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The effects of nitrous oxide (N 2 O) in nitrogen (N 2 ) on the development and morphology of sine-driven dielectric barrier discharges in a single-filament arrangement were studied. Detailed insight in the characteristics of the discharge and its development were obtained from electrical measurements combined with ICCD and streak camera recordings as well as numerical modelling. A miniaturised atmospheric pressure Townsend discharge (APTD) could be generated for admixtures up to 5 vol% N 2 O in N 2 although N 2 O is an efficient collisional quencher of metastable nitrogen molecules. Increasing the high voltage amplitude led to a transition into a hybrid mode with the generation of an intermediate filament in addition to the diffuse, non-constricted APTD. A time-dependent, spatially one-dimensional fluid model was applied in order to study the underlying mechanisms causing the diffuse discharge characteristics. It was found that even for small N 2 O admixtures, the associative ionisation of atomic nitrogen and oxygen (O + N( 2 P) → NO + + e) is the major electron source sustaining the volume memory effect and is therefore the reason for the formation of a diffuse APTD. [ABSTRACT FROM AUTHOR]

The preparation of compact and pinhole-free absorber layers is a major step towards device reproducibility and high performance for planar organic-inorganic perovskite solar cells. It is well known that the sequential deposition method exhibits some advantages over the common one-pot synthesis in terms of controlling the surface coverage. However, it still miscarries to produce pinhole-free layers from solution, mainly due to the occurrence of dissolution and recrystallisation processes. We show that by a careful choice of the permittivity of the alcoholic solvent in the conversion step the surface morphology can be finely modified, thereby yielding pinhole-free and compact absorber films comparable to that from vapour-assisted solution techniques. It is observed that the permittivity controls the intensity of the Ostwald ripening effect and that a low value of the former enables an in situ intercalation of precursor materials into the lead halide framework. We successfully prepared smooth and mirror-like perovskite surfaces that demonstrate enhanced optoelectronic properties and photovoltaic performance compared to films from the native two-step deposition in isopropanol. This strategy provides a facile approach for obtaining high-quality layers in the planar architecture by simple solution processing. [ABSTRACT FROM AUTHOR]

Atmospheric‐pressure dielectric barrier discharges (DBDs) in argon with admixtures of small amounts of hexamethyldisiloxane (HMDSO) have been analysed by means of numerical modelling. A time‐dependent, spatially one‐dimensional fluid‐Poisson model has been used, which takes into account the spatial variation of the discharge plasma between the plane‐parallel dielectrics covering the electrodes. Main features of the model, including the reaction kinetics for HMDSO, are given. Good agreement with related experimental studies of the ignition voltage for HMDSO amounts of up to 200 ppm and the temporal course of the discharge current for conditions typical of deposition experiments is obtained by the model calculations when assuming that 30% of the reactions of HMDSO with excited argon atoms, with a rate coefficient of 5.0 × 10−10 cm3/s, lead to the production of electrons due to Penning ionization. The modelling results for constant frequency f = 86.2 kHz and applied voltage Ua = 4 kV show that the electrical energy dissipated in the DBD decreases with an increasing amount of HMDSO and enable the determination of the energy absorbed per HMDSO molecule on the basis of their energy balance. The analysis of the plasma–chemical processes also makes clear that collision processes of HMDSO with excited argon atoms and molecules leading to neutral reaction products are essential for the formation of thin polymer films. [ABSTRACT FROM AUTHOR]

The development of hybrid organic–inorganic perovskite solar cells is one of the most rapidly growing fields in the photovoltaic community and is on its way to challenge polycrystalline silicon and thin film technologies. High power conversion efficiencies can be achieved by simple processing with low cost. However, due to the limited long-term stability and environmental toxicity of lead in the prototypic CH3NH3PbI3, there is a need to find alternative ABX3 constitutional combinations in order to promote commercialization. The Goldschmidt tolerance factor and the octahedral factor were found to be necessary geometrical concepts to evaluate which perovskite compounds can be formed. It was figured out that the main challenge lies in estimating an effective ionic radius for the molecular cation. We calculated tolerance factors and octahedral factors for 486 ABX3 monoammonium–metal–halide combinations, where the steric size of the molecular cation in the A-position was estimated concerning the total charge density. A thorough inquiry about existing mixed organic–inorganic perovskites was undertaken. Our results are in excellent agreement with the reported hybrid compounds and indicate the potential existence of 106 ABX3 combinations hitherto not discussed in the literature, giving hints for more intense research on prospective individual candidates. [ABSTRACT FROM AUTHOR]

