scholarly journals Studies on the culture of a marine diatom

1954 ◽  
Vol 33 (1) ◽  
pp. 265-290 ◽  
Author(s):  
C. P. Spencer
Keyword(s):  
Incomplete Data ◽  
Culture Media ◽  
Marine Diatom ◽  
Insufficient Information ◽  
Rational Development ◽  
Unicellular Algae ◽  
Total Crop ◽  
Chemical Conditions ◽  
Physical And Chemical ◽  
Growth Experiments

Little is known of the biochemistry of diatoms, although many workers have reported growth experiments with the unicellular algae of the marine phyto-plankton. Experiments have often been performed without due regard for the appropriate control of physical and chemical conditions. Many reports contain only incomplete data of the growth under a given set of conditions, and it is often impossible to say whether the effects recorded are upon the growth rate, the total crop, or both. Other studies have been reported which included the addition of organic matter to cultures which were only uni-algal and not bacteria-free. At the present time even the mere maintenance of stock cultures of the marine unicellular algae is perforce an empirical matter. Results in replicate cultures often show gross differences in growth that are apparent on inspection by eye alone, and insufficient information is available regarding the nature of these variations in growth to allow the rational development of improved culture media. Due therefore to a lack of suitable techniques, most of the results available are difficult, if not impossible, to interpret in terms of the biochemical activities of the algae.

scholarly journals Short communication: The effect of changing temperature and agar concentration at proliferation stage in the final success of Aleppo pine somatic embryogenesis

2018 ◽  
Vol 26 (3) ◽  
pp. eSC05 ◽  
Author(s):  
Catia Pereira ◽  
Itziar A. Montalbán ◽  
Tomás Goicoa ◽  
M. Dolores Ugarte ◽  
Sandra Correia ◽  
...  
Keyword(s):  
Culture Medium ◽  
Short Communication ◽  
Pinus Halepensis ◽  
Culture Media ◽  
Aleppo Pine ◽  
Embryogenic Cell ◽  
Plantlet Production ◽  
Embryogenic Cell Lines ◽  
Chemical Conditions ◽  
Physical And Chemical

Aim of the study: The effect of physical and chemical conditions at proliferation stage was evaluated in order to elucidate if this stage is the determinant phase to induce a marked effect in Pinus halepensis somatic embryogenesis.Area of study: The study was conducted in research laboratories of Neiker (Arkaute, Spain).Material and methods: Pinus halepensis embryonal masses from ten embryogenic cell lines subjected to nine treatments (tissues cultured at three temperatures on media supplemented with three agar concentrations) at proliferation stage.Main results: Significant differences were observed among different proliferation conditions months later at the end of maturation, germination and acclimatization stages.Research highlights: Aleppo pine embryonal masses are cultured under standard conditions on a culture medium supplemented with 4.5 g/L Gelrite® at 23ºC. However, better results in terms of plantlet production can be obtained proliferating the embryonal masses at 18ºC in a culture media with significantly lower water availability. 

Permeability to albumin in isolated coronary venules

1993 ◽  
Vol 265 (2) ◽  
pp. H543-H552 ◽  
Author(s):  
Y. Yuan ◽  
W. M. Chilian ◽  
H. J. Granger ◽  
D. C. Zawieja
Keyword(s):  
Permeability Coefficient ◽  
Filtration Rate ◽  
Intraluminal Pressure ◽  
Apparent Permeability ◽  
Filtration Pressure ◽  
Diffusive Permeability ◽  
Apparent Permeability Coefficient ◽  
Chemical Conditions ◽  
Physical And Chemical ◽  
Intravascular Pressure

This study reports measurements of albumin permeability in isolated coronary venules. The isolated microvessel technique allows the quantification of transmural exchange of macromolecules under tightly controlled physical and chemical conditions. Transvenular exchange of albumin was studied in isolated coronary venules during alterations in filtration rate caused by changes in intravascular pressure. The apparent permeability coefficient of albumin (Pa) at an intraluminal pressure of 11 cmH2O was 3.92 +/- 0.43 x 10(-6) cm/s. Elevating intraluminal pressure to 16 and 21 cmH2O increased Pa to 5.13 +/- 0.57 x 10(-6) and 6.78 +/- 0.66 x 10(-6) cm/s, respectively. Calculation of the true diffusive permeability coefficient of albumin (Pd) at zero filtration rate was 1.54 x 10(-6) cm/s. The product of hydraulic conductance (Lp) and (1 - sigma), where sigma is the solute reflection coefficient, was 3.25 x 10(-7) cm.s-1 x cmH2O-1. At a net filtration pressure of 4-5 cmH2O, diffusion accounts for > 60% of total albumin transport across the venular wall. Transmural albumin flux is very sensitive to filtration rate, rising 6.7% for each cmH2O elevation of net filtration pressure. At 11 cmH2O net filtration pressure, convection accounts for nearly 70% of net albumin extravasation from the venular lumen. We suggest that the isolated coronary venule is a suitable preparation for the study of solute exchange in the heart.

