We have examined the effects of mild, chronic water stress and acute water stress on two water stress sensitive plants, Xanthium strumarium and Helianthus annuus. Using a combination of the leaf disc O(2) electrode to measure the light responses of photosynthesis and 77 K fluorescence to monitor damage to the primary photochemistry, we have found the following: (a) The CO(2) saturated rate of p...

The quantum yield of the initial charge separation steps in bacterial photosynthetic reaction centers has been shown to be reduced in an applied electric field [Part I, Lao et al., J. Phys. Chem. 97 (1993) 13165]. The mechanism of this quantum yield failure is examined further by measuring the orientations of the subpopulations which return to the ground state in an electric field. Information ...

In higher plants, regulation of excess absorbed light is essential for their survival and fitness, as it enables avoidance of a build up of singlet oxygen and other reactive oxygen species. Regulation processes (known as non-photochemical quenching; NPQ) can be monitored by steady-state fluorescence on intact plant leaves. Pulse amplitude modulated (PAM) measurements of chlorophyll a fluorescen...

The development of efficient photocatalytic material for converting solar energy to hydrogen energy as viable alternatives to fossil-fuel technologies is expected to revolutionize energy shortage and environment issues. However, to date, the low quantum yield for solar hydrogen production over photocatalysts has hindered advances in the practical applications of photocatalysis. Here, we show th...

quantum organizations are referred where stakeholders know how to access the infinite potential of the quantum field. viewing healthcare organizations from perspective of quantum theory suggest new approaches into management techniques for effective and efficient delivery of healthcare services. this research is aimed to determine the quantum skills, quantum leadership characteristics and funct...

Recently we reported that close-proximity metallic mum enhancement in the incident electric field has been calculated to be a factor of 140 near appropriately sized silver islands or colloids can alter the radiative decay metallic ellipsoids [8]. Because the incident intensity is rate, ⌫ m , and/or excitation rate, E m , of fluorophores [1–5]. the square of the incident field strength for a 1-p...

Is physiological performance a suitable proxy of fitness in plants? Although, several studies have been conducted to measure some fitness-related traits and physiological performance, direct assessments are seldom found in the literature. Here, we assessed the physiology-fitness relationship using second-generation individuals of the invasive plant species Taraxacum officinale from 17 localitie...

The design of highly near-infrared (NIR) emissive lanthanide (Ln) complexes is challenging, owing to the lack of molecular systems with a high sensitization efficiency and the difficulty of achieving a large intrinsic quantum yield. Previous studies have reported success in optimizing individual factors and achieving high overall quantum yields, with the best yield being 12% for Yb(iii). Herein...

The effect of temperature on ligand photodissociation from protoheme and the heme proteins hemoglobin (Hb) and myoglobin (Mb) has been examined. The quantum yield of photodissociation (phi) is greater at 40 degrees than at 0 degrees; in general, larger increases are seen in the less photosensitive complexes, while phi does not change in the most photosensitive complexes. The ratio of phi at 40 ...

A comprehensive investigation of the solution photophysics of a 5,5'-methylene-bridged polymeric indigo, a statistical copolymer consisting of indigo and N-acetylindigo units, was performed in organic solvents at room temperature and further compared with indigo. A complete spectral and photophysical characterization based on photoacoustic calorimetry, steady-state and time-resolved fluorescenc...