Osmoregulation in Juvenile and Adult Lampreys

1980 ◽  
Vol 37 (11) ◽  
pp. 1739-1750 ◽  
Author(s):  
F. W. H. Beamish
Keyword(s):  
Salt Water ◽  
Chloride Ions ◽  
Body Volume ◽  
Ionic Regulation ◽  
Salinity Change ◽  
River Lamprey ◽  
Control Serum ◽  
Sea Lampreys ◽  
The Relationship ◽  
Anadromous Form

Nonparasitic lampreys are well adapted for a freshwater existence but are less tolerant of salt water than representatives of the parasitic species. Anadromous feeding juvenile sea lampreys, Petromyzon marinus, are able to control serum osmotic and ionic concentrations in all salinities between 0 and 34‰. Juveniles of the anadromous European river lamprey, Lampetra fluviatilis, are slightly less tolerant of salinity change. The transition of P. marinus to a landlocked existence has resulted in a reduction in the capacity for marine osmoregulation. Tolerance to salt water among landlocked P. marinus is related directly to size emphasizing the advantage afforded through a reduction of surface area relative to body volume. Changes in serum osmolality are primarily the result of corresponding shifts in sodium and chloride ions. Changes in chloride are not accompanied by an equivalent shift in sodium suggesting that the relationship between the two ions is not passive. Regulation of sodium by landlocked P. marinus is not precise as that exhibited by the anadromous form particularly in the higher salinities. Nontrophic upstream migrant lampreys display a reduction in their marine osmoregulatory mechanisms and a restoration of the freshwater osmoregulatory apparatus. Freshwater osmotic and ionic regulation deteriorates in spent adult lampreys.Key words: blood, ionic regulation, osmotic regulation, parasitic and nonparasitic lampreys, salinity, life cycle

Do Extra-Platelet Sources Contribute to the Plasma Level of Thrombospondin?

1988 ◽  
Vol 59 (02) ◽  
pp. 273-276 ◽  
Author(s):  
J Dawes ◽  
D A Pratt ◽  
M S Dewar ◽  
F E Preston
Keyword(s):  
Platelet Count ◽  
Background Concentration ◽  
Serum Concentrations ◽  
Bone Marrow Depression ◽  
Serial Sampling ◽  
Control Serum ◽  
Platelet Release ◽  
Highly Correlated ◽  
The Relationship

SummaryThrombospondin, a trimeric glycoprotein contained in the platelet α-granules, has been proposed as a marker of in vivo platelet activation. However, it is also synthesised by a range of other cells. The extraplatelet contribution to plasma levels of thrombospondin was therefore estimated by investigating the relationship between plasma thrombospondin levels and platelet count in samples from profoundly thrombocytopenic patients with marrow hypoplasia, using the platelet-specific α-granule protein β-thromboglobulin as control. Serum concentrations of both proteins were highly correlated with platelet count, but while plasma β-thromboglobulin levels and platelet count also correlated, there was no relationship between the number of platelets and thrombospondin concentrations in plasma. Serial sampling of patients recovering from bone marrow depression indicated that the plasma thrombospondin contributed by platelets is superimposed on a background concentration of at least 50 ng/ml probably derived from a non-platelet source, and plasma thrombospondin levels do not simply reflect platelet release.

scholarly journals Golgi apparatus, GERL, and secretory granule formation within neurons of the hypothalamo-neurohypophysial system of control and hyperosmotically stressed mice.

1981 ◽  
Vol 90 (2) ◽  
pp. 474-484 ◽  
Author(s):  
R D Broadwell ◽  
C Oliver
Keyword(s):  
Golgi Apparatus ◽  
Secretory Granule ◽  
Supraoptic Nucleus ◽  
Salt Water ◽  
Secretory Granules ◽  
Hyperosmotic Stress ◽  
Granule Formation ◽  
Smooth Membrane ◽  
Secondary Lysosomes ◽  
The Relationship

