Crosstalk Level Research Articles

Performance of planar pixel modules for the CMS Phase-2 Inner Tracker

During the Long Shutdown 3, the CMS pixel detector will be replaced to operate during the High Luminosity LHC (HL-LHC) running phase. Hybrid pixel modules of the new tracking detector will have to fulfill stringent requirements to operate in an extremely harsh radiation environment and cope with the high data readout rate. Sensor-readout chip assemblies have been extensively tested in the laboratory and at the DESY test beam facility. This study presents results on the analysis of test beam data acquired with HPK planar pixel sensors interconnected with the RD53B_CMS readout chip, irradiated to fluences up to Φeq=1.0×1016cm−2. For all investigated fluences, the requirements for the efficiency times acceptance and the spatial resolution are met, while keeping the percentage of pixels masked as noisy below 1%. Additionally, measurements of crosstalk levels will be presented.

Evolution of 3D Chromatin Folding.

Studies examining the evolution of genomes have focused mainly on sequence conservation. However, the inner working of a cell implies tightly regulated crosstalk between complex gene networks controlled by small dispersed regulatory elements of physically contacting DNA regions. How these different levels of chromatin organization crosstalk in different species underpins the potential for genome evolutionary plasticity. We review the evolution of chromatin organization across the Animal Tree of Life. We introduce general aspects of the mode and tempo of genome evolution to later explore the multiple layers of genome organization. We argue that both genome and chromosome size modulate patterns of chromatin folding and that chromatin interactions facilitate the formation of lineage-specific chromosomal reorganizations, especially in germ cells. Overall, analyzing the mechanistic forces involved in the maintenance of chromatin structure and function of the germ line is critical for understanding genome evolution, maintenance, and inheritance.

Fabrication of Radial Array Transducers Using 1-3 Composite via a Bending and Superposition Technique

Piezoelectric composite materials, combining the advantages of both piezoelectric materials and polymers, have been extensively used in ultrasonic transducers. However, the pitch size of radial array ultrasonic transducers normally exceeds one wavelength, which limits their performance. In order to minimize grating lobes of current radial transducers and then increase their imaging resolution, a 2.5 MHz 1-3 composite radial array transducer with 64 elements and 600 μm pitch was designed and fabricated by combining flexible circuit board and using a bending-and-superposition method. All the array elements were connected and actuated via the customized circuit board which is thin and soft. The kerf size is set to be 1/3 wavelength. PZT-5H/epoxy 1-3 composite was used as an active material because it exhibits an ultrahigh electromechanical coupling coefficient (kt = 0.74), a very low mechanical quality factor (Qm = 11), and relatively low acoustic impedance (Zc = 13.43 MRayls). The developed radial array transducer exhibited a center frequency of 2.72 MHz, an average −6 dB bandwidth of 36%, an insertion loss of 31.86 dB, and a crosstalk of −26.56 dB between the adjacent elements near the center frequency. These results indicate that the bending-and-superposition method is an effective way to fabricate radial array transducers by binding flexible circuit boards. Furthermore, the utilization of tailored flexible circuitry boards presents an effective approach for realizing reductions in crosstalk level (CTL).

Signal Crosstalk in a Flip-Chip Quantum Processor

Quantum processors require a signal-delivery architecture with high addressability (low crosstalk) to ensure high performance already at the scale of dozens of qubits. Signal crosstalk causes inadvertent driving of quantum gates, which will adversely affect quantum gate fidelities in scaled-up devices. Here, we demonstrate packaged flip-chip superconducting quantum processors with signal-crosstalk performance competitive with those reported in other platforms. For capacitively coupled qubit-drive lines, we find on-resonant crosstalk better than −27 dB (average −37 dB). For inductively coupled magnetic-flux-drive lines, we find less than 0.13% direct-current flux crosstalk (average 0.05%). These observed crosstalk levels are adequately small and indicate a decreasing trend with increasing distance, which is promising for further scaling up to larger numbers of qubits. We discuss the implications of our results for the design of a low-crosstalk on-chip signal-delivery architecture, including the influence of a shielding tunnel structure, potential sources of crosstalk, and estimation of crosstalk-induced qubit-gate error in scaled-up quantum processors. Published by the American Physical Society 2024

Ultra-compact and polarization-insensitive silicon waveguide 3 × 3 star-crossing based on composite subwavelength grating metamaterials.

