scholarly journals ON THE PROBLEM OF USING NATURAL BIOLOGICALLY ACTIVE SUBSTANCES TO ACTIVATE ARTEMIA EGGS

REPORTS ◽  
2020 ◽  
Vol 5 (333) ◽  
pp. 5-12
Author(s):  
A. V. Ubaskin ◽  
◽  
N. E. Tarasovskaya ◽  
K. I. Akhmetov ◽  
A. I. Lunkov ◽  
...  
Keyword(s):  
Lake Water ◽  
Aquatic Organisms ◽  
Biologically Active ◽  
Hatching Rate ◽  
Chemical Effects ◽  
Different Populations ◽  
The Common ◽  
Egg Shell ◽  
Artificial Activation ◽  
Physical And Chemical

. Currently branchiopod from the genus of Artemia Leach, 1819 became the common starting feed №1 for growing young aquatic organisms. However, there is often reduced hatching of nauplius from the collected eggs and artificial activation is required. As a result of empirical research, it was possible to experimentally detect the activating effect of excretion products – diluted adult urine. The research was carried out in several stages. It was found that the rate of germination growth for different populations ranges from 0, 2 to 0, 6% per day. In the first experiment, cysts with 24% of hatching were placed in a solution of lake water diluted with urine to a concentration of 105 g/l. After two weeks, the outage reached 66. 7 % and exceeded the control 2.55 times. But over time, the activity of the embryos decreased and by the end of April, the hatching reached zero. By using eggs from the 1st experiment with 66. 9% hatching in a fresh solution of «lake water + urine» (105 g / l) on the first day, the hatching exceeded the control by 52. 1% and by 23.7% the data from experiment 1.Later, when 80.8% were hatched, a large number of weakened and dead nauplius was observed. In the third experiment, spring egg with a hatching rate of 36. 7% was used. Different salinity concentrations (110-140 g/l) were used due to dilution of lake water (233 g/l) with urine and fresh water. When activated in a solution with a salinity of 110 g/l after one month, the discharge exceeded the control by 1. 65 times. At the end of the experiments, an increase in the salt concentration reduced the activating effect with a slight decrease in hatching. The mechanisms of activating action of the components of the proposed liquid folds the physiological effects of steroid hormone metabolites on the formation of the larva in the egg and the destructive physical and chemical effects of a number of substances on the egg shell. For complex activation of the development of the embryo with the destruction of egg’s shells, savings are achieved in the plastic and energy substances available in the egg, preserving the nutritional value of nauplius.

scholarly journals Microplastic Exposure Across Trophic Levels: Effects on the Host Microbiota of Freshwater Organisms

2021 ◽  
Author(s):  
Javier Edo Varg ◽  
David Outomuro ◽  
Warren Kunce ◽  
Lukas Kuehrer ◽  
Richard Svanbäck ◽  
...  
Keyword(s):  
Aquatic Organisms ◽  
Trophic Levels ◽  
Anthropogenic Sources ◽  
Freshwater Organisms ◽  
Chemical Effects ◽  
Indirect Exposure ◽  
Damselfly Larvae ◽  
Carry Over ◽  
Trophic Webs ◽  
Physical And Chemical

Abstract BackgroundMicroplastics are a pervasive pollutant widespread in sea- and freshwater from anthropogenic sources, and together with the presence of pesticides, they can have physical and chemical effects on aquatic organisms and on their microbiota. Few studies have explored the combined effects of microplastics and pesticides on the host microbiome, and more importantly, the effects across multiple trophic levels. In this work, we studied the effects of exposure to microplastics and the pesticide deltamethrin on the diversity and abundance of the host microbiome across a three-level food chain: daphnids-damselfly-dragonflies. Daphnids were the only organism exposed to 1µm microplastic beads, and they were fed to damselfly larvae. Those damselfly larvae were exposed to delthametrin, and then fed to the dragonfly larvae. The microbiotas of the daphnids, damselflies and dragonflies were analyzed. ResultsOur results suggest that the exposure to microplastics and deltamethrin had negative carry-over effects on the diversity and abundance of the microbiome across the three trophic levels. Moreover, the exposure to deltamethrin on the damselflies negatively affected their survival rate in the presence of the dragonfly predator, but no such effects were found on damselflies exposed to only microplastics. ConclusionsOur study highlights the importance of evaluating ecotoxicological effects at the community level. Importantly, the indirect exposure to microplastics and pesticides through diet can potentially have bottom-up effects in the trophic webs.

