The Effect of Oblique Image Slices on the Accuracy of Quantitative Susceptibility Mapping and a Robust Tilt Correction Method

Quantitative susceptibility mapping (QSM) using the MRI phase to calculate tissue magnetic susceptibility is finding increasing clinical applications. Oblique image slices are often acquired to facilitate radiological viewing and reduce artifacts. Here, we show that artifacts and errors arise in susceptibility maps if oblique acquisition is not properly taken into account in QSM. We performed a comprehensive analysis of the effects of oblique acquisition on brain susceptibility maps and compared tilt correction schemes for three susceptibility calculation methods, using a numerical phantom and human in-vivo images. We demonstrate a robust tilt correction method for accurate QSM with oblique acquisition

Switching from Electron to Hole Transport in Solution-Processed Organic Blend Field-Effect Transistors

Organic electronics became an attractive alternative for practical applications in complementary logic circuits due to the unique features of organic semiconductors such as solution processability and ease of large-area manufacturing. Bulk heterojunctions (BHJ), consisting of a blend of two organic semiconductors of different electronic affinities, allow fabrication of a broad range of devices such as light-emitting transistors, light-emitting diodes, photovoltaics, photodetectors, ambipolar transistors and sensors. In this work, the charge carrier transport of BHJ films in field-effect transistors is switched from electron to hole domination upon processing and post-treatment. Low molecular weight n-type N,N′-bis(n-octyl)-(1,7&1,6)-dicyanoperylene-3,4:9,10-bis(dicarboximide) (PDI8-CN2) was blended with p-type poly[2,5-bis(3-tetradecylthiophene-2-yl)thieno[3,2-b]thiophene] (PBTTT-C14) and deposited by spin-coating to form BHJ films. Systematic investigation of the role of rotation speed, solution temperature, and thermal annealing on thin film morphology was performed using atomic force microscopy, scanning electron microscopy, and grazing incidence wide-angle X-ray scattering. It has been determined that upon thermal annealing the BHJ morphology is modified from small interconnected PDI8-CN2 crystals uniformly distributed in the polymer fraction to large planar PDI8-CN2 crystal domains on top of the blend film, leading to the switch from electron to hole transport in field-effect transistors

The bear in Eurasian plant names: Motivations and models

Ethnolinguistic studies are important for understanding an ethnic group's ideas on the world, expressed in its language. Comparing corresponding aspects of such knowledge might help clarify problems of origin for certain concepts and words, e.g. whether they form common heritage, have an independent origin, are borrowings, or calques. The current study was conducted on the material in Slavonic, Baltic, Germanic, Romance, Finno-Ugrian, Turkic and Albanian languages. The bear was chosen as being a large, dangerous animal, important in traditional culture, whose name is widely reflected in folk plant names. The phytonyms for comparison were mostly obtained from dictionaries and other publications, and supplemented with data from databases, the co-authors' field data, and archival sources (dialect and folklore materials). More than 1200 phytonym use records (combinations of a local name and a meaning) for 364 plant and fungal taxa were recorded to help find out the reasoning behind bear-nomination in various languages, as well as differences and similarities between the patterns among them. Among the most common taxa with bear-related phytonyms were Arctostaphylos uva-ursi (L.) Spreng., Heracleum sphondylium L., Acanthus mollis L., and Allium ursinum L., with Latin loan translation contributing a high proportion of the phytonyms. Some plants have many and various bear-related phytonyms, while others have only one or two bear names. Features like form and/or surface generated the richest pool of names, while such features as colour seemed to provoke rather few associations with bears. The unevenness of bear phytonyms in the chosen languages was not related to the size of the language nor the present occurence of the Brown Bear in the region. However, this may, at least to certain extent, be related to the amount of the historical ethnolinguistic research done on the selected languages

Sand sheets interaction with aeolian dune, alluvial and marginal playa beds in Late Permian Upper Rotliegend setting (western part of the Poznań Basin, Poland)

