Tues. Oct. 23. 6:30 pm. Science Lecture Series Fall 2012. Expanding Deserts: A Global Concern. “Desertification: A Perspective from the UNCCD Drylands Ambassador” by Leila Lopes, UN Ambassador to the United Nations Convention to Combat Desertification and Miss Universe 2011. A native of Angola, Ms. Lopes will discuss the impact of desertification, land degradation and drought and the importance of sustainable land management. Supported by Sara and Don Nelson and the Marjorie Sims Lawrence Fund. Reservations are strongly suggested. Call 203-413-6757. The lecture is free to Museum members and students with ID. Non-members: $5 at the door. Refreshments precede the lecture, which begins promptly at 7 pm.