739 research outputs found

    University Entry Score: Is it a Consideration for Spatial Performance in Architecture Design Students?

    Get PDF
    Purpose – The purpose of this paper is to provide an insight into the relationship between students’ spatial ability and their university entrance score (Australian Tertiary Admissions Rank [ATAR]). The ATAR provides entry into university studies but does not necessary provide a good measure of students’ spatial skills. Spatial abilities are fundamental to success in many design courses. This paper aims to show whether the ATAR is a good predictor of spatial skills and considers the implications of this. Design/methodology/approach – Students entering university design courses in architecture were tested three times during their rst year using a three-dimensional (3D) Ability Test (3DAT), an online psychometric test of 3D spatial ability. The students’ results in 3DAT were then compared to students’ ATAR scores using a Pearson’s correlation test were also conducted to assess the relationship between ATAR and spatial performance. Findings – There was no correlation between ATAR and spatial performance. Therefore, there was no relationship between Participants were required to select their ATAR from ranges, i.e. 71-80, 81-90 and 91-100, which meant their exact ATAR was not recorded. This meant that the participants were clustered, making it dif cult to establish a linear relationship that was a true re ection of the population. Practical implications – Initiatives to support students entering design courses may be necessary to compensate for the range of spatial skills students possess when entering university because of their school experiences. Social implications – Individuals who have strong spatial skills are able to perform spatial problems faster and more ef ciently than those with weak spatial skills. High spatial performance has been shown relate to performance in areas such as mathematics science technology and design. Originality/value – This paper ful ls the need to better understand the diversity of spatial abilities students have on entering design courses

    Enzymatic synthesis of vanillin catalysed by an eugenol oxidase

    Get PDF
    Vanillin is one of the most important flavours produced in the world. Due to its increasing value and its demand, mainly in the food industry, several ways to obtain it at lower prices are under study. One of the routes is based on the oxidation of vanillyl alcohol by Eugenol oxidase (EUGO), which has high potential to be used at industrial scale owing to the high space time yields that can be obtained at lab scale (2.9 g L−1 h−1 of vanillin). Additionally, EUGO can be immobilised efficiently onto different supports (MANA-agarose, Epoxy-agarose and Purolite 8204F) which can be reused several times to perform the oxidation preserving good stability and improving more than 3-fold the biocatalyst yield

    Experimental analysis of sample-based maps for long-term SLAM

    Get PDF
    This paper presents a system for long-term SLAM (simultaneous localization and mapping) by mobile service robots and its experimental evaluation in a real dynamic environment. To deal with the stability-plasticity dilemma (the trade-off between adaptation to new patterns and preservation of old patterns), the environment is represented at multiple timescales simultaneously (5 in our experiments). A sample-based representation is proposed, where older memories fade at different rates depending on the timescale, and robust statistics are used to interpret the samples. The dynamics of this representation are analysed in a five week experiment, measuring the relative influence of short- and long-term memories over time, and further demonstrating the robustness of the approach

    N-Alkyl-α-amino acids in Nature and their biocatalytic preparation

    Get PDF
    PWS would like to acknowledge the European Union for his current funding: “This project has received funding from the European Union’s Horizon 2020 research and innovation programme under Marie SkƂodowska-Curie grant agreement No 665919”.N-alkylated-α-amino acids are useful building blocks for the pharmaceutical and fine chemical industries. Enantioselective methods of N-alkylated-α-amino acid synthesis are therefore highly valuable and widely investigated. While there are a variety of chemical methods for their synthesis, they often employ stoichiometric quantities of hazardous reagents such as pyrophoric metal hydrides or genotoxic alkylating agents, whereas biocatalytic routes can provide a greener and cleaner alternative to existing methods. This review highlights the occurrence of the N-alkyl-α-amino acid motif and its role in nature, important applications towards human health and biocatalytic methods of preparation. Several enzyme classes that can be used to access chiral N-alkylated-α-amino acids and their substrate selectivities are detailed.PostprintPeer reviewe