A precise and reliable assessment of acne severity is unarguably the most essential clinical method when it comes to monitoring and choosing optimal treatment in the daily practice. Since the early 1960s, different severity assessment systems have been described in the literature. The two commonly used concepts are global gradings and lesion counting. Both systems have been controversially discussed as to which is more reliable and providing an objective outcome measurement tool; however, both have some subjectivity involved. More objective methods for assessing the severity of acne vulgaris include photography, fluorescence photography, polarized light photography, video microscopy, and multispectral imaging. Such techniques have limitations such as high cost, complex and sophisticated apparatus, and a sometimes time-consuming imaging process. There are newly developed technologies that could avoid the problems of inter- and intrarater subjectivity. [ABSTRACT FROM AUTHOR]

It is generally thought that children learn more efficiently than adults. One way to accomplish this is to have learning rapidly stabilized such that it is not interfered with by subsequent learning. Although γ-aminobutyric acid (GABA) plays an important role in stabilization, it has been reported that GABAergic inhibitory processing is not fully matured yet in children compared with adults. Does this finding indicate that more efficient learning in children is not due to more rapid stabilization? Here, we measured the concentration of GABA in early visual cortical areas in a time-resolved fashion before, during, and after visual perceptual learning (VPL) within subjects using functional MRS (fMRS) and then compared the concentrations between children (8 to 11 years old) and adults (18 to 35 years old). We found that children exhibited a rapid boost of GABA during visual training that persisted after training ended, whereas the concentration of GABA in adults remained unchanged. Moreover, behavioral experiments showed that children exhibited rapid development of resilience to retrograde interference, which indicates that children stabilize VPL much faster than adults. These results together suggest that inhibitory processing in children's brains is more dynamic and adapts more quickly to stabilize learning than in adults, making learning more efficient in children. [Display omitted] • Visual perceptual learning (VPL) is more efficient in children than adults • VPL is stabilized more rapidly in children than adults • Stabilization of VPL in children is supported by a rapid boost of GABA • This boost of GABA occurs during and after visual training in children Frank et al. find that visual perceptual learning (VPL) is more efficient in children than adults due to more rapid stabilization of VPL in children. A boost of GABA in visual cortex during and after training supports this rapid stabilization in children. [ABSTRACT FROM AUTHOR]

Abstract: The homotrimeric, secondary active betaine carrier BetP from Corynebacterium glutamicum is a model system for stress-regulated transport in bacteria. Its activity responds to hyperosmotic stress and it harbors two different functions, transport catalysis (betaine uptake) and stimulus sensing, resp. activity regulation. Structural information from 2D and 3D crystals as well as functional analysis of monomerized BetP suggested the presence of conformational crosstalk between the individual protomers. To study whether the oligomeric state is functionally significant on a mechanistic level we generated heterooligomeric complexes of BetP in which single protomers within the trimer can be addressed. By testing dominant negative effects in a trimer of one active protomer combined with two protomers in which transport and regulation were abolished, we provide experimental evidence for the absence of functionally significant conformational crosstalk between the protomers on the level of both transport and regulation. This is supported by experiments using mutant forms of putative interacting signal donor and acceptor domains of individual BetP protomers. This result has important consequences for oligomeric transport proteins in general and BetP in particular. [Copyright &y& Elsevier]

