Non-selective Process Research Articles

Non-selective and Selective Processing in Human Visual Search

Event Abstract Back to Event Non-selective and Selective Processing in Human Visual Search Karla K. Evans1, 2* 1 Harvard Medical School, United States 2 Brigham and Women's Hospital, United States Human’s ability to understand complex visual scenes and effectively find visual targets involves rapid assessment of “gist” of the image as well as scrutiny of the image details. When humans search for visual targets in a complex scene it is thought that they engage two types of processing (non-selective and selective processing)(Wolfe et al., 2011, Evans et al., 2011) that involve deployment of two types of spatial attention (distributed and focused) (Treisman, 2006, Chong & Evans, 2011). I will describe two very relevant phenomenon that affect and guide human visual search in real world scenes involving the two types of processing. One part of the research investigating non-selective processing will show that initial gist processing is based on extraction by the observers of global structural and statistical regularities automatically and flexibly during the first 20-250 milliseconds of visual search. The second part of research investigating selective processing will demonstrate a critical role of visual target prevalence on real world searches such as medical screening. In hard visual search tasks that are performed every day in the clinic we find greatly elevated miss errors at low prevalence as compared to lower miss errors when then target appears at least 50% of the time (“high prevalence”). These results indicate that the low prevalence of disease is actually an important contributor to missed detection of cancer in medical screening. This prevalence effect is adaptive in most real world settings, where an observer should be reluctant to assert that she has found a very rare target. Acknowledgements This research was funded by Ruth L. Kirschstein National Research Service Award Grant F32EY019819-01 to Karla K. Evans. Keywords: Attention, non-selective processing, Prevalence, scene categorization, selective processing, visual search Conference: Tenth International Congress of Neuroethology, College Park. Maryland USA, United States, 5 Aug - 10 Aug, 2012. Presentation Type: Invited Symposium (only for people who have been invited to a particular symposium) Topic: Sensory: Vision Citation: Evans KK (2012). Non-selective and Selective Processing in Human Visual Search. Conference Abstract: Tenth International Congress of Neuroethology. doi: 10.3389/conf.fnbeh.2012.27.00015 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 03 Apr 2012; Published Online: 07 Jul 2012. * Correspondence: Dr. Karla K Evans, Harvard Medical School, Cambridge, Massachusetts, 02139, United States, karla.evans@york.ac.uk Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Karla K Evans Google Karla K Evans Google Scholar Karla K Evans PubMed Karla K Evans Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Selective Types of Autophagy

