| 1. |
- Caliandro, Pietro, et al.
(författare)
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Jitter of Corticospinal Neurons During Repetitive Transcranial Magnetic Stimulation : Method and Possible Clinical Implications
- 2014
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Ingår i: Brain Stimulation. - : Elsevier BV. - 1935-861X .- 1876-4754. ; 7:4, s. 580-586
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Tidskriftsartikel (refereegranskat)abstract
- Background: Repetitive transcranial magnetic stimulation (rTMS) of the motor cortex activates corticospinal neurons mainly through the depolarization of cortico-cortical axons belonging to interneurons of superficial layers. Objective: We used single-fiber electromyography (SFEMG) to estimate the "central jitter" of activation latency of interneural pools from one pulse of TMS to another. Methods: We evaluated 10 healthy subjects and one patient with multiple sclerosis. By recording SFEMG evoked activity from the left first dorsal interosseous (FDI), we first used a standard repetitive electrical 3 Hz stimulation of the ulnar nerve at the wrist to calculate the mean consecutive difference from at least 10 different potentials. The same procedure was applied during 3 Hz repetitive TMS of the contralateral motor cortex. The corticospinal monosynaptic connection of the FDI and the selectivity of SFEMG recording physiologically justified the subtraction of the "peripheral jitter" from the whole cortico-muscular jitter, obtaining an estimation of the actual "central jitter." Results: All subjects completed the study. The peripheral jitter was 28 mu s +/- 6 and the cortico-muscular jitter was 344 mu s +/- 97. The estimated central jitter was 343 +/- 97 mu s. In the patient the central jitter was 846 mu s, a value more than twice the central jitter in healthy subjects. Conclusion: Current results demonstrate that the evaluation of the central component of the cumulative cortico-muscular latency variability in healthy subjects is feasible with a minimally invasive approach. We present and discuss this methodology and provide a "proof of concept" of its potential clinical applicability in a patient with multiple sclerosis.
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| 2. |
- Filippou, Georgios, et al.
(författare)
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The predictive role of ultrasound-detected tenosynovitis and joint synovitis for flare in patients with rheumatoid arthritis in stable remission. Results of an Italian multicentre study of the Italian Society for Rheumatology Group for Ultrasound : The STARTER study
- 2018
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 77:9, s. 1283-1289
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To define the role of ultrasound (US) for the assessment of patients with rheumatoid arthritis (RA) in clinical remission, including joint and tendon evaluation. Methods: A multicentre longitudinal study has been promoted by the US Study Group of the Italian Society for Rheumatology. 25 Italian centres participated, enrolling consecutive patients with RA in clinical remission. All patients underwent complete clinical assessment (demographic data, disease characteristics, laboratory exams, clinical assessment of 28 joints and patient/physician-reported outcomes) and Power Doppler (PD) US evaluation of wrist, metacarpalphalangeal joints, proximal interphalangeal joints and synovial tendons of the hands and wrists at enrolment, 6 and 12 months. The association between clinical and US variables with flare, disability and radiographic progression was evaluated by univariable and adjusted logistic regression models. Results: 361 patients were enrolled, the mean age was 56.20 (±13.31) years and 261 were women, with a mean disease duration of 9.75 (±8.07) years. In the 12 months follow-up, 98/326 (30.1%) patients presented a disease flare. The concurrent presence of PD positive tenosynovitis and joint synovitis predicted disease flare, with an OR (95% CI) of 2.75 (1.45 to 5.20) in crude analyses and 2.09 (1.06 to 4.13) in adjusted analyses. US variables did not predict the worsening of function or radiographic progression. US was able to predict flare at 12 months but not at 6 months. Conclusions: PD positivity in tendons and joints is an independent risk factor of flare in patients with RA in clinical remission. Musculoskeletal ultrasound evaluation is a valuable tool to monitor and help decision making in patients with RA in clinical remission.
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| 3. |
- Jung, Christian, et al.
(författare)
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A comparison of very old patients admitted to intensive care unit after acute versus elective surgery or intervention
- 2019
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Ingår i: Journal of critical care. - : W B SAUNDERS CO-ELSEVIER INC. - 0883-9441 .- 1557-8615. ; 52, s. 141-148
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Tidskriftsartikel (refereegranskat)abstract
- Background: We aimed to evaluate differences in outcome between patients admitted to intensive care unit (ICU) after elective versus acute surgery in a multinational cohort of very old patients (80 years; VIP). Predictors of mortality, with special emphasis on frailty, were assessed.Methods: In total, 5063 VIPs were induded in this analysis, 922 were admitted after elective surgery or intervention, 4141 acutely, with 402 after acute surgery. Differences were calculated using Mann-Whitney-U test and Wilcoxon test. Univariate and multivariable logistic regression were used to assess associations with mortality.Results: Compared patients admitted after acute surgery, patients admitted after elective surgery suffered less often from frailty as defined as CFS (28% vs 46%; p < 0.001), evidenced lower SOFA scores (4 +/- 5 vs 7 +/- 7; p < 0.001). Presence of frailty (CFS >4) was associated with significantly increased mortality both in elective surgery patients (7% vs 12%; p = 0.01), in acute surgery (7% vs 12%; p = 0.02).Conclusions: VIPs admitted to ICU after elective surgery evidenced favorable outcome over patients after acute surgery even after correction for relevant confounders. Frailty might be used to guide clinicians in risk stratification in both patients admitted after elective and acute surgery.
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| 4. |
- Pataki, Nathan James, et al.
(författare)
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A Rolled Organic Thermoelectric Generator with High Thermocouple Density
- 2024
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Ingår i: Advanced Functional Materials. - : WILEY-V C H VERLAG GMBH. - 1616-301X .- 1616-3028.
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Tidskriftsartikel (refereegranskat)abstract
- The surge in the number of distributed microelectronics and sensors requires versatile, scalable, and affordable power sources. Heat-harvesting organic thermoelectric generators (TEGs) are regarded as potential key components of the future energy landscape. Recent advances in the performance of organic thermoelectric materials have made practical applications of organic TEGs more feasible than ever before, yet the challenges of designing and fabricating organic TEGs suitable for real scenarios are scarcely addressed. Specifically, small sensors and wearables demand for micro-thermoelectric generators (mu TEGs) with high power density architectures and small form factors, while typical demonstrations of organic TEGs are characterized by < 10 thermocouples (TCs) per cm(2). This work presents a rolled, organic mu TEG architecture combining large-area, solution-based deposition techniques, such as inkjet and spray-coating, and an ultrathin parylene substrate to achieve a thermocouple density of 1842 TCs cm(-2). Such demonstrative mu TEG reaches a thermoelectric conversion performance of 0.15 mu W cm(-2) at Delta T = 50 K. Such power output is well in line with finite element method simulations, which highlight the benefit of the architecture and show that remarkable power densities, in the mW cm(-2) range at Delta T = 10 K, are realistically achievable with geometrical improvements and already ongoing advancements in organic thermoelectric inks.
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| 5. |
- Peng, Y. Y., et al.
(författare)
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Doping dependence of the electron-phonon coupling in two families of bilayer superconducting cuprates
- 2022
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Ingår i: Physical Review B. - 2469-9969 .- 2469-9950. ; 105:11
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Tidskriftsartikel (refereegranskat)abstract
- While electron-phonon coupling (EPC) is crucial for Cooper pairing in conventional superconductors, its role in high-Tc superconducting cuprates is debated. Using resonant inelastic x-ray scattering at the oxygen K edge, we study the EPC in Bi2Sr2CaCu2O8+δ (Bi2212) and Nd1+xBa2-xCu3O7-δ (NBCO) at different doping levels ranging from heavily underdoped (p=0.07) to overdoped (p=0.21). We analyze the data with a localized Lang-Firsov model that allows for the coherent excitations of two phonon modes. While electronic band dispersion effects are non-negligible, we are able to perform a study of the relative values of EPC matrix elements in these cuprate families. In the case of NBCO, the choice of the excitation energy allows us to disentangle modes related to the CuO chains and the CuO2 planes. Combining the results from the two families, we find the EPC strength decreases with doping at q∥=(-0.25,0) r.l.u., but has a nonmonotonic trend as a function of doping at smaller momenta. This behavior is attributed to the screening effect of charge carriers. We also find that the phonon intensity is enhanced in the vicinity of the charge-density-wave excitations while the extracted EPC strength appears to be less sensitive to their proximity. By performing a comparative study of two cuprate families, we are able to identify general trends in the EPC for the cuprates and provide experimental input to theories invoking a synergistic role for this interaction in d-wave pairing.
