| 1. |
- Kadigrobov, Anatoli M., 1937, et al.
(författare)
-
Hot electrons in magnetic point contacts as a photon source
- 2011
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Ingår i: New Journal of Physics. - : IOP Publishing. - 1367-2630. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- We propose to use a point contact between a ferromagnetic and a normal metal in the presence of a magnetic field for creating a large inverted spin population of hot electrons in the contact core. The key point of the proposal is that when these hot electrons relax by flipping their spin, microwave photons are emitted, with a frequency tunable by the applied magnetic field. While point contacts are an established technology, their use as a photon source is a new and potentially very useful application. We show that this photon emission process can be detected by means of transport spectroscopy and demonstrate stimulated emission of radiation in the 10–100 GHz range for a model point contact system using a minority-spin ferromagnetic injector. These results can potentially lead to new types of lasers based on spin injection in metals.
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| 2. |
- Shekhter, Robert I., 1947, et al.
(författare)
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Electronic spin working mechanically
- 2014
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Ingår i: Fizika Nizkikh Temperatur. - 0132-6414 .- 1816-0328. ; 40:7, s. 775-792
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Tidskriftsartikel (refereegranskat)abstract
- A single-electron tunneling (SET) device with a nanoscale central island that can move with respect to the bulk source- and drain electrodes allows for a nanoelectromechanical (NEM) coupling between the electrical current through the device and mechanical vibrations of the island. Although an electromechanical "shuttle" in-stability and the associated phenomenon of single-electron shuttling were predicted more than 15 years ago, both theoretical and experimental studies of NEM-SET structures are still carried out. New functionalities based on quantum coherence, Coulomb correlations and coherent electron-spin dynamics are of particular current interest. In this article we present a short review of recent activities in this area.
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| 3. |
- Shekhter, Robert I., 1947, et al.
(författare)
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Subwavelength terahertz spin-flip laser based on a magnetic point-contact array
- 2011
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Ingår i: Optics Letters. - 0146-9592 .- 1539-4794. ; 36:12, s. 2381-2383
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Tidskriftsartikel (refereegranskat)abstract
- We present a theoretical design for a single-mode, truly subwavelength terahertz disk laser based on a nanocomposite gain medium comprising an array of normal-metal/ferromagnetic (FM) point contacts embedded in a thin dielectric layer. Stimulated emission of light occurs due to spin-flip relaxation of spin-polarized electrons injected from the FM side of the contacts. Ultrahigh electrical current densities in the contacts and a dielectric material with a large refractive index, neither condition being achievable in conventional semiconductor media, enables the thresholds of lasing to be overcome for the lowest-order modes of the disk, making single-mode operation possible.
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| 4. |
- Dancet, Eline A F, et al.
(författare)
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The Role of Scientists and Clinicians in Raising Public Support for Animal Research in Reproductive Biology and Medicine.
- 2012
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Ingår i: Biology of reproduction. - : Oxford University Press (OUP). - 1529-7268 .- 0006-3363.
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Tidskriftsartikel (refereegranskat)abstract
- It is important that researchers active in reproductive animal research, as a group, clearly and compassionately convey specific information to students, patients, and the general public on the merit and need for biomedical research using various formats and seek active support from patient organizations, universities, politicians, celebrities, the media, and international professional organizations related to human and animal health.
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| 5. |
- Hudson, Lawrence N., et al.
(författare)
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The PREDICTS database : a global database of how local terrestrial biodiversity responds to human impacts
- 2014
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 4:24, s. 4701-4735
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Tidskriftsartikel (refereegranskat)abstract
- Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species' threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project - and avert - future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups - including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems - ). We make site-level summary data available alongside this article. The full database will be publicly available in 2015.
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| 6. |
- Kadigrobov, Anatoli M., 1937, et al.
(författare)
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Giant lasing effect in magnetic point contacts and its detection by DC electrical measurements
- 2011
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Ingår i: Proc. of SPIE. - 0277-786X. - 9780819484703 ; 7933
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Konferensbidrag (refereegranskat)abstract
- We propose a new principle for a compact solid-state laser in 1-100 THz regime based on a new mechanism for creating spin-flip processes in ferromagnetic conductors. On the base of this mechanism, a giant lasing effect is predicted. The optical gain is estimated to exceed the optical gain of conventional semiconductor lasers by 4 or 5 orders of magnitude. We propose to use a point contact between ferromagnetic metals in order to create an inverted spin-population of hot electrons in the contact region. While point contact spectroscopy is an established technology the use of magnetic point contacts as a photon source is a new and potentially very useful application. We show that the generated photons conveniently can be detected by measuring the current through the illuminated point contact.
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| 7. |
- Kadigrobov, Anatoli M., 1937, et al.
(författare)
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Microwave-induced spin-flip scattering of electrons in point contacts
- 2011
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Ingår i: Low Temperature Physics. - 1063-777X. ; 37:11, s. 925-932
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Tidskriftsartikel (refereegranskat)abstract
- We investigate resonant interaction of conduction electrons with an electromagnetic field that irradiates a point contact between a ferromagnetic and a normal metal in the presence of a strong magnetic field of order 1 T. We show that electron spin-flips caused by resonant absorption and stimulated emission of photons result in a sharp peak in the magnetic-field dependence of the point-contact resistance. The height of the peak is shown to be directly proportional to the net rate of energy transfer to the electromagnetic field in the point contact due to absorption and stimulated emission of photons. Estimations indicate that our theory can serve as a basis for the explanation of recent experiments [A.M. Kadigrobov et al., New J. Phys. 13, 023007 (2011)].
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| 8. |
- Kulinich, Sergeij I., et al.
(författare)
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Nanomechanics of a magnetic shuttle device
- 2014
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Ingår i: Low temperature physics. - : AIP Publishing. - 1063-777X .- 1090-6517. ; 40:10, s. 1161-1169
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Tidskriftsartikel (refereegranskat)abstract
- We show that self sustained mechanical vibrations in a model magnetic shuttle device can be driven by both the charge and the spin accumulated on the movable central island of the device. Different scenarios for how spin- and charge-induced shuttle instabilities may develop are discussed and shown to depend on whether there is a Coulomb blockade of tunneling or not. The crucial role of electronic spin flips in a magnetically driven shuttle is established and shown to cause giant magnetoresistance and dynamic magnetostriction effects.
