Homogenization and analysis of an expanded long-term monthly rainfall network for the Island of Ireland (1850–2010)

Long-term precipitation series are critical for understanding emerging changes to the hydrological cycle. To this end we construct a homogenized Island of Ireland Precipitation (IIP) network comprising 25 stations and a composite series covering the period 1850–2010, providing the second-longest regional precipitation archive in the British-Irish Isles. We expand the existing catalogue of long-term precipitation records for the island by recovering archived data for an additional eight stations. Following bridging and updating of stations HOMogenisation softwarE in R (HOMER) homogenization software is used to detect breaks using pairwise and joint detection. A total of 25 breakpoints are detected across 14 stations, and the majority (20) are corroborated by metadata. Assessment of variability and change in homogenized and extended precipitation records reveal positive (winter) and negative (summer) trends. Trends in records covering the typical period of digitization (1941 onwards) are not always representative of longer records. Furthermore, trends in post-homogenization series change magnitude and even direction at some stations. While cautionary flags are raised for some series, confidence in the derived network is high given attention paid to metadata, coherence of behaviour across the network and consistency of findings with other long-term climatic series such as England and Wales precipitation. As far as we are aware, this work represents the first application of HOMER to a long-term precipitation network and bodes well for use in other regions. It is expected that the homogenized IIP network will find wider utility in benchmarking and supporting climate services across the Island of Ireland, a sentinel location in the North Atlantic.

Cybersecurity Test-Bed for IEC 61850 based Smart Substations

With the development and deployment of IEC 61850 based smart substations, cybersecurity vulnerabilities of supervisory control and data acquisition (SCADA) systems are increasingly emerging. In response to the emergence of cybersecurity vulnerabilities in smart substations, a test-bed is indispensable to enable cybersecurity experimentation. In this paper, a comprehensive and realistic cyber-physical test-bed has been built to investigate potential cybersecurity vulnerabilities and the impact of cyber-attacks on IEC 61850 based smart substations. This test-bed is close to a real production type environment, and has the ability to carry out end-to-end testing of cyber-attacks and physical consequences. A fuzz testing approach is proposed for detecting IEC 61850 based intelligent electronic devices (IEDs) and validated in the proposed test-bed.

A comparison of gold nanoparticle surface co-functionalization approaches using Polyethylene Glycol (PEG) and the effect on stability, non-specific protein adsorption and internalization

To create clinically useful gold nanoparticle (AuNP) based cancer therapeutics it is necessary to co-functionalize the AuNP surface with a range of moieties; e.g. Polyethylene Glycol (PEG), peptides and drugs. AuNPs can be functionalized by creating either a mixed monolayer by attaching all the moieties directly to the surface using thiol chemistry, or by binding groups to the surface by means of a bifunctional polyethylene glycol (PEG) linker. The linker methodology has the potential to enhance bioavailability and the amount of functional agent that can be attached. While there is a large body of published work using both surface arrangements independently, the impact of attachment methodology on stability, non-specific protein adsorption and cellular uptake is not well understood, with no published studies directly comparing the two most frequently employed approaches. This paper compares the two methodologies by synthesizing and characterizing PEG and Receptor Mediated Endocytosis (RME) peptide co-functionalized AuNPs prepared using both the mixed monolayer and linker approaches. Successful attachment of both PEG and RME peptide using the two methods was confirmed using Dynamic Light Scattering, Fourier Transform Infrared Spectroscopy and gel electrophoresis. It was observed that while the 'as synthesized' citrate capped AuNPs agglomerated under physiological salt conditions, all the mixed monolayer and PEG linker capped samples remained stable at 1M NaCl, and were stable in PBS over extended periods. While it was noted that both functionalization methods inhibited non-specific protein attachment, the mixed monolayer samples did show some changes in gel electrophoresis migration profile after incubation with fetal calf serum. PEG renders the AuNP stable in-vivo however, studies with MDA-MB-231 and MCF 10A cell lines indicated that functionalization with PEG, blocks cellular uptake. It was observed that co-functionalization with RME peptide using both the mixed monolayer and PEG linker methods greatly enhanced cellular internalization compared to PEG capped AuNPs.