Showing 81 - 90 of 733 Items
Precision measurement of the Ds*+-Ds+ mass difference
Date: 1994-01-01
Creator: D. N. Brown, J. Fast, R. L. McIlwain, T. Miao, D. H., Miller, M. Modesitt, D. Payne, E. I. Shibata, I. P.J. Shipsey, P. N. Wang, M. Battle, J. Ernst, Y. Kwon, S. Roberts, E. H. Thorndike, C. H. Wang, J. Dominick, M. Lambrecht, S. Sanghera, V. Shelkov, T. Skwarnicki, R. Stroynowski, I. Volobouev, G. Wei, P. Zadorozhny, M. Artuso, M. Goldberg, D. He, N. Horwitz, R. Kennett, R. Mountain
Access: Open access
- We have measured the vector-pseudoscalar mass splitting M(Ds*+)-M(Ds+)=144.220.470.37 MeV significantly more precisely than the previous world average. We minimize the systematic errors by also measuring the vector-pseudoscalar mass difference M(D*0)-M(D0) using the radiative decay D*0D0, obtaining [M(Ds*+)-M(Ds+)]-[M(D*0)-M(D0)] =2.090.470.37 MeV. This is then combined with our previous high-precision measurement of M(D*0)-M(D0), which used the decay D*0D00. We also measure the mass difference M(Ds+)-M(D+)=99.50.60.3 MeV, using the + decay modes of the Ds+ and D+ mesons. © 1994 The American Physical Society.
Differential gene expression during compensatory sprouting of dendrites in the auditory system of the cricket Gryllus bimaculatus
Date: 2009-08-01
Creator: H. W. Horch, S. S. McCarthy, S. L. Johansen, J. M. Harris
Access: Open access
- Neurones that lose their presynaptic partners because of injury usually retract or die. However, when the auditory interneurones of the cricket Gryllus bimaculatus are denervated, dendrites respond by growing across the midline and forming novel synapses with the opposite auditory afferents. Suppression subtractive hybridization was used to detect transcriptional changes 3 days after denervation. This is a stage at which we demonstrate robust compensatory dendritic sprouting. Whereas 49 unique candidates were down-regulated, no sufficiently up-regulated candidates were identified at this time point. Several candidates identified in this study are known to influence the translation and degradation of proteins in other systems. The potential role of these factors in the compensatory sprouting of cricket auditory interneurones in response to denervation is discussed. © 2009 The Royal Entomological Society.
DC-SSAT: A divide-and-conquer approach to solving stochastic satisfiability problems efficiently
Date: 2005-12-01
Creator: Stephen M. Majercik, Byron Boots
Access: Open access
- We present DC-SSAT, a sound and complete divide-and-conquer algorithm for solving stochastic satisfiability (SSAT) problems that outperforms the best existing algorithm for solving such problems (ZANDER) by several orders of magnitude with respect to both time and space. DC-SSAT achieves this performance by dividing the SSAT problem into subproblems based on the structure of the original instance, caching the viable partial assignments (VPAs) generated by solving these subproblems, and using these VPAs to construct the solution to the original problem. DC-SSAT does not save redundant VPAs and each VPA saved is necessary to construct the solution. Furthermore, DC-SSAT builds a solution that is already human-comprehensible, allowing it to avoid the costly solution rebuilding phase in ZANDER. As a result, DC-SSAT is able to solve problems using, typically, 1-2 orders of magnitude less space than ZANDER, allowing DC-SSAT to solve problems ZANDER cannot solve due to space constraints. And, in spite of its more parsimonious use of space, DC-SSAT is typically 1-2 orders of magnitude faster than ZANDER. We describe the DC-SSAT algorithm and present empirical results comparing its performance to that of ZANDER on a set of SSAT problems. Copyright © 2005, American Association for Artificial Intelligence (www.aaai.org). All rights reserved.
Promoting the "Public Welfare" in Wartime: Stanford University during World War II
Date: 2005-11-01
Creator: Charles Dorn
Access: Open access
- As with many U.S. colleges and universities during World War II, Stanford University responded to the demands of mobilization by increasing its commitment to technical training and adopting a defense research agenda. In a striking departure from this national trend, however, Stanford also established its School of Humanities in 1942. By examining such seemingly disparate pursuits, this study reveals the complexity of the challenges that confronted institutions of higher education throughout the war era. Stanford University's simultaneous embrace of these programs illuminates broad concerns regarding the role of higher education in fostering civic-mindedness in a society denned by rapid technological advance and the perception of an ever-increasing threat to national security. © 2005 by The University of Chicago. All rights reserved.
Evaluating democracy: The 1946 U.S. education mission to Germany
Date: 2005-06-01
Creator: Charles Dorn
Access: Open access
- Following World War II, a group of American educators was assigned the task of evaluating the U.S. military government's program for reconstructing Germany's educational system. Although issuing a generally positive report, this education mission identified a number of persistent tensions that ultimately undermined America's efforts to rehabilitate and reform German schooling. As with the American occupation of Germany during the postwar era, current U.S. foreign policy directives include establishing educational institutions in the "broader Middle East" as a primary mechanism for inculcating democratic values and ideals. Determining America's success with these efforts, especially in ideologically conservative nations, poses a significant challenge to evaluators. Through an analysis of the 1946 Report of the United States Education Mission to Germany, this article presents a historical case study of the stumbling blocks, failings, and successes of one attempt to evaluate efforts in infusing democratic values into educational institutions in a fallen totalitarian state. © 2005 American Evaluation Association.
