Using data from online social networks in conservation science: which species engage people the most on Twitter?

Knowledge about the level of public attention toward different species is crucial to successful conservation. The evolution of online social networks offers new possibilities for collecting data about public interest. Building on an analysis of text messages on Twitter, this study aimed to quantify the level of public attention toward different mammal and bird species listed (at the full species or subspecies/population level) under the United States’ Endangered Species Act (ESA). Once a month during 1 year, I searched recently posted messages (‘tweets’) for the common names of every listed species. The polar bear (Ursus maritimus) was by far the most tweeted species. The other most tweeted mammals were the American bison (Bison bison), brown bear (U. arctos), cougar (Puma concolor), killer whale (Orcinus orca), black bear (U. americanus) and West Indian manatee (Trichechus manatus), respectively. The three most frequently tweeted birds were the sandhill crane (Grus canadensis), whooping crane (G. americana) and spotted owl (Strix occidentalis). Some species, such as the manatee, right whale (Eubalaena glacialis), and gray wolf (Canis lupus) ranked higher when restricting the search to conservation contexts. The results suggest that Twitter users interact about a biased sample of ESA-listed species: mammals were better represented than birds among the most tweeted species and larger-sized species received more tweets. The findings can be used for prioritizing conservation education and marketing campaigns aiming to raise the profile of lesser-known listed species. Data from online social networks open the door for a range of novel applications in conservation science.     

Molecular and immunological characterization of the major outer membrane proteins of Brucella

Abstract Saccharomyces cerevisiae exponentially growing in basic or 0.7 M NaCl medium were isotopically labelled with ³⁵S-methionine, followed by protein separation and quantification by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) combined with computerised image analysis. The electrophoretic separation resolved about 650 proteins of which 13 displayed significant and at least 2-fold changes in rate of synthesis during saline growth. By sequencing of 2D-PAGE resolved proteins, one of the 8 induced spot, p42.9/5.5, was shown to correspond to the full length (containing the N-terminal extension) product of the GPD 1 gene encoding the cytoplasmic glycerol 3-phosphate dehydrogenase. The expression of the TDH 3 gene, glyceraldehyde 3-phosphate dehydrogenase, and the ENO 2 gene, enolase, decreased during growth in NaCl medium, declines hypothesised to have an impact on the flux to glycerol.     

Survival costs of reproduction vary with age in North American red squirrels

The costs of reproduction are expected to be higher under unfavourable conditions, so that breeding in years of low food supply should have important costs. In addition, the costs of reproduction may be contingent on the age of individuals, and young growing and old senescent individuals should suffer higher costs than the prime-age ones. We tested these predictions by investigating the costs of reproduction as a function of food availability and age in female North American red squirrels using the long-term data on survival and reproduction. We found that the costs of reproduction were independent of food supply, and we did not detect any trade-off between the current and future reproduction. We also did not detect any survival cost of reproduction for the prime-age females, but found evidence for survival costs in yearlings and old (6 years or above) females with successfully breeding individuals having a lower chance of survival compared with unsuccessful or non-breeding ones. These results supported our prediction that the costs of reproduction depended on the age of female red squirrels and were higher in young growing and old senescent individuals. Our study also indicated that, in contrast to large herbivores, heterogeneity in individual quality and viability selection in red squirrels do not affect the study of trade-offs and of the age variation in life-history traits.     

The influence of a line with fast diffusion on Fisher-KPP propagation

We propose here a new model to describe biological invasions in the plane when a strong diffusion takes place on a line. We establish the main properties of the system, and also derive the asymptotic speed of spreading in the direction of the line. For low diffusion, the line has no effect, whereas, past a threshold, the line enhances global diffusion in the plane and the propagation is directed by diffusion on the line. It is shown here that the global asymptotic speed of spreading in the plane, in the direction of the line, grows as the square root of the diffusion on the line. The model is much relevant to account for the effects of fast diffusion lines such as roads on spreading of invasive species.     

Change in light quality due to a blue-green pigment, marennine, released in oyster-ponds: effect on growth and photosynthesis in two diatoms, Haslea ostrearia and Skeletonema costatum

Two prominent diatoms encountered in oyster-ponds,Haslea ostrearia and Skeletonema costatum,were grown in batch and in a semi-continuous modeunder light of different spectral quality, white, blueor blue-green. The last corresponded to white lightmodified by a water-soluble pigment, marennine,produced by H. ostrearia. After acclimation tothe different light treatments, the growth rates ofboth species showed little variation with respect tolight quality. The parameters for photosynthesisvs irradiance curves were very similar in H. ostrearia grown under the three light conditions,whereas S. costatum the maximum photosyntheticcapacity (on a chlorophyll a basis) wassignificantly reduced under blue-green light. Fluorescence analyses confirmed the data forphotosynthesis, with the operational fluorescenceyield decreasing faster with increasing irradiance inS. costatum grown under blue-green light. InH. ostrearia, fluorescence yields undersaturating irradiance were closely similar in thethree light conditions. The results are discussed inrelation with the prominent development of H.ostrearia that can outcompete other diatoms inoyster-ponds.     

Production of gallic acid from tara tannin by bacterial strains

Summary Bacterial strains identified as Klebsiella pneumonia and Corynebacterium sp. degraded in few hours a great part of pure tara (Caesalpinia spinosa) tannin or crude water extract of tara pods powder. Large amounts of gallic acid were recovered during some experiments reaching 55 % of the theoretical yield in the best case. The feasibility of gallic acid production by a biotechnological process is discussed.     

Efficient production and secretion of bovine β-lactoglobulin by <Emphasis Type="Italic">Lactobacillus casei</Emphasis>

Background  

Lactic acid bacteria (LAB) are attractive tools to deliver therapeutic molecules at the mucosal level. The model LAB Lactococcus lactis has been intensively used to produce and deliver such heterologous proteins. However, compared to recombinant lactococci, lactobacilli offer some advantages such as better survival in the digestive tract and immunomodulatory properties. Here, we compared different strategies to optimize the production of bovine β-lactoglobulin (BLG), a major cow's milk allergen, in the probiotic strain Lactobacillus casei BL23.     

Cryotolerance and Cold Adaptation in Lactococcus lactis Subsp. lactis IL1403

The physiology of the cold-shock response in Lactococcus lactis subsp. lactis IL1403 at a subzero temperature, and cold-induced adaptation to heat shock, were investigated. Preincubation of cells at 8°C led to the development of cryotolerance, i.e., an enhanced capacity to survive exposure to freezing temperature (-20°C). Pretreatment with chemicals considered to be chaotropic agents did not induce cryotolerance or, in contrast, led to a decrease in survival capacity at -20°C. Interestingly, preincubation at 8°C led also to thermololerance to a 52°C challenge, but preincubation of cells at 42°C for 30 min did not improve their capacity to survive freezing-thawing exposure. These results demonstrate that cold- and heat-shock responses are physiologically linked by a complex relation. Furthermore, food processing at low temperature before subzero or heat treatment may need to be reconsidered.