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Abstract In this work, a paper-based optoelectronic sensor (paper-nose) is presented for sensing volatile gases in air. The proposed optoelectronic sensor is a combination of both colorimetric (optical) and chemiresistive (electronic) sensor arrays in order to improve the selectivity of the paper-nose in the complex air background. The optical sensors are based on chemoresponsive dyes, namely Reichardt's dye (2,6-diphenyl-4-(2,4,6-triphenyl-1-pyridinio)phenolate), bromocresol purple, methyl red, bromothymol blue, brilliant yellow and manganese tetraphenylporphyrin (Mn-TPP). The chemiresistive sensors are based on nanomaterials, such as carbon nanotubes (CNT), PEDOT:PSS, graphite, and an ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMI TFSI). Sensor is fabricated through direct handwriting of sensing materials using a pen on paper without the need of expensive cleanroom facilities. The optoelectronic sensor is tested in ambient air with different volatile gases such as methanol, ammonia, toluene, acetone and ethanol and their mixtures of varying concentrations. The detected electrical and optical responses together form a unique signature for each volatile gas and its mixture. Support-vector machine (SVM) is applied for target classification and detection. From the SVM result, it is found that better discriminative power is achieved by combining optical and electrical responses. Graphical abstract Image 1 Highlights • Presents an array of colorimetric and chemiresistive sensors on paper (paper-nose). • Machine learning assists paper nose to detect volatile gases and their mixtures in air. • Combining colorimetric and chemiresistive sensing is key to improving accuracy. [ABSTRACT FROM AUTHOR]

Seaweed and seagrass communities in the northeast Atlantic have been profoundly impacted by humans, and the rate of change is accelerating rapidly due to runaway CO2 emissions and mounting pressures on coastlines associated with human population growth and increased consumption of finite resources. Here, we predict how rapid warming and acidification are likely to affect benthic flora and coastal ecosystems of the northeast Atlantic in this century, based on global evidence from the literature as interpreted by the collective knowledge of the authorship. We predict that warming will kill off kelp forests in the south and that ocean acidification will remove maerl habitat in the north. Seagrasses will proliferate, and associated epiphytes switch from calcified algae to diatoms and filamentous species. Invasive species will thrive in niches liberated by loss of native species and spread via exponential development of artificial marine structures. Combined impacts of seawater warming, ocean acidification, and increased storminess may replace structurally diverse seaweed canopies, with associated calcified and noncalcified flora, with simple habitats dominated by noncalcified, turf-forming seaweeds. [ABSTRACT FROM AUTHOR]

The value of ammonium sulphate (+SO4) fertilizer as a method of controlling potato common scab varies from field to field and from year to year. We examined the influence of two fertilizer regimes on the biodiversity and antibiosis activity (in vitro) of culturable rhizobacterial populations recovered from fields with a similar history of potato common scab. Root zone soils treated with +SO4 fertilizers were colonized by significantly (P=0.05) more species-diverse communities of bacteria than those managed with ammonium nitrate fertilizers (+NO3). In bioassays conducted on artificial media adjusted to pH 4.9 (acid) or pH 6.8 (base), in vitro antibiosis in bacterial strains against Streptomyces scabies was found to be dependent on fertilizer regime (P=0.023), with more isolates with antibiosis ability being recovered from +SO4 compared to +NO3 treated soils. Overall, bacterial species from the genera Bacillus (18–35%) and Pseudomonas (15–18%) were major components of those rhizoflora communities antagonistic to S. scabies. Under our field conditions, soil acidification with +SO4 treatments stimulated the development of rhizobacterial communities that generated secondary metabolites with (in vitro) antibiosis ability, against S. scabies. This occurred both in the liquid and vapour phase (volatile gases); the latter most notably by Bacillus cereus, Bacillus pumilus and Pseudomonas chlororaphis. We postulate that in hot, dry seasons, antibiosis against S. scabies mediated by +SO4 treatments, and the competitive bacterial communities they engender, would be less effective in controlling potato common scab, as the active moieties would be rapidly volatilized into the atmosphere. In contrast, biocontrol would be more effective in wetter seasons, the active moieties being retained, in and around the potato root zone for greater biologically significant periods of time. [Copyright &y& Elsevier]