Dissipation pattern and risk assessment of flubendiamide on chili at different agro-climatic conditions in India.

Dissipation pattern and risk assessment of flubendiamide and its metabolite (desiodo flubendiamide) on chili were studied at four different agro-climatic locations of India at the standard and double dose at 60 and 120 g a.i. ha(-1) at 10 days interval. Quantification of residues was done on a high-performance liquid chromatograph (HPLC) with a photo diode array detector. The limit of quantification (LOQ) of this method was found to be 0.01 mg kg(-1) while limit of detection (LOD) being 0.003 mg kg(-1). Residues of flubendiamide were found to be below the determination limit in 15 days at both the dosages in all locations. Half-life of flubendiamide when applied at 60 and 120 g a.i. ha(-1) ranged from 0.85 to 1.80 and from 0.95 to 2.79 days, respectively. On the basis of data generated under the All India Network Project on Pesticide Residues, a preharvest interval (PHI) of 1 day has been recommended and the flubendiamide 480 SC has been registered for use on chili in India by the Central Insecticide Board and Registration Committee, Ministry of Agriculture, Government of India. The maximum residue limit (MRL) of flubendiamide on chili has been fixed by the Food Safety Standard Authority of India, Ministry of Health and Family Welfare, Government of India, as 0.02 µg g(-1) after its risk assessment.

Residual behavior and risk assessment of flubendiamide on tomato at different agro-climatic conditions in India.

Supervised field trials were conducted at four different agro-climatic zones in India to evaluate the dissipation pattern and risk assessment of flubendiamide on tomato. Flubendiamide 480 SC was sprayed on tomato at 48 and 96 g active ingredient (a.i.) ha(-1). Samples of tomato fruits were drawn at 0, 1, 3, 5, 7, 10, 15, and 20 days after treatment. Quantification of residues was done on a high-performance liquid chromatography (HPLC) device with a photo diode array detector. The limit of quantification (LOQ) of this method was found to be 0.01 mg kg(-1) while limit of detection (LOD) being 0.003 mg kg(-1). Residues of flubendiamide were found below the determination limit of 0.01 mg kg(-1) in 20 days at both the dosages in all the locations. The half-life of flubendiamide at an application rate of 48 g a.i. ha(-1) varied from 0.33 to 3.28 days and at 48-g a.i. ranged from 1.21 to 3.00 days. On the basis of data generated under the All India Network Project on Pesticide Residues, a preharvest interval (PHI) of 1 day has been recommended, and the flubendiamide 480 SC has been registered for its use on tomato by the Central Insecticide Board and Registration Committee, Ministry of Agriculture, Government of India. The maximum residue limit (MRL) of flubendiamide on tomato has been fixed by the Ministry of Health and Family Welfare, Government of India under Food Safety Standard Authority of India, as 0.07 µg g(-1) after its risk assessment.

Safety evaluation of flubendiamide and its metabolites on cabbage and persistence in soil in different agroclimatic zones of India.

Supervised field trials following good agricultural practices were conducted at the research farms of four agricultural universities located at four different agroclimatic zones of India to evaluate the persistence and dissipation of flubendiamide and its metabolite, des-iodo flubendiamide, on cabbage. Two spray applications of flubendiamide 480 SC of standard and double dose at the rate of 24 and 48 g a.i. ha(-1) were given to the crop at a 15-day interval, and the residues of flubendiamide 2 h after spray were found in the range of 0.107-0.33 and 0.20-0.49 mg kg(-1) at respective doses. Residue of des-iodo flubendiamide was not detected in any cabbage sample during study period. No residues were found in the soil samples collected from all treated fields after 15 days of application. On the basis of data generated under All India Network Project on Pesticide Residues, a preharvest interval (PHI) of 10 days has been recommended, and the flubendiamide 480 SC has been registered for its use on cabbage by Central Insecticide Board and Registration Committee, Ministry of Agriculture, Government of India. The maximum residue limit (MRL) of flubendiamide on cabbage has been fixed by the Ministry of Health and Family Welfare, Government of India, under Food Safety Standard Authority of India as 0.05 µg/g after its risk assessment.

Factors Affecting Perceptual Threshold in Argus II Retinal Prosthesis Subjects.

