1,324 research outputs found
Direct measurements of mean Reynolds stress and ripple roughness in the presence of energetic forcing by surface waves
Author Posting. © American Geophysical Union, 2018. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 123 (2018): 2494-2512, doi:10.1002/2017JC013252.Direct covariance observations of the mean flow Reynolds stress and sonar images of the seafloor collected on a waveâexposed inner continental shelf demonstrate that the drag exerted by the seabed on the overlying flow is consistent with boundary layer models for waveâcurrent interaction, provided that the orientation and anisotropy of the bed roughness are appropriately quantified. Large spatial and temporal variations in drag result from nonequilibrium ripple dynamics, ripple anisotropy, and the orientation of the ripples relative to the current. At a location in coarse sand characterized by large twoâdimensional orbital ripples, the observed drag shows a strong dependence on the relative orientation of the mean current to the ripple crests. At a contrasting location in fine sand, where more isotropic subâorbital ripples are observed, the sensitivity of the current to the orientation of the ripples is reduced. Further, at the coarse site under conditions when the currents are parallel to the ripple crests and the wave orbital diameter is smaller than the wavelength of the relic orbital ripples, the flow becomes hydraulically smooth. This transition is not observed at the fine site, where the observed wave orbital diameter is always greater than the wavelength of the observed subâorbital ripples. Paradoxically, the dominant alongâshelf flows often experience lower drag at the coarse site than at the fine site, despite the larger ripples, highlighting the complex dynamics controlling drag in waveâexposed environments with heterogeneous roughness.National Science Foundation Ocean Sciences Division Award Grant Number: 1356060;
U.S. Geological Survey Coastal and Marine Geology Program2018-09-2
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Selected Legislative Proposals to Reform the Housing Finance System
This report briefly explains the different approaches to housing finance reform proposed by the three bills, focusing on efforts to replace Fannie Mae and Freddie Mac and reform FHA
Developing a Tanshinone IIA Memetic by Targeting MIOS to Regulate mTORC1 and Autophagy in Glioblastoma
Tanshinone IIA (T2A) is a bioactive compound that provides promise in the treatment of Glioblastoma multiforme (GBM), with a range of molecular mechanisms including inhibition of the mechanistic target of rapamycin complex 1 (mTORC1) and the induction of autophagy. Recently, T2A has been demonstrated to function through sestrin 2 (SESN) to inhibit mTORC1 activity, but this pathway has not been investigated regarding autophagy. Here we employed the model system Dictyostelium discoideum and GBM cell lines to investigate the role of T2A in autophagy induction, focusing on the regulation of SESN via a GATOR2 component MIOS, to mTORC1. We show that in D. discoideum, T2A treatment induces autophagy, and both this effect and mTORC1 inhibition is lost upon ablation of either SESN (sesn-) or MIOS (mios-). We then investigated targeting MIOS to reproduce this effect of T2A. Here, computational analysis identified 25 novel compounds predicted to strongly bind the human MIOS protein, and one compound (MIOS inhibitor 3; Mi3) that reduced cell proliferation in two GBM cell lines. Furthermore, Mi3 specificity was demonstrated through the reduction of D. discoideum cell proliferation and induced autophagy, dependent upon MIOS. These effects were also confirmed in GBM cells, where Mi3 treatment also inhibited mTORC1 activity and induced autophagy. Thus, we identify a potential T2A mimetic with demonstrated effects on inhibition of mTORC1 and induction of autophagy in GBM cells
The ORACLE Children Study:Educational outcomes at 11 years of age following antenatal prescription of erythromycin or co-amoxiclav
Background Antibiotics used for women in spontaneous preterm labour without overt infection, in contrast to those with preterm rupture of membranes, are associated with altered functional outcomes in their children. Methods From the National Pupil Database, we used Key Stage 2 scores, national test scores in school year 6 at 11 years of age, to explore the hypothesis that erythromycin and co-amoxiclav were associated with poorer educational outcomes within the ORACLE Children Study. Results Anonymised scores for 97% of surviving children born to mothers recruited to ORACLE and resident in England were analysed against treatment group adjusting for key available socio-demographic potential confounders. No association with crude or with adjusted scores for English, mathematics or science was observed by maternal antibiotic group in either women with preterm rupture of membranes or spontaneous preterm labour with intact membranes. While the proportion receiving special educational needs was similar in each group (range 31.6-34.4%), it was higher than the national rate of 19%. Conclusions Despite evidence that antibiotics are associated with increased functional impairment at 7 years, educational test scores and special needs at 11 years of age show no differences between trial groups. Trial registration number ISCRT Number 52995660 (original ORACLE trial number).</p
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Celtic censure: representing Wales in eighteenth-century Germany
