| 1. |
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| 2. |
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| 3. |
- Kadigrobov, Anatoli M., 1937, et al.
(författare)
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Thermoelectrical manipulation of nano-magnets : A spin-thermionic oscillator
- 2010
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - San Diego, CA : SPIE. - 9780819482563 ; 7760, s. 77600R-1 - 77600R-17-
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Konferensbidrag (refereegranskat)abstract
- We investigate the interplay between the thermodynamic properties and spin-dependent transport in a mesoscopic magnetic multilayer, in which two strongly ferromagnetic layers are exchange-coupled through a weakly ferromagnetic spacer. We show theoretically that the system allows a spin-thermoelectronic control of the relative orientation of the outer layers. Supporting experimental evidence of thermally controlled switching from parallel to anti-parallel magnetization orientations in the sandwich is presented. We show magneto-resistance oscillations may take place with frequencies up to GHz. We discuss in detail an experimental realization of a device that can operate as a thermo-magneto-resistive switch or oscillator.
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| 4. |
- Kadigrobov, Anatoli M., 1937, et al.
(författare)
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Thermoelectrical manipulation of nanomagnets
- 2010
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 107:12, s. 123706-
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the interplay between the thermodynamic properties and spin-dependent transport in a mesoscopic device based on a magnetic multilayer (F/f/F), in which two strongly ferromagnetic layers (F) are exchange-coupled through a weakly ferromagnetic spacer (f) with the Curie temperature in the vicinity of room temperature. We show theoretically that the Joule heating produced by the spin-dependent current allows a spin-thermoelectronic control of the ferromagnetic-to-paramagnetic (f/N) transition in the spacer and, thereby, of the relative orientation of the outer F-layers in the device (spin-thermoelectric manipulation of nanomagnets). Supporting experimental evidence of such thermally-controlled switching from parallel to antiparallel magnetization orientations in F/f(N)/F sandwiches is presented. Furthermore, we show theoretically that local Joule heating due to a high concentration of current in a magnetic point contact or a nanopillar can be used to reversibly drive the weakly ferromagnetic spacer through its Curie point and thereby exchange couple and decouple the two strongly ferromagnetic F-layers. For the devices designed to have an antiparallel ground state above the Curie point of the spacer, the associated spin-thermionic parallel to antiparallel switching causes magnetoresistance oscillations whose frequency can be controlled by proper biasing from essentially dc to GHz. We discuss in detail an experimental realization of a device that can operate as a thermomagnetoresistive switch or oscillator.
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| 5. |
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| 6. |
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| 7. |
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| 8. |
- Abrahamsson, Erik, 1974, et al.
(författare)
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A new reaction path for the C + NO reaction: dynamics on the 4A'' potential-energy surface.
- 2008
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Ingår i: Physical chemistry chemical physics : PCCP. - : Royal Society of Chemistry (RSC). - 1463-9076 .- 1463-9084. ; 10:30, s. 4400-9
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Tidskriftsartikel (refereegranskat)abstract
- We present a new reaction path without significant barriers for the C + NO reaction, forming ground state N((4)S) and CO. Electronic structure (CASPT2) calculations have been performed for the two lowest (4)A'' states of the CNO system. The lowest of these states shows no significant barriers against reaction in the C + NO or O + CN channels. This surface has been fitted to an analytical function using a many-body expansion. Using this surface, and the previously published (2)A' and (2)A'' surfaces [Andersson et al., Phys. Chem. Chem. Phys., 2000, 2, 613; Andersson et al., Chem. Phys., 2000, 259, 99], we have performed quasiclassical trajectory (QCT) calculations, obtaining rate coefficients for the C((3)P) + NO(X(2)Pi) --> CO(X(1)Sigma(+)) + N((4)S,(2)D) and C((3)P) + NO(X(2)Pi) --> O((3)P) + CN(X(2)Sigma(+)) reactions. We have also simulated the crossed molecular beam experiments of Naulin et al. [Chem. Phys., 1991, 153, 519] The inclusion of the (4)A'' surface in the QCT calculations gives excellent agreement with experiments. This is the first time an adiabatic pathway from C((3)P) + NO(X(2)Pi) to CO(X(1)Sigma(+))+N((4)S) has been reported.
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| 9. |
- Abrahamsson, Erik, 1974, et al.
(författare)
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Classical and quantum dynamics of the O+CN reaction
- 2006
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Ingår i: Chemical Physics. - : Elsevier BV. - 0301-0104. ; 324:2-3, s. 507-514
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Tidskriftsartikel (refereegranskat)abstract
- Electronic structure (CASPT2) calculations have been performed for the (2)Pi and (4)Sigma(-) states of the NCO system. To create the potential energy surfaces, the generalized discrete variable representation (GDVR) method has been used. Wave packet calculations have been performed for the collinear O + CN reaction on both surfaces. These are the first reported quantum dynamics calculations on this reaction. State-to-state reaction probabilities are presented. On the (2)Pi surface, which has an almost 6 eV deep well, we obtain structure in the reaction probabilities at low kinetic energies but at higher energies they are smooth. The (4)Sigma(-) surface is highly exoergic and vibrationally non-adiabatic dynamics is observed. The (4)Sigma(-) surface has an early barrier and as a result we find that translational energy more efficiently promotes the reaction than vibrational energy does. The wave packet results are compared with QCT results. Generally the agreement is good as would be expected but some notable differences are found, particularly for reaction out of the vibrational ground state. (c) 2005 Elsevier B.V. All rights reserved.
