| 11. |
- Forsgren, Mikael F, 1983-, et al.
(author)
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Biomarkers of liver fibrosis : prospective comparison of multimodal magnetic resonance, serum algorithms and transient elastography.
- 2020
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In: Scandinavian Journal of Gastroenterology. - : Taylor & Francis. - 0036-5521 .- 1502-7708. ; 55:7, s. 848-859
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Journal article (peer-reviewed)abstract
- BACKGROUND AND AIMS: Accurate biomarkers for quantifying liver fibrosis are important for clinical practice and trial end-points. We compared the diagnostic performance of magnetic resonance imaging (MRI), including gadoxetate-enhanced MRI and 31P-MR spectroscopy, with fibrosis stage and serum fibrosis algorithms in a clinical setting. Also, in a subset of patients, MR- and transient elastography (MRE and TE) was evaluated when available.METHODS: Patients were recruited prospectively if they were scheduled to undergo liver biopsy on a clinical indication due to elevated liver enzyme levels without decompensated cirrhosis. Within a month of the clinical work-up, an MR-examination and liver needle biopsy were performed on the same day. Based on late-phase gadoxetate-enhanced MRI, a mathematical model calculated hepatobiliary function (relating to OATP1 and MRP2). The hepatocyte gadoxetate uptake rate (KHep) and the normalised liver-to-spleen contrast ratio (LSC_N10) were also calculated. Nine serum fibrosis algorithms were investigated (GUCI, King's Score, APRI, FIB-4, Lok-Index, NIKEI, NASH-CRN regression score, Forns' score, and NAFLD-fibrosis score).RESULTS: The diagnostic performance (AUROC) for identification of significant fibrosis (F2-4) was 0.78, 0.80, 0.69, and 0.78 for MRE, TE, LSC_N10, and GUCI, respectively. For the identification of advanced fibrosis (F3-4), the AUROCs were 0.93, 0.84, 0.81, and 0.82 respectively.CONCLUSION: MRE and TE were superior for non-invasive identification of significant fibrosis. Serum fibrosis algorithms developed for specific liver diseases are applicable in this cohort of diverse liver diseases aetiologies. Gadoxetate-MRI was sufficiently sensitive to detect the low function losses associated with fibrosis. None was able to efficiently distinguish between stages within the low fibrosis stages.Lay summaryExcessive accumulation of scar tissue, fibrosis, in the liver is an important aspect in chronic liver disease. To replace the invasive needle biopsy, we have explored non-invasive methods to assess liver fibrosis. In our study we found that elastographic methods, which assess the mechanical properties of the liver, are superior in assessing fibrosis in a clinical setting. Of interest from a clinical trial point-of-view, none of the tested methods was sufficiently accurate to distinguish between adjacent moderate fibrosis stages.
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| 12. |
- Gao, Jitao, et al.
(author)
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Active Mode-Selective Conversion Enabled by an Elliptical-Core Highly Nonlinear Few-Mode Fiber
- 2020
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In: Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS. - 1092-8081. ; 2020-May
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Conference paper (peer-reviewed)abstract
- We design an elliptical-core highly nonlinear few-mode fiber to achieve mode-selective conversion without parasitic wavelength conversion, using intermodal four-wave mixing. The proposed mode converter can be used in optical cross-connects over the C-band.
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| 13. |
- Gao, Jitao, et al.
(author)
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Elliptical-Core Highly Nonlinear Few-Mode Fiber Based OXC for WDM-MDM Networks
- 2021
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In: IEEE Journal of Selected Topics in Quantum Electronics. - 1558-4542 .- 1077-260X. ; 27:2
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Journal article (peer-reviewed)abstract
- In order to realize an optical cross-connect (OXC) converting wavelengths and spatial modes into one-dimensional switching ports, we propose an active mode selective conversion without parasitic wavelength conversion, based on the intermodal four-wave mixing (FWM) arising in a few-mode fiber (FMF). First, we design a dispersion-engineered elliptical-core highly nonlinear FMF (e-HNL-FMF) with a graded refractive index (RI) profile, which can independently guide 3 linearly polarized (LP) spatial modes. Meanwhile, a high doping concentration of germanium in the core leads to relatively high intermodal nonlinear coefficients of 3.23 (W·km)-1 between LP01 and LP11a modes and 3.14 (W·km)-1 between LP01 and LP11b modes. Next, we propose an e-HNL-FMF based OXC scheme for wavelength division multiplexing-mode division multiplexing (WDM-MDM) networks. After optimizing both the e-HNL-FMF length and pump power, we can realize either active mode selective conversion over the designated wavelength-band or three-wavelength to three-mode superchannel conversion for 100 Gbaud 16-quadratic-amplitude modulation (16-QAM) signals over the C-band. Due to excellent characteristics of the e-HNL-FMF, both cost and configuration complexity of the OXC can be reduced, showing great potentials for all-optical signal processing in the future WDM-MDM networks.
