Short-term Osteoclastic Activity Induced by Locally High Concentrations of Recombinant Human Bone Morphogenetic Protein–2 in a Cancellous Bone Environment

Study Design. An experimental study investigating osteoclastic activity induced by rhBMP-2 in sheep. Objective. To examine the effects of increasing local rhBMP-2 concentration on osteoclastic response and peri-implant bone resorption. Summary of Background Data. Level I clinical studies have established the safe and effective volume and concentration of rhBMP-2 delivered on an absorbable collagen sponge. However, peri-implant bone resorption appearing as decreased mineral density has been observed radiographically in rare instances after implantation of rhBMP-2 on an absorbable collagen sponge (rhBMP-2/ACS). Methods. Bilateral corticocancellous defects were created in the distal femora of 30 adult sheep. Combinations of rhBMP-2/ACS implant volume (V) (1V = normal fill or 2V = overfilled) and rhBMP-2 solution concentration (⤫) (1 ⤫ normal concentration or 3.5 ⤫ = hyperconcentrated) resulted in local rhBMP-2 concentrations of 0⤫, 1⤫, 2⤫, 3.5⤫, and 7⤫ the estimated effective concentration for this model. Faxitron radiography, quantitative CT, histology, and quantitative histomorphometry were conducted in a blinded fashion to analyze the effect of the treatments. Results. At 1 week, the normal fill-normal concentration implants (1⤫) produced the least transient osteoclastic activity resulting in limited peri-implant resorption. Overfilledhyperconcentrated implants (2⤫, 3.5⤫) demonstrated moderate resorption zones. Overfilled-hyperconcentrated implants (7⤫) demonstrated extensive osteoclastic activity and marked resorption. Results at 4 and 8 weeks revealed dense osteoid and bone in the voids with progressive bony healing. Control defects showed no osteoclastic activity with little to no bony healing. Conclusion. Increasing the local rhBMP-2 concentration by overfilling the defect with rhBMP-2/ACS or hyper-concentrating the rhBMP-2 solution on the absorbable collagen sponge led to a concentration-dependent osteoclastic resorption of peri-implant bone. The osteoclastic effect was transient, and progressive healing took place over the 8-week survival period

The influence of droplet size and biodegradation on the transport of subsurface oil droplets during the Deepwater Horizon: a model sensitivity study

A better understanding of oil droplet formation, degradation, and dispersal in deep waters is needed to enhance prediction of the fate and transport of subsurface oil spills. This research evaluates the influence of initial droplet size and rates of biodegradation on the subsurface transport of oil droplets, specifically those from the Deepwater Horizon oil spill. A three-dimensional coupled model was employed with components that included analytical multiphase plume, hydrodynamic and Lagrangian models. Oil droplet biodegradation was simulated based on first order decay rates of alkanes. The initial diameter of droplets (10–300 μm) spanned a range of sizes expected from dispersant-treated oil. Results indicate that model predictions are sensitive to biodegradation processes, with depth distributions deepening by hundreds of meters, horizontal distributions decreasing by hundreds to thousands of kilometers, and mass decreasing by 92–99% when biodegradation is applied compared to simulations without biodegradation. In addition, there are two- to four-fold changes in the area of the seafloor contacted by oil droplets among scenarios with different biodegradation rates. The spatial distributions of hydrocarbons predicted by the model with biodegradation are similar to those observed in the sediment and water column, although the model predicts hydrocarbons to the northeast and east of the well where no observations were made. This study indicates that improvement in knowledge of droplet sizes and biodegradation processes is important for accurate prediction of subsurface oil spills.National Science Foundation (U.S.) (RAPID: Deepwater Horizon Grant OCE-1048630)National Science Foundation (U.S.) (RAPID: Deepwater Horizon Grant OCE-1044573)National Science Foundation (U.S.) (RAPID: Deepwater Horizon Grant CBET-1045831)Gulf of Mexico Research Initiativ

Water and Land-surface Feedbacks in a Polygonal Tundra Environment

The Arctic, including Alaska, is currently experiencing an unprecedented degree of environmental change with increases in both the mean annual surface temperature and precipitation. These observed changes in the climate regime has resulted in a permafrost condition that is particularly sensitive to changes in both Changes in the surface energy balance and water balances and is susceptible to degradation. Thermokarst topography forms whenever ice-rich permafrost thaws and the ground subsides into the resulting voids. Extensive areas of thermokarst activity are currently being observed throughout the arctic and sub-arctic environments. The important processes involved with thermokarsting include surface ponding, surface subsidence, changes in drainage patterns, and related erosion. In this research, we are applying the land-surface evolution model, ERODE (http://csdms.colorado.edu/wiki/Model:Erode), to an area dominated by low- center, ice-wedge polygons. We are modifying the ERODE model to include land surface subsistence in areas where the maximum active layer depth exceeds the protective layer – the layer of soil above ice-rich soils that acts as a buffer to surface energy processes. The goal of this modeling study is to better understand and quantify the development of thermokarst features in the polygonal tundra environment, emphasizing the resulting feedbacks and connections between hydrologic processes and a dynamic surface topography. Further, we are working on understanding the balance between thermal and mechanical processes with regard to thermokarst processes. This unique application of a landscape evolution model may provide valuable insight related to the rates and spatial extent of thermokarst development and the subsequent hydrologic responses to degrading permafrost in a changing climate.Office of Biological and Environmental Research, Department of Energy Office of Science, Alaska Climate Science Cente

Narratives of self and identity in women's prisons: stigma and the struggle for self-definition in penal regimes

