Environmental tolerances of free-living coralline algae (maerl): implications for European marine conservation

Maerl is a general term used for loose-lying subtidal beds of nodular coralline red algae. Maerl beds support high associated invertebrate and algal biodiversity, and are subject to European and UK conservation legislation. Previous investigations have shown European maerl to be ecologically fragile due to growth rates of approximately I mm per year. However, these very slow growth rates have hampered attempts to determine the key ecological requirements and sensitivity characteristics of living maerl. In this study, photosynthetic capacity determined by pulse amplitude modulated (PAM) fluorometry was used as a diagnostic of stress caused by various environmental conditions. Maerl species were exposed to a range of temperatures, salinities and light levels and to burial, fragmentation, desiccation and heavy metal treatment. Maerl was not as susceptible as previously assumed to extremes of salinity, temperature and heavy metal pollution, but burial, especially in fine or anoxic sediments, was lethal or caused significant stress. These data indicate that the main anthropogenic hazard for live maerl and the rich communities that depend on them is smothering by fine sediment, such as that produced by trawling or maerl extraction, from sewage discharges or shellfish and fish farm waste, and sedimentation resulting from disruption to tidal flow. (C) 2004 Elsevier Ltd. All rights reserved.

Anomalous helicon wave absorption and parametric excitation of electrostatic fluctuations in a helicon-produced plasma

The nonlinear nature of the rf absorption in a helicon-produced plasma was recently evidenced by the observation that the helicon wave damping as well as the level of short-scale electrostatic fluctuations excited in the helicon plasma increases with rf power. Correlation methods using electrostatic probes as well as microwave back-scattering at the upper-hybrid resonance allow identifying the fluctuations as ion-sound and Trivelpiece– Gould waves satisfying the frequency and wavenumber matching conditions for the parametric decay instability of the helicon pump wave. Furthermore, the growth rates and thresholds deduced from their temporal growth are in good agreement with theoretical predictions for the parametric decay instability that takes into account realistic damping rates for the decay waves as well as a non-vanishing parallel wavenumber of the helicon pump. The close relationship between the rf absorption and the excitation of the fluctuations was investigated in more detail by performing time- and space-resolved measurements of the helicon wave field and the electrostatic fluctuations.

The effect of feeder type and change of feeder type on growing and finishing pig performance and behaviour

Reduced feed intake and hence lower growth rates commonly occur when the environment of the pig changes, e.g. at weaning and when pigs are moved from growing accommodation to finishing accommodation. It is hypothesised that if environmental factors, such as feeder type, remain the same in the weaning and finishing accommodation this 'growth check' may be reduced. A total of 640 pigs in 32 pens of 20 pigs per pen were used to investigate the effects of two feeder types and changing or not changing the feeder type at 10 weeks of age on growth performance and behaviour in the periods from 4 to 10, 10 to finish (22) and from 4 to finish (22) weeks of age, respectively. The two feeder types tested were a 'wet and dry' single-space (S) feeder and a 'dry' multi-space feeder (M).

Desegregation and Place Restructuring in the New Belfast

A sustained reduction in unemployment, economic growth and house price increase have reflected Belfast’s post-conflict renaissance just as readily as the global recession has exposed the fragility of construction-led growth. Rates of segregation had stabilised and new consumption spaces and élite developments further reflected the city’s engagement with globalisation and economic liberalisation. This paper explores the spatial impact of these processes, not least as gentrification has created new layers of residential segregation in a city already preoccupied with high rates of ethno-religious territoriality. A case study of south Belfast connects these shifts to the production of new mixed-religion neighbourhoods. These have the capacity to reduce the relevance of traditional binary identities, but at the same time reproduce new forms of segregation centred on tenure and class. The paper concludes by highlighting the implications for policy and practice, not least as the recession opens new spaces to present alternatives to the market logic.