The focus of this special issue of the International Journal of Cell Biology is to underscore the recent developments in the field of macroautophagy and how this degradative pathway intersects with cellular metabolism, complex physiological functions, and human diseases. During the last decade, autophagy has become an expanding field in biomedical life sciences due to its involvement with numerous intracellular processes. Autophagy also plays a role in pathology, and it has the therapeutic potential to be the target for the treatment of specific human diseases. Early studies suggested that autophagy was a nonselective process in which cytoplasmic structures were randomly sequestered into autophagosomes before being delivered to the mammalian lysosome or the plant and yeast vacuole for degradation. Now there is growing evidence that unwanted cellular structures can be selectively recognized and exclusively eliminated within cells (F. Reggiori et al., “Selective types of autophagy”). This is achieved through the action of specific autophagy receptors, as reviewed by C. Behrends and S. Fulda in “Receptor proteins in selective autophagy”) and studied by K. Marchbank et al. “MAP1B interaction with the FW domain of the autophagic receptor Nbr1 facilitates its association to the microtubule network”. Thus excess or damaged organelles including mitochondria (A. May et al., “The many faces of mitochondrial autophagy: making sense of contrasting observations in recent research”; Y. Hirota et al., “The physiological role of mitophagy: new insights into phosphorylation events”), peroxisomes (A. Till et al., “Pexophagy: the selective degradation of peroxisomes”), lipid droplets (R. Singh and A. Cuervo, “Lipophagy: connecting autophagy and lipid metabolism”), endoplasmic reticulum and ribosomes (E. Cebollero et al., “Reticulophagy and ribophagy: regulated degradation of protein production factories”) can be specifically sequestered by autophagosomes and targeted to the lysosome for degradation. Importantly, there is growing evidence that selective autophagy subtypes also have a wide range of physiological functions. In yeast, the cytosol-to-vacuole (Cvt) pathway transports hydrolases into the vacuole, which is reviewed by M. Umekawa and D. Klionsky in “The cytoplasm-to-vacuole targeting pathway: a historical perspective”. In eukaryotes, autophagy plays a central role in both innate and acquired immunity. Further sequestration and elimination of invading pathogens such as Salmonella and Staphylococcus aureus have been exploited to study autophagosome biogenesis (T. Noda et al., “Three-axis model for Atg recruitment in autophagy against Salmonella”; M. Mauthe et al., “WIPI-1 positive autophagosome-like vesicles entrap pathogenic Staphylococcus aureus for lysosomal degradation”). In pancreas cells, autophagy has recently been shown to specifically turn over secretory granules, as described by M. Vaccaro in “Zymophagy: selective autophagy of secretory granules”. Dysregulation of autophagic function has been implicated in a growing list of disease processes and has underscored the selective or substrate-specific versions of the pathway. Examples in this special issue include the clearance of aggregates associated with neurological diseases, as reviewed by T. Lamark and T. Johansen in “Aggrephagy: selective disposal of protein aggregates by macroautophagy” and by I. Nezis in “Selective autophagy in Drosophila”. In terms of cancer biology, autophagy has been viewed as having dual roles in both tumor suppression and progression. K. Hughson et al. in “Implications of therapy-induced selective autophagy on tumor metabolism and survival” review how activation of autophagy selective forms can be used as a potential therapeutic approach for the treatment of specific cancers. Adding to the complexity of autophagic function and regulation, the article by K. Juenemann and E. Reits “Alternative macroautophagic pathways” explores alternative macroautophagic pathways that are independent of key core autophagy components such as Beclin-1 or Atg5. We expect future research on the mechanism and regulation of selective autophagy, and the physiological importance of this pathway in human disease will be very exciting and expand on the findings highlighted in this issue of IJCB. Fulvio Reggiori Maasaki Komatsu Kim Finley Anne Simonsen

Strategy for focused ion beam compound material removal for circuit editing

Both selective and nonselective focused ion beam (FIB) processes have become critical for enabling fine-scale activities such as nano-machining and nano-fabrication in compound material removal applications. In this paper, we investigate the influence of FIB ion acceleration voltage on gas assisted etch rates for the most frequently used materials in the microelectronic industry, using common FIB etchants. These results can serve as a baseline for FIB process development using various materials for both highly-selective and (almost) nonselective material removal. Etching strategies are suggested. Two test cases are presented here, in which we performed either selective or nonselective material removal processes. The etch rate of different materials was found to be dependent on acceleration voltage, and very specific to the material-precursor system.

Origins of Non-Selective Ion Transport across Lipid Bilayers

The theoretical description of charge transport across biological membranes has remained largely unchanged since the 1960's. However, it is widely accepted that the barriers for unassisted ion permeation via a solubility-diffusion mechanism are too high, and too selective to explain experimental observations, leading to a favoring of a non-selective transient pore process. We demonstrate that an ion-induced defect mechanism, intermediate between these two processes, can yield reduced free energy barriers with little influence of hydration free energy or the membrane dipole potential. We report experimental and computational data for a range of alkali metal, halide and charged amino acid analog molecules. Our simulations reveal that membrane perturbations are central in explaining the shape and magnitude of the free energy barriers, the similarity for ions of different size, charge and chemistry, and for obtaining fluxes consistent with experiment. We will discuss results that suggest a transition from ion-induced defect to the solubility-diffusion mechanism in thicker bilayers, and for larger hydrophobic ions and ionophores. We explore the deformable membrane description to predict a greater common energetics for a range of ions, poly-ions and zwitterions and discuss the consequences for membrane interactions with charged peptides and proteins, and the roles of lipid components in membrane ion transport.

