scholarly journals A computational approach to studying ageing at the individual level

2016 ◽  
Vol 283 (1824) ◽  
pp. 20152346 ◽  
Author(s):  
Zachary M. Harvanek ◽  
Márcio A. Mourão ◽  
Santiago Schnell ◽  
Scott D. Pletcher
Keyword(s):  
Computational Models ◽  
Mortality Rates ◽  
Stochastic Simulations ◽  
Individual Level ◽  
Opposite Sex ◽  
Population Mortality ◽  
The Individual ◽  
Rate Of Ageing ◽  
Key Aspects

The ageing process is actively regulated throughout an organism's life, but studying the rate of ageing in individuals is difficult with conventional methods. Consequently, ageing studies typically make biological inference based on population mortality rates, which often do not accurately reflect the probabilities of death at the individual level. To study the relationship between individual and population mortality rates, we integrated in vivo switch experiments with in silico stochastic simulations to elucidate how carefully designed experiments allow key aspects of individual ageing to be deduced from group mortality measurements. As our case study, we used the recent report demonstrating that pheromones of the opposite sex decrease lifespan in Drosophila melanogaster by reversibly increasing population mortality rates. We showed that the population mortality reversal following pheromone removal was almost surely occurring in individuals, albeit more slowly than suggested by population measures. Furthermore, heterogeneity among individuals due to the inherent stochasticity of behavioural interactions skewed population mortality rates in middle-age away from the individual-level trajectories of which they are comprised. This article exemplifies how computational models function as important predictive tools for designing wet-laboratory experiments to use population mortality rates to understand how genetic and environmental manipulations affect ageing in the individual.

Introduction

2015 ◽  
Keyword(s):  
Young Children ◽  
Father Involvement ◽  
Parental Leave ◽  
Welfare States ◽  
Policy Regimes ◽  
Individual Level ◽  
Structural Context ◽  
The Individual ◽  
Key Aspects ◽  
Workplace Cultures

After outlining the key aspects of the changing social, cultural, and policy context of parenting in Western societies, the introduction clarifies terminology and key concepts used throughout the book, such as the distinction among fatherhood, fathering, and types of fathers. It also presents the theoretical framework used to examine father involvement with young children in six countries. This includes the fatherhood regime, fathers’ agency gap and capability to care for children, and gendered care and workplace cultures. In addition, the structural context of welfare states and policy regimes is reviewed to frame the institutional support for father involvement, such as compensated paternity and parental leave. At the individual level father involvement is conceptualized as encompassing engagement, accessibility and responsibility as expressed in the type and quantity of time of fathers’ activities with their young children. Finally, the chapter briefly outlines the structure of the book.

scholarly journals Emotion and liking: how director emotional expression and knowledge of (dis)liking may impact adults’ ability to follow the instructions of an ignorant speaker

2020 ◽  
Author(s):  
Rebecca L. Monk ◽  
Lauren Colbert ◽  
Gemma Darker ◽  
Jade Cowling ◽  
Bethany Jones ◽  
...  
Keyword(s):  
Perspective Taking ◽  
Real Life ◽  
Target Object ◽  
Individual Level ◽  
Object Selection ◽  
Knowledge And Beliefs ◽  
Correct Object ◽  
The Individual ◽  
Key Aspects ◽  
Accuracy Rates

Abstract Background Theory of mind (ToM), the ability to understand that others have different knowledge and beliefs to ourselves, has been the subject of extensive research which suggests that we are not always efficient at taking another’s perspective, known as visual perspective taking (VPT). This has been studied extensively and a growing literature has explored the individual-level factors that may affect perspective taking (e.g. empathy and group membership). However, while emotion and (dis)liking are key aspects within everyday social interaction, research has not hitherto explored how these factors may impact ToM. Method A total of 164 participants took part in a modified director task (31 males (19%), M age = 20.65, SD age = 5.34), exploring how correct object selection may be impacted by another’s emotion (director facial emotion; neutral × happy × sad) and knowledge of their (dis)likes (i.e. director likes specific objects). Result When the director liked the target object or disliked the competitor object, accuracy rates were increased relative to when he disliked the target object or liked the competitor object. When the emotion shown by the director was incongruent with their stated (dis)liking of an object (e.g. happy when he disliked an object), accuracy rates were also increased. None of these effects were significant in the analysis of response time. These findings suggest that knowledge of liking may impact ToM use, as can emotional incongruency, perhaps by increasing the saliency of perspective differences between participant and director. Conclusion As well as contributing further to our understanding of real-life social interactions, these findings may have implications for ToM research, where it appears that more consideration of the target/director’s characteristics may be prudent.

