Nonlinear inverse synthesis and eigenvalue division multiplexing in optical fiber channels

We scrutinize the concept of integrable nonlinear communication channels, resurrecting and extending the idea of eigenvalue communications in a novel context of nonsoliton coherent optical communications. Using the integrable nonlinear Schrödinger equation as a channel model, we introduce a new approach - the nonlinear inverse synthesis method - for digital signal processing based on encoding the information directly onto the nonlinear signal spectrum. The latter evolves trivially and linearly along the transmission line, thus, providing an effective eigenvalue division multiplexing with no nonlinear channel cross talk. The general approach is illustrated with a coherent optical orthogonal frequency division multiplexing transmission format. We show how the strategy based upon the inverse scattering transform method can be geared for the creation of new efficient coding and modulation standards for the nonlinear channel

Estimation of the OSNR penalty due to in-band crosstalk on the performance of virtual carrier-assisted metropolitan OFDM systems

The impact of the in-band crosstalk on the performance of virtual carrier (VC)-assisted direct detection (DD) multi-band orthogonal frequency division multiplexing (MB-OFDM) systems was numerically assessed via Monte-Carlo simulations, by means of a single interferer and 4-ary, 16-ary and 64-ary quadrature amplitude modulation (QAM) formats in the OFDM subcarriers. It was also investigated the influences of the virtual carrier-to-band power ratio (VBPR) and the virtual carrier-to-band gap (VBG) on the DD in-band crosstalk tolerance of the OFDM receiver. It was shown the modulation format order decrease enhances the tolerance to in-band crosstalk. When the VBG is the same for both interferer and selected signal, the interferer VBPR increase is seen to lead to lower optical signal-to-noise ratio (OSNR) penalties due to in-band crosstalk. Considering that the VCs frequencies of the selected and interferer OFDM signals are equal, the increase of the interferer VBG also gives rise to lower OSNR penalties. When the interferer and selected signals bands central frequencies are the same, the change of interferer VBG can attain 11 dB less tolerance to in-band crosstalk of the VC-assisted DD OFDM system. We also evaluate the error vector magnitude (EVM) accuracy of the in-band crosstalk tolerance of the DD OFDM receiver and our results show that the EVM estimations are inaccurate.info:eu-repo/semantics/acceptedVersio

Epidemiological Evidence for Work Load as a Risk Factor for Osteoarthritis of the Hip: A Systematic Review

Osteoarthritis of the hip (OA) is a common degenerative disorder of the joint cartilage that presents a major public health problem worldwide. While intrinsic risk factors (e.g, body mass and morphology) have been identified, external risk factors are not well understood. In this systematic review, the evidence for workload as a risk factor for hip OA is summarized and used to derive recommendations for prevention and further research.Epidemiological studies on workload or occupation and osteoarthritis of the hip were identified through database and bibliography searches. Using pre-defined quality criteria, 30 studies were selected for critical evaluation; six of these provided quantitative exposure data.Study results were too heterogeneous to develop pooled risk estimates by specific work activities. The weight of evidence favors a graded association between long-term exposure to heavy lifting and risk of hip OA. Long-term exposure to standing at work might also increase the risk of hip OA.It is not possible to estimate a quantitative dose-response relationship between workload and hip OA using existing data, but there is enough evidence available to identify job-related heavy lifting and standing as hazards, and thus to begin developing recommendations for preventing hip OA by limiting the amount and duration of these activities. Future research to identify specific risk factors for work-related hip OA should focus on implementing rigorous study methods with quantitative exposure measures and objective diagnostic criteria

Space Division Multiplexing in Optical Fibres

Optical communications technology has made enormous and steady progress for several decades, providing the key resource in our increasingly information-driven society and economy. Much of this progress has been in finding innovative ways to increase the data carrying capacity of a single optical fibre. In this search, researchers have explored (and close to maximally exploited) every available degree of freedom, and even commercial systems now utilize multiplexing in time, wavelength, polarization, and phase to speed more information through the fibre infrastructure. Conspicuously, one potentially enormous source of improvement has however been left untapped in these systems: fibres can easily support hundreds of spatial modes, but today's commercial systems (single-mode or multi-mode) make no attempt to use these as parallel channels for independent signals.Comment: to appear in Nature Photonic

Abstract C35: Filipinos and blacks at a disadvantage for breast cancer survival and in-state disparities in Nevada

