scholarly journals Pre-immunity: the Schrodinger's cat of immunology

2021 ◽  
Author(s):  
Marcus Carlsson ◽  
Jens Wittsten ◽  
Cecilia Soderberg-Naucler
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Theory ◽  
Population Level ◽  
Individual Variability ◽  
Great Variability ◽  
Transmission Dynamics ◽  
Large Individual ◽  
Macroscopic Scale ◽  
Individual Level ◽  
Mathematical Formulas

Early 2020, catastrophic consequences of COVID-19 was predicted in the do-nothing scenario, based on mathematical models for epidemiology. As data began to emerge, several scientists noted that growth did not seem exponential, as the models predicted, leading to speculations of pre-existing immunity or immunological dark matter to explain this pattern. On the other hand, reports of choir-rehearsals infecting most members seemed to refute this, and the topic remained inconclusive. We provide a mathematical theory in which both observations are true; on a population level, pre-immunity exists, on an individual level, it doesn't. This theory demonstrates that established formulas relating e.g. R0 and the herdimmunity threshold are wrong. We derive new mathematical formulas, which applies to any virus whose transmission dynamics is associated with large individual variability in susceptibility to the infection. Contrary to great variability in infectivity, which we show has no bearing on the mathematical modeling, variability in susceptibility actually manifests itself as pre-immunity on a macroscopic scale, thus making pre-immunity a necessity for accurate mathematical modeling.

The Golden Section and the Aesthetics of Form and Composition: A Cognitive Model

1997 ◽  
Vol 15 (2) ◽  
pp. 209-232 ◽  
Author(s):  
I. C. McManus ◽  
P. Weatherby
Keyword(s):  
Individual Differences ◽  
Fuzzy Set ◽  
Golden Section ◽  
Cognitive Model ◽  
Population Level ◽  
Individual Variability ◽  
Large Individual ◽  
Powerful Method ◽  
Preference Functions ◽  
Geometric Objects

Previous work on the aesthetics of simple figures such as rectangles and triangles, as well as on the aesthetics of color, suggests that although there are clear population level preferences, there are also large individual differences which are temporally stable, and which any adequate theoretical analysis must take into account. Data presented here show similar phenomena in a related problem in composition—where to place an object within the frame of a picture to produce the optimal aesthetic effect. A novel and powerful “method of randomized paired comparisons” first showed that there are overall population level preferences, with objects being placed preferentially at the two golden sections horizontally, and between the two golden sections vertically. As in the studies of simple figures and colors, there are large individual differences. A cognitive model of “sensory aesthetics” is proposed in which continua of any type (space, geometric objects, colors, or whatever), are described categorically, usually in terms of words such as “square,” “rectangle,” “line,” etc., each of which is a fuzzy set. Preference functions are then derived from the union and intersection of the fuzzy set functions, which differ between individuals as their categories differ or as they prefer objects which are prototypical, or are at the boundaries between prototypes. There is therefore wide inter-individual variability.

scholarly journals Influence of HLA Class II Polymorphism on Predicted Cellular Immunity Against SARS-CoV-2 at the Population and Individual Level

2021 ◽  
Vol 12 ◽  
Author(s):  
Hannah C. Copley ◽  
Loren Gragert ◽  
Andrew R. Leach ◽  
Vasilis Kosmoliaptsis
Keyword(s):  
Cellular Immunity ◽  
Experimental Studies ◽  
Population Level ◽  
Class Ii ◽  
Individual Variability ◽  
Hla Class Ii ◽  
Hla Polymorphism ◽  
Individual Level ◽  
Hla Genotype

Development of adaptive immunity after COVID-19 and after vaccination against SARS-CoV-2 is predicated on recognition of viral peptides, presented on HLA class II molecules, by CD4+ T-cells. We capitalised on extensive high-resolution HLA data on twenty five human race/ethnic populations to investigate the role of HLA polymorphism on SARS-CoV-2 immunogenicity at the population and individual level. Within populations, we identify wide inter-individual variability in predicted peptide presentation from structural, non-structural and accessory SARS-CoV-2 proteins, according to individual HLA genotype. However, we find similar potential for anti-SARS-CoV-2 cellular immunity at the population level suggesting that HLA polymorphism is unlikely to account for observed disparities in clinical outcomes after COVID-19 among different race/ethnic groups. Our findings provide important insight on the potential role of HLA polymorphism on development of protective immunity after SARS-CoV-2 infection and after vaccination and a firm basis for further experimental studies in this field.

