229 research outputs found

    A Decade of Encounter Biblical Studies

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    Starting with a brief history of the development of the Encounter Bible curriculum and summary of the evaluative research methodology, this paper draws on teacher, student and administrator interview data in its account of teachers’ attempts to teach Encounter Bible. The writers refer to selected points of interest from their evaluation as they discuss teacher perceptions of the Encounter resource, assessment practice, the theory behind planning, the teaching and learning process, spirituality in schools and classrooms, and professional development. They also review student perceptions of teaching, and administrator involvement in supporting teachers. In surveying teacher achievements and challenges, the paper addresses a limited number of key issues that could ultimately be of critical reflective importance for Christian schools

    Deep three-dimensional solid-state qubit arrays with long-lived spin coherence

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    Nitrogen-vacancy centers (NVCs) in diamond show promise for quantum computing, communication, and sensing. However, the best current method for entangling two NVCs requires that each one is in a separate cryostat, which is not scalable. We show that single NVCs can be laser written 6–15-µm deep inside of a diamond with spin coherence times that are an order of magnitude longer than previous laser-written NVCs and at least as long as naturally occurring NVCs. This depth is suitable for integration with solid immersion lenses or optical cavities and we present depth-dependent T2 measurements. 200 000 of these NVCs would fit into one diamond

    Updating the Antarctic krill biomass estimates for CCAMLR Subareas 48.1 to 48.4 using available data

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    -We present a novel index of Antarctic krill biomass in CCAMLR subareas 48.1 to 48.4, based on data from scientific nets and covering the years between 2000 and 2011. The annual biomass variation was significant (CV=73%) but no systematic change in krill biomass was evident during the period. The index also suggests that realised exploitation rates were below 0.5% (i.e. catch was <0.5% of biomass) and that the potential exploitation rates implied by the operational catch limit (the trigger level) were below 2% during this period. These exploitation rates are much lower than the precautionary yield estimate for the krill fishery (which is 9.3%). Biomass indices from local scale acoustic surveys also suggest that exploitation rates are low and that there is no evidence of a systematic change in the krill stock. This evidence suggests that the trigger level is a highly precautionary operational catch limit which is currently appropriate for achieving the conservation criteria for the krill stock. It also suggests that the catch levels seen in the first decade of the 21st century are unlikely to have adversely impacted the krill stock. Nonetheless the Commission also needs to manage the risk of adverse impacts on dependent and related populations which might occur if fishing is concentrated in sensitive areas. Advances are needed to improve management of krill fisheries to manage these risks and to ensure that management is robust to the potential impacts of climate change. We suggest that frequent assessment of the krill stock, at scales relevant to the Commission’s conservation objectives, is a prerequisite for such advances. The most effective means to achieve this is likely to be through increased use of fishing vessels to collect data, while maintaining current time serie

    Controlling for transactions bias in regional house price indices

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    Transactions bias arises when properties that trade are not a random sample of the total housing stock. Price indices are susceptible because they are typically based on transactions data. Existing approaches to this problem rely on Heckman-type correction methods, where a probit regression is used to capture the differences between properties that sell and those that do not sell in a given period. However, this approach can only be applied where there is reliable data on the whole housing stock. In many countries—the UK included—no such data exist and there is little prospect of correcting for transactions bias in any of the regularly updated mainstream house price indices. Thispaper suggests a possible alternative approach, using information at postcode sector level and Fractional Probit Regression to correct for transactions bias in hedonic price indices based on one and a half million house sales from 1996 to 2004, distributed across 1200 postcode sectors in the South East of England

    Engineering bacteria to control electron transport altering the synthesis of non-native polymer

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    The use of bacteria as catalysts for radical polymerisations of synthetic monomers has recently been established. However, the role of trans Plasma Membrane Electron Transport (tPMET) in modulating these processes is not well understood. We sort to study this by genetic engineering a part of the tPMET system NapC in E. coli. We show that this engineering altered the rate of extracellular electron transfer coincided with an effect on cell-mediated polymerisation using a model monomer. A plasmid with arabinose inducible PBAD promoters were shown to upregulate NapC protein upon induction at total arabinose concentrations of 0.0018% and 0.18%. These clones (E. coli(IP_0.0018%) and E. coli(IP_0.18%), respectively) were used in iron-mediated atom transfer radical polymerisation (Fe ATRP), affecting the nature of the polymerisation, than cultures containing suppressed or empty plasmids (E. coli(IP_S) and E. coli(E), respectively). These results lead to the hypothesis that EET (Extracellular Electron Transfer) in part modulates cell instructed polymerisations

