The effect of magnetic islands on ITG turbulence driven transport

In this work, we address the question of the influence of magnetic islands on the perpendicular transport due to steady-state ITG turbulence on the energy transport time scale. We demonstrate that turbulence can cross the separatrix and enhance the perpendicular transport across magnetic islands. As the perpendicular transport in the interior of the island sets the critical island size needed for growth of neoclassical tearing modes, this increased transport leads to a critical island size larger than that predicted from considering collisional conductivities, but smaller than that using anomalous effective conductivities. We find that on Bohm time scales, the turbulence is able to re-establish the temperature gradient across the island for islands widths $w \lesssim \lambda_{turb}$, the turbulence correlation length. The reduction in the island flattening is estimated by comparison with simulations retaining only the perpendicular temperature and no turbulence. At intermediate island widths, comparable to $\lambda_{turb}$, turbulence is able to maintain finite temperature gradients across the island

Plasma turbulence simulations with X-points using the flux-coordinate independent approach

In this work, the Flux-Coordinate Independent (FCI) approach to plasma turbulence simulations is formulated for the case of generic, static magnetic fields, including those possessing stochastic field lines. It is then demonstrated that FCI is applicable to nonlinear turbulent problems with and without X-point geometry. In particular, by means of simulations with the FENICIA code, it is shown that the standard features of ITG modes are recovered with reduced toroidal resolution. Finally, ITG turbulence under the influence of a static island is studied on the transport timescale with ITER-like parameters, showing the wide range of applicability of the method

Photoacoustic Imaging for Noninvasive Periodontal Probing Depth Measurements.

The periodontal probe is the gold standard tool for periodontal examinations, including probing depth measurements, but is limited by systematic and random errors. Here, we used photoacoustic ultrasound for high-spatial resolution imaging of probing depths. Specific contrast from dental pockets was achieved with food-grade cuttlefish ink as a contrast medium. Here, 39 porcine teeth (12 teeth with artificially deeper pockets) were treated with the contrast agent, and the probing depths were measured with novel photoacoustic imaging and a Williams periodontal probe. There were statistically significant differences between the 2 measurement approaches for distal, lingual, and buccal sites but not mesial. Bland-Altman analysis revealed that all bias values were < ±0.25 mm, and the coefficients of variation for 5 replicates were <11%. The photoacoustic imaging approach also offered 0.01-mm precision and could cover the entire pocket, as opposed to the probe-based approach, which is limited to only a few sites. This report is the first to use photoacoustic imaging for probing depth measurements with potential implications to the dental field, including tools for automated dental examinations or noninvasive examinations

A portable platform for accelerated PIC codes and its application to GPUs using OpenACC

We present a portable platform, called PIC_ENGINE, for accelerating Particle-In-Cell (PIC) codes on heterogeneous many-core architectures such as Graphic Processing Units (GPUs). The aim of this development is efficient simulations on future exascale systems by allowing different parallelization strategies depending on the application problem and the specific architecture. To this end, this platform contains the basic steps of the PIC algorithm and has been designed as a test bed for different algorithmic options and data structures. Among the architectures that this engine can explore, particular attention is given here to systems equipped with GPUs. The study demonstrates that our portable PIC implementation based on the OpenACC programming model can achieve performance closely matching theoretical predictions. Using the Cray XC30 system, Piz Daint, at the Swiss National Supercomputing Centre (CSCS), we show that PIC_ENGINE running on an NVIDIA Kepler K20X GPU can outperform the one on an Intel Sandybridge 8-core CPU by a factor of 3.4

Diffusion-weighted MRI in liver fibrosis staging: Added value of normalized ADC using spleen and renal cortex as reference organs

