Optical performance monitoring for OFDM using low bandwidth coherent receivers.

We propose using low bandwidth coherent receivers for distributed optical performance monitoring. We demonstrate optical signal-to-noise ratio (OSNR) monitoring of both 20-Gb/s single-polarization and 40-Gb/s polarization-multiplexed coherent optical orthogonal frequency-division multiplexing (CO-OFDM) signals with a 0.8-GHz receiver using both data-aided (DA) and non-data-aided (NDA) approaches.

The validity of "Odd and Even" channels for testing all-optical OFDM and Nyquist WDM long-haul fiber systems.

We investigate experimentally the validity of testing all-optical OFDM and Nyquist WDM systems using interleaved test channels derived from only two data sources. These "odd and even" channels are insufficiently decorrelated, so experiments underestimate the inter-carrier interference (ICI). Additionally, numerical simulations demonstrate that using odd and even channels generates stronger nonlinear distortions during transmission, causing an unrealistically large penalty in the nonlinearity-limited region.

Improved two-stage equalization for coherent Pol-Mux QPSK and 16-QAM systems.

We report a two-stage blind frequency domain equalization method for long-haul coherent polarization-multiplexed (pol-mux) systems using quadrature phase shift keying (QPSK) and 16-quadrature amplitude modulation (16-QAM). In the first stage, blind CD parameter prediction is conducted prior to a CD equalizer. This supports flexible path switching in optical networks.

Management of the acute appendix mass: a survey of surgical practice.

Management of the appendix mass is controversial with no consensus in the literature. Traditionally, the approach has been conservative followed by interval appendicectomy. A survey was distributed to 117 surgeons (100 consultants and 17 final year specialist registrars) to determine how the appendix mass is currently treated in Ireland.

Successful introduction of ring-fenced inpatient surgical beds in a general hospital setting.

This study aimed to assess the impact of ring-fenced inpatient general surgical beds on day of surgery (DOS) admission, duration of elective inpatient stay (DEIS), and cancellation rates over a 6 month period. In June 2010 17 of 60 surgical inpatient beds were decommissioned. The remainder (43) were ring-fenced for general surgery patients only.

p120-catenin binding masks an endocytic signal conserved in classical cadherins.

p120-catenin (p120) binds to the cytoplasmic tails of classical cadherins and inhibits cadherin endocytosis. Although p120 regulation of cadherin internalization is thought to be important for adhesive junction dynamics, the mechanism by which p120 modulates cadherin endocytosis is unknown. In this paper, we identify a dual-function motif in classical cadherins consisting of three highly conserved acidic residues that alternately serve as a p120-binding interface and an endocytic signal.

A comparison of microelectrodes for a visual cortical prosthesis using finite element analysis.

Altering the geometry of microelectrodes for use in a cortical neural prosthesis modifies the electric field generated in tissue, thereby affecting electrode efficacy and tissue damage. Commonly, electrodes with an active region located at the tip ("conical" electrodes) are used for stimulation of cortex but there is argument to believe this geometry may not be the best. Here we use finite element analysis to compare the electric fields generated by three types of electrodes, a conical electrode with exposed active tip, an annular electrode with active area located up away from the tip, and a striped annular electrode where the active annular region has bands of insulation interrupting the full active region.

Statistical moments-based OSNR monitoring for coherent optical systems.

We present a novel statistical moments-based method for optical signal-to-noise ratio (OSNR) monitoring in polarization-multiplexed (pol-mux) coherent optical systems. This technique only requires the knowledge of the envelope of the equalized signal before phase correction, which can be achieved by using any two arbitrary statistical moments, and it is suitable for both constant and non-constant modulus modulation formats. The proposed estimation method is experimentally demonstrated for 10-Gbaud pol-mux coherent systems using QPSK and 16-QAM.

Fiber nonlinearity compensation for OFDM super-channels using optical phase conjugation.

We experimentally demonstrate that mid-link optical phase conjugation (OPC) effectively compensates fiber nonlinearity in coherent optical OFDM super-channels. The OPC was produced by pump × subcarrier degenerate four-wave-mixing in a 1-km highly nonlinear fiber. The nonlinear threshold for the 10 × 80-km 604.

Laryngeal cancer: quantitative and qualitative assessment of research output, 1945-2010.

Objectives/hypothesis: To provide an in-depth evaluation of research yield in laryngeal cancer from 1945 to 2010, using large-scale data analysis, employment of bibliometric indicators of production and quality, and density equalizing mapping.

Study Design: Bibliometic analysis incorporating the Web of Science Database.

Methods: The search strategy employed was as follows; "TS = ((Laryngeal Neoplasm$) OR (Larynx Neoplasm$) OR (Larynx Cancer$) OR (Laryngeal Cancer$)).

Management of life-threatening blunt head trauma in childhood-A case report.

Introduction: Traumatic head/brain injury (TBI) is a leading cause of death and life-long disability in children. The key to successful management of extradural haematoma is early recognition and evacuation.

Presentation Of Case: We report the successful management of a child with life-threatening traumatic brain injury requiring timely surgical intervention outside of a specialist neurosurgical unit.

Inserting a cyclic prefix using Arrayed-Waveguide Grating Routers in all-optical OFDM transmitters.

Arrayed-Waveguide Grating Routers (AWGR) can be used as multiplexers and demultiplexers in optical OFDM systems, as they provide both the serial-to-parallel converter and the optical Fourier transform in one component. This paper shows how the design of the AWGR at the transmitter can be modified to insert a cyclic prefix or postfix (CP). We use simulations of a 4-subcarrier system to compare systems without the CP, with a guard-interval, and with a CP.

Quality of life improvement with sublingual immunotherapy: a prospective study of efficacy.

