Capability of meteorological drought indices for detecting soil moisture droughts

Study region Eastern Australia Study focus Long-term monitoring of soil moisture is a time- and cost-intensive challenge. Therefore, meteorological drought indices are commonly used proxies of periods of significant soil moisture deficit. However, the question remains whether soil moisture droughts can be adequately characterised using meteorological variables such as rainfall and potential evaporation, or whether a more physically based approach is required. We applied two commonly used drought indices – the Standardized Precipitation Index and the Reconnaissance Drought Index – to evaluate their performance against soil moisture droughts simulated with the numerical soil water model Hydrus-1D. The performance of the two indices was measured in terms of their correlation with the standardised simulated monthly minimum soil water pressures, and their capability to detect soil moisture droughts that are potentially critical for plant water stress. New hydrological insights for the region For three typical soil types and climate zones in Eastern Australia, and for two soil profiles, we have found a significant correlation between the indices and soil moisture droughts detected by Hydrus-1D. The failure rates and false alarm rates for detecting the simulated soil moisture droughts were generally below 50% for both indices and both soil profiles (the Reconnaissance Drought Index at Melbourne was the only exception). However, the complexity of Hydrus-1D and the uncertainty associated with the available, regionalised soil water retention curves encourage using the indices over Hydrus-1D in absence of appropriate soil moisture monitoring data

Consolidated and labile odor memory are separately encoded within the drosophila brain

Memories are classified as consolidated (stable) or labile according to whether they withstand amnestic treatment, or not. In contrast to the general prevalence of this classification, its neuronal and molecular basis is poorly understood. Here, we focused on consolidated and labile memories induced after a single cycle training in the Drosophila aversive olfactory conditioning paradigm and we used mutants to define the impact of cAMP signals. At the biochemical level we report that cAMP signals misrelated in either rutabaga (rut) or dunce (dnc) mutants separate between consolidated anesthesia-resistant memory (ARM) and labile anesthesia-sensitive memory (ASM). Those functionally distinct cAMP signals act within different neuronal populations: while rut-dependent cAMP signals act within Kenyon cells (KCs) of the mushroom bodies to support ASM, dnc-sensitive cAMP signals support ARM within antennal lobe local neurons (LNs) and KCs. Collectively, different key positions along the olfactory circuitry seem to get modified during storage of ARM or ASM independently. A precise separation between those functionally distinct cAMP signals seems mandatory to allocate how they support appropriate memories