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The annual forage crop production system, enclosing silage corn (Zea mays L.) and following cool-season annual forage, can enhance forage production efficiency where available land is limited for pasture production. In this forage production system, successful silage corn cultivation has a significant value due to the great yield of highly digestible forage. However, some untimely planting or harvesting of corn due to changing weather often reduces biomass and feeding values. Therefore, a study was conducted to quantify the corn silage biomass reductions by the deviations from optimum planting soil temperature and optimum growing degree day (GDD). The approximations of maximum corn production were estimated based on field trial data conducted between 1978 and 2018 with early, medium, and late-maturity corn groups. Based on weather data, the recorded planting dates and harvest dates were converted into the corresponding trials’ soil temperatures at planting (STP) and the GDD. The silage corn biomass data were regressed against STP and GDD using a quadratic function. The maximum biomass point was modeled in a convex upward quadratic yield curve and the optimum STP and GDD were defined as those values at the maximum biomass for each maturity group. Optimized STP was at 16.6°C, 16.2°C, and 15.6°C for early, medium, and late maturity corn groups, respectively, while optimized GDD at harvest was at 1424, 1363, and 1542°C. The biomass reductions demonstrated quadratic functions by the departures of STP or GDD. The 5% reductions were anticipated when STP departed from the optimum temperature by 2.2°C, 2.4°C, and 1.4°C for early, medium, and late maturity corns, respectively; the same degree of reductions were estimated when the GDD departed by 200, 180, and 130°C in the same order of the maturity groups. This result indicates that biomass reductions of late-maturity corn were more sensitive to the departures of STP or GDD than the early-maturity corn. Therefore, early maturing cultivars are more stable in biomass production in a silage corn–winter annual forage crop production system to enhance forage-based livestock production efficiency.

Pseudomonas aeruginosa, a nosocomial pathogen, has strong biofilm capabilities, representing the main source of infection in the human body. Repurposing existing drugs has been explored as an alternative strategy to combat emerging antibiotic-resistant pathogens. Fingolimod hydrochloride (FTY720), an immunomodulatory drug for multiple sclerosis, has shown promising antimicrobial effects against some ESKAPE pathogens. Therefore, the effects of FTY720 on the biofilm capabilities of Pseudomonas aeruginosa were investigated in this study. It was determined that FTY720 inhibited the growth of P. aeruginosa PAO1 at 100 µM. The significant reduction in PAO1 cell viability was observed to be dose-dependent. Additional cytotoxicity analysis on human cell lines showed that FTY720 significantly reduced viabilities at sub-inhibitory concentrations of 25–50 µM. Microtiter assays and confocal analysis confirmed reductions in biofilm mass and thickness and the cell survivability ratio in the presence of FTY720. Similarly, virulence production and biofilm-related gene expression (rhlA, rhlB, pilA, pilI, fliC, fliD and algR) were determined. The results demonstrate that pigment production was affected and quantitative real-time PCR analysis showed a variable degree of reduced gene expression in response to FTY720 at 12.5–50 µM. These findings suggest that FTY720 could be repurposed as an alternative antibiofilm agent against Pseudomonas aeruginosa. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa, a nosocomial pathogen, has strong biofilm capabilities, representing the main source of infection in the human body. Repurposing existing drugs has been explored as an alternative strategy to combat emerging antibiotic-resistant pathogens. Fingolimod hydrochloride (FTY720), an immunomodulatory drug for multiple sclerosis, has shown promising antimicrobial effects against some ESKAPE pathogens. Therefore, the effects of FTY720 on the biofilm capabilities of Pseudomonas aeruginosa were investigated in this study. It was determined that FTY720 inhibited the growth of P. aeruginosa PAO1 at 100 µM. The significant reduction in PAO1 cell viability was observed to be dose-dependent. Additional cytotoxicity analysis on human cell lines showed that FTY720 significantly reduced viabilities at sub-inhibitory concentrations of 25–50 µM. Microtiter assays and confocal analysis confirmed reductions in biofilm mass and thickness and the cell survivability ratio in the presence of FTY720. Similarly, virulence production and biofilm-related gene expression (rhlA, rhlB, pilA, pilI, fliC, fliD and algR) were determined. The results demonstrate that pigment production was affected and quantitative real-time PCR analysis showed a variable degree of reduced gene expression in response to FTY720 at 12.5–50 µM. These findings suggest that FTY720 could be repurposed as an alternative antibiofilm agent against Pseudomonas aeruginosa.

