CDC ROADM design tradeoffs due to physical layer impairments in optical networks

In this work, we assess the impact of several physical layer impairments (PLIs) on the performance of optical networks based on colorless, directionless and contentionless reconfigurable optical add/drop multiplexers (ROADMs), through Monte-Carlo simulation, and considering polarization division multiplexing 4 and 16 quadrature amplitude modulation (QAM) signals, at 28 GBaud, for 37.5 GHz optical channels. The PLIs taken into account are the amplified spontaneous emission noise, optical filtering, in-band crosstalk and nonlinear interference noise caused by Kerr effect. A detailed model of the ROADM node is built considering two typical ROADM architectures, broadcast and select (B&S) and route and select (R&S), and two different add/drop structures, multicast switches (MCSs) and wavelength selective switches (WSSs), resulting in four different ROADM node scenarios. Our results have shown that for 16QAM signals, the B&S ROADMs with WSSs-based add/drop structures is the scenario that has the best relation cost/performance, foreseeing its use in metro networks, while for 4QAM signals, the R&S ROADM with WSSs-based add/drop structure scenario allows a larger ROADM cascade at an expectable lower cost anticipating its implementation in long-haul networks

Impact of physical layer impairments on multi-degree CDC ROADM-based optical networks

Nowadays, optical network nodes are usually based on reconfigurable optical add/drop multiplexers (ROADMs). Due to exponential growth of internet data traffic, ROADMs have evolved to become more flexible, with multi-degree and their add/drop structures are now more complex with enhanced features, such as colorless, directionless and contentionless (CDC). In this work, the impact of in-band crosstalk, optical filtering and amplified spontaneous emission noise on the performance of an optical network based on multi-degree CDC ROADMs is studied considering 100-Gb/s polarisation division multiplexing quadrature phase-shift keying signals for the fixed grid. We show that, an optical signal can pass through a cascade of 19 CDC ROADMs, based on a route and select architecture with 16-degree, until an optical signal-to-noise ratio (OSNR) penalty of 1 dB due to in-band crosstalk is reached. We also show that the ASE noise addition, due to the increase of the number of CDC ROADMs, is more harmful in terms of OSNR penalty than in-band crosstalk.info:eu-repo/semantics/acceptedVersio

A model for assessing the quantitative effects of heterogeneous affinity in malaria transmission along with Ivermectin mass administration

Using an agent-based model of malaria, we present numerical evidence that in communities of individuals having an affinity varying within a broad range of values, disease transmission may increase up to 300%. Moreover, our findings provide new insight into how to combine different strategies for the prevention of malaria transmission. In particular, we uncover a relationship between the level of heterogeneity and the level of conventional and unconventional anti-malarial drug administration (ivermectin and gametocidal agents), which, when taken together, will define a control parameter, tuning between disease persistence and elimination. Finally, we also provide evidence that the entomological inoculation rate, as well as the product between parasite and sporozoite rates are both good indicators of malaria incidence in the presence of heterogeneity in disease transmission and may configure a possible improvement in that setting, upon classical standard measures such as the basic reproductive number.info:eu-repo/semantics/publishedVersio

Analytical tools for evaluating the impact of in-band crosstalk in DP-QPSK signals

An analytical tool based on the moment generating function of the receiver decision variable that can evaluate the impact of multiple in-band crosstalk signals in DP-QPSK (Dual-Polarization Quadrature Phase-Shift Keying) signals is presented. It is shown that when the number of interferers increases from 1 to 64 the crosstalk level, that assure a 2dB power penalty, becomes more stringent, -12 dB for the single interferer scenario and -15 dB for 64 interferers. The Gaussian approximation is also used for comparison purposes.info:eu-repo/semantics/acceptedVersio

Pulmonary ventilation/perfusion single photon emission tomography – Initial experience of a Nuclear Medicine Department

