The observed link between urbanization and invasion can depend on how invasion is measured

Aim Cities are thought to promote biological invasions because invasive species are more often introduced in urban areas and because they are more successful in disturbed environments. However, the association is not as strongly supported by the literature as is generally assumed and might depend on how urbanization and invasion are measured. In this study, we test if the type of data used to assess the link between urbanization and invasion can affect a study's conclusions. Location Europe and middle Rhône valley (~5000 km2 in south-eastern France). Method We studied the spatial distribution of the invasive garden ant Lasius neglectus in its current introduced range in Europe and tested its association with urbanization using three measures of invasion (presence-only, presence–absence and population area) and two measures of urbanization (urban/nonurban land cover classification and proportion of impervious surfaces (buildings, road) per spatial unit). Results Based on presence-only data across Europe, L. neglectus occurred in urban areas 10 times more often than expected from a random geographical distribution. However, when controlling for spatial bias in sampling effort with presence–absence data (1870 sampling locations in the middle Rhône valley, France), the occurrence of the species was independent of urbanization. Moreover, the surface occupied by L. neglectus populations was negatively correlated with urbanization. Main conclusions These findings show that the type of occurrence data used to test the link between urbanization and invasion can strongly affect the conclusion of a study. This is particularly concerning because invasion studies often use presence-only data that are likely biased towards cities. Future urban invasions studies must be carefully designed to avoid this pitfall.Peer reviewe

Efficient electrochemical degradation of poly- and perfluoroalkyl substances (PFASs) from the effluents of an industrial wastewater treatment plant

This paper reports the electrochemical treatment of poly- and perfluoroalkyl substances (PFASs) in the effluent from an industrial wastewater treatment plant (WWTP). While most of the previous research focused on the electrochemical degradation of perfluorooctanoic acid and perfluorooctane sulfonate in model solutions, this work studies the simultaneous removal of 8 PFASs at environmentally relevant concentrations in real industrial emissions, which also contained organic matter and inorganic anions. The overall PFASs content in the WWTP effluent was 1652 µg/L, which emphasized the need to develop innovative technologies for the management of PFASs emissions. 6:2 fluorotelomer sulfonamide alkylbetaine (6:2 FTAB) and 6:2 fluorotelomer sulfonate (6:2 FTSA) were the major contributors (92% w/w) to the overall PFASs content, that also contained significant amounts of short-chain perfluorocarboxylic acids (PFCAs). Using a boron doped diamond (BDD) anode of 0.0070 m2, the effluent (2 L) was treated by applying a current density of 50 mA/cm2 for 10 h, that resulted in 99.7% PFASs removal. The operation at lower current densities (5 and 10 mA/cm2) evidenced the initial degradation of 6:2 fluorotelomers into perfluoroheptanoic and perfluorohexanoic acids, that were later degraded into shorter chain PFCAs. The high TOC removal, >90%, and the fluoride release revealed that PFASs mineralization was effective. These results highlight the potential of the electrochemical technology for the treatment of PFASs contained in industrial wastewaters, which nowadays stands as the main source of this group of persistent pollutants into the environment.Financial support of project CTM2013-44081-R (MINECO, SPAIN-FEDER 2014–2020) is acknowledged. B. Gomez also thanks the FPI grant (BES-2014-071045)

Boron doped diamond electrooxidation of 6:2 fluorotelomers and perfluorocarboxylic acids. Application to industrial wastewaters treatment

The aim of this study was to determine the viability of electrochemical oxidation to degrade and mineralize poly- and perfluoroalkyl substances (PFASs) in wastewaters from an industrial facility dedicated to the production of side-chain-fluorinated polymers and fluorotelomer-based products for fire-fighting foams. 6:2 fluorotelomer sulfonamide alkylbetaine (6:2 FTAB, 1111 μg/L), 6:2 fluorotelomer sulfonic acid (6:2 FTSA, 242.5 μg/L) and 6:2 fluorotelomer sulfonamide propyl N,N dimethylamine (M4, 34.4 μg/L) were the most abundant PFASs in the industrial wastewater, that also contained perfluorocarboxylic acids (ΣPFCAs, 12.2 μg/L), high TOC and chloride as main anion. 2 L samples were treated in bench scale experiments performed at a current density of 50 mA/cm2, in a commercial cell equipped with a boron doped diamond (BDD) anode (70 cm2). 97.1% of the initial PFASs content was removed after 8 h of electrochemical treatment. Furthermore, the TOC removal (82.5%) and the fluoride release confirmed the PFASs mineralization. Based on the evolution of the different PFASs, electrochemical degradation pathways were proposed. Fluorotelomers sulfonamides 6:2 FTAB and M4 would be degraded into 6:2 FTSA, which conversely would give rise to PFHpA and preferentially PFHxA. The latter PFCAs were transformed into shorter-chain PFCAs, and eventually into CO2 and fluoride. The reported results support the technical viability of BDD electrooxidation for the treatment of PFASs in industrial wastewater.This work was supported by the Spanish Ministry of Economy and Competitiveness (CTM2013-44081-R and CTM2016-75509-R). B. Gomez also thanks the FPI postgraduate research grant (BES-2014-071045)

Land-cover and climate factors contribute to the prevalence of the ectoparasitic fungus Laboulbenia formicarum in its invasive ant host Lasius neglectus

International audienceUnderstanding the distribution of parasites is crucial for biodiversity conservation. Here, we studied the distribution of the ectoparasitic fungus Laboulbenia formicarum in native and invasive Lasius ants in a 2000 km2 area. We screened over 16,000 ant workers in 478 colonies of five different species. We found that Lab. formicarum was rare in native Lasius species but infected 58% of the colonies of the invasive species Las. neglectus. At landscape scale, Lab. formicarum presence could not be explained by geographic and genetic distances between Las. neglectus colonies but was associated with hotter and dryer climatic conditions and its prevalence in colonies increased with urbanization. Within infected colonies, fungal prevalence varied from 0 to 100 percent within meters and was negatively correlated with impervious ground cover. In a changing world, our findings emphasize the importance of land-use and climatic factors in shaping the distribution and prevalence of fungal parasites

Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

Nucleosome patterns in four plant pathogenic fungi with contrasted genome structures

Fungal pathogens represent a serious threat towards agriculture, health, and environment. Control of fungal diseases on crops necessitates a global understanding of fungal pathogenicity determinants and their expression during infection. Genomes of phytopathogenic fungi are often compartmentalized: the core genome contains housekeeping genes whereas the fast-evolving genome mainly contains transposable elements and species-specific genes. In this study, we analysed nucleosome landscapes of four phytopathogenic fungi with contrasted genome organizations to describe and compare nucleosome repartition patterns in relation with genome structure and gene expression level. We combined MNase-seq and RNA-seq analyses to concomitantly map nucleosome-rich and transcriptionally active regions during fungal growth in axenic culture; we developed the MNase-seq Tool Suite (MSTS) to analyse and visualise data obtained from MNase-seq experiments in combination with other genomic data and notably RNA-seq expression data. We observed different characteristics of nucleosome profiles between species, as well as between genomic regions within the same species. We further linked nucleosome repartition and gene expression. Our findings support that nucleosome positioning and occupancies are subjected to evolution, in relation with underlying genome sequence modifications. Understanding genomic organization and its role in expression regulation is the next gear to understand complex cellular mechanisms and their evolution

Annual cycles are the most common reproductive strategy in African tropical tree communities

Abstract We present the first cross‐continental comparison of the flowering and fruiting phenology of tropical forests across Africa. Flowering events of 5446 trees from 196 species across 12 sites and fruiting events of 4595 trees from 191 species across 11 sites were monitored over periods of 6 to 29 years and analyzed to describe phenology at the continental level. To study phenology, we used Fourier analysis to identify the dominant cycles of flowering and fruiting for each individual tree and we identified the time of year African trees bloom and bear fruit and their relationship to local seasonality. Reproductive strategies were diverse, and no single regular cycle was found in >50% of individuals across all 12 sites. Additionally, we found annual flowering and fruiting cycles to be the most common. Sub‐annual cycles were the next most common for flowering, whereas supra‐annual patterns were the next most common for fruiting. We also identify variation in different subsets of species, with species exhibiting mainly annual cycles most common in West and West Central African tropical forests, while more species at sites in East Central and East African forests showed cycles ranging from sub‐annual to supra‐annual. Despite many trees showing strong seasonality, at most sites some flowering and fruiting occurred all year round. Environmental factors with annual cycles are likely to be important drivers of seasonal periodicity in trees across Africa, but proximate triggers are unlikely to be constant across the continent.Additional co-authors: Roman M. Wittig, Thomas Breuer, Mireille Breuer‐Ndoundou Hockemba, Crickette M. Sanz, David B. Morgan, Anne E. Pusey, Badru Mugerwa, Baraka Gilagiza, Caroline Tutin, Corneille E. N. Ewango, Douglas Sheil, Edmond Dimoto, Fidèle Baya, Flort Bujo, Fredrick Ssali, Jean‐Thoussaint Dikangadissi, Kim Valenta, Michel Masozera, Michael L. Wilson, Robert Bitariho, Sydney T. Ndolo Ebika, Sylvie Gourlet‐Fleury, Felix Mulindahabi, Colin M. Beal

Mammalian Frataxin: An Essential Function for Cellular Viability through an Interaction with a Preformed ISCU/NFS1/ISD11 Iron-Sulfur Assembly Complex

Frataxin, the mitochondrial protein deficient in Friedreich ataxia, a rare autosomal recessive neurodegenerative disorder, is thought to be involved in multiple iron-dependent mitochondrial pathways. In particular, frataxin plays an important role in the formation of iron-sulfur (Fe-S) clusters biogenesis.. Fe-S cluster biosynthesis

Contribution of Panton-Valentine Leukocidin in Community-Associated Methicillin-Resistant Staphylococcus aureus Pathogenesis

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strains typically carry genes encoding Panton-Valentine leukocidin (PVL). We used wild-type parental and isogenic PVL-deletion (Δpvl) strains of USA300 (LAC and SF8300) and USA400 (MW2) to test whether PVL alters global gene regulatory networks and contributes to pathogenesis of bacteremia, a hallmark feature of invasive staphylococcal disease. Microarray and proteomic analyses revealed that PVL does not alter gene or protein expression, thereby demonstrating that any contribution of PVL to CA-MRSA pathogenesis is not mediated through interference of global gene regulatory networks. Inasmuch as a direct role for PVL in CA-MRSA pathogenesis remains to be determined, we developed a rabbit bacteremia model of CA-MRSA infection to evaluate the effects of PVL. Following experimental infection of rabbits, an animal species whose granulocytes are more sensitive to the effects of PVL compared with the mouse, we found a contribution of PVL to pathogenesis over the time course of bacteremia. At 24 and 48 hours post infection, PVL appears to play a modest, but measurable role in pathogenesis during the early stages of bacteremic seeding of the kidney, the target organ from which bacteria were not cleared. However, the early survival advantage of this USA300 strain conferred by PVL was lost by 72 hours post infection. These data are consistent with the clinical presentation of rapid-onset, fulminant infection that has been associated with PVL-positive CA-MRSA strains. Taken together, our data indicate a modest and transient positive effect of PVL in the acute phase of bacteremia, thereby providing evidence that PVL contributes to CA-MRSA pathogenesis