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Most halogenated organic compounds (HOCs) are toxic and carcinogenic, hence unwanted in the environment. Several technologies exist for the treatment of both legacy and newly contaminated zones. In many contaminated subsurface environments, nano zero-valent iron (nZVI) as a reagent is the tool of choice, while palladium (Pd) as a catalyst faces technical challenges. A system comprising metallic copper and borohydride as a reducing agent (referred herein as copper-borohydride system, CBHS) provides an alternative to nZVI and Pd. This chapter presents a deeper understanding of the CBHS for the treatment of HOCs by highlighting the state of knowledge related to the i) type and classes of compounds that are treatable, ii) possible reaction pathways for their transformation, iii) specific metal activities for transformation of selected classes of HOCs, iv) influence of common water constituents on catalyst stability, and v) future perspectives regarding its application in water treatment applications. Furthermore, an up-to-date discussion is presented regarding the available techniques for the synthesis of copper nanoparticles. Based on the evaluation criteria including product selectivity patterns, amount and the fate of intermediates, and metal cost and stabilities in water, the most suitable application areas for Cu, Pd, and nZVI are presented as recommendations.

Micro (nano)plastics pollution is a noxious menace not only for mankind but also for marine life, as removing microplastics (MPs) is challenging due to their physiochemical properties, composition, and response toward salinity and pH. This review provides a detailed assessment of the MPs pollution in different water types, environmental implications, and corresponding treatment strategies. With the advancement in nanotechnology, mitigation strategies for aqueous pollution are seen, especially due to the fabrication of nanosheets/membranes mostly utilized as a filtration process. Two-dimensional (2D) materials are increasingly used for membranes due to their diverse structure, affinity, cost-effectiveness, and, most importantly, removal efficiency. The popular 2D materials used for membrane-based organic and inorganic pollutants from water mainly include graphene and MXenes however their effectiveness for MPs removal is still in its infancy. Albeit, the available literature asserts a 70- 99% success rate in micro/nano plastics removal achieved through membranes fabricated via graphene oxide (GO), reduced graphene oxide (rGO) and MXene membranes. This review examined existing membrane separation strategies for MPs removal, focusing on the structural properties of 2D materials, composite, and how they adsorb pollutants and underlying physicochemical mechanisms. Since MPs and other contaminants commonly coexist in the natural environment, a brief examination of the response of 2D membranes to MPs removal was also conducted. In addition, the influencing factors regulate MPs removal performance of membranes by impacting their two main operating routes (filtration and adsorption). Finally, significant limitations, research gaps, and future prospects of 2D material-based membranes for effectively removing MPs are also proposed. The conclusion is that the success of 2D material is strongly linked to the types, size of MPs, and characteristics of aqueous media. Future perspectives talk about the problems that need to be solved to get 2D material-based membranes out of the lab and onto the market.

Functional colloidal carbon materials find various applications, including the remediation of contaminated water and soil in so-called particle-based in-situ remediation processes. In this study, uniform and highly dispersible micro-sized carbonaceous spheres (CS) were generated by hydrothermal carbonization (HTC) of sucrose in the presence of carboxymethyl cellulose (CMC) as environmentally friendly polyelectrolyte stabilizer. In order to ensure their optimal subsurface delivery and formation of a self-contained treatment zone, a narrow size distribution and low agglomeration tendency of the particles is desired. Therefore, the obtained CS were thoroughly characterized and optimized with respect to their colloidal properties which are a crucial factor for their application as quasi-liquid sorbent. The as-prepared uniform CS are readily dispersible into single particles in water as confirmed by digital microscopy and form stable suspensions. Due to their perfectly spherical shape, particle sedimentation in aqueous suspensions is well predicted by Stokes' law. High sorption coefficients on the synthesized CS K

Background The changing climate is altering timing of key fruit ripening processes and increasing the occurrence of fruit defects. This work aimed to expand our knowledge of the genetic control of the ripening process in raspberry by examining a biennial x primocane F1 population to determine if the progeny exhibited both primocane and biennial flowering modes, which if any was dominant, and to identify QTL and genome locations associated with fruit development to understand how developmental control in this population differs from a biennial x biennial F1 population previously studied. Results The progeny from this biennial x primocane population exhibited primocane fruiting completing their lifecycle in a single season and also fruiting on second-year wood not removed in season one. QTL associated with rate of fruit development were identified on both primocane and fruiting canes with both parents impacting. Conclusions Novel QTL associated with the developmental process of primocane fruiting were identified. These in the main, differed from developmental QTL for similar developmental stages on fruiting canes (second year canes) with only one significant overlap on linkage group 6. In general, the process of development on fruiting canes overall differed from that in a biennial x biennial population, with the differences being greatest on linkage groups 3 and 6 suggesting control of development differs in the different fruiting types. Further understanding will be achieved by examining genome regions linked to QTL to allow breeding to meet climate requirements for yield stability.

Background Nanoscale zero-valent iron (nZVI) is commonly used for remediation of groundwater contaminated by chlorinated ethenes (CEs); however, its long-term reactivity and subsurface transport are limited. A novel nZVI–AC material, consisting of colloidal activated carbon (AC) with embedded nZVI clusters, was developed with the aim of overcoming the limitations of nZVI alone. Results Application of a limited amount of nZVI–AC to an oxic, nitrate-rich, highly permeable quaternary aquifer triggered time-limited transformation of CEs, with noticeable involvement of reductive dechlorination. Reductive dechlorination of CEs was dominantly abiotic, as an increase in the concentration of vinyl chloride (VC) and ethene did not coincide with an increase in the abundance of reductive biomarkers for complete dechlorination of CEs (Dehalococcoides, Dehalogenimonas, VC reductase genes vcrA and bvcA). Application of nZVI–AC under unfavourable hydrochemical conditions resulted in no dramatic change in the microbial community, the reducing effect resulting in temporal proliferation of nitrate and iron reducers only. At a later stage, generation of reduced iron induced an increase in iron-oxidizing bacteria. High concentrations and a continuous mass influx of competing electron acceptors (nitrate and dissolved oxygen) created unfavourable conditions for sulphate-reducers and organohalide-respiring bacteria, though it allowed the survival of aerobic microorganisms of the genera Pseudomonas, Polaromonas and Rhodoferax, known for their ability to assimilate VC or cis-1,2-dichloroethene. A potential for aerobic oxidative degradation of CE metabolites was also indicated by detection of the ethenotroph functional gene etnE. Conclusions This pilot study, based on the application of nZVI–AC, failed to provide a sustainable effect on CE contamination; however, it provided valuable insights into induced hydrogeochemical and microbial processes that could help in designing full-scale applications.

