The Langmuir probe as a diagnostic of the electron component within low temperature laser ablated plasma plumes

A Langmuir probe has been used as a diagnostic of the temporally evolving electron component within a laser ablated Cu plasma expanding into vacuum, for an incident laser power density on target similar to that used for the pulsed laser deposition of thin films. Electron temperature data were obtained from the retarding region of the probe current/voltage (I/V) characteristic, which was also used to calculate an associated electron number density. Additionally, electron number density data were obtained from the saturation electron current region of the probe (I/V) characteristic. Electron number density data, extracted by the two different techniques, were observed to show the same temporal form, with measured absolute values agreeing to within a factor of 2. The Langmuir probe, in the saturation current region, has been shown for the first time to be a convenient diagnostic of the electron component within relatively low temperature laser ablated plasma plumes. (C) 1999 American Institute of Physics. [S0034-6748(99)01503-8].

Trophic dynamics within a hybrid zone - interactions between an abundant cyprinid hybrid and sympatric parental species

1. Recent proliferation of hybridisation in response to anthropogenic ecosystem change, coupled with increasing evidence of the importance of ancient hybridisation events in the formation of many species, has moved hybridisation to the forefront of evolutionary theory.

2. In spite of this, the mechanisms (e. g. differences in trophic ecology) by which hybrids co-exist with parental taxa are poorly understood. A unique hybrid zone exists in Irish freshwater systems, whereby hybrid offspring off two non-native cyprinid fishes often outnumber both parental species.

3. Using stable isotope and gut content analyses, we determined the trophic interactions between sympatric populations of roach (Rutilus rutilus), bream (Abramis brama) and their hybrid in lacustrine habitats.

4. The diet of all three groups displayed little variation across the study systems, and dietary overlap was observed between both parental species and hybrids. Hybrids displayed diet, niche breadth and trophic position that were intermediate between the two parental species while also exhibiting greater flexibility in diet across systems.

Demersal fish biodiversity: species-level indicators and trends-based targets for the Marine Strategy Framework Directive

The maintenance of biodiversity is a fundamental theme of the Marine Strategy Framework Directive. Appropriate indicators to monitor change in biodiversity, along with associated targets representing "good environmental status" (GES), are required to be in place by July 2012. A method for selecting species-specific metrics to fulfil various specified indicator roles is proposed for demersal fish communities. Available data frequently do not extend far enough back in time to allow GES to be defined empirically. In such situations, trends-based targets offer a pragmatic solution. A method is proposed for setting indicator-level targets for the number of species-specific metrics required to meet their trends-based metric-level targets. This is based on demonstrating significant departures from the binomial distribution. The procedure is trialled using North Sea demersal fish survey data. Although fisheries management in the North Sea has improved in recent decades, management goals to stop further decline in biodiversity, and to initiate recovery, are yet to be met.

Beyond the boundaries in the island of Ireland

The review essay opens with positive attributes of Ireland but then considers that the island has been subject to centuries of bitter dispute and unrest. The historical background to this is outlined, particularly the interactions between Ireland and its neighbouring island, Great Britain, which dominated Irish affairs. One policy adopted by the British was to encourage migration of Protestants into the largely Catholic island in the vain hope that this would reduce unrest. The
two islands were then united from 1801 as the United Kingdom of Great Britain and Ireland but demands from indigenous Irish Catholics for independence continued, resisted by the Protestant minority who wished to remain inside the UK. After the Great War a solution was imposed that granted most of Ireland independence but left the largely Protestant northeast corner within the UK as Northern Ireland. Reaction to and life with the Irish border are considered and the paper concludes with musings about its future.

Preparation of highly stable oligo (ethylene glycol) derivatives-functionalized gold nanoparticles and their application in LSPR-Based detection of PSA/ACT complex

A sandwich immunoassay for PSA/ACT complex detection based on gold nanoparticle aggregation using two probes was developed. The functionalized colloidal gold nanoparticles (AuNPs) showed highly stable not only in the presence of high ionic strength but also in a wide pH range. The functionalized AuNPs were tagged with PSA/ACT complex monoclonal antibody and goat PSA polyclonal antibody and served as the probes to induce aggregation of the colloidal particles. As a result, PSA/ACT complex was detected at concentrations as low as 1 ng/ml. This is the first time that a new aggregation sandwich-immunoassay technique using two gold probes has been used, and the results are generally applicable to other LSPR-based immunoassays.

ENVIRONMENTAL LIMITS ON THE NONRESONANT COSMIC-RAY CURRENT-DRIVEN INSTABILITY

We investigate the so-called nonresonant cosmic-ray streaming instability, first discussed by Bell (2004). The extent to which thermal damping and ion-neutral collisions reduce the growth of this instability is calculated. Limits on the growth of the nonresonant mode in SN1006 and RX J1713.7-3946 are presented.