Correlation Between the Electrical and Optical Properties of an Atmospheric Pressure Plasma During Siloxane Coating Deposition

The effect of varying process parameters on atmospheric plasma characteristics and properties of nanometre thick siloxane coatings is investigated in a reel-to-reel deposition process. Varying plasma operation modes were observed with increasing applied power for helium and helium/oxygen plasmas. The electrical and optical behaviour of the dielectric barrier discharge were determined from current/voltage, emission spectroscopy and time resolved light emission measurements. As applied power increased, multiple discharge events occurred, producing a uniform multi-peak pseudoglow discharge, resulting in an increase in the discharge gas temperature. The effects of different operating modes on coating oxidation and growth rates were examined by injecting hexamethyldisiloxane liquid precursor into the chamber under varying operating conditions. A quenching effect on the plasma was observed, causing a decrease in plasma input power and emission intensity. Siloxane coatings deposited in helium plasmas had a higher organic component and higher growth rates than those deposited in helium/oxygen plasmas.

How the ship of fools was ship-wrecked - The Irish crisis and response

For a decade and half the Irish economy was the poster-boy of Europe. With substantial growth rates, an open economy, flexible labour markets and low levels of taxation, Ireland was seen as evidence of the success of neoliberal policies. Yet in the matter of a few short years Ireland has turned into a one of the peripheral black-holes (along with Greece and Portugal) that are threatening to bring down the whole Eurozone project. Given this context the paper will address two key questions. Firstly how did the much eulogised Celtic Tiger fall so far and so fast? And, secondly, what has been the government’s response to the fall and crash of the Irish economy? These two questions will be addressed through both a general historical analysis of the developments of Irish society up to the crash in 2008 and then the responses to it. Secondly by an analysis of two specific elements of that development; namely the much discussed low corporation tax rate and the failure of social housing to deliver decent affordable homes for those at the bottom of society. The third element is a review of the banking and sovereign debt crisis that led to the IMF/EU deal in November 2010 and a brief outlining of its implications for public finances, especially the question of default. The paper concludes by placing the Irish crisis in a global context.

Influence of molten-state annealing on the phase structure and crystallization behaviour of high impact polypropylene copolymer

The phase structure evolution of high impact polypropylene copolymer (IPC) during molten-state annealing and its influence on crystallization behaviour were studied. An entirely different architecture of the IPC melt was observed after being annealed, and this architecture resulted in variations of the crystallization behaviour. In addition, it was found that the core-shell structure of the dispersed phase was completely destroyed and the sizes of the dispersed domains increased sharply after being annealed at 200 degrees C for 200 min. Through examination of the coarseness of the phase morphology using phase contrast microscopy (PCM), it was found that a co-continuous structure and an abnormal 'sea-island' structure generally appeared with an increase in annealing time. The original matrix PP component appeared as a dispersed phase, whereas the copolymer components formed a continuous 'sea-island' structure. This change is ascribed to the large tension induced by solidification at the phase interface and the great content difference between the components. When the temperature was reduced the structure reverted to its original form. With increasing annealing time, the spherulite profiles became more defined and the spherulite birefringence changed from vague to clear. Overall crystallization rates and nucleation densities decreased, but the spherulite radial growth rates remained almost constant, indicating that molten-state annealing mainly affects the nucleation ability of IPC, due to a coarsened microstructure and decreased interface area. (C) 2011 Elsevier Ltd. All rights reserved.

Variation in stable carbon isotope fractionation during aerobic degradation of phenol and benzoate by contaminant degrading bacteria

Variation in the natural abundance stable carbon isotope composition of respired CO2 and biomass has been measured for two types of aerobic bacteria found in contaminated land sites. Pseudomonas putida strain NCIMB 10015 was cultured on phenol and benzoate and Rhodococcus sp. I-1 was cultured on phenol. Results indicate that aerobic isotope fractionations of differing magnitudes occur during aerobic biodegradation of these substrates with an isotopic depletion in the CO2 (Delta(13)C(phenol-CO2)) as much as 3.7 parts per thousand and 5.6 parts per thousand for Pseudomonas putida and Rhodococcus sp. I-1 respectively. This observation has significant implications for the use of a stable isotope mass balance approach in monitoring degradation processes that rely on indigenous bacterial populations. The effects of the metabolic pathway utilised in degradation and inter-species variation on the magnitude of isotope fractionation are discussed. Possible explanations for the observed isotope fractionation include differences in the metabolic pathways utilised by the organisms and differences in specific growth rates and physiology. (C) 1999 Elsevier Science Ltd. All rights reserved.

