Generation and Structure of Solitary Rossby Vortices in Rotating Fluids

The formation of zonal flows and vortices in the generalized Charney-Hasegawa-Mima equation is studied. We focus on the regime when the size of structures is comparable to or larger than the deformation (Rossby) radius. Numerical simulations show the formation of anticyclonic vortices in unstable shear flows and ring-like vortices with quiescent cores and vorticity concentrated in a ring. Physical mechanisms that lead to these phenomena and their relevance to turbulence in planetary atmospheres are discussed.Comment: 3 pages in REVTeX, 5 postscript figures separately, submitted to Phys. Rev.

Systematic Review and Meta-Analysis Toward Synthesis of Thresholds of Ocean Acidification Impacts on Calcifying Pteropods and Interactions With Warming

Interpreting the vulnerability of pelagic calcifiers to ocean acidification (OA) is enhanced by an understanding of their critical thresholds and how these thresholds are modified by other climate change stressors (e.g., warming). To address this need, we undertook a three-part data synthesis for pteropods, one of the calcifying zooplankton group. We conducted the first meta-analysis and threshold analysis of literature characterizing pteropod responses to OA and warming by synthetizing dataset comprising of 2,097 datapoints. Meta-analysis revealed the extent to which responses among studies conducted on differing life stages and disparate geographies could be integrated into a common analysis. The results demonstrated reduced calcification, growth, development, and survival to OA with increased magnitude of sensitivity in the early life stages, under prolonged duration, and with the concurrent exposure of OA and warming, but not species-specific sensitivity. Second, breakpoint analyses identified OA thresholds for several endpoints: dissolution (mild and severe), calcification, egg development, shell growth, and survival. Finally, consensus by a panel of pteropod experts was used to verify thresholds and assign confidence scores for five endpoints with a sufficient signal: noise ratio to develop life-stage specific, duration-dependent thresholds. The range of aragonite saturation state from 1.5–0.9 provides a risk range from early warning to lethal impacts, thus providing a rigorous basis for vulnerability assessments to guide climate change management responses, including an evaluation of the efficacy of local pollution management. In addition, meta-analyses with OA, and warming shows increased vulnerability in two pteropod processes, i.e., shell dissolution and survival, and thus pointing toward increased threshold sensitivity under combined stressor effect

Nervous System of the Tornaria Larva (Hemichordata: Enteropneusta). A Histochemical and Ultrastructural Study

Volume: 183Start Page: 463End Page: 47

Novel, posterior sensory organ in the trochophore larva of Phyllodoce maculata (Polychaeta).

A new posterior sensory organ (PSO), located at the dorsal midline of the hyposphere, is described by immunocytochemical detection of acetylated alpha tubulin and serotonin (5-HT) in a laser-scanning microscope, as well as three-dimensional reconstructions after optical serial sectioning in the trochophore larva of the polychaete Phyllodoce maculata (Phyllodocidae). The unpaired PSO consists of five bipolar sensory cells, two of them being 5-HT immunopositive, which send axons to the cerebral ganglion and prototroch nerve. The dendrites of these cells project to the surface and bear one cilium each. A single neuronal fibre from the apical sensory organ innervates the PSO

Transmitter-Specific Subsets of Sensory Elements in the Prosobranch Osphradium

Volume: 187Start Page: 174End Page: 18