Catalytic Synthesis of Cyclic Guanidines via Hydrogen Atom Transfer and Radical-Polar Crossover

2020 ◽  
Author(s):  
Shunya Ohuchi ◽  
Hiroki Koyama ◽  
Hiroki Shigehisa
Keyword(s):  
Hydrogen Atom ◽  
Functional Group ◽  
Hydrogen Atom Transfer ◽  
Catalytic Synthesis ◽  
Membered Ring ◽  
Biologically Active ◽  
Atom Transfer ◽  
Powerful Method ◽  
Protective Groups ◽  
The Common

A catalytic synthesis of cyclic guanidines, which are found in many biologically active compounds and natu-ral products, was developed, wherein transition-metal hydrogen atom transfer and radical-polar crossover were employed. This mild and functional-group tolerant process enabled the cyclization of alkenyl guanidines bearing common protective groups, such as Cbz and Boc. This powerful method not only provided the common 5- and 6-membered rings but also an unusual 7-membered ring. The derivatization of the products afforded various heterocycles. We also investigated the se-lective cyclization of mono-protected or hetero-protected (TFA and Boc) alkenyl guanidines and their further derivatiza-tions.

scholarly journals Investigation of Water Quality Parameters from Ramna, Crescent and Hatirjheel Lakes in Dhaka City

2015 ◽  
Vol 8 (1) ◽  
pp. 1-5 ◽  
Author(s):  
MS Islam ◽  
M Rehnuma ◽  
SS Tithi ◽  
MH Kabir ◽  
L Sarkar
Keyword(s):  
Water Quality ◽  
Lake Water ◽  
Public Awareness ◽  
Aquatic Organisms ◽  
Quality Parameters ◽  
Water Runoff ◽  
Dhaka City ◽  
Sound Environment ◽  
Surrounding Areas

The study was conducted to know the status of water quality of the Ramna, Crescent and Hatirjheel lakes in the Dhaka city. Water samples were collected from three different points of each lake and analyzed for various physicochemical parameters including temperature, pH, EC, TDS, DO, BOD, hardness, alkalinity, acidity during the period from November 2013 to April 2014. The mean temperature 22.54, 24.59 and 24.24°C; EC 15400, 282.00 and 618.27 ?Scm-1; TDS 85.38, 155.60 and 339.90 ppm; pH 7.73, 7.85 and 7.67; DO 3.51, 3.92 and 3.65 ppm; BOD 0.93, 0.73 and 3.15 ppm; hardness 95.00, 108.56 and 105.11 ppm; alkalinity 48.9, 120.7 and 249.1 ppm, and acidity 2.18, 2.67 and 2.05 ppm were investigated from Ramna, Crescent and Hatirjheel lakes, respectively. Lower concentration of DO was observed in all three lakes that severely harmed the aquatic organisms and degrade their habitat. The comparative study demonstrated that the concentration of BOD, EC, TDS, alkalinity and acidity of Hatirjheel Lake was higher than Ramna and Crescent lakes which indicated pollution of the lake water. The rain and storm water runoff, lack of awareness of people were responsible for the pollution of Ramna, Crescent and Hatirjheel lakes water. Connection of the sewerage line with the rain water collection channels and mixing of solid waste with lake water are the main reasons for pollution of Hatirjheel lake. Poor water quality of these lakes affects the ecosystem and aesthetic beauty negatively. To maintain the sound environment and healthy ecosystem of the lakes and the surrounding areas need proper management and monitoring and implementation of existing laws and regulations. Moreover public awareness is necessary otherwise it is hardly possible to maintain sound water quality of these three lakes.J. Environ. Sci. & Natural Resources, 8(1): 1-5 2015

