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Search Results: 1 - 10 of 10649 matches for " Tom Ryan "
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The Effects of Podcasting on College Student Achievement and Attitude
Jeff Francom,Tom Ryan,Mumbi Kariuki
Journal of the Research Center for Educational Technology , 2011,
Abstract: This mixed methods study investigated the impact of weekly podcasts, written and recorded by course instructors to summarize college course content, on student achievement and attitudes. Weekly summative podcasts were posted on an Internet website in Windows Media format and downloaded by college students. After four weeks of podcasts, students were assessed and evaluated and results were compared to similar classes that did not use podcasts. Students completed a questionnaire and were interviewed to record their views, perceptions, and attitudes. Participating teachers were also interviewed. Although not generalizable, the results of this study indicate that weekly podcast summaries were an effective teaching tool which produced improved student achievement and caused students to view their evaluation preparation and comprehension of course content optimistically.
Learning Management System Migration: An Analysis of Stakeholder Perspectives
Tom G Ryan,Mary Toye,Kyle Charron,Gavin Park
International Review of Research in Open and Distance Learning , 2012,
Abstract: In this mixed methods study the authors describe the institution-level perceptions of stakeholders transitioning to a new learning management system (LMS). We address issues related to change, the institution’s administration of the transition process, problems encountered, and realized learning via online survey data collection, analysis, and interpretation. We further detail results of a faculty survey, which sought to illuminate the LMS transition experience. The summation includes suggestions for institutions as they prepare for, and move through, foreseeable LMS change and transition.
On the optimal stacking of noisy observations
?. Ryan
Mathematics , 2010,
Abstract: Observations where additive noise is present can for many models be grouped into a compound observation matrix, adhering to the same type of model. There are many ways the observations can be stacked, for instance vertically, horizontally, or quadratically. An estimator for the spectrum of the underlying model can be formulated for each stacking scenario in the case of Gaussian noise. We compare these spectrum estimators for the different stacking scenarios, and show that all kinds of stacking actually decreases the variance when compared to just taking an average of the observations. We show that, regardless of the number of observations, the variance of the estimator is smallest when the compound observation matrix is made as square as possible. When the number of observations grow, however, it is shown that the difference between the estimators is marginal: Two stacking scenarios where the number of columns and rows grow to infinity are shown to have the same variance asymptotically, even if the asymptotic matrix aspect ratios differ. Only the cases of vertical and horizontal stackings display different behaviour, giving a higher variance asymptotically. Models where not all kinds of stackings are possible are also discussed.
Multiple Horizontal Gene Transfer Events and Domain Fusions Have Created Novel Regulatory and Metabolic Networks in the Oomycete Genome
Paul Francis Morris, Laura Rose Schlosser, Katherine Diane Onasch, Tom Wittenschlaeger, Ryan Austin, Nicholas Provart
PLOS ONE , 2009, DOI: 10.1371/journal.pone.0006133
Abstract: Complex enzymes with multiple catalytic activities are hypothesized to have evolved from more primitive precursors. Global analysis of the Phytophthora sojae genome using conservative criteria for evaluation of complex proteins identified 273 novel multifunctional proteins that were also conserved in P. ramorum. Each of these proteins contains combinations of protein motifs that are not present in bacterial, plant, animal, or fungal genomes. A subset of these proteins were also identified in the two diatom genomes, but the majority of these proteins have formed after the split between diatoms and oomycetes. Documentation of multiple cases of domain fusions that are common to both oomycetes and diatom genomes lends additional support for the hypothesis that oomycetes and diatoms are monophyletic. Bifunctional proteins that catalyze two steps in a metabolic pathway can be used to infer the interaction of orthologous proteins that exist as separate entities in other genomes. We postulated that the novel multifunctional proteins of oomycetes could function as potential Rosetta Stones to identify interacting proteins of conserved metabolic and regulatory networks in other eukaryotic genomes. However ortholog analysis of each domain within our set of 273 multifunctional proteins against 39 sequenced bacterial and eukaryotic genomes, identified only 18 candidate Rosetta Stone proteins. Thus the majority of multifunctional proteins are not Rosetta Stones, but they may nonetheless be useful in identifying novel metabolic and regulatory networks in oomycetes. Phylogenetic analysis of all the enzymes in three pathways with one or more novel multifunctional proteins was conducted to determine the probable origins of individual enzymes. These analyses revealed multiple examples of horizontal transfer from both bacterial genomes and the photosynthetic endosymbiont in the ancestral genome of Stramenopiles. The complexity of the phylogenetic origins of these metabolic pathways and the paucity of Rosetta Stones relative to the total number of multifunctional proteins suggests that the proteome of oomycetes has few features in common with other Kingdoms.
