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DTSTAMP:20251017T140157Z
DESCRIPTION:Understanding the spatio-temporal distribution of pollen in Tor
 onto\n\nSara Zapata-Marin\, ºÚÁÏÉç\n	Tuesday November 15\, 12-1p
 m\n	Zoom Link: https://mcgill.zoom.us/j/86855481591\n\nAbstract: Many peopl
 e around the world suffer from respiratory allergies during the pollen sea
 son. Nowadays\, some apps can tell us the pollen levels in a city based on
  the measurement of a single monitoring site. However\, one monitoring sit
 e is not enough to describe what happens in the entire city.\n\nMy Ph.D. r
 esearch focused on developing spatio-temporal models to investigate the di
 stribution of different types of pollen across Toronto. Available data con
 sist of daily and weekly measurements of pollen concentration collected be
 tween March and October 2018 across 18 fixed monitoring sites. Measurement
 s of tree\, weed\, grass\, and total pollen concentration were obtained da
 ily for eleven sites and weekly for the other seven sites.\n\nIn the first
  part of the project\, we modeled the weekly concentration for all pollen 
 types. Instead of considering the temporal window with only positive value
 s\, a hurdle model was proposed to account for the high number of measurem
 ents equal to zero. This allowed us to estimate the probability of the pre
 sence of different pollen types at any given week. Additionally\, a dynami
 c linear model was used to capture the city's weekly trend of pollen conce
 ntration.\n\nIn the second part of the project\, rather than aggregating t
 he data to the weekly scale\, a temporal misalignment model was proposed t
 o account for the difference in temporal scale across sites\, borrowing st
 rength from sites with available daily data.\n\nHigher levels of tree poll
 en were found at the beginning of the pollen season\, followed by an incre
 ase in grass and weed pollen as the season progressed. The predicted surfa
 ces obtained in this project will help inform future health-related studie
 s.\n
DTSTART:20221115T170000Z
DTEND:20221115T180000Z
SUMMARY:QLS Seminar Series - Sara Zapata-Marin
URL:/qls/channels/event/qls-seminar-series-sara-zapata
 -marin-343199
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