scholarly journals Microbial Growth in Shrimp Ponds as Influenced by Monosilicic and Polysilicic Acids

2021 ◽  
Author(s):  
Ruiping Zhang ◽  
Elena Bocharnikova ◽  
Vladimir Matichenkov
Keyword(s):  
Laboratory Experiments ◽  
Microbial Growth ◽  
Pond Water ◽  
Degree Of Polymerization ◽  
Shrimp Ponds ◽  
Cell Abundance ◽  
Monosilicic Acid ◽  
Phytoplankton Communities ◽  
Essential Nutrient ◽  
Positive Effect

Abstract In order to increase shrimp production and minimize detrimental environmental impacts of aquaculture, the maintenance and regulation of the growth and composition of phytoplankton communities and nutritional balance are critical. Silicon (Si) is an essential nutrient for diatoms and other types of microorganisms, but the information about the Si impact on their growth is extremely scarce. Monosilicic and polysilicic acids were tested in several shrimp cultivation systems in Jiangsu Province, China. In pond waters, the concentrations of monosilicic and polysilicic acids sharply reduced by 36–95% and 35–75%, accordingly, as compared with those in supply water sources. The microbial cell abundance was strongly dependent on monosilicic acid, while the correlation with polysilicic acid was absent. In laboratory experiments, monosilicic acid added to pond water or probiotic solution at 1 and 2 mM Si had a significant positive effect on cell abundance. Over three days, the concentrations of monosilicic acid decreased by 81 to 91% in pond water and by 11 to 24% in probiotic solution. In probiotic solutions, the degree of polymerization of silicic acid was more intensive than that in shrimp pond waters. The data obtained demonstrates the importance of systematic studies related to the functions of Si in shrimp aquaculture.

scholarly journals Inhibition or Facilitation? Contrasted Inter-Specific Interactions in Sphagnum under Laboratory and Field Conditions

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1554
Author(s):  
Chao Liu ◽  
Zhao-Jun Bu ◽  
Azim Mallik ◽  
Yong-Da Chen ◽  
Xue-Feng Hu ◽  
...  
Keyword(s):  
Field Experiment ◽  
Species Interactions ◽  
Laboratory Experiments ◽  
Resource Competition ◽  
Specific Interactions ◽  
Interaction Type ◽  
Negative Effects ◽  
Experiment Data ◽  
The Stability ◽  
Positive Effect

In a natural environment, plants usually interact with their neighbors predominantly through resource competition, allelopathy, and facilitation. The occurrence of the positive effect of allelopathy between peat mosses (Sphagnum L.) is rare, but it has been observed in a field experiment. It is unclear whether the stability of the water table level in peat induces positive vs. negative effects of allelopathy and how that is related to phenolic allelochemical production in Sphagnum. Based on field experiment data, we established a laboratory experiment with three neighborhood treatments to measure inter-specific interactions between Sphagnum angustifolium (Russ.) C. Jens and Sphagnum magellanicum Brid. We found that the two species were strongly suppressed by the allelopathic effects of each other. S. magellanicum allelopathically facilitated S. angustifolium in the field but inhibited it in the laboratory, and relative allelopathy intensity appeared to be positively related to the content of released phenolics. We conclude that the interaction type and intensity between plants are dependent on environmental conditions. The concentration of phenolics alone may not explain the type and relative intensity of allelopathy. Carefully designed combined field and laboratory experiments are necessary to reveal the mechanism of species interactions in natural communities.

The Effect of Low-Rate Sand Filtration and Modified Feed Management on Effluent Quality, Pond Water Quality and Production of Intensive Shrimp Ponds

Estuaries ◽  
1995 ◽  
Vol 18 (1) ◽  
pp. 116 ◽  
Author(s):  
J. Stephen Hopkins ◽  
Craig L. Browdy ◽  
Richard D. Hamilton ◽  
Joseph A. Heffernan
Keyword(s):  
Water Quality ◽  
Pond Water ◽  
Sand Filtration ◽  
Shrimp Ponds ◽  
Effluent Quality ◽  
Feed Management ◽  
Low Rate

scholarly journals Potassium Fertigation to Enhance the Performance of Hypoxis hemerocallidea

HortScience ◽  
2021 ◽  
pp. 1-9
Author(s):  
Patience Seyram Akakpo ◽  
Moosa Mahmood Sedibe ◽  
Bello Zaid ◽  
Zenzile P. Khetsha ◽  
Mokgaputsiwa P. Theka-Kutumela ◽  
...  
Keyword(s):  
Nutrient Solution ◽  
Analysis Data ◽  
Dry Mass ◽  
Ionic Balance ◽  
Fresh Weight ◽  
Primary Metabolite ◽  
Essential Nutrient ◽  
Effect On Yield ◽  
Metabolite Content ◽  
Positive Effect

