Kinetics and mechanism of a fast leuco-Methylene Blue oxidation by copper(II)-halide species in acidic aqueous media

The kinetics of a fast leuco-Methylene Blue (LMB) re-oxidation to Methylene Blue (MB) by copper(II)-halide (Cl-, Br-) complexes in acidic aqueous media has been studied spectrophotometrically using a stopped-flow technique. The reaction follows a simple first order rate expression under an excess of the copper(II) species (and H+(aq)), and the pseudo-first order rate constant (k'(obs)) is largely independent of the atmosphere used (air, oxygen, argon). The rate law, at constant Cl- (Br-) anion concentration, is given by the expression: (d[MB+])/dt = ((k(a)K[H+] + k(b))/(1 + K[H+])).[Cu-II][LMB] = k'(obs)[LMB], where K is the protonation constant, and k(a) and k(b) are the pseudo-second order rate constants for protonated and deprotonated forms of LMB, respectively The rate law was determined based on the observed k'(obs) vs. [Cu-II] and [H+] dependences. The rate dramatically increases with [Cl-] over the range: 0.1-1.5 M, reflecting the following reactivity order: Cu2+(aq)

Ecological coherence in marine reserve network design: an empirical evaluation of sequential site selection using genetic structure

Ecological coherence is a multifaceted conservation objective that includes some potentially conflicting concepts. These concepts include the extent to which the network maximises diversity (including genetic diversity) and the extent to which protected areas interact with non-reserve locations. To examine the consequences of different selection criteria, the preferred location to complement protected sites was examined using samples taken from four locations around each of two marine protected areas: Strangford Lough and Lough Hyne, Ireland. Three different measures of genetic distance were used: FST, Dest and a measure of allelic dissimilarity, along with a direct assessment of the total number of alleles in different candidate networks. Standardized site scores were used for comparisons across methods and selection criteria. The average score for Castlehaven, a site relatively close to Lough Hyne, was highest, implying that this site would capture the most genetic diversity while ensuring highest degree of interaction between protected and unprotected sites. Patterns around Strangford Lough were more ambiguous, potentially reflecting the weaker genetic structure around this protected area in comparison to Lough Hyne. Similar patterns were found across species with different dispersal capacities, indicating that methods based on genetic distance could be used to help maximise ecological coherence in reserve networks. ⺠Ecological coherence is a key component of marine protected area network design. ⺠Coherence contains a number of competing concepts. ⺠Genetic information from field populations can help guide assessments of coherence. ⺠Average choice across different concepts of coherence was consistent among species. ⺠Measures can be combined to compare the coherence of different network designs.

Simultaneous optical and X-ray observations of flares and rotational modulation on the RS CVn binary HR 1099 (V711 Tau) from the MUSICOS 1998 campaign

We present simultaneous and continuous observations of the Halpha, Hbeta, He I D-3, Na I D-1,D-2 doublet and the Ca II H&K lines for the RS CVn system HR 1099. The spectroscopic observations were obtained during the MUSICOS 1998 campaign involving several observatories and instruments, both echelle and long-slit spectrographs. During this campaign, HR 1099 was observed almost continuously for more than 8 orbits of 2.(d)8. Two large optical flares were observed, both showing an increase in the emission of Halpha, Ca II H K, Hbeta and He I D-3 and a strong filling-in of the Na I D-1, D-2 doublet. Contemporary photometric observations were carried out with the robotic telescopes APT-80 of Catania and Phoenix-25 of Fairborn Observatories. Maps of the distribution of the spotted regions on the photosphere of the binary components were derived using the Maximum Entropy and Tikhonov photometric regularization criteria. Rotational modulation was observed in Halpha and He I D-3 in anti-correlation with the photometric light curves. Both flares occurred at the same binary phase (0.85), suggesting that these events took place in the same active region. Simultaneous X-ray observations, performed by ASM on board RXTE, show several flare-like events, some of which correlate well with the observed optical flares. Rotational modulation in the X-ray light curve has been detected with minimum flux when the less active G5 V star was in front. A possible periodicity in the X-ray flare-like events was also found.