    Synthetic Biology Toolbox, Including a Single-Plasmid CRISPR-Cas9 System to Biologically Engineer the Electrogenic, Metal-Resistant Bacterium Cupriavidus metallidurans CH34

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    Cupriavidus metallidurans CH34 exhibits extraordinary metabolic versatility, including chemolithoautotrophic growth; degradation of BTEX (benzene, toluene, ethylbenzene, xylene); high resistance to numerous metals; biomineralization of gold, platinum, silver, and uranium; and accumulation of polyhydroxybutyrate (PHB). These qualities make it a valuable host for biotechnological applications such as bioremediation, bioprocessing, and the generation of bioelectricity in microbial fuel cells (MFCs). However, the lack of genetic tools for strain development and studying its fundamental physiology represents a bottleneck to boosting its commercial applications. In this study, inducible and constitutive promoter libraries were built and characterized, providing the first comprehensive list of biological parts that can be used to regulate protein expression and optimize the CRISPR-Cas9 genome editing tools for this host. A single-plasmid CRISPR-Cas9 system that can be delivered by both conjugation and electroporation was developed, and its efficiency was demonstrated by successfully targeting the pyrE locus. The CRISPR-Cas9 system was next used to target candidate genes encoding type IV pili, hypothesized by us to be involved in extracellular electron transfer (EET) in this organism. Single and double deletion strains (ΔpilA, ΔpilE, and ΔpilAE) were successfully generated. Additionally, the CRISPR-Cas9 tool was validated for constructing genomic insertions (ΔpilAE::gfp and ΔpilAE::λPrgfp). Finally, as type IV pili are believed to play an important role in extracellular electron transfer to solid surfaces, C. metallidurans CH34 ΔpilAE was further studied by means of cyclic voltammetry using disposable screen-printed carbon electrodes. Under these conditions, we demonstrated that C. metallidurans CH34 could generate extracellular currents; however, no difference in the intensity of the current peaks was found in the ΔpilAE double deletion strain when compared to the wild type. This finding suggests that the deleted type IV pili candidate genes are not involved in extracellular electron transfer under these conditions. Nevertheless, these experiments revealed the presence of different redox centers likely to be involved in both mediated electron transfer (MET) and direct electron transfer (DET), the first interpretation of extracellular electron transfer mechanisms in C. metallidurans CH34

    A bioluminescent microbial biosensor for in vitro pretreatment assessment of cytarabine efficacy in leukemia

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    BACKGROUND: The nucleoside analog cytarabine (Ara-C [cytosine arabinoside]) is the key agent for treating acute myeloid leukemia (AML); however, up to 30% of patients fail to respond to treatment. Screening of patient blood samples to determine drug response before commencement of treatment is needed. This project aimed to construct and evaluate a self-bioluminescent reporter strain of Escherichia coli for use as an Ara-C biosensor and to design an in vitro assay to predict Ara-C response in clinical samples. METHODS: Weused transposition mutagenesis to create a cytidine deaminase (cdd)-deficient mutant of E. coli MG1655 that responded to Ara-C. The strain was transformed with the luxCDABE operon and used as a whole-cell biosensor for development an 8-h assay to determine Ara-C uptake and phosphorylation by leukemic cells. RESULTS: Intracellular concentrations of 0.025 Οmol/L phosphorylated Ara-C were detected by significantly increased light output (P < 0.05) from the bacterial biosensor. Results using AML cell lines with known response to Ara-C showed close correlation between the 8-h assay and a 3-day cytotoxicity test for Ara-C cell killing. In retrospective tests with 24 clinical samples of bone marrow or peripheral blood, the biosensor-based assay predicted leukemic cell response to Ara-C within 8 h. CONCLUSIONS: The biosensor-based assay may offer a predictor for evaluating the sensitivity of leukemic cells to Ara-C before patients undergo chemotherapy and allow customized treatment of drug-sensitive patients with reduced Ara-C dose levels. The 8-h assay monitors intracellular Ara-CTP (cytosine arabinoside triphosphate) levels and, if fully validated, may be suitable for use in clinical settings. Š 2010 American Association for Clinical Chemistry

    Defining and measuring displacement: is relocation from restructured neighbourhoods always unwelcome and disruptive?