Genome-wide association studies (GWAS) have become a powerful tool for analyzing complex traits in crop plants. The current study evaluates the efficacy of various GWAS models and methods for elucidating population structure in potato. The presence of significant population structure can lead to detection of spurious marker-trait associations, as well as mask true ones. While appropriate statistical models are needed to detect true marker-trait associations, in most published potato GWAS, a ‘one model fits all traits’ approach has been adopted. We have examined various GWAS models on a large association panel comprising diverse tetraploid potato cultivars and breeding lines, genotyped with single nucleotide polymorphism (SNP) markers. Phenotypic data were generated for 20 quantitative traits assessed in different environments. Best Linear Unbiased Estimates (BLUEs) for these traits were obtained for use in assessing GWAS models. Goodness of fit of GWAS models, derived using different combinations of kinship and population structure for all traits, was evaluated using Quantile-Quantile (Q-Q) plots and genomic control inflation factors (λGC). Kinship was found to play a major role in correcting population confounding effects and results advocate a ‘trait-specific’ fit of different GWAS models. A survey of genome-wide linkage disequilibrium (LD), one of the critical factors affecting GWAS, is also presented and our findings are compared to other recent studies in potato. The genetic material used here, and the outputs of this study represent a novel resource for genetic analysis in potato.

Dechlorination of dichlorodiphenyltrichloroethane (DDT) as a model compound was performed with zero-valent iron (micro-ZVI and nano-ZVI) as reductant and carbonaceous adsorbents as sink and catalyst in water. DDT is rapidly converted to dichlorodiphenyldichloroethane (DDD) in direct contact with ZVI. However, up to 90% of the DDD is transformed into non-identified, most likely oligomeric products. There is no indication of dechlorination at the aromatic rings. DDT is still rapidly dechlorinated when it is adsorbed on carbonaceous adsorbents, even though ZVI particles have no direct access to the adsorbed DDT. The carbonaceous materials function as adsorbent and catalyst for the dechlorination reaction at once. From electrochemical experiments, we deduced that direct physical contact between ZVI particles and the adsorbent is essential for enabling a chemical reaction. Electron conduction alone does not effect any dechlorination reaction. We hypothesize hydrogen species (H∗) which spill from the ZVI surface to the carbon surface and initiate reductive transformations there. The role of carbonaceous adsorbents is different for different degradation pathways: in contrast to hydrodechlorination (reduction), adsorption protects DDT from dehydrochlorination (hydrolysis).

As nanoremediation strategies for in-situ groundwater treatment extend beyond nanoiron-based applications to adsorption and oxidation, ecotoxicological evaluations of newly developed materials are required. The biological effects of four new materials with different iron (Fe) speciations ([i] FerMEG12 - pristine flake-like milled Fe(0) nanoparticles (nZVI), [ii] Carbo-Iron® - Fe(0)-nanoclusters containing activated carbon (AC) composite, [iii] Trap-Ox® Fe-BEA35 (Fe-zeolite) - Fe-doped zeolite, and [iv] Nano-Goethite - ‘pure’ FeOOH) were studied using the unicellular green alga Chlamydomonas sp. as a model test system. Algal growth rate, chlorophyll fluorescence, efficiency of photosystem II, membrane integrity and reactive oxygen species (ROS) generation were assessed following exposure to 10, 50 and 500 mg L−1 of the particles for 2 h and 24 h. The particles had a concentration-, material- and time-dependent effect on Chlamydomonas sp., with increased algal growth rate after 24 h. Conversely, significant intracellular ROS levels were detected after 2 h, with much lower levels after 24 h. All Fe-nanomaterials displayed similar Z-average sizes and zeta-potentials at 2 h and 24 h. Effects on Chlamydomonas sp. decreased in the order FerMEG12 > Carbo-Iron® > Fe-zeolite > Nano-Goethite. Ecotoxicological studies were challenged due to some particle properties, i.e. dark colour, effect of constituents and a tendency to agglomerate, especially at high concentrations. All particles exhibited potential to induce significant toxicity at high concentrations (500 mg L−1), though such concentrations would rapidly decrease to mg or µg L−1 in aquatic environments, levels harmless to Chlamydomonas sp. The presented findings contribute to the practical usage of particle-based nanoremediation in environmental restoration.

There is an urgent need to develop new interventions to manage pests because evolution of pesticide resistance and changes in legislation are limiting conventional control options for farmers. We investigated β-aminobutyric acid (BABA), jasmonic acid (JA) and fructose as possible plant defence activators against grey mould disease, Botrytis cinerea , and root knot nematode, Meloidogyne incognita. We also tested Trichogramma achaeae parasitoid wasps and an antifeedant plant extract for biocontrol of the invasive tomato leafminer, Tuta absoluta . BABA and JA enhanced resistance of tomato plants to B. cinerea but neither treatment provided complete protection and the efficacy of treatment varied over time with BABA being more durable than JA. Efficacy was partly dependent on tomato cultivar, with some cultivars responding better to BABA treatment than others. Furthermore, treatment of tomato with BABA, JA and fructose led to partial suppression of M. incognita egg mass development. Biocontrol agent, T. achaeae , performance against T. absoluta could be enhanced by adjusting the rearing conditions. Both attack rate and longevity were improved by rearing the parasitoids on T. absoluta rather than on other insects. Finally, Ajuga chamaepitys extract was shown to have significant antifeedant activity against T. absoluta . Our findings suggest that there are potential new solutions for protection of crops but they are more complicated to deploy, more variable and require more biological knowledge than conventional pesticides. In isolation, they may not provide the same level of protection as pesticides but are likely to be more potent when deployed in combination in IPM strategies.

