Antimicrobials in a rabbit semen extender: effects on reproduction

[EN] The use of fluoroquinolone antibiotics was legally restricted by the European Commission in March 2019. Since the extender for rabbit semen Galap® contained this antibiotic, it became necessary to modify it. The purpose of this study was to search for another molecule, based on its antimicrobial activity and also on the conservation, motility and fertility of semen diluted with the new extender. Several bacterial strains were isolated from 10 poor-quality ejaculates, including Enterococcus spp., Staphylococcus aureus and Proteus spp. They were then tested for antimicrobial susceptibility. Out of 15 antibiotics evaluated, gentamicin was the one targeting such bacteria. In vivo tests were then carried out to assess the effects of this antibiotic change on sperm parameters. Up to 26 pools of good quality semen (total motility >70%) were diluted in original Galap® or in this extender with gentamicin. Ejaculates were analysed on the day (D) of collection and up to 6 d of storage at +17°C. After 24 h storage, the motility in the new extender was reduced by 7.7% compared to the original; this decrease did not worsen by storing. After 6 d of storage, no difference between the two media was detected. A total of 360 females were then inseminated with pools of 4 to 5 good quality semen diluted 1:10 in both extenders, following the routine protocol of rabbit semen processing centres. There was no difference in female fertility or prolificacy between both formulations. In conclusion, these preliminary results suggest that the addition of gentamicin to this extender is useful and also has no adverse effect on fertility or prolificacy.This study was supported by IMV TechnologiesRouillon, C.; Camugli, S.; Carion, O.; Echegaray, A.; Delhomme, G.; Schmitt, E. (2022). Antimicrobials in a rabbit semen extender: effects on reproduction. World Rabbit Science. 30(4):295-308. https://doi.org/10.4995/wrs.2022.1713229530830

Metabolic control of arginine and ornithine levels paces the progression of leaf senescence

Pools of arginine and ornithine generated during protein degradation can pace the progression of leaf senescence by affecting the TCA cycle, polyamine biosynthesis and the ethylene signaling pathway.Leaf senescence can be induced by stress or aging, sometimes in a synergistic manner. It is generally acknowledged that the ability to withstand senescence-inducing conditions can provide plants with stress resilience. Although the signaling and transcriptional networks responsible for a delayed senescence phenotype, often referred to as a functional stay-green trait, have been actively investigated, very little is known about the subsequent metabolic adjustments conferring this aptitude to survival. First, using the individually darkened leaf (IDL) experimental setup, we compared IDLs of wild-type (WT) Arabidopsis (Arabidopsis thaliana) to several stay-green contexts, that is IDLs of two functional stay-green mutant lines, oresara1-2 (ore1-2) and an allele of phytochrome-interacting factor 5 (pif5), as well as to leaves from a WT plant entirely darkened (DP). We provide compelling evidence that arginine and ornithine, which accumulate in all stay-green contexts-likely due to the lack of induction of amino acids (AAs) transport-can delay the progression of senescence by fueling the Krebs cycle or the production of polyamines (PAs). Secondly, we show that the conversion of putrescine to spermidine (SPD) is controlled in an age-dependent manner. Thirdly, we demonstrate that SPD represses senescence via interference with ethylene signaling by stabilizing the ETHYLENE BINDING FACTOR1 and 2 (EBF1/2) complex. Taken together, our results identify arginine and ornithine as central metabolites influencing the stress- and age-dependent progression of leaf senescence. We propose that the regulatory loop between the pace of the AA export and the progression of leaf senescence provides the plant with a mechanism to fine-tune the induction of cell death in leaves, which, if triggered unnecessarily, can impede nutrient remobilization and thus plant growth and survival

Etude de la variabilité et de l'évolution de la composition chimique de l'aérosol organique en fonction du lieu et de la période de prélèvement

