Future development of apricot blossom blight under climate change in Southern France

International audienceClimate change will have several consequences for agro-systems, one of which will concern changes to the development of pathogens. Because of the losses it causes, particularly in organic farming, Monilinia laxa is an important pathogen affecting apricot crops. This study focuses on the consequences of climate change regarding blossom and twig blight (Monilinia laxa) of apricot. To achieve this, a Climatic Index of cumulated Blight risk (CIB) was built, to obtain the weighted sum of blossom blight incidence throughout the blooming period. An epidemiological model to calculate the incidence of blossom blight during every potentially infectious episode and based on biological parameters, was calibrated using a trap pot experiment where trees were placed in orchards and subject to various meteorological conditions. The CIB derived from this model was evaluated on field data, and was shown to be a robust and useful tool to predict the effects of climate change on the development of apricot blight. Then, using the CIB with a phenological model to predict blooming periods in the future, we estimated the risks of apricot blight until 2100 on four contrasted apricot cultivars and in three geographical zones under climate change scenarios RCP 4.5 and 8.5. This study revealed different effects of climate change depending on the cultivar and altitude. Apricot trees would bloom earlier (up to a difference of 50 days between 1950 and 2100) under climate change. Under the combined effects of these shifts of blooming period and changing climatic conditions, late cultivars such as Bergarouge might see a reduction in the risk of blossom blight (down to 31%) because of warmer but dryer blooming periods. Other varieties (e.g.: Bergeron) could experience an increase in this risk by up to 27% with a shift of the blooming period towards rainier conditions at the highest altitudes. The results of this study could be used to anticipate future changes as well as be used at present as a decision-support tool for farmers

The PREDICT study uncovers three clinical courses of acutely decompensated cirrhosis that have distinct pathophysiology

Acute decompensation (AD) of cirrhosis is defined as the acute development of ascites, gastrointestinal hemorrhage, hepatic encephalopathy, infection or any combination thereof, requiring hospitalization. The presence of organ failure(s) in patients with AD defines acute-on-chronic liver failure (ACLF). The PREDICT study is a European, prospective, observational study, designed to characterize the clinical course of AD and to identify predictors of ACLF. A total of 1,071 patients with AD were enrolled. We collected detailed pre-specified information on the 3-month period prior to enrollment, and clinical and laboratory data at enrollment. Patients were then closely followed up for 3 months. Outcomes (liver transplantation and death) at 1 year were also recorded. Three groups of patients were identified. Pre-ACLF patients (n = 218) developed ACLF and had 3-month and 1-year mortality rates of 53.7% and 67.4%, respectively. Unstable decompensated cirrhosis (UDC) patients (n = 233) required ≥1 readmission but did not develop ACLF and had mortality rates of 21.0% and 35.6%, respectively. Stable decompensated cirrhosis (SDC) patients (n = 620) were not readmitted, did not develop ACLF and had a 1-year mortality rate of only 9.5%. The 3 groups differed significantly regarding the grade and course of systemic inflammation (high-grade at enrollment with aggravation during follow-up in pre-ACLF; low-grade at enrollment with subsequent steady-course in UDC; and low-grade at enrollment with subsequent improvement in SDC) and the prevalence of surrogates of severe portal hypertension throughout the study (high in UDC vs. low in pre-ACLF and SDC). Acute decompensation without ACLF is a heterogeneous condition with 3 different clinical courses and 2 major pathophysiological mechanisms: systemic inflammation and portal hypertension. Predicting the development of ACLF remains a major future challenge. ClinicalTrials.gov number: NCT03056612. Lay summary: Herein, we describe, for the first time, 3 different clinical courses of acute decompensation (AD) of cirrhosis after hospital admission. The first clinical course includes patients who develop acute-on-chronic liver failure (ACLF) and have a high short-term risk of death - termed pre-ACLF. The second clinical course (unstable decompensated cirrhosis) includes patients requiring frequent hospitalizations unrelated to ACLF and is associated with a lower mortality risk than pre-ACLF. Finally, the third clinical course (stable decompensated cirrhosis), includes two-thirds of all patients admitted to hospital with AD - patients in this group rarely require hospital admission and have a much lower 1-year mortality risk

The PREDICT study uncovers three clinical courses of acutely decompensated cirrhosis that have distinct pathophysiology