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| 9. |
- Kulinich, Sergeij I., et al.
(författare)
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Single-Electron Shuttle Based on Electron Spin
- 2014
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 112:11
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Tidskriftsartikel (refereegranskat)abstract
- A nanoelectromechanical device based on magnetic exchange forces and electron spin flips induced by a weak external magnetic field is suggested. It is shown that this device can operate as a new type of single-electron "shuttle" in the Coulomb blockade regime of electron transport.
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| 10. |
- Kulinich, Sergeij I., et al.
(författare)
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Umklapp-assisted electron transport oscillations in metal superlattices
- 2012
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Ingår i: Physical Review B. - 1098-0121. ; 85:18, s. artikel nr 184202-
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Tidskriftsartikel (refereegranskat)abstract
- We consider a superlattice of parallel metal tunnel junctions with a spatially nonhomogeneous probability for electrons to tunnel. In such structures tunneling can be accompanied by electron scattering that conserves energy but not momentum. In the special case of a tunneling probability that varies periodically with period a in the longitudinal direction, i.e., perpendicular to the junctions, electron tunneling is accompanied by umklapp scattering, where the longitudinal momentum changes by a multiple of h/a. We predict that as a result a sequence of metal-insulator transitions can be induced by an external electric or magnetic field as the field strength is increased.
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| 11. |
- Mazzuca, Silvia, et al.
(författare)
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Establishing research strategies, methodologies and technologies to link genomics and proteomics to seagrass productivity, community metabolism, and ecosystem carbon fluxes
- 2013
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Ingår i: Frontiers in Plant Science. - : Frontiers Media SA. - 1664-462X. ; 4
-
Tidskriftsartikel (refereegranskat)abstract
- A complete understanding of the mechanistic basis of marine ecosystem functioning is only possible through integrative and interdisciplinary research. This enables the prediction of change and possibly the mitigation of the consequences of anthropogenic impacts. One major aim of the European Cooperation in Science and Technology (COST) Action ES0609 Seagrasses productivity. From genes to ecosystem management, is the calibration and synthesis of various methods and the development of innovative techniques and protocols for studying seagrass ecosystems. During 10 days, 20 researchers representing a range of disciplines (molecular biology, physiology, botany, ecology, oceanography, and underwater acoustics) gathered at The Station de Recherches Sous-marines et Oceanographiques (STARESO, Corsica) to study together the nearby Posidonia oceanica meadow. STARESO is located in an oligotrophic area classified as pristine site where environmental disturbances caused by anthropogenic pressure are exceptionally low. The healthy P. oceanica meadow, which grows in front of the research station, colonizes the sea bottom from the surface to 37 m depth. During the study, genomic and proteomic approaches were integrated with ecophysiological and physical approaches with the aim of understanding changes in seagrass productivity and metabolism at different depths and along daily cycles. In this paper we report details on the approaches utilized and we forecast the potential of the data that will come from this synergistic approach not only for P. oceanica but for seagrasses in general.
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| 12. |
- Naidyuk, Yu. G., et al.
(författare)
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Stimulated emission and absorption of photons in magnetic point contacts
- 2012
-
Ingår i: New Journal of Physics. - : IOP Publishing. - 1367-2630. ; 14
-
Tidskriftsartikel (refereegranskat)abstract
- Point contacts between high anisotropy ferromagnetic SmCo5 and normal metal Cu are used to achieve a strong spin-population inversion in the contact core. Subjected to microwave irradiation in resonance with the Zeeman splitting in Cu, the inverted spin population relaxes through stimulated spin-flip photon emission, detected as peaks in the point-contact resistance. Resonant spin-flip photon absorption is detected as resistance minima, corresponding to sourcing the photon field energy into the electrical circuit. These results demonstrate fundamental mechanisms that are potentially useful in designing metallic spin-based lasers.
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| 13. |
- Nilsson, Hans, et al.
(författare)
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Hot and cold ion outflow : Spatial distribution of ion heating
- 2012
-
Ingår i: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 117
-
Tidskriftsartikel (refereegranskat)abstract
- Ions apparently emanating from the same source, the ionospheric polar cap, can either end up as energized to keV energies in the high-altitude cusp/mantle, or appear as cold ions in the magnetotail lobes. We use Cluster observations of ions and wave electric fields to study the spatial variation of ion heating in the cusp/mantle and polar cap. The average flow direction in a simplified cylindrical coordinate system is used to show approximate average ion flight trajectories, and discuss the temperatures, fluxes and wave activity along some typical trajectories. It is found that it is suitable to distinguish between cusp, central and nightside polar cap ion outflow trajectories, though O+ heating is mainly a function of altitude. Furthermore we use typical cold ion parallel velocities and the observed average perpendicular drift to obtain average cold ion flight trajectories. The data show that the cusp is the main source of oxygen ion outflow, whereas a polar cap source would be consistent with our average outflow paths for cold ions observed in the lobes. A majority of the cusp O+ flux is sufficiently accelerated to escape into interplanetary space. A scenario with significant oxygen ion heating in regions with strong magnetosheath origin ion fluxes, cold proton plasma dominating at altitudes below about 8 RE in the polar cap, and most of the cusp oxygen outflow overcoming gravity and flowing out in the cusp and mantle is consistent with our observations.
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| 14. |
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| 15. |
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| 16. |
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| 17. |
- Shekhter, Robert I., 1947, et al.
(författare)
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Electronic spin working mechanically (Review Article)
- 2014
-
Ingår i: Low temperature physics. - : AIP Publishing. - 1063-777X .- 1090-6517. ; 40:7, s. 600-614
-
Tidskriftsartikel (refereegranskat)abstract
- A single-electron tunneling (SET) device with a nanoscale central island that can move with respect to the bulk source- and drain electrodes allows for a nanoelectromechanical (NEM) coupling between the electrical current through the device and mechanical vibrations of the island. Although an electromechanical “shuttle” instability and the associated phenomenon of single-electron shuttling were predicted more than 15 years ago, both theoretical and experimental studies of NEM-SET structures are still carried out. New functionalities based on quantum coherence, Coulomb correlations and coherent electron-spin dynamics are of particular current interest. In this article we present a short review of recent activities in this area.