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| 10. |
- Abrahamsson, Erik, 1974, et al.
(författare)
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Dynamics of the O + CN Reaction and N + CO Scattering on Two Coupled Surfaces
- 2009
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Ingår i: J. Phys. Chem. A. - : American Chemical Society (ACS). - 1089-5639 .- 1520-5215. ; 113:52, s. 14824-14830
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Tidskriftsartikel (refereegranskat)abstract
- Spin−orbit coupling between the two collinear 2Π and 4Σ− potential energy surfaces for the NCO system are calculated using the RASSI method with CASSCF wave functions as basis set. The GDVR method has been used to interpolate a spin−orbit coupling surface. Wave packet and quasi-classical trajectory surface hopping calculations have been performed and compared for both the O(3P) + CN(X2Σ+) → N(4S) + CO(X1Σ+) reaction and for electronically inelastic scattering in the N + CO channels. The O + CN nonadiabatic reaction probabilities are small. The wavepacket study gives a resonance structure. Also for the N + CO electronically inelastic scattering the wave packet calculations give a distinct resonance structure with peak transition probabilities up to around 10%, which is somewhat lower than the trajectory surface hopping results.
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| 11. |
- Ahmadpour, Doryaneh, 1973, et al.
(författare)
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The mitogen-activated protein kinase Slt2 modulates arsenite transport through the aquaglyceroporin Fps1
- 2016
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Ingår i: FEBS Letters. - : Wiley. - 0014-5793 .- 1873-3468. ; 590:20, s. 3649-3659
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Tidskriftsartikel (refereegranskat)abstract
- © 2016 Federation of European Biochemical Societies Arsenite is widely present in nature; therefore, cells have evolved mechanisms to prevent arsenite influx and promote efflux. In yeast (Saccharomyces cerevisiae), the aquaglyceroporin Fps1 mediates arsenite influx and efflux. The mitogen-activated protein kinase (MAPK) Hog1 has previously been shown to restrict arsenite influx through Fps1. In this study, we show that another MAPK, Slt2, is transiently phosphorylated in response to arsenite influx. Our findings indicate that the protein kinase activity of Slt2 is required for its role in arsenite tolerance. While Hog1 prevents arsenite influx via phosphorylation of T231 at the N-terminal domain of Fps1, Slt2 promotes arsenite efflux through phosphorylation of S537 at the C terminus. Our data suggest that Slt2 physically interacts with Fps1 and that this interaction depends on phosphorylation of S537. We hypothesize that Hog1 and Slt2 may affect each other's binding to Fps1, thereby controlling the opening and closing of the channel.
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| 12. |
- Andersson, Stefan, 1973, et al.
(författare)
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A theoretical and experimental study on translational and internal energies of H2O and OH from the 157 nm irradiation of amorphous solid water at 90 K.
- 2011
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Ingår i: Physical chemistry chemical physics : PCCP. - : Royal Society of Chemistry (RSC). - 1463-9084 .- 1463-9076. ; 13:35, s. 15810-20
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Tidskriftsartikel (refereegranskat)abstract
- The photodesorption of H(2)O in its vibrational ground state, and of OH radicals in their ground and first excited vibrational states, following 157 nm photoexcitation of amorphous solid water has been studied using molecular dynamics simulations and detected experimentally by resonance-enhanced multiphoton ionization techniques. There is good agreement between the simulated and measured energy distributions. In addition, signals of H(+) and OH(+) were detected in the experiments. These are inferred to originate from vibrationally excited H(2)O molecules that are ejected from the surface by two distinct mechanisms: a direct desorption mechanism and desorption induced by secondary recombination of photoproducts at the ice surface. This is the first reported experimental evidence of photodesorption of vibrationally excited H(2)O molecules from water ice.
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| 13. |
- Andersson, Stefan, 1973, et al.
(författare)
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Comparison of quantum dynamics and quantum transition state theory estimates of the H + CH4 reaction rate.
- 2009
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Ingår i: The journal of physical chemistry. A. - : American Chemical Society (ACS). - 1520-5215 .- 1089-5639. ; 113:16, s. 4468-78
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Tidskriftsartikel (refereegranskat)abstract
- Thermal rate constants are calculated for the H + CH(4) --> CH(3) + H(2) reaction employing the potential energy surface of Espinosa-Garcia (Espinosa-Garcia, J. J. Chem. Phys. 2002, 116, 10664). Two theoretical approaches are used. First, we employ the multiconfigurational time-dependent Hartree method combined with flux correlation functions. In this way rate constants in the range 225-400 K are obtained and compared with previous results using the same theoretical method but the potential energy surface of Wu et al. (Wu, T.; Werner, H.-J.; Manthe, U. Science 2004, 306, 2227). It is found that the Espinosa-Garcia surface results in larger rate constants. Second, a harmonic quantum transition state theory (HQTST) implementation of instanton theory is used to obtain rate constants in a temperature interval from 20 K up to the crossover temperature at 296 K. The HQTST estimates are larger than MCTDH ones by a factor of about three in the common temperature range. Comparison is also made with various tunneling corrections to transition state theory and quantum instanton theory.
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| 14. |
- Andersson, Stefan, 1973, et al.
