Tide-well systems II: The frequency response of a linear tide-well system

Recent uses to which tide records have been put have exposed limitations of the nonlinear tide well with an orifice. By replacing the orifice with a long horizontal pipe connection, the system becomes essentially linear and the limitations of the conventional system no longer apply. The analysis in this paper shows that unsteady effects in the pipe flow produce the main features of the frequency response of the system; the hydrodynamic filtering of waves due to the depth of the pipe connection and the effect of the inertia of the water in the well are relatively unimportant...

Tide-well systems I: Some non-linear effects of the conventional tide well

Recent uses to which tide records have been put has revealed that modern analytical techniques have outstripped the quality of available data. Lack of knowledge of the response of the conventional type tide well has been a serious handicap to workers in this field. The analysis in this paper shows that non-linearities, caused by the flow through the orifice, produce the main features of the response of the system; the hydrodynamic filtering of waves, due to the depth of the orifice and the effect of the inertia of the water in the well, are relatively unimportant

Tide-well systems III:Improved interpretation of tide-well records

Recent studies of the non-linear response of the conventional tide-well system have pointed out the deficiencies of the system when the tide records are to be used for scientific purposes requiring very accurate data. An experimental method of checking the response of such tidewells, by means of a drainage test, is described. This provides the basis of a further method, by which the height of the water level in the well may be approximately corrected to give the height of the sea level outside the well. The application of these methods, to a recently advocated linear tide-well system, is also described

Larval dispersion along a straight coast with tidal currents: Complex distribution patterns from a simple model

Copyright © 1995 Inter-Research.The majority of marine species have a complex life cycle where the adult phase is preceded by a pelagic larval phase. The dynamics of the more obvious adult phase may be strongly influenced by the distribution and abundance of larvae. Field experiments have been unable to give a complete picture of the spatial-temporal dynamics of the larval phase. This is due to the extremely small size of the individual larvae and the environment in which they live. Here we present a mathematical model of the dispersal of larvae into a region consisting of a straight coastline and a current dominated by tidal effects. Spawning is near the coast from a well-defined site the size of a small jetty or reef and the larvae have a relatively short pelagic lifetime. The model is based on the advection-diffusion-mortality equation. Using a new analytic solution to the model, we examine the effect of processes such as the current structure, mortality, and the duration and rate at which larvae are released, on dispersal. The model is relatively simple but produces surprisingly complex patterns of dispersal. This has implications for attempts to produce more complex models of dispersal and the way in which field data of larval densities should be interpreted.S. A. Richards, H. P. Possingham, B. J. Noy

A century of sea level measurements at Newlyn, SW England

The Newlyn Tidal Observatory is the most important sea level station in the UK. It commenced operations in 1915 as part of the Second Geodetic Levelling of England and Wales, and the mean sea level determined from the tide gauge during the first six years (May 1915-April 1921) defined Ordnance Datum Newlyn (ODN) which became the national height datum for the whole of Great Britain. The 100 years of sea level data now available have contributed significantly to many studies in oceanography, geology and climate change. This paper marks the centenary of this important station by reviewing the sea level (and, more recently, detailed land level) measurements and Newlyn’s contributions to UK cartography, geodesy and sea-level science in general. Recommendations are made on how sea and land level measurements at Newlyn might be enhanced in the future

The swan genome and transcriptome, its not all black and white

BACKGROUND: The Australian black swan (Cygnus atratus) is an iconic species with contrasting plumage to that of the closely related northern hemisphere white swans. The relative geographic isolation of the black swan may have resulted in a limited immune repertoire and increased susceptibility to infectious diseases, notably infectious diseases from which Australia has been largely shielded. Unlike mallard ducks and the mute swan (Cygnus olor), the black swan is extremely sensitive to highly pathogenic avian influenza. Understanding this susceptibility has been impaired by the absence of any available swan genome and transcriptome information. RESULTS: Here, we generate the first chromosome-length black and mute swan genomes annotated with transcriptome data, all using long-read based pipelines generated for vertebrate species. We use these genomes and transcriptomes to show that unlike other wild waterfowl, black swans lack an expanded immune gene repertoire, lack a key viral pattern-recognition receptor in endothelial cells and mount a poorly controlled inflammatory response to highly pathogenic avian influenza. We also implicate genetic differences in SLC45A2 gene in the iconic plumage of the black swan. CONCLUSION: Together, these data suggest that the immune system of the black swan is such that should any avian viral infection become established in its native habitat, the black swan would be in a significant peril. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13059-022-02838-0

The swan genome and transcriptome, it is not all black and white

Background: The Australian black swan (Cygnus atratus) is an iconic species with contrasting plumage to that of the closely related northern hemisphere white swans. The relative geographic isolation of the black swan may have resulted in a limited immune repertoire and increased susceptibility to infectious diseases, notably infectious diseases from which Australia has been largely shielded. Unlike mallard ducks and the mute swan (Cygnus olor), the black swan is extremely sensitive to highly pathogenic avian influenza. Understanding this susceptibility has been impaired by the absence of any available swan genome and transcriptome information. Results: Here, we generate the first chromosome-length black and mute swan genomes annotated with transcriptome data, all using long-read based pipelines generated for vertebrate species. We use these genomes and transcriptomes to show that unlike other wild waterfowl, black swans lack an expanded immune gene repertoire, lack a key viral pattern-recognition receptor in endothelial cells and mount a poorly controlled inflammatory response to highly pathogenic avian influenza. We also implicate genetic differences in SLC45A2 gene in the iconic plumage of the black swan. Conclusion: Together, these data suggest that the immune system of the black swan is such that should any avian viral infection become established in its native habitat, the black swan would be in a significant peril