Strategies for Improving Semi-automated Topic Classification of Media and Parliamentary documents

Since 1995 the techniques and capacities to store new electronic data and to make it available to many persons have become a common good. As of then, different organizations, such as research institutes, universities, libraries, and private companies (Google) started to scan older documents and make them electronically available as well. This has generated a lot of new research opportunities for all kinds of academic disciplines. The use of software to analyze large datasets has become an important part of doing research in the social sciences. Most academics rely on human coded datasets, both in qualitative and quantitative research. However, with the increasing amount of datasets and the complexity of the questions scholars pose to the datasets, the quest for more efficient and effective methods is now on the agenda. One of the most common techniques of content analysis is the Boolean key-word search method. To find certain topics in a dataset, the researcher creates first a list of keywords, added with certain parameters (AND, OR etc.). All keys are usually grouped in families and the entire list of keys and groups is called the ontology. Then the keywords are searched in the dataset, retrieving all documents containing the specified keywords. The online newspaper dataset, LexisNexis, provides the user with such a Boolean search method. However, the Boolean key-word search is not always satisfying in terms of reliability and validity. For that reason social scientists rely on hand-coding. Two projects that do so are the congressional bills project (www.congressionalbills.org ) and the policy agenda-setting project (see www.policyagendas.org ). They developed a topic code book and coded various different sources, such as, the state of the union speeches, bills, newspaper articles etcetera. The continuous improving automated coding techniques, and the increasing number of agenda setting projects (in especially European countries), however, has made the use of automated coding software a feasible option and also a necessity

Vegetative propagation of the red alga Rhodochorton purpureum by means of fragments that escape digestion by herbivores

Intertidal populations of the filamentous red alga Rhodochorton purpureujn (Lightf.) Rosenv. (Nemaliales, Acrochaetiaceae) in the Northern Netherlands grow as dense velvety turfs in the understory of large fucalean algae. The small and rather constant size of the turf (1 to 1.5 mm) and the high percentage of 'decapitated' filaments suggest that the turf is continually 'shorn' by herbivores. Two grazing invertebrates were found on the turf: the gastropod Littorina littorea (L.) and the amphipod Gamrnarus salinus Spooner Differences between the 2 grazers in the size of ingested R. purpureum fragments and in the proportion of ingested fragments with intact apices were attributed to differences in their feeding mechanisms. Both species egested live R. purpureum fragments In their faecal pellets. These fragments had the capacity to regenerate into new filaments when cultured in the laboratory. In the field small tufts of R. purpureurn filaments were found on bare substratum, originating from fragments contained in sticky, detritus-rich envelopes, probably faecal pellets. Experiments in unlalgal cultures showed that the regeneratlve capacity of fragments is very high, as it proceeds over d broad range of temperature and light conditions, even in total darkness We conclude that the capacity of R. purpureum fragments to escape digestion by herbivores probably plays an important role in vegetative propagation of the species

Nothing moves a surface: vacancy mediated surface diffusion

We report scanning tunneling microscopy observations, which imply that all atoms in a close-packed copper surface move frequently, even at room temperature. Using a low density of embedded indium `tracer' atoms, we visualize the diffusive motion of surface atoms. Surprisingly, the indium atoms seem to make concerted, long jumps. Responsible for this motion is an ultra-low density of surface vacancies, diffusing rapidly within the surface. This interpretation is supported by a detailed analysis of the displacement distribution of the indium atoms, which reveals a shape characteristic for the vacancy mediated diffusion mechanism that we propose.Comment: 4 pages; for associated movie, see http://www-lion.leidenuniv.nl/sections/cm/groups/interface/projects/therm

A randomised controlled trial of the clinical effectiveness and cost-effectiveness of different knee prostheses : the Knee Arthroplasty Trial (KAT)

Peer reviewedPublisher PD

First attempt success of video versus direct laryngoscopy for endotracheal intubation by ambulance nurses: a prospective observational study

