Growth during the first summer at sea modulates sex-specific maturation schedule in Atlantic salmon

2020 ◽  
Author(s):  
Cecile Trehin ◽  
Etienne Rivot ◽  
Ludivine Lamireau ◽  
Lisa Meslier ◽  
Anne-Laure Besnard ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Population Level ◽  
Reaction Norm ◽  
Growth Conditions ◽  
Age At Maturity ◽  
Individual Probability ◽  
Marine Migration ◽  
One Year ◽  
The Individual ◽  
European Populations

Recent decline in abundance of Atlantic salmon and concomitant changes in life history may result from a decline in the growth conditions during marine migration. Available literature suggests the existence of a sex-specific reaction norm linking maturation with environmental growth conditions at sea. However the extent to which this mechanism explains variations in age at maturity remains unclear. Using a historical collection of scales (1987-2017) from the Sélune River, France, we showed that marine growth declined over the first summer, and remained stable during the subsequent periods at sea among returning salmon. Results support the hypothesis of a sex-specific probabilistic reaction norm, with individual probability to return after one year at sea increasing when growth increases. Females may require higher growth than males to attain their maturation threshold. This mechanism is a good candidate to explain temporal variability in sea-age at return at both the individual and population level in the Sélune population and in many other southern European populations.

scholarly journals Dancing with Loneliness in Later Life: A Pilot Study Mapping Seasonal Variations

2015 ◽  
Vol 8 (1) ◽  
pp. 97-104 ◽  
Author(s):  
Christina Victor ◽  
Mary P. Sullivan ◽  
Rachel Woodbridge ◽  
Michael Thomas
Keyword(s):  
Pilot Study ◽  
Seasonal Variations ◽  
Population Level ◽  
Later Life ◽  
Temporal Variations ◽  
Summer Period ◽  
Individual Variations ◽  
Period Data ◽  
One Year ◽  
The Individual

Temporal variations in loneliness at the individual and population level have long been reported in longitudinal studies. Although the evidence is limited due to methodological distinctions among studies, we broadly know that loneliness as one ages is a dynamic experience with people becoming more or less lonely or staying the same over time. There is, however, less evidence to understand individual variations in loneliness over shorter periods of time. This paper reports on one element of a small mixed method pilot study to investigate seasonal variations in loneliness over the course of one year and to test the effectiveness of tools used to collect data at repeated short intervals. Our findings confirm that loneliness is dynamic even over shorter periods of time with participants reporting to be lonelier in the evenings, weekends and spring-summer period. Data measures were at times problematic due to language and/or interpretation and reinforce the relevance of reviewing the more common approaches to studying loneliness to more effectively capture the complex and individual nature of the experience.

scholarly journals Mutability of demographic noise in microbial range expansions

2021 ◽  
Author(s):  
QinQin Yu ◽  
Matti Gralka ◽  
Marie-Cécilia Duvernoy ◽  
Megan Sousa ◽  
Arbel Harpak ◽  
...  
Keyword(s):  
Gene Deletion ◽  
Genetic Manipulation ◽  
Single Gene ◽  
Population Level ◽  
Growth Conditions ◽  
Establishment Probability ◽  
In The Wild ◽  
Order Of Magnitude ◽  
Demographic Noise ◽  
Single Gene Deletion

AbstractDemographic noise, the change in the composition of a population due to random birth and death events, is an important driving force in evolution because it reduces the efficacy of natural selection. Demographic noise is typically thought to be set by the population size and the environment, but recent experiments with microbial range expansions have revealed substantial strain-level differences in demographic noise under the same growth conditions. Many genetic and phenotypic differences exist between strains; to what extent do single mutations change the strength of demographic noise? To investigate this question, we developed a high-throughput method for measuring demographic noise in colonies without the need for genetic manipulation. By applying this method to 191 randomly-selected single gene deletion strains from the E. coli Keio collection, we find that a typical single gene deletion mutation decreases demographic noise by 8% (maximal decrease: 81%). We find that the strength of demographic noise is an emergent trait at the population level that can be predicted by colony-level traits but not cell-level traits. The observed differences in demographic noise from single gene deletions can increase the establishment probability of beneficial mutations by almost an order of magnitude (compared to in the wild type). Our results show that single mutations can substantially alter adaptation through their effects on demographic noise and suggest that demographic noise can be an evolvable trait of a population.

scholarly journals Testing the Role of Emotion Dysregulation as a Predictor of Juvenile Recidivism