AbstractIntroductionLung ventilation/perfusion scintigraphy with planar images (V/QS-planar) is very useful for the diagnosis and follow-up of pulmonary thromboembolism (PTE). Acquiring tomographic images (V/QS-SPECT) is a recent development with potential to increase the technique's accuracy. The purpose of this work is to evaluate the added benefits of V/QS-SPECT studies as opposed to traditional planar imaging.Patients and methodsWe prospectively revised 53 V/QS-planar and V/QS-SPECT exams, performed according to the European Association of Nuclear Medicine guidelines. We evaluated the exams independently, by consensus of two Nuclear Medicine physicians. For both methods, we gave each lung a score expressing the dimension and extension of perfusion defects with normal ventilation. For each lung, we compared the scores with the paired Wilcoxon test, estimating the 95% confidence interval (95CI) for the respective difference.ResultsWe performed V/QS-SPECT exams without technical difficulties. The paired Wilcoxon test estimated the score difference to be −0.75 (95CI of −1.0 to −0.5; p-value=9.6×10−7), expressing a statistically significant difference of about 1 subsegmental defect between both methods, with V/QS-SPECT detecting more defects.DiscussionThe results demonstrate that V/QS-SPECT identifies a slightly larger number of perfusion defects than V/QS-planar, suggesting a higher sensitivity of this technique. However, more studies are necessary to evaluate the clinical meaning of this fact.ConclusionV/QS-SPECT demonstrates a higher capability to identify perfusion defects. This method looks promising, allowing for a greater role of this exam in pulmonary thromboembolism diagnosis and follow-up

Biomechanical Comparison of Open versus Percutaneous Techniques for Primary Mid-Substance Achilles Tendon Repair: A Meta-Analysis

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A validation sensor based on carbon-fiber-reinforced plastic for early activation of automotive occupant restraint systems

In the automotive industry, sensors and sensor systems are one of the most important components in upcoming challenges like highly automated and autonomous driving. Forward-looking sensors (radar, lidar and cameras) have the technical capability to already provide important (pre-)crash information, such as the position of contact, relative crash velocity and overlap (width of contact) before the crash occurs. Future safety systems can improve crash mitigation with sophisticated vehicle safety strategies based on this information. One such strategy is an early activation of restraint systems compared with conventional passive safety systems. These integrated safety systems consist of a combination of predictive forward-looking sensors and occupant restraint systems (airbags, belt tensioners, etc.) to provide the best occupant safety in inevitable crash situations. The activation of the restraint systems is the most critical decision process and requires a very robust validation system to avoid false activation. Hence, the information provided by the forward-looking sensor needs to be highly reliable. A validation sensor is required to check the plausibility of crucial information from forward-looking sensors used in integrated safety systems for safe automated and autonomous driving. This work presents a CFRP-based (carbon-fiber-reinforced plastic) validation sensor working on the principle of change in electrical resistance when a contact occurs. This sensor detects the first contact, gives information on impact position (where the contact occurs) and provides information on the overlap. The aim is to activate the vehicle restraint systems at near T0 (time of first contact). Prototypes of the sensor were manufactured in house and manually and were evaluated. At first, the sensor and its working principle were tested with a pendulum apparatus. In the next stage, the sensor was tested in a real crash test. The comparison of the signals from the CFRP-based sensor with presently used crash sensors in the vehicle highlights its advantages. The crash event can be identified at 0.1&thinsp;ms after the initial contact. The sensor also provides information on impact position at 1.2&thinsp;ms and enables a validation of the overlap development. Finally, a possible algorithm for the vehicle safety system using forward-looking sensors with a validation sensor is described.</p

Quality of life in caregivers of patients with multiple myeloma

Objectives: This study aimed to assess the relationship between sociodemographic, clinical, and psychological variables with quality of life (QoL) and the moderating role of caregivers' age and caregiving duration in caregivers of patients with Multiple Myeloma.Method: The sample included 118 caregivers who completed questionnaires that assessed psychological morbidity, satisfaction with social support, coping, burden, unmet needs, and QoL.Results: High psychological morbidity, burden and information, financial and emotional unmet needs were associated with lower QoL, while higher satisfaction with social support and more effective use of coping strategies were associated with better QoL. Women caregivers reported more satisfaction with social support and those who did not choose to care reported greater financial unmet needs and more use of coping strategies. The relationship between caregivers' psychological morbidity/social support and QoL was mediated by emotional needs and double mediated by coping and burden. The caregivers' age moderated the relationship between psychological morbidity/social support and emotional needs.Conclusion: Interventions to support the caregiver's emotional needs to promote their QoL are needed. These should be particularly tailored for older caregivers reporting greater psychological morbidity and younger caregivers less satisfied with their social support, as they have a negative indirect impact on their QoL.Portuguese Associations of Portuguese Association against Leukemia and the PortugueseAssociation of Leukemias and Lymphoma