THE 2014 MW 6.9 NORTH AEGEAN TROUGH (NAT) EARTHQUAKE: SEISMOLOGICAL AND GEODETIC EVIDENCE

A strong earthquake (Mw 6.9) on 24 May 2014 ruptured the North Aegean Trough (NAT) in Greece, west of the North Anatolian Fault Zone (NAFZ). In order to provide unbiased constrains of the rupture process and fault geometry of the earthquake, seismological and geodetic data were analyzed independently. First, based on teleseismic long-period P- and SH- waveforms a point-source solution yielded dominantly right-lateral strike-slip faulting mechanism. Furthermore, finite fault inversion of broad-band data revealed the slip history of the earthquake. Second, GPS slip vectors derived from 11 permanent GPS stations uniformly distributed around the meizoseismal area of the earthquake indicated significant horizontal coseismic slip. Inversion of GPS-derived displacements on the basis of Okada model and using the new TOPological INVersion (TOPINV) algorithm permitted to model a vertical strike slip fault, consistent with that derived from seismological data. Obtained results are consistent with the NAT structure and constrain well the fault geometry and the dynamics of the 2014 earthquake. The latter seems to fill a gap in seismicity along the NAT in the last 50 years, but seems not to have a direct relationship with the sequence of recent faulting farther east, along the NAFZ

3-D sediment-basement tomography of the Northern Marmara trough by a dense OBS network at the nodes of a grid of controlled source profiles along the North Anatolian fault

A 3-D tomographic inversion of first arrival times of shot profiles recorded by a dense 2-D OBS network provides an unprecedented constraint on the P-wave velocities heterogeneity of the upper-crustal part of the North Marmara Trough (NMT), over a region of 180 km long by 50 km wide. One of the specific aims of this controlled source tomography is to provide a 3-D initial model for the local earthquake tomography (LET). Hence, in an original way, the controlled source inversion has been performed by using a code dedicated to LET. After several tests to check the results trade-off with the inversion parameters, we build up a 3-D a priori velocity model, in which the sea-bottom topography, the acoustic and the crystalline basements and the Moho interfaces have been considered. The reliability of the obtained features has been checked by checkerboard tests and also by their comparison with the deep-penetration multichannel seismic profiles, and with the wide-angle reflection and refraction modelled profiles. This study provides the first 3-D view of the basement topography along the active North Anatolian fault beneath the Marmara Sea, even beneath the deepest part of three sedimentary basins of NMT. Clear basement depressions reaching down 6 km depth below the sea level (bsl) have been found beneath these basins. The North Imralı Basin located on the southern continental shelf is observed with a similar sedimentary thickness as its northern neighbours. Between Central and Çınarcık basins, the Central High rises up to 3 km depth below (bsl). Its crest position is offset by 10 km northwestward relatively to the bathymetric crest. On the contrary, Tekirdağ and Central basins appear linked, forming a 60-km-long basement depression. Beneath the bathymetric relief of Western High low velocities are observed down to 6 km depth (bsl) and no basement high have been found. The obtained 3-D Vp heterogeneity model allows the consideration of the 3-D supracrustal heterogeneity into the future earthquake relocations in this region. The topographic map of the pre-kinematic basement offers the possibility to take into account the locking depth variations in future geohazard estimations by geomechanical modelling in this region

Decentralized subcontractor scheduling with divisible jobs

Subcontracting allows manufacturer agents to reduce completion times of their jobs and thus obtain savings. This paper addresses the coordination of decentralized scheduling systems with a single subcontractor and several agents having divisible jobs. Assuming complete information, we design parametric pricing schemes that strongly coordinate this decentralized system, i.e., the agents’ choices of subcontracting intervals always result in efficient schedules. The subcontractor’s revenue under the pricing schemes depends on a single parameter which can be chosen to make the revenue as close to the total savings as required. Also, we give a lower bound on the subcontractor’s revenue for any coordinating pricing scheme. Allowing private information about processing times, we prove that the pivotal mechanism is coordinating, i.e., agents are better off by reporting their true processing times, and by participating in the subcontracting. We show that the subcontractor’s maximum revenue with any coordinating mechanism under private information equals the lower bound of that with coordinating pricing schemes under complete information. Finally, we address the asymmetric case where agents obtain savings at different rates per unit reduction in completion times. We show that coordinating pricing schemes do not always exist in this case

Металлизация поверхности керамики В4С комбинированным электронно-ионно-плазменным методом

