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Southeast Asia is considered to have some of the highest levels of marine plastic pollution in the world. It is therefore vitally important to increase our understanding of the impacts and risks of plastic pollution to marine ecosystems and the essential services they provide to support the development of mitigation measures in the region. An interdisciplinary, international network of experts (Australia, Indonesia, Ireland, Malaysia, the Philippines, Singapore, Thailand, the United Kingdom, and Vietnam) set a research agenda for marine plastic pollution in the region, synthesizing current knowledge and highlighting areas for further research in Southeast Asia. Using an inductive method, 21 research questions emerged under five non-predefined key themes, grouping them according to which: (1) characterise marine plastic pollution in Southeast Asia; (2) explore its movement and fate across the region; (3) describe the biological and chemical modifications marine plastic pollution undergoes; (4) detail its environmental, social, and economic impacts; and, finally, (5) target regional policies and possible solutions. Questions relating to these research priority areas highlight the importance of better understanding the fate of marine plastic pollution, its degradation, and the impacts and risks it can generate across communities and different ecosystem services. Knowledge of these aspects will help support actions which currently suffer from transboundary problems, lack of responsibility, and inaction to tackle the issue from its point source in the region. Being profoundly affected by marine plastic pollution, Southeast Asian countries provide an opportunity to test the effectiveness of innovative and socially inclusive changes in marine plastic governance, as well as both high and low-tech solutions, which can offer insights and actionable models to the rest of the world. National Research Foundation (NRF) Published version This study was supported by the National Research Foundation, Prime Ministers Office (Singapore) and the Natural Environment Research Council (United Kingdom) under the NRF-NERC-SEAP-2020 grant call ‘Understanding the Impact of Plastic Pollution on Marine Ecosystems in Southeast Asia (South East Asia Plastics [SEAP])’. The four funded projects are Risks and Solutions: Marine Plastics in Southeast Asia – RaSP-SEA (NRF Award No. NRF-NERC-SEAP-2020- 0004, NERC Award No. NE/V009354/1 and NE/V009362/1); Southeast Asia Marine Plastics (SEAmap; NERC Award No. NE/V009427/1): Reduction, Control, and Mitigation of Marine Plastic Pollution in the Philippines; Microbial transformation of plastics in Southeast Asian seas: a hazard and a solution (MicroSEAP; NRF Award No. NRF-NERC-SEAP2020-0002, NERC Award No. NE/V009516/1); and Sources, impacts and solutions for plastics in Southeast Asia coastal environment (NRF Award No. NRF-NERC-SEAP-2020-0003, NERC Award No. NE/V009621/1).

Ecological interactions between marine bacteria and phytoplankton play a pivotal role in governing the ocean’s major biogeochemical cycles. Among these, members of the marine Roseobacter Group (MRG) can establish mutualistic relationships with phytoplankton that are, in part, maintained by exchanges of the organosulfur compound, dimethylsulfoniopropionate (DMSP). Yet most of what is known about these interactions has been derived from culture-based laboratory studies. To investigate temporal and spatial co-occurrence patterns between members of the MRG and DMSP-producing phytoplankton we analysed 16S and 18S rRNA gene amplicon sequence variants (ASVs) derived from 5 years of monthly samples from seven environmentally distinct Australian oceanographic time-series. The MRG and DMSP-producer communities often displayed contemporaneous seasonality, which was greater in subtropical and temperate environments compared to tropical environments. The relative abundance of both groups varied latitudinally, displaying a poleward increase, peaking (MRG at 33% of total bacteria, DMSP producers at 42% of eukaryotic phototrophs) during recurrent spring-summer phytoplankton blooms in the most temperate site (Maria Island, Tasmania). Network analysis identified 20,140 significant positive correlations between MRG ASVs and DMSP producers and revealed that MRGs exhibit significantly stronger correlations to high DMSP producers relative to other DMSP-degrading bacteria (Pelagibacter, SAR86 and Actinobacteria). By utilising the power of a continental network of oceanographic time-series, this study provides in situ confirmation of interactions found in laboratory studies and demonstrates that the ecological dynamics of an important group of marine bacteria are shaped by the production of an abundant and biogeochemically significant organosulfur compound.

Corals and the reef ecosystems that they support are in global decline due to increasing anthropogenic pressures such as climate change1. However, effective reef conservation strategies are hampered by a limited mechanistic understanding of coral biology and the functional roles of the diverse microbial communities that underpin coral health2,3. Here, we present an integrated genomic characterization of the coral species Porites lutea and its microbial partners. High-quality genomes were recovered from P. lutea, as well as a metagenome-assembled Cladocopium C15 (the dinoflagellate symbiont) and 52 bacterial and archaeal populations. Comparative genomic analysis revealed that many of the bacterial and archaeal genomes encode motifs that may be involved in maintaining association with the coral host and in supplying fixed carbon, B-vitamins and amino acids to their eukaryotic partners. Furthermore, mechanisms for ammonia, urea, nitrate, dimethylsulfoniopropionate and taurine transformation were identified that interlink members of the holobiont and may be important for nutrient acquisition and retention in oligotrophic waters. Our findings demonstrate the critical and diverse roles that microorganisms play within the coral holobiont and underscore the need to consider all of the components of the holobiont if we are to effectively inform reef conservation strategies.

