Calcium influx inhibits MT1-MMP processing and blocks MMP-2 activation

We have previously reported that concanavalin A (ConA)-induced MMP-2 activation involves both transcriptional and non-transcriptional mechanisms. Here we examined the effects of calcium influx on MT1-MMP expression and MMP-2 activation in MDA-MB-231 cells. The calcium ionophore ionomycin caused a dose-dependent inhibition of ConA-induced MMP-2 activation, but had no effect on MT1-MMP mRNA levels. However, Western analysis revealed an accumulation of pro-MT1-MMP (63 kDa), indicating that ionomycin blocked the conversion of pro-MT1-MMP protein to the active 60 kDa form. This suggests that increased calcium levels inhibit the processing of MT1-MMP. This finding may help to elucidate the mechanism(s) which regulates MT1-MMP activation.

Low-temperature plasma processing for Si photovoltaics

There has been a recent rapid expansion of the range of applications of low-temperature plasma processing in Si-based photovoltaic (PV) technologies. The desire to produce Si-based PV materials at an acceptable cost with consistent performance and reproducibility has stimulated a large number of major research and research infrastructure programs, and a rapidly increasing number of publications in the field of low-temperature plasma processing for Si photovoltaics. In this article, we introduce the low-temperature plasma sources for Si photovoltaic applications and discuss the effects of low-temperature plasma dissociation and deposition on the synthesis of Si-based thin films. We also examine the relevant growth mechanisms and plasma diagnostics, Si thin-film solar cells, Si heterojunction solar cells and silicon nitride materials for antireflection and surface passivation. Special attention is paid to the low-temperature plasma interactions with Si materials including hydrogen interaction, wafer cleaning, masked or mask-free surface texturization, the direct formation of p-n junction, and removal of phosphorus silicate glass or parasitic emitters. The chemical and physical interactions in such plasmas with Si surfaces are analyzed. Several examples of the plasma processes and techniques are selected to represent a variety of applications aimed at the improvement of Si-based solar cell performance. © 2014 Elsevier B.V.

Nanopore processing in dielectric materials and dielectric template-assisted nanoarray synthesis : using pulsed bias to enhance process throughput and precision

An effective technique to improve the precision and throughput of energetic ion condensation through dielectric nanoporous templates and reduce nanopore clogging by using finely tuned pulsed bias is proposed. Multiscale numerical simulations of ion deposition show the possibility of controlling the dynamic charge balance on the upper template's surface to minimize ion deposition on nanopore sidewalls and to deposit ions selectively on the substrate surface in contact with the pore opening. In this way, the shapes of nanodots in template-assisted nanoarray fabrication can be effectively controlled. The results are applicable to various processes involving porous dielectric nanomaterials and dense nanoarrays.

Self-assembled low-dimensional nanomaterials via low-temperature plasma processing

Examples of successful fabrication of low-dimensional semiconducting nanomaterials in the Integrated Plasma-Aided Nanofabrication Facility are shown. Self-assembled size-uniform ZnO nanoparticles, ultra-high-aspect ratio Si nanowires, vertically aligned cadmium sulfide nanostructures, and quarternary semiconducting SiCAlN nanomaterial have been synthesized using inductively coupled plasma-assisted RF magnetron sputtering deposition. The observed increase in crystallinity and growth rates of the nanostructures are explained by using a model of plasma-enhanced adatom surface diffusion under conditions of local energy exchange between the ion flux and the growth surface. Issues related to plasma-based growth of low-dimensional semiconducting nanomaterials are discussed as well. © 2007 Elsevier B.V. All rights reserved.

The role of the posterior superior temporal sulcus in audiovisual processing

In this study we investigate previous claims that a region in the left posterior superior temporal sulcus (pSTS) is more activated by audiovisual than unimodal processing. First, we compare audiovisual to visual-visual and auditory-auditory conceptual matching using auditory or visual object names that are paired with pictures of objects or their environmental sounds. Second, we compare congruent and incongruent audiovisual trials when presentation is simultaneous or sequential. Third, we compare audiovisual stimuli that are either verbal (auditory and visual words) or nonverbal (pictures of objects and their associated sounds). The results demonstrate that, when task, attention, and stimuli are controlled, pSTS activation for audiovisual conceptual matching is 1) identical to that observed for intramodal conceptual matching, 2) greater for incongruent than congruent trials when auditory and visual stimuli are simultaneously presented, and 3) identical for verbal and nonverbal stimuli. These results are not consistent with previous claims that pSTS activation reflects the active formation of an integrated audiovisual representation. After a discussion of the stimulus and task factors that modulate activation, we conclude that, when stimulus input, task, and attention are controlled, pSTS is part of a distributed set of regions involved in conceptual matching, irrespective of whether the stimuli are audiovisual, auditory-auditory or visual-visual.

