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Strong Potential (strong + potential)
Selected AbstractsEmission of legacy chlorinated pesticides from agricultural and orchard soils in British Columbia, CanadaENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 6 2006Terry F. Bidleman Abstract Air samples were collected above agricultural fields in the Fraser Valley and orchards in the Okanagan Valley, British Columbia, Canada, to investigate volatilization of organochlorine pesticides used in the past. Concentrations of pesticides in air were elevated over soils that contained higher residues. Soil/air fugacity ratios at sites with the higher soil residues were calculated relative to air sampled at 40 cm height and background air. The fugacity ratios in the first case indicated net volatilization or soil-air equilibrium for most compounds and occasional net deposition for p,p, -dichlorodiphenyldichloroethene (p,p, -DDE), whereas those in the second case showed a strong potential for net volatilization of all compounds. The enantiomer fraction (EF) of chiral compounds ,-hexachlorocyclohexane (,-HCH), trans -chlordane, cis -chlordane, and o,p, -DDT were determined in overlying air samples and soils. Enantiomer fractions in air corresponded to those in soils at fields in which soil concentrations were high but were decoupled from soil signatures at fields with low soil residues. Mean EFs in air sampled over soils were significantly (p < 0.001) nonracemic for ,-HCH and the chlordanes and agreed with published EFs in regional ambient air. The mean EF of o,p, -DDT for all air samples did not show a significant deviation from racemic EFs (p > 0.2), but EFs of individual samples reflected the ambivalent nature of o,p, -DDT degradation, sometimes preferring the (+) enantiomer and other times the (,) enantiomer. The study indicates that soils are continuing to emit "legacy" pesticides into the regional atmosphere. [source] Size Independent Shape Memory Behavior of Nickel,Titanium,ADVANCED ENGINEERING MATERIALS, Issue 8 2010Blythe G. Clark While shape memory alloys such as NiTi have strong potential as active materials in many small-scale applications, much is still unknown about their shape memory and deformation behavior as size scale is reduced. This paper reports on two sets of experiments which shed light onto an inconsistent body of research regarding the behavior of NiTi at the nano- to microscale. In situ SEM pillar bending experiments directly show that the shape memory behavior of NiTi is still present for pillar diameters as small as 200,nm. Uniaxial pillar compression experiments demonstrate that plasticity of the phase transformation in NiTi is size independent and, in contrast to bulk single crystal observations, is not influenced by heat treatment (i.e., precipitate structure). [source] Plasma microRNAs are promising novel biomarkers for early detection of colorectal cancerINTERNATIONAL JOURNAL OF CANCER, Issue 1 2010Zhaohui Huang Abstract MicroRNA (miRNA) opens up a new field for molecular diagnosis of cancer. However, the role of circulating miRNAs in plasma/serum in cancer diagnosis is not clear. The aim of this study was to investigate whether plasma miRNAs can be used as biomarkers for the early detection of colorectal carcinoma (CRC). We measured the levels of 12 miRNAs (miR-134, ,146a, ,17-3p, ,181d, ,191, ,221, ,222, ,223, ,25, ,29a, ,320a and ,92a) in plasma samples from patients with advanced colorectal neoplasia (carcinomas and advanced adenomas) and healthy controls using real-time RT-PCR. We found that plasma miR-29a and miR-92a have significant diagnostic value for advanced neoplasia. MiR-29a yielded an AUC (the areas under the ROC curve) of 0.844 and miR-92a yielded an AUC of 0.838 in discriminating CRC from controls. More importantly, these 2 miRNAs also could discriminate advanced adenomas from controls and yielded an AUC of 0.769 for miR-29a and 0.749 for miR-92a. Combined ROC analyses using these 2 miRNAs revealed an elevated AUC of 0.883 with 83.0% sensitivity and 84.7% specificity in discriminating CRC, and AUC of 0.773 with 73.0% sensitivity and 79.7% specificity in discriminating advanced adenomas. Collectively, these data suggest that plasma miR-29a and miR-92a have strong potential as novel noninvasive biomarkers for early detection of CRC. [source] Niche overlap between marsupial and eutherian carnivores: does competition threaten the endangered spotted-tailed quoll?JOURNAL OF APPLIED ECOLOGY, Issue 2 2008A. S. Glen Summary 1The significance of top-down regulation by carnivores is receiving increasing global recognition. As a consequence, key objectives in many programmes that seek to maintain ecosystem function now include conserving carnivores and understanding their interactions. This study examined overlap in resource use (space and diet) of introduced eutherian carnivores and an endangered marsupial carnivore, the spotted-tailed quoll Dasyurus maculatus, in eastern Australia. We also investigated mechanisms of niche partitioning and evidence for interspecific aggression. 