628 research outputs found
Infection-acquired versus vaccine-acquired immunity in an SIRWS model
Despite high vaccine coverage, pertussis has re-emerged as a public health
concern in many countries. One hypothesis posed for re-emergence is the waning
of immunity. In some disease systems, the process of waning immunity can be
non-linear, involving a complex relationship between the duration of immunity
and subsequent boosting of immunity through asymptomatic re-exposure.
We present and analyse a model of infectious disease transmission to examine
the interplay between infection and immunity. By allowing the duration of
infection-acquired immunity to differ from that of vaccine-acquired immunity,
we explore the impact of the difference in durations on long-term disease
patterns and prevalence of infection.
Our model demonstrates that vaccination may induce cyclic behaviour, and its
ability to reduce the infection prevalence increases with both the duration of
infection-acquired immunity and duration of vaccine-acquired immunity. We find
that increasing vaccine coverage, while capable of leading to an increase in
overall transmission, always results in a reduction in prevalence of primary
infections, with epidemic cycles characterised by a longer interepidemic period
and taller peaks.
Our results show that the epidemiological patterns of an infectious disease
may change considerably when the duration of vaccine-acquired immunity differs
from that of infection-acquired immunity. Our study highlights that for any
particular disease and associated vaccine, a detailed understanding of the
duration of protection and how that duration is influenced by infection
prevalence is important as we seek to optimise vaccination strategies.Comment: 21 pages, 5 figure
Contribution of reactive and proactive control to children's working memory performance:Insight from item recall durations in response sequence planning
The present study addressed whether developmental improvement in working memory span task performance relies upon a growing ability to proactively plan response sequences during childhood. Two hundred thirteen children completed a working memory span task in which they used a touchscreen to reproduce orally presented sequences of animal names. Children were assessed longitudinally at 7 time points between 3 and 10 years of age. Twenty-one young adults also completed the same task. Proactive response sequence planning was assessed by comparing recall durations for the 1st item (preparatory interval) and subsequent items. At preschool age, the preparatory interval was generally shorter than subsequent item recall durations, whereas it was systematically longer during elementary school and in adults. Although children mostly approached the task reactively at preschool, they proactively planned response sequences with increasing efficiency from age 7 on, like adults. These findings clarify the nature of the changes in executive control that support working memory performance with age
Executive Control Goes to School: Implications of Preschool Executive Performance for Observed Elementary Classroom Learning Engagement
The transition to elementary school is accompanied by increasing demands for children to regulate their attention and behavior within the classroom setting. Executive control (EC) may be critical for meeting these demands; however, few studies have rigorously examined the association between EC and observed classroom behavior. This study examined EC in preschool (age 5 years, 3 months) as a predictor of classroom learning engagement behaviors in first grade, using a battery of performance-based EC tasks and live classroom observations in a longitudinal sample of 313 children. Multilevel modeling results indicated that stronger EC predicted more focused engagement and fewer task management and competing responses, controlling for socioeconomic status, child sex, and age at observations. Results suggest that early EC may support subsequent classroom engagement behaviors that are critical for successful transition to elementary school and long-term learning trajectories
Recognition and Diagnosis of Obstructive Sleep Apnea in Older Americans
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145334/1/jgs15372.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145334/2/jgs15372_am.pd
Effects of a Community Population Health Initiative on Blood Pressure Control in Latinos.
