A Computational Model of Trust Based on Dynamic Interaction in the Stack Overflow Community

A member’s reputation in an online community is a quantified representation of their trustworthiness within the community. Reputation is calculated using rules-based algorithms which are primarily tied to the upvotes or downvotes a member receives on posts. The main drawback of this form of reputation calculation is the inability to consider dynamic factors such as a member’s activity (or inactivity) within the community. The research involves the construction of dynamic mathematical models to calculate reputation and then determine to what extent these results compare with rules-based models. This research begins with exploratory research of the existing corpus of knowledge. Constructive research in the building of mathematical dynamic models and then empirical research to determine the effectiveness of the models. Data collected from the Stack Overflow (SO) database is used by models to calculate a rule-based and dynamic member reputation and then using statistical correlation testing methods (i.e., Pearson and Spearman) to determine the extent of the relationship. Statistically significant results with moderate relationship size were found from correlation testing between rules-based and dynamic temporal models. The significance of the research and its conclusion that dynamic and temporal models can indeed produce results comparative to that of subjective vote-based systems is important in the context of building trust in online communities. Developing models to determine reputation in online communities based upon member post and comment activity avoids the potential drawbacks associated with vote-based reputation systems

パリ詩篇（フランス国立図書館所蔵の写本 Fonds latin, 8824）に 収録されている古英語で書かれた散文と韻文による詩篇の翻訳について

ウェセックスのアルフレッド王の作とされる古英語散文の詩篇と10世紀に書かれた作者不詳の韻文の詩編を比較し、どのような方法で翻訳が行われているのか、詩篇の解釈にどれほど準拠しているのか、解釈の焦点をどこに合わせているのか、について論じる。特に韻文の詩篇の文体的および修辞的特徴について考察する

On The Use Of Writing Assignments In Intermediate Microeconomic Theory

A typical writing assignment in upper level required courses is a term paper. However many economics majors, particularly those in business schools, need to develop skill at writing shorter pieces. In this paper I describe numerous examples of shorter writing assignments that I have incorporated into an Intermediate Microeconomic Theory course. The assignments include such activities as comparison of competing theories; non-traditional applications of theory; book reviews; and explorations of the nuances of the standard consumer choice model. In addition to describing the details of the various assignments, the paper presents both student and instructor assessment of them

Myths Revisited

Do universities reward teaching? Do universities reward publication? Which is rewarded more: teaching or publication? Do research and publication undermine good teaching? These questions, perhaps more than any others, spark emotional outbursts among academics. Many are quick to champion a view, but their arguments often fly in the face of hard data. What then do the data show? Are they exhaustive? Are they uniform? One set of answers is found in Professor Johnston's article entitled, "Myth Conceptions of Academic Work" which appeared in the Canadian Journal of Higher Education, Vol. XXI-2, 1991. Another set is found in this article. The reader is left to draw his or her own conclusion.Quelles reconnaissances les univesités accordent-elles à l'enseignement? Encouragent-elles la publication? L'une de ces activités est-elle davantage valorisée que l'autre? La recherche et la publication contribuent-elles à diminuer la qualité de l'enseignement? Ces questions, peut-être plus que toutes autres, soulèvent des flambées d'émotion chez les enseignants. Plusieurs n'hésiteront pas à énoncer un point de vue même si ces arguments sont souvent contredits par les données statistiques. Que démontrent donc ces données? Sont-elles exhaustives? Sont-elles cohérentes? Un article de Ian C. Johnstone paru dans la Revue canadienne pour l'enseignement supérieur, vol. XXI-2, 1991, et intitulé "Myth Conceptions of Academic Work," a tenté de répondre à ces questions. Cet article soumet un autre point de vue. Les lecteurs et lectrices sont appelés à tirer leurs propres conclusions

Miscellaneous Notes on the Old English Prose and Metrical Psalms in the Paris Psalter

　“The Paris Psalter” の名称で知られている写本 Paris, Bibliothèque nationale de France, fonds latin, MS 8824には、11世紀中期に書かれた古英語による詩篇150篇のすべてが収録されている。そのうち詩篇1-50は散文、51‒150は韻文にそれぞれラテン語から翻訳されている。これらの散文と韻文の古英語訳について、特に統語法を中心に解決されないままになってきた多くの問題点を取り上げ、正しい解釈を提示する。ここに掲載する小論は、筆者が2016年にHarvard University Press から出版されるOld English Psalms（Dumbarton Oaks Medieval Library series）を執筆している間に生まれた副産物である