Substrates modified by advanced glycation end-products cause dysfunction and death in retinal pericytes by reducing survival signals mediated by platelet-derived growth factor

AIMS/HYPOTHESIS: Premature death of retinal pericytes is a pathophysiological hallmark of diabetic retinopathy. Among the mechanisms proposed for pericyte death is exposure to AGE, which accumulate during diabetes. The current study used an in vitro model, whereby retinal pericytes were exposed to AGE-modified substrate and the mechanisms underlying pericyte death explored. METHODS: Pericytes were isolated from bovine retinal capillaries and propagated on AGE-modified basement membrane (BM) extract or non-modified native BM. The extent of AGE modification was analysed. Proliferative responses of retinal pericytes propagated on AGE-modified BM were investigated using a 5-bromo-2-deoxy-uridine-based assay. The effect of extrinsically added platelet-derived growth factor (PDGF) isoforms on these proliferative responses was also analysed alongside mRNA expression of the PDGF receptors. Apoptotic death of retinal pericytes grown on AGE-modified BM was investigated using terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling labelling, mitochondrial membrane depolarisation and by morphological assessment. We also measured both the ability of PDGF to reverse Akt dephosphorylation that was mediated by AGE-modified BM, and increased pericyte apoptosis. RESULTS: Retinal pericytes exposed to AGE-modified BM showed reduced proliferative responses in comparison to controls (p

The Double Life of Duke of Somerset v Cookson, or a Legal Excavation of the Corbridge Lanx

Duke of Somerset v Cookson (1735) occupies an important place in English legal history as a leading authority for Chancery jurisdiction to order specific delivery of movable property where an award of damages would be inadequate. The property at issue was the Corbridge lanx, now in the British Museum, but then claimed as treasure trove by the duke of Somerset as lord of the manor of Corbridge. This paper re-examines Cookson as the first reported English decision relating to treasure trove, and uses later treasure trove claims by the duke of Somerset's successors to the manor of Corbridge, the dukes of Northumberland, to shed fresh light on the 1735 decision and on the development of treasure trove practice from the eighteenth century onwards.

“Bound in darkness and idolatry”? Protestant working class underachievement and Unionist hegemony

Over the past decade or more there has been a growing concern at the levels of educational underachievement within loyalist working-class areas of Northern Ireland. The inability of both educational and social policy initiatives over the past decade to improve the situation in any meaningful way has raised important questions concerning how the problem can be tackled more effectively. Placing the issue within the theoretical framework of Gramsci’s hegemony, this paper argues that there is a need to better understand the historical nature of the problem and to recognise the political and social forces that have shaped its existence. It argues that there is a need to move away from explaining Protestant underachievement simply by the availability of jobs in Ulster’s industrial past and to place its roots in the complex battle for social, political, and economic power since the 1801 Act of Union.

Depicting Characters and danced Narratives: Handel, 'The Italian troupe', and Marie Sallé

Handel’s London career afforded opportunities for responding to dancers working in distinct styles of movement—most notably the Italian troupe resident at the King’s Theatre in 1726-27, and Marie Sallé at Covent Garden in 1734-35. By studying the dances from Admeto (1727) and Ariodante (1735), this paper will explore Handel's response to the serious and grotesque styles, as well as to the character and narrative modes.

Comparison Method for Differentiation of IEC 61850 based Substation Configuration Files

The increased construction and reconstruction of smart substations has exposed a problem with version management of substation configuration description language (SCL) files due to frequent changes. This paper proposes a comparative approach for differentiation of smart substation SCL configuration files. A comparison model for SCL configuration files is built in this method, which is based on the SCL structure and abstract model defined by IEC 61850. The proposed approach adopts the algorithms of depth-first traversal, sorting, and cross comparison in order to rapidly identify differences of changed SCL configuration files. This approach can also be utilized to detect malicious tampering or illegal manipulation tailoring for SCL files. SCL comparison software is developed using the Qt platform to validate the feasibility and effectiveness of the proposed approach.

Functional identity and diversity of animals predict ecosystem functioning better than species-based indices

Drastic biodiversity declines have raised concerns about the deterioration of ecosystem functions and have motivated much recent research on the relationship between species diversity and ecosystem functioning. A functional trait framework has been proposed to improve the mechanistic understanding of this relationship, but this has rarely been tested for organisms other than plants. We analysed eight datasets, including five animal groups, to examine how well a trait-based approach, compared with a more traditional taxonomic approach, predicts seven ecosystem functions below- and above-ground. Trait-based indices consistently provided greater explanatory power than species richness or abundance. The frequency distributions of single or multiple traits in the community were the best predictors of ecosystem functioning. This implies that the ecosystem functions we investigated were underpinned by the combination of trait identities (i.e. single-trait indices) and trait complementarity (i.e. multi-trait indices) in the communities. Our study provides new insights into the general mechanisms that link biodiversity to ecosystem functioning in natural animal communities and suggests that the observed responses were due to the identity and dominance patterns of the trait composition rather than the number or abundance of species per se.