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Geochemistry and petrogenesis of volcanic rocks from Daimao Seamount (South China Sea) and their tectonic implications
The South China Sea (SCS) experienced three episodes of seafloor spreading and left three fossil spreading centers presently located at 18°N, 17°N and 15.5°N. Spreading ceased at these three locations during magnetic anomaly 10, 8, and 5c, respectively. Daimao Seamount (16.6. Ma) was formed 10. my after the cessation of the 17°N spreading center. Volcaniclastic rocks and shallow-water carbonate facies near the summit of Daimao Seamount provide key information on the seamount's geologic history. New major and trace element and Sr-Nd-Pb isotopic compositions of basaltic breccia clasts in the volcaniclastics suggest that Daimao and other SCS seamounts have typical ocean island basalt-like composition and possess a 'Dupal' isotopic signature. Our new analyses, combined with available data, indicate that the basaltic foundation of Daimao Seamount was formed through subaqueous explosive volcanic eruptions at 16.6. Ma. The seamount subsided rapidly (>. 0.12. mm/y) at first, allowing the deposition of shallow-water, coral-bearing carbonates around its summit and, then, at a slower rate (<. 0.12. mm/y). We propose that the parental magmas of SCS seamount lavas originated from the Hainan mantle plume. In contrast, lavas from contemporaneous seamounts in other marginal basins in the western Pacific are subduction-related
Anoikis resistance is a critical feature of highly aggressive ovarian cancer cells
High-grade serous ovarian cancer is an aggressive form of epithelial ovarian cancer (EOC), and accounts for the majority of deaths due to EOC. The critical cellular processes and underlying molecular mechanisms that define this malignancy remain poorly understood. Using a syngeneic murine model, we investigated the changes that accompanied the progression to increased aggressiveness induced by in vivo passage of mouse EOC cells. We found that enhanced anoikis resistance was a key cellular process associated with greater aggressiveness and tumorigenicity in vivo. Biochemical studies revealed that the enhanced anoikis resistance was associated with the activation of the Src/Akt/Erk signaling pathway. A higher rate of metabolism and autophagy were also associated with increased anoikis resistance. Blocking these pathways with specific inhibitors and/or genetic modifications significantly increased anoikis in vitro and inhibited tumor development in vivo. In addition, we demonstrated that similar signaling pathways were also involved in a human EOC cell line model. Collectively, our data suggest that anoikis resistance represents a critical and a distinguishing feature underlying the aggressiveness of ovarian cancer cells
Decoupling of the superconducting and magnetic (structural) phase transitions in electron-doped BaFe2As2
Study and comparison of over 30 examples of electron doped BaFe2As2 for
transition metal (TM) = Co, Ni, Cu, and (Co/Cu mixtures) have lead to an
understanding that the suppression of the structural/antiferromagnetic phase
transition to low enough temperature in these compounds is a necessary
condition for superconductivity, but not a sufficient one. Whereas the
structural/antiferromagnetic transitions are suppressed by the number of TM
dopant ions (or changes in the c-axis) the superconducting dome exists over a
limited range of values of the number of electrons added by doping (or values
of the {a/c} ratio). By choosing which combination of dopants are used we can
change the relative positions of the upper phase lines and the superconducting
dome, even to the extreme limit of suppressing the upper structural and
magnetic phase transitions without the stabilization of low temperature
superconducting dome
On cost-effective communication network designing
How to efficiently design a communication network is a paramount task for
network designing and engineering. It is, however, not a single objective
optimization process as perceived by most previous researches, i.e., to
maximize its transmission capacity, but a multi-objective optimization process,
with lowering its cost to be another important objective. These two objectives
are often contradictive in that optimizing one objective may deteriorate the
other. After a deep investigation of the impact that network topology, node
capability scheme and routing algorithm as well as their interplays have on the
two objectives, this letter presents a systematic approach to achieve a
cost-effective design by carefully choosing the three designing aspects. Only
when routing algorithm and node capability scheme are elegantly chosen can
BA-like scale-free networks have the potential of achieving good tradeoff
between the two objectives. Random networks, on the other hand, have the
built-in character for a cost-effective design, especially when other aspects
cannot be determined beforehand.Comment: 6 pages, 4 figure
A New Method to Calculate Electromagnetic Impedance Matching Degree in One-Layer Microwave Absorbers
A delta-function method was proposed to quantitatively evaluate the
electromagnetic impedance matching degree. Measured electromagnetic parameters
of {\alpha}-Fe/Fe3B/Y2O3 nanocomposites are applied to calculate the matching
degree by the method. Compared with reflection loss and quarter-wave principle
theory, the method accurately reveals the intrinsic mechanism of microwave
transmission and reflection properties. A possible honeycomb structure with
promising high-performance microwave absorption according to the method is also
proposed.Comment: 13 pages, 3 figure
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