83 research outputs found

    The Lived Experience of Graduate Nursing Students in Distance Education

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    This study explored the lived experience of graduate nursing students enrolled in an interactive television course offered through distance education. Areas of focus were the technology of distance education, instructional strategies, the learning community, and communication. The qualitative research methods of interviewing, observation, and artifact/documentation review were employed. Students reported returning to school for both personal and professional reasons; self-satisfaction was most frequently mentioned. The need to work in a changing health care system was the major professional reason given. Due to multiple role responsibilities which made the participants time- and place-bound, distance education was reported to be the only way the students were able to participate in affordable, quality higher education. Computers appeared to play a major role in the students\u27 learning experience. Commitment by the College of Nursing to deliver the program in an orderly manner was perceived as weak and created anxiety in the students. Student supports such as enrollment services, advisement, library services, and communication channels were present during this distance education event and appeared to be adequate. A variety of teaching/learning strategies used by a dynamic instructor were perceived by the students as being important for their learning

    Fitting a static supply and demand function for labor

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    ”At hedde et billede” : en undersøgelse af betydningsdannelsen i logotyper

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    Vores interesse for logotyper tager sit udgangspunkt to steder: I vores fÌlles interesse for henholdsvis visuelle kommunikationsformer og de müder, hvorpü virksomheder kommunikerer med deres omverden. Vores interesse for visuelle kommunikationsformer er overvejende praktisk funderet, da Christian driver Øje for Øje illustration ved siden af studierne, og Henrik er freelancefotograf. Specialet her er dog udtryk for en lyst til undersøge teorien bag visuel kommunikation. Interessen for virksomheders kommunikation er stadig overvejende teoretisk funderet. Vi har med vores fÌlles uddannelsesbaggrund i Nordisk og Virksomhedskommunikation haft rig lejlighed til, pü et teoretisk niveau, at beskÌftige os med generel kommunikationsteori og mere specifik virksomhedskommunikationsteori. Disse to interesseomrüder smelter sammen i vores intention om at belyse logotyper, der er en kommunikationsform, vi alle konfronteres med dagligt - for langt de flestes vedkommende dog uden at det afføder nogen nÌvnevÌrdig undren. Vi undrer os imidlertid over at logotypen, sü vidt vi har kunnet konstatere, hidtil er blevet overset af sprogteoretikere og aldrig er blevet underkastet en stringent metodisk videnskabelig undersøgelse som en selvstÌndig kommunikationsform. Det ønsker vi med dette speciale at tage de første skridt til at Ìndre. Vi mener, at det er relevant at tage hul pü undersøgelsen af logotyper som selvstÌndig kommunikationsform, fordi tendensen i de vestlige samfund peger i retning af, at det nuvÌrende samfunds hyperkompleksitet (Qvortrup 2000) langt fra har nüet sin kulmination. I det hyperkomplekse samfund vil efterspørgslen efter simple kommunikationsmekanismer, der kan sammenkÌde eller overføre store mÌngder af information og dermed reducere kompleksitet, stige. Som undersøgelsen i specialet vil vise, er logotyper netop en kommunikationsform af den simpelhed, der vil blive efterspurgt i det hyperkomplekse samfund. Paradoksalt nok spiller logotyper i kraft af deres simplicitet en forbløffende stor rolle for moderne virksomheder. Det er ikke uden ürsag at noget af det første, grundlÌggeren af en moderne virksomhed sÌtter sine krÌfter ind pü, er at finde det rigtige navn til virksomheden og i forlÌngelse heraf at fü skabt den rigtige logotype. Først i det øjeblik disse to identifikatorer er pü plads, begynder den ny virksomhed at føles manifest. Logotypen spiller rollen som bÌrer af identitet, og som specialet vil vise, afføder det hyperkomplekse samfund kravet om en fortÌttet identitet

    Foliar lead uptake by lettuce exposed to atmospheric fallouts

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    Metal uptake by plants occurs by soil−root transfer but also by direct transfer of contaminants from the atmosphere to the shoots. This second pathway may be particularly important in kitchen gardens near industrial plants. The mechanisms of foliar uptake of lead by lettuce (Lactuca sativa) exposed to the atmospheric fallouts of a lead-recycling plant were studied. After 43 days of exposure, the thoroughly washed leaves contained 335 ± 50 mg Pb kg−1 (dry weight). Micro-X-ray fluorescence mappings evidenced Pb-rich spots of a few hundreds of micrometers in diameter located in necrotic zones. These spots were more abundant at the base of the central nervure. Environmental scanning electron microscopy coupled with energy dispersive X-ray microanalysis showed that smaller particles (a few micrometers in diameter) were also present in other regions of the leaves, often located beneath the leaf surface. In addition, submicrometric particles were observed inside stomatal openings. Raman microspectrometry analyses of the leaves identified smelter-originated Pb minerals but also secondary phases likely resulting from the weathering of original particles. On the basis of these observations, several pathways for foliar lead uptake are discussed. A better understanding of these mechanisms may be of interest for risk assessment of population exposure to atmospheric metal contamination

    Mercury isotopes in a forested ecosystem: Implications for air‐surface exchange dynamics and the global mercury cycle