    Assessment of Radiative Heating Uncertainty for Hyperbolic Earth Entry

    Get PDF
    This paper investigates the shock-layer radiative heating uncertainty for hyperbolic Earth entry, with the main focus being a Mars return. In Part I of this work, a baseline simulation approach involving the LAURA Navier-Stokes code with coupled ablation and radiation is presented, with the HARA radiation code being used for the radiation predictions. Flight cases representative of peak-heating Mars or asteroid return are de ned and the strong influence of coupled ablation and radiation on their aerothermodynamic environments are shown. Structural uncertainties inherent in the baseline simulations are identified, with turbulence modeling, precursor absorption, grid convergence, and radiation transport uncertainties combining for a +34% and ..24% structural uncertainty on the radiative heating. A parametric uncertainty analysis, which assumes interval uncertainties, is presented. This analysis accounts for uncertainties in the radiation models as well as heat of formation uncertainties in the flow field model. Discussions and references are provided to support the uncertainty range chosen for each parameter. A parametric uncertainty of +47.3% and -28.3% is computed for the stagnation-point radiative heating for the 15 km/s Mars-return case. A breakdown of the largest individual uncertainty contributors is presented, which includes C3 Swings cross-section, photoionization edge shift, and Opacity Project atomic lines. Combining the structural and parametric uncertainty components results in a total uncertainty of +81.3% and ..52.3% for the Mars-return case. In Part II, the computational technique and uncertainty analysis presented in Part I are applied to 1960s era shock-tube and constricted-arc experimental cases. It is shown that experiments contain shock layer temperatures and radiative ux values relevant to the Mars-return cases of present interest. Comparisons between the predictions and measurements, accounting for the uncertainty in both, are made for a range of experiments. A measure of comparison quality is de ned, which consists of the percent overlap of the predicted uncertainty bar with the corresponding measurement uncertainty bar. For nearly all cases, this percent overlap is greater than zero, and for most of the higher temperature cases (T >13,000 K) it is greater than 50%. These favorable comparisons provide evidence that the baseline computational technique and uncertainty analysis presented in Part I are adequate for Mars-return simulations. In Part III, the computational technique and uncertainty analysis presented in Part I are applied to EAST shock-tube cases. These experimental cases contain wavelength dependent intensity measurements in a wavelength range that covers 60% of the radiative intensity for the 11 km/s, 5 m radius flight case studied in Part I. Comparisons between the predictions and EAST measurements are made for a range of experiments. The uncertainty analysis presented in Part I is applied to each prediction, and comparisons are made using the metrics defined in Part II. The agreement between predictions and measurements is excellent for velocities greater than 10.5 km/s. Both the wavelength dependent and wavelength integrated intensities agree within 30% for nearly all cases considered. This agreement provides confidence in the computational technique and uncertainty analysis presented in Part I, and provides further evidence that this approach is adequate for Mars-return simulations. Part IV of this paper reviews existing experimental data that include the influence of massive ablation on radiative heating. It is concluded that this existing data is not sufficient for the present uncertainty analysis. Experiments to capture the influence of massive ablation on radiation are suggested as future work, along with further studies of the radiative precursor and improvements in the radiation properties of ablation products

    The Broad Aryl Acid Specificity of the Amide Bond Synthetase McbA Suggests Potential for the Biocatalytic Synthesis of Amides

    Get PDF
    Amide bond formation is one of the most important reactions in pharmaceutical synthetic chemistry. The development of sustainable methods for amide bond formation, including those that are catalyzed by enzymes, is therefore of significant interest. The ATP-dependent amide bond synthetase (ABS) enzyme McbA, from Marinactinospora thermotolerans, catalyzes the formation of amides as part of the biosynthetic pathway towards the marinacarboline secondary metabolites. The reaction proceeds via an adenylate intermediate, with both adenylation and amidation steps catalyzed within one active site. In this study, McbA was applied to the synthesis of pharmaceutical-type amides from a range of aryl carboxylic acids with partner amines provided at 1-5 molar equivalents. The structure of McbA revealed the structural determinants of aryl acid substrate tolerance and differences in conformation associated with the two half reactions catalyzed. The catalytic performance of McbA, coupled with the structure, suggest that this and other ABS enzymes may be engineered for applications in the sustainable synthesis of pharmaceutically relevant (chiral) amides

    Molecular-orbital theory for the stopping power of atoms in the low velocity regime:the case of helium in alkali metals

    Full text link
    A free-parameter linear-combination-of-atomic-orbitals approach is presented for analyzing the stopping power of slow ions moving in a metal. The method is applied to the case of He moving in alkali metals. Mean stopping powers for He present a good agreement with local-density-approximation calculations. Our results show important variations in the stopping power of channeled atoms with respect to their mean values.Comment: LATEX, 3 PostScript Figures attached. Total size 0.54

    Designing and using incentives to support recruitment and retention in clinical trials:a scoping review and a checklist for design