Western boundary currents (WBCs) redistribute heat and oligotrophic seawater from the tropics to temperate latitudes, with several displaying substantial climate change-driven intensification over the last century. Strengthening WBCs have been implicated in the poleward range expansion of marine macroflora and fauna, however, the impacts on the structure and function of temperate microbial communities are largely unknown. Here we show that the major subtropical WBC of the South Pacific Ocean, the East Australian Current (EAC), transports microbial assemblages that maintain tropical and oligotrophic (k-strategist) signatures, to seasonally displace more copiotrophic (r-strategist) temperate microbial populations within temperate latitudes of the Tasman Sea. We identified specific characteristics of EAC microbial assemblages compared with non-EAC assemblages, including strain transitions within the SAR11 clade, enrichment of Prochlorococcus, predicted smaller genome sizes and shifts in the importance of several functional genes, including those associated with cyanobacterial photosynthesis, secondary metabolism and fatty acid and lipid transport. At a temperate time-series site in the Tasman Sea, we observed significant reductions in standing stocks of total carbon and chlorophyll a, and a shift towards smaller phytoplankton and carnivorous copepods, associated with the seasonal impact of the EAC microbial assemblage. In light of the substantial shifts in microbial assemblage structure and function associated with the EAC, we conclude that climate-driven expansions of WBCs will expand the range of tropical oligotrophic microbes, and potentially profoundly impact the trophic status of temperate waters.

Introduction: There are little data to support the use of continuous aerosolized albuterol (CAA) in the non-intensive care unit (ICU) or non-emergency department (ED) setting for pediatric asthma patients. A 2014 study demonstrated low rates of adverse outcomes associated with administration of CAA on the acute care unit; however, the authors do not describe additional outcomes. We sought to determine whether administration of CAA within a respiratory cohort on an acute care floor was feasible and safe. Methods: This quasi-experimental study evaluates data 1 year before and after (2014–2016) the initiation of CAA on the acute care inpatient unit for asthma patients 2−18 years of age. Outcome measures included ED and hospital length of stay (LOS), readmission rate, rapid response team activations, and transfers to ICU. Use of chest x-rays, viral studies, and hospital charges were also studied. Results: Seven hundred thirty-two patients met study criteria. Population demographics and severity of acute presentation were similar pre- and poststudy. ED LOS decreased poststudy, whereas overall hospital LOS was unchanged. Fifteen-day readmission rate decreased in the poststudy group. Only 4 rapid response activations occurred in the poststudy population. The poststudy group utilized fewer chest x-rays and viral studies. There was no change in overall hospital charges. Conclusions: With appropriate resources and safety processes in place, care of pediatric patients with status asthmaticus receiving CAA on an acute care unit, outside of the ICU, resulted in improved ED LOS with evidence of lower resource utilization and rare adverse outcomes.

Corals and the reef ecosystems that they support are in global decline due to increasing anthropogenic pressures such as climate change

© 2016 International Society for Microbial Ecology. Australia's tropical waters represent predicted 'hotspots' for nitrogen (N 2) fixation based on empirical and modelled data. However, the identity, activity and ecology of diazotrophs within this region are virtually unknown. By coupling DNA and cDNA sequencing of nitrogenase genes (nifH) with size-fractionated N 2 fixation rate measurements, we elucidated diazotroph dynamics across the shelf region of the Arafura and Timor Seas (ATS) and oceanic Coral Sea during Austral spring and winter. During spring, Trichodesmium dominated ATS assemblages, comprising 60% of nifH DNA sequences, while Candidatus Atelocyanobacterium thalassa (UCYN-A) comprised 42% in the Coral Sea. In contrast, during winter the relative abundance of heterotrophic unicellular diazotrophs (δ-proteobacteria and γ-24774A11) increased in both regions, concomitant with a marked decline in UCYN-A sequences, whereby this clade effectively disappeared in the Coral Sea. Conservative estimates of N 2 fixation rates ranged from