Le travail entrepris s inscrit dans la problématique d une meilleure connaissance de la composition chimique de l aérosol atmosphérique, en milieu urbain. Les objectifs sont d étudier la contamination de la phase particulaire par différentes familles de composés, en réalisant un suivi saisonnier et journalier des concentrations. Les campagnes de prélèvements de particules (PM10) ont été réalisées simultanément sur les sites de Besançon, de Spicheren et de Strasbourg, en scindant l échantillonnage d air en quatre périodes de six heures de prélèvement par jour. La plupart des concentrations relevées à Strasbourg sont supérieures à celles observées sur les sites de Besançon et de Spicheren. Le suivi saisonnier de la contamination des composés a permis de mettre en évidence que mis à part quelques exceptions, les concentrations des produits, sont en général supérieures l hiver, que pendant des saisons moins froides. D une manière générale, en période estivale, il ressort de cette étude que la principale source des composés, semble particulièrement liée au trafic automobile. En période hivernale, à cette source, s ajoute le chauffage résidentiel et sur le site de Strasbourg, une source industrielle possible par transport. Une source d émission liée aux activités de cuisine est également présente toute l année, préférentiellement sur le site de Strasbourg. Enfin, pour les composés émis uniquement à partir de la combustion de biomasse, l apport du chauffage résidentiel au bois, en période hivernale, fait augmenter l abondance de ces composés.The purpose of this study is intended to obtain a better knowledge of the chemical composition of atmospheric aerosols in urban areas. The study targets the evaluation of the airborne particulate phase contamination by various families of pollutants compounds, by carrying out seasonal and daily follow-up of their concentration levels. The PM10 particles sampling was carried out simultaneously related to the Besancon, Spicheren and Strasbourg target areas, all conducted by taking air samples on a daily basis, collecting four consecutive batches, each of a duration of six hours along a day.The most of the concentrations levels collected from the Strasbourg area are higher than those observed on the Besancon and Spicheren areas. Seasonal follow-up of the contamination by compounds made it possible to highlight that apart some exceptions, the studied concentrations, are in general higher the winter, than during milder seasons. Generally, regarding the summer period, it appears from the study that the main source of these compounds seems especially related to the automobile traffic. In winter period, this main source is completed by domestic heating, and for the Strasbourg area, by an apparent industrial source by airborne transportation. A source of emission related to the activities of kitchen is also present all over the year, mostly on the Strasbourg area. Last of all, related to the compounds only emitted from the biomass combustion, the contribution from domestic heating using wood in cold season, increases the abundance of the studied compounds.STRASBOURG-Sc. et Techniques (674822102) / SudocSudocFranceF

Temporal Distribution and Gas/Particle Partitioning of Polycyclic Aromatic Hydrocarbons (PAHs) in the Atmosphere of Strasbourg, France

Gas and particulate phase ambient air concentrations of polycyclic aromatic hydrocarbons (Ʃ16PAHs) were determined in Strasbourg, a large city located in the Alsace region of northeastern France, from May 2018 to March 2020, to study the evolution of their temporal variations and their potential origins. The analysis of PAHs was performed using a global analytical method permitting the quantification of pesticides, PAHs, and polychlorobiphenyls (PCBs). Filters and Carbon doped silicon carbide NMC@SiC foams were extracted by accelerated solvent extraction (ASE) followed by a solid-phase extraction (SPE). Afterwards, extracts were analyzed using gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). Prior to analysis, a pre-concentration step based on solid-phase microextraction (SPME) was used with a polydimethylsiloxane (PDMS) 100 µm fiber. The average total (gas plus particulate) concentration of Ʃ16PAHs varied from 0.51 to 117.31 ng m−3 with a mean of 16.87 ng m−3, with higher concentrations in the cold season of more than 2.5-fold and 6-fold that in the warm season for the gas and particulate phases, respectively. Moreover, low molecular weight (LMW) (2-ring and 3-ring) and medium molecular weight (MMW) (4-ring) PAHs contribute dominantly to the gas phase, while the particulate phase is associated with MMW (4-ring) and high molecular weight (HMW) (5-ring and 6-ring) PAHs. Gas/particle partitioning coefficient (log Kp) was calculated, and values varied between −4.13 and −1.49. It can be seen that the log Kp increased with the molecular weight of the PAHs and that the log Kp is different between cold and warm seasons for HMW PAHs but not for LMW PAHs. Diagnostic ratios of PAHs, which were employed to estimate the primary source of PAHs in Strasbourg, indicate that fuel combustion and biomass/coal burning are the possible origins of PAHs in Strasbourg’s atmosphere

Use of PLE-ATD-GC/MSMS for the Quantification of Airborne Pesticides in Active and Passive Samples and in Dust.

