scholarly journals Methods of sampling benthic invertebrates in lotic habitats: a spatial and temporal evaluation

2019 ◽  
Vol 31 ◽  
Author(s):  
Larissa Lima da Cunha ◽  
Maria Ines Bulgari Alves ◽  
Erika Ramos Ono ◽  
Virginia Sanches Uieda
Keyword(s):  
Benthic Invertebrates ◽  
Aquatic Ecosystems ◽  
Riparian Vegetation ◽  
Benthic Fauna ◽  
Temporal Variations ◽  
Spatial And Temporal Variation ◽  
Definition Of ◽  
Number Of Individuals ◽  
Surber Sampler

Abstract Aim We compared the effectiveness of two sampling devices, the Surber sampler and the D-frame net, commonly used in the analysis of invertebrate fauna structure in biomonitoring programs. These programs use the response of benthic invertebrates to assess changes in aquatic ecosystems because they respond quickly to spatial and temporal variations. However, the lack of consensus on the best method of sampling the fauna may reduce the quality of these studies. Methods We evaluated both devices in four structurally different reaches of streams, two in places with preserved riparian vegetation and two occurring in places with many anthropic disturbances. We repeated the analysis at the dry season of two consecutive years. Results The two samplers were equally effective in analyzing the benthic fauna and sensitive enough to identify spatial and temporal variation in the structure of this fauna, influenced by the presence or absence of riparian vegetation, by the position of the reach with this vegetation (upstream or downstream of the reach without vegetation) and the characteristics of the substrate. Conclusions The analyzed fauna structure was similar for the two samplers, but we consider the use of Surber more advantageous and effective because it collects a smaller number of individuals, reducing the time of processing and identifying in the laboratory, and allows a better definition of the area sampled.

scholarly journals Spatial and seasonal variation of zooplankton assemblages in two tidal control structures in Northeastern Brazil

2021 ◽  
Vol 10 (12) ◽  
pp. e137101220062
Author(s):  
Yago Bruno Silveira Nunes ◽  
Ladilson Rodrigues Silva ◽  
Amanda Lorena Lima Oliveira ◽  
Marina Bezerra Figueiredo
Keyword(s):  
Aquatic Ecosystems ◽  
Sampling Site ◽  
Zooplankton Community ◽  
Temporal Variations ◽  
Northeastern Brazil ◽  
Control Structures ◽  
Abiotic Parameters ◽  
Spatial And Seasonal Variation ◽  
Zooplankton Communities

Zooplankton is a group of organisms that can help to understand the quality of aquatic ecosystems, as they are responsible for transforming energy matter, thus making it available to other links, making them important in aquatic trophodynamics. This study analyzed spatial and temporal variations in zooplankton communities found in two tidal control structures on Ilha do Maranhão, northeastern Brazil. Sampling took place from September 2017 to July 2018. Abiotic parameters (temperature, salinity, and transparency) and plankton samples were recorded monthly throughout the study period at each sampling site. The results found for the abiotic parameters showed a well-defined pattern, with a clear division between the dry and rainy periods. Forty taxa represented the zooplankton community of the São Luís tidal control structure, and from São José de Ribamar by 21 taxa, represented mainly by copepods, ichthyoplankton, foraminifera, polychaetes, and mollusks. The analysis of ecological indices of richness, evenness, and diversity showed a difference in the distribution of organisms among the study areas. We identified an important influence of the physicochemical parameters on the zooplankton communities of São Luís and São José de Ribamar, according to the statistical analyzes used in this study.

Vertical distribution of Benthic Invertebrates in the Bed of the Thomson River, Victoria

1988 ◽  
Vol 39 (6) ◽  
pp. 775 ◽  
Author(s):  
R Marchant
Keyword(s):  
Vertical Distribution ◽  
Benthic Invertebrates ◽  
Benthic Fauna ◽  
Late Summer ◽  
Sample Surface ◽  
Depth Range ◽  
The Vertical Distribution ◽  
Surber Sampler

The vertical distribution of the benthic fauna was studied at three sites on the Thomson River using a freeze-corer. Samples were taken over two years in early and late summer. At each site an average of 72 to 84% of the fauna was found in the 0-10 cm zone of the riverbed, 10-20% in the 10-20 cm zone and 6-8% in the 20-30 cm zone; flooding at one site was followed by an increase in the depth to which the fauna penetrated. Surface percentage abundances were probably underestimated because of the inability of the corer to sample surface rocks and their fauna consistently and because the coring operation disturbs the surface fauna to some extent before it can be frozen. Nevertheless, the results indicate that in the Thomson River the majority of the fauna is within the depth range (0-10 cm) of a Surber sampler.

scholarly journals Spatial and temporal variation of the diet of the flag tetra Hyphessobrycon heterorhabdus (Characiformes: Characidae) in streams of the Eastern Amazon

2020 ◽  
Vol 18 (4) ◽  
Author(s):  
Naraiana Loureiro Benone ◽  
Cleonice Maria Cardoso Lobato ◽  
Bruno Eleres Soares ◽  
Luciano Fogaça de Assis Montag
Keyword(s):  
Resource Availability ◽  
Riparian Vegetation ◽  
Temporal Variations ◽  
Spatial And Temporal Variation ◽  
Fish Diet ◽  
Stream Order ◽  
Dry Period ◽  
Large Fluctuations ◽  
Flood Period ◽  
Indirect Source

ABSTRACT Spatial and temporal variations in streams promote large fluctuations of resource availability, thus affecting the diet of fishes. We evaluated the effects of hydrological periods and stream order within periods on the diet of the flag tetra Hyphessobrycon heterorhabdus. We analyzed 160 stomachs in eight streams ranging from 1st to 3rd order between dry and flood period. Sampled streams belonged to a well-preserved area in the Eastern Amazon. The flag tetra is omnivorous, with a tendency towards insectivory. During the dry period, the species exhibited a higher amount of autochthonous than allochthonous items. Fish consumed more allochthonous items in 1st and 2nd order streams in the dry period and in 1st and 3rd order streams in the flood period. These results reflect the interactions between temporal and longitudinal factors on resource availability and its influence on fish diet. This pattern is probably dependent on the extensive riparian vegetation as a direct and indirect source of food for stream fish.

