Influence of milk source on transplantability of histocompatible mammary tumours in mice.

It is confirmed that C3H mammary tumours are much more easily transplantable in histocompatible recipients when these have been reared on C3H milk, than when they have been reared on milk from the inbred Swiss/B strain. By contrast, A.CA mammary tumours transplanted in histocompatible hosts reared on A.CA or Swiss/B milk, grow almost equally well in both sorts of recipient. Thus, rearing on Swiss/B milk has different effects on the transplantability of mammary tumours of C3H and A.CA. On the other hand, recipients which were reared on C3H or A.CA milks accept grafts of C3H mammary tumours about equally, suggesting that milks from A.CA and C3H have the same effect on the transplantability of C3H mammary tumours. The different action of Swiss/B milk on tumours of C3H and A.CA seems best attributed to differences between C3H and A.CA tumours or between mouse strain genotypes. By contrast, the transplantability of C3H mammary tumours is significantly changed when the recipients were reared on milk from the RIII strain instead of C3H. These facts suggest that the milk from RIII has an action which differs from that of both C3H and A.CA in this respect. The data are discussed on the basis of a differential tollerance-inducing action of mammary tumour viruses (MTVs) which infect C3H, A.CA and RIII, and have an important role in tumour induction

Source Spectra and Site Response from S Waves of Intermediate-Depth Vrancea, Romania, Earthquakes

Seismograms from 55 intermediate-depth Vrancea earthquakes (M 4:0– 7:1) recorded at 43 stations of an accelerometric network in Romania are used to derive source spectra and site amplification functions from S waves in the frequency range 0.5–20 Hz with the generalized inversion technique (GIT) (Castro et al., 1990). Attenuation is taken into account using the nonparametric attenuation functions derived by Oth et al. (2008) from the same dataset, and the attenuation-corrected data are then split into source and site contributions. The source spectra follow the ω 2 model (Brune, 1970, 1971) with high corner frequencies and a related Brune stress drop of the order of 100 MPa. The site amplification functions are separately determined for both horizontal and vertical components. Contrary to widespread expectation, the vertical component shows significant amplification effects at high frequencies. The H=Z ratios determined from the GIT results compare well with H=V ratios computed directly from the S-wave window of the accelerograms (Lermo and Chávez-García, 1993). The basic assumption for the determination of site effects from H=V ratios is that the vertical component is not or only little affected by site effects. For Vrancea earthquakes, this assumption is incorrect; consequently, site effects should not be estimated from H=V ratios. The reason for this peculiar fact is the geometry of intermediate-depth seismicity that leads to almost vertical ray paths beneath the stations

S-Wave Attenuation Characteristics beneath the Vrancea Region in Romania: New Insights from the Inversion of Ground-Motion Spectra

The S-wave attenuation characteristics beneath the Vrancea region in Romania are analyzed from the spectra (frequency range 0.5–20 Hz) of more than 850 recordings at 43 accelerometric stations of 55 intermediate-depth earthquakes (M 4:0–7:1) that occurred in the Vrancea seismogenic zone. The method commonly chosen for this type of investigation in the case of crustal earthquakes is the generalized inversion technique (GIT) (e.g., Andrews, 1986; Castro et al., 1990). Yet the Vrancea dataset is entirely different from common crustal datasets. Because of the strong clustering of the hypocenters within a very small focal volume, there are only few crossing ray paths from sources to receivers. As a consequence, inhomogeneities in the attenuation properties are not averaged out, which leads to unphysical results if the standard GIT approach is adopted. The problem is discussed qualitatively by performing tests with synthetic data and solved quantitatively by adapting the GIT technique in view of these peculiarities.With the optimally adapted inversion scheme, it is possible to unravel differences in the attenuation characteristics between two (or more) sets of stations. The results show that the attenuation of seismic waves is roughly comparable in the low frequency range (<4–5 Hz) but stronger by up to an order of magnitude at higher frequencies within the Carpathian mountain arc as compared with the foreland area. Modeling this strongly frequency-dependent lateral variation of seismic attenuation by a significantly lower Q beneath Vrancea (1) provides a very good fit of observed strong-motion characteristics, (2) sheds new light on the distribution of intensities of the previous strong earthquakes, (3) will have strong implications for future hazard assessment, and (4) is fully compatible with structural models from deep seismic sounding, tomography, and teleseismic attenuation

