Global emergence of environmental non-O1/O139 Vibrio cholerae infections linked with climate change: a neglected research field?

The bacterium Vibrio cholerae is a natural inhabitant of aquatic ecosystems across the planet. V. cholerae serogroups O1 and O139 are responsible for cholera outbreaks in developing countries accounting for 3–5 million infections worldwide and 28.800–130.000 deaths per year according to the World Health Organization. In contrast, V. cholerae serogroups other than O1 and O139, also designated as V. cholerae non-O1/O139 (NOVC), are not associated with epidemic cholera but can cause other illnesses that may range in severity from mild (e.g. gastroenteritis, otitis, etc.) to life-threatening (e.g. necrotizing fasciitis). Although generally neglected, NOVC-related infections are on the rise and represent one of the most striking examples of emerging human diseases linked to climate change. NOVC strains are also believed to potentially contribute to the emergence of new pathogenic strains including strains with epidemic potential as a direct consequence of genetic exchange mechanisms such as horizontal gene transfer and genetic recombination. Besides general features concerning the biology and ecology of NOVC strains and their associated diseases, this review aims to highlight the most relevant aspects related to the emergence and potential threat posed by NOVC strains under a rapidly changing environmental and climatic scenario.     

Lead soaps formation and biodiversity in a XVIII Century wax seal coloured with minium

A multidisciplinary approach was carried out in order to study the biodeterioration and the associated microbiome of a XVIII Century wax seal coloured with minium. A small wax seal fragment was observed by scanning electron microscopy combined with energy dispersive spectroscopy in non-destructive mode. The same object was analysed by Raman and Fourier-transform infrared spectroscopy. The identification of the microbiota growing on the seal was performed with both a culture-dependent strategy, combined with hydrolytic assays, and high-throughput sequencing using the MinION platform. The whole bacterial 16S rRNA gene and the fungal markers ITS and 28S rRNA were targeted. It was observed that the carnauba wax coloured with lead tetroxide (minium) was covered by a biofilm consisting of a network of filaments and other structures of microbial origin. The culture-dependent and culture-independent investigations showed the presence of a complex microbiota composed mainly by fungal members, which demonstrated interesting properties related to lipids and lead processing. The formation of lead soaps and secondary biogenic minerals was also described.     

Using anticipatory life cycle assessment to enable future sustainable construction

The built environment is the largest single emitter of CO₂ and an important consumer of energy. Much research has gone into the improved efficiency of building operation and construction products. Life Cycle Assessment (LCA) is commonly used to assess existing buildings or building products. Classic LCA, however, is not suited for evaluating the environmental performance of developing technologies. A new approach, anticipatory LCA (a‐LCA), promises various advantages and can be used as a design constraint during the product development stage. It helps overcome four challenges: (i) data availability, (ii) stakeholder inclusion, (iii) risk assessment, and (iv) multi‐criteria problems. This article's contribution to the line of research is twofold: first, it adapts the a‐LCA approach for construction‐specific purposes in theoretical terms for the four challenges. Second, it applies the method to an innovative prefabricated modular envelope system, the CleanTechBlock (CTB), focusing on challenge (i). Thirty‐six CTB designs are tested and compared to conventional walls. Inclusion of technology foresight is achieved through structured scenario analysis. Moreover, challenge (iv) is tackled through the analysis of different environmental impact categories, transport‐related impacts, and thickness of the wall assemblies of the CTB. The case study results show that optimized material choice and product design is needed to reach the lowest environmental impact. Methodological findings highlight the importance of context‐specific solutions and the need for benchmarking new products.     

Regulation of Gdnf expression by retinoic acid in Sertoli cells

Glial cell line‐derived neurotrophic factor (GDNF) and retinoic acid (RA) are two molecules crucial for the regulation of the spermatogonial compartment of the testis. During the cycle of the seminiferous epithelium, their relative concentration oscillates with lower GDNF levels in stages where RA levels are high. It has been recently shown that RA negatively regulates Gdnf expression but the mechanisms behind are so far unknown. Here, we show that RA directly downregulates Gdnf mRNA levels in primary murine Sertoli cells through binding of RARα to a novel DR5‐RARE on Gdnf promoter. Pharmacological inhibition and chromatin immunoprecipitation–quantitative polymerase chain reaction analysis suggested that the underlying mechanism involved histone deacetylase activity and epigenetic repression of Gdnf promoter upon RA treatment.     

Success of active restoration in grasslands: a case study of birds in southern Brazil

Grasslands in southeastern South America have been extensively converted to various land uses such as agriculture, threatening regional biodiversity. Active restoration has been viewed as a management alternative for recovery of degraded areas worldwide, although most studies are conducted in forests and none has evaluated the effect of active restoration of grasslands in southeastern South America. From 2015 through 2017 we monitored a federally owned tract of grassland from the beginning of the active‐restoration process. We compared the bird community in this active‐restoration area (AR) with a reference area (NG) in Pampa grasslands in southern Brazil. We sampled birds by point counts and surveyed vegetation structure in plots. Over the 3 years of active restoration, bird species richness and abundance were higher in AR (30 species, 171 individuals) than NG (22 species, 154 individuals). The species composition also differed between the two habitats. Grassland bird species were present in both AR and NG. The vegetation structure differed between AR and NG in five attributes: height, short and tall grasses, herbs, and shrubs. Since it has been found that active restoration is useful in promoting species diversity, we encourage studies of the use of long‐term restoration efforts. Our study, even on a local scale, showed a rapid recovery of the bird community in the active‐restoration compared to native grassland, and suggests the potential for recovery of the degraded grasslands of the Brazilian Pampa biome.     

Effect of positive charges in the structural interaction of crabrolin isoforms with lipopolysaccharide

Antimicrobial peptides (AMPs) appear as chemical compounds of increasing interest for their role in killing bacteria and, more recently, for their ability to bind endotoxin (lipopolysaccharide, LPS) that is released during bacterial infection and that may lead to septic shock. This dual role in the mechanism of action can further be enhanced in a synergistic way when two or more AMPs are combined together. Not all AMPs are able to bind LPS, suggesting that several modes of binding to the bacterial surface may exist. Here we analyze a natural AMP, crabrolin, and two mutated forms, one with increased positive charge (Crabrolin Plus) and the other with null charge (Crabrolin Minus), and compare their binding abilities to LPS. While Crabrolin WT as well Crabrolin Minus do not show binding to LPS, the mutated Crabrolin Plus exhibits binding and forms a well defined structure in the presence of LPS. The results strengthen the importance of positive charges for the binding to LPS and suggest the mutated form with increased positive charge as a promising candidate for antimicrobial and antiseptic activity.     

Thinner bark increases sensitivity of wetter Amazonian tropical forests to fire

Understory fires represent an accelerating threat to Amazonian tropical forests and can, during drought, affect larger areas than deforestation itself. These fires kill trees at rates varying from < 10 to c. 90% depending on fire intensity, forest disturbance history and tree functional traits. Here, we examine variation in bark thickness across the Amazon. Bark can protect trees from fires, but it is often assumed to be consistently thin across tropical forests. Here, we show that investment in bark varies, with thicker bark in dry forests and thinner in wetter forests. We also show that thinner bark translated into higher fire‐driven tree mortality in wetter forests, with between 0.67 and 5.86 gigatonnes CO₂ lost in Amazon understory fires between 2001 and 2010. Trait‐enabled global vegetation models that explicitly include variation in bark thickness are likely to improve the predictions of fire effects on carbon cycling in tropical forests.