Immunoferritin localization of intracellular antigens in positively stained frozen sections

1978 ◽  
Vol 36 (2) ◽  
pp. 168-169
Author(s):  
K. T. Tokuyasu
Keyword(s):  
Surface Tension ◽  
Water Surface ◽  
Thin Layers ◽  
The Other ◽  
Positive Staining ◽  
Frozen Sections ◽  
The Past ◽  
Ultrathin Frozen Sections ◽  
Definition Of

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).

The Influence Of The Led Luminaires Electrical Parameters On Their Correlated Colour Temperature During Operation Mode

2020 ◽  
pp. 89-96
Author(s):  
Sergei S. Kapitonov ◽  
Alexei S. Vinokurov ◽  
Sergei V. Prytkov ◽  
Sergei Yu. Grigorovich ◽  
Anastasia V. Kapitonova ◽  
...  
Keyword(s):  
Operation Mode ◽  
Light Sources ◽  
Electrical Parameters ◽  
Colour Temperature ◽  
Radiation Spectra ◽  
Service Period ◽  
Close Proximity ◽  
Definition Of ◽  
Comprehensive Study

The article describes the results of comprehensive study aiming at increase of quality of LED luminaires and definition of the nature of changes in their correlated colour temperature (CCT) in the course of operation. Dependences of CCT of LED luminaires with remote and close location of phosphor for 10 thousand hours of operation in different electric modes were obtained; the results of comparison between the initial and final radiation spectra of the luminaires are presented; using mathematical statistics methods, variation of luminaire CCT over the service period claimed by the manufacturer is forecast; the least favourable electric operation modes with the highest CCT variation observed are defined. The obtained results have confirmed availability of the problem of variation of CCT of LED luminaires during their operation. Possible way of its resolution is application of more qualitative and therefore expensive LEDs with close proximity of phosphor or LEDs with remote phosphor. The article may be interesting both for manufacturers and consumers of LED light sources and lighting devices using them.

Spatial and Temporal variation analysis of water quality of Hemavathi River, Karnataka, India

2018 ◽  
Vol 6 (9) ◽  
pp. 196
Author(s):  
Santhosh K. M ◽  
S. Prashanth
Keyword(s):  
Water Quality ◽  
Agricultural Runoff ◽  
Spatial And Temporal Variation ◽  
Final Conclusion ◽  
Variation Analysis ◽  
Pollution Load ◽  
Quality Of Water ◽  
Pollution Loading ◽  
Origin Point

Urban development, agricultural runoff and industrialization have contributed pollution loading on the environment.  In this study Hemavathi river water from a stretch from its origin point to its sangama was studied for pollution load by determining parameters of water quality like pH, Alkalinity,  Ca, Mg, Nitrate, TDS, BOD, COD , and the results were compared with WHO and BIS standards to draw final conclusion on the quality of water.

Assessment of multimorbidity of diseases in geriatric practice

2020 ◽  
pp. 17-21
Author(s):  
Mark Oprenko
Keyword(s):  
Quality Of Life ◽  
The Core ◽  
Definition Of

The definition of the multimorbidity concept reveals insufficient specificity of the comorbidity and multimorbidity definitions and, as a result, confusion in the use of these terms. Most authors are unanimous that the “core” of multimorbidity is presence of more than one disease in a patient. These coexisting diseases can be pathogenetically interconnected and non-interconnected. Regardless, the degree of multimorbidity always affects prognosis and quality of life.

Guaranteed values – the basis of the analysis of the quality of individual products

2019 ◽  
pp. 20-33
Author(s):  
D. N. Kalacheva
Keyword(s):  
Frequency Distribution ◽  
Distribution Law ◽  
Basic Characteristics ◽  
Definition Of

Herein, the main features and rules of using guaranteed values when analyzing the quality of rocket - space equipment products are considered. The definition of the guaranteed value and the form of its presentation is given. It is indicated that guaranteed value is distributed and is characterized by the frequency distribution law. The main methods of representation and conversion of guaranteed values are statistical. Examples of determining the basic characteristics of guaranteed values are given.

The first flush in sewer systems

1996 ◽  
Vol 33 (9) ◽  
pp. 101-108 ◽  
Author(s):  
Agnès Saget ◽  
Ghassan Chebbo ◽  
Jean-Luc Bertrand-Krajewski
Keyword(s):  
Treatment Strategy ◽  
Real Data ◽  
First Flush ◽  
Clear Definition ◽  
Controversial Subject ◽  
Sewer Systems ◽  
Wet Weather ◽  
Definition Of ◽  
Appearance Frequency

The first flush phenomenon of urban wet weather discharges is presently a controversial subject. Scientists do not agree with its reality, nor with its influences on the size of treatment works. Those disagreements mainly result from the unclear definition of the phenomenon. The objective of this article is first to provide a simple and clear definition of the first flush and then to apply it to real data and to obtain results about its appearance frequency. The data originate from the French database based on the quality of urban wet weather discharges. We use 80 events from 7 separately sewered basins, and 117 events from 7 combined sewered basins. The main result is that the first flush phenomenon is very scarce, anyway too scarce to be used to elaborate a treatment strategy against pollution generated by urban wet weather discharges.

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