Marine Group II (MGII) archaea represent the most abundant planktonic archaeal group in ocean surface waters, but our understanding of the group has been limited by a lack of cultured representatives and few sequenced genomes. Here, we conducted a comparative phylogenomic analysis of 270 recently available MGII metagenome-assembled genomes (MAGs) to investigate their evolution and ecology. Based on a rank-normalised genome phylogeny, we propose that MGII is an order-level lineage for which we propose the name Candidatus Poseidoniales (after Gr. n. Poseidon, God of the sea), comprising the families Candidatus Poseidonaceae fam. nov. (formerly subgroup MGIIa) and Candidatus Thalassarchaeaceae fam. nov. (formerly subgroup MGIIb). Within these families, 21 genera could be resolved, many of which had distinct biogeographic ranges and inferred nutrient preferences. Phylogenetic analyses of key metabolic functions suggest that the ancestor of Ca. Poseidoniales was a surface water-dwelling photoheterotroph that evolved to occupy multiple related ecological niches based primarily on spectral tuning of proteorhodopsin genes. Interestingly, this adaptation appears to involve an overwrite mechanism whereby an existing single copy of the proteorhodopsin gene is replaced by a horizontally transferred copy, which in many instances should allow an abrupt change in light absorption capacity. Phototrophy was lost entirely from five Ca. Poseidoniales genera coinciding with their adaptation to deeper aphotic waters. We also report the first instances of nitrate reductase in two genera acquired via horizontal gene transfer (HGT), which was a potential adaptation to oxygen limitation. Additional metabolic traits differentiating families and genera include flagellar-based adhesion, transporters, and sugar, amino acid, and peptide degradation. Our results suggest that HGT has shaped the evolution of Ca. Poseidoniales to occupy a variety of ecological niches and to become the most successful archaeal lineage in ocean surface waters.

Marine Group II (MGII) archaea represent the most abundant planktonic archaeal group in ocean surface waters, but our understanding of the group has been limited by a lack of cultured representatives and few sequenced genomes. Here, we conducted a comparative phylogenomic analysis of 270 recently available MGII metagenome-assembled genomes (MAGs) to investigate their evolution and ecology. Based on a rank-normalised genome phylogeny, we propose that MGII is an order-level lineage for which we propose the name Candidatus Poseidoniales (after Gr. n. Poseidon, God of the sea), comprising the families Candidatus Poseidonaceae fam. nov. (formerly subgroup MGIIa) and Candidatus Thalassarchaeaceae fam. nov. (formerly subgroup MGIIb). Within these families, 21 genera could be resolved, many of which had distinct biogeographic ranges and inferred nutrient preferences. Phylogenetic analyses of key metabolic functions suggest that the ancestor of Ca. Poseidoniales was a surface water-dwelling photoheterotroph that evolved to occupy multiple related ecological niches based primarily on spectral tuning of proteorhodopsin genes. Interestingly, this adaptation appears to involve an overwrite mechanism whereby an existing single copy of the proteorhodopsin gene is replaced by a horizontally transferred copy, which in many instances should allow an abrupt change in light absorption capacity. Phototrophy was lost entirely from five Ca. Poseidoniales genera coinciding with their adaptation to deeper aphotic waters. We also report the first instances of nitrate reductase in two genera acquired via horizontal gene transfer (HGT), which was a potential adaptation to oxygen limitation. Additional metabolic traits differentiating families and genera include flagellar-based adhesion, transporters, and sugar, amino acid, and peptide degradation. Our results suggest that HGT has shaped the evolution of Ca. Poseidoniales to occupy a variety of ecological niches and to become the most successful archaeal lineage in ocean surface waters.

Sustained observations of microbial dynamics are rare, especially in southern hemisphere waters. The Australian Marine Microbial Biodiversity Initiative (AMMBI) provides methodologically standardized, continental scale, temporal phylogenetic amplicon sequencing data describing Bacteria, Archaea and microbial Eukarya assemblages. Sequence data is linked to extensive physical, biological and chemical oceanographic contextual information. Samples are collected monthly to seasonally from multiple depths at seven sites: Darwin Harbour (Northern Territory), Yongala (Queensland), North Stradbroke Island (Queensland), Port Hacking (New South Wales), Maria Island (Tasmania), Kangaroo Island (South Australia), Rottnest Island (Western Australia). These sites span ~30° of latitude and ~38° longitude, range from tropical to cold temperate zones, and are influenced by both local and globally significant oceanographic and climatic features. All sequence datasets are provided in both raw and processed fashion. Currently 952 samples are publically available for bacteria and archaea which include 88,951,761 bacterial (72,435 unique) and 70,463,079 archaeal (24,205 unique) 16 S rRNA v1-3 gene sequences, and 388 samples are available for eukaryotes which include 39,801,050 (78,463 unique) 18 S rRNA v4 gene sequences.

