INSTITUTIONAL CONSIDERATIONS IN TARGETING SOIL CONSERVATION EFFORTS

This paper will outline an approach to targeting soil conservation efforts that rests upon an analysis of physical, economic, and institutional parameters. Within this context, the literature on the relationship between soil erosion and some common arrangements of land ownership and control will be examined to provide insights useful in the formulation of public policy and to suggest further opportunities for research.Land Economics/Use,

Composing Scalable Nonlinear Algebraic Solvers

Most efficient linear solvers use composable algorithmic components, with the most common model being the combination of a Krylov accelerator and one or more preconditioners. A similar set of concepts may be used for nonlinear algebraic systems, where nonlinear composition of different nonlinear solvers may significantly improve the time to solution. We describe the basic concepts of nonlinear composition and preconditioning and present a number of solvers applicable to nonlinear partial differential equations. We have developed a software framework in order to easily explore the possible combinations of solvers. We show that the performance gains from using composed solvers can be substantial compared with gains from standard Newton-Krylov methods.Comment: 29 pages, 14 figures, 13 table

False discovery rate regression: an application to neural synchrony detection in primary visual cortex

Many approaches for multiple testing begin with the assumption that all tests in a given study should be combined into a global false-discovery-rate analysis. But this may be inappropriate for many of today's large-scale screening problems, where auxiliary information about each test is often available, and where a combined analysis can lead to poorly calibrated error rates within different subsets of the experiment. To address this issue, we introduce an approach called false-discovery-rate regression that directly uses this auxiliary information to inform the outcome of each test. The method can be motivated by a two-groups model in which covariates are allowed to influence the local false discovery rate, or equivalently, the posterior probability that a given observation is a signal. This poses many subtle issues at the interface between inference and computation, and we investigate several variations of the overall approach. Simulation evidence suggests that: (1) when covariate effects are present, FDR regression improves power for a fixed false-discovery rate; and (2) when covariate effects are absent, the method is robust, in the sense that it does not lead to inflated error rates. We apply the method to neural recordings from primary visual cortex. The goal is to detect pairs of neurons that exhibit fine-time-scale interactions, in the sense that they fire together more often than expected due to chance. Our method detects roughly 50% more synchronous pairs versus a standard FDR-controlling analysis. The companion R package FDRreg implements all methods described in the paper

Exploring mutualistic interactions between microalgae and bacteria in the omics age.

Microalgae undertake a wide range of mutualistic interactions with bacteria. Here we consider how transcriptomic, metagenomic and metabolomic approaches have been combined with microbiological and biochemical analyses to expand our understanding of algal-bacterial interactions. Identification of the major bacterial species associated with algae indicates that specific bacterial groups, particularly the alpha-Proteobacteria, are found more frequently, suggesting that these may have the means to initiate and maintain symbiotic relationships. Nutrient exchange is frequently the basis of algal-bacterial mutualism, and as the compounds involved are characterised, evidence is accumulating that these are complex and specific molecules, offering opportunities for signalling processes and regulation rather than merely passive diffusion. At the same time, it is clear that the interactions are not static, but can be initiated and broken in response to environmental and developmental cues.We thank the Biotechnology and Biological Sciences Research Council (BBSRC) of the UK, and PML Applications Ltd., Plymouth UK, for the CASE studentship for MBC.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.pbi.2015.07.00

The Likelihood Ratio as a tool for Radio Continuum Surveys with SKA precursor telescopes