Recent progress on metal core@semiconductor shell nanocomposites as a promising type of photocatalyst

The creation of core-shell nanocomposites (CSNs) has attracted considerable attention and developed into an increasingly important research area at the frontier of advanced materials chemistry. CSNs, which are nanoscaled assemblies with a chemical composition that is different on the surface compared to the core region, have found versatile applications in many fields, such as electrooptics, quantum dots, microscopy labels, drug delivery, chemical sensors, nanoreactors and catalysis. This review is primarily focused on the applications of metal core@semiconductor shell nanocomposites in heterogeneous photocatalysis, including photocatalytic nonselective processes for environmental remediation, selective organic transformations to fine chemicals and water splitting to clean hydrogen energy. It is hoped that this minireview can inspire multidisciplinary research interest in the precisely morphology-controlled synthesis of a variety of metal core@semiconductor shell nanoassemblies and their wide applications in the realm of heterogeneous photocatalysis.

Recent progress on graphene-based photocatalysts: current status and future perspectives

Graphene (GR) has become a sparkling rising star on the horizon of material science. Due to its unique planar structure, excellent transparency, superior electron conductivity and mobility, high specific surface area, and high chemical stability, GR is regarded as an ideal high performance candidate to prepare GR-based nanocomposites for energy storage and conversion. During the past few years, GR-based photocatalysts have been attracting ever-increasing research attention. In this tutorial review, the applications of GR-based nanocomposites in photocatalysis, including nonselective processes for degradation of pollutants, selective transformations for organic synthesis and water splitting to clean hydrogen energy, are summarized systematically. In particular, in addition to discussing opportunities offered by GR, we will also describe the existing challenges for future exploitation and development of GR-based nanocomposites, which we hope would significantly advance us to rationally and efficiently harness the outstanding structural and electronic properties of GR to design smarter and more efficient GR-based photocatalysts instead of joining the graphene "gold rush".

Low temperature catalyst enhanced etch process with high etch rate selectivity for amorphous silicon based alloys over single-crystalline silicon based alloys

We present a catalyst enhanced etch process with high etch rates for amorphous Si based alloys (e.g. α-Si, α-Si:C, α-Si:P, α-SiCP) and low etch rates for crystalline Si (e.g. c-Si, c-Si:C, c-Si:P, c-SiCP) with etch rate ratios up to ~200. The addition of a suitable surface catalyst such as Ge (e.g. from GeH4) during HCl based etch processes increases both, the etch rate of amorphous Si alloys and the etch rate selectivity against c-Si alloys. The Ge source dynamically forms a SiGe surface layer during the etch process. Ge penetrates fast into α-Si through diffusion, forming an α-SiGe film with high [Ge] concentration. Ge diffusion into c-Si however is very limited; a rather slow surface-sub-surface exchange reaction (segregation) causes a penetration depth of only one monolayer. Repeated cycles of a selective chemical vapor etch process following a non-selective deposition process enable effective selective epitaxial growth.

Microautophagy: lesser-known self-eating

Microautophagy, the non-selective lysosomal degradative process, involves direct engulfment of cytoplasmic cargo at a boundary membrane by autophagic tubes, which mediate both invagination and vesicle scission into the lumen. With its constitutive characteristics, microautophagy of soluble substrates can be induced by nitrogen starvation or rapamycin via regulatory signaling complex pathways. The maintenance of organellar size, membrane homeostasis, and cell survival under nitrogen restriction are the main functions of microautophagy. In addition, microautophagy is coordinated with and complements macroautophagy, chaperone-mediated autophagy, and other self-eating pathways. Three forms of selective microautophagy, including micropexophagy, piecemeal microautophagy of the nucleus, and micromitophagy, share common ground with microautophagy to some degree. As the accumulation of experimental data, the precise mechanisms that govern microautophagy are becoming more appreciated. Here, we review the microautophagic molecular machinery, its physiological functions, and relevance to human diseases, especially in diseases involving multivesicular bodies and multivesicular lysosomes.