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| 14. |
- He, Zonglong, 1994, et al.
(author)
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12.2 bit/s/Hz C-band Transmission with High-Gain Low-Complexity 24-Dimensional Geometric Shaping
- 2024
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In: Journal of Lightwave Technology. - 0733-8724 .- 1558-2213. ; In Press
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Journal article (peer-reviewed)abstract
- Multidimensional (MD) modulation formats enable a larger minimum Euclidean distance than conventional two-dimensional formats. As a structured geometric shaping method, MD Voronoi constellations (VCs) avoid the use of look-up tables and can be implemented with low-complexity encoding and decoding algorithms, outperforming quadrature amplitude modulation (QAM) formats in terms of mutual information. However, it is challenging to maintain the shaping gain in a practical system requiring bit-mapping and forward error correction (FEC) coding. By using a hybrid labeling and multilevel coding scheme integrated with soft-decision FEC coding, MD VCs can achieve high shaping gain compared to QAM formats after soft-decision (SD) decoding. In practical systems, transceiver impairments significantly degrade the system performance, especially for high-cardinality constellations. To investigate of performance of high spectral-efficiency (SE) MD VCs, we employ a 24-dimensional (24D) VC with uncoded SE of 8 bit/symbol/dimension-pair to a spectral superchannel spanning the full C-band. Specifically, the 24D VC with a record constellation size of 7.9×10 28 is applied to dual-polarization coherent transmission over six time slots. The superchannel is composed of 5.0 Gbaud channels spaced at 5.2 GHz, resulting in an overall spectral efficiency of 12.2 bit/s/Hz and a net throughput of 54.2 Tb/s over the entire C-band after 40 km single-mode fiber. It is the first experimental demonstration of a high-SE MD format providing a significant shaping gain after SD decoding.
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| 15. |
- Helgason, Òskar Bjarki, 1989, et al.
(author)
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Dissipative solitons in photonic molecules
- 2021
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In: Nature Photonics. - : Springer Science and Business Media LLC. - 1749-4885 .- 1749-4893. ; 15:4, s. 305-310
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Journal article (peer-reviewed)abstract
- Many physical systems display quantized energy states. In optics, interacting resonant cavities show a transmission spectrum with split eigenfrequencies, similar to the split energy levels that result from interacting states in bonded multi-atomic—that is, molecular—systems. Here, we study the nonlinear dynamics of photonic diatomic molecules in linearly coupled microresonators and demonstrate that the system supports the formation of self-enforcing solitary waves when a laser is tuned across a split energy level. The output corresponds to a frequency comb (microcomb) whose characteristics in terms of power spectral distribution are unattainable in single-mode (atomic) systems. Photonic molecule microcombs are coherent, reproducible and reach high conversion efficiency and spectral flatness while operated with a laser power of a few milliwatts. These properties can favour the heterogeneous integration of microcombs with semiconductor laser technology and facilitate applications in optical communications, spectroscopy and astronomy.
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| 16. |
- Johansson, Peter, 1967, et al.
