Department of Mathematics and Statistics

Colloquium for Fall 2021

If you are interested in giving a talk, please email Dr. Nick Lytal (

Colloquia are typically held on Friday in Holt 171.  Refreshments are served at 3:45pm and the talk begins at 4:00pm.  Everyone is invited to attend. 

Join us via Zoom! Link to Colloquium Meeting Room (Meeting ID: 530 898 5800; Passcode: SRSTRAND)(opens in new window)

Past Colloquium Schedules(opens in new window)

Friday, Dec 3 -- Holt 171 and Zoom, 4:00pm

Jane Guo, CSU, Chico

The recent COVID-19 pandemic has caused the loss of many lives worldwide. In the US, as of April 10, 2021, there have been more than 30 million accumulative confirmed cases and more than 550,000 reported COVID-19 related fatalities. Existing published studies presented the clustering results based on incidence and mortality information at different levels, including country and county levels. With the availability and accessibility of the COVID- 19 vaccines, it is essential to characterize the clustering features at the state- level using the information including the number of COVID-19 cases per 100 thousand in the last seven days, testing positivity rate in the last seven days, deaths per 100k in the last seven days as well as the vaccination rates. In the present study, we use principal component analysis to extract features from highly correlated data such as state-level incidence and mortality, as well as vaccination. We further performed hierarchical cluster analysis based on extracted features from state-level COVID-19 data. The presented cluster results could contribute to the pandemic management, including the policy- making process and health education program.

CSU Math Education Colloquium Series 2021: Developing an Access- and Equity-Oriented Mindset in Mathematics Teaching and Learning

This year, for the month of November we are pleased to have you join us for the CSU Math and Math Education Colloquium Series: Developing an Access- and Equity-Oriented Mindset in Mathematics Teaching and Learning!

We are deeply grateful for this year’s colloquium presenters: Daniel Reinholz, Marta Civil, Judit Moschkovich, Bill Zahner, Mark Ellis, and Emily Bonner, for sharing their expertise and providing us a rich opportunity for learning and discourse around access and equity in mathematics.

Below, you will find the dates and times for colloquium evenings and the Zoom Link to access the series(opens in new window).

  • Nov 5, 2021, 4:00-6:00 PM PST

    Topic: Access and Equity Perspectives and Practices in Mathematics Teaching and Learning</strong

  • Nov 12, 2021, 4:00-6:00 PM PST

    Topic: Academic Literacy and Language in Mathematics from an Access and Equity Lens

  • Nov 19, 2021, 4:00-6:00 PM PST

    Topic: Culturally Relevant Mathematics Teaching from an Access and Equity Perspective

Join Zoom Meeting(opens in new window)
Meeting ID: 874 6807 2900
Passcode: 077818

For more information about presentations and topics, please visit the CSU Colloquium Series website at in new window).

Our usual room (HOLT 171) will open at 3:45 PM for those in person to meet and enjoy refreshments. We hope to see you all there!

Friday, Oct 15 -- Holt 171 and Zoom, 4:00pm

Ricardo Aguilar, MS (UCLA)
Fuzzier Forests: Identifying Interactions

Fuzzy forests are a computationally feasible feature selection method for correlated, high dimensional data.  This presentation introduces new capabilities to fuzzy forests that allow researchers to identify interactions among features.  In particular, these methods identify interactions within and across modules. Although random forest variable importance measures can account for interactions, users are unable to identify those interactions from the resulting output. Knowing which features are involved in interactions can elucidate the relationships of the features in the model. The performance of the across and within methods was evaluated using simulated data. The two methods can reliably select the interaction terms included in the true regression models. Additionally, an informal assessment for the interchangeability of correlated features provides evidence that, when using variable importance for feature selection as opposed to maximizing predictive accuracy, the correlated features do not act as proxies for one another.

Friday, Oct 8 -- Holt 171 and Zoom, 4:00pm

Nicholas Lytal (Chico State University)
An Introduction to Single-Cell RNA Sequencing and Related Topics

Abstract: In the field of Bioinformatics, single-cell RNA-sequencing (scRNA-seq) is a subject of recent interest that explores differences among tissue samples on a cell-by-cell basis rather than as a whole. This process has applications in fields such as cancer research, embryonic studies, and more. However, sampling on such a scale has restrictions that often limit the power of scRNA-seq results. 

In this talk, we will explore the basics behind scRNA-seq, as well as some of the statistical methods that have been developed to improve its results.