Atmospheric pressure chemical vapour deposition of titanium dioxide coatings on glass

Atmospheric pressure chemical vapour deposition of titanium dioxide coatings on glass substrates was achieved by the reaction of TiCl4 and a co-oxygen source (MeOH, EtOH, (PrOH)-Pr-i or H2O) at 500-650degreesC. The coatings show excellent uniformity, surface coverage and adherence. Growth rates were of the order of 0.3 mum min(-1) at 500degreesC. All films are crystalline and single phase with XRD showing the anatase TiO2 diffraction pattern; a = 3.78(1), c = 9.51(1) Angstrom. Optically, the films show minimal reflectivity from 300-1600 nm and 50-80% total transmission from 300-800 nm. Contact angles are in the range 20-40degrees for as-prepared films and 1-10degrees after 30 min irradiation at 254 nm. All of the films show significant photocatalyic activity as regards the destruction of an overlayer of stearic acid.

Temporally and spatially resolved measurements of multi-megagauss magnetic fields in high intensity laser-produced plasmas

We report spatially and temporally resolved measurements of self-generated multi-megagauss magnetic fields produced during ultrahigh intensity laser plasma interactions. Spatially resolved measurements of the magnetic fields show an asymmetry in the distribution of field with respect to the angle of laser incidence. Temporally resolved measurements of the self-generated third harmonic suggest that the strength of the magnetic field is proportional to the square root of laser intensity (i.e., the laser B-field) during the rise of the laser pulse. The experimental results are compared with numerical simulations using a particle-in-cell code which also shows clear asymmetry of the field profile and similar magnetic field growth rates and scalings.

Species introduction promotes hybridization and introgression in Coregonus: is there sign of selection against hybrids?

Species introductions are considered one of the major drivers of biodiversity loss via ecological interactions and genetic admixture with local fauna. We examined two well-recognized fish species, native whitefish (Coregonus lavaretus) and introduced vendace (Coregonus albula), as well as their morphological hybrids in a single lake to test for selection against hybrids and backcrosses in the wild. A representative random subsample of 693 individuals (27.8%) was taken from the total catch of coregonids. This subsample was examined with the aim to select c. 50 individuals of pure whitefish (n = 52), pure vendace (n = 55) and putative hybrid (n = 19) for genetic analyses. The subsequent microsatellites and mitochondrial (mt) DNA analyses provided compelling evidence of hybridization and introgression. Of the 126 fish examined, four were found to be F-1, 14 backcrosses to whitefish and seven backcrosses to vendace. The estimates of historical gene flow suggested higher rates from introduced vendace into native whitefish than vice versa, whereas estimates of contemporary gene flow were equal. Mitochondrial introgression was skewed, with 18 backcrosses having vendace mtDNA and only three with whitefish mtDNA. Hybrids and backcrosses had intermediate morphology and niche utilization compared with parental species. No evidence of selection against hybrids or backcrosses was apparent, as both hybrid and backcross growth rates and fecundities were high. Hybrids (F-1) were only detected in 2 year-classes, suggesting temporal variability in mating between vendace and whitefish. However, our data show that hybrids reached sexual maturity and reproduced actively, with backcrosses recorded from six consecutive year-classes, whereas no F-2 individuals were found. The results indicate widespread introgression, as 10.8% of coregonids were estimated to be backcrosses.

Trends in the use of psychotropic medications among adolescents, 1994 to 2001

Objectives: Few psychotropic medications are approved for use among children younger than 18 years. Yet previous studies have shown an increase in the use of psychotropic medications among school-age children and adolescents. Most previous studies examined data only up to 1997; therefore, the results predate any impact of changing federal policies and newly marketed medications. This study examined trends in the prescription of psychotropic medications to adolescents aged 14 to 18 years in office-based care in the United States from 1994 to 2001. Methods: Data from the National Ambulatory Medical Care Survey (NAMCS) were used to determine visit rates and prescribing patterns from 1994 to 2001 for psychotropics that were prescribed in office-based treatment settings to adolescents aged 14 to 18 years. Rates of visits that resulted in a prescription for psychotropic medication were calculated for two-year periods. Analyses were conducted by type of medication, gender, and the prescribing physician's specialty. Results: Rates of visits that resulted in a psychotropic prescription increased from 3.4 percent in 1994-1995 to 8.3 percent in 2000-2001. These trends were evident for males and females. The average annual growth rates for psychotropic prescriptions were much higher after 1999. Trends were also significant across drug classes. By 2001, one out of ten office visits by adolescent males resulted in a prescription for a psychotropic medication. Conclusions: Average annual growth rates for the prescription of psychotropics to adolescents increased from 1994 to 2001, with especially rapid acceleration after 1999. This increase may be associated with changing thresholds of diagnosis and treatment, availability of new medications, and changes in federal regulatory policies concerning promotion of medications by the pharmaceutical industry.

