A buoyancy mechanism found in cranchid squid

Three species of cranchid squid have been studied at sea and found to be nearly neutrally buoyant in sea water. They each possess a very large coelom filled with a fluid whose density is low in comparison with sea water and this gives a lift sufficient to balance the denser tissues of the animal. This coelomic fluid is nearly iso-osmotic with sea water and its relatively low density arises because it is principally a solution of ammonium chloride in water. The fluid is acid and the significance of this is discussed. Two additional species of cranchid squid whose buoyancies were not measured were also shown to have very high concentrations of ammonium chloride in their coeloms and it seems likely that this buoyancy mechanism is used by all the Cranchidae.

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The aggregation of isolated human platelets in the presence of lipoproteins and prostacyclin

Biochemical Journal ◽

10.1042/bj2160043 ◽

1983 ◽

Vol 216 (1) ◽

pp. 43-49 ◽

Cited By ~ 93

Author(s):

D G Hassall ◽

J S Owen ◽

K R Bruckdorfer

Keyword(s):

Platelet Aggregation ◽

Normal Subjects ◽

Inhibitory Effect ◽

Human Platelets ◽

Low Density Lipoproteins ◽

High Density Lipoproteins ◽

Low Density ◽

Very Low Density Lipoproteins ◽

High Concentrations ◽

Very High

Addition of prostacyclin (PGI2) temporarily inhibits platelet aggregation and permits the isolation of platelets free from plasma proteins, which have the same sensitivity as those in plasma [Moncada, Radomski & Vargas (1982) Br. J. Pharmacol. 75, 165P]. By using a modification of this technique we have established that platelets isolated from normal subjects aggregate more readily in response to ADP and adrenaline when physiological concentrations of low-density lipoproteins (LDL) are present. At high LDL concentrations spontaneous aggregation occurs. High-density lipoproteins (HDL) and very-low-density lipoproteins (VLDL) had no effect on agonist-induced platelet aggregation at normal concentrations, but HDL sensitized at higher concentrations. These effects by lipoproteins are not accompanied by changes in platelet lipid content. Cyclohexanedione treatment of LDL to modify apolipoproteins appeared to abolish the sensitization effect, indicating that binding to receptors was essential for the effects of LDL. LDL, but not HDL, overcame the inhibitory effect of PGI2 on platelet aggregation, except at very high concentrations of PGI2. PGI2 raised the cyclic AMP content of isolated platelets, but LDL only partially prevented this rise. These results suggest that LDL may have a greater role in platelet aggregation than previously recognized and may also regulate effects of PGI2. These findings may be of relevance to an understanding of cardiovascular diseases.

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Bioaccumulation of marine pollutants

Philosophical Transactions of the Royal Society of London Series B Biological Sciences ◽

10.1098/rstb.1979.0042 ◽

1979 ◽

Vol 286 (1015) ◽

pp. 483-505 ◽

Cited By ~ 172

Keyword(s):

Environmental Factors ◽

Sea Water ◽

Suspended Particles ◽

Food Chains ◽

Equilibrium Level ◽

High Concentrations ◽

Very High ◽

Development Of Tolerance

Bioaccumulation of pollutants can occur from sea water, from suspended particles, from sediments and through food chains. The rate at which accumulation occurs in an organism depends not only on the availability of the pollutant but also on a whole range of biological, chemical and environmental factors. The ultimate level which is reached is governed by the ability of the organism to excrete the pollutant or, alternatively, store it. This latter course often leads to the attainment of very high concentrations and sometimes no equilibrium level is ever reached. Two particular topics which are considered are the biological amplification of pollutants along food chains and the development of tolerance which sometimes occurs.