Dissociating verbal and nonverbal audiovisual object processing

This fMRI study investigates how audiovisual integration differs for verbal stimuli that can be matched at a phonological level and nonverbal stimuli that can be matched at a semantic level. Subjects were presented simultaneously with one visual and one auditory stimulus and were instructed to decide whether these stimuli referred to the same object or not. Verbal stimuli were simultaneously presented spoken and written object names, and nonverbal stimuli were photographs of objects simultaneously presented with naturally occurring object sounds. Stimulus differences were controlled by including two further conditions that paired photographs of objects with spoken words and object sounds with written words. Verbal matching, relative to all other conditions, increased activation in a region of the left superior temporal sulcus that has previously been associated with phonological processing. Nonverbal matching, relative to all other conditions, increased activation in a right fusiform region that has previously been associated with structural and conceptual object processing. Thus, we demonstrate how brain activation for audiovisual integration depends on the verbal content of the stimuli, even when stimulus and task processing differences are controlled.

Nanofabrication of single-crystalline flat-panel display microemitters : a plasma-building unit approach

This contribution is focused on plasma-enhanced chemical vapor deposition systems and their unique features that make them particularly attractive for nanofabrication of flat panel display microemitter arrays based on ordered patterns of single-crystalline carbon nanotip structures. The fundamentals of the plasma-based nanofabrication of carbon nanotips and some other important nanofilms and nanostructures are examined. Specific features, challenges, and potential benefits of using the plasma-based systems for relevant nanofabrication processes are analyzed within the framework of the "plasma-building unit" approach that builds up on extensive experimental data on plasma diagnostics and nanofilm/nanostructure characterization, and numerical simulation of the species composition in the ionized gas phase (multicomponent fluid models), ion dynamics and interaction with ordered carbon nanotip patterns, and ab initio computations of chemical structure of single crystalline carbon nanotips. This generic approach is also applicable for nanoscale assembly of various carbon nanostructures, semiconductor quantum dot structures, and nano-crystalline bioceramics. Special attention is paid to most efficient control strategies of the main plasma-generated building units both in the ionized gas phase and on nanostructured deposition surfaces. The issues of tailoring the reactive plasma environments and development of versatile plasma nanofabrication facilities are also discussed.

Unbalance identification in large steam turbo-generator unit using a model-based method

Fault identification in industrial machine is a topic of major importance under engineering point of view. In fact, the possibility to identify not only the type, but also the severity and the position of a fault occurred along a shaft-line allows quick maintenance and shorten the downtime. This is really important in the power generation industry where the units are often of several tenths of meters long and where the rotors are enclosed by heavy and pressure-sealed casings. In this paper, an industrial experimental case is presented related to the identification of the unbalance on a large size steam turbine of about 1.3 GW, belonging to a nuclear power plant. The case history is analyzed by considering the vibrations measured by the condition monitoring system of the unit. A model-based method in the frequency domain, developed by the authors, is introduced in detail and it is then used to identify the position of the fault and its severity along the shaft-line. The complete model of the unit (rotor – modeled by means of finite elements, bearings – modeled by linearized damping and stiffness coefficients and foundation – modeled by means of pedestals) is analyzed and discussed before being used for the fault identification. The assessment of the actual fault was done by inspection during a scheduled maintenance and excellent correspondence was found with the identified one by means of authors’ proposed method. Finally a complete discussion is presented about the effectiveness of the method, even in presence of a not fine tuned machine model and considering only few measuring planes for the machine vibration.

Independent functions of yeast Pcf11p in pre-mRNA 3' end processing and in transcription termination

Pcf11p, an essential subunit of the yeast cleavage factor IA, is required for pre‐mRNA 3′ end processing, binds to the C‐terminal domain (CTD) of the largest subunit of RNA polymerase II (RNAP II) and is involved in transcription termination. We show that the conserved CTD interaction domain (CID) of Pcf11p is essential for cell viability. Interestingly, the CTD binding and 3′ end processing activities of Pcf11p can be functionally uncoupled from each other and provided by distinct Pcf11p fragments in trans. Impaired CTD binding did not affect the 3′ end processing activity of Pcf11p and a deficiency of Pcf11p in 3′ end processing did not prevent CTD binding. Transcriptional run‐on analysis with the CYC1 gene revealed that loss of cleavage activity did not correlate with a defect in transcription termination, whereas loss of CTD binding did. We conclude that Pcf11p is a bifunctional protein and that transcript cleavage is not an obligatory step prior to RNAP II termination.