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| 18. |
- Siesing, Leif, et al.
(författare)
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Alternative production process for electric machine windings
- 2012
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Ingår i: 2012 2nd International Electric Drive Production Conference (EDPC). - 9781467330060 ; , s. 161-167
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Konferensbidrag (refereegranskat)abstract
- The development of production methods, research on material engineering and analysis tools for energy conversion processes establish a powerful design environment for any unconventional electromagnetic or electromechanical device. The design for manufacturability becomes the one of the main goals of the design apart from cost and performance improvement. The main focus of this paper lies on the development of production methods, the design of the product, a wave-winding, and the component assessment in an electrical machine. The production of non-complex coil with maximized performance capability of the molded core machine is the target for the design of the winding and also the design for the winding machine. Four different types of wave-windings are described and evaluated. One of them, wind and bend with conventional wire, has main focus in this work, and a prototype of the winding machine is built to produce the single-layer whole-lap wave-winding. The production method, manufacturing process and the processed component features are analyzed in this paper.
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| 19. |
- Siesing, Leif, et al.
(författare)
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New manufacturing methods for electric motors using different soft magnetic material combinations
- 2012
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Ingår i: [Host publication title missing]. - 9781467330060 ; , s. 366-372
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Konferensbidrag (refereegranskat)abstract
- This paper presents the manufacturing experience of an outer rotor permanent magnet synchronous machine with four different stators. The advantageous features of powder technology and molding techniques are tested when constructing and manufacturing the stators for a 28-pole 30-slot machine. The selected machine configuration is taking advantages of the concept of the modular windings and at the same time facing the challenges of undemanding winding production, which is suitable for injection and rotation molded magnetic cores. The geometric tolerances of the modular winding segments and the requirements for the electric insulation system have the main influence on the selection of alternatives methods for manufacturing powdered magnetic cores. The tight connection between the material engineering, research on the production techniques and the modeling of energy conversion processes have positively influenced the machine design towards improved electromagnetic and thermal characteristics of the product. The main outcomes of the manufacturing methods and electromagnetic design are discussed when combining the modular windings together with compression and molded soft magnetic composite powders.
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| 20. |
- Skorobagatko, G. A., et al.
(författare)
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Magnetopolaronic effects in electron transport through a single-level vibrating quantum dot
- 2011
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Ingår i: Low Temperature Physics. - 1063-777X. ; 37:12, s. 1032-1037
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Tidskriftsartikel (refereegranskat)abstract
- Magnetopolaronic effects are considered in electron transport through a single-level vibrating quantum dot subjected to a transverse (to the current flow) magnetic field. It is shown that the effects are most pronounced in the regime of sequential electron tunneling, where a polaronic blockade of the current at low temperatures and an anomalous temperature dependence of the magnetoconductance are predicted. In contrast, for resonant tunneling of polarons the peak conductance is not affected by the magnetic field.
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| 21. |
- Thernström Blomqvist, Ylva, 1974-
(författare)
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Kangaroo Mother Care : Parents’ experiences and patterns of application in two Swedish neonatal intensive care units
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Kangaroo Mother Care (KMC) is an alternative model of care that prevents parent-infant separation when preterm infants need neonatal intensive care by skin-to-skin contact between infants and their parents. KMC is also a strategy that involves parents in their infants’ care and enables them to assume the responsibility for the care. Furthermore, KMC promotes parent-infant bonding and attachment.The overall aim of this thesis was to gain a deeper understanding and knowledge about parents’ capacity, willingness, and experiences of KMC and to which extent parents choose to use KMC throughout their infants' hospital stay. These studies were conducted in the NICUs at two Swedish university hospitals (NICU A and NICU B).Mothers of infants cared for at NICU A (n=17) answered a questionnaire about their experiences of KMC (Paper I). Twenty parents of infants cared for at NICU A recorded the duration of each KMC session during a period of 24 hours and the identity the KMC provider (Paper II). Seven fathers were interviewed about their experiences of KMC (Paper III) and 76 mothers and 74 fathers completed a questionnaire about what facilitated or rendered it difficult to perform KMC (Paper IV). The time of initiation of KMC and duration in minutes, and the identity of the KMC providers was recorded continuously during the infants’ (n=104) hospital stay: 83 mothers and 80 fathers also completed a questionnaire during their infants’ hospital stay (Paper V).This thesis provides new knowledge about parents’ practice of KMC, also continuously day and night, in a high tech NICU in an affluent society, with good resources for infant care in an incubator by trained staff. The accuracy of parents’ records of KMC were comparable to nurses’ records. The results indicate that parents want to be together with their infant in the NICU and be actively involved in the infants’ care. Although parents may experience KMC as exhausting and uncomfortable, they still prefer KMC to conventional neonatal intensive care as it supports their parental role. Early initiation of KMC after birth appears to result in a longer total duration of KMC during the infants’ hospital stay.
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| 22. |
- Umbach, T. R., et al.
(författare)
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Atypical charge redistribution over a charge-transfer monolayer on a metal
- 2013
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Ingår i: New Journal of Physics. - : IOP Publishing. - 1367-2630. ; 15
-
Tidskriftsartikel (refereegranskat)abstract
- We report an atypical charge distribution in a highly ordered monolayer of sodium (Na) and tetracyanoquinodimethane (TCNQ) on a Au(111) surface. Na atoms incorporated in the charge-transfer layer donate their 3s electron to the lowest unoccupied orbital of the TCNQ acceptor. A fingerprint of such a TCNQ anion is observed in scanning tunneling spectroscopy as a zero-bias peak characteristic of the Kondo effect. Spatial maps of the Kondo resonance surprisingly reveal that it appears most intense on top of the Na sites. Supported by density functional theory simulations, we interpret this peculiar charge distribution pattern as originating from the extension of the singly occupied molecular orbital beyond the molecular backbone, and cloaking the Na cations. We further suggest that this deformation of molecular orbitals is a consequence of the electrostatic potential landscape of the polar Na-TCNQ layer.
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| 23. |
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| 24. |
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| 25. |
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| 26. |
- Björnetun Haugen, Astri, et al.
