Impact Of Crosstalk Research Articles

A Proposal to Eliminate the Impact of Crosstalk on Resistive Sensor Array Readouts

Completely eliminating crosstalk effect is the most important challenge when reading a resistive sensor array with ${M}$ rows and ${N}$ columns. It may require complex electronics, ranging from a large number of multiplexers and switches to use of ${M}$ AC voltage sources. More measurements than those considered strictly necessary, ${M}\,\cdot {N}$ , may also be required. Thus, an implementation with multiplexers and switches uses $2\,\cdot {M}\,\cdot {N}$ measurements, while this number rises to ${M}\,\cdot {N}\,\cdot {L}$ in the one that uses AC voltage sources, where L is the Fourier Transform length required to obtain the sensor readings. This article presents a new circuit and readout method to eliminate crosstalk that simultaneously reduces the total number of multiplexers to ${M}+{N}$ and the number of measurements to ${N}\,\cdot ({M}+1+({N}+1$ )/2). The unique source of error comes from the non-idealities of the only operational amplifier used. As an added benefit, the new circuit also reduces power consumption of the array by including a single additional resistor.

Abstract IA-06: Heterotypic 3D bioprinted tissues to study pancreatic cancer

Abstract Crosstalk between tumor cells and the tumor microenvironment contributes critically to tumor initiation, tumor progression, and therapeutic response. The tumor microenvironment (TME) is composed of multiple cell types (e.g. fibroblast, vascular, and immune cells) that are temporally and spatially dynamic. Stromal cells in the TME respond not only to the growing tumor cells, but are also affected by concurrent changes in the accessibility and composition of the extracellular matrix (ECM), signaling molecules, nutrients and oxygen. Together, the interactions of tumor cells and stromal cells regulates the tumor phenotype and, ultimately, affects patient outcomes. As more is understood about the dynamic relationship of multiple cell types in the tumor microenvironment, it has become clear that better models of human cancer are needed. In order to understand the impact of heterotypic crosstalk on tumor behaviors such as initiation, progression, and response to therapies, we recently developed heterotypic, scaffold-free tissue models of advanced cancer using an extrusion-based bioprinter system. Multiple cell types including cancer cells, fibroblasts, endothelial cells, mesenchymal stem cells, and immune cells can be incorporated into bioprinted tissues with defined spatial architecture, and the system is compatible with patient-derived cells. Within these structures, cells exhibit a tissue-like cellular density, deposit ECM, and self-organize to form complex structures, as illustrated by formation of nascent endothelial networks. Cell intrinsic, extrinsic, and spatial phenotypes, including cell survival, cell proliferation, differentiation state, ECM deposition, and cellular migration, can be assessed within these tissues following exposure to extrinsic signals or therapies. Our current work is focused in three main areas. First, we aim to understand the signaling between tumor and stromal cell types in early cancer development that contributes to malignant progression. Second, we are working to understand the influence of fibroblast heterogeneity on tumor cell phenotypes, using genetic or non-genetic perturbagens to alter fibroblast activation. Finally, we are building tissues comprising patient-derived cells to understand how the microenvironment influences therapeutic response. Together, our work demonstrates that bioprinted tumor tissues recapitulate many aspects of in vivo neoplastic tissues, and provides a manipulable model system to interrogate molecular mechanisms of tumor development, progression, and treatment response. Citation Format: Ellen M Langer, Brittany L Allen-Petersen, Isabel A English, Jason M Link, Rosalie C Sears. Heterotypic 3D bioprinted tissues to study pancreatic cancer [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2020 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2020;80(22 Suppl):Abstract nr IA-06.

