Excessive irradiance and antioxidant responses of an Antarctic marine diatom exposed to iron limitation and to dynamic irradiance

The synergistic effects of iron limitation and irradiance dynamics on growth, photosynthesis, antioxidant activity and excessive PAR (400-700 nm) and UV (280-400 nm) sensitivity were investigated for the Antarctic marine diatom Chaetoceros brevis. Iron-limited and iron-replete cultures were exposed to identical daily irradiance levels, supplied as dynamic (20-1350 micromol m(-2) s(-1)) and constant (260 micromol m(-2) s(-1)) irradiance. After acclimation, growth, maximal quantum yield of PSII (F(v)/F(m)), pigment composition, and the activities of the antioxidant enzymes superoxide dismutase (SOD), ascorbate peroxidase (APX) and glutathione reductase (GR) were determined. Then, excessive irradiance sensitivity was assessed by monitoring pigment composition, F(v)/F(m) and viability loss during a single excessive PAR and UV treatment. Iron limitation reduced growth rates, F(v)/F(m) dynamics, and cellular pigments pools. Cellular pigment concentrations were higher under dynamic irradiance than under constant irradiance but this difference was less pronounced under iron limitation compared to iron-replete conditions. SOD and APX activities increased during dynamic irradiance under iron limitation, suggesting increased radical formation around PSII. Despite these physiological differences, no effects on growth were observed between constant and dynamic irradiance cultivation in iron-limited and iron-replete cells. The applied culturing conditions did not affect glutathione reductase activity in C. brevis. F(v)/F(m) and xanthophyll de-epoxidation dynamics during excessive irradiance were not different for iron-limited and replete cells and viability loss was not found during excessive irradiance. This study revealed photoacclimation differences between iron-limited and iron-replete C. brevis cultures that did not affect growth rates and excessive irradiance sensitivity after acclimation to constant and dynamic irradiance.     

Biosensor immunoassay for traces of hazelnut protein in olive oil

The fraudulent addition of hazelnut oil to more expensive olive oil not only causes economical loss but may also result in problems for allergic individuals as they may inadvertently be exposed to potentially allergenic hazelnut proteins. To improve consumer safety, a rapid and sensitive direct biosensor immunoassay, based on a highly specific monoclonal antibody, was developed to detect the presence of hazelnut proteins in olive oils. The sample preparation was easy (extraction with buffer); the assay time was fast (4.5 min only) and the limit of detection was low (0.08 μg/g of hazelnut proteins in olive oil). Recoveries obtained with an olive oil mixed with different amounts of a hazelnut protein containing hazelnut oil varied between 93% and 109%. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Superconducting gap structure of the 115s revisited

Density functional theory calculations of the electronic structure of Ce- and Pu-based heavy fermion superconductors in the so-called 115 family are performed. The gap equation is used to consider which superconducting order parameters are most favorable assuming a pairing interaction that is peaked at (π, π, qz)—the wavevector for the antiferromagnetic ordering found in close proximity. In addition to the commonly accepted dx2?y2 order parameter, there is evidence that an extended s-wave order parameter with nodes is also plausible. We discuss whether these results are consistent with current observations and possible measurements that could help distinguish between these scenarios.     

The graph with spectrum 141 240 (?4)10?(?6)9

We show that there is a unique graph with spectrum as in the title. It is a subgraph of the McLaughlin graph. The proof uses a strong form of the eigenvalue interlacing theorem to reduce the problem to one about root lattices.     

Growth and basic dielectric data of high quality TSCC crystals

Tris-sarcosine calcium chloride (TSCC) single crystals were grown from water solutions by the isothermal evaporation method. The growth solutions contained sarcosine and CaCl₂ either in stoichiometric or nonstoichiometric ratio. The required phase diagram sarcosine–CaCl₂ H₂O at 40 °C was determined by the synthetic method. PFT 400 MHz NMR was used for the analysis of organic impurities in sarcosine and TSCC. The crystals grown from both types of solutions had maximum values of the dielectric permittivity 10 to 200 times larger than those measured by other authors at comparable measuring frequencies and fields. It is discussed in terms of crystal quality.     

Coating systems for infra structural works

“Rijkswaterstaat” is a government organisation responsible for the construction, operation and maintenance of a large number of structures. The organisation consist of a general engineering division and a number of regional offices responsible for the Rijkswaterstaat objects in their particular region. Rijkswaterstaat spends between 40 to 50 K€ per year on coating and coating related activities. When the steel structures of the Eastern Scheldt barrier (± 200,000 m² of steel) were coated in the mid eighties the applied high solid epoxy system developed extensive cracking. This resulted in numerous locations with pit corrosion. Investigations were carried out and it was concluded that the cracking of this specific high-solids epoxy system was caused by restrained shrinkage. This resulted in the build up of high internal mechanical stresses in the coating system. Problems with stress build up were also encountered on other projects, although less severe and mainly concentrated at edges and welded joints. To prevent future problems, RWS has taken a number of initiatives such as the developed a procedure for the selection of coating systems. This selection procedure has proven to be useful for RWS in selecting coating systems for use on infra structural works. The basic principle of the selection procedure of the RWS selection procedure is different from most other procedures. The RWS selection procedure uses the object to be coated as a starting point instead of the coating system. This is done by first evaluating all relevant aspects of the object which may influence the selection of a system. These aspects are then translated into so called “Functional requirements”. Coating systems with properties that are in compliance with the performance requirements are gathered and through comparison of requirements and properties a selection is made. The objects that, until now, have been coated with systems selected with the selection procedure have performed adequately. Systems that have been selected with the procedure to replace or repair those that have developed cracking have until now not shown any new problems. At the present time more and more alternative tests and test procedures become available, most of them derived from ISO 12944. These will be studied closely and compared with the currently used methods on the level of functional requirements. RWS is already actively involved in the search for alternative test methods and will remain to do so in the future. In view of this the Rijkswaterstaat selection procedure will remain in function.     

Leitfähigkeits- und Halleffektmessungen an Tellur-Epitaxieschichten auf KCl

The temperature dependence of resistivity of epitactixial thin tellurium films grown on (110) KCl is contrary to the results well known from single crystals. For interpretation of this discrepancy a model is proposed which makes use of piezoresistance effects. This model is in qualitative and quantitative agreement with measurements.     

Novel low‐loss waveguide delay lines using Vernier ring resonators for on‐chip multi‐λ microwave photonic signal processors

In this paper, novel photonic delay lines (DLs) using Vernier/non‐identical ring resonators (VRRs) are proposed and demonstrated, which are capable of simultaneous generation of multiple different delays at different wavelengths (frequencies). The simple device architectures and full reconfigurability allow the DLs to be integrated with other functional building blocks in photonic integrated circuits to realize on‐chip, complex multi‐λ microwave photonic signal processors with reduced system complexity. To prove the concept, DLs using VRRs in cascaded and coupled configurations have been fabricated in TriPleX^TM waveguide technology, which enables a very low delay‐induced loss of approximately 0.18 dB/100 ps. The fabricated DLs demonstrated simultaneous generation of four incremental delays, where a maximum incremental step of 550 ps and a corresponding top delay of 1650 ps were measured for a bandwidth up to 1 GHz. To our knowledge, this is the first report on VRRs for delay generation functionalities.