scholarly journals Origin of Life on Mars: Suitability and Opportunities

Life ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 539
Author(s):  
Benton C. Clark ◽  
Vera M. Kolb ◽  
Andrew Steele ◽  
Christopher H. House ◽  
Nina L. Lanza ◽  
...  
Keyword(s):  
Origin Of Life ◽  
Energy Sources ◽  
Early Earth ◽  
Sediment Samples ◽  
Life On Mars ◽  
Eventual Return ◽  
History Of ◽  
Early Mars ◽  
Chemical Conditions ◽  
Physical And Chemical

Although the habitability of early Mars is now well established, its suitability for conditions favorable to an independent origin of life (OoL) has been less certain. With continued exploration, evidence has mounted for a widespread diversity of physical and chemical conditions on Mars that mimic those variously hypothesized as settings in which life first arose on Earth. Mars has also provided water, energy sources, CHNOPS elements, critical catalytic transition metal elements, as well as B, Mg, Ca, Na and K, all of which are elements associated with life as we know it. With its highly favorable sulfur abundance and land/ocean ratio, early wet Mars remains a prime candidate for its own OoL, in many respects superior to Earth. The relatively well-preserved ancient surface of planet Mars helps inform the range of possible analogous conditions during the now-obliterated history of early Earth. Continued exploration of Mars also contributes to the understanding of the opportunities for settings enabling an OoL on exoplanets. Favoring geochemical sediment samples for eventual return to Earth will enhance assessments of the likelihood of a Martian OoL.

scholarly journals Ekosistem Mangrove Binuangeun, Banten: Kondisi Fisik Dan Kimia Serta Ragam Ikan

2020 ◽  
Vol 5 (2) ◽  
pp. 32-40
Author(s):  
Fitri Andriyani
Keyword(s):  
Research Method ◽  
Mangrove Ecosystem ◽  
Water Current ◽  
Root Structure ◽  
Chemical Condition ◽  
Literature Study ◽  
Marine Animals ◽  
Mangrove Ecosystems ◽  
Chemical Conditions ◽  
Physical And Chemical

Binuangeun Mangrove Ecosystem is located in the south western Java Island, in the area of ​​Lebak Regency, Banten Province. Mangrove ecosystems are ecosystems that located at the Coastal areas which are a habitat for a variety of marine animals which are associated with it, mostly fish, because of its complex or a very effective root structure which can provide a place for fish to be able to live, take shelter, develop, breed and also look for food. This research was conducted to determine the physical and chemical condition and the variety of fishes which found in the Binuangeu, Banten Mangrove Ecosystem. This research method uses literature study. Physical and chemical conditions of the Binuangeun Mangrove Ecosystem, Banten have degrees of temperature ranging from 28.20 - 32.20; acidity range between 7.00 - 8.09; turbidity ranges from 22.50 - 76.00 NTU; water current ranged from 0.079 to 0.189; phosphate content ranges from 0.02 - 0.008; salinity ranges from 30-35 PSU; and dissolved oxygen content ranges from 5.67 - 8.70. The types of fish found in the Binuangeun Mangrove Ecosystem, Banten are 45 species from 22 Family. The most abundant and relatively high species of existence is the Gobiidae with 10 species.   Keywords: Banten, Binuangeun, Ecosystems, Fish, Mangroves

Suspension Plasma Spraying (SPS) of Cobalt Spinel

1997 ◽  
Author(s):  
G. Schiller ◽  
M. Müller ◽  
F. Gitzhofer ◽  
M.I. Boulos ◽  
R.B. Heimann
Keyword(s):  
Plasma Spraying ◽  
Inductively Coupled Plasma ◽  
Solid Phase ◽  
Spinel Phase ◽  
Rf Plasma ◽  
Dry Powders ◽  
Inductively Coupled ◽  
Cobalt Spinel ◽  
Chemical Conditions ◽  
Physical And Chemical

Abstract Fine (median size 6 μm and 0.3 μm) cobalt spinel (Co3O4) powders were processed suspended in a suitable liquid phase. Suspensions exceeding 50 wt.% solid phase content were successfully injected into an inductively coupled plasma. Spheroidized powders with large particle size (up to 80 μm) were prepared, and cobalt oxide coatings were produced by this novel RF-SPS method. The microstructural features of the coatings can be controlled by parameter optimization similarly to plasma spraying of dry powders. Numerous variations of the physical and chemical conditions of the process were performed in an attempt to overcome the main disadvantage of the process, i.e. the decomposition of the spinel phase to CoO. So far, the spinel phase could be reestablished only by a post-treatment of the deposited coatings with atomic oxygen in the RF plasma.