In konventionellen Ackerbausystemen werden derzeit überwiegend Herbizide zur Kontrolle von Unkräutern eingesetzt. Der Einsatz von Herbiziden wird wegen unerwünschter Wirkungen auf abiotische Ressourcen sowie die Biodiversität kritisch diskutiert. Um ihren Einsatz zu reduzieren, müssen mittelfristig alternative Lösungen gefunden werden. Als Alternative kommt UV-C Strahlung in Frage. Diese wirkt ab einer bestimmten Dosis irreversibel zellschädigend, wodurch das Wachstum von Pflanzen reduziert wird. Der wichtigste Parameter der UV-C Applikation ist die Dosis, die sich aus der Strahlungsstärke des Strahlfeldes und der Dauer der Bestrahlung ergibt. Ziel der Untersuchungen war es, eine UV-C Dosis zur Unkrautkontrolle zu finden, mit der das Wachstums von Unkrautpflanzen beeinträchtigt wird. Am Beispiel von Raphanus sativus wird eine Dosis-abhängige Wachstumshemmung der UV-C Strahlung gezeigt. Die höchste Reduktion im Vergleich zur unbehandelten Kontrolle betrug 93 % der Trockenmasse. Neben der UV-C Dosis hatte auch der zeitliche Abstand zwischen wiederholten Bestrahlungen einen Einfluss auf die Biomasseentwicklung der Pflanzen.

ABSTRACT Plant primary productivity and crop yields have been reduced due to the doubled level of global tropospheric ozone. Little is known about how elevated ozone affects soil microbial communities in the cropland ecosystem and whether such effects are sensitive to the nitrogen (N) supply. Here, we examined the responses of bacterial and fungal communities in maize soils to elevated ozone (+60 ppb ozone) across different levels of N fertilization (+60, +120, and +240 kg N ha−1yr−1). The fungal alpha diversity was decreased (P 0.1). The bacterial responses to N fertilization as well as the bacterial and fungal responses to elevated ozone were all phylogenetically conserved, showing universal homogeneous selection (homogeneous environmental conditions leading to more similar community structures). In detail, bacterial Alphaproteobacteria, Actinobacteria, and Chloroflexi, as well as fungal Ascomycota, were increased by elevated ozone, whereas bacterial Gammaproteobacteria, Bacteroidetes, and Elusimicrobia, as well as fungal Glomeromycota, were decreased by elevated ozone (P

The identification of new genotypes tolerant to the boron toxicity is very important for the breeding programs carried out in the arid and semiarid regions of West Asia and North Africa region. This study aims to determine the genotypes tolerant to the boron toxicity in 141 F6 recombinant inbred lines (RILs) of durum wheat. 141 RILs were characterized in terms of their tolerance to boron toxicity using the parameters: 1–5 scale of symptom score, dry matter yield, biomass reduction, tissue boron concentration. The component of variance varied from 0.69 to 0.95. 22 RILs tolerant for 1–5 scale, 121 RILs ranged from moderately tolerant to tolerant for the biomass reduction, 22 RILs moderately tolerant for the tissue concentration, and 75 RILs varied from moderately tolerant to the most tolerant for the boron content. The B toxicity evaluation parameters used in this study are efficient when they are used all together, and they produced fast and reliable results. However, the principal component analyses displayed that BC, DMY (%) and BR parameters were the most effective and reliable for the evaluation of B toxicity tolerance. The RILs represented a wide range of the genetic variation in response to the B toxicity treatments. The boron toxicity tolerance could be improved by the breeding studies. [ABSTRACT FROM AUTHOR]

Enhanced crop competition could aid in the management of annual sowthistle (Sonchus oleraceus L.), a dominant weed of Australian cropping systems. A two‐year pot study was conducted to evaluate the effect of wheat (Triticum aestivum L.) planting densities (0, 82, and 164 wheat plants/m2) on growth and seed production of glyphosate‐resistant (GR) and glyphosate‐susceptible (GS) biotypes of annual sowthistle. Without competition, both biotypes produced a similar number of leaves and biomass, but the GS biotype produced 80% more seeds (46,050 per plant) than the GR biotype. In competition with 164 wheat plants/m2, the number of leaves in the GR and GS biotypes was reduced by 62 and 61%, respectively, in comparison with the no‐competition treatment, and similarly, weed biomass was reduced by 78 and 77%, respectively. Compared to no‐competition treatment, the seed production of GR and GS biotypes was reduced by 33 and 69%, respectively, when grown with 82 wheat plants/m2, but increasing wheat density from 82 to 164 plants/m2 reduced the number of seeds only in the GS biotype (81%). Both biotypes produced greater than 6,000 seeds per plant when grown in competition with 164 plants/m2, suggesting that increased crop density should be integrated with other weed management strategies for efficient control of annual sowthistle. [ABSTRACT FROM AUTHOR]

