Modeling of Energy Amplification Recorded within Greater Los Angeles Using Irregular Structure

We have investigated energy amplification observed within Greater Los Angeles basin by analyzing regional waveforms recorded from several Nevada Test Site (NTS) nuclear explosions. Although the stations are located nearly at the same azimuth (distances ranging from 350 to 400 km), the seismograms recorded in Compton (the central part of the basin), Long Beach (the southern edge of the basin), and downtown Los Angeles are remarkably different, even for a common explosion. Following the onset of L_g waves, the Long Beach sites have recorded surface waves for more than 100 sec. From one explosion, the sites within downtown Los Angeles have recorded seismograms with strong 3-sec surface waves. These waves are not observed on the seismograms recorded in the neighboring hard-rock site California Institute of Technology (CIT) station. Thus, they must have been generated by local wave guides. Numerically, we modeled these 3-sec waves by convolving the CIT seismogram with the response of a sedimentary strata dipping gently (about 6°) from CIT toward downtown. We also examined the irregular basin effect by analyzing the variation of cumulative temporal energy across the basin relative to the energy recorded at CIT from the same explosion. Variation up to a factor of 30 was observed. To model the energy variation that is caused by extended surface waves in the Long Beach area, we used numerically simulated site transfer functions (STF) from a NNE-SSW oriented two-dimensional basin structure extending from Montebello to Palos Verdes that included low-velocity sedimentary material in the uppermost layers. These STFs were convolved with the CIT seismogram recorded from the MAST explosion. To simulate elongated duration of surface waves, we introduced in the upper sedimentary structure some discontinuous microbasin structures of varying size, each microbasin delaying the seismic waves propagating through them. Consequently, the surface-reflected phases through these structures are delayed and reflected into the upper medium by the underlying interfaces. This mechanism helps delayed energy to appear at a later time and result in a longer time duration at sites located at southern edge of the basin

Microseismic joint location and anisotropic velocity inversion for hydraulic fracturing in a tight Bakken reservoir

To improve the accuracy of microseismic event locations, we developed a new inversion method with double-difference constraints for determining the hypocenters and the anisotropic velocity model for unconventional reservoirs. We applied this method to a microseismic data set monitoring a Middle Bakken completion in the Beaver Lodge area of North Dakota. Geophone arrays in four observation wells improved the ray coverage for the velocity inversion. Using an accurate anisotropic velocity model is important to correctly assess the height growth of the hydraulically induced fractures in the Middle Bakken. Our results showed that (1) moderate-to-strong anisotropy exists in all studied sedimentary layers, especially in the Upper and Lower Bakken shale formations, where the Thomsen parameters (ϵ and γ) can be greater than 0.4, (2) all the events selected for high signal-to-noise ratio and used for the joint velocity inversion are located in the Bakken and overlying Lodgepole formations, i.e., no events are detected in the Three Forks formation below the Bakken, and (3) more than half of the strong events are in two clusters at approximately 100 and 150 m above the Middle Bakken. Reoccurrence of strong, closely clustered events suggested activation of natural fractures or faults in the Lodgepole formation. The sensitivity analysis for the inversion results showed that the relative uncertainty in parameter δ is larger than other anisotropy parameters. The microseismic event locations and the anisotropic velocity model are validated by comparing synthetic and observed seismic waveforms and by S-wave splitting.Shell Oil Compan

2-D or not 2-D, that is the question: A Northern California test

Reliable estimates of the seismic source spectrum are necessary for accurate magnitude, yield, and energy estimation. In particular, how seismic radiated energy scales with increasing earthquake size has been the focus of recent debate within the community and has direct implications on earthquake source physics studies as well as hazard mitigation. The 1-D coda methodology of Mayeda et al. has provided the lowest variance estimate of the source spectrum when compared against traditional approaches that use direct S-waves, thus making it ideal for networks that have sparse station distribution. The 1-D coda methodology has been mostly confined to regions of approximately uniform complexity. For larger, more geophysically complicated regions, 2-D path corrections may be required. The complicated tectonics of the northern California region coupled with high quality broadband seismic data provides for an ideal ''apples-to-apples'' test of 1-D and 2-D path assumptions on direct waves and their coda. Using the same station and event distribution, we compared 1-D and 2-D path corrections and observed the following results: (1) 1-D coda results reduced the amplitude variance relative to direct S-waves by roughly a factor of 8 (800%); (2) Applying a 2-D correction to the coda resulted in up to 40% variance reduction from the 1-D coda results; (3) 2-D direct S-wave results, though better than 1-D direct waves, were significantly worse than the 1-D coda. We found that coda-based moment-rate source spectra derived from the 2-D approach were essentially identical to those from the 1-D approach for frequencies less than {approx}0.7-Hz, however for the high frequencies (0.7{le} f {le} 8.0-Hz), the 2-D approach resulted in inter-station scatter that was generally 10-30% smaller. For complex regions where data are plentiful, a 2-D approach can significantly improve upon the simple 1-D assumption. In regions where only 1-D coda correction is available it is still preferable over 2-D direct wave-based measures

