2,473 research outputs found
The influence of distraction on speech processing: How selective is selective attention?
-* indicates shared first authorship - The present study investigated the effects of selective attention on the processing of morphosyntactic errors in unattended parts of speech. Two groups of German native (L1) speakers participated in the present study. Participants listened to sentences in which irregular verbs were manipulated in three different conditions (correct, incorrect but attested ablaut pattern, incorrect and crosslinguistically unattested ablaut pattern). In order to track fast dynamic neural reactions to the stimuli, electroencephalography was used. After each sentence, participants in Experiment 1 performed a semantic judgement task, which deliberately distracted the participants from the syntactic manipulations and directed their attention to the semantic content of the sentence. In Experiment 2, participants carried out a syntactic judgement task, which put their attention on the critical stimuli. The use of two different attentional tasks allowed for investigating the impact of selective attention on speech processing and whether morphosyntactic processing steps are performed automatically. In Experiment 2, the incorrect attested condition elicited a larger N400 component compared to the correct condition, whereas in Experiment 1 no differences between conditions were found. These results suggest that the processing of morphosyntactic violations in irregular verbs is not entirely automatic but seems to be strongly affected by selective attention
Life Of Alexander G. Gurwitsch And His Relevant Contribution To The Theory Of Morphogenetic Fields
Using airborne LiDAR Survey to explore historic-era archaeological landscapes of Montserrat in the eastern Caribbean
This article describes what appears to be the first archaeological application of airborne LiDAR survey to historic-era landscapes in the Caribbean archipelago, on the island of Montserrat. LiDAR is proving invaluable in extending the reach of traditional pedestrian survey into less favorable areas, such as those covered by dense neotropical forest and by ashfall from the past two decades of active eruptions by the Soufrière Hills volcano, and to sites in localities that are inaccessible on account of volcanic dangers. Emphasis is placed on two aspects of the research: first, the importance of ongoing, real-time interaction between the LiDAR analyst and the archaeological team in the field; and second, the advantages of exploiting the full potential of the three-dimensional LiDAR point cloud data for purposes of the visualization of archaeological sites and features
Electrocatalysis of Lithium (Poly-) Sulfides in Organic Ether-Based Electrolytes
This work aims at identifying an effective electrocatalyst for polysulfide reactions to improve the electrode kinetics of the sulfur half-cell in liquid organic electrolytes for alkali-sulfur cells. To increase the charge and discharge rates and energy efficiency of the cell, functionalized electrocatalytic coatings have been prepared and their electrode kinetics have been measured. To the best of our knowledge, there is no extensive screening of electrocatalysts for the sulfur electrode in dimethoxyethane:1,3-dioxolane (DME:DOL) electrolytes. In order to identify a suitable electrocatalyst, apparent exchange current densities at various materials (Al, Co, Cr, Cu, Fe, Steel, glassy carbon, ITO, Ni, Pt, Ti, TiN, Zn) are evaluated in a polysulfide electrolyte using potentiodynamic measurements with a Butler-Volmer fit. The chemical stability and surface morphology changes after electrochemical measurements are assessed with X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The results show that cobalt is a promising candidate with appropriate electrocatalytic properties for polysulfide reactions while being stable in the electrochemical environment, followed by chromium in terms of catalytic activity and stability. Sputtered TiN was found to be a very stable material with very low catalytic activity, a possible current collector for the cell
Transcriptional repression of Hox genes by C. elegans HP1/HPL and H1/HIS-24.
