1,640 research outputs found

    THE PROBIOTICS OF BIOFUEL: A METAGENOMIC STUDY OF MICROALGAE GROWN FOR FUEL PRODUCTION

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    Ponds in Frederick, MD were fertilized with chicken manure to increase the nutrient load in the water and stimulate microalgal growth. Nutrient analyses indicate that fertilization results in significant increases in the DOC, TDN, and TDP. The bacterial and eukaryotic microalgal communities were analyzed using 16S and 18S rRNA gene sequencing, respectively. Communities were analyzed pre-fertilization and for 15 days following fertilization. Molecular data reveals a decrease in diversity as microalgal blooms form. The microalgal density increased following fertilization, with enrichment for the Chlamydomonadales order. Prior to fertilization the bacterial communities were dominated by five phyla: Actinobacteria, Bacteroidetes, Cyanobacteria, Proteobacteria, and Verrucomicrobia. Dominant bacterial genera post-fertilization included Flavobacterium, Limnohabitans, and Polynucleobacter. Bacteria isolated from the ponds were screened for effects on Scenedesmus sp. HTB1 to identify bacteria that either enhance or inhibit microalgal growth. The growth-promoting bacteria were closely related to bacteria found to be enriched during microalgal bloom formation

    A method for measuring the dielectric constant at microwave frequencies using a standing wave detector

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    Call number: LD2668 .T4 1952 M32Master of Scienc

    Bone Marrow Mesenchymal Stem Cells Provide an Antibiotic-Protective Niche for Persistent Viable Mycobacterium tuberculosis that Survive Antibiotic Treatment

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    During tuberculosis (TB), some Mycobacterium tuberculosis bacilli persist in the presence of an active immunity and antibiotics that are used to treat the disease. Herein, by using the Cornell model of TB persistence, we further explored our recent finding that suggested that M. tuberculosis can escape therapy by residing in the bone marrow (BM) mesenchymal stem cells. We initially showed that M. tuberculosis rapidly disseminates to the mouse BM after aerosol exposure and maintained a stable burden for at least 220 days. In contrast, in the lungs, the M. tuberculosis burden peaked at 28 days and subsequently declined approximately 10-fold. More important, treatment of the mice with the antibiotics rifampicin and isoniazid, as expected, resulted in effective clearance of M. tuberculosis from the lungs and spleen. In contrast, M. tuberculosis persisted, albeit at low numbers, in the BM of antibiotic-treated mice. Moreover, most viable M. tuberculosis was recovered from the bone marrow CD271+CD45−-enriched cell fraction, and only few viable bacteria could be isolated from the CD271−CD45+ cell fraction. These results clearly show that BM mesenchymal stem cells provide an antibiotic-protective niche for M. tuberculosis and suggest that unraveling the mechanisms underlying this phenomenon will enhance our understanding of M. tuberculosis persistence in treated TB patients

    Spatially resolved photoluminescence analysis of Se passivation and defect formation in CdSex_{x}Te1−x_{1-x} thin films

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    CdTe is the most commercially successful thin-film photovoltaic technology to date. The recent development of Se-alloyed CdSex_{x}Te1−x_{1-x} layers in CdTe solar cells has led to higher device efficiencies, due to a lowered bandgap improving the photocurrent, improved voltage characteristics and longer carrier lifetimes. Evidence from cross-sectional electron microscopy is widely believed to indicate that Se passivates defects in CdSex_{x}Te1−x_{1-x} solar cells, and that this is the reason for better lifetimes and voltages in these devices. Here, we utilise spatially resolved photoluminescence measurements of CdSex_{x}Te1−x_{1-x} thin films on glass to study the effects of Se on carrier recombination in the material, isolated from the impact of conductive interfaces and without the need to prepare cross-sections through the samples. We find further evidence to support Se passivation of grain boundaries, but also identify an associated increase in below-bandgap photoluminescence that indicates the presence of Se-enhanced luminescent defects. Our results show that Se treatment, in tandem with Cl passivation, does increase radiative efficiencies. However, the simultaneous enhancement of defects within the grain interiors suggests that although it is overall beneficial, Se incorporation may still ultimately limit the maximum attainable efficiency of CdSex_{x}Te1−x_{1-x} solar cells

    Beyond the island story? the opening ceremony of the London 2012 Olympic Games as public history

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    This paper evaluates the opening ceremony of the London 2012 Olympic Games as an exercise in public history. Public events have been widely identified within the study of nationalism as festivals that attempt to reinforce national identity and belonging. Contemporary Olympic Games figure in this literature as a specific form of event where the nature and content of a host state's identity is displayed for the global gaze of other nations. While opening ceremonies perform a rich display of national identity in any case, London 2012 is particularly significant for taking place at a time of major political contestation in the United Kingdom and has frequently been interpreted as an expression of radical patriotism. Traces of such patriotic thought associated particularly with England can be found in the opening ceremony's historical pageant and overall concept, showing resonances with the work of Raphael Samuel, who argued for a radical patriotism grounded in a multiplicity of accounts of the national past from many social positions. Depicting the nation through a multiplicity of biographical narratives produces a ‘mosaic' mode of representation which can be seen in other documentary and public history projects and in the political context of British public multiculturalism in the 2000s. This responds to the need for any national narrative to be composed through compressing the lives of millions of people into one coherent story, but complicates attempts to read a text such as the opening ceremony for what they ‘really' mean. A model for understanding narratives of the past as being produced in interaction between their initial creator(s) and their reader(s) is necessary for understanding not only the London 2012 opening ceremony in particular but public history and narratives of the national past in general

