A heuristic quantum theory of the integer quantum Hall effect

Contrary to common belief, the current emitted by a contact embedded in a two-dimensional electron gas (2DEG) is quantized in the presence of electric and magnetic fields. This observation suggests a simple, clearly defined model for the quantum current through a Hall device that does not invoke disorder or interactions as the cause of the integer quantum Hall effect (QHE), but is based on a proper quantization of the classical electron drift motion. The theory yields a quantitative description of the breakdown of the QHE at high current densities that is in agreement with experimental data. Furthermore, several of its key points are in line with recent findings of experiments that address the dependency of the QHE on the 2DEG bias voltage, results that are not easily explained within the framework of conventional QHE models.Comment: 20 pages, 6 figure

Brachial Approach As an Alternative Technique of Fibrin Sheath Removal for Implanted Venous Access Devices.

Implanted venous access device (IVAD) late dysfunction is commonly caused by fibrin sheath formation. The standard method of endovascular fibrin sheath removal is performed via the femoral vein. However, it is not always technically feasible and sometimes contraindicated. Moreover, approximately 4-6 h of bed rest is necessary after the procedure. In this article, we describe an alternative method of fibrin sheath removal using the brachial vein approach in a young woman receiving chemotherapy for breast cancer. The right basilic vein was punctured, and a long 6°F introducer sheath was advanced into the right subclavian vein. Endovascular maneuvers consisted on advancing Atrieve™ Vascular Snare 15-9 mm after catheter insertion in the superior vena cava through a 5.2°F Judkins left catheter. IVAD patency was restored without any complication, and the patient was discharged immediately after the procedure. In conclusion, fibrin sheath removal from an obstructed IVAD could be performed via the right brachial vein. Further research is necessary in order to prove efficacy of this technique

Stress model for the wrinkling of ion-implanted layers

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Integrating soil moisture measurements into pasture growth forecasting in New Zealand's hill country

Forecasting pasture growth in hill country landscapes requires information about soil water retention characteristics, which will help to quantify both water uptake, and its percolation below the root zone. Despite the importance of soil moisture data in pasture productivity predictions, current models use low-resolution estimates of water input into their soil water balance equations and plant growth simulations. As a result, they frequently fail to capture the spatial and temporal variability of soil moisture in hill country soils. Wireless Sensor Networks (WSN) are promising in-situ measurement systems for monitoring soil moisture dynamics with high temporal resolution in agricultural soils. This paper presents the deployment of a soil moisture sensing network, utilising WSN technology and multi-sensor probes, to monitor soil water changes over a hill country farm in the northern Wairarapa region of the North Island. Processed capacitance-based raw data was converted to volumetric water content by means of a factory calibration function to assess sensor accuracy and to calculate soil water storage within the pasture root zone. The derived volumetric soil moisture data was examined in terms of its dependence on the variability and influences of hill country landscape characteristics such as aspect. The integration of spatially distributed sensors and multi-depth soil moisture measurements from various hillslope positions showed that slope and aspect exerted a significant impact on soil moisture values. Furthermore, considerable differences were identified in soil water profile responses to significant rainfall events and subsequent soil water redistribution. Initial indications are that high-resolution time series of accurate multi-depth soil moisture measurements collected by a WSN are valuable for investigating root zone water movement. Sensor evaluation and data analysis suggest that these devices and their associated datasets are able to contribute to an improved understanding of drying and wetting cycles and soil moisture variability. Potentially, this will create an opportunity to generate improved pasture growth predictions in pastoral hill country environments

Narráció és retorika = Narrative and Rhetoric

A kutatás a narratológiai és a retorikai elemzések egymással való kapcsolatba hozásának lehetőségeit vizsgálta. Különös figyelmet fordítottunk az irodalomtörténeti elbeszélésre, amely egyrészt történetet mond, másrészt meggyőzni igyekszik, következésképpen narratív és retorikai formáltsága elvileg sem választható szét, valamint a fenségesre, amely az elbeszélhetetlen elbeszélése, és így a lehetetlen megvalósítására talál retorikai stratégiákat, a narratíva megszakításaként is értelmezhető. Prométheusz mítoszát választottuk ki annak vizsgálatára, milyen retorikával beszélhető el újra és újra az európai kultúra egyik alaptörténete. | The project focused on the potentials of connecting narratological and rhetorical analyses. A special emphasis was laid on the literary historical narration, which both tells a (hi)story and tries to persuade readers, and therefore its narrative and rhetorical formations cannot be theoretically separated; another important issue was the sublime, which can be described as the narration of what cannot be narrated, and therefore it seeks for rhetoric strategies to realize the impossible. The project has chosen the myth of Prometheus to analyze which rhetoric strategies make possible the repeated retelling of a basic story of the European culture

Ascending aortic remodelling in Fabry disease after long-term enzyme replacement therapy.

Previous cross-sectional studies reported a high prevalence of ascending aorta dilations/aneurysms in male adults with Fabry disease, independently of cardiovascular risk factors. To characterise the remodelling of the ascending aorta in classic Fabry disease under long-term enzyme replacement therapy. Diameter of the ascending aorta was measured with magnetic resonance imaging at the sino-tubular junction (STJ), and proximal (pAsAo), and distal ascending aorta (dAsAo) at baseline, and after 5 and 10 years of enzyme replacement therapy in 15 adult Fabry patients (10 males; 5 females). Over a mean follow-up of 9.5 years, the annual expansion rates measured in 10 males with Fabry disease were 0.41 ± 0.16, 0.36 ± 0.25 and 0.41 ± 0.26 mm/y at the STJ, pAsAo and dAsAo, respectively. Expansion rate at the pAsAo level in male patients was significantly higher than the expected expansion projected from theoretical normal values: 0.36 ± 0.25 vs 0.13 ± 0.05, p = 0.017. In 5 females, the annual expansion rates at the STJ, pAsAo and dAsAo were 0.14 ± 0.11, 0.21 ± 0.18 and 0.26 ± 0.24 mm/y, respectively. There was no significant difference from the projected normal expansion rate at the level of the pAsAo: 0.21 ± 0.18 vs 0.13 ± 0.04, p = 0.39. Our data suggest that the remodelling of the ascending aorta is more pronounced in male patients with Fabry disease under long-term enzyme replacement therapy compared with the progression observed in a large population study

Evolution of the Cross-Sectional Area of the Osseous Lumbar Spinal Canal across Decades: A CT Study with Reference Ranges in a Swiss Population.

Spinal canal dimensions may vary according to ethnicity as reported values differ among studies in European and Chinese populations. Here, we studied the change in the cross-sectional area (CSA) of the osseous lumbar spinal canal measured in subjects from three ethnic groups born 70 years apart and established reference values for our local population. This retrospective study included a total of 1050 subjects born between 1930 and 1999 stratified by birth decade. All subjects underwent lumbar spine computed tomography (CT) as a standardized imaging procedure following trauma. Three independent observers measured the CSA of the osseous lumbar spinal canal at the L2 and L4 pedicle levels. Lumbar spine CSA was smaller at both L2 and L4 in subjects born in later generations (p < 0.001; p = 0.001). This difference reached significance for patients born three to five decades apart. This was also true within two of the three ethnic subgroups. Patient height was very weakly correlated with the CSA at both L2 and L4 (r = 0.109, p = 0.005; r = 0.116, p = 0.002). The interobserver reliability of the measurements was good. This study confirms the decrease of osseous lumbar spinal canal dimensions across decades in our local population