scholarly journals Ionic Relations of Marine Algae I. Griffithsia: Membrane Electrical Properties

1969 ◽  
Vol 22 (5) ◽  
pp. 1163 ◽  
Author(s):  
GP Findlay ◽  
AB Hope ◽  
EJ Williams
Keyword(s):  
Electrical Properties ◽  
Marine Algae ◽  
Potassium Concentration ◽  
Membrane Properties ◽  
Ionic Relations ◽  
Marine Algal ◽  
Ionic Movements

Several species of Griifithsia were studied as part of an investigation into the ionic movements and membrane properties in marine algal cells. Vacuolar potassium concentration was normally 500-600 mM, that of sodium 30--90 mM, and of chloride 600-650mM.

scholarly journals Ionic Relations of Marine Algae III. Chaetomorpha: Membrane Electrical Properties and Chloride Fluxes

1971 ◽  
Vol 24 (3) ◽  
pp. 731 ◽  
Author(s):  
GP Findlay ◽  
AB Hope ◽  
MG Pitman ◽  
FA Smith ◽  
NA Walker
Keyword(s):  
Electrical Properties ◽  
Green Alga ◽  
Electric Potential ◽  
Electrical Resistance ◽  
Marine Algae ◽  
Negative State ◽  
Ionic Relations ◽  
The Difference ◽  
Usual State ◽  
Positive State

In the large coenocytic cell of the marine green alga Chaetomorpha darwin ii, the electric potential difference, .pvo, between the vacuole and the outside seawater can have either of two distinct states, a positive, and more usual state, with .pvo = +5 mY, and a negative state with .pvo = - 29 m V. The p.d. across the plasmalemma of the cell was approximately -72 mY, and the difference between the positive and negative states occurred at the tonoplast with .pvc = + 77 m V or + 43 m V respectively. In the change from the positive state to the negative state, the electrical resistance of the plasmalemma increased from 510 to 750 n cm2 , and the resistance of the tonoplast increased from 4900 to 7100 n cm2

scholarly journals Betaine Yields from Marine Algal Species Utilized in the Preparation of Seaweed Extracts Used in Agriculture

2010 ◽  
Vol 5 (4) ◽  
pp. 1934578X1000500 ◽  
Author(s):  
Gerald Blunden ◽  
Peter F. Morse ◽  
Imre Mathe ◽  
Judit Hohmann ◽  
Alan T. Critchley ◽  
...  
Keyword(s):  
Marine Algae ◽  
Algal Species ◽  
First Record ◽  
Commercial Production ◽  
The Other ◽  
Minor Constituent ◽  
Laminaria Digitata ◽  
Seaweed Extracts ◽  
Marine Algal ◽  
A Minor

Ascophyllum nodosum, and to a lesser extent, Laminaria digitata, L. hyperborea and Fucus serratus, are marine algal species utilized in the commercial production of seaweed extracts used in agriculture. Betaines have been shown to be important constituents of these extracts, but there appears to have been no study made on whether there are variations in the betaine contents of these species based on either the place or date of collection. Samples of each of the four species were collected from widely separated areas at different times of the year. Also, in the case of A. nodosum, approximately monthly collections were made from one location. The betaines detected in the various collections of the same species showed little variation, although in the case of A. nodosum, glycinebetaine was found as a minor constituent in some samples, but was not detected in others. Trigonelline was found in all the tested samples of the two Laminaria species; this is, to our knowledge, the first record of this betaine in marine algae. With the exception of trigonelline in the Laminaria species, the betaine yields from the various samples of L. digitata, L. hyperborea and F. serratus showed little variation, regardless of either the place or date of collection. The trigonelline contents of the Laminaria species collected at one location (Finavarra, Ireland), in particular of L. hyperborea, was substantially greater than those from the other places of collection. In the case of A. nodosum, the betaine yields from samples collected at one site (Dale, Pembrokeshire, UK) were significantly higher than those from the other places of collection, which were very similar to each other. There was no clear indication of seasonal variation in betaine yields from A. nodosum.

The shallow sublittoral marine ecology of Aldabra

1971 ◽  
Vol 260 (836) ◽  
pp. 123-171 ◽  
Keyword(s):  
Marine Algae ◽  
Marine Ecology ◽  
Preliminary Treatment ◽  
Algal Flora ◽  
Direct Wave ◽  
Calm Water ◽  
Marine Angiosperms ◽  
Marine Algal ◽  
Pool Area ◽  
Marine Angiosperm

