A look at this week's top stories from across Penn State:

PRESIDENT'S BLOG: Despite years of efforts to address the problems plaguing Greek-letter organizations, including excessive drinking, hazing and sexual assaults, Penn State President Eric Barron writes in his latest blog post how troubling behavior persists.

EARTH DAY: Events across Penn State's campuses are celebrating Earth Day throughout April.

LEARFIELD CUP: Penn State's athletic teams helped the University to remain at a No. 5 ranking in the second winter sports compilation of the Learfield Directors' Cup standings.

SCIENCE EXPO: The Blue-White Science Expo on April 22 will offer the community a chance to show their support for research while learning about the newest work from research faculty.

ONLINE PERSONAS: A research team is theorizing that people create different personas as part of a desire to fit within the distinctive culture or etiquette of each social media website.

EXERCISE ADDICTION: Penn State researchers look into whether it is possible for people to become addicted to exercise.

DUAL-TITLE DEGREE: The food science graduate program will offer the International Agriculture and Development dual-title degree, a course of study that will provide students with international perspectives and expertise to strengthen their primary graduate degree.

CAFÉ RAVE: The Pennsylvania Restaurant and Lodging Association offered a rave review for Penn State hospitality management students who hosted a luncheon for the organization at Café Laura, the School of Hospitality Management's "living lab" in Mateer Building.