scholarly journals Changes in Potential Evaporation in the Years 1952–2018 in North-Western Poland in Terms of the Impact of Climatic Changes on Hydrological and Hydrochemical Conditions

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 877 ◽  
Author(s):  
Monika Okoniewska ◽  
Danuta Szumińska
Keyword(s):  
Water Resources ◽  
Air Temperature ◽  
21St Century ◽  
Climatic Factors ◽  
Potential Evaporation ◽  
Relative Air Humidity ◽  
Chemical Conditions ◽  
Physical And Chemical ◽  
The Impact ◽  
North Western

The paper analyses changes in potential evaporation E0 (mm) in north-western Poland in the years 1952–2018. E0 (mm) has been calculated according to Ivanov’s formula based on the monthly values of air temperature (t, °C) and relative air humidity (f, %) for six weather stations of the Institute of Meteorology and Water Management. The data were collected using the Statistica software ver. 13 and the QGIS software ver. 3.80. The results indicate statistically significant trends in the increase of E0 during the period 1952–2018, and that it is particularly high during the spring and summer months, which should be associated with a statistically significant increase in air temperature and a decrease in relative humidity at all examined stations. The results also indicate an exceptionally high increase in evaporation since the end of the 20th century and in the 21st century, which reflects a potentially higher risk of permanent changes in hydrological conditions. The research results point to the major role of climatic factors in the often-dramatic decreases in water resources observed in the 21st century, particularly in lakes and small watercourses. The progressing reduction of water resources may cause permanent changes in physical and chemical conditions in waterbodies.

scholarly journals Soil Factors Related to the Severity of Clubroot in Rio de Janeiro, Brazil

Plant Disease ◽  
2017 ◽  
Vol 101 (8) ◽  
pp. 1345-1353 ◽  
Author(s):  
Aline da S. Bhering ◽  
Margarida G. F. do Carmo ◽  
Talita de S. Matos ◽  
Erica S. A. Lima ◽  
Nelson M. B. do Amaral Sobrinho
Keyword(s):  
Rio De Janeiro ◽  
Principal Component ◽  
Inoculum Potential ◽  
Family Farms ◽  
Tropical Regions ◽  
Soil Attributes ◽  
Brassica Spp ◽  
History Of ◽  
Chemical Conditions ◽  
Physical And Chemical

Soil pH and calcium levels are determining factors in the success or failure of managing clubroot during the cultivation of Brassica spp. The aim of the present study was to evaluate the influence of soil attributes in tropical regions on the development of roots and clubroot and the accumulation of biomass and nutrients in cauliflower. One hundred and fifty-one samples of soil and plants were collected from 16 family farms that have a history of more than 50 years of regular cauliflower cultivation in Nova Friburgo, Rio de Janeiro, Brazil. Chemical and physical analyses were performed on the soil samples, and the severity of clubroot and the accumulation of biomass and macronutrients in individual plants and plant tissues. Clustering and main principal component analyses were performed on the data. The disease occurred on all farms, but with different intensities. A direct relationship was observed for the soil attributes (acidity and exchangeable aluminum content in particular) with the percentage of roots with clubroot and with the accumulation of biomass and macronutrients in the different plant organs. To reduce losses from clubroot in weathered soils, practices should aim to reduce the pathogen’s inoculum potential and improve the physical and chemical conditions of the soil, which would favor root development of the plants.

scholarly journals Search for DIBs in Emission: MWC 922 - The Red Square Nebula

2013 ◽  
Vol 9 (S297) ◽  
pp. 226-228 ◽  
Author(s):  
N. Wehres ◽  
B. Ochsendorf ◽  
J. Bally ◽  
T Snow ◽  
V. Bierbaum ◽  
...  
Keyword(s):  
Spectral Range ◽  
Emission Lines ◽  
Central Object ◽  
Medium Resolution ◽  
Chemical Conditions ◽  
Physical And Chemical ◽  
Future Work ◽  
Insight Into

AbstractThis work focusses on MWC 922, the central object in the Red Square Nebula. We obtained low and medium resolution spectra of both, the central object and the surrounding nebula, using the DIS and TSpec spectrograph. The spectra show the whole spectral range between ~3 500 Å up to ~25 000 Å. The central object shows a plethora of emission lines, including many Fe II and forbidden Fe [II] lines. Here, we present the inventory of the emission lines of the central object, MWC 922. Future work will comprise the identification of the nebula emission lines by using newly obtained X-Shooter spectra. That way we want to gain further insight into the physical and chemical conditions in this environment. A comparison of the Red Square to the Red Rectangle Nebula is anticipated and will guide our search for DIBs in emission.

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