A user-oriented network forensic analyser: the design of a high-level protocol analyser

Network forensics is becoming an increasingly important tool in the investigation of cyber and computer-assisted crimes. Unfortunately, whilst much effort has been undertaken in developing computer forensic file system analysers (e.g. Encase and FTK), such focus has not been given to Network Forensic Analysis Tools (NFATs). The single biggest barrier to effective NFATs is the handling of large volumes of low-level traffic and being able to exact and interpret forensic artefacts and their context – for example, being able extract and render application-level objects (such as emails, web pages and documents) from the low-level TCP/IP traffic but also understand how these applications/artefacts are being used. Whilst some studies and tools are beginning to achieve object extraction, results to date are limited to basic objects. No research has focused upon analysing network traffic to understand the nature of its use – not simply looking at the fact a person requested a webpage, but how long they spend on the application and what interactions did they have with whilst using the service (e.g. posting an image, or engaging in an instant message chat). This additional layer of information can provide an investigator with a far more rich and complete understanding of a suspect’s activities. To this end, this paper presents an investigation into the ability to derive high-level application usage characteristics from low-level network traffic meta-data. The paper presents a three application scenarios – web surfing, communications and social networking and demonstrates it is possible to derive the user interactions (e.g. page loading, chatting and file sharing ) within these systems. The paper continues to present a framework that builds upon this capability to provide a robust, flexible and user-friendly NFAT that provides access to a greater range of forensic information in a far easier format

Ternatin and improved synthetic variants kill cancer cells by targeting the elongation factor-1A ternary complex.

Cyclic peptide natural products have evolved to exploit diverse protein targets, many of which control essential cellular processes. Inspired by a series of cyclic peptides with partially elucidated structures, we designed synthetic variants of ternatin, a cytotoxic and anti-adipogenic natural product whose molecular mode of action was unknown. The new ternatin variants are cytotoxic toward cancer cells, with up to 500-fold greater potency than ternatin itself. Using a ternatin photo-affinity probe, we identify the translation elongation factor-1A ternary complex (eEF1A·GTP·aminoacyl-tRNA) as a specific target and demonstrate competitive binding by the unrelated natural products, didemnin and cytotrienin. Mutations in domain III of eEF1A prevent ternatin binding and confer resistance to its cytotoxic effects, implicating the adjacent hydrophobic surface as a functional hot spot for eEF1A modulation. We conclude that the eukaryotic elongation factor-1A and its ternary complex with GTP and aminoacyl-tRNA are common targets for the evolution of cytotoxic natural products

No Small Scale Radio Jets Here: Multi-Epoch Observations of Radio Continuum Structures in NGC 1068 with the VLBA

We present recent Very Long Baseline Array (VLBA) 5 GHz radio observations of the nearby, luminous Seyfert 2 galaxy NGC 1068 for comparison to similar VLBA observations made on 1997 April 26. By cross-correlating the positions of emitting regions across both epochs, we find that spatially-resolved extra-nuclear radio knots in this system have sub-relativistic transverse speeds (v < 0.1c). We discuss sources of the observed knots and how the radio emission relates to additional phases of gas in the central ~150 pcs of this system. We suggest that the most likely explanation for the observed emission is synchrotron radiation formed by shocked host media via interactions between AGN winds and the host environment.Comment: 13 pages, 4 figures, accepted for publication in Ap

Highly coloured and electrophoretically active polymer microparticles via staggered dispersion polymerisation in supercritical carbon dioxide and dodecane

Devices featuring electrophoretic displays (EPD) have become extremely popular in recent years because of their low power consumption, high readability and thin display designs, but a product with a full colour gamut comparable with liquid crystal displays (LCDs) has not yet been commercialised. In this article, we demonstrate that staggering the addition of methyl methacrylate (MMA) monomer and low quantities of a coloured dye crosslinker is an effective route to producing well-defined and covalently-linked, strongly coloured PMMA microparticles in one-pot, via dispersion polymerisation in supercritical carbon dioxide (scCO2). This novel methodology is synthetically simple, readily scalable and has the added cachet of being cost effective because the functional molecules can be confined on the microparticle surface such that even at low concentrations, the resulting materials are brightly coloured. We then demonstrate the applicability of this approach to another functional comonomer/crosslinker system in 2-dimethylaminoethyl methacrylate (DMAEMA)/ethyleneglycol dimethacrylate (EGDMA), in this case allowing hierarchically structured ‘pomegranate-like’ microparticles with polarisable charge to be produced over a range of DMAEMA loadings as high as 44 wt%. Finally, the performance of these materials in out-of-plane EPD test cells is compared against analogues synthesised in dodecane. These tests revealed that the coloured microparticles fabricated in scCO2 performed as well as or better than their dodecane synthesised counterparts, consistently producing the cleanest white state and achieving effective colour switching over ten cycles

MAPPFinder: using Gene Ontology and GenMAPP to create a global gene-expression profile from microarray data

MAPPFinder is a tool that creates a global gene-expression profile across all areas of biology by integrating the annotations of the Gene Ontology (GO) Project with the free software package GenMAPP . The results are displayed in a searchable browser, allowing the user to rapidly identify GO terms with over-represented numbers of gene-expression changes. Clicking on GO terms generates GenMAPP graphical files where gene relationships can be explored, annotated, and files can be freely exchanged

A comparison across non-model animals suggests an optimal sequencing depth for de novo transcriptome assembly

Background: The lack of genomic resources can present challenges for studies of non-model organisms. Transcriptome sequencing offers an attractive method to gather information about genes and gene expression without the need for a reference genome. However, it is unclear what sequencing depth is adequate to assemble the transcriptome de novo for these purposes. Results: We assembled transcriptomes of animals from six different phyla (Annelids, Arthropods, Chordates, Cnidarians, Ctenophores, and Molluscs) at regular increments of reads using Velvet/Oases and Trinity to determine how read count affects the assembly. This included an assembly of mouse heart reads because we could compare those against the reference genome that is available. We found qualitative differences in the assemblies of whole-animals versus tissues. With increasing reads, whole-animal assemblies show rapid increase of transcripts and discovery of conserved genes, while single-tissue assemblies show a slower discovery of conserved genes though the assembled transcripts were often longer. A deeper examination of the mouse assemblies shows that with more reads, assembly errors become more frequent but such errors can be mitigated with more stringent assembly parameters. Conclusions: These assembly trends suggest that representative assemblies are generated with as few as 20 million reads for tissue samples and 30 million reads for whole-animals for RNA-level coverage. These depths provide a good balance between coverage and noise. Beyond 60 million reads, the discovery of new genes is low and sequencing errors of highly-expressed genes are likely to accumulate. Finally, siphonophores (polymorphic Cnidarians) are an exception and possibly require alternate assembly strategies