scholarly journals Rare morph Lake Malawi mbuna cichlids benefit from reduced aggression from con- and hetero-specifics

2021 ◽  
Author(s):  
Alexandra M Tyers ◽  
Gavan M Cooke ◽  
George F Turner
Keyword(s):  
Genetic Drift ◽  
Relative Frequency ◽  
Balancing Selection ◽  
Lake Malawi ◽  
Disruptive Selection ◽  
Field Observations ◽  
Two Factors ◽  
Males And Females ◽  
Heterospecific Aggression

Balancing selection is important for the maintenance of polymorphism as it can prevent either fixation of one morph through directional selection or genetic drift, or speciation by disruptive selection. Polychromatism can be maintained if the fitness of alternative morphs depends on the relative frequency in a population. In aggressive species, negative frequency-dependent antagonism can prevent an increase in the frequency of rare morphs as they would only benefit from increased fitness while they are rare. Heterospecific aggression is common in nature and has the potential to contribute to rare morph advantage. Here we carry out field observations and laboratory aggression experiments with mbuna cichlids from Lake Malawi, to investigate the role of con- and heterospecific aggression in the maintenance of polychromatism and identify benefits to rare mores which are likely to result from reduced aggression. Within species we found that males and females bias aggression towards their own morph, adding to the evidence that inherent own-morph aggression biases can contribute to balancing selection. Over-representation of rare morph territory owners may be influenced by two factors; higher tolerance of different morph individuals as neighbours, and ability of rare morphs to spend more time feeding. Reduced aggression to rare morph individuals by heterospecifics may also contribute to rare morph advantage.

scholarly journals Heterospecific aggression differs predominately by species, rather than sex, in Lake Malawi cichlid fish

2019 ◽  
Author(s):  
Emily C. Moore ◽  
Reade B. Roberts
Keyword(s):  
Community Structure ◽  
Rapid Evolution ◽  
Cichlid Fish ◽  
Lake Malawi ◽  
Male Aggression ◽  
Males And Females ◽  
Potential Impact ◽  
Cortisol Levels ◽  
Species Specific ◽  
Heterospecific Aggression

ABSTRACTBecause of their striking diversity, Lake Malawi cichlid fish have been well studied for male aggression, particularly among dominant males of closely related sister species within the framework of mate-choice and speciation. However, aggression in females has been largely ignored, and variation in aggressive behaviors between more distantly-related taxa is not well understood despite its potential impact in a complex community structure. To better understand variation in patterns of aggression between species, we presented males and females from five species of Lake Malawi cichlid with a non-predator intruder and recorded all movement and aggressive acts. Additionally, we measured excreted cortisol levels the day after the intruder assay to evaluate one physiological aspect of stress response. We identified species-specific patterns in both specific aggressive acts, and overall level of aggression. Additionally, we found that sexual dimorphism in aggressive acts varies by species and act, where the species with the most aggressive males also has aggressive females. Additionally, cortisol levels vary by taxa, and are associated with restless behavior in the intruder assay, but not levels of aggression. These findings have bearing on understanding sex differences in aggression and their impact on community structure in this important model of rapid evolution.

ROLE OF ADDED PHOSPHOGYPSUM AND HUMIC ACIDS IN THE KINETIC RELEASE OF SALT FROM SALT AFFECTED SOIL (SALINE – SODIC)

2020 ◽  
pp. 15-27
Keyword(s):  
Electrical Conductivity ◽  
Humic Acids ◽  
Release Rate ◽  
Release Kinetics ◽  
Sodium Adsorption Ratio ◽  
Salt Affected Soil ◽  
Two Factors ◽  
Dissolved Ions ◽  
Kinetic Release

In order to study the effect of phosphogypsum and humic acids in the kinetic release of salt from salt-affected soil, a laboratory experiment was conducted in which columns made from solid polyethylene were 60.0 cm high and 7.1 cm in diameter. The columns were filled with soil so that the depth of the soil was 30 cm inside the column, the experiment included two factors, the first factor was phosphogypsum and was added at levels 0, 5, 10 and 15 tons ha-1 and the second-factor humic acids were added at levels 0, 50, 100 and 150 kg ha-1 by mixing them with the first 5 cm of column soil and one repeater per treatment. The continuous leaching method was used by using an electrolytic well water 2.72 dS m-1. Collect the leachate daily and continue the leaching process until the arrival of the electrical conductivity of the filtration of leaching up to 3-5 dS m-1. The electrical conductivity and the concentration of positive dissolved ions (Ca, Mg, Na) were estimated in leachate and the sodium adsorption ratio (SAR) was calculated. The results showed that the best equation for describing release kinetics of the salts and sodium adsorption ratio in soil over time is the diffusion equation. Increasing the level of addition of phosphogypsum and humic acids increased the constant release velocity (K) of salts and the sodium adsorption ratio. The interaction between phosphogypsum and humic acids was also affected by the constant release velocity of salts and the sodium adsorption ratio. The constant release velocity (K) of the salts and the sodium adsorption ratio at any level of addition of phosphogypsum increased with the addition of humic acids. The highest salts release rate was 216.57 in PG3HA3, while the lowest rate was 149.48 in PG0HA0. The highest release rate of sodium adsorption ratio was 206.09 in PG3HA3, while the lowest rate was 117.23 in PG0HA0.

