Adaptive Ecology, Growth Strategies and the Global Bloom Expansion of Dinoflagellates

Dinoflagellates exhibit unique differences from diatoms in their adaptive ecologies that may be favoring their increasingly successful exploitation of coastal waters and global bloom expansion. Dinoflagellates behave as annual species, bloom soloists, are ecophysiologically diverse and habitat specialists, whereas diatoms behave as perennial species, guild members and are habitat cosmopolites. Diatoms have a relatively uniform bloom strategy based on species-rich pools and exhibit limited habitat specialization. Dinoflagellates have multiple life-form strategies consistent with their diverse habitat specializations, but rely on impoverished bloom species pools. Niche structure and dinoflagellate competition for niche space are considered. The “open niche period” formulated originally for Narragansett Bay is extrapolated as a general bloom paradigm. It is suggested that successful niche occupancy leading to blooms involves adaptive strategies at three heirarchic taxonomic elements: phylogenetic, generic and species-specific, and in that sequence. Transoceanic expatriation of emigrant species leading to indigenous status and blooms requires completion of a three-stage colonization process. Anthropogenic seedings are not, in themselves, bloom stimulation events; they are only the first phase of a multiple-step process. The organismal and niche features required for a hidden flora member to become a bloom species are considered, and the interplay between niche structure, habitat carrying capacity, colonization requirements and stochasticity as factors in the changing global bloom behavior of dinoflagellates discussed. The question is posed whether traditional perspectives of phytoplankton behavior apply completely to dinoflagellates. This revised version was published online in August 2006 with corrections to the Cover Date.     

Primitivism and the other. History of art and cultural geography

The article advocates an articulation of cultural geography and art history, and in this perspective focuses on the analysis of the primitivist movement and particularly on Gauguin's work and personal itinerary. Primitivism introduced artefacts of ‘primitive’ people into the history of Western art and signalled a change in the relationship between the West and the ‘Other’ and ‘Elsewhere’. This reversal of values has a major geographical dimension. Primitivism manifests the contradiction-rife colonial ideology, but can also challenge colonization. Tourism, which is, in the case of Tahiti, directly linked to Gauguin and to his myth, inherited a lot from primitivism, in terms of hopes and ambiguities. Conversely, primitivism casts light on geographical features of these places, instituted as ‘Elsewheres‘ by the West, and visited, even transformed by painters, colonizers and tourists. This revised version was published online in July 2006 with corrections to the Cover Date.     

绿色荧光蛋白标记的病原性河流弧菌在青石斑肠道的黏附定植研究

通过灌胃将绿色荧光蛋白标记的病原性河流弧菌导入青石斑鱼消化道内,追踪标记菌在青石斑肠道中的黏附和定植及对肠道消化酶活性的影响。结果表明,青石斑前肠和中肠在河流弧菌灌胃12 h即可检出,前肠在24 h达到峰值,大约为7.1×105 cfu/g,中肠则在36 h达到峰值,约为5.39×105 cfu/g,而后肠则是在24 h才开始检出,且检出时即达到峰值,但仅为2.44×104 cfu/g,说明青石斑鱼的前肠和中肠都是河流弧菌的主要黏附部位。灌胃96 h后前肠和中肠仍有标记菌存在,但在后肠已检测不到标记菌,反映出标记菌已在前肠和中肠定植下来,但没有在后肠定植。此外,标记河流弧菌的定植能够显著降低前肠蛋白酶活性和淀粉酶活性以及后肠脂肪酶活性。研究结果说明,病原性河流弧菌可通过黏附定植于鱼类肠道影响鱼类肠道消化酶活力,这可能是病原性河流弧菌引发鱼类病害的原因之一。