16,319 research outputs found
On the relationship between stomatal characters and atmospheric CO2
Leaf stomatal characters influence the response of terrestrial evapotranspiration to climate change and are used as proxies for the reconstruction of past atmospheric [CO2]. We examined the phenotypic response of stomatal index (SI), density (SD) and aperture (AP) to rising atmospheric CO2 in 15 species after four years exposure to a field CO2 gradient (200 to 550 ÎŒmol molâ1 atmospheric [CO2]) or at three Free Air CO2 Enrichment (FACE) sites. Along the CO2 gradient, SI and SD showed no evidence of a decline to increasing [CO2], while AP decreased slightly. There was no significant change in SI, SD or AP with CO2 across FACE experiments. Without evolutionary changes, SI and SD may not respond to atmospheric [CO2] in the field and are unlikely to decrease in a future high CO2 world
Excitation spectrum of a two-component Bose-Einstein condensate in a ring potential
A mixture of two distinguishable Bose-Einstein condensates confined in a ring
potential has numerous interesting properties under rotational and
solitary-wave excitation. The lowest-energy states for a fixed angular momentum
coincide with a family of solitary-wave solutions. In the limit of weak
interactions, exact diagonalization of the many-body Hamiltonian is possible
and permits evaluation of the complete excitation spectrum of the system.Comment: 4 pages, 1 figur
Religion and religious education : comparing and contrasting pupilsâ and teachersâ views in an English school
This publication builds on and develops the English findings of the qualitative study of European teenagersâ perspectives on religion and religious education (Knauth et al. 2008), part of âReligion in Education: A contribution to dialogue or a factor of conflict in transforming societies of European countries?â (REDCo) project. It uses data gathered from 27 pupils, aged 15-16, from a school in a multicultural Northern town in England and compares those findings with data gathered from ten teachers in the humanities faculty of the same school, collected during research for the Warwick REDCo Community of Practice. Comparisons are drawn between the teachersâ and their pupilsâ attitudes and values using the same structure as the European study: personal views and experiences of religion, the social dimension of religion, and religious education in school. The discussion offers an analysis of the similarities and differences in worldviews and beliefs which emerged. These include religious commitment/observance differences between the mainly Muslim-heritage pupils and their mainly non-practising Christian-heritage teachers. The research should inform the ways in which the statutory duties to promote community cohesion and equalities can be implemented in schools. It should also facilitate intercultural and interreligious understanding between teachers and the pupils from different ethnic and religious backgrounds
Exact solutions for interacting boson systems under rotation
We study a class of interacting, harmonically trapped boson systems at
angular momentum L. The Hamiltonian leaves a L-dimensional subspace invariant,
and this permits an explicit solution of several eigenstates and energies for a
wide class of two-body interactionsComment: 8 pages, error corrected (concerns generalization of subspace
structure
The properties of AGN in dwarf galaxies identified via SED fitting
© 2024 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/Given their dominance of the galaxy number density, dwarf galaxies are central to our understanding of galaxy formation. While the incidence of active galactic nuclei (AGN) and their impact on galaxy evolution have been extensively studied in massive galaxies, much less is known about the role of AGN in the evolution of dwarfs. We search for radiatively efficient AGN in the nearby (0.1 < z < 0.3) dwarf (10 8 M â < M * < 10 10 M â) population, using spectral energy distribution fitting (via PROSPECTOR) applied to deep ultraviolet to mid-infrared photometry of 508 dwarf galaxies. Around a third (32 ± 2 per cent) of our dwarfs show signs of AGN activity. We compare the properties of our dwarf AGN to control samples, constructed from non-AGN, which have the same distributions of redshift and stellar mass as their AGN counterparts. KolmogorovâSmirnov tests between the AGN and control distributions indicate that the AGN do not show differences in their distances to nodes, filaments, and nearby massive galaxies from their control counterparts. This indicates that AGN triggering in the dwarf regime is not strongly correlated with local environment. The fraction of AGN hosts with early-type morphology and those that are interacting are also indistinguishable from the controls within the uncertainties, suggesting that interactions do not play a significant role in inducing AGN activity in our sample. Finally, the star formation activity in dwarf AGN is only slightly lower than that in their control counterparts, suggesting that the presence of radiatively efficient AGN does not lead to significant, prompt quenching of star formation in these systems.Peer reviewe