Potassium (K) is an essential nutrient in plant metabolism, ionic balance, and stress resistance. In this study, the effects of K on agronomic attributes and on mineral and primary metabolite content in African potato were determined. K was administered hydroponically at four concentrations (4.00, 6.00, 8.00, and 10.00 meq·L−1) using Steiner’s universal nutrient solution. Chlorophyll content (CHL), leaf area (LA), fresh corm mass (FCM), number of roots (NR), root fresh weight (RFM), and root dry mass (RDM) were measured 18, 32, and 40 weeks after transplanting. Mineral analysis data were collected at 18 weeks, and primary metabolite data were collected at 32 weeks. Significant effects of K were observed after 18 weeks, and all test concentrations had a positive effect on yield. Calcium and boron significantly accumulated in the corm at 4.00 meq·L−1 K. Alanine and malic acid were the only metabolites affected by K concentrations. More minerals accumulated in the corm at 4.00 meq·L−1 K, whereas at 10.00 meq·L−1 K, more minerals clustered in the leaf. K applied at 4.00 meq·L−1 is recommended when growing African potato using a nutrient solution to improve corm mineral and metabolite accumulation.

Investigation the influences of B2O3and R2O on the structure and crystallization behaviors of CaO–Al2O3based F-free mold flux

2018 ◽  
Vol 115 (3) ◽  
pp. 304 ◽  
Author(s):  
Jiangling Li ◽  
Bowen Kong ◽  
Xiangyu Gao ◽  
Qingcai Liu ◽  
Qifeng Shu ◽  
...  
Keyword(s):  
Liquidus Temperature ◽  
Mold Flux ◽  
Crystallization Process ◽  
Degree Of Polymerization ◽  
Scanning Calorimetry ◽  
Structural Investigations ◽  
Crystallization Ability ◽  
Mold Fluxes ◽  
New Type ◽  
Positive Effect

The influences of B2O3and R2O on the structure and crystallization of CaO–Al2O3based F-free mold flux were investigated by Raman Spectroscopy and Differential Scanning Calorimetry Technique, respectively, for developing a new type of F-free mold flux. The results of structural investigations showed that B3+is mainly in the form of [BO3]. And [BO3] appears to form BIII–O–Al linkage which will produce a positive effect on forming [AlO4] network. The number of bridging oxygen and the degree of polymerization of [AlO4] network structure for CaO–Al2O3system were also increased with the increasing of B2O3. On the contrary, with the addition of R2O into CaO–Al2O3–B2O3system, the number of bridging oxygen and the degree of polymerization of [AlO4] network were decreased. DSC results showed that the crystallization process became more sluggish with the increase of B2O3, which indicated that the crystallization ability was weakened. While the quenched mold fluxes crystallized more rapidly when introducing R2O. In other word, the crystallization rates of CaO–Al2O3based slags were accelerated by the introduction of R2O. The liquidus temperature and crystallization temperature were decreased with the increasing amount of B2O3or by addition of R2O into CaO–Al2O3system. Only one kind of crystal was precipitated in 8% B2O3and %R2O-containing samples, which was CaAl2O4identified by SEM-EDS. When the content of B2O3increased from 8% to 16%, Ca3B2O6is clearly observed, demonstrating that the crystallization ability of Ca3B2O6is enhanced by the increasing concentration of B2O3in mold flux. The Ca/Al ratio of the generated calcium aluminate has been altered from 1:2 to 1:4 with the increasing of B2O3. The size of CaAl2O4crystal is gradually increased with the addition of R2O. The crystallization ability of CaAl2O4is promoted by R2O.

scholarly journals MODELING OF A VENTILATED CAVITY BEHIND A STREAMLINED BODY

2021 ◽  
pp. 73-79
Author(s):  
G. O. Voropaiev ◽  
V. I. Korobov ◽  
N. F. Dimitrieva
Keyword(s):  
Open Source Software ◽  
Gas Flow ◽  
Laboratory Experiments ◽  
Gas Flow Rate ◽  
Two Phase ◽  
Air Cavity ◽  
Streamlined Body ◽  
Ventilated Cavity ◽  
Gas Blowing ◽  
Positive Effect