2021 ◽  
Vol 11 (1) ◽  
pp. 83-95
Author(s):  
Kalin Z. Salinas ◽  
Amanda Venta
Keyword(s):  
Emotion Regulation ◽  
Juvenile Offenders ◽  
Emotion Dysregulation ◽  
Longitudinal Research ◽  
Future Research ◽  
Individual Factor ◽  
Treatment And Prevention ◽  
One Year ◽  
The Individual

The current study proposed to determine whether adolescent emotion regulation is predictive of the amount and type of crime committed by adolescent juvenile offenders. Despite evidence in the literature linking emotion regulation to behaviour problems and aggression across the lifespan, there is no prior longitudinal research examining the predictive role of emotion regulation on adolescent recidivism, nor data regarding how emotion regulation relates to the occurrence of specific types of crimes. Our primary hypothesis was that poor emotion regulation would positively and significantly predict re-offending among adolescents. We tested our hypothesis within a binary logistic framework utilizing the Pathways to Desistance longitudinal data. Exploratory bivariate analyses were conducted regarding emotion regulation and type of crime in the service of future hypothesis generation. Though the findings did not indicate a statistically significant relation between emotion regulation and reoffending, exploratory findings suggest that some types of crime may be more linked to emotion regulation than others. In sum, the present study aimed to examine a hypothesized relation between emotion regulation and juvenile delinquency by identifying how the individual factor of dysregulated emotion regulation may have played a role. This study’s findings did not provide evidence that emotion regulation was a significant predictor of recidivism over time but did suggest that emotion regulation is related to participation in certain types of crime one year later. Directions for future research that build upon the current study were described. Indeed, identifying emotion regulation as a predictor of adolescent crime has the potential to enhance current crime prevention efforts and clinical treatments for juvenile offenders; this is based on the large amount of treatment literature, which documents that emotion regulation is malleable through treatment and prevention programming.

scholarly journals A methodological framework to predict the individual and population‐level distributions from tracking data

Ecography ◽  
2021 ◽  
Author(s):  
Philippine Chambault ◽  
Tarek Hattab ◽  
Pascal Mouquet ◽  
Touria Bajjouk ◽  
Claire Jean ◽  
...  
Keyword(s):  
Population Level ◽  
Tracking Data ◽  
Methodological Framework ◽  
The Individual

scholarly journals Phenotypic plasticity of labile traits in the wild

2013 ◽  
Vol 59 (4) ◽  
pp. 485-505 ◽  
Author(s):  
Jon E. Brommer
Keyword(s):  
Life History ◽  
Phenotypic Plasticity ◽  
Statistical Approach ◽  
Scale Up ◽  
Population Level ◽  
Wild Populations ◽  
Quantitative Genetic ◽  
In The Wild ◽  
The Individual ◽  
Quantitative Genetic Parameters

Abstract Individual-based studies allow quantification of phenotypic plasticity in behavioural, life-history and other labile traits. The study of phenotypic plasticity in the wild can shed new light on the ultimate objectives (1) whether plasticity itself can evolve or is constrained by its genetic architecture, and (2) whether plasticity is associated to other traits, including fitness (selection). I describe the main statistical approach for how repeated records of individuals and a description of the environment (E) allow quantification of variation in plasticity across individuals (IxE) and genotypes (GxE) in wild populations. Based on a literature review of life-history and behavioural studies on plasticity in the wild, I discuss the present state of the two objectives listed above. Few studies have quantified GxE of labile traits in wild populations, and it is likely that power to detect statistically significant GxE is lacking. Apart from the issue of whether it is heritable, plasticity tends to correlate with average trait expression (not fully supported by the few genetic estimates available) and may thus be evolutionary constrained in this way. Individual-specific estimates of plasticity tend to be related to other traits of the individual (including fitness), but these analyses may be anti-conservative because they predominantly concern stats-on-stats. Despite the increased interest in plasticity in wild populations, the putative lack of power to detect GxE in such populations hinders achieving general insights. I discuss possible steps to invigorate the field by moving away from simply testing for presence of GxE to analyses that ‘scale up’ to population level processes and by the development of new behavioural theory to identify quantitative genetic parameters which can be estimated.