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| 6. |
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| 7. |
- Albrecht, Stefano V., et al.
(författare)
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Reports on the 2015 AAAI Workshop Series
- 2015
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Ingår i: The AI Magazine. - : Wiley. - 0738-4602 .- 2371-9621. ; 36:2, s. 90-101
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Tidskriftsartikel (refereegranskat)abstract
- AAAI's 2015 Workshop Program was held Sunday and Monday, January 25-26, 2015, at the Hyatt Regency Austin Hotel in Austin, Texas, USA. The AAAI-15 workshop program included 16 workshops covering a wide range of topics in artificial intelligence. Most workshops were held on a single day. The titles of the workshops included Algorithm Configuration; Artificial Intelligence and Ethics; Artificial Intelligence Applied to Assistive Technologies and Smart Environments; Artificial Intelligence for Cities; Artificial Intelligence for Transportation: Advice, Inter-activity, and Actor Modeling; Beyond the Turing Test; Computational Sustainability; Computer Poker and Imperfect Information; Incentive and Trust in E-Communities; Knowledge, Skill, and Behavior Transfer in Autonomous Robots; Learning for General Competency in Video Games; Multiagent Interaction without Prior Coordination; Planning, Search, and Optimization; Scholarly Big Data: AI Perspectives, Challenges, and Ideas; Trajectory-Based Behaviour Analytics; and World Wide Web and Public Health Intelligence.
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| 8. |
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| 9. |
- Archilletti, Federico, et al.
(författare)
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Coronary angiography- or fractional flow reserve-guided complete revascularization in multivessel disease STEMI : A Bayesian hierarchical network meta-analysis
- 2023
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Ingår i: International Journal of Cardiology. - : Elsevier BV. - 0167-5273. ; 370, s. 122-128
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Tidskriftsartikel (refereegranskat)abstract
- Aims: To identify the best strategy to achieve complete revascularization (CR) in patients with ST-elevation myocardial infarction (STEMI) and multi-vessel disease (MVD). Methods and results: We systematically reviewed the literature for randomized controlled trials (RCTs) comparing IRA-only PCI and CR guided by angiography or fractional flow reserve (FFR) in MVD-STEMI. Both frequentist (classical) and Bayesian network meta-analysis were performed, including a comparative hierarchy estimation of the probability to reduce the primary composite endpoint of all-cause death and new myocardial infarction (MI). We identified 11 RCTs, including 8193 STEMI patients. Compared with IRA-only strategy, CR significantly reduced the primary endpoint (OR: 0.73; 95%CI0.55–0.97). We observed non-significant difference between angiography and FFR guidance in reducing the primary endpoint (OR: 0.73, 95% CI 0.35–1.57). The Bayesian probability analysis ranked angio-guided CR as the best intervention yielding lowest risk of all-cause death or new MI (SUCRA92%). Conclusions: In patients with MVD-STEMI, CR is associated with a reduction in all-cause mortality and new MI compared with IRA-only PCI. Angio-guided CR is associated with the lowest risk of all-cause death or new MI, therefore the role of FFR-guidance in this setting is questionable. Condensed abstract: Both frequentist and Bayesian network meta-analysis were performed to compare infarct-related artery (IRA)-only percutaneous coronary intervention (PCI) and complete revascularization (CR) guided by angiography or fractional flow reserve (FFR) in multivessel disease (MVD) and acute ST-elevation myocardial infarction (STEMI). Eleven randomized controlled trials were identified, including 8193 STEMI patients. Compared with IRA-only strategy, CR significantly reduced the incidence of the composite endpoint of all-cause death and new myocardial infarction without significant difference in angio-guided and FFR-guided CR. The Bayesian probability analysis ranked angio-guided CR as the best intervention yielding lowest risk of the composite endpoint and, therefore the role of FFR-guidance in this setting is questionable.
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| 10. |
- Ashcroft, Michael, et al.
(författare)
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Multilayer Analysis of Online Illicit Marketplaces
- 2016
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Ingår i: 2016 European Intelligence And Security Informatics Conference (EISIC). - : IEEE. - 9781509028573 ; , s. 199-199
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Konferensbidrag (refereegranskat)
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| 11. |
- Askarpour, Mehrnoosh, et al.
(författare)
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RoboMAX: Robotic Mission Adaptation eXemplars
- 2021
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Ingår i: Proceedings - 2021 International Symposium on Software Engineering for Adaptive and Self-Managing Systems, SEAMS 2021. ; , s. 245-251
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Konferensbidrag (refereegranskat)abstract
- Emerging and future applications of robotic systems pose unique self-adaptation challenges. To support the research needed to address these challenges, we provide an extensible repository of robotic mission adaptation exemplars. Co-designed with robotic application stakeholders including researchers, developers, operators, and end-users, our repository captures key sources of uncertainty, adaptation concerns, and other distinguishing characteristics of such applications. An online form enables external parties to supply new exemplars for curation and inclusion into the repository. We envisage that our RoboMAX repository will enable the development, evaluation, and comparison of self-adaptation approaches for the robotic systems domain.
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| 12. |
- Backes, Claudia, et al.
(författare)
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Production and processing of graphene and related materials
- 2020
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Ingår i: 2D Materials. - : IOP Publishing. - 2053-1583. ; 7:2
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Tidskriftsartikel (refereegranskat)abstract
- We present an overview of the main techniques for production and processing of graphene and related materials (GRMs), as well as the key characterization procedures. We adopt a 'hands-on' approach, providing practical details and procedures as derived from literature as well as from the authors' experience, in order to enable the reader to reproduce the results. Section I is devoted to 'bottom up' approaches, whereby individual constituents are pieced together into more complex structures. We consider graphene nanoribbons (GNRs) produced either by solution processing or by on-surface synthesis in ultra high vacuum (UHV), as well carbon nanomembranes (CNM). Production of a variety of GNRs with tailored band gaps and edge shapes is now possible. CNMs can be tuned in terms of porosity, crystallinity and electronic behaviour. Section II covers 'top down' techniques. These rely on breaking down of a layered precursor, in the graphene case usually natural crystals like graphite or artificially synthesized materials, such as highly oriented pyrolythic graphite, monolayers or few layers (FL) flakes. The main focus of this section is on various exfoliation techniques in a liquid media, either intercalation or liquid phase exfoliation (LPE). The choice of precursor, exfoliation method, medium as well as the control of parameters such as time or temperature are crucial. A definite choice of parameters and conditions yields a particular material with specific properties that makes it more suitable for a targeted application. We cover protocols for the graphitic precursors to graphene oxide (GO). This is an important material for a range of applications in biomedicine, energy storage, nanocomposites, etc. Hummers' and modified Hummers' methods are used to make GO that subsequently can be reduced to obtain reduced graphene oxide (RGO) with a variety of strategies. GO flakes are also employed to prepare three-dimensional (3d) low density structures, such as sponges, foams, hydro- or aerogels. The assembly of flakes into 3d structures can provide improved mechanical properties. Aerogels with a highly open structure, with interconnected hierarchical pores, can enhance the accessibility to the whole surface area, as relevant for a number of applications, such as energy storage. The main recipes to yield graphite intercalation compounds (GICs) are also discussed. GICs are suitable precursors for covalent functionalization of graphene, but can also be used for the synthesis of uncharged graphene in solution. Degradation of the molecules intercalated in GICs can be triggered by high temperature treatment or microwave irradiation, creating a gas pressure surge in graphite and exfoliation. Electrochemical exfoliation by applying a voltage in an electrolyte to a graphite electrode can be tuned by varying precursors, electrolytes and potential. Graphite electrodes can be either negatively or positively intercalated to obtain GICs that are subsequently exfoliated. We also discuss the materials that can be amenable to exfoliation, by employing a theoretical data-mining approach. The exfoliation of LMs usually results in a heterogeneous dispersion of flakes with different lateral size and thickness. This is a critical bottleneck for applications, and hinders the full exploitation of GRMs produced by solution processing. The establishment of procedures to control the morphological properties of exfoliated GRMs, which also need to be industrially scalable, is one of the key needs. Section III deals with the processing of flakes. (Ultra)centrifugation techniques have thus far been the most investigated to sort GRMs following ultrasonication, shear