scholarly journals Models of tendon development and injury

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Sophia K. Theodossiou ◽  
Nathan R. Schiele
Keyword(s):  
Computational Models ◽  
Ex Vivo ◽  
Current Model ◽  
Stem Cell Differentiation ◽  
Tendon Injury ◽  
Model Systems ◽  
Tendon Development ◽  
Key Aspects

AbstractTendons link muscle to bone and transfer forces necessary for normal movement. Tendon injuries can be debilitating and their intrinsic healing potential is limited. These challenges have motivated the development of model systems to study the factors that regulate tendon formation and tendon injury. Recent advances in understanding of embryonic and postnatal tendon formation have inspired approaches that aimed to mimic key aspects of tendon development. Model systems have also been developed to explore factors that regulate tendon injury and healing. We highlight current model systems that explore developmentally inspired cellular, mechanical, and biochemical factors in tendon formation and tenogenic stem cell differentiation. Next, we discuss in vivo, in vitro, ex vivo, and computational models of tendon injury that examine how mechanical loading and biochemical factors contribute to tendon pathologies and healing. These tendon development and injury models show promise for identifying the factors guiding tendon formation and tendon pathologies, and will ultimately improve regenerative tissue engineering strategies and clinical outcomes.

scholarly journals The computation of strategic learning in repeated social competitive interactions: Learning sophistication, reward attractor points and strategic asymmetry

2018 ◽  
Author(s):  
Thibaud Griessinger ◽  
Giorgio Coricelli ◽  
Mehdi Khamassi
Keyword(s):  
Computational Models ◽  
Computational Modelling ◽  
Repeated Game ◽  
Data Availability ◽  
Cognitive Capacity ◽  
Strategic Learning ◽  
Individual Level ◽  
Game Environment ◽  
The Individual ◽  
Recursive Thinking

ABSTRACTSocial interactions rely on our ability to learn and adjust our behavior to the behavior of others. Strategic games provide a useful framework to study the cognitive processes involved in the formation of beliefs about the others’ intentions and behavior, what we may call strategic theory of mind. Through the years, the growing field of behavioral economics provided evidence of a systematic departure of human’s behavior from the optimal game theoretical prescriptions. One hypothesis posits that human’s ability to accurately process the other’s behavior is somehow bounded. The question of what constraints the formation of sufficiently high order beliefs remained unanswered. We hypothesize that maximizing final earnings in a competitive repeated game setting, requires moving away from reward-based learning to engage in sophisticated belief-based learning. Overcoming the attraction of the immediate rewards by displaying a computationally costly type of learning might not be a strategy shared among all individuals. In this work, we manipulated the reward structure of the interaction so that the action displayed by the two types of learning becomes (respectively not) discriminable, giving a relative strategic (resp. dis) advantage to the participant given the role endorsed during the interaction. We employed a computational modeling approach to characterize the individual level of belief learning sophistication in three types of interactions (agent-agent, human-human and human-agent). The analysis of the participants’ choice behavior revealed that the strategic learning level drives the formation of more accurate beliefs and eventually leads to convergence towards game optimality (equilibrium). More specifically we show that the game structure interacts with the level of engagement in strategically sophisticated learning to explain the outcome of the interaction. This study provides the first evidence of a key implication of strategic learning heterogeneity in equilibrium departure and provides insight to explain the emergence of a leader-follower dynamics of choice.AUTHOR SUMMARYDynamic interaction between individuals appears to be a cornerstone for understanding how humans grasp other minds. During a strategic interaction, in which the outcome of one’s action depends directly on what the other individual decides, it appears crucial to anticipate the other’s actions in order to adjust our own behavior. In theory, choosing optimally in a strategic setting requires that both players hold correct beliefs over their opponent’s behavior and best-respond to it. However, in practice humans systematically deviate from the game-theoretical (equilibrium), suggesting that our ability to form accurate beliefs is cognitively and/or contextually constrained. Previous studies using computational modelling suggested that during a repeated game interaction humans vary in the sophistication of their learning process leading to the formation of beliefs over their opponent’s behavior of different orders of complexity (level of recursive thinking such as “I think that you think that …”). In this work we show that the individual engagement in sophisticated (belief-based) learning drives the convergence towards equilibrium and ultimately performance. Moreover, we show that this effect is influenced by both the game environment and the cognitive capacity of the participants, shaping the very dynamic of the social interaction.DATA AVAILABILITYThe authors confirm that upon publication the raw behavioral data and Matlab code for reconstruction of all figures, computational models and statistical analyses will be made available for download at the following URL: https://zenodo.org/