Protected Resource Allocation in Space Division Multiplexing-Elastic Optical Networks with Fluctuating Traffic

In this paper, we introduce a Protected Routing, Modulation, Spectrum, and Core Allocation (RMSCA) algorithms with fluctuating traffic in Space Division Multiplexing-Elastic Optical Networks (SDM-EONs). This RMSCA algorithm is called Traffic Awareness Cross-talk Interference Avoidance (TACIA-RMSCA). We investigate the efficiency of efficient allocation of spectrum resources to minimize the impact of crosstalk (XT), and blocking probability. We first assess the impact inter-core crosstalk in Multi-Core Fiber (MCF) with the peak load of the fluctuating traffic. This is usually caused by signal leaks generated by the adjacent cores. It can occur whenever the transmitted optical signals overlap their spectrum segments. We design the Triangular Iterative Core Assignment (TICA) strategy to overcome XT, and to minimize the blocking probability. We evaluate the performance of TACIA-RMSCA with the benchmark algorithm (GAK-RMSCA). Experimental results demonstrate that the proposed algorithm can achieve promising performance with the peak load of the fluctuating traffic.

Photodestruction of Stromal Fibroblasts Enhances Tumor Response to PDT in 3D Pancreatic Cancer Coculture Models.

Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal of human cancers. The dismal response of PDAC to virtually all therapeutics is associated, in part, with a characteristically dense fibrotic stroma. This stroma not only acts as a barrier to drug perfusion, but also promotes tumor survival through paracrine crosstalk and biophysical interactions. Photodynamic therapy (PDT) is being explored for PDAC treatment, though the impact of tumor-promoting stromal crosstalk on PDT response in PDAC is not well-characterized. The current study assesses the effect of tumor-stroma interactions on response to PDT or chemotherapy in heterocellular 3D cocultures using PDAC cells and two different fibroblastic cell types (pancreatic stellate cells, PSCs, and a normal human fibroblast cell line, MRC5) embedded in extracellular matrix (ECM). While stromal fibroblasts promote resistance to chemotherapy as expected, PDAC 3D nodules in coculture with fibroblasts exhibit increased response to PDT relative to homotypic cultures. These results point to the potential for PDT to overcome tumor-promoting stromal interactions associated with poor therapeutic response in PDAC.

Cross-polarization induced crosstalk impact analysis on the BER performance of 100-Gbps CPDM 8-QAM CO-FOC system over unrepeatered 100-km SSMF link

This proposed article presents a comprehensive investigation of a coherent optical (CO) circular-polarization division multiplexed (CPDM) 8-quadrature amplitude modulation (8-QAM) for the fiber optic communication (FOC) system over an unrepeatered 100 km SSMF link to find the impact of cross-polarization (XPol) induced crosstalk by arbitrary misalignment of the states of polarization (SOPs) on the bit error rate (BER) performance. A thorough study with a mathematical analysis is demonstrated, considering the Maxwellian distribution for the mean misalignment angle, to acquire the output expression of the signal to cross-talk plus noise ratio (SCNR) and average BER for a CO homodyne CPDM 8-QAM receiver. Numerical simulations exhibit that BER performance deteriorates due to the XPol effects. Results show that the system experiences a power penalty for the mean misalignment angle to acquire a definite BER of 10−9 for a fixed local oscillator power. Besides, a detailed comparison between the existing PDM-QPSK and our proposed CPDM 8-QAM model is elucidated where our proposed model is significantly better than the existing model in terms of SCNR-BER performances, spectral-efficiency (SE) and capacity of the system as well.

200G self-homodyne detection with 64QAM by endless optical polarization demultiplexing.

This paper investigates the self-homodyne detection system with orthogonal polarization between pilot and signal (oSHD) through optical polarization demultiplexing of carrier and signal at receiver. Compared to digital demultiplexing, optical demultiplexing provides around a 0.9dB benefit in receiver sensitivity. The impact of crosstalk due to optical demultiplexing has been investigated in terms of carrier-to-signal power ratio, and delay between signal and carrier. Results show that the oSHD system is very tolerant to crosstalk, with a negligible penalty for crosstalk up to -22dB. Experiments were carried out to evaluate the system performance, including polarization tracking performance, long term stability, bit error rate performance, and tolerance to laser linewidth and delay between signal and pilot. 41Gbaud 64QAM oSHD with 200Gb/s net data rate has been realized by using the scheme with receiver sensitivity better than -4dBm, providing a promising candidate solution for 800Gb/s Ethernet.

