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Genetics ◽  
2021 ◽  
Author(s):  
Bogi Trickovic ◽  
Sylvain Glémin

Abstract Populations often inhabit multiple ecological patches and thus experience divergent selection, which can lead to local adaptation if migration is not strong enough to swamp locally adapted alleles. Conditions for the establishment of a locally advantageous allele have been studied in randomly mating populations. However, many species reproduce, at least partially, through self-fertilization, and how selfing affects local adaptation remains unclear and debated. Using a two-patch branching process formalism, we obtained a closed-form approximation under weak selection for the probability of establishment of a locally advantageous allele (P) for arbitrary selfing rate and dominance level, where selection is allowed to act on viability or fecundity, and migration can occur via seed or pollen dispersal. This solution is compared to diffusion approximation and used to investigate the consequences of a shift in a mating system on P, and the establishment of protected polymorphism. We find that selfing can either increase or decrease P, depending on the patterns of dominance in the two patches, and has conflicting effects on local adaptation. Globally, selfing favors local adaptation when locally advantageous alleles are (partially) recessive, when selection between patches is asymmetrical and when migration occurs through pollen rather than seed dispersal. These results establish a rigorous theoretical background to study heterogeneous selection and local adaptation in partially selfing species.


2021 ◽  
Vol 6 (2) ◽  
pp. 72-82
Author(s):  
Vina Triesa Putri ◽  
Nidya Kartini ◽  
Indra Gumay Yudha ◽  
Abdullah Aman Damai

Macrozoobenthos is one of the organisms that can be used as biological indicators because it tends to live in an area and has sensitivity to environmental changes. The Hurun River had many community activities. Based on this, it was necessary to analyze the diversity of macrozoobenthos which will be compared with the physical and chemical parameters of water in order to find out the indicators that affect the abundance of macrozoobenthos in the river. The purpose of this research was to determine the macrozoobenthic community structure which found in the Hurun River based on diversity, uniformity and dominance indices, to build multiple linear regression models, and to determine the bioindicators of pollution in the Hurun River. The factors that influence the abundance of macrozoobenthos are temperature, depth, brightness, DO, TOM, and salinity. The types of macrozoobenthos obtained were 87 species with the highest abundance of macrozoobenthic animals of 70,666.56 ind/m3 while the lowest abundance of macrozoobenthic animals was 13,000.96 ind/m3. Based on data analysis, the macrozoobenthic diversity index was included in the medium category, the level of macrozoobenthic uniformity was included in the high, medium, and low categories, and the dominance level which was included in the medium and low categories. Multiple regression models with a confidence level of 5% get R2 results of 0.86. The level of pollution that occured in the Hurun River based on bioindicators with the ABC curve shows moderately polluted.


Author(s):  
L. Korneva ◽  
I. Mitropol'skaya ◽  
N. Makarenkova ◽  
A. Cvetkov

A comparative analysis of the diversity, abundance, biomass, composition of dominant species, size characteristics of phytoplankton and saprobity of the waters of shallow large overgrown lakes Vozhe, Lacha, as well as the rivers Svid and Onega in June 2015 is presented. The data obtained are compared with the results of previous studies in the 1970s years. It was found that in the 2000s, there was a significant increase in the number of phytoplankton in lakes and a change in the composition of dominant species. Non-heterocyst cyanoprokaryotes (Aphanocapsa holsatica, Planktolyngbya limnetica) began to dominate in phytoplankton, which is associated with increase of ammonium concentration. The average biomass of phytoplankton in lakes (2.6 g/m3) has remained practically unchanged since the 1970s and was typical for mesotrophic type waters. In the Lacha Lake characterized by lower transparency, high degree of overgrowth, salinity and saprobity of waters, phytoplankton was distinguished by lower floristic diversity, higher abundance, dominance level, and the smallest cell sizes.


2021 ◽  
Author(s):  
Bogi Trickovic ◽  
Sylvain Glémin

Populations often inhabit multiple ecological patches and thus experience divergent selection, which can lead to local adaptation if migration is not strong enough to swamp locally adapted alleles. Conditions for the establishment of a locally advantageous allele have been studied in randomly mating populations. However, many species reproduce, at least partially, through self-fertilization, and how selfing affects local adaptation remains unclear and debated. Using a two-patch branching process formalism, we obtained a close-form approximation for the probability of establishment of a locally advantageous allele (P) for arbitrary selfing rate and dominance level, where selection is allowed to act on viability or fecundity, and migration can occur via seed or pollen dispersal. This solution is used to investigate the consequences of a shift in a mating system on P, and the establishment of protected polymorphism. We find that selfing can either increase or decrease P, depending on the patterns of dominance in the two patches, and has contradictory effect on local adaptation. Globally, selfing favors local adaptation when locally advantageous alleles are (partially) recessive, when selection between patches is asymmetrical and when migration occurs through pollen rather than seed dispersal. These results establish a rigorous theoretical background to study heterogeneous selection and local adaptation in partially selfing species.