mixing, ball milling, microfluidization, and wet-jet milling. It allows sorting by size and thickness. Inks formulated from GRM dispersions can be printed using a number of processes, from inkjet to screen printing. Each technique has specific rheological requirements, as well as geometrical constraints. The solvent choice is critical, not only for the GRM stability, but also in terms of optimizing printing on different substrates, such as glass, Si, plastic, paper, etc, all with different surface energies. Chemical modifications of such substrates is also a key step. Sections IV-VII are devoted to the growth of GRMs on various substrates and their processing after growth to place them on the surface of choice for specific applications. The substrate for graphene growth is a key determinant of the nature and quality of the resultant film. The lattice mismatch between graphene and substrate influences the resulting crystallinity. Growth on insulators, such as SiO2, typically results in films with small crystallites, whereas growth on the close-packed surfaces of metals yields highly crystalline films. Section IV outlines the growth of graphene on SiC substrates. This satisfies the requirements for electronic applications, with well-defined graphene-substrate interface, low trapped impurities and no need for transfer. It also allows graphene structures and devices to be measured directly on the growth substrate. The flatness of the substrate results in graphene with minimal strain and ripples on large areas, allowing spectroscopies and surface science to be performed. We also discuss the surface engineering by intercalation of the resulting graphene, its integration with Si-wafers and the production of nanostructures with the desired shape, with no need for patterning. Section V deals with chemical vapour deposition (CVD) onto various transition metals and on insulators. Growth on Ni results in graphitized polycrystalline films. While the thickness of these films can be optimized by controlling the deposition parameters, such as the type of hydrocarbon precursor and temperature, it is difficult to attain single layer graphene (SLG) across large areas, owing to the simultaneous nucleation/growth and solution/precipitation mechanisms. The differing characteristics of polycrystalline Ni films facilitate the growth of graphitic layers at different rates, resulting in regions with differing numbers of graphitic layers. High-quality films can be grown on Cu. Cu is available in a variety of shapes and forms, such as foils, bulks, foams, thin films on other materials and powders, making it attractive for industrial production of large area graphene films. The push to use CVD graphene in applications has also triggered a research line for the direct growth on insulators. The quality of the resulting films is lower than possible to date on metals, but enough, in terms of transmittance and resistivity, for many applications as described in section V. Transfer technologies are the focus of section VI. CVD synthesis of graphene on metals and bottom up molecular approaches require SLG to be transferred to the final target substrates. To have technological impact, the advances in production of high-quality large-area CVD graphene must be commensurate with those on transfer and placement on the final substrates. This is a prerequisite for most applications, such as touch panels, anticorrosion coatings, transparent electrodes and gas sensors etc. New strategies have improved the transferred graphene quality, making CVD graphene a feasible option for CMOS foundries. Methods based on complete etching of the metal substrate in suitable etchants, typically iron chloride, ammonium persulfate, or hydrogen chloride although reliable, are time- and resource-consuming, with damage to graphene and production of metal and etchant residues. Electrochemical delamination in a low-concentration aqueous solution is an alternative. In this case metallic substrates can be reused. Dry transfer is less detrimental for the SLG quality, enabling a deterministic transfer. There is a large range of layered materials (LMs) beyond graphite. Only few of them have been already exfoliated and fully characterized. Section VII deals with the growth of some of these materials. Amongst them, h-BN, transition metal tri- and di-chalcogenides are of paramount importance. The growth of h-BN is at present considered essential for the development of graphene in (opto) electronic applications, as h-BN is ideal as capping layer or substrate. The interesting optical and electronic properties of TMDs also require the development of scalable methods for their production. Large scale growth using chemical/physical vapour deposition or thermal assisted conversion has been thus far limited to a small set, such as h-BN or some TMDs. Heterostructures could also be directly grown. Section VIII discusses advances in GRM functionalization. A broad range of organic molecules can be anchored to the sp(2) basal plane by reductive functionalization. Negatively charged graphene can be prepared in liquid phase (e.g. via intercalation chemistry or electrochemically) and can react with electrophiles. This can be achieved both in dispersion or on substrate. The functional groups of GO can be further derivatized. Graphene can also be noncovalently functionalized, in particular with polycyclic aromatic hydrocarbons that assemble on the sp(2) carbon network by pi-pi stacking. In the liquid phase, this can enhance the colloidal stability of SLG/FLG. Approaches to achieve noncovalent on-substrate functionalization are also discussed, which can chemically dope graphene. Research efforts to derivatize CNMs are also summarized, as well as novel routes to selectively address defect sites. In dispersion, edges are the most dominant defects and can be covalently modified. This enhances colloidal stability without modifying the graphene basal plane. Basal plane point defects can also be modified, passivated and healed in ultra-high vacuum. The decoration of graphene with metal nanoparticles (NPs) has also received considerable attention, as it allows to exploit synergistic effects between NPs and graphene. Decoration can be either achieved chemically or in the gas phase. All LMs,
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| 13. |
- Barack, Leor, et al.
(författare)
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Black holes, gravitational waves and fundamental physics : a roadmap
- 2019
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Ingår i: Classical and quantum gravity. - : IOP Publishing. - 0264-9381 .- 1361-6382. ; 36:14
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Forskningsöversikt (refereegranskat)abstract
- The grand challenges of contemporary fundamental physics dark matter, dark energy, vacuum energy, inflation and early universe cosmology, singularities and the hierarchy problem all involve gravity as a key component. And of all gravitational phenomena, black holes stand out in their elegant simplicity, while harbouring some of the most remarkable predictions of General Relativity: event horizons, singularities and ergoregions. The hitherto invisible landscape of the gravitational Universe is being unveiled before our eyes: the historical direct detection of gravitational waves by the LIGO-Virgo collaboration marks the dawn of a new era of scientific exploration. Gravitational-wave astronomy will allow us to test models of black hole formation, growth and evolution, as well as models of gravitational-wave generation and propagation. It will provide evidence for event horizons and ergoregions, test the theory of General Relativity itself, and may reveal the existence of new fundamental fields. The synthesis of these results has the potential to radically reshape our understanding of the cosmos and of the laws of Nature. The purpose of this work is to present a concise, yet comprehensive overview of the state of the art in the relevant fields of research, summarize important open problems, and lay out a roadmap for future progress. This write-up is an initiative taken within the framework of the European Action on 'Black holes, Gravitational waves and Fundamental Physics'.
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| 14. |
- Barone, Ilaria, et al.
(författare)
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Evidence of attenuation and interference phenomena in GPR signals for archaeological application
- 2021
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Ingår i: 11th International Workshop on Advanced Ground Penetrating Radar, IWAGPR 2021. - 9781665422536
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Konferensbidrag (refereegranskat)abstract
- We conducted an extensive geophysical field campaign using ground-penetrating radar (GPR) and electrical resistivity tomography (ERT) in a former military area at the archaeological site of Nora (South-Western Sardinia). The purpose was to identify a Phoenician, and then Punic and Roman, necropolis of considerable interest, subject of a long-term investigation and currently under excavation. In the same area other buried structures, including a Roman road, were also investigated. The ERT and GPR surveys (the latter conducted with two different frequencies - 200 and 600 MHz), carried out in a sector where the Roman road was known to exist, did not reveal any clear evidence of the presence of this structure. However, the road was then found, by direct excavation, at 0.5 m depth. The failure in the identification of the road at this shallow depth has therefore led to hypothesize possible phenomena of high GPR signal attenuation and/or destructive interference related to the geometry and specific characteristics of the system. We performed synthetic GPR modeling by using the information provided by the excavation and constrained, in terms of electrical conductivity, by ERT measurements. The preliminary results of this simulation confirm the hypothesis of interference and attenuation phenomena, suggesting how the GPR signal may fail to provide an apparently simple piece of information at this archaeological site.
