122 research outputs found
The effect of Holstein-Friesian genotype and feeding system on selected performance parameters of dairy cows on grass-based systems of milk production in Ireland
End of project reportThe overall objective of this project was to assess, the effect of strain of Holstein-Friesian dairy cow, pasture-based feed system (FS) and their interaction on animal performance in terms of milk productivity and lactation profile, body weight (BW), body condition score (BCS), feed intake and energy balance (EB), reproductive performance and overall economic profitability
Enhanced optical field intensity distribution in organic photovoltaic devices using external coatings
An external dielectric coating is shown to enhance energy conversion in an organic photovoltaic cell with metal anode and cathode by increasing the optical field intensity in the organic layers. Improved light incoupling in the device is modeled using transfer matrix simulations and is confirmed by in situ measurement of the photocurrent during growth of the coating. The optical field intensity in optimized cell geometries is predicted to exceed that in analogous devices using indium tin oxide, both cell types having equivalent anode sheet resistance, suggesting a broader range of compatible substrates (e.g., metal foils) and device processing techniques.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87812/2/233502_1.pd
Organic light-emitting device on a scanning probe cantilever
Organic light-emitting devices (OLEDs) were fabricated on scanning probe cantilevers using a combination of thermally evaporated molecular organic compounds and metallic electrodes. Ion beam milling was used to define the emissive region in the shape of a ring having a diameter of less than 5âÎŒm5ÎŒm and a narrow width. Stable light emission was observed from the device at forward bias, with a current-voltage response similar to that of archetypal OLEDs. Based on this device, a novel electrically pumped scanning optical microscopy tool is suggested.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87792/2/111117_1.pd
Starling1: Swarm Technology Demonstration
The Starling series of demonstration missions will test technologies required to achieve affordable, distributed spacecraft (âswarmâ) missions that: are scalable to at least 100 spacecraft for applications that include synchronized multipoint measurements; involve closely coordinated ensembles of two or more spacecraft operating as a single unit for interferometric, synthetic aperture, or similar sensor architectures; or use autonomous or semi-autonomous operation of multiple spacecraft functioning as a unit to achieve science or other mission objectives with low-cost small spacecraft. Starling1 will focus on developing technologies that enable scalability and deep space application. The mission goals include the demonstration of a Mobile Ad-hoc NETwork (MANET) through an in-space communication experiment and vision based relative navigation through the Starling Formation-flying Optical eXperiment (StarFOX)
Kilimanjaro: A Case of Meaningful Adventure And Service Learning Abroad
This qualitative evaluation explored how female undergraduate students developed an understanding of themselves and the broader world as a result of an adventure and service learning experience in Tanzania, Africa. The project built upon theoretical frameworks regarding meaningful learningâactive, constructive, intentional, and authenticâand applied activity theory as a framework for interpreting outcomes. The study included multi-faceted examination of student perceptions of the effects of the year-long experience that culminated in a ten day trip to Tanzania, including a climb to the summit of Mount Kilimanjaro. Studentsâ reflections on the impacts of the trip focused on wanting, doing, reflecting, and relating. Thus, the experience catalyzed change in studentsâ understanding of the world that strongly indicates a meaningful learning experience
Solvent and thermal stability, and pH kinetics, of proline-specific dipeptidyl peptidase IV-like enzyme from bovine serum
Proline-specific dipeptidyl peptidase-like (DPP IV; EC 3.4.14.5) activity in bovine serum has attracted little attention despite its ready availability
and the paucity of useful proline-cleaving enzymes. Bovine serum DPP IV-like peptidase is very tolerant of organic solvents, particularly acetonitrile: upon incubation for 1 h at room temperature in 70% acetonitrile, 47% dimethylformamide, 54% DMSO and 33% tetrahydrofuran (v/v
concentrations) followed by dilution into the standard assay mixture, the enzyme retained half of its aqueous activity. As for thermal performance in aqueous buffer, its relative activity increased up to 50 âŠC. Upon thermoinactivation at 71 âŠC, pH 8.0 (samples removed periodically, cooled on ice, then assayed under optimal conditions), residual activities over short times fit a first-order decay with a k-value of 0.071±0.0034 minâ1. Over
longer times, residual activities fit to a double exponential decay with k1 and k2 values of 0.218±0.025 minâ1 (46±4% of overall decay) and 0.040±0.002 minâ1 (54±4% of overall decay), respectively. The enzymeâs solvent and thermal tolerances suggest that it may have potential for use as a biocatalyst in industry. Kinetic analysis with the
fluorogenic substrate Gly-Pro-7-aminomethylcoumarin over a range of pH values indicated two pK values at 6.18±0.07 and at 9.70±0.50. We ascribe the lower value to the active site histidine; the higher may be due to the active site serine or to a free amino group in the substrate
Optimisation of the enzyme-linked lectin assay for enhanced glycoprotein and glycoconjugate analysis
Lectinâs are proteins capable of recognising and binding to specific oligosaccharide tructures found on glycoproteins and other biomoloecules. As such they have found tility for glycoanalytical applications. One common difficulty encountered in the pplication of these proteins, particularly in multi-well plate assay formats known as Enzyme Linked Lectin Assays (ELLAâs), is in finding appropriate blocking solutions to prevent non-specific binding with plate surfaces. Many commonly used blocking agents contain carbohydrates and generate significant background signals in ELLAâs, limiting the utility of the assay.
