Ab initio calculations of the hydrogen bond

Recent x-ray Compton scattering experiments in ice have provided useful information about the quantum nature of the interaction between H$_2$O monomers. The hydrogen bond is characterized by a certain amount of charge transfer which could be determined in a Compton experiment. We use ab-initio simulations to investigate the hydrogen bond in H$_2$O structures by calculating the Compton profile and related quantities in three different systems, namely the water dimer, a cluster containing 12 water molecules and the ice crystal. We show how to extract estimates of the charge transfer from the Compton profiles.Comment: 16 pages, 7 figures, to appear in Phys. Rev.

Affordances-in-practice:an ethnographic critique of social media logic and context collapse

Drawing on data gathered during ethnographic fieldwork in Mardin, a medium-sized town in southeast Turkey, this article shows that social media users actively appropriate online platforms and change privacy settings in order to keep different social spheres and social groups apart. Keeping different online social contexts distinct from each other is taken for granted as a way of using social media in Mardin. By contrast, social media scholars have extensively discussed the effects of social media in terms of context collapse. The article highlights how context collapse is the result of patterns of usage within Anglo-American contexts and not the consequence of a platform's architecture or social media logic. It then suggests a theoretical refinement of affordances, and proposes the concept of affordances-in-practice

Conceptualizing a distributed, multi-scalar global public sphere through activist communication practices in the World Social Forum

This article contributes to debate about how to conceptualize the global public sphere. Drawing on media practice theory and ethnographic research on media activism in the World Social Forum, it shows how ‘global publics’ can be constituted through a diverse range of activist communication practices that complicate both conventional hierarchies of scale and contemporary theorizations of publics as personalized networks. It develops an understanding of the global public sphere as an emergent formation made up of multiple, interlinked publics at different scales and emphasizes the significance of collective communication spaces for actors at the margins of the global network society

Bird pollination of Canary Island endemic plants

The Canary Islands are home to a guild of endemic, threatened bird pollinated plants. Previous work has suggested that these plants evolved floral traits as adaptations to pollination by flower specialist sunbirds, but subsequently they appear to be have co-opted passerine birds as sub-optimal pollinators. To test this idea we carried out a quantitative study of the pollination biology of three of the bird pollinated plants, Canarina canariensis (Campanulaceae), Isoplexis canariensis (Veronicaceae) and Lotus berthelotii (Fabaceae), on the island of Tenerife. Using colour vision models, we predicted the detectability of flowers to bird and bee pollinators. We measured pollinator visitation rates, nectar standing crops, as well as seed set and pollen removal and deposition. These data showed that the plants are effectively pollinated by non-flower specialist passerine birds that only occasionally visit flowers. The large nectar standing crops and extended flower longevities (>10days) of Canarina and Isoplexis suggests that they have evolved bird pollination system that effectively exploits these low frequency non-specialist pollen vectors and is in no way suboptimal. Seed set in two of the three species was high, and was significantly reduced or zero in flowers where pollinator access was restricted. In L. berthelotii, however, no fruit set was observed, probably because the plants were self incompatible horticultural clones of a single genet. We also show that, while all three species are easily detectable for birds, the orange Canarina and the red Lotus (but less so the yellow-orange Isoplexis) should be difficult to detect for insect pollinators without specialised red receptors, such as bumblebees. Contrary to expectations if we accept that the flowers are primarily adapted to sunbird pollination, the chiffchaff (Phylloscopus canariensis) was an effective pollinator of these species

New localities of the subendemic species Berberis croatica, Teucrium arduini and Micromeria croatica in the Dinaric Alps

New localities of three subendemic species (Berberis croatica, Teucrium arduini and Micromeria croatica) have been found in the Dinaric Alps. Berberis croatica was found at ten new locations, nine of them in Croatia and one in Bosnia and Herzegovina. Teucrium arduini was found on Mt Učka, Mt Velebit, Mt Biokovo and Mt Sniježnica, at nine new locations while Micromeria croatica was found at four new locations, only on Mt Velebit

Religious conflicts in cyberage

10.1080/13621020701476012Citizenship Studies114329-34

A comeback of tradition? The revitalisation of Adat in eastern Indonesia

Zeitschrift fur Ethnologie132137-5

The revitalisation of tradition: Agency and negotiations between state law and local law

Zeitschrift fur Ethnologie13215-1

News from the early spring flora of Albania

Six new species for the flora of Albania ( Convolvulus siculus, Gagea amblyopetala, Gagea bohemica agg., Ptilostemon chamaepeuce, Spergula pentandra and Stachys canescens ) were collected during the 2010 March field trip and are discussed here. Additionally, the occurrence of Ceratocephala falcata in Albania is confirmed and contributions to the distribution of other four, rare and of insufficiently known range taxa ( Bellevalia dubia, Hyacinthella leucophaea, Phagnalon saxatile and Teline monspessulana ) are given. The listed species are the members of the native flora of Albania, except for Stachys canescens , which, according to the assumption of the authors can be an old introduction