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| 15. |
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| 16. |
- Bolivar, Paulina, et al.
(författare)
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Biased Inference of Selection Due to GC-Biased Gene Conversion and the Rate of Protein Evolution in Flycatchers When Accounting for It
- 2018
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Ingår i: Molecular biology and evolution. - : OXFORD UNIV PRESS. - 0737-4038 .- 1537-1719. ; 35:10, s. 2475-2486
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Tidskriftsartikel (refereegranskat)abstract
- The rate of recombination impacts on rates of protein evolution for at least two reasons: it affects the efficacy of selection due to linkage and influences sequence evolution through the process of GC-biased gene conversion (gBGC). We studied how recombination, via gBGC, affects inferences of selection in gene sequences using comparative genomic and population genomic data from the collared flycatcher (Ficedula albicollis). We separately analyzed different mutation categories ("strong"-to-"weak" "weak-to-strong," and GC-conservative changes) and found that gBGC impacts on the distribution of fitness effects of new mutations, and leads to that the rate of adaptive evolution and the proportion of adaptive mutations among nonsynonymous substitutions are underestimated by 22-33%. It also biases inferences of demographic history based on the site frequency spectrum. In light of this impact, we suggest that inferences of selection (and demography) in lineages with pronounced gBGC should be based on GC-conservative changes only. Doing so, we estimate that 10% of nonsynonymous mutations are effectively neutral and that 27% of nonsynonymous substitutions have been fixed by positive selection in the flycatcher lineage. We also find that gene expression level, sex-bias in expression, and the number of protein-protein interactions, but not Hill-Robertson interference (HRI), are strong determinants of selective constraint and rate of adaptation of collared flycatcher genes. This study therefore illustrates the importance of disentangling the effects of different evolutionary forces and genetic factors in interpretation of sequence data, and from that infer the role of natural selection in DNA sequence evolution.
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| 17. |
- Braicovich, Lucio, et al.
(författare)
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Determining the electron-phonon coupling in superconducting cuprates by resonant inelastic x-ray scattering: Methods and results on Nd1+xBa2-xCu3O7-δ
- 2020
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Ingår i: Physical Review Research. - 2643-1564. ; 2:2
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Tidskriftsartikel (refereegranskat)abstract
- The coupling between lattice vibration quanta and valence electrons can induce charge-density modulations and decisively influence the transport properties of materials, e.g., leading to conventional superconductivity. In high-critical-temperature superconductors, where electronic correlation is the main actor, the actual role of electron-phonon coupling (EPC) is being intensely debated theoretically and investigated experimentally. We present an in-depth study of how the EPC strength can be obtained directly from resonant inelastic x-ray scattering (RIXS) data through the theoretical approach derived by Ament et al. [Europhys. Lett. 95, 27008 (2011)]. The role of the model parameters (e.g., phonon energy ω0, intermediate state lifetime 1/Γ, EPC matrix element M, and detuning energy Ω) is thoroughly analyzed, providing general relations among them that can be used to make quantitative estimates of the dimensionless EPC g=(M/ω0)2 without detailed microscopic modeling. We then apply these methods to very high-resolution Cu L3-edge RIXS spectra of three Nd1+xBa2−xCu3O7−δ films. For the insulating antiferromagnetic parent compound, the value of M as a function of the in-plane momentum transfer is obtained for Cu-O bond-stretching (breathing) and bond-bending (buckling) phonon branches. For the underdoped and the nearly optimally doped samples, the effects of Coulomb screening and of charge-density-wave correlations on M are assessed. In light of the anticipated further improvements of the RIXS experimental resolution, this work provides a solid framework for an exhaustive investigation of the EPC in cuprates and other quantum materials.
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| 18. |
- Cassiani, Giorgio, et al.
(författare)
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Ground-based remote sensing of the shallow subsurface : Geophysical methods for environmental applications
- 2020
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Ingår i: Remote Sensing of Geomorphology. - 0928-2025. - 9780444641779 - 9780444641786 ; 23, s. 55-89
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Bokkapitel (refereegranskat)abstract
- Noninvasive methods for the characterization of shallow subsurface have been used routinely for some 20–30 years. The growth in these methods has been driven by a variety of breakthroughs in the use of electrical, electromagnetic, and seismic methods, to mention only the most common techniques. Increasing field capabilities and computational power have yet to yield all their potential fruits. In this chapter, we introduce readers to the basic concepts of shallow subsurface methods. We guide them through some of the physical details and present a number of application examples all derived from our own experience, concerning both structural characterization and (fluid)-dynamic understanding of the shallow subsurface. Finally, we propose ideas concerning the future development of this wide and exciting discipline.
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| 19. |
- Castelnuovo, Gianluca, et al.
(författare)
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What Is the Role of the Placebo Effect for Pain Relief in Neurorehabilitation? : Clinical Implications From the Italian Consensus Conference on Pain in Neurorehabilitation
- 2018
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Ingår i: Frontiers in Neurology. - : Frontiers Media SA. - 1664-2295. ; 9
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Forskningsöversikt (refereegranskat)abstract
- Background: It is increasingly acknowledged that the outcomes of medical treatments are influenced by the context of the clinical encounter through the mechanisms of the placebo effect. The phenomenon of placebo analgesia might be exploited to maximize the efficacy of neurorehabilitation treatments. Since its intensity varies across neurological disorders, the Italian Consensus Conference on Pain in Neurorehabilitation (ICCP) summarized the studies on this field to provide guidance on its use.Methods: A review of the existing reviews and meta-analyses was performed to assess the magnitude of the placebo effect in disorders that may undergo neurorehabilitation treatment. The search was performed on Pubmed using placebo, pain, and the names of neurological disorders as keywords. Methodological quality was assessed using a pre-existing checklist. Data about the magnitude of the placebo effect were extracted from the included reviews and were commented in a narrative form.Results: 11 articles were included in this review. Placebo treatments showed weak effects in central neuropathic pain (pain reduction from 0.44 to 0.66 on a 0-10 scale) and moderate effects in postherpetic neuralgia (1.16), in diabetic peripheral neuropathy (1.45), and in pain associated to HIV (1.82). Moderate effects were also found on pain due to fibromyalgia and migraine; only weak short-term effects were found in complex regional pain syndrome. Confounding variables might have influenced these results.Clinical implications: These estimates should be interpreted with caution, but underscore that the placebo effect can be exploited in neurorehabilitation programs. It is not necessary to conceal its use from the patient. Knowledge of placebo mechanisms can be used to shape the doctor-patient relationship, to reduce the use of analgesic drugs and to train the patient to become an active agent of the therapy.
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| 20. |
- Chouaia, Bessem, et al.
(författare)
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Molecular Evidence for Multiple Infections as Revealed by Typing of Asaia Bacterial Symbionts of Four Mosquito Species
- 2010
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Ingår i: Applied and Environmental Microbiology. - 0099-2240 .- 1098-5336. ; 76:22, s. 7444-7450
-
Tidskriftsartikel (refereegranskat)abstract
- The recent increased detection of acetic acid bacteria (AAB) of the genus Asaia as symbionts of mosquitoes, such as Anopheles spp. and Aedes spp., prompted us to investigate the diversity of these symbionts and their relationships in different mosquito species and populations. Following cultivation-dependent and -independent techniques, we investigated the microbiota associated with four mosquito species, Anopheles stephensi, Anopheles gambiae, Aedes aegypti, and Aedes albopictus, which are important vectors of human and/or animal pathogens. Denaturing gradient gel electrophoresis (DGGE) analysis based on the 16S rRNA gene revealed the presence of several bacterial taxa, among which Asaia sequences were among the dominant in most of the samples. A collection of 281 Asaia isolates in cell-free media was established from individuals belonging to the four species. The isolates were typed by internal transcribed spacer (ITS)-PCR, tRNA-PCR, BOX-PCR, and randomly amplified polymorphic DNA (RAPD)-PCR, revealing that different Asaia strains are present in different mosquito populations, and even in single individuals.