Объектом исследования является керамика В4С с металлизированной поверхностью. Цель работы – исследование структуры и свойств систем «пленка (Ti)/(В4С-керамика) подложка» и «пленка (Cu)/(В4С-керамика) подложка», обработанных интенсивным импульсным электронным пучком. В процессе исследования проводились рентгенофазовые исследование; исследование поверхности и излома образцов методом сканирующей электронной микроскопии; исследование микротвердости и коэффициента вязкости разрушения образов. В результате исследования установлено формированию в поверхностном слое толщиной (5-7) мкм многофазной структуры эвтектического типа, состоящей из кристаллитов карбида бора, диборида титана и титана; снижение микротвердости модифицированных образцов керамики Ti/В4С в ≈1,2 раза относительно микротвёрдости исходных образцов. Основные конструктивные, технологические и технико-эксплуатационные характеристики: температура разложения >2450 °C; плотность 2,52 г/см³; теплопроводность 121 Вт/(мК) при 300 °К; микротвёрдость 49,1 ГПа; модуль упругости 450 ГПа; полупроводник p-типа.The object of the research is B4C ceramics with metallized surface. Objective - to study the structure and properties of systems "film (Ti) / (B4C-ceramic) substrate" and "film (Cu) / (B4C-ceramic) substrate" treated with intense pulsed electron beam. The study carried out X-ray phase study; study the surface and break the samples by scanning electron microscopy; study of microhardness and fracture toughness ratio images. The study showed the formation of a surface layer (5-7) m multiphase eutectic structure consisting of crystallites of boron carbide, titanium diboride, and titanium; decrease in microhardness modified ceramic samples Ti / B4C in ≈1,2 times the microhardness of the initial samples. The basic constructive, technological and technical and operational characteristics: the decomposition temperature of> 2450 ° C; density 2.52 g / cm³; thermal conductivity of 121 W / (mK) at 300 ° K; microhardness 49.1 GPa; modulus 450 GPa; p-type semiconductor

The Development of Metabolomic Sampling Procedures for Pichia pastoris, and Baseline Metabolome Data

Metabolic profiling is increasingly being used to investigate a diverse range of biological questions. Due to the rapid turnover of intracellular metabolites it is important to have reliable, reproducible techniques for sampling and sample treatment. Through the use of non-targeted analytical techniques such as NMR and GC-MS we have performed a comprehensive quantitative investigation of sampling techniques for Pichia pastoris. It was clear that quenching metabolism using solutions based on the standard cold methanol protocol caused some metabolite losses from P. pastoris cells. However, these were at a low level, with the NMR results indicating metabolite increases in the quenching solution below 5% of their intracellular level for 75% of metabolites identified; while the GC-MS results suggest a slightly higher level with increases below 15% of their intracellular values. There were subtle differences between the four quenching solutions investigated but broadly, they all gave similar results. Total culture extraction of cells + broth using high cell density cultures typical of P. pastoris fermentations, was an efficient sampling technique for NMR analysis and provided a gold standard of intracellular metabolite levels; however, salts in the media affected the GC-MS analysis. Furthermore, there was no benefit in including an additional washing step in the quenching process, as the results were essentially identical to those obtained just by a single centrifugation step. We have identified the major high-concentration metabolites found in both the extra- and intracellular locations of P. pastoris cultures by NMR spectroscopy and GC-MS. This has provided us with a baseline metabolome for P. pastoris for future studies. The P. pastoris metabolome is significantly different from that of Saccharomyces cerevisiae, with the most notable difference being the production of high concentrations of arabitol by P. pastoris

Seismic site characterization of the Kastelli (Kissamos) Basin in northwest Crete (Greece): Assessments using ambient noise recordings

Crete is actively seismic and site response studies are needed for estimating local site conditions subjected to seismic activity. In order to collect basic data, we performed ambient noise recordings to estimate the site response of the surface and near subsurface structure of the small-scale Kastelli Basin in northwest Crete. The spatial horizontal to vertical spectral ratios (HVSR) resonance pattern of the investigated sites in the centre of the Basin consists of either one or two peaks divided into low to high frequency range in different sites as follows: (a) in some sites only one amplified peak at low frequencies (0.6–1.2 Hz), (b) in other sites only one amplified peak at medium frequencies (2.9–8.5 Hz) and (c) in yet other sites two amplified peaks in the low to high frequency range (0.6–15.5 Hz). The investigated sites are amplified in the frequency range 0.6–15.5 Hz, while the amplitude reaches to a factor of 4 in the spectral ratios. The one HVSR amplified peak at low frequencies is related to locally soft or thick Quaternary deposits. Microtremors were measured in the coastal northwest part of the Basin in a well—lithified Cretaceous limestone site characterized by fractures and faults striking predominantly in a sector NNE to NNW. Sites of one amplified peak at medium frequencies are extended from coastal northwest to southwest delineating a structure striking to NNW. The two amplified peaks are attributed to shallow subsurface heterogeneities/irregularities, locally induced by fault zones and to the overlying Quaternary deposits. Spatial HVSR variations in the frequency and HVSR shape delineate four structures striking NNE, NNW and in a sector NW to WNW, crosscutting the dense populated Basin suggesting that microtremors could be a valuable tool for providing a first approximation of fault zone delineation at least for the Kastelli-Kissamos Basin. The Basin is classified into the X soil category of the Greek Seismic Code 2000.This work was implemented through the project entitled “Interdisciplinary Multi-Scale Research of Earth-quake Physics and Seismotectonics at the Front of the Hellenic Arc (IMPACT-ARC)” in the framework of action “ARCHIMEDES III—Support of Research Teams at TEI of Crete” (MIS380353) of the Operational Program “Education and Lifelong Learning” and is co-financed by the European Union (European Social Fund) and Greek national fund

