Heterotrophic Bacterial Biomasses, Activities, and Productivities Within The Fraser River Plume

1983 ◽  
Vol 40 (S1) ◽  
pp. s216-s220 ◽  
Author(s):  
L. J. Albright
Keyword(s):  
Surface Water ◽  
Microbial Biomass ◽  
Bacterial Production ◽  
Preliminary Evidence ◽  
Bacterial Activity ◽  
Fraser River ◽  
Free Living ◽  
Strait Of Georgia ◽  
Heterotrophic Activity ◽  
Stimulation Of

Most of the microorganisms within the silt-laden Fraser River water are bacteria, the majority of which are attached to detritus and suspended silt. However, within surface water of the Strait of Georgia bacteria constitute only about 4% of the microbial biomass; most are free-living. Within the plume, which results when the freshwater of the Fraser River mixes with the seawater of the Strait of Georgia (salinity of about 27‰ and containing mainly phytoplankton) stimulations of bacterial glucose heterotrophic activity and productivity occur throughout the year. Bacterial production is a relatively greater proportion of the total microbial, i.e. both algal and bacterial production, in the winter than in the spring or fall. Preliminary evidence indicates that the stimulation of bacterial activity and productivity may be, at least partially, due to entrainment of nitrate and phosphate-rich deep water of the Strait of Georgia into the Fraser plume.Key words: Fraser plume, bacteria, production, heterotrophic activity, Strait of Georgia

Drift Bottle Observations in the Strait of Georgia

1958 ◽  
Vol 15 (5) ◽  
pp. 1065-1102 ◽  
Author(s):  
Michael Waldichuk
Keyword(s):  
Surface Water ◽  
River Estuary ◽  
Surface Current ◽  
Fraser River ◽  
Strait Of Georgia ◽  
Average Speed ◽  
Local Areas ◽  
Strong Surface ◽  
Gulf Islands ◽  
Western Side

Drift bottle observations were carried out in the Strait of Georgia during the summers of 1926–1929. A total of 1,636 bottles was released of which 672 were recovered, giving an over-all return of 41%.No consistent pattern of drift in the strait as a whole could be clearly drawn from the recoveries. Some consistency of circulation in local areas can be inferred from the net drift of bottles.Winds dominated drift bottle movements in the open strait, where tidal currents are weak. A general northwestward drift was noted from releases along the eastern side of the strait and a southeastward drift along the western side. This suggests a large counterclockwise circulation of surface water over the whole strait. A smaller gyral circulating in the same direction is apparent in the southern strait, south of a line from Sand Heads to Active Pass.A strong surface current is directed from the Fraser River estuary across the strait to the passes among the Gulf Islands. This seaward flow of fresh water is augmented by a strong seaward tidal current during large ebb tides.Tidal currents are strong with definite periodicities in the channels bordering the strait. Current speeds of more than 26 cm./sec. (0.5 knot) were calculated from data on drift bottles whose drift was of brief duration. Average speed of drift was about 10 cm./sec. (0.2 knot).

Physical Oceanography of the Strait of Georgia, British Columbia

1957 ◽  
Vol 14 (3) ◽  
pp. 321-486 ◽  
Author(s):  
Michael Waldichuk
Keyword(s):  
Surface Water ◽  
Fresh Water ◽  
Deep Water ◽  
Physical Oceanography ◽  
Intermediate Water ◽  
Fraser River ◽  
Strait Of Georgia ◽  
Juan De Fuca ◽  
Oceanographic Data ◽  
Juan De Fuca Strait