The vasopressin-producing neurons of the hypothalamo-neurohypophysial system are a particularly good model with which to consider the relationship between the Golgi apparatus nd GERL and their roles in secretory granule production because these neurons increase their synthesis and secretion of vasopressin in response to hyperosmotic stress. Enzyme cytochemical techniques for acid phosphatase (AcPase) and thiamine pyrophosphatase (TPPase) activities were used to distinguish GERL from the Golgi apparatus in cell bodies of the supraoptic nucleus from normal mice, mice hyperosmotically stressed by drinking 2% salt water, and mice allowed to recover for 5-10 d from hyperosmotic stress. In nonincubated preparations of control supraoptic perikarya, immature secretory granules at the trans face of the Golgi apparatus were frequently attached to a narrow, smooth membrane cisterna identified as GERL. Secretory granules were occasionally seen attached to Golgi saccules. TPPase activity was present in one or two of the trans Golgi saccules; AcPase activity appeared in GERL and attached immature secretory granules, rarely in the trans Golgi saccules, and in secondary lysosomes. As a result of hyperosmotic stress, the Golgi apparatus hypertrophied, and secretory granules formed from all Golgi saccules and GERL. Little or no AcPase activity could be demonstrated in GERL, whereas all Golgi saccules and GERL-like cisternae were TPPase positive. During recovery, AcPase activity in GERL returned to normal; however, the elevated TPPase activity and secretory granule formation seen in GERL-like cisternae and all Golgi saccules during hyperosmotic stress persisted. These results suggest that under normal conditions GERL is the predominant site for the secretory granule formation, but during hyperosmotic stress, the Golgi saccules assume increased importance in this function. The observed cytochemical modulations in Golgi saccules and GERL suggest that GERL is structurally and functionally related to the Golgi saccules.

A Micropuncture Study of Kidney Function in the River Lamprey Lampetra Fluviatilis Adapted to Sea Water

1980 ◽  
Vol 88 (1) ◽  
pp. 239-248
Author(s):  
A. G. LOGAN ◽  
R. MORRIS ◽  
J. C. RANKIN
Keyword(s):  
Fresh Water ◽  
Kidney Function ◽  
Sea Water ◽  
Chloride Ions ◽  
Water Reabsorption ◽  
Plasma Electrolyte ◽  
River Lamprey ◽  
Micropuncture Study ◽  
Urine Composition ◽  
High Concentrations

Micropuncture techniques have been used to investigate kidney function in lampreys adapted to hyperosmotic media. Plasma electrolyte concentrations were maintained well below corresponding concentrations in the external environment. Urine composition was variable, but generally showed high concentrations of magnesium, sulphate and chloride ions. Lampreys in 50% sea water produced urine which was hypo or iso-osmotic to plasma, whereas those in 100% sea water produced hyperosmotic urine. Urine flow rate in 50% sea water was one tenth of that in fresh water, due to a reduction in filtration rate and an increase in water reabsorption by the kidney. As in fresh water, little if any filtered water was reabsorbed by the proximal segment. Almost 90% of filtered water was reabsorbed by the kidney of 100% sea water lampreys and most of this must have occurred in the distal and collecting segments.

Study on the Concrete in Chloride Environment Based on Electrochemical Impedance Spectroscopy

2019 ◽  
Vol 34 (06) ◽  
pp. 2059017
Author(s):  
Fengjiao Jiang ◽  
Jinxin Gong ◽  
Jichao Zhu ◽  
Huan Wang
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Electric Double Layer ◽  
Electrochemical Impedance ◽  
Pore Solution ◽  
Salt Water ◽  
Chloride Ions ◽  
Double Layer Capacitance ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Electric Double Layer Capacitance

In this paper, the effect of water-cement ratio and chloride ions on the concrete meso-structure was studied. Three kinds of concrete cubes with different water-cement ratios were immersed in fresh water and salt water, respectively. Then, the Electrochemical Impedance Spectroscopy (EIS) analysis of various test cubes were carried out by using electrochemical workstation. The results show that the salt water can improve electric double layer capacitance in the test cubes with the same water-cement ratio, but it can reduce some other parameters such as resistance of pore solution, resistance to transfer the hydrated electron, coefficient of diffusion impedance of concreter, which shows that the chloride ions diffused into the concrete in salt water and increase the ionic concentration in pore solution and C-S-H gel. However, the phase angle index is constant whether in fresh water or salt water, which shows chloride ions cannot affect the concrete meso-structure even though they can improve the ion concentration of pore structure. For the concrete test cubes which has different water-cement ratio in salt water, with the reduction of water-cement ratio, the electric double-layer capacitance of concrete remains unchanged, which indicates when the water-cement ratio becomes smaller, the porosity becomes lower, and the internal structure of concrete becomes denser.

