100 GHz Multiple Colliding Pulse Generation From Cleaved Facet-Free Multi-Section Semiconductor Laser Diode

We present a monolithically integrated mode-locked laser (MLL) with 25 GHz fundamental repetition rate frequency, which has been designed to operate in a fourth-order colliding regime, to generate 100 GHz. This device has been fabricated within a multi-project wafer (MPW) run in an InP-based active-passive generic foundry. The Fabry-Perot laser resonator, of around 1.66 mm length, is defined by two on-chip reflectors, eliminating the need of cleaved facet. Three saturable absorber sections are symmetrically located by spacing them a quarter of this total length, dividing the cavity into four gain segments. We show that this structure can generate an electrical beat note at 25 GHz as well as 100 GHz, with a linewidth of 350 kHz and 150 kHz, respectively, operating in passive operation regime

28 GBd PAM-8 transmission over a 100 nm range using an InP-Si3N4 based integrated dual tunable laser module

This paper describes the detailed characterization of a novel InP-Si3N4 dual laser module with results revealing relative intensity noise (RIN) as low as -165 dB/Hz and wide wavelength tunability (100 nm). The hybrid coupled laser is deployed in an unamplified 28 GBd 8 level pulse amplitude modulation (PAM) short-reach data center (DC) transmission system. System performance, which is experimentally evaluated in terms of received signal bit error ratio (BER), demonstrates the ability of the proposed laser module to support PAM-8 transmission across a 100 nm tuning range with less than 1 dB variance in receiver sensitivity over the operating wavelength range. Comparative performance studies not only indicate that the proposed source can outperform a commercial external cavity laser (ECL) in an intensity modulation/direct detection (IM/DD) link but also highlight the critical impact of RIN in the design of advanced modulation short-reach systems.Science Foundation Ireland (12/RC/2276_P2, 13/RC/2077_P2, 16/RI/3698, 18/EPSRC/3591, 18/SIRG/5579)

Non-motor symptom burden in patients with Parkinson's disease with impulse control disorders and compulsive behaviours : results from the COPPADIS cohort

The study was aimed at analysing the frequency of impulse control disorders (ICDs) and compulsive behaviours (CBs) in patients with Parkinson's disease (PD) and in control subjects (CS) as well as the relationship between ICDs/CBs and motor, nonmotor features and dopaminergic treatment in PD patients. Data came from COPPADIS-2015, an observational, descriptive, nationwide (Spain) study. We used the validated Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale (QUIP-RS) for ICD/CB screening. The association between demographic data and ICDs/CBs was analyzed in both groups. In PD, this relationship was evaluated using clinical features and treatment-related data. As result, 613 PD patients (mean age 62.47 ± 9.09 years, 59.87% men) and 179 CS (mean age 60.84 ± 8.33 years, 47.48% men) were included. ICDs and CBs were more frequent in PD (ICDs 12.7% vs. 1.6%, p < 0.001; CBs 7.18% vs. 1.67%, p = 0.01). PD patients had more frequent previous ICDs history, premorbid impulsive personality and antidepressant treatment (p < 0.05) compared with CS. In PD, patients with ICDs/CBs presented younger age at disease onset, more frequent history of previous ICDs and premorbid personality (p < 0.05), as well as higher comorbidity with nonmotor symptoms, including depression and poor quality of life. Treatment with dopamine agonists increased the risk of ICDs/CBs, being dose dependent (p < 0.05). As conclusions, ICDs and CBs were more frequent in patients with PD than in CS. More nonmotor symptoms were present in patients with PD who had ICDs/CBs compared with those without. Dopamine agonists have a prominent effect on ICDs/CBs, which could be influenced by dose

THz and Microwave Dual-Band Ultrafast Photoconductive Antenna

We present here experimental results for a new type of broadband emitter that covers two RF bands, one around 300 GHz and the other between 10 and 20 GHz. The higher band is excited by a square-spiral antenna driven at its center by a photoconductive switch. The lower band is excited by a dumbbell dipole antenna that is connected serially to the square spiral and also acts as the bias line for the switch. This type of dual-band performance should be beneficial for multiple system applications including free-space radar without atmospheric dropout, and biomedical reflective imaging

Non-motor symptoms burden, mood, and gait problems are the most significant factors contributing to a poor quality of life in non-demented Parkinson's disease patients: Results from the COPPADIS Study Cohort