A descriptive and quantitative analysis of the physical oceanography of the Strait of Georgia has been made.The area has been characterized by extreme seasonal and regional variability of the surface waters. Deep water undergoes only small change. Runoff, principally from the Fraser River, is the major cause of salinity variation. Surface warming by insolation is reflected in high summer surface water temperatures in the Central and Northern Strait.Analysis of the Strait of Georgia has been based on a hypothetical model of a deep, rectangular basin connected to the sea by mixing baffles and a long channel. Fresh water inflow is concentrated near the southern end of the basin. The Strait of Georgia–Juan de Fuca Strait system has basically three water masses: (1) the brackish surface water from runoff in the Strait of Georgia; (2) the deep water of oceanic origin in Juan de Fuca Strait; and (3) a mixture of (1) and (2) which forms at the sills. This mixture contributes to the deep water in the Strait of Georgia and to the upper seaward-flowing layer in Juan de Fuca Strait. Bottom water is formed in late autumn when dense sea water from Juan de Fuca Strait intrudes into the mixing area of the southern sills. An Intermediate Water is formed during some cold winters in the Northern Strait. A slow intrusion of warm Intermediate Water occurs from the southern sills in late summer.A general counter-clockwise circulation exists in the Strait of Georgia. Tides, runoff, and winds are the principal generating forces. Topography, Coriolis force, and centrifugal force are the main directive factors. Circulation has been studied from drift bottle experiments, mass distribution, and isentropic analysis.Some of the effects of winds in mean sea level changes and surface currents have been evaluated. Wind effects are most pronounced in influencing the circulation of the upper brackish layer.Waters are most stable in the Central and Northern Strait. Intensive tidal mixing renders the waters of the Southern Strait nearly homogeneous, particularly in winter. The largest amount of mixing energy comes from the tide, but winds contribute substantially to mixing in the surface water. The potential energy change from a stratified to a mixed column of water in the Southern Strait has been computed. Keulegan's criterion of mixing is applied to the system at the Fraser River estuary.A technique for determining the fresh water budget in the Strait of Georgia has been developed. This has been evaluated on the basis of the 1950 meteorological, hydrological, and oceanographic data. At a particular time there is a volume of fresh water in the Strait of Georgia equivalent to 1⅓ years of Fraser River discharge based on an average salinity of 33.8‰ in the inflowing oceanic water. Little effect in the overall fresh water content of the system is caused by sudden increases or decreases in the runoff.The heat budget based on five stations where the necessary meteorological and oceanographic data were available has been evaluated for 1950. Considerable variation in evaporation is largely dependent on the variation in surface water temperature. Peak evaporation occurs in the Southern Strait in late autumn with negative (condensation) values in late summer. Maximum evaporation occurs in mid-summer in the Central and Northern Strait. On a yearly basis, there is a loss of heat from the system through the transport seaward of surface water.Some concepts of inshore oceanography are given with general guiding principles for the planning and conduct of surveys.

The Qualitative and Quantitative Distribution of Plankton in the Strait of Georgia in Relation to Certain Oceanographic Factors

1957 ◽  
Vol 14 (4) ◽  
pp. 521-552 ◽  
Author(s):  
Joseph Eugène Henri Légaré
Keyword(s):  
Salinity Gradient ◽  
General Distribution ◽  
Fraser River ◽  
Strait Of Georgia ◽  
Quantitative Distribution ◽  
Qualitative And Quantitative ◽  
Chemical Factors ◽  
Physical And Chemical ◽  
Plankton Communities ◽  
Made In

In order to gain some picture of the seasonal variations in the plankton communities two cruises were made in the Strait of Georgia, one in June 1955, and the other in November 1955; 165 plankton collections were taken, also surface temperatures.The correlation of these data have resulted in a number of conclusions concerning the distribution of plankton in the Strait of Georgia. The chief factor affecting the general distribution of plankton is the salinity gradient. The inflow of fresh water from the Fraser River forms zones of varying properties, and leads to the development of different plankton communities. The extent to which physical and chemical factors may determine the presence or absence of certain organisms from the zones described is discussed.

