Phased burst error-correcting array codes

Various aspects of single-phased burst-error-correcting array codes are explored. These codes are composed of two-dimensional arrays with row and column parities with a diagonally cyclic readout order; they are capable of correcting a single burst error along one diagonal. Optimal codeword sizes are found to have dimensions n1×n2 such that n2 is the smallest prime number larger than n1. These codes are capable of reaching the Singleton bound. A new type of error, approximate errors, is defined; in q-ary applications, these errors cause data to be slightly corrupted and therefore still close to the true data level. Phased burst array codes can be tailored to correct these codes with even higher rates than befor

Gene Transfer in Crop Improvement - An Introduction and Overview

The application of recombinant DNA technology to plant breeding promises important applications in agriculture and advances in many plant science disciplines. Gene transfer at the molecular level can be routinely accomplished in an increasing number of plant species. For many of the world\u27s important crops, new methods or refinements of proven methods will be needed and are being developed. Experience with gene regulation in transgenic plants is accumulating in many laboratories around the world. The action of any particular gene cannot be predicted precisely without reference to the genetic background in which it acts, but, qualitatively speaking, the cis-acting elements located near and within coding sequences of genes appear co play a dominant role in governing gene expression. This result means that chimeric genes can be constructed and expressed with at least qualitatively predictable results. Several agriculturally interesting traits have been engineered and are undergoing field trials. These traits include several different herbicide resistances, modified fruit characteristics, viral disease resistance, and insect tolerance in rapeseed, tobacco, tomato, potato, alfalfa and cotton. Much work is underway to provide a better understanding of plant metabolism and development with a view to engineering ocher traits. These traits include the composition of storage lipids, regulation of fruit development, and disease resistance. The new tools for genetic manipulation of crop plants provide important opportunities for improving crop performance and the economic and environmental performance of agriculture

Research Notes : United States : Instability of virulence characters of soybean mosaic virus strains after seed transmission

Soybean mosaic virus (SMV) is distributed worldwide. The primary mode of transmission is through seed (Goodman and Oard, 1980), although the virus is also nonpersistently transmitted by aphids (Irwin and Goodman, 1981). Cul-tivars have been identified which combine tolerance to SMV infection and low incidence of transmission through seed (Goodman and Oard, 1980)

Research notes: A new source of resistance to soybean mosaic virus

We have been screening tropical and temperate soybean germplasm lines to test for variation in the rate of seed transmission of soybean mosaic virus (SMV). In the course of field screening of 400 tropical soybean lines and varieties with the Illinois 11 severe11 isolate of SMV (SMV-Il-S) we were unable to infect the cultivar \u27Buffalo\u27. Our subsequent studies have shown that Buffalo is i111T1une to most SMV isolates and possesses a hypersensitive form of resistance to the isolates that can infect it. Here we present a preliminary report of our findings

Single Phased Burst Error Correcting Array Codes

Array codes composed of row and column parities with a diagonally cyclic readout order are capable of correcting a single burst error along one diagonal. A new equation which defines permissible array sizes is presented. These codes have an optimal size which is shown to be a number theoretic problem. In addition, correction of approximate errors is presented; this can be generalized for many classes of error correcting codes

Health capabilities and diabetes self-management: The impact of economic, social, and cultural resources

While the “social determinants of health” view compels us to explore how social structures shape health outcomes, it often ignores the role individual agency plays. In contrast, approaches that focus on individual choice and personal responsibility for health often overlook the influence of social structures. Amartya Sen\u27s “capabilities” framework and its derivative the “health capabilities” (HC) approach attempts to accommodate both points of view, acknowledging that individuals function under social conditions over which they have little control, while also acting as agents in their own health and well-being. This paper explores how economic, social, and cultural resources shape the health capability of people with diabetes, focusing specifically on dietary practices. Health capability and agency are central to dietary practices, while also being shaped by immediate and broader social conditions that can generate habits and a lifestyle that constrain dietary behaviors. From January 2011 to December 2012, we interviewed 45 people with diabetes from a primary care clinic in Ontario (Canada) to examine how their economic, social, and cultural resources combine to influence dietary practices relative to their condition. We classified respondents into low, medium, and high resource groups based on economic circumstances, and compared how economic resources, social relationships, health-related knowledge and values combine to enhance or weaken health capability and dietary management. Economic, social, and cultural resources conspired to undermine dietary management among most in the low resource group, whereas social influences significantly influenced diet among many in the medium group. High resource respondents appeared most motivated to maintain a healthy diet, and also had the social and cultural resources to enable them to do so. Understanding the influence of all three types of resources is critical for constructing ways to enhance health capability, chronic disease self-management, and health