PERAN MASYARAKAT TERHADAP PEMBAYARAN RETRIBUSI SAMPAH DI KOTA SAMARINDA

2018 ◽  
Vol 2 (1) ◽  
pp. 33
Author(s):  
Abd Rachim AF,
Keyword(s):  
Waste Management ◽  
Population Growth ◽  
Frequency Analysis ◽  
Urban Areas ◽  
Relative Frequency ◽  
Environmental Problems ◽  
Living Standards ◽  
The Public ◽  
And Behavior

One of the environmental problems in urban areas is the pollution caused by garbage. The waste problem is caused by various factors such as population growth, living standards changes, lifestyles and behavior, as well as how the waste management system. This study aims to determine how the role of society to levy payments garbage in Samarinda. This research was descriptive; where the data is collected then compiled, described and analyzed used relative frequency analysis. The participation of the public to pay a "levy junk", which stated to pay 96.67%, for each month and the rates stated society cheap, moderate and fairly, respectively 46.08%, 21.21%, 21.04%. Base on the data , the role of the community to pay "levy junk" quite high.

Gender Diversity in Computing: An Environmental Perspective

10.28945/3248 ◽  
2008 ◽  
Author(s):  
Cecille Marsh
Keyword(s):  
Gender Diversity ◽  
Household Head ◽  
Female Students ◽  
Political Factors ◽  
Female Household Head ◽  
Dominant Female ◽  
Computer Confidence ◽  
Males And Females ◽  
Research Questions

Previous research conducted by the author investigated the socio-political backgrounds of two groups of female students studying computer-related university programmes. They came from distinctly different backgrounds and were enrolled at two institutions with very different legacies. The author found that socio-political factors, in particular the role of a dominant female household head and aggressive governmental affirmative action, had a significant effect on the girls’ levels of confidence and subsequently on their decision to study computer-related courses. Based on this insight, the researcher undertook to look further into gender diversity with respect to self-perceived general computer confidence and self-perceived ability to program a computer. A sample of both female and male Information T echnology students from very similar disadvantaged socio-economic backgrounds was surveyed. The sample of 204 students was drawn from all three years of the National Diploma in Information Technology. The author considered the following research questions: (i) Do males and females studying computer-related courses have differing computer selfefficacy levels? (ii) Do males and females studying computer programming have differing attitudes towards their ability to program? (iii) Do males and females differ in their attitudes towards the programming learning environment?

Saturated Hydraulic Conductivity of Clayey Tills and the Role of Fractures

1990 ◽  
Vol 21 (2) ◽  
pp. 119-132 ◽  
Author(s):  
Johnny Fredericia
Keyword(s):  
Hydraulic Conductivity ◽  
American Studies ◽  
Field Measurements ◽  
Present Knowledge ◽  
Saturated Hydraulic Conductivity ◽  
Field Observations ◽  
Laboratory Measurements ◽  
Vertical Hydraulic Conductivity ◽  
Data Field

The background for the present knowledge about hydraulic conductivity of clayey till in Denmark is summarized. The data show a difference of 1-2 orders of magnitude in the vertical hydraulic conductivity between values from laboratory measurements and field measurements. This difference is discussed and based on new data, field observations and comparison with North American studies, it is concluded to be primarily due to fractures in the till.

Selenium Role in Reproduction, Pregnant/Postpartum Women and Neonates: A Current Study

2020 ◽  
Vol 17 (1) ◽  
pp. 28-37
Author(s):  
Tabinda Sattar
Keyword(s):  
Infant Development ◽  
Selenium Deficiency ◽  
Human Reproduction ◽  
Postpartum Women ◽  
Female Reproduction ◽  
Pregnancy And Lactation ◽  
Males And Females ◽  
One Year ◽  
Selenium Supplements

Background: Selenium is a micronutrient, although required in low amounts, its importance in male and female reproduction is well known. Objectives: The core purpose of this study is to evaluate the role of selenium in human reproduction, during pregnancy/ lactation in women and newborns. The review explains side by side the sources of selenium, required amounts of selenium in humans and during pregnancy or lactation. Methods: Selenium deficiency is a major cause of male infertility. Similarly, selenium deficiency, both in pregnant and postpartum women, would greatly affect the health of the newborn baby in all respects. The effect of maternal selenium upon the fetus and the neonates even one year after birth has been explained with some recent examples. Results: The study elaborates the fact that the selenium deficiency in pregnancy and lactation is common due to fetal/infant development, so selenium supplements must be provided in order to overcome these deficiency symptoms. Conclusions: The better reproductive health in humans is possible due to the sufficient amounts of selenium present both in males and females as well.

scholarly journals An Overview of Adipose Tissue ACE2 Modulation by Diet and Obesity. Potential Implications in COVID-19 Infection and Severity