[Objective] To identify factors related to a poor health-related and global quality of life (QoL) in a cohort of non-demented Parkinson's disease (PD) patients and compare to a control group.[Methods] The data correspond to the baseline evaluation of the COPPADIS-2015 Study, an observational, 5-year follow-up, multicenter, evaluation study. Three instruments were used to assess QoL: (1) the 39-item Parkinson's disease Questionnaire (PDQ-39), (2) a subjective rating of global QoL (PQ-10), and (3) the EUROHIS-QOL 8-item index (EUROHIS-QOL8). Multiple linear regression methods were used to evaluate the direct impact of different variables on these QoL measures.[Results] QoL was worse in PD patients (n = 692; 62.6 ± 8.9 years old, 60.3% males) than controls (n = 206; 61 ± 8.3 years old, 49.5% males): PDQ-39, 17.1 ± 13.5 vs 4.4 ± 6.3 (p < 0.0001); PQ-10, 7.3 ± 1.6 vs 8.1 ± 1.2 (p < 0.0001); EUROHIS-QOL8, 3.8 ± 0.6 vs 4.2 ± 0.5 (p < 0.0001). A high correlation was observed between PDQ-39 and Non-Motor Symptoms Scale (NMSS) (r = 0.72; p < 0.0001), and PDQ-39 and Beck Depression Inventory-II (BDI-II) (r = 0.65; p < 0.0001). For health-related QoL (PDQ-39), non-motor symptoms burden (NMSS), mood (BDI-II), and gait problems (Freezing Of Gait Questionnaire [FOGQ]) provided the highest contribution to the model (β = 0.32, 0.28, and 0.27, respectively; p < 0.0001); whereas mood and gait problems contributed the most to global QoL (PQ-10, β = -0.46 and −0.21, respectively; EUROHIS-QOL8, β = -0.44 and −0.23, respectively).[Conclusions] QoL is worse in PD patients than in controls. Mood, non-motor symptoms burden, and gait problems seem to be the most relevant factors affecting health-related and global perceived QoL in non-demented PD patients.Peer reviewe

Predictors of clinically significant quality of life impairment in Parkinson's disease

Quality of life (QOL) plays an important role in independent living in Parkinson's disease (PD) patients, being crucial to know what factors impact QoL throughout the course of the disease. Here we identified predictors of QoL impairment in PD patients from a Spanish cohort. PD patients recruited from 35 centers of Spain from the COPPADIS cohort from January 2016, to November 2017, were followed up during 2 years. Health-related QoL (HRQoL) and global QoL (GQoL) were assessed with the 39-item Parkinson's disease Questionnaire (PDQ-39) and the EUROHIS-QOL 8-item index (EUROHIS-QOL8), respectively, at baseline (V0) and at 24 months ± 1 month (V2). Clinically significant QoL impairment was defined as presenting an increase (PDQ-39SI) or decrement (EUROHIS-QOL8) at V2 ≥ 10% of the score at baseline (V0). A comparison with a control group was conducted for GQoL. GQoL did not change significantly in PD patients (N = 507; p = 0.686) or in the control group (N = 119; p = 0.192). The mean PDQ-39SI was significantly increased in PD patients (62.7 ± 8.5 years old; 58.8% males; N = 500) by 21.6% (from 16.7 ± 13 to 20.3 ± 16.4; p < 0.0001) at V2. Ninety-three patients (18.6%) presented a clinically significant HRQoL impairment at V2. To be younger (OR = 0.896; 95% CI 0.829-0.968; p = 0.006), to be a female (OR = 4.181; 95% CI 1.422-12.290; p = 0.009), and to have a greater increase in BDI-II (Beck Depression Inventory-II) (OR = 1.139; 95% CI 1.053-1.231; p = 0.001) and NMSS (Non-Motor Symptoms Scale) (OR = 1.052; 95% CI 1.027-1.113; p < 0.0001) total scores from V0 to V2 were associated with clinically significant HRQoL impairment at the 2-year follow-up (Hosmer-Lemeshow test, p = 0.665; R = 0.655). An increase in ≥5 and ≥10 points of BDI-II and NMSS total score at V2 multiplied the probability of presenting clinically significant HRQoL impairment by 5 (OR = 5.453; 95% CI 1.663-17.876; p = 0.005) and 8 (OR = 8.217; 95% CI, 2.975-22.696; p = 0.002), respectively. In conclusion, age, gender, mood, and non-motor impairment were associated with clinically significant HRQoL impairment after the 2-year follow-up in PD patients