The draw-a-computational-creativity-researcher test (DACCRT): Exploring stereotypic images and descriptions of computational creativity
Date: 2019-01-01
Creator: Sarah Harmon, Katie McDonough
Access: Open access
- Prior work investigating student perceptions of scientists has revealed commonly-held beliefs, stereotypes, and even connections to career choices. We adapt the “Draw-A-Scientist” instrument to examine how undergraduates depict computational creativity researchers and the field of computational creativity as a whole. Our results indicate that there are significant differences when students are asked to draw or describe a computer scientist versus a computational creativity researcher. Whether the student is an upper-level or introductory computer science student appears to also influence responses.
“I Never Saw as Good a Nature Show Before”: Walt Disney, Environmental Education, and the True-Life Adventures
Date: 2022-01-01
Creator: Charles Dorn
Access: Open access
- Alongside Walt Disney’s animated movies, television programming, and theme parks, scholars have examined The Walt Disney Studios’ True-Life Adventures series of live-action nature documentary films for their impact on popular culture. Historians, however, have mostly overlooked the significance of the True-Life Adventures for student learning about the natural world. Amending this historiographical shortcoming, this essay examines Disney’s innovative approach to wildlife filmmaking, describes viewers’ reactions to the True-Life Adventures’ educational qualities, and investigates the Studios’ efforts to use the films to enter the education market. The study breaks new ground by analyzing seldom accessed documents preserved in theWalt Disney Archives both to reveal how students, teachers, and college and university faculty responded to the films and to examine the extension of the nature documentaries through related media.
Whole genome sequence of the heterozygous clinical isolate Candida krusei 81-B-5
Date: 2017-09-01
Creator: Christina A. Cuomo, Terrance Shea, Bo Yang, Reeta Rao, Anja, Forche
Access: Open access
- Candida krusei is a diploid, heterozygous yeast that is an opportunistic fungal pathogen in immunocompromised patients. This species also is utilized for fermenting cocoa beans during chocolate production. One major concern in the clinical setting is the innate resistance of this species to the most commonly used antifungal drug fluconazole. Here, we report a high-quality genome sequence and assembly for the first clinical isolate of C. krusei, strain 81-B-5, into 11 scaffolds generated with PacBio sequencing technology. Gene annotation and comparative analysis revealed a unique profile of transporters that could play a role in drug resistance or adaptation to different environments. In addition, we show that, while 82% of the genome is highly heterozygous, a 2.0 Mb region of the largest scaffold has undergone loss of heterozygosity. This genome will serve as a reference for further genetic studies of this pathogen.
Correction of profiles of in-situ chlorophyll fluorometry for the contribution of fluorescence originating from non-algal matter
Date: 2017-01-01
Creator: Xiaogang Xing, Hervé Claustre, Emmanuel Boss, Collin Roesler, Emanuele, Organelli, Antoine Poteau, Marie Barbieux, Fabrizio D’Ortenzio
Access: Open access
- In situ chlorophyll fluorometers have been widely employed for more than half a century, and to date, it still remains the most used instrument to estimate chlorophyll-a concentration in the field, especially for measurements onboard autonomous observation platforms, e.g., Bio-Argo floats and gliders. However, in deep waters (> 300 m) of some specific regions, e.g., subtropical gyres and the Black Sea, the chlorophyll fluorescence profiles frequently reveal "deep sea red fluorescence" features. In line with previous studies and through the analysis of a large data set (cruise transect in the South East Pacific and data acquired by 82 Bio- Argo floats), we show that the fluorescence signal measured by a humic-like DOM fluorometer is highly correlated to the "deep sea red fluorescence." Both fluorescence signals are indeed linearly related in deep waters. To remove the contribution of non-algal organic matter from chlorophyll fluorescence profiles, we introduce a new correction. Rather that removing a constant value (generally the deepest chlorophyll a fluorescence value from the profile, i.e., so-called "deep-offset correction"), we propose a correction method which relies on DOM fluorometry and on its variation with depth. This new method is validated with chlorophyll concentration extracted from water samples and further applied on the Bio-Argo float data set. More generally, we discuss the potential of the proposed method to become a standard and routine procedure in quality-control and correction of chlorophyll a fluorescence originating from Bio-Argo network.
Incorporating an ERP project into undergraduate instruction
Date: 2016-01-01
Creator: Erika Nyhus, Nancy Curtis
Access: Open access
- Electroencephalogram (EEG) is a relatively non-invasive, simple technique, and recent advances in open source analysis tools make it feasible to implement EEG as a component in undergraduate neuroscience curriculum. We have successfully led students to design novel experiments, record EEG data, and analyze event-related potentials (ERPs) during a one-semester laboratory course for undergraduates in cognitive neuroscience. First, students learned how to set up an EEG recording and completed an analysis tutorial. Students then learned how to set up a novel EEG experiment; briefly, they formed groups of four and designed an EEG experiment on a topic of their choice. Over the course of two weeks students collected behavioral and EEG data. Each group then analyzed their behavioral and ERP data and presented their results both as a presentation and as a final paper. Upon completion of the group project students reported a deeper understanding of cognitive neuroscience methods and a greater appreciation for the strengths and weaknesses of the EEG technique. Although recent advances in open source software made this project possible, it also required access to EEG recording equipment and proprietary software. Future efforts should be directed at making publicly available datasets to learn ERP analysis techniques and making publicly available EEG recording and analysis software to increase the accessibility of hands-on research experience in undergraduate cognitive neuroscience laboratory courses. Copyright