Architecture of source-drain cavity of a p-channel field effect transistor for embedding with epitaxial SiGe for enhanced performance

Increase in power consumption in field effect transistors has been curtailed in recent years by introduction of mechanical stress to achieve device speed gain over and above the traditional speed vs. power tradeoffs achieved only by scaling gate lengths. Increasingly, the source-drain region of p-channel field effect transistors are etched and epitaxial SiGe re-grown in the cavity to enhance hole mobility. However, the addition of stress as a method to improve performance would add to the process variability beyond the traditional source of lithography, now related to structure and dimension of the cavity and composition of SiGe. In this paper, compressive stress induced in the channel was directly measured using synchrotron x-ray diffraction. The samples were a set of gratings designed to map the transistor performance with varying design space. The x-ray beam was systematically stepped across the gratings at an interval of 200 nm and diffraction data collected to assess the extent of stress field. Diffraction space maps were created around the symmetric (004) and asymmetric (115) planes. Strain was deduced from Si peak shift and stress calculated from the Si elastic constants. Diffraction space maps around the asymmetric plane were used to deduce the mechanism and subsequent relaxation of strain. Diffraction data collected with x-ray beam placement close to the Si-SiGe vertical interface provided information from lateral SiGe epitaxy on the (110) plane. The presence of strained SiGe peak exhibiting tilt as well as “relaxed” SiGe peak surrounded by diffuse scattering due to dislocations were observed. The use of non-selective etch process resulted in cavity formation with multiple crystallographic planes. The subsequent relaxation mechanism that was dependent on the formation of misfit dislocations was perturbed, possibly due to pinning of the dislocations at the intersection of two crystallographic planes and served as the source of variability. Measured stress variation from 90 to 220 MPa was seen that resulted in estimated drive current enhancement variability from 5% to 15%. The maximum strain was seen where the SiGe film saw no relaxation and the energy formed due to hetero-epitaxy was transferred elastically as channel stress. The elastic relaxation was also accompanied by formation of tilted boundary. Based on these findings, the design of an ideal cavity that would maximize strain and minimize variability with layout was proposed.

Geographic distribution of genetic variation among native and introduced populations of Chinese tallow tree, Triadica sebifera (Euphorbiaceae)

Invasive plants often display genetically determined variation in patterns of growth and resource allocation between native and introduced genotypes, as well as among genotypes within different regions of the introduced range. We examined patterns of genetic variation within and among native and introduced populations of the tetraploid Chinese tallow tree (Triadica sebifera, Euphorbiaceae) to determine whether nonselective evolutionary processes or the introduction history could contribute to previously observed phenotypic differences between native and introduced populations as well as among introduced populations. We used six microsatellite markers to study 12 native populations in China, 51 introduced populations in the southeastern USA, and one introduced population in Australia. Genetic diversity was greater within and among native populations than introduced populations. Within the southeastern USA, populations in Georgia and South Carolina differed substantially in their genetic composition and had greater genetic diversity than the rest of the southeastern USA. Greater genetic similarity between some populations in the native range and introduced range indicate a common provenance for Georgia and South Carolina populations that could have come from any of several western or southern Chinese populations and a different provenance for other southeastern USA populations and the Australian population, which were most similar to more northeastern Chinese populations. Differences among introduced populations in potentially adaptive traits (e.g., herbivore tolerance, herbivore resistance, growth rates) may result in part from the introduction history, in particular from differences present among source populations in the native range.

