Min waves without MinC can pattern FtsA-anchored FtsZ filaments on model membranes

Although the essential proteins that drive bacterial cytokinesis have been identified, the precise mechanisms by which they dynamically interact to enable symmetrical division are largely unknown. In Escherichia coli, cell division begins with the formation of a proto-ring composed of FtsZ and its membrane-tethering proteins FtsA and ZipA. In...

Shaping Liposomes by Cell-Free Expressed Bacterial Microtubules

Genetic control over a cytoskeletal network inside lipid vesicles offers a potential route to controlled shape changes and DNA segregation in synthetic cell biology. Bacterial microtubules (bMTs) are protein filaments found in bacteria of the genus Prosthecobacter. They are formed by the tubulins BtubA and BtubB, which polymerize in the...

In vitro synthesis of 32 translation-factor proteins from a single template reveals impaired ribosomal processivity

The Protein synthesis Using Recombinant Elements (PURE) system enables transcription and translation of a DNA template from purified components. Therefore, the PURE system-catalyzed generation of RNAs and proteins constituting the PURE system itself represents a major challenge toward a self-replicating minimal cell. In this work, we show...

A different cup of TI? The added value of commercial threat intelligence

Commercial threat intelligence is thought to provide unmatched coverage on attacker behavior, but it is out of reach for many organizations due to its hefty price tag. This paper presents the first empirical assessment of the services of commercial threat intelligence providers. For two leading vendors, we describe what these services consist of...

Cell-free biogenesis of bacterial division proto-rings that can constrict liposomes

A major challenge towards the realization of an autonomous synthetic cell resides in the encoding of a division machinery in a genetic programme. In the bacterial cell cycle, the assembly of cytoskeletal proteins into a ring defines the division site. At the onset of the formation of the Escherichia coli divisome, a proto-ring consisting of...

Modelling cell-free RNA and protein synthesis with minimal systems

DNA-guided cell-free protein synthesis using a minimal set of purified components has emerged as a versatile platform in constructive biology. The E. coli-based PURE (protein synthesis using recombinant elements) system offers the basic protein synthesis factory in a prospective minimal cell relying on extant molecules. However, there is an...

De novo synthesized Min proteins drive oscillatory liposome deformation and regulate FtsA-FtsZ cytoskeletal patterns

The Min biochemical network regulates bacterial cell division and is a prototypical example of self-organizing molecular systems. Cell-free assays relying on purified proteins have shown that MinE and MinD self-organize into surface waves and oscillatory patterns. In the context of developing a synthetic cell from elementary biological...

Statistics and simulation of growth of single bacterial cells: Illustrations with B. subtilis and E. coli

The inherent stochasticity of molecular reactions prevents us from predicting the exact state of single-cells in a population. However, when a population grows at steady-state, the probability to observe a cell with particular combinations of properties is fixed. Here we validate and exploit existing theory on the statistics of single-cell...

Lognormal infection times of online information spread

The infection times of individuals in online information spread such as the inter-arrival time of Twitter messages or the propagation time of news stories on a social media site can be explained through a convolution of lognormally distributed observation and reaction times of the individual participants. Experimental measurements support the...

Challenge-Aware Traffic Protection in Wireless Mobile Backhaul Networks

To protect active traffic against link or node failures in multi-hop communications networks, several so-called protection schemes have been introduced in the past. The most established ones are path, segment, node and link protection. However, these schemes are limited as challenges are modelled abstractly whereas challenges in real networks...

How Much do Your Friends Tell About You?: Reconstructing Private Information from the Friendship Graph

After the early land rush and fast exponential growth of online social networking platforms, concerns about how data placed in online social networks may be exploited and abused have begun to appear among mainstream users. Social networking sites have responded to these new public sentiments by introducing privacy filters to their site, allowing...

Lognormal distribution in the digg online social network

We analyse the number of votes, called the digg value, which measures the impact or popularity of submitted information in the Online Social Network Digg. Experiments over five years indicate that the digg value of a story on the first frontpage follows closely a lognormal distribution. While the law of proportionate effect explains lognormal...

Are Friends Overrated?: A Study for the Social Aggregator Digg.com

The key feature of online social networks is the ability of users to become active, make friends and interact with those around them. Such interaction is typically perceived as critical to these platforms; therefore, a significant share of research has investigated the characteristics of social links, friendship relations, community structure,...

A computational approach to multi-level analysis of network resilience

As communication and network technology has advanced into all areas of human life, large-scale failures of such infrastructures can have a drastic impact on its users, the economy and society in general. Significant attention has been paid to study and improve the dependability of such systems, intending to augment their resilience against...

Local control of cognitive radio networks

In a network deployment, a cognitive radio will have to perform two fundamental tasks. First, each cognitive radio needs to optimize its internal operation, and second, it needs to derive a configuration that will enable and optimize communication with other nodes in the network. This latter requirement, however, relies on knowledge about the...

Establishing Evidence for Safety Cases in Automotive Systems – A Case Study

The upcoming safety standard ISO/WD 26262 that has been derived from the more general IEC 61508 and adapted for the automotive industry, introduces the concept of a safety case, a scheme that has already been successfully applied in other sectors of industry such as nuclear, defense, aerospace, and railway. A safety case communicates a clear,...

Crawling and Detecting Community Structure in Online Social Networks using Local Information

As Online Social Networks (OSNs) become an intensive sub- ject of research for example in computer science, networking, social sci- ences etc., a growing need for valid and useful datasets is present. The time taken to crawl the network is however introducing a bias which should be minimized. Usual ways of addressing this problem are sampling...

Context-Sensitive Sentiment Classification of Short Colloquial Text

The wide-spread popularity of online social networks and the resulting availability of data to researchers has enabled the investigation of new research questions, such as the analysis of information diffusion and how individuals are influencing opinion formation in groups. Many of these new questions however require an automatic assessment of...