Background Hypertension remains one of the most important, modifiable cardiovascular risk factors. Yet, the largest minority ethnic group (Hispanics/Latinos) often have different health outcomes and behavior, making hypertension management more difficult. We explored the effects of an American Heart Association-sponsored population health intervention aimed at modifying behavior of Latinos living in Texas. Methods and Results We enrolled 8071 patients, and 5714 (65.7%) completed the 90-day program (58.5 years Ā±11.7; 59% female) from July 2016 to June 2018. Navigators identified patients with risk factors; initial and final blood pressure ( BP ) readings were performed in the physician\u27s office; and interim home measurements were recorded telephonically. The intervention incorporated home BP monitoring, fitness and nutritional counseling, and regular follow-up. Primary outcomes were change in systolic BP and health-related quality of life. Using a univariate paired-samples pre-post design, we found an average 5.5% (7.6-mm Hg) improvement in systolic BP (139.1 versus 131.5, t=10.32,
HCV Broadly Neutralizing Antibodies Use a CDRH3 Disulfide Motif to Recognize an E2 Glycoprotein Site that Can Be Targeted for Vaccine Design
Hepatitis C virus (HCV) vaccine efforts are hampered by the extensive genetic diversity of HCV envelope glycoproteins E1 and E2. Structures of broadly neutralizing antibodies (bNAbs) (e.g., HEPC3, HEPC74) isolated from individuals who spontaneously cleared HCV infection facilitate immunogen design to elicit antibodies against multiple HCV variants. However, challenges in expressing HCV glycoproteins previously limited bNAb-HCV structures to complexes with truncated E2 cores. Here we describe crystal structures of full-length E2 ectodomain complexes with HEPC3 and HEPC74, revealing lock-and-key antibody-antigen interactions, E2 regions (including a target of immunogen design) that were truncated or disordered in E2 cores, and an antibody CDRH3 disulfide motif that exhibits common interactions with a conserved epitope despite different bNAb-E2 binding orientations. The structures display unusual features relevant to common genetic signatures of HCV bNAbs and demonstrate extraordinary plasticity in antibody-antigen interactions. In addition, E2 variants that bind HEPC3/HEPC74-like germline precursors may represent candidate vaccine immunogens
Engineered Polymer Composites Through Electrospun Nanofiber Coating of Fiber Tows
Composite materials offer significant weight savings in many aerospace applications. The toughness of the interface of fibers crossing at different angles often determines failure of composite components. A method for toughening the interface in fabric and filament wound components using directly electrospun thermoplastic nanofiber on carbon fiber tow is presented. The method was first demonstrated with limited trials, and then was scaled up to a continuous lab scale process. Filament wound tubes were fabricated and tested using unmodified baseline towpreg material and nanofiber coated towpreg
Early executive control buffers risk for adolescent psychopathology during the COVIDā19 pandemic
Background: The coronavirus disease 2019 (COVIDā19) pandemic has had a global impact on youth mental health, and there is a critical need for research examining individual factors that contribute to increased psychopathology during the pandemic. The current study explored whether executive control (EC) abilities in early childhood interact with COVIDārelated stress to attenuate risk for adolescent psychopathology during the first 6 months of the pandemic.
Methods: Participants were 337 youth (49% female) living in a small midwestern city in the United States. Participants completed EC tasks when they were approximately 4.5 years old as part of a longitudinal study investigating cognitive development. At annual laboratory visits during adolescence and before the pandemic, participants (Mage = 14.57) reported on mental health symptoms. In July and August of 2020, participants (Mage = 16.57) reported on COVIDārelated stress and depression, anxiety, and trauma symptoms.
Results: COVIDārelated stress was associated with increased internalizing problems after controlling for prepandemic symptom levels. Further, the impact of COVID-related stress on adolescent internalizing problems was moderated by preschool EC, with higher levels of EC buffering the effects of COVIDārelated stress on adolescent internalizing problems.
Conclusions: Findings highlight the importance of promoting EC early in development, as well as screening for EC deficits and implementing targeted intervention strategies across the lifespan to help reduce the impact of stress on adolescent internalizing problems
Executive Control in Early Childhood as an Antecedent of Adolescent Problem Behaviors: A Longitudinal Study with Performance-based Measures of Early Childhood Cognitive Processes
Identifying childhood cognitive processes that predict adolescent problem behaviors can help guide understanding and prevention of these behaviors. In a community sample of 313 youth recruited in a small Midwestern city between 2006 and 2012 (49% male, 64% European American), executive control and foundational cognitive abilities were assessed at age 5 in a lab setting with performance-based measures. In adolescence, youth provided self-report of problem behaviors in surveys administered annually between ages 14 and 16. Executive control was negatively associated with externalizing behavior problems and adolescents getting in trouble at school, accounting for foundational cognitive abilities and family background covariates. Executive control had negative but nonsignificant associations with internalizing problems and substance use initiation. The findings point to deficits in executive control as a childhood risk factor for later problems and a potential target for preventive interventions
- ā¦