Palladium catalysts protected by embedding in polymer films proved suitable as a means to markedly prolong the life-time of the catalyst in hydrodechlorination and hydrogenation reactions for substrates from the water phase. The present work examines and summarizes optimization strategies for synthesis of embedded Pd catalysts. The polymer and the type of Pd catalyst were varied and several synthesis strategies were compared. Poly(dimethylsiloxane) (PDMS) was confirmed to best maintaining long-term stability and offering easy surface coating with highly permeable but resistant membrane layers. The generation of catalytically active Pd species in situ within the polymer (in situ synthesis) allows higher catalyst activities due to suppression of Pd agglomeration which was omnipresent when embedding unsupported nanoparticles (ex situ synthesis). Highest Pd activities were achieved with supported porous catalysts, such as Pd on γ-Al2O3. The loss in catalyst activity due to embedding compared to freely water-suspended catalysts is less pronounced for nano-sized and supported nano-sized Pd than for micro-sized Pd. Polymer embedded Pd/Al2O3 better maintains its catalytic activity than unsupported Pd nanoparticles and Pd black. The loss of activity due to PDMS embedding is a factor of 3, 190 and 1000 respectively. Higher catalyst dispersion and Pd loadings (up to 4 wt%) were obtained with condensation-vulcanizing PDMS instead of addition-vulcanizing PDMS, where the Pd load was limited due to lower Pd precursor solubility. Tailoring of the catalyst behaviour using in situ synthesized Pd-PDMS was successful by making a selection in the PDMS type, Pd loading, temperature of nanoparticle generation and type of Pd precursor.

Nano-sized palladium (Pd) catalysts are known for their high intrinsic hydrodechlorination (HDC) activity towards many chlorinated water pollutants, converting them into non-harmful compounds. Optimization of catalyst protection by embedding various types of Pd catalysts (Pd on oxidic supports and in-situ generated Pd clusters) into poly(dimethylsiloxane) (PDMS) layers was studied together with their use in HDC reactions. The catalyst performance in standard batch and long-term experimental set-ups was used to better understand and optimize the Pd-PDMS system. The phenomenon of polymer deterioration by entrapped HDC-generated HCl is studied for various systems and found to be the main reason for limited life times of Pd-PDMS systems. Pd-PDMS composites were found to provide long-term protection from ionic catalyst poisons. This gain in prolonged catalyst protection goes along with an inevitable decrease in specific catalyst activity which is unhesitantly accepted for the benefit of a longer-lasting catalytic activity. However, when comparing the relative loss of the specific Pd activity due to embedding, it is found to be much lower for initially less active catalyst particles (e.g. a factor of 2 for Pd/Al2O3) compared to about two orders of magnitude for the highly active nanoscale Pd particles. It could be shown that embedded catalysts in continuously operated long-term set-ups have enhanced resistance and longevity compared to those tested in repeated batch-type reaction cycles. PDMS-embedded Pd/Al2O3 maintains its full initial activity up to turnover numbers of >750 (for trichloroethene as probe substance), whereas the catalyst system loses more than 50% of its initial activity for a comparable catalyst utilization (TON ≈ 750) operated in batch cycles.

Trichloroethene (TCE) dechlorination by nanoscale zero-valent iron (nZVI) in aqueous suspension was investigated in absence and presence of microscale activated carbon (AC). The TCE adsorbed within the AC micropores is available to dechlorination, although a direct contact between sorbed TCE and nZVI is ruled out. The AC functions as a mediator of redox equivalents between the external reductant and the internal sorbate. Therefore, AC plays the role of an adsorbent as well as a dechlorination catalyst driven by the reductive power of nZVI. The dechlorination product patterns in the AC–nZVI mixture and the AC-free slurry are similar, yielding ethane, ethene and ethyne as primary products. One can interpret this as spillover-like transport of mobile reactive species from the iron surface via the carbon matrix to the sorbate. In order to distinguish between transported electrons or hydrogen species, electrochemical experiments with and without the generation of nascent hydrogen (H*) were conducted. They prove the significant role of reactive hydrogen in the nZVI–AC system and favour the spillover mechanism. Ethyne and cis -DCE are the dominant products from TCE in the absence of H* species, whereas total dechlorination and hydrogenation occurred in the presence of H*, yielding ethane and ethene as the dominant primary products. The observed interplay between sorptive enrichment and chemical degradation of pollutants inside the AC pores may offer options for improved iron-carbon composite materials and reactor designs.

FeS was evaluated as heterogeneous activator for peroxydisulfate (PS) with trichloroethene (TCE) chosen as model substance representing organic water pollutants prone to fast oxidation by sulfate radicals. The TCE degradation followed in most cases pseudo-first-order kinetics with a FeS-normalized maximum rate constant of k’TCE = 140 M−1min−1 (with cFeS,0 = 0.28 mM and cPS,0 = 5 mM). Sulfate radicals were determined as predominant radical species formed during PS activation by FeS by evaluation of the kinetic isotope effect for oxidation of cyclohexanes C6H12 vs. C6D12 (kC6H12: kC6D12 = 2.22). Monitoring of sulfur and iron species during the course of the reaction revealed that sulfide is rapidly oxidized, whereas Fe(II)solid is rather stable over time. The present study describes in detail the influence of the pH value on the reaction and the long-term performance of FeS as activator for PS with an optimum pH value of 5. On the basis of the radical yield from PS of 1.6 mols SO4− per mol S2O82− and the activation energy of EA = (31 ± 1) kJ mol−1 for the heterogeneous radical generation, a surface-assisted homolytic bond cleavage without simultaneous electron transfer is proposed as activation mechanism, which is contrary to the currently prevailing opinion.

