288 research outputs found

    Modern Learning Theories Provide Applications For Distance Learning Practice

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    This article reports the findings of a recent empirical study that was conducted at a large university in the United States.  The study compared the findings from modern learning theories to reported perceptions of undergraduate and graduate students taking courses in online learning environments.  The intention of the study was to compare perceived student learning preferences with theories that support distance learning design and delivery.  The article provides a report of objectives, methodology, findings, discussion, conclusions, and implications relative to the study.  Final suggestions concerning online courses aimed at satisfying student learning expectations are implicated from the findings of the study

    A World Ranking of the Top 100 Hospitality and Tourism Programs

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    The article provides an analysis of scholarly contributions to 11 hospitality and tourism refereed journals for the years 2002 to 2006. It presents the top 100 programs as ranked by instances of publications across 11 journals for a recent 5-year period. For the 5-year period, results indicate The Hong Kong Polytechnic University in the top position based on sums of instances, authors, and articles. Second, the researchers updated, modified, and extended a previous study published by the Journal of Hospitality & Tourism Research for similar information for the years 1992 to 2001. Following the update, an additional 15-year aggregate snapshot of research output for top producing institutions provided a top 18 over the last 15-year period. Next, researchers provide an updated analysis by contribution and world region among the specific journals with results indicating a large growth in the number of articles produced in Asia going from 6% of all publications over the earlier 10-year period from 1992 through 2001 to nearly 15% of published articles over the past 5-year period from 2002 through 2006. The article concludes with suggestions for the extension of similar studies and provides implications for hospitality and tourism educators

    Angular Differential and Total Cross Sections for the Excitation of Atomic Hydrogen to Its n=2 Level by 25-150-kev Hydrogen Molecular Ions

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    Experimentally and theoretically determined differential and total cross sections are reported for excitation of atomic hydrogen to its n=2 level by 25-150-keV hydrogen molecular ions. The differential cross sections decrease 3-4 orders of magnitude over the measured center-of-mass scattering-angular range from 0 to 4.5 mrad. The results of a first Born approximation and two other theoretical calculations based upon the Glauber approximation are presented and compared with the experimental results. Both calculations based on the Glauber approximation agree fairly well with the experimental results. The Born approximation agrees moderately well with the experimental results at the very small scattering angles but is well below the experimental results at the larger scattering angles. None of the theoretical calculations presented agree well with the total cross section. However, the results for the total cross section of the two calculations based on the Glauber approximation agree with the experimental results in curve shape better than the Born-approximation results

    The Pan-STARRS Moving Object Processing System

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    We describe the Pan-STARRS Moving Object Processing System (MOPS), a modern software package that produces automatic asteroid discoveries and identifications from catalogs of transient detections from next-generation astronomical survey telescopes. MOPS achieves > 99.5% efficiency in producing orbits from a synthetic but realistic population of asteroids whose measurements were simulated for a Pan-STARRS4-class telescope. Additionally, using a non-physical grid population, we demonstrate that MOPS can detect populations of currently unknown objects such as interstellar asteroids. MOPS has been adapted successfully to the prototype Pan-STARRS1 telescope despite differences in expected false detection rates, fill-factor loss and relatively sparse observing cadence compared to a hypothetical Pan-STARRS4 telescope and survey. MOPS remains >99.5% efficient at detecting objects on a single night but drops to 80% efficiency at producing orbits for objects detected on multiple nights. This loss is primarily due to configurable MOPS processing limits that are not yet tuned for the Pan-STARRS1 mission. The core MOPS software package is the product of more than 15 person-years of software development and incorporates countless additional years of effort in third-party software to perform lower-level functions such as spatial searching or orbit determination. We describe the high-level design of MOPS and essential subcomponents, the suitability of MOPS for other survey programs, and suggest a road map for future MOPS development.Comment: 57 Pages, 26 Figures, 13 Table