Potassium accumulation is an essential aspect of bacterial response to diverse stress situations; consequently its uptake plays a pivotal role. Here, we show that the Gram-positive soil bacterium Corynebacterium glutamicum which is employed for the large-scale industrial production of amino acids requires potassium under conditions of ionic and non-ionic osmotic stress. Besides the accumulation of high concentrations of potassium contributing significantly to the osmotic potential of the cytoplasm, we demonstrate that glutamate is not the counter ion for potassium under these conditions. Interestingly, potassium is required for the activation of osmotic stress-dependent expression of the genes betP and proP. The Kup-type potassium transport system which is present in C. glutamicum in addition to the potassium channel CglK does not contribute to potassium uptake at conditions of hyperosmotic stress. Furthermore, we established a secondary carrier of the KtrAB type from C. jeikeium in C. glutamicum thus providing an experimental comparison of channel- and carrier-mediated potassium uptake under osmotic stress. While at low potassium availability, the presence of the KtrAB transporter improves both potassium accumulation and growth of C. glutamicum upon osmotic stress, at proper potassium supply, the channel CglK is sufficient. [ABSTRACT FROM AUTHOR]

The article discusses a study which analyzed the effects of the plasminogen activator inhibitor type 1 (PAI-1) on the prognosis of patients with transitional cell carcinoma (TCC) of the urinary bladder. It shows that the elevated gene expression in tissues and plasma protein levels of patients with TCC were not associated with the clinical characteristics of bladder TCC. It also reveals that the detection of single PAI-1-positive cells may be a predictor of survival and an indication of metastasis.

Abstract: The concept of organizational routine can foster our understanding of the behavior of organizations and of organizational change [Nelson, R.R., Winter, S.G., 1982. An Evolutionary Theory of Economic Change. Belknap Press/Harvard University Press, Cambridge; March, J.G., Simon, H.A., 1958. Organizations. Blackwell, Oxford (1993); Cyert, R.M., March, J.G., 1963. A Behavioral Theory of the Firm. Blackwell, Oxford (1992)], but since empirical studies employing organizational routines as analytical perspective are still relatively rare, how to conduct such an analysis and what are its benefits is not yet fully evident. We wish to shed light on how employing routines contributes to understanding the behavior of organizations and to demonstrate the potential of such analysis. The empirical analysis of the product development process at an engineering centre shows that using organizational routines presents advantages over alternative analytical approaches. The paper also contributes to shed light on how to fruitfully employ an organizational routines perspective in analyzing the behavior of organizations, providing the foundation for further empirical work. [Copyright &y& Elsevier]

Abstract: We present a new approach for efficient collision handling of meshless objects undergoing geometric deformation. The presented technique is based on bounding sphere hierarchies. We show that information of the geometric deformation model can be used to significantly accelerate the hierarchy update. The cost of the presented hierarchy update depends on the number of primitives in close proximity, but not on the total number of primitives. Further, the hierarchical collision detection is combined with a level-of-detail response scheme. Since the collision response can be performed on any level of the hierarchy, it allows for balancing accuracy and efficiency. Thus, the collision handling scheme is particularly useful for time-critical applications. [Copyright &y& Elsevier]

The electrical discharge characteristics of a large‐area experimental dielectric barrier discharge in argon–hexamethyldisiloxane mixtures containing up to about 1,600 ppm of the monomer is analysed by means of electrical measurements and numerical modelling. A time‐dependent, spatially one‐dimensional fluid model is employed, taking into account the spatial variation of the discharge plasma between the two plane‐parallel dielectrics covering the electrodes. Reasonable agreement between electrical measurements and modelling results is generally found for the gap voltages and discharge currents. Remaining differences between the measured and calculated electrical energy dissipated in the plasma per period are discussed. [ABSTRACT FROM AUTHOR]

This paper describes the behaviour of the plasma parameters of microarcs generated between a cooled copper anode and a ceriated tungsten cathode by means of a one‐dimensional unified non‐equilibrium model for gap lengths between 15 and 200 μm and current densities from 2 × 105 up to 106 A/m2. The results obtained show that the decrease of the gap length to a few tens of micrometres for a given current density results in a progressive shrinking of the quasi‐neutral bulk in the microplasma and its complete disappearance. The decrease of the gap length further leads to an increase of the discharge voltage and the electron temperature and to slightly less heating of the gas. [ABSTRACT FROM AUTHOR]