(författare)
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Computational studies of the kinetics of the C+NO and O+CN reactions
- 2003
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Ingår i: Journal of Physical Chemistry A. - : American Chemical Society (ACS). - 1089-5639 .- 1520-5215. ; 107:28, s. 5439-5447
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Tidskriftsartikel (refereegranskat)abstract
- Thermal rate coefficients for the reactions C(3P) + NO(X2Π) → CN(X2Σ+) + O(3P), C(3P) + NO(X2Π) → CO(X1Σ+) + N(2D), and O(3P) + CN(X2Σ+) → CO(X1Σ+) + N(2D) in the temperature range from 5 to 5000 K have been obtained using quasiclassical trajectory calculations. Results are reported for two ab initio potential energy surfaces corresponding to states of 2A‘ and 2A‘ ‘ symmetry. Good agreement between calculated and experimental rate coefficients are obtained for the C + NO reactions for all temperatures, whereas the rate coefficient for the O + CN reaction at room temperature is larger than that found experimentally. The dynamics is considerably different on the two potential energy surfaces with the 2A‘ ‘ giving rate coefficients in better agreement with experiments. The quality of the potential energy surfaces are discussed in the light of new electronic structure calculations including spin−orbit coupling.
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| 15. |
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| 16. |
- Andersson, Stefan, 1973, et al.
(författare)
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Mechanisms of SiO oxidation: Implications for dust formation
- 2023
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Ingår i: Frontiers in Astronomy and Space Sciences. - : Frontiers Media SA. - 2296-987X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Reactions of SiO molecules have been postulated to initiate efficient formation of silicate dust particles in outflows around dying (AGB) stars. Both OH radicals and H2O molecules can be present in these environments and their reactions with SiO and the smallest SiO cluster, Si2O2, affect the efficiency of eventual dust formation. Rate coefficients of gas-phase oxidation and clustering reactions of SiO, Si2O2 and Si2O3 have been calculated using master equation calculations based on density functional theory calculations. The calculations show that the reactions involving OH are fast. Reactions involving H2O are not efficient routes to oxidation but may under the right conditions lead to hydroxylated species. The reaction of Si2O2 with H2O, which has been suggested as efficient producing Si2O3, is therefore not as efficient as previously thought. If H2O molecules dissociate to form OH radicals, oxidation of SiO and dust formation could be accelerated. Kinetics simulations of oxygen-rich circumstellar environments using our proposed reaction scheme suggest that under typical conditions only small amounts of SiO2 and Si2O2 are formed and that most of the silicon remains as molecular SiO.
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| 17. |
- Andersson, Stefan, 1973, et al.
(författare)
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Molecular dynamics simulations of water ice photochemistry
- 2007
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Ingår i: Molecules in space and laboratory. - 9782901057581
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Konferensbidrag (refereegranskat)abstract
- Molecular dynamics simulations of the dynamics following the absorption of an ultraviolet photon in amorphous water ice have been performed. Large probabilities of the desorption of H atoms are found. The desorption of OH radicals and H2O molecules is much less probable, but is still nonnegligible.
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| 18. |
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| 19. |
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| 20. |
- Andersson, Stefan, 1973, et al.
(författare)
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Photodesorption of water ice: a molecular dynamics study
- 2008
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Ingår i: Astronomy & Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 491, s. 907-916
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Tidskriftsartikel (refereegranskat)abstract
- Context. Absorption of ultraviolet radiation by water ice coating interstellar grains can lead to dissociation and desorption of the ice molecules. These processes are thought to be important in the gas-grain chemistry in molecular clouds and protoplanetary disks, but very few quantitative studies exist. Aims. We compute the photodesorption efficiencies of amorphous water ice and elucidate the mechanisms by which desorption occurs. Methods. Classical molecular dynamics calculations were performed for a compact amorphous ice surface at 10 K thought to be representative of interstellar ice. Dissociation and desorption of H2O molecules in the top six monolayers are considered following absorption into the first excited electronic state with photons in the 1300−1500 Å range. The trajectories of the H and OH photofragments are followed until they escape or become trapped in the ice. Results. The probability for H2O desorption per absorbed UV photon is 0.5−1% in the top three monolayers, then decreases to 0.03% in the next two monolayers, and is negligible deeper into the ice. The main H2O removal mechanism in the top two monolayers is through separate desorption of H and OH fragments. Removal of H2O molecules from the ice, either as H2O itself or its products, has a total probability of 2−3% per absorbed UV photon in the top two monolayers. In the third monolayer the probability is about 1% and deeper into the ice the probability of photodesorption falling to insignificant numbers. The probability of any removal of H2O per incident photon is estimated to be 3.7 × 10−4, with the probability for photodesorption of intact H2O molecules being 1.4 × 10−4 per incident photon. When no desorption occurs, the H and OH products can travel up to 70 and 60 Å inside or on top of the surface, respectively, during which they can react with other species, such as CO, before they become trapped.
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| 21. |
- Andersson, Stefan, 1973, et al.