The results of physical and numerical modeling of a ventilated air cavity behind a streamlined body are presented. The results of laboratory experiments to determine the amount of gas flowing from the ventilated cavity are presented. It is formed behind the cavitator depending on a number of geometric and dynamic parameters. Numerical simulation of non-stationary 3D two-phase flow was performed on the basis of open source software OpenFOAM. The influence of gas blowing parameters on the formation of an air cavity, size, shape and stability has been investigated. Good qualitative agreement with experimental data was obtained. It is shown that the thickness of the ventilated cavity is determined by the diameter of the cavitator regardless of the diameter of the blow hole, and the increase in velocity or gas flow rate has a positive effect on the length and stability of the formed cavity.

scholarly journals The effect of parsley seed hydration treatment and pelleting on seed vigour

2011 ◽  
Vol 49 (No. 3) ◽  
pp. 114-118 ◽  
Author(s):  
S. Podlaski ◽  
Z. Chrobak ◽  
Z. Wyszkowska
Keyword(s):  
Laboratory Experiments ◽  
Respiratory Activity ◽  
Solid Matrix ◽  
Seed Vigour ◽  
Germination Ability ◽  
Germination Speed ◽  
Radicle Emergence ◽  
The Moment ◽  
Positive Effect ◽  
Scanning Electron

The effect of two priming techniques: hardening (prehydration treatment) and solid matrix priming (SMP) was studied on the seeds of two parsley varieties (Cukrowa and Berlińska) in 3-year laboratory experiments. On the images obtained from scanning electron microscope (SEM) there is a parsley embryo developing during germination up to the moment of radicle emergence. On the surface of primed seeds, in particular using the hardening method, lateral cracks are visible. The respiratory activity of primed seeds was similar to that of non-primed in the period of initial 24 h of germination, but significantly higher after 48 h. As compared to non primed seeds solid matrix priming significantly increased the percentage and the speed of germination. Nevertheless, pelleting reduced the positive effect of priming on the germination ability, without affecting the germination speed. After 18 months of storage, the vigour of primed seeds, particularly through hardening, had significantly decreased.

Terrestrial hibernation in the northern cricket frog, Acris crepitans

1999 ◽  
Vol 77 (8) ◽  
pp. 1240-1246 ◽  
Author(s):  
Jason T Irwin ◽  
Jon P Costanzo ◽  
Richard E Lee, Jr.
Keyword(s):  
Habitat Selection ◽  
Laboratory Experiments ◽  
Pond Water ◽  
Field Observations ◽  
Supercooling Point ◽  
Acris Crepitans ◽  
Selection Experiments ◽  
Cricket Frog ◽  
Freeze Tolerant ◽  
Cricket Frogs

We used laboratory experiments and field observations to explore overwintering in the northern cricket frog, Acris crepitans, in southern Ohio and Indiana. Cricket frogs died within 24 h when submerged in simulated pond water that was anoxic or hypoxic, but lived 8-10 days when the water was oxygenated initially. Habitat selection experiments indicated that cricket frogs prefer a soil substrate to water as temperature decreases from 8 to 2°C. These data suggested that cricket frogs hibernate terrestrially. However, unlike sympatric hylids, this species does not tolerate extensive freezing: only 2 of 15 individuals survived freezing in the -0.8 to -2.6°C range (duration 24-96 h). Cricket frogs supercooled when dry (mean supercooling point -5.5°C; range from -4.3 to -6.8°C), but were easily inoculated by external ice at temperatures between -0.5 and -0.8°C. Our data suggested that cricket frogs hibernate terrestrially but are not freeze tolerant, are not fossorial, and are incapable of supercooling in the presence of external ice. Thus we hypothesized that cricket frogs must hibernate in terrestrial sites that adequately protect against freezing. Indeed, midwinter surveys revealed cricket frogs hibernating in crayfish burrows and cracks of the pond bank, where wet soils buffered against extensive freezing of the soil.

Intensification of Arsenic and Zinc Mobilization by Combination of Bio-Chemical Leaching with EDTA in the Soil and Sediment Bioremediation

2017 ◽  
Vol 262 ◽  
pp. 634-637
Author(s):  
Iveta Štyriaková ◽  
Darina Štyriaková ◽  
Alexandra Bekényiová ◽  
Jaroslav Šuba
Keyword(s):  
Laboratory Experiments ◽  
Surface Coatings ◽  
Chemical Pretreatment ◽  
Column Tests ◽  
Chemical Leaching ◽  
Batch Tests ◽  
Heterotrophic Microorganisms ◽  
Negative Effect ◽  
Positive Effect ◽  
Soil And Sediment

