Organization of the Drosophila larval visual circuit

Visual systems transduce, process and transmit light-dependent environmental cues. Computation of visual features depends on the types of photoreceptor neurons (PR) present, the organization of the eye and the wiring of the underlying neural circuit. Here, we describe the circuit architecture of the visual system of Drosophila larvae by mapping the synaptic wiring diagram and neurotransmitters. By contacting different targets, the two larval PR-subtypes create parallel circuits potentially underlying the computation of absolute light intensity and temporal light changes already within this first visual processing center. Locally processed visual information then signals via dedicated projection interneurons to higher brain areas including the lateral horn and mushroom body. The stratified structure of the LON suggests common organizational principles with the adult fly and vertebrate visual systems. The complete synaptic wiring diagram of the LON paves the way to understanding how circuits with reduced numerical complexity control wide ranges of behaviors

Evidence of environmental transfer of tebuconazole to the eggs in the house sparrow (Passer domesticus): An experimental study

International audienceTriazole compounds are among the most widely used fungicides in agroecosystems to protect crops from potential fungal diseases. Many farmland birds spend a significant part of their life cycle in agroecosystems, which may chronically expose them to pesticides. We experimentally tested whether exposure to environmental concentrations of tebuconazole could induce a contamination of the eggs by tebuconazole in an agroecosystem sentinel species, the house sparrow (Passer domesticus). Wild-caught adult sparrows were maintained in captivity and exposed (exposed group) or not (control group) for seven months to tebuconazole through drinking water. Eggs were opportunistically collected for the determination of tebuconazole concentration by Liquid Chromatography coupled to tandem Mass Spectrometry in eggs. We found that eggs from exposed parents all contained tebuconazole with a mean concentration of 1.52 ng g−1 dry weight. In eggs from control parents, the tebuconazole concentration was below the limit of quantification (0.23 ng g−1 dry weight) for 11 out of 13 eggs. Thus, our study demonstrates for the first time that environmental exposure of female bi

Effet de la hauteur de prélèvement sur la composition quantitative et qualitative des polyphénols de l’écorce d’Abies alba Mill.

International audienceThe bark of coniferous trees grown for a commercial purpose is a potential precious source of secondary metabolites such as polyphenols. Tannins are among the polyphenols found in the bark. They are used to manufacture adhesives and resins, but also as tanning agents, antibacterial agents, antifungal agents, antitermite agents and antioxidants. Little information is available on the yield and composition of bark extracts depending on the height at which samples are taken from the trunk and on the presence or absence of branches. The present study examines the variability of the secondary metabolites present in Abies alba bark depending on sampling height on the tree, but also on variability at specific heights among several trees. The aim of the study was to determine which bark fraction contained the greatest quantity of extractible compounds in this species. To this end, eight trees were selected, and a maximum of thirteen discs was cut out along each trunk. The samples were taken down the trunk (30 cm from the ground) and then at different heights. The heights were chosen based on industrial criteria (maximum height for lumber production of forindustrial use), but also on physiological parameters (e g height at the base of the crown, height of the first green branch). The samples were ground, and then polyphenols were extracted with water/ethanol (1:1, v/v) in fast extraction conditions at high temperature and under high pressure A first – quantitative – study was carried out to determine the total quantities of extractables present in the bark. The second study was qualitative, and aimed at determining which types of extractables were present in the barks. The extracts were analysed by liquid chromatography coupled to a UV-visible spectrometer and a mass spectrometer. The results showed that the quantity of compounds in the total bark extracts increased proportionally to sampling height. The highest proportion of polyphenols was found in the section below the crownL’écorce de résineux, cultivés dans un but commercial, est une source potentielle précieuse de métabolites secondaires tels que les polyphénols. Les tannins, qui font partie des polyphénols présents dans l’écorce, sont utilisés dans la fabrication d’adhésifs et de résines, mais également en tant qu’agent de tannage, antibactérien, antifongique, antitermite et antioxydant. Peu d’informations existent à propos du rendement et de la composition des extraits d’écorce en fonction de la hauteur de l’échantillon prélevé dans le tronc ainsi qu’en fonction de la présence ou l’absence de branches. Cette étude a pour but d’examiner la variabilité des métabolites secondaires présents dans l’écorce d’Abies alba à la fois en fonction de la hauteur de l’échantillon prélevé dans un arbre, mais également la variabilité présente à des hauteurs spécifiques entre plusieurs arbres. La finalité de cette étude est de déterminer quelle fraction d’écorce contient le plus d’extractibles chez cette essence. Pour cela, huit arbres ont été sélectionnés dans lesquels un maximum de treize disques a été coupé tout le long du tronc. Ces échantillons ont été prélevés en bas du tronc à une hauteur de 30 cm dusol puis à différentes hauteurs Ces différentes hauteurs ont été choisies pour des raisons industrielles (hauteur limite pour le bois d’œuvre ou pour l’utilisation industrielle) mais également pour des raisons physiologiques (hauteur à la base du houppier, hauteur de la première branche verte…). Les échantillons prélevés ont été broyés puis extraits avec un mélange eau/éthanol (1 :1, v/v) en réalisant une extraction accélérée à chaudet sous pression. Une première étude quantitative est réalisée pour connaître la quantité d’extractibles totale présente dans l’écorce. La seconde étude est qualitative, afin de connaître quels types d’extractibles sont présents dans ces écorces. Ces extraits ont donc été examinés par chromatographie liquide couplée à un spectromètre UV-visible et un spectromètre de masse .Les résultats ont montré que la composition de l’extrait total d’écorce augmente en même temps que la hauteur dans le tronc. La proportion la plus élevée en composés polyphénoliques se trouve dans la section inférieure sous la couronne