Drawing on Pierre Bourdieu's notion of regionalist discourse as the performative legitimation of specific frontiers, this article examines how the English traveller Samuel Jackson Pratt mediated a picture of the Welsh to late eighteenth-century readers in his Gleanings Through Wales, Holland and Westphalia (1795). This process of mediation was further complicated by the translation of this work into German as the Aehrenlese auf einer Reise durch Wallis, which appeared with the Leipzig publisher Lincke in 1798. While this work made an important contribution to German Celtophilia in the Romantic period, the German translator was careful to omit its more Sternean passages, in favour of factual narrative. Pratt's account of his travel through Wales, mediated in turn to a German audience through its Leipzig translator, therefore embodies several layers of cultural transfer that generate a complex and multifaceted image of Wales at the close of the eighteenth century
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Evaluating Multi-Level Models to Test Occupancy State Responses of Plethodontid Salamanders
Correction
23 Dec 2015: The PLOS ONE Staff (2015) Correction: Evaluating Multi-Level Models to Test Occupancy State Responses of Plethodontid Salamanders. PLOS ONE 10(12): e0145899. https://doi.org/10.1371/journal.pone.0145899Plethodontid salamanders are diverse and widely distributed taxa and play critical roles in ecosystem processes. Due to salamander use of structurally complex habitats, and because only a portion of a population is available for sampling, evaluation of sampling designs and estimators is critical to provide strong inference about Plethodontid ecology and responses to conservation and management activities. We conducted a simulation study to evaluate the effectiveness of multi-scale and hierarchical single-scale occupancy models in the context of a Before-After Control-Impact (BACI) experimental design with multiple levels of sampling. Also, we fit the hierarchical single-scale model to empirical data collected for Oregon slender and Ensatina salamanders across two years on 66 forest stands in the Cascade Range, Oregon, USA. All models were fit within a Bayesian framework. Estimator precision in both models improved with increasing numbers of primary and secondary sampling units, underscoring the potential gains accrued when adding secondary sampling units. Both models showed evidence of estimator bias at low detection probabilities and low sample sizes; this problem was particularly acute for the multi-scale model. Our results suggested that sufficient sample sizes at both the primary and secondary sampling levels could ameliorate this issue. Empirical data indicated Oregon slender salamander occupancy was associated strongly with the amount of coarse woody debris (posterior mean = 0.74; SD = 0.24); Ensatina occupancy was not associated with amount of coarse woody debris (posterior mean = -0.01; SD = 0.29). Our simulation results indicate that either model is suitable for use in an experimental study of Plethodontid salamanders provided that sample sizes are sufficiently large. However, hierarchical single-scale and multi-scale models describe different processes and estimate different parameters. As a result, we recommend careful consideration of study questions and objectives prior to sampling data and fitting models
C-STICH2: emergency cervical cerclage to prevent miscarriage and preterm birthâstudy protocol for a randomised controlled trial
Abstract Background Cervical cerclage is a recognised treatment to prevent late miscarriage and pre-term birth (PTB). Emergency cervical cerclage (ECC) for cervical dilatation with exposed unruptured membranes is less common and the potential benefits of cerclage are less certain. A randomised control trial is needed to accurately assess the effectiveness of ECC in preventing pregnancy loss compared to an expectant approach. Methods C-STICH2 is a multicentre randomised controlled trial in which women presenting with cervical dilatation and unruptured exposed membranes at 16 +â0 to 27 +â6âweeks gestation are randomised to ECC or expectant management. Trial design includes 18âmonth internal pilot with embedded qualitative process evaluation, minimal data set and a within-trial health economic analysis. Inclusion criteria are â„16âyears, singleton pregnancy, exposed membranes at the external os, gestation 16 +â0â27 +â6âweeks, and informed consent. Exclusion criteria are contraindication to cerclage, cerclage in situ or previous cerclage in this pregnancy. Randomisation occurs via an online service in a 1:1 ratio, using a minimisation algorithm to reduce chance imbalances in key prognostic variables (site, gestation and dilatation). Primary outcome is pregnancy loss; a composite including miscarriage, termination of pregnancy and perinatal mortality defined as stillbirth and neonatal death in the first week of life. Secondary outcomes include all core outcomes for PTB. Two-year development outcomes will be assessed using general health and Parent Report of Childrenâs Abilities-Revised (PARCA-R) questionnaires. Intended sample size is 260 participants (130 each arm) based on 60% rate of pregnancy loss in the expectant management arm and 40% in the ECC arm, with 90% power and alpha 0.05. Analysis will be by intention-to-treat. Discussion To date there has been one small trial of ECC in 23 participants which included twin and singleton pregnancies. This small trial along with the largest observational study (n = 161) found ECC to prolong pregnancy duration and reduce deliveries before 34âweeks gestation. It is important to generate high quality evidence on the effectiveness of ECC in preventing pregnancy loss, and improve understanding of the prevalence of the condition and frequency of complications associated with ECC. An adequately powered RCT will provide the highest quality evidence regarding optimum care for these women and their babies. Trial registration ISRCTN Registry ISRCTN12981869 . Registered on 13th June 2018
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