In this paper we investigate the performance of the likelihood ratio method as a tool for identifying optical and infrared counterparts to proposed radio continuum surveys with SKA precursor and pathfinder telescopes. We present a comparison of the infrared counterparts identified by the likelihood ratio in the VISTA Deep Extragalactic Observations (VIDEO) survey to radio observations with 6, 10 and 15 arcsec resolution. We cross-match a deep radio catalogue consisting of radio sources with peak flux density $>$ 60 $\mu$Jy with deep near-infrared data limited to $K_{\mathrm{s}}\lesssim$ 22.6. Comparing the infrared counterparts from this procedure to those obtained when cross-matching a set of simulated lower resolution radio catalogues indicates that degrading the resolution from 6 arcsec to 10 and 15 arcsec decreases the completeness of the cross-matched catalogue by approximately 3 and 7 percent respectively. When matching against shallower infrared data, comparable to that achieved by the VISTA Hemisphere Survey, the fraction of radio sources with reliably identified counterparts drops from $\sim$89%, at $K_{\mathrm{s}}\lesssim$22.6, to 47% with $K_{\mathrm{s}}\lesssim$20.0. Decreasing the resolution at this shallower infrared limit does not result in any further decrease in the completeness produced by the likelihood ratio matching procedure. However, we note that radio continuum surveys with the MeerKAT and eventually the SKA, will require long baselines in order to ensure that the resulting maps are not limited by instrumental confusion noise.Comment: 10 pages, 7 figures, accepted for publication in mnra

Evidence-Based Programming for Older Adults

There is increased world-wide concern about the impact of multiple chronic conditions, especially among the rapidly aging population. Simultaneously, over the past decade there has been an emergence of state-wide and national initiatives to reduce the burden of chronic conditions that draw upon the translation of evidence-based programs (EPB) into community practice. Yet, little has been written about the national and international implementation, dissemination, and sustainability of such programs. This Research Topic features articles about EBPs for older adults, including a range of articles that focus on the infrastructure needed to widely disseminate EBP as well as individual participant impacts on physical, mental, and social aspects of health and well-being. Using a pragmatic research perspective, this Research Topic will advance knowledge that aims to enhance practice, inform policy and build systems of support and delivery in regard to the reach, effectiveness, adoption, implementation, and maintenance of evidence-based interventions for older adults. The focus is on knowledge transfer rather than knowledge generation but with a dual emphasis on the dissemination and sustainability of EBP that have been tested and shown effective as well as the adaptation of practice-based interventions into evidence-based programs. This Research Topic draws upon grand-scale efforts to deliver these programs, and include both U.S. as well as international examples. Commentaries discuss processes in the development and measurement of EBP and reflect perspectives from program developers and major national and regional funders of EBP as well as professionals and practitioners in the field. The full-length articles focus on four major programmatic areas: (1) chronic disease self-management programs; (2) fall prevention programs; (3) general wellness and physical activity programs; and (4) mental health programs. Additionally, articles are included to discuss cross-cutting issues related to building partnerships and the research infrastructure for the implementation, evaluation, and dissemination of evidence-based programming. The intent of this Research Topic is to enhance practice, inform policy, and build systems of support and delivery for EBP. It is written for a diverse audience and contains practical implications and recommendations for introducing, delivering, and sustaining EBP in a multitude of settings

Development and Application of a 1D Compaction Model to Understand 65 Years of Subsidence in the San Joaquin Valley

High rates of land subsidence, caused by groundwater overdraft, are resulting in millions of dollars of infrastructure damage in California\u27s San Joaquin Valley (SJV). In recent years, the use of interferometric synthetic aperture radar (InSAR) has enabled us to substantially improve our understanding of this subsidence. However, only very occasionally have the InSAR data been integrated with a physical model of subsurface compaction. Here, we have used InSAR and other data to parameterize and calibrate a 1D compaction model. We applied our model to a study area in the SJV where we had access to the necessary information on hydraulic head to develop model inputs. Our model simulated subsidence in the three aquifer system layers over the period 1952–2017, and is the first 1D compaction model in the SJV to simulate multiple aquifer system layers from the 1950s to 2017. The results from our model suggest that previous studies have significantly underestimated the time constants governing the slow, residual compaction of subsurface clays. We suggest that residual compaction of clays is a process that continues for decades-to-centuries, indicating that to significantly reduce subsidence requires some recovery of head, not just a stabilization. We also show how compaction in the lower, confined aquifer has accounted for over 90% of subsidence in the past 20 years. Although our study area is small, our findings are likely representative of the subsiding regions of the SJV, and our methodology can be applied to unconsolidated aquifer systems exhibiting subsidence worldwide