(författare)
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Rotational Transitions of CO+ Induced by Atomic Hydrogen
- 2008
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Ingår i: The Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 678, s. 1042-1048
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Tidskriftsartikel (refereegranskat)abstract
- The CO+ molecular ion has been observed in photon-dominated regions. Recent modeling has not been able to explain the abundances of CO+ in these regions. The most abundant collision partners are believed to be hydrogen atoms, hydrogen molecules, and electrons. The reactions of these species with CO+ have been studied previously and found to be fast. The only inelastic processes studied before were collisions of CO+ with electrons. Here we investigate the inelastic collisions of CO+ with hydrogen atoms. We argue that this can be done on the lowest triplet electronic state. This implies that CO+ ions, in a hydrogen atom dominated surrounding, experiences a few inelastic collisions before reacting. Rotationally inelastic state-to-state cross sections ( ) are presented together with state-resolved thermal rate coefficients. The results suggest that the rotationally inelastic collision cross sections can be of comparable magnitude to the reactive ones. Implications for the rotational temperature of CO+ in PDRs are discussed. To perform the calculations, a potential energy surface is fitted using the reproducing-kernel Hilbert space method based on multireference configuration-interaction calculations employing the aug-cc-pVQZ basis set.
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| 22. |
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| 23. |
- Andersson, Stefan, 1973, et al.
(författare)
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Tunneling in hydrogen and deuterium addition to CO at low temperatures
- 2011
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Ingår i: Chemical physics letters. - : Elsevier BV. - 0009-2614. ; 513:1-3, s. 31-36
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Tidskriftsartikel (refereegranskat)abstract
- The hydrogen and deuterium atom addition reactions of CO to form HCO and DCO are addressed by Harmonic Quantum Transition State Theory calculations. Special attention is paid to the reactions at very low temperatures (5–20 K) where it is found that quantum tunneling leads to substantial rates of reaction. This supports experiments in the solid phase, which conclude that these reactions are driven by tunneling at low temperatures. The calculated kinetic isotope effect of kD/kH = 1/250 is found to be lower than the experimentally deduced value of 0.08 for the surface reaction. Possible reasons for this discrepancy are discussed.
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| 24. |
- Andersson, Tobias, 1973-, et al.
(författare)
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Planning for effective use of fire and rescue service resources
- 2007
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Ingår i: Interflam 2007 (Vol.2). - London, UK : Interscience Communications. - 9780955654800 ; , s. 1561-1566
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In this work, a model has been developed that can support and evaluate decisions on the location of rescue service resources. The main contributions are the possibilities to model multiple events and multiple resources, and foremost providing a method of quantifying the interaction between events and resources. In the model, it is possible to analyse different ways of organising the fire and rescue service, e.g. comparing the effect of small units in multiple locations with a traditional way of organising, where most resources comes from a single fire station. The model can also suggest advantageous locations for the resources.
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| 25. |
- Arasa, C, et al.
(författare)
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Molecular dynamics simulations of D2O ice photodesorption.
- 2011
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Ingår i: The Journal of chemical physics. - : AIP Publishing. - 1089-7690 .- 0021-9606. ; 134:16
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Tidskriftsartikel (refereegranskat)abstract
- Molecular dynamics (MD) calculations have been performed to study the ultraviolet (UV) photodissociation of D(2)O in an amorphous D(2)O ice surface at 10, 20, 60, and 90 K, in order to investigate the influence of isotope effects on the photodesorption processes. As for H(2)O, the main processes after UV photodissociation are trapping and desorption of either fragments or D(2)O molecules. Trapping mainly takes place in the deeper monolayers of the ice, whereas desorption occurs in the uppermost layers. There are three desorption processes: D atom, OD radical, and D(2)O molecule photodesorption. D(2)O desorption takes places either by direct desorption of a recombined D(2)O molecule, or when an energetic D atom produced by photodissociation kicks a surrounding D(2)O molecule out of the surface by transferring part of its momentum. Desorption probabilities are calculated for photoexcitation of D(2)O in the top four monolayers and are compared quantitatively with those for H(2)O obtained from previous MD simulations of UV photodissociation of amorphous water ice at different ice temperatures [Arasa et al., J. Chem. Phys. 132, 184510 (2010)]. The main conclusions are the same, but the average D atom photodesorption probability is smaller than that of the H atom (by about a factor of 0.9) because D has lower kinetic energy than H, whereas the average OD radical photodesorption probability is larger than that of OH (by about a factor of 2.5-2.9 depending on ice temperature) because OD has higher translational energy than OH for every ice temperature studied. The average D(2)O photodesorption probability is larger than that of H(2)O (by about a factor of 1.4-2.3 depending on ice temperature), and this is entirely due to a larger contribution of the D(2)O kick-out mechanism. This is an isotope effect: the kick-out mechanism is more efficient for D(2)O ice, because the D atom formed after D(2)O photodissociation has a larger momentum than photogenerated H atoms from H(2)O, and D transfers momentum more easily to D(2)O than H to H(2)O. The total (OD + D(2)O) yield has been compared with experiments and the total (OH + H(2)O) yield from previous simulations. We find better agreement when we compare experimental yields with calculated yields for D(2)O ice than when we compare with calculated yields for H(2)O ice.
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| 26. |
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| 27. |
- Bhatt, Deepak L., et al.
