Neonicotinoid insecticides imidacloprid and clothianidin affect differently neural Kenyon cell death in the cockroach Periplaneta americana

The intracellular toxicity of the neonicotinoid insecticides imidacloprid and clothianidin was studied on cockroach Periplaneta americana Kenyon cells using the trypan blue exclusion test and the adenylate kinase (AK) detection reagent. To evaluate cytotoxicity. Kenyon cells were exposed to different concentrations (1, 5, 10, 50 and 100 mu M) of both imidacloprid and clothianidin at different delays (1, 3, 5, 8 and 24 h). Our data show that both imidacloprid and clothianidin decreased cell viability, with a more pronounced effect following imidacloprid exposure. Indeed, a significant decrease of cell viability was observed for 50 and 100 mu M imidacloprid at 8 and 24 h, with trypan blue exclusion test. Study of the AK activity revealed that 50 and 100 mu M imidacloprid induced an increase of AK activity, except for 50 mu M at 24 h whereas at the same concentrations, clothianidin induced a transient effect at 5 and 8 h. According to previous studies showing that imidacloprid was a partial agonist and clothianidin a full agonist of insect nicotinic acetylcholine receptors, we demonstrated that both imidacloprid and clothianidin were also able to induce distinct intracellular toxic effects

Modification des récepteurs cholinergiques de type nicotinique par des doses sublétales d'imidaclopride chez la blatte Periplaneta americana

Les insecticides néonicotinoïdes sont une classe d\u27insecticides utilisée pour contrôler les insectes ravageurs de cultures. Ces molécules miment l\u27effet de l\u27acétylcholine (ACh) en agissant comme des agonistes des récepteurs cholinergiques de type nicotinique (nAChRs) au niveau du système nerveux central des insectes. Suite à l\u27utilisation des néonicotinoïdes ces dernières années, des phénomènes de résistance ont été révélés chez beaucoup d\u27espèces. Ces phénomènes menacent d\u27une part l\u27agriculture et d\u27autre part la santé publique. Afin de comprendre les facteurs impliqués dans les phénomènes de résistance aux néonicotinoïdes, nous avons étudié les mécanismes d\u27adaptation développés suite à une exposition chronique à des doses sublétales de néonicotinoïde. Dans un premier temps, nous avons étudié la toxicité d\u27une molécule néonicotinoïde (l\u27imidaclopride) chez la blatte Periplaneta americana . Ensuite, l\u27effet d\u27une exposition chronique à une dose sublétale d\u27imidaclopride a été exploré sur neurones DUM (Dorsal Unpaired Median) de la blatte grâce à la technique électrophysiologique de patch - clamp, dans des conditions de potentiel imposé. Les premiers résultats obtenus montrent que cette exposition chronique peut modifier le profil pharmacologique des nAChRs au niveau des neurones DUM. En effet, une diminution de la sensibilité à l\u27imidaclopride des nAChRs a été mise en évidence. Dans un deuxième temps, nous avons montré en PCR quantitative que la diminution de la sensibilité des nAChRs pourrait avoir un lien avec une modification du niveau d\u27expression des différentes sous – unités qui composent ces récepteurs

Quinuclidine compounds differently act as agonists of Kenyon cell nicotinic acetylcholine receptors and induced distinct effect on insect ganglionic depolarizations

We have recently demonstrated that a new quinuclidine benzamide compound named LMA10203 acted as an agonist of insect nicotinic acetylcholine receptors. Its specific pharmacological profile on cockroach dorsal unpaired median neurons (DUM) helped to identify alpha-bungarotoxin-insensitive nAChR2 receptors. In the present study, we tested its effect on cockroach Kenyon cells. We found that it induced an inward current demonstrating that it bounds to nicotinic acetylcholine receptors expressed on Kenyon cells. Interestingly, LMA10203-induced currents were completely blocked by the nicotinic antagonist alpha-bungarotoxin. We suggested that LMA10203 effect occurred through the activation of alpha-bungarotoxin-sensitive receptors and did not involve alpha-bungarotoxin-insensitive nAChR2, previously identified in DUM neurons. In addition, we have synthesized two new compounds, LMA10210 and LMA10211, and compared their effects on Kenyon cells. These compounds were members of the 3-quinuclidinyl benzamide or benzoate families. Interestingly, 1 mM LMA10210 was not able to induce an inward current on Kenyon cells compared to LMA10211. Similarly, we did not find any significant effect of LMA10210 on cockroach ganglionic depolarization, whereas these three compounds were able to induce an effect on the central nervous system of the third instar M. domestica larvae. Our data suggested that these three compounds could bind to distinct cockroach nicotinic acetylcholine receptors