© 2017 Messer, Brown, Furnas, Carney, McKinnon and Seymour. Discrepancies between bioavailable nitrogen (N) concentrations and phytoplankton growth rates in the oligotrophic waters of the Great Barrier Reef (GBR) suggest that undetermined N sources must play a significant role in supporting primary productivity. One such source could be biological dinitrogen (N2) fixation through the activity of "diazotrophic" bacterioplankton. Here, we investigated N2 fixation and diazotroph community composition over 10° S of latitude within GBR surface waters. Qualitative N2 fixation rates were found to be variable across the GBR but were relatively high in coastal, inner and outer GBR waters, reaching 68 nmol L-1 d-1. Diazotroph assemblages, identified by amplicon sequencing of the nifH gene, were dominated by the cyanobacterium Trichodesmium erythraeum, γ-proteobacteria from the Gamma A clade, and δ-proteobacterial phylotypes related to sulfate-reducing genera. However, diazotroph communities exhibited significant spatial heterogeneity, correlated with shifts in dissolved inorganic nutrient concentrations. Specifically, heterotrophic diazotrophs generally increased in relative abundance with increasing concentrations of phosphate and N, while Trichodesmium was proportionally more abundant when concentrations of these nutrients were low. This study provides the first in-depth characterization of diazotroph community composition and N2 fixation dynamics within the oligotrophic, N-limited surface waters of the GBR. Our observations highlight the need to re-evaluate N cycling dynamics within oligotrophic coral reef systems, to include diverse N2 fixing assemblages as a potentially significant source of dissolved N within the water column.

The intensification of western boundary currents in the global ocean will potentially influence meso-scale eddy generation, and redistribute microbes and their associated ecological and biogeochemical functions. To understand eddy-induced changes in microbial community composition as well as how they control growth, we targeted the East Australian Current (EAC) region to sample microbes in a cyclonic (cold-core) eddy (CCE) and the adjacent EAC. Phototrophic and diazotrophic microbes were more diverse (2–10 times greater Shannon index) in the CCE relative to the EAC, and the cell size distribution in the CCE was dominated (67%) by larger micro-plankton \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$(\geq 20\lrm{\mu }\mathrm{m})$\end{document}≥20μm, as opposed to pico- and nano-sized cells in the EAC. Nutrient addition experiments determined that nitrogen was the principal nutrient limiting growth in the EAC, while iron was a secondary limiting nutrient in the CCE. Among the diazotrophic community, heterotrophic NifH gene sequences dominated in the EAC and were attributable to members of the gamma-, beta-, and delta-proteobacteria, while the CCE contained both phototrophic and heterotrophic diazotrophs, including Trichodesmium, UCYN-A and gamma-proteobacteria. Daily sampling of incubation bottles following nutrient amendment captured a cascade of effects at the cellular, population and community level, indicating taxon-specific differences in the speed of response of microbes to nutrient supply. Nitrogen addition to the CCE community increased picoeukaryote chlorophyll a quotas within 24 h, suggesting that nutrient uplift by eddies causes a ‘greening’ effect as well as an increase in phytoplankton biomass. After three days in both the EAC and CCE, diatoms increased in abundance with macronutrient (N, P, Si) and iron amendment, whereas haptophytes and phototrophic dinoflagellates declined. Our results indicate that cyclonic eddies increase delivery of nitrogen to the upper ocean to potentially mitigate the negative consequences of increased stratification due to ocean warming, but also increase the biological demand for iron that is necessary to sustain the growth of large-celled phototrophs and potentially support the diversity of diazotrophs over longer time-scales.

Postmortem studies have documented abnormalities in the dorsolateral prefrontal cortex (dlPFC) in depressed subjects. In this study we used magnetic resonance imaging to test for dlPFC volume differences between older depressed and non-depressed individuals. Eighty-eight subjects meeting DSM IV criteria for major depressive disorder and thirty-five control subjects completed clinical evaluations and cranial 3T magnetic resonance imaging. After tissue types were identified using an automated segmentation process, the dlPFC was measured in both hemispheres using manual delineation based on anatomical landmarks. Depressed subjects had significantly lower gray matter in the left and right dorsolateral prefrontal cortex (standardized to cerebral parenchyma) after controlling for age and sex. Our study confirmed the reduction of dorsolateral prefrontal cortex in elderly depressed subjects, especially in the gray matter. These regional abnormalities may be associated with psychopathological changes in late-life depression.

Flow and deformation of powder injection moulding (PIM) feedstocks are considered to occur in similar ways to those observed in materials containing substantial amounts of clay and water, i.e. by a slip band mechanism. A slip band model for PIM feedstocks has been postulated, which allows flow behaviour and void formation to be explained qualitatively. For feedstocks, the slip bands are assumed to be layers of mobile liquid, which, for polyethyleneglycol/polymethylmethacrylate (PEG/PMMA) binders, are considered to be mainly PEG. It is proposed that some of the slip band liquid is drawn from between the randomly densely packed particles between slip bands to form voids. It is considered for given moulding conditions that increasing the apparent viscosity of a feedstock, by decreasing the volume fraction of binder in slip bands, reduces voidage. This can be achieved by increasing the nominal powder loading of a feedstock and/or increasing the effectiveness of the PMMA in holding the particles togeth...

