Changes in Periphytic Algae Following Bicarbonate Additions to a Small Stream

1973 ◽  
Vol 30 (12) ◽  
pp. 1882-1884 ◽  
Author(s):  
M. Dickman

Additions of less than 50 mg/liter sodium bicarbonate significantly increased algal standing crop on glass slides exposed in the treated portion of a small stream during a 2-month period. Filamentous green algae dominated the periphyton community of both bicarbonate treated and control slides when the study was terminated after 63 days. A slight shift in species composition toward the Cyanophycea on the bicarbonate treated slides was also noted.

1989 ◽  
Vol 46 (5) ◽  
pp. 827-835 ◽  
Author(s):  
Dolors Planas ◽  
Louise Lapierre ◽  
Guy Moreau ◽  
Martine Allard

Changes in species composition, richness, diversity, biomass (biovolume), and spatial community structure of a lotic periphyton community were observed under experimental acidification (mean pH 4.5) with and without aluminum, in troughs fed from an oligo-dystrophic creek (mean pH 6.7). in experimental and control troughs, the community was dominated by diatoms throughout the treatment. Achnanthes linearis was dominant in all troughs before treatment as well as in the control during the experiment. Eunotia pectinalis, which was rare in all troughs before treatment, became dominant in the acidified troughs. After 3 mo of acidification, algal cell density and biomass were respectively 30 and 40–70 times higher in the treated troughs as compared with that in the control. The Sow diversity (H = 1.45–2.30) characteristic of the control trough, increased to 3.3 in the treated troughs after 1 mo of acidification, but after 3 mo of experiment the diversity was slightly lower in experimental troughs. In the control trough, spatial organization of the community was characterized by monolayered arrangements during the whole experiment, in both acidified troughs (acid and acid plus aluminum) the community became multilayered (3–4 layers). The increased complexity of the community in the acidified troughs seemed to be related to a decrease in the abundance of grazers in the periphytic community, mainly the collector–gatherers Ephemeroptera and Orthocladiinae.


Coatings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 549 ◽  
Author(s):  
Bruna Sinjari ◽  
Gianmaria D’Addazio ◽  
Martina Bozzi ◽  
Manlio Santilli ◽  
Tonino Traini ◽  
...  

The aim of this in vitro study was to evaluate the enamel surface topography after treatment with three air polishing powders: Glycine (A), erythritol (B), and sodium bicarbonate (C) (Air Flow Soft, Plus and Classic powders, EMS Electro Medical Systems S.A., Nyon, Switzerland). Fifteen extracted incisors were randomly divided into three groups of five teeth each, A, B and C, respectively. The teeth were blocked in plaster bases, washed, dried and half-covered with polytetrafluoroethylene strips before treatment. In this way, each half-treated dental element became test and control of itself. Comparative statistical analysis of Rq (geometric average of the deviations occurring in roughness profile) was performed. The scanning electron microscope (SEM) analysis showed different degrees of surface roughness between the groups, decreasing after treatment. In addition, a statistically significant reduction p < 0.05 was present in group C (Rq mean non-treated 108.17 µm, 95% CI: 97.29–124.01 and Rq mean treated 86.78 µm, 95% CI: 80.63–93.70). A decrease in surface roughness post-treatment was not observed in group A and B. Therefore, it may be concluded that the air flow powders tested herein can be used on dental enamel to reduce the surface roughness due to function and the action of dental therapies.


2014 ◽  
Vol 43 (2) ◽  
pp. 137-142 ◽  
Author(s):  
Cíntia Lima Gouveia ◽  
Isabelle Cristine Melo Freire ◽  
Maria Luísa de Alencar e Silva Leite ◽  
Rebeca Dantas Alves Figueiredo ◽  
Leopoldina de Fátima Dantas de Almeida ◽  
...  

Introduction: The effectiveness of antimicrobial solutions employed in dental prosthesis decontamination is still uncertain. Aim: To evaluate the antifungal activity of cleaners used in the decontamination of dental prostheses on the growth of Candida albicans. Material and method: The evaluated products were: Corega Tabs(r) (S1), Sodium Hypochlorite 1% (S2), Sodium Bicarbonate 1% (S3), Hydrogen Peroxide 1% (S4), Chlorhexidine Digluconate 0.12% - Periogard (r) (S5), Mouthrinse based on essential oils - Listerine(r) (S6), essential oil from Rosmarinus officinalis (rosemary) at concentrations of 1% (S7) and 2% (S8). The antifungal activity of the products was evaluated by agar diffusion technique and the determination of microbial death curve of samples of C. albicans (ATCC 90028) in concentration 1.5 × 106 CFU/mL. The tests were performed in triplicate and statistical analysis was made by ANOVA Two-Way and Tukey tests, with the confidence level of 95%. Result: The average of the zones of inhibition growth, in millimeters, obtained for the products were: 0.0 (S1), 44.7 (S2), 0.0 (S3), 21.6 (S4), 10.0 (S5), 6.1 (S6), 0.0 (S7) and 2.4 (S8). Considering the determination of microbial death curve, all products showed a statistical difference (p<0.01) from control (0.85% sodium chloride) and S3 groups. Fungal growth less than 2×104 CFU/mL and an accentuation of the microbial death curve were observed after 30 minutes, with exception for S3 and control groups. Conclusion: The studied compounds, with the exception of Sodium Bicarbonate, have antifungal effect against C. albicans, which contribute for dental prostheses hygiene.


