Near-bottom seismic profiling: High lateral variability, anomalous amplitudes, and estimates of attenuation

For almost a decade the Marine Physical Laboratory of Scripps Institution of Oceanography has been conducting near‐bottom geophysical surveys involving quantitative seismic profiling. Operating initially at 4 kHz and more recently at 6 kHz, this system has provided a wealth of fine scale quantitative data on the acoustic properties of ocean sediments. Over lateral distances of a few meters, 7‐dB changes in overall reflected energy as well as 10‐dB changes from individual reflectors have been observed. Anomalously high amplitudes from deep reflectors have been commonly observed, suggesting that multilayer interference is prevalent in records from such pulsed cw profilers. This conclusion is supported by results from sediment core physical property work and related convolution modeling, as well as by the significant differences observed between 4‐ and 6‐kHz profiles. In general, however, lateral consistency has been adequate in most areas surveyed to permit good estimates of acoustic attenuation from returns from dipping reflectors and sediment wedges

SeisCORK meeting report

SeisCORK meeting, November 15 and 16, 2004, Stress/Mohr Engineering, Houston, Texas 77041-1205The purpose of this meeting was to explore design options to simultaneously acquire borehole seismic data and hydro-geological data (pressure, temperature, fluid sampling and microbiological sampling) on a single CORK system. The scientific focus was to add a seismic component to the Juan de Fuca Hydrogeology program. By permanently installing a sensor string in the borehole our goal was to enable: l) time-lapse VSP's and offset VSP's with sufficient data quality to study amplitude versus offset, shear wave anisotropy, and lateral heterogeneity; 2) monitoring of micro- and nano- earthquake activity around the site for correlation with pressure transients. Because of the difficulty in ensuring adequate coupling through multiple casing strings we concluded that it was impractical to install the vertical seismic array with 10m spacing (50-60 nodes) that would be necessary for VSP's and time-lapse VSP's. We did describe a scenario for a vertical seismic array with approximately 100m spacing (5-6 nodes) that could be used for offset-VSP's and seismic monitoring. This uses some unique technology and involves two seismic strings: one in the annulus between the 4- 1/2" and 10-3/4" casings and one in the middle of the 4-1/2" casing.Funding was provided by the National Science Foundation under Grant No. OCE-0450318

Good things take time – diversity effects on tree growth shift from negative to positive during stand development in boreal forests

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Report of a workshop on technical approaches to construction of a seafloor geomagnetic observatory

This report considers the technical issues on sensors, data recording and transmission, control and timing, power, and packaging associated with constricting a seafloor geomagnetic observatory. Existing technologies either already in use for oceanographic purposes or adapted from terrestral geomagnetic observatories could be applied to measure the vector magnetic field components and absolute intensity with minimal development. The major technical challenge arises in measuring absolute direction on the seafloor because terrestral techniques are not transferrable to the deep ocean. Two solutions to this problem were identified. The first requires the development of an instrument which measures the instantaneous declination and inclination of the magnetic field relative to a north-seeking gyroscope and the local vertical. The second is a straightforward extension of a precision acoustic method for determining absolute position on the seafloor.Funding was provided by the National Science Foundation under grant EAR94-21712 and the National Aeronautics and Space Administration

Concomitant CIS on TURBT does not impact oncological outcomes in patients treated with neoadjuvant or induction chemotherapy followed by radical cystectomy