The paper represents a preliminary treatment of the marine ecology of certain areas of the shallow sublittoral, mostly on West Island, on Aldabra. Seaward reefs on West Island are, for this island group, calm water localities. Detailed examinations of profiles, and additional observations, indicate that ‘ zones ’ can be recognized in the shallow sublittoral, but these ‘zones’ are more a function of the nature and physiography of the substrate and of the presence and density of marine Angiosperm vegetation than of the marine algae. Luxuriant marine algal flora is, on the reef-flat, found only in deep pools or channels landward of the ‘reef-ridge’, most commonly in the inner ridge/pool area. These circumstances seem to provide protection from direct wave action, together with adequate depth of water at all times. Similar conditions apparently apply in the area immediately lagoon ward of Western Channels, where a most luxuriant ‘turf’ of marine algae and marine angiosperms was located. The biomass of marine vegetation there was quite outstanding for Aldabra, representing a cover of virtually 100%, with much additional growth of one species over another throughout most of the `turf’ area.

scholarly journals Ionic Relations of Cells of Ohara Australis VII. The Separate Electrical Oharacteristics of the Plasmalemma and Tonoplast

1964 ◽  
Vol 17 (1) ◽  
pp. 62 ◽  
Author(s):  
GP Findlay ◽  
AB Hope
Keyword(s):  
Electrical Properties ◽  
Ionic Relations

A study of the electrical properties of tho two membranes bounding the cytoplasm in almra cells was made. Three electrodes were employed: a metal probe to pass current, inserted longitudinally into the vacuole, and two glass microelectrodes, to measure potential differences, inserted into the vacuole and cytoplasm.

scholarly journals Ionic Relations of Cells of Chara Australls X. Effects of Bicarbonate Ions on Electrical Properties

1965 ◽  
Vol 18 (4) ◽  
pp. 789 ◽  
Author(s):  
AB Hope
Keyword(s):  
Electrical Properties ◽  
External Medium ◽  
Membrane Resistance ◽  
Potential Difference ◽  
Bicarbonate Ions ◽  
Ionic Relations

When bicarbonate ions were added to the external medium the plasmalemma of cells of Ohwra australis became hyperpolarized. The potential difference (p.d.) frequently changed from -150 or -160 mY to -200 or -220 mY. An increal!El in membrane resistance also occurred.

scholarly journals Passive Electrical Properties of Ventral Horn Neurons in Rat Spinal Cord Slices

1998 ◽  
Vol 79 (5) ◽  
pp. 2485-2502 ◽  
Author(s):  
David Thurbon ◽  
Hans-R. Lüscher ◽  
Thomas Hofstetter ◽  
Stephen J. Redman
Keyword(s):  
Spinal Cord ◽  
Electrical Properties ◽  
Compartmental Model ◽  
Ventral Horn ◽  
Membrane Properties ◽  
Rat Spinal Cord ◽  
Synaptic Potentials ◽  
Whole Cell Recordings ◽  
Passive Electrical Properties ◽  
Large Neurons

Thurbon, David, Hans-R. Lüscher, Thomas Hofstetter, and Stephen J. Redman. Passive electrical properties of ventral horn neurons in rat spinal cord slices. J. Neurophysiol. 79: 2485–2502, 1998. Recordings were made from large neurons located in the ventral horn of transverse spinal cord slices from young rats (7–15 days). Whole cell recordings were made simultaneously with two electrodes from the soma of these neurons, visualized using infra-red differential interference contrast optics. Positive identification of motoneurons could not always be achieved. The response of a neuron to a brief pulse of current delivered by one electrode, and recorded by the other electrode, were matched optimally to responses of a compartmental model of the same neuron with an identical current pulse as input. The compartmental model was based on a reconstruction of the neuron, using Biocytin staining. The compartmental model had three free parameters: specific membrane capacitance ( C m), membrane resistivity ( R m), and cytoplasmatic resistivity ( R i), all assumed to be uniform throughout the neuron. The experimental and model responses could be matched unequivocally for four neurons, giving C m = 2.4 ± 0.5 μF/cm2, R m = 5.3 ± 0.9 kΩ/cm2, and R i = 87 ± 22 Ω/cm. No somatic shunt was required. For the remaining six neurons, a less perfect fit (but still within 95% confidence limits) was indicative of nonhomogeneous membrane properties. The electrotonic length of uncut dendrites was 0.85 ± 0.14 λ. The results resolve the issue of a somatic shunt conductance for motoneurons, relegating it to a microelectrode impalement artifact. They are consistent with previous reports on the electrical compactness of motoneurons to steady state currents and voltages. However, the much higher value of C m (than the previously assumed 1 μF/cm2) implies much greater dendritic attenuation of fast synaptic potentials, and a much enhanced integrative response of motoneurons to synaptic potentials.