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| 21. |
- Citerio, Giuseppe, et al.
(författare)
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Management of arterial partial pressure of carbon dioxide in the first week after traumatic brain injury : results from the CENTER-TBI study
- 2021
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Ingår i: Intensive Care Medicine. - : Springer. - 0342-4642 .- 1432-1238. ; 47:9, s. 961-973
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To describe the management of arterial partial pressure of carbon dioxide (PaCO2) in severe traumatic brain-injured (TBI) patients, and the optimal target of PaCO2 in patients with high intracranial pressure (ICP).METHODS: Secondary analysis of CENTER-TBI, a multicentre, prospective, observational, cohort study. The primary aim was to describe current practice in PaCO2 management during the first week of intensive care unit (ICU) after TBI, focusing on the lowest PaCO2 values. We also assessed PaCO2 management in patients with and without ICP monitoring (ICPm), and with and without intracranial hypertension. We evaluated the effect of profound hyperventilation (defined as PaCO2 < 30 mmHg) on long-term outcome.RESULTS: We included 1100 patients, with a total of 11,791 measurements of PaCO2 (5931 lowest and 5860 highest daily values). The mean (± SD) PaCO2 was 38.9 (± 5.2) mmHg, and the mean minimum PaCO2 was 35.2 (± 5.3) mmHg. Mean daily minimum PaCO2 values were significantly lower in the ICPm group (34.5 vs 36.7 mmHg, p < 0.001). Daily PaCO2 nadir was lower in patients with intracranial hypertension (33.8 vs 35.7 mmHg, p < 0.001). Considerable heterogeneity was observed between centers. Management in a centre using profound hyperventilation (HV) more frequently was not associated with increased 6 months mortality (OR = 1.06, 95% CI = 0.77-1.45, p value = 0.7166), or unfavourable neurological outcome (OR 1.12, 95% CI = 0.90-1.38, p value = 0.3138).CONCLUSIONS: Ventilation is manipulated differently among centers and in response to intracranial dynamics. PaCO2 tends to be lower in patients with ICP monitoring, especially if ICP is increased. Being in a centre which more frequently uses profound hyperventilation does not affect patient outcomes.
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| 22. |
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| 23. |
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| 24. |
- Dahlin, Torleif, et al.
(författare)
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Large Scale IP Survey at Önneslöv in Southern Sweden
- 2016
-
Ingår i: Proceedings of the 4th international workshop on induced polarization. ; , s. 1-4
-
Konferensbidrag (refereegranskat)abstract
- A DCIP survey, i.e. a geoelectrical survey with combinedmeasurement of DC resistivity and induced polarization(IP), was conducted in southern Sweden. The purposewas to identify soil depth and bedrock structures andvariations in rock quality.Data were acquired data with 100% waveform fromwhich IP of good quality data were extracted. Theinverted model sections show a wide variation in theelectrical properties of the bedrock that are expected torelate to variation in rock quality. The results, togetherwith results of other geophysical methods, form the basisfor a drilling program in order to identify variations inquality rock of importance to the construction of anunderground facility.
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| 25. |
- Dickison, Mark E., et al.
(författare)
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Multilayer Social Networks
- 2016
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- Multilayer networks, in particular multilayer social networks, where users belong to and interact on different networks at the same time, are an active research area in social network analysis, computer science, and physics. These networks have traditionally been studied within these separate research communities, leading to the development of several independent models and methods to deal with the same set of problems. This book unifies and consolidates existing practical and theoretical knowledge on multilayer networks including data collection and analysis, modeling, and mining of multilayer social network systems, the evolution of interconnected social networks, and dynamic processes such as information spreading. A single real dataset is used to illustrate the concepts presented throughout the book, demonstrating both the practical utility and the potential shortcomings of the various methods. Researchers from all areas of network analysis will learn new aspects and future directions of this emerging field.
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| 26. |
- Ermondi, Giuseppe, et al.
(författare)
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Conformational Sampling Deciphers the Chameleonic Properties of a VHL-Based Degrader
- 2023
-
Ingår i: Pharmaceutics. - : MDPI. - 1999-4923. ; 15:1
-
Tidskriftsartikel (refereegranskat)abstract
- Chameleonicity (the capacity of a molecule to adapt its conformations to the environment) may help to identify orally bioavailable drugs in the beyond-Rule-of-5 chemical space. Computational methods to predict the chameleonic behaviour of degraders have not yet been reported and the identification of molecular chameleons still relies on experimental evidence. Therefore, there is a need to tune predictions with experimental data. Here, we employ PROTAC-1 (a passively cell-permeable degrader), for which NMR and physicochemical data prove the chameleonic behaviour, to benchmark the capacity of two conformational sampling algorithms and selection schemes. To characterize the conformational ensembles in both polar and nonpolar environments, we compute three molecular properties proven to be essential for cell permeability: conformer shape (radius of gyration), polarity (3D PSA), and the number of intramolecular hydrogen bonds. Energetic criteria were also considered. Infographics monitored the simultaneous variation of those properties in computed and NMR conformers. Overall, we provide key points for tuning conformational sampling tools to reproduce PROTAC-1 chameleonicity according to NMR evidence. This study is expected to improve the design of PROTAC drugs and the development of computational sustainable strategies to exploit the potential of new modalities in drug discovery.
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| 27. |
- Festa, Giuseppe, et al.
(författare)
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Potential connections between innovation and branding in healthcare – A case study
- 2022
-
Ingår i: 15th Annual Conference of the EuroMed Academy of Business. - : EuroMed Press. - 9789963711963 ; , s. 304-318
-
Konferensbidrag (refereegranskat)abstract
- Innovation is the most relevant lever for enterprises to increase the business efficiency and competitiveness; the technological component of innovation, more specifically, has become in recent years ever more focused on digitalization, even in terms of disruption. This trend has been much more evident with the COVID-19 pandemic, which has forced to accelerate on the virtualization of processes/operations and products/services; this effect has interested every sector, but naturally, due to the pandemic emergency, has affected above all the healthcare companies, revealing potential impact even on their brand reputation. This study, based on the investigation of the data from 2010 to 2011 about Johnson & Johnson, one of the most important healthcare companies in the world (if not the most), provides evidence about the existence of a significant correlation between the R&D – Research & Development investments of the company and its brand value. With all the physiological limits of the case study methodology, the outcome of the research has allowed related considerations in this respect, particularly with reference to the disruptive technologies in the field like telemedicine and Medicine 4.0.
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| 28. |
- Hanteer, Obaida, et al.
(författare)
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From Interaction to Participation : The Role of the Imagined Audience in Social Media Community Detection and an Application to Political Communication on Twitter
- 2018
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Ingår i: 2018 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining (ASONAM). - : IEEE Computer Society. - 9781538660515 ; , s. 531-534
-
Konferensbidrag (refereegranskat)abstract
- In the context of community detection in online social media, a lot of effort has been put into the definition of sophisticated network clustering algorithms and much less on the equally crucial process of obtaining high-quality input data. User-interaction data explicitly provided by social media platforms has largely been used as the main source of data because of its easy accessibility. However, this data does not capture a fundamental and much more frequent type of participatory behavior where users do not explicitly mention others but direct their messages to an invisible audience following a common hashtag. In the context of multiplex community detection, we show how to construct an additional data layer about user participation not relying on explicit interactions between users, and how this layer can be used to find different types of communities in the context of Twitter political communication.
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| 29. |
- Henein, Michael Y., et al.
