A model-free control strategy for an experimental greenhouse with an application to fault accommodation

Writing down mathematical models of agricultural greenhouses and regulating them via advanced controllers are challenging tasks since strong perturbations, like meteorological variations, have to be taken into account. This is why we are developing here a new model-free control approach and the corresponding intelligent controllers, where the need of a good model disappears. This setting, which has been introduced quite recently and is easy to implement, is already successful in many engineering domains. Tests on a concrete greenhouse and comparisons with Boolean controllers are reported. They not only demonstrate an excellent climate control, where the reference may be modified in a straightforward way, but also an efficient fault accommodation with respect to the actuators

On the model-free control of an experimental greenhouse

International audienceIn spite of a large technical literature, an efficient climate control of a greenhouse remains a very difficult task. Indeed, this process is a complex nonlinear system with strong meteorological disturbances. The newly introduced ''model-free control'' setting is employed here. It is easy to implement, and has already shown excellent performances in many other concrete domains. Successful experimental tests are presented and discussed. They are compared to a Boolean approach, which is often utilized in practice

Model-free control and fault accommodation for an experimental greenhouse

International audienceThe greenhouse climate control is important in modern agriculture. It is also rather difficult to design: as a matter of fact writing down a "good" mathematical model, which takes into account strong meteorological disturbances, might be an impossible task. The control is here synthesized via a new "model-free" setting, which yields an "intelligent" proportional feedback controller, the tuning of which is straightforward, and even simpler than the intelligent proportional-integral controller, which was already utilized in a previous publication. Our control strategy is successfully tested via an experimental greenhouse. The comparison with the classic Boolean approach, which is popular among manufacturers, demonstrates the superiority of our viewpoint, which permits moreover an efficient actuator fault accommodation. It might be the first model-free fault-tolerant control, which works satisfactorily in practice

Contraction-free proofs and finitary games for Linear Logic

In the standard sequent presentations of Girard's Linear Logic (LL), there are two "non-decreasing" rules, where the premises are not smaller than the conclusion, namely the cut and the contraction rules. It is a universal concern to eliminate the cut rule. We show that, using an admissible modification of the tensor rule, contractions can be eliminated, and that cuts can be simultaneously limited to a single initial occurrence. This view leads to a consistent, but incomplete game model for LL with exponentials, which is finitary, in the sense that each play is finite. The game is based on a set of inference rules which does not enjoy cut elimination. Nevertheless, the cut rule is valid in the model.Comment: 19 pages, uses tikz and Paul Taylor's diagram

Utilisation des communautés d’oligochètes pour l’évaluation de la qualité biologique et du fonctionnement des cours d’eau : un bilan à partir de données genevoises (Suisse)

Use of oligochaete communities for the assessment of the biological quality and the functioning of watercourses : a review of data from the Geneva area (Switzerland). – Oligochaetes are used in some cantons in Switzerland to assess the biological quality of watercourse and lake sediments. The oligochaete index of sediment bioindication (IOBS) allows to assess the quality of fine/sandy sediments of watercourses, while the Functional traits method (TRF) is dedicated to assess the quality of surficial coarse sediments and of the hyporheic zone. The TRF method also allows to know the dynamics of hydrological exchanges between surface water and groundwater. In the Geneva area, the IOBS index was applied in routine from 2008 to 2013 (92 samples) and the TRF method was tested in 2012 and 2013. The IOBS index proved to be a good bioindicator of chemical quality of the sediments. Metal toxicity thresholds in sediments were established and proposed. The implementation of the IOBS index in complement to the Swiss Biotic Index (IBCH) allowed to refine the ecological diagnostics. The TRF approach proved to be of great interest to simultaneously assess the biological quality of coarse habitats and of the vertical hydrological exchanges. The IOBS and TRF methods should be more integrated in the monitoring programs of watercourse quality. The current development of methods based on the identification of oligochaetes using genetic barcodes could allow to overcome the problems related to the morphological identification of species and a wider use of oligochaetes as bioindicators

Assessment of the effects of wastewater treatment plant effluents on receiving streams using oligochaete communities of the porous matrix