(författare)
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Rationale, design and baseline characteristics of the effect of ticagrelor on health outcomes in diabetes mellitus patients Intervention study
- 2019
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Ingår i: Clinical Cardiology. - : Wiley. - 0160-9289 .- 1932-8737. ; 42:5, s. 498-505
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Tidskriftsartikel (refereegranskat)abstract
- In the setting of prior myocardial infarction, the oral antiplatelet ticagrelor added to aspirin reduced the risk of recurrent ischemic events, especially, in those with diabetes mellitus. Patients with stable coronary disease and diabetes are also at elevated risk and might benefit from dual antiplatelet therapy. The Effect of Ticagrelor on Health Outcomes in diabEtes Mellitus patients Intervention Study (THEMIS, NCT01991795) is a Phase 3b randomized, double-blinded, placebo-controlled trial of ticagrelor vs placebo, on top of low dose aspirin. Patients >= 50 years with type 2 diabetes receiving anti-diabetic medications for at least 6 months with stable coronary artery disease as determined by a history of previous percutaneous coronary intervention, bypass grafting, or angiographic stenosis of >= 50% of at least one coronary artery were enrolled. Patients with known prior myocardial infarction (MI) or stroke were excluded. The primary efficacy endpoint is a composite of cardiovascular death, myocardial infarction, or stroke. The primary safety endpoint is Thrombolysis in Myocardial Infarction major bleeding. A total of 19 220 patients worldwide have been randomized and at least 1385 adjudicated primary efficacy endpoint events are expected to be available for analysis, with an expected average follow-up of 40 months (maximum 58 months). Most of the exposure is on a 60 mg twice daily dose, as the dose was lowered from 90 mg twice daily partway into the study. The results may revise the boundaries of efficacy for dual antiplatelet therapy and whether it has a role outside acute coronary syndromes, prior myocardial infarction, or percutaneous coronary intervention.
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| 28. |
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| 29. |
- Dinér, Peter, 1976, et al.
(författare)
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Design, synthesis, and characterization of a highly effective Hog1 inhibitor: a powerful tool for analyzing MAP kinase signaling in yeast.
- 2011
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 6:5
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Tidskriftsartikel (refereegranskat)abstract
- The Saccharomyces cerevisiae High-Osmolarity Glycerol (HOG) pathway is a conserved mitogen-activated protein kinase (MAPK) signal transduction system that often serves as a model to analyze systems level properties of MAPK signaling. Hog1, the MAPK of the HOG-pathway, can be activated by various environmental cues and it controls transcription, translation, transport, and cell cycle adaptations in response to stress conditions. A powerful means to study signaling in living cells is to use kinase inhibitors; however, no inhibitor targeting wild-type Hog1 exists to date. Herein, we describe the design, synthesis, and biological application of small molecule inhibitors that are cell-permeable, fast-acting, and highly efficient against wild-type Hog1. These compounds are potent inhibitors of Hog1 kinase activity both in vitro and in vivo. Next, we use these novel inhibitors to pinpoint the time of Hog1 action during recovery from G(1) checkpoint arrest, providing further evidence for a specific role of Hog1 in regulating cell cycle resumption during arsenite stress. Hence, we describe a novel tool for chemical genetic analysis of MAPK signaling and provide novel insights into Hog1 action.
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| 30. |
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| 31. |
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| 32. |
- Frankcombe, Terry J, et al.
(författare)
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An Adiabatic Capture Theory and Quasiclassical Trajectory Study of C plus NO and O plus CN on the (2)A ', (2)A '', and (4)A '' Potential Energy Surfaces
- 2012
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Ingår i: Journal of Physical Chemistry A. - : American Chemical Society (ACS). - 1089-5639 .- 1520-5215. ; 116:19, s. 4705-4711
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Tidskriftsartikel (refereegranskat)abstract
- The adiabatic capture centrifugal sudden approximation (ACCSA) has been applied to the C + NO and O + CN reactions, along with quasiclassical trajectory simulations. Existing global analytic fits to the potential energy surfaces of the CNO system in the (2)A', (2)A '', and (4)A '' electronic states have been used. Thermal rate constants for reaction in each of the electronic states have been calculated. In all cases a strong temperature dependence is evident in the calculated rate constants. The agreement between the calculated adiabatic capture and quasiclassical trajectory rate constants is excellent in some cases, but these rate constants differ considerably in other cases. This behavior is analyzed in terms of the anisotropy of the potential energy surfaces. On the basis of this analysis, we propose a new diagnostic for the reliability of ACCSA capture calculations.
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| 33. |
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| 34. |
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| 35. |
- Fälth, Linda, 1973-, et al.
(författare)
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An intervention study to prevent ‘summer reading loss’ in a socioeconomically disadvantaged area with second language learners
- 2019
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Ingår i: Nordic Journal of Literacy Research. - : NOASP. - 2464-1596. ; 5:3, s. 10-23
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Tidskriftsartikel (refereegranskat)abstract
- Summer reading loss is a documented reality for many students. Research has established differences in the contribution of summer reading activity between children from families with different economic status. In this study, 120 students in Grade 2 and 115 students in Grade 3 from a socioeconomically vulnerable area participated in a summer reading intervention. In addition, a control group from the same schools comprised of 106 students from Grade 2 and 94 students from Grade 3. Almost 90% of the participating students did not have Swedish as their native language. The participants were tested on reading skills, including word decoding, nonsense-word reading, word comprehension and reading comprehension, before and after the summer vacation. The intervention was planned together with teachers from three participant schools and leisure centers. Before the summer holiday the schools arranged reading weeks and library visits. The students were encouraged to read at home during the vacation and record the number of books read on a digital platform. The results showed that the largest effect sizes between groups (intervention and control) were observed for word decoding in Grade 2 and word comprehension in Grade 3 where the intervention group improved more than the control group. If summer learning loss can be avoided or limited, the treatment can be considered worth implementing
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| 36. |
- Fälth, Linda, 1973-, et al.
