The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Isaac Ishaaya - One of the best experts on this subject based on the ideXlab platform.
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dynamics of resistance to the neonicotinoids Acetamiprid and thiamethoxam in bemisia tabaci homoptera aleyrodidae
Journal of Economic Entomology, 2004Co-Authors: Rami A Horowitz, Svetlana Kontsedalov, Isaac IshaayaAbstract:The dynamics of resistance in the sweetpotato whitefly, Bemisia tabaci (Gennadius), to the neonicotinoids Acetamiprid and thiamethoxam was studied extensively in cotton fields in Israel during the cotton-growing seasons 1999–2003. Whitefly strains were collected in early and late seasons mainly in three locations in northern, central, and southern Israel. The whiteflies were assayed under laboratory conditions for susceptibility to neonicotinoids, as part of the Israeli cotton insecticide resistance management strategy. Selections to both Acetamiprid and thiamethoxam and cross-resistance between them also were conducted in the laboratory. Although no appreciable resistance to Acetamiprid was observed up to 2001, a slight increase of approximately five-fold resistance was detected during 2002 and 2003. However, from 2001 to 2003 thiamethoxam resistance increased >100-fold in the Ayalon Valley and Carmel Coast cotton fields. In cross-resistance assays with both neonicotinoids, the strain that had been selected with thiamethoxam for 12 generations demonstrated almost no cross-resistance to Acetamiprid, whereas the Acetamiprid-selected strain exhibited high cross-resistance of >500-fold to thiamethoxam.
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comparative toxicity of foliar and systemic applications of Acetamiprid and imidacloprid against the cotton whitefly bemisia tabaci hemiptera aleyrodidae
Bulletin of Entomological Research, 1998Co-Authors: A R Horowitz, Z Mendelson, Phyllis G Weintraub, Isaac IshaayaAbstract:Comparative bioassays of two chloronicotinyl insecticides, Acetamiprid and imidacloprid, against the whitefly Bemisia tabaci (Gennadius), using foliar and systemic applications, were conducted under laboratory conditions and in field trials. Under controlled conditions, the ovicidal activity of foliar applications of Acetamiprid on cotton seedlings was much higher than that of imidacloprid. According to LC50 and LC90 values, Acetamiprid was 10- and 18-fold more potent than imidacloprid. Both compounds were effective when applied to soil against whitefly adults; however, the potency of imidacloprid was somewhat higher than that of Acetamiprid 2, 7 and 14 days after application; resulting (with the concentration of 25 ml a.i./l) in adult mortality of 90, 93, and 96% and 76, 84, and 76% respectively. In an experimental cotton field, the efficacy of foliar applications of 60 g a.i./ha Acetamiprid and 210 g a.i./ha imidacloprid was compared. Field residual activity of Acetamiprid to whitefly adults lasted for approximately ten days, compared with three days for imidacloprid.
Theodore P Labuza - One of the best experts on this subject based on the ideXlab platform.
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rapid detection of Acetamiprid in foods using surface enhanced raman spectroscopy sers
Journal of Food Science, 2014Co-Authors: Wisiani Wijaya, Shintaro Pang, Theodore P LabuzaAbstract:Acetamiprid is a neonicotinoid pesticide that is commonly used in modern farming. Acetamiprid residue in food commodities can be a potential harm to human and has been implicated in the honey bee hive die off crisis. In this study, we developed rapid, simple, and sensitive methods to detect Acetamiprid in apple juice and on apple surfaces using surface-enhanced Raman spectroscopy (SERS). No pretreatment of apple juice sample was performed. A simple surface swab method was used to recover Acetamiprid from the apple surface. Samples were incubated with silver dendrites for several minutes and SERS spectra were taken directly from the silver surface. Detection of a set of 5 apple juice samples can be done within 10 min. The swab-SERS method took 15 min for a set of 5 samples. Resulting spectral data were analyzed using principal component analysis. The highest Acetamiprid peak at 634 cm−1 was used to detect and quantify the amount of Acetamiprid spiked in 1:1 water–methanol solvent, apple juice, and on apple surface. The SERS method was able to successfully detect Acetamiprid at 0.5 μg/mL (0.5 ppm) in solvent, 3 μg/mL (3 ppm) in apple juice, and 0.125 μg/cm2 on apple surfaces. The SERS methods provide simple, rapid, and sensitive ways to detect Acetamiprid in beverages and on the surfaces of thick skinned fruits and vegetables. Practical Application We developed rapid, simple, and sensitive methods using surface-enhanced Raman spectroscopy to detect Acetamiprid in apple juice and on apple surfaces. These methods require no pretreatment to detect Acetamiprid in apple juice and combined a simple swab method to detect Acetamiprid on apple surfaces. The methods can be modified to detect Acetamiprid and other pesticides or toxins in beverages and on the surfaces of thick-skinned fruits and vegetables.
