Circular polarisation frequency selective surface operating in Ku and Ka band

Single and double layer frequency selective surfaces (FSS) for Circular polarization (CP) operation were designed. The designed FSS provide reflection in the Ku-band (11.7 – 12.75 GHz) and transmission in the Ka-band (17.3 – 20.2 GHz). CP is conserved in each of the bands. For the double layer design over the Ku-band the reflection loss was less than 0.05 dB for TE and TM polarizations while the axial ratio was below 0.2 dB. Over the Ka-band transmission loss and axial ratio were each less than 0.25 dB.

Tackling Invasive Alien Species in Europe: the Top 20 Issues

Globally, Invasive Alien Species (IAS) are considered to be one of the major threats to native biodiversity, with the World Conservation Union (IUCN) citing their impacts as ?immense, insidious, and usually irreversible?. It is estimated that 11% of the c. 12,000 alien species in Europe are invasive, causing environmental, economic and social damage; and it is reasonable to expect that the rate of biological invasions into Europe will increase in the coming years. In order to assess the current position regarding IAS in Europe and to determine the issues that were deemed to be most important or critical regarding these damaging species, the international Freshwater Invasives - Networking for Strategy (FINS) conference was convened in Ireland in April 2013. Delegates from throughout Europe and invited speakers from around the world were brought together for the conference. These comprised academics, applied scientists, policy makers, politicians, practitioners and representative stakeholder groups. A horizon scanning and issue prioritization approach was used by in excess of 100 expert delegates in a workshop setting to elucidate the Top 20 IAS issues in Europe. These issues do not focus solely on freshwater habitats and taxa but relate also to marine and terrestrial situations. The Top 20 issues that resulted represent a tool for IAS management and should also be used to support policy makers as they prepare European IAS legislation.

Navigating Risk: Understanding the Impact of the Conflict on Children and Young People in Northern Ireland:Special Issue: Northern Ireland: 20 Years After the Cease-Fires

Twenty years on from the 1994 cease-fires, Northern Ireland is a markedly safer place for children and young people to grow up. However, for a significant number, growing up in post-conflict Northern Ireland has brought with it continued risks and high levels of marginalization. Many young people growing up on the sharp edge of the transition have continued to experience troubling levels of poverty, lower educational attainment, poor standards of childhood health, and sustained exposure to risk-laden environments. Reflecting on interdisciplinary research carried out since the start of the “transition” to peace, this article emphasizes the impact that embedded structural inequalities continue to have on the social, physical, mental, and emotional well-being of many children and young people. In shining a light on the enduring legacy of the conflict, this article moves to argue that greater attention needs to be given to the ongoing socioeconomic factors that result in limited lifetime opportunities, marginalization, and sustained poverty for many young people growing up in “peacetime” Northern Ireland.

Northern Ireland: 20 Years After the Cease-Fires

In the closing months of 1994, the principal paramilitary organizations in Northern Ireland declared that their campaigns of violence were at an end. The cease-fires called by republican and loyalist groupings represented the most significant heralds of a complex process of conflict transformation that continues to unfold even twenty years on. In this introduction, we set out to map the key developments that have shaped the tortuous narrative of the Northern Irish 'peace process', thereby providing the historical backdrop for the articles that follow. While remarkable progress has been made over the two decades since the paramilitary cease-fires, the political context and future of the region remain rather more fraught than is often assumed abroad. It is perhaps best, then, to speak of the six counties in terms not of resolution but rather of ambiguity. Twenty years on from the optimism that greeted the paramilitary cease-fires, Northern Ireland retains the essential 'inbetweenness' of a political space that has moved from a 'long war' through a 'long peace' and into a profoundly undecided future. © 2014 Taylor & Francis Group, LLC.

Synergistic effects on gene delivery - co-formulation of small disulfide-linked dendritic polycations with Lipofectamine 2000 (TM)

This paper describes the application of gene delivery vectors based on connecting together two well-defined low-generation poly(L-lysine) (PLL) dendrons using a disulfide-containing linker unit. We report that the transfection ability of these vectors in their own right is relatively low, because the low-generation number limits the endosomal buffering capacity. Importantly, however, we demonstrate that when applied in combination with Lipofectamine 2000 (TM), a vector from the cationic lipid family, these small cationic additives significantly enhance the levels of gene delivery (up to four-fold). Notably, the cationic additives have no effect on the levels of transfection observed with a cationic polymer, such as DEAE dextran. We therefore argue that the synergistic effects observed with Lipofectamine 2000 (TM) arise as a result of combining the delivery advantages of two different classes of vector within a single formulation, with our dendritic additives providing a degree of pH buffering within the endosome. As such, the data we present indicate that small dendritic structures, although previously largely overlooked for gene delivery owing to their inability to transfect in their own right, may actually be useful well-defined additives to well-established vector systems in order to enhance the gene delivery payload.

Energy levels, radiative rates, and electron impact excitation rates for transitions in Li-like ions with 12≤Z≤20

We report calculations of energy levels, radiative rates, and electron impact excitation rates for transitions in Li-like ions with 12≤Z≤20. The grasp (general-purpose relativistic atomic structure package) is adopted for calculating energy levels and radiative rates, while for determining the collision strengths and subsequently the excitation rates, the Dirac atomic R-matrix code is used. Oscillator strengths, radiative rates, and line strengths are reported for all E1, E2, M1, and M2 transitions among the lowest 24 levels of the Li-like ions considered. Collision strengths have been averaged over a Maxwellian velocity distribution, and the effective collision strengths obtained are reported over a wide temperature range up to 10^7.4 K. Additionally, lifetimes are also listed for all calculated levels of the ions. Finally, extensive comparisons are made with results available in the literature, as well as with our parallel calculations for all parameters with the Flexible Atomic Code, in order to assess the accuracy of the reported results.