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    Forests mediate the biogeochemical cycling of mercury (Hg) between the atmosphere and terrestrial ecosystems; however, there remain many gaps in our understanding of these processes. Our objectives in this study were to characterize Hg isotopic composition within forests, and use natural abundance stable Hg isotopes to track sources and reveal mechanisms underlying the cycling of Hg. We quantified the stable Hg isotopic composition of foliage, forest floor, mineral soil, precipitation, and total gaseous mercury (THg (g) ) in the atmosphere and in evasion from soil, in 10‐year‐old aspen forests at the Rhinelander FACE experiment in northeastern Wisconsin, USA. The effect of increased atmospheric CO 2 and O 3 concentrations on Hg isotopic composition was small relative to differences among forest ecosystem components. Precipitation samples had δ 202 Hg values of −0.74 to 0.06‰ and ∆ 199 Hg values of 0.16 to 0.82‰. Atmospheric THg (g) had δ 202 Hg values of 0.48 to 0.93‰ and ∆ 199 Hg values of −0.21 to −0.15‰. Uptake of THg (g) by foliage resulted in a large (−2.89‰) shift in δ 202 Hg values; foliage displayed δ 202 Hg values of −2.53 to −1.89‰ and ∆ 199 Hg values of −0.37 to −0.23‰. Forest floor samples had δ 202 Hg values of −1.88 to −1.22‰ and ∆ 199 Hg values of −0.22 to −0.14‰. Mercury isotopes distinguished geogenic sources of Hg and atmospheric derived sources of Hg in soil, and showed that precipitation Hg only accounted for ~16% of atmospheric Hg inputs. The isotopic composition of Hg evasion from the forest floor was similar to atmospheric THg (g) ; however, there were systematic differences in δ 202 Hg values and MIF of even isotopes (∆ 200 Hg and ∆ 204 Hg). Mercury evasion from the forest floor may have arisen from air‐surface exchange of atmospheric THg (g) , but was not the emission of legacy Hg from soils, nor re‐emission of wet‐deposition. This implies that there was net atmospheric THg (g) deposition to the forest soils. Furthermore, MDF of Hg isotopes during foliar uptake and air‐surface exchange of atmospheric THg (g) resulted in the release of Hg with very positive δ 202 Hg values to the atmosphere, which is key information for modeling the isotopic balance of the global mercury cycle, and may indicate a shorter residence time than previously recognized for the atmospheric mercury pool. Key points Atmospheric Hg was fractionated during uptake by foliage (‐2.89 permil δ202Hg) Hg evading from soil was from atmospheric Hg interaction with soil environment Air‐surface exchange of Hg releases Hg with positive δ202Hg to global reservoirPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97463/1/2011GB004202RRts04.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/97463/2/2011GB004202RRts05.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/97463/3/2011GB004202RRts01.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/97463/4/gbc20021.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/97463/5/2011GB004202RRts06.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/97463/6/2011GB004202RRts02.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/97463/7/2011GB004202RRts07.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/97463/8/2011GB004202RRts03.pd

    Enhancing methane production from lignocellulosic biomass by combined steam‑explosion pretreatment and bioaugmentation with cellulolytic bacterium Caldicellulosiruptor bescii

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    Background: Biogas production from lignocellulosic biomass is generally considered to be challenging due to the recalcitrant nature of this biomass. In this study, the recalcitrance of birch was reduced by applying steam-explosion (SE) pretreatment (210 °C and 10 min). Moreover, bioaugmentation with the cellulolytic bacterium Caldicellulosiruptor bescii was applied to possibly enhance the methane production from steam-exploded birch in an anaerobic digestion (AD) process under thermophilic conditions (62 °C). Results: Overall, the combined SE and bioaugmentation enhanced the methane yield up to 140% compared to untreated birch, while SE alone contributed to the major share of methane enhancement by 118%. The best methane improvement of 140% on day 50 was observed in bottles fed with pretreated birch and bioaugmentation with lower dosages of C. bescii (2 and 5% of inoculum volume). The maximum methane production rate also increased from 4-mL CH4/ g VS (volatile solids)/day for untreated birch to 9-14-mL CH4/ g VS/day for steam-exploded birch with applied bioaugmentation. Bioaugmentation was particularly effective for increasing the initial methane production rate of the pretreated birch yielding 21-44% more methane than the pretreated birch without applied bioaugmentation. The extent of solubilization of the organic matter was increased by more than twofold when combined SE pretreatment and bioaugmentation was used in comparison with the methane production from untreated birch. The beneficial effects of SE and bioaugmentation on methane yield indicated that biomass recalcitrance and hydrolysis step are the limiting factors for efficient AD of lignocellulosic biomass. Microbial community analysis by 16S rRNA amplicon sequencing showed that the microbial community composition was altered by the pretreatment and bioaugmentation processes. Notably, the enhanced methane production by pretreatment and bioaugmentation was well correlated with the increase in abundance of key bacterial and archaeal communities, particularly the hydrolytic bacterium Caldicoprobacter, several members of syntrophic acetate oxidizing bacteria and the hydrogenotrophic Methanothermobacter. Conclusion: Our findings demonstrate the potential of combined SE and bioaugmentation for enhancing methane production from lignocellulosic biomass
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