Non-radial pulsation, rotation and outburst in the Be star omega Orionis from the MuSiCoS 1998 campaign

omega Ori (HD37490, HR1934) is a Be star known to have presented variations. In order to investigate the nature and origin of its short-term and mid-term variability, a study is performed of several spectral lines (Halpha, Hdelta, HeI 4471, 4713, 4921, 5876, 6678, CII 4267, 6578, 6583, Mg II 4481, Si III 4553 and Si II 6347), based on 249 high signal-to-noise high-resolution spectra taken with 8 telescopes over 22 consecutive nights during the MuSiCoS (Multi SIte COntinuous Spectroscopy) campaign in November-December 1998. The stellar parameters are revisited and the projected rotational velocity (v sin i = 179 km s(-1)) is redetermined using several methods. With the MuSiCoS 98 dataset, a time series analysis of line-profile variations (LPVs) is performed using the Restricted Local Cleanest (RLC) algorithm and a least squares method. The behaviour of the velocity of the centroid of the lines, the equivalent widths and the apparent vsini for several lines, as well as Violet and Red components of photospheric lines affected by emission (red He i lines, Si II 6347, CII 6578, 6583) are analyzed. The non-radial pulsation (NRP) model is examined using phase diagrams and the Fourier-Doppler Imaging (FDI) method. The LPVs are consistent with a NRP mode with l = 2 or 3, \m\ = 2 with frequency 1.03 cd(-1). It is shown that an emission line outburst occurred in the middle of the campaign. Two scenarios are proposed to explain the behaviour of a dense cloud, temporarily orbiting around the star with a frequency 0.46 c d(-1), in relation to the outburst.

High contrast plasma mirror: spatial filtering and second harmonic generation at 10(19)Wcm(-2)

Recently, the use of plasma optics to improve temporal pulse contrast has had a remarkable impact on the field of high- power laser-solid density interaction physics. Opening an avenue to previously unachievable plasma density gradients in the high intensity focus, this advance has enabled researchers to investigate new regimes of harmonic generation and ion acceleration. Until now, however, plasma optics for fundamental laser reflection have been used in the sub-relativistic intensity regime (10(15) - 10(16)Wcm(-2)) showing high reflectivity (similar to 70%) and good focusability. Therefore, the question remains as to whether plasma optics can be used for such applications in the relativistic intensity regime (> 10(18)Wcm(-2)). Previous studies of plasma mirrors (PMs) indicate that, for 40 fs laser pulses, the reflectivity fluctuates by an order of magnitude and that focusability of the beam is lost as the intensity is increased above 5 x 10(16)Wcm(-2). However, these experiments were performed using laser pulses with a contrast ratio of similar to 10(7) to generate the reflecting surface. Here, we present results for PM operation using high contrast laser pulses resulting in a new regime of operation - the high contrast plasma mirror (HCPM). In this regime, pulses with contrast ratio > 10(10) are used to form the PM surface at > 10(19)Wcm(-2), displaying excellent spatial filtering, reflected near- field beam profile of the fundamental beam and reflectivities of 60 +/- 5%. Efficient second harmonic generation is also observed with exceptional beam quality suggesting that this may be a route to achieving the highest focusable harmonic intensities. Plasma optics therefore offer the opportunity to manipulate ultra-intense laser beams both spatially and temporally. They also allow for ultrafast frequency up-shifting without detrimental effects due to group velocity dispersion (GVD) or reduced focusability which frequently occur when nonlinear crystals are used for frequency conversion.

Transport Properties Investigation of Aqueous Protic Ionic Liquid Solutions through Conductivity, Viscosity, and NMR Self-Diffusion Measurements

We present a study on the transport properties through conductivity (s), viscosity (?), and self-diffusion coefficient (D) measurements of two pure protic ionic liquids—pyrrolidinium hydrogen sulfate, [Pyrr][HSO4], and pyrrolidinium trifluoroacetate, [Pyrr][CF3COO]—and their mixtures with water over the whole composition range at 298.15 K and atmospheric pressure. Based on these experimental results, transport mobilities of ions have been then investigated in each case through the Stokes–Einstein equation. From this, the proton conduction in these PILs follows a combination of Grotthuss and vehicle-type mechanisms, which depends also on the water composition in solution. In each case, the displacement of the NMR peak attributed to the labile proton on the pyrrolidinium cation with the PILs concentration in aqueous solution indicates that this proton is located between the cation and the anion for a water weight fraction lower than 8%. In other words, for such compositions, it appears that this labile proton is not solvated by water molecules. However, for higher water content, the labile protons are in solution as H3O+. This water weight fraction appears to be the solvation limit of the H+ ions by water molecules in these two PILs solutions. However, [Pyrr][HSO4] and [Pyrr][CF3COO] PILs present opposed comportment in aqueous solution. In the case of [Pyrr][CF3COO], ?, s, D, and the attractive potential, Epot, between ions indicate clearly that the diffusion of each ion is similar. In other words, these ions are tightly bound together as ion pairs, reflecting in fact the importance of the hydrophobicity of the trifluoroacetate anion, whereas, in the case of the [Pyrr][HSO4], the strong H-bond between the HSO4– anion and water promotes a drastic change in the viscosity of the aqueous solution, as well as on the conductivity which is up to 187 mS·cm–1 for water weight fraction close to 60% at 298 K.