© Springer-Verlag GmbH Germany, part of Springer Nature 2018Background: Cisplatin-based neoadjuvant chemotherapy (NAC) for muscle invasive bladder cancer improves all-cause and cancer specific survival. We aimed to evaluate whether the detection of carcinoma in situ (CIS) at the time of initial transurethral resection of bladder tumor (TURBT) has an oncological impact on the response to NAC prior to radical cystectomy. Patients and methods: Patients were identified retrospectively from 19 centers who received at least three cycles of NAC or induction chemotherapy for cT2-T4aN0-3M0 urothelial carcinoma of the bladder followed by radical cystectomy between 2000 and 2013. The primary and secondary outcomes were pathological response and overall survival, respectively. Multivariable analysis was performed to determine the independent predictive value of CIS on these outcomes. Results: Of 1213 patients included in the analysis, 21.8% had concomitant CIS. Baseline clinical and pathologic characteristics of the ‘CIS’ versus ‘no-CIS’ groups were similar. The pathological response did not differ between the two arms when response was defined as pT0N0 (17.9% with CIS vs 21.9% without CIS; p = 0.16) which may indicate that patients with CIS may be less sensitive to NAC or ≤ pT1N0 (42.8% with CIS vs 37.8% without CIS; p = 0.15). On Cox regression model for overall survival for the cN0 cohort, the presence of CIS was not associated with survival (HR 0.86 (95% CI 0.63–1.18; p = 0.35). The presence of LVI (HR 1.41, 95% CI 1.01–1.96; p = 0.04), hydronephrosis (HR 1.63, 95% CI 1.23–2.16; p = 0.001) and use of chemotherapy other than ddMVAC (HR 0.57, 95% CI 0.34–0.94; p = 0.03) were associated with shorter overall survival. For the whole cohort, the presence of CIS was also not associated with survival (HR 1.05 (95% CI 0.82–1.35; p = 0.70). Conclusion: In this multicenter, real-world cohort, CIS status at TURBT did not affect pathologic response to neoadjuvant or induction chemotherapy. This study is limited by its retrospective nature as well as variability in chemotherapy regimens and surveillance regimens.Peer reviewedFinal Accepted Versio

Deep CO₂ in the end-Triassic Central Atlantic Magmatic Province

Large Igneous Province eruptions coincide with many major Phanerozoic mass extinctions, suggesting a cause-effect relationship where volcanic degassing triggers global climatic changes. In order to fully understand this relationship, it is necessary to constrain the quantity and type of degassed magmatic volatiles, and to determine the depth of their source and the timing of eruption. Here we present direct evidence of abundant CO2 in basaltic rocks from the end-Triassic Central Atlantic Magmatic Province (CAMP), through investigation of gas exsolution bubbles preserved by melt inclusions. Our results indicate abundance of CO2 and a mantle and/or lower-middle crustal origin for at least part of the degassed carbon. The presence of deep carbon is a key control on the emplacement mode of CAMP magmas, favouring rapid eruption pulses (a few centuries each). Our estimates suggest that the amount of CO2 that each CAMP magmatic pulse injected into the end-Triassic atmosphere is comparable to the amount of anthropogenic emissions projected for the 21st century. Such large volumes of volcanic CO2 likely contributed to end-Triassic global warming and ocean acidification

Removal of homeostatic cytokine sinks by lymphodepletion enhances the efficacy of adoptively transferred tumor-specific CD8(+) T cells

Depletion of immune elements before adoptive cell transfer (ACT) can dramatically improve the antitumor efficacy of transferred CD8(+) T cells, but the specific mechanisms that contribute to this enhanced immunity remain poorly defined. Elimination of CD4(+)CD25(+) regulatory T (T reg) cells has been proposed as a key mechanism by which lymphodepletion augments ACT-based immunotherapy. We found that even in the genetic absence of T reg cells, a nonmyeloablative regimen substantially augmented CD8(+) T cell reactivity to self-tissue and tumor. Surprisingly, enhanced antitumor efficacy and autoimmunity was caused by increased function rather than increased numbers of tumor-reactive T cells, as would be expected by homeostatic mechanisms. The γ (C) cytokines IL-7 and IL-15 were required for augmenting T cell functionality and antitumor activity. Removal of γ (C) cytokine–responsive endogenous cells using antibody or genetic means resulted in the enhanced antitumor responses similar to those seen after nonmyeloablative conditioning. These data indicate that lymphodepletion removes endogenous cellular elements that act as sinks for cytokines that are capable of augmenting the activity of self/tumor-reactive CD8(+) T cells. Thus, the restricted availability of homeostatic cytokines can be a contributing factor to peripheral tolerance, as well as a limiting resource for the effectiveness of tumor-specific T cells

Growing Correlation Length on Cooling Below the Onset of Caging in a Simulated Glass-Forming Liquid

We present a calculation of a fourth-order, time-dependent density correlation function that measures higher-order spatiotemporall correlations of the density of a liquid. From molecular dynamics simulations of a glass-forming Lennard-Jones liquid, we find that the characteristic length scale of this function has a maximum as a function of time which increases steadily beyond the characteristic length of the static pair correlation function $g(r)$ in the temperature range approaching the mode coupling temperature from above