scholarly journals Multi-scale immunoepidemiological modeling of within-host and between-host HIV dynamics: systematic review of mathematical models

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3877 ◽  
Author(s):  
Nargesalsadat Dorratoltaj ◽  
Ryan Nikin-Beers ◽  
Stanca M. Ciupe ◽  
Stephen G. Eubank ◽  
Kaja M. Abbas
Keyword(s):  
Systematic Review ◽  
Population Level ◽  
Transmission Dynamics ◽  
Time Varying ◽  
Individual Level ◽  
Multi Scale ◽  
Hiv Dynamics ◽  
Single Scale ◽  
Scale Models ◽  
The Individual

Objective The objective of this study is to conduct a systematic review of multi-scale HIV immunoepidemiological models to improve our understanding of the synergistic impact between the HIV viral-immune dynamics at the individual level and HIV transmission dynamics at the population level. Background While within-host and between-host models of HIV dynamics have been well studied at a single scale, connecting the immunological and epidemiological scales through multi-scale models is an emerging method to infer the synergistic dynamics of HIV at the individual and population levels. Methods We reviewed nine articles using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) framework that focused on the synergistic dynamics of HIV immunoepidemiological models at the individual and population levels. Results HIV immunoepidemiological models simulate viral immune dynamics at the within-host scale and the epidemiological transmission dynamics at the between-host scale. They account for longitudinal changes in the immune viral dynamics of HIV+ individuals, and their corresponding impact on the transmission dynamics in the population. They are useful to analyze the dynamics of HIV super-infection, co-infection, drug resistance, evolution, and treatment in HIV+ individuals, and their impact on the epidemic pathways in the population. We illustrate the coupling mechanisms of the within-host and between-host scales, their mathematical implementation, and the clinical and public health problems that are appropriate for analysis using HIV immunoepidemiological models. Conclusion HIV immunoepidemiological models connect the within-host immune dynamics at the individual level and the epidemiological transmission dynamics at the population level. While multi-scale models add complexity over a single-scale model, they account for the time varying immune viral response of HIV+ individuals, and the corresponding impact on the time-varying risk of transmission of HIV+ individuals to other susceptibles in the population.

scholarly journals Components of standard metabolic rate variability in three species of gammarids

Web Ecology ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Milad Shokri ◽  
Mario Ciotti ◽  
Fabio Vignes ◽  
Vojsava Gjoni ◽  
Alberto Basset
Keyword(s):  
Body Size ◽  
Metabolic Rate ◽  
Body Condition ◽  
Population Level ◽  
Functional Trait ◽  
Standard Metabolic Rate ◽  
Individual Variability ◽  
Population Variation ◽  
Metabolic Rates ◽  
Individual Level

Abstract. Standard metabolic rate is a major functional trait with large inter-individual variability in many groups of aquatic species. Here we present results of an experimental study to address variation in standard metabolic rates, over different scales of organisation and environments, within a specific group of aquatic macro-invertebrates (i.e. gammarid amphipods) that represent the primary consumers in detritus food webs. The study was carried out using flow-through microrespirometric techniques on male specimens of three gammarid species from freshwater, transitional water and marine ecosystems. We examined individual metabolic rate variations at three scales: (1) at the individual level, during an 8 h period of daylight; (2) at the within-population level, along body-size and body-condition gradients; (3) at the interspecific level, across species occurring in the field in the three different categories of aquatic ecosystems, from freshwater to marine. We show that standard metabolic rates vary significantly at all three scales examined, with the highest variation observed at the within-population level. Variation in individual standard metabolic rates during the daylight hours was generally low (coefficient of variation, CV<10 %) and unrelated to time. The average within-population CV ranged between 30.0 % and 35.0 %, with body size representing a significant source of overall inter-individual variation in the three species and individual body condition exerting only a marginal influence. In all species, the allometric equations were not as steep as would be expected from the 3∕4 power law, with significant variation in mass-specific metabolic rates among populations. The population from the transitional water ecosystem had the highest mass-specific metabolic rates and the lowest within-population variation. In the gammarid species studied here, body-size-independent variations in standard individual metabolic rates were higher than those explained by allometric body size scaling, and the costs of adaptation to short-term periodic variations in water salinity in the studied ecosystems also seemed to represent a major source of variation.