peer reviewedAn analytical method coupling pressurized liquid extraction (PLE), pre-concentration by thermal desorption (ATD) and analysis by GC/MSMS was developed for the quantification of pesticides in air and dust near vineyards crops to evaluate potential exposure of residents living near these crops. PLE was done using acetonitrile and extracts were concentrated under fume hood to 1 mL. 100 μL of the extract was spiked in a Tenax TA tube and internal standards and N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide were added before thermal desorption at 300°C for 30 min. GC/MSMS analysis was done in MRM mode and limits of quantification and limits of detection were determined for each matrix (passive air sample, active air sample and dust). The method was applied in the field and shows good sensitivity and accuracy.PRIMEQUALECOPHYT

Ultrasound-coupled semi-supervised nonnegative matrix factorisation for speech enhancement

We present an extension to an existing speech enhancement tech-nique, whereby the incorporation of easily obtained Doppler-based ultrasound data, obtained from frequency shifts caused by a talker’s mouth movements, is shown to improve speech enhancement re-sults. Noisy speech mixtures were enhanced using semi-supervised nonnegative matrix factorisation (NMF). Ultrasound data recorded alongside the speech is transformed into the spectral domain and used additionally to audio in the mixture to be separated. Speech components are learned from a training set, whilst noise compo-nents are estimated from the mixture signal. We show that the ultra-sound data can improve source-to-distortion ratios for the enhanced speech, relative to both the non-ultrasound NMF case and an estab-lished Wiener filter-based speech enhancement method

Environmental analysis of polar and non-polar Polycyclic Aromatic Compounds in airborne particulate matter, settled dust and soot: Part I: Sampling and sample preparation

Interests in PAHs and their derivatives (NPAHs, OPAHs, Azaarenes and PASHs) have been growing because of their toxicity. The second part of this review gathers information on the separation and detection of Polycyclic Aromatic Compounds (PACs) and on their occurrence levels in airborne particulate matter, dust and soot. Chromatography is used to separate PACs before their identification and quantification. For both GC and LC, the choice of the stationary phase is crucial to obtain good resolution of PACs, which can be difficult when a lot of compounds are included in the same analysis. Mass Spectrometry is ideal for PACs detection. It can be hyphenated to both GC and LC, is applicable to all subclasses of PACs and its sensitivity and specificity enables environmental assessment of ultratrace levels. PACs are generally around the ng.m3 level in atmospheric PM and at several mg.g1 in dust and soot. Some geographical and seasonal trends of their occurrence can be highlighted

Environmental analysis of polar and non-polar Polycyclic Aromatic Compounds in airborne particulate matter, settled dust and soot: Part II: Instrumental analysis and occurrence

Interests in PAHs and their derivatives (NPAHs, OPAHs, Azaarenes and PASHs) have been growing because of their toxicity. The second part of this review gathers information on the separation and detection of Polycyclic Aromatic Compounds (PACs) and on their occurrence levels in airborne particulate matter, dust and soot. Chromatography is used to separate PACs before their identification and quantification. For both GC and LC, the choice of the stationary phase is crucial to obtain good resolution of PACs, which can be difficult when a lot of compounds are included in the same analysis. Mass Spectrometry is ideal for PACs detection. It can be hyphenated to both GC and LC, is applicable to all subclasses of PACs and its sensitivity and specificity enables environmental assessment of ultratrace levels. PACs are generally around the ng•m-3 level in atmospheric PM and at several µg•g-1 in dust and soot. Some geographical and seasonal trends of their occurrence can be highlighted

Glyphosate and glufosinate-based herbicides: fate in soil, transfer to, and effects on land snails

International audiencePurpose The aim of this work was to assess the transfer and effects of two widely used herbicides on the land snail Helix aspersa during long-term exposure under laboratory conditions. Materials and methods Newly hatched snails were exposed for 168 days to soil and/or food contaminated with a formulation of glyphosate (Bypass®) or glufosinate (Basta®) at the recommended field doses and also at 10-fold this dose. Results and discussion Herbicide degradation patterns showed that snails were mainly exposed during the first 28 days. The DT50 of glyphosate and glufosinate was established at 10.6 and 3.7 days, respectively. No significant effects on survival and growth were determined. Concerning genital tract maturation of the snails, exposure to herbicides tended to decrease the development of the albumen gland (inhibition of 43.5 ± 32.8%). The presence of glyphosate (6 mg kg âˆ'1 dry weight) was demonstrated in snails exposed continuously to this active ingredient at the highest concentration in their food. Conclusions These results showed a low effect of herbicides at relevant concentrations in soil but the detection of residues in tissues indicated a potential risk of transfer to the food chain. This chronic toxicity bioassay could complete the available tests to assess toxicity of contaminants, and more particularly pesticides, in soil