scholarly journals Towards harmonizing subtyping methods for neuroimaging studies in Alzheimer’s disease

2020 ◽  
Author(s):  
Rosaleena Mohanty ◽  
Gustav Mårtensson ◽  
Konstantinos Poulakis ◽  
J-Sebastian Muehlboeck ◽  
Elena Rodriguez-Vieitez ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Reference Group ◽  
Group Level ◽  
Individual Level ◽  
Dementia Patients ◽  
Positron Emission ◽  
Tau Pet ◽  
The Individual

ABSTRACTBackgroundBiological subtypes in Alzheimer’s disease (AD), originally identified on neuropathological data, have been translated to in vivo biomarkers such as structural magnetic resonance imaging (sMRI) and positron emission tomography (PET), to disentangle the heterogeneity within AD. Although there is methodological variability across studies, comparable characteristics of subtypes are reported at the group level. In this study, we investigated whether group-level similarities translate to individual-level agreement across subtyping methods, in a head-to-head context.MethodsWe compared five previously published subtyping methods. Firstly, we validated the subtyping methods in 89 amyloid-beta positive (Aβ+) AD dementia patients (reference group: 70 Aβ-healthy individuals; HC) using sMRI. Secondly, we extended and applied the subtyping methods to 53 Aβ+ prodromal AD and 30 Aβ+ AD dementia patients (reference group: 200 Aβ-HC) using both sMRI and tau PET. Subtyping methods were implemented as outlined in each original study. Group-level and individual-level comparisons across methods were performed.ResultsEach individual method was replicated and the proof-of-concept was established. All methods captured subtypes with similar patterns of demographic and clinical characteristics, and with similar maps of cortical thinning and tau PET uptake, at the group level. However, large disagreements were found at the individual level.ConclusionsAlthough characteristics of subtypes may be comparable at the group level, there is a large disagreement at the individual level across subtyping methods. Therefore, there is an urgent need for consensus and harmonization across subtyping methods. We call for establishment of an open benchmarking framework to overcome this problem.

Similarities in Human Visual and Declared Measures of Preference for Opposite-Sex Faces

2014 ◽  
Vol 61 (4) ◽  
pp. 301-309 ◽  
Author(s):  
Jack A. F. Griffey ◽  
Anthony C. Little
Keyword(s):  
Population Level ◽  
Three Dimensions ◽  
Sexually Dimorphic ◽  
Individual Level ◽  
Facial Stimuli ◽  
Visual Preferences ◽  
Opposite Sex ◽  
The Individual ◽  
Negative Factors ◽  
The Relationship

