Beyond Filter Bubbles and Echo Chambers: The Integrative Potential of the Internet

Are online audiences today fragmented into echo chambers or filter bubbles? Do users only see what digital platforms (like search engines or social media) let them see? And if so, what are the consequences for the cohesion of a society? Concerns like these abound in recent years. They attest to widely held assumptions about a negative influence of digital media or even the Internet in general on society. Empirical studies on these phenomena are, however, not as unequivocal. To understand why results from previous research are so far inconclusive, this study investigates the role of the Internet for social integration from a more general point of view. The integrative potential of the Internet is assessed to compare it with other media and ultimately better understand to what degree and due to which factors the Internet may or may not help bring society together. Using survey data, clickstream data on actual usage of websites, and data on content structures, the present work investigates how user behavior and structural features of the Internet determine its positive or negative effects on social integration. The results reveal that the Internet in general is not as bad as popular accounts of digital fragmentation may suggest. How much integrative potential can be realized via online offerings, however, depends on numerous factors on the side of the users as well as content and platform providers

Periodic bottlenecks in experimental antibiotic resistance evolution of Pseudomonas aeruginosa

Over the past decades, the spread of antibiotic resistance among nosocomial bacterial pathogens has developed into a global problem. Population bottlenecks are an important factor for bacterial evolution. Their influence on antibiotic resistance evolution is however not yet fully understood. Bottlenecks are defined as a strong reduction of population size that can lower the population‘s genetic diversity drastically. Population bottlenecks frequently occur in nature and play a significant role in the evolutionary history of populations. Bacterial populations can evolve resistance by various adaptive paths. However, the serial bottlenecks experienced by bacteria both in nature and in experimental evolution influence the direction of adaptation. After surviving a narrow bottleneck, future adaptation is more likely influenced by selective sweeps and periodic selection, rendering the adaptive paths less predictable. In contrast, higher degrees of parallel evolution and clonal interference are expected in case of a wider bottleneck, as higher genetic diversity is likely maintained. In this thesis, I validated the influence of different bottleneck sizes at different levels of selectivity on the evolvability of resistance in populations of the pathogenic bacterium Pseudomonas aeruginosa (subclone PA14). Three different evolution experiments were performed to simulate single drug treatments with carbenicillin (beta-lactam), ciprofloxacin (quinolone) and gentamicin (aminoglycoside) against PA14, for approximately 100 generations. While high inhibitory concentrations selected for the highest resistance under large transfer sizes, the highest resistance in low inhibitory concentrations populations emerged when the transfer size was small. These different dynamics are reflected by mutational patterns in the evolving bacterial genomes. Even though the total number of mutations per population for each treatment depended on the treatment drug, the diversity of the most frequent mutations at the final growth season was higher for small transfer sizes than for large transfer sizes. Surprisingly, only few mutations have completely fixed by the final transfer. These results may indicate that clonal interference of de novo mutations occurs regularly at sub-inhibitory drug concentrations. Overall, my data suggests that bottlenecks, in combination with antibiotic-induced selective pressure, can be a key determinant of resistance evolution and can shape genetic diversity within and between populations

The Cessation of Music in the \u27Paradiso\u27

This article explores Dante’s narrative use of music in the Paradiso as it leads to his ultimate vision of God. Unlike the Inferno and Purgatorio, the Paradiso seems to be suffused with continuous music, one that is inherent in the unending motions of the heavens. In the Paradiso, however, there is also much mention of the absence of sound. There are at least fifteen instances that describe a person or a group suddenly falling into silence, either as a natural conclusion of a speech, or unexpectedly as a momentary interruption of music. This article contends that the purpose of these sudden and unexpected cessations of music is that they are types of the greatest antitype of the poem, the silence of God—the only entity transcending the two fundamental conditions of any music: time and motio

Euphoria

This fictional creative thesis follows two kids in high school, Eva and Conner, struggling in unhealthy households. The two quickly become friends, and as they discover similar interests between each other like music, the lives they keep hidden begin to unravel. “Euphoria” is a novella length realistic fiction piece directed towards young adult readers and explores themes of friendships, high school, and abuse

Why we find little evidence of digital fragmentation, but should not stop researching it

Während Massenmedien üblicherweise integratives Potenzial zugeschrieben wird, wird dem Internet eher eine schädliche Wirkung auf den gesellschaftlichen Zusammenhalt unterstellt. Entsprechende Metaphern zu "Filterblasen" und "Echokammern" haben inzwischen auch in den öffentlichen Diskurs Einzug gehalten. Studien, die entsprechende Wirkungen einer digitalen Fragmentierung nachweisen, sind allerdings bisher eher selten. Der empirische Forschungsstand stützt Befürchtungen zu einem deutlichen Verlust an gesellschaftlichem Zusammenhalt durch das Internet somit nicht. Allerdings gibt es bei Extremgruppen am politischen Rand Anzeichen für digitale Fragmentierung. Angesichts des heterogenen Forschungsstands systematisiert der Beitrag theoretische Annahmen und empirische Befunde und argumentiert, dass die Erfassung digitaler Fragmentierung und ihrer Wirkungen weiter notwendig ist.While mass media are generally ascribed integrative potential, scholars assume negative effects on social cohesion for the Internet. Respective metaphors such as "filter bubbles" and "echo chambers" have meanwhile found their way into public discourse. However, empirical research that documents detrimental effects of digital fragmentation remains the exception. The state of research thus does not support fears about a stark loss of social cohesion due to the Internet. Yet there are groups on the fringe of the political spectrum that appear to be digitally fragmented. Given these heterogeneous results, the article systematizes theoretical assumptions and empirical findings and argues that it remains necessary to assess the extent and effects of digital fragmentation

