A Tandem Fluid Network with L\'evy Input in Heavy Traffic

In this paper we study the stationary workload distribution of a fluid tandem queue in heavy traffic. We consider different types of L\'evy input, covering compound Poisson, $\alpha$-stable L\'evy motion (with $1<\alpha<2$), and Brownian motion. In our analysis we separately deal with L\'evy input processes with increments that have finite and infinite variance. A distinguishing feature of this paper is that we do not only consider the usual heavy-traffic regime, in which the load at one of the nodes goes to unity, but also a regime in which we simultaneously let the load of both servers tend to one, which, as it turns out, leads to entirely different heavy-traffic asymptotics. Numerical experiments indicate that under specific conditions the resulting simultaneous heavy-traffic approximation significantly outperforms the usual heavy-traffic approximation

The potential impact of CT-MRI matching on tumor volume delineation in advanced head and neck cancer

To study the potential impact of the combined use of CT and MRI scans on the Gross Tumor Volume (GTV) estimation and interobserver variation. Four observers outlined the GTV in six patients with advanced head and neck cancer on CT, axial MRI, and coronal or sagittal MRI. The MRI scans were subsequently matched to the CT scan. The interobserver and interscan set variation were assessed in three dimensions. The mean CT derived volume was a factor of 1.3 larger than the mean axial MRI volume. The range in volumes was larger for the CT than for the axial MRI volumes in five of the six cases. The ratio of the scan set common (i.e., the volume common to all GTVs) and the scan set encompassing volume (i.e., the smallest volume encompassing all GTVs) was closer to one in MRI (0.3-0.6) than in CT (0.1-0.5). The rest volumes (i.e., the volume defined by one observer as GTV in one data set but not in the other data set) were never zero for CT vs. MRI nor for MRI vs. CT. In two cases the craniocaudal border was poorly recognized on the axial MRI but could be delineated with a good agreement between the observers in the coronal/sagittal MRI. MRI-derived GTVs are smaller and have less interobserver variation than CT-derived GTVs. CT and MRI are complementary in delineating the GTV. A coronal or sagittal MRI adds to a better GTV definition in the craniocaudal directio

Cortical Tonotopic Map Changes in Humans Are Larger in Hearing Loss Than in Additional Tinnitus

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IFNGR1 single nucleotide polymorphisms in rheumatoid arthritis

On the basis of their biological function, potential genetic candidates for susceptibility to rheumatoid arthritis can be postulated. IFNGR1, encoding the ligand-binding chain of the receptor for interferon gamma, IFNγR1, is one such gene because interferon gamma is involved in the pathogenesis of the disease. In the coding sequence of IFNGR1, two nucleotide positions have been described to be polymorphic in the Japanese population. We therefore investigated the association of those two IFNGR1 single nucleotide polymorphisms with rheumatoid arthritis in a case-control study in a central European population. Surprisingly, however, neither position was polymorphic in the 364 individuals examined, indicating that IFNGR1 does not contribute to susceptibility to rheumatoid arthritis, at least in Caucasians

Origin of the shadow Fermi surface in Bi-based cuprates

We used angle-resolved photoemission spectroscopy to study the shadow Fermi surface in one layer Bi2Sr1.6La0.4CuO6+delta and two layer (Bi,Pb)2Sr2CaCu2O8+delta. We find the shadow band to have the same peakwidth and dispersion as the main band. In addition, the shadow band/main band intensity ratio is found to be binding energy independent. Consequently, it is concluded that the shadow bands in Bi-based HTSC do not originate from antiferromagnetic interactions but have a structural origin.Comment: 10 pages, 2 figure

Is radiographic progression of late-onset rheumatoid arthritis different from young-onset rheumatoid arthritis? Results from the Swiss prospective observational cohort

Objective. RA can be categorized into late-onset RA (LORA, >60-65 years) and young-onset RA (YORA, 30-55 years), depending on the patient's age at disease onset. Since the average age of the population is continuously increasing, LORA will most probably gain in importance in the future. Despite this growing importance, LORA has not been the focus of much interest in the past. The aim of this study was to analyse radiographic damage progression of early disease in LORA compared with YORA patients. Methods. We included all patients from the Swiss RA registry, Swiss Clinical Quality Management in RA, with recent-onset arthritis, either RA (disease duration ≤1 year) or undifferentiated arthritis, as diagnosed by the data-entering physician. Patients were followed for 5 years. The cut-off between YORA and LORA was operationally set at 60 years of age. The primary outcome of this study was disease progression and activity, which was assessed based on the 28-joint DAS (DAS28) and the progression of joint erosions using a validated scoring system (Ratingen score). Results. A total of 592 patients with early disease were analysed. The age at disease onset had a Gaussian distribution, with a single peak at 54 years of age; 366 patients were categorized as YORA and 226 as LORA at disease onset. DAS28 scores were significantly higher among LORA as compared with YORA patients (4.8 vs 4.5, P = 0.049). Corticosteroids were used in 68% of LORA patients as a first-line treatment, compared with 25.4% in YORA patients (χ2 test: 54.58; P < 0.0001). In contrast, DMARDs were used in 100% of the YORA patients as first-line treatment, compared with 91.2% of the LORA patients. During follow-up, new glucocorticoids, synthetic DMARDs or biologic DMARDs were initiated in 32.8%, 61.1% and 14.1% of all YORA patients and 17.5%, 54.6% and 6.6% of LORA patients, respectively (χ2 test: 7.08, 22.53, 54.4; all P < 0.01). The DAS28 scores decreased in both groups during the observed time period, and the initial differences in disease activity vanished after 6 months and during the subsequent follow-up. The Ratingen score was higher in LORA than in YORA patients at inclusion (12.7 vs 5.6, P < 0.0001). The rate of radiographic progression at 5 years was similar when comparing LORA and YORA (3.3 vs 2.6, respectively, P = 0.64). The Ratingen scores at onset and during follow-up over 5 years did not clearly separate LORA and YORA into two groups, but rather, increased linearly when comparing the patients in groups per decade from 20 to 92 years of age. Conclusion. Our results did not show LORA as a separate subgroup of RA with a different prognosis with regard to radiographic progressio