Conceptual Design of Superbend and Hardbend Magnets for Advance Light Source Upgrade Project

ALS-U is an ongoing upgrade of the Advance Light Source (ALS) at Lawrence Berkeley National Laboratory (LBL). The upgraded ring of the ALS will use a multi-bend-archomat (MBA) lattice, which will allow increasing the brightness of soft x-ray sources 2-3 orders of magnitude with respect to current ALS ca-pabilities. One of the goals of the project is maintaining support for existing x-ray beamlines with useful intensity around 12.5 keV, which are used for a macromolecular crystallography. The medium energy x-ray source points will be provided by replacing six gradient-dipole magnets of the upgraded ring with high-field magnets generating a higher peak field at the source point. Two defocusing quadrupoles will be installed together with each high-field magnet in order to match the quadrupole field component of removed gradient dipole. Two alternative designs were investigated. The first design is a warm-bore superconducting magnet. Its coils are made of an internally reinforced bronze-route Nb 3 Sn wire and a holmium pole is used as a flux concentrator. The second option is NdFeB permanent magnet system with build-in field clamps. Due to limited space in the accelerator lattice and the magnetic field requirements for the x-ray source points, both designs present challenges due to high magnetic forces acting on the magnet components and due to impact of the magnet cross-talk on the beam trajectory.

Logical performance of 9 qubit compass codes in ion traps with crosstalk errors

We simulate four quantum error correcting codes under error models inspired by realistic noise sources in near-term ion trap quantum computers: T2 dephasing, gate overrotation, and crosstalk. We use this data to find preferred codes for given error parameters along with logical error biases and a pseudothreshold which compares the physical and logical gate failure rates for a CNOT gate. Using these results we conclude that Bacon–Shor-13 is the most promising near term candidate as long as the impact of crosstalk can be mitigated through other means.

Impact of intercellular crosstalk between epidermal keratinocytes and dermal fibroblasts on skin homeostasis

Dermal fibroblasts seem critical for epidermal maturation and differentiation and recent work demonstrated that diseased fibroblasts may drive pathophysiological processes. Nevertheless, still very little is known about the actual crosstalk between epidermal keratinocytes and dermal fibroblasts and the impact of dermal fibroblasts on epidermal maturation and differentiation. Aiming for a more fundamental understanding of the impact of the cellular crosstalk between keratinocytes and fibroblasts on the skin homeostasis, we generated full-thickness skin equivalents with and without fibroblasts and subsequently analysed them for the expression of skin differentiation markers, their barrier function, skin lipid content and epidermal cell signalling. Skin equivalents without fibroblasts consistently showed an impaired differentiation and dysregulated expression of skin barrier and tight junction proteins, increased skin permeability, and a decreased skin lipid/protein ratio. Most interestingly, impaired Ras/Raf/ERK/MEK signalling was evident in skin equivalents without fibroblasts.Our data clearly indicate that the epidermal-dermal crosstalk between keratinocytes and fibroblasts is critical for adequate skin differentiation and that fibroblasts orchestrate epidermal differentiation processes.

In Silico Models Accurately Predict In Vivo Response for IL6 Blockade in Head and Neck Cancer.

Malignant features of head and neck squamous cell carcinoma (HNSCC) may be derived from the presence of stem-like cells that are characterized by uniquely high tumorigenic potential. These cancer stem cells (CSC) function as putative drivers of tumor initiation, therapeutic evasion, metastasis, and recurrence. Although they are an appealing conceptual target, CSC-directed cancer therapies remain scarce. One promising CSC target is the IL6 pathway, which is strongly correlated with poor patient survival. In this study we created and validated a multiscale mathematical model to investigate the impact of cross-talk between tumor cell- and endothelial cell (EC)-secreted IL6 on HNSCC growth and the CSC fraction. We then predicted and analyzed the responses of HNSCC to tocilizumab (TCZ) and cisplatin combination therapy. The model was validated with in vivo experiments involving human ECs coimplanted with HNSCC cell line xenografts. Without artificial tuning to the laboratory data, the model showed excellent predictive agreement with the decrease in tumor volumes observed in TCZ-treated mice, as well as a decrease in the CSC fraction. This computational platform provides a framework for preclinical cisplatin and TCZ dose and frequency evaluation to be tested in future clinical studies. SIGNIFICANCE: A mathematical model is used to rapidly evaluate dosing strategies for IL6 pathway modulation. These results may lead to nonintuitive dosing or timing treatment schedules to optimize synergism between drugs.

