35 research outputs found
Identity of the Qingdao algal bloom
In early July 2008, news agencies worldwide reported on a vast algal bloom that was threatening the upcoming Olympic sailing events in Qingdao, China. The identity of the culpable alga, however, remained undiscussed. We have identified the alga that caused the bloom by means of morphological and molecular data, including sequence data of the plastid encoded large subunit ribulose 1,5-bisphosphate carboxylase gene (rbcL) and the nuclear encoded rDNA internal transcribed spacer (ITS) region. The bloom-forming alga falls within the morphological limits of the green seaweed Ulva prolifera O.F. Muller ('Enteromorpha prolifera (O.F. Muller) J. Agardh') but our phylogenetic analyses show that it forms a clade with representatives of the Ulva linza-procera-prolifera (LPP) complex. The Chinese rbcL sequences are identical to those of specimens collected from Japan, New Zealand, Finland and Portugal, suggesting that the taxon is widely distributed. rDNA ITS sequences showed a close affinity with Japanese isolates of the species complex. The Qingdao bloom is a typical illustration of a green tide, which occurs increasingly along several coasts worldwide
Newly identified biologically active and proteolysis-resistant VEGF-A isoform VEGF111 is induced by genotoxic agents
Ultraviolet B and genotoxic drugs induce the expression of a vascular endothelial growth factor A (VEGF-A) splice variant (VEGF111) encoded by exons 1–4 and 8 in many cultured cells. Although not detected in a series of normal human and mouse tissue, VEGF111 expression is induced in MCF-7 xenografts in nude mice upon treatment by camptothecin. The skipping of exons that contain proteolytic cleavage sites and extracellular matrix–binding domains makes VEGF111 diffusible and resistant to proteolysis. Recombinant VEGF111 activates VEGF receptor 2 (VEGF-R2) and extracellularly regulated kinase 1/2 in human umbilical vascular endothelial cells and porcine aortic endothelial cells expressing VEGF-R2. The mitogenic and chemotactic activity and VEGF111's ability to promote vascular network formation during embyonic stem cell differentiation are similar to those of VEGF121 and 165. Tumors in nude mice formed by HEK293 cells expressing VEGF111 develop a more widespread network of numerous small vessels in the peritumoral tissue than those expressing other isoforms. Its potent angiogenic activity and remarkable resistance to proteolysis makes VEGF111 a potential adverse factor during chemotherapy but a beneficial therapeutic tool for ischemic diseases
Fronts, jumps and secondary introductions suggested as different invasion patterns in marine species, with an increase in spread rates over time
Not all introduced (invasive) species in a region will spread from a single point of introduction. Long-distance dispersal or further introductions can obscure the pattern of spread, but the regional importance of such processes is difficult to gauge. These difficulties are further compounded when information on the multiple scale process of invasive species range expansion is reduced to one-dimensional estimates of spread (e.g. km yr−1). We therefore compared the results of two different metrics of range expansion: maximum linear rate of spread and accumulation of occupied grid squares (50 × 50 km) over time. An analysis of records for 54 species of introduced marine macrophytes in the Mediterranean and northeast Atlantic revealed cases where the invasion process was probably missed (e.g. Atlantic Bonnemaisonia hamifera) and suggested cases of secondary introductions or erratic jump dispersal (Dasysiphonia sp. and Womersleyella setacea). A majority of species analysed showed evidence for an accumulation of invaded sites without a clear invasion front. Estimates of spread rate are increasing for more recent introductions. The increase is greater than can be accounted for by temporally varying search effort and implies a historical increase in vector efficiency and/or a decreased resistance of native communities to invasion
Genetic parameters of novel mid-infrared predicted milk traits in three dual-purpose cattle breeds
peer reviewedThe objective of this study was to estimate genetic parameters of 39 novel mid-infrared predicted milk traits (e.g. nutritional quality, technological properties, metabolic status, environmental fingerprint) for three dual purpose cattle breeds (i.e. Dual-Purpose Belgian Blue (dpBB), Montbéliarde (MON) and Normande (NOR)), which are also used in organic farming in the Walloon Region of Belgium, as part of the 2-Org-Cows project. Edited data included 21,287, 10,062 and 4,637 first-lactation test-day records collected in the Walloon region of Belgium from 2,988, 1,330 and 621 dpBB, MON and NOR cows, respectively. Genetic parameters were estimated using REML applied to single-trait random regression test-day models for six conventional traits (yields, contents and somatic cell score) and the 39 novel mid-infrared predicted milk traits. Results for conventional traits allowed comparison to literature showing values that were close to the expected ones. For novel traits, comparison with available literature values for Holstein breed showed generally similar estimated heritabilities. Reported average daily heritabilities estimated for the 39 novel traits tended to be higher for dpBB (0.13-0.64) than MON and NOR (0.03-0.60) breeds. Few novel traits showed large differences between breeds except between dpBB and NOR for milk composition traits. However, results for NOR breed have to be taken very carefully given the low number of animals. Even if the used methane prediction equation was not yet validated for these breeds, estimated average daily heritability was moderately high for dpBB (0.41) and MON (0.36) and moderate for NOR (0.23) indicating that this prediction might also be useful in these dual purpose breeds.ERANET CoreOrganic+ 2-Org-Cow
Changing coasts: marine aliens and artificial structures
Marine aliens are non-native species that have been transported across major geographical barriers by human activities, involving vectors that move propagules along pathways. Species may also be newly observed in a geographical area due to range shifts, generally in association with climate change. Artificial structures are considered to be either man-made materials or natural materials shaped or displaced to serve a specific function for human activities. All types of artificial structures are currently increasing dramatically in coastal zones due to increasing human populations on coastlines. Most of the significant marine vectors and pathways involve mobile artificial structures and are reviewed here. These include shipping (ballast water and hull fouling) and aquaculture, including stock transfer and unintentional introductions, all of which can move species into new biogeographical provinces. Some types of structures frequently move long distances but have low fouling loads (e.g., commercial shipping), whereas others (e.g., barges and pontoons) can be hyperfouled due to long stationary periods such that when moved they transport mature fouling communities. We also examine the presence of alien marine species on static (immobile) artificial structures, which support different communities from those on natural hard substrata. We consider the role of these structures, such as coastal defences, artificial reefs, and offshore platforms, in the dispersal and abundance of alien species. Marinas include both mobile and immobile structures and are apparently particularly favourable habitats for many aliens. For example, in coastal North America approximately 90% of the alien species inhabiting hard substrata have been reported from docks and marinas. Detailed case studies of alien marine species (two seaweeds and four invertebrates) are provided, with an analysis of their origin, vectors of transport, habitat in the introduced range, and potential impact. Although there are exceptions, a large majority of marine alien species seem to be associated, at least for some of the time, with artificial structures. It is clear that artificial structures can pave the way and act as stepping stones or even corridors for some marine aliens, as do urban areas, roads and riparian environments in terrestrial ecosystems. The observed acceleration of spread rates for marine invasions over the course of the last two centuries may partly be a result of the increase of artificial structures in coastal environments coupled with greater activity of vectors