(författare)
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Assessment Support as Part of Teacher Duties in the Subject of Swedish at the Elementary Level
- 2019
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Ingår i: International Journal of Learning, Teaching and Educational Research. - Flacq : Society for Research and Knowledge Management. - 1694-2493 .- 1694-2116. ; 18:4, s. 85-109
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to examine and describe the use of a formative assessment support regarding reading instruction in grades 1-3, viewed from a teacher perspective. Sixty-five teachers from all parts of Sweden responded to a questionnaire, who had used the support for at least one year. Of the participant teachers, nine were interviewed for the purpose of performing an in-depth analysis of the questions. The teachers stated that the primary use of the assessment results was to identify students in need of extra support, as a basis for performance appraisals, as well as for further lesson planning. Formative assessment was, on the one hand, described as a concrete practical method and, on the other hand, as an attitude. The results also indicate a feeling of frustration that, notwithstanding the current deeper insight into what every student needs, the teaching still proceeds on some middle-ground path or level.
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| 37. |
- Geijer, Cecilia, 1980, et al.
(författare)
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Initiation of the transcriptional response to hyperosmotic shock correlates with the potential for volume recovery.
- 2013
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Ingår i: The FEBS journal. - : Wiley. - 1742-4658 .- 1742-464X. ; 280:16, s. 3854-67
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Tidskriftsartikel (refereegranskat)abstract
- The control of activity and localization of transcription factors is critical for appropriate transcriptional responses. In eukaryotes, signal transduction components such as mitogen-activated protein kinase (MAPK) shuttle into the nucleus to activate transcription. It is not known in detail how different amounts of nuclear MAPK over time affect the transcriptional response. In the present study, we aimed to address this issue by studying the high osmolarity glycerol (HOG) system in Saccharomyces cerevisiae. We employed a conditional osmotic system, which changes the period of the MAPK Hog1 signal independent of the initial stress level. We determined the dynamics of the Hog1 nuclear localization and cell volume by single-cell analysis in well-controlled microfluidics systems and compared the responses with the global transcriptional output of cell populations. We discovered that the onset of the initial transcriptional response correlates with the potential of cells for rapid adaptation; cells that are capable of recovering quickly initiate the transcriptional responses immediately, whereas cells that require longer time to adapt also respond later. This is reflected by Hog1 nuclear localization, Hog1 promoter association and the transcriptional response, but not Hog1 phosphorylation, suggesting that a presently uncharacterized rapid adaptive mechanism precedes the Hog1 nuclear response. Furthermore, we found that the period of Hog1 nuclear residence affects the amplitude of the transcriptional response rather than the spectrum of responsive genes.
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| 38. |
- Gustafson, Stefan, 1968-, et al.
(författare)
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Effects of a formative assessment system on early reading development
- 2019
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Ingår i: Education. - Mobile, AL, United States : Project Innovation. - 0013-1172. ; 140:1, s. 17-27
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Tidskriftsartikel (refereegranskat)abstract
- We present quantitative results from the pilot-year of a large scale Swedish educational project in reading development called LegiLexi, inspired by research within the Response to intervention and Formative assessment traditions. The vision of the project is that every pupil should reach adequate reading skills at the end of grade 3 in primary school. LegiLexi contains a formative assessment tool and a teacher course, which are linked together. We describe LegiLexi and analyze quantitative effects of the pilot year regarding reading development for pupils in grade 1. The design included three conditions; full access to LegiLexi, access only to the formative assessment tool, and control. Results showed that the group with full access to LegiLexi improved their word decoding and reading comprehension the most. For language comprehension, the Formative assessment only group showed the highest improvements. Thus, the features of LegiLexi seem to help enhance critical reading skills. Some changes will be made in the project to strengthen methodological aspects and further facilitate pupils’ reading development.
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| 39. |
- Hama, Tetsuya, et al.
(författare)
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A desorption mechanism of water following vacuum-ultraviolet irradiation on amorphous solid water at 90 K
- 2010
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Ingår i: JOURNAL OF CHEMICAL PHYSICS. - 0021-9606. ; 132:16
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Tidskriftsartikel (refereegranskat)abstract
- Following 157 nm photoexcitation of amorphous solid water and polycrystalline water ice, photodesorbed water molecules (H2O and D2O), in the ground vibrational state, have been observed using resonance-enhanced multiphoton ionization detection methods. Time-of-flight and rotationally resolved spectra of the photodesorbed water molecules were measured, and the kinetic and internal energy distributions were obtained. The measured energy distributions are in good accord with those predicted by classical molecular dynamics calculations for the kick-out mechanism of a water molecule from the ice surface by a hot hydrogen (deuterium) atom formed by photodissociation of a neighboring water molecule. Desorption of D2O following 193 nm photoirradiation of a D2O/H2S mixed ice was also investigated to provide further direct evidence for the operation of a kick-out mechanism.
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| 40. |
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| 41. |
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| 42. |
- Karlsson, Stefan, et al.
(författare)
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Detection of abnormal activities on a SM or MM fiber
- 2023
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Ingår i: 2023 Optical Fiber Communications Conference and Exhibition, OFC 2023 - Proceedings.
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Konferensbidrag (refereegranskat)abstract
- We demonstrate eavesdrop detection based on polarization signatures by analyzing polarization state changes at the receiver. We identify changes related to the normal operation and the ones caused by eavesdropping.
