Transmission line matching effects on the performance of shunt-C/series-tuned and series-L/parallel-tuned Class-E amplifiers

The impact that the transmission-line load-network has on the performance of the recently introduced series-L/parallel-tuned Class-E amplifier and the classic shunt-C/series-tuned configuration when compared to optimally derived lumped load networks is discussed. In addition an improved load topology which facilitates harmonic suppression of up to 5 order as required for maximum Class-E efficiency as well as load resistance transformation and a design procedure involving the use of Kuroda's identity and Richard's transformation enable a distributed synthesis process which dispenses with the need for iterative tuning as previously required in order to achieve optimum Class-E operation. © 2005 IEEE.

A density functional theory study of the reaction of C+O, C+N, and C+H on close packed metal surfaces

Density functional theory (DFT) has been used to determine reaction pathways for several reactions taking place on Pt(111) and Cu(111) surfaces. On Pt(111), the reactions of C+O and C+N were studied, and on Cu(111) we investigated the reaction of C+H. The structures of the transition states accessed in each reaction are similar. An equivalent distance separates the reactants with the first located at a three-fold hollow site and the second close to a bridge site. Previous DFT studies have, in fact, often identified transition states of this type and in every case it is the reactant with the weaker chemisorption energy that is located close to the bridge site. An explanation as to why this is so is provided. (C) 2001 American Institute of Physics.

The application of a Trous wave filtering and Monte Carlo analysis on secis 2001 solar eclipse observations

Eight thousand images of the solar corona were captured during the June 2001 total solar eclipse. New software for the alignment of the images and an automated technique for detecting intensity oscillations using multi-scale wavelet analysis were developed. Large areas of the images covered by the Moon and the upper corona were scanned for oscillations and the statistical properties of the atmospheric effects were determined. The a Trous wavelet transform was used for noise reduction and Monte Carlo analysis as a significance test of the detections. The effectiveness of those techniques is discussed in detail.

‘Risk, Politics and the ‘Scientification’ of Political Judgement: Prisoner Release and Conflict Transformation in Northern Ireland’

Drawing on research in Northern Ireland into the process of release under the Belfast/Good Friday Agreement, this article explores the identification and classification of risk in relation to prisoners released early under the Sentences (NI) Act. The main argument is that conflict, post-conflict and transitional conditions expose more starkly the political underpinnings of risk-management strategy and the article demonstrates the particular variant of Politicized Risk Assessment (PRA) recently used in the release of prisoners in Northern Ireland

Protest practice and (tree) cultures of conflict: understanding the spaces of ‘tree maiming’ in eighteenth- and early nineteenth-century England

Developing understandings of protest and cultures of resistance has been a central theme of the 'new' cultural geography of the 1990s and 2000s. But whilst geographers of the here and now have been highly sensitive to the importance of acts of protest which occur outside of the context of broader social movements, geographers concerned with past protests have tended to focus overwhelmingly upon either understanding the development of social movements or highly specific place-based studies. Through a focus upon the hitherto ignored practice of 'tree maiming', this paper demonstrates not only the value of examining specific protest practices in helping to better understand the complexity of conflict, but also how in periods of acute socio-economic change the evolving relationship between humans and the non-human – in this case trees – is a central discourse to the protest practices of the poor. Such attacks often involved complex cultural understandings about the ways in which trees should – and should not – be socially enrolled.

Strategies toward the design of energetic ionic liquids: nitro- and nitrile-substituted N,N '-dialkylimidazolium salts

Twelve novel 1,3-dialkylimidazolium salts containing strongly electron-withdrawing nitro-and cyano-functionalities directly appended to the cationic heterocyclic rings have been synthesized; the influences of the substituents on both formation and thermal properties of the resultant ionic liquids have been determined by DSC, TGA, and single crystal X-ray diffraction, showing that an electron-withdrawing nitro-substituent can be successfully appended and has a similar influence on the melting behaviour as that of corresponding methyl group substitution. Synthesis of di-, or trinitro-substituted 1,3-dialkylimidazolium cations was unsuccessful due to the resistance of dinitro-substituted imidazoles to undergo either N-alkylation or protonation, while 1-alkyl- 4,5-dicyanoimidazoles were successfully alkylated to obtain 1,3-dialkyl-4,5-dicyanoimidazolium salts. Five crystal structures ( one of each cation type) show that, in the solid state, the NO2-group has little significant effect, beyond the steric contribution, on the crystal packing.

