28 research outputs found

    Novel Pink Bollworm Resistance to the Bt Toxin Cry 1Ac: Effects on Mating, Oviposition, Larval Development and Survival

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    Bt cotton plants are genetically engineered to produce insecticidal toxins from the Bacillus thuringiensis (Bt) Berliner (Bacillales: Bacillaceae) bacterium and target key lepidopteran pests. In all previous strains of pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae) selected in the laboratory for resistance to insecticidal Cry1Ac toxin using an artificial diet containing the toxin, resistance to Cry1Ac and to Bt cotton is linked to three cadherin alleles (r1, r2, and r3). In contrast, the BG(4) pink bollworm strain was selected for resistance to Bt cotton by feeding larvae for four days in each of 42 generations on bolls of ‘NuCOTN33B®’ that expressed Cry1Ac toxin. After additional selection for eleven generations on Cry1Ac-incorporated diet, the susceptibility to Cry1Ac, fecundity, egg viability, and mating of this strain (Bt4R) was compared with the unselected Cry1Ac-susceptible parent strain. Some larvae of the Bt4R strain survived on diet containing ≥ 10 µg Cry1Ac per milliliter artificial diet, but none survived on transgenic cotton bolls. In contrast to strains selected exclusively on Cry1Ac diet, some survival of progeny of reciprocal moth crosses of Bt4R resistant and Bt-susceptible strains occurred on Cry1Ac-treated diet, suggesting differences in levels of dominance. The Bt4R resistant strain does not have the r1, r2, or r3 mutant cadherin genes as do all previous strains of pink bollworm selected on Cry1Ac-treated artificial diet. The combined results suggest a mechanism of resistance to Cry1Ac that is different from previously described cadherin mutations

    Loss-of-Function Variants in HOPS Complex Genes VPS16 and VPS41 Cause Early Onset Dystonia Associated with Lysosomal Abnormalities.

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    OBJECTIVES: The majority of people with suspected genetic dystonia remain undiagnosed after maximal investigation, implying that a number of causative genes have not yet been recognized. We aimed to investigate this paucity of diagnoses. METHODS: We undertook weighted burden analysis of whole-exome sequencing (WES) data from 138 individuals with unresolved generalized dystonia of suspected genetic etiology, followed by additional case-finding from international databases, first for the gene implicated by the burden analysis (VPS16), and then for other functionally related genes. Electron microscopy was performed on patient-derived cells. RESULTS: Analysis revealed a significant burden for VPS16 (Fisher's exact test p value, 6.9 × 109 ). VPS16 encodes a subunit of the homotypic fusion and vacuole protein sorting (HOPS) complex, which plays a key role in autophagosome-lysosome fusion. A total of 18 individuals harboring heterozygous loss-of-function VPS16 variants, and one with a microdeletion, were identified. These individuals experienced early onset progressive dystonia with predominant cervical, bulbar, orofacial, and upper limb involvement. Some patients had a more complex phenotype with additional neuropsychiatric and/or developmental comorbidities. We also identified biallelic loss-of-function variants in VPS41, another HOPS-complex encoding gene, in an individual with infantile-onset generalized dystonia. Electron microscopy of patient-derived lymphocytes and fibroblasts from both patients with VPS16 and VPS41 showed vacuolar abnormalities suggestive of impaired lysosomal function. INTERPRETATION: Our study strongly supports a role for HOPS complex dysfunction in the pathogenesis of dystonia, although variants in different subunits display different phenotypic and inheritance characteristics. ANN NEUROL 2020;88:867-877

    Calibration of acoustic instruments

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    Acoustic instrument calibration is fundamental to the quantitative use of its data for estimating aquatic resource abundance. Regular calibrations also allow instrument performance to be monitored to detect changes due to the environment or component dynamics, degradation, or failure. This is the second ICES Cooperative Research Report (CRR) focussed on calibrations of acoustic instruments. The first, CRR No. 144 (Foote et al., 1987), was published during the era of analogue electronics more than a quarter of a century ago. Since then, not only has the acoustic equipment improved vastly with digital electronics and signal processing, but the techniques for applying them to studies of marine organisms have both advanced and diversified. Motivating, facilitating, and expediting these developments is the work of the Fisheries Acoustics, Science and Technology Working Group (WGFAST) of the International Council for the Exploration of the Sea (ICES). CRR No. 144 guided the fisheries acoustics community to uniformly apply the sphere method to calibrate survey equipment, generally single-frequency, split-beam echosounders. Today, surveys of fishery resources are conducted using a large variety of acoustic instruments including, but not limited to, single-frequency, multifrequency, single-beam, split-beam, broad bandwidth, and multibeam echosounders; side-scan and scanning sonars; acoustic Doppler current profilers; and acoustic cameras. These instruments differ in the ways in which they function, are utilized, and the types of measurements they provide. In most cases, they also require different calibration techniques for optimizing the accuracy and characterizing the precision of the measurements. With technological innovation proceeding at an ever faster pace, the challenge to create a comprehensive and practical guide to calibrating acoustic instruments is formidable. Obviously, not all acoustic instrumentation and methods are addressed here. The ones that are addressed are in various states of maturity. Therefore, the practical aims of this CRR are to document (i) acoustic instruments currently used in fisheries research and surveys, (ii) theoretical principles of calibrating these instruments, and (iii) methods currently being practiced for a selection of commonly used instruments. To meet these goals, the WGFAST formed the Study Group on Calibration of Acoustic Instruments (SGCal) at its meeting in April 2009. The SGCal first met in San Diego, CA, USA in April 2010 to outline the document. Some chapters were drafted intersessionally. The SGCal met for the second time in Reykjavik, Iceland in May 2011 to collectively review some draft chapters. The drafts were refined intersessionally and merged. The draft CRR was collectively reviewed at meetings of the SGCal, in Pasaia, Spain in April 2013 and in New Bedford, MA, USA in May 2014. Multiple independent reviewers provided input, and the final editing was completed in 2014. The authors hope that this CRR will be a valuable reference to both novice and experienced users of fishery acoustic instruments, but recognize that it is a provisional guide that requires refinement and update as the field continues to progress

    Highly integrated model assessment technology and tools

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    Effective and efficient measurement of the development of skill and knowledge, especially in domains of human activity that involve complex and challenging problems, is important with regard to workplace and academic performance. However, there has been little progress in the area of practical measurement and assessment, due in part to the lack of automated tools that are appropriate for assessing the acquisition and development of complex cognitive skills. In the last 2 years, an international team of researchers has developed and validated an integrated set of assessment tools called highly integrated model assessment technology and tools (HIMATT) which addresses this deficiency. HIMATT is web-based and has been shown to scale up for practical use in educational and workplace settings, unlike many of the research tools developed solely to study basic issues in human learning and performance. In this paper, we describe the functions of HIMATT and demonstrate several applications for its use. Additionally, we present two studies on the quality and usability of HIMATT. We conclude with research suggestions for the use of HIMATT and for its further development. © 2009 Association for Educational Communications and Technology
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