ALBERT

Description: The boundary between the American and European plates emerges in Iceland, an outstanding natural laboratory where it is possible to analyse ongoing rifting processes. In the North Volcanic Zone, we studied with unprecedented detail an active rift, known as the Theistareykir Fissure Swarm (ThFS). We surveyed an area of 85 km2 with 694 measurement sites along 1537 post-Late Glacial Maximum extension fractures. In the southern sector of the study area, fractures strike N30–40° with opening directions about N120°. Fractures in the central sector strike about N00° and opening directions are N90–100°. In the northern sector, fractures strike about N30° with opening directions about N125°. Through a comparison with older faults cropping out in the substrate at the shoulder of the ThFS, we are able to suggest that variations in fracture strike are the effect of substrate structural inheritance as well as the possible interaction with the Tjörnes Fracture Zone. With regard to kinematics, we highlight that most fractures show a small, but systematic, strike-slip component (a more frequent right-lateral component and a less common, left-lateral one). This cannot be explained as the result of fracture strike rotation relative to the regional, tectonic least principal stress. We conclude that the net opening directions can result from the combination of tectonic offsets and events caused by shallow magma chamber inflation and/or dyke intrusions. The latter can produce transcurrent components of displacement along new or already existing fractures.

Description: This study investigated photosynthetic and oxidative stress-related responses to moderate (500 μmol photons m −2 s −1 ) and high irradiances (1500 μmol photons m −2 s −1 ) in two tropical intertidal seagrasses, Halophila ovalis and Thalassia hemprichii . Exposure to high irradiance for 3 h resulted in a large decline in the maximum quantum yield of photosystem II (Fv/Fm) and in the effective quantum yield of photosystem II (ΦPSII) but induced non-photochemical quenching (NPQ) and chloroplast clumping in H. ovalis . Thalassia hemprichii , however, showed only a minor decrease in Fv/Fm and ΦPSII, and no change in either NPQ or the intracellular arrangement of chloroplasts. The irradiance did not affect reactive oxygen species (ROS) or superoxide dismutase (SOD) activity in either seagrass, whereas high irradiance enhanced ascorbate peroxidase (APX) activity in H. ovalis . The results from a subsequent experiment using an oxidative stress inducer, methyl viologen (MV), also showed a higher degree of Fv/Fm inhibition in H. ovalis . These results show that H. ovalis is much more physiologically responsive to high irradiances and oxidative stress than T. hemprichii and that its photoprotective mechanisms involve NPQ, APX and reduction of the amount of light absorbed through the clumping of its chloroplasts.

Description: Vibrios are rod-shaped bacteria, and are a functionally and phylogenetically diverse grouping of Gram-negative microbes found widely in aquatic, estuarine, and marine habitats. Approximately a dozen Vibrio species are known to cause disease in humans, and infection is usually initiated from exposure to seawater or consumption of raw or undercooked seafood. Although a wide range of different bacterial species contain multiple chromosomes, Vibrio species are noted in that they possess two circular chromosomes. Bacteria of the genus Vibrio are commonly found in tropical and temperate coastal and estuarine waters. Vibrios are among the most common bacteria that inhabit surface waters throughout the world and are responsible for a number of severe infections both in humans and animals. Vibriosis is characterized by diarrhea, primary septicemia, wound infections, or other extraintestinal infections. Select strains of V. cholerae, V. parahaemolyticus, V. vulnificus, and V. alginolyticus are perhaps considered the most serious human pathogens from this genus. Two Vibrio species in particular, V. vulnificus and V. parahaemolyticus are significant foodborne human pathogens, and most frequently infections occur via the consumption of naturally contaminated shellfish produce. It is worth noting that these pathogens represent a significant cause of morbidity and mortality. For example, an estimated 80,000 people contract Vibrio infections each year in the United States, with a sizeable fraction originating from foodborne sources, such as consumption of raw or undercooked seafood produce. Recent data from the Centers for Disease Control and Prevention (CDC) in the United States have indicated that there has been a significant increase in reported infections associated with vibrios, particularly in the last two decades. The annual incidence of reported vibriosis per 100,000 population has increased significantly in the United States from 1996 to 2010, highlighting the importance of these pathogens from a clinical context. Calculations based upon probable incidence of vibriosis have estimated that V. vulnificus and V. parahaemolyticus are the first and third most costly marine-borne pathogens, costing $233 and $20 million, respectively. From a foodborne perspective V. vulnificus and V. parahaemolyticus represent the major pathogens from the Vibrio genus in terms of clinical impact and relevance, and as such this chapter is mostly concerned with these species. These taxa do not sustain prolonged presence in clinical or agricultural settings, where it would likely undergo human-induced selection for antibiotic resistance. As such, these bacteria represent a particularly interesting group of pathogens to study antibiotic resistance, as they provide a “snapshot” of resistance presumably acquired from environmental rather than clinical settings. Despite their public-health significance, strains of V. parahaemolyticus and V. vulnificus have not been extensively monitored for antimicrobial resistance, in contrast to enteric pathogens such as Salmonella or Campylobacter. Given their increasing incidence, global distribution, and severity of disease progression (especially V. vulnificus) it is critical to gain a better understanding of the antimicrobial susceptibility patterns of V. vulnificus and V. parahaemolyticus originating from the environment (Shaw et al., 2014). Data from such sources is invaluable, particularly from routine antimicrobial screening of large numbers of environmental and clinical Vibrio strains as it can provide effective baseline data for treatment purposes.