Experimental Exposure to Tebuconazole Affects Metabolism and Body Condition in a Passerine Bird, the House Sparrow ( Passer domesticus )

International audienceTriazole compounds are among the most widely used fungicides in agroecosystems to protect crops from potential fungal diseases. Triazoles are suspected to have an impact on nontarget species due to their interactions with nonfungal sterol synthesis, and wild birds are likely to be contaminated by triazole fungicides because many of them live in agroecosystems. We experimentally tested whether exposure to environmental concentrations of a triazole could alter key integrative traits (metabolic rates and body condition) of an agroecosystem sentinel species, the house sparrow (Passer domesticus). Wild-caught adult sparrows were maintained in captivity and exposed (exposed group) or not (control group) for 7 continuous months to tebuconazole through drinking water. The metabolic rates of exposed and control sparrows were then measured at two different temperatures (12 °C and 25 °C), which correspond, respectively, to the thermoregulation and thermoneutrality temperatures of this species. We found that exposed sparrows had lower resting metabolic rates (i.e., measured at thermoneutrality, 25 °C) than controls. However, the thermoregulatory metabolic rates (i.e., measured at 12 °C) did not differ between exposed and control sparrows. Although the body mass and condition were not measured at the beginning of the exposure, sparrows at the time of the metabolic measurements 7 months after the onset of such exposure had a higher body condition than controls, supporting further the idea that tebuconazole affects metabolic functions. Our study demonstrates for the first time that the use of tebuconazole can alter metabolism and could potentially lead to adverse effects in bird

Chronic exposure to tebuconazole alters thyroid hormones and plumage quality in house sparrows (Passer domesticus)

International audienceTriazoles belong to a family of fungicides that are ubiquitous in agroecosystems due to their widespread use in crops. Despite their efficiency in controlling fungal diseases, triazoles are also suspected to affect non-target vertebrate species through the disruption of key physiological mechanisms. Most studies so far have focused on aquatic animal models, and the potential impact of triazoles on terrestrial vertebrates has been overlooked despite their relevance as sentinel species of contaminated agroecosystems. Here, we examined the impact of tebuconazole on the thyroid endocrine axis, associated phenotypic traits (plumage quality and body condition) and sperm quality in wild-caught house sparrows (Passer domesticus). We experimentally exposed house sparrows to realistic concentrations of tebuconazole under controlled conditions and tested the impact of this exposure on the levels of thyroid hormones (T3 and T4), feather quality (size and density), body condition and sperm morphology. We found that exposure to tebuconazole caused a significant decrease in T4 levels, suggesting that this azole affects the thyroid endocrine axis, although T3 levels did not differ between control and exposed sparrows. Importantly, we also found that exposed females had an altered plumage structure (larger but less dense feathers) relative to control females. The impact of tebuconazole on body condition was dependent on the duration of exposure and the sex of individuals. Finally, we did not show any effect of exposure to tebuconazole on sperm morphology. Our study demonstrates for the first time that exposure to tebuconazole can alter the thyroid axis of wild birds, impact their plumage quality and potentially affect their body condition. Further endocrine and transcriptomic studies are now needed not only to understand the underlying mechanistic effects of tebuconazole on these variables, but also to further investigate their ultimate consequences on performance (i.e. reproduction and survival)

Multicenter Prospective Cohort Study of the Patient-Reported Outcome Measures PRO-CTCAE and CAT EORTC QLQ-C30 in Major Abdominal Cancer Surgery (PATRONUS): A Student-Initiated German Medical Audit (SIGMA) Study

Background!#!The patient-reported outcomes (PRO) version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) and the computerized adaptive testing (CAT) version of the EORTC quality-of-life questionnaire QLQ-C30 have been proposed as new PRO measures in oncology; however, their implementation in patients undergoing cancer surgery has not yet been evaluated.!##!Methods!#!Patients undergoing elective abdominal cancer surgery were enrolled in a prospective multicenter study, and postoperative complications were recorded according to the Dindo-Clavien classification. Patients reported PRO data using the CAT EORTC QLQ-C30 and the PRO-CTCAE to measure 12 core cancer symptoms. Patients were followed-up for 6 months postoperatively. The study was carried out by medical students of the CHIR-Net SIGMA study network.!##!Results!#!Data of 303 patients were obtained and analyzed across 15 sites. PRO-CTCAE symptoms 'poor appetite', 'fatigue', 'exhaustion' and 'sleeping problems' increased after surgery and climaxed 10-30 days postoperatively. At 3-6 months postoperatively, no PRO-CTCAE symptom differed significantly to baseline. Patients reported higher 'social functioning' (p = 0.021) and overall quality-of-life scores (p < 0.05) 6 months after cancer surgery compared with the baseline level. There was a lack of correlation between postoperative complications or death and any of the PRO items evaluated. Feasibility endpoints for student-led research were met.!##!Conclusion!#!The two novel PRO questionnaires were successfully applied in surgical oncology. Postoperative complications do not affect health-reported quality-of-life or common cancer symptoms following major cancer surgery. The feasibility of student-led multicenter clinical research was demonstrated, but might be enhanced by improved student training