Photoinhibition and continuous growth of the wild-type and a high-light tolerant strain of Chlamydomonas reinhardtii

The volumetric productivity of the high-light tolerant strain hit2 of Chlamydomonas reinhardtii was found to be higher than that of the parental strain CC124 during continuous growth at PPFD from 200 to 1,500 mu mol m(-2) s(-1). At PPFD of 1,250 mu mol m(-2) s(-1), hit2 produced 2.53 +/- 0.18 and CC124 produced 2.05 +/- 0.12 g(biomass) dm(-3) d(-1). The rate constant of photoinhibition of hit2 was less than half of that of CC124, suggesting that hit2 produces more biomass than CC124 because hit2 does not need to allocate as much resources for PSII repair as CC124. Growth in high light triggered similar loss of chlorophyll, increase in the carotenoid-to-chlorophyll ratio, and decrease in PSI fluorescence in both strains. Thermoluminescence B band was shifted toward the Q band in hit2, suggesting that low redox potential of the Q(B)/Q(B)(-) pair contributes to the photoinhibition tolerance of hit2

Women and Illegal Activities: Gender Differences and Women's Willingness to Comply Over Time

In recent years the topics of illegal activities such as corruption or tax evasion have attracted a great deal of attention. However, there is still a lack of substantial empirical evidence about the determinants of compliance. The aim of this paper is to investigate empirically whether women are more willing to be compliant than men and whether we observe (among women and in general) differences in attitudes among similar age groups in different time periods (cohort effect) or changing attitudes of the same cohorts over time (age effect) using data from eight Western European countries from the World Values Survey and the European Values Survey that span the period from 1981 to 1999. The results reveal higher willingness to comply among women and an age rather than a cohort effect. Working Paper 06-5

Degradation of chlorophyll and synthesis of flavonols during autumn senescence-the story told by individual leaves

Autumn senescence of deciduous trees is characterized by chlorophyll degradation and flavonoid synthesis. In the present study, chlorophyll and flavonol contents were measured every morning and evening during the whole autumn with a non-destructive method from individual leaves of Sorbus aucuparia, Acer platanoides, Betula pendula and Prunus padus. In most of the studied trees, the chlorophyll content of each individual leaf remained constant until a phase of rapid degradation commenced. The fast phase lasted only similar to 1 week and ended with abscission. In S. aucuparia, contrary to the other species, the chlorophyll content of leaflets slowly but steadily decreased during the whole autumn, but rapid chlorophyll degradation commenced only prior to leaflet abscission also in this species. An increase in flavonols commonly accompanied the rapid degradation of chlorophyll. The results may suggest that each individual tree leaf retains its photosynthetic activity, reflected by a high chlorophyll content, until a rapid phase of chlorophyll degradation and flavonoid synthesis begins. Therefore, in studies of autumn senescence, leaves whose chlorophyll content is decreasing and leaves with summertime chlorophyll content (i.e. the leaves that have not yet started to degrade chlorophyll) should be treated separately

VALIDATION OF SCIAMACHY NO 2 VERTICAL COLUMN DENSITIES WITH MT.CIMONE AND STARA ZAGORA GROUND-BASED ZENITH SKY DOAS OBSERVATIONS

ABSTRACT Ground-based zenith sky Differential Optical Absorption Spectroscopy (DOAS) measurements performed by means of GASCOD instruments at Mt. Cimone (44N 11E), Italy and Stara Zagora (42N, 25E), Bulgaria are used for validation of SCIAMACHY NO 2 vertical column density (vcd) of ESA SCI_NL product retrieved with 5.01 processor version. The results presented in this work regard satellite data for the JulyDecember 2002 period. On this base it is concluded that during summer-autumn period the overall NO 2 vcd above both stations is fairly well reproduced by the SCIAMACHY data, while towards the winter period they deviate from the seasonal behaviour of NO 2 vcd derived at both stations

Excitation-energy-dependent molecular beacon detects early stage neurotoxic Aβ aggregates in the presence of cortical neurons

There is now crucial medical importance placed on understanding the role of early stage, subvisible protein aggregation, particularly in neurodegenerative disease. While there are strategies for detecting such aggregates in vitro, there is no approach at present that can detect these toxic species associated with cells and specific subcellular compartments. We have exploited excitation-energy-dependent fluorescence edge-shift of recombinant protein labeled with a molecular beacon, to provide a sensitive read out for the presence of subvisible protein aggregates. To demonstrate the potential utility of the approach, we examine the major peptide associated with the initiation of Alzheimer’s disease, amyloid β-protein (Aβ) at a patho-physiologically relevant concentration in mouse cortical neurons. Using our approach, we find preliminary evidence that subvisible Aβ aggregates are detected at specific subcellular regions and that neurons drive the formation of specific Aβ aggregate conformations. These findings therefore demonstrate the potential of a novel fluorescence-based approach for detecting and imaging protein aggregates in a cellular context, which can be used to sensitively probe the association of early stage toxic protein aggregates within subcellular compartments