Multiple Haemoglobins of the Atlantic Salmon (Salmo salar)

1968 ◽  
Vol 25 (12) ◽  
pp. 2651-2663 ◽  
Author(s):  
N. P. Wilkins
Keyword(s):  
Life Cycle ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Gel Electrophoresis ◽  
Initial Increase ◽  
Small Fish ◽  
Starch Gel Electrophoresis ◽  
Complete Development ◽  
Starch Gel ◽  
The Individual

The haemoglobins of over 500 salmon of different lengths, from Scotland, Greenland, and Canada have been analysed by vertical starch–gel electrophoresis at pH 8.1. Complex ontogenetic variations, involving an initial increase and later reduction in the number of fractions evident, have been observed among the anodally migrating haemoglobins. The variations observed have been correlated with changes in length, and the complete development of the anodal haemoglobin complex from the single fraction of small fish to the nine-fraction pattern of adults is outlined. The individual haemoglobin fractions appear to represent structurally distinct molecules whose regulated occurrence at different phases of the life cycle is discussed at the individual and population levels.

scholarly journals Healthy ageing, resilience and wellbeing

2017 ◽  
Vol 26 (6) ◽  
pp. 579-583 ◽  
Author(s):  
T. D. Cosco ◽  
K. Howse ◽  
C. Brayne
Keyword(s):  
Population Level ◽  
Healthy Ageing ◽  
Ageing Population ◽  
Environmental Resources ◽  
Great Achievement ◽  
Health Concept ◽  
Ageing Model ◽  
The Face ◽  
The Individual ◽  
High Level

The extension of life does not appear to be slowing, representing a great achievement for mankind as well as a challenge for ageing populations. As we move towards an increasingly older population we will need to find novel ways for individuals to make the best of the challenges they face, as the likelihood of encountering some form of adversity increases with age. Resilience theories share a common idea that individuals who manage to navigate adversity and maintain high levels of functioning demonstrate resilience. Traditional models of healthy ageing suggest that having a high level of functioning across a number of domains is a requirement. The addition of adversity to the healthy ageing model via resilience makes this concept much more accessible and more amenable to the ageing population. Through asset-based approaches, such as the invoking of individual, social and environmental resources, it is hoped that greater resilience can be fostered at a population level. Interventions aimed at fostering greater resilience may take many forms; however, there is great potential to increase social and environmental resources through public policy interventions. The wellbeing of the individual must be the focus of these efforts; quality of life is an integral component to the enjoyment of additional years and should not be overlooked. Therefore, it will become increasingly important to use resilience as a public health concept and to intervene through policy to foster greater resilience by increasing resources available to older people. Fostering wellbeing in the face of increasing adversity has significant implications for ageing individuals and society as a whole.

scholarly journals Thevgll3locus controls age at maturity in wild and domesticated Atlantic salmon (Salmo salarL.) males

2015 ◽  
Author(s):  
Fernando Ayllon ◽  
Erik Kjærner-Semb ◽  
Tomasz Furmanek ◽  
Vidar Wennevik ◽  
Monica F Solberg ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Homo Sapiens ◽  
Complex Nature ◽  
Missense Mutations ◽  
Age At Maturity ◽  
Specific Sequence ◽  
Wild Salmon ◽  
Late Maturity ◽  
Age At Maturation ◽  
Sexually Mature

Wild and domesticated Atlantic salmon males display large variation for sea age at sexual maturation, which varies between 1-5 years. Previous studies have uncovered a genetic predisposition for age at maturity with moderate heritability, thus suggesting a polygenic or complex nature of this trait. The aim of this study was to identify associated genetic loci, genes and ultimately specific sequence variants conferring sea age at maturity in salmon. We performed a GWAS using a pool sequencing approach (20 individuals per river and trait) of salmon returning to rivers as sexually mature either after one sea winter (2009) or three sea winters (2011) in six rivers in Norway. The study revealed one major selective sweep, which covered 76 significant SNP in which 74 were found in a 370 kb region of chromosome 25. Genotyping other smolt year classes of wild salmon and domesticated salmon confirmed this finding. Genotyping domesticated fish narrowed the haplotype region to four SNPs covering 2386 bp, containing thevgll3gene, including two missense mutations explaining 33-36% phenotypic variation. This study demonstrates a single locus playing a highly significant role in governing sea age at maturation in this species. The SNPs identified may be both used as markers to guide breeding for late maturity in salmon aquaculture and in monitoring programs of wild salmon. Interestingly, a SNP in proximity of the VGLL3 gene in human (Homo sapiens), has previously been linked to age at puberty suggesting a conserved mechanism for timing of puberty in vertebrates.

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