    Get PDF
    BACKGROUND: Recruitment and retention of participants are both critical for the success of trials, yet both remain significant problems. The use of incentives to target participants and trial staff has been proposed as one solution. The effects of incentives are complex and depend upon how they are designed, but these complexities are often overlooked. In this paper, we used a scoping review to 'map' the literature, with two aims: to develop a checklist on the design and use of incentives to support recruitment and retention in trials; and to identify key research topics for the future.METHODS: The scoping review drew on the existing economic theory of incentives and a structured review of the literature on the use of incentives in three healthcare settings: trials, pay for performance, and health behaviour change. We identified the design issues that need to be considered when introducing an incentive scheme to improve recruitment and retention in trials. We then reviewed both the theoretical and empirical evidence relating to each of these design issues. We synthesised the findings into a checklist to guide the design of interventions using incentives.RESULTS: The issues to consider when designing an incentive system were summarised into an eight-question checklist. The checklist covers: the current incentives and barriers operating in the system; who the incentive should be directed towards; what the incentive should be linked to; the form of incentive; the incentive size; the structure of the incentive system; the timing and frequency of incentive payouts; and the potential unintended consequences. We concluded the section on each design aspect by highlighting the gaps in the current evidence base.CONCLUSIONS: Our findings highlight how complex the design of incentive systems can be, and how crucial each design choice is to overall effectiveness. The most appropriate design choice will differ according to context, and we have aimed to provide context-specific advice. Whilst all design issues warrant further research, evidence is most needed on incentives directed at recruiters, optimal incentive size, and testing of different incentive structures, particularly exploring repeat arrangements with recruiters.</p

    Comparative transcriptomics in the Triticeae

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Barley and particularly wheat are two grass species of immense agricultural importance. In spite of polyploidization events within the latter, studies have shown that genotypically and phenotypically these species are very closely related and, indeed, fertile hybrids can be created by interbreeding. The advent of two genome-scale Affymetrix GeneChips now allows studies of the comparison of their transcriptomes.</p> <p>Results</p> <p>We have used the Wheat GeneChip to create a "gene expression atlas" for the wheat transcriptome (cv. Chinese Spring). For this, we chose mRNA from a range of tissues and developmental stages closely mirroring a comparable study carried out for barley (cv. Morex) using the Barley1 GeneChip. This, together with large-scale clustering of the probesets from the two GeneChips into "homologous groups", has allowed us to perform a genomic-scale comparative study of expression patterns in these two species. We explore the influence of the polyploidy of wheat on the results obtained with the Wheat GeneChip and quantify the correlation between conservation in gene sequence and gene expression in wheat and barley. In addition, we show how the conservation of expression patterns can be used to elucidate, probeset by probeset, the reliability of the Wheat GeneChip.</p> <p>Conclusion</p> <p>While there are many differences in expression on the level of individual genes and tissues, we demonstrate that the wheat and barley transcriptomes appear highly correlated. This finding is significant not only because given small evolutionary distance between the two species it is widely expected, but also because it demonstrates that it is possible to use the two GeneChips for comparative studies. This is the case even though their probeset composition reflects rather different design principles as well as, of course, the present incomplete knowledge of the gene content of the two species. We also show that, in general, the Wheat GeneChip is not able to distinguish contributions from individual homoeologs. Furthermore, the comparison between the two species leads us to conclude that the conservation of both gene sequence as well as gene expression is positively correlated with absolute expression levels, presumably reflecting increased selection pressure on genes coding for proteins present at high levels. In addition, the results indicate the presence of a correlation between sequence and expression conservation within the Triticeae.</p

    Identification of Colletotrichum species associated with anthracnose disease of coffee in Vietnam

    Get PDF
    Colletotrichum gloeosporioides, C. acutatum, C. capsici and C. boninense associated with anthracnose disease on coffee (Coffea spp.) in Vietnam were identified based on morphology and DNA analysis. Phylogenetic analysis of DNA sequences from the internal transcribed spacer region of nuclear rDNA and a portion of mitochondrial small subunit rRNA were concordant and allowed good separation of the taxa. We found several Colletotrichum isolates of unknown species and their taxonomic position remains unresolved. The majority of Vietnamese isolates belonged to C. gloeosporioides and they grouped together with the coffee berry disease (CBD) fungus, C. kahawae. However, C. kahawae could be distinguished from the Vietnamese C. gloeosporioides isolates based on ammonium tartrate utilization, growth rate and pathogenictity. C. gloeosporioides isolates were more pathogenic on detached green berries than isolates of the other species, i.e. C. acutatum, C capsici and C. boninense. Some of the C. gloeosporioides isolates produced slightly sunken lesion on green berries resembling CBD symptoms but it did not destroy the bean. We did not find any evidence of the presence of C. kahawae in Vietnam
    • 

    corecore