Current animal protection laws require replacement of animal experiments with alternative methods, whenever such methods are suitable to reach the intended scientific objective. However, searching for alternative methods in the scientific literature is a time-consuming task that requires careful screening of an enormously large number of experimental biomedical publications. The identification of potentially relevant methods, e.g. organ or cell culture models, or computer simulations, can be supported with text mining tools specifically built for this purpose. Such tools are trained (or fine tuned) on relevant data sets labeled by human experts. We developed the GoldHamster corpus, composed of 1,600 PubMed (Medline) articles (titles and abstracts), in which we manually identified the used experimental model according to a set of eight labels, namely: "in vivo", "organs", "primary cells", "immortal cell lines", "invertebrates", "humans", "in silico" and "other" (models). We recruited 13 annotators with expertise in the biomedical domain and assigned each article to two individuals. Four additional rounds of annotation aimed at improving the quality of the annotations with disagreements in the first round. Furthermore, we conducted various machine learning experiments based on supervised learning to evaluate the corpus for our classification task. We obtained more than 7,000 document-level annotations for the above labels. After the first round of annotation, the inter-annotator agreement (kappa coefficient) varied among labels, and ranged from 0.42 (for "others") to 0.82 (for "invertebrates"), with an overall score of 0.62. All disagreements were resolved in the subsequent rounds of annotation. The best-performing machine learning experiment used the PubMedBERT pre-trained model with fine-tuning to our corpus, which gained an overall f-score of 0.83. We obtained a corpus with high agreement for all labels, and our evaluation demonstrated that our corpus is suitable for training reliable predictive models for automatic classification of biomedical literature according to the used experimental models. Our SMAFIRA - "Smart feature-based interactive" - search tool (https://smafira.bf3r.de) will employ this classifier for supporting the retrieval of alternative methods to animal experiments. The corpus is available for download (https://doi.org/10.5281/zenodo.7152295), as well as the source code (https://github.com/mariananeves/goldhamster) and the model (https://huggingface.co/SMAFIRA/goldhamster). [ABSTRACT FROM AUTHOR]

We studied the requirement for potassium and for potassium transport activity for the biotechnologically important bacterium Corynebacterium glutamicum, which is used for large-scale production of amino acids. Different from many other bacteria, at alkaline or neutral pH, C. glutamicum is able to grow without the addition of potassium, resulting in very low cytoplasmic potassium concentrations. In contrast, at acidic pH, the ability for growth was found to depend on the presence of K+. For the first time, we provide experimental evidence that a potential potassium channel (CglK) acts as the major potassium uptake system in a bacterium and proved CglK's function directly in its natural membrane environment. A full-length CglK protein and a separate soluble protein harboring the RCK domain can be translated from the cglK gene, and both are essential for full CglK functionality. As a reason for potassium-dependent growth limitation at acidic pH, we identified the impaired capacity for internal pH homeostasis, which depends on the availability and internal accumulation of potassium. Potassium uptake via CglK was found to be relevant for major physiological processes, like the activity of the respiratory chain, and to be crucial for maintenance of the internal pH, as well as for the adjustment of the membrane potential in C. glutamicum. [ABSTRACT FROM AUTHOR]

Im Rahmen eines Ringversuchs wurden verschiedene Strukturdefekte und Einbauteile in Elementwände eingebaut. Die Messung der Wände erfolgte anschließend durch mehrere Messteams mit unterschiedlichen zerstörungsfreien Prüfverfahren. Zum Einsatz kamen hierbei das Ultraschall-Echo- und das Impact-Echo-Verfahren sowie das Impuls-Radar-Verfahren. Zur Verbesserung der Vergleichbarkeit zwischen den unterschiedlichen Prüfverfahren wurde auf die Elementwände ein einheitliches Messraster aufgebracht. Für eine möglichst objektive Messung der Wände erhielten die Messteams vor den Messungen keine Detailinformationen zu den Strukturdefekten oder Einbauteilen. Die Prüfaufgabe bestand darin, die Wände mit dem jeweiligen Prüfverfahren zu untersuchen. Anschließend wurden die Ergebnisse der Messteams zentral gesammelt und ausgewertet. Anhand der zentralen Auswertung sollten Aussagen zu den eingebauten Inhomogenitäten abgeleitet werden. Hierdurch kann zum einen die Leistungsfähigkeit der Prüfverfahren an unterschiedlichsten Inhomogenitäten getestet werden, zum anderen können die Ergebnisse und somit die Prüfverfahren untereinander verglichen werden. Zu diesen in der Praxis immer häufiger vorkommenden Fragestellungen können grundsätzliche Aussagen zum Einsatz von zerstörungsfreien Prüfungen bei Elementwänden erhalten werden. Über die Ergebnisse dieses Ringversuchs wird nachfolgend berichtet. Detection of structural defects and built-in parts in prefabricated walls using non-destructive testing methods In cooperative tests, different structural defects and built-in parts were embedded in prefabricated walls. Series of tests for measurement were conducted by several researchers, using three different non-destructive testing methods: Ultrasonic-Echo, Impact-Echo and Impulse-Radar Technique. To increase comparison between testing methods, a standardized measuring grid was placed on the prefabricated walls. For objective results researchers did not get any detailed information in regard to the structural defects or built-in parts. Testing task was to scan the walls, using the described methods. To derive conclusions about the embedded inhomogeneities, data was centrally selected/pooled and analyzed. Hereby the effectiveness of testing methods can be validated and results hence testing methods can be compared. For the described incidences, essential conclusions can be obtained for using of non-destructive testing methods in prefabricated walls. Results of the investigation will be reported in the following article. [ABSTRACT FROM AUTHOR]