scholarly journals Mathematical modeling of COVID-19 infection dynamics in Ghana: Impact evaluation of integrated government and individual level interventions

2021 ◽  
Vol 6 ◽  
pp. 381-397
Author(s):  
Duah Dwomoh ◽  
Samuel Iddi ◽  
Bright Adu ◽  
Justice Moses Aheto ◽  
Kojo Mensah Sedzro ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Impact Evaluation ◽  
Individual Level ◽  
Infection Dynamics

scholarly journals Blood Pressure Trajectories Across the Life Course

2021 ◽  
Vol 34 (3) ◽  
pp. 234-241
Author(s):  
Norrina B Allen ◽  
Sadiya S Khan
Keyword(s):  
Blood Pressure ◽  
Measurement Errors ◽  
Clinical Care ◽  
Population Level ◽  
Cumulative Exposure ◽  
Older Adulthood ◽  
Individual Level ◽  
The Life Course ◽  
Level Group ◽  
Improve Health

Abstract High blood pressure (BP) is a strong modifiable risk factor for cardiovascular disease (CVD). Longitudinal BP patterns themselves may reflect the burden of risk and vascular damage due to prolonged cumulative exposure to high BP levels. Current studies have begun to characterize BP patterns as a trajectory over an individual’s lifetime. These BP trajectories take into account the absolute BP levels as well as the slope of BP changes throughout the lifetime thus incorporating longitudinal BP patterns into a single metric. Methodologic issues that need to be considered when examining BP trajectories include individual-level vs. population-level group-based modeling, use of distinct but complementary BP metrics (systolic, diastolic, mean arterial, mid, and pulse pressure), and potential for measurement errors related to varied settings, devices, and number of readings utilized. There appear to be very specific developmental periods during which divergent BP trajectories may emerge, specifically adolescence, the pregnancy period, and older adulthood. Lifetime BP trajectories are impacted by both individual-level and community-level factors and have been associated with incident hypertension, multimorbidity (CVD, renal disease, cognitive impairment), and overall life expectancy. Key unanswered questions remain around the additive predictive value of BP trajectories, intergenerational contributions to BP patterns (in utero BP exposure), and potential genetic drivers of BP patterns. The next phase in understanding BP trajectories needs to focus on how best to incorporate this knowledge into clinical care to reduce the burden of hypertensive-related outcomes and improve health equity.

scholarly journals Interannual comparison of core taxa and community composition of the blow microbiota from East Australian humpback whales

2019 ◽  
Vol 95 (8) ◽  
Author(s):  
C Vendl ◽  
B C Ferrari ◽  
T Thomas ◽  
E Slavich ◽  
E Zhang ◽  
...  
Keyword(s):  
Multiple Stressors ◽  
Physiological State ◽  
Temporal Stability ◽  
Individual Variability ◽  
Habitat Destruction ◽  
Humpback Whales ◽  
Large Individual ◽  
Rrna Gene ◽  
Alpha And Beta Diversity ◽  
Transient Nature

ABSTRACT Cetacean represent vulnerable species impacted by multiple stressors, including reduction in prey species, habitat destruction, whaling and infectious disease. The composition of blow microbiota has been claimed to provide a promising tool for non-invasive health monitoring aiming to inform conservation management. Still, little is known about the temporal stability and composition of blow microbiota in whales. We used East Australian humpback whales (Megaptera novaeangliae) as a model species and collected blow and control samples in August 2016 and 2017 for an interannual comparison. We analysed the blow by barcode tag sequencing of the bacterial 16S rRNA gene. We found that the microbial communities in 2016 and 2017 were statistically similar regarding alpha and beta diversity but distinct to seawater. Zero-radius operational taxonomic units (zOTUs) shared by both groups accounted for about 50% of all zOTUs present. Still, the large individual variability in the blow microbiota resulted in a small number of core taxa (defined as present in at least 60% of whales). We conclude that the blow microbiota of humpback whales is either generally limited and of transient nature or the reduced airway microbiota is the symptom of a compromised physiological state potentially due to the challenges of the whales‘ annual migration.