AbstractAimTo evaluate the potential value of the spleen and renal cortex as a reference organ to improve the performance of DWI in the assessment of liver fibrosis.Material and methods44 subjects were included: 30 patients with chronic viral hepatitis and 14 age matched volunteers. They were subjected to diffusion weighted MRI (DWI). Liver ADC, normalized ADC (ratio between ADC of liver to spleen (S-ADC) and renal cortex (R-ADC)) was calculated. Data was analyzed and ROC was used to evaluate the performance of ADC, S-ADC and R-ADC.ResultsNo significant difference between spleen ADC and renal ADC values between patient group and control group or in-betweens different fibrosis stages. The mean liver ADC was significantly lower in cirrhotic patients than control group (1.59±0.024 versus 1.55±0.036×10−3mm2/s, P=0.009) with some overlap in different fibrosis grades.With exception to stage 1 fibrosis, the mean S-ADC value was significantly lower in patients with different hepatic fibrosis stages in comparison to control group (P 0.02–<0.001). Significant negative correlation was noted between S-ADC value and fibrosis stage (r=−0.75, p<0.001). It had significant difference between stage 0 compared to stage 2, 3, and 4 as well as between stage 4 in comparison to stage 1, 2 and 3. S-ADC had a significant ability to differentiate between stages 0–1 Vs stage 2–4, stage 0–2 Vs stage 3–4 as well as stage 0–3 Vs stage 4.Significant negative correlation was noted between R-ADC value and fibrosis stage (r=−0.68, p<0.001). The mean R-ADC value was lower in patients with liver fibrosis compared to volunteers with significant difference between stage 0 and 3 and between stage 0 and 4 (P<0.001). It had significant difference between stage 0 compared to stage 3, and 4 as well as in stage 4 in comparison to stage 1 and 2. R-ADC has a significant ability to differentiate between stages 0–1 Vs stage 2–4, stage 0–2 Vs stage 3–4 as well as stage 0–3 Vs stage 4.ROC analysis showed higher performance using S-ADC in comparison to liver ADC and R-ADC while R-ADC had higher performance in comparison to liver ADC. The AUC, sensitivity, specificity, PPV, NPV and k-value for detection of fibrotic stages ⩾2 (0.85, 95.8%, 60%, 74%, 92% and 0.85 for S-ADC Vs 0.68, 66.7%, 60%, 66%, 60% and 0.28 for ADC and 0.85, 95.8%, 50%, 69%, 91% and 0.47 for R-ADC). and in detection of fibrotic stages ⩾3 was (0.86, 100%, 52%, 61%, 100% and 0.48 for S-ADC Vs 0.63, 63%, 52%, 50%, 65% and 0.14 for ADC and 0.88, 100%, 44%, 57%, 100% and 0.40 for R-ADC) while for fibrosis stage 4, the corresponding values was (1, 100%, 100%, 100%, 100% and 1 for S-ADC Vs 0.7, 81%, 54%, 37%, 90% and 0.26 for ADC and 0.65, 100%, 65%, 45%, 100% and 0.43 for R-ADC) respectively.ConclusionNormalized liver ADC using the spleen and kidney increases the performance of ADC in the evaluation of liver fibrosis which is highest in spleen normalized ADC

Inventarisasi Hama Persemaian di Hutan Tanaman Rakyat Desa Ngambur Kecamatan Bengkunat Belimbing Kabupaten Lampung Barat

Forest pest inventory is research activity to gather and arrange the data of pests existing in seedling periode. Pest inventory activites are used to determine pest types, the number and crop damage order to apply appropriate control. This research was aimed to identity the pest types and its attack levels at community plantation forest nursery. This research was conducted at Community Plantation Forest in Ngambur Village of Bengkunat subdistrict, West Lampung on April to May 2012. The collected data was identified taxonomically. The data was included of pest types, pest density, attack levels, and demages. All samples were collected using systematic method in diagonal pattern. The results was obtained 9 types in kadam nurseries, white albizia, and umbrella tree, which caterpillars (Daphnis hypothous), locust (Locusta migratoria),moths (Hyblaea puera), bag worm (Pteroma plagiophelps), bug (Cosmoleptrus sumatranus), mealy bug (Planococcus citri), leaf caterpillar (Doleschallia polibete), yellow butterfly (Eurema spp.), snail (Achatina fulica) and 1 type of insect predators that weaver ants (Oecophylla smaragdina). Insect population was high enough but not damage the plant nursery while the most dangerous insect pest was a bag worm (Pteroma plagiophelps) and moth (Hyblaea puera). Bag worm larvae cause severe damage, the loss on the leaves. The extent of damage by insect pests classified in the category of still mild attacks. Pest control can be done mechanically or chemically