(författare)
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Biomarkers predict in-hospital major adverse cardiac events in covid-19 patients : A multicenter international study
- 2021
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Ingår i: Journal of Clinical Medicine. - : MDPI. - 2077-0383. ; 10:24
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The COVID-19 pandemic carries a high burden of morbidity and mortality worldwide. We aimed to identify possible predictors of in-hospital major cardiovascular (CV) events in COVID-19.Methods: We retrospectively included patients hospitalized for COVID-19 from 10 centers. Clinical, biochemical, electrocardiographic, and imaging data at admission and medications were collected. Primary endpoint was a composite of in-hospital CV death, acute heart failure (AHF), acute myocarditis, arrhythmias, acute coronary syndromes (ACS), cardiocirculatory arrest, and pulmonary embolism (PE).Results: Of the 748 patients included, 141(19%) reached the set endpoint: 49 (7%) CV death, 15 (2%) acute myocarditis, 32 (4%) sustained-supraventricular or ventricular arrhythmias, 14 (2%) cardiocirculatory arrest, 8 (1%) ACS, 41 (5%) AHF, and 39 (5%) PE. Patients with CV events had higher age, body temperature, creatinine, high-sensitivity troponin, white blood cells, and platelet counts at admission and were more likely to have systemic hypertension, renal failure (creatinine ≥ 1.25 mg/dL), chronic obstructive pulmonary disease, atrial fibrillation, and cardiomyopathy. On univariate and multivariate analysis, troponin and renal failure were associated with the composite endpoint. Kaplan–Meier analysis showed a clear divergence of in-hospital composite event-free survival stratified according to median troponin value and the presence of renal failure (Log rank p < 0.001).Conclusions: Our findings, derived from a multicenter data collection study, suggest the routine use of biomarkers, such as cardiac troponin and serum creatinine, for in-hospital prediction of CV events in patients with COVID-19.
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| 30. |
- Hey Tow, Kenny, et al.
(författare)
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Monitoring mining induced seismicity using optical fibre sensors during mine exploitation
- 2023
-
Ingår i: Proc SPIE Int Soc Opt Eng. - : SPIE. - 1996-756X .- 0277-786X. - 9781510665002
-
Konferensbidrag (refereegranskat)abstract
- Fibre-optic based sensing technologies are becoming popular in the field of geophysics since enable long range and high spatial resolution acoustic measurements. In this work, we present preliminary results obtained using quasi-distributed Fibre-Bragg grating sensing and Distributed Acoustic Sensing (DAS) to monitor seismic activities in an operational underground mine. 12 FBGs and 800 metres of fiber optic cable was installed in the tunnel lining an operational mine and recorded mine seismicity such as production blasts and a small seismic activity of magnitude 1.41 in September 2022.
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| 31. |
- Johansson, Sara, et al.
(författare)
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Combining spectral induced polarization with x-ray tomography to investigate the importance of DNAPL geometry in sand samples
- 2019
-
Ingår i: Geophysics. - : Society of Exploration Geophysicists. - 0016-8033 .- 1942-2156. ; 84:3, s. 173-188
-
Tidskriftsartikel (refereegranskat)abstract
- Whilst many studies have been performed to investigate the spectral induced polarization (SIP) response of Non-aqueous Phase Liquid (NAPL) contaminated soil samples there are still many uncertainties in the interpretation of the data. A key issue is that altered pore space geometries due to the presence of a NAPL phase will change the measured IP spectra. However, without any information on the NAPL distribution in the pore space, assumptions are necessary for the SIP data interpretation. Therefore, experimental data of SIP signals directly associated with different NAPL distributions is needed. We use high-resolution x-ray tomography and 3D image processing to quantitatively assess NAPL distributions in samples of fine-grained sand containing different concentrations of tetrachloroethylene (PCE) and link this to SIP measurements on the same samples. The total concentration of the sample constituents as well as the volumes of the individual NAPL blobs were calculated and used for the interpretation of the associated SIP responses. The x-ray tomography and image analysis showed that the real sample properties (porosity and NAPL distributions) differed from the targeted ones. Both contaminated samples contained less NAPL than expected from the manual sample preparation. The SIP results showed higher real conductivity and lower imaginary conductivity in the contaminated samples compared to a clean sample. This is interpreted as an effect of increased surface conductivity along interconnected NAPL blobs and decreased surface areas in the samples due to NAPL blobs larger than and enclosing grains. We conclude that the combination of SIP, x-ray tomography and image analysis is a very promising approach to achieve a better understanding of the measured SIP responses of NAPL contaminated samples.
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| 32. |
- Kattge, Jens, et al.
(författare)
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TRY plant trait database - enhanced coverage and open access
- 2020
-
Ingår i: Global Change Biology. - : Wiley-Blackwell. - 1354-1013 .- 1365-2486. ; 26:1, s. 119-188
-
Tidskriftsartikel (refereegranskat)abstract
- Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives.
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| 33. |
- Kotsios, Andreas, et al.
(författare)
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An Analysis of the Consequences of the General Data Protection Regulation on Social Network Research
- 2019
-
Ingår i: ACM Transactions on Social Computing. - : Association for Computing Machinery (ACM). - 2469-7818 .- 2469-7826. ; 2:3
-
Tidskriftsartikel (refereegranskat)abstract
- This article examines the principles outlined in the General Data Protection Regulation in the context of social network data. We provide both a practical guide to General Data Protection Regulation--compliant social network data processing, covering aspects such as data collection, consent, anonymization, and data analysis, and a broader discussion of the problems emerging when the general principles on which the regulation is based are instantiated for this research area.
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| 34. |
- Magnani, Matteo, et al.
(författare)
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Analysis of Multiplex Social Networks with R
- 2021
-
Ingår i: Journal of Statistical Software. - : Foundation for Open Access Statistic. - 1548-7660. ; 98:8, s. 1-30
-
Tidskriftsartikel (refereegranskat)abstract
- Multiplex social networks are characterized by a common set of actors connected through multiple types of relations. The multinet package provides a set of R functions to analyze multiplex social networks within the more general framework of multilayer networks, where each type of relation is represented as a layer in the network. The package contains functions to import/export, create and manipulate multilayer networks, implementations of several state-of-the-art multiplex network analysis algorithms, e.g., for centrality measures, layer comparison, community detection and visualization. Internally, the package is mainly written in native C++ and integrated with R using the Rcpp package.
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| 35. |
- Magnani, Matteo, et al.
(författare)
-
Community Detection in Multiplex Networks
- 2021
-
Ingår i: ACM Computing Surveys. - : Association for Computing Machinery (ACM). - 0360-0300 .- 1557-7341. ; 54:3
-
Tidskriftsartikel (refereegranskat)abstract
- A multiplex network models different modes of interaction among same-type entities. In this article, we provide a taxonomy of community detection algorithms in multiplex networks. We characterize the different algorithms based on various properties and we discuss the type of communities detected by each method. We then provide an extensive experimental evaluation of the reviewed methods to answer three main questions: to what extent the evaluated methods are able to detect ground-truth communities, to what extent different methods produce similar community structures, and to what extent the evaluated methods are scalable. One goal of this survey is to help scholars and practitioners to choose the right methods for the data and the task at hand, while also emphasizing when such choice is problematic.
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| 36. |
- Magnani, Matteo, et al.
(författare)
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Factors Enabling Information Propagation in a Social Network Site
- 2013
-
Ingår i: The Influence of Technology on Social Network Analysis and Mining. - Vienna : Springer Vienna. - 9783709113455 ; , s. 411-426
-
Bokkapitel (refereegranskat)abstract
- A relevant feature of Social Network Sites is their ability to propagate units of information and create large distributed conversations. This phenomenon is particularly relevant because of the speed of information propagation, which is known to be much faster than within traditional media, and because of the very large amount of people that can potentially be exposed to information items. While many general formal models of network propagation have been developed in different research fields, in this chapter we present the result of an empirical study on a Large Social Database (LSD) aimed at measuring specific socio-technical factors enabling information spreading in Social Network Sites.
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| 37. |
- Magnani, Matteo, et al.
(författare)
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Formation of multiple networks
- 2013
-
Ingår i: Social Computing, Behavioral-Cultural Modeling and Prediction. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 9783642372094 ; , s. 257-264
-
Konferensbidrag (refereegranskat)abstract
- While most research in Social Network Analysis has focused on single networks, the availability of complex on-line data about individuals and their mutual heterogenous connections has recently determined a renewed interest in multi-layer network analysis. To the best of our knowledge, in this paper we introduce the first network formation model for multiple networks. Network formation models are among the most popular tools in traditional network studies, because of both their practical and theoretical impact. However, existing models are not sufficient to describe the generation of multiple networks. Our model, motivated by an empirical analysis of real multi-layered network data, is a conservative extension of single-network models and emphasizes the additional level of complexity that we experience when we move from a single- to a more complete and realistic multi-network context.
