Comparison of Multi-Channel Nonlinear Equalization using Inverse Volterra Series versus Digital Backpropagation in 400 Gb/s Coherent Superchannel

We investigate the performance of a Volterra-based nonlinear equalizer and the digitalbackpropagation (DBP) method in multi-channel nonlinear equalization after 20×80 km transmission distance. The Volterra equalizer, which operates with single-step-per-span, performs similarly compared to DBP with 40 steps-per-span

Comparison of Linear and Nonlinear Equalization for Ultra-High Capacity Spectral Superchannels

In ultra-high-speed (>400Gb/s per wavelength), high-spectral efficiency coherent optical communication systems using multi-carrier spectral superchannels, the maximum reach is severely limited due to linear and, foremost, nonlinear impairments. Hence, the implementation of advanced digital signal processing (DSP) techniques in optical transceivers is crucial for alleviating the impact of such impairments. However, the DSP performance improvement comes at the expense of increased cost and power consumption. Given that the computational complexity of the applied linear and nonlinear equalizers is the factor that determines the trade-off between the performance improvement and cost, in this study we provide an extended analysis on the computational complexity of various linear and nonlinear equalization approaches. First, we draw a complexity comparison between a conventional OFDM coherent receiver versus a filter-bank based OFDM receiver and it is shown that the latter provides significant complexity savings. Second, we present a comparison between the digital back-propagation split-step Fourier (DBP-SSF) method and the inverse Volterra series transfer function nonlinear equalizer (IVSTF-NLE) in terms of performance and computational complexity for a 32 Gbaud polarization multiplexed (PM)-16 quadrature amplitude modulation (QAM) OFDM superchannel

The relationship between the systemic inflammatory response, tumour proliferative activity, T-lymphocytic and macrophage infiltration, microvessel density and survival in patients with primary operable breast cancer

The significance of the inter-relationship between tumour and host local/systemic inflammatory responses in primary operable invasive breast cancer is limited. The inter-relationship between the systemic inflammatory response (pre-operative white cell count, C-reactive protein and albumin concentrations), standard clinicopathological factors, tumour T-lymphocytic (CD4+ and CD8+) and macrophage (CD68+) infiltration, proliferative (Ki-67) index and microvessel density (CD34+) was examined using immunohistochemistry and slide-counting techniques, and their prognostic values were examined in 168 patients with potentially curative resection of early-stage invasive breast cancer. Increased tumour grade and proliferative activity were associated with greater tumour T-lymphocyte (P<0.05) and macrophage (P<0.05) infiltration and microvessel density (P<0.01). The median follow-up of survivors was 72 months. During this period, 31 patients died; 18 died of their cancer. On univariate analysis, increased lymph-node involvement (P<0.01), negative hormonal receptor (P<0.10), lower albumin concentrations (P<0.01), increased tumour proliferation (P<0.05), increased tumour microvessel density (P<0.05), the extent of locoregional control (P<0.0001) and limited systemic treatment (Pless than or equal to0.01) were associated with cancer-specific survival. On multivariate analysis of these significant covariates, albumin (HR 4.77, 95% CI 1.35–16.85, P=0.015), locoregional treatment (HR 3.64, 95% CI 1.04–12.72, P=0.043) and systemic treatment (HR 2.29, 95% CI 1.23–4.27, P=0.009) were significant independent predictors of cancer-specific survival. Among tumour-based inflammatory factors, only tumour microvessel density (P<0.05) was independently associated with poorer cancer-specific survival. The host inflammatory responses are closely associated with poor tumour differentiation, proliferation and malignant disease progression in breast cancer

Volterra-based nonlinear compensation in 400 Gb/s WDM multiband coherent optical OFDM systems

\u3cp\u3eWe apply a 3\u3csup\u3erd\u3c/sup\u3e-order inverse Volterra series nonlinear equalizer to a 400 Gb/s WDM multiband PM-16QAM OFDM signal. IVSTF-NLE provides a 0.6 dB Q-factor improvement and 1 dB nonlinear threshold increase compared to linear equalization.\u3c/p\u3

Using the autism diagnostic Interview-Revised and the Autism diagnostic Observation Schedule-Generic for the diagnosis of Autism spectrum disorders in a Greek sample with a wide range of intellectual abilities

We studied the interrelationship between the Autism Diagnostic Observation Schedule-Generic (ADOS-G), the Autism Diagnostic Interview-Revised (ADI-R) and DSM-IV clinical diagnosis, in a Greek sample of 77 children and adolescents, referred for the assessment of a possible pervasive developmental disorder (PDD) and presenting a wide range of cognitive abilities. The agreement of the ADOS-G and the ADI-R with the clinical diagnosis was estimated as satisfactory and moderate, respectively, while both instruments presented with excellent sensitivity for the diagnosis of autistic disorder along with satisfactory specificity. ADOS-G/ADI-R agreement was estimated as fair. Our results confirm the discriminant validity of ADI-R and ADOS-G in diagnosing pervasive developmental disorders in children and adolescents with a wide range of intellectual abilities. © 2008 Springer Science+Business Media, LLC

The effect of S427F mutation on RXRα activity depends on its dimeric partner

RXRs are nuclear receptors acting as transcription regulators that control key cellular processes in all tissues. All type II nuclear receptors require RXRs for transcriptional activity by forming heterodimeric complexes. Recent whole-exome sequencing studies have identified the RXRα S427F hotspot mutation in 5% of the bladder cancer patients, which is always located at the interface of RXRα with its obligatory dimerization partners. Here, we show that mutation of S427 deregulates transcriptional activity of RXRα dimers, albeit with diverse allosteric mechanisms of action depending on its dimeric partner. S427F acts by allosteric mechanisms, which range from inducing the collapse of the binding pocket to allosteric stabilization of active co-activator competent RXRα states. Unexpectedly, RXR S427F heterodimerization leads to either loss- or gain-of-function complexes, in both cases likely compromising its tumor suppressor activity. This is the first report of a cancer-associated single amino acid substitution that affects the function of the mutant protein variably depending on its dimerization partner. This journal is © The Royal Society of Chemistry

Immunohistochemical evaluation of immune response in invasive ductal breast cancer of not-otherwise-specified type

We investigated endotumoral and peritumoral lymphocytic subsets [natural killer cells (NK), B-cells and cytotoxic/suppressor (CD8+) T-cells], and expression of MUC1 and MUC6 glycoprotein with regard to various clinicopathological parameters in invasive breast cancer tissues. The study population consisted of 64 female patients with invasive ductal breast cancer of not-otherwise-specified type. Thirty-five women with benign breast lesions served as controls. High-grade carcinomas exhibited higher numbers of endotumoral NK cells and B-cell aggregates than the rest of the tumors examined (P = 0.0003 and 0.027, respectively). Cases with more than three positive lymph nodes and with tumors over 2 cm in diameter exhibited higher numbers of endotumoral NK cells (P = 0.047 and 0.023, respectively). Increased numbers of peritumoral CD8+ T-cells were detected in cases with lymph node metastases (P = 0.045). MUC1 was expressed with weaker staining intensity in the control group than in the group with breast cancer (P = 0.011). Grade III carcinomas exhibited significantly stronger expression of MUC6 glycoprotein (P = 0.001) than the control group. In conclusion, tumors with markers of poor prognosis exhibited increased numbers of lymphocytic infiltrates, and of NK cells in particular, and stronger MUC1 and MUC6 glycoprotein immunoreactivity than did the other tumors. (C) 2003 Elsevier Science Ltd. All rights reserved