scholarly journals Physiological Responses of Sargassum muticum, a Potential Golden Tide Species, to Different Levels of Light and Nitrogen

2021 ◽  
Vol 9 ◽  
Author(s):  
Fang Yan ◽  
Lingxue Li ◽  
Daode Yu ◽  
Cuiju Cui ◽  
Shasha Zang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Algal Growth ◽  
Light Level ◽  
Marine Ecology ◽  
Sargassum Muticum ◽  
Natural Seawater ◽  
Rocky Shores ◽  
High Nitrogen ◽  
Nitrogen Levels ◽  
Significant Difference

Sargassum golden tides have bloomed frequently in many sea areas throughout the world, and negatively impacted on the local marine ecology. Sargassum muticum commonly inhabits rocky shores. It is now distributed worldwide due to its invasiveness, and recently drifting individuals have been observed on the coasts of Canary Islands. However, as a potential golden tide alga, physiological, and ecological studies of this species have not been frequently explored. To investigate the responses of S. muticum to light and nitrogen, two key environmental factors in golden tide formation, we established three light levels (LL, low light, 10 μmol photons m–2 s–1; ML, medium light, 60 μmol photons m–2 s–1, and HL, high light, 300 μmol photons m–2 s–1) and two nitrogen levels (LN, low nitrogen, 25.0 μM of natural seawater; HN, high nitrogen, 125.0 μM), and cultivated the thalli under different conditions for 12 days before measuring the physiological properties of alga. The results showed that higher light and/or nitrogen levels enhanced the relative algal growth rate. The maximum net photosynthesis rate of alga increased with the light, while it remained unaffected by the nitrogen. The HN treatment had no effect on the apparent photosynthetic efficiency of algae in the LL culture, while increased it in the ML and HL cultures. The irradiance saturation point of photosynthesis was approximately 300 μmol photons m–2 s–1 with no significant difference among the six treatments, except for a slight increase under HLHN in contrast to the LLHN and MLLN treatments. HL treatment decreased the maximum quantum yield of photosynthesis (Fv/Fm) in both nitrogen levels. In the HN culture, ML and HL led to lower values of photoinhibition, indicating higher survivability in the alga. The HN culture led to higher nitrogen uptake but had no effects on Fv/Fm and the contents of pigments and soluble protein, regardless of culture light level. Based on these results, we speculate that drifting individuals of S. muticum would be possible to form a golden tide owing to its rapid growth rate at light level of 300 μmol photons m–2 s–1, when they encountered the sustained lower light level on the sea surface (≤300 μmol photons m–2 s–1). A high nitrogen supply caused by eutrophication of seawater might facilitate this process. Our results provide an important reference for the prediction of golden tides formed by S. muticum.

scholarly journals The role of salt stress on laboratory cultivation of green macroalga Enteromorpha compressa and its antioxidant activity

2021 ◽  
Vol 18 (1) ◽  
pp. 0054
Author(s):  
Sanaa Shanab ◽  
Emad Shalaby
Keyword(s):  
Growth Rate ◽  
Antioxidant Activity ◽  
Salt Stress ◽  
Radical Scavenging ◽  
Algal Growth ◽  
Ethanolic Extract ◽  
Natural Seawater ◽  
Green Seaweed ◽  
Metabolic Activities ◽  
The Impact

Cultivation of the green seaweed Enteromorpha compressa was performed under natural laboratory spring environmental conditions of temperature, light intensity and photoperiod to study the salinity tolerance of this intertidal green macroalga. Cultivation was carried out under artificial seawater (ASW) of different concentrations (18, 35, 53 and 106 g/l sea salt) compared to the control using natural seawater (NSW). Growth rate and pigment content of the cultivated alga were recorded at regular intervals during the experimental duration. Antioxidant activity of the crude ethanolic extract and its fractions (petroleum ether, chloroform, ethyl acetate and acetone) was performed against DPPH radical scavenging assay and compared to the standard synthetic antioxidant butylated hydroxy-toluene (BHT). The finding showed that enhancement of algal growth rate under ASW concentrations of 35, 53 and to a lesser extent at 106 g/L during the first 15 days of cultivation were due to the increased pigment biosynthesis, photosynthetic and metabolic activities and followed by gradual retardation due to the impact of prolonged salt stress. Antioxidant activity of alga was found to be concentration, type of extract and incubation time dependent. Acetone fraction of all salt concentrations showed higher antioxidant activity compared to other fractions. Pronounced activity was recorded at higher seawater conc. (106g/l).