2021 ◽  
Vol 2021 (2) ◽  
pp. 57-80
Author(s):  
Vladimir Zolotarev

The area of natural growth and the scale of economic use of white clover among perennial legumes are spatially one of the most global. Due to the constant presence of wild white clover in many natural phyto-cenoses of most agricultural landscapes of different geographical zones, a certain complex of phytophages has evolved from various classes of invertebrate animal organisms that feed on various parts of this plant and reproduce on it. With the introduction of white clover into the culture and the spread of production crops of this plant over large areas, more favorable conditions are created for uncontrolled mass re-production of pests, which can cause already economically and economically significant crop losses. White clover is affected by multi-eating and specialized pests, the damage from which is determined by their biological characteristics and climatic conditions. The high population of white clover crops with a complex of herbivorous invertebrates implies constant monitoring and control of the species composition of the harmful fauna of white clover crops in order to organize, if necessary, protective measures against them. This issue is especially relevant for seed crops. The main pests of seed stands are considered to be weevils of the genera Apion Herbs., Phytonomus Herbs., Sitona Germar., Hypera Germar., which can re-duce seed yield by 50% or more. To reduce the economic losses of the crop on white clover, an integrated protection system should be implemented using chemical, biological and agrotechnical pest control meas-ures based on taking into account their economic harmfulness thresholds. One of the important directions of increasing the efficiency of the production use of white clover is the development of varieties of this crop that are resistant to damage by pathogenic organisms and pests.


2021 ◽  
Author(s):  
Geoffrey Kariuki Kinuthia ◽  
Veronica Ngure ◽  
Luna Kamau

Abstract Background Levels of Mercury (Hg), Lead (Pb), Chromium (Cr), Cadmium (Cd), Thallium (Tl), and Nickel (Ni) in samples of wastewater, filamentous green algae (spirogyra) and urban mosquitoes obtained from open wastewater channels in Nairobi industrial area, Kenya, was established. Industrial wastewater may contain hazardous heavy metals upon exposure. Aquatic organisms in wastewater may accumulate the toxic elements with time. Therefore, human population living in informal settlements in Nairobi industrial area risk exposure to such toxic elements. Biomonitoring using aquatic organisms can be key in metal exposure assessment. Results Pb, Cr, & Ni levels ranged from 3.08 to 15.31 µg/L while Tl, Hg, & Cd levels ranged from 0.05 to 0.12 µg/L in wastewater. Pb, Cr, Ni, & Cd levels were above WHO, Kenya & US EPA limits for wastewater but Hg was not. Metals in tap water (control) which ranged from 0.01 to 0.2 µg/L was below WHO, US EPA, & Kenya standard limits. Pb, Cr, Tl, & Ni levels in assorted field mosquitoes were 1.3 to 2.4 times higher than in assorted laboratory-reared mosquitoes. Hg & Cd concentrations in laboratory-reared mosquitoes (0.26 mg/L & 1.8 mg/L respectively) was higher than in field mosquitoes (0.048 mg/L & 0.12 mg/L respectively). Pb, Cr, Ni, & Cd levels in green filamentous algae were 110.62, 29.75, 14.45, & 0.44 mg/L respectively and above WHO limits for vegetable plants. Hg level in algae samples (0.057 mg/L) was below WHO standard limits but above Kenya & US EPA limits in vegetables. Correlations for Pb & Hg (r = 0.957; P < 0.05); Cd & Cr (r = 0.985; P < 0.05) in algae samples were noted. The metal concentrations in the samples were in the order, wastewater < mosquitoes < filamentous green algae. Conclusion Samples of wastewater, mosquitoes and filamentous green algae from open wastewater channels and immediate vicinity, in Nairobi industrial area (Kenya) contained Hg, Pb, Cr, Cd, Tl, and Ni. Urban mosquitoes and filamentous green algae can play a role of metal biomonitoring in wastewater. The possibility of urban mosquitoes transferring the heavy metals to their hosts when sucking blood should be investigated.


2016 ◽  
Author(s):  
Burak Öterler

The aim of this paper is to determine and compare the environmental factors controlling longitudinal colonisation of periphytic algae in agricultural and urbanization effects of a lowland river, the Tundzha River, located in Turkish Tunca. To investigate the effect of the environmental factors on periphyton colonization at the river, 6 stations were selected and samples were collected between April 2012 and March 2013. Canonical correspondence analyses have been applied to clarify relationships between environmental variables and periphytic algae. During the study, the Shannon-Wiener diversity index (H′) varied from 1.62 to 3.91. The phytoplankton biovolume was positively related to pH, temperature, salinity, chlorophyll- a and nutrients, and was negatively correlated with dissolved oxygen, turbidity, and silicate. Out of the 5 divisions and of 73 identified species of phytoplankton, the diatoms, namely Fragilaria ulna, Cymbella tumida, Cocconeis placentula, Gomphonema acuminatum and Cymbella cystula were found to be dominant. In addition to these species, the biovolumes of filamentous diatom Melosira varians, filamentous blue-green algae Oscillatoria limosa, and placcoderm desmids Cosmarium botrytis were determined to be at high levels during the year. The euglenoid blooms in St.5 showed many times during the study period.