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Further Studies on Ionic Regulation in Marine Invertebrates

Journal of Experimental Biology ◽

10.1242/jeb.30.2.277 ◽

1953 ◽

Vol 30 (2) ◽

pp. 277-296 ◽

Cited By ~ 1

Author(s):

JAMES D. ROBERTSON

Keyword(s):

Marine Invertebrates ◽

Sea Water ◽

Magnesium Content ◽

Aqueous Fluid ◽

Coelomic Fluid ◽

Free Fluid ◽

Ionic Regulation ◽

High Concentrations ◽

Species Being ◽

Plasma Ultrafiltrate

1. The blood or coelomic fluid has been analysed in sixteen marine invertebrates to determine the amount of ionic regulation. 2. Little regulation is shown by Holothuria and the bivalves Ostrea and Mytilus except in potassium. The bivalves accumulate potassium (up to 135% of the concentration in sea water), and Mytilus galloprovincialis accumulates sulphate (to 120%), an unusual feature. 3. The nudibranch Archidoris accumulates potassium (128%), calcium (132%) and magnesium (107%), while the sipunculid Phascolosoma has lower magnesium (69%) and sulphate (91%) but higher sodium (104%). 4. The cephalopod Sepia regulates all its ions except magnesium, range of values (expressed as percentage of concentration in dialysed plasma) being Na 92-94%, K 193-223%, Ca 84-97%, Mg 97-100%, Cl 105-106%, SO4 17-29%. Protein averages 109 g./l. in the three specimens analysed. Fluid from the renal sacs contains high concentrations of NH4+ ions, in two specimens 146 and 59 m.equiv./kg. water, and differs from a plasma ultrafiltrate in the concentration of all other ions. 5. The vitreous humour in the cephalopod eye is a clear protein-free fluid, isosmotic with the plasma within 1% but having ionic concentrations markedly different from those of a plasma ultrafiltrate or dialysate. In Sepia, Loligo and Eledone magnesium may be only 10-20% and sodium over 115% of the concentrations in a dialysate of the plasma. In one specimen of Sepia the aqueous fluid in front of the lens largely resembled sea water except for lower concentrations of magnesium and sulphate. 6. Among the decapod and stomatopod Crustacea regulation of all ions exists, ranges in eight species being Na 97-111%, K 120-156%, Ca 84-137%, Mg 32-99%, Cl 96-103%, SO4 53-135%. Species of Portunus and Eupagurus show more regulation than Dromia and the spider-crabs Maia and Hyas. Regulation in the stomatopod Squilla resembles that in the portunid family. In the grapsoid crab Pachygrapsus each ion in the plasma is maintained below its equilibrium value: Na 94%, K 95%, Ca 92%, Mg 24%, Cl 87%, SO4 46%; total ions 1.163g. ions/kg. water compared with 1.353 in sea water. 7. In sixteen crustaceans an inverse relationship exists between the degree of activity and the magnesium content of the blood: the more active ones have low values of magnesium.

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COASTAL AND ESTUARINE SEDIMENT DYNAMICS IN THE MEZEN BAY AND ESTUARIES MEZEN AND KULOY

Materials of XXIV International Coastal Conference, devoted to the 60th anniversary of the “Sea Coasts” Working Group of RAS Council SEA COASTS – EVOLUTION, ECOLOGY, ECONOMY ◽

10.31519/conferencearticle_5b5ce39a80e646.57291683 ◽

2018 ◽

Author(s):

Н. Демиденко ◽

N. Demidenko

Keyword(s):

River Water ◽

River Discharge ◽

Sea Water ◽

Sediment Dynamics ◽

Estuarine Sediment ◽

Sea Surface ◽

Cross Sectional ◽

Sand Waves ◽

Tidal Estuaries ◽

High Concentrations

In the Mezen bay and estuaries Mezen and Kuloy can be high concentrations of mud suspension there, involving the formation at times mobile suspensions and settled mud. Within estuaries the river water is mixed with the sea water by the action of tidal motions, by waves on the sea surface and by the river discharge forcing its way to the sea. Nearly all shallow tidal estuaries, where currents exceed about 1,0m s-1 and where sand is present, have sand waves. Sand waves have a variety of cross-sectional and plan forms.