Natural selection drives clinal life history patterns in the perennial sunflower species, Helianthus maximiliani

In plants, ecologically important life history traits often display clinal patterns of population divergence. Such patterns can provide strong evidence for spatially varying selection across environmental gradients but also may result from nonselective processes, such as genetic drift, population bottlenecks and spatially restricted gene flow. Comparison of population differentiation in quantitative traits (measured as Q(ST) ) with neutral molecular markers (measured as F(ST) ) provides a useful tool for understanding the relative importance of adaptive and nonadaptive processes in the formation and maintenance of clinal variation. Here, we demonstrate the existence of geographic variation in key life history traits in the diploid perennial sunflower species Helianthus maximiliani across a broad latitudinal transect in North America. Strong population differentiation was found for days to flowering, growth rate and multiple size-related traits. Differentiation in these traits greatly exceeds neutral predictions, as determined both by partial Mantel tests and by comparisons of global Q(ST) values with theoretical F(ST) distributions. These findings indicate that clinal variation in these life history traits likely results from local adaptation driven by spatially heterogeneous environments.

Beyond the Memory Mechanism: Person-selective and Nonselective Processes in Recognition of Personally Familiar Faces

Special processes recruited during the recognition of personally familiar people have been assumed to reflect the rich episodic and semantic information that selectively represents each person. However, the processes may also include person nonselective ones, which may require interpretation in terms beyond the memory mechanism. To examine this possibility, we assessed decrease in differential activation during the second presentation of an identical face (repetition suppression) as an index of person selectivity. During fMRI, pictures of personally familiar, famous, and unfamiliar faces were presented to healthy subjects who performed a familiarity judgment. Each face was presented once in the first half of the experiment and again in the second half. The right inferior temporal and left inferior frontal gyri were activated during the recognition of both types of familiar faces initially, and this activation was suppressed with repetition. Among preferentially activated regions for personally familiar over famous faces, robust suppression in differential activation was exhibited in the bilateral medial and anterior temporal structures, left amygdala, and right posterior STS, all of which are known to process episodic and semantic information. On the other hand, suppression was minimal in the posterior cingulate, medial prefrontal, right inferior frontal, and intraparietal regions, some of which were implicated in social cognition and cognitive control. Thus, the recognition of personally familiar people is characterized not only by person-selective representation but also by nonselective processes requiring a research framework beyond the memory mechanism, such as a social adaptive response.

Surface Photochemistry: on the Search of Efficient Photodegradation Methods for Indigo Dyes Through Advanced Oxidative Processes

PP-29-115 Background/Aims: Immobilization of TiO2 layers on glass and Modified Fenton test of the effect of advance oxidative processes on photocatalytic degradation of indigo blue. Particularly TiO2 photocatalysis and Fenton are known for being nonselective processes able to mineralize recalcitrant chemicals. Methods: A TiO2 emulsion was prepared, mixing 12 g TiO2, 4 mL H2O and 0.4 mL acethylketone for 10 minutes. Then, 25 mL H2O and 0.2 mL Triton X-100 were added. After proving that TiO2 deposited on glass effectively enhances the photodegradation of adsorbed indigo, we test various continuous flow and batch reactors, with and without TiO2 adsorbed on internal reactor wall, using different irradiation sources. Modified Fenton approaches are also being tested. Results: TiO2-coated glass enhances photodegradation of adsorbed indigo and dye absorption totally disappears after 6 hours irradiation with 125 watts Hg lamp; approximately 40% of color disappears in the first 1 hour. We tested continuous flow and batch reactors also on treatment of dye liquid streams (with or without TiO2 on internal reactor wall) using lamps. In TiO2 absence, there is no indigo degradation. Irrespective reactor or irradiation source used, very low % of degradations (<10%) with TiO2 introduction in the system. Fenton-based processes gave more promising results, with more than 50% color removed in about 0.5 hour. The problem of iron residue removal remains to be solved. Conclusion: To date, only Fenton-based methodologies seem to be able to remove the indigo blue color from those model waters.