We present what we believe is the first report on a polarization-insensitive 3 × 3 silicon star-crossing utilizing a composite subwavelength metamaterial waveguide structure. Two different types of subwavelength grating metamaterials (nanohole grating and fan-shaped bent subwavelength grating) are respectively used to address diffraction issues in the crossing region and mode interference issues caused by a compact non-adiabatic design. This approach results in a device with an ultra-compact footprint of 12.68 × 10.98 µm2 on a standard 220 nm silicon-on-insulator (SOI) platform. Simulation results show low insertion loss (IL) values of <0.2 dB/0.3 dB and suppressed cross talk (CT) levels of <-27.2 dB/-23.6 dB for TE/TM polarizations across a wavelength range of 100 nm (1500-1600 nm). Experimental measurements of the fabricated devices confirm outstanding performance, with IL values of <0.35 dB/0.4 dB and CT levels of <-31.5 dB/-28.6 dB for TE/TM polarization in the C-band.

P-335 Integrative analysis of endometriosis and adenomyosis through single-cell transcriptomics

Abstract Study question What are the shared and unique cell type -specific molecular pathways in endometriosis and adenomyosis? Summary answer Our analysis focuses on hormonal pathways and those regulating cell proliferation and apoptosis, which are crucial for the persistence of the lesions. What is known already Estrogen-driven proliferation and progesterone unresponsiveness are key mechanisms in the pathogenesis of endometriosis and adenomyosis. It has been recently observed that core pathways governing proliferation and apoptosis, such as the Wnt/beta-catenin and KRAS pathways, are involved in the etiology. The precise mechanisms of how estrogen and progesterone signaling interact with the Wnt/beta-catenin and KRAS pathways, which contribute to lesion growth maintenance, are not fully understood, but preliminary evidence suggests some level of cross-talk in both conditions. Study design, size, duration Although endometriosis and adenomyosis share similar mechanisms, they have mostly been studied in isolation. We propose a comprehensive study using an integrated approach to gain a deeper understanding of their pathophysiology. We will combine recent single-cell study data from both disorders, and examine the shared and unique cell-type-specific molecular pathways diverging from the eutopic endometrium. Participants/materials, setting, methods We will employ publicly available single-cell transcriptomic data from cases of endometriosis, adenomyosis, and controls with eutopic endometrium. Tissue sections from an extensive collection of patient samples will be examined for validation. Main results and the role of chance We will integrate single-cell transcriptomic data for endometriosis, adenomyosis, and eutopic endometrium controls. For each cell type, we will conduct comprehensive differential expression analysis between lesions and endometrium, study cell-to-cell communication among major cell types, and construct gene regulatory networks that are either shared or specific to endometriosis and adenomyosis. We will also consider GWAS lead genes and investigate their cell type-specific expression, focusing on hormonally regulated genes. Tissue sections of patient samples, apoptosis measurements, and clinical parameters including pain data will be utilized for validation. Limitations, reasons for caution The public single-cell transcriptomic data for endometriosis and adenomyosis have limitations in sample size and menstrual cycle distribution. The utilized single-cell transcriptomics data and the in-house tissue collections for validations studies are not matched. Wider implications of the findings This project aims to identify molecular pathways in endometriosis and adenomyosis, potentially revealing common disease development mechanisms and unique molecular signatures. Both endometriosis and adenomyosis are significant health issues affecting women, and their study contributes to the broader understanding of women’s health. Trial registration number not applicable

Pulse duration, frequency band, and sweep direction effects on crosstalk in wideband backscattering measurements.

