32 research outputs found

    Cellular mechanisms regulating synthetic sex ratio distortion in the Anopheles gambiae germline

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    Genetic control strategies aimed to bias the sex of progenies towards males present a promising new paradigm to eliminate malaria-transmitting mosquitoes. A synthetic sex-ratio distortion (SD) system was successfully engineered in Anopheles gambiae by exploiting the meiotic activity of the I-PpoI endonuclease targeting ribosomal DNA (rDNA) repeats, exclusively located on the X chromosome. Males carrying the SD construct produce highly male-biased progenies without evident reduction in fertility. In this study, we investigated the fate of X and Y chromosomes in these SD males and found that ratios of mature X:Y-bearing sperm were comparable to wild-type insects, indicating absence of selection mechanisms during sperm maturation. We therefore tested the effect of meiotic cleavage of both X and Y chromosomes in a lab-generated SD strain carrying rDNA on both sex chromosomes, showing fertility comparable to wild-type and a reduced male-bias compared to SD males in which only the X is targeted. Exposure of Y-linked rDNA to I-PpoI cleavage for consecutive generations rapidly restored the male-bias to typical high frequencies, indicating a correlation between the number of cleavable targets in each sex chromosome and the sex-ratios found in the progeny. Altogether our results indicate that meiotic cleavage of rDNA repeats, located in the sex chromosomes of A. gambiae SD males, affects the competitiveness of mature sperm to fertilize the female oocyte, thereby generating sex-biased progenies. We also show that the presence of rDNA copies on the Y chromosome does not impair the effectiveness of engineered synthetic SD systems for the control of human malaria mosquitoes

    Comprehensive characterization of a transgene insertion in a highly repetitive, centromeric region of Anopheles mosquitoes

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    The availability of the genomic sequence of the malaria mosquito Anopheles gambiae has in recent years sparked the development of transgenic technologies with the potential to be used as novel vector control tools. These technologies rely on genome editing that confer traits able to affect vectorial capacity. This can be achieved by either reducing the mosquito population or by making mosquitoes refractory to the parasite infection. For any genetically modified organism that is regarded for release, molecular characterization of the transgene and flanking sites are essential for their safety assessment and post-release monitoring. Despite great advancements, Whole-Genome Sequencing data are still subject to limitations due to the presence of repetitive and unannotated DNA sequences. Faced with this challenge, we describe a number of techniques that were used to identify the genomic location of a transgene in the male bias mosquito strain Ag(PMB)1 considered for potential field application. While the initial inverse PCR identified the most likely insertion site on Chromosome 3 R 36D, reassessment of the data showed a high repetitiveness in those sequences and multiple genomic locations as potential insertion sites of the transgene. Here we used a combination of DNA sequencing analysis and in-situ hybridization to clearly identify the integration of the transgene in a poorly annotated centromeric region of Chromosome 2 R 19D. This study emphasizes the need for accuracy in sequencing data for the genome of organisms of medical importance such as Anopheles mosquitoes and other tools available that can support genomic locations of transgenes

    Using Motor Tempi to Understand Rhythm and Grammatical Skills in Developmental Language Disorder and Typical Language Development

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    Children with developmental language disorder (DLD) show relative weaknesses on rhythm tasks beyond their characteristic linguistic impairments. The current study compares preferred tempo and the width of an entrainment region for 5- to 7-year-old typically developing (TD) children and children with DLD and considers the associations with rhythm aptitude and expressive grammar skills in the two populations. Preferred tempo was measured with a spontaneous motor tempo task (tapping tempo at a comfortable speed), and the width (range) of an entrainment region was measured by the difference between the upper (slow) and lower (fast) limits of tapping a rhythm normalized by an individual’s spontaneous motor tempo. Data from N = 16 children with DLD and N = 114 TD children showed that whereas entrainment-region width did not differ across the two groups, slowest motor tempo, the determinant of the upper (slow) limit of the entrainment region, was at a faster tempo in children with DLD vs. TD. In other words, the DLD group could not pace their slow tapping as slowly as the TD group. Entrainment-region width was positively associated with rhythm aptitude and receptive grammar even after taking into account potential confounding factors, whereas expressive grammar did not show an association with any of the tapping measures. Preferred tempo was not associated with any study variables after including covariates in the analyses. These results motivate future neuroscientific studies of low-frequency neural oscillatory mechanisms as the potential neural correlates of entrainment-region width and their associations with musical rhythm and spoken language processing in children with typical and atypical language development

