Stabilisation of immunoconjugates by trehalose

Stable immunoconjugates were prepared in the presence of 400 mM trehalose. Their residual activity after freeze-drying, rehydration and incubation for 9 h at 40?°C was 35%. Freeze-dried conjugates containing 400 mM trehalose incubated at 40?°C for 4 days retained 80% of their original activity.     

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Dissolved organic carbon (DOC) and nitrogen (DON) derived from aquatic and terrestrial vascular plants provide a major energy and nutrient source for freshwater and coastal marine biota. The bioavailability of this material may to a large extent depend on plant species. In this study, we have compared the bioavailability of DOC and DON sampled in two distinct stands of Typha domingensisand Eleocharis mutatain a coastal tropical lake and in the adjacent ocean in the state of Rio de Janeiro, Brazil. Bioavailability of organic matter was assessed by regrowth bioassays using natural bacterial inocula. Nutrients were added to achieve carbon or nitrogen limitation. At all sampling sites, DON comprised over 95% of the total bioavailable nitrogen, suggesting its dominant role as a nitrogen source. The bioavailability of lacustrine DON (22% in the Typhastand and 34% in the Eleocharisstand) exceeded the bioavailability of DOC (8 and 10%, respectively) and exhibited a larger difference between the stands. ³H-leucine incorporation studies showed that lake bacterioplankton had a well balanced supply of C, N and P. Therefore, an accumulation of labile DON due to an excess nitrogen supply is not probable. We propose that a substantial part of the lake DON was newly formed within the macrophyte stands, while DOC was predominantly of terrestrial origin and more diagenetically changed.     

Life cycle and production of Campsurus notatus (Ephemeroptera,Polymitarcyidae) in an Amazonian lake impacted by bauxite tailings (Pará, Brazil)

A synoptic survey of the distribution and abundance of occurrence of bloom-forming Cyanobacteria in 55 lakes in the Republic of Ireland revealed strong positive correlations with the traditional trophic gradient. Analysis of the data shows that the perceived trophic state may be correctly viewed as a function of phosphorus availability. The distribution of dominant bloom-forming Cyanobacteria is strongly related to the geology of the catchments and the incidence of significant bicarbonate buffering.     

Impacts of anthropogenic stresses on the early development stages of seaweeds

Seaweeds are important primary producers, and as such contributesignificantly to nearshore ecosystems. Studies on the effects ofanthropogenic stresses on these organisms have largely been concernedwith the vegetative adult stages of the life cycle. Here we review thelimited information on the sensitivity of early stages in the life cycleof seaweeds to global change (UV increase; global warming;increased storm frequencies) and pollution (eutrophication, trace metalsand oil). Impacts on fertility, substrate attachment, development,photosynthesis, growth and mortality are highlighted. In their naturalhabitats, early stages are shade-adapted, as they live shel tered underadult canopies and in pores of the substrata. Although some acclimationunder increased moderate irradiance is seen, higher solar irradiance,and especially ultraviolet-B, inhibits early development. Global warmingmay decrease the fertility and shorten the fertile period of somespecies. With the increasing likelihood of storms associated with globalwarming, gamete release may be inhibited while scouring by suspendedsediments may detach newly settled stages. Succession and localdistribution patterns are likely to be affected. Eutrophication canresult in accelerated development of the early stages of some algalspecies but sewage discharges have a negative impact on sperm motility,fertilisation and can cause increased mortality in germlings. Impacts ofother, indirect effects of eutrophication, including increased sedimentcover of substrata, scouring caused by wind-induced resuspension ofsediments, and grazing, are also expected to be negative. Toxic tracemetals affect gamete viability, inhibit fertilisation and development,and reduce growth rates. Gametes are particularly susceptible to oilpollution and interactions between hydrocarbons and the adhesive mucussurrounding the embryonic stages seem to inhibit settlement.Recommendations for future studies are provided that are aimed atgaining greater insight into the effects of anthropogenic stress on theweakest links in the development cycle of seaweeds.     

Semimicroscopical observations on the crista stapedis.

