An Active Source EM Method for the Seafloor

An active source EM method has been used on the deep seafloor near the East Pacific Rise. The source consisted of an 800 meter long horizontal antenna grounded at the ends and supplied with 100 ampere excitation in a range of frequencies extending from 1/4 to 3 Hz. Power for the source was supplied from a surface ship. Receivers were autonomous units each detecting the horizontal components of the electric field by a crossed pair of 9 m antennas. The r.m.s. noise voltage in the receivers was several times greater than the thermal agitation noise in the electrode-ta-sea water resistance of 4 ohms. Electromagnetic induction from turbulence induced by water flow past the electrodes may be a contribution to the excess noise. A signal/noise ratio of more than 20 dB was evident at a distance of 18.9 km from the source in a bandwidth of 2 X 10 -3 Hz

A description of tides near the Chesapeake Bay entrance using in situ data with an adjoint model

Time series of surface elevation and current velocity in the vicinity of the Chesapeake Bay entrance are assimilated into a linear, barotropic model using an iterative adjoint method. Tide surface elevations, NOAA‐NOS tidal data, moored acoustic Doppler current profiler (ADCP), and ocean surface current radar (OSCR) data are included in the assimilation. Data are analyzed for three tidal constituents (M2, S2, O1); tidal series are constructed from these constituents and then used in the model assimilations. Statistics of predicted currents compare favorably with those calculated from data not used in the assimilation. An error analysis of the data distribution is performed for the M2 tidal component, showing lower errors near assimilation data series but large errors, particularly for velocity, at some locations. Addition of a hypothetical current mooring dramatically reduces errors over most of the domain. We believe these results give the most demonstrably accurate description now available of tidal currents for this region of strong currents and heavy shipping

International Journal of Molecular Sciences / Loss of SR-BI Down-Regulates MITF and Suppresses Extracellular Vesicle Release in Human Melanoma

Melanoma is a skin tumor with a high tendency for metastasis and thus is one of the deadliest cancers worldwide. Here, we investigated the expression of the scavenger receptor class B type 1 (SR-BI), a high-density lipoprotein (HDL) receptor, and tested for its role in melanoma pigmentation as well as extracellular vesicle release. We first analyzed the expression of SR-BI in patient samples and found a strong correlation with MITF expression as well as with the melanin synthesis pathway. Hence, we asked whether SR-BI could also play a role for the secretory pathway in metastatic melanoma cells. Interestingly, gain- and loss-of-function of SR-BI revealed regulation of the proto-oncogene MET. In line, SR-BI knockdown reduced expression of the small GTPase RABB22A, the ESCRT-II protein VPS25, and SNAP25, a member of the SNARE complex. Accordingly, reduced overall extracellular vesicle generation was detected upon loss of SR-BI. In summary, SR-BI expression in human melanoma enhances the formation and transport of extracellular vesicles, thereby contributing to the metastatic phenotype. Therapeutic targeting of SR-BI would not only interfere with cholesterol uptake, but also with the secretory pathway, therefore suppressing a key hallmark of the metastatic program.(VLID)491292