154 research outputs found
Multi-layer Biosensor for Pre-symptomatic Detection of Puccinia strifformis, the Causal Agent of Yellow Rust
The yellow rust of wheat (caused by Puccinia striiformis f. sp. tritici) is a devastating fungal infection that is responsible for significant wheat yield losses. The main challenge with the detection of this disease is that it can only be visually detected on the leaf surface between 7 and 10 days after infection, and by this point, counter measures such as the use of fungicides are generally less effective. The hypothesis of this study is to develop and use a compact electrochemical-based biosensor for the early detection of P. striiformis, thus enabling fast countermeasures to be taken. The biosensor that was developed consists of three layers. The first layer mimics the wheat leaf surface morphology. The second layer consists of a sucrose/agar mixture that acts as a substrate and contains a wheat-derived terpene volatile organic compound that stimulates the germination and growth of the spores of the yellow rust pathogen P. s. f. sp. tritici. The third layer consists of a nonenzymatic glucose sensor that produces a signal once invertase is produced by P. striiformis, which comes into contact with the second layer, thereby converting sucrose to glucose. The results show the proof that this innovative biosensor can enable the detection of yellow rust spores in 72 h
Aldehyde-mediated protein-to-surface tethering via controlled diazonium electrode functionalization using protected hydroxylamines
We report a diazonium electro-grafting method for the covalent modification of conducting surfaces with aldehyde-reactive hydroxylamine functionalities that facilitate the wiring of redox-active (bio)molecules to electrode surfaces. Hydroxylamine monolayer formation is achieved via a phthalimide-protection and hydrazine-deprotection strategy that overcomes the multilayer formation that typically complicates diazonium surface modification. This surface modification strategy is characterized using electrochemistry (electrochemical impedance spectroscopy and cyclic voltammetry), X-ray photoelectron spectroscopy and quartz crystal microbalance with dissipation monitoring. Thus-modified glassy carbon, boron-doped diamond and gold surfaces are all shown to ligate to small molecule aldehydes, yielding surface coverages of 150-170, 40 and 100 pmol cm-2, respectively. Bio-conjugation is demonstrated via the coupling of a dilute (50 µM) solution of periodate-oxidized horseradish peroxidase enzyme to a functionalized gold surface under bio-compatible conditions (H2O solvent, pH 4.5, 25 °C)
Emissions and Energy Impacts of the Inflation Reduction Act
If goals set under the Paris Agreement are met, the world may hold warming
well below 2 C; however, parties are not on track to deliver these commitments,
increasing focus on policy implementation to close the gap between ambition and
action. Recently, the US government passed its most prominent piece of climate
legislation to date, the Inflation Reduction Act of 2022 (IRA), designed to
invest in a wide range of programs that, among other provisions, incentivize
clean energy and carbon management, encourage electrification and efficiency
measures, reduce methane emissions, promote domestic supply chains, and address
environmental justice concerns. IRA's scope and complexity make modeling
important to understand impacts on emissions and energy systems. We leverage
results from nine independent, state-of-the-art models to examine potential
implications of key IRA provisions, showing economy wide emissions reductions
between 43-48% below 2005 by 2035
Effects of intrauterine exposure to synthetic glucocorticoids on fetal, newborn, and infant hypothalamic-pituitary-adrenal axis function in humans : a systematic review
BACKGROUND: Synthetic glucocorticoids are commonly used in reproductive medicine. Fetal organ systems are highly sensitive to changes in the intrauterine environment, including overexposure to glucocorticoids. Structural and functional alterations resulting from such changes may persist throughout life and have been associated with diverse diseases. One system that could be particularly sensitive to fetal glucocorticoid overexposure is the hypothalamic-pituitary-adrenal (hpa) axis. Many human studies have investigated this possibility, but a systematic review to identify consistent, emergent findings is lacking. METHODS: We systematically review 49 human studies, assessing the effects of intrauterine exposure to synthetic glucocorticoids on fetal, neonate, and infant hpa function. RESULTS: Study quality varied considerably, but the main findings held true after restricting the analyses to higher-quality studies: intrauterine exposure to synthetic glucocorticoids reduces offspring hpa activity under unstimulated conditions after pain but not pharmacological challenge. Although reduced unstimulated hpa function appears to recover within the first 2 wk postpartum, blunted hpa reactivity to pain is likely to persist throughout the first 4 months of life. There is some evidence that the magnitude of the effects is correlated with the total amount of glucocorticoids administered and varies with the time interval between glucocorticoid exposure and hpa assessment. CONCLUSIONS: This systematic review has allowed the demonstration of the way in which intrauterine exposure to various regimens of synthetic glucocorticoids affects various forms of hpa function. As such, it guides future studies in terms of which variables need to be focused on in order to further strengthen the understanding of such therapy, whilst continuing to profit from its clinical benefits
Voluntary Cleanups and Redevelopment Potential: Lessons from Baltimore, Maryland
Policy has increasingly shifted towards economic incentives and liability attenuation for promoting cleanup and redevelopment of contaminated sites, but little is known about the effectiveness of such policies. An example of such legislation is State Voluntary Cleanup Programs (VCPs), which were established in the US in the 1990s and to date have been implemented in almost every state. We examine Baltimore properties that participated in the Maryland VCP from its inception in 1997 to the end of 2006. Specifically, we examine what type of properties tend to participate in these programs, how these properties compare to other eligible but non-participating sites, and what is the redevelopment potential of VCP properties and implications towards open space conversion. We find that most applicants (66%) actually requested a No Further Action Determination directly, rather than proposing cleanup. VCP properties tend to be industrial, located in industrial areas, and away from residential neighborhoods. In more recent years larger industrial properties have increasingly enrolled in the program. The majority of sites are reused as industrial or commercial. In contrast to Alberini (2007), this suggests that pressure for residential development does not drive VCP participation. Based on differences in zoning requirements, the VCP may reduce demand for potentially contaminating activities on pristine land by as much as 1,238 to 6,444 acres, in Baltimore alone
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