The use of chemical pretreatment with 10mM EDTA to enhance the arsenic microbial mobilization was evaluated in this study. The bioleaching involved the use of the indigenous sedimentary and soil heterotrophic microorganisms, whose leaching media contained 2mM EDTA. The main objectives of using the chemical pretreatment was the removal of metal surface coatings from the iron minerals, such as Cu and Zn, which inhibited the iron microbial dissolution in the soil and sediment environment and thus increasing the mobilization of the retained As. To examine the effect of the chemical pretreatment and the biological leaching on the mobilization of Cu, Zn, and As, batch and column tests were conducted within the laboratory experiments. The removal of As and Zn from the soil and sediment was greatly enhanced by the co-treatment in the batch solution conditions than in the column percolate conditions and had negative effect only for Cu. In the batch tests, the heterotrophic bioleaching of the soil and sediment was found to have a pronounced positive effect on the extraction of As and Zn.

scholarly journals Does it pay off to smile even it is not authentic? Customers’ involvement and the effectiveness of authentic emotional displays

2021 ◽  
Author(s):  
Stephan Olk ◽  
Dieter K. Tscheulin ◽  
Jörg Lindenmeier
Keyword(s):  
Real World ◽  
Emotional Labor ◽  
Laboratory Experiments ◽  
Contextual Factor ◽  
Service Encounters ◽  
Customer Involvement ◽  
Emotional Displays ◽  
Expectation Disconfirmation ◽  
Positive Effect

AbstractResearch has shown that while the authenticity of positive emotional displays plays an important role in service encounters, it has not yet demonstrated a universally positive effect on customers’ behavior. This study, which is the first to present customer involvement as a contextual factor that influences customers’ processing, provides a deeper understanding of the effectiveness of the authenticity of emotional displays. The model is based on expectation disconfirmation theory and emotional contagion theory and is validated in a field experiment and two laboratory experiments that use video stimuli with actors in real-world contexts. The results show that even inauthentic displays can meet customers’ expectations depending on their involvement and that high-involvement customers adapt to employees’ authentic emotions more strongly than low-involvement customers do. In summary, the presented model strengthens the understanding of the role of authentic displays and provides an approach to improve the effectiveness of emotional labor strategies.

scholarly journals Characteristics of anti-Vibrio harveyi compounds produced by Bacillus spp. isolated from shrimp ponds

2021 ◽  
Vol 22 (11) ◽  
Author(s):  
Iman Rusmana ◽  
ISRAMILDA ISRAMILDA ◽  
Alina Akhdiya
Keyword(s):  
Vibrio Vulnificus ◽  
Vibrio Harveyi ◽  
Pond Water ◽  
Bacillus Sp ◽  
Shrimp Ponds ◽  
Pathogenic Vibrio ◽  
Bacillus Spp ◽  
Ph Range ◽  
Vibrio Spp ◽  
Filtration Technique

Abstract. Rusmana I, Isramilda, Akhdiya A. 2021. Characteristics of anti-Vibrio harveyi compounds produced by Bacillus spp. isolated from shrimp ponds. Biodiversitas 22: 4872-4879. Pathogenic Vibrio spp. such as Vibrio vulnificus, V. alginolyticus, V. fluvialis, V. anguillarum, and V. harveyi caused shrimp diseases. The application of bacterial probiotics can control the growth of pathogenic Vibrio in shrimp. Bacillus spp. can produce antimicrobial compounds that inhibit the growth of pathogenic Vibrio spp. Isolation of Bacillus from several pond water samples, pond sediment, and shrimp intestines was successfully collected 175 isolates of Bacillus spp. Three isolates, i.e., Ltw54, Lts36, dan Lts40 had a high inhibitory index and stability in inhibiting the growth of Vibrio harveyi. Verification assay showed that Bacillus sp. Lts40 had the highest antimicrobial activity. The competition assay showed that Bacillus sp Lts40 isolates inhibited the growth of V. harveyi up to 81,8%. The antimicrobial compound produced by Bacillus sp. Lts40 was stable at the pH range of 3-11 and remained stable after heating at 100ºC for 20 minutes. The purification results using the chromatographic filtration technique showed that the protein fraction with a molecular weight of 47,38 kDa effectively inhibited V. harveyi growth. Bacillus sp. Lts40 isolate has potential application as a probiotic agent in shrimp ponds to control the growth of V. harveyi that causes luminous vibriosis diseases and the antimicrobial substance is potentially to be developed and produced as an anti-V. harveyi product that can be applied in a shrimp hatchery.

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