175 research outputs found
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Evolution of DebrisâFlow Initiation Mechanisms and Sediment Sources During a Sequence of Postwildfire Rainstorms
Wildfire alters vegetation cover and soil hydrologic properties, substantially increasing the likelihood of debris flows in steep watersheds. Our understanding of initiation mechanisms of postwildfire debris flows is limited, in part, by a lack of direct observations and measurements. In particular, there is a need to understand temporal variations in debris-flow likelihood following wildfire and how those variations relate to wildfire-induced hydrologic and geomorphic changes. In this study, we use a combination of in situ measurements, hydrologic monitoring equipment, and numerical modeling to assess the impact of wildfire-induced hydrologic and geomorphic changes on debris-flow initiation during seven postwildfire rainstorms. We predict the impact of hillslope erosion on debris-flow initiation by combining terrestrial laser scanning surveys of a hillslope burned during the 2016 Fish Fire with numerical modeling of sediment transport throughout a 0.12-km(2) basin in southern California. We use measurements of sediment thickness within the channel to constrain numerical experiments and to assess the role of channel sediment supply on debris-flow initiation. Results demonstrate that debris flows initiated during rainstorms where hillslopes contributed minimally to the event sediment yield and suggest that large inputs of sediment from rill and gully networks are not essential for runoff-generated debris flows. Simulations suggest that both the gradual entrainment of sediment and the mass failure of channel bed sediment can increase sediment concentration to levels associated with debris flows. Finally, postwildfire debris-flow initiation appears closely linked to the same rainfall intensity-duration threshold despite temporal changes in the sediment source, initiation processes, and hydraulic roughness.U.S. Geological Survey (USGS) Landslide Hazards ProgramPublic domain articleThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Analyzing high resolution topography for advancing the understanding of mass and energy transfer through landscapes: A review
International audienceThe study of mass and energy transfer across landscapes has recently evolved to comprehensive considerations acknowledging the role of biota and humans as geomorphic agents, as well as the importance of small-scale landscape features. A contributing and supporting factor to this evolution is the emergence over the last two decades of technologies able to acquire high resolution topography (HRT) (meter and sub-meter resolution) data. Landscape features can now be captured at an appropriately fine spatial resolution at which surface processes operate; this has revolutionized the way we study Earth-surface processes. The wealth of information contained in HRT also presents considerable challenges. For example, selection of the most appropriate type of HRT data for a given application is not trivial. No definitive approach exists for identifying and filtering erroneous or unwanted data, yet inappropriate filtering can create artifacts or eliminate/distort critical features. Estimates of errors and uncertainty are often poorly defined and typically fail to represent the spatial heterogeneity of the dataset, which may introduce bias or error for many analyses. For ease of use, gridded products are typically preferred rather than the more information-rich point cloud representations. Thus many users take advantage of only a fraction of the available data, which has furthermore been subjected to a series of operations often not known or investigated by the user. Lastly, standard HRT analysis work-flows are yet to be established for many popular HRT operations, which has contributed to the limited use of point cloud data.In this review, we identify key research questions relevant to the Earth-surface processes community within the theme of mass and energy transfer across landscapes and offer guidance on how to identify the most appropriate topographic data type for the analysis of interest. We describe the operations commonly performed from raw data to raster products and we identify key considerations and suggest appropriate work-flows for each, pointing to useful resources and available tools. Future research directions should stimulate further development of tools that take advantage of the wealth of information contained in the HRT data and address the present and upcoming research needs such as the ability to filter out unwanted data, compute spatially variable estimates of uncertainty and perform multi-scale analyses. While we focus primarily on HRT applications for mass and energy transfer, we envision this review to be relevant beyond the Earth-surface processes community for a much broader range of applications involving the analysis of HRT
Observation of Parametric Instability in Advanced LIGO
Parametric instabilities have long been studied as a potentially limiting
effect in high-power interferometric gravitational wave detectors. Until now,
however, these instabilities have never been observed in a kilometer-scale
interferometer. In this work we describe the first observation of parametric
instability in an Advanced LIGO detector, and the means by which it has been
removed as a barrier to progress
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Epilepsy Benchmarks Area III: Improved Treatment Options for Controlling Seizures and Epilepsy-Related Conditions Without Side Effects.