Multiple broadband transducers are typically used to cover both a wide frequency range and fill in gaps resulting from sampling with multiple narrowband echosounders. Synchronized operation of these echosounders is preferred in many cases. Simultaneous operation of multiple broadband echosounders, even when using non-overlapping primary bands, can result in cross-channel interferences caused by nonlinear generation of sound and can contaminate backscattered signal. Decreasing the transmit power of channels with lower frequencies has been demonstrated as an effective technique for reducing the level of crosstalk. Reducing the transmit power inherently decreases the signal energy. Hence, the reduction in crosstalk also reduces signal-to-noise ratio and consequently observation range. Increasing the broadband pulse duration is an alternative to compensate for the reduced signal energy from lower transmit power. This paper examines the effects of increasing pulse duration on crosstalk through numerical modeling and field experiments. Raising the transmit power amplifies the higher-harmonic level more than the main band, while extending the pulse duration increases the levels of both main-band and higher harmonics the same amount. Additionally, the study explores the influence of frequency band and sweep direction on crosstalk.

Crosstalk- and fragmentation-aware survivable routing, modulation, space, and spectrum assignment using Ant Colony Optimization

The use of Space Division Multiplexing (SDM) technology in Elastic Optical Networks (EONs) is a promising solution to improve the transport capability and flexibility required by next-generation applications. In this work, we have illustrated that Ant Colony Optimization (ACO) algorithms can be incorporated into the network control plane and associated with a crankback mechanism to provision and restore lightpaths in a fully distributed manner. In effect, by tackling the challenging Routing, Modulation, Spectrum, and Space Assignment (RMSSA) problem, ACO algorithms can address the inter-core crosstalk and spectrum fragmentation that may limit the potential of the SDM-EON. By comparing different levels of resource state accuracy at the control plane, the simulation results demonstrate the superior performance of the ACO algorithms compared to routing algorithms based on a centralized control plane with a link-state routing protocol, showcasing lower bandwidth blocking rate, comparable restorability, controlled crosstalk levels, and higher scalability, all achieved without a significant increase in setup and restoration times.

A photonic crystal waveguide intersection using phase change material for optical neuromorphic synapses

This paper introduces an innovative photonic crystal device that amalgamates a low cross-talk GaAs waveguide intersection with a ring employing phase change material (PCM) for application in all-optical neuromorphic synapses. The device uses a degenerate optical cavity housing Germanium–Antimony-Telluride (GST) phase-change material whose optical properties can be manipulated via a control signal. The proposed design facilitates the development of a non-volatile synapse for photonic neural networks and optical neuromorphic circuits. Numerical simulations using the finite difference time domain method (FDTD) exhibit a notably high-quality factor of 900 and a minimal cross-talk level of −60 dB at the intersection of two waveguides. To validate the FDTD results, the structure undergoes further simulations using the finite element method (FEM), confirming the accuracy of the initial calculations. The resultant structure achieves transmissions of 81 % and 13 % in the amorphous and fully crystalline states of PCM, respectively, enabling low output power in the crystalline state and high output power in the amorphous state. Moreover, modulation of the transmission coefficient between 13 % and 81 % is feasible by manipulating the crystallization coefficient of GST materials. To reduce the effect of the imaginary part of the refractive index of the GST material, the evaluation of the output transmission results for the GSST material (Ge2Sb2Se4Te1) has been performed. The results revealed that, despite having a lower imaginary part of the refractive index compared to GST, GSST exhibits lower absorption in both amorphous and crystalline states. However, the use of GSST materials shows a 27 % reduction in the figure of merit (FOM), indicating a lower effective range and fewer degrees of freedom in the different crystallization levels of the PCM ring. To investigate the effect of fabrication defects and structural sensitivity, the radius of photonic crystal rods and the rings of GaAs and GST have been changed, and the results indicate that the radius of the photonic crystal rods and the GST ring have negligible effects on the output transmission and resonant wavelength. However, the thickness of the GaAs ring shows a high sensitivity, which leads to a change in the resonance wavelength that is utilized as an effective tool for tuning the pass wavelength through the structure within the 171 nm bandgap range. The transmission loss in the amorphous state is −0.6 dB and in the fully crystalline state −7.5 dB, which is attributed to the absorption of GST material. This proposed photonic crystal synapse structure with an area of less than 30 μm2 significantly minimizes the required space compared to similar silicon photonic structures and increases the prospects for integration and scalability. The compatibility of the materials employed with optical fibre communications at the 1310 nm wavelength further bolsters the practical feasibility of this design. In summary, this paper presents a significant advancement in the domain of neuromorphic photonics by introducing a promising structure with substantial potential for neural network synapses.

