Variations of the abundance and nucleic acid content of heterotrophic bacteria in Beaufort Shelf waters during winter and spring

Depth profiles of heterotrophic bacteria abundance were measured weekly over a 6-month period from December to May in Franklin Bay, a 230 m-deep coastal Arctic Ocean site of the southeastern Beaufort Sea. Total bacteria, low nucleic acid (LNA) and high nucleic acid (HNA) bacteria abundances were measured using flow cytometry after SYBR Green I staining. The HNA bacteria abundance in surface waters started to increase 5–6 weeks after phytoplankton growth resumed in spring, increasing from 1 × 10⁵ to 3 × 10⁵ cells mL^− 1 over an 8-week period, with a net growth rate of 0.018 d^− 1. LNA bacteria response was delayed by more than two months relative to the beginning of the phytoplankton biomass accumulation and had a lower net growth rate of 0.013 d^− 1. The marked increase in bacterial abundance occurred before any significant increase in organic matter input from river discharge (as indicated by the unchanged surface water salinity and DOC concentrations), and in the absence of water temperature increase. The abundance of bacteria below the halocline was relatively high until January (up to 5 × 10⁵ cells mL^− 1) but then decreased to values close to 2 × 10⁵ cells mL^− 1. The three-fold bacterial abundance increase observed in surface waters in spring was mostly due to HNA bacteria, supporting the idea that these cells are the most active.     

Strategic alliances in the container shipping industry: a global perspective

This paper examines developments in container shipping in light of the formation of strategic alliances by many of the leading companies. It focuses on three features: the transformation of services, the evolution of the fleet, and the adjustments made to the ports of call. These elements are analysed on a global basis for 3 years: 1989, 1994 and 1999. Some of the changes wrought by the alliances are identified, including the spread and intensification of services, and the deployment of the largest vessels on alliance routes. While the individual companies that have come together in alliances are serving many more ports than before, it is also demonstrated that the total number of ports served by the industry has remained constant. The results are interpreted in the context of globalization that is tending to impose greater standardization on the container shipping industry.     

Analysis of the parasitic copepod species richness among Mediterranean fish

The Mediterranean ichthyofauna is composed of 652 species belonging to 405 genera and 117 families. Among these, 182 were studied for their parasitic copepods. The analysis of all the works conducted on these crustacea yielded 226 species distributed in 88 genera and 20 families. For each fish species we have established a file providing the species name of the fish, its family, its geographical distribution within the Mediterranean and some of its bio-ecological characteristics. Within each file, all the parasitic copepod species reported on each host species were listed. This allowed to know the species richness (SR) of these hosts. We thus produced 182 files within which 226 copepod species are distributed. A program was created under the Hypercard software, in order to analyse our data. Two parameters were studied. The first one is the mean species richness (MSR), which corresponds to the mean of the different SR found on the different host species. The second is the parasite–host ratio (P/H), which is the ratio of the number of copepod species by the number of host species. These parameters are calculated by our program for all the 182 species of Mediterranean fishes retained in our investigation, on the first hand, and, on the second hand, for one particular group of fish species. We used the following variables to investigate their correlations with copepod species richness: taxonomy—fish families, genera and species; biometry—maximal size of the adult fish; eco-ethology—mode of life (benthic, pelagic or nectonic), displacements (sedentary, migratory with environmental change, or migratory without environmental change), behaviour (solitary or gregarious). Other variables (colour, food, reproduction, abundance, distribution area) were also analysed but did not reveal any clear correlation. Providing that our study does not rely on quantitative (prevalence, intensity) but qualitative basis our aim was only to reveal some tendencies. These tendencies are as follows: (1) In many cases, parasite and host phylogeny seem to play an important role. There are fish families with copepods and families with few species of these parasites. The phyletic constraints could be due to the morphological characteristics of the habitat (e.g. structure of the gills) or biological/ecological characteristics that we were unable to identify. (2) It appears that the presence in a same environment of related fish species (e.g. several species of the same genus, or numerous genera of the same family) is correlated with high parasite richness. A likely explanation is that such situations favours alternated processes of lateral transfers and speciation. (3) Some eco-ethological criteria seem to favour the establishment of a large parasite species richness. It should be noted for instance that Mediterranean fishes the most often infected with copepods are generally nectonic or pelagic, migratory, and gregarious species.     

