Sediments from five Leg 167 drill sites and three piston cores were analyzed for C[subscript ORG] and CaCO₃. Oxygen isotope stratigraphy on benthic foraminifers was used to assign age models to these sedimentary records. We find that the northern and central California margin is characterized by k.y.-scale events that can...
Carbon isotopically based estimates of CO₂ levels have been generated from a record of the photosynthetic fractionation of ¹³C (≡εp) in a central equatorial Pacific sediment core that spans the last ~255 ka. Contents of ¹³C in phytoplanktonic biomass were determined by analysis of C37 alkadienones. These compounds are exclusive...
The down‐regulation of dominant oncogenes, including C‐MYC, in tumor cells often leads to the induction of
senescence via mechanisms that are not completely identified. In the current study, we demonstrate that MYC‐depleted
melanoma cells undergo extensive DNA damage that is caused by the underexpression of thymidylate synthase (TS) and
ribonucleotide...
During July 1970, albacore boats trolling surface jigs (jig boats) had record catches in an area off the mouth of the Columbia River. The jig fishery declined suddenly in late July and was poor throughout the remainder of the summer. No obvious oceanographic changes were correlated with these drastic changes...
In this letter, a simple and highly efficient successive-approximation
Registers (SAR) ADC realization is proposed. It requires an op-amp,
a comparator and only three equal-valued capacitors. The proposed
scheme is insensitive to the capacitor parasitics, and has a small
capacitance spread. With an oversampled scheme, it also allows
noise-shaping the...
Extended-counting A/D converters are proposed which achieve a high
accuracy by performing the conversion in several cycles. During the
first cycle, the circuit performs as an incremental ADC, while during the
remaining ones it acts as a multi-slope counting converter. With only
one opamp and a single-slope ADC, the accuracy...
A highly-digital technique is proposed for excess loop delay (ELD)
compensation in multi-bit continuous-time ΔΣ modulators. A digitally
controlled reference switching matrix is used to replace the power-hungry
signal adder and extra DAC driving the quantizer, which are
commonly used in ELD compensation. With the proposed technique,
the feedback DAC...
Aim C-4 grasses are distinct from C-3 grasses, because C-4 grasses respond in a different manner to light, temperature, CO2 and nitrogen and often have higher resource-use efficiencies. C-3 and C-4 grasses are typically represented in earth system models (ESMs) by different plant functional types (PFTs). The ability of ESMs...
Core-top benthic foraminifera (Cibicidoides wuellerstorfi) from a depth transect of Soutar box cores from the Ontong-Java Plateau (1.6 – 4.4 km) were analyzed for cadmium, barium, and strontium (Cd/Ca, Ba/Ca, and Sr/Ca) and for their stable isotopic composition (δ¹³C and δ¹⁸O). We also measure bottom water δ¹³C, Cd, and Ba...
Oceanic iron (Fe) fertilization experiments have advanced the understanding of how Fe regulates biological productivity and air–sea carbon dioxide (CO₂) exchange. However, little is known about the production and consumption of halocarbons and other gases as a result of Fe addition. Besides metabolizing inorganic carbon, marine microorganisms produce and consume...