Conventional thermocatalytic hydrogenation employs high temperatures and pressures and often exhibits low selectivity toward desired products. Electrochemical hydrogenation can reduce energy input by operating at ambient conditions and improving process control and selectivity; however, electrocatalysts face stability and conductivity limitations. To overcome these obstacles, we physically mixed a traditional electrocatalyst (Pd black) with a hydrogenation‐active metal (Pd) supported on a conventional metal oxide support (alumina, Al2O3) and investigated electrochemical hydrogenation of furfural, a model biomass compound. Experiments were conducted in a proton exchange membrane (PEM) reactor, in which synthesized electrocatalysts were used as cathodes. Catalysts with Pd black and varying loadings of Pd on Al2O3 were used to determine the impact of hydrogen spillover on electrocatalytic hydrogenation mechanisms, selectivity, and rates. Observed hydrogenation rates and selectivities were linked to structural and compositional properties of the catalyst mixtures. Of the Pd black cathodes tested, 5 wt % Pd/Al2O3 exhibited production rates as high as pure Pd black and higher selectivity towards completely hydrogenated products. Improved selectivity and rates were attributed to a synergistic interaction between Pd black and 5 wt % Pd/Al2O3 in which Pd/Al2O3 increased the number of active sites, while Pd black provided stable conductivity. [ABSTRACT FROM AUTHOR]

Abstract Improper disposal of arsenic-rich biomass and the lack of efficient methods to treat it may cause contamination in the environment. We developed an efficient method for arsenic (As) removal and biomass reduction of As-rich biomass of the As-hyperaccumulator Pteris vittata by coupling ethanol extraction with anaerobic digestion. This study assessed As partitioning among the three phases (gas, liquid and solid) after anaerobic digestion of P. vittata biomass. Biomass with and without As was first extracted with ethanol. Ethanol extraction removed ~93% As, with remaining As concentration at 197 mg kg−1. The extracted biomass was then digested at 35 °C under anaerobic conditions for 35 d. Arsenic in the digested biomass was reduced by 89%, with remaining As concentration at 60 mg kg−1. In addition, anaerobic digestion reduced the biomass by 64–71% and decreased the volatile solids content from 94 to 15–18%. Methane production was 145 and 160 L N CH 4 /kgVS after 35 d for As-rich and control biomass, respectively. As a final step, As concentration in anaerobic digestate supernatant was reduced to 0.26 mg L−1 by As-Mg precipitation. Overall, coupling ethanol extraction with anaerobic digestion decreased As concentration in P. vittata biomass from 2665 to 60 mg kg−1, or by 98%. At this level (<100 mg As kg−1), P. vittata biomass can be considered a safe material based on USEPA regulations. Effective As removal from P. vittata biomass prior to disposal improves the phytoremediation process and lowers biomass transport and landfill disposal costs. Graphical abstract Unlabelled Image Highlights • A novel treatment method was used to remove arsenic from Pteris vittata biomass. • Ethanol extraction removed 93% As in P. vittata biomass, reducing As to 197 mg kg−1. • Anaerobic digestion further reduced As in P. vittata biomass by 89% to 60 mg kg−1. • Coupling ethanol extraction with anaerobic digestion removed 98% As in total. • Anaerobic digestion also reduced biomass of arsenic-rich P. vittata by 64%. [ABSTRACT FROM AUTHOR]

Alopecurus myosuroides Huds. is an important pinoxaden-resistant grass weed in many countries of Europe. Recently, the low efficacy of pinoxaden was reported in winter cereals in Croatia, but a preliminary dose–response trial showed no herbicide resistance for the investigated weed population. Therefore, a two-year experiment was conducted under greenhouse conditions to determine the efficacy of various pinoxaden doses (20, 40 and 80 g a.i. ha−1) on weed visual injuries and biomass reduction after herbicide application at different growth stages. As expected, the maximum weed biomass reduction (97.3%) was achieved by applying the highest dose (80 g a.i. ha−1) at the earliest growth stage (ZCK 12–14). A pinoxaden dose of 20 g a.i. ha−1 resulted in satisfactory weed biomass reduction (88.9%) only when applied at ZCK 12–14. The recommended dose (40 g a.i. ha−1) also provided sufficient weed control up to the growth stage ZCK 21–25. Slightly delayed (ZCK 31–32) application of the recommended dose brought about a low weed biomass reduction (60.1%). Double than the recommended dose also failed to provide satisfactory weed control at the advanced weed growth stages (ZCK 31–32 and ZCK 37–39). Thus, reported low efficacy of pinoxaden is most likely because of delayed herbicide application when A. myosuroides is overgrown.