Construction of the Iona Outfall submarine section

1990 ◽  
Vol 17 (1) ◽  
pp. 113-118 ◽  
Author(s):  
T. W. Lively ◽  
C. D. Gowe ◽  
H. R. Woodhead
Keyword(s):  
Key Words ◽  
Joint Venture ◽  
Sewage Treatment ◽  
Bolted Joints ◽  
Fraser River ◽  
Strait Of Georgia ◽  
Alternative Method

In February 1987, the Greater Vancouver Sewerage and Drainage District awarded an $8.5 million contract for the construction of the Iona Outfall submarine section. The contract awarded to the Dillingham–Manson joint venture involved the installation of approximately 3200 m of twin 2.3 m diameter steel outfall, of which 500 m was twin 2.1, 1.8, and 1.4 m diameter steel diffuser sections. The outfall extended from the end of the Iona Jetty into the Strait of Georgia near the mouth of the Fraser River and was 107 m deep at the end of the diffuser. The tender documents suggested a method of installation such that the entire twin outfall pipe was fabricated on an existing jetty complete with flotation pipe and pulled into the water. The contractor submitted an alternative method with the tender and was the successful low bidder. The proposed installation method was to assemble the pipe into nominal 300 m lengths in Dillingham's North Vancouver yard, launch them, tow them to the site, and sink and bolt them together underwater. This paper discusses the more interesting aspects of the project. Key words: construction, pipelines, robotics, sewage treatment, bolted joints.

Stimulation of cell division and DNA replication inPrototheca richardsiby passage through larval amphibian guts

Parasitology ◽  
1993 ◽  
Vol 107 (2) ◽  
pp. 119-124 ◽  
Author(s):  
T. J. C. Beebee ◽  
A. L.-C. Wong
Keyword(s):  
Cell Division ◽  
Dna Replication ◽  
Growth Inhibition ◽  
Dna Synthesis ◽  
Free Living ◽  
Leucine Uptake ◽  
Amphibian Larvae ◽  
Larval Amphibian ◽  
Stimulation Of

SUMMARYPrototheca richardsi, an unpigmented heterotrophic alga, causes growth inhibition in amphibian larvae and has proved refractory to culturein Vitro.P. richardsireplication is dependent on regular passaging through tadpole digestive systems; uptake of thymidine by free-livingProtothecacells and incorporation into DNA are very low by comparison with leucine uptake and incorporation into protein, but DNA synthesis is detectable in cells isolated from tadpole intestines. DNA replication was elicited 6–8 h after ingestion in protothecans fed to tadpoles and subsequently re-isolated from them, providing that the tadpoles were fed subsequent to the ingestion. It appears that passaging through tadpole intestines provides an essential stimulus to maintaining an active cell division cycle inP. richardsi.

scholarly journals Effects of Deep Brain Stimulation of the Subthalamic Nucleus Settings on Voice Quality, Intensity, and Prosody in Parkinson’s Disease: Preliminary Evidence for Speech Optimization

2019 ◽  
Vol 46 (3) ◽  
pp. 287-294 ◽  
Author(s):  
Anita Abeyesekera ◽  
Scott Adams ◽  
Cynthia Mancinelli ◽  
Thea Knowles ◽  
Greydon Gilmore ◽  
...  
Keyword(s):  
Deep Brain Stimulation ◽  
Subthalamic Nucleus ◽  
Brain Stimulation ◽  
Pulse Width ◽  
Voice Quality ◽  
Preliminary Evidence ◽  
Clinical Settings ◽  
Stn Dbs ◽  
Deep Brain ◽  
Stimulation Of

ABSTRACT:Objective: To systematically evaluate how different deep brain stimulation of the subthalamic nucleus (STN-DBS) amplitude, frequency, and pulse-width electrical parameter settings impact speech intensity, voice quality, and prosody of speech in Parkinson’s disease (PD). Methods: Ten individuals with PD receiving bilateral STN-DBS treatments were seen for three baseline and five treatment visits. The five treatment visits involved an examination of the standard clinical settings as well as manipulation of different combinations of frequency (low, mid, and high), pulse width (low, mid, and high), and voltage (low, mid, and high) of stimulation. Measures of speech intensity, jitter, shimmer, harmonics–noise ratio, semitone standard deviation, and listener ratings of voice quality and prosody were obtained for each STN-DBS manipulation. Results: The combinations of lower frequency, lower pulse width, and higher voltage settings were associated with improved speech outcomes compared to the current standard clinical settings. In addition, decreased total electrical energy delivered to the STN appears to be associated with speech improvements. Conclusions: This study provides preliminary evidence that STN-DBS may be optimized for Parkinson-related problems with voice quality, speech intensity, and prosody of speech.

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