A focused ultrasoft X-ray microbeam for targeting cells individually with submicrometer accuracy

The application of microbeams is providing new insights into the actions of radiation at the cell and tissue levels. So far, this has been achieved exclusively through the use of collimated charged particles. One alternative is to use ultrasoft X rays, focused by X-ray diffractive optics. We have developed a unique facility that uses 0.2-0.8-mm-diameter zone plates to focus ultrasoft X rays to a beam of less than 1 mum diameter. The zone plate images characteristic K-shell X rays of carbon or aluminum, generated by focusing a beam of 5-10 keV electrons onto the appropriate target. By reflecting the X rays off a grazing-incidence mirror, the contaminating bremsstrahlung radiation is reduced to 2%. The focused X rays are then aimed at selected subcellular targets using rapid automated cell-finding and alignment procedures; up to 3000 cells per hour can be irradiated individually using this arrangement. (C) 2001 by Radiation Research Society.

Observational and Dynamical Characterization of Main-belt Comet P/2010 R2 (La Sagra)

We present observations of the recently discovered comet-like main-belt object P/2010 R2 (La Sagra) obtained by Pan-STARRS1 and the Faulkes Telescope-North on Haleakala in Hawaii, the University of Hawaii 2.2 m, Gemini-North, and Keck I telescopes on Mauna Kea, the Danish 1.54 m telescope (operated by the MiNDSTEp consortium) at La Silla, and the Isaac Newton Telescope on La Palma. An antisolar dust tail is observed to be present from 2010 August through 2011 February, while a dust trail aligned with the object's orbit plane is also observed from 2010 December through 2011 August. Assuming typical phase darkening behavior, P/La Sagra is seen to increase in brightness by >1 mag between 2010 August and December, suggesting that dust production is ongoing over this period. These results strongly suggest that the observed activity is cometary in nature (i.e., driven by the sublimation of volatile material), and that P/La Sagra is therefore the most recent main-belt comet to be discovered. We find an approximate absolute magnitude for the nucleus of HR = 17.9 ± 0.2 mag, corresponding to a nucleus radius of ~0.7 km, assuming an albedo of p = 0.05. Comparing the observed scattering surface areas of the dust coma to that of the nucleus when P/La Sagra was active, we find dust-to-nucleus area ratios of Ad /AN = 30-60, comparable to those computed for fellow main-belt comets 238P/Read and P/2008 R1 (Garradd), and one to two orders of magnitude larger than for two other main-belt comets (133P/Elst-Pizarro and 176P/LINEAR). Using optical spectroscopy to search for CN emission, we do not detect any conclusive evidence of sublimation products (i.e., gas emission), finding an upper limit CN production rate of Q CN 100 Myr, suggesting that it is likely native to its current location and that its composition is likely representative of other objects in the same region of the main belt, though the relatively close proximity of the 13:6 mean-motion resonance with Jupiter and the (3,-2,-1) three-body mean-motion resonance with Jupiter and Saturn mean that dynamical instability on larger timescales cannot be ruled out.

Children's rights and educational policy in Europe: the implementation of the United Nations Convention on the Rights of the Child

This article aims to shed light on the impact of the United Nations Convention on the Rights of the Child (CRC) on education policy in Europe. The findings are based on a documentary analysis of the published reports of the Committee on the Rights of the Child (the Committee) on the implementation of the education rights in the CRC in every EU state. This included: a review of the state of children's rights to education in Europe as perceived by the Committee; a summary of the Committee's key recommendations for governments; and an assessment of whether the CRC can be considered to have influenced domestic education law and policies. The findings suggest that the CRC is having an impact on domestic education policy and that the child rights framework could be harnessed further by those seeking to influence government. The article concludes by reflecting on the factors which affect the processes of translating the CRC into policy and practice and explores the role that educationalists, both academic and practitioners, might play in its implementation.

Special Needs Education, eLearning and the Reflective ePortfolio: Implications for Developing and Assessing Competence in Pre-Service Education.

This paper reports on the use of an eportfolio for assessing aspects of a Post-Graduate pre-service teacher education programme specifically in the context of special needs education in Northern Ireland. Participants were challenged to develop their individual eportfolios by selecting and presenting evidence for assessment drawn from diverse sources. The rationale for using eportfolios for assessment purposes was to offer students the opportunity to demonstrate competencies by documenting and reflecting upon academic and pedagogical learning during a one year Post Graduate Certificate of Education (PGCE) programme.