2021 ◽  
Vol 22 (15) ◽  
pp. 7975
Author(s):  
Saioa Gómez-Zorita ◽  
Iñaki Milton-Laskibar ◽  
Laura García-Arellano ◽  
Marcela González ◽  
María P. Portillo
Keyword(s):  
Adipose Tissue ◽  
Protective Role ◽  
Inflammatory Factors ◽  
Current Evidence ◽  
Disease Outcomes ◽  
Lower Activation ◽  
Two Factors ◽  
Obese Subjects ◽  
Ace2 Gene

The present review is aimed at analysing the current evidence concerning the potential modulation of obesity and/or diet in adipose tissue ACE2. Additionally, the potential implications of these effects on COVID-19 are also addressed. The results published show that diet and obesity are two factors that effectively influence the expression of Ace2 gene in adipose tissue. However, the shifts in this gene do not always occur in the same direction, nor with the same intensity. Additionally, there is no consensus regarding the implications of increased adipose tissue ACE2 expression in health. Thus, while in some studies a protective role is attributed to ACE2 overexpression, other studies suggest otherwise. Similarly, there is much debate regarding the role played by ACE2 in COVID-19 in terms of degree of infection and disease outcomes. The greater risk of infection that may hypothetically derive from enhanced ACE2 expression is not clear since the functionality of the enzyme seems to be as important as the abundance. Thus, the greater abundance of ACE2 in adipose tissue of obese subjects may be counterbalanced by its lower activation. In addition, a protective role of ACE2 overexpression has also been suggested, associated with the increase in anti-inflammatory factors that it may produce.

scholarly journals Genetic Studies of mei-P26 Reveal a Link Between the Processes That Control Germ Cell Proliferation in Both Sexes and Those That Control Meiotic Exchange in Drosophila

Genetics ◽  
2000 ◽  
Vol 155 (4) ◽  
pp. 1757-1772 ◽  
Author(s):  
Scott L Page ◽  
Kim S McKim ◽  
Benjamin Deneen ◽  
Tajia L Van Hook ◽  
R Scott Hawley
Keyword(s):  
Meiotic Recombination ◽  
Double Mutant ◽  
P Element ◽  
Genetic Studies ◽  
Germline Differentiation ◽  
Males And Females ◽  
Bag Of Marbles ◽  
Differentiation And Proliferation

Abstract We present the cloning and characterization of mei-P26, a novel P-element-induced exchange-defective female meiotic mutant in Drosophila melanogaster. Meiotic exchange in females homozygous for mei-P261 is reduced in a polar fashion, such that distal chromosomal regions are the most severely affected. Additional alleles generated by duplication of the P element reveal that mei-P26 is also necessary for germline differentiation in both females and males. To further assess the role of mei-P26 in germline differentiation, we tested double mutant combinations of mei-P26 and bag-of-marbles (bam), a gene necessary for the control of germline differentiation and proliferation in both sexes. A null mutation at the bam locus was found to act as a dominant enhancer of mei-P26 in both males and females. Interestingly, meiotic exchange in mei-P261; bamΔ86/+ females is also severely decreased in comparison to mei-P261 homozygotes, indicating that bam affects the meiotic phenotype as well. These data suggest that the pathways controlling germline differentiation and meiotic exchange are related and that factors involved in the mitotic divisions of the germline may regulate meiotic recombination.

scholarly journals Balancing selection, genetic drift, and human‐mediated introgression interplay to shape MHC (functional) diversity in Mediterranean brown trout

2021 ◽  
Author(s):  
Lorenzo Talarico ◽  
Silvio Marta ◽  
Anna Rita Rossi ◽  
Simone Crescenzo ◽  
Gerardo Petrosino ◽  
...  
Keyword(s):  
Functional Diversity ◽  
Genetic Drift ◽  
Brown Trout ◽  
Balancing Selection

scholarly journals The Role of Emotionality and Power on Tendency to Unethical Behaviors

2012 ◽  
Vol 2 (4) ◽  
pp. 187
Author(s):  
Hossein Safarzadeh ◽  
Alireza Soloukdar ◽  
Ali Alipour ◽  
Seyedeh Akram Parpanchi
Keyword(s):  
Correlation Coefficient ◽  
Organizational Citizenship ◽  
Significant Relationship ◽  
Independent Variables ◽  
Ethical Behaviors ◽  
Two Factors ◽  
Unethical Behaviors ◽  
The Common ◽  
Two Independent Variables

Emotion and power have been studied very deeply especially during the last decade; however, the common effects of these two factors on individuals' optional behaviors (organizational citizenship, anti-productivity, unethical behaviors) have been less focused. In the present paper, the role of individuals' emotionality, their interest in power, and their tendency to unethical behaviors will be discussed according to the model of Levine. Three questionnaires were distributed and the collected data were analyzed using Pearson’s Correlation Coefficient, Multiple Regression, and T- test. Findings indicated that there is a significant relationship between the two independent variables of emotionality and power and tendency to unethical behaviors. Moreover, according to the results of the tests, men are more emotion-oriented and power seekers than women. Keywords: Power, Emotion, Ethical Behaviors

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