Unique stable isotope signatures of large cyclonic events as a tracer of soil moisture dynamics in the semiarid subtropics

Evaporative flux from soils in arid and semi-arid climates can be very high and may substantially reduce soil moisture retained between infrequent rainfall events. Direct measurement of the evaporative losses from soils is technically challenging. However, environmental tracers such as water stable hydrogen and oxygen isotope composition can be used to calculate evaporation rates if the initial signature of the infiltrating rainwater is distinct from the signature of residual soil moisture. Large tropical cyclones typically result in rainfall events of large volume and very negative δ18O signatures that are significantly lower than the signatures of more frequent and smaller rainfall events. These very negative stable isotope signatures are retained in the soil and can be used to understand the depth of water infiltration, retention and subsequent rate of evaporation from the soil. At our study site in dry subtropical northwest Australia, we repeatedly sampled rainwater and soil moisture prior to, during and after tropical Cyclones Heidi and Lua in 2012. Site inundation from Cyclone Heidi (rainfall 213 mm, δ18O −17.6‰) replenished soil moisture in the unsaturated zone for several months, completely replacing soil moisture down to depths of ~3.5 m and contributing to groundwater recharge. The transient momentary evaporative losses from wet soil at the time of sampling varied between 0.21 and 0.60 mm × day−1 (equivalent to 76 to 220 mm × yr−1 recalculated as an annual rate). During the prolonged dry period between cyclones, evaporative losses decreased to between 8 and 30 mm × yr−1. Mean long-term groundwater recharge for the study site was low (−1). Recharge is primarily driven by infrequent but high-volume cyclones that are an important source of soil moisture and an essential water source for vegetation in this semi-arid environment. However, variation in lithology, position in the landscape and time since the last inundation contribute to highly heterogeneous patterns of δ18O in the vadose zone, which complicates upscaling observations from a local to a regional scale model of evaporative demand

Interaction between photoperiod and variation in circadian rhythms in tomato

12 Pág.Many biological processes follow circadian rhythmicity and are controlled by the circadian clock. Predictable environmental changes such as seasonal variation in photoperiod can modulate circadian rhythms, allowing organisms to adjust the timing of their biological processes to the time of the year. In some crops such as rice, barley or soybean, mutations in circadian clock genes have altered photoperiod sensitivity, enhancing their cultivability in specific seasons and latitudes. However, how changes in circadian rhythms interact with the perception of photoperiod in crops remain poorly studied. In tomato, the appearance during domestication of mutations in EMPFINDLICHER IM DUNKELROTEN LICHT 1 (EID1, Solyc09g075080) and NIGHT LIGHT-INDUCIBLE AND CLOCK-REGULATED GENE 2 (LNK2, Solyc01g068560) delayed both the phase and period of its circadian rhythms. The fact that variation in period and phase are separated in tomato provides an optimal tool to study how these factors affect the perception of photoperiod.This research was funded by Saclay Plant Sciences grant SPS-2020-LIGHT. Funding for X.Y., P.R and T.S. was provided by ANR grants ANR-18-CE92-0039–01 and ANR-17-CE20-0024–02.Peer reviewe

El trabajo de las mujeres en España

En España, el desarrollo de la historia de las mujeres a lo largo de los años 80 coincidió con los profundos cambios que afectaron a la sociedad en el proceso de transición a la democracia. Después de la transición, las reivindicaciones feministas se han dirigido especialmente al acceso al mercado laboral y el reconocimiento de la aportación femenina a la economía. Esta concomitancia contribuye a explicar que la atención de los historiadores se haya dirigido desde época muy temprana al lugar que ocupan las mujeres en las actividades de servicio y producción, sean asalariadas o no. Aunque es evidente que aún no puede realizarse un balance de resultados, el dossier incluido en este número permite apreciar los progresos alcanzados en esta cuestión. Más que una evolución lineal, los autores han intentado mostrar la variedad de situaciones, la diversidad de fuentes y las implicaciones heurísticas de este campo de estudio. En Espagne, le développement de l’histoire des femmes, dans les années 1980, est contemporain des profonds changements qui ont affecté la société après l’avènement de la démocratie. Aux lendemains de la Transition, les revendications féministes ont porté, tout particulièrement, sur l’accès au marché du travail et sur la reconnaissance de la contribution féminine à l’économie. Cette concomitance contribue à expliquer que l’attention des historiens se soit portée très tôt sur la place des femmes dans les activités de service et de production, qu’elles soient salariées ou pas. Sans doute l’heure n’est-elle pas encore au bilan, mais le dossier présenté dans ce numéro permet d’apprécier les progrès accomplis sur cette question. Plus qu’une évolution linéaire, c’est la variété des situations, la diversité des sources et les enjeux heuristiques de ce champ d’étude que les auteurs ont cherché à montrer. Female labour in Spain (from ancient times to the 20th century) In Spain, the history of women in the 1980s developed in parallel with profound changes, which have affected that society since the advent of democracy. In the wake of the Transition, feminist demands laid particular stress on access to the labour market and recognition of the contribution of women to the economy. This coincidence helps to explain why the attention of historians was quick to focus on the place of women in service and productive activities, as employees or otherwise. It is obviously too early yet to draw up a balance, but the dossier presented in this edition does give an idea of the progress that has been made on this question. Rather than a line of progress, what the authors have sought to illustrate is the variety of the situations, the diversity of the sources and the heuristic challenges posed by this field of study

Firefly: The Case for a Holistic Understanding of the Global Structure and Dynamics of the Sun and the Heliosphere

This white paper is on the HMCS Firefly mission concept study. Firefly focuses on the global structure and dynamics of the Sun's interior, the generation of solar magnetic fields, the deciphering of the solar cycle, the conditions leading to the explosive activity, and the structure and dynamics of the corona as it drives the heliosphere