Effect of thiamethoxam on cockroach locomotor activity is associated with its metabolite clothianidin

BACKGROUND: In the present study, the effect of thiamethoxam and clothianidin on the locomotor activity of American cockroach, Periplaneta americana (L.), was evaluated. Because it has been proposed that thiamethoxam is metabolised to clothianidin, high-performance liquid chromatography coupled with mass spectrometry was used to evaluate the amount of clothianidin on thiamethoxam-treated cockroaches. RESULTS: One hour after neonicotinoid treatment, the time spent in the open-field-like apparatus significantly increased, suggesting a decrease in locomotor activity. The percentage of cockroaches displaying locomotor activity was significantly reduced 1 h after haemolymph application of 1 nmol g(-1) neonicotinoid, while no significant effect was found after topical and oral administration. However, at 24 and 48 h, all neonicotinoids were able to reduce locomotor activity, depending on their concentrations and the way they were applied. Interestingly, it was found that thiamethoxam was converted to clothianidin 1 h after application, but the amount of clothianidin did not rise proportionately to thiamethoxam, especially after oral administration. CONCLUSION: The data suggest that the effect of thiamethoxam on cockroach locomotor activity is due in part to clothianidin action because (1) thiamethoxam levels remained persistent 48 h after application and (2) the amount of clothianidin in cockroach tissues was consistent with the toxicity of thiamethoxam

Pretreatment of the cockroach cercal afferent/giant interneuron synapses with nicotinoids and neonicotinoids differently affects acetylcholine and nicotine-induced ganglionic depolarizations

We have recently demonstrated that neonicotinoid insecticides were able to act as agonists of postsynaptic nicotinic acetylcholine receptors (nAChRs) expressed at the synapse between the cercal nerve XI and the giant interneurons, in the sixth abdominal ganglion. In this work, we demonstrated that nicotinoids such as nornicotine acted as an agonist of nicotinic acetylcholine receptors expressed at cercal afferent/giant interneurons while cotinine was a poor agonist. Indeed, nornicotine induced a ganglionic depolarization which was blocked by the nicotinic antagonist mecamylamine. In addition, we found that pretreatment of the sixth abdominal ganglion with 1 and 10 muM nornicotine and cotinine had no significant effect on acetylcholine and nicotine-induced depolarization. But pretreatment with 1 and 10 muM acetamiprid and imidacloprid had a strong effect. 1 and 10 muM acetamiprid completely blocked acetylcholine-induced depolarization, whereas imidacloprid had a partial effect. The present work therefore suggests, in agreement with previous studies, that nornicotine and cotinine bind to distinct cockroach postsynaptic nAChRs, whereas acetamiprid and imidacloprid have competitive effects with acetylcholine and nicotine on ganglionic depolarization

Effectiveness of plyometric exercises to improve muscular strength and digital achievement for students in shot put

To identify the effectiveness of plyometric exercises to improve muscular strength and achievement in shot put event by students (20-22 years old). The researchers used an experimental method; the sample was formed by students belonging to the institute of physical education & sports, University of Mostaganem (Algeria). Thus it was the application of the experimental method was applied on a sample of third-year students (males) of 45 students divided into two groups, first control group of 22 students and an experimental group of 23 students. While the tests used were (strength test, achievement test). After the treatment of the results by statistical means, and through these results it have been reached several conclusions of them, plyometric Exercises to develop muscular strength and achievement in shot put [discussion significant difference (*p≤0.05)]. And best improve of the experimental sample based on plyometric exercises compared to the control sample, which rely more on the technical side only in shot put event

Cost Effective Cloud Storage Interoperability Between Public Cloud Platforms

With recent advancement in technology, cloud storage became cheaper enabling organizations around the world to store more data on the cloud (texts, images, videos, databases etc.), whereas it’s for a backup, archiving or just storing data streams. New digital laws and regulation (eg. General Data Protection Regulation) require these organizations to change their way of processing or handling data, which results usually in a change of cloud providers or adoption of hybrid architecture or multi-cloud one. With the amount of data stored increasing year after year, it becomes difficult for these organizations to change cloud platforms or cloud provider and migrate their data without thinking about the technical complexity, the time and the huge cost it may incur. This article discusses the data migration and interoperability issues between cloud platforms; the proposed approach provides a simple cost-effective migration that would help organizations save time and money in this process based on a  hybrid ontology approach for the brokerage of data transfers.. Keywords-Cloud Computing; Storage; Security; data; migration; cost optimization