Adult and fetal human stapes were removed by means of the stereoscopic microscope in order to compare the size of the lamina or crista that joins the crura of the stapes and rests in the lateral aspect of the basis. 65 out of 110 specimens showed cristae of different sizes, whereas the remaining 35% did not possess this structure. The cristae were classified into large, medium-sized and rudimentary. Several incomplete or irregular structures were also found. The cristae or laminae divide the lateral aspect of the base into two fossae: a small upper one and a large lower one, although several variations were found. An edge of the pillar groove was usually continuous with the cristae; however, compact pillars were found at the point where they reach the base, where the cristae orginates. Asymmetrical cristae and changes in the general shape of the stapes were found in several specimens. Two ossicles showed crista with orifices due to resorption or to the passage of vessels.     

Gene flow and population structure of the endemic Azorean bat (<Emphasis Type="Italic">Nyctalus azoreum</Emphasis>) based on microsatellites: implications for conservation

The Azorean bat (Nyctalus azoreum) is endemic to the Azores archipelago and is listed as endangered due to its reduced and fragmented distribution range. We assessed genetic diversity at eight microsatellite loci in 280 individuals from 14 locations throughout six islands. Overall, we found that the Azorean bat populations are not genetically impoverished. Indeed, the number of alleles per locus ranged from 8 to 10 and the observed heterozygosity ranged from 0.77 in Terceira to 0.83 in Faial. The highest genetic diversity and level of private alleles was observed in S. Miguel, the largest island, and the closest to the mainland. Private alleles occurred at all islands except in Graciosa. Global and pairwise F _ST among islands were all statistically significant, suggesting restricted gene flow. These results, together with those of factorial correspondence analysis, Bayesian clustering method, and individual assignment tests, corroborate the conclusions of a previous mtDNA based study, providing strong support for the existence of two major subpopulations: one includes all islands of the Central Group and the other corresponds to S. Miguel. Gene flow between them is very limited, suggesting that management plans should avoid translocations between these subpopulations. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Analysis of Pseudomonas aeruginosa Cell Envelope Proteome by Capture of Surface-Exposed Proteins on Activated Magnetic Nanoparticles

We report on specific magneto-capturing followed by Multidimensional Protein Identification Technology (MudPIT) for the analysis of surface-exposed proteins of intact cells of the bacterial opportunistic pathogen Pseudomonas aeruginosa. The magneto-separation of cell envelope fragments from the soluble cytoplasmic fraction allowed the MudPIT identification of the captured and neighboring proteins. Remarkably, we identified 63 proteins captured directly by nanoparticles and 67 proteins embedded in the cell envelope fragments. For a high number of proteins, our analysis strongly indicates either surface exposure or localization in an envelope district. The localization of most identified proteins was only predicted or totally unknown. This novel approach greatly improves the sensitivity and specificity of the previous methods, such as surface shaving with proteases that was also tested on P. aeruginosa. The magneto-capture procedure is simple, safe, and rapid, and appears to be well-suited for envelope studies in highly pathogenic bacteria.     

Effects of neutrality and productivity on mammal richness and evolutionary history in Australia

Explaining how heterogeneous spatial patterns of species diversity emerge is one of the most fascinating questions of biogeography. One of the great challenges is revealing the mechanistic effect of environmental variables on diversity. Correlative analyses indicate that productivity is associated with taxonomic, phylogenetic, and functional diversity of communities. Surprisingly, no unifying body of theory have been developed to understand the mechanism by which spatial variation of productivity affects the fundamental processes of biodiversity. Based on widely discussed verbal models in ecology about the effect of productivity on species diversity, we developed a spatially explicit neutral model that incorporates the effect of primary productivity on community size and confronted our model's predictions with observed patterns of species richness and evolutionary history of Australian terrestrial mammals. The imposed restrictions on community size create larger populations in areas of high productivity, which increases community turnover and local speciation, and reduces extinction. The effect of productivity on community size modeled in our study causes higher accumulation of species diversity in productive regions even in the absence of niche‐based processes. However, such a simple model is not capable of reproducing spatial patterns of mammal evolutionary history in Australia, implying that more complex evolutionary mechanisms are involved. Our study demonstrates that the overall patterns of species richness can be directly explained by changes in community sizes along productivity gradients, supporting a major role of processes associated with energetic constraints in shaping diversity patterns.