Facial appearance in humans is associated with attraction and mate choice. Numerous studies have identified that adults display directional preferences for certain facial traits including symmetry, averageness, and sexually dimorphic traits. Typically, studies measuring human preference for these traits examine declared (e.g., choice or ratings of attractiveness) or visual preferences (e.g., looking time) of participants. However, the extent to which visual and declared preferences correspond remains relatively untested. In order to evaluate the relationship between these measures we examined visual and declared preferences displayed by men and women for opposite-sex faces manipulated across three dimensions (symmetry, averageness, and masculinity) and compared preferences from each method. Results indicated that participants displayed significant visual and declared preferences for symmetrical, average, and appropriately sexually dimorphic faces. We also found that declared and visual preferences correlated weakly but significantly. These data indicate that visual and declared preferences for manipulated facial stimuli produce similar directional preferences across participants and are also correlated with one another within participants. Both methods therefore may be considered appropriate to measure human preferences. However, while both methods appear likely to generate similar patterns of preference at the sample level, the weak nature of the correlation between visual and declared preferences in our data suggests some caution in assuming visual preferences are the same as declared preferences at the individual level. Because there are positive and negative factors in both methods for measuring preference, we suggest that a combined approach is most useful in outlining population level preferences for traits.

scholarly journals Ethnic variations in sexual partnerships and mixing, and their association with STI diagnosis: findings from a cross-sectional biobehavioural survey of attendees of sexual health clinics across England

2019 ◽  
Vol 96 (4) ◽  
pp. 283-292 ◽  
Author(s):  
Catherine RH Aicken ◽  
Sonali Wayal ◽  
Paula Blomquist ◽  
Stella Fabiane ◽  
Makeda Gerressu ◽  
...  
Keyword(s):  
Sexual Health ◽  
Population Level ◽  
Health Clinic ◽  
Age Difference ◽  
Sex Partners ◽  
Cross Sectional ◽  
Sexual Partnerships ◽  
Individual Level ◽  
Opposite Sex ◽  
The Individual

ObjectivesEthnic differences in partnership types and sexual mixing patterns may contribute to elevated STI diagnosis rates among England’s Black Caribbean (BC) population. We examined the differences between BC and White British/Irish (WBI) sexual health clinic (SHC) attendees’ reported partnerships and sexual mixing, and whether these differences could explain ethnic inequalities in STI, focusing on attendees reporting only opposite-sex partners (past year).MethodsWe surveyed attendees at 16 SHCs across England (May to September 2016), and linked their survey responses to routinely collected data on diagnoses of bacterial STI or trichomoniasis ±6 weeks of clinic attendance (‘acute STI’). Behaviourally-heterosexual BC and WBI attendees (n=1790) reported details about their ≤3 most recent opposite-sex partners (past 3 months, n=2503). We compared BC and WBI attendees’ reported partnerships and mixing, in gender-stratified analyses, and used multivariable logistic regression to examine whether they independently explained differences in acute STI.ResultsWe observed differences by ethnic group. BC women’s partnerships were more likely than WBI women’s partnerships to involve age-mixing (≥5 years age difference; 31.6% vs 25.5% partnerships, p=0.013); BC men’s partnerships were more often ‘uncommitted regular’ (35.4% vs 20.7%) and less often casual (38.5% vs 53.1%) than WBI men’s partnerships (p<0.001). Acute STI was higher among BC women than WBI women (OR: 2.29, 95% CI 1.24 to 4.21), with no difference among men. This difference was unaffected by partnerships and mixing: BC women compared with WBI women adjusted OR: 2.31 (95% CI 1.30 to 4.09) after adjusting for age and partner numbers; 2.15 (95% CI 1.07 to 4.31) after additionally adjusting for age-mixing, ethnic-mixing and recent partnership type(s).ConclusionWe found that differences in sexual partnerships and mixing do not appear to explain elevated risk of acute STI diagnosis among behaviourally-heterosexual BC women SHC attendees, but this may reflect the measures used. Better characterisation of ‘high transmission networks’ is needed, to improve our understanding of influences beyond the individual level, as part of endeavours to reduce population-level STI transmission.

scholarly journals Imaging the pathoanatomy of amyotrophic lateral sclerosis in vivo: targeting a propagation-based biological marker

