Circular Dichroism (CD) spectroscopy is a powerful method for investigating conformational changes in proteins and therefore has numerous applications in structural and molecular biology. Here a computational investigation of the CD spectrum of the Human Carbonic Anhydrase II (HCAII), with main focus on the near-UV CD spectra of the wild-type enzyme and it seven tryptophan mutant forms, is presented and compared to experimental studies. Multilevel computational methods (Molecular Dynamics, Semiempirical Quantum Mechanics, Time-Dependent Density Functional Theory) were applied in order to gain insight into the mechanisms of interaction between the aromatic chromophores within the protein environment and understand how the conformational flexibility of the protein influences these mechanisms. The analysis suggests that combining CD semi empirical calculations, crystal structures and molecular dynamics (MD) could help in achieving a better agreement between the computed and experimental protein spectra and provide some unique insight into the dynamic nature of the mechanisms of chromophore interactions. / <p>Funding Agencies|UK National Service for Computational Chemistry Software||UK National Supercomputer Service Hector||Marie Curie Fellowships (FP7 of EU)||</p>

In this paper we present a novel numerical approximation scheme for anisotropic diffusion which is at the same time a special case of iterated adaptive filtering. By assuming a sufficiently smooth diffusion tensor field, we simplify the divergence term and obtain an evolution equation that is computed from a scalar product of diffusion tensor and the Hessian. We propose further a set of filters to approximate the Hessian on a minimized spatial support. On standard benchmarks, the resulting method performs in average nearly as good as the best known denoising methods from the literature, although it is significantly faster and easier to implement. In a GPU implementation video real-time performance is achieved for moderate noise levels.

In this experimental study of single InGaAs/GaAs quantum dots (QDs) the photoluminescence intensity of the second order LO-phonon replica of the excitonic interband recombination was measured along with the intensities of the first and zeroth orders. The results show that the intensity of the second-order replica is three to four times stronger than expected from the adiabatic Huang-Rhys theory, indicating that the neglected nonadiabaticity plays an important role for the understanding of the exciton-phonon coupling in QDs. / <p>Funding Agencies|Science Foundation Ireland|05/IN.1/I2510/IN.1/I3000|Swedish Research Council (VR)||K. A. Wallenberg Foundation||Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU)|2009-00971|</p>

The longitudinal-optical (LO)-phonon coupling is experimentally examined by the optical decay of various charged and neutral exciton species in single quantum dots, and the related Huang-Rhys parameters are extracted. A positive trion exhibits significantly weaker LO-phonon replicas in the photoluminescence spectrum than the neutral and negatively charged species. Model computations show that the strength of the replicas is determined by the Coulomb interactions between electrons and holes, which modify the localization of the envelope wave functions and the net charge distribution. / <p>Original Publication: Daniel Dufåker, Fredrik Karlsson, V Dimastrodonato, L O Mereni, Bo Sernelius, Per-Olof Holtz and E Pelucchi, Phonon replicas of charged and neutral exciton complexes in single quantum dots, 2010, PHYSICAL REVIEW B, (82), 20, 205421. http://dx.doi.org/10.1103/PhysRevB.82.205421 Copyright: American Physical Society http://www.aps.org/</p>

Defect properties of quaternary GaNAsP/GaP epilayers grown by vapor phase epitaxy (VPE) are studied by photoluminescence and optically detected magnetic resonance techniques. Incorporation of more than 0.6% of nitrogen is found to facilitate formation of several paramagnetic defects which act as competing carrier recombination centers. One of the defects (labeled as Ga-i-D) is identified as a complex defect that has a Ga interstitial (Ga-i) atom residing inside a Ga tetrahedron as its core. A comparison of Ga-i-D with other Ga-i-related defects known in ternary GaNP and GaNAs alloys suggests that this defect configuration is specific to VPE-grown dilute nitrides. / <p>Funding Agencies|Swedish Research Council|621-2010-3815|Swedish Institute via Visby Programme||Linkoping Linnaeus Initiative for Novel Functional Materials (LiLI-NFM) by the Swedish Research Council|2008-6582|</p>