Human activities can disturb the natural dynamics of exchanges between surface water and groundwater in rivers. Such exchanges contribute to the self-purification of the environment and an excess of infiltration can lead to contamination of groundwater. In addition, the porous matrix (coarse surface sediments and hyporheic zone), through which water exchanges occur, is a sink for pollutants. For environmental monitoring programs, it is therefore essential to take into account both the dynamics of vertical hydrological exchanges and the biological quality of this matrix. The functional trait (FTR) method, which is based on the study of oligochaete communities in coarse surface sediments and the hyporheic zone, was proposed as a tool to simultaneously assess the dynamics of vertical hydrological exchanges and the effects of pollutants present in the porous matrix. Here, we applied this method during two different periods (in March and September 2016), upstream and downstream of locations affected by discharges from wastewater treatment plants (WWTP) located in Switzerland. The biological quality of surface sediments and the hyporheic zone was shown to be better upstream of the WWTP in both campaigns. In addition, results suggested that the capacity for self-purification was lower downstream of the WWTP, and that groundwater at these locations was vulnerable to pollution by surface water. The FTR method proved valuable as a field method for detecting the effects of point source contamination on receiving streams. In the near future, this community-based approach will benefit from advances in the use of DNA barcodes for oligochaete species identification

Characterization of a nuclear pore protein sheds light on the roles and composition of the Toxoplasma gondii nuclear pore complex

International audienceThe nuclear pore is a key structure in eukaryotes regulating nuclear-cytoplasmic transport as well as a wide range of cellular processes. Here, we report the characterization of the first Toxoplasma gondii nuclear pore protein, named TgNup302, which appears to be the orthologue of the mammalian Nup98-96 protein. We produced a conditional knock-down mutant that expresses TgNup302 under the control of an inducible tetracycline-regulated promoter. Under ATc treatment, a substantial decrease of TgNup302 protein in inducible knock-down (iKD) parasites was observed, causing a delay in parasite proliferation. Moreover, the nuclear protein TgENO2 was trapped in the cytoplasm of ATc-treated mutants, suggesting that TgNup302 is involved in nuclear transport. Fluorescence in situ hybridization revealed that TgNup302 is essential for 18S RNA export from the nucleus to the cytoplasm, while global mRNA export remains unchanged. Using an affinity tag purification combined with mass spectrometry, we identified additional components of the nuclear pore complex, including proteins potentially interacting with chromatin. Furthermore, reverse immunoprecipitation confirmed their interaction with TgNup302, and structured illuminated microscopy confirmed the NPC localization of some of the TgNup302-interacting proteins. Intriguingly, facilitates chromatin transcription complex (FACT) components were identified, suggesting the existence of an NPC-chromatin interaction in T. gondii. Identification of TgNup302-interacting proteins also provides the first glimpse at the NPC structure in Apicomplexa, suggesting a structural conservation of the NPC components between distant eukaryotes

Inpatient mother-and-child postpartum psychiatric care: factors associated with improvement in maternal mental health.

International audiencePURPOSE: This study assessed the underexplored factors associated with significant improvement in mothers' mental health during postpartum inpatient psychiatric care. METHODS: This study analyzed clinical improvement in a prospective cohort of 869 women jointly admitted with their infant to 13 psychiatric Mother-Baby Units (MBUs) in France between 2001 and 2007. Predictive variables tested were: maternal mental illness (ICD-10), sociodemographic characteristics, mental illness and childhood abuse history, acute or chronic disorder, pregnancy and birth data, characteristics and mental health of the mother's partner, and MBU characteristics. RESULTS: Two thirds of the women improved significantly by discharge. Admission for 25% was for a first acute episode very early after childbirth. Independent factors associated with marked improvement at discharge were bipolar or depressive disorder, a first acute episode or relapse of such an episode. Schizophrenia, a personality disorder, and poor social integration (as measured by occupational status) were all related to poor clinical outcomes. DISCUSSION: Most women improved significantly while under care in MBUs. Our results emphasize the importance of the type of disease but also its chronicity and the social integration when providing postpartum psychiatric care

Temperature extremes of 2022 reduced carbon uptake by forests in Europe

The year 2022 saw record breaking temperatures in Europe during both summer and fall. Similar to the recent 2018 drought, close to 30% (3.0 million km2) of the European continent was under severe summer drought. In 2022, the drought was located in central and southeastern Europe, contrasting the Northern-centered 2018 drought. We show, using multiple sets of observations, a reduction of net biospheric carbon uptake in summer (56-62 TgC) over the drought area. Specific sites in France even showed a widespread summertime carbon release by forests, additional to wildfires. Partial compensation (32%) for the decreased carbon uptake due to drought was offered by a warm autumn with prolonged biospheric carbon uptake. The severity of this second drought event in 5 years suggests drought-induced reduced carbon uptake to no longer be exceptional, and important to factor into Europe’s developing plans for net-zero greenhouse gas emissions that rely on carbon uptake by forests