Development of a Production Worthy Non-Selective Slurry W-CMP for Logic Applications at 28nm Technology Node and Beyond

In this paper, the electrical failure is analyzed in failure map of 28nm logic pattern wafer. As CD shrinks to 28nm and beyond, the contact metallization face poor gap fill of tungsten and low process win tolerance, is like erosion and within-wafer uniformity. The poor interconnection between metal copper via and contact tungsten via of failure include metal1 (M1) Cu bridge and metal1 open. The M1 bridge is induced by large erosion at high contact via density. Another M1 open is induced by W recess at iso via. A novel non-selective slurry buff process provide non-selective removal speciality and splendid uniformity to reduce erosion and recess, are less than 50A to meet 28nm technology node and beyond.

Particle selection by the sea lily Metacrinus rotundus Carpenter 1884 (Echinodermata, Crinoidea)

Crinoids feed on particles less than 1 mm in diameter and are regarded as passive suspension feeders. Previous studies on crinoid gut contents have revealed that crinoids catch a variety of particles, including biotic crusts (e.g. algal filament, sponge spiracle, crustacean appendage), unicellular organisms, detritus, and inorganic grains, and transport them to their intestines, suggesting that feeding is a nonselective process. In this study, we quantitatively examined the gut contents of the stalked crinoid Metacrinus rotundus and assessed whether preferential particle selection was occurring. Crinoid individuals were held in an aquarium and provided with a model food consisting of a mixture of glass beads (to mimic sand particles) in two different sizes, phytoplankton cells (approximately 30 μm), and copepods (approximately 300 μm to 2 mm). M. rotundus took both organic and inorganic particles, but phytoplankton cells were taken in larger numbers than other particles. Our results showed that crinoids selectively took phytoplankton, followed by copepods and glass beads. The ancestor of echinoderms is presumed to have been a sessile filter feeder, and therefore the crinoid food selection process has most likely been maintained since its early Paleozoic ancestors. Because passive suspension feeders filter a smaller volume of seawater per unit time compared to active suspension feeders and because organic matter generally decreases with depth, food selectivity is a key function for passive suspension feeders living in deeper water.

ChemInform Abstract: Chelation-Controlled, Palladium-Catalyzed Vinylic Substitution Reactions of Vinyl Ethers. 2-Arylethanal Equivalents from Aryl Halides.

The regioselectivity of palladium-catalyzed arylation reactions of a series of nitrogen-containing vinyl ethers is reported. The presence of a β-amino substituent gives a profound influence on regiochemistry. Thus, the arylation of [2-(dimethylamino)ethoxy]ethene (1c) with a variety of aryl iodides and bromides provides the β-arylation products [2-[2-(dimethylamino)ethoxy]ethenyl]arenes (3) with at least 95% selectivity and in good yields. The corresponding arylation of butoxyethene is a nonselective process giving a mixture of α- and β-substitution products. The palladium-catalyzed arylation of 1c constitutes an entry to 2-arylethanals after cleavage of the enol ether. The directing effect of the amino group is discussed in terms of chelation with the intermediate arylpalladium halide

When the animal destroys the beach, the beach destroys the animal. Mutually assured destruction in gist processing

Observers can report some semantic content of scenes when those scenes are presented for 20 msec, flanked in time by masks. It is likely that only a single object could be selected for attentional processing in this time so this gist processing would seem to involve non-selective processing of the entire image. Similarly, we find that expert observers (radiologists and cytopathologists) can detect subtle signs of cancer at above chance levels in 250 msec exposures of mammograms and Pap-smears. These exposures are unmasked but still preclude normal extended attentional scrutiny. Can multiple gist’s be computed concurrently? Last year, we demonstrated limits on this ability. We cued observers with one of nine target categories (e.g. beach, animal, bridge) before presenting a masked scene for 20 msec. Targets were present on 50% of trials. Critically, on half of target present trials, an un-cued target category was also present. That is, “beach” would be cued but the scene might include both beach and animal – a “trial-irrelevant”, but “task-relevant” target category. Observers were 76% correct when trials contained only cued targets but only 52% correct when trial-irrelevant targets were also present. Critically, animal would not interfere with beach if it were not a target on other trials in the same block. This year, we show that interference is mutual. On each trial, observers reported on the presence of the target and were also asked if any other categories were present. If observers missed the task-relevant “animal”, they were actually LESS likely to be able to report a task-irrelevant beach. Of course, in real life, if you were looking for your fork and now for your glass, you are not blinded by the presence of both items in the visual field. We find that “mutually assured destruction” occurs for exposures shorter than 200 msec.