Abstract Health disparities may differ by geographical area depending on contextual factors. With below average incidence, low mammography prevalence and above average mortality rates, the study of breast cancer survival outcomes is of particular interest in the state of Nevada. The health infrastructure in Southern Nevada is currently not supported by an established MD-type School of Medicine, despite the size of the Las Vegas metropolis, 2 million. We studied survival disparities for females with breast cancer in the Silver State for the period 2003-2010. Data came from the Nevada Central Cancer Registry and cases were followed-up until Dec 31 2012 using hospital records as well as in-state and national death index linkages. We analyzed cause-specific survival rates using the actuarial method. We assessed the impact of (1) tumor-related factors: AJCC stage at diagnosis, grade of differentiation, estrogen receptors; (2) demographic factors including age, race-ethnicity (non-Hispanic Whites, non-Hispanic Blacks, Hispanics, Asian Filipino, Asian other, American Indian) , marital status; and (3) social factors such as insurance and socio-economic status on survival outcomes for breast cancer using Cox regression. For censoring times, we used the presumed-alive assumption. A total of 11,110 cases of breast cancer cases diagnosed between 2003 and 2010 were analyzed. Survival in Northern Nevada –Reno was 88.2% after 5 years (95%CI 86.9-89.5) well within the US-SEER average of 87.0% (95%CI 86.9-87.2). Southern Nevada - Las Vegas lagged significantly behind with 83.1% (95%CI 82.2-84.0). Non-Hispanic Blacks had a 76.0% 5 year-survival (95%CI 72.6-79.4) and Filipino women 76.6% (71.3-82.0). In the multivariate analysis, Stage I, estrogen-receptor positive, and high grade of differentiation showed a lower mortality risk, while low SES and lack of insurance showed a higher mortality risk. After adjustment for all confounders, Black women showed higher mortality risk than Whites (HR 1.26 95%CI 1.06-1.50) and Southern Nevada had a 14% higher mortality risk compared to Northern Nevada for patients of the same age, race, insurance, stage at diagnosis (HR 1.14, 95%CI 1.00-1.30). The initial disadvantage for Filipino women in relation to Whites was no longer shown after adjustment for AJCC stage at diagnosis (HR 1.17, p&amp;lt; 0.05). Disparities according to tumor-related factors in Nevada were not different from those in the rest of the nation. However, unique disparities were observed according to demographic factors. A significant survival difference between the Northern and Southern regions of Nevada, with similar prevalence of mammography, and after adjustment for all known confounders, suggests disparities in quality of healthcare associated or not with different treatment compliance patterns. Black women are disadvantaged despite adjustment for SES, stage and insurance type, while the Filipino disadvantage is modifiable since it is caused by an unfavorable distribution of stage at diagnosis. Citation Format: Paulo S. Pinheiro, Nevena Cvijetic, Rachel Kelly, Carmen Ponce, Erin Kobetz-Kerman. Filipinos and blacks at a disadvantage for breast cancer survival and in-state disparities in Nevada. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr C35.</jats:p

Generation of a 3D proximal femur shape from a single projection 2D radiographic image

Summary Generalized Procrustes analysis and thin plate splines were employed to create an average 3D shape template of the proximal femur that was warped to the size and shape of a single 2D radiographic image of a subject. Mean absolute depth errors are comparable with previous approaches utilising multiple 2D input projections. Introduction Several approaches have been adopted to derive volumetric density (g cm-3) from a conventional 2D representation of areal bone mineral density (BMD, g cm-2). Such approaches have generally aimed at deriving an average depth across the areal projection rather than creating a formal 3D shape of the bone. Methods Generalized Procrustes analysis and thin plate splines were employed to create an average 3D shape template of the proximal femur that was subsequently warped to suit the size and shape of a single 2D radiographic image of a subject. CT scans of excised human femora, 18 and 24 scanned at pixel resolutions of 1.08 mm and 0.674 mm, respectively, were equally split into training (created 3D shape template) and test cohorts. Results The mean absolute depth errors of 3.4 mm and 1.73 mm, respectively, for the two CT pixel sizes are comparable with previous approaches based upon multiple 2D input projections. Conclusions This technique has the potential to derive volumetric density from BMD and to facilitate 3D finite element analysis for prediction of the mechanical integrity of the proximal femur. It may further be applied to other anatomical bone sites such as the distal radius and lumbar spine