Background & Aims: Acute decompensation (AD) of cirrhosis is defined as the acute development of ascites, gastrointestinal hemorrhage, hepatic encephalopathy, infection or any combination thereof, requiring hospitalization. The presence of organ failure(s) in patients with AD defines acute-on-chronic liver failure (ACLF). The PREDICT study is a European, prospective, observational study, designed to characterize the clinical course of AD and to identify predictors of ACLF. Methods: A total of 1,071 patients with AD were enrolled. We collected detailed pre-specified information on the 3-month period prior to enrollment, and clinical and laboratory data at enrollment. Patients were then closely followed up for 3 months. Outcomes (liver transplantation and death) at 1 year were also recorded. Results: Three groups of patients were identified. Pre-ACLF patients (n = 218) developed ACLF and had 3-month and 1-year mortality rates of 53.7% and 67.4%, respectively. Unstable decompensated cirrhosis (UDC) patients (n = 233) required ≥1 readmission but did not develop ACLF and had mortality rates of 21.0% and 35.6%, respectively. Stable decompensated cirrhosis (SDC) patients (n = 620) were not readmitted, did not develop ACLF and had a 1-year mortality rate of only 9.5%. The 3 groups differed significantly regarding the grade and course of systemic inflammation (high-grade at enrollment with aggravation during follow-up in pre-ACLF; low-grade at enrollment with subsequent steady-course in UDC; and low-grade at enrollment with subsequent improvement in SDC) and the prevalence of surrogates of severe portal hypertension throughout the study (high in UDC vs. low in pre-ACLF and SDC). Conclusions: Acute decompensation without ACLF is a heterogeneous condition with 3 different clinical courses and 2 major pathophysiological mechanisms: systemic inflammation and portal hypertension. Predicting the development of ACLF remains a major future challenge. ClinicalTrials.gov number: NCT03056612. Lay summary: Herein, we describe, for the first time, 3 different clinical courses of acute decompensation (AD) of cirrhosis after hospital admission. The first clinical course includes patients who develop acute-on-chronic liver failure (ACLF) and have a high short-term risk of death – termed pre-ACLF. The second clinical course (unstable decompensated cirrhosis) includes patients requiring frequent hospitalizations unrelated to ACLF and is associated with a lower mortality risk than pre-ACLF. Finally, the third clinical course (stable decompensated cirrhosis), includes two-thirds of all patients admitted to hospital with AD – patients in this group rarely require hospital admission and have a much lower 1-year mortality risk

PREDICT identifies precipitating events associated with the clinical course of acutely decompensated cirrhosis

Background & Aims: Acute decompensation (AD) of cirrhosis may present without acute-on-chronic liver failure (ACLF) (ADNo ACLF), or with ACLF (AD-ACLF), defined by organ failure(s). Herein, we aimed to analyze and characterize the precipitants leading to both of these AD phenotypes. Methods: The multicenter, prospective, observational PREDICT study (NCT03056612) included 1,273 non-electively hospitalized patients with AD (No ACLF = 1,071; ACLF = 202). Medical history, clinical data and laboratory data were collected at enrolment and during 90-day follow-up, with particular attention given to the following characteristics of precipitants: induction of organ dysfunction or failure, systemic inflammation, chronology, intensity, and relationship to outcome. Results: Among various clinical events, 4 distinct events were precipitants consistently related to AD: proven bacterial infections, severe alcoholic hepatitis, gastrointestinal bleeding with shock and toxic encephalopathy. Among patients with precipitants in the AD-No ACLF cohort and the AD-ACLF cohort (38% and 71%, respectively), almost all (96% and 97%, respectively) showed proven bacterial infection and severe alcoholic hepatitis, either alone or in combination with other events. Survival was similar in patients with proven bacterial infections or severe alcoholic hepatitis in both AD phenotypes. The number of precipitants was associated with significantly increased 90day mortality and was paralleled by increasing levels of surrogates for systemic inflammation. Importantly, adequate first-line antibiotic treatment of proven bacterial infections was associated with a lower ACLF development rate and lower 90-day mortality. Conclusions: This study identified precipitants that are significantly associated with a distinct clinical course and prognosis in patients with AD. Specific preventive and therapeutic strategies targeting these events may improve outcomes in patients with decompensated cirrhosis. Lay summary: Acute decompensation (AD) of cirrhosis is characterized by a rapid deterioration in patient health. Herein, we aimed to analyze the precipitating events that cause AD in patients with cirrhosis. Proven bacterial infections and severe alcoholic hepatitis, either alone or in combination, accounted for almost all (96-97%) cases of AD and acute-on-chronic liver failure. Whilst the type of precipitant was not associated with mortality, the number of precipitant(s) was. This study identified precipitants that are significantly associated with a distinct clinical course and prognosis of patients with AD. Specific preventive and therapeutic strategies targeting these events may improve patient outcomes. (c) 2020 European Association for the Study of the Liver. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Temple building on the Egyptian margins: the geopolitical issues behind Seti II and Ramesses IX’s activity at Amheida

Middle Eastern Studie

Quantification du rôle des prédateurs généralistes dans la régulation du charançon du bananier grâce à de l'analyse d'images prises in situ

