976 research outputs found
A study of the relative effectiveness and cost of computerized information retrieval in the interactive mode
Results of a number of experiments to illuminate the relative effectiveness and costs of computerized information retrieval in the interactive mode are reported. It was found that for equal time spent in preparing the search strategy, the batch and interactive modes gave approximately equal recall and relevance. The interactive mode however encourages the searcher to devote more time to the task and therefore usually yields improved output. Engineering costs as a result are higher in this mode. Estimates of associated hardware costs also indicate that operation in this mode is more expensive. Skilled RECON users like the rapid feedback and additional features offered by this mode if they are not constrained by considerations of cost
Reporting of scar outcomes in the hand and wrist; a state-of-the-art literature review
Objectives The aim of this literature review was to synthesise and report current practice in evaluation and reporting of scar outcomes in hand and wrist clinical research. Methods A systematic search from inception to 2022 was conducted using three electronic databases. English language randomized controlled trials and observational cohort studies reporting standardised scar outcome measures and/or scar symptoms, appearance, impairment, function, or mental health outcomes in patients with hand and wrist scars were included. Two independent reviewers determined study eligibility and performed data extraction of a priori identified scar outcome domains. Data analysis included descriptive statistics and identification of discordance in taxonomy. Results Fifty-nine studies were included. Elective surgery cohorts were the most frequently included clinical population (nâ=â28; 47%) followed by burns (nâ=â16; 27%). Six different standardised scar outcome measures were reported by 25% of studies however only 7% of studies utilised a patient-reported measure. Scar symptoms were the most frequently reported outcome domain (81%); but taxonomy was incongruous, constructs lacked working definitions required for generalisability and outcome measurement was variable and unreported. Nineteen different measures of scar appearance and structure were reported by 30 (51%) of studies however only nine (23%) were patient-reported. Seven different hand function PROMs were reported by 25 (43%) studies. Person-centred domains including scar acceptability (12%), mental health impact (5%), and social participation (4%) were rarely reported. Conclusions This review highlights that evaluation and reporting of hand and wrist scar outcomes is not standardised, assessment methods and measures are under-reported and there is discordance in taxonomy. Evaluation is not person-centred, rather it is dependent on clinician assessment. Domains including scar acceptability, mental health, and social participation are rarely addressed. A stakeholder consensus derived hand and wrist scar core outcome measurement set will promote standardisation and underpin improvements in clinical research quality, transparency, and rigour
Cryogenic mechanisms for scanning and interchange of the Fabry-Perot interferometers in the ISO long wavelength spectrometer
The Infrared Space Observatory (ISO) is an ESA cornerstone mission for infrared astronomy. Schedules for launch in 1993, its four scientific instruments will provide unprecedented sensitivity and spectral resolution at wavelengths which are inaccessible using ground-based techniques. One of these, the Long Wavelength Spectrometer (LWS), will operate in the 45 to 180 micron region (Emery et. al., 1985) and features two Fabry-Perot interferometers mounted on an interchange mechanism. The entire payload module of the spacecraft, comprising the 60 cm telescope and the four focal plane instruments, is maintained at 2 to 4 K by an onboard supply of liquid helium. The mechanical design and testing of the cryogenic interferometer and interchange mechanisms are described
Spin dynamics of heterometallic Cr7M wheels (M = Mn, Zn, Ni) probed by inelastic neutron scattering
Inelastic neutron scattering has been applied to the study of the spin
dynamics of Cr-based antiferromagnetic octanuclear rings where a finite total
spin of the ground state is obtained by substituting one Cr(III) ion (s = 3/2)
with Zn (s = 0), Mn (s = 5/2) or Ni (s = 1) di-cations. Energy and intensity
measurements for several intra-multiplet and inter-multiplet magnetic
excitations allow us to determine the spin wavefunctions of the investigated
clusters. Effects due to the mixing of different spin multiplets have been
considered. Such effects proved to be important to correctly reproduce the
energy and intensity of magnetic excitations in the neutron spectra. On the
contrary to what is observed for the parent homonuclear Cr8 ring, the symmetry
of the first excited spin states is such that anticrossing conditions with the
ground state can be realized in the presence of an external magnetic field.
