Bacterial epiphyte and endophyte communities of seagrass Thalassia hemprichii : the impact of feed extract solution

2021 ◽  
Author(s):  
Zefu Cai ◽  
Lei Zhou ◽  
Lihua Liu ◽  
Daoru Wang ◽  
Wei Ren ◽  
...  
Keyword(s):  
Thalassia Hemprichii ◽  
Extract Solution ◽  
The Impact

scholarly journals Carbon storage variability in seagrass meadows of Marine Poton Bako, East Lombok, West Nusa Tenggara, Indonesia

2018 ◽  
Vol 19 (5) ◽  
pp. 1626-1631 ◽  
Author(s):  
FIRMAN ALI RAHMAN ◽  
IBNUL QAYIM ◽  
YUSLI WARDIATNO
Keyword(s):  
Global Warming ◽  
Carbon Content ◽  
Carbon Storage ◽  
Co2 Concentration ◽  
Total Carbon ◽  
Total Biomass ◽  
Thalassia Hemprichii ◽  
Seagrass Meadows ◽  
Plot Area ◽  
The Impact

Rahman FA, Qayim I, Wardiatno Y. 2018. Carbon storage variability in seagrass meadows of Marine Poton Bako, EastLombok, West Nusa Tenggara, Indonesia. Biodiversitas 19: 1626-1631. The increase of atmospheric CO2 concentration in the lastdecades leads to global warming, having an adverse effect on the environment condition on the Earth. One of the natural mechanism asan effort to reduce the impact of global warming is carbon absorption and storage through photosynthesis mechanism of seagrassvegetation. Research conducted at Poton Bako, a district in East Lombok was aimed to reveal the composition of seagrass species,density, seagrass coverage, the biomass of seagrass tissue, content of carbon storage in seagrass tissue (above and below substrates),carbon content in seagrass sediments, and estimation of carbon stock in the area. The research included observation of speciescomposition, and the sample was collected from 0.5 m × 0.5 m plot area. The total plot area was 36 on six lanes with the space betweenplots 25 m and between lanes 100 m. Six species from two families were found in the seagrass meadows, i.e., Cymodocea rotundata,Enhalus acoroides, Halophila minor, Holodule uninervis, Thalassia hemprichii and Thalassodendron ciliatum. The three highest totaldensities were C. rotundata 214.67±110.469 stands m-2, T. hemprichii 85.11±41.471 stands m-2, and H. minor 42.22±44.204 stands m-2.Species with the highest coverage value at all observation plots was C. rotundata (33.47±26.748 %), and T. ciliatum had the lowestvalue (2.12±5.071 %). The total biomass was 676.32 g DW m-2 with biomass above substrate 329.94±57.725 g DW m-2 and belowsubstrate 654.88±81.199 g DW m-2. The carbon content of substrate ranged from 0.11% to 0.51% with the average of 0.35±0.081%,which was categorized low. The total average of carbon storage in seagrass was 447.92 g C m-2 comprising 142.77 g C m-2 of theirtissue above substrate and 305.15 g C m-2 below substrate. Regarding the area, the total carbon stored in seagrass meadows with 56.65ha area was 249.27 t C ha-1.

scholarly journals Seaweed farming pressure affects seagrass and benthic macroalgae dynamics in Chwaka Bay (Zanzibar, Tanzania)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Agustín Moreira-Saporiti ◽  
Dieuwke Hoeijmakers ◽  
Flower E. Msuya ◽  
Hauke Reuter ◽  
Mirta Teichberg
Keyword(s):  
Community Dynamics ◽  
Growth Cycle ◽  
Shoot Density ◽  
Thalassia Hemprichii ◽  
Seaweed Farming ◽  
Seagrass Meadows ◽  
Macrophyte Community ◽  
The Impact ◽  
Seaweed Farm ◽  
Benthic Macroalgae

AbstractFarming of Eucheuma denticulatum is a major activity in Zanzibar affecting seagrass ecosystems primarily through shading and trampling. The aim of this study was to test the impacts of shading and trampling during seaweed farming on seagrass meadows composed by Halophila stipulacea and Thalassia hemprichii and their associated benthic macroalgae. Areas covered by these species were selected for the building of seaweed farms in three treatments: seaweed farm plots (with shading and trampling effects), trampling plots (with trampling effects only), and control plots (with no shading or trampling effects). Reduction of light within the plots was recorded over 9 weeks. Percentage cover of seagrasses and macroalgae and shoot density of seagrasses were measured over 12 weeks to assess the impact of shading and trampling by seaweed farming activities. Light was significantly reduced in the seaweed farm plots by 75 to 90% by the end of a seaweed growth cycle. H. stipulacea, despite its capacity for rapid growth, was significantly affected by the combination of shading and trampling under the seaweed farm treatment, while the climax seagrass species T. hemprichii was unaffected. Due to the decline in H. stipulacea, benthic macroalgae cover increased in the seaweed farm treatment, suggesting a change in seagrass community dynamics. In contrast, trampling had a negative effect on the benthic macroalgae as an isolated disturbance, which suggests that seagrasses are more resistant to trampling than macroalgae and would likely dominate the benthic macrophyte community under these conditions.