The boron (B) concentration surpasses the plant need in arid and semi-arid regions of the world, resulting in phyto-toxicity. Salicylic acid (SA) is an endogenous signaling molecule responsible for stress tolerance in plants and is a potential candidate for ameliorating B toxicity. In this study, the effects of seed priming with SA (0, 50, 100 and 150 µM for 12 h) on the growth, pigmentation and mineral concentrations of maize (Zea mays L.) grown under B toxicity were investigated. One-week old seedlings were subjected to soil spiked with B (0, 15 and 30 mg kg−1 soil) as boric acid. Elevating concentrations of B reduced the root and shoot length, but these losses were significantly restored in plants raised from seeds primed with 100 µM of SA. The B application decreased the root and shoot fresh/dry biomasses significantly at 30 mg kg−1 soil. The chlorophyll and carotenoid contents decreased with increasing levels of B, while the contents of anthocyanin, H2O2, ascorbic acid (ASA) and glycinebetaine (GB) were enhanced. The root K and Ca contents were significantly increased, while a reduction in the shoot K contents was recorded. The nitrate concentration was significantly higher in the shoot as compared to the root under applied B toxic regimes. However, all of these B toxicity effects were diminished with 100 µM SA applications. The current study outcomes suggested that the exogenously applied SA modulates the response of plants grown under B toxic conditions, and hence could be used as a plant growth regulator to stimulate plant growth and enhance mineral nutrient uptake under B-stressed conditions.

Large volumes of residual biomass could represent a matter of concern for large-scale purification of natural compounds, heavily influencing processing industries and logistic sizing, amount of solvents employed for the extraction processes and the final chemical and biological waste generation. In the present study, carried out in Brazil, the production of curcuminoids in Curcuma longa L. rhizomes was maximized as a function of plant maturity and solar UV exclusion. Noteworthy, curcuminoid content reached its maximum at around the end of the early vegetative phase (65 days after planting), henceforward plant growth determined only a detrimental accumulation of wastes. The harvesting at this early phase of plant maturation led to a more than tenfold reduction of exceeding biomass. In addition, by means of an innovative, sustainable and high efficient magnetic purification process for curcuminoids based on Surface Active Maghemite Nanoparticles (SAMNs), an outstanding yield of 90% and >98% purity, were achieved in a single magnetic purification step. The formation of the SAMN-curcuminoid complex (SAMN@curcuminoid) was demonstrated by optical and electron spin resonance spectroscopy and electron microscopy. The scalability of the purification method was proved by the application of an automatic modular pilot system for continuous magnetic purification of curcuminoids, capable of managing 100 L day −1 of SAMN@curcuminoid suspensions. The presented multidisciplinary approach embodies the fundamental principles of cleaner production providing a paradigm for the utilization of magnetic nanoparticles for biomolecule purification. Moreover, Brazilian agro-industries can benefit from sustainable innovation strategy outlined by the current study. [ABSTRACT FROM AUTHOR]

Biofouling on cultivated kelp in open sea conditions is a challenge when fouling species such as the encrusting bryozoans Membranipora membranacea and Electra pilosa develop colonies that cover the surface of the kelp lamina. The bryozoan colonies make the flexible lamina brittle and susceptible to breakage and reduce the commercial value of the biomass for both human consumption and industrial applications. The development of the bryozoan fouling on cultivated Saccharina latissima in temperate coastal waters was studied at two locations in Norway from April to September. The time of settling and development of colonies of M. membranacea and E. pilosa were characterized. Sampling of bryozoan larvae abundance at the cultivation locations showed that the bryozoan colonies settled on the cultivated kelp in mid-June at both locations, followed by a rapid colony growth during late June and July. In August and September, the kelp was highly degraded by the bryozoan coverage and highly subjected to breakage of the lamina. Membranipora membranacea was the most prevailing of the two species. Although abundant at all cultivation depths, the results showed a decrease in bryozoan coverage with increasing depth. From a commercial point of view, S. latissima deployed in temperate Norwegian coastal waters in winter should be harvested in early June to avoid the negative impact from bryozoan fouling. [ABSTRACT FROM AUTHOR]

This study was performed to explore the relationships between some parameters of the French cider-making process and the odourant compounds of cider. Sixteen ciders were prepared on a pilot plant scale using experimental design and varying according to apple blends, pressing conditions, pre-fermentation clarification implementation and conditions, and biomass reduction during fermentation. Odourant compounds were extracted from final ciders by headspace solid-phase microextraction with a CAR/PDMS fibre, a method previously shown to provide extracts representative of the studied cider. Extracts were analysed by gas chromatography coupled with mass spectrometry and flame ionization detection. All of the parameters tested had at least a slight effect on the odourant composition and particularly on the esters, which bring fruity notes that are appreciated by consumers. Clarification and biomass reduction had a greater impact than apple blend and pressing conditions. This could be explained by the influence of the nitrogen content on fermentation rate and efficiency, which affects the production of secondary metabolites. Under the conditions tested, a juice obtained from a bitter blend of apples by a slow pressing of the pulp at low temperature, after 1 h of cuvage, clarified by keeving and fermented without biomass reduction, produced a cider with the highest quantity of esters. These results could help cider-makers enhance product quality according to consumer expectations. Copyright © 2015 The Institute of Brewing & Distilling [ABSTRACT FROM AUTHOR]

