2,326 research outputs found

    An Ecological Survey of Forest Succession in a Northeast Ohio Ecosystem Following an Emerald Ash Borer Infestation

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    This paper will be an ecological survey of a selected 28 acre piece of land in northeast Ohio impacted by the Emerald Ash Borer. This invasive species arrived in North America in 2002 and has since spread throughout the country wreaking havoc on the ash tree population. The purpose of this study is to determine what tree species are replacing the native ash trees in the succession of the forest. In order to achieve this goal, a section of the selected land will be blocked off and subdivided into manageable sections to facilitate data collection, namely the location of the ash trees, their condition, and the frequency of other tree species. Once data is collected, it will be interpreted to identify what tree species are the most successful in replacing the ash trees. This information could help show what the property’s emerging forest may look like

    Stellar Signatures of AGN Jet Triggered Star Formation

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    To investigate feedback between relativistic jets emanating from Active Galactic Nuclei (AGN) and the stellar population of the host galaxy, we analyze the long-term evolution of the galaxy-scale simulations by Gaibler et al. (2012) of jets in massive, gas-rich galaxies at z ~ 2 - 3 and of stars formed in the host galaxies. We find strong, jet-induced differences in the resulting stellar populations of galaxies that host relativistic jets and galaxies that do not, including correlations in stellar locations, velocities, and ages. Jets are found to generate distributions of increased radial and vertical velocities that persist long enough to effectively extend the stellar structure of the host. The jets cause the formation of bow shocks that move out through the disk, generating rings of star formation within the disk. The bow shock often accelerates pockets of gas in which stars form, yielding populations of stars with significant radial and vertical velocities, some of which have large enough velocities to escape the galaxy. These stellar population signatures can serve to identify past jet activity as well as jet-induced star formation

    Music, masculinity, and tradition: a musical ethnography of Dagbamba warriors in Tamale, Ghana

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    Chronic unemployment and decreased agricultural production over the last two decades have left an increasing number of men throughout Ghana’s historically under-developed North unable to meet the financial and moral expectations traditionally associated with masculinity. Paralleling the liberalization of Ghana’s political economy over this period, this “crisis of masculinity” has resulted in unprecedented transformations in traditional kinship structures, patriarchy, and channels for the transmission of traditional practices in Dagbamba communities. Driven by anxieties over these changes, Dagbamba “tradition” is being promoted as a prescription for problems stemming from poverty, environmental degradation, and political conflict, placing music and dance at the center of this discourse. Music, Masculinity, and Tradition, investigates the mobilization of traditional music as a site for the restoration of masculinity within the Dagbamba community of northern Ghana. Drawing on eleven months of participant-observation conducted with Dagbamba warriors in Ghana’s Northern Region, archival research, and ethnographic interviews, this dissertation explores the relationship between performances of traditional music, preservationist discourses, and the construction of masculinity in the first decades of the 21st century. Through analyses of the warriors’ ritual performances, including sounds, movements, and dramatized violence, I ask how traditional ideals and contemporary realities of Dagbamba masculinity are constructed, negotiated, and reinforced through performances of traditional music, suggesting links between the “iterative performativity” of the ritual and evolving constructions of gender. This dissertation offers insight into the musical construction of masculinity and the place of “tradition” in the 21st century. It also challenges over-determined notions of power/resistance through a critical evaluation of traditional musical performances as sites for the negotiation of ideas about gender, power, and history in contemporary Africa

    A Decision-Theoretic Approach to Resource Allocation in Wireless Multimedia Networks

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    The allocation of scarce spectral resources to support as many user applications as possible while maintaining reasonable quality of service is a fundamental problem in wireless communication. We argue that the problem is best formulated in terms of decision theory. We propose a scheme that takes decision-theoretic concerns (like preferences) into account and discuss the difficulties and subtleties involved in applying standard techniques from the theory of Markov Decision Processes (MDPs) in constructing an algorithm that is decision-theoretically optimal. As an example of the proposed framework, we construct such an algorithm under some simplifying assumptions. Additionally, we present analysis and simulation results that show that our algorithm meets its design goals. Finally, we investigate how far from optimal one well-known heuristic is. The main contribution of our results is in providing insight and guidance for the design of near-optimal admission-control policies.Comment: To appear, Dial M for Mobility, 200

    The Grizzly, April 2, 2020

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    The Canvas Commencement? • Film Festival Adapts to Online World • The Circle Brazil and Demystifying the Foreign • Profile: Hailey DiCiccohttps://digitalcommons.ursinus.edu/grizzlynews/1960/thumbnail.jp

    Prevalence of obesity, type II diabetes mellitus, hyperlipidemia, and hypertension in the United States: findings from the GE Centricity Electronic Medical Record database.