Wnt4 and LAP2alpha as pacemakers of Thymic Epithelial Senescence

Age-associated thymic involution has considerable physiological impact by inhibiting de novo T-cell selection. This impaired T-cell production leads to weakened immune responses. Yet the molecular mechanisms of thymic stromal adipose involution are not clear. Age-related alterations also occur in the murine thymus providing an excellent model system. In the present work structural and molecular changes of the murine thymic stroma were investigated during aging. We show that thymic epithelial senescence correlates with significant destruction of epithelial network followed by adipose involution. We also show in purified thymic epithelial cells the age-related down-regulation of Wnt4 (and subsequently FoxN1), and the prominent increase in LAP2α expression. These senescence-related changes of gene expression are strikingly similar to those observed during mesenchymal to pre-adipocyte differentiation of fibroblast cells suggesting similar molecular background in epithelial cells. For molecular level proof-of-principle stable LAP2α and Wnt4-over-expressing thymic epithelial cell lines were established. LAP2α over-expression provoked a surge of PPARγ expression, a transcription factor expressed in pre-adipocytes. In contrast, additional Wnt4 decreased the mRNA level of ADRP, a target gene of PPARγ. Murine embryonic thymic lobes have also been transfected with LAP2α- or Wnt4-encoding lentiviral vectors. As expected LAP2α over-expression increased, while additional Wnt4 secretion suppressed PPARγ expression. Based on these pioneer experiments we propose that decreased Wnt activity and increased LAP2α expression provide the molecular basis during thymic senescence. We suggest that these molecular changes trigger thymic epithelial senescence accompanied by adipose involution. This process may either occur directly where epithelium can trans-differentiate into pre-adipocytes; or indirectly where first epithelial to mesenchymal transition (EMT) occurs followed by subsequent pre-adipocyte differentiation. The latter version fits better with literature data and is supported by the observed histological and molecular level changes

Salvage high-dose chemotherapy in female patients with relapsed/refractory germ-cell tumors: A retrospective analysis of the European Group for Blood and Marrow Transplantation (EBMT)

Background: High-dose chemotherapy (HDC) with hematopoietic progenitor cell transplantation is a standard option for relapsed/refractory testicular germ-cell tumor (GCT), but only few data have been reported in female patients with GCT. We conducted a retrospective analysis of female patients with GCT treated with HDC and registered with the European Society for Blood and Marrow Transplantation. Patients and methods: Between 1985 and 2013, 60 registered female patients with GCT, median age 27 years (range 15-48), were treated with salvage HDC. Forty patients (67%) had primary ovarian GCT, 8 (13%) mediastinal, 7 (12%) retroperitoneal and 5 (8%) other primary sites/unknown. Twenty-two patients (37%) received HDC as second-line therapy, 29 (48%) as third-line, and 9 (15%) as fourth- to sixth-line. Nine of 60 patients (15%) received HDC as late-intensification with no evidence of metastasis before HDC. The conditioning HDC regimens comprised carboplatin in 51 of 60 cases (85%), and consisted of a single HDC cycle in 31 cases (52%), a multi-cycle HDC regimen in 29 (48%). Results: Nine cases who underwent late intensification HDC were not evaluable for response. Of the other 51 assessable patients, 17 (33%) achieved a complete response (CR), 8 (16%) a marker-negative partial remission (PRm-), 5 (10%) a marker-positive partial remission, 5 (10%) stable disease, and 13 (25%) progressive disease. There were 3 toxic deaths (6%). With an overall median follow-up of 14 months (range 1-219), 7 of 9 (78%) patients with late intensification and 18 of the 25 patients (72%) achieving a CR/PRm- following HDC were free of relapse/progression. In total, 25 of 60 patients (42%) were progression-free following HDC at a median follow-up of 87 months (range 3-219 months). Conclusions: Salvage HDC based on carboplatin represents a therapeutic option for female patients with relapsed/refractory GCT