(författare)
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Effect of crystallographic orientation in textured Ba0.92Ca0.08TiO3 piezoelectric ceramics
- 2014
-
Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 116:13, s. 134102-
-
Tidskriftsartikel (refereegranskat)abstract
- Strongly textured lead-free Ba0.92Ca0.08TiO3 piezoelectric ceramics were fabricated by tape casting and templated grain growth. Dense ceramics with both favorable < 100 > and unfavorable < 111 > texture were successfully prepared. Enhanced piezoelectric performance was demonstrated for ceramics with < 100 > texture, in line with the predictions based on reported piezoelectric coefficients of tetragonal BaTiO3. Due to the expanded tetragonal range through Ca-substitution, < 100 > texture is favorable over a wide temperature range. The < 100 > texture also results in the enhanced piezoelectric performance being temperature-independent. In addition to engineering of stable, high-performance lead-free piezoelectric ceramics, this study has demonstrated that consideration of the extender/rotator nature of piezoelectric properties is imperative for improving the piezoelectric response through texturing.
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| 27. |
- Bäckström, Torbjörn, et al.
(författare)
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Paradoxical effects of GABA-A modulators may explain sex steroid induced negative mood symptoms in some persons
- 2011
-
Ingår i: Neuroscience. - Oxford : Elsevier BV. - 0306-4522 .- 1873-7544. ; 191:Special issue, s. 46-54
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Forskningsöversikt (refereegranskat)abstract
- Some women have negative mood symptoms, caused by progestagens in hormonal contraceptives or sequential hormone therapy or by progesterone in the luteal phase of the menstrual cycle, which may be attributed to metabolites acting on the GABA-A receptor. The GABA system is the major inhibitory system in the adult CNS and most positive modulators of the GABA-A receptor (benzodiazepines, barbiturates, alcohol, GABA steroids), induce inhibitory (e.g. anesthetic, sedative, anticonvulsant, anxiolytic) effects. However, some individuals have adverse effects (seizures, increased pain, anxiety, irritability, aggression) upon exposure. Positive GABA-A receptor modulators induce strong paradoxical effects including negative mood in 3%-8% of those exposed, while up to 25% have moderate symptoms. The effect is biphasic: low concentrations induce an adverse anxiogenic effect while higher concentrations decrease this effect and show inhibitory, calming properties. The prevalence of premenstrual dysphoric disorder (PMDD) is also 3%-8% among women in fertile ages, and up to 25% have more moderate symptoms of premenstrual syndrome (PMS). Patients with PMDD have severe luteal phase-related symptoms and show changes in GABA-A receptor sensitivity and GABA concentrations. Findings suggest that negative mood symptoms in women with PMDD are caused by the paradoxical effect of allopregnanolone mediated via the GABA-A receptor, which may be explained by one or more of three hypotheses regarding the paradoxical effect of GABA steroids on behavior: (1) under certain conditions, such as puberty, the relative fraction of certain GABA-A receptor subtypes may be altered, and at those subtypes the GABA steroids may act as negative modulators in contrast to their usual role as positive modulators; (2) in certain brain areas of vulnerable women the transmembrane C1(-) gradient may be altered by factors such as estrogens that favor excitability; (3) inhibition of inhibitory neurons may promote disinhibition, and hence excitability. This article is part of a Special Issue entitled: Neuroactive Steroids: Focus on Human Brain. (C) 2011 Published by Elsevier Ltd on behalf of IBRO.
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| 28. |
- Börjesson, Mats, 1965, et al.
(författare)
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Fysisk aktivitet och stress
- 2010
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Ingår i: Svensk Idrottsforskning. ; 19, s. 10-12
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 29. |
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| 30. |
- Caster, Ola, 1982-
(författare)
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Quantitative methods to support drug benefit-risk assessment
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Joint evaluation of drugs’ beneficial and adverse effects is required in many situations, in particular to inform decisions on initial or sustained marketing of drugs, or to guide the treatment of individual patients. This synthesis, known as benefit-risk assessment, is without doubt important: timely decisions supported by transparent and sound assessments can reduce mortality and morbidity in potentially large groups of patients. At the same time, it can be hugely complex: drug effects are generally disparate in nature and likelihood, and the information that needs to be processed is diverse, uncertain, deficient, or even unavailable. Hence there is a clear need for methods that can reliably and efficiently support the benefit-risk assessment process. For already marketed drugs, this process often starts with the detection of previously unknown risks that are subsequently integrated with all other relevant information for joint analysis.In this thesis, quantitative methods are devised to support different aspects of drug benefit-risk assessment, and the practical usefulness of these methods is demonstrated in clinically relevant case studies. Shrinkage regression is adapted and implemented for large-scale screening in collections of individual case reports, leading to the discovery of a link between methylprednisolone and hepatotoxicity. This adverse effect is then considered as part of a complete benefit-risk assessment of methylprednisolone in multiple sclerosis relapses, set in a general framework of probabilistic decision analysis. Two methods devised in the thesis substantively contribute to this assessment: one for efficient generation of utility distributions for the considered clinical outcomes, driven by modelling of qualitative information; and one for computing risk limits for rare and otherwise non-quantifiable adverse effects, based on collections of individual case reports.
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| 31. |
- Chinnasamy, Thiruppathiraja, et al.
(författare)
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A lateral flow paper microarray for rapid allergy point of care diagnostics
- 2014
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Ingår i: The Analyst. - : Royal Society of Chemistry. - 0003-2654 .- 1364-5528. ; 139:10, s. 2348-2354
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Tidskriftsartikel (refereegranskat)abstract
- There is a growing need for multiplexed specific IgE tests that can accurately evaluate patient sensitization profiles. However, currently available commercial tests are either single/low-plexed or require sophisticated instrumentation at considerable cost per assay. Here, we present a novel convenient lateral flow microarray-based device that employs a novel dual labelled gold nanoparticle-strategy for rapid and sensitive detection of a panel of 15 specific IgE responses in 35 clinical serum samples. Each gold nanoparticle was conjugated to an optimized ratio of HRP and anti-IgE, allowing significant enzymatic amplification to improve the sensitivity of the assay as compared to commercially available detection reagents. The mean inter-assay variability of the developed LFM assay was 12% CV, and analysis of a cohort of clinical samples (n = 35) revealed good general agreement with ImmunoCAP, yet with a varying performance among allergens (AUC = [0.54-0.88], threshold 1 kU). Due to the rapid and simple procedure, inexpensive materials and read-out by means of a consumer flatbed scanner, the presented assay may provide an interesting low-cost alternative to existing multiplexed methods when thresholds > 1 kU are acceptable.