2020 ◽  
Vol 8 (1) ◽  
pp. 50-57
Author(s):  
Amalia Putri Firdausi ◽  
Rahman Rahman ◽  
Respati Mahadhika ◽  
Adna Sumadikarta

The aim of this study is to inventory various types of ectoparasites found in koi fish that are reared in the nursery phase at the Sukabumi Freshwater Aquaculture Center (BPAT Sukabumi). Briefly, a total of 30 koi fish were taken randomly, then the scales, fins, and gills were examined and stained either with procedures of AgNO3. The type of parasite was identified and analyzed based on the rate of prevalence, also the intensity and dominance. The infesting parasite found were Trichodina sp, Oodinium sp, and Ichthyophthirius multifiliis. Overall, Trichodina sp is the most dominating parasite with a dominance level, prevalence, and intensity of 57,028%, 80%, and 10,833 respectively.


2018 ◽  
Vol 15 (5) ◽  
pp. 646-658 ◽  
Author(s):  
Vinod Nistane ◽  
Suraj Harsha

Purpose In rotary machines, the bearing failure is one of the major causes of the breakdown of machinery. The bearing degradation monitoring is a great anxiety for the prevention of bearing failures. This paper aims to present a combination of the stationary wavelet decomposition and extra-trees regression (ETR) for the evaluation of bearing degradation. Design/methodology/approach The higher order cumulants features are extracted from the bearing vibration signals by using the stationary wavelet decomposition (stationary wavelet transform [SWT]). The extracted features are then subjected to the ETR for obtaining normal and failure state. A dominance level curve build using the dissimilarity data of test object and retained as health degradation indicator for the evaluation of bearing health. Findings Experiment conducts to verify and assess the effectiveness of ETR for the evaluation of performance of bearing degradation. To justify the preeminence of recommended approach, it is compared with the performance of random forest regression and multi-layer perceptron regression. Originality/value The experimental results indicated that the presently adopted method shows better performance for detecting the degradation more accurately at early stage. Furthermore, the diagnostics and prognostics have been getting much attention in the field of vibration, and it plays a significant role to avoid accidents.


Author(s):  
Shengbo Shan ◽  
Li Cheng ◽  
Fuzhen Wen

Structural health monitoring (SHM) methods based on the cumulative second harmonic Lamb waves show attractive advantages. An ideal nonlinear parameter should allow precise characterization of the cumulative effects of the distributed nonlinear sources such as the material nonlinearity of a plate (MNP), in the presence of other unavoidable localized nonlinear components. While highlighting the deficiencies of the traditional nonlinear parameter (TNP) in the nonplanar cases, a refined nonlinear parameter (RNP) is proposed. Through compensations for the wave attenuation associated with the wave divergence, the new parameter entails a better characterization and differentiation of the cumulative MNP and other noncumulative localized nonlinear sources. Theoretical findings are ascertained by both finite element (FE) simulations and experiments, through tactically adjusting the dominance level of different nonlinear sources in the system. Results confirm the appealing features of the proposed RNP for SHM applications.


2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Lani Puspita ◽  
Notowinarto Notowinarto ◽  
Rudi Gunawan

Phytoplankton as a producers  and natural food for fish have an important role in aquatic ecosystems, thus indirectly affecting the availability of fish catches. The research was conducted at Siantan Island Coastal Area Anambas Islands District Riau Islands Province. This coastal area is one of the fishing grounds in Anambas Island. This study aims to analyze the community structure of phytoplankton at Siantan Island Coastal Area Anambas Islands District Riau Islands Province. Sampling was conducted during March and April 2012. Community structure parameters analyzed include Species Diversity Level, Species Uniformity Level, and Species Dominance Level. Data were analyzed spatially and temporally. Similarity between the sampling locations was conduted by Multivariate Analysis - Cluster. Results of data analysis showed that the phytoplankton of Bacillariophyceae Class found in the most abundant amount. Diversity Index Value indicates that the level of phytoplankton plankton community in a state of moderate. Species Uniformity Index Value and Species Dominance Index Value indicates that phytoplankton in the three sampling locations are generally in a state of uniform and no one dominates. All three sampling locations have relatively the same condition and between sampling times (morning, afternoon, and evening) are also not very different condition. Keywords: phytoplankton, coastal, Anambas Islands  


2016 ◽  
Vol 109 (5) ◽  
pp. 2182-2189 ◽  
Author(s):  
Claire Mottet ◽  
Séverine Fontaine ◽  
Laëtitia Caddoux ◽  
Christine Brazier ◽  
Frédérique Mahéo ◽  
...  

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