Heterometallic Cr7M wheels are therefore good candidates for macroscopic
observations of quantum effects.Comment: 9 pages, 11 figures, submitted to Phys. Rev. B, corrected typos and
added references, one sentence change
Vibrational strong coupling in liquid water from cavity molecular dynamics
We assess the cavity molecular dynamics method for the calculation of
vibrational polariton spectra, using liquid water as a specific example. We
begin by disputing a recent suggestion that nuclear quantum effects may lead to
a broadening of polariton bands, finding instead that they merely result in
anharmonic red shifts in the polariton frequencies. We go on to show that our
simulated cavity spectra can be reproduced to graphical accuracy with a
harmonic model that uses just the cavity-free spectrum and the geometry of the
cavity as input. We end by showing that this harmonic model can be combined
with the experimental cavity-free spectrum to give results in good agreement
with optical cavity measurements. Since the input to our harmonic model is
equivalent to the input to the transfer matrix method of applied optics, we
conclude that cavity molecular dynamics cannot provide any more insight into
the effect of vibrational strong coupling on the absorption spectrum than this
transfer matrix method, which is already widely used by experimentalists to
corroborate their cavity results.Comment: 10 pages, 5 figure
James Huttonâs geological tours of Scotland : romanticism, literary strategies, and the scientific quest
This article explores a somewhat neglected part of the story of the emergence of geology as a science and discourse in the late eighteenth century â James Huttonâs posthumously published accounts of the geological tours of Scotland that he undertook in the years 1785 to 1788 in search of empirical evidence in support of his theory of the Earth and that he intended to include in the projected third volume of his Theory of the Earth of 1795. The article brings some of the assumptions and techniques of literary criticism to bear on Huttonâs scientific travel writing in order to open up new connections between geology, Romantic aesthetics and eighteenth-century travel writing about Scotland. Close analysis of Huttonâs accounts of his field trips to Glen Tilt, Galloway and Arran, supplemented by later accounts of the discoveries at Jedburgh and Siccar Point, reveals the interplay between desire, travel and the scientific quest and foregrounds the textual strategies that Hutton uses to persuade his readers that they share in the experience of geological discovery and interpretation as âvirtual witnessesâ. As well as allowing us to revisit the interrelation between scientific theory and discovery, this article concludes that Hutton was a much better writer than he has been given credit for and suggests that if these geological tours had been published in 1795 they would have made it impossible for critics to dismiss him as an armchair geologist
Pressure-induced Miscibility Increase of CH4 in H2O: A Computational Study Using Classical Potentials
Methane and water demix under normal (ambient) pressure and temperature conditions, due to the polar nature of water and the apolar nature of methane. Recent experimental work has shown, though, that increasing the pressure to values between 1 and 2 GPa (10 to 20 kbar) leads to a marked increase of methane solubility in water, for temperatures which are well below the critical temperature for water. Here we perform molecular dynamics simulations based on classical force fields â which are well-used and have been validated at ambient conditions â for different values of pressure and temperature. We find the expected increase in miscibility for mixtures of methane and supercritical water; however our model fails to reproduce the experimentally observed increase in methane solubility at large pressures and below the critical temperature of water. This points to the need to develop more accurate force fields for methane and
methane-water mixtures under pressure
Land cover change in marginalised landscapes of South Africa (1984â2014): Insights into the influence of socio-economic and political factors
Rural landscapes in South Africa experience high conversion rates due to intense land use; however, the changes are site specific and depend on the socio-economic and political history of the area. Land cover change (LCC) was assessed in response to socio-economic and political factors in uThukela Municipal District, KwaZulu-Natal, using Landsat imagery from 1984 to 2014, while making comparisons to other studies in South Africa. Socio-economic/political data were used to gain insights into the observed LCC patterns. Land cover was classified using a random forest classifier, and accuracies ranging from 87% to 92% were achieved. Systematic and intensity analysis methods were used to describe patterns, rates, and transitions of LCC in Imbabazane (ILM) and Okhahlamba (OLM) local municipalities. The results showed a reduced rate of change intensity from 3.4% to 0.9% in ILM and from 3.1% to 1.1% in OLM between 1984 and 2014. Grassland was persistent, covering over 70% in both local municipalities between 1984 and 2014. Although persistent, grassland experienced respective losses of 3.7% and 14.3% in both observation periods in ILM and of 10.2% and 13.3% in OLM. During the analysis period, settlements and cropland gained actively in both local municipalities. The changes represent a degree of population, local authority, and peopleâs perception as influencers of land use and LCC. It is therefore argued that socio-economic and political changes can potentially influence land use and LCC; however, natural ecosystems can persist under those conditions, and this requires more research efforts.
Significance:
This study contributes towards a growing knowledge and understanding of land cover change studies in marginalised landscapes in South Africa. The findings enforce the notion that natural vegetation systems can be altered by human-induced land use such as expansion of settlement and commercial agricultural. We show that in recent times there has been a decline in the overall rate of land cover conversion, and a high persistence of grassland amid global change, although the quality of the vegetation needs further research. We argue that the changes observed in marginalised landscapes are potentially driven by socio-economic and political dynamics
Recommended from our members
Detection of [O I] 63 <i>Ό</i>m in absorption toward Sgr B2
A high signal-to-noise 52-90 ÎŒm spectrum is presented for the central part of the Sagittarius B2 complex. The data were obtained with the Long Wavelength Spectrometer on board the Infrared Space Observatory (ISO). The [O I] 63 ÎŒm line is detected in absorption even at the grating spectral resolution of 0.29 ÎŒm. A lower limit for the column density of atomic oxygen of the order of 1019 cm-2 is derived. This implies that more than 40% of the interstellar oxygen must be in atomic form along the line of sight toward the Sgr B2 molecular cloud
Recommended from our members
Thermal H<sub>2</sub>O emission from the Herbig-Haro flow HH 54
The first detection of thermal water emission from a Herbig-Haro object is presented. The observations were performed with the LWS (Long Wavelength Spectrograph) aboard ISO (Infrared Space Observatory). Besides H2O, rotational lines of CO are present in the spectrum of HH 54. These high-J CO lines are used to derive the physical model parameters of the FIR (far-infrared) molecular line emitting regions. This model fits simultaneously the observed OH and H2O spectra for an OH abundance X(OH)=10-6 and a water vapour abundance X(H2O)=10-5.
At a distance of 250pc, the total CO, OH and H2O rotational line cooling rate is estimated to be 1.3x10-2 Lâ, which is comparable to the mechanical luminosity generated by the 10km s-1 shocks, suggesting that practically all of the cooling of the weak-shock regions is done by these three molecular species alone
- âŠ