Instantaneous Growth Rate of Freshwater Nannochloropsis spp. at Different Salinity Levels

2015 ◽  
Vol 16 (1) ◽  
Author(s):  
Lady Gem H. Maquirang ◽  
Romeo D. Caturao ◽  
Jessy H. Maquirang
Keyword(s):  
Growth Rate ◽  
Cell Density ◽  
Instantaneous Growth Rate ◽  
Nitrogen Levels ◽  
Instantaneous Growth ◽  
Randomized Design ◽  
Significant Difference ◽  
Salinity Levels ◽  
Initial Sampling ◽  
Range Test

A study was conducted to determine the instantaneous growth rate of freshwater Nannochloropsis spp. at five different salinity levels (T1, 0 ppt - control; T2, 5 ppt; T3, 10 ppt; T 4, 15 ppt; and T5, 20 ppt) and were arranged in a Complete Randomized Design (CRD). Nannochloropsis spp. was cultured in fifteen 500 ml plastic experimental bottles based on the assigned treatment for eleven days. Initial sampling was done during the start of the experiment, and everyday thereafter. Cell density was counted using haemacytometer and viewed under the microscope. Results showed that the highest cell density and instantaneous growth rate of freshwater Nannochloropsis spp. was obtained in Treatment 3 with 18,510,000.00 cells/ml and16.00±0.36 cells/ml, respectively, while Treatment 5 had the lowest cell density and growth rate (10,040,833.33 cells/ml; 15.38±0.46 cells/ml).One-way ANOVA and Duncan’s Multiple Range Test revealed there was a significant difference (p<0.05) on the days of culture (days 3, 7 and 8) among treatments. Results for both cell density (cells/ml) and instantaneous growth rate (K) proved that freshwater Nannochloropsis spp. can tolerate a wider range of salinity from 5 ppt to 15 ppt. However, further studies should be conducted at a wider range of salinity levels and other variables such as nitrogen levels and light intensity to have a complete picture of the reproductive biology of this species. Keywords - Aquatic Ecology, instantaneous growth rate, freshwater Nannochloropsis spp., salinity levels, experimental design, Philippines, Asia

scholarly journals Assessment of the Growth and Reproductive Performance of Cloned Pietrain Boars

Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2053
Author(s):  
Junsong Shi ◽  
Baohua Tan ◽  
Lvhua Luo ◽  
Zicong Li ◽  
Linjun Hong ◽  
...  
Keyword(s):  
Growth Rate ◽  
Body Size ◽  
Growth Performance ◽  
Reproductive Performance ◽  
Semen Quality ◽  
Small Body ◽  
Economic Benefits ◽  
Large Animal ◽  
Significant Difference ◽  
F1 Progeny

How to maximize the use of the genetic merits of the high-ranking boars (also called superior ones) is a considerable question in the pig breeding industry, considering the money and time spent on selection. Somatic cell nuclear transfer (SCNT) is one of the potential ways to answer the question, which can be applied to produce clones with genetic resources of superior boar for the production of commercial pigs. For practical application, it is essential to investigate whether the clones and their progeny keep behaving better than the “normal boars”, considering that in vitro culture and transfer manipulation would cause a series of harmful effects to the development of clones. In this study, 59,061 cloned embryos were transferred into 250 recipient sows to produce the clones of superior Pietrain boars. The growth performance of 12 clones and 36 non-clones and the semen quality of 19 clones and 28 non-clones were compared. The reproductive performance of 21 clones and 25 non-clones were also tested. Furthermore, we made a comparison in the growth performance between 466 progeny of the clones and 822 progeny of the non-clones. Our results showed that no significant difference in semen quality and reproductive performance was observed between the clones and the non-clones, although the clones grew slower and exhibited smaller body size than the non-clones. The F1 progeny of the clones showed a greater growth rate than the non-clones. Our results demonstrated through the large animal population showed that SCNT manipulation resulted in a low growth rate and small body size, but the clones could normally produce F1 progeny with excellent growth traits to bring more economic benefits. Therefore, SCNT could be effective in enlarging the merit genetics of the superior boars and increasing the economic benefits in pig reproduction and breeding.