Crosstalk Impact on the Performance of Wideband Multicore-Fiber Transmission Systems

This work presents an evaluation of the crosstalk impact on the signal-to-noise ratio (SNR) of long-distance C and L band wavelength-division multiplexing (WDM) systems using homogeneous multicore fibers with weakly coupled cores. It is experimentally shown that the crosstalk-induced SNR penalty is independent of the transmission distance on sufficiently long uniform links. This results from the approximately linear scaling of the noise contributions from amplified spontaneous emission, fiber nonlinearity, and crosstalk with the transmission distance. The crosstalk-induced SNR penalty on C and L band WDM long distance links is experimentally evaluated, showing significant degradation of signals located towards the long edge of the L-band. Up to 3.8 dB penalty was observed on a 3866 km link, in agreement with theoretical predictions. We perform a theoretical analysis of the wavelength allocation of densely packed channels for long distance WDM systems with and without the presence of crosstalk. It is shown that these systems favor the use of relatively short transmission wavelength ranges to minimize the crosstalk impact at long wavelengths. This contrasts with systems without crosstalk, which favor the low loss wavelength region of the transmission fiber.

Importance of osteocyte-mediated regulation of bone remodelling in inflammatory bone disease.

Although the impact of osteoblast-osteoclast crosstalk in bone remodelling has been intensively studied, the importance of osteocytes, descendants of osteoblasts, in this process has for a long time been neglected. During their embedding phase, osteocytes undergo considerable phenotypic transformation, from a cuboidal, highly metabolically active osteoblast secreting extracellular matrix to a small, stellate, quiescent osteocyte with numerous long dendrites. Osteocytes are encysted in cavities (lacunae) and their dendritic extensions are located in tunnels (canaliculi) forming a remarkable, highly branched, lacunar-canalicular signalling network that spans the entire bone matrix. Osteocytes and their dendrites can communicate directly with each other and through the release of effector proteins such as sclerostin and nuclear factor κB ligand (RANKL), influence osteoblast and osteoclast formation. This allows osteocytes embedded within the bone matrix to communicate and coordinate activity of cells on the bone surface to adapt to mechanical needs and hormonal changes. Besides their importance in sustaining physiological bone homeostasis, accumulating evidence suggests that dysregulated osteocyte function and alterations in the osteocyte lacunar-canalicular network structure are characteristics of skeletal diseases. This review highlights some aspects of osteocyte communication with osteoclasts and mesenchymal stromal cells, the importance of blood vessel-osteocyte interaction and describes central functions of these cells in rheumatoid arthritis, osteoarthritis, osteomyelitis and osteoporosis. Within the last decade new technologies and tools have facilitated the study of osteocyte biology and the search for therapeutic targets to address bone fragility in the near future.

Thermal Crosstalk Measurements and Simulations for an X-ray Microcalorimeter Array

Arrays of high-density microcalorimeters require careful heat sinking in order to minimize the thermal crosstalk between nearby pixels. For the array of microcalorimeters developed for the Athena X-ray Integral Field Unit instrument, which has more than 3000 pixels on a 275 µm pitch, it is essential to address this problem in order to meet the energy-resolution requirements. The instrument’s energy-resolution budget requires that the impact of the thermal crosstalk on the energy resolution be a contribution that, added in quadrature to other energy-resolution contributions, is less than 0.2 eV. This value results in a derived requirement that the ratio between the amplitude of the crosstalk signal to an X-ray pulse (for example at 6 keV) is less than 1 × 10−3 (for the first neighbor), less than 4 × 10−4 (for the diagonal neighbor) and less than 8 × 10−5 (for the second nearest neighbor). We have measured the thermal crosstalk levels between pixels in various geometries and configurations. The results show a crosstalk ratio which is at least a factor of 4 lower than the derived requirement. We also developed a finite element (FEM) 2D thermal model to predict the thermal behavior of large-scale arrays. This model successfully simulates the measured data in terms of pulse amplitude and time constants.