Event-B Patterns for Specifying Fault-Tolerance in Multi-Agent Interaction
Interaction in a multi-agent system is susceptible to failure. A rigorous development of a multi-agent system must include the treatment of fault-tolerance of agent interactions for the agents to be able to continue to function independently. Patterns can be used to capture fault-tolerance techniques. A set of modelling patterns is presented that specify fault-tolerance in Event-B specifications of multi-agent interactions. The purpose of these patterns is to capture common modelling structures for distributed agent interaction in a form that is re-usable on other related developments. The patterns have been applied to a case study of the contract net interaction protocol
Distinguishing between similar tubular objects using pulse reflectometry:a study of trumpet and cornet leadpipes
This paper considers the measurement of the internal radius of a number of similar, short, tubular leadpipes using pulse reflectometry. Pulse reflectometry is an acoustical technique for measuring the internal bore of a tubular object by analysing the reflections which occur when an acoustical pulse is directed into the object. The leadpipes are designed to form the initial, or lead, part of a trumpet or cornet and their internal radii differ by less than 0.1 mm between similar pipes. The ability of the reflectometer to detect these small differences, which are considered by players to produce a noticeable difference in the sound of an instrument, are investigated. It is seen that the pulse reflectometer is able to distinguish between leadpipes with different nominal radii varying by as little as 0.03 mm, demonstrating its potential in the study of musical instruments and showing that it can be used as a diagnostic tool by the instrument manufacturer to detect defects which are significant enough to acoustically alter performance. The absolute accuracy of the radius measurements is also considered at the end of the leadpipe, where the uncertainty is ±0.05 mm
Lack of association between first myocardial infarction and past use of erythromycin, tetracycline, or doxycycline.
To evaluate the association of prior treatment with antibiotics active against Chlamydia pneumoniae with the risk for incident myocardial infarction, we conducted a population-based case-control study. We found that use of erythromycin, tetracycline, or doxycycline during the previous 5 years was not associated with risk for first myocardial infarction. These results suggest little or no association between the use of these antibiotics and the risk for first myocardial infarction in the primary prevention setting
Is Active Transport and Leisure-Time Physical Activity Associated With Inflammatory Markers in US Adults? A Cross-Sectional Analyses From NHANES
Background: To investigate the association between levels of active transport and leisure-time physical activity (LTPA) with C-reactive protein, white blood cell count, body mass index, waist circumference, and lipids in a large representative sample of adults residing in the United States. // Methods: Cross-sectional data from the National Health and Nutrition Examination Survey. Adjusted multinomial logistic regressions were carried out to quantify associations between levels of self-reported active transport (or LTPA) and quintiles of anthropometric measures and serum markers. // Results: A total of 3248 adults were included. For serum inflammatory biomarkers, the authors observed a lower likelihood of being in the top quintile groups of circulating C-reactive protein (adjusted odds ratio [aOR]: 0.60; 95% confidence interval [CI], 0.40â0.90) and white blood cell count (aOR: 0.65; 95% CI, 0.44â0.95) with engaging in low to medium levels of active transport but not with high levels of active transport. Higher levels of LTPA were associated with lower likelihood of having high levels of serum inflammatory biomarkers (aOR: 0.60; 95% CI, 0.42â0.86 in the top C-reactive protein group and aOR: 0.58; 95% CI, 0.39â0.87 in top white blood cell group). // Conclusions: Promoting active transport and/or LTPA may be a beneficial strategy to improving some, but not all, cardiometabolic health outcomes
Quantum Phases of Vortices in Rotating Bose-Einstein Condensates
We investigate the groundstates of weakly interacting bosons in a rotating
trap as a function of the number of bosons, , and the average number of
vortices, . We identify the filling fraction as the
parameter controlling the nature of these states. We present results indicating
that, as a function of , there is a zero temperature {\it phase
transition} between a triangular vortex lattice phase, and strongly-correlated
vortex liquid phases. The vortex liquid phases appear to be the Read-Rezayi
parafermion states
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