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The metachor as a characteristic of the association of electrolytes in aqueous solutions

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19841061 ◽

1984 ◽

Vol 49 (5) ◽

pp. 1061-1078 ◽

Cited By ~ 1

Author(s):

Jiří Čeleda ◽

Stanislav Škramovský

Keyword(s):

Aqueous Solutions ◽

Apparent Volume ◽

Solutions Of Electrolytes ◽

Molal Volumes ◽

The Difference ◽

High Concentrations ◽

Experimental Values ◽

Suitable Characteristic ◽

Association Of Ions ◽

Very High

Based on the earlier paper introducing a concept of the apparent parachor of a solute in the solution, we have eliminated in the present work algebraically the effect which is introduced into this quantity by the additivity of the apparent molal volumes. The difference remaining from the apparent parachor after substracting the contribution corresponding to the apparent volume ( for which the present authors suggest the name metachor) was evaluated from the experimental values of the surface tension of aqueous solutions for a set of 1,1-, 1,2- and 2,1-valent electrolytes. This difference showed to be independent of concentration up to the very high values of the order of units mol dm-3 but it was directly proportional to the number of the free charges (with a proportionality factor 5 ± 1 cm3 mol-1 identical for all studied electrolytes). The metachor can be, for this reason, a suitable characteristic for detection of the association of ions and formation of complexes in the solutions of electrolytes, up to high concentrations where other methods are failing.

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Nitrification Process in a Nuclear Wastewater with High Load of Nitrogen, Uranium and Organic Matter under ORP Controlled

Water ◽

10.3390/w13111607 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1607

Author(s):

Mariano Venturini ◽

Ariana Rossen ◽

Patricia Silva Paulo

Keyword(s):

Ammonia Oxidation ◽

High Load ◽

Nuclear Fuels ◽

Monod Model ◽

Nernst Equation ◽

Nitrification Process ◽

Real Wastewater ◽

High Concentrations ◽

Wastewater Samples ◽

Very High

To produce nuclear fuels, it is necessary to convert uranium′s ore into UO2-ceramic grade, using several quantities of kerosene, methanol, nitric acid, ammonia, and, in low level, tributyl phosphate (TBP). Thus, the effluent generated by nuclear industries is one of the most toxic since it contains high concentrations of dangerous compounds. This paper explores biological parameters on real nuclear wastewater by the Monod model in an ORP controlled predicting the specific ammonia oxidation. Thermodynamic parameters were established using the Nernst equation to monitor Oxiders/Reductors relationship to obtain a correlation of these parameters to controlling and monitoring; that would allow technical operators to have better control of the nitrification process. The real nuclear effluent is formed by a mixture of two different lines of discharges, one composed of a high load of nitrogen, around 11,000 mg/L (N-NH4+-N-NO3−) and 600 mg/L Uranium, a second one, proceeds from uranium purification, containing TBP and COD that have to be removed. Bioprocesses were operated on real wastewater samples over 120 days under controlled ORP, as described by Nernst equations, which proved to be a robust tool to operate nitrification for larger periods with a very high load of nitrogen, uranium, and COD.

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Halogenated Volatile Organic Compounds in Water Samples and Inorganic Elements Levels in Ores for Characterizing a High Anthropogenic Polluted Area in the Northern Latium Region (Italy)

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18041628 ◽

2021 ◽

Vol 18 (4) ◽

pp. 1628

Author(s):

Mario Vincenzo Russo ◽

Ivan Notardonato ◽

Alberto Rosada ◽

Giuseppe Ianiri ◽

Pasquale Avino

Keyword(s):