Description: El Niño events are characterized by surface warming of the tropical Pacific Ocean and weakening of equatorial trade winds that occur every few years. Such conditions are accompanied by changes in atmospheric and oceanic circulation, affecting global climate, marine and terrestrial ecosystems, fisheries and human activities. The alternation of warm El Niño and cold La Niña conditions, referred to as the El Niño–Southern Oscillation (ENSO), represents the strongest year-to-year fluctuation of the global climate system. Here we provide a synopsis of our current understanding of the spatio-temporal complexity of this important climate mode and its influence on the Earth system.

Description: Bacteria use quorum sensing to orchestrate gene expression programmes that underlie collective behaviours. Quorum sensing relies on the production, release, detection and group-level response to extracellular signalling molecules, which are called autoinducers. Recent work has discovered new autoinducers in Gram-negative bacteria, shown how these molecules are recognized by cognate receptors, revealed new regulatory components that are embedded in canonical signalling circuits and identified novel regulatory network designs. In this Review we examine how, together, these features of quorum sensing signal–response systems combine to control collective behaviours in Gram-negative bacteria and we discuss the implications for host–microbial associations and antibacterial therapy.

Description: The Science Platform at a glance In the new version of the German Sustainable Development Strategy, the Federal Government called on the scientific community to create a platform that is systematically involved in the steering, dialogue and implementation processes of the 2030 Agenda and its sustainability architecture. In response to this, the Science Platform Sustainability 2030 was launched on 8 May 2017 and was presented to the public one day later at the 13th BMBF Forum for Sustainability. The platform is supported by three organising institutions: the Sustainable Development Solutions Network Germany (SDSN Germany), the German Committee Future Earth (DKN Future Earth) and the Institute for Advanced Sustainability Studies (IASS), which houses the platform’s secretariat. A steering committee consisting of 26 members from science, the business community, and civil society is responsible for the platform’s activities and operative management. The committee also links the platform with other actors from science, politics, economics and civil society in an effort to build an effective, representative and internationally anchored platform. Additional support is provided by a circle of government agencies (open to all federal ministries) – currently including the BMBF, the BMUB, the BMZ, the BMEL and the Federal Chancellery.

Description: Green infrastructures play an essential role in urban planning, namely with their potential to reduce the impact from air pollution episodes together with extreme weather events. This chapter focuses on the assessment of green infrastructures’ benefits on current and future microclimate and air quality patterns in Porto’s urban area (Portugal). The effects of green infrastructures on flow dynamics are evaluated for the baseline scenarios by means of numerical and physical simulations, using the computational fluid dynamics (CFD) model VADIS and the wind tunnel of the University of Aveiro. The baseline morphological (BM) scenario focuses on the current morphological characteristics of Porto’s urban area, while a baseline green (BG) scenario comprises the replacement of built-up areas by green areas and parks. In addition, the benefits of green infrastructures on air quality are assessed for the baseline and under future climate scenarios. The air quality simulations focus on particulate matter, one of the most critical air pollutants with severe impacts on human health. For the BM scenario, the simulated concentrations are compared with hourly averaged PM10 concentrations measured during a weekday at the air quality station located within the study domain.