scholarly journals Description of a new beaked whale echolocation pulse type in the California Current

2018 ◽  
Vol 35 (3) ◽  
pp. 1058-1069 ◽  
Author(s):  
Emily T. Griffiths ◽  
Jennifer L. Keating ◽  
Jay Barlow ◽  
Jeffrey E. Moore
Keyword(s):  
California Current ◽  
Beaked Whale ◽  
Pulse Type ◽  
Echolocation Pulse

An annotated checklist of mesoplodont whale species (Cetacea, Ziphiidae) discovered during the nineteenth century

2015 ◽  
Vol 42 (2) ◽  
pp. 226-235 ◽  
Author(s):  
G. N. H. Waller
Keyword(s):  
Nineteenth Century ◽  
Additional Data ◽  
Original Description ◽  
Type Specimen ◽  
External Morphology ◽  
Type Locality ◽  
Type Material ◽  
Beaked Whale ◽  
Registration Number ◽  
Annotated Checklist

Eight species of mesoplodont whales (genus Mesoplodon Gervais, 1850) named during the nineteenth century are based on valid descriptions. A checklist with the original description and type material for each of these species is provided. Additional data given may include type locality and illustrative sources, type material holding institution and type registration number(s). The only type specimen for which a record of external morphology was published relates to the 1803 stranding of Sowerby's beaked whale (Mesoplodon bidens).

Low Capacity Implementation of a Pulse-Type Chaotic Neuron Model

2016 ◽  
Vol 136 (10) ◽  
pp. 1424-1430 ◽  
Author(s):  
Yoshiki Sasaki ◽  
Katsutoshi Saeki ◽  
Yoshifumi Sekine
Keyword(s):  
Neuron Model ◽  
Pulse Type ◽  
Chaotic Neuron

The Carbon:²³⁴Thorium ratios of sinking particles in the California Current Ecosystem 2: Examination of a thorium sorption, desorption, and particle transport model

2019 ◽  
Author(s):  
Michael Stukel ◽  
Thomas Kelly
Keyword(s):  
Organic Carbon ◽  
Water Column ◽  
Particulate Organic Carbon ◽  
Transport Model ◽  
California Current ◽  
In Situ Measurements ◽  
Power Law Distribution ◽  
Sinking Particles ◽  
Organic Carbon Concentration

Thorium-234 (234Th) is a powerful tracer of particle dynamics and the biological pump in the surface ocean; however, variability in carbon:thorium ratios of sinking particles adds substantial uncertainty to estimates of organic carbon export. We coupled a mechanistic thorium sorption and desorption model to a one-dimensional particle sinking model that uses realistic particle settling velocity spectra. The model generates estimates of 238U-234Th disequilibrium, particulate organic carbon concentration, and the C:234Th ratio of sinking particles, which are then compared to in situ measurements from quasi-Lagrangian studies conducted on six cruises in the California Current Ecosystem. Broad patterns observed in in situ measurements, including decreasing C:234Th ratios with depth and a strong correlation between sinking C:234Th and the ratio of vertically-integrated particulate organic carbon (POC) to vertically-integrated total water column 234Th, were accurately recovered by models assuming either a power law distribution of sinking speeds or a double log normal distribution of sinking speeds. Simulations suggested that the observed decrease in C:234Th with depth may be driven by preferential remineralization of carbon by particle-attached microbes. However, an alternate model structure featuring complete consumption and/or disaggregation of particles by mesozooplankton (e.g. no preferential remineralization of carbon) was also able to simulate decreasing C:234Th with depth (although the decrease was weaker), driven by 234Th adsorption onto slowly sinking particles. Model results also suggest that during bloom decays C:234Th ratios of sinking particles should be higher than expected (based on contemporaneous water column POC), because high settling velocities minimize carbon remineralization during sinking.

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