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| 32. |
- Chinnasamy, Thiruppathiraja, et al.
(författare)
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Point-of-Care Vertical Flow Allergen Microarray Assay : Proof of Concept
- 2014
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Ingår i: Clinical Chemistry. - : Oxford University Press (OUP). - 0009-9147 .- 1530-8561. ; 60:9, s. 1209-1216
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Sophisticated equipment, lengthy protocols, and skilled operators are required to perform protein microarray-based affinity assays. Consequently, novel tools are needed to bring biomarkers and biomarker panels into clinical use in different settings. Here, we describe a novel paper-based vertical flow microarray (VFM) system with a multiplexing capacity of at least 1480 microspot binding sites, colorimetric readout, high sensitivity, and assay time of < 10 min before imaging and data analysis. METHOD: Affinity binders were deposited on nitrocellulose membranes by conventional microarray printing. Buffers and reagents were applied vertically by use of a flow controlled syringe pump. As a clinical model system, we analyzed 31 precharacterized human serum samples using the array system with 10 allergen components to detect specific IgE reactivities. We detected bound analytes using gold nanoparticle conjugates with assay time of <= 10 min. Microarray images were captured by a consumer-grade flatbed scanner. RESULTS: A sensitivity of 1 ng/mL was demonstrated with the VFM assay with colorimetric readout. The reproducibility (CV) of the system was < 14%. The observed concordance with a clinical assay, Immuno-CAP, was R-2 = 0.89 (n = 31). CONCLUSIONS: In this proof-of-concept study, we demonstrated that the VFM assay, which combines features from protein microarrays and paper-based colorimetric systems, could offer an interesting alternative for future highly multiplexed affinity point-of-care testing.
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| 33. |
- Christiansson, Lisa, et al.
(författare)
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Increased Level of Myeloid-Derived Suppressor Cells, Programmed Death Receptor Ligand 1/Programmed Death Receptor 1, and Soluble CD25 in Sokal High Risk Chronic Myeloid Leukemia
- 2013
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:1, s. e55818-
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Tidskriftsartikel (refereegranskat)abstract
- Immunotherapy (eg interferon α) in combination with tyrosine kinase inhibitors is currently in clinical trials for treatment of chronic myeloid leukemia (CML). Cancer patients commonly have problems with so called immune escape mechanisms that may hamper immunotherapy. Hence, to study the function of the immune system in CML is of interest. In the present paper we have identified immune escape mechanisms in CML with focus on those that directly hamper T cells since these cells are important to control tumor progression. CML patient samples were investigated for the presence of myeloid-derived suppressor cells (MDSCs), expression of programmed death receptor ligand 1/programmed death receptor 1 (PD-L1/PD-1), arginase 1 and soluble CD25. MDSC levels were increased in samples from Sokal high risk patients (p<0,05) and the cells were present on both CD34 negative and CD34 positive cell populations. Furthermore, expression of the MDSC-associated molecule arginase 1, known to inhibit T cells, was increased in the patients (p = 0,0079). Myeloid cells upregulated PD-L1 (p<0,05) and the receptor PD-1 was present on T cells. However, PD-L1 blockade did not increase T cell proliferation but upregulated IL-2 secretion. Finally, soluble CD25 was increased in high risk patients (p<0,0001). In conclusion T cells in CML patients may be under the control of different immune escape mechanisms that could hamper the use of immunotherapy in these patients. These escape mechanisms should be monitored in trials to understand their importance and how to overcome the immune suppression.
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| 34. |
- Dahlin, Karin I. E., 1945-
(författare)
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Does It Pay to Practice? : A Quasi-Experimental Study on Working Memory Training and Its Effects on Reading and Basic Number Skills
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation is based on results from an intervention study targeting working memory training. A group of 46 boys and 11 girls (aged 10.7) that were attending special units in 16 regular schools participated in the study. The treatment group (n = 42) trained at school every day for 30-40 minutes with an interactive computer program (Cogmed training) for five weeks. The performances of the treatment group on reading related measures and basic number skills are compared to those of a group of students (n =15) that were attending similar special units and received only ordinary special educational instruction. Working memory measures and non-verbal problem solving were compared to students (n = 25) in a control group from a previous study.In Study I, it was found that reading comprehension and working memory measures correlated and improved at post-tests (T2, T3) for the treatment group to a larger extent than for the comparison group.In Study II, it was found that working memory measures and basic number skills were highly related. The performance of the boys in the treatment group improved more than that of the boys in the comparison group on basic number test at both post-tests.In Study III, basic skills assessed three years later (T4) are reported. The treatment group achieved higher scores in reading comprehension compared to pre-tests and compared to the control group.The treatment group seems to have gained from the cognitive training of working memory with the computer assisted program directly after training, after seven months and at the three year follow-up. The gains were observed on visuo-spatial working memory measure (T2, T3), reading comprehension and on basic number skills in boys (T2, T3, T4).The possible mechanisms that may be involved in and may explain the observed improvements of performances are discussed: executive function, attention, memory, motivation, emotions. The study has some methodological limitations and more research is needed to substantiate the efficacy of the program.
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| 35. |
- Di Paolo, Antonello, et al.