Crosstalk reduction for Arrayed waveguide gratings on Silicon-on-Insulator platform

Ultracompact silicon-based arrayed waveguide gratings (AWGs) with low loss and low crosstalk are essential for on-chip optical interconnect and miniaturized spectroscopic analysis systems. In our previous research, we demonstrated the crosstalk reduction by utilizing constant projection period for phased array waveguide on the tangent line to the grating pole to reduce the imaging error induced by phased array waveguide end point positions [1] and using deep etching waveguides at the interface of free propagation region to further decrease the footprint of phase region of an AWG to reduce fabrication imperfections induced phase error [2]. Here we first study the effect of curved waveguides in the phased array of 16 × 400 GHz AWGs on the adjacent crosstalk of output channels. According to the AWGs made in our fabrication platform and the testing results of five dies from one wafer at different locations, the AWGs with equal length of single-mode curved waveguides have an average adjacent crosstalk level of ∼ 4 dB smaller than those with equal length of narrow single-mode waveguides composed of straight and curved waveguides in their phased array. Based on the design of equal curved waveguide length in phased array, in combination with our reported approaches on crosstalk reduction, 16 × 200 GHz, 8 × 800 GHz and 8 × 1250 GHz AWGs are fabricated. For characterization, five dies including all designs from different locations of the fabricated wafer are tested. Experimental results show that among these five dies, the best adjacent crosstalk levels are less than − 21.97 dB, −25.72 dB, −24.83 dB and the worst adjacent crosstalk levels are less than − 20.51 dB, −25.03 dB, −24.34 dB for 16 × 200 GHz, 8 × 800 GHz and 8 × 1250 GHz AWGs with FPR angle of 120°, respectively, within the passband width of 25 % channel spacing. The on-chip insertion losses for all output channels of these fabricated AWGs are less than 3 dB.

High-performance silicon nitride (de)multiplexer based on ring-assisted MZIs.

We present the design and experimental characterization of the first multistage ring-assisted Mach-Zehnder interferometer (RAMZI) lattice (de)multiplexer implemented with silicon nitride optimized for four channels with a spacing of 100 GHz in the L-band. The device comprises two RAMZI stages to provide a sharp box-like response characterized by a shape factor of 0.9, a flat passband over the entire channel, and a crosstalk level better than -14 dB. The maximally flat passband of the demultiplexer enables a passband width twice that of the maximum spectral excursion defined in the NG-PON2 standard.

