613 research outputs found

    Systematics of Amanita (Amanitaceae, Agaricales, Basidiomycota) from the Guiana Shield and Central Africa

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    This study is a systematic assessment of ten species of ectomycorrhizal fungi of the genus Amanita (Amanitaceae, Agaricales, Basidiomycota) from the lowland tropical rainforests of the Guiana Shield and Central Africa. Fungi were collected in each of the above regions, analyzed morphologically, and compared to the literature on Amanita diversity worldwide. All species addressed herein are given full formal taxonomic descriptions including complete macro- and microscopic character profiles, habit, habitat, and distribution. Phylogenetic assessments using ribosomal DNA and protein coding genes are provided for Guiana Shield taxa, and sequence data for two non-protein coding regions, the internal transcribed spacer (ITS) and nuclear ribosomal large subunit (nrLSU) are provided for Central African taxa. to support infrageneric placement of each taxon. Chapter one describes three new species from the Guiana Shield: A. cyanochlorinosma, A. fulvoalba, and A. guyanensis. Chapter two describes four epitypes of otherwise poorly known Central African species: A. echinulata, A. fulvopulverulenta, A. robusta, and A. bingensis, and three new species from Cameroon: A. minima, A. leucolamellata, and A. goossens-fontanae. Each chapter is a manuscript that has been published in, or submitted to, a peer-reviewed mycological journal

    Evaluating Bucknell\u27s Waste Stream

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    This thesis examines three questions regarding the content of Bucknell University‟s waste stream and the contributors to campus recycling and solid waste disposal. The first asks, “What does Bucknell‟s waste stream consist of?” To answer this question, I designed a campus-wide waste audit procedure that sampled one dumpster from each of the eleven „activity‟ types on campus in order to better understand Bucknell‟s waste composition. The audit was implemented during the Fall semester of the 2011-2012 school year. The waste from each dumpster was sorted into several recyclable and non-recyclable categories and then weighed individually. Results showed the Bison and Carpenter Shop dumpsters to contain the highest percentage of divertible materials (through recycling and/or composting). When extrapolated, results also showed the Dining Services buildings and Facilities buildings to be the most waste dense in terms of pounds of waste generated per square foot. The Bison also generated the most overall waste by weight. The average composition of all dumpsters revealed that organic waste composed 24% of all waste, 23% was non-recyclable paper, and 20% was non-recyclable plastic. It will be important to move forward using these results to help create effective waste programs that target the appropriate areas of concern. My second question asks, “What influences waste behavior to contribute to this „picture‟ of the waste stream?” To answer this question, I created a survey that was sent out to randomly selected sub-group of the university‟s three constituencies: students, faculty, and staff. The survey sought responses regarding each constituency‟s solid waste disposal and recycling behavior, attitudes toward recycling, and motivating factors for solid waste disposal behaviors across different sectors of the university. Using regression analysis, I found three statistically significant motivating factors that influence solid waste disposal behavior: knowledge and awareness, moral value, and social norms. I further examined how a person‟s characteristics associate to these motivating factors and found that one‟s position on campus proved a significant association. Consistently, faculty and staff were strongly influenced by the aforementioned motivating factors, while students‟ behavior was less influenced by them. This suggests that new waste programs should target students to help increase the influence of these motivators to improve the recycling rate and lower overall solid waste disposal on campus. After making overall conclusions regarding the waste audit and survey, I ask my third question, which inquires, “What actions can Bucknell take to increase recycling rates and decrease solid waste generation?” Bucknell currently features several recycling and waste minimization programs on campus. However, using results from the waste audit and campus survey, we can better understand what are the issues of the waste stream, how do we go about addressing these issues, and who needs to be addressed. I propose several suggestions for projects that future students may take on for summer or thesis research. Suggestions include targeting the appropriate categories of waste that occur most frequently in the waste stream, as well as the building types that have the highest waste density and potential recovery rates. Additionally, certain groups on campus should be targeted more directly than others, namely the student body, which demonstrates the lowest influence by motivators of recycling and waste behavior. Several variables were identified as significant motivators of waste and recycling behavior, and could be used as program tactics to encourage more effective behavior