Screening for Chlamydia trachomatis in Low-Risk Obstetric Patients

Objective: The purpose of this study was to evaluate the prevalence of Chlamydia trachomatis in our rural obstetric population and assess the appropriateness of selective vs. universal prenatal screening

Considerations for Estimating Remote Operator Dust Exposure Using Fixed-Point Samples on Continuous Mining Sections

Respirable dust studies were conducted at several underground coal mining operations to evaluate and compare the dust measurements of fixed-point machine-mounted samples on a continuous miner and personal samples of the remote miner operator. Fixed-point sampling was conducted at the right rear corner of the continuous miner which corresponded to the traditional location of the operator\u27s cab. Although it has been documented that higher concentrations of dust are present at the machine-mounted position, this work sought to determined whether a relationship exists between the concentrations at the fixed-point position and the dust levels experienced at the remote operator position and whether this relationship could be applied on a industry-wide basis. To achieve this objective, gravimetric samplers were used to collect respirable dust data on continuous miner sections. These samplers were placed at a fixed position at the cab location of the continuous mining machine and on or near the remote miner operator during the 1 shift/day sampling periods. Dust sampling took place at mines with a variety of geographic locations and in-mine conditions. The dust concentration data collected at each site and for each sampling period were reduced to ratios of fixed-point to operator concentration. The ratios were calculated to determine similarities, differences, and/or variability at the two positions. The data show that dust concentrations at the remote operator position were always lower than dust concentrations measured at the fixed-point continuous miner location. However, the ratios of fixed-point to remote operator dust levels showed little consistency from shift to shift or from operation to operation. The fact that these ratios are so variable may introduce some uncertainty into attempting to correlate dust exposures of the remote operator to dust levels measured on the continuous mining machine

Magnetohydrodynamics of the Weakly Ionized Solar Photosphere

We investigate the importance of ambipolar diffusion and Hall currents for high-resolution comprehensive ('realistic') photospheric simulations. To do so we extended the radiative magnetohydrodynamics code \emph{MURaM} to use the generalized Ohm's law under the assumption of local thermodynamic equilibrium. We present test cases comparing analytical solutions with numerical simulations for validation of the code. Furthermore, we carried out a number of numerical experiments to investigate the impact of these neutral-ion effects in the photosphere. We find that, at the spatial resolutions currently used (5-20 km per grid point), the Hall currents and ambipolar diffusion begin to become significant -- with flows of 100 m/s in sunspot light bridges, and changes of a few percent in the thermodynamic structure of quiet-Sun magnetic features. The magnitude of the effects is expected to increase rapidly as smaller-scale variations are resolved by the simulations.Comment: accepted Ap

Mindfulness enhances episodic memory performance: Evidence from a multimethod investigation

Training in mindfulness, classically described as a receptive attentiveness to present events and experiences, has been shown to improve attention and working memory. Both are key to long-term memory formation, and the present three-study series used multiple methods to examine whether mindfulness would enhance episodic memory, a key form of long-term memory. In Study 1 (N = 143), a self-reported state of mindful attention predicted better recognition performance in the Remember-Know (R-K) paradigm. In Study 2 (N = 93), very brief training in a focused attention form of mindfulness also produced better recognition memory performance on the R-K task relative to a randomized, well-matched active control condition. Study 3 (N = 57) extended these findings by showing that relative to randomized active and inactive control conditions the effect of very brief mindfulness training generalized to free-recall memory performance. This study also found evidence for mediation of the mindfulness training—episodic memory relation by intrinsic motivation. These findings indicate that mindful attention can beneficially impact motivation and episodic memory, with potential implications for educational and occupational performance