Results 61 to 70 of about 2,980 (171)

Evaluating Causal Links Between Chlorophyll a and Environmental Data in the Illinois River (USA)

Ecology and Evolution, Volume 16, Issue 4, April 2026.
Chlorophyll a is widely used as a proxy for algal abundance due to its universality among algae and the practicality of measuring it with in situ sensors. In this study, we analyzed high‐frequency chlorophyll a and water quality data from the Illinois River to assess relationships between algal abundance and environmental drivers using both statistical
James H. Larson, Lynn A. Bartsch, Kathi Jo Jankowski, Jennifer C. Murphy, Rebecca M. Kreiling   +4 more
wiley   +1 more source

Codd's Theorem for Databases over Semirings

Proceedings of the ACM on Management of Data
Codd's Theorem, a fundamental result of database theory, asserts that relational algebra and relational calculus have the same expressive power on relational databases. We explore Codd's Theorem for databases over semirings and establish two different versions of this result for such databases: the first version involves the five basic operations of ...
Guillermo Badia, Phokion G. Kolaitis, Carles Noguera   +2 more
openaire   +3 more sources

OBITUARY

Bothalia: African Biodiversity & Conservation, 1988
ROBERT ALLEN DYER (1900-1987)
L. E. Codd
doaj   +1 more source

LILIACEAE

Bothalia: African Biodiversity & Conservation, 1986
NOTES ON ...
L. E. Codd
doaj   +1 more source

LAMIACEAE

Bothalia: African Biodiversity & Conservation, 1982
A NEW SUBSPECIES IN ...
L. E. Codd
doaj   +1 more source

OBITUARY

Bothalia: African Biodiversity & Conservation, 1983
JAN ERENS (1911-1982)
L. E. Codd
doaj   +1 more source

Notes on Certain South African Erythrina Species.

Bothalia: African Biodiversity & Conservation, 1956
No abstract ...
L. E. Codd
doaj   +1 more source

Commercialisation potential of Tetradenia riparia (Hochst.) Codd: A review based on traditional uses and scientific validation

Journal of Medicinal Plants for Economic Development
Background: Globally, medicinal plants and their health-related products provide significant income and are recognised as important contributors to livelihoods. There still exist challenges in the commercialisation of certain medicinal plants over others.
Sithembiso L. Ndwandwe, Sechene S. Gololo   +1 more
doaj   +1 more source

LAMIACEAE

Bothalia: African Biodiversity & Conservation, 1984
A NEW SPECIES OF ...
L. E. Codd
doaj   +1 more source

Celastraceae

Bothalia: African Biodiversity & Conservation, 1973
Author Citation For Putterlickia ...
L. E, Codd
doaj   +1 more source