ZnO layers for opto-electronic applications from solution-based and low-temperature processing of an organometallic precursor

As printed and flexible plastic electronic gadgets become increasingly viable today, there is a need to develop materials that suit the fabrication processes involved. Two desirable requirements are solution-processable active materials or precursors and low-temperature processability. In this article, we describe a straightforward method of depositing ZnO films by simple spin coating of an organometallic diethylzinc precursor solution and annealing the resulting film at low temperatures (≤200 °C) without involving any synthetic steps. By controlling the humidity in which annealing is conducted, we are able to adjust the intrinsic doping level and carrier concentration in diethylzinc-derived ZnO. Doped or conducting transport layers are greatly preferable to undoped layers as they enable low-resistance contacts and minimize the potential drops. This ability to controllably realize doped ZnO is a key feature of the fabrication process that we describe in this article. We employ field-effect measurements as a diagnostic tool to measure doping levels and mobilities in ZnO and demonstrate that doped ZnO with high charge carrier concentration is ideal for solar cell applications. Respectable power conversion efficiencies (up to 4.5%) are achieved in inverted solar cells that incorporate diethylzinc-derived ZnO films as the electron transport layer and organic blends as the active material. Extensions of this approach to grow ternary and quaternary films with organometallic precursor chemicals will enable solution based growth of a number of semiconductor films as well as a method to dope them.

4-hexylbithieno[3,2-b:2′3′-e]pyridine: An efficient electron-accepting unit in fluorene and indenofluorene copolymers for light-emitting devices

4-Hexylbithienopyridine has been prepared as a novel electron-accepting monomer for conjugated polymers. To test its electronic properties, alternating copolymers with fluorene and indenofluorene polymers have been prepared. The copolymers displayed reduction potentials about 0.5 V lower than for the corresponding fluorene and indenofluorene homopolymers, indicating much improved electron-accepting properties. Analysis of the microscopic morphology of thin films of the copolymers by AFM shows that they lack the extensive supramolecular order seen with the homopolymers, which is attributed to the bithienopyridine units disrupting the π-stacking. LEDs using these polymers as the emitting layer produce blue-green emission with low turn-on voltages with aluminum electrodes confirming their improved electron affinity. The indenofluorene copolymer displayed an irreversible red shift in emission at high voltages, which is attributed to oxidation of the indenofluorene units. This red shift occurred at higher potentials than for indenofluorene homopolymers in LEDs, suggesting that the heterocyclic moieties offer some protection against electrically promoted oxidation.

Developments in mud filtration technology in the sugarcane industry

Dirt collected with sugarcane is processed and separated from the juice in the sugar factory by filtration equipment for return to the cane fields. New technologies over the past decade have enabled performance improvements to be obtained for this key unit operation. Filter mud product still contains a reasonable amount of sugar and the transportation of high moisture mud product has considerable cost. Australia’s traditional approach has been to use Rotary Vacuum Filters for processing and separating mud and other impurities from juice, but in recent years there has been interest in reducing sugar losses and transportation costs through utilisation of new technologies such as Horizontal Bed Filters, Vacuum Belt Press Filters, Membrane Press Filters and Centrifuges. Increasingly, these alternative equipment are being installed in new factories. This chapter describes the general principles of mud filtration theory and mud conditioning followed by a detailed description and review of the various filtration technologies and analysis of the relative merits associated with the equipment.

Rescaling clustering trees using impact ratios for robust hierarchical speaker clustering

We present a novel method for improving hierarchical speaker clustering in the tasks of speaker diarization and speaker linking. In hierarchical clustering, a tree can be formed that demonstrates various levels of clustering. We propose a ratio that expresses the impact of each cluster on the formation of this tree and use this to rescale cluster scores. This provides score normalisation based on the impact of each cluster. We use a state-of-the-art speaker diarization and linking system across the SAIVT-BNEWS corpus to show that our proposed impact ratio can provide a relative improvement of 16% in diarization error rate (DER).

Organizations as distinction generating and processing systems : Niklas Luhmann's contribution to organization studies

Niklas Luhmann's theory of social systems has been widely influential in the German-speaking countries in the past few decades. However, despite its significance, particularly for organization studies, it is only very recently that Luhmann's work has attracted attention on the international stage as well. This Special Issue is in response to that. In this introductory paper, we provide a systematic overview of Luhmann's theory. Reading his work as a theory about distinction generating and processing systems, we especially highlight the following aspects: (i) Organizations are processes that come into being by permanently constructing and reconstructing themselves by means of using distinctions, which mark what is part of their realm and what not. (ii) Such an organizational process belongs to a social sphere sui generis possessing its own logic, which cannot be traced back to human actors or subjects. (iii) Organizations are a specific kind of social process characterized by a specific kind of distinction: decision, which makes up what is specifically organizational about organizations as social phenomena. We conclude by introducing the papers in this Special Issue. Copyright © 2006 SAGE.