    “making space” in practice and education: Research support services in academic libraries

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    Design/methodology/approach – The present paper uses data from a recent survey of research support provision by academic libraries in Australia, New Zealand, the UK and Ireland, (authors 2013), and provides additional in depth analysis of the textual responses to extend the analysis in the light of forces for change in higher education. The original online questionnaire surveyed current and planned research support in academic libraries, and constraints or support needs related to service developments. It was distributed to 219 institutions in Australia, New Zealand, the UK, and Ireland, and obtained 140 valid responses (response rate of 63.9 percent). Results were analyzed using descriptive statistics with thematic categorization and coding for the textual responses

    IS Early Career Job Advertisements: A Content Analysis

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    In this paper we examine through the content analysis of job advertisements the required knowledge, skills and competencies demanded of early career information systems graduates. Jobs appropriate for graduates with three or fewer years in the workforce were investigated. The job advertisement data was gathered in 2006. The analysis showed a wide variety of job titles. There was a high demand for technical knowledge and competencies as well as communication skills. A core cluster of IS knowledge and skills emerged which appear to be in demand across a wide variety of jobs. Issues raised include the role of entry level positions in the preparation of their incumbents for future more senior positions

    Acceptance, Communication Mode and Use of Audio Computer- Assisted Self Interview Using Touchscreen to Identify Risk Factors among Pregnant Minority Women

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    This paper evaluates the acceptability, communication mode and use of audio computer-assisted self-interview (A-CASI) among minority pregnant women receiving prenatal care in six Washington, DC sites. A total of 2,913 women were screened for demographic eligibility (18+ years old,gestation, Black/African-American or Hispanic) and risk (smoking, environmental tobacco smoke exposure, depression, intimate partner violence). Questions were displayed on touch screen laptop monitors and heard through earphones. The mean length of time to complete the screener was almost 6 minutes. A-CASI experience, which included difficulty in using the computer, acceptability (enjoyment), and preferred communication mode, was compared across sites, the eligibility and risk groups and a subset of 878 enrolled women for whom educational attainment and receipt of WIC (a proxy for income) were available. Respondents thought A-CASI was not difficult to use and liked using the computer. Black/African-American or Hispanic respondents enjoyed it significantly more than did respondents of other race/ethnicities. Respondents who were demographically eligible, Black/ African-American or Hispanic, or with lower education levels listened to questions significantly more than did their counterparts. Mainly listening or listening and reading does not impact burden in terms of the length of time it took to complete the screener. The acceptance of A-CASI as a screening tool opens the door for more uses of this technology in health-related fields. The laptop computer and headphones provide privacy and mobility so the technology can be used to ask sensitive questions in almost any locale, including busy clinic settings

    Metabolic analysis of the soil microbe Dechloromonas aromatica str. RCB: indications of a surprisingly complex life-style and cryptic anaerobic pathways for aromatic degradation