After the injection of Carbo-Iron® into an aquifer contaminated with tetrachloroethene (PCE), combined chemical and microbiological contaminant degradation processes were found in a long-term study of the field site in Lower Saxony (Germany). The applied composite material Carbo-Iron, which consists of colloidal activated carbon and embedded nanoscale zero-valent iron (ZVI) structures, functioned as intended: accumulating the pollutants and promoting their reductive dechlorination. Furthermore, the particles decreased the redox potential of the groundwater due to their reaction with oxygen and to the ZVI-corrosion-induced formation of molecular hydrogen up to 190 days after the injection, the latter promoting sulphate-reducing conditions. The emergence of cis-dichloroethene (cis-DCE), which was only found in trace quantities before the injection of Carbo-Iron, together with the presence of organisms related to Sulfospirillum multivorans, Desulfitobacterium spp. and Dehalococcoides mccartyi, indicate that Carbo-Iron is also able to support microbial degradation of PCE. However, cis-DCE did not accumulate in the present case study, although it is often observed at sites with active microbial dechlorination. The results of compound-specific isotope analysis in combination with pyrosequencing data suggested the oxidative degradation of cis-DCE by an organism related to Polaromonas sp. strain JS666. Consequently, the formation of the carcinogenic degradation intermediate vinyl chloride was circumvented. Overall, the moderate and slow change of environmental conditions mediated by Carbo-Iron not only supported organohalide-respiring bacteria, but also created the basis for a subsequent microbial oxidation step.

Although grass dominates most agricultural systems in the North Atlantic region (NAR), spring barley is the most important cereal and is used for animal feed and food and drink products. Recent changes in climate have resulted in warmer conditions across the NAR which have major implications for crop production. In this paper, we investigate the thermal requirement of spring barley in the region and use the results to examine the effects of recent trends in temperature and rainfall on barley cultivation, based on 11 regional meteorological sites. At these sites, between 1975 and 2015, we found significant warming trends for several months of the cropping season and significant trends for increases in the cropping season degree days (CSDD). In recent years, this has resulted in an increased proportion of years when the estimated minimum thermal requirement for barley has been met at sites above about 60°N. However, annual variations in CSDD are large and years still occur at these sites where this is insufficient. While warming could potentially allow an earlier start and later end to the cropping season, it is likely that high rainfall at maritime sites, and low rainfall at continental sites, will limit the ability of growers to benefit from this. Warming is considered to have been one of the main factors contributing to the large expansion of the area of barley cultivated in Iceland since the 1990s., Research contributing to this publication was supported by project grants from the Nordic Atlantic Cooperation (NORA; Northern cereals—new opportunities. Project number 515-005) and the Northern Periphery and Arctic Programme (Northern cereals—new markets for a changing environment; CAV Diary Number 304-8673-2014).

Field trials were carried out over a 4 year period (2004–2007) to determine the effect of agronomic factors, specifically cultivar resistance, irrigation, crop duration and chemical control (in-furrow application of azoxystrobin), on black dot development on potato tubers grown in fields where soilborne inoculum of Colletotrichum coccodes was present. In 2004, 2005 and 2006, two field trials were performed each year and in 2007, 19 mini-field trials were carried out across Scotland and England. Cultivar resistance was clearly demonstrated to be an effective method of reducing black dot disease severity on tubers (described here as the percentage of unmarketable tubers, i.e. those with symptoms covering a surface area of >10%). In the four field trials carried out in 2004 and 2005, in irrigated and fungicide-untreated plots, 43·8% of tubers of cv. Maris Piper were unmarketable, compared with 17·0% of tubers of cv. Sante. Assessments of disease development on underground plant parts (stems, stolons and roots) revealed that cultivar resistance acted only at the tuber level, as disease symptoms on other parts were often high irrespective of published disease resistance ratings. Irrigation increased the severity of disease on tubers in two trials (England 2004 and 2006), but its effect was less significant when rainfall was high. Delaying harvest by 2 weeks increased disease severity in all six trials, whilst application of azoxystrobin consistently reduced black dot severity. There were significant interactions between factors. The results clearly show how black dot disease severity can be reduced through an integrated approach to disease management.

Palladium is an efficient catalyst for hydrodechlorination (HDC) of aliphatic and aromatic chlorinated organic compounds in water. However, its applicability in water treatment processes is limited because of its sensitivity to catalyst poisons. In the present study, Pd/Al2O3 was modified by various silicone-based fillings and coatings. The modified catalysts proved to be active in the HDC of chlorobenzene with APd = 35–65 L gPd−1 min−1 vs. 570 L gPd−1 min−1 for the unprotected catalyst. It was insusceptible against sulphite as a model catalyst-deactivating ionic water constituent. However, under HDC conditions the silicone appeared to be degraded, becoming gradually permeable for sulphite. Hydrolysis of the silicone polymers, initiated and promoted by the HDC product HCl, is assumed to be responsible for the polymer ageing. Release of chloride from the coated catalyst into the bulk water phase has been revealed as a crucial step in this concept of hydrophobic catalyst protection. It could be shown that with Pd/Al2O3, HDC also proceeds in dry organic solvents such as n-hexane at significant reaction rates (APd = 18–28 L gPd−1 min−1).

Carbo-Iron – a novel composite material is presented, which consists of nanoscale zero-valent iron (nZVI) clusters on activated carbon colloids (ACC). The material is especially designed for the in situ generation of reactive zones and contaminant source removal when applied in groundwater remediation processes. This paper deals with the tailored synthesis of the composite material to create a reducing agent with properties optimized for subsurface transport of the particles and improved source affinity when compared to pure nZVI. Various iron precursors and impregnation methods are discussed with regard to their influence on the material properties. The impregnated ACCs were reduced by either H 2 or C/CO in order to achieve the desired Carbo-Iron colloids. By means of thermogravimetric analysis the optimal reduction temperatures were determined for H 2 (500 °C) and for the carbon carrier material (700 °C) as reducing agent. For stabilization of the initially generated pyrophoric highly dispersed iron nanoclusters various approaches were studied in order to generate an air-stable material without significant loss of metallic iron. Stabilization with traces of gaseous HCl gave the best results. Finally, the influence of the nZVI and residual iron oxide deposits on the sorption properties of the ACC carrier is discussed.

The analysis of association mapping populations is frequently complicated by substructure within the population. If this is unaccounted for, it generally results in many false positive marker-trait associations. In this study, we simulate a large barley population, modelling inbreeding and selection, and compare five models for analysing marker-trait associations. One of these includes no population substructure, one includes information about geographical origin and type of barley to represent structure within the population and three use different approaches that have been proposed for estimating marker-based kinship. Kinship methods reduced the number of false positives substantially compared to the other models but none of these approaches had a clear advantage over the others. One solution is to fit more than one model and to consider as candidate associations those markers that are significant by all models. None of the approaches were very successful at detecting true associations at the lowest level of heritability considered (25%), suggesting it is important to consider power in association mapping studies to avoid missing some true associations and overestimating others.