Gender, and other variables, affecting graduation outcomes and the future of science. Male vs. female students 1995-2003 Rochester Institute of Technology’s College of Science

This thesis focuses on the impact of retention of undergraduate students on the future of science. If there are insufficient numbers of science students pursuing and succeeding in Science, Technology, Engineering and Mathematics education and careers, it has been argued that the United States will lose its innovative, competitive, and technological edge. The focus is on the challenges of retaining students, both male and female, in the sciences at Rochester Institute of Technology from 1995-2003. This thesis will describe and analyze existing data in an effort to develop a case specific understanding of retention metrics, student retention dynamics, and consideration of possible strategies

NASA Cold Land Processes Experiment (CLPX 2002/03): ground-based and near-surface meteorological observations

A short-term meteorological database has been developed for the Cold Land Processes Experiment (CLPX). This database includes meteorological observations from stations designed and deployed exclusively for CLPXas well as observations available from other sources located in the small regional study area (SRSA) in north-central Colorado. The measured weather parameters include air temperature, relative humidity, wind speed and direction, barometric pressure, short- and long-wave radiation, leaf wetness, snow depth, snow water content, snow and surface temperatures, volumetric soil-moisture content, soil temperature, precipitation, water vapor flux, carbon dioxide flux, and soil heat flux. The CLPX weather stations include 10 main meteorological towers, 1 tower within each of the nine intensive study areas (ISA) and one near the local scale observation site (LSOS); and 36 simplified towers, with one tower at each of the four corners of each of the nine ISAs, which measured a reduced set of parameters. An eddy covariance system within the North Park mesocell study area (MSA) collected a variety of additional parameters beyond the 10 standard CLPX tower components. Additional meteorological observations come from a variety of existing networks maintained by the U.S. Forest Service, U.S. Geological Survey, Natural Resource Conservation Service, and the Institute of Arctic and Alpine Research. Temporal coverage varies from station to station, but it is most concentrated during the 2002/ 03 winter season. These data are useful in local meteorological energy balance research and for model development and testing. These data can be accessed through the National Snow and Ice Data Center Web site

A High Speed Particle Phase Discriminator (PPD-HS) for the classification of airborne particles, as tested in a continuous flow diffusion chamber

© Author(s) 2019. This work is distributed under the Creative Commons Attribution 4.0 License.A new instrument, the High-speed Particle Phase Discriminator (PPD-HS), developed at the University of Hertfordshire, for sizing individual cloud hydrometeors and determining their phase is described herein. PPD-HS performs an in situ analysis of the spatial intensity distribution of near-forward scattered light for individual hydrometeors yielding shape properties. Discrimination of spherical and aspherical particles is based on an analysis of the symmetry of the recorded scattering patterns. Scattering patterns are collected onto two linear detector arrays, reducing the complete 2-D scattering pattern to scattered light intensities captured onto two linear, one-dimensional strips of light sensitive pixels. Using this reduced scattering information, we calculate symmetry indicators that are used for particle shape and ultimately phase analysis. This reduction of information allows for detection rates of a few hundred particles per second. Here, we present a comprehensive analysis of instrument performance using both spherical and aspherical particles generated in a well-controlled laboratory setting using a vibrating orifice aerosol generator (VOAG) and covering a size range of approximately 3-32 μm. We use supervised machine learning to train a random forest model on the VOAG data sets that can be used to classify any particles detected by PPD-HS. Classification results show that the PPD-HS can successfully discriminate between spherical and aspherical particles, with misclassification below 5% for diameters >3μm. This phase discrimination method is subsequently applied to classify simulated cloud particles produced in a continuous flow diffusion chamber setup. We report observations of small, near-spherical ice crystals at early stages of the ice nucleation experiments, where shape analysis fails to correctly determine the particle phase. Nevertheless, in the case of simultaneous presence of cloud droplets and ice crystals, the introduced particle shape indicators allow for a clear distinction between these two classes, independent of optical particle size. From our laboratory experiments we conclude that PPD-HS constitutes a powerful new instrument to size and discriminate the phase of cloud hydrometeors. The working principle of PPD-HS forms a basis for future instruments to study microphysical properties of atmospheric mixed-phase clouds that represent a major source of uncertainty in aerosol-indirect effect for future climate projections..Peer reviewe

Comparison of Welfare Status of districts in Zambia

In this paper we make welfare comparisons among districts of Zambia using multidimensional wellbeing indicators observed at the household level. The comparisons are conducted using a first order dominance approach developed by Arndt et al. (2012). It is assumed that the levels of deprivation for each indicator can be ranked ordinally from worse to better. The ranking is done without making any assumptions about the relative importance of any of the indicators. This approach is applied to the 2010 Census of Population and Housing data. The analysis has generated information on the poverty status of provinces and districts in Zambia and has ranked them from the relatively well off to the worse off. This information has been presented on a map showing the districts according to their poverty status. It is expected that this paper will contribute to fine tuning geographic poverty targeting efforts in Zambia. The rationale is that with the availability of such analysis, it will be possible to make budgetary provisions that allow for the equitable distribution of public resources. The overriding objective of the government should be to channel public resources based on the spatial distribution of poverty