OBJECTIVE To assess the presence of matrix metalloproteinase (MMP)-7 in urine samples of patients with bladder cancer and to investigate the correlation between MMP-7 urine concentration and clinicopathological variables. PATIENTS AND METHODS The presence of MMP-7 in the urine of patients with bladder cancer was tested in 32 representative cases using immunoprecipitation followed by western blot analysis. Urinary MMP-7 concentration levels were analyzed in 132 patients with bladder cancer and 96 controls using an enzyme-linked immunosorbent assay.RESULTS MMP-7 levels did not differ significantly between patients with localized bladder cancer and controls ( P = 0.174). On the other hand, we detected a fourfold, significantly elevated MMP-7 concentration in urine samples of patients with bladder cancer with regional or distant metastasis ( P = 0.003). Using a threshold value of 6.88 ng/ml, determined by receiver-operating characteristic curve analysis, a specificity of 82% and a sensitivity of 78% were observed. Western blot analysis revealed that the 55-kDa tissue inhibitor of metalloproteinase 1 complexed MMP-7 is the dominant form of urinary matrilysin. CONCLUSIONS MMP-7 is present in detectable amounts in the urine of patients with bladder cancer. Its concentrations are significantly elevated in patients with metastatic disease. Determination of urinary matrilysin level could help to detect bladder cancer metastasis, and may therefore provide a more reliable prognosis and influence therapy decisions. [ABSTRACT FROM AUTHOR]

MCPlas is introduced as a powerful tool for automated fluid model generation with application to the analysis of dielectric barrier discharges (DBDs) operating in different regimes. MCPlas consists of a number of Matlab scripts and uses the COMSOL Multiphysics module LiveLink for MATLAB to build up equation-based COMSOL Multiphysics models from scratch. The present contribution highlights how MCPlas is used to implement time-dependent models for nonthermal plasmas in spatially one-dimensional (1-D) and axisymmetric two-dimensional (2-D) geometries and stresses out the benefit of automation of the modeling procedure. The modeling codes generated by MCPlas are used to study diffuse and filamentary DBDs in argon at subatmospheric and atmospheric pressure, respectively. The seamless transition between different levels of model complexity with respect to the considered model geometry is demonstrated. The presented investigation of a single-filament DBD interacting with a dielectric surface shows that complex phenomena of high technological relevance can be tackled using plasma models implemented in COMSOL Multiphysics via MCPlas. [ABSTRACT FROM AUTHOR]

Experimental studies of DBD-based atmospheric-pressure plasma polymerization from mixtures of hexamethyldisiloxane (HMDSO) with argon are presented and interpreted using an analytical model of the plasma-chemical kinetics. Gradient films are obtained using a special DBD-PACVD reactor. Growth-rate profiles and their monomer fraction dependence show that long-living excited Ar species play a major role in the deposition mechanism. Reactions of HMDSO with metastable and resonance argon atoms as well as argon excimers are considered within the presented model which may be simplified by introducing a lumped excited argon species Ar*. Model predictions are compared with experimental results. Recombination reactions must be included in order to reproduce characteristic features of the measured growth-rate curves. [ABSTRACT FROM AUTHOR]