The banana weevil Cosmopolites sordidus (Germar Col. Curculionidae) is the most important pest of banana. In order to develop conservation biological control of C. sordidus, it is necessary to identify the species involved and to quantify their impacts in terms of regulation. Conventional methods to estimate the regulation of a pest by its predators are often biased : limited to certain groups, with sampling biases, underestimating certain interactions. In order to limit these biases, this work aims to use in situ images and automatic analysis approach to better understand the food webs related to C. sordidus.Monitored sentinel prey experiments followed by the analysis of the image sequences by convolutional neural networks have been shown to be effective in determining the species present and their interactions (86.6% precision and 88.9% recall for the detection of 21 different species). This method also makes it possible to observe the temporal dynamics of predation events, and non-trophic interactions such as cooperation between individuals of the same species. This method is then improved by integrating a hierarchical classification step in order to improve the robustness of the analyses in the face of constraining biological data sets.On La Reunion Island, experiments with live sentinel prey (adult weevils and eggs) were conducted on five plots. Three thousand hours of observation allowed the capture of 375 000 images. Automatic image analysis (using background subtractio) identified predators and quantified predation of adult weevils (33.6%) and eggs (58.7%). Unexpectedly, regulation of adult weevils was performed by vertebrates (shrews Suncus murinus, mice Mus musculus, lizards Calotes versicolor and toads Sclerophrys gutturalis). Until now, the role of vertebrates in the regulation of the banana weevil seems to have been underestimated ; the search for natural enemies of the weevil had so far focused on arthropods (ants, dermaptera, beetles, spiders).These results make it possible to revisit the management of plots in order to promote the biological control of the banana weevil (habitats favorable to vertebrates and their predation). More generally, this work suggests that the importance of vertebrates in biological control may be underestimated. These results confirm the potential of image analysis for ecological studies.Le charançon noir Cosmopolites sordidus (Germar Col. Curculionidae) est le principal ravageur des bananiers. Afin de développer le contrôle biologique par conservation de C. sordidus, il est nécessaire d'identifier les espèces impliquées et de quantifier leurs impacts en termes de régulation. Les méthodes classiques pour estimer la régulation d'un ravageur par ses prédateurs sont souvent biaisées : limitées à certains groupes, avec des biais d'échantillonnage, sous-estimant certaines interactions. Afin de limiter ces biais, ce travail vise à utiliser une approche d'imagerie in situ et d'analyse automatique pour mieux comprendre les réseaux trophiques liés à C. sordidus.Des expériences de proies sentinelles sous des caméras puis l'analyse des séquences d'images par des réseaux de neurones convolutifs se sont avérées efficaces pour déterminer les espèces présentes et leurs interactions (86,6 % de précision et 88,9 % de rappel pour la détection de 21 espèces différentes). Cette méthode rend également possible l'observation de la dynamique temporelle des évènements de prédation, et des interactions non-trophiques comme la coopération entre individus d'une même espèce. Cette méthode est ensuite améliorée en intégrant une étape de classification hiérarchique afin d'améliorer la robustesse des analyses face à des jeux de données biologiques contraignants.Sur l'île de la Réunion, des expériences de proies sentinelles vivantes (charançons adultes et œufs) ont été conduites sur cinq parcelles. Trois mille heures d'observation ont permis la capture de 375 000 images. L'analyse automatique des images (par soustraction de fond) a permis d'identifier les prédateurs et de quantifier la prédation des charançons adultes (33,6 %) et des œufs (58,7 %). De manière inattendue, la régulation des adultes de charançons a été effectuée par des vertébrés (Musaraignes Suncus murinus, Souris Mus musculus, lézards Calotes versicolor et crapauds Sclerophrys gutturalis). Jusqu'ici, le rôle des vertébrés dans la régulation du charançon du bananier semble donc avoir été sous-estimé ; la recherche d'ennemis naturels du charançon s'était jusqu'alors concentrée sur des arthropodes (fourmis, dermaptères, coléoptères, araignées).Ces résultats permettent de revisiter l'aménagement des parcelles afin de favoriser le contrôle du charançon (habitats favorables aux vertébrés et à leur prédation). De manière plus générale, ces travaux suggèrent que l'importance des vertébrés dans le contrôle biologique pourrait être sous-estimé. Ces résultats confirment le potentiel de l'analyse d'images pour des études en écologie

L'étude d'une oeuvre intégrale par le biais du support informatique

Professorat de lycée professionnelDésireux de faire étudier une œuvre complète à mes élèves de seconde BEP STE, j’ai choisi L’écume des jours de Boris Vian. Cette séquence d’enseignement se place à la confluence de savoirs généraux et professionnels, débouche sur l’écriture d’une nouvelle de trois à quatre pages par chaque binôme d’élèves, la nouvelle étant exposé par la suite au CDI du lycée. L’utilisation du support informatique permet de profiter de l’engouement naturel des élèves pour tout ce qui touche au multimédia. Le résultat (au niveau des évaluations) global est plus qu’encourageant, et les élèves ont tous été très motivés par cette séquence ; il reste cependant difficile de faire la part des choses entre le succès de l’œuvre chez les élèves et le succès de la salle informatique

