When response-contingent delivery of nicotine and its associated visual cues were both discontinued, response rates decreased to very low levels (Figure 4c and d, 'Vehicle+No cues' conditions).
Next, mice were trained to press one of 2 levers to receive response-contingent delivery of the US (Figure 1A, center).
Acute cocaine or AMPH exposure reduces DYN peptide levels in the DS [ 348] and increases DYN mRNA expression in the DS, but not the NAc, and has no effect on ENK mRNA in either region [ 349, 350].. Chronic cocaine or AMPH administration (either self-administered or "yoked" non-contingent delivery) increases DYN mRNA expression in the DS, but not the NAc [ 348, 351].
After achieving >70% correct responding using these parameters, tone duration was finally decreased to 2 s with a single lever press contingent sucrose delivery of 40 µl.
In addition self-administered drugs induce striatal ACh release, which is greater compared to non-contingent drug delivery [ 408- 410].
Following successful sucrose consumption under non-contingent reward delivery conditions, subjects were trained to press a right forepaw lever to receive sucrose reinforcement.
On the other hand, chronic cocaine administration (either self-administered or non-contingent "yoked" delivery) has no effect on DYN or ENK mRNA in the CeA [ 351].
A fixed-time 120-s (FT-120-s) schedule of non-contingent water delivery was operated while the levers were retracted at the start of training; shaping ended on a variable interval 20-s (VI-20-s) schedule.
If the freight revenue is contingent upon safe delivery of the goods, the carrier insures the freight as a part of the regular hull coverage.
"This is why our childcare initiative for families is contingent on the delivery of savings to pay for it, because we can't have the spending without the saving to make it sustainable," he said.
A meta-analysis of the studies suggests that impact of decentralization on public service delivery is contingent on factors such as the design of the decentralization policy; implementation bottlenecks and diluting the model of decentralization for accommodating the dissenting segments of stakeholders including employees; and participatory governance.
