1,737 research outputs found

    Project Portfolio Synthesis

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    Application Paper: What to Listen for in Music by Aaron Copland -- Rationale Paper for George Frideric Handel -- Harmonic Analysis of And the Glory of the Lord (from Messiah ) by George Frideric Handel -- Melodic Analysis of And the Glory of the Lord (from Messiah ) by George Frideric Handel -- Rhythmic/Stylistic Analysis of And the Glory of the Lord (from Messiah ) by George Frideric Handel -- Formal Analysis of And the Glory of the Lord (from Messiah ) by George Frideric Handel -- Textural Analysis of And the Glory of the Lord (from Messiah ) by George Frideric Handel -- Interpretation Paper on And the Glory of the Lord (from Messiah ) by George Frideric Handel

    A Fair Share - Burden-Sharing Preferences in the United States and China

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    Using a choice experiment, we investigated preferences for distributing the economic burden of decreasing CO2 emissions in the two largest CO2-emitting countries: the United States and China. We asked respondents about their preferences for four burden-sharing rules to reduce CO2 emissions according to their country's 1) historical emissions, 2) income level, 3) equal right to emit per person, and 4) current emissions. We found that U.S. respondents preferred the rule based on current emissions, while the equal right to emit rule was clearly least preferred. The Chinese respondents, on the other hand, preferred the historical rule, while the current emissions rule was the least preferred. Respondents overall favored the rule that was least costly for their country. These marked differences may explain the difficulties countries face in agreeing how to share costs, presenting a tough hurdle to overcome in future negotiations. We also found that the strength of the preferences was much stronger in China, suggesting that how mitigation costs are shared across countries is more important there.Climate, burden-sharing, fairness, China, United States

    Novel diterpenes with potent conidiation inducing activity

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    The isolation and structure determination of conidiogenol and conidiogenone, tetracyclic diterpenes with a novel carbon skeleton, from extracts of the fermentation broth of Penicillium cyclopium is reported. Conidiogenol and conidiogenone are potent and selective inducers of conidiogenesis in P. cyclopium in liquid culture, and relay information about the environmental conditions to the producing organism. (C) 2002 Elsevier Science Ltd. All rights reserved

    Electromechanical Piezoresistive Sensing in Suspended Graphene Membranes

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    Monolayer graphene exhibits exceptional electronic and mechanical properties, making it a very promising material for nanoelectromechanical (NEMS) devices. Here, we conclusively demonstrate the piezoresistive effect in graphene in a nano-electromechanical membrane configuration that provides direct electrical readout of pressure to strain transduction. This makes it highly relevant for an important class of nano-electromechanical system (NEMS) transducers. This demonstration is consistent with our simulations and previously reported gauge factors and simulation values. The membrane in our experiment acts as a strain gauge independent of crystallographic orientation and allows for aggressive size scalability. When compared with conventional pressure sensors, the sensors have orders of magnitude higher sensitivity per unit area.Comment: 20 pages, 3 figure

    Synthetic fluid inclusions in natural quartz. IV. Chemical analyses of fluid inclusions by SEM/EDA: Evaluation of method

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    The compositions of individual synthetic fluid inclusions in the systems NaCl-KCl, NaCl-CaCl2 and NaCl-KCl-CaCl2 have been semi-quantitatively determined by energy dispersive analysis of precipitates produced during thermal decrepitation. Inclusions containing known mixtures of 20 wt.% total salinity were synthesized by healing fractures in natural quartz at 600-700[deg]C and 5-7 kbars for 7-10 days. The two-phase, daughter-free inclusions homogenized at 170-250[deg]C, began to decrepitate after about 100[deg] of overheating and by 360-420[deg]C a significant number of decrepitates had formed on the polished surface. Peak heights generated by EDA (raster mode) of these decrepitates were standardized using both single and mixed salt standards evaporated to dryness in a vacuum. Although the mixed salt standards better approximated the decrepitate compositions, difficulties were encountered in producing micronscale homogeneity and the single salts yielded more reliable results.Eight different solutions of 20-23 wt.% total salinity were run and in all the samples the average compositions of 10-20 discrete, single inclusion decrepitates fell with 6 wt.% (0.2 to 5.2) of the actual composition, suggesting that the decrepitates were chemically representative of their precursor inclusions. However, not all decrepitates analyzed provided similarly accurate results. Electron mapping revealed that fracture-aligned decrepitates were often chemically inhomogeneous and thus had to be avoided. A sample decrepitated at 500[deg]C yielded spurious results suggesting that chloride volatility may become a significant problem when temperatures in excess of 450[deg]C are required for decrepitation. Decrepitates with diameters between 10 and 30 [mu]m yielded more consistent and accurate results than smaller or larger decrepitates on the same samples.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27326/1/0000349.pd

    Convergence of detrital stoichiometry predicts thresholds of nutrient-stimulated breakdown in streams

