Mamma Mia Instrumental Download ((TOP))

Prenatal treatment of rats on gestation day 15 with methylazoxymethanol (MAM) caused forebrain microencephaly. The behavioral analyses included measures of spontaneous motor activity and tests for cognitive deficits, and were performed when the rats had reached adult age. Female MAM-treated rats failed to demonstrate contextual control of latent inhibition, which confirms earlier findings with male rats. Male MAM-treated rats demonstrated a notable impairment of place navigation in a swim-maze, but showed as strong sensory preconditioning as the control animals. Biochemical analyses indicated considerable increases in catecholamine levels in the cerebral cortex, hippocampus and striatum. The cognitive deficits, characterised by the various conditioning (taste-aversion) and instrumental learning (swim-maze) tasks, suggested that the MAM rats are deficient in their capacity to attend selectively to the relevant stimulus in complex arrangements of the stimulus situation.

An understanding of tropical hydroclimate variability, the associated drivers and how it is likely to change is a major scientific and societal challenge that is acutely hampered by short instrumental records. We present a 246-year tree-ring drought reconstruction of the Standardised Precipitation Evaporation Index (SPEI) for monsoonal northern Australia for the end of the wet season (March-May; MAM). This reconstruction extends the instrumental record back by 150 years. Around one third of total annual rainfall falls during MAM, making it a crucial component of the monsoonal cycle. MAM is also the season most impacted by the differential decay process of Central Pacific (as opposed to Western Pacific) El Nio events that are linked with dry conditions over northern and northwestern Australia more generally. Our reconstruction therefore provides an opportunity to consider how central Pacific variability has modulated MAM hydroclimate in Australia's monsoonal north over the past two and a half centuries. We found that MAM hydroclimate extremes in the region have a strong, but asymmetric relationship with central Pacific sea surface temperatures (SSTs) and ENSO indices. Extremely wet MAMs in monsoonal north Australia were associated with cooler SSTs, above average rainfall across much of Australia, and often coincided with La Nia events. The spatial relationship between dry extremes and Pacific SSTs during dry events was generally, but weakly, consistent with the SST signature of central Pacific El Nio events. The association between reconstructed dry extremes in the monsoonal north and dry conditions across the rest of Australia is also less extensive and weaker than for wet events. Results suggest that more extreme wet events in the Australian monsoonal north likely reflect cool central Pacific SSTs and later termination of the Australian monsoon. Consecutive years with extremely dry MAMs became more frequent over the latter part of the 20th Century while the probability of an extreme dry MAM followed by an extreme wet MAM the next year peaked in the mid 20th Century and has since declined.