A Comparison of Techniques for Estimating NDVI for Agricultural Intervention Impact Assessment

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An iterative inversion of back-scattered acoustic waves

The application of the Born approximation to the scattered wave field, followed by a WKBJ and far-field approximation on the propagation Green's function for a slowly varying background medium, leads to a simple integral relation between the density and bulk-modulus anomalies superimposed on the background medium and the scattered wave field. An iterative inversion scheme based on successive back-projections of the wave field is used to reconstruct the two acoustic parameters. The scheme, when applied to data generated using the direct integral relation, shows that the variations of the parameters can be reconstructed. The procedure is readily applicable to actual data, since every iterative step is essentially a prestack Kirchhoff migration followed by the application of the direct Born approximation and far-field operator

Using numerical plant models and phenotypic correlation space to design achievable ideotypes

Numerical plant models can predict the outcome of plant traits modifications resulting from genetic variations, on plant performance, by simulating physiological processes and their interaction with the environment. Optimization methods complement those models to design ideotypes, i.e. ideal values of a set of plant traits resulting in optimal adaptation for given combinations of environment and management, mainly through the maximization of a performance criteria (e.g. yield, light interception). As use of simulation models gains momentum in plant breeding, numerical experiments must be carefully engineered to provide accurate and attainable results, rooting them in biological reality. Here, we propose a multi-objective optimization formulation that includes a metric of performance, returned by the numerical model, and a metric of feasibility, accounting for correlations between traits based on field observations. We applied this approach to two contrasting models: a process-based crop model of sunflower and a functional-structural plant model of apple trees. In both cases, the method successfully characterized key plant traits and identified a continuum of optimal solutions, ranging from the most feasible to the most efficient. The present study thus provides successful proof of concept for this enhanced modeling approach, which identified paths for desirable trait modification, including direction and intensity.Comment: 25 pages, 5 figures, 2017, Plant, Cell and Environmen

Hardware processors for pairing-based cryptography

Bilinear pairings can be used to construct cryptographic systems with very desirable properties. A pairing performs a mapping on members of groups on elliptic and genus 2 hyperelliptic curves to an extension of the finite field on which the curves are defined. The finite fields must, however, be large to ensure adequate security. The complicated group structure of the curves and the expensive field operations result in time consuming computations that are an impediment to the practicality of pairing-based systems. The Tate pairing can be computed efficiently using the ɳT method. Hardware architectures can be used to accelerate the required operations by exploiting the parallelism inherent to the algorithmic and finite field calculations. The Tate pairing can be performed on elliptic curves of characteristic 2 and 3 and on genus 2 hyperelliptic curves of characteristic 2. Curve selection is dependent on several factors including desired computational speed, the area constraints of the target device and the required security level. In this thesis, custom hardware processors for the acceleration of the Tate pairing are presented and implemented on an FPGA. The underlying hardware architectures are designed with care to exploit available parallelism while ensuring resource efficiency. The characteristic 2 elliptic curve processor contains novel units that return a pairing result in a very low number of clock cycles. Despite the more complicated computational algorithm, the speed of the genus 2 processor is comparable. Pairing computation on each of these curves can be appealing in applications with various attributes. A flexible processor that can perform pairing computation on elliptic curves of characteristic 2 and 3 has also been designed. An integrated hardware/software design and verification environment has been developed. This system automates the procedures required for robust processor creation and enables the rapid provision of solutions for a wide range of cryptographic applications

Three-dimensional imaging of steeply dipping structure near the San Andreas fault, Parkfield, California

Shot gathers from the Parkfield, California, deep crustal seismic reflection line, recorded in 1977 by COCORP, reveal coherent events having horizontal to reverse moveouts. These events were migrated using a multioffset three-dimensional Kirchhoff summation method. This method is a ray-equation back projection inversion of the acoustic wave field, which is valid under the Born, WKBJ, and far-field assumptions. Migration of full-wave acoustic synthetics, having the same limitations in geometric coverage as the COCORP survey, demonstrates the utility of the imaging process. The images obtained from back projection of the survey data suggest that the Gold Hill fault carries ultramafic rocks from the surface to 3 km depth at a dip greater than 45 degrees, where it joins the San Andreas fault, which may cut through more homogeneous materials at shallow depths. To the southwest, a 2 km Tertiary sedimentary section appears to terminate against a near-vertical fault. The zone between this fault and the San Andreas may be floored at 3 km by flat-lying ultramafics. Lateral velocity inhomogeneities are not accounted for in the migration but, in this case, do not seriously hinder the reconstruction of reflectors

Book Reviews

Cases and Materials on Debtor and Creditor By Vern Countryman Boston: Little, Brown & Co., 1964. Pp. lxiii, 841. $12.50. reviewer: Ronan E. Degnan ================================ The Supreme Court on Trial By Charles S. Hyneman New York: Atherton Press, 1963. Pp. IX, 308.$6.50. reviewer: Jerold Israel ================================= Religion and American Constitutions (1963 Rosenthal Lectures) By Wilbur G. Katz Northwestern University Press 1964. Pp. 114. $3.50. reviewer: Rev. Robert F. Drinan, S.J