Mitigation of crosstalk between RSB and LSB signals generated by one I/Q modulator.

Optical independent sideband (ISB) signals can be generated by exploiting one external In-phase/Quadrature (I/Q) modulator. Our theoretical analysis shows crosstalk between the two ISB (right and left side) signals can attribute to two main imperfections: amplitude difference and phase unmatched in I/Q data. To reduce the impact of crosstalk between the two ISB signals, we propose three schemes. The first is precise phase match of the I and Q data. The second has been made possible by setting different frequencies for the left sideband (LSB) and the right sideband (RSB) signals, and the last is achieved by adding Multiple-Input Multiple-Output (MIMO) equalization digital signal processing (DSP) at the receiver side. Our experimental results have shown that these schemes can improve the performance of ISB signals. In our experimental system we designed dual ISB system with different modulation formats in two sidebands. Precise phase match can bring a ∼2.2dB improvement at BER of 1×10-2 and a ∼4.3dB improvement at BER of 1×10-3 for 16-ary quadrature-amplitude-modulation (16QAM) and quadrature-phase-shift-keying (QPSK) signals, respectively, in 4Gbaud with carrier frequency of 36GHz system. The BER of 4Gbaud 16QAM ISB signal at 30GHz and 4Gbaud QPSK ISB signal at 38GHz can reach hard-decision forward-error-correction (HD-FEC) when the input power is larger than -5.5 and -7.4dBm respectively in different frequencies system. For 4Gbaud with carrier frequency of 36GHz system, the BER of 16QAM signal and QPSK signal reduce ∼2.1 and ∼2.2dB at HD-FEC after using MIMO. In addition, MIMO can further improve the performance of the matched phase system or the system with different frequencies.

Routing Core and Spectrum Allocation Algorithm for Inter-Core Crosstalk and Energy Efficiency in Space Division Multiplexing Elastic Optical Networks

Elastic optical networks (EONs) and space-division multiplexing (SDM) have emerged as a promising technology to accommodate the high-capacity and dynamic bandwidth demands of next-generation network. However, the problems of high energy consumption and inter-core crosstalk (ICXT) in space-division multiplexing elastic optical networks (SDM-EONs) are also particularly prominent. In this paper, we proposed an energy efficient grooming and hybrid crosstalk solution (EEG-HCS) algorithm. Firstly, in the routing strategy, a candidate path sorting formula combined the path length and path load state is designed to select the candidate paths and balance the network load. According to the sorting result, whether the current candidate path satisfied the energy efficiency grooming condition or not is determined. When the candidate path meet the energy efficiency grooming condition, the energy efficiency grooming algorithm is used to reduce the transmission energy consumption. For traffic request that do not satisfied the grooming condition, a new optical path is established. Through the core priority grouping, combined with crosstalk avoidance strategy and ICXT aware algorithm, the impact of inter-core crosstalk is minimized, and the probability of successful transmission is improved. In order to evaluate the performance of proposed algorithm, ICXT improvement index is defined. The simulation results show that the proposed algorithm can significantly reduce the energy consumption of space-division multiplexing elastic optical network system while ensuring the optimal blocking probability performance.

Design and Simulation of Thermo-Optic Phase Shifters With Low Thermal Crosstalk for Dense Photonic Integration

We investigate and demonstrate the thermal crosstalk problem in integrated photonic circuits with metal and silicon doped heaters. Further, we illustrate that due to the localized heating effect, integrated doped heaters are out-performed in terms of thermal crosstalk as compared to integrated metal heaters. To mitigate thermal crosstalk and enhance phase tuning efficiency further, a CMOS compatible air-filled trench region is realized between the doped heater and the adjacent element. The performances of three fundamental building blocks of integrated photonic circuits, namely, a PN phase shifter, an optical attenuator, and a ring resonator, are tested by full-wave thermal, charge, and optical simulations. Additionally, the impact of thermal crosstalk on the performance of integrated PN phase shifters and optical attenuators is examined thoroughly. The proposed low crosstalk thermal phase shifters might be very beneficial for densely routed complex integrated photonic circuits like photonic transceivers for data centers, optical phased array antennas, and photonic reservoirs.

