219 research outputs found

    The potential of transgenic legumes in integrated bruchid management: assessing the impact on bruchid parasitoids

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    Leguminous seeds are an important staple food and source of nutrition in many countries. Bruchid beetles (Coleoptera: Bruchidae) are responsible for the greatest post-harvest losses to stored legumes. A powerful strategy to control bruchid infestations is the combination of plant resistance factors and biological control provided by parasitoids. Potent resistance factors are α-amylase inhibitors (αAI) which inhibit the starch metabolism in sensitive insects. Genetic engineering has been used to transfer αAI-1 from the common bean (Phaseolus vulgaris) to other leguminous plants which are subsequently protected from the attack by several bruchid species. However, there are concerns regarding the effects that the expressed insecticidal protein might have on non-target organisms. Here, we present an approach to assess the impact of αAI-1 genetically modified legumes on bruchid parasitoids. Keywords: Risk assessment, Genetically modified plants, Non-target organisms; α-amylase inhibitor; αAI-

    Multimodality Imaging Of Torpedo Maculopathy With Swept-Source, En Face Optical Coherence Tomography And Optical Coherence Tomography Angiography.

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    PURPOSE: Multimodality image analysis of two cases of torpedo maculopathy. METHODS: Imaging with fundus photography, autofluorescence (AF), swept-source optical coherence tomography (OCT), en face OCT, and OCT angiography. RESULTS: The basal diameter of the torpedo lesions was 1 mm × 2 mm. One case had a satellite lesion. Autofluorescence indicated variable loss of signal. Swept-source OCT and en face OCT demonstrated fundus excavation, attenuation of nuclear layers and disruption of the outer plexiform layer, loss of photoreceptors and a subretinal cleft. In one case, Sattler layer appeared extended at the cleft. Optical coherence tomography angiography indicated loss of flow in deep retinal vessels and increased flow in choroidal vessels surrounding the cleft. CONCLUSION: Multimodal imaging findings of torpedo maculopathy include disruption of the deep retinal capillary network, expansion of Sattler layer, and increased signal around the subretinal cleft

    Félix de Azara, ingeniero y naturalista del siglo XVIII

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    Bibliografía: p. 119-126

    Validation of Concentric Rings Method as a Topographic Measure of Retinal Nonperfusion in Ultra-Widefield Fluorescein Angiography

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    PURPOSE: To validate the use of concentric rings as a method to measure topographic area of retinal nonperfusion in ultra-widefield angiography with the ischemic index method, which is the most frequently used method to measure nonperfusion in ultra-widefield angiography. DESIGN: Validation study and reliability analysis. METHODS: setting: Single-center study performed at National Institute for Health Research Moorfields Biomedical Research Centre, London, United Kingdom. STUDY POPULATION: Twenty-eight ultra-widefield angiogram images of eyes with central retinal vein occlusion. OBSERVATION PROCEDURE: The concentric rings method consists of 6 macula-centered concentric rings divided into 12 segments each. Each image was graded by 5 graders using both the concentric rings and the ischemic index methods. MAIN OUTCOME MEASURES: Agreement between the 2 methods was calculated using the intraclass correlation coefficient. Intertest agreement, intergrader agreement, test-retest reliability, and the time taken to grade using these 2 methods were compared. RESULTS: The intertest agreement between concentric rings method and ischemic index method was 0.965. The intergrader agreement was 0.910 for the concentric rings method and 0.898 with the ischemic index method. The test-retest reliability was 0.975 for the rings and 0.979 for the ischemic index. Average grading time per image was 187 s and 297 s for the concentric rings method and ischemic index method, respectively, P < .001. CONCLUSION: The concentric rings method has an "almost-perfect" intergrader agreement and intertest agreement with the ischemic index method, with a shorter grading time

    The Relationship Between Retinal Vessel Oxygenation and Spatial Distribution of Retinal Nonperfusion in Retinal Vascular Diseases

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    Purpose: We study the relationship between retinal vessel oxygenation and the spatial distribution of retinal nonperfusion using ultrawide field angiography in eyes with retinal vascular diseases. Methods: This prospective single center study recruited 57 eligible eyes from 44 patients with retinal vascular diseases. Retinal oximetry measurements were obtained using the Oxymap T1 device to determine the arteriovenous (AV) difference. Retinal nonperfusion was measured from ultrawide field angiography images taken with the Optos 200TX system and superimposing the images with the concentric rings template to determine the area and distribution of retinal nonperfusion. Results: Seven (12.3%) eyes had a diagnosis of a branch or hemiretinal vein occlusion, 24 (42.1%) with central retinal vein occlusion and 26 (45.6%) with diabetic retinopathy (11 [19.3%] nonproliferative and 15 [26.3%] proliferative diabetic retinopathy). The correlation between the total area of retinal nonperfusion with the AV difference controlling for age was not statistically significant (R = -0.103, P = 0.449). However, when analyzing the correlation of AV difference with the area of retinal nonperfusion in the posterior pole controlling for age and peripheral nonperfusion, this was significant (R = -0.295, P = 0.029). This was not significant for the area of retinal nonperfusion in the periphery while controlling for posterior pole nonperfusion and age (R = 0.124, P = 0.368). Conclusions: Retinal nonperfusion has a negative correlation with AV difference measured on retinal oximetry. This correlation is significant in the posterior pole, but not in the peripheral retina

