It could be possible to test this hypothesis, by delaying reward receipt in the Liquid condition (e.g., accumulating rewards across trials and delivering at the end of the block).
Liquid nitrogen stocks were made upon receipt and maintained until the start of each study.
Blood samples were centrifuged, separated into plasma and buffy coat, and stored in −80 °C freezers on the day of receipt before transfer to liquid nitrogen tanks for long-term storage.
However, an alternative interpretation of the effects is that they reflect the direct and immediate receipt of rewards in the Liquid condition, rather than something about the category of reinforcer per se.
Like banks, government liabilities are much more liquid than their assets -- largely future tax receipts.
Liquid or semisolid stool samples were tested within 24 h of receipt.
On receipt, the blood samples were centrifuged, aliquoted, and stored in liquid nitrogen freezers at -70°F (-57°C).
Buccal samples are logged in on receipt, the DNA is extracted, and the extracted DNA is archived in liquid nitrogen freezers using specific tracking software.
Upon receipt, blood samples were immediately centrifuged, aliquoted into plasma, and stored in continuously monitored liquid nitrogen freezers (−130 °C or below).
Receipt of antenatal and postnatal iron supplementation by the mother was evaluated: mothers were shown bottles (liquid formulations) and strips (tablets) of iron supplements and asked to recall if they had received these.
