Redundant Mesh Trees for Robust Scalable Low-latency P2P Media Distribution

A redundant mesh (RMS) tree structure is proposed as a P2P network topology for reducing network latency. The RMS tree structure may enable low-latency network scalability through redundant connections within tree nodes, and a fully connected mesh cluster at each node of the tree structure. When compared to a traditional P2P or client-server network topology, bandwidth demands may be reduced at every node of the network. Thus, latent network capabilities may be utilized, and overall system latency may decrease

Evolution of a field: Swiss media and communication studies

In this paper, we present the evolution of Swiss Media and Communication Studies over the last decade by summarizing the main results from a project funded by the Swiss University Conference (2008–2017). We give an overall picture of the growth in the field (in terms of student numbers, resources and activities), look at diversity in terms of topics (two clusters are identified and presented with respect to various indicators), present changes at the level of individual research units (where we find variance in terms of evolution), give insights into publication patterns (two different publication cultures are found) and describe mobility and career pathways in the field. We observe limited mobility within Switzerland, internal pathways at the level of doctoral students and post-docs, and international mobility, mainly within the same linguistic region, at the professorial level. We conclude that the field has reached a consolidation phase and achieved a rather stable situation, but faces new challenges, with digitalization and the pressure towards homogenization in publication output among the most important

Spin Filter Properties of Armchair Graphene Nanoribbons with Substitutional Fe Atoms

The spin filter capability of a (0,8) armchair graphene nanoribbon with Fe atoms at substitutional sites is investigated by density functional theory in combination with the non-equilibrium Greens function technique. For specific arrangements, a high degree of spin polarization is achieved. These include a single substitution at an edge position or double substitution in the central sector of the transmission element. The possibility of switching between majority and minority spin polarization by changing the double substitution geometry is predicted. Including the bias dependence of the transmission function proves to be essential for correct representation of the spin-resolved current-voltage profiles

Evolution of a field: Swiss media and communication studies

In this paper, we present the evolution of Swiss Media and Communication Studies over the last decade by summarizing the main results from a project funded by the Swiss University Conference (2008–2017). We give an overall picture of the growth in the field (in terms of student numbers, resources and activities), look at diversity in terms of topics (two clusters are identified and presented with respect to various indicators), present changes at the level of individual research units (where we find variance in terms of evolution), give insights into publication patterns (two different publication cultures are found) and describe mobility and career pathways in the field. We observe limited mobility within Switzerland, internal pathways at the level of doctoral students and post-docs, and international mobility, mainly within the same linguistic region, at the professorial level. We conclude that the field has reached a consolidation phase and achieved a rather stable situation, but faces new challenges, with digitalization and the pressure towards homogenization in publication output among the most important

Particle detection by means of neural networks and synthetic training data refinement in defocusing particle tracking velocimetry

The presented work addresses the problem of particle detection with neural networks (NNs) in defocusing particle tracking velocimetry. A novel approach based on synthetic training data refinement is introduced, with the scope of revising the well documented performance gap of synthetically trained NNs, applied to experimental recordings. In particular, synthetic particle image (PI) data is enriched with image features from the experimental recordings by means of deep learning through an unsupervised image-to-image translation. It is demonstrated that this refined synthetic training data enables the neural-network-based particle detection for a simultaneous increase in detection rate and reduction in the rate of false positives, beyond the capability of conventional detection algorithms. The potential for an increased accuracy in particle detection is revealed with NNs that utilise small scale image features, which further underlines the importance of representative training data. In addition, it is demonstrated that NNs are able to resolve overlapping PIs with a higher reliability and accuracy in comparison to conventional algorithms, suggesting the possibility of an increased seeding density in real experiments. A further finding is the robustness of NNs to inhomogeneous background illumination and aberration of the images, which opens up defocusing PTV for a wider range of possible applications. The successful application of synthetic training-data refinement advances the neural-network-based particle detection towards real world applicability and suggests the potential of a further performance gain from more suitable training data

Making Complex Prediction Rules Applicable for Readers: Current Practice in Random Forest Literature and Recommendations