Channel Crosstalk Impact on OCDMA Performance Under Efficient Diagonal Code and Optimized Pulse Shaping

This paper examines the four-wave mixing (FWM) effect on optical code-division multiple-access (OCDMA) performance systems in the presence of Multi-Diagonal code (MD). System performance improvement is accomplished by means of fibre length tuning and stratified different modulation shapes, which are Non-return-to-Zero (NRZ), Gaussian, and Sine wave, all examined with 500 and 1Gb/s data rate values. The tests show that the NRZ modulation offers better system performance compared with other modulations for all data rate values used. Moreover, the second channel of each user offered better system performance than the other channels used. For instance, for 1Gb/s, at the second channel, the NRZ modulation offered the best performance with a quality factor (Q –factor) of 5.1 at 100 km fibre length, whereas the first channel introduced a worse Q-factor of 3.1 at the same fibre length value.

Crosstalk between SHH and FGFR Signaling Pathways Controls Tissue Invasion in Medulloblastoma.

In the Sonic Hedgehog (SHH) subgroup of medulloblastoma (MB), tumor initiation and progression are in part driven by smoothened (SMO) and fibroblast growth factor (FGF)-receptor (FGFR) signaling, respectively. We investigated the impact of the SMO-FGFR crosstalk on tumor growth and invasiveness in MB. We found that FGFR signaling represses GLI1 expression downstream of activated SMO in the SHH MB line DAOY and induces MKI67, HES1, and BMI1 in DAOY and in the group 3 MB line HD-MBO3. FGFR repression of GLI1 does not affect proliferation or viability, whereas inhibition of FGFR is necessary to release SMO-driven invasiveness. Conversely, SMO activation represses FGFR-driven sustained activation of nuclear ERK. Parallel activation of FGFR and SMO in ex vivo tumor cell-cerebellum slice co-cultures reduced invasion of tumor cells without affecting proliferation. In contrast, treatment of the cells with the SMO antagonist Sonidegib (LDE225) blocked invasion and proliferation in cerebellar slices. Thus, sustained, low-level SMO activation is necessary for proliferation and tissue invasion, whereas acute, pronounced activation of SMO can repress FGFR-driven invasiveness. This suggests that the tumor cell response is dependent on the relative local abundance of the two factors and indicates a paradigm of microenvironmental control of invasion in SHH MB through mutual control of SHH and FGFR signaling.

Mitigation techniques for crosstalk in ICs

Crosstalk is a major concern among integrated circuit (IC) designers as it may contribute significantly to the amount of noise presented in a device. Hence, there is a need to mitigate the impact of crosstalk in order to preserve the signal integrity between interconnections. This paper will review several methods to mitigate crosstalk in high speed ICs. The methods include the usage of repeater, Schmitt trigger, shielding, skewing, space adjustment between signal wires and setting the coupling length of the signal wires. Although these methods are effective for crosstalk mitigation, the features might only be applicable due to certain constraints. Consequently, this paper will provide a sufficient review on each method as a guideline for crosstalk mitigation method selection in which the crosstalk is largely regulated in long interconnections.

Modal crosstalk in Silicon photonic multimode interconnects.

We investigate modal crosstalk in silicon photonic MDM-based interconnects using tapered multiplexers. Crosstalk from coherent optical interference originates from variation in the physical structure and alters the transmission link performance. Through simulations and experimental work, optical crosstalk as a function of wavelength is analyzed to understand its impact in MDM and MDM-WDM dual-multiplexing applications. The detrimental effects are validated in the frequency and time domains through fabricated MDM interconnects of various lengths. Results indicate modal crosstalk must be < -22 dB to maintain a BER of 10-12. The experimental methodology assesses the optical modal crosstalk's impact on the data, towards a mitigation approach to improve the payload signal integrity and enable system-level optimization such as channel wavelength allocation.