scholarly journals Potential and limitations of finite element modelling in assessing structural integrity of coralline algae under future global change

2015 ◽  
Vol 12 (19) ◽  
pp. 5871-5883 ◽  
Author(s):  
L. A. Melbourne ◽  
J. Griffin ◽  
D. N. Schmidt ◽  
E. J. Rayfield
Keyword(s):  
Climate Change ◽  
Finite Element ◽  
Structural Integrity ◽  
Geometric Model ◽  
Algal Growth ◽  
Coralline Algae ◽  
Rocky Shores ◽  
Element Analysis ◽  
Scan Data ◽  
The Impact

Abstract. Coralline algae are important habitat formers found on all rocky shores. While the impact of future ocean acidification on the physiological performance of the species has been well studied, little research has focused on potential changes in structural integrity in response to climate change. A previous study using 2-D Finite Element Analysis (FEA) suggested increased vulnerability to fracture (by wave action or boring) in algae grown under high CO2 conditions. To assess how realistically 2-D simplified models represent structural performance, a series of increasingly biologically accurate 3-D FE models that represent different aspects of coralline algal growth were developed. Simplified geometric 3-D models of the genus Lithothamnion were compared to models created from computed tomography (CT) scan data of the same genus. The biologically accurate model and the simplified geometric model representing individual cells had similar average stresses and stress distributions, emphasising the importance of the cell walls in dissipating the stress throughout the structure. In contrast models without the accurate representation of the cell geometry resulted in larger stress and strain results. Our more complex 3-D model reiterated the potential of climate change to diminish the structural integrity of the organism. This suggests that under future environmental conditions the weakening of the coralline algal skeleton along with increased external pressures (wave and bioerosion) may negatively influence the ability for coralline algae to maintain a habitat able to sustain high levels of biodiversity.

scholarly journals Does galvanic cathodic protection by aluminum anodes impact marine organisms?

2020 ◽  
Vol 32 (1) ◽  
Author(s):  
Anna Maria Bell ◽  
Marcus von der Au ◽  
Julia Regnery ◽  
Matthias Schmid ◽  
Björn Meermann ◽  
...  
Keyword(s):  
Marine Environment ◽  
Cathodic Protection ◽  
Algal Growth ◽  
Wind Farms ◽  
Marine Organisms ◽  
Offshore Wind ◽  
Natural Seawater ◽  
Corophium Volutator ◽  
Offshore Wind Farms ◽  
Ecotoxicological Effects

Abstract Background Cathodic protection by sacrificial anodes composed of aluminum-zinc-indium alloys is often applied to protect offshore support structures of wind turbines from corrosion. Given the considerable growth of renewable energies and thus offshore wind farms in Germany over the last decade, increasing levels of aluminum, indium and zinc are released to the marine environment. Although these metals are ecotoxicologically well-studied, data regarding their impact on marine organisms, especially sediment-dwelling species, as well as possible ecotoxicological effects of galvanic anodes are scarce. To investigate possible ecotoxicological effects to the marine environment, the diatom Phaedactylum tricornutum, the bacterium Aliivibrio fischeri and the amphipod Corophium volutator were exposed to dissolved galvanic anodes and solutions of aluminum and zinc, respectively, in standardized laboratory tests using natural seawater. In addition to acute toxicological effects, the uptake of these elements by C. volutator was investigated. Results The investigated anode material caused no acute toxicity to the tested bacteria and only weak but significant effects on algal growth. In case of the amphipods, the single elements Al and Zn showed significant effects only at the highest tested concentrations. Moreover, an accumulation of Al and In was observed in the crustacea species. Conclusions Overall, the findings of this study indicated no direct environmental impact on the tested marine organisms by the use of galvanic anodes for cathodic protection. However, the accumulation of metals in, e.g., crustaceans might enhance their trophic transfer within the marine food web.