The goals of Epilepsy Benchmark Area III involve identifying areas that are ripe for progress in terms of controlling seizures and patient symptoms in light of the most recent advances in both basic and clinical research. These goals were developed with an emphasis on potential new therapeutic strategies that will reduce seizure burden and improve quality of life for patients with epilepsy. In particular, we continue to support the proposition that a better understanding of how seizures are initiated, propagated, and terminated in different forms of epilepsy is central to enabling new approaches to treatment, including pharmacological as well as surgical and device-oriented approaches. The stubbornly high rate of treatment-resistant epilepsy-one-third of patients-emphasizes the urgent need for new therapeutic strategies, including pharmacological, procedural, device linked, and genetic. The development of new approaches can be advanced by better animal models of seizure initiation that represent salient features of human epilepsy, as well as humanized models such as induced pluripotent stem cells and organoids. The rapid advances in genetic understanding of a subset of epilepsies provide a path to new and direct patient-relevant cellular and animal models, which could catalyze conceptualization of new treatments that may be broadly applicable across multiple forms of epilepsies beyond those arising from variation in a single gene. Remarkable advances in machine learning algorithms and miniaturization of devices and increases in computational power together provide an enhanced opportunity to detect and mitigate seizures in real time via devices that interrupt electrical activity directly or administer effective pharmaceuticals. Each of these potential areas for advance will be discussed in turn
Fifteen new risk loci for coronary artery disease highlight arterial-wall-specific mechanisms
Coronary artery disease (CAD) is a leading cause of morbidity and mortality worldwide. Although 58 genomic regions have been associated with CAD thus far, most of the heritability is unexplained, indicating that additional susceptibility loci await identification. An efficient discovery strategy may be larger-scale evaluation of promising associations suggested by genome-wide association studies (GWAS). Hence, we genotyped 56,309 participants using a targeted gene array derived from earlier GWAS results and performed meta-analysis of results with 194,427 participants previously genotyped, totaling 88,192 CAD cases and 162,544 controls. We identified 25 new SNP-CAD associations (P < 5 Ă 10(-8), in fixed-effects meta-analysis) from 15 genomic regions, including SNPs in or near genes involved in cellular adhesion, leukocyte migration and atherosclerosis (PECAM1, rs1867624), coagulation and inflammation (PROCR, rs867186 (p.Ser219Gly)) and vascular smooth muscle cell differentiation (LMOD1, rs2820315). Correlation of these regions with cell-type-specific gene expression and plasma protein levels sheds light on potential disease mechanisms
Combined experimental and computational approach to identify non-protein-coding RNAs in the deep-branching eukaryote Giardia intestinalis
Non-protein-coding RNAs represent a large proportion of transcribed sequences in eukaryotes. These RNAs often function in large RNAâprotein complexes, which are catalysts in various RNA-processing pathways. As RNA processing has become an increasingly important area of research, numerous non-messenger RNAs have been uncovered in all the model eukaryotic organisms. However, knowledge on RNA processing in deep-branching eukaryotes is still limited. This study focuses on the identification of non-protein-coding RNAs from the diplomonad parasite Giardia intestinalis, showing that a combined experimental and computational search strategy is a fast method of screening reduced or compact genomes. The analysis of our Giardia cDNA library has uncovered 31 novel candidates, including C/D-box and H/ACA box snoRNAs, as well as an unusual transcript of RNase P, and double-stranded RNAs. Subsequent computational analysis has revealed additional putative C/D-box snoRNAs. Our results will lead towards a future understanding of RNA metabolism in the deep-branching eukaryote Giardia, as more ncRNAs are characterized
A randomised controlled feasibility trial of family and social network intervention for young people who misuse alcohol and drugs : study protocol (Y-SBNT)
Background: A growing body of research has identified family interventions to be effective in treating young peopleâs substance use problems. However, despite this evidence, take-up of family-based approaches in the UK has been low. Key factors for this appear to include the resource-intensive nature of most family interventions which challenges implementation and delivery in many service settings and the cultural adaptation of approaches developed in the USA to a UK setting. This study aims to demonstrate the feasibility of recruiting young people to a specifically developed family- and wider social network-based intervention by testing an adapted version of adult social behaviour and network therapy (SBNT).
Methods: A pragmatic, randomised controlled, open feasibility trial delivered in two services for young people in the UK. Potential participants are aged 12â18 years referred for drug or alcohol problems to either service. The main purpose of this study is to demonstrate the feasibility of recruiting young people to a specifically developed family and social network-based intervention. The feasibility and acceptability of this intervention will be measured by recruitment rates, treatment retention, follow-up rates and qualitative interviews. The feasibility of training staff from existing services to deliver this intervention will be explored. Using this opportunity to compare the effectiveness of the intervention against treatment as usual, Timeline Follow-Back interviews will document the proportion of days on which the main problem substance was used in the preceding 90-day period at each assessment point. The economic component will examine the feasibility of conducting a full incremental cost-effectiveness analysis of the two treatments. The study will also explore and develop models of patient and public involvement which support the involvement of young people in a study of this nature.