Purpose: The aim of this study was to compare the rate of first attempt success of endotracheal intubation performed by ambulance nurses in patients with a Glasgow Coma Scale (GCS) of 3 using video laryngoscopy versus direct laryngoscopy. Methods: A prospective cohort study was conducted in a single, independent ambulance service. Twenty of a total of 65 nurse-staffed ambulances were equipped with a video laryngoscope; a classic direct laryngoscope (Macintosh) was available on all 65 ambulances. The primary outcome was first attempt success of the intubation. Secondary outcomes were overall success, time needed for intubation, adverse events, technical or environmental issues encountered, and return of spontaneous circulation (ROSC). Ambulance nurses were asked if the intubation device had affected the outcome of the intubation. Results: The first attempt success rate in the video laryngoscopy group [53 of 93 attempts (

Decision making in prehospital traumatic cardiac arrest; A qualitative study

Background: Despite improving survival of patients in prehospital traumatic cardiac arrest (TCA), initiation and/or discontinuation of resuscitation of TCA patients remains a subject of debate among prehospital emergency medical service providers. The aim of this study was to identify factors that influence decision making by prehospital emergency medical service providers during resuscitation of patients with TCA. Methods: Twenty-five semi-structured interviews were conducted with experienced ambulance nurses, HEMS nurses and HEMS physicians individually, followed by a focus group discussion. Participants had to be currently active in prehospital medicine in the Netherlands. Interviews were encoded for analysis using ATLAS.ti. Using qualitative analysis, different themes around decision making in TCA were identified. Results: Eight themes were identified as being important factors for decision making during prehospital TCA. These themes were: (1) factual information (e.g., electrocardiography rhythm or trauma mechanism); (2) fear of providing futile care or major impairment if return of spontaneous circulation was obtained; (3) potential organ donation; (4) patient age; (5) suspicion of attempted suicide; (6) presence of bystanders or family; (7) opinions of other team members; and (8) training and education. Several ambulance nurses reported they do not feel adequately supported by the current official national ambulance guidelines on TCA, nor did they feel sufficiently trained to perform pre-hospital interventions such as endotracheal intubation or needle thoracocentesis on these patients. Conclusion: Eight themes were identified as being important for decision making during prehospital TCA. While guidelines based on prognostic factors are important, it should be recognized that decision making in TCA is impacted by more than factual information alone. This should be reflected in educational programs and future guidelines

Deep-water macroalgae from the Canary Islands: new records and biogeographical relationships

Due to the geographical location and paleobiogeography of the Canary Islands, the seaweed flora contains macroalgae with different distributional patterns. In this contribution, the biogeographical relations of several new records of deep-water macroalgae recently collected around the Canarian archipelago are discussed. These are Bryopsidella neglecta (Berthotd) Rietema,Discosporangium mesarthrocarpum (Meneghini) Hauck, Hincksia onslowensis (Amsler et Kapraun)P.C. Silva, Syringoderma floridana Henry, Peyssonnelia harveyana J. Agardh, Cryptonemia seminervis(C. Agardh) J. Agardh, Botryodadia wynnei Ballantine, Gloiocladia blomquistii (Searles) R. E.Norris, PIahchrysis peltata (W. R. Taylor) P. Huv4 et H. Huv4, Leptofauchea brasiliensis Joly, and Sarcodiotheca divaricata W. R. Taylor. These new records, especially those in the Florideophyceae,support the strong affinity of the Canary Islands seaweed flora with the warm-temperate Mediterranean-Atlantic region. Some species are recorded for the first time from the east coast of the Atlantic Ocean, enhancing the biogeographic relations of the Canarian marine flora with that of the western Atlantic regions

Comparison of three radiolabelled peptide analogues for CCK-2 receptor scintigraphy in medullary thyroid carcinoma

