scholarly journals Pike Esox Lucius Distribution and Feeding Comparisons in Natural and Historically Channelized River Sections

2016 ◽  
Vol 18 (1) ◽  
pp. 33-41
Author(s):  
Kaspars Ivanovs

Abstract During the last century a large portion of small and medium-sized rivers in Latvia were channelized, hydroelectric power stations were also built, which led to changes in the hydrodynamic conditions, geomorphological structure, as well as a change in the fish fauna. Fish are an integral part of any community in natural or man-made bodies of water. They actively participate in maintaining the system, balancing/equilibrium, energy, substance transformation and biomass production. They are able to influence other organisms in the ecosystem in which they live. The aim of the paper “Pike distribution and feeding comparisons in natural and historically channelized river sections” is to find out what pike feed on in different environments in Latvian rivers, such as natural and straightened river sections, as well as what main factors determine the composition of their food. Several points were assessed during the course of the study: the impact of environmental conditions on the feeding habits and the distribution of pike; the general feeding habits of predators in Latvian rivers; the feeding differences of predators in natural and straightened river sections; and lastly, rhithral and pothamal habitats were compared. The study was based on data from 2014 and 2015 on fish fauna monitoring. During the study, 347 pike were collected from 136 plots using electrofishing method.

2019 ◽  
Vol 139 ◽  
pp. 01005
Author(s):  
Yuri Chukreyev ◽  
Mikhail Chukreyev

The is UPS of the impact of accounting for the energy supply of hydroelectric power plants on the means of ensuring the balance reliability of the UPS of Russia for the conditions of conducting commercial power take-offs are considered. The analysis of predicted and reported data on the generation of electricity at hydroelectric power stations and their impact on the rationale for backup tools.


2019 ◽  
pp. 124-136
Author(s):  
Victor D. Gazman

The article considers prerequisites for the formation of a new paradigm in the energy sector. The factors that may affect the imminent change of leadership among the energy generation are analyzed. The variability of the projects of creation and functioning of power stations is examined. The focus is made on problematic aspects of the new generation, especially, storage and supply of energy, achieving a system of parity that ensures balance in pricing generations. The author substantiates the principles of forming system of parities arising when comparing traditional and new generations. The article presents the results of an empirical analysis of the 215 projects for the construction of facilities for renewable energy. The significance and direction of the impact of these factors on the growth in investment volumes of transactions are determined. The author considers leasing as an effective financial instrument for overcoming stereotypes of renewable energy and as a promising direction for accelerated implementation of investment projects.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Luís Crisóstomo ◽  
Ivana Jarak ◽  
Luís P. Rato ◽  
João F. Raposo ◽  
Rachel L. Batterham ◽  
...  

AbstractThe consumption of energy-dense diets has contributed to an increase in the prevalence of obesity and its comorbidities worldwide. The adoption of unhealthy feeding habits often occurs at early age, prompting the early onset of metabolic disease with unknown consequences for reproductive function later in life. Recently, evidence has emerged regarding the intergenerational and transgenerational effects of high-fat diets (HFD) on sperm parameters and testicular metabolism. Hereby, we study the impact of high-fat feeding male mice (F0) on the testicular metabolome and function of their sons (F1) and grandsons (F2). Testicular content of metabolites related to insulin resistance, cell membrane remodeling, nutritional support and antioxidative stress (leucine, acetate, glycine, glutamine, inosine) were altered in sons and grandsons of mice fed with HFD, comparing to descendants of chow-fed mice. Sperm counts were lower in the grandsons of mice fed with HFD, even if transient. Sperm quality was correlated to testicular metabolite content in all generations. Principal Component Analysis of sperm parameters and testicular metabolites revealed an HFD-related phenotype, especially in the diet-challenged generation and their grandsons. Ancestral HFD, even if transient, causes transgenerational “inherited metabolic memory” in the testicular tissue, characterized by changes in testicular metabolome and function.


Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1901
Author(s):  
Ana Gonzalez-Martinez ◽  
Carmen De-Pablos-Heredero ◽  
Martin González ◽  
Jorge Rodriguez ◽  
Cecilio Barba ◽  
...  