Discussion: An earlier phase of work adapted social behaviour and network therapy (adult approach) to produce a purpose-designed youth version supported by a therapy manual and associated resources. This was achieved by consultation with young people with experience of services and professionals working in services for young people. This feasibility trial alongside ongoing consultations with young people will offer a meaningful understanding of processes of delivery and implementation.
Trial registration: ISRCTN93446265; Date ISRCTN assigned 31/05/2013
Youth social behaviour and network therapy (Y-SBNT) : adaptation of a family and social network intervention for young people who misuse alcohol and drugs â a randomised controlled feasibility trial
Background: Family interventions appear to be effective at treating young peopleâs substance misuse. However, implementation of family approaches in UK services is low. This study aimed to demonstrate the feasibility of recruiting young people to an intervention based on an adaptation of adult social behaviour and network therapy. It also sought to involve young people with experience of using substance misuse services in the research process.
Objectives: To demonstrate the feasibility of recruiting young people to family and social network therapy and to explore ways in which young people with experience of using substance misuse services could be involved in a study of this nature.
Design: A pragmatic, two-armed, randomised controlled open feasibility trial.
Setting: Two UK-based treatment services for young people with substance use problems, with recruitment taking place from May to November 2014.
Participants: Young people aged 12â18 years, newly referred and accepted for structured interventions for drug and/or alcohol problems.
Interventions: A remote, web-based computer randomisation system allocated young people to adapted youth social behaviour and network therapy (Y-SBNT) or treatment as usual (TAU). Y-SBNT participants were intended to receive up to six 50-minute sessions over a maximum of 12 weeks. TAU participants continued to receive usual care delivered by their service.
Main outcome measures: Feasibility was measured by recruitment rates, retention in treatment and follow-up completion rates. The main clinical outcome was the proportion of days on which the main problem substance was used in the preceding 90-day period as captured by the Timeline Follow-Back interview at 3 and 12 months.
Results: In total, 53 young people were randomised (Y-SBNT, nâ=â26; TAU, nâ=â27) against a target of 60 (88.3%). Forty-two young people attended at least one treatment session [Y-SBNT 22/26 (84.6%); TAU 20/27 (74.1%)]; follow-up rates were 77.4% at month 3 and 73.6% at month 12. Data for nine young people were missing at both months 3 and 12, so the main clinical outcome analysis was based on 24 young people (92.3%) in the Y-SBNT group and 20 young people (74.1%) in the TAU group. At month 12, the average proportion of days that the main problem substance was used in the preceding 90 days was higher in the Y-SBNT group than in the TAU group (0.54 vs. 0.41; adjusted mean difference 0.13, 95% confidence interval â0.12 to 0.39; pâ=â0.30). No adverse events were reported. Seventeen young people with experience of substance misuse services were actively involved throughout the study. They informed key elements of the intervention and research process, ensuring that the intervention was acceptable and relevant to our target groups; contributing to the design of key trial documents, ideas for a new model of public involvement and this report. Two parents were also involved.
Conclusions: The adapted intervention could be delivered in young peopleâs services, and qualitative interviews found that Y-SBNT was acceptable to young people, family members and staff. Engagement of family and network members proved difficult within the intervention and research aspects. The study proved the feasibility of this work in routine services but outcome measurement based on narrow substance use variables may be limited and may fail to capture other important changes in wider areas of functioning for young people. Validation of the EuroQol-5 Dimensions for young people aged 12â18 years should be considered and flexible models for involvement of young people in research are required to achieve inclusive representation throughout all aspects of the research process. Although recommendation of a full trial of the Y-SBNT intervention compared with TAU is not supported, this study can inform future intervention development and UK research within routine addiction services.
Trial registration: Current Controlled Trials ISRCTN93446265.
Funding: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 15. See the NIHR Journals Library website for further project information
Comparing Notes: Recording and Criticism
This chapter charts the ways in which recording has changed the nature of music criticism. It both provides an overview of the history of recording and music criticism, from the advent of Edisonâs Phonograph to the present day, and examines the issues arising from this new technology and the consequent transformation of critical thought and practice
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