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    Current regeneration policy has been described as ‘state-led gentrification’, with comparisons made with the ‘social disruption’ caused by slum clearance of the 1950s and 1960s. This article takes issue with this approach in relation to the study of the restructuring of social housing areas. The terms ‘forced relocation’ and ‘displacement’ are often too crude to describe what actually happens within processes of restructuring and the effects upon residents. Displacement in particular has important dimensions other than the physical one of moving. Evidence from a recent study of people who have moved out of restructured areas shows that although there is some evidence of physical displacement, there is little evidence of social or psychosocial displacement after relocation. Prior attitudes to moving and aspects of the process of relocation—the degree of choice and distance involved—are important moderators of the outcomes. Issues of time and context are insufficiently taken into consideration in studies and accounts of restructuring, relocation and displacement

    Do krill fisheries compete with macaroni penguins? Spatial overlap in prey consumption and catches during winter

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    Aim To infer the potential for competition between an important Antarctic predator, the macaroni penguin, and the krill fishery by examining the spatial overlap in prey consumption and catches. Location Scotia Sea and adjacent waters. Methods The study focused on the winter period as this is the only time of the year when spatio-temporal overlaps between macaroni penguin foraging and the krill fishery can occur. We tracked adult macaroni penguins from a colony in South Georgia using global location sensors to determine winter distribution, and bioenergetics models to calculate the biomass of food consumed during the winter period. We combined these to produce a surface of the tonnes of krill consumed, which could be compared directly with the spatial distribution of the tonnes of krill caught by the fishery. Results Adult macaroni penguins from South Georgia consumed 135,826 tonnes of krill (95% CIs: 83,446–188,140) during the winter, which is similar to the 98,431 tonnes caught by fisheries over the same period. However, macaroni penguins had a very wide pelagic distribution across the Scotia Sea, whereas the fishery was restricted to three small areas on shelf edges, such that their spatial overlap was negligible. The proportion of the estimated krill stock taken by macaroni penguins and the krill fishery was small at both the scale of the Scotia Sea and the local areas within which the fisheries operate. Main conclusions Competition between macaroni penguins and the krill fishery is low under current management and far less than that among the various species of krill predators that occur in the Scotia Sea. Our method will allow quantification of changes in competition between macaroni penguins and krill fisheries should the latter expand in the future, and provides a framework for assessing predator-fishery competition in other systems

    Providing a Framework for Seagrass Mapping in United States Coastal Ecosystems Using High Spatial Resolution Satellite Imagery

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    Seagrasses have been widely recognized for their ecosystem services, but traditional seagrass monitoring approaches emphasizing ground and aerial observations are costly, time-consuming, and lack standardization across datasets. This study leveraged satellite imagery from Maxar\u27s WorldView-2 and WorldView-3 high spatial resolution, commercial satellite platforms to provide a consistent classification approach for monitoring seagrass at eleven study areas across the continental United States, representing geographically, ecologically, and climatically diverse regions. A single satellite image was selected at each of the eleven study areas to correspond temporally to reference data representing seagrass coverage and was classified into four general classes: land, seagrass, no seagrass, and no data. Satellite-derived seagrass coverage was then compared to reference data using either balanced agreement, the Mann-Whitney U test, or the Kruskal-Wallis test, depending on the format of the reference data used for comparison. Balanced agreement ranged from 58% to 86%, with better agreement between reference- and satellite-indicated seagrass absence (specificity ranged from 88% to 100%) than between reference- and satellite-indicated seagrass presence (sensitivity ranged from 17% to 73%). Results of the Mann-Whitney U and Kruskal-Wallis tests demonstrated that satellite-indicated seagrass percentage cover had moderate to large correlations with reference-indicated seagrass percentage cover, indicative of moderate to strong agreement between datasets. Satellite classification performed best in areas of dense, continuous seagrass compared to areas of sparse, discontinuous seagrass and provided a suitable spatial representation of seagrass distribution within each study area. This study demonstrates that the same methods can be applied across scenes spanning varying seagrass bioregions, atmospheric conditions, and optical water types, which is a significant step toward developing a consistent, operational approach for mapping seagrass coverage at the national and global scales. Accompanying this manuscript are instructional videos describing the processing workflow, including data acquisition, data processing, and satellite image classification. These instructional videos may serve as a management tool to complement field- and aerial-based mapping efforts for monitoring seagrass ecosystems
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