(författare)
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Population pharmacokinetics of daptomycin in patients affected by severe Gram-positive infections
- 2013
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Ingår i: International Journal of Antimicrobial Agents. - : Elsevier BV. - 0924-8579 .- 1872-7913. ; 42:3, s. 250-255
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Tidskriftsartikel (refereegranskat)abstract
- A population pharmacokinetic analysis of daptomycin was performed based on therapeutic drug monitoring (TDM) data from 58 patients receiving doses of 4–12 mg/kg for the treatment of severe Gram-positive infections. At a daily dose of 8 mg/kg, daptomycin plasma concentrations (mean ± S.D.) were 76.9 ± 9.8 mg/L at the end of infusion and 52.7 ± 15.4 mg/L and 11.4 ± 5.4 mg/L at 0.5 h and 23 h after drug administration, respectively. The final model was a one-compartmental model with first-order elimination, with estimated clearance (CL) of 0.80 ± 0.14 L/h and a volume of distribution (Vd) of 0.19 ± 0.05 L/kg. Creatinine clearance (CLCr) was identified as having a significant influence on daptomycin CL, and a decrease in CLCr of 30 mL/min from the median value (80 mL/min) was associated with a reduction of daptomycin CL from 0.80 L/h to 0.73 L/h. These results confirm that the presence of severe infection may be associated with an altered disposition of daptomycin, with an increased Vd. MICs were available in 41 patients and results showed that 38 and 31 subjects achieved AUC/MIC values associated with bacteriostatic (>400) and bactericidal effects (>800), respectively. Of note, 31 of these 41 subjects experienced a clinical improvement or were cured. Although daptomycin pharmacokinetics may be influenced by infections, effective AUC/MIC values were achieved in the majority of patients. The present model may be applied in clinical settings for a TDM routine on the basis of a sparse blood sampling protocol.
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| 36. |
- Ekholm, Kristoffer, et al.
(författare)
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Modeling Slip in Stress-Laminated Timber Bridges: Comparison of Two Finite-Element-Method Approaches and Test Values
- 2014
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Ingår i: Journal of Bridge Engineering. - 1084-0702 .- 1943-5592. ; 19:9
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Tidskriftsartikel (refereegranskat)abstract
- Finite-element (FE) simulations of the deformation behavior of a 5.4-m-long, 8-m-wide, and 0.27-m-thick stress-laminated timber bridge deck were conducted. The simulation results were compared with full-scale test results when using a load resembling an axle load placed near the edge and when cycling the load between a high and low value. Two separate approaches to nonlinear FE modeling were used. The first FE model simulates a frictional slip between the glulam beams with an elastic-plastic material model. The second FE model simulates a frictional slip by modeling each discrete contact surface between each beam in the deck. The results show good agreement between simulation and test results and reveal that the simulation model that models contact surfaces produces slightly better results at the expense of a greater modeling effort and increased computational time. Hysteresis in the load versus deformation curves is clearly visible and was due to significant slip between the glulam beams, which was successfully simulated.
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| 37. |
- Fowkes, F. G. R., et al.
(författare)
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Development and validation of an ankle brachial index risk model for the prediction of cardiovascular events
- 2014
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Ingår i: European Journal of Preventive Cardiology. - : Oxford University Press (OUP). - 2047-4881 .- 2047-4873. ; 21:3, s. 310-320
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Tidskriftsartikel (refereegranskat)abstract
- Background The ankle brachial index (ABI) is related to risk of cardiovascular events independent of the Framingham risk score (FRS). The aim of this study was to develop and evaluate a risk model for cardiovascular events incorporating the ABI and FRS. Design An analysis of participant data from 18 cohorts in which 24,375 men and 20,377 women free of coronary heart disease had ABI measured and were followed up for events. Methods Subjects were divided into a development and internal validation dataset and an external validation dataset. Two models, comprising FRS and FRS + ABI, were fitted for the primary outcome of major coronary events. Results In predicting events in the external validation dataset, C-index for the FRS was 0.672 (95% CI 0.599 to 0.737) in men and 0.578 (95% CI 0.492 to 0.661) in women. The FRS + ABI led to a small increase in C-index in men to 0.685 (95% CI 0.612 to 0.749) and large increase in women to 0.690 (95% CI 0.605 to 0.764) with net reclassification improvement (NRI) of 4.3% (95% CI 0.0 to 7.6%, p = 0.050) and 9.6% (95% CI 6.1 to 16.4%, p < 0.001), respectively. Restricting the FRS + ABI model to those with FRS intermediate 10-year risk of 10 to 19% resulted in higher NRI of 15.9% (95% CI 6.1 to 20.6%, p < 0.001) in men and 23.3% (95% CI 13.8 to 62.5%, p = 0.002) in women. However, incorporating ABI in an improved newly fitted risk factor model had a nonsignificant effect: NRI 2.0% (95% CI 2.3 to 4.2%, p = 0.567) in men and 1.1% (95% CI 1.9 to 4.0%, p = 0.483) in women. Conclusions An ABI risk model may improve prediction especially in individuals at intermediate risk and when performance of the base risk factor model is modest.
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| 38. |
- Fredenberg, Erik, PhD, 1979-, et al.
(författare)
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Photon-Counting Spectral Phase-Contrast Mammography
- 2012
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Ingår i: Medical Imaging 2012. - : SPIE - International Society for Optical Engineering. - 9780819489623
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Konferensbidrag (refereegranskat)abstract
- Phase-contrast imaging is an emerging technology that may increase the signal-difference-to-noise ratio in medical imaging. One of the most promising phase-contrast techniques is Talbot interferometry, which, combined with energy-sensitive photon-counting detectors, enables spectral differential phase-contrast mammography. We have evaluated a realistic system based on this technique by cascaded-systems analysis and with a task-dependent ideal-observer detectability index as a figure-of-merit. Beam-propagation simulations were used for validation and illustration of the analytical framework. Differential phase contrast improved detectability compared to absorption contrast, in particular for fine tumor structures. This result was supported by images of human mastectomy samples that were acquired with a conventional detector. The optimal incident energy was higher in differential phase contrast than in absorption contrast when disregarding the setup design energy. Further, optimal weighting of the transmitted spectrum was found to have a weaker energy dependence than for absorption contrast. Taking the design energy into account yielded a superimposed maximum on both detectability as a function of incident energy, and on optimal weighting. Spectral material decomposition was not facilitated by phase contrast, but phase information may be used instead of spectral information.
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| 39. |
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| 40. |
- Fyhr, Pontus, et al.