Formation of Lunar Craters and Bright Rays as a Result of Meteorite Impacts

1962 ◽  
Vol 14 ◽  
pp. 415-418
Author(s):  
K. P. Stanyukovich ◽  
V. A. Bronshten
Keyword(s):  
Explosive Charge ◽  
The Moon ◽  
Meteorite Impacts ◽  
The Earth ◽  
Lunar Craters ◽  
The Impact

The phenomena accompanying the impact of large meteorites on the surface of the Moon or of the Earth can be examined on the basis of the theory of explosive phenomena if we assume that, instead of an exploding meteorite moving inside the rock, we have an explosive charge (equivalent in energy), situated at a certain distance under the surface.

The Geosciences Applied to Lunar Exploration

1962 ◽  
Vol 14 ◽  
pp. 169-257 ◽  
Author(s):  
J. Green
Keyword(s):  
Lunar Surface ◽  
Probable Mechanism ◽  
Point Of View ◽  
Lunar Exploration ◽  
Geological Model ◽  
Apply Geophysics ◽  
Surface Features ◽  
The Impact

The term geo-sciences has been used here to include the disciplines geology, geophysics and geochemistry. However, in order to apply geophysics and geochemistry effectively one must begin with a geological model. Therefore, the science of geology should be used as the basis for lunar exploration. From an astronomical point of view, a lunar terrain heavily impacted with meteors appears the more reasonable; although from a geological standpoint, volcanism seems the more probable mechanism. A surface liberally marked with volcanic features has been advocated by such geologists as Bülow, Dana, Suess, von Wolff, Shaler, Spurr, and Kuno. In this paper, both the impact and volcanic hypotheses are considered in the application of the geo-sciences to manned lunar exploration. However, more emphasis is placed on the volcanic, or more correctly the defluidization, hypothesis to account for lunar surface features.

Asteroid and Comet Impact Speeds upon Mars: Significance for Panspermia and the Supply of Organics

1997 ◽  
Vol 161 ◽  
pp. 197-201 ◽  
Author(s):  
Duncan Steel
Keyword(s):  
Probability Distributions ◽  
Regions Of Interest ◽  
Significant Fraction ◽  
Organic Chemicals ◽  
Impact Speed ◽  
The Mean ◽  
The Impact

AbstractWhilst lithopanspermia depends upon massive impacts occurring at a speed above some limit, the intact delivery of organic chemicals or other volatiles to a planet requires the impact speed to be below some other limit such that a significant fraction of that material escapes destruction. Thus the two opposite ends of the impact speed distributions are the regions of interest in the bioastronomical context, whereas much modelling work on impacts delivers, or makes use of, only the mean speed. Here the probability distributions of impact speeds upon Mars are calculated for (i) the orbital distribution of known asteroids; and (ii) the expected distribution of near-parabolic cometary orbits. It is found that cometary impacts are far more likely to eject rocks from Mars (over 99 percent of the cometary impacts are at speeds above 20 km/sec, but at most 5 percent of the asteroidal impacts); paradoxically, the objects impacting at speeds low enough to make organic/volatile survival possible (the asteroids) are those which are depleted in such species.

Organic Syntheses During the Impact of a Comet with a Gaseous Planet

1997 ◽  
Vol 161 ◽  
pp. 189-195
Author(s):  
Cesare Guaita ◽  
Roberto Crippa ◽  
Federico Manzini
Keyword(s):  
Polymeric Material ◽  
Molecular Form ◽  
Parent Compound ◽  
Blue Filter ◽  
Organic Syntheses ◽  
The Impact

AbstractA large amount of CO has been detected above many SL9/Jupiter impacts. This gas was never detected before the collision. So, in our opinion, CO was released from a parent compound during the collision. We identify this compound as POM (polyoxymethylene), a formaldehyde (HCHO) polymer that, when suddenly heated, reformes monomeric HCHO. At temperatures higher than 1200°K HCHO cannot exist in molecular form and the most probable result of its decomposition is the formation of CO. At lower temperatures, HCHO can react with NH3 and/or HCN to form high UV-absorbing polymeric material. In our opinion, this kind of material has also to be taken in to account to explain the complex evolution of some SL9 impacts that we observed in CCD images taken with a blue filter.