(author)
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Cultural expertise in Sami land rights litigation: Epistemic strategies in the Girjas and Fosen cases
- 2023
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In: Jindal Global Law Review. - : Springer Nature. - 0975-2498 .- 2364-4869. ; 14:2, s. 217-240
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Journal article (peer-reviewed)abstract
- How do parties mobilise cultural expertise in Indigenous rights litigation in Scandinavia? Recently, Sami groups have litigated to claim Indigenous rights to land and natural resources, winning some remarkable victories in the Supreme Courts of Norway and Sweden. In this paper, we draw on socio-legal mobilisation theory to analyse the epistemic strategies of Sami litigants and their adversaries in two recent landmark Supreme Court cases on Indigenous rights to usage of land: the 2020 Girjas case in Sweden and the 2021 Fosen case in Norway. Conceptualising cultural expertise as a strategic framing contest, we analyse how the parties struggled over the epistemic basis of the respective case by legitimating their claims to cultural knowledge, drawing on academic research, and discrediting their opponents’ epistemic claims. Our findings suggest that in both cases, Sami claimants successfully established an epistemic basis where their traditional, experiential knowledge combined with independent academic expertise effectively challenged the knowledge claims of their adversaries. Yet, both cases also demonstrate how the linkage between Sami Indigeneity and reindeer husbandry in the national law of both countries excludes non-reindeer herding Sami persons from the Indigenous rights affirmed by the courts.
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| 17. |
- Jorgensen, A. A., et al.
(author)
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Petabit-per-second data transmission using a chip-scale microcomb ring resonator source
- 2022
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In: Nature Photonics. - : Springer Science and Business Media LLC. - 1749-4885 .- 1749-4893. ; 16:11, s. 798-802
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Journal article (peer-reviewed)abstract
- Optical fibre communication is the backbone of the internet. As essential core technologies are approaching their limits of size, speed and energy-efficiency, there is a need for new technologies that offer further scaling of data transmission capacity. Here we show that a single optical frequency-comb source based on a silicon nitride ring resonator supports data capacities in the petabit-per-second regime. We experimentally demonstrate transmission of 1.84 Pbit s–1 over a 37-core, 7.9-km-long fibre using 223 wavelength channels derived from a single microcomb ring resonator producing a stabilized dark-pulse Kerr frequency comb. We also present a theoretical analysis that indicates that a single, chip-scale light source should be able to support 100 Pbit s–1 in massively parallel space-and-wavelength multiplexed data transmission systems. Our findings could mark a shift in the design of future communication systems, targeting device-efficient transmitters and receivers.
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| 18. |
- Karlsson, Magnus, 1967, et al.
(author)
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Analytic theory for parametric gain in lossy integrated waveguides
- 2021
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In: Optics InfoBase Conference Papers. - 2162-2701. - 9781943580910
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Conference paper (peer-reviewed)abstract
- We provide an accurate yet simple analytic formula for the parametric gain in phase (in-) sensitive parametric amplifiers where the waveguide loss cannot be neglected. This is of significance for integrated parametric devices.
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| 19. |
- Kong, D., et al.
(author)
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Single Dark-Pulse Kerr Comb Supporting 1.84 Pbit/s Transmission over 37-Core Fiber
- 2020
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In: Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS. - 1092-8081. ; 2020-May
-
Conference paper (peer-reviewed)abstract
- We show that a single dark-pulse Kerr comb can generate high enough OSNR to carry 1.84 Pbit/s data, achieved by 223 WDM spectral lines modulated with 32-Gbaud, SNR-adapted probabilistically shaped DP-QAM, over a 37-core fiber.
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| 20. |
- Lagerkvist, Johan, 1983, et al.
(author)
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Climate impact estimation – from feasibility study to handover
- 2021
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In: IABSE Congress, Ghent 2021: Structural Engineering for Future Societal Needs. - Zurich, Switzerland : International Association for Bridge and Structural Engineering (IABSE). ; , s. 622-628
-
Conference paper (peer-reviewed)abstract
- Responsible for 1/5 of the total CO2-equivalents emissions and 50% of the materials resources used globally, the construction industry plays a vital role for a sustainable future. All parties in the construction industry address the challenge from their perspective and national transport administrations are often considered as the driver toward a fossil free industry. In this study, three Swedish infrastructure projects are studied by means of interviews, focusing on the usage and acceptance of the recently implemented climate estimation process. From the interviews, it is found that currently there is a lack of knowledge regarding climate estimations among bridge and environmental specialists as well as project managers. To address this challenge, it is important to educate the industry and increase the knowledge about climate estimations and declarations as well as inform which actions have the largest impact to reduce the CO2-equivalents emissions.
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