Research of Treatment Technology for Electroplating Wastewater

2014 ◽  
Vol 487 ◽  
pp. 713-716 ◽  
Author(s):  
Yi Dan Zhou ◽  
Miao Sun ◽  
Li Juan Wang ◽  
Guan Nan Xi
Keyword(s):  
Waste Water ◽  
Wastewater Treatment ◽  
Electrochemical Method ◽  
Chemical Process ◽  
Biological Treatment ◽  
Chemical Method ◽  
Treatment Technology ◽  
Electroplating Wastewater ◽  
The Common ◽  
Physical And Chemical

The sources and composition of electroplating waste water are summarized. The common wastewater treatment technology, such as physical and chemical method, physic-chemical process, biological treatment and electrochemical method, and so on. Then the vision for the development of electroplating wastewater treatment technology is made.

scholarly journals When Bilingualism is the Common Factor: Switch Reference at the Junction of Competence and Performance in Both Second Language and Heritage Language Performance

2018 ◽  
Vol 11 (3) ◽  
pp. 590-616 ◽  
Author(s):  
Tiffany Judy ◽  
Michael T. Putnam ◽  
Jason Rothman
Keyword(s):  
Second Language ◽  
Adult Learners ◽  
Heritage Language ◽  
Common Factor ◽  
Language Performance ◽  
Subject Pronouns ◽  
Different Populations ◽  
The Common ◽  
And Performance ◽  
Heritage Language Speakers

In this paper we take a closer look at the oft-touted divide between heritage language speakers and adult second language (L2) learners. Here, we explore whether some properties of language may display general effects across different populations of bilinguals, explaining, at least partially, why these two groups show some common differences when compared with monolinguals. To test this hypothesis, we adduce data from two unique populations of bilinguals: a moribund variety of heritage German spoken in southwestern Kansas (Moundridge Schweitzer German) and L2 adult learners of Spanish. Empirically, we investigate whether the confound of switch reference adds an additional cognitive burden to these bilinguals in licensing object control predicates in the former and referential subject pronouns in the latter. Our preliminary findings support the view that overarching concepts such as incomplete acquisition cannot capture the variability observed in these populations, thus further supporting approaches that interpret findings such as these to be the result of specific variables.

scholarly journals Lake water dissolved inorganic carbon dynamics revealed from monthly measurements of radiocarbon in the Fuji Five Lakes, Japan

Elem Sci Anth ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Kosuke Ota ◽  
Yusuke Yokoyama ◽  
Yosuke Miyairi ◽  
Shinya Yamamoto ◽  
Toshihiro Miyajima
Keyword(s):  
Lake Water ◽  
Inorganic Carbon ◽  
Environmental Changes ◽  
Dissolved Inorganic Carbon ◽  
Anthropogenic Activities ◽  
Aquatic Organisms ◽  
Human Society ◽  
History Of ◽  
Lake Waters ◽  
Reservoir Age

Lakes are sensitive recorders of anthropogenic activities, as human society often develops in their vicinity. Lake sediments thus have been widely used to reconstruct the history of environmental changes in the past, anthropogenic, or otherwise, and radiocarbon dating provides chronological control of the samples. However, specific values of radiocarbon in different carbon reservoirs due to the different pathways of radiocarbon from the upper atmosphere to the lake, called the radiocarbon reservoir age, is always difficult to evaluate because of dynamic processes in and around lakes. There are few systematic studies on radiocarbon reservoir ages for lakes owing to the complex radiocarbon transfer processes for lakes. Here, we investigate lake waters of the Fuji Five Lakes with monthly monitoring of the radiocarbon reservoir effects. Radiocarbon from dissolved inorganic carbon (DIC) for groundwater and river water is also measured, with resulting concentrations (Δ14C) at their lowest at Lake Kawaguchi in August 2018 (–122.4 ± 3.2‰), and at their highest at Lake Motosu in January 2019 (–22.4 ± 2.5‰), despite a distance of 25 km. However, winter values in both lakes show similar trends of rising Δ14C (about 20‰). Our lake water DIC Δ14C results are compared to previously published records obtained from sediments in Lake Motosu and Lake Kawaguchi. These suggest that total organic carbon and compound-specific radiocarbon found in sediments are heavily influenced by summer blooms of aquatic organisms that fix DIC in water. Thus, future studies to conduct similar analyses at the various lakes would be able to provide further insights into the carbon cycle around inland water, namely understanding the nature of radiocarbon reservoir ages.

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