Cloaked websites: propaganda, cyber-racism and epistemology in the digital era

This article analyzes cloaked websites, which are sites published by individuals or groups who conceal authorship in order to disguise deliberately a hidden political agenda. Drawing on the insights of critical theory and the Frankfurt School, this article examines the way in which cloaked websites conceal a variety of political agendas from a range of perspectives. Of particular interest here are cloaked white supremacist sites that disguise cyber-racism. The use of cloaked websites to further political ends raises important questions about knowledge production and epistemology in the digital era. These cloaked sites emerge within a social and political context in which it is increasingly difficult to parse fact from propaganda, and this is a particularly pernicious feature when it comes to the cyber-racism of cloaked white supremacist sites. The article concludes by calling for the importance of critical, situated political thinking in the evaluation of cloaked websites

Co(II)-detection does not follow Kco(II) gradient: channelling in Co(II)-sensing

The MerR-like transcriptional activator CoaR detects surplus Co(II) to regulate Co(II) efflux in a cyanobacterium. This organism also has cytosolic metal-sensors from three further families represented by Zn(II)-sensors ZiaR and Zur plus Ni(II)-sensor InrS. Here we discover by competition with Fura-2 that CoaR has KCo(II) weaker than 7 × 10−8 M, which is weaker than ZiaR, Zur and InrS (KCo(II) = 6.94 ± 1.3 × 10−10 M; 4.56 ± 0.16 × 10−10 M; and 7.69 ± 1.1 × 10−9 M respectively). KCo(II) for CoaR is also weak in the CoaR–DNA adduct. Further, Co(II) promotes DNA-dissociation by ZiaR and DNA-association by Zur in vitro in a manner analogous to Zn(II), as monitored by fluorescence anisotropy. After 48 h exposure to maximum non-inhibitory [Co(II)], CoaR responds in vivo yet the two Zn(II)-sensors do not, despite their tighter KCo(II) and despite Co(II) triggering allostery in ZiaR and Zur in vitro. These data imply that the two Zn(II) sensors fail to respond because they fail to gain access to Co(II) under these conditions in vivo. Several lines of evidence suggest that CoaR is membrane associated via a domain with sequence similarity to precorrin isomerase, an enzyme of vitamin B12 biosynthesis. Moreover, site directed mutagenesis reveals that transcriptional activation requires CoaR residues that are predicted to form hydrogen bonds to a tetrapyrrole. The Co(II)-requiring vitamin B12 biosynthetic pathway is also membrane associated suggesting putative mechanisms by which Co(II)-containing tetrapyrroles and/or Co(II) ions are channelled to CoaR

Older and wiser: improvements in breeding success are linked to better foraging performance in European shags

1. An increase in average breeding performance with age and experience among younger age classes has been recorded in numerous studies of iteroparous breeders. An important component of this pattern is thought to be improvements in foraging performance, resulting in delivery of more or better quality food to offspring by older, more experienced individuals. 2. Young, inexperienced breeders may exhibit lower foraging efficiency or foraging effort, and it has been predicted that differences in foraging performance with age and experience will be more marked when environmental conditions are poor. However, as the timing of breeding generally differs with age and experience, intrinsic differences in foraging abilities are typically confounded by variation in extrinsic conditions, and hence food availability. 3. To disentangle these effects, we experimentally manipulated the timing of breeding in European shags, Phalacrocorax aristotelis Linnaeus. We used a cross-fostering protocol, such that naive, young birds reared their chicks at the same time as older, experienced individuals. Our design produced simultaneous chick rearing during two periods in the same breeding season that differed markedly in environmental conditions: early, when conditions were good; and late, when conditions were poorer. We examined foraging efficiency, foraging effort and amount of food delivered to offspring by the two classes of breeder. We predicted that any differences in foraging performance would be more marked under the poorer conditions later in the season. 4. We found that experienced parents delivered more food than naive parents, irrespective of the time of season. This was due partly to the consistently higher foraging efficiency of the experienced parents. In addition, experienced parents adjusted their foraging effort to the environmental conditions. Early in the breeding season, they made less foraging effort than naive parents. Under the poorer foraging conditions, experienced parents increased their foraging effort but naive parents did not, being either unable or unwilling to do so. 5. Our results suggest that an increase in foraging efficiency, and the capacity to adjust foraging effort in response to food availability, are important components of the observed improvements in breeding performance with age and experience