Comprehensive characterization of defects formed in bulk ZnO single crystals co-implanted with N and Zn as well as N and O atoms is performed by means of optically detected magnetic resonance (ODMR) complemented by Raman and photoluminescence (PL) spectroscopies. It is shown that in addition to intrinsic defects such as Zn vacancies and Zn interstitials, several N-related defects are formed in the implanted ZnO. The prevailed configuration of the defects is found to depend on the choices of the co-implants and also the chosen annealing ambient. Specifically, co-implantation with O leads to the formation of (i) defects responsible for local vibrational modes at 277, 511, and 581 cm−1; (ii) a N-related acceptor with the binding energy of 160 ± 40 meV that is involved in the donor-acceptor pair emission at 3.23 eV; and (iii) a deep donor and a deep NO acceptor revealed from ODMR. Activation of the latter defects is found to require post-implantation annealing in nitrogen ambient. None of these defects are detected when N is co-implanted with Zn. Under these conditions, the dominant N-induced defects include a deep center responsible for the 3.3128 eV PL line, as well as an acceptor center of unknown origin revealed by ODMR. Formation mechanisms of the studied defects and their role in carrier recombination are discussed. / <p>Funding Agencies|Swedish Research Council|621-2010-3971|</p>

Min målsättning med denna uppsats har varit att forska kring hur kortvågsradion kan öka rörligheten på svenska förband i utlandsstyrkan. Inledningsvis har jag definerat vad jag menar med manöverkrigsföring, uppdragstaktik, de sex grundläggande förmågorna och radio. Jag har intervjuat individer som varit på enheter som rört sig i terrängen i Afghanistan och Kosovo. Jag har sedan diskuterat kring hur man kan öka rörligeheten genom att använd sig av uppdragstaktik och kortvågsradion. Jag har jämfört ledningsätt och radioanvändande mellan Afghanistan och Kosovo och dragit slutsatser från detta. En av slutsatserna som har dragits ur uppsatsen är att det är räckvidden som möjliggör en högre rörlighet genom att enheterna inte blir styrda till att hålla sig inom t.ex. en RAP-täckningskarta utan ger dem större möjlighet att själva välja framryckningsväg och möjliggöra att uppdragstaktik[1] kan utnyttjas på ett effektivare sätt. Denna slutsats beskriver hur rörlighet och uppdragstaktik blir effektivare genom att använda sig av kortvågsradion. Jag anser att kortvågsradion är ett radiosystem som försvarsmakten böra behålla och utveckla. Det som bör utvecklas är antenner och radio utrustningen som har tagit upp i uppsatsen. Förslag på förbättringar är att antennerna utvecklas så att man kan ha en antenn för alla frekvensområden så man inte behöver stanna fordonet och upprätta en deltaantenn[2] för att kunna sända på den lämpligaste frekvensen vid tillfället. Att det finns en individ vid campen som har som uppgift att uppdaterade frekvenspaketen varje vecka eftersom frekvenserna är väderberoende, för att mögligöra att radioförbindelsen blir så bra som mögligt. Radioapparaterna borde byggas med dagen elektronikkomponenter vilket skulle medföra mindre radioapparater, bättre batteritid och en mer lättmanövrerad radioapparat.  Jag kommer att avsluta med ett citat ur doktrin för markoperationer som jag anser styrker min uppsats: ”De ledningssystem som försvarsmakten använder ska medge en så stor flexibilitet som mögligt i valet av medel och metoder. Detta innebär att det bör finnas en inbyggd förmåga som möjliggör ledning från såväl en framskjuten plats inom ett operationsområde som från en stabsplats[3]”. / <p>Avdelning: ALB – Slutet Mag. 3 Hylla: Upps. YOP 06-09 // Avdelning:  Karlberg-filial - Karlberg Öppen hylla Hylla: K Upps. YOP REF</p>

Microtools that will be useful for the positioning and investigation microstructures must operate relevant environments, such as cell culture media or blood plasma. They must also be comparatively strong, and preferably allow a muscle like mode of movement. This is given by a novel family of actuators based on conjugated polymers (like polypyrrole, PPy). By miniaturising these structures using standard photolithographic techniques, the authors can reduce the size down to 10-micrometer dimensions and build mechanically active microdevices. These can be moved and positioned by applying a potential to dope or undope the PPy. These novel structures are now being developed as a unique microactuator technology, suitable for operation in applications coupled to cell biology and biomedicine

No description available.

Using in situ transmission electron microscopy, we investigated the kinetics of liquid Ga droplet decay on thin amorphous carbon films during annealing at 773 K. The transmission electron microscopy images reveal that liquid Ga forms spherical droplets and undergo coarsening/decay with increasing time. We find that the droplet volumes change non-linearly with time and the volume decay rates depend on their local environment. By comparing the late-stage decay behavior of the droplets with the classical mean-field theory model for Ostwald ripening, we determine that the decay of Ga droplets occurs in the surface diffusion limited regime. / <p>Funding Agencies|AFOSR|FA9550-10-1-0496|STINT||Swedish Foundation for International Cooperation in Research and Higher Education||Swedish Research Council||Austrian Science Fund FWF, START project|Y371|Knut and Alice Wallenberg Foundation||</p>