Photo Degradation of Cotnaminants of Emerging concern (CECs) under Simulated Solar Radiation: Implications for their Environmental Fate

Contaminants of emerging concern (CECs) are continuously being released into the environment mainly because of their incomplete removal in the sewage treatment plants (STPs). The CECs selected for the study include antibiotics (macrolides, sulfonamides and ciprofloxacin), sucralose (an artificial sweetener) and dioctyl sulfosuccinate (DOSS, chemical dispersant used in the Deepwater Horizon oil spill). After being discharged into waterways from STPs, photo degradation is a key factor in dictating the environmental fate of antibiotics and sucralose. Photodegradation efficiency depends on many factors such as pH of the matrix, matrix composition, light source and structure of the molecule. These factors exert either synergistic or antagonistic effects in the environment and thus experiments with isolated factors may not yield the same results as the natural environmental processes. Hence in the current study photodegradation of 13 CECs (antibiotics, sucralose and dicotyl sulfosuccinate) were evaluated using natural water matrices with varying composition (deionized water, fresh water and salt water) as well as radiation of different wavelengths (254 nm, 350 nm and simulated solar radiation) in order to mimic natural processes. As expected the contribution of each factor on the overall rate of photodegradation is contaminant specific, for example under similar conditions, the rate in natural waters compared to pure water was enhanced for antibiotics (2-11 fold), significantly reduced for sucralose (no degradation seen in natural waters) and similar in both media for DOSS. In general, it was observed that the studied compounds degraded faster at 254 nm, while when using a simulated sunlight radiation the rate of photolysis of DOSS increased and the rates for antibiotics decreased in comparison to the 350 nm radiation. The photo stability of the studied CECs followed the order sucralose > DOSS > macrolides > sulfonamides > ciprofloxacin and a positive relationship was observed between photo stability and their ubiquitous presence in natural aquatic matrices. An online LC-MS/MS method was developed and validated for sucralose and further applied to reclaimed waters (n =56) and drinking waters (n = 43) from South Florida. Sucralose was detected in reclaimed waters with concentrations reaching up to 18 µg/L. High frequency of detection (> 80%) in drinking waters indicate contamination of ground waters in South Florida by anthropogenic activity.

UV-A radiation effects on higher plants: exploring the known unknown

Ultraviolet-A radiation (UV-A: 315–400 nm) is a component of solar radiation that exerts a wide range of physiological responses in plants. Currently, field attenuation experiments are the most reliable source of information on the effects of UV-A. Common plant responses to UV-A include both inhibitory and stimulatory effects on biomass accumulation and morphology. UV-A effects on biomass accumulation can differ from those on root: shoot ratio, and distinct responses are described for different leaf tissues. Inhibitory and enhancing effects of UV-A on photosynthesis are also analysed, as well as activation of photoprotective responses, including UV-absorbing pigments. UV-A-induced leaf flavonoids are highly compound-specific and species-dependent. Many of the effects on growth and development exerted by UV-A are distinct to those triggered by UV-B and vary considerably in terms of the direction the response takes. Such differences may reflect diverse UV-perception mechanisms with multiple photoreceptors operating in the UV-A range and/or variations in the experimental approaches used. This review highlights a role that various photoreceptors (UVR8, phototropins, phytochromes and cryptochromes) may play in plant responses to UV-A when dose, wavelength and other conditions are taken into account.

Contemplating Open Source Enterprise Systems

Until recently, integration of enterprise systems has been supported largely by monolithic architectures. From a technical perspective, this approach has been challenged by the suggestion of component-based enterprise systems. Lately, the nature of software as proprietary item has been questioned through the increased use of open source software in business computing in general. This suggests the potential for altered technological and commercial constellations for the design of enterprise systems, which are presented in four scenarios. © Springer-Verlag 2004.

Open Source Enterprise Systems: Towards a Viable Alternative

Enterprise systems are located within the antinomy of appearing as generic product, while being means of multiple integrations for the user through configuration and customisation. Technological and organisational integrations are defined by architectures and standardised interfaces. Until recently, technological integration of enterprise systems has been supported largely by monolithic architectures that were designed, and maintained by the respective developers. From a technical perspective, this approach had been challenged by the suggestion of component-based enterprise systems that would allow for a more user-focused system through strict modularisation. Lately, the product nature of software as proprietary item has been questioned through the rapid increase of open source programs that are being used in business computing in general, and also within the overall portfolio that makes up enterprise systems. This suggests the potential for altered technological and commercial constellations for the design of enterprise systems, which are presented in different scenarios. The technological and commercial decomposition of enterprise software and systems may also address some concerns emerging from the users’ experience of those systems, and which may have arisen from their proprietary or product nature.