Primers to 43 genes, including those involved in the phenylpropanoid and volatile pathways, cell wall, ethylene and polyamine metabolism, and from Prunus linkage group (LG) 6 were tested in red raspberry (Rubus idaeus) cultivars Latham and Glen Moy, and 40 were polymorphic. Thirty-seven genes were subsequently mapped in the ‘Latham’ × ‘Glen Moy’ population and were placed across all seven Rubus LG. This brings to 97 the total number of genic markers mapped in this Rubus mapping population. Fifteen genes are associated with existing quantitative trait loci for ripening, cane diseases, including yellow rust (Phragmidium rubi-idaei), cane botrytis (Botrytis cinerea), spur blight (Didymella applanata), and cane spot (Elsinoe veneta) or fruit color in R. idaeus and can be used for identifying bacterial artificial chromosome clones for physical mapping studies. A cluster of four genes from Prunus LG6 mapped together to Rubus LG3, suggesting that there may be sufficient synteny between these Rosaceae over small genomic regions that can be exploited in future studies.

Many chlorinated aromatic and aliphatic hydrocarbons dissolved in water can be rapidly and selectively hydrodechlorinated by means of Pd catalysts. However, if they appear in a complex water matrix, as is common for wastewater treatment or after soil extraction, the protection of the Pd sites against catalyst poisons may become the key step for applicability of this reaction. In the present study, Pd/Al2O3 was tested as hydrodechlorination (HDC) catalyst in various soil washing effluents. As probe compounds 3-chlorobiphenyl (3-CBP), monochlorobenzene (MCB) and trichloroethene (TCE) were chosen. Specific catalyst activities up to APd = 200 L g−1 min−1 were measured in clean water. The influence of surfactants and co-solvents was studied. In addition, soil slurry supernatant was employed as reaction medium to appraise the influence of soil co-extractants (dissolved organic matter, DOM) on the dechlorination reaction. Results show that commercially available surfactants such as Tween 80, Triton X-100, SDBS, and CTMAOH as well as methanol as co-solvent with concentrations up to 20 vol% did not strongly affect the catalyst activity. However, the catalyst performance was heavily decreased in the presence of a soil slurry supernatant (40 mg L−1 DOM). Hydrophobic coating of the catalyst by silicone polymers was successful in protecting the Pd sites against ionic catalyst poisons such as DOM and bisulphite for at least 24 h.

Palladium/magnetite nanoparticulate catalysts were developed for efficient elimination of halogenated organic pollutants from contaminated wastewater. Particle recovery from treated water can be ensured via magnetic separation. However, in worst-case scenarios, this catalyst removal step might fail, leading to particle release into the environment. Therefore, a toxicological study was conducted to investigate the impact of both pure magnetite and palladium/magnetite nanoparticle exposure upon human skin (HaCaT) and human colon (CaCo-2) cell lines and a cell line from rainbow trout gills (RTgill-W1). To quantify cell viability after particle exposure, three endpoints were examined for all tested cell lines. Additionally, the formation of reactive oxygen species was studied for the human cells. The results showed only minor effects of the particles on the tested cell systems and support the assumption that palladium/magnetite nano-catalysts can be implemented for a new wastewater treatment technology in which advantageous catalyst properties outweigh the risks.

Palladium catalysts can be used for the selective removal of halogenated organic compounds from aqueous waste via hydrodehalogenation reactions in the presence of other omnipresent constituents of industrial wastewaters. This detoxification of the water and drastic lowering of the AOX value (adsorbable organically bound halogens) can prevent the need for further cost-intensive treatment or discharge into waste incineration plants. Often, the water can then be released to municipal sewage plants. The present paper deals with a highly active, magnetically re-extractable nanoscale Pd-on-magnetite catalyst (Pd/Fe3O4) which has been developed for application in wastewater treatment processes. The study provides insight into the performance of this catalyst and gives information about its general applicability under wastewater conditions and its sensitivity towards constituents of a wastewater matrix. The catalyst can tolerate various inorganic and organic substances in relevant concentrations. Wastewaters containing a high background concentration of organic solvents can also be cleaned from halogenated pollutants. However, waters which contain heavy metals such as lead or mercury or reduced sulphur species such as sulphides need specific pre-treatments prior to Pd-catalysed hydrodehalogenation.

Pd-based catalysts have become important in environmental catalysis for their ability to hydrodechlorinate a wide range of chlorinated organic contaminants in water under ambient conditions. The success of their application in the remediation practice, e.g. for groundwater treatment, is often hindered by the sensitivity of Pd to poisoning by sulphur compounds. In this study, the stability and sulphide-induced deactivation behaviour of a highly active Pd/Al2O3 catalyst was investigated. The specific activity of Pd for the hydrodechlorination of chlorobenzene corresponds to rate coefficients up to kPd = 350 L g−1 min−1. The totally deactivated catalyst, resultant of sulphide poisoning, was regenerated with potassium permanganate. The pH value, as a key parameter which may influence the degree of deactivation as well as the efficiency of catalyst regeneration, was evaluated. Results show that in clean water the Pd/Al2O3 catalyst showed no inherent deactivation regardless of the ageing time and the pH value of the catalyst suspension. The degree of catalyst poisoning effected by 1.8–5.4 μM sulphide, corresponding to molar ratios of S:Pdsurface = 1.5–8.5, was observed to be higher under neutral and alkaline than under acidic conditions. The exposure of the catalyst to higher sulphide concentration of 14.2 μM resulted in complete catalyst deactivation regardless of the pH conditions. However, the efficacy of permanganate as oxidative regenerant for the fouled catalyst showed strong pH-dependence. A regeneration time of 10–30 min at low pH was sufficient to recover completely the high catalytic activity of Pd/Al2O3 for the hydrodechlorination reaction.

