60 research outputs found

    Radial flow through deformable porous shells

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    Techniques in data communications

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    LD:f83/5432 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

    C. elegans SUP-46, an HNRNPM family RNA-binding protein that prevents paternally-mediated epigenetic sterility

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    Abstract Background In addition to DNA, gametes contribute epigenetic information in the form of histones and non-coding RNA. Epigenetic programs often respond to stressful environmental conditions and provide a heritable history of ancestral stress that allows for adaptation and propagation of the species. In the nematode C. elegans, defective epigenetic transmission often manifests as progressive germline mortality. We previously isolated sup-46 in a screen for suppressors of the hexosamine pathway gene mutant, gna-2(qa705). In this study, we examine the role of SUP-46 in stress resistance and progressive germline mortality. Results We identified SUP-46 as an HNRNPM family RNA-binding protein, and uncovered a highly novel role for SUP-46 in preventing paternally-mediated progressive germline mortality following mating. Proximity biotinylation profiling of human homologs (HNRNPM, MYEF2) identified proteins of ribonucleoprotein complexes previously shown to contain non-coding RNA. Like HNRNPM and MYEF2, SUP-46 was associated with multiple RNA granules, including stress granules, and also formed granules on active chromatin. SUP-46 depletion disrupted germ RNA granules and caused ectopic sperm, increased sperm transcripts, and chronic heat stress sensitivity. SUP-46 was also required for resistance to acute heat stress, and a conserved “MYEF2” motif was identified that was needed for stress resistance. Conclusions In mammals, non-coding RNA from the sperm of stressed males has been shown to recapitulate paternal stress phenotypes in the offspring. Our results suggest that HNRNPM family proteins enable stress resistance and paternally-mediated epigenetic transmission that may be conserved across species

    Factors affecting accuracy and precision in ultrasound guided radiotherapy.

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    Background and purposeTransperineal ultrasound (TPUS) is used clinically for directly assessing prostate motion. Factors affecting accuracy and precision in TPUS motion estimation must be assessed to realise its full potential.Methods and materialsPatients were imaged using volumetric TPUS during the Clarity-Pro trial (NCT02388308). Prostate motion was measured online at patient set-up and offline by experienced observers. Cone beam CT with markers was used as a comparator and observer performance was also quantified. The influence of different clinical factors was examined to establish specific recommendations towards efficacious ultrasound guided radiotherapy.ResultsFrom 330 fractions in 22 patients, offline observer random errors were 1.5 mm, 1.3 mm, 1.9 mm (left-right, superior-inferior, anteroposterior respectively). Errors increased in fractions exhibiting poor image quality to 3.3 mm, 3.3 mm and 6.8 mm. Poor image quality was associated with inconsistent probe placement, large anatomical changes and unfavourable imaging conditions within the patient. Online matching exhibited increased observer errors of: 3.2 mm, 2.9 mm and 4.7 mm. Four patients exhibited large systematic residual errors, of which three had poor quality images. Patient habitus showed no correlation with observer error, residual error, or image quality.ConclusionsTPUS offers the unique potential to directly assess inter- and intra-fraction motion on conventional linacs. Inconsistent image quality, inexperienced operators and the pressures of the clinical environment may degrade precision and accuracy. Experienced operators are essential and cross-centre standards for training and QA should be established that build upon current guidance. Greater use of automation technologies may further minimise uncertainties

    Aggress Behav

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    Rough‐and‐tumble play (RTP), also known as play fighting, is a common form of play frequently reported and studied by researchers. However, one important limitation of past research in the area of RTP has been the neglect of the adolescence period. Consequently, little is known about the function of adolescent RTP as well as about clinical characteristics of youth who engage in this activity after childhood. In a school‐based sample of 1,771 middle school students (ages 9–16 years), the current study sought to address this gap by examining, via bivariate and multivariate logistic regression analyses, the potential cross‐sectional associations of adolescent RTP with (a) selected demographic variables, (b) conduct problem symptoms, (c) substance use, and (d) risk‐taking behaviors, including adjustment for several demographic confounders. Results indicated that adolescents reporting higher rates of conduct problem symptoms were more likely to report a recent participation in RTP. In addition, substance use (experimentation and current consumption of tobacco, alcohol, and marijuana) and risk behaviors assessed all were strongly associated with an increased likelihood of reporting an engagement in RTP. This finding suggests that participation in this activity probably implicates particular phenotypic characteristics including the propensity to engage in health‐damaging behaviors. But the most profound issue raised by this research concerns the strong relationship between RTP and great levels of conduct disorder symptoms, suggesting a possible significant change in the functional significance of RTP in the adolescence period
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