We report a case of a 41-year-old man presenting with persisting fevers over 2 weeks. The patient had spent 4 weeks in Central America. He was in control of a stable stage II sarcoidosis. Laboratory and various microbiological tests as well as chest radiography led to no diagnosis. Activated sarcoidosis was hypothesized as the most likely diagnosis. However, we considered an infectious process as a differential diagnosis, in detail, the travel history imposed histoplasmosis. Chest-CT documented localized interstitial consolidations. Bronchoscopy with bronchoalveolar lavage (BAL) and biopsy was performed. Results of BAL fluid, biopsy, distinct sarcoidosis serum markers and a borderline positive histoplasmosis-serology yielded in a diagnostic dilemma as no distinct diagnosis was drawable. After the patient was already started on a prednisolone trial, the final diagnosis - pulmonary histoplasmosis - could be achieved via positive culture and PCR out of the BAL fluid. This case shows the difficult differentiation between an acute exacerbation of a chronic pulmonary disease and a concomitant infection, which was especially aggravated in this case as the histoplasmosis masqueraded an acute picture of sarcoidosis. [ABSTRACT FROM AUTHOR]

Introduction: Cystoscopy and cytology are standard procedures for diagnosis and follow-up of patients with bladder cancer. Urinary cytodiagnosis is a descriptive method for tumor characterization. We correlated histopathologic diagnosis of noninvasive urothelial carcinomas with cytological evaluation and, furthermore, we validated cytology by cytometric analysis. Patients and Methods: 94 patients with a history of bladder cancer were included in the study. 25 patients were negative for tumors, 22 showed pTa G1 carcinomas, 25 had pTaG2 and 22 patients had G3 carcinomas. All patients underwent cytological and cytometric evaluation. Nuclear diameter and circumference were measured for 15 representative nuclei per specimen. Statistical evaluation was performed using Graph Pad Software. Results: Cytology showed excellent tumor detection for G2 and G3 carcinomas, with a sensitivity of 100% combined with a specificity of 100%. Using cytometry, we can significantly distinguish between unsuspicious patients and G1 carcinomas on the one hand and high-grade carcinomas on the other. Furthermore, in 6 of 25 patients (24%) with noninvasive G2 carcinomas, but G3 cytological evaluation, tumor progression occurred. Conclusions: Urinary cytology is an excellent instrument for detection of clinically relevant high-grade bladder cancer. Descriptive alterations of the cytopathology can be validated by objective data using cytometric analysis. Copyright © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Noninvasive imaging at the molecular level is an emerging field in biomedical research. This paper introduces a new technology synergizing two leading imaging methodologies: positron emission tomography (PET) and magnetic resonance imaging (MRI). Although the value of PET lies in its high-sensitivity tracking of biomarkers in vivo, it lacks resolving morphology. MRI has lower sensitivity, but produces high soft-tissue contrast and provides spectroscopic information and functional MRI (fMRI). We have developed a three-dimensional animal PET scanner that is built into a 7-T MRI. Our evaluations show that both modalities preserve their functionality, even when operated isochronously. With this combined imaging system, we simultaneously acquired functional and morphological PET-MRI data from living mice. PET-MRI provides a powerful tool for studying biology and pathology in preclinical research and has great potential for clinical applications. Combining fMRI and spectroscopy with PET paves the way for a new perspective in molecular imaging. [ABSTRACT FROM AUTHOR]