Phylogenetic analyses of cellulose synthase (CesA) and cellulose synthase-like (Csl) families from the cellulose synthase gene superfamily were used to reconstruct their evolutionary origins and selection histories. Counterintuitively, genes encoding primary cell wall CesAs have undergone extensive expansion and diversification following an ancestral duplication from a secondary cell wall-associated CesA. Selection pressure across entire CesA and Csl clades appears to be low, but this conceals considerable variation within individual clades. Genes in the CslF clade are of particular interest because some mediate the synthesis of (1,3;1,4)-β-glucan, a polysaccharide characteristic of the evolutionarily successful grasses that is not widely distributed elsewhere in the plant kingdom. The phylogeny suggests that duplication of either CslF6 and/or CslF7 produced the ancestor of a highly conserved cluster of CslF genes that remain located in syntenic regions of all the grass genomes examined. A CslF6-specific insert encoding approximately 55 amino acid residues has subsequently been incorporated into the gene, or possibly lost from other CslFs, and the CslF7 clade has undergone a significant long-term shift in selection pressure. Homology modeling and molecular dynamics of the CslF6 protein were used to define the three-dimensional dispositions of individual amino acids that are subject to strong ongoing selection, together with the position of the conserved 55-amino acid insert that is known to influence the amounts and fine structures of (1,3;1,4)-β-glucans synthesized. These wall polysaccharides are attracting renewed interest because of their central roles as sources of dietary fiber in human health and for the generation of renewable liquid biofuels.

Hydrodehalogenation using Pd catalysts has proved to be an efficient reaction for water detoxification. In the present study, reaction rates for a variety of halogenated hydrocarbons with hydrogen as reductant in aqueous catalyst suspensions have been measured. Structure–reactivity considerations allow the prediction of reactivities of various halogenated organic compounds in water clean-up processes. The correlation of C Cl bond strength with the hydrodechlorination rate earlier reported was reassessed. In contrast to straightforward structure–reactivity correlations found for chloroalkanes, hydrodehalogenation rates of chloroethenes and halobenzenes do not follow the order of the C X bond strength. Here, the addition of an activated hydrogen species from the catalyst to the unsaturated hydrocarbon seems to be the rate-determining step. For pollutant mixtures, hydrodehalogenation rates were influenced by competition for Pd surface sites. Competitors diminish reaction rates depending on their sorption strength towards the Pd surface. Substances subject to extremely slow hydrodehalogenation (such as methylene chloride and fluorobenzene) showed no marked influence on other competitors. The heavier halogens, bromine and iodine (whether as R–X or as X−), dominate all competing effects. However, no self-poisoning of the catalyst for hydrodehalogenation of iodo- and bromohydrocarbons occurred in the water phase. This makes it possible to reduce these halogenated compounds at reasonable rates over Pd catalysts. Under optimal conditions, the activity of Pd catalysts is so high that external and intraparticle mass transfer limitations cannot be ruled out for hydrodehalogenation of many substrates in aqueous catalyst suspensions.

The hydrolysis reaction of 1,1,2,2-tetrachloroethane (TeCA) is significantly enhanced by sorption on activated carbon. TeCA is quantitatively transformed into trichloroethene (TCE) at moderate pH values. This transformation is exploited as the basic step of a site-adapted groundwater-cleanup technology. The volatility of TCE is a factor of 23 higher than that of TeCA such that the partially dehydrochlorinated product can be easily stripped out of the groundwater flow. The base-mediated and the neutral dehydrochlorination of TeCA were studied as a function of temperature and pH value in batch and column experiments. Surprisingly, it was found that despite high loadings of the sorbent with TeCA and TCE (≥20 wt.%) the TeCA remains available for the hydrolysis reaction.

Dehydrochlorination of γ-hexachlorocyclohexane (γ-HCH or lindane) in aqueous solution in the presence of activated carbon (AC) was studied. Hydrolysis of lindane is accelerated in the presence of AC at moderate pH values, which is ascribed to a catalytic effect of the AC in the dehydrochlorination reaction. A novel reaction pathway leading to dichlorobenzenes was found in the presence of AC, whereas the hydrolysis in homogeneous solution stops at the stage of trichlorobenzenes. The contribution of the novel pathway to the overall reaction depends on the pH value. Indications for a slow neutral hydrolysis reaction were found. Conducting the hydrolysis in AC suspension with D 2 O/NaOD, no deuterium was found in the DCB formed, which implies that all hydrogen in the DCB originates from the parent molecule lindane. A hypothesis for the reaction mechanism is proposed.

Formic acid, isopropanol and hydrazine were investigated as reductants for the Pd-catalyzed hydrodechlorination of chlorobenzene in water at ambient temperature. The intention was to find alternatives to molecular hydrogen with high water solubilities. Formic acid was found to be as reactive as H 2 under acidic and neutral conditions, but less reactive under alkaline conditions. The observed kinetics imply two pH-controlled reaction mechanisms (possibly H-atom and hydride transfer). H-consumers, such as chlorinated compounds, strongly stimulate the decomposition of formic acid. The half-life of 5 mg L −1 chlorobenzene in the presence of 1 mg L −1 Pd is about 2 min under optimal reaction conditions. Rh was found to be inactive in the formic acid driven hydrodechlorination. Isopropanol is less reactive by about five orders of magnitude than H 2 . Hydrazine is effective as a H-donor for the hydrodechlorination under alkaline conditions. However, the reaction is slower than with H 2 by a factor of 30. From the technical and economic point of view, formic acid is a promising substitute for H 2 .

Pd/-Al2O3 can be used as a hydrodechlorination catalyst for both the water and the gas phase. A comparison of the catalytic hydrodechlorination of 1,1,2,2-tetrachloroethane (TeCA) in water and in the gas phase at various temperatures with Pd/-Al2O3 revealed Arrhenius parameters identical for the reaction in both phases: ln ( APd (l/(g min))) = 22.8 ± 0.9, EA = 58.0 ± 2.3 kJ/mol. Catalysts are deactivated by sulphur compounds but can be fully regenerated by oxidative treatment at elevated temperatures. A selectivity shift depending on the catalyst deactivation state was observed: unsaturated chlorocompounds react with the highest rate on fresh catalyst, whereas on partially deactivated catalysts saturated compounds such as tetrachloroethane are most rapidly dechlorinated. Apparently, saturated and unsaturated chloroorganic compounds react via different mechanisms. The relative reactivities of the C–Cl and C–Br bonds in bromochloromethane (BCM) are temperature dependent. At a low temperature (100 ◦ C) methyl chloride is the dominant side product, whereas at a higher temperature (200 ◦ C) methyl bromide is preferred. © 2003 Elsevier Science B.V. All rights reserved.