A R Horowitz - One of the best experts on this subject based on the ideXlab platform.
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comparative toxicity of foliar and systemic applications of Acetamiprid and imidacloprid against the cotton whitefly bemisia tabaci hemiptera aleyrodidae
Bulletin of Entomological Research, 1998Co-Authors: A R Horowitz, Z Mendelson, Phyllis G Weintraub, Isaac IshaayaAbstract:Comparative bioassays of two chloronicotinyl insecticides, Acetamiprid and imidacloprid, against the whitefly Bemisia tabaci (Gennadius), using foliar and systemic applications, were conducted under laboratory conditions and in field trials. Under controlled conditions, the ovicidal activity of foliar applications of Acetamiprid on cotton seedlings was much higher than that of imidacloprid. According to LC50 and LC90 values, Acetamiprid was 10- and 18-fold more potent than imidacloprid. Both compounds were effective when applied to soil against whitefly adults; however, the potency of imidacloprid was somewhat higher than that of Acetamiprid 2, 7 and 14 days after application; resulting (with the concentration of 25 ml a.i./l) in adult mortality of 90, 93, and 96% and 76, 84, and 76% respectively. In an experimental cotton field, the efficacy of foliar applications of 60 g a.i./ha Acetamiprid and 210 g a.i./ha imidacloprid was compared. Field residual activity of Acetamiprid to whitefly adults lasted for approximately ten days, compared with three days for imidacloprid.
Bruno Lapied - One of the best experts on this subject based on the ideXlab platform.
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Transmembrane Potential Polarization, Calcium Influx, and Receptor Conformational State Modulate the Sensitivity of the Imidacloprid-Insensitive Neuronal Insect Nicotinic Acetylcholine Receptor to Neonicotinoid Insecticides
Journal of Pharmacology and Experimental Therapeutics, 2012Co-Authors: Beatrice Bodereau-dubois, Steeve H Thany, Olivier List, Delphine Calas-list, Olivier Marques, Pierre-yves Communal, Bruno LapiedAbstract:Neonicotinoid insecticides act selectively on insect nicotinic acetylcholine receptors (nAChRs). Recent studies revealed that their efficiency was altered by the phosphorylation/dephosphorylation process and the intracellular signaling pathway involved in the regulation of nAChRs. Using whole-cell patch-clamp electrophysiology adapted for dissociated cockroach dorsal unpaired median (DUM) neurons, we demonstrated that intracellular factors involved in the regulation of nAChR function modulated neonicotinoid sensitivity. DUM neurons were known to express two α-bungarotoxin-insensitive nAChR subtypes: nAChR1 and nAChR2. Whereas nAChR1 was sensitive to imidacloprid, nAChR2 was insensitive to this insecticide. Here, we demonstrated that, like nicotine, Acetamiprid and clothianidin, other types of neonicotinoid insecticides, acted as agonists on the nAChR2 subtype. Using Acetamiprid, we revealed that both steady-state depolarization and hyperpolarization affected nAChR2 sensitivity. The measurement of the input membrane resistance indicated that change in the Acetamiprid-induced agonist activity was related to the receptor conformational state. Using cadmium chloride, ω-conotoxin GVIA, and (R,S)-(3,4-dihydro-6,7-dimethoxy-isoquinoline-1-yl)-2-phenyl-N,N-di-acetamide (LOE 908), we found that inhibition of calcium influx through high voltage-activated calcium channels and transient receptor potential γ (TRPγ) activated by both depolarization and hyperpolarization increased nAChR2 sensitivity to Acetamiprid. Finally, using N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide hydrochloride (W7), forskolin, and cAMP, we demonstrated that adenylyl cyclase sensitive to the calcium/calmodulin complex regulated internal cAMP concentration, which in turn modulated TRPγ function and nAChR2 sensitivity to Acetamiprid. Similar TRPγ-induced modulatory effects were also obtained when clothianidin was tested. These findings bring insights into the signaling pathway modulating neonicotinoid efficiency and open novel strategies for optimizing insect pest control