A cosmic ray current-driven instability in partially ionised media

Context. We investigate the growth of hydromagnetic waves driven by streaming cosmic rays in the precursor environment of a supernova remnant shock.

Aims. It is known that transverse waves propagating parallel to the mean magnetic field are unstable to anisotropies in the cosmic ray distribution, and may provide a mechanism to substantially amplify the ambient magnetic field. We quantify the extent to which temperature and ionisation fractions modify this picture.

Methods. Using a kinetic description of the plasma we derive the dispersion relation for a collisionless thermal plasma with a streaming cosmic ray current. Fluid equations are then used to discuss the effects of neutral-ion collisions.

Results. We calculate the extent to which the environment into which the cosmic rays propagate influences the growth of the magnetic field, and determines the range of possible growth rates.

Conclusions. If the cosmic ray acceleration is efficient, we find that very large neutral fractions are required to stabilise the growth of the non-resonant mode. For typical supernova parameters in our Galaxy, thermal effects do not significantly alter the growth rates. For weakly driven modes, ion-neutral damping can dominate over the instability at more modest ionisation fractions. In the case of a supernova shock interacting with a molecular clouds, such as in RX J1713.7-3946, with high density and low ionisation, the modes can be rapidly damped.

On the maximum energy of shock-accelerated cosmic rays at ultra-relativistic shocks

The maximum energy to which cosmic rays can be accelerated at weakly magnetised ultra-relativistic shocks is investigated. We demonstrate that for such shocks, in which the scattering of energetic particles is mediated exclusively by ion skin-depth scale structures, as might be expected for a Weibel-mediated shock, there is an intrinsic limit on the maximum energy to which particles can be accelerated. This maximum energy is determined from the requirement that particles must be isotropized in the downstream plasma frame before the mean field transports them far downstream, and falls considerably short of what is required to produce ultra-high-energy cosmic rays. To circumvent this limit, a highly disorganized field is required on larger scales. The growth of cosmic ray-induced instabilities on wavelengths much longer than the ion-plasma skin depth, both upstream and downstream of the shock, is considered. While these instabilities may play an important role in magnetic field amplification at relativistic shocks, on scales comparable to the gyroradius of the most energetic particles, the calculated growth rates have insufficient time to modify the scattering. Since strong modification is a necessary condition for particles in the downstream region to re-cross the shock, in the absence of an alternative scattering mechanism, these results imply that acceleration to higher energies is ruled out. If weakly magnetized ultra-relativistic shocks are disfavoured as high-energy particle accelerators in general, the search for potential sources of ultra-high-energy cosmic rays can be narrowed.

Monodomain strained ferroelectric PbTiO(3) thin films: Phase transition and critical thickness study

This work demonstrates that instead of paraelectric PbTiO(3), completely c-oriented ferroelectric PbTiO(3) thin films were directly grown on (001)-SrTiO(3) substrates by pulsed-laser deposition with thickness up to 340 nm at a temperature well above the Curie temperature of bulk PbTiO(3). The influence of laser-pulse frequency, substrate-surface termination on growth, and functional properties were studied using x-ray diffraction, transmission electron microscopy, and piezoresponse force microscopy. At low growth rates (frequency 8 Hz) a domains were formed for film thickness above 20-100 nm. Due to coherency strains the Curie temperature (T(c)) of the monodomain films was increased approximately by 350 degrees C with respect to the T(c) of bulk PbTiO(3) even for 280-nm-thick films. Nonetheless, up to now this type of growth mode has been considered unlikely to occur since the Matthews-Blakeslee (MB) model already predicts strain relaxation for films having a thickness of only similar to 10 nm. However, the present work disputes the applicability of the MB model. It clarifies the physical reasons for the large increase in T(c) for thick films, and it is shown that the experimental results are in good agreement with the predictions based on the monodomain model of Pertsev et al. [Phys. Rev. Lett. 80, 1988 (1998)].