Influence of saline drinking water on the flow and mineral composition of saliva and rumen fluid of sheep

1975 ◽  
Vol 26 (3) ◽  
pp. 585 ◽  
Author(s):  
FM Tomas ◽  
BJ Potter
Keyword(s):  
Drinking Water ◽  
Sodium Chloride ◽  
Flow Rate ◽  
Rumen Fluid ◽  
Salt Water ◽  
Chloride Ions ◽  
Saliva Flow Rate ◽  
Parotid Duct ◽  
Saliva Flow ◽  
Drinking Fluid

The influence of sodium chloride ingestion via the drinking water upon the flux of fluid and minerals to and from the rumen of sheep has been examined. Four Merino wethers were each prepared with ruminal and bilateral parotid duct fistulas to allow continuous sampling and measurement of flow rates and were offered rainwater which was zero, 136 or 221mM with respect to sodium chloride as the only source of drinking fluid. Parotid salivary flow rate decreased by up to 43% when the saline concentration of the drinking water was increased. There was an inverse relationship between saliva flow rate and the fluid intake, but much of the effect appeared to be due to ingestion of sodium chloride per se. Salt water ingestion caused an increase in the salivary concentration of sodium and phosphate; a decrease in that of potassium; and no change in that of chloride or osmolality. The rate of secretion of sodium varied directly with saliva flow rate. The outflow of water from the rumen to the omasum, or its net absorption across the rumen wall, were not influenced by treatment. In centrifuged rumen fluid samples saline ingestion caused increased levels of sodium, chloride and osmolality; decreased levels of potassium; and no change in calcium, magnesium or phosphate. Outflows of sodium and chloride to the omasum were increased. The apparent absorption of sodium and chloride from the rumen increased proportionately to the inflows of these ions via the saliva and drinking fluid. The additional sodium and chloride ions arising from the ingested saline were absorbed in approximately equal amounts. Saline drinking by sheep leads to a reduction in the rate of secretion of parotid saliva and its accompanying ions, which partially compensates for the added amount of fluid and electrolyte which enter the rumen in the drinking water.

Effect of Stray Current on Chloride Binding Mechanism in Concrete

2012 ◽  
Vol 204-208 ◽  
pp. 3720-3723 ◽  
Author(s):  
Qiao Zhu ◽  
Lin Hua Jiang ◽  
Yi Chen
Keyword(s):  
Chloride Ion ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Chloride Binding ◽  
Stray Current ◽  
Total Chloride ◽  
Binding Rate ◽  
Free Chloride ◽  
The Relationship ◽  
Bound Chloride

In this article, simulation tests of chloride binding were made under the condition of sodium chloride as an internal admixture while loaded with stray current externally. Through the potential titration method, free chloride ion concentration Cf 、 total chloride ion concentration Ct and chloride binding rate RCl were determined. The results show that: With the increase of the strength and action time of the stray current, the number of internal free chloride ions in the cement paste increases while that of the corresponding bound chloride ions reduces significantly, leading to the decrease of chloride binding rate. The relationship between chloride binding rate and the two can be shown as follows respectively:RCl=50.754e(-I/28.258)+42.532、RCl=63.427 e(-T/8.238)+27.325.

scholarly journals An Experimental Study for Quantitative Estimation of Rebar Corrosion in Concrete Using Ground Penetrating Radar

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Md Istiaque Hasan ◽  
Nur Yazdani
Keyword(s):  
Reinforced Concrete ◽  
Quantitative Estimation ◽  
Salt Water ◽  
Water Solution ◽  
Maximum Amplitude ◽  
Accelerated Corrosion ◽  
Oil Emulsion ◽  
Steel Rebar ◽  
Ground Penetrating ◽  
The Relationship

Corrosion of steel rebar in reinforced concrete is one the most important durability issues in the service life of a structure. In this paper, an investigation is conducted to find out the relationship between the amount of reinforced concrete corrosion and GPR maximum positive amplitude. Accelerated corrosion was simulated in the lab by impressing direct current into steel rebar that was submerged in a 5% salt water solution. The amount of corrosion was varied in the rebars with different levels of mass loss ranging from 0% to 45%. The corroded rebars were then placed into three different oil emulsion tanks having different dielectric properties similar to concrete. The maximum amplitudes from the corroded bars were recorded. A linear relationship between the maximum positive amplitudes and the amount of corrosion in terms of percentage loss of area was observed. It was proposed that the relationship between the GPR maximum amplitude and the amount of corrosion can be used as a basis of a NDE technique of quantitative estimation of corrosion.