Compact SOI Dual-Mode (De)multiplexer Based on the Level Set Method

Mode (de)multiplexer is an essential device in integrated multimode photonic systems. Here, we present a dual-mode (de)multiplexer that separates two input modes, TE0 and TE1, into two output ports while converting TE1 to TE0 mode. Based on the adjoint and level set method, the device features a small footprint of 9.4 μm × 2.9 μm, and a minimum feature size over 200 nm is achieved, affirming stable and reliable fabrication. Through simulations, we observed insertion losses of less than 0.28 dB for TE0 mode and 0.35 dB for TE1 mode within the wavelength range of 1500–1600 nm, accompanied by crosstalk levels lower than −30 dB. In our experimental tests, we achieved insertion losses of less than 0.89 dB for TE0 mode and 0.44 dB for TE1 modes within the 1530 nm to 1570 nm range, with crosstalk maintained below −25 dB. Furthermore, we conducted an experimental verification of the differences between the standard device and the boundary dilation/erosion device, observing an insertion loss degradation by 0.61 dB within a deviation range of ±40 nm, which demonstrates the device’s robustness to the fabrication. The proposed devices exhibit exceptional performance and feature a compact structure, thus holding significant potential for the development of future multimode integrated photonic circuits.

Novel dynamic impairment-aware algorithm for modulation, core, and spectrum assignment in SDM-EONs

Space-division multiplexed elastic optical networks (SDM-EONs) utilizing multi-core fiber (MCF) have been considered to address the growing traffic demand in transport networks. The quality of transmission (QoT) of MCF-based SDM-EONs is affected by inter-core and intra-core physical layer impairments (PLIs). This paper proposes an inter-core crosstalk-aware and intra-core impairment-aware algorithm for modulation, core, and spectrum assignment (CIA-MCSA) in MCF-based SDM-EONs. The CIA-MCSA considers PLI estimation in a dynamic traffic scenario and allocates new lightpaths using strategies to avoid blocking by insufficient QoT of the new lightpath and of already active lightpaths. Using numerical simulation, the performance of the CIA-MCSA is compared with five algorithms proposed by other authors, considering two distinct network topologies, heterogeneous traffic demands, and different levels of inter-core crosstalk. The results show that, when compared with the most competitive of the other algorithms, (i) CIA-MCSA achieves an average reduction of the request blocking probability by at least 33.87%; (ii) CIA-MCSA achieves an average reduction of the bandwidth blocking probability by at least 20.74%; and (iii) CIA-MCSA increases the network spectrum utilization by at least 3.04%.

Generalized Mach Zehnder Interferometers Integrated on Si3N4 Waveguide Platform

We demonstrate 3 × 3 and 4 × 4 Generalized Mach Zehnder Interferometers (GMZI) integrated on the Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> waveguide platform and present their experimental performance as switching and variable power splitting modules. The GMZI structures have been theoretically modelled by means of a transfer matrix model, evaluating also the GMZI spectral response in the case of fabrication errors that may lead to variations in GMZI arm lengths, MMI phase shifts and MMI splitting ratios. Both 3 × 3 and 4 × 4 GMZI structures were fabricated as integrated Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> -based circuits and were experimentally characterized with the experimental results being in close agreement with the theoretical predictions. They both reveal a resonant spectral behavior with an FSR of 1.9 nm and low average insertion losses per port that were measured to be 1 ± 0.2 and 2.4 ± 0.4 dB. The two GMZI structures were utilized as 1:3 and 1:4 switching elements, respectively, with average crosstalk levels being always greater than 10 dB for all possible input-output port combinations. Finally, their credentials to serve within linear optical circuit implementations were evaluated through their experimental characterization in variable power splitting applications, showing that the power level at a single output port can take any value between 0 and 100% of the input signal.

Reconfigurable polarization processor based on coherent four-port micro-ring resonator