Marine algae of the Champlain Sea episode near Ottawa

1970 ◽  
Vol 7 (6) ◽  
pp. 1583-1585 ◽  
Author(s):  
W. I. Illman ◽  
J. McLachlan ◽  
T. Edelstein
Keyword(s):  
Marine Algae ◽  
Red Alga ◽  
Plant Pigments ◽  
Single Fragment ◽  
Marine Algal

Examination of a marine algal deposit from the Champlain Sea (10 800 ± 150 y old) found by Mott (1968) revealed that it is composed mainly of well preserved blades of Laminaria. These were associated with another brown species not susceptible of definite identification and a single fragment of a foliose red species, probably Rhodymenia.Filaments of Audouinella membranacea were found in hydroids in the deposit and another small red alga, Acrochaetium identified. The presence of several plant pigments was indicated by chromatographic and spectrographic techniques.

scholarly journals Potential Antiviral Properties of Industrially Important Marine Algal Polysaccharides and Their Significance in Fighting a Future Viral Pandemic

Viruses ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1817
Author(s):  
Renu Geetha Bai ◽  
Rando Tuvikene
Keyword(s):  
Biomedical Applications ◽  
Marine Algae ◽  
Therapeutic Potential ◽  
Structural Diversity ◽  
Sulfated Polysaccharides ◽  
Inhibitory Effects ◽  
Marine Algal ◽  
Infection Processes ◽  
Algal Polysaccharides ◽  
Diverse Virus

Over the decades, the world has witnessed diverse virus associated pandemics. The significant inhibitory effects of marine sulfated polysaccharides against SARS-CoV-2 shows its therapeutic potential in future biomedical applications and drug development. Algal polysaccharides exhibited significant role in antimicrobial, antitumor, antioxidative, antiviral, anticoagulant, antihepatotoxic and immunomodulating activities. Owing to their health benefits, the sulfated polysaccharides from marine algae are a great deal of interest globally. Algal polysaccharides such as agar, alginate, carrageenans, porphyran, fucoidan, laminaran and ulvans are investigated for their nutraceutical potential at different stages of infection processes, structural diversity, complexity and mechanism of action. In this review, we focus on the recent antiviral studies of the marine algae-based polysaccharides and their potential towards antiviral medicines.

scholarly journals Marine algal flora of São Miguel Island, Azores

2021 ◽  
Vol 9 ◽  
Author(s):  
Ana I Neto ◽  
Ignacio Moreu ◽  
Edgar Rosas Alquicira ◽  
Karla León-Cisneros ◽  
Eva Cacabelos ◽  
...  
Keyword(s):  
Marine Algae ◽  
New Records ◽  
Algal Flora ◽  
Eastern Group ◽  
The Past ◽  
Presence Data ◽  
Marine Algal ◽  
The Many ◽  
The University

The macroalgal flora of the Island of São Miguel (eastern group of the Azores Archipelago) has attracted the interest of many researchers in the past, the first publications going back to the nineteenth century. Initial studies were mainly taxonomic, resulting in the publication of a checklist of the Azorean benthic marine algae. Later, the establishment of the University of the Azores on the Island permitted the logistic conditions to develop both temporal studies and long-term research and this resulted in a significant increase on research directed at the benthic marine algae and littoral communities of the Island and consequent publications. Prior to the present paper, the known macroalgal flora of São Miguel Island comprised around 260 species. Despite this richness, a significant amount of the research was never made public, notably Masters and PhD theses encompassing information regarding presence data recorded at littoral and sublittoral levels down to a depth of approximately 40 m around the Island and the many collections made, which resulted in vouchers deposited in the AZB Herbarium Ruy Telles Palhinha and the LSM- Molecular Systematics Laboratory at the Faculty of Sciences and Technology of the University of the Azores. The present publication lists the macroalgal taxonomic records, together with information on their ecology and occurrence around São Miguel Island, improving the knowledge of the Azorean macroalgal flora at local and regional scales. A total of 12,781 specimens (including some identified only to genus) belonging to 431 taxa of macroalgae are registered, comprising 284 Rhodophyta, 59 Chlorophyta and 88 Ochrophyta (Phaeophyceae). Of these, 323 were identified to species level (212 Rhodophyta, 48 Chlorophyta and 63 Ochrophyta), of which 61 are new records for the Island (42 Rhodophyta, 9 Chlorophyta and 10 Ochrophyta), one an Azorean endemic (Predaea feldmannii subsp. azorica Gabriel), five are Macaronesian endemisms (the red algae Botryocladia macaronesica Afonso-Carrillo, Sobrino, Tittley & Neto, Laurencia viridis Gil-Rodríguez & Haroun, Millerella tinerfensis (Seoane-Camba) S.M.Boo & J.M.Rico, Phyllophora gelidioides P.Crouan & H.Crouan ex Karsakoff and the green alga Codium elisabethiae O.C.Schmidt), 19 are introduced species (15 Rhodophyta, two Chlorophyta and two Ochrophyta) and 32 are of uncertain status (21 Rhodophyta, five Chlorophyta and six Ochrophyta).

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