Quantification du rôle des prédateurs généralistes dans la régulation du charançon du bananier grâce à de l'analyse d'images prises in situ

The banana weevil Cosmopolites sordidus (Germar Col. Curculionidae) is the most important pest of banana. In order to develop conservation biological control of C. sordidus, it is necessary to identify the species involved and to quantify their impacts in terms of regulation. Conventional methods to estimate the regulation of a pest by its predators are often biased : limited to certain groups, with sampling biases, underestimating certain interactions. In order to limit these biases, this work aims to use in situ images and automatic analysis approach to better understand the food webs related to C. sordidus.Monitored sentinel prey experiments followed by the analysis of the image sequences by convolutional neural networks have been shown to be effective in determining the species present and their interactions (86.6% precision and 88.9% recall for the detection of 21 different species). This method also makes it possible to observe the temporal dynamics of predation events, and non-trophic interactions such as cooperation between individuals of the same species. This method is then improved by integrating a hierarchical classification step in order to improve the robustness of the analyses in the face of constraining biological data sets.On La Reunion Island, experiments with live sentinel prey (adult weevils and eggs) were conducted on five plots. Three thousand hours of observation allowed the capture of 375 000 images. Automatic image analysis (using background subtractio) identified predators and quantified predation of adult weevils (33.6%) and eggs (58.7%). Unexpectedly, regulation of adult weevils was performed by vertebrates (shrews Suncus murinus, mice Mus musculus, lizards Calotes versicolor and toads Sclerophrys gutturalis). Until now, the role of vertebrates in the regulation of the banana weevil seems to have been underestimated ; the search for natural enemies of the weevil had so far focused on arthropods (ants, dermaptera, beetles, spiders).These results make it possible to revisit the management of plots in order to promote the biological control of the banana weevil (habitats favorable to vertebrates and their predation). More generally, this work suggests that the importance of vertebrates in biological control may be underestimated. These results confirm the potential of image analysis for ecological studies.Le charançon noir Cosmopolites sordidus (Germar Col. Curculionidae) est le principal ravageur des bananiers. Afin de développer le contrôle biologique par conservation de C. sordidus, il est nécessaire d'identifier les espèces impliquées et de quantifier leurs impacts en termes de régulation. Les méthodes classiques pour estimer la régulation d'un ravageur par ses prédateurs sont souvent biaisées : limitées à certains groupes, avec des biais d'échantillonnage, sous-estimant certaines interactions. Afin de limiter ces biais, ce travail vise à utiliser une approche d'imagerie in situ et d'analyse automatique pour mieux comprendre les réseaux trophiques liés à C. sordidus.Des expériences de proies sentinelles sous des caméras puis l'analyse des séquences d'images par des réseaux de neurones convolutifs se sont avérées efficaces pour déterminer les espèces présentes et leurs interactions (86,6 % de précision et 88,9 % de rappel pour la détection de 21 espèces différentes). Cette méthode rend également possible l'observation de la dynamique temporelle des évènements de prédation, et des interactions non-trophiques comme la coopération entre individus d'une même espèce. Cette méthode est ensuite améliorée en intégrant une étape de classification hiérarchique afin d'améliorer la robustesse des analyses face à des jeux de données biologiques contraignants.Sur l'île de la Réunion, des expériences de proies sentinelles vivantes (charançons adultes et œufs) ont été conduites sur cinq parcelles. Trois mille heures d'observation ont permis la capture de 375 000 images. L'analyse automatique des images (par soustraction de fond) a permis d'identifier les prédateurs et de quantifier la prédation des charançons adultes (33,6 %) et des œufs (58,7 %). De manière inattendue, la régulation des adultes de charançons a été effectuée par des vertébrés (Musaraignes Suncus murinus, Souris Mus musculus, lézards Calotes versicolor et crapauds Sclerophrys gutturalis). Jusqu'ici, le rôle des vertébrés dans la régulation du charançon du bananier semble donc avoir été sous-estimé ; la recherche d'ennemis naturels du charançon s'était jusqu'alors concentrée sur des arthropodes (fourmis, dermaptères, coléoptères, araignées).Ces résultats permettent de revisiter l'aménagement des parcelles afin de favoriser le contrôle du charançon (habitats favorables aux vertébrés et à leur prédation). De manière plus générale, ces travaux suggèrent que l'importance des vertébrés dans le contrôle biologique pourrait être sous-estimé. Ces résultats confirment le potentiel de l'analyse d'images pour des études en écologie