Summer distribution of seabirds in the North-East Water polynya, Greenland

The distribution at sea of seabirds was studied in the North-East Water (NEW) polynya, Greenland, during transect counts in the summers of 1991, 1992 and 1993 on board the ice-breaking RVs Polarstern and Polar Sea. Data collected within the polynya ‘box’ (78–82°N; 5–18°W) concern observations of 8000 birds counted during 1350 half-hour counts. Distribution is presented as density (N/km²) and calculated daily food intake. Five bird species were selected for discussion, representing more than 95% of the total numbers encountered: Fulmar (Fulmarus glacialis), Ivory Gull (Pagophila eburnea), Kittiwake (Rissa tridactyla), Glaucous Gull (Larus hyperboreus) and Ross's Gull (Rhodostethia rosea). For these species, densities are comparable in the NE Greenland polynya and in other European Arctic seas. The main difference is the absence in NEW of the species playing the main role in Arctic seas: Brünnich's Guillemot (Uria lomvia) and Little Auk (Alle alle). In the absence of fish-eating birds and of birds consuming zooplankton in the water column, the NEW polynya ecosystem is thus dominated by surface feeders and, closer to the coast, by benthic feeders like eiders, Somateria mollissima and S. spectabilis, and walrus, Odobenus rosmarus. The density and daily food intake for all seabirds are one order of magnitude lower in the polynya than in the Arctic seas. The distribution and abundance of seabirds in the NEW polynya seems to reflect a very low density of pelagic fish and Zooplankton in the water column, while Zooplankton must be present at ‘normal’ concentrations in the upper layer.     

The Caribbean basin: adjusting to global trends in containerization

Positioned strategically between major east-west and north-south trading routes, the Caribbean basin has become a locus of new service configurations in container shipping. Over the last decade global shipping lines have been restructuring their service networks in the region in order to integrate local services with the newly rationalized intercontinental connections. By comparing service network structures in 1994 and 2002 at three levels of organization—local, regional and global—we are able to show that although Caribbean ports are well connected to the global system, and while the total number of services has declined between the two years, those mounted by members of global alliances have increased. Moreover, services of the global carriers at the local and regional levels are on the increase. As much as the alliances are reshaping Caribbean networks, the smaller carriers are still playing a role, but at a reduced spatial scale. Parallel with the modifications to network configurations are the changes in the port system. Essentially, traffic of the most important ports in the north and western part of the basin has grown at slower rates than the ports in the south and east. These traffic changes are only partly related to network changes. It is the growth of transshipments that is driving the most important developments in port traffic and bringing to the forefront the development of hub ports. The most important are: Colon, Panama (southwest), Freeport, Bahamas (north), Port of Spain, Trinidad and Tobago (southeast), Kingston, Jamaica and Rio Haina, Dominican Republic (middle), and Cartagena, Colombia and Puerto Cabello, Venezuela (south).     

Mental flexibility impairment in drivers with early Alzheimer's disease: A simulator-based study

After memory impairment, one of the most common troubles of early Alzheimer's disease (AD) is the impairment of executive functioning. However, it can have major consequences on daily life, notably on the driving activity. The present study focused on one important executive function involved in driving: mental flexibility; and considered how this impairment can affect driving. Ten patients with early AD were matched with 29 healthy older drivers. All participants were given an evaluation of mental flexibility through neuropsychological tests and an experimental test developed on a static driving simulator. The experiment was divided in two conditions; one without mental flexibility and another condition with a mental flexibility demand. AD patients showed impairments in the neuropsychological tests evaluating mental flexibility. These deficits are linked to the deficits they showed in the driving simulator flexibility tests. This study contributes to the understanding of mental flexibility mechanisms and on their role in driving activity. It also confirms that the driving simulator is a suitable tool to explore cognitive disorders and driving ability.     

Strategic alliances in the container shipping industry: a global perspective

This paper examines developments in container shipping in light of the formation of strategic alliances by many of the leading companies. It focuses on three features: the transformation of services, the evolution of the fleet, and the adjustments made to the ports of call. These elements are analysed on a global basis for 3 years: 1989, 1994 and 1999. Some of the changes wrought by the alliances are identified, including the spread and intensification of services, and the deployment of the largest vessels on alliance routes. While the individual companies that have come together in alliances are serving many more ports than before, it is also demonstrated that the total number of ports served by the industry has remained constant. The results are interpreted in the context of globalization that is tending to impose greater standardization on the container shipping industry.     

The evolution of containerization in East Asia

This paper examines the development and growth of container traffic in the Asia-Pacific region. It is hypothesised that containerization is losing its national character as the geography of container transport changes port hierarchies where only a few ports have become locationally favorable. The organizatioon of the paper is straightforward. First, the development and growth of container traffic in the Asia-Pacific region is examined in order to provide understanding of changes associated with containerization. Second, the role of selected Asian-Pacific ports as key economic players is reviewed, and container development in each port is analysed so as to measure the differences explaining the position of Asian-Pacific ports in the maritime system. Third, the degree of concentration and competition that exist among the container ports of the region is analysed with a view to evaluate what rate of expansion can be expected in the foreseeable future that will shape the network of the container market in the region. The paper concludes on a possible research agenda.