The Upper Rotliegend deposits of the western part of the Poznań Basin, Poland, represent three main sedimentary environments: aeolian desert (dunes and sand sheets), alluvial plain (alluvial covers with wadi deposits) and marginal playa. In arid periods, dunes prograded into areas dominated by alluvial sedimentation. During wet periods, alluvial deposits eroded the aeolian deposits and prograded onto dune fields. Playa sediments were deposited among aeolian or alluvial sediments during periodic expansions of the playa. These aeolian, alluvial and playa deposits are arranged in depositional sequences. Boundaries between sequences are marked by rapid changes in depositional facies; and by erosional bounding surfaces. Maximum Wetting Surfaces have been distinguished within some parts of the depositional sequences, which enable regional correlations. The sections studied are composed of thick sequences of sand and sand-gravel sheets. The sand sheets represent periods of stratigraphic condensation. Systems of sand sheets are typical of marginal areas of ergs. We distinguish nine depositional complexes (units) numbered 1-9 from base to top, respectively. These subdivisions are based on the interpretation of the sedimentological record in palaeoclimatic terms, and in terms of major erosional boundaries, which are probably of regional extent. In the aeolian deposits, major boundaries are associated with deflation surfaces related to the stabilization of groundwater levels. In the marginal playa deposits, the most important boundaries are correlated to transgressive surfaces that developed during playa expansion. Time gaps represented by the boundaries and the scale of erosion below them, are difficult to estimate. The depositional system of the Upper Rotliegend was dominated by sand and sand-gravel sheets, and is either a unique feature in the entire Southern Permian Basin or, as we assume, sand sheets occur more com monly in the Rotliegend than has been previously thought

Evolution of the Rotliegend Basin of northwestern Poland

The Rotliegend Basin of northwestern Poland is characterized by a complex structure that reflects syndepositional reactivation of fault systems related to the Teisseyre-Tornquist (TTZ) and Sorgenfrei-Tornquist (STZ) zones. This basin is superimposed on the Caledonian Trans-European Suture Zone and encroaches eastward onto the East European Craton and southwestward onto the Variscan Externides. Latest Carboniferous and Early Permian sinistral wrench movements along the TTZ and STZ, causing disruption and erosional truncation of the Variscan foreland basin and the external Variscan fold-and-thrust belt, were accompanied by the extrusion of voluminous volcanics. During the deposition of the Upper Rotliegend sediments, earlier formed fault systems were recurrently reactivated, controlling the subsidence of an array of troughs and uplift of horst blocks. During deposition of the upper parts of the Upper Rotliegend, when tectonic activity had abated, subsidence and broadening of the Polish Basin was controlled by thermal relaxation of the lithosphere. Analysis of wireline logs, calibrated by cores, and their regional correlations permits to distinguish nine successive Upper Rotliegend depositional cycles. These involve alluvial fan, fluvial, lacustrine, playa-lake and aeolian deposits and are separated by conspicuous lithofacies and/or erosional boundaries. Lithofacies maps developed for each of these depositional cycles allowed to retrace the palaeogeographic evolution of the Polish Rotliegend Basin, with supporting cross-sections providing insight into its structural development. Palaeoclimatic factors, such as rapid humidity changes, combined with tectonic activity, played an important role in the development of the different depositional cycles and their boundaries. Tectonics controlled the development of accommodation space and the lack thereof, as well as uplift and erosion of clastic source areas. The Polish and North German Rotliegend basins were separated during the deposition of the Drawa (Parchim and Mirow) and the earlier part of the Noteć (Rambow and Eldna) formations by the vast area of palaeohigh. Subsequently this high was overstepped by sediments of the upper part of the Noteć (Peckensen and Mellin) Formation, resulting in the coalescence of these basins. A tentative correlation of depositional cycles evident in the Polish and North German Rotliegend basins is presented