rRNA gene activity and control of expression mediated by methylation and imprinting during embryo development in wheat x rye hybrids

Ribosomal RNA genes originating from one parent are often suppressed in interspecific hybrids. We show that treatments during germination with the cytosine analogue 5-azacytidine stably reactivate the expression of the suppressed rRNA genes of rye origin in the wheat x rye amphiploid, triticale, by preventing methylation of sites in the rye rDNA. When 5-azacytidine is applied to embryos of triticale and wheat x rye F1 hybrids nine, or more, days after fertilization, rye rRNA gene expression is stably reactivated in the resulting seedling. Earlier treatments have no effect on rye rRNA gene expression, indicating that undermethylation of DNA early in embryo development is reversible. After 9 days, the methylation status of rRNA genes in maintained throughout development. Since the change in expression follows a methylation change at particular restriction-enzyme sites, the data establish a clear correlation between gene activity and methylation in plants

The meaning of maxima and minima in first order reversal curves: Determining the interaction between species in a sample

First-order reversal curves (FORCs) are a characterization technique for magnetic materials used in a wide range of research fields. Since their first application in the Earth Sciences two decades ago, their importance in science has been continuously growing and new experimental techniques have been subsequently designed based on the original idea of FORCs. Nonetheless, very recent experimental works on very well designed and simple magnetic structures demonstrate that even for the most simple cases the interpretation of FORC data lacks understanding. In this work, we address this problem analytically, explaining the meaning of maxima, minima and noisy tails and set a strategy to extract the interaction field between magnetic structures. The origin of this interaction field is often the magnetostatic energy, however, we propose that this strategy could be applied for estimating exchange interactions too

ECONOMIC BENEFITS OF WEATHER PROTECTION FOR LARGE ROUND BALES

. 1986. Economic benefits of weather protection for large round bales. Can. An economic evaluation ofthe storage losses ofvarious haying systems isreported. This information was necessary to augment a study of the effect of storage characteristicson round bale quality in which round bales from two different round baler types (fixed and variable bale chamber) were stored in five different manners. In addition, the costs of harvesting and storing hay by several methods were evaluated. These costs were translated into costs per "useable" tonneof hay. Values of spoiledhay were compared with the values of weather protection for round bales. The values ofhay spoilage indifferent types of storage were combined with detailed costs of growing, harvesting and storing hay and compared. Economic comparison with traditional rectangular bale harvesting methods is also included. It was found that round bale harvesting was the least expensive method at all volumes. Round bale harvesting with inside storage or plastic wrap protection provided a higher value than outside storage of round bales because of the increased spoilage when not protected. The cost of inside storage was equal to 14% spoilage of round bales

New methods for unmixing sediment grain size data

Grain size distribution (GSD) data are widely used in Earth sciences and although large data sets are regularly generated, detailed numerical analyses are not routine. Unmixing GSDs into components can help understand sediment provenance and depositional regimes/processes. End-member analysis (EMA), which fits one set of end-members to a given data set, is a powerful way to unmix GSDs into geologically meaningful parts. EMA estimates end-members based on covariability within a data set and can be considered as a nonparametric approach. Available EMA algorithms, however, either produce suboptimal solutions or are time consuming. We introduce unmixing algorithms inspired by hyperspectral image analysis that can be applied to GSD data and which provide an improvement over current techniques. Nonparametric EMA is often unable to identify unimodal grain size subpopulations that correspond to single sediment sources. An alternative approach is single-specimen unmixing (SSU), which unmixes individual GSDs into unimodal parametric distributions (e.g., lognormal). We demonstrate that the inherent nonuniqueness of SSU solutions renders this approach unviable for estimating underlying mixing processes. To overcome this, we develop a new algorithm to perform parametric EMA, whereby an entire data set can be unmixed into unimodal parametric end-members (e.g., Weibull distributions). This makes it easier to identify individual grain size subpopulations in highly mixed data sets. To aid investigators in applying these methods, all of the new algorithms are available in AnalySize, which is GUI software for processing and unmixing grain size data

Addressing School Related Gender Based Violence in Zambia: A Scoping Study

This report presents findings from a scoping study of policy, practice and evidence on school-related gender-based violence (SRGBV) in Zambia, which was carried out in 2016. The main objective of the study was to analyse responses to gender-based violence in and around schools in Zambia, in order to inform future planning of policy and practice initiatives. The study was a collaboration between the government of Zambia, UNICEF, and researchers at the UCL Institute of Education working alongside consultant, Romana Maumbu. Its core elements consist of: analysis of legislation and policy; analysis of programming on SRGBV; mapping of stakeholders working on SRGBV; and the identification and evaluation of research and data sets. The findings presented here will be used to guide decision making for phase two of the initiative which will take place during 2017, as well as longer term planning and action on SRGBV in Zambia. The findings will provide the basis for reflection and the development of the action plan for the next phase of the EGVS initiative

What Brown saw and you can too

A discussion is given of Robert Brown's original observations of particles ejected by pollen of the plant \textit{Clarkia pulchella} undergoing what is now called Brownian motion. We consider the nature of those particles, and how he misinterpreted the Airy disc of the smallest particles to be universal organic building blocks. Relevant qualitative and quantitative investigations with a modern microscope and with a "homemade" single lens microscope similar to Brown's, are presented.Comment: 14.1 pages, 11 figures, to be published in the American Journal of Physics. This differs from the previous version only in the web site referred to in reference 3. Today, this Brownian motion web site was launched, and http://physerver.hamilton.edu/Research/Brownian/index.html, is now correc

Enseignement de l'échographie au chevet à l'aide d'une technique de visioconférence

Implication Statement Point-of-care ultrasound (POCUS) has usually been taught using a hands-on, in-person approach. We present a novel approach to delivering POCUS virtually using a dual image videoconferencing technique. We outline an easily implementable approach and summarize medical students’ experience and feedback. This form of delivery has potential to improve instructional delivery in resource restricted settings or during pandemic restrictions where a hands-on approach may not be possible.Énoncé des implications de la recherche L'échographie au chevet fait généralement l’objet d’un enseignement pratique, en personne. Nous présentons une nouvelle approche, virtuelle, pour son enseignement, par visioconférence à double flux vidéo. L’approche que nous décrivons est facile à mettre en œuvre. Nous résumons l'expérience et les commentaires des étudiants en médecine sur cette modalité qui est susceptible d'améliorer l'enseignement dans des contextes où les ressources sont limitées ou en cas de pandémie, lorsque l’approche pratique n'est pas possible

Fermi surface and order parameter driven vortex lattice structure transitions in twin-free YBa2Cu3O7

We report on small-angle neutron scattering studies of the intrinsic vortex lattice (VL) structure in detwinned YBa2Cu3O7 at 2 K, and in fields up to 10.8 T. Because of the suppressed pinning to twin-domain boundaries, a new distorted hexagonal VL structure phase is stabilized at intermediate fields. It is separated from a low-field hexagonal phase of different orientation and distortion by a first-order transition at 2.0(2) T that is probably driven by Fermi surface effects. We argue that another first-order transition at 6.7(2) T, into a rhombic structure with a distortion of opposite sign, marks a crossover from a regime where Fermi surface anisotropy is dominant, to one where the VL structure and distortion is controlled by the order-parameter anisotropy.Comment: 4 pages, 3 figures (2 color), minor change