In this study we examined the suitability of a range of blocking reagents, including rotein based, synthetic and commercially available carbohydrate free blocking eagents, for ELLA applications. Each blocking reagent was assessed against a panel f 19 commercially available biotinylated lectins exhibiting diverse structures and arbohydrate specificities. We identified the synthetic polymer Polyvinyl Alcohol PVA) as the best global blocking agent for performing ELLAâs. We ultimately present n ELLA methodology facilitating broad spectrum lectin analysis of glycoconjugates nd extending the utility of the ELLA
Emergent molecular traits of lettuce and tomato grown under wavelength-selective solar cells
The integration of semi-transparent organic solar cells (ST-OSCs) in greenhouses offers new agrivoltaic opportunities to meet the growing demands for sustainable food production. The tailored absorption/transmission spectra of ST-OSCs impacts the power generated as well as crop growth, development and responses to the biotic and abiotic environments. To characterize crop responses to ST-OSCs, we grew lettuce and tomato, traditional greenhouse crops, under three ST-OSC filters that create different light spectra. Lettuce yield and early tomato development are not negatively affected by the modified light environment. Our genomic analysis reveals that lettuce production exhibits beneficial traits involving nutrient content and nitrogen utilization while select ST-OSCs impact regulation of flowering initiation in tomato. These results suggest that ST-OSCs integrated into greenhouses are not only a promising technology for energy-neutral, sustainable and climate-change protected crop production, but can deliver benefits beyond energy considerations
A Reemerging Bright Soft X-Ray State of the Changing-look Active Galactic Nucleus 1ES 1927+654:A Multiwavelength View
1ES1927+654 is a nearby active galactic nucleus (AGN) that has shown an enigmatic outburst in optical/UV followed by X-rays, exhibiting strange variability patterns at timescales of months to years. Here we report the unusual X-ray, UV, and radio variability of the source in its postflare state (2022 Januaryâ2023 May). First, we detect an increase in the soft X-ray (0.3â2 keV) flux from 2022 May to 2023 May by almost a factor of 5, which we call the bright soft state. The hard X-ray 2â10 keV flux increased by a factor of 2, while the UV flux density did not show any significant changes (â€30%) in the same period. The integrated energy pumped into the soft and hard X-rays during this period of 11 months is âŒ3.57 Ă 10 ^50 erg and 5.9 Ă 10 ^49 erg, respectively. From the energetics, it is evident that whatever is producing the soft excess (SE) is pumping out more energy than either the UV or hard X-ray source. Since the energy source presumably is ultimately the accretion of matter onto the supermassive black hole, the SE-emitting region must be receiving the majority of this energy. In addition, the source does not follow the typical diskâcorona relation found in AGNs, neither in the initial flare (from 2017 to 2019) nor in the current bright soft state (2022â2023). We found that the core (<1 pc) radio emission at 5 GHz gradually increased until 2022 March, but showed a dip in 2022 August. The GĂŒdelâBenz relation ( L _radio / L _X-ray ⌠10 ^â5 ), however, is still within the expected range for radio-quiet AGNs, and further follow-up radio observations are currently being undertaken
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