In macaque monkeys, the geniculocortical afferents serving each eye segregate in layer IVc of striate cortex during early life into a pattern of alternating inputs called ocular dominance columns. It has been disputed whether visual experience is necessary for the formation of ocular dominance columns. To settle this issue, fetal monkeys were delivered prematurely by Caesarean section at embryonic day 157 (E157), 8 d before the end of normal gestation. To avoid light exposure, the Caesarean section and all subsequent feedings and procedures were done in absolute darkness, using infrared night-vision goggles. Tritiated proline was injected into the right eye 1 d after delivery (E158). One week later at postnatal age 0 (P0), the equivalent of a full-term pregnancy (E165/P0), alternate sections of unfolded and flattened visual cortex were prepared for autoradiography or cytochrome oxidase (CO). All three newborns studied at E165/P0 had well segregated ocular dominance columns organized into the characteristic mosaic present in adults. In the upper layers, a mature pattern of CO patches (also known as blobs or puffs) was visible, aligned with the ocular dominance columns in layer IVc. Every other row of patches in layers II, III was labeled by [3H]proline. In V2, a distinct system of alternating thick-pale-thin-pale CO stripes was present. These findings indicate that stimulation of the retina by light is not necessary for the development of columnar systems in the visual cortex. Ocular dominance columns, patches, and V2 stripes all are well formed before visual experience. Even the thalamic input to the patches in the upper layers of striate cortex is segregated by eye in newborns.

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BackgroundRecent studies of anadromous salmon (Oncorhynchus spp.) on the Pacific Coast of North America indicate an important and previously unrecognized role of salmonid nutrients to terrestrial biota. However, the extent of this uptake by primary producers and consumers and the influences on community structure remain poorly described. We examine here the contribution of salmon nutrients to multiple taxa of riparian vegetation (Blechnum spicant, Menziesii ferruginea, Oplopanax horridus, Rubus spectabilis, Vaccinium alaskaense, V. parvifolium, Tsuga heterophylla) and measure foliar δ15N, total %N and plant community structure at two geographically separated watersheds in coastal British Columbia. To reduce potentially confounding effects of precipitation, substrate and other abiotic variables, we made comparisons across a sharp ecological boundary of salmon density that resulted from a waterfall barrier to salmon migration.Resultsδ15N and %N in foliage, and %cover of soil nitrogen indicators differed across the waterfall barrier to salmon at each watershed. δ15N values were enriched by 1.4‰ to 9.0‰ below the falls depending on species and watershed, providing a relative contribution of marine-derived nitrogen (MDN) to vegetation of 10% to 60%. %N in foliar tissues was slightly higher below the falls, with the majority of variance occurring between vegetation species. Community structure also differed with higher incidence of nitrogen-rich soil indicator species below the waterfalls.ConclusionsMeasures of δ15N, %N and vegetation cover indicate a consistent difference in the riparian community across a sharp ecological boundary of salmon density. The additional N source that salmon provide to nitrogen-limited habitats appears to have significant impacts on the N budget of riparian vegetation, which may increase primary productivity, and result in community shifts between sites with and without salmon access. This, in turn, may have cascading ecosystem effects in forests adjacent to salmon streams.

Internet memes are online fads or trends consisting of a combination of image, verbiage, audio, and video that are repeatedly altered by Internet users and shared on the Internet, often in a rapid, viral-like manner. The constant process of mutation that an Internet meme undergoes as it spreads across the Internet typically involves repetition, rhetorical play, pattern reformulation, and punning, among others—all characteristics that Ronald Carter has defined in his analysis of spoken conversation as examples of demotic and ordinary creativity. Drawing upon and extending Carter’s description of the everyday creativity of spoken language, this study seeks to systematically investigate and describe the creative and conversational characteristics of Internet memes and in doing so provide further insights into the nature of both Internet creativity and popular culture.

In this article, we look at data based on the work of EAP (English for Academic Purposes) practitioners at Goldsmiths College, University of London in the 1990s collected for the purposes of identifying the generic characteristics of two contexts in contemporary fine art study; the tutorial and the postgraduate dissertation. The rhetorical moves on the part of the tutor in the intercultural tutorials and a micro-analysis of the language used in the introductory sections of selected, positively evaluated MA student dissertations form the basis of our analysis and interpretation. We see the aim of both of those genres as facilitating development, both with regard to the individual student’s development of practice, and in respect of integrating theoretical perspectives into assessed writing. While the spoken mode of the tutorial primarily mediates reflection on, critique of, and thence development of practice, the written mode promotes an engagement with theory that is reflected back in the writing. We further suggest that development in both cases is dialectical, and that the language work and visual work in tandem have synergistic effects. In conclusion, we reiterate the synergy between the visual and the verbal and suggest that this synergy can be re-enacted in collaborative strategies between art tutors and language tutors in the wider development of students’ communicative practice.