Inward propagating chemical waves in Taylor vortices

Advection-reaction-diffusion (ARD) waves in the Belousov-Zhabotinsky reaction in steady Taylor-Couette vortices have been visualized using magnetic-resonance imaging and simulated using an adapted Oregonator model. We show how propagating wave behavior depends on the ratio of advective, chemical and diffusive time scales. In simulations, inward propagating spiral flamelets are observed at high Damköhler number (Da). At low Da, the reaction distributes itself over several vortices and then propagates inwards as contracting ring pulses—also observed experimentally

What makes medical students better listeners?

Diagnosing heart conditions by auscultation is an important clinical skill commonly learnt by medical students. Clinical proficiency for this skill is in decline [1], and new teaching methods are needed. Successful discrimination of heartbeat sounds is believed to benefit mainly from acoustical training [2]. From recent studies of auditory training [3,4] we hypothesized that semantic representations outside the auditory cortex contribute to diagnostic accuracy in cardiac auscultation. To test this hypothesis, we analysed auditory evoked potentials (AEPs) which were recorded from medical students while they diagnosed quadruplets of heartbeat cycles. The comparison of trials with correct (Hits) versus incorrect diagnosis (Misses) revealed a significant difference in brain activity at 280-310 ms after the onset of the second cycle within the left middle frontal gyrus (MFG) and the right prefrontal cortex. This timing and locus suggest that semantic rather than acoustic representations contribute critically to auscultation skills. Thus, teaching auscultation should emphasize the link between the heartbeat sound and its meaning. Beyond cardiac auscultation, this issue is of interest for all fields where subtle but complex perceptual differences identify items in a well-known semantic context

Building information deduced : state and potentials for Information query in building information modelling

In recent years, Building Information Models have become commonplace in building profession. The extensive use and increasing experience with BIM models offers new perspectives and potentials for design and planning. A recent stakeholder study conducted by the authors of this paper show that in practice models are no longer solely observed as culmination of knowledge in a 3d representation of future built structures, but as a source of information in itself. Experienced users of BIM want to Find Information within a model or across a set of these and Compare models in order to evaluate states of a model, differences in separate models or models from different point of time. Current BIM tools support both modes only in a rudimentary form. This paper discusses current modes of information query within and across BIM models, shows beneficial scenarios for building and planning practice through customised queries and exemplifies these on the base of a scripted tool. This customized approach is used to test approaches for a machine-based assessment of Level of detail and BIM-readiness in BIM models

ESC NN-Potentials in Momentum Space. I. PS-PS Exchange Potentials

A momentum space representation is derived for the Nijmegen Extended-Soft-Core (ESC) interactions. The partial wave projection of this representation is carried through, in principle for Two-Meson-Exchange (TME) in general. Explicit results for the momentum space partial wave NN-potentials from PS-PS-Exchange are given.Comment: 23 pages, 2 PostScript figures, revtex

<i>Vibrio neptunius</i> sp. nov., <i>Vibrio brasiliensis</i> sp. nov. and <i>Vibrio xuii</i> sp. nov., isolated from the marine aquaculture environment (bivalves, fish, rotifers and shrimps)

The fluorescent amplified fragment length polymorphism (FAFLP) groups A5 (21 isolates), A8 (6 isolates) and A23 (3 isolates) distinguished in an earlier paper (Thompson et al., Syst Appl Microbiol 24, 520-538, 2001) were examined in more depth. These three groups were phylogenetically related to Vibrio tubiashii, but DNA-DNA hybridization experiments proved that the three AFLP groups are in fact novel species. Chemotaxonomic and phenotypic analyses further revealed several differences among the 30 isolates and known Vibrio species. It is proposed to accommodate these isolates in three novel species, namely Vibrio neptunius (type strain LMG 20536T; EMBL accession no. AJ316171; G + C content of the type strain 46·0 mol%), Vibrio brasiliensis (type strain LMG 20546T; EMBL accession no. AJ316172; G + C content of the type strain 45·9 mol%) and Vibrio xuii (type strain LMG 21346T; EMBL accession no. AJ316181; G + C content of the type strain 46·6 mol%). These species can be differentiated on the basis of phenotypic features, including fatty acid composition (particularly 14 : 0 iso, 14 : 0 iso 3-OH, 16 : 0 iso, 16 : 0, 17 : 0 and 17 : 1?8c), enzyme activities and utilization and fermentation of various carbon sources

The physiological effects of elevated intra-abdominal pressure following aneurysm repair

AbstractObjectives: elevated intra-abdominal pressure (IAP) may cause widespread organ dysfunction (abdominal compartment syndrome) through effects on the respiratory, cardiac, renal and gastro-intestinal systems. The aim of this study was to document IAP following aneurysm surgery, and to determine the effect of IAH on outcome. Design: prospective observational study. Setting: University Hospital. Subjects: the patient cohort comprised 75 patients undergoing infra-renal aneurysm repair (53 non-ruptured [40 conventional - 1 death, 13 endovascular] and 22 conventionally repaired ruptured AAA - 8 deaths). IAP was quantified by bladder manometry at the termination of the procedure and at 24 h intervals in patients who remained intubated. Physiological indices of organ function were recorded. Statistical analysis utilized the unpaired t-test, Fischer's exact test and Pearson's correlation. Results: IAP was significantly higher at abdominal closure following ruptured aneurysm repair (15.4 mmHg [SE 1.6]) than conventional (10.5 [0.89]) or endovascular elective repair (6.4 [1.0]) of non-ruptured AAA. The sensitivity and specificity of IAP to predict subsequent mortality was analysed using a receiver characteristic operating curve. This analysis demonstrated that a cut off of 15 mmHg was the most useful for indicating patients at risk (sensitivity 0.66, specificity 0.79). Physiological indices of organ dysfunction (pH[p = 0.027], base excess [p = 0.005], peak inspiratory pressure [p = 0.0015], CVP and urine output [p = 0.0029]) were significantly impaired in patients with IAP ≥ 15 mmHg, in comparison to patients with lower pressures. IAP correlated significantly with indices of cardiac (CVP p = 0.038), respiratory (PaO2/FiO2, p = 0.026), and renal function (urine output p = 0.046). Conclusions: these data suggest that the management of IAH may have a role following repair of ruptured AAA. High intra-abdominal pressures rarely complicate elective or endovascular aneurysm repair.Eur J Vasc Endovasc Surg 26, 293-298 (2003