PURPOSE: The Argus II epiretinal prosthesis has been developed to provide partial restoration of vision to subjects blinded from outer retinal degenerative disease. Participants were surgically implanted with the system in the United States and Europe in a single arm, prospective, multicenter clinical trial. The purpose of this investigation was to determine which factors affect electrical thresholds in order to inform surgical placement of the device. METHODS: Electrode-retina and electrode-fovea distances were determined using SD-OCT and fundus photography, respectively. Perceptual threshold to electrical stimulation of electrodes was measured using custom developed software, in which current amplitude was varied until the threshold was found. Full field stimulus light threshold was measured using the Espion D-FST test. Relationships between electrical threshold and these three explanatory variables (electrode-retina distance, electrode-fovea distance, and monocular light threshold) were quantified using regression. RESULTS: Regression analysis showed a significant correlation between electrical threshold and electrode-retina distance (R2 = 0.50, P = 0.0002; n = 703 electrodes). 90.3% of electrodes in contact with the macula (n = 207) elicited percepts at charge densities less than 1 mC/cm2/phase. These threshold data also correlated well with ganglion cell density profile (P = 0.03). A weaker, but still significant, inverse correlation was found between light threshold and electrical threshold (R2 < 0.52, P = 0.01). Multivariate modeling indicated that electrode-retina distance and light threshold are highly predictive of electrode threshold (R2 = 0.87; P < 0.0005). CONCLUSIONS: Taken together, these results suggest that while light threshold should be used to inform patient selection, macular contact of the array is paramount. TRANSLATIONAL RELEVANCE: Reported Argus II clinical study results are in good agreement with prior in vitro and in vivo studies, and support the development of higher-density systems that employ smaller diameter electrodes. (clinicaltrials.gov identifier: NCT00407602).

Development of an analytical method for analysis of flubendiamide, des-iodo flubendiamide and study of their residue persistence in tomato and soil.

Flubendiamide is a new insecticide that has been found to give excellent control of lepidopterous pests of tomato. This study has been undertaken to develop an improved method for analysis of flubendiamide and its metabolite des-iodo flubendiamide and determine residue retention in tomato and soil. The analytical method developed involved extraction of flubendiamide and its metabolite des-iodo flubendiamide with acetonitrile, liquid-liquid partitioning into hexane-ethyl acetate mixture (6:4, v v⁻¹) and cleanup with activated neutral alumina. Finally the residues were dissolved in gradient high pressure liquid chromatography (HPLC) grade acetonitrile for analysis by HPLC. The mobile phase, acetonitrile-water at 60:40 (v v⁻¹) proportion and the wavelength of 235 nm gave maximum peak resolution. Using the above method and HPLC parameters described, nearly 100 % recovery of both insecticides were obtained. There was no matrix interference and the limit of quantification (LOQ) of the method was 0.01 mg kg⁻¹. Initial residue deposits of flubendiamide on field-treated tomato from treatments @ 48 and 96 g active ingredient hectare⁻¹ were 0.83 and 1.68 mg kg⁻¹, respectively. The residues of flubendiamide dissipated at the half-life of 3.9 and 4.4 days from treatments @ 48 and 96 g a.i. ha⁻¹, respectively and persisted for 15 days from both the treatments. Des-iodo flubendiamide was not detected in tomato fruits at any time during the study period. Residues of flubendiamide and des-iodo flubendiamide in soil from treatment @ 48 and 96 g a.i. ha⁻¹ were below detectable level (BDL, < 0.01 mg kg⁻¹) after 20 days. Flubendiamide completely dissipated from tomato within 20 days when the 480 SC formulation was applied at doses recommended for protection against lepidopterous pests.

Persistence and dissipation of fluopicolide in/on grape berries and soil under semi arid tropical climatic conditions of India.

Fluopicolide, a relatively new fungicide is used for control of downy mildew of grape. Persistence study of fluopicolide was carried out on grape berries following treatment of the combination product, fluopicolide 4.44% + fosetyl aluminium 66.7% (Profiler 71.14 WG) at the recommended and double the recommended dose of 2.5 and 5.0 kg ha⁻¹. Four treatment sprays were given at 15 day intervals, starting from 1 month after pruning of the vines. Residues of fluopicolide in grape berries were estimated on 0 (1 h), 1, 3, 5, 7, 10, 15, 20, 25, 30 day and at harvest (64 days after the last spray application). The initial residue deposits of fluopicolide on grape berries were 0.58 and 1.32 mg kg⁻¹ from treatment at the recommended and double dose, respectively. Dissipation of fluopicolide residues was a slow process. After 30 days of treatment, 0.068 and 0.204 mg kg⁻¹ of residues still remained in the berries from treatment at the recommended and double dose, respectively. Fluopicolide residues in grape berries dissipated with the half-life of 10.2 and 12.3 days. Residues in grape berries and soil at harvest were below the quantifiable limit of 0.01 mg kg⁻¹ from both the treatments.