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| 38. |
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| 39. |
- Magnani, Matteo, et al.
(författare)
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Pareto Distance for Multi-layer Network Analysis
- 2013
-
Ingår i: Social Computing, Behavioral-Cultural Modeling and Prediction. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 9783642372094 ; , s. 249-256
-
Konferensbidrag (refereegranskat)abstract
- Social Network Analysis has been historically applied to single networks, e.g., interaction networks between co-workers. However, the advent of on-line social network sites has emphasized the stratified structure of our social experience. Individuals usually spread their identities over multiple services, e.g., Facebook, Twitter, LinkedIn and Foursquare. As a result, the analysis of on-line social networks requires a wider scope and, more technically speaking, models for the representation of this fragmented scenario. The recent introduction of more realistic layered models has however determined new research problems related to the extension of traditional single-layer network measures. In this paper we take a step forward over existing approaches by defining a new concept of geodesic distance that includes heterogeneous networks and connections with very limited assumptions regarding the strength of the connections. This is achieved by exploiting the concept of Pareto efficiency to define a simple and at the same time powerful measure that we call Pareto distance, of which geodesic distance is a particular case when a single layer (or network) is analyzed. The limited assumptions on the nature of the connections required by the Pareto distance may in theory result in a large number of potential shortest paths between pairs of nodes. However, an experimental computation of distances on multi-layer networks of increasing size shows an interesting and non-trivial stable behavior.
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| 40. |
- Nivorlis, Aristeidis, et al.
(författare)
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Multidisciplinary characterization of chlorinated solvents contamination and in-situ remediation with the use of the direct current resistivity and time-domain induced polarization tomography
- 2019
-
Ingår i: Geosciences (Switzerland). - : MDPI AG. - 2076-3263. ; 9:12
-
Tidskriftsartikel (refereegranskat)abstract
- Soil contamination is a widespread problem and action needs to be taken in order to prevent damage to the groundwater and the life around the contaminated sites. In Sweden, it is estimated that more than 80,000 sites are potentially contaminated, and therefore, there is a demand for investigations and further treatment of the soil. In this paper, we present the results from a methodology applied in a site contaminated with chlorinated solvents, for characterization of the contamination in order to plan the remediation and to follow-up the initial step of in-situ remediation in an efficient way. We utilized the results from three different methods; membrane interface probe for direct measurement of the contaminant concentrations; seismic refraction tomography for investigating the depth to the bedrock interface; and direct current resistivity and time-domain induced polarization tomography to acquire a high-resolution imaging of the electrical properties of the subsurface. The results indicate that our methodology is very promising in terms of site characterization, and furthermore, has great potential for real-time geophysical monitoring of contaminated sites in the future.
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| 41. |
- Nivorlis, Aristeidis, et al.
(författare)
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Multidisciplinary monitoring of an in-situ remediation test of chlorinated solvents
- 2024
-
Ingår i: Science of the Total Environment. - 0048-9697. ; 922
-
Tidskriftsartikel (refereegranskat)abstract
- Pollutions on and within the underground poses risks for groundwater contamination and is a widespread global problem. Common remediation methods based on digging and removal can be expensive and have limitations, while in-situ remediation is an attractive alternative. However, there is a need to develop tools to monitor the effectiveness both in terms of the successful injection of remediation fluids but also the effectiveness of the treatment, i.e., degree of degradation/removal of the pollutants and possible metabolites. This paper presents a methodology for monitoring the changes following an in-situ remediation treatment of a site contaminated with chlorinated solvents. The methodology consists of two different methods, where Direct Current resistivity and time-domain Induced Polarization (DCIP) was used to acquire daily data and geochemical analyses on water samples were collected approximately every three months. The geophysical results provide insights on how the injected fluids are spreading and assist in acquiring a better understanding of the geological and hydrogeological system. On the other hand, the geochemical sampling enhances our knowledge about the hydrochemistry of the system and the concentration of the pollutants. Our research highlights the challenges of monitoring in-situ bioremediation experiments in complex environments and in cases where pollutants are situated in low hydraulic conductivity formations. The joint interpretation of the data shows the importance of an interdisciplinary approach to understand complex systems.
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| 42. |
- Nivorlis, Aristeidis, et al.
(författare)
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Temporal filtering and time-lapse inversion of geoelectrical data for long-term monitoring with application to a chlorinated hydrocarbon contaminated site
- 2022
-
Ingår i: Geophysical Journal International. - : Oxford University Press (OUP). - 0956-540X .- 1365-246X. ; 228:3, s. 1648-1664
-
Tidskriftsartikel (refereegranskat)abstract
- We present a solution for long-term direct current resistivity and time-domain induced polarization (DCIP) monitoring, which consists of a monitoring system and the associated software that automates the data collection and processing. This paper describes the acquisition system that is used for remote data collection and then introduces the routines that have been developed for pre-processing of the monitoring data set. The collected data set is pre-processed using digital signal processing algorithms for outlier detection and removal; the resulting data set is then used for the inversion procedure. The suggested processing workflow is tested against a simulated time-lapse experiment and then applied to field data. The results from the simulation show that the suggested approach is very efficient for detecting changes in the subsurface; however, there are some limitations when no a priori information is used. Furthermore, the mean weekly data sets that are generated from the daily collected data can resolve low-frequency changes, making the approach a good option for monitoring experiments where slow changes occur (i.e. leachates in landfills, internal erosion in dams, bioremediation). The workflow is then used to process a large data set containing 20 months of daily monitoring data from a field site where a pilot test of in situ bioremediation is taking place. Based on the time-series analysis of the inverted data sets, we can detect two portions of the ground that show different geophysical properties and that coincide with the locations where the different fluids were injected. The approach that we used in this paper provides consistency in the data processing and has the possibility to be applied to further real-time geophysical monitoring in the future.
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| 43. |
- Olsson, Per-Ivar, et al.
(författare)
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DCIP tomografi för kartläggning av jorddjup och strukturer i berg
- 2017
-
Konferensbidrag (refereegranskat)abstract
- There are plans to build an energy storage in the rock at Önneslöv near Dalby in Skåne. The bedrock is of a part of Romeleåsen and mainly comprises gneiss, with elements of amphibolite and dolerite intrusions. The area is located immediately south of the Sydsten’s large rock quarry, which shows that the rock is mostly heavily fractured with clay weathered zones of different sizes. In connection with underground construction fractured zones and weathering constitutes a risk for problems with water inflow and stability. Furthermore, variations in depth to the upper surface of the rock can lead to stability problems in the upper portions of a planned construction.Electric resistivity tomography (ERT) is now an established pre-investigation method for tunnel projects, and it has been used on a large scale in connection with for example the Hallandsås Tunnel. The method provides continuous models of variations in the electrical properties of the rock in two (2D) and three dimensions (3D) that can be linked to variations in the rock mechanical and hydraulic properties. ERT measured by a combination of DC resistivity and induced polarization can be called DCIP tomography, which can provide additional information about the variation in the material properties of the rock. With the help of new and improved methods of data acquisition, processing and interpretation it is possible to collect large amounts of good quality IP data in a time and cost effective way, paving the way for better and more nuanced models of the rock and variations in its properties. The newly developed technology has been tested in full scale at Önneslöv. Three parallel DCIP sections about 1 km long, with a maximum survey depth of about 170 m were measured, plus a 800 m long cross-section. Furthermore, DCIP logging was carried out in two percussion drill holes down to 200 m depth in which it is furthermore made logging of diameter, natural gamma radiation, seismic velocity and flow rate during pumping.Geological interpretation of the DCIP results agree well with what one can expect from the documentation of soil depth, and variation in degree of fracturing and weathering as documented from drilling. A major advantage is continuous models that can be linked to variation in soil depth, structures in the rock and hydrogeological conditions. The combined surveys with surface-based measurements and borehole measurements are complementary and provide a more reliable overall picture of the variations in rock conditions.