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Transmembrane potential polarization, calcium influx, and receptor conformational state modulate the sensitivity of the imidacloprid-insensitive neuronal insect nicotinic acetylcholine receptor to neonicotinoid insecticides
'American Society for Pharmacology & Experimental Therapeutics (ASPET)', 2012Co-Authors: Beatrice Bodereau-dubois, Olivier List, Delphine Calas-list, Olivier Marques, Pierre-yves Communal, S.h. Thany, Bruno LapiedAbstract:Neonicotinoid insecticides act selectively on insect nicotinic acetylcholine receptors (nAChRs). Recent studies revealed that their efficiency was altered by the phosphorylation/dephosphorylation process and the intracellular signaling pathway involved in the regulation of nAChRs. Using whole-cell patch-clamp electrophysiology adapted for dissociated cockroach dorsal unpaired median (DUM) neurons, we demonstrated that intracellular factors involved in the regulation of nAChR function modulated neonicotinoid sensitivity. DUM neurons were known to express two alpha-bungarotoxin-insensitive nAChR subtypes: nAChR1 and nAChR2. Whereas nAChR1 was sensitive to imidacloprid, nAChR2 was insensitive to this insecticide. Here, we demonstrated that, like nicotine, Acetamiprid and clothianidin, other types of neonicotinoid insecticides, acted as agonists on the nAChR2 subtype. Using Acetamiprid, we revealed that both steady-state depolarization and hyperpolarization affected nAChR2 sensitivity. The measurement of the input membrane resistance indicated that change in the Acetamiprid-induced agonist activity was related to the receptor conformational state. Using cadmium chloride, omega-conotoxin GVIA, and (R,S)-(3,4-dihydro-6,7-dimethoxy-isoquinoline-1-yl)-2-phenyl-N,N-di-acetamide (LOE 908), we found that inhibition of calcium influx through high voltage-activated calcium channels and transient receptor potential gamma (TRPgamma) activated by both depolarization and hyperpolarization increased nAChR2 sensitivity to Acetamiprid. Finally, using N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide hydrochloride (W7), forskolin, and cAMP, we demonstrated that adenylyl cyclase sensitive to the calcium/calmodulin complex regulated internal cAMP concentration, which in turn modulated TRPgamma function and nAChR2 sensitivity to Acetamiprid. Similar TRPgamma-induced modulatory effects were also obtained when clothianidin was tested. These findings bring insights into the signaling pathway modulating neonicotinoid efficiency and open novel strategies for optimizing insect pest control
Manli Guo - One of the best experts on this subject based on the ideXlab platform.
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Turn-on sensor for quantification and imaging of Acetamiprid residues based on quantum dots functionalized with aptamer
Sensors and Actuators B: Chemical, 2016Co-Authors: Bixia Lin, Ruoying Li, Yujuan Cao, Ying Yu, Manli GuoAbstract:In this paper, a novel turn-on sensor was constructed for quantification and imaging of Acetamiprid. Acetamiprid aptamer-modified ZnS:Mn probe (ZnS:Mn-Aptamer) was obtained by conjugating ZnS:Mn QDs with Acetamiprid binding aptamer. The fluorescence of the probe was turn off by multi-walled carbon nanotubes (MWCNTs) based on fluorescence resonance energy transfer (FRET) between ZnS:Mn-Aptamer and MWCNTs. After Acetamiprid was introduced, the fluorescence was turn on because ZnS:Mn-Aptamer specifically binded with Acetamiprid. Based on the above-mentioned principle, the quantitative detection and imaging of Acetamiprid in real samples were achieved. The linear equation could be described as F/F0= 1.101 + 0.0312CA(CArepresented the concentration of Acetamiprid, nM) in a linear range of 0-150 nM with a detection limit of 0.7 nM. The results suggested this method had remarkable sensitivity, selectivity, and was very simple without complex operation. Meanwhile, this novel turn-on sensor has the potential of in situ visual determination for pesticide residues in complex system.
