From NASA's Socioeconomic Data and Applications Center (SEDAC), I found this dataset: Gridded Population of the World (GPW), v4.
30 arc-second (approx 1 km) native resolution, which is aggregated to four lower resolutions:
2.5 arc-minute (approx 5 km)
15 arc-minute (approx 30 km)
30 arc-minute (approx 55 km)
1 degree (approx 110 km)
You can now download certain historical datasets for the US directly within R, using the USABoundaries package. The code to do so is straightforward. For example, to download a shapefile containing the boundaries of US counties in 1910:
map <- us_counties(map_date = "1910-01-01", resolution = "high")
st_write(obj = map,...
I found a portal that lists PhD topics, coincidentally called "find a phd"
returns these 3 PhD programs (2019-03-12):
University of East Anglia, School of Environmental Sciences
University of Bath, Centre for Accountable, Responsible and Transparent AI
Northumbria University, Faculty of Business ...