Widespread bone-based fluorescence in chameleons

Fluorescence is widespread in marine organisms but uncommon in terrestrial tetrapods. We here show that many chameleon species have bony tubercles protruding from the skull that are visible through their scales, and fluoresce under UV light. Tubercles arising from bones of the skull displace all dermal layers other than a thin, transparent layer of epidermis, creating a 'window' onto the bone. In the genus Calumma, the number of these tubercles is sexually dimorphic in most species, suggesting a signalling role, and also strongly reflects species groups, indicating systematic value of these features. Co-option of the known fluorescent properties of bone has never before been shown, yet it is widespread in the chameleons of Madagascar and some African chameleon genera, particularly in those genera living in forested, humid habitats known to have a higher relative component of ambient UV light. The fluorescence emits with a maximum at around 430 nm in blue colour which contrasts well to the green and brown background reflectance of forest habitats. This discovery opens new avenues in the study of signalling among chameleons and sexual selection factors driving ornamentation

At the heart of the growing Anglo-German imperialist rivalry Two British ambassadors in Berlin, 1884-1908

Available from British Library Document Supply Centre-DSC:DN048025 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Mycorrhizal fungi control phosphorus value in trade symbiosis with host roots when exposed to abrupt ‘crashes’ and ‘booms’ of resource availability

Biological market theory provides a conceptual framework to analyse trade strategies in symbiotic partnerships. A key prediction of biological market theory is that individuals can influence resource value – meaning the amount a partner is willing to pay for it – by mediating where and when it is traded. The arbuscular mycorrhizal symbiosis, characterised by roots and fungi trading phosphorus and carbon, shows many features of a biological market. However, it is unknown if or how fungi can control phosphorus value when exposed to abrupt changes in their trade environment. We mimicked an economic ‘crash’, manually severing part of the fungal network (Rhizophagus irregularis) to restrict resource access, and an economic ‘boom’ through phosphorus additions. We quantified trading strategies over a 3-wk period using a recently developed technique that allowed us to tag rock phosphate with fluorescing quantum dots of three different colours. We found that the fungus: compensated for resource loss in the ‘crash’ treatment by transferring phosphorus from alternative pools closer to the host root (Daucus carota); and stored the surplus nutrients in the ‘boom’ treatment until root demand increased. By mediating from where, when and how much phosphorus was transferred to the host, the fungus successfully controlled resource value.</p

Effectieve prestatiesturing met data voor de brandveiligheidssector

Binnen publieke organisaties bestaat steeds meer aandacht voor prestatiesturing. Zowel om de uitgaven te rechtvaardigen als om de publieke dienstverlening te verbeteren. Door de explosieve toename van data om de maatschappij en de activiteiten van de overheid in kaart te brengen heeft deze ontwikkelingeen extra impuls gekregen. Effectieve prestatiesturing is echter niet makkelijk. Regelmatig leidt het tot frustratie, inefficiëntie en andere ‘perverse effecten’.3D Geo-Informatio

J. Med. Genet.

Key points * Acropectorovertebral dysgenesis, also called F syndrome, is a unique skeletal malformation syndrome, originally described in a four generation American family of European origin. The dominantly inherited disorder is characterised by carpal and tarsal synostoses, syndactyly between the first and the second fingers, hypodactyly and polydactyly of feet, and abnormalities of the sternum and spine. * We have mapped F syndrome in the original family and were able to localise the gene for F syndrome to a 6.5 cM region on chromosome 2q36 with a maximum lod score of 4.21 for marker D2S2250. The region contains a number of genes expressed during limb development such as IHH, WNT6a, WNT10a, PAX3, and STK36. Genomic sequencing of these genes showed no mutation. * This region harbours two further limb malformation phenotypes, namely syndactyly type I and the mouse mutant doublefoot (Dbf), of which both show overlapping features with F syndrome. * Our results indicate that F syndrome is clinically and genetically distinct from a previously published acropectoral syndrome located on 7q36

Mycorrhizal Fungi Respond to Resource Inequality by Moving Phosphorus from Rich to Poor Patches across Networks

The world’s ecosystems are characterized by an unequal distribution of resources [1]. Trade partnerships between organisms of different species—mutualisms—can help individuals cope with such resource inequality [2, 3, 4]. Trade allows individuals to exchange commodities they can provide at low cost for resources that are otherwise impossible or more difficult to access [5, 6]. However, as resources become increasingly patchy in time or space, it is unknown how organisms alter their trading strategies [7, 8]. Here, we show how a symbiotic fungus mediates trade with a host root in response to different levels of resource inequality across its network. We developed a quantum-dot-tracking technique to quantify phosphorus-trading strategies of arbuscular mycorrhizal fungi simultaneously exposed to rich and poor resource patches. By following fluorescent nanoparticles of different colors across fungal networks, we determined where phosphorus was hoarded, relocated, and transferred to plant hosts. We found that increasing exposure to inequality stimulated trade. Fungi responded to high resource variation by (1) increasing the total amount of phosphorus distributed to host roots, (2) decreasing allocation to storage, and (3) differentially moving resources within the network from rich to poor patches. Using single-particle tracking and high-resolution video, we show how dynamic resource movement may help the fungus capitalize on value differences across the trade network, physically moving resources to areas of high demand to gain better returns. Such translocation strategies can help symbiotic organisms cope with exposure to resource inequality

Data from: Mycorrhizal fungi respond to resource inequality by moving phosphorus from rich to poor patches across networks

The world’s ecosystems are characterized by an unequal distribution of resources. Trade partnerships between organisms of different species - mutualisms - can help individuals cope with such resource inequality. Trade allows individuals to exchange commodities they can provide at low cost, for resources that are otherwise impossible, or more difficult, to access. However, as resources become increasingly patchy in time or space, it is unknown how organisms alter their trading strategies. Here we show how a symbiotic fungus mediates trade with a host root in response to different levels of resource inequality across its network. We developed a quantum-dot tracking technique to quantify phosphorus trading strategies of arbuscular mycorrhizal fungi simultaneously exposed to rich and poor resource patches. By following fluorescent nanoparticles of different colors across fungal networks, we determined where phosphorus was hoarded, relocated and transferred to plant hosts. We found that increasing exposure to inequality stimulated trade. Fungi responded to high resource variation by: (1) increasing the total amount of phosphorus distributed to host roots; (2) decreasing allocation to storage; (3) differentially moving resources within the network, from rich to poor patches. Using single-particle tracking and high-resolution video, we show how dynamic resource movement may help the fungus capitalize on value differences across the trade network, physically moving resources to areas of high demand to gain better returns. Such translocation strategies can help symbiotic organisms cope with exposure to resource inequality