scholarly journals Nematodes as bioindicators of the state of disturbance of edaphic ecosystems irrigated with natural and polluted water

2021 ◽  
Vol 11 (3) ◽  
pp. 275-279
Author(s):  
Michael Niño de Guzman Tito ◽  
Guido Zumarán Martinez
Keyword(s):  
2021 ◽  
Author(s):  
Sergey V. Kholodkevich ◽  
Maxim K. Motruk ◽  
Vasiliy A. Lyubimtsev ◽  
Olga N. Susloparova

The objects of bioindication of the ecological state were 3 channels of the Volga Delta, located both directly in Astrakhan and in the Astrakhan region. The aim of the work was to conduct a comparative bioelectronic diagnosis of the ecological state of the selected channels with different local anthropogenic loads, both by type and size, based on assessments of the functional state (health) of the bivalve mollusks Anodonta anatina living in them, estimated on the basis of an analysis of their cardiorhythm, measured using an original fiber-optic bioelectronic system. It was found that shellfish selected from different water areas, after 1hour functional load, restore the original heart rate for different times, but in the range from 117 to 166 minutes, which is typical for shellfish living in significantly polluted reservoirs of the same ecological status - "Bad". This characteristic of the water areas completely coincides with the characteristic of the ecological state of the channels of the Volga River Delta specified in the State Report "On the state and on Environmental Protection of the Russian Federation in 2017". The authors proposed and justified the possibility of using the water area of the Gandurino River as a conditional reference for the Volga Delta region. In this case, according to the value of the environmental quality coefficient EQR, the channels of the Urban Branch and the Small Channel can be attributed to the regional environmental status - "Good".


Author(s):  
Sharon Levy

Bob Gearheart emerged as Arcata’s marsh guru during the city’s long battle with the state water bureaucracy. This unpaid post demanded that Gearheart crank out proposals for wetland treatment at a frenetic pace, knowing that the city’s financial future depended on his work. He wore a smile, energized by the pressure. Gearheart’s son, Greg, grew up to become an environmental engineer working for the state water board. He earned his engineering degree at Humboldt State, studying with his father. He remembers his dad happily engaged during the battle for Arcata’s alternative treatment system, at the same time he was teaching a full load of classes. “My dad likes a fight,” Greg says. “He adapts well. People put an obstacle in front of him, and he figures out a way to make it look like it’s not really a problem. He makes it look like it was stupid on his opponent’s part to put the obstacle there.” In 1977, the elder Gearheart proposed a first: a wetland built to treat municipal wastewater to the standards required under the Clean Water Act. He possessed a serene certainty that he could make this untried system work. “I had no data until we did the pilot study,” he remembers, “but I was one hundred percent confident.” The power of aquatic plants to cleanse polluted water had first been tested in the 1950s by Käthe Seidel, a researcher at the Max Planck Institute in Germany. She showed that while some wild plants were killed off by waters tainted with phenol—a toxic organic compound used in making plastics—others had a remarkable ability to adapt. At first contact, effluent containing phenol caused bul­rush stems to wither away, but the roots survived and in time sent up healthy new shoots. Bulrush, it turned out, could break down phenol, metabolizing it into the amino acids that build protein. The plant also thrived in domestic sewage. Seidel used carefully groomed cultures of wetland plants, rooted in beds of gravel or sand through which effluent flowed.


Author(s):  
T. A. Welton

Various authors have emphasized the spatial information resident in an electron micrograph taken with adequately coherent radiation. In view of the completion of at least one such instrument, this opportunity is taken to summarize the state of the art of processing such micrographs. We use the usual symbols for the aberration coefficients, and supplement these with £ and 6 for the transverse coherence length and the fractional energy spread respectively. He also assume a weak, biologically interesting sample, with principal interest lying in the molecular skeleton remaining after obvious hydrogen loss and other radiation damage has occurred.


1980 ◽  
Vol 11 (2) ◽  
pp. 85-94 ◽  
Author(s):  
Jack Damico ◽  
John W. Oller

Two methods of identifying language disordered children are examined. Traditional approaches require attention to relatively superficial morphological and surface syntactic criteria, such as, noun-verb agreement, tense marking, pluralization. More recently, however, language testers and others have turned to pragmatic criteria focussing on deeper aspects of meaning and communicative effectiveness, such as, general fluency, topic maintenance, specificity of referring terms. In this study, 54 regular K-5 teachers in two Albuquerque schools serving 1212 children were assigned on a roughly matched basis to one of two groups. Group S received in-service training using traditional surface criteria for referrals, while Group P received similar in-service training with pragmatic criteria. All referrals from both groups were reevaluated by a panel of judges following the state determined procedures for assignment to remedial programs. Teachers who were taught to use pragmatic criteria in identifying language disordered children identified significantly more children and were more often correct in their identification than teachers taught to use syntactic criteria. Both groups identified significantly fewer children as the grade level increased.


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