A Longitudinal Study of the Effects of Childhood Trauma on Symptoms and Functioning of People with Severe Mental Health Problems

This study examines the relationship between childhood trauma and the psychiatric symptoms and psychosocial functioning of adults with severe mental health problems. Participants (n = 31) were recruited from the caseloads of community mental health services in Northern Ireland and assessed at baseline, 9 months, and 18 months. More than half had a history of childhood trauma (n = 17). There were no differences between the no childhood trauma (n = 14) and childhood trauma groups on psychiatric symptoms, but a significant relationship was found between trauma history and all aspects of social functioning. Those with no history of trauma showed improved psychosocial functioning over time, whereas those with a history of trauma deteriorated. These findings have implications for current service provision.

An exploration of the experience of cancer cachexia: What patients and their families want from health care professionals

The aim of this paper is to investigate the perceptions of patients and family members with regard to care received for cancer cachexia. A qualitative study recruited 27 participants, of which 15 were patients with advanced cancer who had primary cachexia and 12 were family members. Participants were recruited from a regional cancer centre in the UK. All participants took part in a domiciliary interview, which was transcribed verbatim for analysis. A major finding from analysis was ‘lack of response from health care professionals’ in relation to cancer cachexia management. This finding illuminated that patients and their family members wanted three things from healthcare professionals. They wanted their profound weight loss acknowledged, they wanted information about it and why it was happening and they wanted interventions to deal with it. This paper provides powerful messages for healthcare professionals and highlights the needs of patients and their family regarding cancer cachexia management. Patients and their families want this problem addressed by healthcare professionals. This client group requires supportive healthcare interventions, so that they can understand the nature and impact of this syndrome.

Langerhans cells are critical in the development of atopic dermatitis-like inflammation and symptoms in mice

Genetic or vitamin D3-induced overexpression of thymic stromal lymphopoietin (TSLP) by keratinocytes results in an atopic dermatitis (AD)-like inflammatory phenotype in mice echoing the discovery of high TSLP expression in epidermis from AD patients. Although skin dendritic cells (DC) are suspected to be involved in AD, direct evidence of a pathogenetic role for skin DC in TSLP-induced skin inflammation has not yet been demonstrated. In a mouse model of AD, i.e. mice treated with the low-calcemic vitamin D3 analogue, MC903, we show that epidermal Langerhans cells (LC)-depleted mice treated with MC903 do neither develop AD-like inflammation nor increased serum IgE as compared to vitamin D3 analogue-treated control mice. Accordingly, we show that, in mice treated with MC903 or in K14-TSLP transgenic mice, expression of maturation markers by LC is increased whereas maturation of dermal DC is not altered. Moreover, only LC are responsible for the polarization of naive CD4+ T cells to a Th2 phenotype, i.e. decrease in interferon-gamma and increase in interleukin (IL)-13 production by CD4+ T cells. This effect of LC on T-lymphocytes does not require OX40-L/CD134 and is mediated by a concomitant down-regulation of IL-12 and CD70. Although it was previously stated that TSLP up-regulates the production of thymus and activation-regulated chemokine (TARC)/chemokine (C-C motif) ligand 17 (CCL17) and macrophage-derived chemokine (MDC)/CCL22 by human LC in vitro, our work shows that production of these Th2- cell attracting chemokines is increased only in keratinocytes in response to TSLP overexpression. These results demonstrate that LC are required for the development of AD in mouse models of AD involving epidermal TSLP overexpression.