(författare)
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A modular framework for evaluation of electrical machine production costs
- 2013
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Ingår i: 3rd International Electric Drives Conference (E|DPC). ; , s. 136-140
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Konferensbidrag (refereegranskat)abstract
- A framework structure for solving multiple option production economic models is described, showing the possibilities in defining independent process modules according to a defined set of rules. The modules are then scanned and inserted into appropriate locations in the solver framework based on naming scheme and linking information, allowing both re-use of knowledge as well as rapid development and deployment of models for new production. The methodology is applied to the production of an electric machine, showing the ability to assess options with regard to for example technical infeasibilities such as the combination of incompatible production method selections, splitting and joining process flows and maintaining a continuous solution space. The structured framework approach also allows extraction of data from any point in the production flow, for any option or nominal batch size.
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| 41. |
- Fyhr, Pontus, et al.
(författare)
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Statistical interfaces for production of a permanent magnet based rotor
- 2014
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Ingår i: Electric Drives Production Conference (EDPC), 2014 4th International. - 9781479950089 ; , s. 1-6
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Konferensbidrag (refereegranskat)abstract
- A production-system simulation model for manufacturing cost of a permanent-magnet based rotor, analyzing the influence of uncertain parameters by utilizing the Monte Carlo method. The uncertain parameters studied include investment and bill of materials costs as well as cycle time. The resulting influence of these uncertainties are presented for each case individually, as well as all possible combinations, giving seven total cases studied. Cutting tool costs over a range of batch sizes show that investment uncertainty has rapidly declining impact even within fairly low batch sizes. BOM cost variations, especially for the permanent magnets maintain a sizeable influence over the range of batch sizes. The Weibull distribution based model for permanent magnet insertion shows that profit margins derived from point based nominal data is not reliable for pricing of manual production processes. The presented approach is useful both for decision making regarding new production, as well as pricing in competitive markets with narrow margins.
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| 42. |
- Förschler, Marc I., et al.
(författare)
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Gene flow and range expansion in a mountain-dwelling passerine with a fragmented distribution
- 2011
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Ingår i: Biological Journal of the Linnean Society. - : Oxford University Press (OUP). - 0024-4066 .- 1095-8312. ; 103:3, s. 707-721
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Tidskriftsartikel (refereegranskat)abstract
- We studied gene flow and bottleneck events in the population history of locally isolated citril finches endemic to European mountains. For the present study, we used two genetic markers with different rates of evolution: a fast evolving mitochondrial marker (ATPase6/8) and a more slowly evolving nuclear marker (02401). Populations north of the Pyrenees showed in general fewer haplotypes and a considerable lower nucleotide and gene diversity than the Iberian populations. Unexpectedly, we found very little genetic variability in the fast evolving mitochondrial marker, arguing for a strong and relatively recent bottleneck event in the species population history. This pattern potentially reflects a sudden decrease of crucial resources during Mid-Holocene (mountain pine, Scots pine, and black pine) and a subsequent breakdown of the population. The bottleneck could also have been caused or coincide with a selective sweep in the mitochondrion. By contrast, the slowly evolving nuclear marker showed a much higher variability. This marker probably reflects major gene flow along a potential expansion pathway from the Eastern Pyrenees, northwards to the populations of Central Europe, and southwards to the more fragmented populations of central and southern Spain. The population of the Western Pyrenees (Navarra) appears to be cut-off from this major gene flow and our data indicate a certain degree of partial isolation, probably reflecting more ancient events (e.g. the separation in distinct refuge sites during the last glacial maximum).
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| 43. |
- Gorelik, Leonid, 1952, et al.
(författare)
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Suppression of thermal fluctuations of nanomechanical resonator (ground state cooling) by thermally activated electronic flow
- 2011
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Ingår i: 21st International Conference on Noise and Fluctuations, ICNF 2011; Toronto, ON; 12 June 2011 through 16 June 2011. - 9781457701924 ; , s. 223-226
-
Konferensbidrag (refereegranskat)abstract
- We consider a doubly clamped suspended metallic carbon nanotube in which extra charge is injected from the tipof a scanning tunneling microscopy (STM). Our analysis shows that the quantum superposition between the different inelastic electronic tunneling paths can be controlled by the bias voltage. In particular, we find that below Coulomb blockade threshold the vibron emission induced by thermally activated electron transportation can be significantly reduced in comparison to the vibron absorption. As a consequence a net suppression of the thermal fluctuations ("cooling") of the vibrational degrees of freedom can be achieved. © 2011 IEEE.
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| 44. |
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| 45. |
- Gullström, Martin, et al.
(författare)
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Seagrass Meadows in Chwaka Bay : Socio-ecological and Management Aspects
- 2012
-
Ingår i: People, Nature and Research in Chwaka Bay, Zanzibar, Tanzania. - Zanzibar : Western Indian Ocean Marine Science Associoation (WIOMSA). - 9789987955916 ; , s. 89-110
-
Bokkapitel (refereegranskat)abstract
- The shallow-water seascape of Chwaka Bay consists of diverse habitats including coral reefs, sand/mud flats, algal belts and mangrove forests, but the embayment is primarily characterized by its widespread and highly productive seagrass beds. The Bay is a unique seagrass diversity “hotspot”, with eleven species observed, from small, fast-growing and thin-leaved “pioneer” species like Halophila ovalis and H. stipulacea to large, slower-growing “climax species” with thick and long leaves like Thalassodendron ciliatum and Enhalus acoroides. Consequently, it is not surprising that the small-scale subsistence fishery of Chwaka Bay can be seen as a seagrass fishery, with catches consisting primarily of species intimately associated with the seagrass meadows (de la Torre-Castro and Rönnbäck 2004; de la Torre-Castro 2006).Seagrasses are a polyphyletic group of marine vascular, rhizomal plants (den Hartog 1970, 12-13), which form stands of varying sizes usually called “beds” or “meadows” in intertidal and subtidal coastal waters across the globe. Seagrass meadows typically occur on nearshore soft bottoms (although some species are found on rocky bottoms) in single- or mixed-species assemblages, with the typical wide range from tropical to boreal margins of coastal waters (Green and Short 2003, 21-22). They form one of the most productive aquatic ecosystems on Earth (Duarte and Chiscano 1999) and in most areas occur intermixed with other large primary producers like macroalgae. Seagrass ecosystems support multiple ecological functions, including nursery grounds, food and refuge for many benthic,
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| 46. |
- Gunell, H., et al.