Word repetition, masked orthographic priming, and language switching: bilingual studies and BIA+ simulations

Daily conversations contain many repetitions of identical and similar word forms. For bilinguals, the words can even come from the same or different languages. How do such repetitions affect the human word recognition system? The Bilingual Interactive Activation Plus (BIA+) model provides a theoretical and computational framework for understanding word recognition and word repetition in bilinguals. The model assumes that both phenomena involve a language non-selective process that is sensitive to the task context. By means of computer simulations, the model can specify both qualitatively and quantitatively how bilingual lexical processing in one language is affected by the other language. Our review discusses how BIA+ handles cross-linguistic repetition and masked orthographic priming data from two key empirical studies. We show that BIA+ can account for repetition priming effects within- and between-languages through the manipulation of resting-level activations of targets and neighbors (words sharing all but one letter with the target). The model also predicts cross-linguistic performance on within- and between-trial orthographic priming without appealing to conscious strategies or task schema competition as an explanation. At the end of the paper, we briefly evaluate the model and indicate future developments.

Biocatalytic dechlorination of hexachlorocyclohexane by immobilized bio-Pd in a pilot scale fluidized bed reactor

Lindane (γ-hexachlorocyclohexane, γ-HCH) is a recalcitrant and toxic organochlorine insecticide. Due to its non-selective production process and widespread use, HCH isomers and their degradation products have been detected frequently in soils and groundwater. An innovative technology using microbial produced Pd(0) nanoparticles, i.e. bio-Pd, was developed to treat groundwater containing a mixture of HCHs and chlorobenzenes. In a first step, the groundwater was de-ironized and most of the chlorobenzenes were removed in a biological trickling filter. The μg L−1 levels of HCHs and chlorobenzenes were removed in a second step by the bio-Pd-based technology. Therefore, a 200-L pilot scale reactor was developed with 100 mg L−1 bio-Pd encapsulated in alginate beads. Hydrogen gas was bubbled at the bottom of the reactor and served to charge the bio-Pd catalyst. The reactor influent contained 5.2 μg L−1 HCHs and 51.1 μg L−1 chlorobenzenes. During a test period of 10 days, 29% of the HCH isomers and 63% of the chlorobenzenes were removed applying a nominal hydraulic residence time of 4 h. These removal percentages could be increased to 75 and 68% by doubling the nominal hydraulic residence time to 8 h. This study demonstrated that biologically produced nanoparticles of Pd can be applied for the large-scale remediation of groundwater contaminated with HCHs.

Chemo-enzymatic functionalisation of lignocellulose materials using oxiranes

A new non-selective chemo-enzymatic process using oxiranes for functionalisation of lignocellulose materials has been developed. Using a lipase and hydrogen peroxide, soybean oil and linoleic acid were epoxidised resulting in a 52.7% and 92.4% relative conversion to oxirane, respectively. A commercial oxirane, 1,2-epoxyoctane and oxiranes generated from epoxidation of oils (using lipase and hydrogen peroxide) were successfully coupled onto long chain alkylamines while the oxiranes were in turn readily coupled onto phenolic lignin model compounds. Treatment of beech veneers with dodecylamine using this process resulted in a reduction in surface O/C ratio and a 90% increase in hydrophobicity. Since oxiranes react directly with hydroxyl groups and other functional groups this method may provide a new enzymatic non-targeted approach for the functionalisation of various polymeric materials.