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Abstract: Fourier Transform Infra-Red (FTIR) spectroscopy was used to investigate whether algae belonging to the green evolutionary lineage and algae belonging to the red evolutionary lineage consistently differ for their biomass composition and for the way their composition responds to changes in NO3 − availability. For this purpose, the FTIR spectra of eleven algal species cultured in media containing different amount of NO3 − were subjected to Hierarchical Cluster Analysis (HCA). The same analysis was conducted on the differential FTIR spectra of cells grown at different NO3 − concentrations. Although the organic composition of cells was affected by the availability of NO3 −, the analysis of its change did not elicit a clear relationship with the phylogenetic position of the species used. However, when the two evolutionary lineages, and not the individual species, are compared, some differences emerge: the species belonging to the green lineage reorganize their biomass composition similarly in response to variations in N availability, whereas the species of the red lineage modulate their allocation patterns more heterogeneously. This difference may contribute to the ecological fitness of microalgae and may have had an influence on the evolutionary trajectories of phytoplankton groups. [Copyright &y& Elsevier]

We tested a hypothesis based on life history theory that examines reproductive costs incurred by individuals in consecutive years of their life. A multi-year dataset of resource allocation to vegetative and reproductive structures was analysed in Carex secalina - a perennial, monoecious sedge, reproducing only sexually. In a four-year garden experiment, we assessed above-ground biomass at the end of each season and reproductive allocation expressed as the total length of male and female spikes. The study was aimed at determining how size and age of a plant relates to its reproduction, and how the rate of reproduction affects the year-toyear biomass change in Carex secalina. We observed that after each reproductive episode, individuals had significantly smaller sizes and produced a lower number of generative tillers. The total production of reproductive structures decreased significantly with age in all populations. Moreover, the decrease in plant biomass was greater when more reproductive structures were produced in a previous year, which indicates that the plants incur costs of reproduction in terms of above-ground biomass production. [ABSTRACT FROM AUTHOR]

Records of effects of ambient ozone pollution on vegetation have been compiled for Europe for the years 1990-2006. Sources include scientific papers, conference proceedings, reports to research funders, records of confirmed ozone injury symptoms and an international biomonitoring experiment coordinated by the ICP Vegetation. The latter involved ozone-sensitive (NC-S) and ozone-resistant (NC-R) biotypes of white clover ( Trifolium repens L.) grown according to a common protocol and monitored for ozone injury and biomass differences in 17 European countries, from 1996 to 2006. Effects were separated into visible injury or growth/yield reduction. Of the 644 records of visible injury, 39% were for crops (27 species), 38.1% were for (semi-) natural vegetation (95 species) and 22.9% were for shrubs (49 species). Owing to inconsistencies in reporting effort from year to year it was not possible to determine geographical or temporal trends in the data. Nevertheless, this study has shown effects in ambient air in 18 European countries from Sweden in the north to Greece in the south. These effects data were superimposed on AOT40 (accumulated ozone concentrations over 40 ppb) and POD3 (modelled accumulated stomatal flux over a threshold of 3 nmol m s) maps generated by the EMEP Eulerian model (50 km × 50 km grid) that were parameterized for a generic crop based on wheat and NC-S/NC-R white clover. Many effects were found in areas where the AOT40 (crops) was below the critical level of 3 ppm h. In contrast, the majority of effects were detected in grid squares where POD3 (crops) were in the mid-high range (>12 mmol m). Overall, maps based on POD3 provided better fit to the effects data than those based on AOT40, with the POD3 model for clover fitting the clover effects data better than that for a generic crop. [ABSTRACT FROM AUTHOR]

A pilot-scale membrane bioreactor was operated for advanced treatment of secondary effluent from a wastewater treatment plant. The performance and biomass characteristics were evaluated under two different hydraulic retention time (HRT) values (7.5 and 15 hours). The system was operated successfully without biomass purge and, after an initial phase, evolved until reaching a constant mixed-liquor volatile suspended solids (MLVSS) concentration, which resulted in the same value of carbon utilization rate (0.067 ± 0.004 kg COD kg-1 MLVSS d-1) for both HRTs. Respiration tests (maximum and endogenous oxygen uptake rates) confirmed a low microbial activity, which approached constant values (0.132 ± 0.001 and 0.064 ± 0.007 g O2 g-1 MLVSS d-1, respectively), regardless of the HRT. The sludge morphology and bound and supernatant extracellular polymeric substances also were assessed. Membrane performance was characterized by a stable behavior occurring simultaneously with a high level of biodegradation in the microcolloidal and soluble fraction. [ABSTRACT FROM AUTHOR]

