Evolutionary trade-offs at the Arabidopsis WRR4A resistance locus underpin alternate Albugo candida race recognition specificities

The oomycete Albugo candida causes white rust of Brassicaceae, including vegetable and oilseed crops, and wild relatives such as Arabidopsis thaliana. Novel White Rust Resistance (WRR) genes from Arabidopsis enable new insights into plant/parasite co-evolution. WRR4A from Arabidopsis accession Columbia (Col-0) provides resistance to many but not all white rust races, and encodes a nucleotide-binding, leucine-rich repeat immune receptor. Col-0 WRR4A resistance is broken by AcEx1, an isolate of A. candida. We identified an allele of WRR4A in Arabidopsis accession Øystese-0 (Oy-0) and other accessions that confers full resistance to AcEx1. WRR4A^Oy-0 carries a C-terminal extension required for recognition of AcEx1, but reduces recognition of several effectors recognized by the WRR4A^Col-0 allele. WRR4A^Oy-0 confers full resistance to AcEx1 when expressed in the oilseed crop Camelina sativa.     

EPS and SMP dynamics at different heights of a submerged anaerobic membrane bioreactor (SAMBR)

Membrane bioreactors (MBR) technology for wastewater offers many advantages over conventional technologies such as high effluent quality, less footprint and others. The main disadvantage of membrane bioreactors (MBR) is related to membrane fouling, which is mainly caused by extracellular polymeric substance (EPS) and soluble microbial products (SMP). This research studied EPS and SMP dynamics at different heights of a submerged anaerobic membrane bioreactor (SAMBR). The SAMBR was operated under two organic loading rates (OLR) (0.79 and 1.56 kg/m³ d) and was fed with synthetic wastewater with glucose as the carbon source. The results showed percentages of chemical oxygen demand (COD) removal above 95% and the highest COD removal rates were observed at the bottom of the reactor (>83%) for both OLR. The EPS showed a stratification with highest quantities in the supernatant. For the SMP the highest concentration was in the bottom of SAMBR where utilization predominated associated products whereas in the SAMBR supernatant predominated biomass associated products. The OLR change led to a significant increase in SMP accumulation but not in EPS. These facts showed that EPS and SMP dynamic in the SAMBR seemed to be mainly influenced by biological activity, total suspended solids concentration and substrate composition.     

Conservation implications of adaptation to tropical climates from a historical perspective

Tropical climates and the biodiversity associated with them have long interested natural historians. Alexander von Humboldt inspired a generation of scientists, such as Charles Darwin and Alfred Russel Wallace, to observe and study tropical ecosystems. More recently, the mid‐20th century saw Theodosius Dobzhansky and Daniel Janzen lay the foundations for studying adaptation to tropical climates. Now in the 21st century, we are beginning to realize the threats posed by current and future climate change to tropical populations which, despite relatively low levels of projected warming for low‐latitude regions, face potentially significant detrimental impacts. Building on the insights of researchers in decades and centuries past, improved understanding of tropical ecology, evolution and biogeography will help us to conceive how future global change will impact on biodiversity.     

The Blue Water Footprint of Primary Copper Production in Northern Chile

Water consumption related to the life cycle of metals is seldom reported, even though mines are often situated in very dry regions. In this study we quantified the life cycle consumption of groundwater and fresh surface water (blue water footprint [WF_blue]) for the extraction and production of high‐grade copper refined from both a copper sulfide ore and a copper oxide ore in the Atacama Desert of northern Chile. Where possible, we used company‐specific data. The processes for extracting copper from the two types of ore are quite different from each other, and the WF_blue of the sulfide ore refining process is 2.4 times higher than that of the oxide ore refining process (i.e., 96 cubic meters per metric ton [tonne] of copper versus 40 cubic meters per tonne of copper). Most of the water consumption (59% of WF_blue) in the sulfide ore process occurred at the concentrator plant, via seepage, accumulation, and also by evaporation. In the oxide ore process, the main user of water is the heap‐leaching process, with 45% of WF_blue. The crushing and agglomeration operations, electrowinning cells, and solution pools are also significant contributors to the total consumption of water in the oxide ore process. Most of the water consumed in the oxide ore process was lost to evaporation. The WF_blue of the oxide ore process can be reduced by preventing water evaporation and using more sophisticated devices during irrigation of the leaching heaps. The WF_blue of the sulfide ore refining process can be reduced by improving water recovery (i.e., reducing seepage, accumulation, and evaporation) from the tailings dam at the concentrator plant. Using seawater in the production of copper is also a promising option to reduce the WF_blue by up to 62%.     

Selection of flowering forbs for conserving natural enemies in rice fields

The diversity of natural enemies harboured by flowering forbs on rice field bunds was recorded. Ageratum conozoides with a maximum Shannon diversity index of 1.8 followed by Acmella uliginosa, Eclipta alba and Tridax procumbens are amenable for ecological engineering, providing nectar, pollen and alternate prey to natural enemies.     

Bottom‐up Conservation

Conservation initiatives that have worked well in temperate and developed regions have often been applied in the tropics but with only limited success. Part of this failure is due to top–down conservation planning that has been conducted without taking local socio‐economic considerations into adequate account. Here, we argue that conservation approaches would benefit from a deeper understanding of human–nature interactions.     

Randomness and Order in a Forest with Trees in Rows-a Case Study

The correlations between intertree distances and stem volumina of trees in an artificial pine wood with trees in rows are studied. Several stochastic models are suggested, and methods of the theory of random measures are used. A method for estimating the produce of woods of the type considered is suggested.     

Maturation of Fermented Rice-koji Miso Can Be Monitored by an Increase in Fatty Acid Ethyl Ester

A mixture of steamed soybean and boiled rice with seeded Aspergillus oryzae was naturally fermented without addition of yeasts or Lactobacilli, and kept matured for 12 months at room temperature. Chemical analysis of this rice-koji miso sample for lipid changes during maturation showed that triacylglycerol was gradually decomposed into free fatty acid, with distinct formation of fatty acid ethyl ester which, six months after the start of fermentation, came to account for 35.0% of total lipid. The ester was constituted primarily with linoleic acid (ca. 50%) and oleic acid (ca. 20%), no appreciable change in this proportion being observed during maturation. Also, the proportion was unique in that this did not reflect the fatty acid composition in a mixture of the two materials. It is possible to monitor the maturation of the rice-koji miso by following up the increase with time in fatty acid ethyl ester.     

Evolution of dispersal and life history interact to drive accelerating spread of an invasive species

Populations on the edge of an expanding range are subject to unique evolutionary pressures acting on their life‐history and dispersal traits. Empirical evidence and theory suggest that traits there can evolve rapidly enough to interact with ecological dynamics, potentially giving rise to accelerating spread. Nevertheless, which of several evolutionary mechanisms drive this interaction between evolution and spread remains an open question. We propose an integrated theoretical framework for partitioning the contributions of different evolutionary mechanisms to accelerating spread, and we apply this model to invasive cane toads in northern Australia. In doing so, we identify a previously unrecognised evolutionary process that involves an interaction between life‐history and dispersal evolution during range shift. In roughly equal parts, life‐history evolution, dispersal evolution and their interaction led to a doubling of distance spread by cane toads in our model, highlighting the potential importance of multiple evolutionary processes in the dynamics of range expansion.