally recorded. Therefore this study provides evidence for active deformation that is not localized, but distributed across a wide zone. It accommodates the convergence and transfers it from collision to subduction by transpressional tectonics without any partitioning process in the present-day period
Neutronic simulation of a research reactor core of (232Th, 235U)O 2 fuel using MCNPX2.6 code
Trustworthy 100-Year Digital Objects: Evidence Even After Every Witness is Dead
How can a publisher store digital information so that any reader can reliably test its authenticity,
even years later when no witness can vouch for its validity? What is the simplest security
infrastructure sufficient to protect and later test evidence of authenticity?
In ancient times, wax seals impressed with signet rings were affixed to documents as evidence of
their authenticity. A digital counterpart is a message authentication code fixed firmly to each
important document. If a digital object is sealed together with its own audit trail, each user can
examine this evidence to decide whether to trust the contentâno matter how distant this user is
in time, space, and social affiliation from the documentâs source.
We suggest technical means for accomplishing this: encapsulation of the document content with
metadata describing its origins, cryptographic sealing, webs of trust for public keys rooted in a
forest of respected institutions, and a certain way of managing document identifiers. These
means will satisfy emerging needs in civilian and military record management, including medical
patient records, regulatory records for aircraft and pharmaceuticals, business records for
financial audit, legislative and legal briefs, and scholarly works.
This is true for any kind of document, independently of its purposes and of most data type and
representation details, and provides each user with autonomy for most of what he does.
Producers can prepare works for preservation without permission from or synchronization with
any authority or service agent. Librarians can add metadata without communicating with
document originators or repository managers. Consumers can test authenticity without Internet
delays, apart from those for fetching cryptographic certificates.
Our method accomplishes much of what is sought under labels such as âtrusted digital
repositoriesâ, and does so more flexibly and economically than any method yet proposed. It
requires at most easy extensions of available content management software, and is therefore
compatible with what most digital repositories have installed and are using today.