    The psychological science accelerator’s COVID-19 rapid-response dataset

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    In response to the COVID-19 pandemic, the Psychological Science Accelerator coordinated three large-scale psychological studies to examine the effects of loss-gain framing, cognitive reappraisals, and autonomy framing manipulations on behavioral intentions and affective measures. The data collected (April to October 2020) included specific measures for each experimental study, a general questionnaire examining health prevention behaviors and COVID-19 experience, geographical and cultural context characterization, and demographic information for each participant. Each participant started the study with the same general questions and then was randomized to complete either one longer experiment or two shorter experiments. Data were provided by 73,223 participants with varying completion rates. Participants completed the survey from 111 geopolitical regions in 44 unique languages/dialects. The anonymized dataset described here is provided in both raw and processed formats to facilitate re-use and further analyses. The dataset offers secondary analytic opportunities to explore coping, framing, and self-determination across a diverse, global sample obtained at the onset of the COVID-19 pandemic, which can be merged with other time-sampled or geographic data

    The Psychological Science Accelerator's COVID-19 rapid-response dataset

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    A global experiment on motivating social distancing during the COVID-19 pandemic

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    Finding communication strategies that effectively motivate social distancing continues to be a global public health priority during the COVID-19 pandemic. This cross-country, preregistered experiment (n = 25,718 from 89 countries) tested hypotheses concerning generalizable positive and negative outcomes of social distancing messages that promoted personal agency and reflective choices (i.e., an autonomy-supportive message) or were restrictive and shaming (i.e., a controlling message) compared with no message at all. Results partially supported experimental hypotheses in that the controlling message increased controlled motivation (a poorly internalized form of motivation relying on shame, guilt, and fear of social consequences) relative to no message. On the other hand, the autonomy-supportive message lowered feelings of defiance compared with the controlling message, but the controlling message did not differ from receiving no message at all. Unexpectedly, messages did not influence autonomous motivation (a highly internalized form of motivation relying on one’s core values) or behavioral intentions. Results supported hypothesized associations between people’s existing autonomous and controlled motivations and self-reported behavioral intentions to engage in social distancing. Controlled motivation was associated with more defiance and less long-term behavioral intention to engage in social distancing, whereas autonomous motivation was associated with less defiance and more short- and long-term intentions to social distance. Overall, this work highlights the potential harm of using shaming and pressuring language in public health communication, with implications for the current and future global health challenges

    Erratum: Author Correction: A multi-country test of brief reappraisal interventions on emotions during the COVID-19 pandemic (Nature human behaviour (2021) 5 8 (1089-1110))

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    A multi-country test of brief reappraisal interventions on emotions during the COVID-19 pandemic.

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    The COVID-19 pandemic has increased negative emotions and decreased positive emotions globally. Left unchecked, these emotional changes might have a wide array of adverse impacts. To reduce negative emotions and increase positive emotions, we tested the effectiveness of reappraisal, an emotion-regulation strategy that modifies how one thinks about a situation. Participants from 87 countries and regions (n = 21,644) were randomly assigned to one of two brief reappraisal interventions (reconstrual or repurposing) or one of two control conditions (active or passive). Results revealed that both reappraisal interventions (vesus both control conditions) consistently reduced negative emotions and increased positive emotions across different measures. Reconstrual and repurposing interventions had similar effects. Importantly, planned exploratory analyses indicated that reappraisal interventions did not reduce intentions to practice preventive health behaviours. The findings demonstrate the viability of creating scalable, low-cost interventions for use around the world
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