1,343 research outputs found

    Polar coralline algal CaCO<sub>3</sub>-production rates correspond to intensity and duration of the solar radiation

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    In this study we present a comparative quantification of CaCO3 production rates by rhodolith-forming coralline red algal communities situated in high polar latitudes and assess which environmental parameters control these production rates. The present rhodoliths act as ecosystem engineers, and their carbonate skeletons provide an important ecological niche to a variety of benthic organisms. The settings are distributed along the coasts of the Svalbard archipelago, being Floskjeret (78◦180N) in Isfjorden, Krossfjorden (79◦080N) at the eastern coast of Haakon VII Land, Mosselbukta (79◦530N) at the eastern coast of Mosselhalvøya, and Nordkappbukta (80◦310N) at the northern coast of Nordaustlandet. All sites feature Arctic climate and strong seasonality

    Data report: bulk mineralogical composition of Cascadia margin sediments, IODP Expedition 311

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    The bulk mineralogical compositions of sediment samples from Sites U1325–U1329, northern Cascadia margin, were determined by X-ray diffraction analyses. The results document a highly variable mineralogy dominated by detrital components, mainly quartz, feldspar, mica, and clay minerals. Carbonate minerals are present only in minor amounts (<5 wt%). The long-term variations in the relative abundance of each mineral correspond to the particular lithostratigraphic units

    Anticholinesterase activity of endemic plant extracts from Soqotra

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    A total of 30 chloroform and methanol extracts from the following endemic Soqotran plants Acridocarpus socotranus Olive, Boswellia socotranao Balf.fil, Boswellia elongata Balf. fil., Caralluma socotrana N. Br, Cephalocroton socotranus Balf.f, Croton socotranus Balf. fil.., Dendrosicycos socotrana Balf.f., Dorstenia gigas Schweinf. ex Balf. fil., Eureiandra balfourii Cogn. & Balf. fil., Kalanchoe farinaceae Balf.f, Limonium sokotranum (Vierh) Radcl. Sm), Oldenlandia pulvinata, Pulicaria diversifolia( Balf. and Pulicaria stephanocarpa Balf. were screened for their acetylcholinesterase inhibitory activity by using in vitro Ellman method at 50 and 200 μg/ml concentrations. Chloroform extracts of Croton socotranus, Boswellia socotrana, Dorstenia gigas, and Pulicaria stephanocarpa as well as methanol extracts of Eureiandra balfourii exhibited inhibitory activities higher than 50 % at concentration of 200 μg. At a concentrations of 50 μg, the chloroform extract of Croton socotranus exhibited an inhibition of 40.6 %.Key words: plant extracts, acetylcholinesterase inhibitors, Soqotra, Alzheimer’s diseas

    MS

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    thesisThe Stansbury Mountains consist of a single north-south trend­ing range located west of Tooele, Utah. Approximately 70 square miles of the southern Stansbury Mountains were mapped and studied for this report. A section of Paleozoic rocks, in excess of 27,000 feet is present. This includes 4,800+ feet of Cambrian (not includ­ing several thousand feet of unmeasured Tintic quartzite), 1,600+ feet of Ordovician, 600+ feet of Silurian, 600+ feet of Devonian, 3,400+feet of Mississippian (not including 1,200+ feet of unmeasur­ed Manning Canyon shale), and 14,000+feet of Pennsylvanian. Due to a pre-Mississippian uplift, Ordovician, Silurian, and Devonian rocks are absent in the central part of the range. The basal Mississippian rocks rest unconformably on Cambrian beds. Late Devonian beds, where present, are represented by a coarse conglomerate referred to as the Stansbury conglomerate. This formation which is hundreds of feet thick at the north end of the range, thins to a few tens of feet at the south end. Precambrian, Mesozozic and Tertiary rocks are not exposed in the area studied. Quaternary deposits includes pre-Lake Bonneville fan gravels, Lake Bonneville beds, creep and glacial deposits, Recent sand dune deposits and alluvium. Structurally the range consists of a north-south anticline. At the south end following folding., the west limb was removed by Laramide thrusting. Also during the Laramide period, high angle northwest- southeast normal faulting occurred. Later Basin and Range normal type faults roughly parallel the Laramide faults and fold structures

    Measures of implicit cognition for marketing research

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    Automatic, unconscious processes largely influence human decision-making. However, quantitative market research focuses on eliciting conscious responses. This foregoes the opportunity to investigate - and steer - preceding cognitive processes of decision-making. Three implicit cognitions are of special relevance along consumers' journey: Implicit attention introduces the first perception of a stimulus. Implicit associations can cause attitude and preference formation. Finally, approach tendencies can induce impulse buying. This paper provides a broad methodological overview of these implicit cognition measures to guide future researchers' marketing applications. It presents the methods' theoretical foundations, outlines how they can overcome explicit measures' limitations, and sketches their potential for marketing applications. In addition, the authors describe important research paradigms, alternative experimental setups, and data analyses steps to enable researchers to use implicit measurement tools. The measurement instruments are implemented in a non-profit software (AskYourBrain) and tested in an illustrative study. Key findings are summarized and marketing application suggestions made

    Pygmy dipole strength close to particle-separation energies - the case of the Mo isotopes

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    The distribution of electromagnetic dipole strength in 92, 98, 100 Mo has been investigated by photon scattering using bremsstrahlung from the new ELBE facility. The experimental data for well separated nuclear resonances indicate a transition from a regular to a chaotic behaviour above 4 MeV of excitation energy. As the strength distributions follow a Porter-Thomas distribution much of the dipole strength is found in weak and in unresolved resonances appearing as fluctuating cross section. An analysis of this quasi-continuum - here applied to nuclear resonance fluorescence in a novel way - delivers dipole strength functions, which are combining smoothly to those obtained from (g,n)-data. Enhancements at 6.5 MeV and at ~9 MeV are linked to the pygmy dipole resonances postulated to occur in heavy nuclei.Comment: 6 pages, 5 figures, proceedings Nuclear Physics in Astrophysics II, May 16-20, Debrecen, Hungary. The original publication is available at www.eurphysj.or

    Hierarchy of adhesion forces in patterns of photoreactive surface layers

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    Precise control of surface properties including electrical characteristics, wettability, and friction is a prerequisite for manufacturing modern organic electronic devices. The successful combination of bottom up approaches for aligning and orienting the molecules and top down techniques to structure the substrate on the nano and micrometer scale allows the cost efficient fabrication and integration of future organic light emitting diodes and organic thin film transistors. One possibility for the top down patterning of a surface is to utilize different surface free energies or wetting properties of a functional group. Here, we used friction force microscopy (FFM) to reveal chemical patterns inscribed by a photolithographic process into a photosensitive surface layer. FFM allowed the simultaneous visualization of at least three different chemical surface terminations. The underlying mechanism is related to changes in the chemical interaction between probe and film surface.Comment: 11 pages, 5 figures The following article has been submitted to Journal of Chemical Physics. After it is published, it will be found at http://jcp.aip.org
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