Abstract Polarization processors with versatile functionalities are needed in optical systems, which use or manipulate polarized light. In this paper, we propose and realize an integrated polarization processor based on a coherent 4-port micro-ring resonator. The arbitrary unknown polarization state is input to the polarization processor via a 2-dimensional grating coupler (2DGC), which serves as a polarization beam splitter. The coherent 4-port micro-ring resonator (MRR) operates as a unitary processor and is formed by one crossbar micro-ring resonator and two thermally tunable phase shifters, one of which tunes the micro-ring while the other tunes the coherent interference between the two inputs from the 2DGC. The 4-port system can be used to control the input polarization states that appear at the two output ports and, therefore, can be used to implement a multi-function polarization processor, including polarization descrambler, polarization switch, polarizers, and polarization analyzer (both division of space (DOS) and division of time (DOT)). In this paper, we experimentally demonstrate the use of coherent 4-port MRR for polarization mode switching and for polarization mode unscrambling. The polarization unscrambler was capable of separating two polarization-multiplexed 40 GHz data lanes from the input fiber with crosstalk levels below −21 dB and is suitable for use in the receiver for polarization-multiplexed direct-detection optical communications systems. The same photonic circuit may be used as a polarization analyzer, either as a DOS polarization analyzer or a DOT polarization analyzer. The DOS polarization analyzer measured the polarization with measured deviation of the orientation angle (2ψ) varying from −0.5° to 1.3°and deviation of ellipticity angle (2χ) varying from −0.98° to 7.27°. The DOT polarization analyzer measured the polarization with a deviation of the orientation angle (2ψ) that varied from −2.93° to 3.49° and deviation of ellipticity angle (2χ) that varied from −3.5° to 3.05°.

Dual-function plasmonic device on photonic crystal fiber for near to mid-infrared regions

Broadband multifunction optical devices can play an important role in the field of integrated photonics but achieving high tunability and versatility on a fabricated device by implementing external control or structural modification is still challenging. In this article, what we believe to be a new dual-function optical device based on photonic crystal fiber, having an ultra-broad bandwidth that partially covers near-infrared (IR) to mid-IR regions, is proposed and analyzed. This device is designed on a fabrication friendly geometry such a way that it can be used as a polarization filter as well as refractive index sensor without any external tuning or structural modification. In this case, plasmonic material plays a crucial role for achieving simultaneous operation of the device both in communication and sensing applications. Our proposed device, with a fiber length of 100 µm, can effectively suppress the y-polarized light within the wavelength range of 1.29 µm to 1.60 µm, while the x-polarized light is maintained properly in the core, and vice-versa for the region of 1.69 µm to 4.39 µm. The maximum confinement losses of 840.8 dB/cm, 1013.2 dB/cm, 659.65 dB/cm, and 792.68 dB/cm are obtained at wavelengths of 1.37 µm, 1.56 µm, 1.72 µm, and 2.65 µm, respectively. By maintaining a crosstalk level of better than 20 dB, this device achieves broad bandwidths of 310 nm over the 1.29 µm to 1.60 µm wavelength range and 2700 nm over the 1.69 µm to 4.39 µm wavelength range. In addition to the filtering performance, our device possesses sensing capabilities, which is also well discussed as an example of refractive index sensor. Considering the analyte refractive index of 1.10-1.40, this device shows an average wavelength sensitivity of 1000 nm/RIU. Therefore, the above exceptional characteristics of our proposed device make it suitable for both optical communication and sensing systems.

Agata detector technology: recent progress and future developments

gamma -ray tracking is based on a new generation of position sensitive high-purity germanium (HPGe) detectors. A novel type of cluster detector was successfully developed and assembled for the high-resolution gamma -ray spectrometer Advanced Gamma Tracking Array AGATA. The core part of the detector consists of three encapsulated, 36-fold segmented HPGe detectors which are operated in a common cryostat. The Ge crystal is hermetically sealed inside an aluminium can. All energy channels provide best energy resolution of core and segment signals for an extended energy range well above 50 MeV. A low cross-talk level was determined for the HPGe detectors and its preamplifier circuitry. Related cross-talk corrections are essential for highest energy resolution and improved position dependent pulse shape information. Recently a new encapsulation technology was put into operation which is based on a renewable metal elastic seal. HPGe detector developments are concerned with technologies for the production of p+ and n+ contacts, the segmentation and passivation of encapsulated HPGe crystals. Semiconductor processing research specifically aimed to develop a stable, thin and easy to segment n+ contact. A novel process, based on pulsed laser melting PLM, was successfully employed to produce very thin n+ and p+ contacts preserving the Ge purity. The contacts were segmented using a photolithographic process and then the intrinsic surface between contacts was passivated to assure the electrical insulation between them. A small detector prototype with three segments was made using these new techniques and then successfully tested.

