Towards an Abrahamic Ecumenism? The Search for the Universality of the Divine Mystery

This contribution explores the notion of an Abrahamic ecumenism as proposed by Hans Küng and others in search for a way in which Islam, Judaism and Christianity can live peacefully together. It is argued, however, that to pursue a viable political pluralism, it is more promising for Christian theology to take into account the historical development of the image of God instead of an orientation on a common historical origin in Abraham. The elaboration of the universality of the divine mystery in history does not have to be won by going back to Abraham, but by going forward to Jesus Christ and by thinking of and living out of Him. © UV/UFS

Parthenogenesis: birth of a new lineage or reproductive accident?

Parthenogenesis - the ability to produce offspring from unfertilized eggs - is widespread among invertebrates and now increasingly found in normally sexual vertebrates. Are these cases reproductive errors or could they be a first step in the emergence of new parthenogenetic lineages

Achromatic cues are important for flower visibility to hawkmoths and other insects

Studies on animal colour vision typically focus on the chromatic aspect of colour, which is related to the spectral distribution, and disregard the achromatic aspect, which is related to the intensity (“brightness”) of a stimulus. Although the chromatic component of vision is often most reliable for object recognition because it is fairly context independent, the achromatic component may provide a reliable signal under specific conditions, for example at night when light intensity is low. Here we make a case for the importance of achromatic cues in plant-pollinator signalling, based on experimental data on naïve Deilephila elpenor and Macroglossum stellatarum hawkmoths, optical modelling and synthesising published experiments on bees, flies, butterflies and moths. Our experiments show that in ecologically relevant light levels hawkmoths express a strong preference for brighter stimuli. Published experiments suggest that for flower-visiting bees, butterflies, moths and flies, achromatic cues may be more important for object detection than often considered. Our optical modelling enabled disentangling the contribution of pigments and scattering structures to the flower’s achromatic contrast, and illustrates how flower anatomy and background are important mediating factors. We discuss our findings in the context of the often-assumed dichotomy between detection and discrimination, chromatic versus achromatic vision, and the evolution of floral visual signals

Clinical and Genetic Determinants of the Impact of Childhood Cancer on Reproductive Health

Over the past five decades, survival of childhood cancer has improved throughout Europe, with survival rates now approximating 80% as a result of improved treatment strategies. Despite this accomplishment, around 75% of the resulting growing population of long-term childhood cancer survivors (CCS) develops at least one long-term complication as a result of their cancer treatment. Major effects on reproductive health include gonadal function damage and pregnancy complications. The general aim of research described in this thesis was to evaluate the impact of cancer on clinical and genetic aspects of reproductive health. In this thesis, we demonstrate that gonadal function is impaired already prior to cancer treatment, and show that gonadal function is further decreased in both boys and girls by childhood cancer treatment. However, as gonadal function markers can show recovery, we conclude that evaluation of gonadal function markers within the first year after end of treatment is unreliable. In adult CCS, the decline of gonadal function markers was not accelerated as compared to the physiological decline of AMH levels in healthy women of the same age. A genetic variation possibly modifies the association between chemotherapy and reduced ovarian function, making girls with cancer with this particular genetic variation more sensitive for the adverse effects of chemotherapy on their ovarian function. We conclude with addressing obstetric outcomes in CCS. Especially after radiotherapy on the uterus, CCS are more at risk for miscarriages, premature delivery and giving birth to a child with a low birth weight. We present recommendations for counseling and surveillance of obstetric risks for CCS resulting from our worldwide collaborative effort to harmonize these recommendations

Surprising absence of association between flower surface microstructure and pollination system

The epidermal cells of flowers come in different shapes and have different functions, but how they evolved remains largely unknown. Floral micro-texture can provide tactile cues to insects, and increases in surface roughness by means of conical (papillose) epidermal cells may facilitate flower handling by landing insect pollinators. Whether flower microstructure correlates with pollination system remains unknown. Here, we investigate the floral epidermal microstructure in 29 (congeneric) species pairs with contrasting pollination system. We test whether flowers pollinated by bees and/or flies feature more structured, rougher surfaces than flowers pollinated by non-landing moths or birds and flowers that self-pollinate. In contrast with earlier studies, we find no correlation between epidermal microstructure and pollination system. The shape, cell height and roughness of floral epidermal cells varies among species, but is not correlated with pollinators at large. Intriguingly, however, we find that the upper (adaxial) flower surface that surrounds the reproductive organs and often constitutes the floral display is markedly more structured than the lower (abaxial) surface. We thus conclude that conical epidermal cells probably play a role in plant reproduction other than providing grip or tactile cues, such as increasing hydrophobicity or enhancing the visual signal

Caution with colour calculations:Spectral purity is a poor descriptor of flower colour visibility

BACKGROUND: The colours of flowers are of key interest to plant and pollination biologists. An increasing number of studies investigates the importance of saturation of flower colours (often called "spectral purity" or "chroma") for visibility to pollinators, but the conceptual, physiological and behavioural foundations for these metrics as well as used calculations rest on slender foundations. METHODS: We discuss the caveats of colour attributes that are derived from human perception, and in particular spectral purity and chroma, as variables in flower colour analysis. We reanalysed seven published datasets encompassing 774 measured reflectance spectra to test for correlations between colour contrast, spectral purity and chroma. MAIN FINDINGS AND CONCLUSIONS: We identify several concerns with common calculation procedures in animal colour spaces. Studies on animal colour vision provide no ground to assume that any pollinator perceives (or responds to) saturation, chroma or spectral purity in the way humans do. A reanalysis of published datasets revealed that values for colour contrast between flowers and their background is highly correlated with measures for spectral purity and chroma, which invalidates treating these factors as independent variables as is currently commonplace. Strikingly, spectral purity and chroma - which both are metrics for saturation and are often used synonymously - are not correlated at all. We conclude that alternative, behaviourally validated metrics for the visibility of flowers to pollinators, such as colour contrast and achromatic contrast, are better in understanding the role of flower colour in plant-pollinator signalling