Mixtures of 94 wt-% tungsten carbide (WC) and 6 wt-% cobalt (Co) powders with different particle sizes have been formed with binders composed of polyethyleneglycol (PEG) and polymethylmethacrylate (PMMA), in some cases with the addition of stearic acid (SA) as a lubricant. The presence of voids has had to be invoked to explain why, when the same moulding conditions were used, the as moulded and as leached densities varied with binder composition and in some cases, why the former were lower than expected from the proportions of binder components and solids used to prepare the feedstocks. For a given nominal binder content (vol.-%), calculated on the assumption of zero voidage, and using constant moulding conditions, it appears that the actual voidage tended to decrease as PMMA progressively replaced PEG, and to increase as SA was introduced to replace PEG. The former change to the binder composition should, with constant binder content and moulding conditions, increase the apparent viscosity of the feedstock, while the latter should reduce it. A slip band model is postulated which allows flow behaviour and void formation to be explained qualitatively. This is further developed in Part 2 of this paper. Data from previous studies using PEG/PMMA binders with stainless steel powders are included as these can now be given a qualitative explanation with the slip band model.

Powder injection moulding (PIM) is a cost effective powder metallurgical process for the fabrication of small, complex-shaped components for high performance applications. A binder system, which comprises a major fraction of polyethylene glycol (PEG) and a minor fraction of a very finely dispersed polymethyl methacrylate (PMMA), has been applied for tungsten carbide (WC) – cobalt (Co) hardmetal powders. PEG can be removed rapidly by water leaching and PMMA is removed by subsequent pyrolysis when the components are ramped up to the sintering temperature. In this work, the development of feedstock formulations and of the processing parameters for a successful injection moulding and to achieve high density has been investigated. The present study has demonstrated that the binder can be employed for the production of WC-Co hardmetal components by PIM process. The maximum density achieved thus far is 97% of the theoretical value.

© Inter-Research 2015 The ecology of microbial assemblages inhabiting classical (positive) estuaries has been well documented. However, we know relatively little about the microbial ecology of inverse (negative) estuaries, which exhibit different physical and hydrodynamic properties, including oligotrophy and hypersalinity. We investigated the dynamics of bacterioplankton communities in Spencer Gulf, an inverse estuary in temperate South Australia. We characterised patterns in the overall diversity and composition of the resident microbial assemblage, and tested the hypothesis that pelagic nitrogen-fixing bacteria (diazotrophs) could be an important functional group in the nutrient limited waters of the region. Prokaryotic and diazotrophic communities were evaluated using 16S ribosomal DNA and nifH amplicon tag pyrosequencing, respectively. Significant heterogeneity in microbial community composition and diazotrophic population structure was observed, which was driven by shifts in the relative importance of temperate vs. subtropical and oceanic vs. coastal ecotypes of Cyanobacteria throughout the inverse estuary. The globally significant unicellular cyanobacterium, UCYN-A 'Candidatus Atelocyano-bacterium thalassa', was the dominant diazotrophic phylotype. Temperature, chlorophyll a and nitrogen availability were all significant drivers of bacterioplankton dynamics within the gulf. These results demonstrate the heterogeneous microbiology of inverse estuaries, indicating that specific abiotic and biotic characteristics select for discrete microbial communities, and that pelagic nitrogen fixation may be important in this temperate oligotrophic system.

Rising seawater temperature associated with global climate change is a significant threat to coral health and is linked to increasing coral disease and pathogen-related bleaching events. We performed heat stress experiments with the coral Pocillopora damicornis, where temperature was increased to 31°C, consistent with the 2–3°C predicted increase in summer sea surface maxima. 16S rRNA amplicon sequencing revealed a large shift in the composition of the bacterial community at 31°C, with a notable increase in Vibrio, including known coral pathogens. To investigate the dynamics of the naturally occurring Vibrio community, we performed quantitative PCR targeting (i) the whole Vibrio community and (ii) the coral pathogen Vibrio coralliilyticus. At 31°C, Vibrio abundance increased by 2–3 orders of magnitude and V. coralliilyticus abundance increased by four orders of magnitude. Using a Vibrio-specific amplicon sequencing assay, we further demonstrated that the community composition shifted dramatically as a consequence of heat stress, with significant increases in the relative abundance of known coral pathogens. Our findings provide quantitative evidence that the abundance of potential coral pathogens increases within natural communities of coral-associated microbes as a consequence of rising seawater temperature and highlight the potential negative impacts of anthropogenic climate change on coral reef ecosystems., Frontiers in Microbiology, 6, ISSN:1664-302X

Body mixes for stoneware containing a Brazilian red clay, nepheline syenite, and quartz with two different median particle sizes (∼2 and 18 μm) were fired under oxidizing and reducing atmospheres. The densification behavior was followed by dilatometry simulating the firing schedule, as well as by water absorption, linear shrinkage, and bulk density measurements on as-fired specimens. It was revealed that finer quartz led to interconnected pore closure at 1125°C when fired under an oxidizing atmosphere. Densification was systematically related to the uniformity of the compacts in the unfired state. Phase and microstructural examination by X-ray diffractometry, scanning electron microscopy/energy-dispersive spectroscopy (EDS), and transmission electron microscopy/EDS showed that mullite developed more extensively in the stonewares fired in an oxidizing atmosphere, along with cristobalite and haematite, whereas metallic iron was found in stonewares fired under a reducing atmosphere.