Evolution of NMDA receptor cytoplasmic interaction domains: implications for organisation of synaptic signalling complexes
Tomás J Ryan, Richard D Emes, Seth GN Grant, Noboru H Komiyama
BMC Neuroscience , 2008, DOI: 10.1186/1471-2202-9-6
Abstract: The vertebrate NMDA receptor was found to have subunits with C-terminal domains up to 500 amino acids longer than invertebrates. This extension was specific to the NR2 subunit and occurred before the duplication and subsequent divergence of NR2 in the vertebrate lineage. The shorter invertebrate C-terminus lacked vertebrate protein interaction motifs involved with forming a signaling complex although the terminal PDZ interaction domain was conserved. The vertebrate NR2 C-terminal domain was predicted to be intrinsically disordered but with a conserved secondary structure.We highlight an evolutionary adaptation specific to vertebrate NMDA receptor NR2 subunits. Using in silico methods we find that evolution has shaped the NMDA receptor C-terminus into an unstructured but modular intracellular domain that parallels the expansion in complexity of an NMDA receptor signalling complex in the vertebrate lineage. We propose the NR2 C-terminus has evolved to be a natively unstructured yet flexible hub organising postsynaptic signalling. The evolution of the NR2 C-terminus and its associated signalling complex may contribute to species differences in behaviour and in particular cognitive function.One of the most striking evolutionary adaptations of mammals is their capacity for learning and memory [1]. Such higher cognitive abilities are generally attributed to increased brain size and elaborations of cortical structure [2]. However the contribution that evolution of molecular complexity of the synapse has made to cognitive properties of higher organisms has yet to be fully assessed [3].The N-methyl-D-aspartate (NMDA) receptor is a class of glutamate gated transmembrane ion channel that functions at the postsynaptic membrane of excitatory synapses [4]. When opened, Ca2+ influx through the NMDA receptor into the postsynaptic cell activates second messengers responsible for long lasting synaptic plasticity. Genetic and pharmacological studies have shown that NMDA receptors are
Fecal Contamination of Drinking-Water in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis
Robert Bain ,Ryan Cronk,Jim Wright,Hong Yang,Tom Slaymaker,Jamie Bartram
PLOS Medicine , 2014, DOI: 10.1371/journal.pmed.1001644
Abstract: Background Access to safe drinking-water is a fundamental requirement for good health and is also a human right. Global access to safe drinking-water is monitored by WHO and UNICEF using as an indicator “use of an improved source,” which does not account for water quality measurements. Our objectives were to determine whether water from “improved” sources is less likely to contain fecal contamination than “unimproved” sources and to assess the extent to which contamination varies by source type and setting. Methods and Findings Studies in Chinese, English, French, Portuguese, and Spanish were identified from online databases, including PubMed and Web of Science, and grey literature. Studies in low- and middle-income countries published between 1990 and August 2013 that assessed drinking-water for the presence of Escherichia coli or thermotolerant coliforms (TTC) were included provided they associated results with a particular source type. In total 319 studies were included, reporting on 96,737 water samples. The odds of contamination within a given study were considerably lower for “improved” sources than “unimproved” sources (odds ratio [OR] = 0.15 [0.10–0.21], I2 = 80.3% [72.9–85.6]). However over a quarter of samples from improved sources contained fecal contamination in 38% of 191 studies. Water sources in low-income countries (OR = 2.37 [1.52–3.71]; p<0.001) and rural areas (OR = 2.37 [1.47–3.81] p<0.001) were more likely to be contaminated. Studies rarely reported stored water quality or sanitary risks and few achieved robust random selection. Safety may be overestimated due to infrequent water sampling and deterioration in quality prior to consumption. Conclusion Access to an “improved source” provides a measure of sanitary protection but does not ensure water is free of fecal contamination nor is it consistent between source types or settings. International estimates therefore greatly overstate use of safe drinking-water and do not fully reflect disparities in access. An enhanced monitoring strategy would combine indicators of sanitary protection with measures of water quality. Please see later in the article for the Editors' Summary
The DRAO Planck Deep Fields: the polarization properties of radio galaxies at 1.4 GHz
Julie Grant,Russ Taylor,Jeroen Stil,Tom Landecker,Roland Kothes,Ryan Ransom,Douglas Scott
Physics , 2010, DOI: 10.1088/0004-637X/714/2/1689
Abstract: We present results of deep polarization imaging at 1.4 GHz with the Dominion Radio Astrophysical Observatory as part of the DRAO Planck Deep Fields project. This deep extragalactic field covers 15.16 square degrees centered at RA = 16h 14m and DEC = 54d 56', has an angular resolution of 42" x 62" at the field center, and reaches a sensitivity of 55 microJy/beam in Stokes I and 45 microJy/beam in Stokes Q and U. We detect 958 radio sources in Stokes I of which 136 are detected in polarization. We present the Euclidean-normalized polarized differential source counts down to 400 microJy. These counts indicate that sources have a higher degree of fractional polarization at fainter Stokes I flux density levels than for brighter sources, confirming an earlier result. We find that the majority of our polarized sources are steep-spectrum objects with a mean spectral index of -0.77, and there is no correlation between fractional polarization and spectral index. We also matched deep field sources to counterparts in the Faint Images of the Radio Sky at Twenty Centimeters catalogue. Of the polarized sources, 77% show structure at the arc-second scale whereas only 38% of the sources with no detectable polarization show such structure. The median fractional polarization is for resolved sources is 6.8%, while it is 4.4% for compact objects. The polarized radio sources in our deep field are predominantly those sources which are resolved and show the highest degrees of fractional polarization, indicating that the lobe dominated structure may be the source of the highly polarized sources. These resolved radio galaxies dominate the polarized source counts at P_0 = sqrt(Q^2 + U^2) < 3 mJy.