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| 43. |
- Modin, Stefan, 1973-
(författare)
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Developments in the Field of Aza-Diels-Alder Reactions, Catalytic Michael Additions and Automated Synthesis
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The development of new aza-bicyclic structures with potential applications as ligands synthesised via an aza-Diels-Alder cycloaddition has been studied. The studies are concerning the i) development of large scale aza-Diels-Alder reaction, ii) development of a fast and simple route to bicyclic diamine ligands, iii) development of new aza-Diels-Alder adducts from different dienes, iv) development and application of bicyclic N,P ligands for catalytic Michael additions and v) development of robotized asymmetric transfer hydrogenation reactions.i) Development of large-scale aza-Diels-Alder reaction giving up to 110 g pure product, in ordinary laboratory equipment without the need of any flash chromatography.ii) Development of a new synthetic route to bicyclic diamine ligands highly useful for asymmetric rearrangement of olefin oxides to allylic alcohols and thereby shortening the ligand synthesis dramatically and moreover providing with a faster access to those ligands.iii) Expanding the scope of the aza-Diels-Alder reaction by the use of spirodienes and anthracene as dienes.iv) Development and application of a new bidentate ligands for catalytic Michael addition to cyclic enones using 5 mol % ligand giving the product in 71 % ee.v) Utilisation of Chemspeed ASW 2000 in catalytic transfer hydrogenation and solving of problems regarding use of highly air sensitive reactions in an automated environment.
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| 44. |
- Nordström, Thomas, Filosofie doktor i psykologi, 1977-, et al.
(författare)
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Teacher inquiry of using assessments and recommendations in teaching early reading
- 2019
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Ingår i: Studies in Educational Evaluation. - : Elsevier. - 0191-491X .- 1879-2529. ; 63, s. 9-16
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Tidskriftsartikel (refereegranskat)abstract
- Previous research point to difficulties for teachers to interpret reading assessment data with regard to instructional decisions. This study explored Swedish primary teachers' use of assessments and recommendations, in order to be able to target individual needs. Eight teachers participated in a reading program and were interviewed in focus-group meetings. The analysis of teacher narratives stemming from assessment use resulted in three themes: Awareness of student learning, Changes in the organization of teaching, but not regarding individualized content and Strengthened teacher role, but modest professional growth. The themes indicated that the teachers had become aware of their students’ learning, had employed teaching based on informed decisions, and showed initial professional growth.However, the assessment details and the recommendations allowed for more adjustments than was evident in the teachers’ narratives. The results point to the relative difficulty of targeting individual needs in the general classroom education, and to the challenges of changing teaching practices.
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| 45. |
- Nordström, Thomas, Filosofie doktor i psykologi, 1977-, et al.
(författare)
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The potential of a forward-looking assessment and teaching system on students' reading gains
- 2019
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Ingår i: European Dyslexia Association Autumn Seminar, Växjö, Sweden, September 27-29.
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Konferensbidrag (refereegranskat)abstract
- PurposeHow can teachers optimize reading instruction in Swedish schools? This poster presents findings from two studies investigating A) grade 1-3 teachers’ use of a forward-looking assessment and teaching system (LegiLexi) and B), its effect on student reading gains in Grade 1. The purpose of study A was to support teachers with an assessment system which included teaching recommendations for individual students and to study how that support enabled teachers to individualize instruction. The purpose of study B was to gather evidence that such support is superior in relation to “teaching as usual”.MethodIn study A, focus group meetings of eight active LegiLexi teachers were used as to answer the question of the extent teachers managed to individualize instruction in their everyday practice. In study B, we randomly assigned schools to three conditions; full access to LegiLexi (8 schools/217 students), access only to part of LegiLexi (4 schools/86 students) and control (9 schools/208 students), following estimated effects of LegiLexi across three test occasions containing reading measures. Results/conclusionsIn study A, results revealed that teachers were supported by LegiLexi, and were able to individualize instruction primarily by creating dynamic reading groups of students. However, individualizing further proved challenging. In study B, findings revealed that the group with full access to LegiLexi improved their word decoding (d=1.79 vs 1.33 and 1.20) and reading comprehension the most (d=1.75 vs 1.45 and 1.16). Thus, the findings show promising results for Swedish schools of how to improve reading instruction by focusing on students’ individual needs.
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| 46. |
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| 47. |
- Park, Hee-Bok, 1973-
(författare)
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Genetic Analysis of Quantitative Traits Using Domestic Animals : A Candidate Gene and Genome Scanning Approach
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Domestication has led to genetic changes that affect quantitative traits in farm animals. Both candidate gene analysis using association tests and genome scans based on linkage analysis have been performed to understand the molecular basis underlying quantitative genetic variation in horses, pigs and chickens. To test a possible association of polymorphisms in the PRKAG3 gene, previously found to be associated with excess glycogen content in pig skeletal muscle, with quantitative traits in the horse, the major coding part of the equine PRKAG3 sequence was identified. Bioinformatic characterization of the equine PRKAG3 gene was conducted. A single nucleotide polymorphism (SNP) causing a missense mutation (Pro258Leu) was found. Screening this SNP showed that the Leu258 allele was more frequent in breeds with heavy muscularity. To assess previously reported associations between polymorphisms in the MC4R gene and obesity-related traits further, we conducted linkage analysis between the MC4R locus and fatness-related traits using a Wild BoarxLarge White intercross. No significant association between segregation at the MC4R locus and fatness was detected in this pedigree. A genome scan of quantitative trait loci (QTLs) has been performed in an intercross between chicken lines divergently selected for growth. Divergent parental lines have been established by selecting for high and low 56-day body weight for over 40 generations. The selection has led to approximately a 9-fold difference in 56-day body weight between lines and resulted in correlated responses for a number of traits including appetite, immune response, body composition and metabolic traits. Phenotypic data on growth and other correlated traits were collected from more than 800 F2 individuals. Genome scans using 145 markers on 26 linkage groups have identified QTLs affecting growth and correlated responses to selection for 56-day body weight. No major QTL explaining a large portion of phenotypic variation in growth was revealed in this study.
