Remarks on the stability analysis of reactive flows

A simple model of compressible reacting flow is studied. First, a dispersion relation is derived for the linearized problem making a distinction between frozen and equilibrium sound speed. Second, the stability of the Von Neumann-Richtmyer scheme applied to this model is studied. A natural generalization of the C.F.L. condition is found

Perception of pain as a result of orthodontic treatment with fixed appliances

The aims of this study were to investigate the intensity, location and duration of patients' discomfort following insertion of orthodontic appliances, and to examine for interactions between patient age, gender, appliance type and the perception of pain. After insertion of orthodontic appliances, 170 patients received eight questionnaires, one they completed and returned after 4 h, then one daily for 7 days. The respondents' ages ranged from 8-53 years (median age 13 years 7 months); 45 per cent were male and 55 per cent female. Of the patients, 65 per cent reported pain after 4 h and 95 per cent after 24 h. After 7 days, 25 per cent of the patients still reported discomfort. Patients' pain intensity scores were significantly higher for the anterior than for the posterior teeth. On day 1, 16 per cent took analgesics and 18 per cent reported being awakened the first night. Comparing a 2 × 4 appliance, a full appliance in one arch and in both arches, no statistical differences were found for reported pain frequency, general intensity of pain, pain at the teeth, discomfort when biting and chewing and analgesic consumption. The perception of general pain intensity, analgesic consumption, pain when eating and the influence of discomfort on daily life were all significantly greater in girls than in boys. Patients younger than 13 years reported pain significantly less frequently than the older patients. The highest frequency of pain was found in the group of 13-16 year olds. The pain intensity did not differ among the age group

Abdominaler Schmerz

Zusammenfassung: Abdominalschmerzen können Ausdruck einer Vielzahl intra- und extraabdomineller Erkrankungen sein. Angesichts dieses breiten ätiologischen Spektrums gilt es, im Initialstadium der Diagnostik zielgerichtet vorzugehen, um ohne Zeitverzug die Ursache und damit letzlich die Dringlichkeit weitergehender Maßnahmen zu bestimmen. Ziel dieser Evaluation ist eine initiale risikostratifizierte Triagierung des Patienten. Im Gegensatz zu somatischen Ursachen abdominalen Schmerzes ist eine derartige kausale Therapie bei funktionellen Erkrankungen des Gastrointestinaltraktes zum gegenwärtigen Zeitpunkt nur sehr begrenzt möglich, sodass hierbei der Fokus auf eine bedarfs- und symptomadaptierte Behandlung gelegt werden sol

The performance of human papillomavirus high-risk DNA testing in the screening and diagnostic settings.

OBJECTIVE: We sought to evaluate the performance of the human papillomavirus high-risk DNA test in patients 30 years and older. MATERIALS AND METHODS: Screening (n=835) and diagnosis (n=518) groups were defined based on prior Papanicolaou smear results as part of a clinical trial for cervical cancer detection. We compared the Hybrid Capture II (HCII) test result with the worst histologic report. We used cervical intraepithelial neoplasia (CIN) 2/3 or worse as the reference of disease. We calculated sensitivities, specificities, positive and negative likelihood ratios (LR+ and LR-), receiver operating characteristic (ROC) curves, and areas under the ROC curves for the HCII test. We also considered alternative strategies, including Papanicolaou smear, a combination of Papanicolaou smear and the HCII test, a sequence of Papanicolaou smear followed by the HCII test, and a sequence of the HCII test followed by Papanicolaou smear. RESULTS: For the screening group, the sensitivity was 0.69 and the specificity was 0.93; the area under the ROC curve was 0.81. The LR+ and LR- were 10.24 and 0.34, respectively. For the diagnosis group, the sensitivity was 0.88 and the specificity was 0.78; the area under the ROC curve was 0.83. The LR+ and LR- were 4.06 and 0.14, respectively. Sequential testing showed little or no improvement over the combination testing. CONCLUSIONS: The HCII test in the screening group had a greater LR+ for the detection of CIN 2/3 or worse. HCII testing may be an additional screening tool for cervical cancer in women 30 years and older

Structure of self-organized Fe clusters grown on Au(111) analyzed by Grazing Incidence X-Ray Diffraction

We report a detailed investigation of the first stages of the growth of self-organized Fe clusters on the reconstructed Au(111) surface by grazing incidence X-ray diffraction. Below one monolayer coverage, the Fe clusters are in "local epitaxy" whereas the subsequent layers adopt first a strained fcc lattice and then a partly relaxed bcc(110) phase in a Kurdjumov-Sachs epitaxial relationship. The structural evolution is discussed in relation with the magnetic properties of the Fe clusters.Comment: 7 pages, 6 figures, submitted to Physical Review B September 200

Low energy measurement of the 7Be(p,gamma)8B cross section

We have measured the cross section of the 7Be(p,gamma)8B reaction for E_cm = 185.8 keV, 134.7 keV and 111.7 keV using a radioactive 7Be target (132 mCi). Single and coincidence spectra of beta^+ and alpha particles from 8B and 8Be^* decay, respectively, were measured using a large acceptance spectrometer. The zero energy S factor inferred from these data is 18.5 +/- 2.4 eV b and a weighted mean value of 18.8 +/- 1.7 eV b (theoretical uncertainty included) is deduced when combining this value with our previous results at higher energies.Comment: Accepted for publication in Phys. Rev. Let

Future orientation and planning in forestry: a comparison of forest managers' planning horizons in Germany and the Netherlands

Long range (or strategic) planning is an important tool for forest management to deal with the complex and unpredictable future. However, it is the ability to make meaningful predictions about the rapidly changing future that is questioned. What appears to be particularly neglected is the question of the length of time horizons and the limits (if any) to these horizons, despite being considered one of the most critical factors in strategic planning. As the future creation of values lies within individual responsibility, this research empirically explored the limits (if any) of individual foresters¿ time horizons. To draw comparisons between countries with different traditions in forest management planning, data were collected through telephone surveys of forest managers in the state/national forest services of the Netherlands and Germany. In order to minimize other cultural differences, the research in Germany concentrated on the federal state of Nordrhein-Westfalen, which has considerable similarities with the Netherlands, e.g. in topography, forest types and forest functions. The results show that, in practice, 15 years appears to be the most distant horizon that foresters can identify with. This is in sharp contrast to the time horizons spanning decades and even generations that are always said to exist in forestry. The ¿doctrine of the long run¿¿the faith in the capacity of foresters to overcome the barriers of the uncertain future and look ahead and plan for long-range goals¿which in many countries still underlies traditional forest management, can therefore be rejected