Hydrogen Cyanide Polymers from the Impact of Comet P/Shoemaker-Levy 9 on Jupiter

1997 ◽  
Vol 161 ◽  
pp. 179-187
Author(s):  
Clifford N. Matthews ◽  
Rose A. Pesce-Rodriguez ◽  
Shirley A. Liebman
Keyword(s):  
Amino Acids ◽  
Solar System ◽  
Hydrogen Cyanide ◽  
Nitrogen Heterocycles ◽  
Laboratory Studies ◽  
Heterogeneous Solids ◽  
The Many ◽  
Comet Halley ◽  
The Impact ◽  
By Products

AbstractHydrogen cyanide polymers – heterogeneous solids ranging in color from yellow to orange to brown to black – may be among the organic macromolecules most readily formed within the Solar System. The non-volatile black crust of comet Halley, for example, as well as the extensive orangebrown streaks in the atmosphere of Jupiter, might consist largely of such polymers synthesized from HCN formed by photolysis of methane and ammonia, the color observed depending on the concentration of HCN involved. Laboratory studies of these ubiquitous compounds point to the presence of polyamidine structures synthesized directly from hydrogen cyanide. These would be converted by water to polypeptides which can be further hydrolyzed to α-amino acids. Black polymers and multimers with conjugated ladder structures derived from HCN could also be formed and might well be the source of the many nitrogen heterocycles, adenine included, observed after pyrolysis. The dark brown color arising from the impacts of comet P/Shoemaker-Levy 9 on Jupiter might therefore be mainly caused by the presence of HCN polymers, whether originally present, deposited by the impactor or synthesized directly from HCN. Spectroscopic detection of these predicted macromolecules and their hydrolytic and pyrolytic by-products would strengthen significantly the hypothesis that cyanide polymerization is a preferred pathway for prebiotic and extraterrestrial chemistry.

Unusual Microstructure in Shock-Compacted Graphite

1970 ◽  
Vol 28 ◽  
pp. 474-475
Author(s):  
Lucien F. Trueb
Keyword(s):  
Mechanical Characteristic ◽  
Compression Wave ◽  
Gray Zone ◽  
Flyer Plate ◽  
Compacted Graphite ◽  
The Impact

Crushed and statically compressed Madagascar graphite that was explosively shocked at 425 kb by means of a planar flyer-plate is characterized by a black zone extending for 2 to 3 nun below the impact plane of the driver. Beyond this point, the material assumes the normal gray color of graphite. The thickness of the black zone is identical with the distance taken by the relaxation wave to overtake the compression wave.The main mechanical characteristic of the black material is its great hardness; steel scalpels and razor blades are readily blunted during attempts to cut it. An average microhardness value of 95-3 DPHN was obtained with a 10 kg load. This figure is a minimum because the indentations were usually cracked; 14.8 DPHN was measured in the gray zone.

Drug Induced Changes in Cell Organelles

1968 ◽  
Vol 26 ◽  
pp. 110-111
Author(s):  
Sarah A. Luse
Keyword(s):  
Clinical Medicine ◽  
Cell Organelles ◽  
Riboflavin Deficiency ◽  
Drug Induced ◽  
New Era ◽  
Health And Disease ◽  
In The Beginning ◽  
Cellular Pathology ◽  
Induced Changes ◽  
The Impact

In the mid-nineteenth century Virchow revolutionized pathology by introduction of the concept of “cellular pathology”. Today, a century later, this term has increasing significance in health and disease. We now are in the beginning of a new era in pathology, one which might well be termed “organelle pathology” or “subcellular pathology”. The impact of lysosomal diseases on clinical medicine exemplifies this role of pathology of organelles in elucidation of disease today.Another aspect of cell organelles of prime importance is their pathologic alteration by drugs, toxins, hormones and malnutrition. The sensitivity of cell organelles to minute alterations in their environment offers an accurate evaluation of the site of action of drugs in the study of both function and toxicity. Examples of mitochondrial lesions include the effect of DDD on the adrenal cortex, riboflavin deficiency on liver cells, elevated blood ammonia on the neuron and some 8-aminoquinolines on myocardium.

Fluorescent potentiometric dyes for membrane-potential imaging

1994 ◽  
Vol 52 ◽  
pp. 166-167
Author(s):  
Leslie M. Loew
Keyword(s):  
Membrane Potential ◽  
Single Cells ◽  
Quantitative Imaging ◽  
Optical Recording ◽  
Biological Processes ◽  
Major Focus ◽  
The Past ◽  
Excitable Systems ◽  
Major Application ◽  
The Impact

A major application of potentiometric dyes has been the multisite optical recording of electrical activity in excitable systems. After being championed by L.B. Cohen and his colleagues for the past 20 years, the impact of this technology is rapidly being felt and is spreading to an increasing number of neuroscience laboratories. A second class of experiments involves using dyes to image membrane potential distributions in single cells by digital imaging microscopy - a major focus of this lab. These studies usually do not require the temporal resolution of multisite optical recording, being primarily focussed on slow cell biological processes, and therefore can achieve much higher spatial resolution. We have developed 2 methods for quantitative imaging of membrane potential. One method uses dual wavelength imaging of membrane-staining dyes and the other uses quantitative 3D imaging of a fluorescent lipophilic cation; the dyes used in each case were synthesized for this purpose in this laboratory.

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