    Mapping Pediatric Oncology Clinical Trial Collaborative Groups on the Global Stage

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    The global pediatric oncology clinical research landscape, particularly in Central and South America, Africa, and Asia, which bear the highest burden of global childhood cancer cases, is less characterized in the literature. Review of how existing pediatric cancer clinical trial groups internationally have been formed and how their research goals have been pursued is critical for building global collaborative research and data-sharing efforts, in line with the WHO Global Initiative for Childhood Cancer. METHODS: A narrative literature review of collaborative groups performing pediatric cancer clinical research in each continent was conducted. An inventory of research groups was assembled and reviewed by current pediatric cancer regional and continental leaders. Each group was narratively described with identification of common structural and research themes among consortia. RESULTS: There is wide variability in the structure, history, and goals of pediatric cancer clinical trial collaborative groups internationally. Several continental regions have longstanding endogenously-formed clinical trial groups that have developed and published numerous adapted treatment regimens to improve outcomes, whereas other regions have consortia focused on developing foundational database registry infrastructure supported by large multinational organizations or twinning relationships. CONCLUSION: There cannot be a one-size-fits-all approach to increasing collaboration between international pediatric cancer clinical trial groups, as this requires a nuanced understanding of local stakeholders and resources necessary to form partnerships. Needs assessments, performed either by local consortia or in conjunction with international partners, have generated productive clinical trial infrastructure. To achieve the goals of the Global Initiative for Childhood Cancer, global partnerships must be sufficiently granular to account for the distinct needs of each collaborating group and should incorporate grassroots approaches, robust twinning relationships, and implementation science

    The Lantern Vol. 58, No. 2, Summer 1991

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    • We All Fall Up • Clerical Nightmares • The Brass Bed • Mon Amour • The Lady of J. Alfred Prufrock • Forbidden Places • Edge of the Dance • Crystal World • Saturday, July 12, 1978, 4:59 pm • Of You I Think • Just Another Statistic • A 16Wordina16 Word in a 4.99 Trashcan • Souvenir • The Jester • Against a Rock • I Wish I Were a Fish • Too Small, Too Weak • Somewheres in N.Y.C. • Stuck Up • Patterns • I Should Tell You Now • Me, Tommy, and Miss May • Two Hands • All-Natural, Organically Grown Macadamia Butter • Irony of a Suburban Deathhttps://digitalcommons.ursinus.edu/lantern/1138/thumbnail.jp

    Befriending older adults in nursing homes: volunteer perceptions of switching to remote befriending in the COVID-19 era

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    Objectives: Residents in nursing homes are being isolated to prevent exposure to COVID-19. Many are prone to depression, anxiety and loneliness, and extra isolation leaves them vulnerable to compromised mental health. In this study, trained volunteers providing befriending for residents with symptoms of depression, anxiety and loneliness switched to remote befriending during COVID-19. The purpose of this study was to gauge volunteer perceptions of the switch. Methods: A qualitative phenomenological approach was used to understand how switching to remote befriending impacted on volunteers and residents. A convenience sample of 18 participants responded to questions either in individual or group interviews. Results: Volunteers adapted their befriending visits, switching from face to face visits to remote options. The format was decided collaboratively. Hearing impairments hindered phone calls. Residents sometimes felt uncomfortable with digital technology but on the whole, the change to remote ‘visiting’ was accepted. Conclusions: Further research is being conducted to gauge mental health outcomes for residents. Most volunteers and residents accepted the switch to remote befriending as better than no contact. Clinical implications: Volunteers can provide valuable support for residents living with social isolation during COVID-19. The format for social support needs to be decided collaboratively between volunteer and resident

    Background Independent Quantum Gravity: A Status Report

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    The goal of this article is to present an introduction to loop quantum gravity -a background independent, non-perturbative approach to the problem of unification of general relativity and quantum physics, based on a quantum theory of geometry. Our presentation is pedagogical. Thus, in addition to providing a bird's eye view of the present status of the subject, the article should also serve as a vehicle to enter the field and explore it in detail. To aid non-experts, very little is assumed beyond elements of general relativity, gauge theories and quantum field theory. While the article is essentially self-contained, the emphasis is on communicating the underlying ideas and the significance of results rather than on presenting systematic derivations and detailed proofs. (These can be found in the listed references.) The subject can be approached in different ways. We have chosen one which is deeply rooted in well established physics and also has sufficient mathematical precision to ensure that there are no hidden infinities. In order to keep the article to a reasonable size, and to avoid overwhelming non-experts, we have had to leave out several interesting topics, results and viewpoints; this is meant to be an introduction to the subject rather than an exhaustive review of it.Comment: 125 pages, 5 figures (eps format), the final version published in CQ
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