Buoyancy of Atlantic and Pacific Herring

1969 ◽  
Vol 26 (8) ◽  
pp. 2077-2091 ◽  
Author(s):  
Vivien M. Brawn
Keyword(s):  
Vertical Movement ◽  
Body Volume ◽  
Pacific Herring ◽  
Natural Conditions ◽  
The Pacific ◽  
In Captivity ◽  
The Mean ◽  
Total Body ◽  
Total Body Volume ◽  
The Relationship

Pacific and Atlantic herring after adjustment to water 36 cm deep had sinking-factors between 1000 and 1008 and showed an inverse relationship between oil content and swimbladder volume up to 12% oil. At higher oil contents a swimbladder volume between 2.6 and 3.0% of total body volume was maintained. The mean volumes and densities of various components of the Pacific herring held in captivity were: swimbladder gas 4.1% of total volume,.0013 g/ml; oil 3.5%,.926 g/ml; scales 0.5%, 1.966 g/ml; skeleton 1.2%, 1.993 g/ml; rest of fish 90.6%, 1.057 g/ml. These components on the average exerted upward forces of 41.4 and 3.3 dynes/ml of fish due to gas and oil, and downward forces of 4.6, 11.2, and 32.1 dynes/ml due to scales, skeleton, and the rest of the fish respectively. Under natural conditions herring usually have high oil contents so the relationship observed here suggests they have low swimbladder volumes. This combined with a duct direct from the swimbladder to the exterior and the lack of gas secretion would give the herring freedom of vertical movement and a low change of sinking factor with depth.

scholarly journals The universal aspect ratio of vortices in rotating stratified flows: experiments and observations

2012 ◽  
Vol 706 ◽  
pp. 34-45 ◽  
Author(s):  
Oriane Aubert ◽  
Michael Le Bars ◽  
Patrice Le Gal ◽  
Philip S. Marcus
Keyword(s):  
Aspect Ratio ◽  
Salt Water ◽  
Boussinesq Equations ◽  
Companion Paper ◽  
Buoyancy Frequency ◽  
Coriolis Parameter ◽  
Aspect Ratios ◽  
Horizontal Length ◽  
The Law ◽  
The Relationship

AbstractWe validate a new law for the aspect ratio $\ensuremath{\alpha} = H/ L$ of vortices in a rotating, stratified flow, where $H$ and $L$ are the vertical half-height and horizontal length scale of the vortices. The aspect ratio depends not only on the Coriolis parameter $f$ and buoyancy (or Brunt–Väisälä) frequency $\bar {N} $ of the background flow, but also on the buoyancy frequency ${N}_{c} $ within the vortex and on the Rossby number $\mathit{Ro}$ of the vortex, such that $\ensuremath{\alpha} = f \mathop{ [\mathit{Ro}(1+ \mathit{Ro})/ ({ N}_{c}^{2} \ensuremath{-} {\bar {N} }^{2} )] }\nolimits ^{1/ 2} $. This law for $\ensuremath{\alpha} $ is obeyed precisely by the exact equilibrium solution of the inviscid Boussinesq equations that we show to be a useful model of our laboratory vortices. The law is valid for both cyclones and anticyclones. Our anticyclones are generated by injecting fluid into a rotating tank filled with linearly stratified salt water. In one set of experiments, the vortices viscously decay while obeying our law for $\ensuremath{\alpha} $, which decreases over time. In a second set of experiments, the vortices are sustained by a slow continuous injection. They evolve more slowly and have larger $\vert \mathit{Ro}\vert $ while still obeying our law for $\ensuremath{\alpha} $. The law for $\ensuremath{\alpha} $ is not only validated by our experiments, but is also shown to be consistent with observations of the aspect ratios of Atlantic meddies and Jupiter’s Great Red Spot and Oval BA. The relationship for $\ensuremath{\alpha} $ is derived and examined numerically in a companion paper by Hassanzadeh, Marcus & Le Gal (J. Fluid Mech., vol. 706, 2012, pp. 46–57).

Sign in / Sign up

Export Citation Format

Share Document