A polymer-based catalytic membrane reactor was developed and applied for hydrodechlorination of chlorobenzene as a model compound of ground and waste water contaminants. The catalytically active membrane consists of a non-porous, thin film (about 3–7 μm) of poly(dimethylsiloxane) (PDMS) loaded with nano-sized Pd clusters. They were built-in either directly or as nano-sized, supported catalysts. A composite membrane, consisting of porous poly(acrylonitrile) (PAN) support and a Pd-loaded thin PDMS film, was fabricated on a coating machine. Defect-free membrane envelopes of 0.1 m 2 were produced and fitted into a membrane test cell. Gaseous hydrogen as reductant for hydrodechlorination is fed from the membrane’s back side directly to the catalyst, embedded in the PDMS layer. The chemical reactions at the Pd surface are accompanied by absorption of chlorobenzene from the water phase into the PDMS layer and desorption of benzene and HCl back to the water phase. The specific activity of supported catalysts decreased only slightly by PDMS incorporation, e.g., from 31 l/g(Pd) min for Pd/Fe on titania to 16 l/g(Pd) min for the same catalyst built-in a 7 μm thick supported PDMS membrane and measured in the membrane test cell. Directly built-in Pd clusters are less active and more difficult to prepare on a larger scale. Some catalyst deactivation was observed and may be balanced by development of more suited nano-sized supported catalysts.

Colloidal activated carbon can be considered as a versatile adsorbent and carrier material for in-situ groundwater remediation. In analogy to other nanoremediation approaches, activated carbon colloids (ACC) can be injected into the subsurface as aqueous suspensions. Deposition of ACC on the sediment creates a sorption barrier against further spreading of hydrophobic pollutants. This study deals with the optimization of ACC and their suspensions with a focus on suspension stability, ACC mobility in saturated porous media and sorption efficiency towards organic contaminants. ACC with an appropriate particle size range (d50 = 0.8 μm) were obtained from a commercial powdered activated carbon product by means of wet-grinding. Among the various methods tested for stabilization of ACC suspensions, addition of humic acid (HA) and carboxymethyl cellulose (CMC) showed the best results. Due to electrosteric stabilization by adsorption of CMC, suspensions remained stable even at high ACC concentrations (11 g L− 1) and conditions typical of very hard water (5 mM divalent cations). Furthermore, CMC-stabilized ACC showed high mobility in a water-saturated sandy sediment column (filter coefficient λ = 0.2 m− 1). Such mobility is a pre-requisite for in-situ installation of sorption or reaction barriers by simple injection-well or direct-push application of ACC suspensions. Column experiments with organic model compounds proved the efficacy of ACC deposits on sediment for contaminant adsorption and retardation under flow-through conditions.

The thermal degradation of poly(lactic acid) (PLA) and poly(β- hydroxybutyric acid) (PHB) was investigated by means of several thermoanalytical methods, including thermogravimetry, differential scanning calorimetry, pyrolysis-MS and pyrolysis-GC-MS. These methods supplied information on the kinetics of the polymer decomposition as well as on the product composition. The analysis of LA-oligomers provided new insights into the stereo-chemistry of the degradation. The results are discussed in view of the known reaction mechanisms for ester pyrolysis. Some of the present results cannot be explained on this basis.

Epoxy resins containing the flame retardant Tetrabromobisphenol A chemically bound to their structures were successfully dehalogenated with Na/NH3 in an autoclave at elevated temperatures. Four loaded printed circuit boards of various origins and one unloaded circuit board were investigated. Debromination efficiencies of solvolysis with ethyl acetate (280°C, 15 MPa) and dehalogenation with Na/NH3 (100°C, 6 MPa) are compared.

In the search for a safe and complete dehalogenation method for environmentally hazardous halogenated hydrocarbons, the reduction with solvated electrons generated by dissolving sodium in liquid ammonia was applied to various organohalogens in solution or sorbed on solid matrices. Polluted materials such as adsorber charcoal, soil, sediments, ashes and even polymers are readily accessible for dehalogenation with sodium in liquid ammonia. This procedure is already well established as a useful preparation tool and overcomes the scientific and technological shortcomings of traditional processes using dispersed sodium. The described method is remarkably effective, fast and distinguished by a high dehalogenation efficiency for a wide variety of halogenated compounds.

Background The potato genome sequence derived from the Solanum tuberosum Group Phureja clone DM1-3 516 R44 provides unparalleled insight into the genome composition and organisation of this important crop. A key class of genes that comprises the vast majority of plant resistance (R) genes contains a nucleotide-binding and leucine-rich repeat domain, and is collectively known as NB-LRRs. Results As part of an effort to accelerate the process of functional R gene isolation, we performed an amino acid motif based search of the annotated potato genome and identified 438 NB-LRR type genes among the ~39,000 potato gene models. Of the predicted genes, 77 contain an N-terminal toll/interleukin 1 receptor (TIR)-like domain, and 107 of the remaining 361 non-TIR genes contain an N-terminal coiled-coil (CC) domain. Physical map positions were established for 370 predicted NB-LRR genes across all 12 potato chromosomes. The majority of NB-LRRs are physically organised within 63 identified clusters, of which 50 are homogeneous in that they contain NB-LRRs derived from a recent common ancestor. Conclusions By establishing the phylogenetic and positional relationship of potato NB-LRRs, our analysis offers significant insight into the evolution of potato R genes. Furthermore, the data provide a blueprint for future efforts to identify and more rapidly clone functional NB-LRR genes from Solanum species.