The production of hairdressing scissors, which are a high value added product, by a metal injection moulding route, using a 440 type hardenable stainless steel powder and a PEG/PMMA composite binder system has been investigated. Previous research has highlighted a number of problems associated with the PM processing of 440 type stainless steels; however, the present study has ascertained that, with careful control of the sintering conditions, a microstructure with finely distributed, spheroidal chromium carbide and high hardness could be attained following subsequent heat treatment.

Alumina and aluminosilicate flakes with compositions Al2O3, 3Al2O3⋅2SiO2 and Al2O3⋅2SiO2 have been produced from commercial raw materials using a direct current plasma spray process in air. The microstructure and phase constitution of the as-sprayed flakes were examined with optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD). Changes in phase constitution of the flakes with heat-treatment were examined using differential thermal analysis (DTA) and XRD of heat-treated samples. The as-sprayed Al2O3 flakes consisted of α -Al2O3 phase plus a minor γ-Al2O3 phase. The γ-phase could be removed by heat treating the flakes at 1300∘C for 2 h. The aluminosilicate flakes consisted of 3Al2O3:2SiO2 (mullite) and an amorphous phase which crystallised to 3Al2O3:2SiO2 (mullite) after heat treatment at 1100∘C for 2 h. These flakes may find applications as high temperature thermal insulation materials.

The PHENIX tracking system consists of Drift Chambers (DC), Pad Chambers (PC) and the Time Expansion Chamber (TEC). PC1/DC and PC2/TEC/PC3 form the inner and outer tracking units, respectively. These units link the track segments that transverse the RICH and extend to the EMCal. The DC measures charged particle trajectories in the r-phi direction to determine P-T of the particles and the invariant mass of particle pairs. The PCs perform 3D spatial point measurements for pattern recognition and longitudinal momentum reconstruction and provide spatial resolution of a few mm in both r-phi and z. The TEC tracks particles passing through the region between the RICH and the EMCal. The design and operational parameters of the detectors are presented and running experience during the first year of data taking with PHENIX is discussed. The observed spatial and momentum resolution is given which imposes a limitation on the identification and characterization of charged particles in various momentum ranges. (C) 2002 Published by Elsevier Science B.V.

The PHENIX magnet system is composed of three spectrometer magnets with warm iron yokes and water-cooled copper coils. The Central Magnet (CM) is energized by two pairs of concentric coils and provides a field around the interaction vertex that is parallel to the beam. This allows momentum analysis of charged particles in the polar angle range from 70° to 110°. The north and south Muon Magnets (MMN and MMS) use solenoid coils to produce a radial magnetic field for muon analysis. They each cover a pseudorapidity interval of 1.1–2.3 and full azimuth. The coils are wound on cylindrical surfaces at the end of large tapered pistons. Each of the three magnets provides a field integral of about 0.8 T -m. The physical and operating parameters of the magnets and their coils are given along with a description of the magnetic fields generated. The geometric, thermal and magnetic analysis leading to the coil design is discussed. The magnetic volumes of the PHENIX magnets are very large and complex, so a new technique was developed to map the fields based on surface measurements of a single field component using single axis Hall probes mounted on a rotating frame. A discussion of the performance of the CM during the first year of PHENIX running is given.

During the 1999 lead run, CERES has measured hadron and electron-pair production at 40 A GeV/c beam momentum with the spectrometer upgraded by the addition of a radial TPC. Here the analysis of lambda and antilambda will be presented.

Flakes of zirconia–mullite with different zirconia contents varying from 3 to 24 wt% were produced from sol–gel derived raw materials via a plasma melting method followed by a rapid solidification process using a rotating copper roll. The morphology, phase constitution and microstructure development of the as-prepared flakes and of the flakes after various heat treatments were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). It was found that the starting materials could be transformed from the initial irregular-shaped powders into flakes which consisted of mullite, zirconia phase, a relatively large amount of glassy phase and pores. Using TEM, it was shown that the crystalline phases consisted of zirconia polymorphs and mullite. The glassy phases consisted of Al2O3–SiO2 solid solution supersaturated with zirconia. Firing at 1500 °C or 1700 °C resulted in full crystallisation of the flakes and a fairly homogeneous distribution of zirconia particles in terms of size and shape dispersed in the mullite matrix, which contained both intra-granular and inter-granular precipitates. The microstructural characteristics of the flakes may provide promising physical properties for applications in high temperature thermal insulation materials.