Prototyping of the ILC Baseline Positron Target
Jeff Gronberg,Craig Brooksby,Tom Piggott,Ryan Abbott,Jay Javedani,Ed Cook
Physics , 2012,
Abstract: The ILC positron system uses novel helical undulators to create a powerful photon beam from the main electron beam. This beam is passed through a titanium target to convert it into electron-positron pairs. The target is constructed as a 1 m diameter wheel spinning at 2000 RPM to smear the 1 ms ILC pulse train over 10 cm. A pulsed flux concentrating magnet is used to increase the positron capture efficiency. It is cooled to liquid nitrogen temperatures to maximize the flatness of the magnetic field over the 1 ms ILC pulse train. We report on prototyping effort on this system.
A Bayesian Approach for Modeling Cattle Movements in the United States: Scaling up a Partially Observed Network
Tom Lindstr?m, Daniel A. Grear, Michael Buhnerkempe, Colleen T. Webb, Ryan S. Miller, Katie Portacci, Uno Wennergren
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0053432
Abstract: Networks are rarely completely observed and prediction of unobserved edges is an important problem, especially in disease spread modeling where networks are used to represent the pattern of contacts. We focus on a partially observed cattle movement network in the U.S. and present a method for scaling up to a full network based on Bayesian inference, with the aim of informing epidemic disease spread models in the United States. The observed network is a 10% state stratified sample of Interstate Certificates of Veterinary Inspection that are required for interstate movement; describing approximately 20,000 movements from 47 of the contiguous states, with origins and destinations aggregated at the county level. We address how to scale up the 10% sample and predict unobserved intrastate movements based on observed movement distances. Edge prediction based on a distance kernel is not straightforward because the probability of movement does not always decline monotonically with distance due to underlying industry infrastructure. Hence, we propose a spatially explicit model where the probability of movement depends on distance, number of premises per county and historical imports of animals. Our model performs well in recapturing overall metrics of the observed network at the node level (U.S. counties), including degree centrality and betweenness; and performs better compared to randomized networks. Kernel generated movement networks also recapture observed global network metrics, including network size, transitivity, reciprocity, and assortativity better than randomized networks. In addition, predicted movements are similar to observed when aggregated at the state level (a broader geographic level relevant for policy) and are concentrated around states where key infrastructures, such as feedlots, are common. We conclude that the method generally performs well in predicting both coarse geographical patterns and network structure and is a promising method to generate full networks that incorporate the uncertainty of sampled and unobserved contacts.
What’s Wrong with Requirements Specification? An Analysis of the Fundamental Failings of Conventional Thinking about Software Requirements, and Some Suggestions for Getting it Right  [PDF]
Tom Gilb
Journal of Software Engineering and Applications (JSEA) , 2010, DOI: 10.4236/jsea.2010.39096
Abstract: We know many of our IT projects fail and disappoint. The poor state of requirements methods and practice is frequently stated as a factor for IT project failure. In this paper, I discuss what I believe is the fundamental cause: we think like programmers, not engineers and managers. We do not concentrate on value delivery, but instead on functions, on use-cases and on code delivery. Further, management is not taking its responsibility to make things better. In this paper, ten practical key principles are proposed, which aim to improve the quality of requirements specification.
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