Preliminary Report on the 22 December 2003, M 6.5 San Simeon, California Earthquake

The Mw 6.5 San Simeon earthquake struck the central California coast on 22 December 2003 at 19:15:56 UTC (11:15:56 am local time.) The epicenter was located 11 km northeast of the town of San Simeon, and 39 km west-northwest of Paso Robles (Figure 1), as reported by the California Integrated Seismic Network (CISN, the California region of the Advanced National Seismic System [ANSS]). The mainshock nucleated at 35.702°N, 121.108°W and a depth of 7.1 km, and the rupture propagated unilaterally to the southeast. The strong directivity of the rupture resulted in a concentration of damage and aftershock..

Regional Analysis of Lg Attenuation: Comparison of 1D Methods in Northern California and Application to the Yellow Sea / Korean Peninsula

The measurement of regional attenuation Q{sup -1} can produce method dependent results. The discrepancies among methods are due to differing parameterizations (e.g., geometrical spreading rates), employed datasets (e.g., choice of path lengths and sources), and methodologies themselves (e.g., measurement in the frequency or time domain). We apply the coda normalization (CN), two-station (TS), reverse two-station (RTS), source-pair/receiver-pair (SPRP), and the new coda-source normalization (CS) methods to measure Q of the regional phase, Lg (Q{sub Lg}), and its power-law dependence on frequency of the form Q{sub 0}f{sup {eta}} with controlled parameterization in the well-studied region of northern California using a high-quality dataset from the Berkeley Digital Seismic Network. We test the sensitivity of each method to changes in geometrical spreading, Lg frequency bandwidth, the distance range of data, and the Lg measurement window. For a given method, there are significant differences in the power-law parameters, Q{sub 0} and {eta}, due to perturbations in the parameterization when evaluated using a conservative pairwise comparison. The CN method is affected most by changes in the distance range, which is most probably due to its fixed coda measurement window. Since, the CS method is best used to calculate the total path attenuation, it is very sensitive to the geometrical spreading assumption. The TS method is most sensitive to the frequency bandwidth, which may be due to its incomplete extraction of the site term. The RTS method is insensitive to parameterization choice, whereas the SPRP method as implemented here in the time-domain for a single path has great error in the power-law model parameters and {eta} is greatly affected by changes in the method parameterization. When presenting results for a given method it is best to calculate Q{sub 0}f{sup {eta}} for multiple parameterizations using some a priori distribution. We also investigate the difference in power-law Q calculated among the methods by considering only an approximately homogeneous subset of our data. All methods return similar power-law parameters, though the 95% confidence region is large. We adapt the CS method to calculate Q{sub Lg} tomography in northern California. Preliminary results show that by correcting for the source, tomography with the CS method may produce better resolved attenuation structure

The Controversy Surrounding The Man Who Would Be Queen: A Case History of the Politics of Science, Identity, and Sex in the Internet Age

In 2003, psychology professor and sex researcher J. Michael Bailey published a book entitled The Man Who Would Be Queen: The Science of Gender-Bending and Transsexualism. The book’s portrayal of male-to-female (MTF) transsexualism, based on a theory developed by sexologist Ray Blanchard, outraged some transgender activists. They believed the book to be typical of much of the biomedical literature on transsexuality—oppressive in both tone and claims, insulting to their senses of self, and damaging to their public identities. Some saw the book as especially dangerous because it claimed to be based on rigorous science, was published by an imprint of the National Academy of Sciences, and argued that MTF sex changes are motivated primarily by erotic interests and not by the problem of having the gender identity common to one sex in the body of the other. Dissatisfied with the option of merely criticizing the book, a small number of transwomen (particularly Lynn Conway, Andrea James, and Deirdre McCloskey) worked to try to ruin Bailey. Using published and unpublished sources as well as original interviews, this essay traces the history of the backlash against Bailey and his book. It also provides a thorough exegesis of the book’s treatment of transsexuality and includes a comprehensive investigation of the merit of the charges made against Bailey that he had behaved unethically, immorally, and illegally in the production of his book. The essay closes with an epilogue that explores what has happened since 2003 to the central ideas and major players in the controversy