    What voters want: reactions to candidate characteristics in a survey experiment

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    There has been extensive research into the extent to which voters utilise short cuts based on gender and race stereotypes when evaluating candidates, but relatively little is known about how they respond to other background characteristics. We compare the impact of candidates' sex, religion, age, education, occupation and location/residence through a survey experiment in which respondents rate two candidates based on short biographies. We find small differences in the ratings of candidates in response to sex, religion, age and education cues but more sizeable effects are apparent for the candidate's occupation and place of residence. Even once we introduce a control for political party into our experimental scenarios the effect of candidate's place of residence continues to have a sizeable impact on candidate evaluations. Our research suggests that students of electoral behaviour should pay attention to a wider range of candidate cues

    MutLα heterodimers modify the molecular phenotype of Friedreich ataxia

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    This article has been made available through the Brunel Open Access Publishing Fund.Background: Friedreich ataxia (FRDA), the most common autosomal recessive ataxia disorder, is caused by a dynamic GAA repeat expansion mutation within intron 1 of FXN gene, resulting in down-regulation of frataxin expression. Studies of cell and mouse models have revealed a role for the mismatch repair (MMR) MutS-heterodimer complexes and the PMS2 component of the MutLα complex in the dynamics of intergenerational and somatic GAA repeat expansions: MSH2, MSH3 and MSH6 promote GAA repeat expansions, while PMS2 inhibits GAA repeat expansions. Methodology/Principal Findings: To determine the potential role of the other component of the MutLα complex, MLH1, in GAA repeat instability in FRDA, we have analyzed intergenerational and somatic GAA repeat expansions from FXN transgenic mice that have been crossed with Mlh1 deficient mice. We find that loss of Mlh1 activity reduces both intergenerational and somatic GAA repeat expansions. However, we also find that loss of either Mlh1 or Pms2 reduces FXN transcription, suggesting different mechanisms of action for Mlh1 and Pms2 on GAA repeat expansion dynamics and regulation of FXN transcription. Conclusions/Significance: Both MutLα components, PMS2 and MLH1, have now been shown to modify the molecular phenotype of FRDA. We propose that upregulation of MLH1 or PMS2 could be potential FRDA therapeutic approaches to increase FXN transcription. © 2014 Ezzatizadeh et al.This article has been made available through the Brunel Open Access Publishing Fund

    Comparative Genomics of Wolbachia–Cardinium Dual Endosymbiosis in a Plant-Parasitic Nematode

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    Wolbachia and Cardinium are among the most important and widespread of all endosymbionts, occurring in nematodes and more than half of insect and arachnid species, sometimes as coinfections. These symbionts are of significant interest as potential biocontrol agents due to their abilities to cause major effects on host biology and reproduction through cytoplasmic incompatibility, sex ratio distortion, or obligate mutualism. The ecological and metabolic effects of coinfections are not well understood. This study examined a Wolbachia–Cardinium coinfection in the plant-parasitic nematode (PPN), Pratylenchus penetrans, producing the first detailed study of such a coinfection using fluorescence in situ hybridization (FISH), polymerase chain reaction (PCR), and comparative genomic analysis. Results from FISH and single-nematode PCR showed 123/127 individuals in a focal population carried Cardinium (denoted strain cPpe), and 48% were coinfected with Wolbachia strain wPpe. Both endosymbionts showed dispersed tissue distribution with highest densities in the anterior intestinal walls and gonads. Phylogenomic analyses confirmed an early place of cPpe and long distance from a sister strain in another PPN, Heterodera glycines, supporting a long history of both Cardinium and Wolbachia in PPNs. The genome of cPpe was 1.36 Mbp with 35.8% GC content, 1,131 predicted genes, 41% having no known function, and missing biotin and lipoate synthetic capacity and a plasmid present in other strains, despite having a slightly larger genome compared to other sequenced Cardinium. The larger genome revealed expansions of gene families likely involved in host–cellular interactions. More than 2% of the genes of cPpe and wPpe were identified as candidate horizontally transferred genes, with some of these from eukaryotes, including nematodes. A model of the possible Wolbachia–Cardinium interaction is proposed with possible complementation in function for pathways such as methionine and fatty acid biosynthesis and biotin transport
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