2Dietary overlap between quolls, red foxes Vulpes vulpes and wild dogs Canis lupus ssp. was assessed by analysis of scats. Trapping, radio-tracking and direct observations were used to quantify spatial overlap between quolls, foxes, wild dogs and feral cats Felis catus. 3Dietary overlap among the carnivores was extensive. Medium-sized mammals were the most important prey for all three predators, indicating potential for exploitative interactions. However, hunting of different size classes of secondary prey and consumption by quolls of more arboreal prey than their counterparts may assist coexistence. Remains of quoll were found in two dog scats, and cat hair in another, possibly indicating intraguild predation. 4We observed extensive spatial overlap between quolls and eutherian carnivores. However, we inferred from dietary data that quolls foraged primarily in forested habitat, while canids foraged mainly in cleared habitat. 5Synthesis and applications. Our results indicate strong potential for competition between spotted-tailed quolls and eutherian carnivores, and thus a situation where control of introduced predators may be desirable, not only for the conservation of prey species but also for the protection of native carnivores. Concern over potential non-target mortality of quolls has hindered efforts to control foxes in eastern Australia using poison baits. We contend that, rather than harming quoll populations, baiting for foxes should aid the conservation of quolls and should be implemented in areas of sympatry where fox numbers are high. [source] Comparative foraging and nutrition of horses and cattle in European wetlandsJOURNAL OF APPLIED ECOLOGY, Issue 1 2002Catherine Menard Summary 1Equids are generalist herbivores that co-exist with bovids of similar body size in many ecosystems. There are two major hypotheses to explain their co-existence, but few comparative data are available to test them. The first postulates that the very different functioning of their digestive tracts leads to fundamentally different patterns of use of grasses of different fibre contents. The second postulates resource partitioning through the use of different plant species. As domestic horses and cattle are used widely in Europe for the management of conservation areas, particularly in wetlands, a good knowledge of their foraging behaviour and comparative nutrition is necessary. 2In this paper we describe resource-use by horses and cattle in complementary studies in two French wetlands. Horses used marshes intensively during the warmer seasons; both species used grasslands intensively throughout the year; cattle used forbs and shrubs much more than horses. Niche breadth was similar and overlap was high (Kulczinski's index 0·58,0·77). Horses spent much more time feeding on short grass than cattle. These results from the two sites indicate strong potential for competition. 3Comparative daily food intake, measured in the field during this study for the first time, was 63% higher in horses (144 gDM kg W,0·75 day,1) than in cattle (88 gDM kg W,0·75 day,1). Digestibility of the cattle diets was a little higher, but daily intake of digestible dry matter (i.e. nutrient extraction) in all seasons was considerably higher in horses (78 gDM kg W,0·75 day,1) than in cattle (51 gDM kg W,0·75 day,1). When food is limiting, horses should outcompete cattle in habitats dominated by grasses because their functional response is steeper; under these circumstances cattle will require an ecological refuge for survival during winter, woodland or shrubland with abundant dicotyledons. 4Horses are a good tool for plant management because they remove more vegetation per unit body weight than cattle, and use the most productive plant communities and plant species (especially graminoids) to a greater extent. They feed closer to the ground, and maintain a mosaic of patches of short and tall grass that contributes to structural diversity at this scale. Cattle use broadleaved plants to a greater extent than horses, and can reduce the rate of encroachment by certain woody species. [source] Creating Mature Thinkers in Interior Design: Pathways of Intellectual DevelopmentJOURNAL OF INTERIOR DESIGN, Issue 3 2010Candy Carmel-Gilfilen M. Arch. Critical thinking skills are essential to meeting the economic, sustainable, and social challenges of the future. The purpose of this study was to explore critical thinking in interior design students using the W. G. Perry (1968) scheme, a model of epistemic cognitive development describing how thinking in college students progresses from black-and-white absolutes to a contextual understanding of knowledge. The authors present findings from a study involving 32 beginning and intermediate interior design students who were empirically assessed on global and design-specific thought development using the Measure of Intellectual Development (Widick & Knefelkamp, 1974) and the Measure of Designing (Portillo, 1987), respectively. The study objectives were to examine thought development in interior design students, investigate the relationship between global and design thinking, and explore relationships between thought development, student performance, and class standing. The results supported three levels of thought development: dualistic, transitional, and multiplistic with overall