The influence of the PMMA content in a composite binder comprising PMMA and PEG on the moulding, debinding and sintering behaviour of injection moulded samples of 316L stainless steel powder has been investigated. The PEGs component of the binder is readily soluble in water, so that, after leaching, a network of open pores is provided to facilitate the extraction of the PMMA by pyrolysis. This has been shown to lead to a reduction in overall debinding time. It is shown in the present study that reduction in the PMMA content allows injection moulding to be carried out at a lower temperature, while having the unfavourable consequences of reducing the stiffness and the green and brown strengths of the mouldings. It was also found that the mouldings had to be left in the die for a longer period before ejection because the temperature at which the binder stiffens was significantly reduced. It was shown that reducing the PMMA content of the binder enhanced the rate of removal of the PEGs during the leaching. The sintered densities of the mouldings were found to increase as the PMMA content increased as, consequently, did the hardness.

We present results for the charged-particle multiplicity distribution at midrapidity in Au-Au collisions at square root of [s(NN)] = 130 GeV measured with the PHENIX detector at RHIC. For the 5% most central collisions we find dN(ch)/d eta(vertical line eta = 0) = 622+/-1(stat)+/-41(syst). The results, analyzed as a function of centrality, show a steady rise of the particle density per participating nucleon with centrality.

This study was undertaken to test a new and original orthodontic bracket base, consisting of a porous lamella, which was designed to facilitate removal of ceramic brackets from the enamel surface after treatment. In the phase of the study presented here, two types of lamella and the adhesive resin used to bond them to brackets and teeth, were evaluated in vitro. Two types of test were carried out on bracketed teeth. The tensile bond strength was measured for specimens that had been either kept in water for 24 h at 37°C or subjected to 18000 cycles in water between 6°C and 55°C. The stress required to remove brackets with debracketing pliers was measured and the mode of failure recorded for specimens that had been kept in water for 24 h at 37°C. The results indicate that bracket/lamella assemblies can be bonded to enamel sufficiently strongly for clinical application and can be safely removed without damage to enamel.

This study was undertaken to test a new and original orthodontic bracket base, consisting of a porous lamella, which was designed to facilitate removal of ceramic brackets from the enamel surface after treatment. In the phase of the study presented here, porous pellets were made by bonding coarse alumina particles (calcined or fused) with mullite, formed by their reaction with fine quartz particles during firing of the mixture at 1700 degrees C. After machining the pellets to the desired shape, nine types of lamellae with different porosities were attached to the brackets using two different adhesive resins, and also bonded to bovine enamel using the same adhesives. The tensile bond strengths for the assemblies were determined so that the lamellae and the bonding adhesive that might be suitable for clinical application could be selected for testing in vitro in the second phase of the study.

Powder injection moulding based on a novel binder system, and using 316L stainless steel powder as a test material, is described. The binder system comprises a major fraction of polyethyleneglycols (PEGs) of various molecular weights and a minor fraction of very finely dispersed polymethylmethacrylate (PMMA) incorporated in the form of an emulsion. The feedstock was mixed as a thick, aqueous slurry at room temperature and was rapidly homogenised by stirring at a low shear force, which should minimise contamination because of a much reduced wear rate of the mixing equipment. The possible demixing during the drying of the slurry was minimised by frequent stirring during this stage and the use of some shear mixing of the dried feedstock. The green strength of the moulded specimens was measured by a three point bend test. In the first stage of debinding, the PEGs were removed by water leaching from the moulded components. This opened up pore channels which allowed much faster removal of the remaining PMMA binder during subsequent thermal debinding. The debinded samples were sintered at different temperatures and the sintered samples were examined by SEM and optical microscopy for pore structure and defects such as cracks

In this study the effect of size and distribution of leucite crystals on the biaxial flexural strength of five leucite reinforced glass-ceramics used in dentistry for the construction of veneers was investigated. Three of these were found to have a non-uniform distribution of leucite crystals, which were associated with a considerable degree of microcracking in the glassy matrix around the leucite crystals. The mean values of biaxial flexural strength of these ceramics ranged from 56 to 70 MPa. The other two ceramics exhibited a more uniform distribution in their leucite crystals, which were also finer in size. The latter ceramics had a significantly higher biaxial flexural strength which ranged from 120 to 137 MPa. When the particle size of the starting powders of the three low strength ceramics was reduced, a more uniform microstructure with less evidence of microcracking was produced in the fired ceramics and the biaxial flexural strength values were significantly increased. We conclude that uniformity of microstructure and leucite crystal size are major factors in determining the biaxial flexural strength of leucite reinforced glass-ceramics.

Aligned polycrystalline YBa 2 Cu 3 O 7−δ has been produced by a new process using simultaneous application of pressure and a magnetic field. The process is much faster than other techniques and optical microscopy, XRD and SQUID magnetometry show that a high degree of alignment is obtained.