Fluid shear stress-modulated chromatin accessibility reveals the mechano-dependency of endothelial SMAD1/5-mediated gene transcription

Bone morphogenetic protein (BMP) signaling and fluid shear stress (FSS) mediate complementary functions in vascular homeostasis and disease development. It remains to be shown whether altered chromatin accessibility downstream of BMP and FSS offers a crosstalk level to explain changes in SMAD-dependent transcription. Here, we employed ATAC-seq to analyze arterial endothelial cells stimulated with BMP9 and/or FSS. We found that BMP9-sensitive regions harbor non-palindromic GC-rich SMAD-binding elements (GGCTCC) and 69.7% of these regions become BMP-insensitive in the presence of FSS. While GATA and KLF transcription factor (TF) motifs are unique to BMP9- and FSS-sensitive regions, respectively, SOX motifs are common to both. Finally, we show that both SOX(13/18) and GATA(2/3/6) family members are directly upregulated by SMAD1/5. These findings highlight the mechano-dependency of SMAD-signaling by a sequential mechanism of first elevated pioneer TF expression, allowing subsequent chromatin opening to eventually providing accessibility to novel SMAD binding sites.

Comparative transcriptome profiling reveals the multiple levels of crosstalk in phytohormone networks in Brassica napus.

Plant hormones are the intrinsic factors that control plant development. The integration of different phytohormone pathways in a complex network of synergistic, antagonistic and additive interactions has been elucidated in model plants. However, the systemic level of transcriptional responses to hormone crosstalk in Brassica napus is largely unknown. Here, we present an in-depth temporal-resolution study of the transcriptomes of the seven hormones in B. napus seedlings. Differentially expressed gene analysis revealed few common target genes that co-regulated (up- and down-regulated) by seven hormones; instead, different hormones appear to regulate distinct members of protein families. We then constructed the regulatory networks between the seven hormones side by side, which allowed us to identify key genes and transcription factors that regulate the hormone crosstalk in B. napus. Using this dataset, we uncovered a novel crosstalk between gibberellin and cytokinin in which cytokinin homeostasis was mediated by RGA-related CKXs expression. Moreover, the modulation of gibberellin metabolism by the identified key transcription factors was confirmed in B. napus. Furthermore, all data were available online from http://yanglab.hzau.edu.cn/BnTIR/hormone. Our study reveals an integrated hormone crosstalk network in Brassica napus, which also provides a versatile resource for future hormone studies in plant species.

Synergy between Membrane Currents Prevents Severe Bradycardia in Mouse Sinoatrial Node Tissue

Bradycardia is initiated by the sinoatrial node (SAN), which is regulated by a coupled-clock system. Due to the clock coupling, reduction in the 'funny' current (If), which affects SAN automaticity, can be compensated, thus preventing severe bradycardia. We hypothesize that this fail-safe system is an inherent feature of SAN pacemaker cells and is driven by synergy between If and other ion channels. This work aimed to characterize the connection between membrane currents and their underlying mechanisms in SAN cells. SAN tissues were isolated from C57BL mice and Ca2+ signaling was measured in pacemaker cells within them. A computational model of SAN cells was used to understand the interactions between cell components. Beat interval (BI) was prolonged by 54 ± 18% (N = 16) and 30 ± 9% (N = 21) in response to If blockade, by ivabradine, or sodium current (INa) blockade, by tetrodotoxin, respectively. Combined drug application had a synergistic effect, manifested by a BI prolonged by 143 ± 25% (N = 18). A prolongation in the local Ca2+ release period, which reports on the level of crosstalk within the coupled-clock system, was measured and correlated with the prolongation in BI. The computational model predicted that INa increases in response to If blockade and that this connection is mediated by changes in T and L-type Ca2+ channels.