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    <p>Abstract</p> <p>Background</p> <p>Initial interest in <it>Dechloromonas aromatica </it>strain RCB arose from its ability to anaerobically degrade benzene. It is also able to reduce perchlorate and oxidize chlorobenzoate, toluene, and xylene, creating interest in using this organism for bioremediation. Little physiological data has been published for this microbe. It is considered to be a free-living organism.</p> <p>Results</p> <p>The <it>a priori </it>prediction that the <it>D. aromatica </it>genome would contain previously characterized "central" enzymes to support anaerobic aromatic degradation of benzene proved to be false, suggesting the presence of novel anaerobic aromatic degradation pathways in this species. These missing pathways include the benzylsuccinate synthase (<it>bss</it>ABC) genes (responsible for fumarate addition to toluene) and the central benzoyl-CoA pathway for monoaromatics. In depth analyses using existing TIGRfam, COG, and InterPro models, and the creation of <it>de novo </it>HMM models, indicate a highly complex lifestyle with a large number of environmental sensors and signaling pathways, including a relatively large number of GGDEF domain signal receptors and multiple quorum sensors. A number of proteins indicate interactions with an as yet unknown host, as indicated by the presence of predicted cell host remodeling enzymes, effector enzymes, hemolysin-like proteins, adhesins, NO reductase, and both type III and type VI secretory complexes. Evidence of biofilm formation including a proposed exopolysaccharide complex and exosortase (epsH) are also present. Annotation described in this paper also reveals evidence for several metabolic pathways that have yet to be observed experimentally, including a sulphur oxidation (<it>sox</it>FCDYZAXB) gene cluster, Calvin cycle enzymes, and proteins involved in nitrogen fixation in other species (including RubisCo, ribulose-phosphate 3-epimerase, and nif gene families, respectively).</p> <p>Conclusion</p> <p>Analysis of the <it>D. aromatica </it>genome indicates there is much to be learned regarding the metabolic capabilities, and life-style, for this microbial species. Examples of recent gene duplication events in signaling as well as dioxygenase clusters are present, indicating selective gene family expansion as a relatively recent event in <it>D. aromatica</it>'s evolutionary history. Gene families that constitute metabolic cycles presumed to create <it>D. aromatica'</it>s environmental 'foot-print' indicate a high level of diversification between its predicted capabilities and those of its close relatives, <it>A. aromaticum </it>str EbN1 and <it>Azoarcus </it>BH72.</p

    Young carers in England: findings from the 2018 BBC survey on the prevalence and nature of caring among young people

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    Background Many young people are involved in caring for parents, siblings, or other relatives who have an illness or disability. The aim of this study was to estimate the prevalence of caring by young people in England. Method A national survey of 925 English young people was conducted using the 18‐item survey version of the Multidimensional Assessment of Caring Activities Checklist for Young Carers. Results Around 7% of young people were identified as doing at least a high amount of caring activity and 3% a very high amount. Most frequently, caring by a young person is for a mother or a sibling, with a physical disability. Caring activity consisted mostly of domestic activities, household management, and emotional care. Conclusion This study provides the most up to date and methodologically sophisticated survey data on the prevalence of young caring in England, with implications for policy and practice

    Parametrically excited surface waves: Two-frequency forcing, normal form symmetries, and pattern selection

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    Motivated by experimental observations of exotic standing wave patterns in the two-frequency Faraday experiment, we investigate the role of normal form symmetries in the pattern selection problem. With forcing frequency components in ratio m/n, where m and n are co-prime integers, there is the possibility that both harmonic and subharmonic waves may lose stability simultaneously, each with a different wavenumber. We focus on this situation and compare the case where the harmonic waves have a longer wavelength than the subharmonic waves with the case where the harmonic waves have a shorter wavelength. We show that in the former case a normal form transformation can be used to remove all quadratic terms from the amplitude equations governing the relevant resonant triad interactions. Thus the role of resonant triads in the pattern selection problem is greatly diminished in this situation. We verify our general results within the example of one-dimensional surface wave solutions of the Zhang-Vinals model of the two-frequency Faraday problem. In one-dimension, a 1:2 spatial resonance takes the place of a resonant triad in our investigation. We find that when the bifurcating modes are in this spatial resonance, it dramatically effects the bifurcation to subharmonic waves in the case of forcing frequencies are in ratio 1/2; this is consistent with the results of Zhang and Vinals. In sharp contrast, we find that when the forcing frequencies are in ratio 2/3, the bifurcation to (sub)harmonic waves is insensitive to the presence of another spatially-resonant bifurcating mode

    Quarterly U.S. unemployment: cycles, seasons and asymmetries

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    This paper documents three stylized facts for the quarterly unemployment rate in the United States. Firstly, unemployment is asymmetric over the business cycle, i.e. it rises sharply in recessions and it falls slowly in expansions. Secondly, its seasonal fluctuations are not constant across the two business cycle stages in the sense that there is less seasonality in recession periods. Thirdly, the effect of shocks to the unemployment rate in expansions seem transitory, while this effect is permanent in recessions. Some implications of these stylized facts for empirical macroeconomics and seasonal adjustment are discussed
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