(författare)
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Plasma penetration of the dayside magnetopause
- 2012
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Ingår i: Physics of Plasmas. - Melville, NY : AIP Publishing. - 1070-664X .- 1089-7674. ; 19:7, s. 072906-
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Tidskriftsartikel (refereegranskat)abstract
- Data from the Cluster spacecraft during their magnetopause crossing on 25 January 2002 are presented. The magnetopause was in a state of slow non-oscillatory motion during the observational period. Coherent structures of magnetosheath plasma, here typified as plasmoids, were seen on closed magnetic field lines on the inside of the magnetopause. Using simultaneous measurements on two spacecraft, the inward motion of the plasmoids is followed from one spacecraft to the next, and it is found to be in agreement with the measured ion velocity. The plasma characteristics and the direction of motion of the plasmoids show that they have penetrated the magnetopause, and the observations are consistent with the concept of impulsive penetration, as it is known from theory, simulations, and laboratory experiments. The mean flux across the magnetopause observed was 0.2%-0.5% of the solar wind flux at the time, and the peak values of the flux inside the plasmoids reached approximately 20% of the solar wind flux.
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| 47. |
- Gunell, H., et al.
(författare)
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Waves in high-speed plasmoids in the magnetosheath and at the magnetopause
- 2014
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Ingår i: Annales Geophysicae. - : Copernicus GmbH. - 0992-7689 .- 1432-0576. ; 32:8, s. 991-1009
-
Tidskriftsartikel (refereegranskat)abstract
- Plasmoids, defined here as plasma entities with a higher anti-sunward velocity component than the surrounding plasma, have been observed in the magnetosheath in recent years. During the month of March 2007 the Cluster spacecraft crossed the magnetopause near the subsolar point 13 times. Plasmoids with larger velocities than the surrounding magnetosheath were found on seven of these 13 occasions. The plasmoids approach the magnetopause and interact with it. Both whistler mode waves and waves in the lower hybrid frequency range appear in these plasmoids, and the energy density of the waves inside the plasmoids is higher than the average wave energy density in the magnetosheath. When the spacecraft are in the magnetosphere, Alfvenic waves are observed. Cold ions of ionospheric origin are seen in connection with these waves, when the wave electric and magnetic fields combine with the Earth's dc magnetic field to yield an E x B/B-2 drift speed that is large enough to give the ions energies above the detection threshold.
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| 48. |
- Hafström, L., et al.
(författare)
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An exploration of Swedish companies' offshoring of R&D activities to China
- 2010
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Ingår i: 5th IEEE International Conference on Management of Innovation and Technology, ICMIT2010, Singapore; 2 June 2010 through 5 June 2010. - 9781424465675 ; , s. 306-311
-
Konferensbidrag (refereegranskat)abstract
- A trend among manufacturing companies is offshoring of R & D. The aim of this study is to investigate Swedish companies' offshoring of R & D activities to China, utilizing both a survey and explorative case studies. The survey results show that 9% of the companies have offshored R & D to China, that performance in China is satisfactory, primarily in terms of costs, and that there is a need for strong integration mechanisms to handle coordination and information sharing. Based on the case studies, a categorization of firms offshoring R & D into Market- & Talent-driven firms and Low-cost & Supplydriven firms is proposed, as these have different challenges and require different managerial solutions. Finally, a dilemma concerning information sharing and innovation is identified and discussed. © 2010 IEEE.
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| 49. |
- Hamrin, Maria, et al.
(författare)
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Energy conversion regions as observed by Cluster in the plasma sheet
- 2011
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Ingår i: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 116, s. A00K08-
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Tidskriftsartikel (refereegranskat)abstract
- In this article we present a review of recent studies of observations of localized energy conversion regions (ECRs) observed by Cluster in the plasma sheet at altitudes of 15-20R(E). By examining variations in the power density, E . J, where E is the electric field and J is the current density, we show that the plasma sheet exhibits a high level of fine structure. Approximately three times as many concentrated load regions (CLRs) (E . J > 0) as concentrated generator regions (CGRs) (E . J < 0) are identified, confirming the average load character of the plasma sheet. Some ECRs are found to relate to auroral activity. While ECRs are relevant for the energy conversion between the electromagnetic field and the particles, bursty bulk flows (BBFs) play a central role for the energy transfer in the plasma sheet. We show that ECRs and BBFs are likely to be related, although details of this relationship are yet to be explored. The plasma sheet energy conversion increases rather simultaneously with increasing geomagnetic activity in both CLRs and CGRs. Consistent with large-scale magnetotail simulations, most of the observed ECRs appear to be rather stationary in space but varying in time. We estimate that the ECR lifetime and scale size are a few minutes and a few R(E), respectively. It is conceivable that ECRs rise and vanish locally in significant regions of the plasma sheet, possibly oscillating between load and generator character, while some energy is transmitted as Poynting flux to the ionosphere.
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| 50. |
- Hamrin, Maria, et al.
(författare)
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Evidence for the braking of flow bursts as they propagate toward the Earth
- 2014
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Ingår i: Journal of Geophysical Research - Space Physics. - 2169-9380 .- 2169-9402. ; 119:11, s. 9004-9018
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Tidskriftsartikel (refereegranskat)abstract
- In this article we use energy conversion arguments to investigate the possible braking of flow bursts as they propagate toward the Earth. By using EJ data (E and J are the electric field and the current density) observed by Cluster in the magnetotail plasma sheet, we find indications of a plasma deceleration in the region -20 R-E < X < - 15 R-E. Our results suggest a braking mechanism where compressed magnetic flux tubes in so-called dipolarization fronts (DFs) can decelerate incoming flow bursts. Our results also show that energy conversion arguments can be used for studying flow braking and that the position of the flow velocity peak with respect to the DF can be used as a single-spacecraft proxy when determining energy conversion properties. Such a single-spacecraft proxy is invaluable whenever multispacecraft data are not available. In a superposed epoch study, we find that a flow burst with the velocity peak behind the DF is likely to decelerate and transfer energy from the particles to the fields. For flow bursts with the peak flow at or ahead of the DF we see no indications of braking, but instead we find an energy transfer from the fields to the particles. From our results we obtain an estimate of the magnitude of the deceleration of the flow bursts, and we find that it is consistent with previous investigations.
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