Blind subjects implanted with the Argus II retinal prosthesis are able to improve performance in a spatial-motor task.

BACKGROUND/AIMS: To determine to what extent subjects implanted with the Argus II retinal prosthesis can improve performance compared with residual native vision in a spatial-motor task. METHODS: High-contrast square stimuli (5.85 cm sides) were displayed in random locations on a 19″ (48.3 cm) touch screen monitor located 12″ (30.5 cm) in front of the subject. Subjects were instructed to locate and touch the square centre with the system on and then off (40 trials each). The coordinates of the square centre and location touched were recorded. RESULTS: Ninety-six percent (26/27) of subjects showed a significant improvement in accuracy and 93% (25/27) show a significant improvement in repeatability with the system on compared with off (p<0.05, Student t test). A group of five subjects that had both accuracy and repeatability values <250 pixels (7.4 cm) with the system off (ie, using only their residual vision) was significantly more accurate and repeatable than the remainder of the cohort (p<0.01). Of this group, four subjects showed a significant improvement in both accuracy and repeatability with the system on. CONCLUSION: In a study on the largest cohort of visual prosthesis recipients to date, we found that artificial vision augments information from existing vision in a spatial-motor task. Clinical trials registry no NCT00407602.

Residues of acephate and its metabolite methamidophos in/on mango fruit (Mangifera indica L.).

Mango, the major fruit crop of India is affected by stone weevil, which can cause serious damage to the fruits. Acephate gives good control of mango stone weevil. Residues of acephate and its major metabolite, methamidophos were evaluated on mango fruits following repeated spray applications at the recommended dose (0.75 kg a.i. ha⁻¹) and double the recommended dose (1.5 kg a.i. ha⁻¹). Acephate residues mostly remained on the fruit peel which persisted up to 30 days. Movement of residues to the fruit pulp was detected after 1 day of application, increased to maximum of 0.14 and 0.26 mg kg⁻¹ after 3 days and reached to below detectable level (BDL) after 20 days. Methamidophos, a metabolite of acephate, was detected from 3rd day onwards in both peel and pulp and persisted up to 15 days. The residues (acephate + methamidophos) dissipated with the half-life of 5 days in peel and pulp. A safe pre-harvest interval of 30 days is recommended for consumption of mango fruits following treatment of acephate at the recommended dose of 0.75 kg a.i. ha⁻¹.

Persistence and dissipation of flubendiamide and des-iodo flubendiamide in cabbage (Brassica oleracea Linne) and soil.

Flubendiamide belongs to a novel class of insecticide which controls lepidopteran pest complex of cabbage such as diamondback moth, cabbage white butterfly, cluster caterpillar etc. Being a newly introduced insecticide no information is available on its residue persistence in cabbage. A study was undertaken to evaluate the residue persistence of flubendiamide in cabbage and soil following 2 applications of flubendiamide 480 SC at the recommended and double the recommended dose of 24 and 48 g a.i. ha(-1). Initial residue deposits of flubendiamide in cabbage were 0.33 and 0.49 mg kg(-1) respectively. The residues persisted for 10 days from the both the treatments and dissipated with the half-life of 3.9 and 4.45 days, respectively. Des-iodo flubendiamide, a metabolite of flubendiamide, was not detected in cabbage at any time during the study period. Soil sample collected from the treated field after 15 days was free from any residue of flubendiamide or its metabolite.

Correlation of brain-specific S-100 protein and shock-avoidance behaviour with lactational undernourishment in rats.

A study has been undertaken to find out a possible role of brain-specific S-100 protein in the impairment of learned behaviour with lactational undernourishment of rats. The results showed a decrease in the body weight, brain weight as well as brain DNA and S-100 protein of the weanling undernourished rats while the concentration of soluble brain proteins was similar in the weanling undernourished and weanling control rats. When both the groups were subjected to shock-avoidance criterion, the learning and memory were found to be deficient in the undernourished group. It was further observed that nutritional rehabilitation at weaning could not restore the learning and memory of the undernourished animals. The decrease in the concentration of brain-specific S-100 and the deficient learning and memory could be due to a possible structural underdevelopment of brain in these animals.