• We describe the protocol and design of the ASVspoof Challenge 2019 database • We detail the speech synthesis and voice conversion algorithms used in the database • We detail the carefully controlled simulation to generate replay spoofing speech • We evaluate of baseline countermeasure and ASV systems on the database • Human assessment found that one spoofing system can fool human listeners Automatic speaker verification (ASV) is one of the most natural and convenient means of biometric person recognition. Unfortunately, just like all other biometric systems, ASV is vulnerable to spoofing, also referred to as "presentation attacks." These vulnerabilities are generally unacceptable and call for spoofing countermeasures or "presentation attack detection" systems. In addition to impersonation, ASV systems are vulnerable to replay, speech synthesis, and voice conversion attacks. The ASVspoof challenge initiative was created to foster research on anti-spoofing and to provide common platforms for the assessment and comparison of spoofing countermeasures. The first edition, ASVspoof 2015, focused upon the study of countermeasures for detecting of text-to-speech synthesis (TTS) and voice conversion (VC) attacks. The second edition, ASVspoof 2017, focused instead upon replay spoofing attacks and countermeasures. The ASVspoof 2019 edition is the first to consider all three spoofing attack types within a single challenge. While they originate from the same source database and same underlying protocol, they are explored in two specific use case scenarios. Spoofing attacks within a logical access (LA) scenario are generated with the latest speech synthesis and voice conversion technologies, including state-of-the-art neural acoustic and waveform model techniques. Replay spoofing attacks within a physical access (PA) scenario are generated through carefully controlled simulations that support much more revealing analysis than possible previously. Also new to the 2019 edition is the use of the tandem detection cost function metric, which reflects the impact of spoofing and countermeasures on the reliability of a fixed ASV system. This paper describes the database design, protocol, spoofing attack implementations, and baseline ASV and countermeasure results. It also describes a human assessment on spoofed data in logical access. It was demonstrated that the spoofing data in the ASVspoof 2019 database have varied degrees of perceived quality and similarity to the target speakers, including spoofed data that cannot be differentiated from bona fide utterances even by human subjects. It is expected that the ASVspoof 2019 database, with its varied coverage of different types of spoofing data, could further foster research on anti-spoofing. [ABSTRACT FROM AUTHOR]

B Outside Front Cover b : Outside Front Cover: A novel plasma source "HelixJet", operated at atmospheric pressure is introduced. Double helix electrodes driven by a radio frequency power supply generate a homogeneous glow discharge in a large volume quartz pipe. This renders the "HelixJet" as a potential new additive manufacturing tool, in which polyamide powders can be simultaneously surface treated and partially melted to enable plasma-based 3D printing of powders usually used in Laser Sintering. [Extracted from the article]

A novel plasma source (HelixJet) for use in additive manufacturing (AM)/3D printing is proposed. The HelixJet is a capacitively coupled radio frequency plasma with a double‐helix electrode configuration that generates a surprisingly stable and homogeneous glow plasma at low flow rates of argon and its mixtures at atmospheric pressure. The HelixJet was tested on three polyamide powders usually used to produce parts by laser sintering, a powder‐based AM process, to form local deposits. The chemical composition of such plasma‐printed samples is compared with thermally produced and laser‐sintered samples with respect to differences in morphology that result from the different thermal cycles on several length scales. Plasma prints exhibit unique features attributable to the nonequilibrium chemistry and to the high‐speed heat exchange. [ABSTRACT FROM AUTHOR]

Abstract: The phenomenology and breakdown mechanism of dielectric barrier discharges are strongly determined by volume and surface memory effects. In particular, the pre-ionization provided by residual species in the volume or surface charges on the dielectrics influences the breakdown behavior of filamentary and diffuse discharges. This was investigated by advanced diagnostics such as streak camera imaging, laser photodetachment of negative ions and laser photodesorption of electrons from dielectric surfaces in correlation with 1D fluid modeling. The streak camera images show that an increasing number of residual charges in the volume changes the microdischarge breakdown in air-like gas mixtures from a cathode-directed streamer to a simultaneous propagation of cathode- and anode-directed streamers. In contrast, seed electrons are important for the pre-ionization if the density of residual charges in the volume is low. One source of seed electrons are negative ions, whose density exceeds the electron density during the pre-phase of diffuse helium-oxygen barrier discharges as indicated by the laser photodetachment experiments. Electrons desorbed from the cathodic dielectric have an even larger influence. They induce a transition from the glow-like to the Townsend-like discharge mode in nominally pure helium. Apart from analyzing the importance of the pre-ionization for the breakdown mechanism, the opportunities for manipulating the lateral structure and discharge modes are discussed. For this purpose, the intensity and diameter of a diffuse discharge in helium are controlled by an illuminated semiconducting barrier. Graphical abstract: [ABSTRACT FROM AUTHOR]