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    This study analyzed GE Centricity Electronic Medical Record (EMR) data to examine the effects of body mass index (BMI) and obesity, key risk factor components of metabolic syndrome, on the prevalence of 3 chronic diseases: type II diabetes mellitus, hyperlipidemia, and hypertension. These chronic diseases occur with high prevalence and impose high disease burdens. The rationale for using Centricity EMR data is 2-fold. First, EMRs may be a good source of BMI/obesity data, which are often underreported in surveys and administrative databases. Second, EMRs provide an ideal means to track variables over time and, thus, allow longitudinal analyses of relationships between risk factors and disease prevalence and progression. Analysis of Centricity EMR data showed associations of age, sex, race/ethnicity, and BMI with diagnosed prevalence of the 3 conditions. Results include uniform direct correlations between age and BMI and prevalence of each disease; uniformly greater disease prevalence for males than females; varying differences by race/ethnicity (ie, African Americans have the highest prevalence of diagnosed type II diabetes and hypertension, while whites have the highest prevalence of diagnosed hypertension); and adverse effects of comorbidities. The direct associations between BMI and disease prevalence are consistent for males and females and across all racial/ethnic groups. The results reported herein contribute to the growing literature about the adverse effects of obesity on chronic disease prevalence and about the potential value of EMR data to elucidate trends in disease prevalence and facilitate longitudinal analyses

    First flea (Siphonaptera) records for Kanuti National Wildlife Refuge, Central Alaska

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    Kanuti National Wildlife Refuge (KNWR) was established in 1980 in Central Alaska. Collections of mammal fleas began in 1991. Six species resulted: Catallagia dacenkoi Ioff, Corrodopsylla curvata (Rothschild), Ctenophthalmus pseudagyrtes Baker, Megabothris calcarifer (Wagner), Amalaraeus dissimilis (Jordan) and Peromyscopsylla ostsibirica (Scalon). Ten species of fleas were previously recorded from the upper Koyukuk River watershed. One female specimen each of C. curvata and Ct. pseudagyrtes from the KNWR are the only new fleas added to the upper watershed list

    First flea (Siphonaptera) records for Kanuti National Wildlife Refuge, Central Alaska

    Get PDF
    Kanuti National Wildlife Refuge (KNWR) was established in 1980 in Central Alaska. Collections of mammal fleas began in 1991. Six species resulted: Catallagia dacenkoi Ioff, Corrodopsylla curvata (Rothschild), Ctenophthalmus pseudagyrtes Baker, Megabothris calcarifer (Wagner), Amalaraeus dissimilis (Jordan) and Peromyscopsylla ostsibirica (Scalon). Ten species of fleas were previously recorded from the upper Koyukuk River watershed. One female specimen each of C. curvata and Ct. pseudagyrtes from the KNWR are the only new fleas added to the upper watershed list

    Measuring Transit Signal Recovery in the Kepler Pipeline II: Detection Efficiency as Calculated in One Year of Data

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    The Kepler planet sample can only be used to reconstruct the underlying planet occurrence rate if the detection efficiency of the Kepler pipeline is known, here we present the results of a second experiment aimed at characterising this detection efficiency. We inject simulated transiting planet signals into the pixel data of ~10,000 targets, spanning one year of observations, and process the pixels as normal. We compare the set of detections made by the pipeline with the expectation from the set of simulated planets, and construct a sensitivity curve of signal recovery as a function of the signal-to-noise of the simulated transit signal train. The sensitivity curve does not meet the hypothetical maximum detection efficiency, however it is not as pessimistic as some of the published estimates of the detection efficiency. For the FGK stars in our sample, the sensitivity curve is well fit by a gamma function with the coefficients a = 4.35 and b = 1.05. We also find that the pipeline algorithms recover the depths and periods of the injected signals with very high fidelity, especially for periods longer than 10 days. We perform a simplified occurrence rate calculation using the measured detection efficiency compared to previous assumptions of the detection efficiency found in the literature to demonstrate the systematic error introduced into the resulting occurrence rates. The discrepancies in the calculated occurrence rates may go some way towards reconciling some of the inconsistencies found in the literature.Comment: 13 pages, 7 figures, 1 electronic table, accepted by Ap
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