Summary: Pseudomonas corrugata, a soil bacterium originally isolated from a temperate site of Indian Himalayan Region (IHR) is examined for its antagonistic activities against two phytopathogenic fungi, Alternaria alternata and Fusarium oxysporum. Although the bacterium did not show inhibition zones due to production of diffusible antifungal metabolites, a reduction in growth between 58% and 49% in both test fungi, A. alternata and F. oxysporum, was observed in sealed Petri plates after 120h of incubation due to production of volatile antifungal metabolites. Reduction in biomass of A. alternata (93.8%) and F. oxysporum (76.9%) in Kings B broth was recorded after 48h of incubation in dual culture. The antagonism was observed to be affected by growth medium, pH and temperature. The reduction in fungal biomass due to antagonism of bacteria was recorded maximum in the middle of the stationary phase after 21h of inoculation. The production of siderophore, ammonia, lipase and chitinase in growth medium by P. corrugata were considered contributing to the antagonistic activities of the bacterium. [Copyright &y& Elsevier]

Pilot-scale experiments were continuously carried out for more than 9 months to study the excess biomass reduction effect using a biophase-separation bioreactor, which was designed based on food-chain theory. By separating the biophase in the wastewater treatment system, bacteria, protozoa, and metazoa could be separated from each other and dominated in different microbial communities. After degrading organic matter, bacteria were consumed by protozoa or metazoa in the following process in such a reactor. Thus, both chemical oxygen demand (COD) and biomass were reduced. During the process of treating restaurant wastewater, the excess biomass yield in this biophase-separation technique varied from 0.13 to 0.22 kg/kg COD removed, 50% lower than that from the reference system. Apart from low biomass production, this biophase-separation technique can simultaneously achieve a high COD removal efficiency and improve settleability of biosolids at a hydraulic retention time of 6 to 13 hours. [ABSTRACT FROM AUTHOR]

Depuration is a common practice in aquatic organisms culture. The exposure time of animals to the treated water is one of the most important factors for efficiency and can affect their biomass. The effect of depuration in Pomacea patula adults using the condition index (IC) was evaluated under laboratory conditions. Cultured adults snails were maintained in clean aquaria and exposed to a constant flow water treated with ultraviolet radiation (Group 1), meanwhile that Group 2 was kept under normal culture conditions. There were 5 replicates per group. The wet weight and total length was obtained individually, at the beginning and after the depuration time of 10 days. The mean correlation coefficient value (initial animals, Groups 1 and 2) was higher than 0.90. The initial IC (771.81 ± 40.41) and those for Group 1 and 2 (763.527 ± 25.24 and 765.465 ± 38.59, respectively) were not significant different (P > 0.05) at the end of the experiment. The results suggest that the depuration process used did not affect the adult P. patula biomass. The IC represented an useful tool for evaluation of depuration despite the differences found in the initial size of adult snails. [ABSTRACT FROM AUTHOR]

Abstract: Four Mediterranean tree taxa, Quercus ilex subsp. ilex, Quercus ilex subsp. ballota, Olea europaea cv. vulgaris and Ceratonia siliqua, were exposed to different ozone (O3) concentrations in open top chambers (OTCs) during 2 years. Three treatments were applied: charcoal-filtered air (CF), non-filtered air (NF) and non-filtered air plus 40 ppbv of O3 (NF+). The photochemical maximal efficiency, Fv/Fm, decreased in NF+ plants during the second year of exposure, especially during the most stressful Mediterranean seasons (winter and summer). An increase of δ13C was found in three of the four studied species during the first year of exposure. This finding was only maintained in C. siliqua during the second year. Decreases in the chlorophyll content were detected during the first year of fumigations in all the species studied, but not during the second year. The NF+ treatment induced changes in foliar anatomical characteristics, especially in leaf mass per area (LMA) and spongy parenchyma thickness, which increased in some species. A reduction in N content and an increase in δ15N were found in all species during the second year when exposed in the NF+ OTCs, suggesting a change in their retranslocation pattern linked to an acceleration of leaf senescence, as also indicated by the above mentioned biochemical and anatomical foliar changes. The two Q. ilex subspecies were the most sensitive species since the changes in N concentration, δ15N, chlorophyll, leaf area, LMA and biomass occurred at ambient O3 concentrations. However, C. siliqua was the most responsive species (29% biomass reduction) when exposed to the NF+ treatment, followed by the two Q. ilex subspecies (14–20%) and O. europaea (no significant reduction). Ozone resistance of the latter species was linked to some plant traits such as chlorophyll concentrations, or spongy parenchyma thickness. [Copyright &y& Elsevier]