Organic Compounds ◽

Mean Value ◽

Greenhouse Crops ◽

River Waters ◽

Liquid Liquid Extraction ◽

Volatile Organic ◽

High Concentrations ◽

Very High ◽

Inorganic Fraction

This paper shows a characterization of the organic and inorganic fraction of river waters (Tiber and Marta) and ores/soil samples collected in the Northern Latium region of Italy for evaluating the anthropogenic/natural source contribution to the environmental pollution of this area. For organic compounds, organochloride volatile compounds in Tiber and Marta rivers were analyzed by two different clean-up methods (i.e., liquid–liquid extraction and static headspace) followed by gas chromatography–electron capture detector (GC-ECD) analysis. The results show very high concentrations of bromoform (up to 1.82 and 3.2 µg L−1 in Tiber and Marta rivers, respectively), due to the presence of greenhouse crops, and of chloroform and tetrachloroethene, due to the presence of handicrafts installations. For the qualitative and quantitative assessment of the inorganic fraction, it is highlighted the use of a nuclear analytical method, instrumental neutron activation analysis, which allows having more information as possible from the sample without performing any chemical-physical pretreatment. The results have evidenced high levels of mercury (mean value 88.6 µg g−1), antimony (77.7 µg g−1), strontium (12,039 µg g−1) and zinc (103 µg g−1), whereas rare earth elements show levels similar to the literature data. Particular consideration is drawn for arsenic (414 µg g−1): the levels found in this paper (ranging between 1 and 5100 µg g−1) explain the high content of such element (as arsenates) in the aquifer, a big issue in this area.

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THE SELECTIVE PROTEOLYTIC ENZYME INHIBITORY ACTION OF BENZETHONIUM CHLORIDE

Canadian Journal of Biochemistry and Physiology ◽

10.1139/y60-004 ◽

1960 ◽

Vol 38 (1) ◽

pp. 25-32 ◽

Cited By ~ 4

Author(s):

Ivan T. Beck ◽

E. Pinter ◽

R. D. McKenna ◽

H. Griff

Keyword(s):

Subcutaneous Injection ◽

Proteolytic Enzyme ◽

Inhibitory Action ◽

Hemorrhagic Pancreatitis ◽

Benzethonium Chloride ◽

Tryptic Activity ◽

High Concentrations ◽

Acute Hemorrhagic Pancreatitis ◽

Very High

Acute hemorrhagic pancreatitis in humans is thought to be perpetuated by the autolytic processes catalyzed by trypsin and lipase. This study is an integral part of our search for trypsin and lipase inhibitors to be used in the treatment of this disease.Benzethonium chloride was found to inhibit tryptic activity in vitro. The proteolytic activity of rabbit's serum was inhibited, and the inhibition was most pronounced 6 to 12 hours after the subcutaneous injection of the compound. Fibrinolysin was also inhibited in vitro but benzethonium chloride had no inhibitory action on chymotrypsin, pepsin, or lipase.Serum proteins in vitro were precipitated only with very high concentrations of the compound. No significant protein changes were observed in sera of rabbits after the subcutaneous injection of the compound.

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Molecule-Based Magnets—An Overview

MRS Bulletin ◽

10.1557/mrs2000.221 ◽

2000 ◽

Vol 25 (11) ◽

pp. 21-30 ◽

Cited By ~ 115

Author(s):

Joel S. Miller ◽

Arthur J. Epstein

Keyword(s):

Low Temperature ◽

Vapor Deposition ◽

Room Temperature ◽

Chemical Vapor ◽

Magnetic Ordering ◽

Low Density ◽

Materials Properties ◽

The Common ◽

New Processing ◽

Very High

Molecule-based magnets are a broad, emerging class of magnetic materials that expand the materials properties typically associated with magnets to include low density, transparency, electrical insulation, and low-temperature fabrication, as well as combine magnetic ordering with other properties such as photoresponsiveness. Essentially all of the common magnetic phenomena associated with conventional transition-metal and rare-earth-based magnets can be found in molecule-based magnets. Although discovered less than two decades ago, magnets with ordering temperatures exceeding room temperature, very high (∼27.0 kOe or 2.16 MA/m) and very low (several Oe or less) coercivities, and substantial remanent and saturation magnetizations have been achieved. In addition, exotic phenomena including photoresponsiveness have been reported. The advent of molecule-based magnets offers new processing opportunities. For example, thin-film magnets can be prepared by means of low-temperature chemical vapor deposition and electrodeposition methods.

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