Two-way feedback between chromatin compaction and histone modification state explains heterochromatin bistability.

Compact chromatin is closely linked with gene silencing in part by sterically masking access to promoters, inhibiting transcription factor binding and preventing polymerase from efficiently transcribing a gene. However, a broader hypothesis suggests that chromatin compaction can be both a cause and a consequence of the locus histone modification state, with a tight bidirectional interaction underpinning bistable transcriptional states. To rigorously test this hypothesis, we developed a mathematical model for the dynamics of the locus in , that incorporates activating histone modifications, silencing proteins, and a dynamic, acetylation-dependent, three-dimensional locus size.

Two-way feedback between chromatin compaction and histone modification state explains heterochromatin bistability.

Compact chromatin is closely linked with gene silencing in part by sterically masking access to promoters, inhibiting transcription factor binding and preventing polymerase from efficiently transcribing a gene. Here, we propose a broader view: chromatin compaction can be both a cause and a consequence of the histone modification state, and this tight bidirectional interaction can underpin bistable transcriptional states. To test this theory, we developed a mathematical model for the dynamics of the HMR locus in , that incorporates activating histone modifications, silencing proteins and a dynamic, acetylation-dependent, three-dimensional locus size.

Distinct silencer states generate epigenetic states of heterochromatin.

Heterochromatic loci can exhibit different transcriptional states in genetically identical cells. A popular model posits that the inheritance of modified histones is sufficient for inheritance of the silenced state. However, silencing inheritance requires silencers and therefore cannot be driven by the inheritance of modified histones alone.

The Effect of Postpartum Depressive Symptoms (PDS) on Maternal Health Practices After Childbirth, Texas Pregnancy Risk Assessment Monitoring System, 2012-2015.

Objectives: This study examined the contribution of postpartum depressive symptoms (PDS) on select maternal health practices among Texas women, using 2012-2015 survey data from the Pregnancy Risk Assessment Monitoring System.

Methods: Multiple logistic regression was used to assess the effect of PDS on postpartum checkups, postpartum dental visits, and use of postpartum birth control. Covariates included maternal age, race/ethnicity, marital status, education, and depression before birth.

It takes a community to save a life in cardiac arrest: Heart safe community pilots, Australia.

Issue Addressed: In Australia only 1 in 12 people will survive an out of hospital cardiac arrest (OHCA). Heart Safe Community (HSC) is a public health initiative being implemented by the Heart Foundation, Victoria in partnership with Ambulance Victoria. It aims to improve survival from OHCA by improving public access to 24 hours Automated External Defibrillators (AEDs) and by building local community skills and confidence in basic resuscitation.