Genioplasty with surgical guide using 3D-printing technology : a systematic review

The purpose of this systematic review is to evaluate the current state of the art of making genioplasties using 3D printing technology. A multi-database single-reviewer systematic review identified sixteen papers that fulfilled the selection criteria. There were mainly case series and case reports available (Level IV of the Oxford Evidence-based medicine scale); only two prospective study (Level III) evaluated this subject. These articles are analyzed in details and summarized in this review. The realization of genioplasties with surgical guide using 3D-printing technology could improve predictability and accuracy. It protects anatomical structures in the environment of the surgery, reducing by this way the morbidity and providing safer results. The type of printer and material used as well as the sterilization techniques should be further developed by the authors. The use of open-access software should also be further explored to allow the use of these new technologies by the largest number of surgeons. Finally, prospective multi-center studies with larger samples should be performed to definitively conclude the benefits of this new technology and allow for its routine use. This article is the first systematic review on this topic

Evaluation and optimization of seismic networks and algorithms for earthquake early warning – the case of Istanbul (Turkey)

Earthquake early warning (EEW) systems should provide reliable warnings as quickly as possible with a minimum number of false and missed alarms. Using the example of the megacity Istanbul and based on a set of simulated scenario earthquakes, we present a novel approach for evaluating and optimizing seismic networks for EEW, in particular in regions with a scarce number of instrumentally recorded earthquakes. We show that, while the current station locations of the existing Istanbul EEW system are well chosen, its performance can be enhanced by modifying the parameters governing the declaration of warnings. Furthermore, unless using ocean bottom seismometers or modifying the current EEW algorithm, additional stations might not lead to any significant performance increase

Source processes and spectral ground motion models of intermediate depth Vrancea (Romania) earthquakes

For successful assessment and mitigation of earthquake hazards, it is necessary to be able to reliably predict the level of ground shaking which has to be expected from future large earthquakes. This prediction of ground motion can be done either by using empirical relations (derived from past earthquakes) between some ground motion parameter and the source and observer location, so-called attenuation relations, or by performing numerical simulations of future earthquakes based on models of the earthquake source and the propagation medium (i.e. the Earth). The capacity of the first option is at times rather limited, for instance if only very few large earthquakes occurred in the region of interest in instrumental times. Numerical simulations, on the other hand, cannot provide reliable results without a detailed description of the underlying source process and a thorough understanding of path and site effects. This thesis aims at a better understanding of the source process and the spectral characteristics of the intermediate-depth Vrancea (Romania) earthquakes...thesi

Structural Health Monitoring Using Wireless Technologies: An Ambient Vibration Test on the Adolphe Bridge, Luxembourg City

Major threats to bridges primarily consist of the aging of the structural elements, earthquake-induced shaking and standing waves generated by windstorms. The necessity of information on the state of health of structures in real-time, allowing for timely warnings in the case of damaging events, requires structural health monitoring (SHM) systems that allow the risks of these threats to be mitigated. Here we present the results of a short-duration experiment carried out with low-cost wireless instruments for monitoring the vibration characteristics and dynamic properties of a strategic civil infrastructure, the Adolphe Bridge in Luxembourg City. The Adolphe Bridge is a masonry arch construction dating from 1903 and will undergo major renovation works in the upcoming years. Our experiment shows that a network of these wireless sensing units is well suited to monitor the vibration characteristics of such a historical arch bridge and hence represents a low-cost and efficient solution for SHM