Applying principal component pursuit to investigate the association between source-specific fine particulate matter and myocardial infarction hospitalizations in New York City.

Unlabelled: The association between fine particulate matter (PM) and cardiovascular outcomes is well established. To evaluate whether source-specific PM is differentially associated with cardiovascular disease in New York City (NYC), we identified PM sources and examined the association between source-specific PM exposure and risk of hospitalization for myocardial infarction (MI).

Methods: We adapted principal component pursuit (PCP), a dimensionality-reduction technique previously used in computer vision, as a novel pattern recognition method for environmental mixtures to apportion speciated PM to its sources.

Can weather help explain 'why now?': The potential role of hourly temperature as a stroke trigger.

Background: While evidence suggests that daily ambient temperature exposure influences stroke risk, little is known about the potential triggering role of ultra short-term temperature.

Methods: We examined the association between hourly temperature and ischemic and hemorrhagic stroke, separately, and identified any relevant lags of exposure among adult New York State residents from 2000 to 2015. Cases were identified via ICD-9 codes from the New York Department of Health Statewide Planning and Reearch Cooperative System.