2,064 research outputs found
Marine benthic plants of Western Australia's shelf-edge atolls
One hundred and twenty-one species of marine algae, seagrasses and cyanobacteria are reported from the offshore atolls of northwestern Western Australia (the Rowley Shoals, Scott Reef and Seringapatam Reef). Included are 65 species of Rhodophyta, 40 species of Chlorophyta, nine species of Phaeophyceae, three species of Cyanophyta and four species of seagrasses. This report presents the first detailed account of marine benthic algae from these atolls. Twenty-four species are newly recorded for Western Australia, with four species (Anadyomene wrightii, Rhipilia nigrescens, Ceramium krameri and Zellera tawallina) also newly recorded for Australia
Resistance of superconducting nanowires connected to normal metal leads
We study experimentally the low temperature resistance of superconducting
nanowires connected to normal metal reservoirs. We find that a substantial
fraction of the nanowires is resistive, down to the lowest temperature
measured, indicative of an intrinsic boundary resistance due to the
Andreev-conversion of normal current to supercurrent. The results are
successfully analyzed in terms of the kinetic equations for diffusive
superconductors
Quantitative Systems Biology to decipher design principles of a dynamic cell cycle network:the "Maximum Allowable mammalian Trade-Off-Weight" (MAmTOW)
Instructed and acquired contingencies in response-inhibition tasks
This is the author accepted manuscript. The final version is available from Ubiquity Press via the DOI in this record.Inhibitory control can be triggered directly via the retrieval of previously acquired stimulusstop
associations from memory. However, a recent study suggests that this item-specific stop
learning may be mediated via expectancies of the contingencies in play (Best, Lawrence,
Logan, McLaren, & Verbruggen, 2016). This could indicate that stimulus-stop learning also
induces strategic, proactive changes in performance. We further tested this hypothesis in the
present study. In addition to measuring expectancies following task completion, we introduced
a between-subjects expectancy manipulation in which one group of participants were
informed about the stimulus-stop contingencies and another group did not receive any
information about the stimulus-stop contingencies. Moreover, we combined this instruction
manipulation with a distractor manipulation that was previously used to examine strategic
proactive adjustments. We found that the stop-associated items slowed responding in both
conditions. Furthermore, participants in both conditions generated expectancies following
task completion that were consistent with the stimulus-stop contingencies. The distractor
manipulation was ineffective. However, we found differences in the relationship between the
expectancy ratings and task performance: in the instructed condition, the expectancies
reliably correlated with the response slowing for the stop-associated items, whereas in the
uninstructed condition we found no reliable correlation. These differences between the
correlations were reliable, and our conclusions were further supported by Bayesian analyses.
We conclude that stimulus-stop associations that are acquired either via task instructions or
via task practice have similar effects on behavior but could differ in how they elicit response
slowing.Economic and Social Research Council (ESRC
A comparative study of ethylene emanation upon nitrogen deficiency in natural accessions of Arabidopsis thaliana
An original approach to develop sustainable agriculture with less nitrogen fertilizer inputs is to tackle the cross-talk between nitrogen nutrition and plant growth regulators. In particular the gaseous hormone, ethylene, is a prime target for that purpose. The variation of ethylene production in natural accessions of the model species Arabidopsis thaliana was explored in response to the nitrate supply. Ethylene was measured with a laser-based photoacoustic detector. First, experimental conditions were established with Columbia-0 (Col-0) accession, which was grown in vitro on horizontal plates across a range of five nitrate concentrations (0.5, 1, 2.5, 5, or 10 mM). The concentrations of 1 and 10 mM nitrate were retained for further characterization. Along with a decrease of total dry biomass and higher biomass allocation to the roots, the ethylene production was 50% more important at 1 mM than at 10 mM nitrate. The total transcript levels of 1-AMINOCYCLOPROPANE-1-CARBOXYLIC ACID SYNTHASES (ACS) in roots and those of ACC OXIDASES (ACO) in shoots increased by 100% between the same treatments. This was mainly due to higher transcript levels of ACS6 and of ACO2 and ACO4 respectively. The assumption was that during nitrogen deficiency, the greater biomass allocation in favor of the roots was controlled by ethylene being released in the shoots after conversion of ACC originating from the roots. Second, biomass and ethylene productions were measured in 20 additional accessions. Across all accessions, the total dry biomass and ethylene production were correlated negatively at 1 mM but positively at 10 mM nitrate. Furthermore, polymorphism was surveyed in ACC and ethylene biosynthesis genes and gene products among accessions. Very few substitutions modifying the amino acids properties in conserved motifs of the enzymes were found in the accessions. Natural variation of ethylene production could be further explored to improve Nitrogen Use Efficiency (NUE), in particular by manipulating features like the biomass production and the timing of senescence upon nitrogen limitation
Soft computing applications in aircraft sensor management and flight control law reconfiguration
Nitrogen Use Efficiency of Specialized Dairy Farms in Flanders: Evolution and Future Goals
Efficient use of nutrients is one of the major aims of eco-efficient and sustainable agricultural production systems. We determined the nitrogen use efficiency of a representative set of specialised dairy farms in Flanders, between 1989-1990 and 2000-2001 and set achievable eco-efficiency targets for sustainability
Structure and implementation of novel task rules: A cross-sectional developmental study
This is the author accepted manuscript. The final version is available from SAGE Publications via the DOI in this record.Rule-based performance improves remarkably throughout childhood. The present study
examined how children and adolescents structured tasks and implemented rules when novel
task instructions were presented in a child-friendly version of a novel instruction-learning
paradigm. Each mini-block started with the presentation of the new stimulus-response
mappings for a GO task. Prior to implementing this mapping, responses were required to
advance through screens during a preparatory (NEXT) phase. Children (4-11 years) and late
adolescents (17-19 years) responded more slowly during the NEXT phase when the NEXT
response was incompatible with the instructed stimulus-response mapping. This instructionbased
interference effect was more pronounced in young children than in older children. We
argue that these findings are most consistent with age-related differences in rule structuring.
We discuss the implications of our findings for theories of rule-based performance,
instruction-based learning, and development.This work was supported by an ERC starting grant to FV (No. 312445)
Atomic Layer Deposition-Based Synthesis of Photoactive TiO2 Nanoparticle Chains by Using Carbon Nanotubes as Sacrificial Templates
Highly ordered and self supported anatase TiO2 nanoparticle chains were
fabricated by calcining conformally TiO2 coated multi-walled carbon nanotubes
(MWCNTs). During annealing, the thin tubular TiO2 coating that was deposited
onto the MWCNTs by atomic layer deposition (ALD) was transformed into chains of
TiO2 nanoparticles (~12 nm diameter) with an ultrahigh surface area (137 cm2
per cm2 of substrate), while at the same time the carbon from the MWCNTs was
removed. Photocatalytic tests on the degradation of acetaldehyde proved that
these forests of TiO2 nanoparticle chains are highly photo active under UV
light because of their well crystallized anatase phase
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