2017 ◽  
Vol 89 (4) ◽  
pp. 374-381 ◽  
Author(s):  
Jan Kassubek ◽  
Hans-Peter Müller ◽  
Kelly Del Tredici ◽  
Dorothée Lulé ◽  
Martin Gorges ◽  
...  
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Rating Scale ◽  
Diffusion Tensor ◽  
Biological Marker ◽  
Longitudinal Diffusion ◽  
Individual Level ◽  
Disease Patterns ◽  
The Individual ◽  
Lateral Sclerosis

ObjectiveNeuropathological studies in amyotrophic lateral sclerosis (ALS) have shown a dissemination in a regional sequence in four anatomically defined patterns. The aim of this retrospective study was to see whether longitudinal diffusion tensor imaging (DTI) data support the pathological findings.MethodsThe application of DTI analysis to fibre structures that are prone to be involved at each neuropathological pattern of ALS was performed in a monocentre sample of 67 patients with ALS and 31 controls that obtained at least one follow-up scan after a median of 6 months.ResultsAt the group level, longitudinal ALS data showed significant differences for the stage-related tract systems. At the individual level, 27% of the longitudinally scanned patients with ALS showed an increase in ALS stage, while the remaining were stable or were at the highest ALS stage. Longitudinal fractional anisotropy changes in the respective tract systems correlated significantly with the slope of the revised ALS functional rating scale.InterpretationThe DTI-based protocol was able to image the disease patterns of ALS in vivo cross-sectionally and longitudinally, in support of DTI as a technical marker to image ALS stages.

When organization meets emotions, does the socio-relational framework fail?

2009 ◽  
Vol 32 (5) ◽  
pp. 391-391 ◽  
Author(s):  
Frédéric Basso ◽  
Olivier Oullier
Keyword(s):  
Sex Differences ◽  
Social Interactions ◽  
Professional Activity ◽  
Organizational Contexts ◽  
Individual Level ◽  
Cost Benefits ◽  
Trade Offs ◽  
The Individual ◽  
Relational Framework

AbstractWe suggest that the framework proposed by Vigil is useful in laboratory contexts but might come up short for in vivo social interactions. Emotions result from cost-benefits trade-offs but are not solely generated at the individual level to establish emotional social spheres. In organizational contexts, emotion expression can be a constitutive part of a professional activity, and observed sex differences might vanish.

Diagnosis of bovine neosporosis: Recent advances and perspectives

2006 ◽  
Vol 51 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Luis Ortega-Mora ◽  
Aurora Fernández-García ◽  
Mercedes Gómez-Bautista
Keyword(s):  
Neospora Caninum ◽  
Diagnostic Procedures ◽  
Control Measures ◽  
Individual Level ◽  
Control Programmes ◽  
Typing Methods ◽  
Bovine Neosporosis ◽  
The Individual ◽  
Foetal Infection

AbstractNeospora caninum is considered a major cause of abortion in cattle. Appropriate techniques for diagnosis of bovine neosporosis, both in vivo and in aborted foetuses, have been developed in the last ten years and some of them are commercially available. For diagnosis in live animals, detection of antibodies in serum or milk has been shown to be the best option both at the herd and the individual level. These techniques are excellent tools to examine N. caninum-associated abortion problems and to adopt some basic herd-control measures. Concerning foetal diagnosis, detection of compatible lesions by histological examination and parasites by PCR in brain (as well as heart and liver) are the best choices. Diagnostic criteria to distinguish foetal infection and Neospora-associated abortion are based not only on the demonstration of the parasite in the foetus but also on the extent and severity of the lesions in the foetus, foetal age and the assessment of neosporosis at the herd level. In the near future, new tools to diagnose infection should help to detect animals with parasite reactivation by testing the immune response to stage-specific antigens and lead to the development of molecular typing methods to characterise different parasite isolates. Finally, uniform diagnostic procedures need to be established between laboratories and countries in order to standardise result interpretation. The role of National or Regional Reference Laboratories is essential in countries or regions where control programmes for the disease are being developed.

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