scholarly journals Examining the Effects of the Sacramento Dockless E-Bike Share on Bicycling and Driving

2021 ◽  
Vol 13 (1) ◽  
pp. 368
Author(s):  
Dillon T. Fitch ◽  
Hossain Mohiuddin ◽  
Susan L. Handy
Keyword(s):  
Travel Behavior ◽  
Regression Models ◽  
Population Level ◽  
Panel Survey ◽  
Multilevel Regression ◽  
Combine Data ◽  
Cross Sectional ◽  
Individual Level ◽  
Before And After ◽  
Bike Share

One way cities are looking to promote bicycling is by providing publicly or privately operated bike-share services, which enable individuals to rent bicycles for one-way trips. Although many studies have examined the use of bike-share services, little is known about how these services influence individual-level travel behavior more generally. In this study, we examine the behavior of users and non-users of a dockless, electric-assisted bike-share service in the Sacramento region of California. This service, operated by Jump until suspended due to the coronavirus pandemic, was one of the largest of its kind in the U.S., and spanned three California cities: Sacramento, West Sacramento, and Davis. We combine data from a repeat cross-sectional before-and-after survey of residents and a longitudinal panel survey of bike-share users with the goal of examining how the service influenced individual-level bicycling and driving. Results from multilevel regression models suggest that the effect of bike-share on average bicycling and driving at the population level is likely small. However, our results indicate that people who have used-bike share are likely to have increased their bicycling because of bike-share.

Medication Adherence: Expanding the Conceptual Framework

2021 ◽  
Author(s):  
Marie Krousel-Wood ◽  
Leslie S Craig ◽  
Erin Peacock ◽  
Emily Zlotnick ◽  
Samantha O’Connell ◽  
...  
Keyword(s):  
Older Adults ◽  
Medication Adherence ◽  
Conceptual Framework ◽  
Clinical Outcomes ◽  
Implicit Attitudes ◽  
Explanatory Power ◽  
Population Level ◽  
Time Preferences ◽  
Adherence Behavior ◽  
Individual Level

Abstract Interventions targeting traditional barriers to antihypertensive medication adherence (AHMA) have been developed and evaluated, with evidence of modest improvements in adherence. Translation of these interventions into population-level improvements in adherence and clinical outcomes among older adults remains suboptimal. From the Cohort Study of Medication Adherence among Older adults (CoSMO), we evaluated traditional barriers to AHMA among older adults with established hypertension (N=1544; mean age=76.2 years, 59.5% women, 27.9% Black, 24.1% and 38.9% low adherence by proportion of days covered (i.e., PDC&lt;0.80) and the 4-item Krousel-Wood Medication Adherence Scale (i.e., K-Wood-MAS-4≥1), respectively), finding that they explained 6.4% and 14.8% of variance in pharmacy refill and self-reported adherence, respectively. Persistent low adherence rates, coupled with low explanatory power of traditional barriers, suggest that other factors warrant attention. Prior research has investigated explicit attitudes toward medications as a driver of adherence; the roles of implicit attitudes and time preferences (e.g., immediate versus delayed gratification) as mechanisms underlying adherence behavior are emerging. Similarly, while associations of individual-level social determinants of health (SDOH) and medication adherence are well-reported, there is growing evidence about structural SDOH and specific pathways of effect. Building on published conceptual models and recent evidence, we propose an expanded conceptual framework that incorporates implicit attitudes, time preferences and structural SDOH, as emerging determinants that may explain additional variation in objectively and subjectively measured adherence. This model provides guidance for design, implementation and assessment of interventions targeting sustained improvement in implementation medication adherence and clinical outcomes among older women and men with hypertension.

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