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    Nutrient enrichment of detritus‐based streams increases detrital resource quality for consumers and stimulates breakdown rates of particulate organic carbon (C). The relative importance of dissolved inorganic nitrogen (N) vs. phosphorus (P) for detrital quality and their effects on microbial‐ vs. detritivore‐mediated detrital breakdown are poorly understood. We tested effects of experimental N and P additions on detrital stoichiometry (C:N, C:P) and total and microbial breakdown (i.e., with and without detritivorous shredders, respectively) of five detritus types (four leaf litter species and wood) with different initial C : nutrient content. We enriched five headwater streams continuously for two years at different relative availabilities of N and P and compared breakdown rates and detrital stoichiometry to pretreatment conditions. Total breakdown rates increased with nutrient enrichment and were predicted by altered detrital stoichiometry. Streamwater N and P, fungal biomass, and their interactions affected stoichiometry of detritus. Streamwater N and P decreased detrital C:N, whereas streamwater P had stronger negative effects on detrital C:P. Nutrient addition and fungal biomass reduced C:N by 70% and C:P by 83% on average after conditioning, compared to only 26% for C:N and 10% for C:P under pretreatment conditions. Detritus with lowest initial nutrient content changed the most and had greatest increases in total breakdown rates. Detrital stoichiometry was reduced and differences among detritus types were homogenized by nutrient enrichment. With enrichment, detrital nutrient content approached detritivore nutritional requirements and stimulated greater detritivore vs. microbial litter breakdown. We used breakpoint regression to estimate values of detrital stoichiometry that can potentially be used to indicate elevated breakdown rates. Breakpoint ratios for total breakdown were 41 (C:N) and 1518 (C:P), coinciding with total breakdown rates that were ~1.9 times higher when C:N or C:P fell below these breakpoints. Microbial and shredder‐mediated breakdown rates both increased when C:N and C:P were reduced, suggesting that detrital stoichiometry is useful for predicting litter breakdown dominated by either microbial or shredder activity. Our results show strong effects of nutrient enrichment on detrital stoichiometry and offer a robust link between a potential holistic nutrient loading metric (decreased and homogenized detrital stoichiometry) and increased C loss from stream ecosystems

    Subtle Differences in Cognition in 70-Year-Olds with Elevated Cerebrospinal Fluid Neurofilament Light and Neurogranin: A H70 Cross-Sectional Study

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    BACKGROUND: Most research on cerebrospinal fluid (CSF) neurofilament light protein (NfL) as a marker for neurodegeneration and neurogranin (Ng) for synaptic dysfunction has largely focused on clinical cohorts rather than population-based samples. OBJECTIVE: We hypothesized that increased CSF levels of NfL and Ng are associated with subtle cognitive deficits in cognitively unimpaired (CU) older adults. METHODS: The sample was derived from the Gothenburg H70 Birth Cohort Studies and comprised 258 CU 70-year-olds, with a Clinical Dementia Rating score of zero. All participants underwent extensive cognitive testing. CSF levels of NfL and Ng, as well as amyloid β1 - 42, total tau, and phosphorylated tau, were measured. RESULTS: Participants with high CSF NfL performed worse in one memory-based test (Immediate recall, p = 0.013) and a language test (FAS, p = 0.016). Individuals with high CSF Ng performed worse on the memory-based test Supra Span (p = 0.035). When stratified according to CSF tau and Aβ42 concentrations, participants with high NfL and increased tau performed worse on a memory test than participants normal tau concentrations (Delayed recall, p = 0.003). In participants with high NfL, those with pathologic Aβ42 concentrations performed worse on the Delayed recall memory (p = 0.044). In the high Ng group, participants with pathological Aβ42 concentrations had lower MMSE scores (p = 0.027). However, in regression analysis we found no linear correlations between CSF NfL or CSF Ng in relation to cognitive tests when controlled for important co-variates. CONCLUSION: Markers of neurodegeneration and synaptic pathology might be associated with subtle signs of cognitive decline in a population-based sample of 70-year-olds

    Triptycene-Roofed Quinoxaline Cavitands for the Supramolecular Detection of BTEX in Air

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    Two novel triptycene quinoxaline cavitands (DiTriptyQxCav and MonoTriptyQxCav) have been designed, synthesized, and applied in the supramolecular detection of benzene, toluene, ethylbenzene, and xylenes (BTEX) in air. The complexation properties of the two cavitands towards aromatics in the solid state are strengthened by the presence of the triptycene moieties at the upper rim of the tetraquinoxaline walls, promoting the confinement of the aromatic hydrocarbons within the cavity. The two cavitands were used as fiber coatings for solid-phase microextraction (SPME) BTEX monitoring in air. The best performances in terms of enrichment factors, selectivity, and LOD (limit of detection) values were obtained by using the DiTriptyQxCav coating. The corresponding SPME fiber was successfully tested under real urban monitoring conditions, outperforming the commercial divinylbenzene\u2013Carboxen\u2013polydimethylsiloxane (DVB\u2013CAR\u2013PDMS) fiber in BTEX adsorption
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