Purpose: Cholecystokinin 2 (CCK-2) receptor overexpression has been demonstrated in a high percentage of medullary thyroid carcinomas (MTC). Analogous to somatostatin receptors, CCK-2 receptors might be viable targets for radionuclide scintigraphy and/or radionuclide therapy. Several CCK-2 receptor-binding radiopeptides have been developed, and some have been carried through into clinical studies. However, these studies are mostly limited and difficult to compare. The aim of this study was to evaluate the diagnostic and therapeutic potential of three promising CCK-2 receptor-binding radiopeptides in patients with MTC. Methods: 111In-DOTA-(D)Asp-Tyr-Nle-Gly-Trp-Nle- Asp-Phe-NH2 (111In-DOTA-CCK), a CCK analogue, and the gastrin-based ligands 99mTc-N4-Gly-(D)Glu-(Glu) 5-Ala-Tyr-Gly-Trp-Met-Asp-Phe-NH2 (99mTc- demogastrin 2) and 111In-DOTA-(D)Glu-Ala-Tyr-Gly-Trp-Met-Asp-Phe- NH2 (111In-DOTA-MG11) were each administered to the same group of six patients. Planar images made at 3-5, 7 and 24 h p.i. were used for comparison of tumour visualisation and renal uptake. Results: 99mTc-demogastrin 2 scintigraphy visualised all known lesions and new lesions in four of six patients. 111In-DOTA-CCK and 111In-DOTA-MG11 on the other hand missed several lesions; tumour uptake of these two radiopharmaceuticals was quite low. Comparison of retention of renal activity showed no major differences between the three radiopeptides. Conclusion: 99mTc-demogastrin 2 scintigraphy appeared most promising as a diagnostic tool in patients with MTC. Further studies are required to evaluate its value in patient management. Direct comparisons of the compounds studied strongly suggests that 111In-DOTA-CCK and 111In-DOTA-MG11 have less potential as imaging agents than 99mTc-demogastrin 2. These DOTA-linked compounds are considered unlikely to be useful for radionuclide therapy because of low tumour uptake

Self-diffusion of adatoms, dimers, and vacancies on Cu(100)

We use ab initio static relaxation methods and semi-empirical molecular-dynamics simulations to investigate the energetics and dynamics of the diffusion of adatoms, dimers, and vacancies on Cu(100). It is found that the dynamical energy barriers for diffusion are well approximated by the static, 0 K barriers and that prefactors do not depend sensitively on the species undergoing diffusion. The ab initio barriers are observed to be significantly lower when calculated within the generalized-gradient approximation (GGA) rather than in the local-density approximation (LDA). Our calculations predict that surface diffusion should proceed primarily via the diffusion of vacancies. Adatoms are found to migrate most easily via a jump mechanism. This is the case, also, of dimers, even though the corresponding barrier is slightly larger than it is for adatoms. We observe, further, that dimers diffuse more readily than they can dissociate. Our results are discussed in the context of recent submonolayer growth experiments of Cu(100).Comment: Submitted to the Physical Review B; 15 pages including postscript figures; see also http://www.centrcn.umontreal.ca/~lewi

Decay of isolated surface features driven by the Gibbs-Thomson effect in analytic model and simulation

A theory based on the thermodynamic Gibbs-Thomson relation is presented which provides the framework for understanding the time evolution of isolated nanoscale features (i.e., islands and pits) on surfaces. Two limiting cases are predicted, in which either diffusion or interface transfer is the limiting process. These cases correspond to similar regimes considered in previous works addressing the Ostwald ripening of ensembles of features. A third possible limiting case is noted for the special geometry of "stacked" islands. In these limiting cases, isolated features are predicted to decay in size with a power law scaling in time: A is proportional to (t0-t)^n, where A is the area of the feature, t0 is the time at which the feature disappears, and n=2/3 or 1. The constant of proportionality is related to parameters describing both the kinetic and equilibrium properties of the surface. A continuous time Monte Carlo simulation is used to test the application of this theory to generic surfaces with atomic scale features. A new method is described to obtain macroscopic kinetic parameters describing interfaces in such simulations. Simulation and analytic theory are compared directly, using measurements of the simulation to determine the constants of the analytic theory. Agreement between the two is very good over a range of surface parameters, suggesting that the analytic theory properly captures the necessary physics. It is anticipated that the simulation will be useful in modeling complex surface geometries often seen in experiments on physical surfaces, for which application of the analytic model is not straightforward.Comment: RevTeX (with .bbl file), 25 pages, 7 figures from 9 Postscript files embedded using epsf. Submitted to Phys. Rev. B A few minor changes made on 9/24/9