A concern with questions of selfhood and identity has been central to penal practices in women's prisons, and to the sociology of women's imprisonment. Studies of women's prisons have remained preoccupied with women prisoners’ social identities, and their apparent tendency to adapt to imprisonment through relationships. This article explores the narratives of women in two English prisons to demonstrate the importance of the self as a site of meaning for prisoners and the central place of identity in micro-level power negotiations in prisons

Effective modeling for integrated water resource management: a guide to contextual practices by phases and steps and future opportunities

The effectiveness of Integrated Water Resource Management (IWRM) modeling hinges on the quality of practices employed through the process, starting from early problem definition all the way through to using the model in a way that serves its intended purpose. The adoption and implementation of effective modeling practices need to be guided by a practical understanding of the variety of decisions that modelers make, and the information considered in making these choices. There is still limited documented knowledge on the modeling workflow, and the role of contextual factors in determining this workflow and which practices to employ. This paper attempts to contribute to this knowledge gap by providing systematic guidance of the modeling practices through the phases (Planning, Development, Application, and Perpetuation) and steps that comprise the modeling process, positing questions that should be addressed. Practice-focused guidance helps explain the detailed process of conducting IWRM modeling, including the role of contextual factors in shaping practices. We draw on findings from literature and the authors’ collective experience to articulate what and how contextual factors play out in employing those practices. In order to accelerate our learning about how to improve IWRM modeling, the paper concludes with five key areas for future practice-related research: knowledge sharing, overcoming data limitations, informed stakeholder involvement, social equity and uncertainty management. © 2019 Elsevier Lt

The Earth System Prediction Suite: Toward a Coordinated U.S. Modeling Capability

The Earth System Prediction Suite (ESPS) is a collection of flagship U.S. weather and climate models and model components that are being instrumented to conform to interoperability conventions, documented to follow metadata standards, and made available either under open source terms or to credentialed users.The ESPS represents a culmination of efforts to create a common Earth system model architecture, and the advent of increasingly coordinated model development activities in the U.S. ESPS component interfaces are based on the Earth System Modeling Framework (ESMF), community-developed software for building and coupling models, and the National Unified Operational Prediction Capability (NUOPC) Layer, a set of ESMF-based component templates and interoperability conventions. This shared infrastructure simplifies the process of model coupling by guaranteeing that components conform to a set of technical and semantic behaviors. The ESPS encourages distributed, multi-agency development of coupled modeling systems, controlled experimentation and testing, and exploration of novel model configurations, such as those motivated by research involving managed and interactive ensembles. ESPS codes include the Navy Global Environmental Model (NavGEM), HYbrid Coordinate Ocean Model (HYCOM), and Coupled Ocean Atmosphere Mesoscale Prediction System (COAMPS); the NOAA Environmental Modeling System (NEMS) and the Modular Ocean Model (MOM); the Community Earth System Model (CESM); and the NASA ModelE climate model and GEOS-5 atmospheric general circulation model

The ethics of ‘Trials within Cohorts’ (TwiCs): 2nd international symposium - London, UK. 7-8 November 2016

On 7-8 th November 2016, 60 people with an interest in the ‘ Trials within Cohorts ’ (TwiCs) approach for randomised controlled trial design met in London. The purpose of this 2 nd TwiCs international symposium was to share perspectives and experiences on ethical aspects of the TwiCs design, discuss how TwiCs relate to the current ethical frame- work, provide a forum in which to discuss and debate ethical issues and identify future directions for conceptual and empirical research. The symposium was supported by the Wellcome Trust and the NIHR CLAHRC Yorkshire and Humber and organised by members of the TwiCs network led by Clare Relton and attended by people from the UK, the Netherlands, Norway, Canada and USA. The two-day sympo- sium enabled an international group to meet and share experiences of the TwiCs design (also known as the ‘ cohort multiple RCT design ’ ), and to discuss plans for future research. Over the two days, invited plenary talks were interspersed by discussions, posters and mini pre- sentations from bioethicists, triallists and health research regulators. Key findings of the symposium were: (1) It is possible to make a compelling case to ethics committees that TwiCs designs are ap- propriate and ethical; (2) The importance of wider considerations around the ethics of inefficient trial designs; and (3) some questions about the ethical requirements for content and timing of informed consent for a study using the TwiCs design need to be decided on a case-by-case basis

Determinants of a GP visit and cervical cancer screening examination in Great Britain.

Objective: In the UK, women are requested to attend a cervical cancer test every 3 years as part of the NHS Cervical Screening Programme. This analysis compares the determinants of a cervical cancer screening examination with the determinants of a GP visit in the same year and investigates if cervical cancer screening participation is more likely for women who visit their GP. Methods: A recursive probit model was used to analyse the determinants of GP visits and cervical cancer screening examinations. GP visits were considered to be endogenous in the cervical cancer screening examination. The analysed sample consisted of 52,551 observations from 8,386 women of the British Household Panel Survey. Results: The analysis showed that a higher education level and a worsening self-perceived health status increased the probability of a GP visit, whereas smoking decreased the probability of a GP visit. GP visits enhanced the uptake of a cervical cancer screening examination in the same period. The only variables which had the same positive effect on both dependent variables were higher education and living with a partner. The probability of a cervical cancer screening examination increased also with previous cervical cancer screening examinations and being in the recommended age groups. All other variables had different results for the uptake of a GP visit or a cervical cancer screening examination. Conclusions: Most of the determinants of visiting a GP and cervical cancer screening examination differ from each other and a GP visit enhances the uptake of a smear test