    Expression of a barley cystatin gene in maize enhances resistance against phytophagous mites by altering their cysteine-proteases

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    Phytocystatins are inhibitors of cysteine-proteases from plants putatively involved in plant defence based on their capability of inhibit heterologous enzymes. We have previously characterised the whole cystatin gene family members from barley (HvCPI-1 to HvCPI-13). The aim of this study was to assess the effects of barley cystatins on two phytophagous spider mites, Tetranychus urticae and Brevipalpus chilensis. The determination of proteolytic activity profile in both mite species showed the presence of the cysteine-proteases, putative targets of cystatins, among other enzymatic activities. All barley cystatins, except HvCPI-1 and HvCPI-7, inhibited in vitro mite cathepsin L- and/or cathepsin B-like activities, HvCPI-6 being the strongest inhibitor for both mite species. Transgenic maize plants expressing HvCPI-6 protein were generated and the functional integrity of the cystatin transgene was confirmed by in vitro inhibitory effect observed against T. urticae and B. chilensis protein extracts. Feeding experiments impaired on transgenic lines performed with T. urticae impaired mite development and reproductive performance. Besides, a significant reduction of cathepsin L-like and/or cathepsin B-like activities was observed when the spider mite fed on maize plants expressing HvCPI-6 cystatin. These findings reveal the potential of barley cystatins as acaricide proteins to protect plants against two important mite pests

    The AKARI/IRC Mid-Infrared All-Sky Survey

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    Context : AKARI is the first Japanese astronomical satellite dedicated to infrar ed astronomy. One of the main purposes of AKARI is the all-sky survey performed with six infrared bands between 9 and 200um during the period from 2006 May 6 to 2007 August 28. In this paper, we present the mid-infrared part (9um and 18um b ands) of the survey carried out with one of the on-board instruments, the Infrar ed Camera (IRC). Aims : We present unprecedented observational results of the 9 and 18um AKARI al l-sky survey and detail the operation and data processing leading to the point s ource detection and measurements. Methods : The raw data are processed to produce small images for every scan and point sources candidates, above the 5-sigma noise level per single scan, are der ived. The celestial coordinates and fluxes of the events are determined statisti cally and the reliability of their detections is secured through multiple detect ions of the same source within milli-seconds, hours, and months from each other. Results : The sky coverage is more than 90% for both bands. A total of 877,091 s ources (851,189 for 9um, 195,893 for 18um) are confirmed and included in the cur rent release of the point source catalogue. The detection limit for point source s is 50mJy and 90mJy for the 9um and 18um bands, respectively. The position accu racy is estimated to be better than 2". Uncertainties in the in-flight absolute flux calibration are estimated to be 3% for the 9um band and 4% for the 18um ban d. The coordinates and fluxes of detected sources in this survey are also compar ed with those of the IRAS survey and found to be statistically consistent.Comment: Accepted for publication in AandA AKARI special issu

    Quantifying Retinal Area in Ultra-Widefield Imaging Using a 3-Dimensional Printed Eye Model

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    Purpose: To study the effects of different axial lengths on ultra-widefield imaging to determine the presence of distortion in images despite software correction and calculate an enlargement factor based on angular location. / Design: Experimental image analysis study. / Study Objects: Three 3-dimensional printed model eyes simulating eyes with axial lengths of 22, 24, and 26 mm. Each model has a grid of rings 9° apart centered at the posterior pole. / Methods: Single-center study performed at the National Institute for Health Research Moorfields Biomedical Research Centre (London, UK). Each model was imaged using Optos 200TX (Optos, Dunfermline, UK). Two images for each model eye that were corrected using V2 Vantage Pro software (Optos) were used for analysis and the average values obtained. Each image inter-ring area was measured using ImageJ to obtain a measured image area in pixel and square millimeters. This was compared with the true calculated object inter-ring area and an enlargement factor was determined. / Main Outcome Measures: Measured image inter-ring area in pixels and square millimeters. True calculated object inter-ring area in square millimeters. / Results: The enlargement factor of the rings gradually increases toward the periphery with factors of 1.4 at 45° and 1.9 at the equator. The axial lengths did not affect the enlargement factor of the rings imaged in 3 different model eyes (P = 0.9512). The anterior equator exhibits a significant distortion despite the software correction. / Conclusion: The enlargement factor depends on angular location and not axial length. The enlargement factors can be used in clinical practice to more accurately measure area in ultra-widefield imaging
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