Elucidation of the biological role of linker histone (H1) and heterochromatin protein 1 (HP1) in mammals has been difficult owing to the existence of a least 11 distinct H1 and three HP1 subtypes in mice. Caenorhabditis elegans possesses two HP1 homologues (HPL-1 and HPL-2) and eight H1 variants. Remarkably, one of eight H1 variants, HIS-24, is important for C. elegans development. Therefore we decided to analyse in parallel the transcriptional profiles of HIS-24, HPL-1/-2 deficient animals, and their phenotype, since hpl-1, hpl-2, and his-24 deficient nematodes are viable. Global transcriptional analysis of the double and triple mutants revealed that HPL proteins and HIS-24 play gene-specific roles, rather than a general repressive function. We showed that HIS-24 acts synergistically with HPL to allow normal reproduction, somatic gonad development, and vulval cell fate decision. Furthermore, the hpl-2; his-24 double mutant animals displayed abnormal development of the male tail and ectopic expression of C. elegans HOM-C/Hox genes (egl-5 and mab-5), which are involved in the developmental patterning of male mating structures. We found that HPL-2 and the methylated form of HIS-24 specifically interact with the histone H3 K27 region in the trimethylated state, and HIS-24 associates with the egl-5 and mab-5 genes. Our results establish the interplay between HPL-1/-2 and HIS-24 proteins in the regulation of positional identity in C. elegans males
Developmental changes in neuronal processing of irregular morphosyntactic rules during childhood
Metacarpophalangeal pattern profile analysis in fragile X syndrome
We analyzed the metacarpophalangeal pattern profile (MCPP) on 18 male individuals from 16 families with fragile X—fra (X), or Martin-Bell—syndrome and calculated a mean syndrome profile. Fourteen of 18 individuals with fra (X) syndrome had significant positive correlations which indicated clinical homogeneity. Discriminant analysis of individuals with fra (X) syndrome compared with a sample of normal individuals produced a correct classification rate of 88% based on a function of 3 MCPP variables that may provide a useful tool in screening individuals for the fra (X) syndrome. Discriminant and correlation analyses of individuals with Sotos sequence and individuals with fra (X) syndrome did not identify MCPP similarities. Therefore, there was no MCPP evidence in our study of patients with Sotos sequence and fra (X) chromosome expression
Development of a lectin-affinity chromatography step for the downstream processing of influenza virus vaccines
Influenza remains due to its annual death rate and potential to cause pandemics a major public health concern. Efforts to control the annual spread of influenza have centered on prophylactic vaccinations. Human influenza vaccines are traditionally produced in embryonated hen s eggs. However, major constraints with this method, e.g. allergic reactions induced by egg proteins and lack of scalability have lead to the development of cell culture based production processes. In recent years, several continuous cell lines such as the Madin Darby canine kidney (MDCK) or the African green monkey kidney Vero cells have been successfully established for the production of influenza vaccines in cell culture. These processes require the modification of existing but also the development of new downstream strategies to account for the changed upstream technology. Downstream processing of biological products is conventionally subdivided into three steps: capture or concentration, separation or fractionation and polishing. The capture step is commonly the most expensive unit operation. Hence, the efficiency of this step has a large impact on the total process economics. The presented study focuses on the development of a proficient capture step based on lectin-affinity chromatography. Lectins are a class of carbohydrate specific proteins of non-immune origin that have a selective affinity for a carbohydrate or a group of carbohydrates. Immobilized lectins have been used successfully for many years to separate and isolate glycoconjugates, polysaccharides, soluble cell components, and cells containing glycoproteins with specific carbohydrate structures on its surface. The influenza A virus contains two spike glycoproteins on its surface: hemagglutinin (HA) and neuraminidase (NA). HA is the most abundant surface protein. It is a trimeric glycoprotein containing per subunit 3 to 9 N-linked glycosylation sites depending on the viral strain. Here the influenza A/PR/8/34 virus has been selected as a model. The HA molecule of this particular virus contains according to the NetNGlyc 1.0 Server prediction six glycosylation sites. Detailed analysis of these sites and their individual glycan structures are presently performed. Based on preliminary structural glycan analysis studies and literature data several HA-binding lectins are selected for a pre-screening via lectin-blots. The most promising lectinblot results are obtained from lectins specific for terminal galactose e.g. Erythrina cristagalli (ECL), Arachis hypogaea (PNA). Lectins, by which lectin-blot analysis suggests an interaction with viral membrane proteins, are currently screened for their suitability as an affinity matrix ligand. Therefore, centrifuged cultivation broths of influenza A/PR/8/34 virus infected MDCK cells are applied to various agaroseimmobilized lectins. Components interfering with the immobilized lectins are selectively adsorbed. Non or weak binding components are washed from the column. Subsequently, bound components are dissociated from the lectin by competitive elution with suitable hapten carbohydrates. This fraction contains the influenza virus particles and virally encoded membrane proteins, which have to be further processed for vaccine manufacturing. The extend of the subsequent purification depends on the specificity of the lectin binding to virally encoded surface proteins. Lectins with weak or no interaction with host cell proteins or medium components and strong interaction with viral membrane glycoproteins represent a powerful tool to concentrate and purify viral surface proteins from contaminating nucleic acids, medium components, and non-virally encoded host cell proteins
A comparative investigation of thickness measurements of ultra-thin water films by scanning probe techniques
The reliable operation of micro and nanomechanical devices necessitates a
thorough knowledge of the water film thickness present on the surfaces of these
devices with an accuracy in the nm range. In this work, the thickness of an
ultra-thin water layer was measured by distance tunnelling spectroscopy and
distance dynamic force spectroscopy during desorption in an ultra-high vacuum
system, from about 2.5 nm up to complete desorption at 1E-8 mbar. The
tunnelling current as well as the amplitude of vibration and the normal force
were detected as a function of the probe-sample distance. In these experiments,
a direct conversion of the results of both methods is possible. From the
standpoint of surface science, taking the state-of-the-art concerning
adsorbates on surfaces into consideration, dynamic force spectroscopy provides
the most accurate values. The previously reported tunnelling spectroscopy,
requiring the application of significantly high voltages, generally leads to
values that are 25 times higher than values determined by dynamic force
spectroscopy
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