Stability of Metabolic Correlations under Changing Environmental Conditions in Escherichia coli – A Systems Approach

Background: Biological systems adapt to changing environments by reorganizing their cellular and physiological program with metabolites representing one important response level. Different stresses lead to both conserved and specific responses on the metabolite level which should be reflected in the underlying metabolic network. Methodology/Principal Findings: Starting from experimental data obtained by a GC-MS based high-throughput metabolic profiling technology we here develop an approach that: (1) extracts network representations from metabolic condition-dependent data by using pairwise correlations, (2) determines the sets of stable and condition-dependent correlations based on a combination of statistical significance and homogeneity tests, and (3) can identify metabolites related to the stress response, which goes beyond simple observations about the changes of metabolic concentrations. The approach was tested with Escherichia coli as a model organism observed under four different environmental stress conditions (cold stress, heat stress, oxidative stress, lactose diauxie) and control unperturbed conditions. By constructing the stable network component, which displays a scale free topology and small-world characteristics, we demonstrated that: (1) metabolite hubs in this reconstructed correlation networks are significantly enriched for those contained in biochemical networks such as EcoCyc, (2) particular components of the stable network are enriched for functionally related biochemical pathways, and (3) independently of the response scale, based on their importance in the reorganization of the correlation network a set of metabolites can be identified which represent hypothetical candidates for adjusting to a stress-specific response. Conclusions/Significance: Network-based tools allowed the identification of stress-dependent and general metabolic correlation networks. This correlation-network-based approach does not rely on major changes in concentration to identify metabolites important for stress adaptation, but rather on the changes in network properties with respect to metabolites. This should represent a useful complementary technique in addition to more classical approaches

Starting-up unregistered and firm performance in Turkey

© 2016 The Author(s) Recent years have seen a questioning of the negative representation of informal sector entrepreneurship and an emergent view that it may offer significant benefits. This paper advances this rethinking by evaluating the relationship between business registration and future firm performance. Until now, the assumption has been that starting-up unregistered is linked to weaker firm performance. Using World Bank Enterprise Survey data on 2494 formal enterprises in Turkey, and controlling for other determinants of firm performance as well as the endogeneity of the registration decision, the finding is that formal enterprises that started-up unregistered and spent longer unregistered have significantly higher subsequent annual sales and productivity growth rates compared with those registered from the outset. This is argued to be because in such weak institutional environments, the advantages of registering from the outset are outweighed by the benefits of deferring business registration and the low risks of detection and punishment. The resultant implication is that there is a need to shift away from the conventional eradication approach based on the negative depiction of informal entrepreneurship as poorly performing, and towards a more facilitating approach that improves the benefits of business registration and tackles the systemic formal institutional deficiencies that lead entrepreneurs to decide to delay the registration of their ventures

A reassessment of outer-rise seismicity and its implications for the mechanics of oceanic lithosphere

We use body-waveform modelling to constrain the source parameters of earthquakes occurring globally in oceanic lithosphere beneath the subduction zone outer rise and outer trench slope. These data are then used to map the stress state in the lithosphere of the downgoing plate as it bends into the subduction zone. Our results provide new constraints on the faulting of oceanic lithosphere at the outer rise, which is important for understanding the transmission of plate-driving forces through the subduction system. In all cases, shallow normal-faulting earthquakes are observed at the top of the plate, and are separated in depth from any deeper thrust-faulting earthquakes. No temporal variation associated with large thrust-faulting earthquakes on the subduction interface is seen in the depth extent of each type of faulting at the outer rise. The transition depth from trench-normal extension to compression is found to vary in agreement with models in which deformation is driven by the combination of in-plane stresses and bending stresses, resulting principally from slab pull. Combining the seismologically derived constraints on the thickness of the elastic core of the plate with estimates of the plate curvature, we place upper bounds on the strength of the lithosphere at the outer rise, which is required to be ≲300 MPa for a constant yield stress model, or governed by an effective coefficient of friction of ≲0.3