Sturdier DNA nanotubes via ligation

DNA nanotubes are crystalline self-assemblies of DNA tiles ~10 nm in diameter that readily grow tens of micrometers in length. Easy assembly, programmability, and stiffness make them interesting for many applications, but DNA nanotubes begin to melt at temperatures below 40 °C, break open when deposited on mica or scanned by AFM, and disintegrate in deionized water. These weaknesses can be traced to the presence of discontinuities in the phosphate backbone, called nicks. The nanotubes studied here have five nicks, one in the core of a tile and one at each corner. We report the successful ligation of all four corner nicks by T4 DNA ligase. Although ligation does not change the nanotubes’ stiffness, ligated nanotubes withstand temperatures over 70 °C, resist breaking during AFM, and are stable in pure water for over a month. Ligated DNA nanotubes are thus physically and chemically sturdy enough to withstand the manipulations necessary for many technological applications

Wave-number Selection by Target Patterns and Side Walls in Rayleigh-Benard Convection

We present experimental results for Rayleigh-Benard convection patterns in a cylindrical container with static side-wall forcing induced by a heater. This forcing stabilized a pattern of concentric rolls (a target pattern) with the central roll (the umbilicus) at the center of the cell after a jump from the conduction to the convection state. A quasi-static increase of the control parameter (epsilon) beyond 0.8 caused the umbilicus of the pattern to move off center. As observed by others, a further quasi-static increase of epsilon up to 15.6 caused a sequence of transitions. Each transition began with the displacement of the umbilicus and then proceeded with the loss of one convection roll at the umbilicus and the return of the umbilicus to a location near the center of the cell. Alternatively, with decreasing epsilon new rolls formed at the umbilicus but large umbilicus displacements did not occur. In addition to quantitative measurements of the umbilicus displacement, we determined and analyzed the entire wave-director field of each image. The wave numbers varied in the axial direction, with minima at the umbilicus and at the cell wall and a maximum at a radial position close to 2/3 Gamma. The wave numbers at the maximum showed hysteretic jumps at the transitions, but on average agreed well with the theoretical predictions for the wave numbers selected in the far field of an infinitely extended target pattern.Comment: ReVTeX, 11 pages, 16 eps figures include

Assessing Ozone-Related Health Impacts under a Changing Climate

Climate change may increase the frequency and intensity of ozone episodes in future summers in the United States. However, only recently have models become available that can assess the impact of climate change on O(3) concentrations and health effects at regional and local scales that are relevant to adaptive planning. We developed and applied an integrated modeling framework to assess potential O(3)-related health impacts in future decades under a changing climate. The National Aeronautics and Space Administration–Goddard Institute for Space Studies global climate model at 4° × 5° resolution was linked to the Penn State/National Center for Atmospheric Research Mesoscale Model 5 and the Community Multiscale Air Quality atmospheric chemistry model at 36 km horizontal grid resolution to simulate hourly regional meteorology and O(3) in five summers of the 2050s decade across the 31-county New York metropolitan region. We assessed changes in O(3)-related impacts on summer mortality resulting from climate change alone and with climate change superimposed on changes in O(3) precursor emissions and population growth. Considering climate change alone, there was a median 4.5% increase in O(3)-related acute mortality across the 31 counties. Incorporating O(3) precursor emission increases along with climate change yielded similar results. When population growth was factored into the projections, absolute impacts increased substantially. Counties with the highest percent increases in projected O(3) mortality spread beyond the urban core into less densely populated suburban counties. This modeling framework provides a potentially useful new tool for assessing the health risks of climate change

Structural and functional characterization of the oxidoreductase a-DsbA1 from wolbachia pipientis

The &alpha;-proteobacterium Wolbachia pipientis is a highly successful intracellular endosymbiont of invertebrates that manipulates its host\u27s reproductive biology to facilitate its own maternal transmission. The fastidious nature of Wolbachia and the lack of genetic transformation have hampered analysis of the molecular basis of these manipulations. Structure determination of key Wolbachia proteins will enable the development of inhibitors for chemical genetics studies. Wolbachia encodes a homologue (&alpha;-DsbA1) of the Escherichia coli dithiol oxidase enzyme EcDsbA, essential for the oxidative folding of many exported proteins. We found that the active-site cysteine pair of Wolbachia &alpha;-DsbA1 has the most reducing redox potential of any characterized DsbA. In addition, Wolbachia &alpha;-DsbA1 possesses a second disulfide that is highly conserved in &alpha;-proteobacterial DsbAs but not in other DsbAs. The &alpha;-DsbA1 structure lacks the characteristic hydrophobic features of EcDsbA, and the protein neither complements EcDsbA deletion mutants in E. coli nor interacts with EcDsbB, the redox partner of EcDsbA. The surface characteristics and redox profile of &alpha;-DsbA1 indicate that it probably plays a specialized oxidative folding role with a narrow substrate specificity. This first report of a Wolbachia protein structure provides the basis for future chemical genetics studies.<br /