Colorectal Cancer Screening and Perceived Disgust:The Importance of the Ick Factor in Faecal Occult Blood Test Uptake

Background: Colorectal cancer is a major cause of cancer deaths worldwide. Screening is key to early detection but uptake of national programmes is poor, especially amongst those from lower socio-economic backgrounds. Decisions not to take up screening may be based more on emotional rather than rational evaluations. We aimed to examine the importance of perceived disgust (the ‘ICK’ factor) in determining colorectal cancer screening uptake, in a large, randomised controlled trial. Methods: This paper reports secondary analysis of a randomised controlled trial of a simple, questionnaire-based Anticipated Regret (AR) intervention, which was delivered alongside existing pre-notification letters. 60,000 adults aged 50- 74 who were participant in the Scottish National Screening programme were randomised to one of 3 treatment arms: 1) no questionnaire (control), 2) Health Locus of Control (HLOC) questionnaire or 3) AR questionnaire. Primary outcome was Faecal Occult Blood Test kit return (FOBT uptake). 13,645 people completed questionnaires of secondary outcomes including intention to return test kit and a new self-report measure of perceived disgust (ICK-C). Results: Intentions, ICK and AR were all predictors of FOBT uptake; however, for people who expressed strong intentions to return their FOBT kit, only ICK differentiated kit returners from non-returners, with non-returners reporting higher disgust (mean difference=0.51; 95% CI for difference (0.37, 0.64), Cohen’s d=0.34). The 4-item ICK-C showed excellent internal reliability and predictive validity with regard to an objective measure i.e., FOBT uptake. Conclusions: The findings show that perceived disgust is an important emotional psychological construct in determining uptake of colorectal cancer screening. We also demonstrated that a simple 4-item scale (the ‘ICK-C), developed to be used in research on colorectal cancer screening, has excellent psychometric properties

Identification and annotation of conserved promoters and macrophage-expressed genes in the pig genome.

BACKGROUND: The FANTOM5 consortium used Cap Analysis of Gene Expression (CAGE) tag sequencing to produce a comprehensive atlas of promoters and enhancers within the human and mouse genomes. We reasoned that the mapping of these regulatory elements to the pig genome could provide useful annotation and evidence to support assignment of orthology. RESULTS: For human transcription start sites (TSS) associated with annotated human-mouse orthologs, 17% mapped to the pig genome but not to the mouse, 10% mapped only to the mouse, and 55% mapped to both pig and mouse. Around 17% did not map to either species. The mapping percentages were lower where there was not clear orthology relationship, but in every case, mapping to pig was greater than to mouse, and the degree of homology was also greater. Combined mapping of mouse and human CAGE-defined promoters identified at least one putative conserved TSS for >16,000 protein-coding genes. About 54% of the predicted locations of regulatory elements in the pig genome were supported by CAGE and/or RNA-Seq analysis from pig macrophages. CONCLUSIONS: Comparative mapping of promoters and enhancers from humans and mice can provide useful preliminary annotation of other animal genomes. The data also confirm extensive gain and loss of regulatory elements between species, and the likelihood that pigs provide a better model than mice for human gene regulation and function

The impact of personalised risk information compared to a positive/negative result on informed choice and intention to undergo colonoscopy following colorectal Cancer screening in Scotland (PERICCS) - a randomised controlled trial:study protocol

Background In Scotland a new, easier to complete bowel screening test, the Faecal Immunochemical Test (FIT), has been introduced. This test gives more accurate information about an individual’s risk of having colorectal cancer (CRC), based on their age and gender, and could lead to fewer missed cancers compared to the current screening test. However, there is no evidence of the effect on colonoscopy uptake of providing individuals with personalised risk information following a positive FIT test. The objectives of the study are: 1) To develop novel methods of presenting personalised risk information in an easy-to-understand format using infographics with involvement of members of the public 2) To assess the impact of different presentations of risk information on informed choice and intention to take up an offer of colonoscopy after FIT 3) To assess participants’ responses to receiving personal risk information (knowledge, attitudes to screening/risk, emotional responses including anxiety). Methods Adults (age range 50–74) registered on the Scottish Bowel Screening database will be invited by letter to take part. Consenting participants will be randomised to one of three groups to receive hypothetical information about their risk of cancer, based on age, gender and faecal haemoglobin concentration: 1) personalised risk information in numeric form (e.g. 1 in 100) with use of infographics, 2) personalised information described as ‘highest’, ‘moderate’ or ‘lowest’ risk with use of infographics, and 3) as a ‘positive’ test result, as is current practice. Groups will be compared on informed choice, intention to have a colonoscopy, and satisfaction with their decision. Follow-up semi-structured qualitative interviews will be conducted, by telephone, with a small number of consenting participants (n = 10 per group) to explore the acceptability/readability and any potential negative impact of the risk information, participants’ understanding of risk factors, attitudes to the different scenarios, and reasons for reported intentions. Discussion Proving personalised risk information and allowing patient choice could lead to improved detection of CRC and increase patient satisfaction by facilitating informed choice over when/whether to undergo further invasive screening. However, we need to determine whether/how informed choice can be achieved and assess the potential impact on the colonoscopy service