This method, which employs an internal standard, is both easy to use and accurate. The required weight fraction of a phase in the mixture to be analysed is determined from the ratio of slopes of two linear plots passing through their respective origins, designated as the analysis and reference lines. The analysis line is obtained by plotting the intensity ratio of the required phase to the standard against the weight ratio of the mixture to the standard, for different proportions of mixture and standard. The reference line for the required phase is obtained by plotting the intensity ratio against the weight ratio of the reference material to the standard, using a pure phase or a reference material of known composition. The ease of use comes when weighing out the samples to be X-rayed. The weight of the mixture to be analysed, the reference material and the internal standard need not be any specific values or in any fixed proportions but, of course, require to be determined precisely. The weight ratios can be chosen so that peak intensities can be measured accurately. Precise weighing and the ability to use various weight ratios can give this method greater accuracy than that of the conventional internal standard method.

We tested for differences in temporal lobe volume in bipolar disorder and the relationship between these volumes and psychotropic medication use.125 subjects with bipolar disorder and 87 comparison subjects with no psychiatric illness completed clinical interviews and 1.5T MRI brain scans. Temporal lobe volumes were manually traced and segmented into gray matter and white matter volumes using an automated process. General linear models examined the relationship between these volumes and diagnosis as the primary predictor with age, sex, education, and race as copredictors. Secondary analyses incorporated the use of psychotropic medication into the linear models, and parsimonious models developed through backwards regression.In initial models, subjects with bipolar disorder exhibited larger temporal lobe white matter bilaterally (left: F(1,211)=2.86, p=0.0047; right: F(1,211)=3.25, p=0.0014). Current antipsychotic use was significantly associated with larger bilateral temporal lobe white matter volumes (left: F(2,211)=9.45, p=0.0001; right: F(2,211)=10.79, p0.0001), wherein bipolar subjects taking antipsychotics had larger volumes than bipolar subjects not taking antipsychotics or healthy comparison subjects. Temporal lobe gray matter volume was not significantly associated with diagnosis or medication use.Excluding subjects with substance use disorders may limit the study's generalizability.These findings indicate that differences in temporal lobe white matter are associated with bipolar disorder and use of antipsychotic medications.

Muon production at forward rapidity (1.5

Measurements of neutral pion (pi(0)) production at midrapidity in root s(NN)=200 GeV Au+Au collisions as a function of transverse momentum, p(T), collision centrality, and angle with respect to reaction plane are presented. The data represent the final pi(0) results from the PHENIX experiment for the first RHIC Au+Au run at design center-of-mass energy. They include additional data obtained using the PHENIX Level-2 trigger with more than a factor of 3 increase in statistics over previously published results for p(T)>6 GeV/c. We evaluate the suppression in the yield of high-p(T) pi(0)'s relative to pointlike scaling expectations using the nuclear modification factor R-AA. We present the p(T) dependence of R-AA for nine bins in collision centrality. We separately integrate R-AA over larger p(T) bins to show more precisely the centrality dependence of the high-p(T) suppression. We then evaluate the dependence of the high-p(T) suppression on the emission angle Delta phi of the pions with respect to event reaction plane for seven bins in collision centrality. We show that the yields of high-p(T) pi(0)'s vary strongly with Delta phi, consistent with prior measurements 1,2. We show that this variation persists in the most peripheral bin accessible in this analysis. For the peripheral bins we observe no suppression for neutral pions produced aligned with the reaction plane, whereas the yield of pi(0)'s produced perpendicular to the reaction plane is suppressed by a factor of similar to 2. We analyze the combined centrality and Delta phi dependence of the pi(0) suppression in different p(T) bins using different possible descriptions of parton energy loss dependence on jet path-length averages to determine whether a single geometric picture can explain the observed suppression pattern.

Longitudinal density correlations of produced matter in Au+Au collisions at sqrt(s{sub NN})=200 GeV have been measured from the inclusive charged particle distributions as a function of pseudorapidity window sizes. The extracted {alpha}{xi} parameter, related to the susceptibility of the density fluctuations in the long-wavelength limit, exhibits a nonmonotonic behavior as a function of the number of participant nucleons, N{sub part}. A local maximum is seen at N{sub part}{approx}90, with corresponding energy density based on the Bjorken picture of {epsilon}{sub Bj}{tau}{approx}2.4 GeV/(fm{sup 2}c) with a transverse area size of 60 fm2. This behavior may suggest a critical phase boundary based on the Ginzburg-Landau framework.

Emission source functions are extracted from correlation functions constructed from charged pions produced at midrapidity in Au+Au collisions at s(NN)=200 GeV. The source parameters extracted from these functions at low k(T) give first indications of a long tail for the pion emission source. The source extension cannot be explained solely by simple kinematic considerations. The possible role of a halo of secondary pions from resonance emissions is explored.