2021 ◽  
Vol 42 (3(SI)) ◽  
pp. 895-902
Author(s):  
M.D. Quan ◽  
◽  
T.T. Hang ◽  
S.T. Nam ◽  
◽  
...  

Aim: This study was conducted to provide data on weed species composition and biodiversity indexes at different rice crops inside and outside of the dike system in An Giang province, Vietnam. Methodology: Weeds were collected from paddy rice of inner and outer side of dike system from six districts of An Giang province, Vietnam. From each sampling sites, two quadrats with 100 m2 (10 m × 10 m) per quadrat were selected to collect weed after 75-80 days of rice planting. Weeds were collected and identified for their scientific name, and the number of each species was defined, followed by calculation of the occurrence frequency and density of samples. Biodiversity indices viz. Shannon-Weaver (H’), Simpson (1- λ), Margalef (d), and similarity index were also studied among three crops and two sides of dike system. Results: The weed composition in the paddy rice in An Giang was diversity with 137 species. Among them, the most species belonged to families Poaceae, Cyperaceae, and Compositae. The species composition of Crop 3 was the highest one. Species occurrence frequency and weed density of groups C, D, E reached the highest value in Crop 1, followed by Crop 2 and 3. The biodiversity indices of weed species composition in the studied sites were high, reaching the highest value in Crop 3. Interpretation: The results of this study enhance the knowledge of weed species composition and biodiversity indexes to effectively manage and control weeds in rice cultivation.


2016 ◽  
Author(s):  
Burak Öterler

The aim of this paper is to determine and compare the environmental factors controlling longitudinal colonisation of periphytic algae in agricultural and urbanization effects of a lowland river, the Tundzha River, located in Turkish Tunca. To investigate the effect of the environmental factors on periphyton colonization at the river, 6 stations were selected and samples were collected between April 2012 and March 2013. Canonical correspondence analyses have been applied to clarify relationships between environmental variables and periphytic algae. During the study, the Shannon-Wiener diversity index (H′) varied from 1.62 to 3.91. The phytoplankton biovolume was positively related to pH, temperature, salinity, chlorophyll- a and nutrients, and was negatively correlated with dissolved oxygen, turbidity, and silicate. Out of the 5 divisions and of 73 identified species of phytoplankton, the diatoms, namely Fragilaria ulna, Cymbella tumida, Cocconeis placentula, Gomphonema acuminatum and Cymbella cystula were found to be dominant. In addition to these species, the biovolumes of filamentous diatom Melosira varians, filamentous blue-green algae Oscillatoria limosa, and placcoderm desmids Cosmarium botrytis were determined to be at high levels during the year. The euglenoid blooms in St.5 showed many times during the study period.


Author(s):  
I. S. Agasieva ◽  
V. Ya. Ismailov ◽  
A. S. Nastasiy ◽  
M. V. Nefedova

Synthetic sex pheromones have found wide application in plant protection as a mean of early detection of pests that allows observation of the phenology of insects to optimise protective measures. Insect sex pheromones can be applied for different purposes in protecting crops such as monitoring, determining the species composition and combating harmful species (by using sex pheromones for disorientation). The present work studies the species composition, dynamics of the number of basic pests of an apple tree, synchronisation of the seasonal and circadian activity of phytophages of an apple tree in the central zone of the Krasnodar Territory. The results of the field assessment of the male complex disorientation method of apple and eastern moths are presented. It was shown that the species-specificity of sex pheromones in the apple orchard depends on the faunistic diversity of Lepidoptera species with similar pheromone systems that develop at a given point in space and time. It was revealed that the behaviour of this complex changes during the season and over years, depending on the climate and natural dynamics of insect populations. The quantitative ratio and species-specificity of pheromones will probably be different in ecosystems with various species composition and different geographic zones. A novelty of this research is the division of the studied Lepidoptera phytophage species into three groups according to a decrease in the absolute species-specificity in the forest biotope in comparison with the garden one. The most widespread and coinciding in terms of summer synchronicity are apple (Cydia pomonella L.), plum (Grapholitha funebrana Tr.), eastern (Grapholitha molesta Tr.) and pomegranate moth (Euzophera bigella Zell.). The disorientation method, applied using a complex system of dispensers with apple and eastern moth pheromones, showed that installing 500 dispensers/ha allowed 99.3 % efficiency to be achieved. Fruit damage amounted to 1.2 % and 2.7 % in the experimental and control groups, respectively. The duration of the disorienting effect of the pheromone formulations lasted for over 4 months.


Sign in / Sign up

Export Citation Format

Share Document