The Guayas, located in Ecuador, is the largest basin in the Pacific Ocean and has an inventory of 123 native freshwater species. Most of these are endemic species that are threatened or at-risk due to anthropogenic activity and the modification, fragmentation, and destruction of habitats. The aim of this study was to determine the morphometric variation in three wild populations of Brycon dentex in the Guayas basin rivers and their connections to fishing management and environmental conditions. A total of 200 mature fish were captured, and 26 morphometric parameters were measured. The fishing policies (Hypothesis 1) and environmental conditions (Hypothesis 2) were considered fixed factors and were validated by t-tests. The morphological variation among the three populations (Hypothesis 3) was validated through a discriminant analysis. Fishing policies and resource management were found to generate morphological differences associated with body development. In addition, the environmental conditions were found to influence the size and structure of Brycon dentex populations. The analyzed populations were discriminated by the generated morphometric models, which differentiated Cluster 1 (Quevedo and Mocache rivers) with high fishing pressure from Cluster 2 (Pintado river) with medium–low fishing pressure. Morphometric differentiation by discriminant analysis is a direct and economic methodology that can be applied as an indicator of diversity maintenance.


2021 ◽  
Vol 22 (7) ◽  
pp. 3382
Author(s):  
Silvia Saturio ◽  
Alicja M. Nogacka ◽  
Marta Suárez ◽  
Nuria Fernández ◽  
Laura Mantecón ◽  
...  

The establishment of the gut microbiota poses implications for short and long-term health. Bifidobacterium is an important taxon in early life, being one of the most abundant genera in the infant intestinal microbiota and carrying out key functions for maintaining host-homeostasis. Recent metagenomic studies have shown that different factors, such as gestational age, delivery mode, or feeding habits, affect the gut microbiota establishment at high phylogenetic levels. However, their impact on the specific bifidobacterial populations is not yet well understood. Here we studied the impact of these factors on the different Bifidobacterium species and subspecies at both the quantitative and qualitative levels. Fecal samples were taken from 85 neonates at 2, 10, 30, 90 days of life, and the relative proportions of the different bifidobacterial populations were assessed by 16S rRNA–23S rRNA internal transcribed spacer (ITS) region sequencing. Absolute levels of the main species were determined by q-PCR. Our results showed that the bifidobacterial population establishment is affected by gestational age, delivery mode, and infant feeding, as it is evidenced by qualitative and quantitative changes. These data underline the need for understanding the impact of perinatal factors on the gut microbiota also at low taxonomic levels, especially in the case of relevant microbial populations such as Bifidobacterium. The data obtained provide indications for the selection of the species best suited for the development of bifidobacteria-based products for different groups of neonates and will help to develop rational strategies for favoring a healthy early microbiota development when this process is challenged.


Author(s):  
L. M. Manici ◽  
F. Caputo ◽  
G. A. Cappelli ◽  
E. Ceotto

Abstract Soil suppressiveness which is the natural ability of soil to support optimal plant growth and health is the resultant of multiple soil microbial components; which implies many difficulties when estimating this soil condition. Microbial benefits for plant health from repeated digestate applications were assessed in three experimental sites surrounding anaerobic biogas plants in an intensively cultivated area of northern Italy. A 2-yr trial was performed in 2017 and 2018 by performing an in-pot plant growth assay, using soil samples taken from two fields for each experimental site, of which one had been repeatedly amended with anaerobic biogas digestate and the other had not. These fields were similar in management and crop sequences (maize was the recurrent crop) for the last 10 yr. Plant growth response in the bioassay was expressed as plant biomass production, root colonization frequency by soil-borne fungi were estimated to evaluate the impact of soil-borne pathogens on plant growth, abundance of Pseudomonas and actinomycetes populations in rhizosphere were estimated as beneficial soil microbial indicators. Repeated soil amendment with digestate increased significantly soil capacity to support plant biomass production as compared to unamended control in both the years. Findings supported evidence that this increase was principally attributable to a higher natural ability of digestate-amended soils to reduce root infection by saprophytic soil-borne pathogens whose inoculum was increased by the recurrent maize cultivation. Pseudomonas and actinomycetes were always more abundant in digestate-amended soils suggesting that both these large bacterial groups were involved in the increase of their natural capacity to control soil-borne pathogens (soil suppressiveness).


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