Temperature Effects Explain Continental Scale Distribution of Cyanobacterial Toxins

Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI) increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains.Peer reviewe

Valerie Wellington (1984)

https://egrove.olemiss.edu/bluesphoto_fel/1186/thumbnail.jp

Mobile Media: Content and Services for Wireless Communication

The proliferation of mobile in recent years is an international phenomenon, with billions of devices sold annually. Mobile communication are now moving beyond individualized voice to mass media content-text, voice, sound, image, even video. This will create new types of content that allow media companies and user to interact in new ways. There is a strong interest from the media and telecom industries in what manner of applications and content can be distributed in that fashion, and at what cost. To answer these questions, the book provides 18 chapters from internationally renowed authors. They identified likely types of content such as news, entertainment, peer to peer, and location specific information, evaluate the economics, business models, and payment, mechanisms necessary to support these media : and cover policy dimensions such as copyright, competitiveness, and access rights for content providers. Mobile media takes the reader through the various element that need to be considered in the development of third generation (3G) content, and explains pitfalls and barriers. The result is a volume of interest to business professionals, academics, and policymakers. The book is international in focus and glossary of term is provided. There are few publications available that provide an overview of this rapidly changing field

Mobile Media : Content and Services for Wireless Communications

The proliferation of mobile in recent years is an international phenomenon, with billions of devices sold annually. Mobile communication are now moving beyond individualized voice to mass media content-text, voice, sound, image, even video. This will create new types of content that allow media companies and user to interact in new ways. There is a strong interest from the media and telecom industries in what manner of applications and content can be distributed in that fashion, and at what cost. To answer these questions, the book provides 18 chapters from internationally renowed authors. They identified likely types of content such as news, entertainment, peer to peer, and location specific information, evaluate the economics, business models, and payment, mechanisms necessary to support these media : and cover policy dimensions such as copyright, competitiveness, and access rights for content providers. Mobile media takes the reader through the various element that need to be considered in the development of third generation (3G) content, and explains pitfalls and barriers. The result is a volume of interest to business professionals, academics, and policymakers. The book is international in focus and glossary of term is provided. There are few publications available that provide an overview of this rapidly changing field

Stratification strength and light climate explain variation in chlorophyll a at the continental scale in a European multilake survey in a heatwave summer

To determine the drivers of phytoplankton biomass, we collected standardized morphometric, physical, and biological data in 230 lakes across the Mediterranean, Continental, and Boreal climatic zones of the European continent. Multilinear regression models tested on this snapshot of mostly eutrophic lakes (median total phosphorus [TP] = 0.06 and total nitrogen [TN] = 0.7 mg L-1), and its subsets (2 depth types and 3 climatic zones), show that light climate and stratification strength were the most significant explanatory variables for chlorophyll a (Chl a) variance. TN was a significant predictor for phytoplankton biomass for shallow and continental lakes, while TP never appeared as an explanatory variable, suggesting that under high TP, light, which partially controls stratification strength, becomes limiting for phytoplankton development. Mediterranean lakes were the warmest yet most weakly stratified and had significantly less Chl a than Boreal lakes, where the temperature anomaly from the long-term average, during a summer heatwave was the highest (+4 degrees C) and showed a significant, exponential relationship with stratification strength. This European survey represents a summer snapshot of phytoplankton biomass and its drivers, and lends support that light and stratification metrics, which are both affected by climate change, are better predictors for phytoplankton biomass in nutrient-rich lakes than nutrient concentrations and surface temperature.Peer reviewe