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| 48. |
- Saladino, Giovanni Marco
(författare)
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Preclinical X-Ray Fluorescence Imaging with Multifunctional Nanoparticles
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- X-ray fluorescence imaging (XFI) is an emerging technique for preclinical studies, characterized by high resolution, specificity, and sensitivity. It relies on nanoparticles (NPs) as contrast agents, which must be constituted of specific elements that match the X-ray source energy for detection. Laboratory liquid metal-jet X-ray sources enable compact in vivo XFI, thereby extending the accessibility of this imaging technique beyond synchrotron facilities.When designing NPs as contrast agents, biocompatibility is essential for both preclinical and clinical imaging, often requiring a passivating biocompatible coating on the NP surface. The NP cores can provide contrast by their elemental composition, while coating, conjugation, and decoration strategies can add other functionalities and improve biocompatibility.In this thesis, multifunctional NPs are designed to extend the functionality of XFI contrast agents by incorporating optically fluorescent or magnetically active components: conjugated carbon quantum dots, dye-doped silica shell, and decorated superparamagnetic iron oxide NPs. The designed multifunctional NPs allow correlative and multiscale imaging with complementary techniques such as confocal optical microscopy or magnetic resonance imaging (MRI). Furthermore, these NPs also facilitate more comprehensive studies on NP pharmacokinetics, paving the way for more robust investigations in the field of nanomedicine.The benefits of multifunctional NPs are demonstrated with two approaches. First, in vivo correlative imaging with MRI and XFI is shown to reduce false positives caused by MRI artifacts in the lungs and abdomen. Second, XFI is employed to enable rapid NP bioengineering, by iteratively improving NP properties and administration strategies for passive tumor targeting. Optical and X-ray fluorescent multifunctional NPs enable the co-localization of NPs at both macroscopic and microscopic levels with XFI and confocal microscopy, correlating NP accumulation in organs with NP-cell interactions. These results highlight the role of XFI in the field of nanomedicine, with potential applications in pharmacokinetics, tumor targeting, treatment monitoring, and the development of medical devices.
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| 49. |
- Sameera, W. M. C., et al.
(författare)
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CH3O Radical Binding on Hexagonal Water Ice and Amorphous Solid Water
- 2021
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Ingår i: Journal of Physical Chemistry A. - : American Chemical Society (ACS). - 1089-5639 .- 1520-5215. ; 125:1, s. 387-393
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Tidskriftsartikel (refereegranskat)abstract
- Binding energies of the CH3O radical on hexagonal water ice (I-h) and amorphous solid water (ASW) were calculated using the ONIOM(QM:MM) method. A range of binding energies is found (0.10-0.50 eV), and the average binding energy is 0.32 eV. The CH3O radical binding on the ASW surfaces is stronger than on the I-h surfaces. The computed binding energies from the ONIOM(wB97X-D/def2-TZVP:AMBER) and wB97X-D/def2-TZVP methods agree quite well. Therefore, the ONIOM(QM:MM) method is expected to give accurate binding energies at a low computational cost. Binding energies from the ONIOM(wB97X-D/def2-TZVP:AMBER) and ONIOM(wB97X-D/def2-TZVP:AMOE-BA09) methods differ noticeably, indicating that the choice of force field matters. According to the energy decomposition analysis, the electrostatic interactions and Pauli repulsions between the CH3O radical and ice play a crucial role in the binding energy. This study gives quantitative insights into the CH3O radical binding on interstellar ices.
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| 50. |
- Sameera, W M C, et al.
(författare)
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ONIOM(QM:AMOEBA09) Study on Binding Energies and Binding Preference of OH, HCO, and CH3 Radicals on Hexagonal Water Ice (I-h)
- 2017
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Ingår i: Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 121:28, s. 15223-15232
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Tidskriftsartikel (refereegranskat)abstract
- We have combined the AMOEBA09 polarizable force field with the ONIOM(QM:MM) method to rationalize binding energies and binding preferences of the OH, HCO, and CH3 radicals on crystalline water ice (I-h). ONIOM(M062X:AMOEBA09) and ONIOM(wB97XD:AMOEBA) calculations suggest that the dangling hydrogen (d-H) or dangling oxygen (d-O) on the binding sites play an important role on the binding energies. Depending On the dangling nature at the binding site, a range of binding energies is found for the OH radical (0.67-0.20 eV), HCO radical (0.42--0.12 eV), and CH3 radical (0.26-0.11 eV). The binding energies of these radicals are larger in the presence of both d-H and d-O at the binding site. On the other hand, binding energies are weaker in the presence of only d-H or d-O at the binding site. The ONIOM(QM:AMOEBA09) methodology is found to be a useful approach to calculate binding energies of atoms, radicals, and molecules on I-h.
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