Evaluation and Comparison of Artificial Intelligence Vision Aids: Orcam MyEye 1 and Seeing AI

2021 ◽  
pp. 0145482X2110274
Author(s):  
Christina Granquist ◽  
Susan Y. Sun ◽  
Sandra R. Montezuma ◽  
Tu M. Tran ◽  
Rachel Gage ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Human Performance ◽  
Visual Impairments ◽  
Light Level ◽  
Viewing Distance ◽  
Light Perception ◽  
Time To Completion ◽  
Significant Difference ◽  
Text Reading ◽  
Size Contrast

Introduction: We compared the print-to-speech properties and human performance characteristics of two artificial intelligence vision aids, Orcam MyEye 1 (a portable device) and Seeing AI (an iPhone and iPad application). Methods: There were seven participants with visual impairments who had no experience with the two reading aids. Four participants had no light perception. Two individuals with measurable acuity and one with light perception were tested while blindfolded. We also tested performance with text of varying appearance in varying viewing conditions. To evaluate human performance, we asked the participants to use the devices to attempt 12 reading tasks similar to activities of daily living. We assessed the ranges of text attributes for which reading was possible, such as print size, contrast, and light level. We also assessed if individuals could complete tasks with the devices and measured accuracy and completion time. Participants also completed a survey concerning the two aids. Results: Both aids achieved greater than 95% accuracy in text recognition for flat, plain word documents and ranged from 13 to 57% accuracy for formatted text on curved surfaces. Both aids could read print sizes as small as 0.8M (20/40 Snellen equivalent, 40 cm viewing distance). Individuals successfully completed 71% and 55% ( p = .114) of tasks while using Orcam MyEye 1 and Seeing AI, respectively. There was no significant difference in time to completion of tasks ( p = .775). Individuals believed both aids would be helpful for daily activities. Discussion: Orcam MyEye 1 and Seeing AI had similar text-reading capability and usability. Both aids were useful to users with severe visual impairments in performing reading tasks. Implications for Practitioners: Selection of a reading device or aid should be based on individual preferences and prior familiarity with the platform, since we found no clear superiority of one solution over the other.

scholarly journals Responses of Root Characteristic Parameters and Plant Dry Matter Accumulation, Distribution and Transportation to Nitrogen Levels for Spring Maize in Northeast China

Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 308
Author(s):  
Yang Yu ◽  
Chunrong Qian ◽  
Wanrong Gu ◽  
Caifeng Li
Keyword(s):  
Surface Area ◽  
Nitrogen Fertilizer ◽  
Root Length ◽  
Dry Matter ◽  
Projection Area ◽  
Dry Matter Accumulation ◽  
Characteristic Parameters ◽  
High Nitrogen ◽  
Nitrogen Levels ◽  
Matter Transport

Improving nitrogen use efficiency is a significant scientific problem to be solved. Two maize hybrids JD27 (Jidan 27) and SD19 (Sidan 19) were selected to study the effects of nitrogen levels on root characteristic parameters and plant dry matter accumulation, distribution and transportation. We set five different nitrogen levels, which were nitrogen deficiency (000N), low nitrogen (075N), medium nitrogen (150N), high nitrogen (225N) and excessive nitrogen (300N). The results showed that the root length and root surface area of JD27 were significantly higher than those of SD19 under 075N. With the increase of nitrogen levels, the root difference among varieties gradually decreased. The root length, projection area, total surface area and total volume reached the maximum values at silking stage. The average root diameter kept stable or decreased slowly with the growth stage. The dry matter accumulation of JD27 was higher than that of SD19 at all growth stages. Increasing the amount of nitrogen fertilizer can promote the transport of dry matter to grain and improve dry matter transport efficiency after anthesis. Under the treatment of medium and high nitrogen fertilizer, maize was easy to obtain a higher yield, but excessive nitrogen fertilizer inhibited the increase of yield. This study provides theoretical and practical guidance for maize production techniques.