thinking appeared to be more advanced than thinking in design. The study also revealed both types of thinking significantly related to studio performance and class standing. The Perry model appears to have strong potential for understanding thought development in interior design students. [source] Synergistic routes to liquid fuel for a petroleum-deprived futureAICHE JOURNAL, Issue 7 2009Rakesh Agrawal Abstract When compared with biomass gasification/Fischer-Tropsch synthesis, hydropyrolysis/hydrodeoxygenation (HDO)-based processes have a potential to achieve high biomass carbon conversion to liquid fuel with much lower amounts of supplementary H2. On the basis of this observation, we suggest a Hydrogen Bio-oil (H2Bioil) process using fast hydropyrolysis/HDO that has a potential to produce nearly double the amount of liquid fuel when compared with the existing biofuel processes while requiring only modest quantities of supplementary H2. The optimal operating mode for the H2Bioil process is suggested to be in an entrained bed mode in presence of H2 with gas phase HDO of hydropyrolyzed vapors. A remarkable result due to reduced need for the supplementary H2 is that it provides synergistic integration of the H2Bioil process with a coal gasification power plant or a small scale steam natural gas (NG) reformer leading to a dramatic increase in the liquid fuel production from biomass and coal or NG. Here, hot synthesis gas (T>500°C) from a coal gasifier or methane reformer supplies H2/CO for hydropyrolysis and deoxygenation as well as heat for the process. This result is exciting, because it presents us with an option to build integrated H2Bioil processes sooner rather than later when the cost effective H2 becomes available from a carbon-free energy source such as solar or nuclear. The H2Bioil process and its integrated version with a small scale NG reformer have strong potential to be attractive on a small scale while being more efficient than any current biomass to liquid fuel process in operation. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source] PROPOSAL OF ECTOCARPUS SILICULOSUS (ECTOCARPALES, PHAEOPHYCEAE) AS A MODEL ORGANISM FOR BROWN ALGAL GENETICS AND GENOMICS,JOURNAL OF PHYCOLOGY, Issue 6 2004Akira F. Peters The emergence of model organisms that permit the application of a powerful combination of genomic and genetic approaches has been a major factor underlying the advances that have been made in the past decade in dissecting the molecular basis of a wide range of biological processes. However, the phylogenetic distance separating marine macroalgae from these model organisms, which are mostly from the animal, fungi, and higher plant lineages, limits the latters' applicability to problems specific to macroalgal biology. There is therefore a pressing need to develop similar models for the macroalgae. Here we describe a survey of potential model brown algae in which particular attention was paid to characteristics associated with a strong potential for genomic and genetic analysis, such as a small nuclear genome size, sexuality, and a short life cycle. Flow cytometry of nuclei isolated from zoids showed that species from the Ectocarpales possess smaller haploid genomes (127,290 Mbp) than current models among the Laminariales (580,720 Mbp) and Fucales (1095,1271 Mbp). Species of the Ectocarpales may complete their life histories in as little as 6 weeks in laboratory culture and are amenable to genetic analyses. Based on this study, we propose Ectocarpus siliculosus (Dillwyn) Lyngbye as an optimal choice for a general model organism for the molecular genetics of the brown algae. [source] Review of Urban Stormwater Quality Models: Deterministic, Stochastic, and Hybrid Approaches,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 6 2007Christopher C. Obropta Abstract:, The growing impact of urban stormwater on surface-water quality has illuminated the need for more accurate modeling of stormwater pollution. Water quality based regulation and the movement towards integrated urban water management place a similar demand for improved stormwater quality model predictions. The physical, chemical, and biological processes that affect stormwater quality need to be better understood and simulated, while acknowledging the costs and benefits that such complex modeling entails. This paper reviews three approaches to stormwater quality modeling: deterministic, stochastic, and hybrid. Six deterministic, three stochastic, and three hybrid models are reviewed in detail. Hybrid approaches show strong potential for reducing stormwater quality model prediction error and uncertainty. Improved stormwater quality models will have wide ranging benefits for combined sewer overflow management, total maximum daily load development, best management practice design, land use change impact assessment, water quality trading, and integrated modeling. [source] Infrared detector based on modulation-doped quantum-dot structuresPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 11 2006V. Mitin Abstract We investigate a detector model, where quantum dots are surrounded by potential barriers created by modulation doping. Strong separation of the localized ground states and continuum conducting states drastically increases the photoelectron capture time. At room temperatures the photoelectron capture is conditioned by electron diffusion in the potential relief. Monte-Carlo modeling with diffusion-limited capture in the modulation-doped quantum-dot structures is used to calculate carrier lifetime and photoconductive gain as functions of the electric field. We evaluate the photodetector characteristics and show that photoconductive gain is substantially improved due to longer lifetimes of photoelectrons. Optimized quantum-dot structures have a strong potential for development IR room-temperature detectors. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Epitaxial Growth of AlN Layers on SiC Substrates in a Hot-Wall MOCVD SystemPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 1 2003A. Kakanakova-Georgieva Abstract In this study we report the successful growth of AlN and AlN/GaN on SiC substrates in a MOCVD process based on a hot-wall susceptor design. Different features of AlN growth are established depending on the total reactor pressure, temperature, off-cut SiC substrate orientation and V-to-III gas-flow ratio. The feasibility of the hot-wall MOCVD concept is demonstrated by the performance of AlN/GaN structures with state-of-the-art properties with strong potential for further optimization. A narrower X-ray rocking curve over the asymmetric 10.4 than the symmetric 00.2 reflection clearly underlines the high overall crystal quality of the GaN layers on AlN buffers grown in this type of MOCVD reactor. [source] Mixed-mode chromatography/isotope ratio mass spectrometry,RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 5 2010James S. O. McCullagh Liquid chromatography coupled to molecular mass spectrometry (LC/MS) has been a standard technique since the early 1970s but liquid chromatography coupled to high-precision isotope ratio mass spectrometry (LC/IRMS) has only been available commercially since 2004. This development has, for the first time, enabled natural abundance and low enrichment ,13C measurements to be applied to individual analytes in aqueous mixtures creating new opportunities for IRMS applications, particularly for the isotopic study of biological molecules. A growing number of applications have been published in a range of areas including amino acid metabolism, carbohydrates studies, quantification of cellular and plasma metabolites, dietary tracer and nucleic acid studies. There is strong potential to extend these to new compounds and complex matrices but several challenges face the development of LC/IRMS methods. To achieve accurate isotopic measurements, HPLC separations must provide baseline-resolution between analyte peaks; however, the design of current liquid interfaces places severe restrictions on compatible flow rates and in particular mobile phase compositions. These create a significant challenge on which reports associated with LC/IRMS have not previously focused. Accordingly, this paper will address aspects of chromatography in the context of LC/IRMS, in particular focusing on mixed-mode separations and their benefits in light of these restrictions. It aims to provide an overview of mixed-mode stationary phases and of ways to improve high aqueous separations through manipulation of parameters such as column length, temperature and mobile phase pH. The results of several practical experiments are given using proteogenic amino acids and nucleosides both of which are of noted importance in the LC/IRMS literature. This communication aims to demonstrate that mixed-mode stationary phases provide a flexible approach given the constraints of LC/IRMS interface design and acts as a practical guide for the development of new chromatographic methods compatible with LC/IRMS applications. Copyright © 2010 John Wiley & Sons, Ltd. [source] Imaging of the Calf Vocal Fold With High-Frequency Ultrasound,THE LARYNGOSCOPE, Issue 10 2008Conor J. Walsh MSME Abstract Objectives/Hypothesis: High-frequency ultrasound imaging offers the potential for assisting in the diagnosis and treatment of vocal fold pathology if it allows aspects of vocal fold microstructure to be visualized noninvasively. The objective of this study was to assess the ability of high-frequency ultrasound to image vocal fold anatomy and injected biomaterials. Study Design: The vocal folds of two excised calf larynges were imaged ex vivo and compared with corresponding histological sections. Methods: High-frequency ultrasound imaging was performed under saline submersion using 40 and 50 MHz transducers, and corresponding cryostat cross-sections were stained with H&E, Trichome, and Verhoeff's Van Gieson stains. Results: The epithelial surface, lamina propria, and underlying muscle were easily identified with the high-frequency ultrasound as verified with histological sections representing each imaged region. The arytenoid cartilage vocal process can also be clearly distinguished from the surrounding tissue, as can the full extent of injected biomaterials within the superficial lamina propria. Useful ultrasound resolution was obtained to depths of at least 10 mm within the tissue with the 40 MHz transducer. Conclusions: This preliminary study demonstrates the capability of high-frequency ultrasound to image the layered anatomy of the calf vocal fold and to discern materials injected into the superficial lamina propria, indicating that this technology holds a strong potential for use in phonosurgery. [source] Photocatalytic membrane reactors: case studies and perspectivesASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 3 2009V. Loddo Abstract Photocatalysis by polycrystalline semiconductor oxides is being successfully applied to the abatement of organic and inorganic pollutants both in gas and in liquid phase. In order to increase the efficiency of this method, the coupling of this technology with the membrane separation process has been the object of sound investigation. In this combination, the membrane may act in different ways: to confine the photocatalytic powder in the reacting suspension, to selectively separate the photoreaction products, or to be the support of photocatalyst. This article reports recent studies in which different types of membranes (such as distillation, dialysis, nanofiltration, pervaporation and osmosis membranes) are used in hybrid systems. An additional advantage of coupling is that the photocatalyst prevents the microbial fouling offering a strong potential for the use of new types of thin-film-composite membrane. Perspectives and future possible application of the synergy between membranes and photocatalytic reactors are also emphasised. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source] Formation of palladium(0) nanoparticles at microbial surfacesBIOTECHNOLOGY & BIOENGINEERING, Issue 2 2010Michael Bunge Abstract The increasing demand and limited natural resources for industrially important platinum-group metal (PGM) catalysts render the recovery from secondary sources such as industrial waste economically interesting. In the process of palladium (Pd) recovery, microorganisms have revealed a strong potential. Hitherto, bacteria with the property of dissimilatory metal reduction have been in focus, although the biochemical reactions linking enzymatic Pd(II) reduction and Pd(0) deposition have not yet been identified. In this study we investigated Pd(II) reduction with formate as the electron donor in the presence of Gram-negative bacteria with no documented capacity for reducing metals for energy production: Cupriavidus necator, Pseudomonas putida, and Paracoccus denitrificans. Only large and close-packed Pd(0) aggregates were formed in cell-free buffer solutions. Pd(II) reduction in the presence of bacteria resulted in smaller, well-suspended Pd(0) particles that were associated with the cells (called "bioPd(0)" in the following). Nanosize Pd(0) particles (3,30,nm) were only observed in the presence of bacteria, and particles in this size range were located in the periplasmic space. Pd(0) nanoparticles were still deposited on autoclaved cells of C. necator that had no hydrogenase activity, suggesting a hydrogenase-independent formation mechanism. The catalytic properties of Pd(0) and bioPd(0) were determined by the amount of hydrogen released in a reaction with hypophosphite. Generally, bioPd(0) demonstrated a lower level of activity than the Pd(0) control, possibly due to the inaccessibility of the Pd(0) fraction embedded in the cell envelope. Our results demonstrate the suitability of bacterial cells for the recovery of Pd(0), and formation and immobilization of Pd(0) nanoparticles inside the cell envelope. However, procedures to make periplasmic Pd(0) catalytically accessible need to be developed for future nanobiotechnological applications. Biotechnol. Bioeng. 2010;107: 206,215. © 2010 Wiley Periodicals, Inc. [source] 1,3,5-Triazepan-2,6-diones as Structurally Diverse and Conformationally Constrained Dipeptide Mimetics: Identification of Malaria Liver Stage Inhibitors from a Small Pilot LibraryCHEMISTRY - A EUROPEAN JOURNAL, Issue 33 2006Gersande Lena Abstract The development of the 1,3,5-triazepan-2,6-dione system as a novel, conformationally restricted, and readily accessible class of dipeptidomimetics is reported. The synthesis of the densely functionalized 1,3,5-triazepan-2,6-dione skeleton was achieved in only four steps from a variety of simple linear dipeptide precursors. To extend the practical value of 1,3,5-triazepane-2,6-diones, a general polymer-assisted solution-phase synthesis approach amenable to library production in a multiparallel format was developed. The conformational preferences of the 1,3,5-triazepan-2,6-dione skeleton were investigated in detail by NMR spectroscopy and X-ray diffraction. The ring exhibits a characteristic folded conformation which was compared to that of related dipeptide-derived scaffolds including the more planar 2,5-diketopiperazine (DKP). Molecular and structural diversity was increased further through post-cyclization appending operations at urea nitrogens. Preliminary biological screens of a small collection of 1,3,5-triazepan-2,6-diones revealed inhibitors of the underexplored malaria liver stage and suggest strong potential for this dipeptide-derived scaffold to interfere with and to modulate biological pathways. [source] | |||||||||||||||||||