We carried out a genome-wide analysis of polymorphism (4,596 SNP loci across 190 elite cultivated accessions) chosen to represent the available genetic variation in current elite North West European and North American barley germplasm. Population sub-structure, patterns of diversity and linkage disequilibrium varied considerably across the seven barley chromosomes. Gene-rich and rarely recombining haplotype blocks that may represent up to 60% of the physical length of barley chromosomes extended across the ‘genetic centromeres’. By positioning 2,132 bi-parentally mapped SNP markers with minimum allele frequencies higher than 0.10 by association mapping, 87.3% were located to within 5 cM of their original genetic map position. We show that at this current marker density genetically diverse populations of relatively small size are sufficient to fine map simple traits, providing they are not strongly stratified within the sample, fall outside the genetic centromeres and population sub-structure is effectively controlled in the analysis. Our results have important implications for association mapping, positional cloning, physical mapping and practical plant breeding in barley and other major world cereals including wheat and rye that exhibit comparable genome and genetic features. Electronic supplementary material The online version of this article (doi:10.1007/s00122-010-1466-7) contains supplementary material, which is available to authorized users.

Palladium-catalyzed hydrodechlorination is a promising alternative for the treatment of environmentally relevant water bodies, such as groundwater, contaminated with chlorinated organic compounds (COCs). In the aqueous phase hydrodechlorination of COCs, Pd-based catalysts were found to have a very high catalytic activity. However, the full utilization of the catalyst-s potential is impeded by the sensitivity of the catalyst to poisoning and deactivation induced by reduced sulfur compounds (e.g. sulfides). Several regenerants have been tested before to recover the performance of sulfide-fouled Pd catalyst. But these only delivered partial success with respect to re-establishment of the catalyst activity. In this study, the deactivation behaviour of Pd/Al2O3 in the presence of sulfide was investigated. Subsequent to total deactivation the catalyst was regenerated in the aqueous phase using potassium permanganate. Under neutral pH condition, oxidative regeneration with permanganate delivered a slow recovery of catalyst activity. However, changing the pH of the bulk solution to acidic resulted in the complete recovery of catalyst activity within a regeneration time of about half an hour. These findings suggest the superiority of permanganate as regenerant in re-activating Pd/Al2O3 by oxidizing Pd-bound sulfide., {"references":["Lowry, G. V.; Reinhard, M. Hydrodehalogenation of 1- to 3-carbon\nhalogenated organic compounds in water using a palladium catalyst and\nhydrogen gas. Environ. Sci. Technol. 1999, 33, 1905-1910.","Schueth, C.; Reinhard, M. Hydrodechlorination and hydrogenation of\naromatic compounds over palladium on alumina in hydrogen-saturated\nwater. Appl. Catal. B 1998, 18, 215-221.","Fritsch, D.; Kuhr, K.; Mackenzie, K.; Kopinke, F.-D.\nHydrodechlorination of chloroorganic compounds in ground water by\npalladium catalysts: Part 1. Development of polymer-based catalysts and\nmembrane reactor tests. Catal. Today 2003, 82, 105-118.","Schueth, C.; Disser S.; Schueth F.; Reinhard M. Tailoring catalysts for\nhydrodechlorinating chlorinated hydrocarbon contaminants in\ngroundwater. Appl. Catal. B 2000, 28, 147-152.","Angeles-Wedler, D.; Mackenzie, K.; Kopinke, F.-D. Permanganate\noxidation of sulfur compounds to prevent poisoning of Pd catalysts in\nwater treatment processes. Environ. Sci. Technol. in press.","Chaplin, B. P.; Shapley J. R.; Werth C. J. Regeneration of sulfur-fouled\nbimetallic Pd-based catalysts. Environ. Sci. Technol. 2007, 41, 5491-\n5497.","Lowry, G. V.; Reinhard M. Pd-Catalyzed TCE dechlorination in\ngroundwater: Solute effects, biological control, and oxidative catalyst\nregeneration. Environ. Sci. Technol. 2000, 34, 3217-3223.","Kopinke, F.-D.; Mackenzie K.; Koehler R. Catalytic\nhydrodechlorination of groundwater contaminants in water and in the\ngas phase using Pd/╬│-Al2O3. Appl. Catal. B 2003, 44, 15-24.","Yu, T. C.; Shaw, H. The effect of sulfur poisoning on methane oxidation\nover palladium supported on g-alumina catalysts. Appl. Catal. B 1998,\n18, 105-114.\n[10] Jones, J. M.; Dupont, V. A.; Brydson, R.; Fullerton, D. J.; Nasri, N. S.;\nRoss, A. B.; Westwood, A. V. K. Sulphur poisoning and regeneration of\nprecious metal catalysed methane combustion. Catal. Today 2003, 81,\n589-601."]}

Fluorescence recovery after photobleaching (FRAP) was used to study the mechanism by which fluorescent-protein-tagged movement protein (MP) of tobacco mosaic virus (TMV) is targeted to plasmodesmata (PD). The data show that fluorescence recovery in PD at the leading edge of an infection requires elements of the cortical actin/endoplasmic reticulum (ER) network and can occur in the absence of an intact microtubule (MT) cytoskeleton. Inhibitors of the actin cytoskeleton (latrunculin and cytochalasin) significantly inhibited MP targeting, while MT inhibitors (colchicine and oryzalin) did not. Application of sodium azide to infected cells implicated an active component of MP transfer to PD. Treatment of cells with Brefeldin A (BFA) at a concentration that caused reabsorption of the Golgi bodies into the ER (precluding secretion of viral MP) had no effect on MP targeting, while disruption of the cortical ER with higher concentrations of BFA caused significant inhibition. Our results support a model of TMV MP function in which targeting of MP to PD during infection is mediated by the actin/ER network.

Genomewide association studies depend on the extent of linkage disequilibrium (LD), the number and distribution of markers, and the underlying structure in populations under study. Outbreeding species generally exhibit limited LD, and consequently, a very large number of markers are required for effective whole-genome association genetic scans. In contrast, several of the world's major food crops are self-fertilizing inbreeding species with narrow genetic bases and theoretically extensive LD. Together these are predicted to result in a combination of low resolution and a high frequency of spurious associations in LD-based studies. However, inbred elite plant varieties represent a unique human-induced pseudooutbreeding population that has been subjected to strong selection for advantageous alleles. By assaying 1,524 genomewide SNPs we demonstrate that, after accounting for population substructure, the level of LD exhibited in elite northwest European barley, a typical inbred cereal crop, can be effectively exploited to map traits by using whole-genome association scans with several hundred to thousands of biallelic SNPs.