Due to its excellent safety profile, ease of administration, and economic considerations, sublingual immunotherapy (SLIT) is becoming a preferred form of allergen specific immunotherapy. The efficacy of SLIT is still debated. The purpose of this act of practice trial is to evaluate quality of life outcomes in patients treated with SLIT.

Spectrum of all-terrain vehicle injuries in adults: A case series and review of the literature.

Introduction: Serious injury secondary to all terrain vehicle usage has been widely reported since the 1970s. All-terrain vehicles (ATV) or 'quad bikes' are four wheeled vehicles used for agricultural work, recreation and adventure sport. Data collected in the U.

Sensitivity improvement and carrier power reduction in direct-detection optical OFDM systems by subcarrier pairing.

This paper introduces subcarrier pairing to optical OFDM systems and shows, using simulations, that the sensitivity of Direct-Detection Optical Orthogonal Frequency Division Multiplexed (DDO-OFDM) systems can be improved by 0.7 dB, without any coding overheads. Subcarrier pairing works because each subcarrier acquires a different electrical Signal to Interference plus Noise Ratio (SINR), which typically increases with the subcarrier's frequency.

Pilot-based XPM nonlinearity compensator for CO-OFDM systems.

We experimentally verify that pilot-based nonlinearity compensation is effective for mitigating XPM in CO-OFDM systems, if SPM is compensated first. A 6-dB increase in the nonlinear limit was produced by pilot-based XPM compensation after a single-step SPM compensator in a 400-km link with periodic dispersion compensation. In addition, we use numerical simulations to show that the required bandwidth of the guard-band around the pilot is almost independent of the bandwidth of the data-carrying sidebands.

Locoregional recurrence after breast cancer surgery: a systematic review by receptor phenotype.

Molecular subtyping confirms that breast cancer comprises at least four genetically distinct entities based on the expression of specific genes including estrogen receptor (ER), progesterone receptor (PR), and HER2/neu receptor. The quantitative influence of subtype on ipsilateral locoregional recurrence (LRR) is unknown. The aim of this study was to systematically appraise the influence of breast cancer subtype on LRR following breast conserving therapy (BCT) and mastectomy.

Changing practices in the surgical management of hyperparathyroidism - a 10-year review.

Aim: Parathyroid surgery has undergone a paradigm shift over the last decade, with a move from traditional bilateral neck exploration to minimally invasive parathyroidectomy (MIP), and increasing reliance on pre- and intra-operative localization of overactive glands. We aimed to assess changing surgical practices and their impact on the management of parathyroid disease in a tertiary referral centre in the West of Ireland.

Methods: A retrospective cohort analysis of those patients undergoing a surgical intervention for parathyroid disease in the period between 1999 and 2009 in our centre was carried out.

Seatbelt injury causing small bowel devascularisation: case series and review of the literature.

The use of seatbelts has increased significantly in the last twenty years, leading to a decrease in mortality from road traffic accidents (RTA). However, this increase in seatbelt use has also led to a change in the spectrum of injuries from RTA; abdominal injuries, particularly intestinal injuries have dramatically increased with the routine use of seatbelts. Such intestinal injuries frequently result from improper placement of the "lap belt".

All-optical OFDM transmitter design using AWGRs and low-bandwidth modulators.

An Arrayed-Waveguide Grating Router (AWGR) can be used as a demultiplexer for an optical OFDM system, as it provides both the serial-to-parallel converter and the optical Fourier transform (FT) in one component. Because an inverse FT is topologically identical to a Fourier transform, the AWGR can also be used as a FT in an OFDM transmitter. In most all-optical OFDM systems the optical modulators are fed with CW tones; however, the subcarriers (SC) will only be perfectly orthogonal if the bandwidth of the data modulators is similar to the total bandwidth of all subcarriers.

Trends in use of high-risk medications for older veterans: 2004 to 2006.

Objectives: To examine the change in use of high-risk medications for the elderly (HRME), as defined by the National Committee on Quality Assurance's Healthcare Effectiveness Data and Information Set (HEDIS) quality measure (HEDIS HRME), by older outpatient veterans over a 3-year period and to identify risk factors for HEDIS HRME exposure overall and for the most commonly used drug classes.

Design: Longitudinal retrospective database analysis.

Setting: Outpatient clinics within the Department of Veterans Affairs (VA).

Validation of a needs-based biopsychosocial distress instrument for cancer patients.

Objective: People with cancer may experience distress related to diagnoses, disease-related symptoms, and treatment side effects. Assessment of cancer-related needs can facilitate timely triage and intervention and contribute to individualized comprehensive cancer care. This study assessed the internal consistency, test-retest reliability and construct validity of the Cancer Needs Distress Inventory (CaNDI), a self-report, needs-based measure of cancer-related distress.

Psychological variables potentially implicated in opioid-related mortality as observed in clinical practice.

Opioid-related deaths in the United States have become a public health problem, with accidental and unintended overdoses being especially troubling. Screening for psychological risk factors is an important first step in safeguarding against nonadherence practices and identifying patients who may be vulnerable to the risks associated with opioid therapy. Validated screening instruments can aid in this attempt as a complementary tool to clinicians' assessments.

Optimizing the subcarrier granularity of coherent optical communications systems.

In this paper, we use numerical simulations to show that the symbol rate has a significant effect on the nonlinearity-limited performance of coherent optical communication systems. We consider the case where orthogonal subcarriers are used to maximize the spectral efficiency. Symbol rates from 0.

Assessment of tumor response to tyrosine kinase inhibitors.

This review briefly summarizes recent developments in the use of non-invasive imaging to assess tumor response to TKI therapy. Receptor tyrosine kinases play important roles in cancer development. A new class of drugs, tyrosine kinase inhibitors (TKI) can induce rapid and dramatic tumor suppression when administered to carefully selected patient groups.