Abstract: The effects of ozone (O3) exposure under different water availabilities were studied in two Mediterranean tree species: Quercus ilex and Ceratonia siliqua. Plants were exposed to different O3 concentrations in open top chambers (charcoal-filtered air (CF), non-filtered air (NF)) and non-filtered air plus 40ppbv of O3 ((7:00–17:00 solar time) (NF+)) during 2 years, and to different water regimes (IR, sample irrigation, and WS, reduced water dose to 50%) through the last of those 2 years. AOT40 in the NF+ treatment was 59265ppbvh (from March 1999 to August 1999) while in the NF treatment, the AOT40 was 6727ppbvh for the same period. AOT40 was always 0 in the CF treatment. WS plants presented lower stomatal conductances and net photosynthetic rates, and higher foliar N concentrations than IR plants in both species. The irrigation treatment did not change the response trends to ozone in Q. ilex, the most sensitive species to O3 ambient concentrations, but it changed those of C. siliqua, the least sensitive species, since its ozone-fumigated WS plants did not decrease their net photosynthetic rates nor their biomass accumulation as it happened to its ozone-fumigated IR plants. These results show interspecific variations in O3 sensitivity under different water availabilities. [Copyright &y& Elsevier]

In order to test the hypothesis that ozone-induced limitation of biomass production in juvenile silver birch (Betula pendula Roth) is driven by stomatal uptake of ozone (O3) rather than external exposure, biomass reduction was related to the cumulative uptake of O3 through stomata over an uptake cut-off threshold of x nmol O3 m-2 s-1 (CUO>x), to the accumulated exposure to O3 over a threshold of y nmol mol-1 during daylight hours (daylight AOTy) or during 24 h (24 h AOTy), and to the sum of daytime concentrations exceeding 60 nmol mol-1 (SUM06). The analysis included data from nine different experiments conducted in Sweden, Finland and Switzerland. Stomatal uptake of O3 was estimated using a stomatal conductance (gs) model including gs response functions for photosynthetic photon flux density, water vapour pressure deficit of the air and air temperature. Experiment-specific maximum gs (gmax) as well as gs in darkness (gdark) were assessed through local measurements. Biomass reduction was more strongly related to CUO>x than to SUM06 and daylight or 24 h AOTy, but the difference between CUO>x and 24 h AOTy was small. The better performance of CUO>x was dependent on the use of site- and experiment-specific gmax and gdark values, and there was a positive relationship between gmax and biomass reduction per unit AOT40. Daylight AOTy and SUM06 could not account for the growth limiting impact of nocturnal O3 uptake in the Swiss experiments. A sensitivity analysis revealed that the CUO>x estimates were largely insensitive to the estimate of the conductance for non-stomatal leaf surface deposition of O3, as a result of turbulent conditions at the experimental plots. In summary, we conclude that CUO>x was more successful in accounting for the variation in biomass reduction in juvenile birch as compared to indices based on external exposure, if gmax and gdark were locally parameterised. [Copyright &y& Elsevier]

Leaf or needle ozone uptake was estimated for young trees at seven experimental sites across Europe using a stomatal conductance simulation model. Dose–response relationships based on cumulative leaf uptake of ozone (CUO) were calculated using different hourly ozone flux thresholds and these were compared to dose–response relationships based on daylight AOT40, which is currently used within the UNECE Convention on Long-Range Transboundary Air Pollution (CLRTAP). Regression analysis showed that the CUO–biomass response relationships were highly significant for both coniferous and broadleaf trees, and independent of which ozone flux threshold was applied. On the basis of this regressions analysis, an hourly flux threshold of 1.6 nmol m−2 s−1 (CUO>1.6) is proposed as the most appropriate for all species categories in deriving dose–response relationships. The analysis indicated that the current critical level for ozone impacts on European forests of AOT40 10 ppm h may not protect the most sensitive receptors and that critical levels for AOT40 and CUO>1.6 of 5 ppm h and 4 mmol m−2, respectively, are more appropriate. The research identified weaker dose–response relationships for the CUO exposure index compared with AOT40. Distinguishing between sensitive and less sensitive species substantially improved the CUO–biomass response relationships although, still, to a lesser extent than when exposure was expressed as AOT40. [Copyright &y& Elsevier]