Ideally, prediction rules (including classifiers as a special case) should be published in such a way that readers may apply them, for example to make predictions for their own data. While this is straightforward for simple prediction rules, such as those based on the logistic regression model, this is much more difficult for complex prediction rules derived by machine learning tools. We conducted a survey of articles reporting prediction rules that were constructed using the random forest algorithm and published in PLOS ONE in 2014-2015 with the aim to identify issues related to their applicability. The presented prediction rules were applicable in only 2 of 30 identified papers, while for further 8 prediction rules it was possible to obtain the necessary information by contacting the authors. Various problems, such as non-response of the authors, hampered the applicability of prediction rules in the other cases. Based on our experiences from the survey, we formulate a set of recommendations for authors publishing complex prediction rules to ensure their applicability for readers

Isolation of Resistance-Bearing Microorganisms

To better exploit the principles of gas transport and mass transport during the processes of cell seeding of 3D scaffolds and in vitro culture of 3D tissue engineered constructs, the oscillatory cell culture bioreactor provides a flow of cell suspensions and culture media directly through a porous 3D scaffold (during cell seeding) and a 3D construct (during subsequent cultivation) within a highly gas-permeable closed-loop tube. This design is simple, modular, and flexible, and its component parts are easy to assemble and operate, and are inexpensive. Chamber volume can be very low, but can be easily scaled up. This innovation is well suited to work with different biological specimens, particularly with cells having high oxygen requirements and/or shear sensitivity, and different scaffold structures and dimensions. The closed-loop changer is highly gas permeable to allow efficient gas exchange during the cell seeding/culturing process. A porous scaffold, which may be seeded with cells, is fixed by means of a scaffold holder to the chamber wall with scaffold/construct orientation with respect to the chamber determined by the geometry of the scaffold holder. A fluid, with/without biological specimens, is added to the chamber such that all, or most, of the air is displaced (i.e., with or without an enclosed air bubble). Motion is applied to the chamber within a controlled environment (e.g., oscillatory motion within a humidified 37 C incubator). Movement of the chamber induces relative motion of the scaffold/construct with respect to the fluid. In case the fluid is a cell suspension, cells will come into contact with the scaffold and eventually adhere to it. Alternatively, cells can be seeded on scaffolds by gel entrapment prior to bioreactor cultivation. Subsequently, the oscillatory cell culture bioreactor will provide efficient gas exchange (i.e., of oxygen and carbon dioxide, as required for viability of metabolically active cells) and controlled levels of fluid dynamic shear (i.e., as required for viability of shear-sensitive cells) to the developing engineered tissue construct. This bioreactor was recently utilized to show independent and interactive effects of a growth factor (IGF-I) and slow bidirectional perfusion on the survival, differentiation, and contractile performance of 3D tissue engineering cardiac constructs. The main application of this system is within the tissue engineering industry. The ideal final application is within the automated mass production of tissue- engineered constructs. Target industries could be both life sciences companies as well as bioreactor device producing companies

Rapid inoculation of single bacteria into parallel picoliter fermentation chambers

Probst C, Grünberger A, Braun N, et al. Rapid inoculation of single bacteria into parallel picoliter fermentation chambers. Analytical methods. 2015;7(1):91-98.Microfluidic single-cell cultivation devices have been successfully utilized in a variety of biological research fields. One major obstacle to the successful implementation of high throughput single-cell cultivation technology is the requirement for a simple, fast and reliable cell inoculation procedure. In the present report, an air-bubble-based cell loading methodology is described and validated for inoculating single bacteria into multiple picoliter sized growth chambers arranged in a highly parallel manner. It is shown that the application of the injected air bubble can serve as a reproducible mechanism to modify laminar flow conditions. In this way, convective flow was temporarily induced in more than 1000 cultivation chambers simultaneously, which under normal conditions operate exclusively under diffusive mass transport. Within an inoculation time of 100 s, Corynebacterium glutamicum cells were inoculated by convection at minimal stress level and single bacteria remain successfully trapped by cell-wall interactions. The procedure is easy, fast, gentle and requires only minimal fluidic control and equipment. The technique is well suited for microbial cell loading into commonly used microfluidic growth sites arranged in parallel intended for high throughput single-cell analysis