Enhancement of Hydrocarbon Productivity of Botryococcus braunii by an Adenine Type Phytohormone

2012 ◽  
Vol 512-515 ◽  
pp. 397-400
Author(s):  
Jun Zhi Liu ◽  
Ya Ming Ge ◽  
Guang Ming Tian
Keyword(s):  
Growth Rate ◽  
Low Dose ◽  
Algal Growth ◽  
Botryococcus Braunii ◽  
Biofuel Production ◽  
Carotenoid Content ◽  
Algae Biofuels ◽  
Hydrocarbon Content ◽  
Algal Growth Rate ◽  
Hydrocarbon Productivity

This study examined the effects of an adenine-type cytokinin 6-benzylaminopurine (6-BA) on the growth and metabolism characteristics of Botryococcus braunii, one of the most promising oil-rich algae for biofuel production. The results showed that 6-BA of low dose (0.1-1.0 mg L-1) would enhance the algal growth rate and biochemical synthesis, whereas too much (5.0 mg L-1) would be lethally toxic for B. braunii. Noticingly, though the maximum algal growth rate, chlorophyll and β-carotenoid content were observed in the treatment with 0.5 and/or 1.0 mg L-1 6-BA, both the maximum algal hydrocarbon content and the highest hydrocarbon productivity were observed in the treatment with 0.1 mg L-1 6-BA, which were respectively 2.45 and 3.48 times of the control (39.1% vs. 16.0%, 546 mg L-1 vs. 157 mg L-1). This finding has great implications for improving algae biofuels production by phytohormone.

scholarly journals In Vivo Radioprotective Activity of Cell-Permeable Bifunctional Antioxidant Enzyme GST-TAT-SOD against Whole-Body Ionizing Irradiation in Mice

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Jianru Pan ◽  
Huocong He ◽  
Ying Su ◽  
Guangjin Zheng ◽  
Junxin Wu ◽  
...  
Keyword(s):  
Growth Rate ◽  
Antioxidant Activity ◽  
Body Weight ◽  
Whole Body ◽  
White Pulp ◽  
Radioprotective Activity ◽  
Significant Difference ◽  
Wbc Count

GST-TAT-SOD was the fusion of superoxide dismutase (SOD), cell-permeable peptide TAT, and glutathione-S-transferase (GST). It was proved to be a potential selective radioprotector in vitro in our previous work. This study evaluated the in vivo radioprotective activity of GST-TAT-SOD against whole-body irradiation. We demonstrated that intraperitoneal injection of 0.5 ml GST-TAT-SOD (2 kU/ml) 2 h before the 6 Gy whole-body irradiation in mice almost completely prevented the splenic damage. It could significantly enhance the splenic antioxidant activity which kept the number of splenic white pulp and consequently resisted the shrinkage of the spleen. Moreover, the thymus index, hepatic antioxidant activity, and white blood cell (WBC) count of peripheral blood in irradiated mice pretreated with GST-TAT-SOD also remarkably increased. Although the treated and untreated irradiated mice showed no significant difference in the growth rate of animal body weight at 7 days postirradiation, the highest growth rate of body weight was observed in the GST-TAT-SOD-pretreated group. Furthermore, GST-TAT-SOD pretreatment increased resistance against 8 Gy whole-body irradiation and enhanced 30 d survival. The overall effect of GST-TAT-SOD seemed to be a bit more powerful than that of amifostine. In conclusion, GST-TAT-SOD would be a safe and potentially promising radioprotector.

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