Neolithic farming in north-western Europe: archaeobotanical evidence from Ireland

This paper presents significant new insights into the appearance of agriculture at the north- western edge of Europe, focusing on Neolithic Ireland (4000-2500 cal BC). Previous studies were based upon a limited plant macro-remains dataset, as much of the Irish evidence is unpublished. A research project, 'Cultivating Societies', was implemented to examine the nature, timing and extent of agricultural activity in Neolithic Ireland through collation and analysis of different strands of published and unpublished archaeological and environmental evidence, with a particular focus on plant macro- remains, pollen, settlement and 14C data. Plant macro-remains from a total of 52 excavated sites were collated and analysed, representing the most comprehensive study to date of Neolithic plant remains from this region. Cereals were present at many locations and site types, sometimes in large quantities and most often at sites dating to the earlier Neolithic (3750-3600 cal BC). Emmer wheat was the dominant crop, at least at this time. Other crops included naked and hulled barley, naked wheat, einkorn wheat and flax. Analysis of arable weeds indicates that early plots were not managed under a shifting cultivation regime, which has important implications for understanding Neolithic settlement practices and how communities engaged with landscapes. The variety of crops cultivated in Neolithic Ireland is similar to those in Britain, reflecting a decreasing diversity in crop types as agriculture spread from south-east to north-west Europe.

Bacteriophages as anti-infective agents: recent developments and regulatory challenges.

The biennial meeting on 'Exploiting Bacteriophages for Bioscience, Biotechnology and Medicine', held in London, UK, on 20 January 2012, and chaired by George Salmond (University of Cambridge, UK) hosted over 50 participants representing 13 countries. The highly multidisciplinary meeting covered a diverse range of topics, reflecting the current expansion of interest in this field, including the use of bacteriophages as the source of biochemical reagents for molecular biology, bacteriophages for the treatment of human and animal diseases, bacteriophage-based diagnostics and therapeutic delivery technologies and necessity for, and regulatory challenges associated with, robust clinical trials of phage-based therapeutics. This report focuses on a number of presentations from the meeting relating to cutting-edge research on bacteriophages as anti-infective agents.

Defending the Faith(s)?:Democracy and Hereditary Right in England

The persistence of traditional monarchies in modern societies, which are otherwise characterized by democratic and egalitarian values, remains a paradox in the social sciences. In part this is attributable to the lack of psychological investigation into the relationship between subject and sovereign, and in particular the ways in which the political and social values of the citizenry shape understandings of a hereditary monarch’s right to represent a national community. Adopting the qualitative analysis methods of discursive psychology and grounded theory, the current study examines vernacular accounts of nationhood and monarchy in England in both formalized conversational interviews (n = 60) and impromptu street interviews (n = 56). Focusing on accounts of Prince Charles’s recent proposal to change the role of the monarch, from “Defender of the (Christian) Faith” to “Defender of Faiths,” those in favor treated it as a positive step towards reflecting a diverse (religious) community, bringing the monarchy into line with current concerns of pluralism and upholding
values of personal choice and individual rights. Participants who rejected the proposed change in title construed it as antithetical to these values in terms of reflecting personal stake and interest, an abuse of power, or an imposition on other faiths. In all accounts, the prime concern was in safeguarding the political and social values of the citizenry. In conclusion it is argued that the study of subjects’ relationship to the monarch, its function and legitimacy, can provide an opportunity to examine how values can characterize a national community and facilitate national diversity.

Using solute/ micro organism comparative tracer testing to investigate hydrogeological heterogeneity in a fluvioglacial sand and gravel aquifer.

Groundwater drawn from fluvioglacial sand and gravel aquifers form the principal source of drinking water in many part of central Western Europe. High population densities and widespread organic agriculture in these same areas constitute hazards that may impact the microbiological quality of many potable supplies. Tracer testing comparing two similarly sized bacteria (E.coli and P. putida) and the smaller bacteriophage (H40/1) with the response of non-reactive solute tracer (uranine) at the decametre scale revealed that all tracers broke through up to 100 times more quickly than anticipated using conventional rules of thumb. All microbiological tracer responses were less disperse than the solute, although bacterial peak relative concentrations consistently exceeded those of the solute tracer at one sampling location reflecting exclusion processes influencing micro biological tracer migration. Relative recoveries of H40/1 and E.coli proved consistent at both monitoring wells, while responses of H40/1 and P.putida differed. Examination of exposures of the upper reaches of the aquifer in nearby sand and gravel quarries revealed the aquifer to consist of laterally extensive layers of open framework (OW) gravel enveloped in finer grained gravelly sand. Granulometric analysis of these deposits suggested that the OW gravel was up to two orders of magnitude more permeable than the surrounding deposits giving rise to the preferential flow paths. By contrast fine grained lenses of silty sand within the OW gravels are suspected to play an important role in the exclusion processes that permit solutes to access them but exclude larger micro organisms.