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| 44. |
- Pelliciari, Jonathan, et al.
(författare)
-
Evolution of spin excitations from bulk to monolayer FeSe
- 2021
-
Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723 .- 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- In ultrathin films of FeSe grown on SrTiO (FeSe/STO), the superconducting transition temperature T is increased by almost an order of magnitude, raising questions on the pairing mechanism. As in other superconductors, antiferromagnetic spin fluctuations have been proposed to mediate SC making it essential to study the evolution of the spin dynamics of FeSe from the bulk to the ultrathin limit. Here, we investigate the spin excitations in bulk and monolayer FeSe/STO using resonant inelastic x-ray scattering (RIXS) and quantum Monte Carlo (QMC) calculations. Despite the absence of long-range magnetic order, bulk FeSe displays dispersive magnetic excitations reminiscent of other Fe-pnictides. Conversely, the spin excitations in FeSe/STO are gapped, dispersionless, and significantly hardened relative to its bulk counterpart. By comparing our RIXS results with simulations of a bilayer Hubbard model, we connect the evolution of the spin excitations to the Fermiology of the two systems revealing a remarkable reconfiguration of spin excitations in FeSe/STO, essential to understand the role of spin fluctuations in the pairing mechanism.
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| 47. |
- Rosqvist, Håkan, et al.
(författare)
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Development of an innovative methodology for monitoring of in situ remediation of chlorinated solvents – the MIRACHL-project
- 2018
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Ingår i: ; , s. 112-112
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Konferensbidrag (refereegranskat)abstract
- BackgroundDense Non Aqueous Phase Liquids (DNAPL) such as chlorinated solvents are common pollutants stemming from different types of industries including dry cleaning facilities, and reports on cases showing serious risk to soil and ground water are frequent on a global scale. DNAPLs are especially problematic as they are denser than water and move down through the groundwater, not always following the groundwater flow but are mainly driven by gravitational forces. Difficulties associated with remediation activities of DNAPLs are many, especially delineation of the source plume, and understanding of the migration of contaminated groundwater in the underground.Therefore, the Swedish national environmental authority, (SEPA) has called for new and innovative in-situ remediation techniques.The MIRACHL-project (monitoring of in situ remediation of chlorinated hydrocarbon contaminants - http://mirachl.com/) are focused on developing new and innovative methods for better understanding of the transport and fate of chlorinated solvents in soil and groundwater. The MIRACHL-project combine three methods; i)geoelectrical imaging by the geophysical method Direct Current resistivity and Induced Polarisation (DCIP), ii)Physical and BioGeochemical Characterisation (PBGC) and iii)the method Compound-specific isotope analysis (CSIA). The MIRACHL-project, based at the Engineering Geology at Lund University, is a collaborative project including several other universities and other relevant organizations, In particular, the collaboration on field sites with the Geological Survey of Sweden (SGU) is of great importance.AimIn the MIRACHL project we develop an integrated methodology based on threemethods, i.e., Direct Current resistivity and Induced Polarisation (DCIP), Physical and BioGeochemical Characterisation (PBGC) and the method Compound-specific isotope analysis (CSIA), to better understand and map in situ remediation processes. A combination of continuous geo-electrical observations during the decontamination, together with the analysis of biogeochemistry and isotope fractionation, provides opportunities to follow transport and fate of chlorinated solvents during different types of in-situ remediation processes.The MIRACHL-project started in 2016 and will continue until 2022. In 2017, theMIRACHL methodology was established at two sites in collaboration with SGU, i.e., in Hagfors and Alingsås. At both site contaminations coming from dry cleaning facilities are in focus. The geology and hydrogeology is very different at these sites and the presentation will show the status in mapping and monitoring the ongoing remediation at the sites.ConclusionInitial studies performed at a site in Kristianstad (Färgaren 3) show the combination of DCIP, PBGC, and CSIA are promising methodology for mapping of transport and fate of chlorinated solvents. We will present on-going research on two sites where contamination from chlorinated solvents are in focus, i.e, contamination due to dry cleaning activities in Hagfors and Alingsås.
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| 48. |
- Rossi, Andrea, et al.
(författare)
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Left atrial structural and mechanical remodelling in heart failure with reduced ejection fraction
- 2021
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Ingår i: ESC Heart Failure. - : John Wiley & Sons. - 2055-5822. ; 8:6, s. 4751-4759
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Tidskriftsartikel (refereegranskat)abstract
- Aims: In patients with heart failure with reduced ejection fraction (HFrEF), an association between left atrial (LA) dilatation and dysfunction is expected, but the degree of coexistence of the two abnormalities and their relative prognostic role is not known.Methods and results: A total of 626 HFrEF patients formed the study population. All of them underwent a comprehensive echocardiographic evaluation. LA maximal volume was indexed to body surface area (LAVi); LA function was assessed using strain analysis during the reservoir phase: peak atrial longitudinal strain (PALS) analysis. Study primary endpoint was overall mortality or hospitalization for worsening heart failure. Four groups of patients were included in this study according to LAVi (≤34 or >34 mL/m2 ) and PALS (≤23% or >23%); 61 (10%) patients had normal LA volume and function (Group 1), 58 (9%) had LA dilatation but normal function (Group 2), 100 (16%) had normal volume but abnormal function (Group 3), and 407 (65%) had enlarged left atrium and abnormal function (Group 4). PALS was associated with primary endpoint in patients with both normal-size [Groups 1 and 3: hazard ratio (HR) 0.92, 95% confidence interval (CI) 0.88-0.96; P = 0.0006] and dilated left atria (Groups 2 and 4: HR 0.93, 95% CI 0.91-0.96; P < 0.0001). In contrast, LAVi was associated with the primary endpoint in patients with abnormal LA function (Groups 3 and 4: HR 1.018, 95% CI 1.011-1.024; P < 0.00001) but not in those with normal PALS (Groups 1 and 2: HR 1.023, 95% CI 0.99-1.057; P = 0.1).Conclusions: Left atrial dilatation and dysfunction frequently but not invariably coexist. PALS emerged as a significant prognostic parameter in HFrEF even in the absence of LA dilation.
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| 49. |
- Rossi, Luca, et al.
(författare)
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Observing the tech, using meetup data to observe the evolution of the discourse around IoT
- 2019
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Ingår i: Selected Papers of Internet Research, SPIR. - : Annual Conference of the Association of Internet Researchers. - 2162-3317.
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Tidskriftsartikel (refereegranskat)abstract
- This paper proposes to use MeetUp data to study the emergence and the evolution of the technological trend commonly known as Internet of Things (IoT). Starting from a manually selected sample of 220 European MeetUp groups we used MeetUp's APIs, to retrieve additional information about the events and participating users. The final dataset consists of 220 groups, 32967 members and 2386 events from 2011 until now (Jan 2019). The results suggest the presence of clearly identifiable European hubs for IoT development but a worldwide crowd of users. From a temporal perspective the MeetUp data shows how IoT exploded in 2015 and how it might have peaked in 2017. Within this period of time IoT has not been a “stable technology” but as evolved incorporating, within its area of “related topics” new and emerging technologies such as Cryptocurrency or cloud computing.
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| 50. |
- Rossi, Luca, et al.
(författare)
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Towards effective visual analytics on multiplex and multilayer networks
- 2015
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Ingår i: Chaos, Solitons & Fractals. - : Elsevier BV. - 0960-0779 .- 1873-2887. ; 72, s. 68-76
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Tidskriftsartikel (refereegranskat)abstract
- In this article we discuss visualisation strategies for multiplex networks. Since Moreno's early works on network analysis, visualisation has been one of the main ways to understand networks thanks to its ability to summarise a complex structure into a single representation highlighting multiple properties of the data. However, despite the large renewed interest in the analysis of multiplex networks, no study has proposed specialised visualisation approaches for this context and traditional methods are typically applied instead. In this paper we initiate a critical and structured discussion of this topic, and claim that the development of specific visualisation methods for multiplex networks will be one of the main drivers pushing current research results into daily practice.
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