Clarification of municipal wastewater was shown to be improved significantly by the addition of cultured bdelloid rotifers. The rate and degree of suspended particle removal were correlated with rotifer number. The size range of unsettled particles suspended in wastewater was determined and found to overlap with the size range of particles consumed by rotifers. Rotifers were shown to have two distinct effects on suspended particles: consumption of biomass due to feeding activity; and improved settling, probably due to enhanced aggregation. These experiments demonstrate the potential for the use of bdelloid rotifers in an enhanced wastewater treatment process, with reduced biomass production and improved effluent clarity. [Copyright &y& Elsevier]

Summary • Species of fen and fen-meadow communities, well supplied with water and nutrients, are characterised by high rates of growth, stomatal conductance values and specific leaf areas, all factors which have been associated with high sensitivity to ozone. We therefore examined the effects of ozone on 12 characteristic fen and fen-meadow species. • Plants received either filtered air or ozone; AOT40 exposures ranged from 9200 to 14 300 ppb h. Eight of the 12 species exhibited foliar injury in response to ozone exposure, with the first signs of injury on Vicia cracca , following an AOT40 exposure of only 1950 pbb h. • Ozone exposure significantly reduced plant photosynthetic rate, stomatal conductance and biomass production in four species. Cirsium arvense exhibited the greatest biomass response to ozone (32% and 58% reduction in above- and below-ground weight, respectively). Species with higher levels of visible injury tended to show greater reductions in biomass. There was a significant positive association between stomatal conductance and the magnitude of ozone effects on root biomass. • The widespread occurrence of either visible injury or growth reductions amongst the species screened, and the magnitude of effects on the most sensitive species, indicate that species of fens and fen-meadows may be more sensitive to ozone than other seminatural ecosystems which have been the focus of recent ozone studies. [ABSTRACT FROM AUTHOR]

Alopecurus myosuroides Huds. is an important pinoxaden-resistant grass weed in many countries of Europe. Recently, the low efficacy of pinoxaden was reported in winter cereals in Croatia, but a preliminary dose–response trial showed no herbicide resistance for the investigated weed population. Therefore, a two-year experiment was conducted under greenhouse conditions to determine the efficacy of various pinoxaden doses (20, 40 and 80 g a.i. ha−1) on weed visual injuries and biomass reduction after herbicide application at different growth stages. As expected, the maximum weed biomass reduction (97.3%) was achieved by applying the highest dose (80 g a.i. ha−1) at the earliest growth stage (ZCK 12–14). A pinoxaden dose of 20 g a.i. ha−1 resulted in satisfactory weed biomass reduction (88.9%) only when applied at ZCK 12–14. The recommended dose (40 g a.i. ha−1) also provided sufficient weed control up to the growth stage ZCK 21–25. Slightly delayed (ZCK 31–32) application of the recommended dose brought about a low weed biomass reduction (60.1%). Double than the recommended dose also failed to provide satisfactory weed control at the advanced weed growth stages (ZCK 31–32 and ZCK 37–39). Thus, reported low efficacy of pinoxaden is most likely because of delayed herbicide application when A. myosuroides is overgrown. [ABSTRACT FROM AUTHOR]

The boron (B) concentration surpasses the plant need in arid and semi-arid regions of the world, resulting in phyto-toxicity. Salicylic acid (SA) is an endogenous signaling molecule responsible for stress tolerance in plants and is a potential candidate for ameliorating B toxicity. In this study, the effects of seed priming with SA (0, 50, 100 and 150 µM for 12 h) on the growth, pigmentation and mineral concentrations of maize (Zea mays L.) grown under B toxicity were investigated. One-week old seedlings were subjected to soil spiked with B (0, 15 and 30 mg kg−1 soil) as boric acid. Elevating concentrations of B reduced the root and shoot length, but these losses were significantly restored in plants raised from seeds primed with 100 µM of SA. The B application decreased the root and shoot fresh/dry biomasses significantly at 30 mg kg−1 soil. The chlorophyll and carotenoid contents decreased with increasing levels of B, while the contents of anthocyanin, H2O2, ascorbic acid (ASA) and glycinebetaine (GB) were enhanced. The root K and Ca contents were significantly increased, while a reduction in the shoot K contents was recorded. The nitrate concentration was significantly higher in the shoot as compared to the root under applied B toxic regimes. However, all of these B toxicity effects were diminished with 100 µM SA applications. The current study outcomes suggested that the exogenously applied SA modulates the response of plants grown under B toxic conditions, and hence could be used as a plant growth regulator to stimulate plant growth and enhance mineral nutrient uptake under B-stressed conditions. [ABSTRACT FROM AUTHOR]

B The Front Cover b shows the controlled variation of furfural hydrogenation product speciation based on varying cathode formulations of hybrid Pd black and Pd on alumina support. Electrocatalysts, selective hydrogenation, electrode material, furfural, biomass reduction. [Extracted from the article]